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CHICKEN User`s Manual - The User`s Manual

1. 30 511A Tane rer 30 8 11 2 Bof Object rct n ER V EREE PO RAF RE ERR REOR Ue EY Dae TIERE E Tue eges 30 8 11 3 DSSSL Formal Parameter List Annotaton eene 30 8 11 4 Read Mark Invocation csse emen et eter ee ente ee ene 30 8 12 Case Sensitive E e DE 31 8 13 Case Insensitive e 31 8 14 Conditional SEET 31 9 Non standard macros and Special FOE eres ritos renr n FhE Ye P patro hot R Eu PER VENE Pe ou SE ENEE TEEN 32 9 1 Making extra libraries and extensions 2valable seen 32 9 11 requir extenstOn O EVE ela 32 9 1 2 define EE 33 CHICKEN User s Manual The User s Manual Chicken User s Manual 9 Non standard macros and special forms 9 2 Binding forms for optional areuments oooooococcnonocononcconnncnonannnnnccnnoconnn concern nn naar nn cnn cn nn nr nora ran nn naar na nnn sten rennen 34 Ve e EE 34 PAS AMD EE 34 ODS Ee e EE 34 9 2 4 A A A RN 35 9 3 Other binding re 35 IL E Bs CREE 35 A 1 E a EE E AAE EEE NEE A EE E 35 Ee EE EEN 35 IA deftin values E 36 9 35 E 36 Se E E 36 SA Loi ea V EE 36 9 38 IEE CE values acier E er D rave ten meten iade ae sapevo te ERN RENE TONER 36 9 3 9 parameterize E 37 EARN KOE LELE T T Tn 37 A mele vu eva tera Ee ee GE Ee 37 9 4 Substitution forms and macros e nnn n nnn nennen EEEE EEEE a este ees sese se eese sete enn 37 94 1 E KEE EE 37 DAD MIME EE 38 9 4 3 GEPME MACTO 4 0ss0000ssseonscenvndasaracacaenenvatesarconedoacacasscacecasssoceqees
2. 151 PA EE dee 151 23 18 3 efFHO SECTE EE 151 23 8 ACO EE 151 23 18 5 Ee E 151 xii CHICKEN User s Manual The User s Manual Chicken User s Manual 23 Unit posix 23 1S G Su gll AI C ssyc e Ge EE EE 2318 7 CM DA iii ete tete Puer s av Eo vasa o bao esa tete eases bester eden Uk PR TR ee PUER Ca 23 18 8 errno child EE e Renee E 23 18 KEE ACCES ees ege dE dad E Een eu cab 23 18 11 eene EI dea E Reno vansksaaavanbontaraberabasguawanesnteanseseevanees ER e EE 23 18 13 enee E NES Ee EE EE 23 18 15 EMO MV E 23 18 16 O las ii A AA A a 23 18 17 frno nOSDCG EE 23 18 18 errno Spipe uere torre tener tte te eto td eee PUE nandi ee PU Loa Cg eee e P dead AA isr n a E E E E EE O E ER le 23 18 2 errno TOLs adas CHICKEN User s Manual The User s Manual Chicken User s Manual 24 Unit utils 24 213 directory null s iie nett rre ete eres Rae eee th neos elo tena rete En Uer haeo Ue tae e Te Xr eoe ENS EE deas 164 24 3 Temporary filesini ai EO PURI Pet dde 164 GN WEE EE 165 24 4 Deleting a file without signalling an error entente entere nns 165 KEEN EE E KEEN 165 24 5 Iterating over input lines and les eee eee ceeeceeeccesseecesaeceeneecescecesceeesaeceaaeceeaeeceaceceeeesseeeeaaeceeaeeneneeeeaees 165 24 5 1 OCA A a da 165 IAS E E 165 24 5 3 A A 166 ZA SA TE map eth cg idaadeaades E gdas eeceaacee stages agus aad EROR ERE RENTRER TENERAS 166 24 5 5 NN 166 24 6 Executing shell commands with formatstring and error c
3. Calls to Scheme C may be nested arbitrarily and Scheme continuations can be invoked as usual but keep in mind that C stack frames will not be recovered when a Scheme procedure call from C does not return normally When multiple threads are running concurrently and control switches from one thread to another then the continuation of the current thread is captured and saved Any pending C stack frame still active from a callback will remain on the stack until the threads is re activated again This means that in a multithreading situation when C callbacks are involved the available nursery space can be smaller than expected So doing many nested SchemeCScheme calls can reduce the available memory up to the point of thrashing It is advisable to have only a single thread with pending C stack frames at any given time Pointers to Scheme data objects should not be stored in local or global variables while calling back to Scheme Any Scheme object not passed back to Scheme will be reclaimed or moved by the garbage collector Calls from C to Scheme are never tail recursive Continuations captured via Call with current continuation and passed to C code can be invoked like any other Scheme procedure Previous Other support procedures Next chicken setup 34 48 An example for simple calls to foreign code involvingcallbacks 223 35 chicken setup 35 1 Extension libraries Extension libraries eggs are extensions to the core functionality
4. key rest and eof The easiest way is to use the SCript option like this cat foo usr local bin csi script print eval with input from string car command line arguments read chmod x foo foo 3 4 N o o The parameter command Line arguments is set to a list of the parameters that were passed to the Scheme script Scripts can be compiled to standalone executables don t forget to declare used library units CHICKEN supports writing shell scripts in Scheme for these platforms as well using a slightly different approach The first example would look like this on Windows C gt type foo bat csibatch 0 1 2 3 4 5 6 7 8 9 print eval with input from string car command line arguments read C gt foo 3 4 7 Like UNIX scripts batch files can be compiled Windows batch scripts do not accept more than 8 arguments Since it is sometimes useful to run a script into the interpreter without actually running it for example to test specific parts of it the option SS can be used as an alternative to script ss PATHNAME is equivalent to script PATHNAME but invokes main command line arguments after loading all top level forms of the script file The result of Main is returned as the exit status to the shell Any non numeric result exits with status zero 4 1 Interpreter command line format 16 CHICKEN User s Manual The User s Manual cat hi scm define main a
5. procedure substring index WHICH WHERE START procedure substring index ci WHICH WHERE START Searches for first index in string WHERE where string WHICH occurs If the optional argument START is given then the search starts at that index substring index Ci is a case insensitive version of substring index 15 9 8 string translate 102 CHICKEN User s Manual The User s Manual 15 10 Combinators 15 10 1 any procedure any X Ignores its argument and always returns t This is actually useful sometimes 15 10 2 constantly procedure constantly X Returns a procedure that always returns the values X regardless of the number and value of its arguments constantly X lt gt lambda args X 15 10 3 complement procedure complement PROC Returns a procedure that returns the boolean inverse of PROC complement PROC lt gt lambda x not PROC x 15 10 4 compose procedure compose PROC1 PROC2 Returns a procedure that represents the composition of the argument procedures PROC1 PROC2 compose F G lambda args call with values Lambda apply G args F compose is equivalent to values 15 10 Combinators 103 CHICKEN User s Manual The User s Manual 15 10 5 conjoin procedure conjoin PRED Returns a procedure that returns t if its argument satisfies the predicates PRED conjoin odd positive 33 gt gt conjoin odd positive
6. write line Good Bye o print read line i Server scm declare uses tcp define l tcp listen 4242 define values i o tcp accept 1 write line Hello o print read line i close input port i close output port o csc server scm csc client scm Server A 25 14 tcp write timeout 172 CHICKEN User s Manual The User s Manual client Good Bye Hello Previous Unit utils Next Unit lolevel 25 17 Example 173 26 Unit lolevel This unit provides a number of handy low level operations Use at your own risk This unit uses the srfi 4 and extras units 26 1 Foreign pointers 26 1 1 addresspointer procedure address gt pointer ADDRESS Creates a new foreign pointer object initialized to point to the address given in the integer ADDRESS 26 1 2 allocate procedure allocate BYTES Returns a pointer to a freshly allocated region of static memory This procedure could be defined as follows define allocate foreign lambda c pointer malloc integer 26 1 3 free procedure free POINTER Frees the memory pointed to by POINTER This procedure could be defined as follows define free foreign lambda c pointer free integer 26 1 4 null pointer procedure null pointer Another way to say address gt pointer 0 26 Unit lolevel 174 CHICKEN User s Manual The User s Manual 26 1 5 null pointer procedure null pointer PTR Returns t if PTR contai
7. 15 8 0 EE 69 13 8 DA Sadao A e EEE 69 13 8 1 1 SO WATE VETSION Loci cccecascsancsecesocecscasacsssessdevessecssesseavedacscvbessvesondasavnoadavanacdsunasaccsansionceBavecacacadacases 69 EA Te 70 ERE EE 70 13 9 EXECUTION EG 70 13 9 T Er 70 13 9 2 ee Ee E 70 13 93 e re EE 71 13 9 4 e E Ee E 71 iv CHICKEN User s Manual The User s Manual Chicken User s Manual 13 Unit library 13 10 Interrupts and error handling 0 2 eee ceseceeceeeececeeeesaeceeaaeceececeeeeecaeeesaecseaaecesaeceeeeeeeesaaeceeaaeseaeeseeeee 71 13 10 EA ie eL HR ERE HERES TRE EAT HEURE In ENTRE CE ETRa dS 71 HEU TOM EE 71 13 10 53 EE 71 EN E ee rion reete eerte tei enr etre oie tte er e edere ede eter oed 72 13 105 print error message rer ENEE gd REESEN ARR CREER IER Ee EE ST 72 13 10 6 procedures OMA iii alii 72 13 TO TE ridad 72 EPA RIN 72 E O 72 13 11 Garbage collect a aaa 73 USR E 73 APA EE E 73 13 11 3 set frhaltzer iecore i tadas 73 13114 RCI Pesce HE 73 13 12 Other Control StHUCHUTES 5 ione tenet tnn rer ao rhe Fake eara raro Een eno adela oa dando 73 EPA A OR ANO 74 13 13 String TEE 74 13 13 1 EE 74 13 14 Generating uninterned Symbols ee eeceessecesseceeseeceececsueceeaaeceaceceaeececessaeceeateneaceceeeeeeeeseaaeceeaeceeaeeceaees 74 IER DNE EEN 74 13 14 2 stringuninterned symbol eee eesecesceceeeeeceeeeesaeceeaeeseacecesceeaeceeaaecseneceeaeeceaeeseaeeeeaaeceaaeceeneeeaes 74 13 15 Stan
8. 9 7 Other forms 9 7 1 assert syntax assert EXP STRING ARG Signals an error if EXP evaluates to false An optional message STRING and arguments ARG may be supplied to give a more informative error message If compiled in unsafe mode either by specifying the unsafe compiler option or by declaring unsafe then this expression expands to an unspecified value The result is the value of EXP 9 6 2 define record printer 40 CHICKEN User s Manual The User s Manual 9 7 2 cond expand syntax cond expand FEATURE CLAUSE Expands by selecting feature clauses This form is allowed to appear in non toplevel expressions Predefined feature identifiers are situation specific compile eval Library match compiling srfi 11 srfi 15 srfi 31 srfi 26 srfi 16 utils regex srfi 4 match srfi 1 srfi 69 srfi 28 extras srfi 8 srfi 6 srfi 2 srfi 0 srfi 10 srfi 9 srfi 55 srfi 61 chicken srfi 23 srfi 30 srfi 39 srfi 62 srfi 17 srfi 12 load srfi 69 srfi 28 extras srfi 8 srfi 6 srfi 2 srfi 0 srfi 10 srfi 9 srfi 55 srfi 61 chicken srfi 23 srfi 30 srfi 39 srfi 62 srfi 17 Srfi 12 library is implicit eval match csi srfi 11 srfi 15 srfi 31 srfi 26 srfi 16 srfi 69 srfi 28 extras srfi 8 srfi 6 srfi 2 srfi 0 srfi 10 srfi 9 srfi 55 srfi 61 chicken srfi 23 srfi 30 srfi 39 srfi 62 srfi 17 srfi 12 library is implicit The following feature identifiers are available in all s
9. Creates a new child process and replaces the running process with it using the C library function execvp 3 If the optional argument ARGUMENT LIST is given then it should contain a list of strings which are passed as arguments to the subprocess If the optional argument ENVIRONMENT LIST is supplied then the library function execve 2 is used and the environment passed in ENVIRONMENT LIST which should be of the form lt NAME gt lt VALUE gt is given to the invoked process Note that execvp 3 respects the current setting of the PATH environment variable while execve 3 does not 23 8 5 process fork procedure process fork THUNK Creates a new child process with the UNIX system call fork Returns either the PID of the child process or 0 If THUNK is given then the child process calls it as a procedure with no arguments and terminates 23 8 6 process run procedure process run COMMANDLINE procedure process run COMMAND ARGUMENT LIST Creates a new child process The PID of the new process is returned e The single parameter version passes the COMMANDLINE to the system shell so usual argument expansion can take place e The multiple parameter version directly invokes the COMMAND with the ARGUMENT LIST 23 8 2 parent process id 138 CHICKEN User s Manual The User s Manual 23 8 7 process signal procedure process signal PID SIGNAL Sends SIGNAL to the process with the id PID using the UNI
10. DIRECTORY can be f meaning no directory component a string or a list of strings FILENAME and EXTENSION should be strings or f make absolute pathname returns always an absolute pathname 24 2 5 pathname directory procedure pathname directory PATHNAME 24 2 6 pathname file procedure pathname file PATHNAME 24 2 7 pathname extension procedure pathname extension PATHNAME Accessors for the components of PATHNAME If the pathname does not contain the accessed component then f is returned 24 2 2 decompose pathname 163 CHICKEN User s Manual The User s Manual 24 2 8 pathname replace directory procedure pathname replace directory PATHNAME DIRECTORY 24 2 9 pathname replace file procedure pathname replace file PATHNAME FILENAME 24 2 10 pathname replace extension procedure pathname replace extension PATHNAME EXTENSION Return a new pathname with the specified component of PATHNAME replaced by a new value 24 2 11 pathname strip directory procedure pathname strip directory PATHNAME 24 2 12 pathname strip extension procedure pathname strip extension PATHNAME Return a new pathname with the specified component of PATHNAME stripped 24 2 13 directory null procedure directory null DIRECTORY Does the DIRECTORY consist only of path separators and the period DIRECTORY may be a string or a list of strings 24 3 Temporary files 24 2 8 pathname replace directory 164 CHIC
11. NAME EXPRESSION NAME and rec NAME VARIABLE BODY is the same as letrec NAME Lambda VARIABLE BODY NAME 9 3 3 cut syntax cut SLOT syntax cute SLOT Syntactic sugar for specializing parameters 9 2 4 let optionals 35 CHICKEN User s Manual The User s Manual 9 3 4 define values syntax define values NAME EXP Defines several variables at once with the result values of expression EXP 9 3 5 fluid let syntax fluid let VAR1 X1 BODY Binds the variables VAR1 dynamically to the values X1 during execution of BODY 9 3 6 let values syntax let values NAME EXP BODY Binds multiple variables to the result values of EXP All variables are bound simultaneously 9 3 7 let values syntax let values NAME EXP BODY Binds multiple variables to the result values of EXP The variables are bound sequentially let values i b values 2 3 a p a b p gt 5 9 3 8 letrec values syntax letrec values NAME EXP BODY Binds the result values of EXP to multiple variables at once All variables are mutually recursive letrec values odd even values lambda n if zero n f even subl n lambda n if zero n t odd subl n odd 17 gt t 9 3 4 define values 36 CHICKEN User s Manual The User s Manual 9 3 9 parameterize s
12. Returns the number of bytes that would be needed to evict the data object X 26 4 5 object release procedure object release X RELEASER Frees memory occupied by the evicted object X recursively RELEASER should be a procedure of a single argument a foreign pointer object to the static memory to be freed and defaults to f ree 26 4 6 object unevict procedure object unevict X FULL 26 4 1 object evict 181 CHICKEN User s Manual The User s Manual Copies the object X and nested objects back into the normal Scheme heap Symbols are re interned into the symbol table Strings and byte vectors are not copied unless FULL is given and not f 26 5 Locatives A locative is an object that points to an element of a containing object much like a pointer in low level imperative programming languages like C The element can be accessed and changed indirectly by performing access or change operations on the locative The container object can be computed by calling the location gt object procedure Locatives may be passed to foreign procedures that expect pointer arguments The effect of creating locatives for evicted data see obj ect evict is undefined 26 5 1 make locative procedure make locative EXP INDEX Creates a locative that refers to the element of the non immediate object EXP at position INDEX EXP may be a vector pair string blob SRFI 4 number vector or record INDEX should be a fixnum INDEX defaults
13. t no such wrapping occurs 23 24 2 Unsupported Definitions The following definitions are not supported for native Windows builds compiled with the Microsoft tools or with MinGW open noctty open nonblock open fsync open sync perm isvtx perm isuid perm isgid file select file control Signal except signal term signal int signal fpe signal ill signal segv set signal mask signal mask signal masked signal mask signal unmask user information group information get groups set groups initialize groups errno wouldblock Change file owner current user id current group id current effective user id current effective set user id set group id create session process group id set process group id create symbolic link read symbolic link file truncate file lock file lock blocking file unlock file test lock create fifo fifo prot map map file to memory unmap file from memory memory mapped file pointer memory set alarm terminal port terminal name process fork process signal parent process id set root directory utc time gt seconds 23 24 1 Procedure Changes 160 CHICKEN User s Manual The User s Manual 23 24 3 Additional Definitions Only available for Windows e open noinherit This variable is a mode value for create pipe Useful when spawning a child process e spawn overlay e spawn wait e spawn nowait e spawn nowaito e spawn detach These variables contains special flags that specify
14. unsigned char unsigned short unsigned int unsigned integer unsigned long float double number nonnull c pointer nonnull blob nonnull u8vector nonnull s8vector nonnull ul6vector nonnull s16vector nonnull u32vector nonnull s32vector nonnull f32vector nonnull f64vector nonnull c string nonnull unsigned c string c string list symbol void nonnull c pointer TYPE enum NAME struct NAME ref TYPE template T1 T2 union NAME function RTYPE ATYPE CALLCONV instance CNAME SNAME instance ref CNAME SNAME Previous Accessing external objects Next Embedding 29 38 Mappings int unsigned char unsigned short unsigned int unsigned int unsigned long float double double void unsigned char unsigned char char unsigned short short uint32 t int32 t float double char unsigned char char char void TYPE enum NAME struct NAME TYPE amp T1 lt T2 gt union NAME CALLCONV RTYPE ATYPE CNAME CNAME amp 202 30 Embedding Compiled Scheme files can be linked with C code provided the Scheme code was compiled in embedded mode by passing DC EMBEDDED to the C compiler this will disable generation of a main function CSC will do this when given the embedded option Alternatively pass embedded to csc The following C API is available 30 1 CHICKEN_parse_command_line C fu
15. uses SYMBOL Gives a list of used library units Before the toplevel expressions of the main module are executed all used units evaluate their toplevel expressions in the order in which they appear in this declaration If a library unit A uses another unit B then B s toplevel expressions are evaluated before A s Furthermore the used symbols are registered as features during compile time so cond expand knows about them Previous Pattern matching Next Parameters 11 33 unsafe 55 12 Parameters Certain behavior of the interpreter and compiled programs can be customized via parameters where a parameter is a procedure of zero or one arguments To retrieve the value of a parameter call the parameter procedure with zero arguments To change the setting of the parameter call the parameter procedure with the new value as argument define foo make parameter 123 foo gt 123 foo 99 foo gt 99 Parameters are fully thread local each thread of execution owns a local copy of a parameters value CHICKEN implements SRFI 39 12 1 make parameter procedure make parameter VALUE GUARD Returns a procedure that accepts zero or one argument Invoking the procedure with zero arguments returns VALUE Invoking the procedure with one argument changes its value to the value of that argument subsequent invocations with zero parameters return the new value GUARD should be a procedure of a single argument Any
16. 13 21 Setters SRFI 17 is fully implemented For more information see SRFI 17 13 21 1 setter procedure setter PROCEDURE Returns the setter procedure of PROCEDURE or signals an error if PROCEDURE has no associated setter procedure Note that set setter PROC for a procedure that has no associated setter procedure yet is a very slow operation the old procedure is replaced by a modified copy which involves a garbage collection 13 21 2 getter with setter procedure getter with setter GETTER SETTER Returns a copy of the procedure GETTER with the associated setter procedure SETTER Contrary to the SRFI specification the setter of the returned procedure may be changed 13 22 Reader extensions 13 22 1 define reader ctor procedure define reader ctor SYMBOL PROC Define new read time constructor for read syntax For further information see the documentation for SRFI 10 13 22 2 set read syntax procedure set read syntax CHAR OR SYMBOL PROC When the reader encounters the non whitespace character CHAR while reading an expression from a given port then the procedure PROC will be called with that port as its argument The procedure should return a value that will be returned to the reader A simple RGB color syntax set read syntax 13 21 Setters 79 CHICKEN User s Manual The User s Manual Lambda port apply vector map cut string gt number lt gt 16 string chop read string 6 po
17. 26 7 9 recordvector procedure record gt vector BLOCK 26 7 4 make record instance 185 CHICKEN User s Manual The User s Manual Returns a new vector with the type and the elements of the record BLOCK 26 8 Procedure call and variable reference hooks 26 8 1 set invalid procedure call handler procedure set invalid procedure call handler PROC Sets an internal hook that is invoked when a call to an object other than a procedure is executed at runtime The procedure PROC will in that case be called with two arguments the object being called and a list of the passed arguments Access sequence elements as in ARC set invalid procedure call handler Lambda proc args cond string proc vector proc else error c apply string ref proc args apply vector ref proc args f ll of non procedure proc a hello 4 gt Ho This facility does not work in code compiled with the unsafe setting 26 8 2 unbound variable value procedure unbound variable value X Defines the value that is returned for unbound variables Normally an error is signalled use this procedure to override the check and return X instead To set the default behavior of signalling an error call unbound variable value with no arguments This facility does not work in code compiled with the unsafe setting 26 9 Magic 26 9 1 object become procedure object become ALIST 26 7 9 recordvector
18. 30 22 CHICKEN global set C function void CHICKEN global set void global C word value Sets the value of the global variable referenced by the GC root global to value Previous Foreign type specifiers Next Callbacks 30 20 CHICKEN global lookup 209 31 Callbacks To enable an external C function to call back to Scheme the form foreign safe Lambda or foreign safe lambda has to be used This generates special code to save and restore important state information during execution of C code There are two ways of calling Scheme procedures from C the first is to invoke the runtime function C callback with the closure to be called and the number of arguments The second is to define an externally visible wrapper function around a Scheme procedure with the define external form Note the names of all functions variables and macros exported by the CHICKEN runtime system start with C Itis advisable to use a different naming scheme for your own code to avoid name clashes Callbacks defined by def ine externaLl do not capture the lexical environment Non local exits leaving the scope of the invocation of a callback from Scheme into C will not remove the C call frame from the stack and will result in a memory leak 31 1 define external syntax define external QUALIFIERS NAME ARGUMENTTYPE1 VARIABLE1 RET syntax define external NAME TYPE INIT The first form defines an externally callable Scheme procedure NAME shou
19. C bar scm csc C foo scm That should produce two files bar o and foo o They contain the code from your source files in compiled form To link your compiled files use the following command csc foo o bar o o foo This should produce the foo executable which you can run just as in the previous example At this point you 3 3 2 An example with multiple files 11 CHICKEN User s Manual The User s Manual can also erase the 0 files You could avoid one step and link the two files just as foo scm is compiled csc cC bar scm csc foo scm bar o o foo Note that if you want to distribute your program you might want it to follow the GNU Coding Standards One relatively easy way to achieve this is to use Autoconf and Automake two tools made for this specific purpose 3 4 Extending the compiler The compiler supplies a couple of hooks to add user level passes to the compilation process Before compilation commences any Scheme source files or compiled code specified using the extend option are loaded and evaluated The parameters user options pass user read pass user preprocessor pass user pass user pass 2and user post analysis pass can be set to procedures that are called to perform certain compilation passes instead of the usual processing for more information about parameters see Supported language parameter user options pass Holds a procedure that will be called with a list of command line arguments and shou
20. The User s Manual applies the exception is re signaled in the same dynamic context as the condition case form define check thunk condition case thunk exn file print file error exn print other error var print something else check lambda open input file gt file error check lambda some unbound variable othererror check lambda signal 99 gt something else condition case some unbound variable exn file print ignored gt Signals error 13 7 2 breakpoint procedure breakpoint NAME Programmatically triggers a breakpoint similar to the Dr top level csi command All error conditions signaled by the system are of kind exn The following composite conditions are additionally defined exn arity Signaled when a procedure is called with the wrong number of arguments exn type Signaled on type mismatch errors for example when an argument of the wrong type is passed to a built in procedure exn arithmetic Signaled on arithmetic errors like division by zero exn i o Signaled on input output errors exn i o file Signaled on file related errors exn i o net Signaled on network errors exn bounds Signaled on errors caused by accessing non existent elements of a collection exn runtime Signaled on low level runtime system error situations 13 7 1 condition case 66 CHICKEN User s Manual The User s Ma
21. procedure procedure procedure Each of these procedures return the contents of the given vector as a packed blob The byte order in that procedure s8vector gt blob shared S8VECTOR U16VECTOR S16VECTOR U32VECTOR S32VECTOR F32VECTOR F64VECTOR e ws ee vector is platform dependent for example little endian on an Intel processor The shared variants return a blob that shares memory with the contents of the vector 17 18 blobu8vector 17 19 blobs8vector 17 20 blobu16vector 17 21 blobs16vector 17 22 blobu32vector 17 23 blobs32vector 17 24 blobf32vector 17 17 f64vectorblob shared 110 CHICKEN User s Manual The User s Manual 17 25 blobf64vector 17 26 blobu8vector shared 17 27 blobs8vector shared 17 28 blobu16vector shared 17 29 blobs16vector shared 17 30 blobu32vector shared 17 31 blobs32vector shared 17 32 blobf32vector shared 17 33 blobf64vector shared procedure procedure procedure procedure procedure procedure procedure procedure procedure procedure procedure procedure procedure procedure 17 25 blobf64 vector blob gt u8vector BLOB blob gt s8vector BLOB blob gt ul6vector blob gt sl6vector blob gt u32vector blob gt s32vector blob gt f32vector blob gt f64vector blob gt u8vector shared BLOB blob gt s8vector shared BLOB blob gt ul6vector shared BLOB blob gt sl6vector shared BL
22. procedure queue empty QUEUE Returns t if QUEUE is empty or f otherwise 15 5 7 queue first procedure queue first QUEUE Returns the first element of QUEUE If QUEUE is empty an error is signaled 15 5 8 queue last procedure queue last QUEUE Returns the last element of QUEUE If QUEUE is empty an error is signaled 15 5 9 queue remove procedure queue remove QUEUE Removes and returns the first element of QUEUE If QUEUE is empty an error is signaled 15 5 10 queue push back procedure queue push back QUEUE ITEM Pushes an item into the first position of a queue i e the next queue remove will return ITEM 15 5 4 queuelist 95 CHICKEN User s Manual The User s Manual 15 5 11 queue push back list procedure queue push back list QUEUE LIST Pushes the items in item list back onto the queue so that car LIST becomes the next removable item 15 6 Sorting 15 6 1 merge procedure merge LIST1 LIST2 LESS procedure merge LIST1 LIST2 LESS Joins two lists in sorted order merge is the destructive version of merge LESS should be a procedure of two arguments that returns true if the first argument is to be ordered before the second argument 15 6 2 sort procedure sort SEQUENCE LESS procedure sort SEQUENCE LESS Sort SEQUENCE which should be a list or a vector Sort is the destructive version of sort 15 6 3 sorted procedure sorted SEQUENCE LESS Returns t
23. this operation and any I O on the ports returned will not block other running threads 25 Unit tcp 169 CHICKEN User s Manual The User s Manual 25 5 tcp accept ready procedure tcp accept ready LISTENER Returns t if there are any connections pending on LISTENER or f otherwise 25 6 tcp listener port procedure tcp listener port LISTENER Returns the port number assigned to LISTENER If you pass 0 to tcp Listen then the system will choose a port number for you 25 7 tcp listener fileno procedure tcp listener fileno LISTENER Returns the file descriptor associated with LISTENER 25 8 tcp connect procedure tcp connect HOSTNAME TCPPORT Establishes a client side TCP connection to the machine with the name HOSTNAME a string at TCPPORT an exact integer and returns two values an input and output port for communicating with the remote process The current value of tcp connect timeout is used to determine the maximal number of milliseconds if any to wait until the connection is established When the connection takes place any read and write operations on the returned ports will use the current values at the time of the call to tcp connect of tcp read timeout and tcp write timeout respectively to determine the maximal number of milliseconds to wait for input output before a timeout error is signalled If the TCPPORT is omitted the port is parsed from the HOSTNAME string The format expected is HO
24. 13 C pair C function C word C pair C word ptr C word car C word cdr 34 7 C word C SCHEME FALSE 216 CHICKEN User s Manual The User s Manual 34 14 C flonum C function C word C flonum C word ptr double number 34 15 C int to num C function C word C int to num C word ptr int integer 34 16 C mpointer C function C word C mpointer C word ptr void pointer 34 17 C vector C function C word C vector C word ptr int length 34 18 C list C function C word C list C word ptr int length These functions allocate memory from ptr and initialize a fresh data object The new data object is returned ptr should be the address of an allocation pointer created with C alloc 34 19 C alloc C macro C word C alloc int words Allocates memory from the C stack C al loc and returns a pointer to it words should be the number of words needed for all data objects that are to be created in this function Note that stack allocated data objects have to be passed to Scheme callback functions or they will not be seen by the garbage collector This is really only usable for callback procedure invocations make sure not to use it in normal code because the allocated memory will be re used after the foreign procedure returns When invoking Scheme callback procedures a minor garbage collection is performed so data allocated with C alloc will already have moved to a safe place Note that C alloc is r
25. 4 file link procedure file link OLDNAME NEWNAME Creates a hard link from OLDNAME to NEWNAME both strings 23 10 Retrieving user amp group information 23 10 1 current user id procedure current user id setter set current user id UID Get or set the real user id of the current process 23 10 2 current effective user id procedure current effective user id setter set current effective user id UID Get or set the effective user id of the current process 23 10 3 user information procedure user information USER AS VECTOR If USER specifes a valid username as a string or user ID then the user database is consulted and a list of 7 values are returned the user name the encrypted password the user ID the group ID a user specific string the home directory and the default shell When AS VECTOR is Ft a vector of 7 elements is returned instead of a list If no user with this name or id then f is returned 23 10 4 current group id procedure current group id setter set current group id GID Get or set the real group id of the current process 23 9 4 file link 141 CHICKEN User s Manual The User s Manual 23 10 5 current effective group id procedure current effective group id setter set current effective group id GID Get or set the effective group id of the current process ID can be found then f is returned 23 10 6 group information procedure group infor
26. Asked Questions about Chicken Scheme If you have a question not answered here feel free to post to the chicken users mailing list if you consider your question general enough feel free to add it to this list 38 1 General 38 1 1 Why yet another Scheme implementation Since Scheme is a relatively simple language a large number of implementations exist and each has its specific advantages and disadvantages Some are fast some provide a rich programming environment Some are free others are tailored to specific domains and so on The reasons for the existence of CHICKEN are e CHICKEN is portable because it generates C code that runs on a large number of platforms e CHICKEN is extendable since its code generation scheme and runtime system garbage collector fits neatly into a C environment e CHICKEN is free and can be freely distributed including its source code e CHICKEN offers better performance than nearly all interpreter based implementations but still provides full Scheme semantics e As far as we know CHICKEN is the first implementation of Scheme that uses Henry Baker s Cheney on the M T A concept 38 1 2 What should do if find a bug Send e mail to felix O call with current continuation org with some hints about the problem like version build of the compiler platform system configuration code that causes the bug etc 38 1 3 Why are values defined with define foreign variable or define constant Or define inline
27. CHICKEN INCLUDE PATH e the current directory ID should be a string or a symbol The difference between require and require for syntax is the the latter loads the extension library at compile time the argument is still evaluated while the former loads it at run time 14 4 6 set extension specifier procedure set extension specifier SYMBOL PROC Registers the handler procedure PROC as a extension specifier with the name SYMBOL This facility allows extending the set of valid extension specifiers to be used with require extension When register extension is called with an extension specifier of the form SPEC and SPEC has been registered with set extension specifier then PROC will be called with two arguments the specifier and the previously installed handler or f if no such handler was defined The handler should return a new specifier that will be processed recursively If the handler returns a vector then each element of the vector will be processed recursively Alternatively the handler may return a string which specifies a file to be loaded eval when compile eval set extension specifier my package Lambda spec old 14 4 3 provide 87 CHICKEN User s Manual The User s Manual make pathname my package directory gt string cadr spec require extension my package stuff expands into load my packag Note that the handler has to be registered at compile time 1f it is to be visible
28. EH 100 Vil CHICKEN User s Manual The User s Manual Chicken User s Manual 15 Unit extras 15 93 SUTIN E CHOPy oie erre rena N oeantew aaa dewceeataa eee ta een E T 100 15 9 4 string A 101 15 925 stt g COT NA 101 15 9 6 string Intersperse etos reete rite a e ras ee Ee 101 S MAE D o PEERS E 101 UR ET GE 102 15 9 9 string trans ates EE 102 Js Re B 10 SUDSHIM AT 102 15 9 T1 substtinp Index uiro ette rite en a Peine desee sade ane eade eee te bee Ane ENN 102 INTO WEE EE 103 PS VO AA ERES 103 VSM RTE ER E 103 15 1023 complem nt torre naoinear ENEE deeg 103 15 LO COMPOSE E 103 15 103 CONJOIM enee da ais dis 104 A RR 104 e O O EE 104 15 10 8 E 104 15109 identity NO cane 105 EE eege 105 SELON 105 15 1012 ROOD DE 105 SADO rT E E 105 T511 Bitary Searching RA 105 TST Binary anes enisinia ete ep Ee ean e eek e sade iR eese Ee tue acea Eee eeu dean 106 DECIES LEE I I R 107 CTA oca 108 EIA EE 108 RT ege e 108 173 SSVECLOLDIOD E 108 RTR ere gel e 108 171 351 Ovector ol ii dai 108 MAREA O 108 17 7 S32 vectorblob erret tr reo EA 109 IR AS 2vector blo AAA A aED 109 RS 109 17 10 u8vectorblob shared iii Se a aia das 109 17 11 s vectorblobichared no nono emen n na nnn nono nonononononananons 109 17 12 l6vectorblob shared no nono nono nnn nono nono cnn SEa 109 17 13 sT6vectorblob Shated ads 109 17 14 u32vectorblob shared ni as 109 1715 532 A TN 109 IU lof ivectorblob ehare
29. ES EED A 227 SS EE 227 REE HA DE HE 228 BD ALO move KE 228 e LA le E KU 228 39 4 11 MGMT E 228 35 412 find he agen g geed ee E a aE 228 35 4 15 COMO E 229 EN cr ate direCtOry A sd nee ee eite eode Lo Pee eda eee ela eee ten dean 229 35 4 15 1nstall tion e ee to pre ero e re TEE equ bread deaths epar ie Tapes da 229 SEN Lee EE EE 229 ESE AN tee rro eee troia eo De ee eae ea ea HR ER Y kN ER EUR E A sa odo 229 35 4 18 setup build directory sss enne ener enhn enne 229 35 4 19 setup verbose flag noie eerie ERE RR I CREME EE ERE sa vassoeanepabaceuacveana apenas 230 33 4 20 setup mstall EE 230 234 7lreoured chucken verston 230 35 4 22 reoured etepsiop verston 230 354 23 CTOSSSCOICK E 230 33424 EE 231 35 5 REENERT Ee E 231 3526 chicken setup AAA Hs eet de ted ceo t e Et ied dus use eie suse dev pedes e oeste o aa etn 234 35 7 WidO WS TOTES somieres cera 235 DDB CU ii ia 235 35 9 Other modes of mstallaton nn nono nononnnnononononononononononnnonnnonnnonnnnnnnno eee sene e nennen 236 35 10 Linking extensions statically eene nennen enne nnne nene nnns tnnt niea iaee nns 236 TIA EE 238 36 Immediate ODJECtS eo neret rrr EEE EE reo uero re Uo Fee e We ETE ee peel E EP ERR RR 238 36 2 N n imm diate E EE 238 HU DTP ERE 240 A 241 36 1 General id iii ds EA 241 38 1 1 Why yet anot
30. Ee ra ERE E PARU YT 58 IU RISUS 59 DD SATIRE Ee rr P EE Ee Eech 59 Se AE e BEE 59 13 1 2 Binary Integer EE 59 13 1 3 ANNO 59 111 CHICKEN User s Manual The User s Manual Chicken User s Manual 13 Unit librar 35 ENEE 59 13 1 5 Arithmetic fixnum Operations eccceecceessecesseceeeeeceeeecaeceeaaeneaeeceeeeeeeessnaeceeaeceeaeeeeaees 60 13 1 6 Arithmetic floating point OperatiONns cecesecceenceceeeeeseeceenceeeaeeceeeeeeeeeesaeceeaeeeeaeeetaees 60 DB LEP e ies ie E 61 LER SE 61 13 2 File Input Output E 61 13 2 1 current o tp t pOrt TEE 61 13 2 2 Cutrent error DOFU us cero eterne eo nde ehe Eee on ete ee EE Ee SR NAE de edd EN EY ERE RS TRES TY CEN Du Read 61 Ke n EE E 61 13 2 eg E 62 13 25 POPt POSTHIOM EE 62 SE EE EE 62 15 a EE 62 13 3 T Sete e 62 RE EE 62 AP RA 63 DSA SWIM 0101 EE 63 13 4 1 get output string O 63 EXP Ee 63 15 43 0pen oUtpu t stEIDg ic EEE EE OEE E ES AE aii is 63 13 5 Feature identifiers ece iie aiaa iie i Ea e E es EE aE ie aa oeaan 63 J35 E EE 64 SRL EAS TENERETUR 64 13 5 3 Tepister Teatut l NN 64 IR EE ER 64 13 6 KeyWord Si NR AS 64 13 6 1 S6t KEY EE 64 OOZ AUGUE 65 ARA RRA 65 13 6 4 String E 65 13 7 E le EE 65 Rer Aer Ee EE 65 13 7 2 breakpoint eege NN 66 13 8 Environment information and system Interface 67 IE NECATUS EET 67 RS EE 67 KSE Ee e 68 1358 4 le E 68 13 BD EEN 68 13 86 ANN 68 ER NAAA ANO 68 ERA O 69
31. LIST Not using the shell may be preferrable for security reasons 23 8 10 process procedure process COMMANDLINE procedure process COMMAND ARGUMENT LIST ENVIRONMENT LIST Like process but returns 4 values an input port from which data written by the sub process can be read an output port from which any data written to will be received as input in the sub process the process id of the 23 8 7 process signal 139 CHICKEN User s Manual The User s Manual started sub process and an input port from which data written by the sub process to stderr can be read 23 8 11 sleep procedure sleep SECONDS Puts the process to sleep for SECONDS Returns either 0 if the time has completely elapsed or the number of remaining seconds if a signal occurred 23 8 12 create session procedure create session Creates a new session if the calling process is not a process group leader and returns the session ID 23 9 Hard and symbolic links 23 9 1 symbolic link procedure symbolic link FILENAME Returns true if FILENAME names a symbolic link 23 9 2 create symbolic link procedure create symbolic link OLDNAME NEWNAME Creates a symbolic link with the filename NEWNAME that points to the file named OLDNAME 23 9 3 read symbolic link procedure read symbolic link FILENAME Returns the filename to which the symbolic link FILENAME points 23 8 10 process 140 CHICKEN User s Manual The User s Manual 23 9
32. Manual 21 4 regexp procedure regexp STRING IGNORECASE IGNORESPACE UTF8 Returns a precompiled regular expression object for string The optional arguments IGNORECASE IGNORESPACE and UTF8 specify whether the regular expression should be matched with case or whitespace differences ignored or whether the string should be treated as containing UTF 8 encoded characters respectively 21 5 regexp procedure regexp STRING OPTIONS TABLES Returns a precompiled regular expression object for string The optional argument OPTIONS must be a list of option symbols The optional argument TABLES must be a character definitions table not defined here Option Symbols caseless Character case insensitive match multiline Equivalent to Perl s m option dotall Equivalent to Perl s s option extended Ignore whitespace anchored Anchor pattern match dollar endonly metacharacter in the pattern matches only at the end of the subject string extra Currently of very little use notbol First character of the string is not the beginning of a line noteol End of the string is not the end of a line ungreedy Inverts the greediness of the quantifiers so that they are not greedy by default notempty The empty string is not considered to be a valid match utf8 UTF 8 encoded characters no auto capture Disables the use of numbered capturing parentheses no utf8 check Skip valid UTF 8 sequence check auto callout Automati
33. NN 134 23 0 1 til aCCesS RE 135 23 6 2 TEE EE 135 23 6 3 file moOdification tiMe cccccccsesesessssccccccscccecececececececscecscscseseseseseeseseseseseseseseeeeeseeeseeeseeereenes 135 DF OVA RE EE 135 23 6 5 DEELER iacta nore deed SNE deed 135 PRKEN EE 135 PANIER 136 CHICKEN User s Manual The User s Manual Chicken User s Manual 23 Unit posix PER A dee canes dasa vot resis tea wes aa tac Aan nate soa EE ee ZE Ee 23 6 0 e e EE PAROI LUB Ul E Ee 23 7 Changing tile Atri Ou tes s een erre d Eae Ee e PREIS Ee RE EE ARE ERREUR ERE SERRE FIRE e EE SEE ENSE aes 23 7 1 filectruncate eco EE Ee dore EORR v Coe Eee E uer OR EE 23 10 Retrieving user amp group oformaon nennen nene nennen stehen neret nns 23 101 current Uset 1d ia ER Kale giele a SAA sce oobi sy steve A 23 13 6 EE Ee 136 145 xi CHICKEN User s Manual The User s Manual Chicken User s Manual 23 Unit posix 23 137 SISAL TAS Kl e cemere reo HT IR YER UA RR eerta neos wo kun EU unde On Edeka ee Ue aUe ede Kee ue ENS Eo Reds 145 SEENEN 145 23 13 9 SiS Al 8 10 EE 145 ANECA RN 145 23 13 11 A re roe EO rete Fe tdi ret ex Et teda eset e suse ev pede e eode ioa evo Lad 145 PARS EE ET 145 ER E EE LE 145 AE LTE 145 ER E ENEE 146 23 AS EE 146 ER E RE Let EE 146 23 V3 EERSUIIER IE 146 EEE ers rettet ie oi Dual oai Hg eee e P PP eio eeu te duo 146 EE EE LA ET 146 ER EE Ltr EE 146 AI Le 146 PENE ON 146 23 13 24 A Le DE 146 23 EAS EE 146 23 13
34. Returns an unspecified value 13 20 Continuations 13 17 6 blob TI CHICKEN User s Manual The User s Manual 13 20 1 call cc procedure call cc PROCEDURE An alias for Call with current continuation 13 20 2 continuation capture procedure continuation capture PROCEDURE Creates a continuation object representing the current continuation and tail calls PROCEDURE with this continuation as the single argument More information about this continuation API can be found in the paper http repository readscheme org ftp papers sw2001 feeley pdf A Better API for first class Continuations by Marc Feeley 13 20 3 continuation procedure continuation X Returns t if X is a continuation object or f otherwise Please note that this applies only to continuations created by the Continuation API but not by call cc i e Call with current continuation continuation returns f whereas continuation capture continuation returns t 13 20 4 continuation graft procedure continuation graft CONT THUNK Calls the procedure THUNK with no arguments and the implicit continuation CONT 13 20 5 continuation return procedure continuation return CONT VALUE Returns the value s to the continuation CONT continuation return could be implemented like this define continuation return k vals continuation graft k Lambda apply values vals 13 20 1 call cc 78 CHICKEN User s Manual The User s Manual
35. Unit library 12 12 program name 58 13 Unit library This unit contains basic Scheme definitions This unit is used by default unless the program is compiled with the explicit use option 13 1 Arithmetic 13 1 1 add1 sub1 procedure add1 N procedure sub1 N Adds subtracts 1 from N 13 1 2 Binary integer operations Binary integer operations arithmetic shift shifts the argument N1 by N2 bits to the left If N2 is negative than N1 is shifted to the right These operations only accept exact integers or inexact integers in word range 32 bit signed on 32 bit platforms or 64 bit signed on 64 bit platforms procedure bitwise and N1 procedure bitwise ior N1 procedure bitwise xor N1 procedure bitwise not N procedure arithmetic shift N1 N2 13 1 3 bit set procedure bit set N INDEX Returns t if the bit at the position INDEX in the integer N is set or f otherwise The rightmost least significant bit is bit 0 13 1 4 fixnum procedure fixnum X Returns t if X is a fixnum or f otherwise 13 Unit library 59 CHICKEN User s Manual The User s Manual 13 1 5 Arithmetic fixnum operations These procedures do not check their arguments so non fixnum parameters will result in incorrect results fxneg negates its argument On division by zero FX and f xmod signal a condition of kind exn arithmetic fxshl and fxshr perform arithmetic shift left and right res
36. argv procedure argc argv Returns two values an integer and a foreign pointer object representing the argc and argv arguments passed to the current process Previous Locations Next C interface 33 Other support procedures 214 34 C interface The following functions and macros are available for C code that invokes Scheme or foreign procedures that are called by Scheme 34 1 C save C macro void C save C word x Saves the Scheme data object X on the temporary stack 34 2 C restore C macro void C restore Pops and returns the topmost value from the temporary stack 34 3 C fix C macro C word C fix int integer 34 4 C make character C macro C word C make character int char code 34 5 C SCHEME END OF LIST C macro C SCHEME END OF LIST 34 6 C word C SCHEME END OF FILE C macro C SCHEME END OF FILE 34 C interface 215 CHICKEN User s Manual The User s Manual 34 7 C word C SCHEME FALSE C macro C SCHEME FALSE 34 8 C word C SCHEME TRUE C macro C SCHEME TRUE These macros return immediate Scheme data objects 34 9 C string C function C word C string C word ptr int length char string 34 10 C string2 C function C word C string2 C word ptr char zero terminated string 34 11 C intern2 C function C word C intern2 C word ptr char zero terminated string 34 12 C intern3 C function C word C intern3 C word ptr char zero terminated string C wo 34
37. be made much more complicated since the location of every object whether it is allocated on the stack or on the heap or completely outside the GC able data space has to be checked this would be rather complex and inefficient in a situation where multiple threads are involved 38 1 11 Does CHICKEN support Unicode strings Yes as an extension By default all string and character functions operate bytewise so that characters with an iteger value greater than 255 don t make much sense and multibyte UTF 8 characters are seen and manipulated as separate bytes analogous to what a C program would see You can enable UTF 8 support by placing the following two lines at the beginning of your source file or in your csirc for interactive sessions before any other code including other use directives use iset syntax case utf8 import utf8 This will replace all builtin string operators with UTF 8 aware versions that will treat strings as sequences of multibyte UTF 8 characters thus enabling you to represent and manipulate Unicode characters while remaining compatible with most C libraries and system interfaces 38 1 8 Why doesn t CHICKEN support the full numeric tower bydefault 243 CHICKEN User s Manual The User s Manual Most eggs should work correctly in utf8 mode including the regex extension but you still have the option of working around incompatibilities of specific eggs by loading them before the import utf8 directive K
38. code that is to be loaded at run time of any Scheme code that uses that extension We create a glass lambda a procedure with free variables that can be manipulated from outside glass scm define macro glass lambda llist vars body Low level macros are fun let lvar gensym svar gensym x gensym y gensym yn gensym let map lambda v list v f vars define svar x y let yn pair y and yn caf yy case x 35 5 Examples for extensions 232 CHICKEN User s Manual The User s Manual L nbhep v if yn v set v y iv vars else efror variable not found x define lvar lambda llist body extend procedure lvar svar Here some support code that needs to be loaded at runtime glass support scm require extension lolevel define glass lambda accessor procedure data define glass lambda ref gl v procedure data gl v define glass lambda set gl v x procedure data gl v x The setup script looks like this compile s glass support scm install extension glass glass s Ctsyntax cm glass support so require at runtime glass support The invocation of install extension provides the files that are to be copied into the extension repository and a metadata list that specifies that the extension glass is a syntax extension and that if it is declared to be used by other code either with the
39. compiled into a DLL to be loaded dynamically must be linked with the same runtime system as the loading application That means that all dynamically loaded entities including extensions built and installed with chicken setup must be compiled with the windows CSC option 38 1 11 Does CHICKEN support Unicode strings 244 CHICKEN User s Manual The User s Manual 38 2 6 On Windows csc exe seems to be doing something wrong The Windows development tools include a C compiler with the same name Either invoke CSC exe with a full pathname or put the directory where you installed CHICKEN in front of the MS development tool path in the PATH environment variable 38 2 7 On Windows source and or output filenames with embedded whitespace are not found There is no current workaround Do not use filenames with embedded whitespace for code However command names with embedded whitespace will work correctly 38 3 Customization 38 3 1 How do run custom startup code before the runtime system is invoked When you invoke the C compiler for your translated Scheme source program add the C compiler option DC EMBEDDED or pass embedded to the CSC driver program so no entry point function will be generated main When your are finished with your startup processing invoke CHICKEN main argc argv C toplevel where C toplevel is the entry point into the compiled Scheme code You should add the following declarations at the head of
40. d eee deed tetas 129 23 24 delete dir ctoty eoo ree arae n E E EEE O ERE VERE EE TREE EES e 129 23 2 9 rte 129 23 2 0 iuto ad E 129 PENA ut E NN 129 23 2 8 S t rootdirectory l dore t dieere RR GEO UAR S PRG PEE EN PUR EE EE INTO dani 130 PARS alU ERI REUS 130 23 3 1 call with mput pipe tette tonne ene tete ta Yo eee aee nut en a e ii aii 130 23 3 2 call with output ptpe ioter rte teet deett ota Penne ae eia ea foe oe dene e ene lod erheben 130 23 5 3 O O 130 23 3 4 close o tput ptpe eret tet ie eet t edet eel epe edere cea e o T ee ae e eg Ee Pe i Ed Rae dn 130 A ET SPEED LLL LII ULLULL DU 130 ER EBEN 131 23 3 7 A O 131 ERR O EE 131 23 529 with imput fromr plpe eege eege tuere era un ene nep o aia dla ETE T eR n 131 23 3 10 with output to ptD6 iier ite terree tetro tede ette I E nd eed ee Pus ed dig te eee ete eode yip eeu teta 131 DIA ANOS ess Saas Pe UP E eee a 132 23 4 A fifa EE 132 DIA E 132 23 5 File descriptors and low level I Q nenei eene eene eene ennt eainiie viies taion setae 132 23 5 l duplicate filen resi dion ere OR GT OO FERRE ONE DRE EE ERE Nea ira 132 23 5 2 e Te EEN 132 23 Dig SMILE OP E 133 23 34 O A 133 QS De Ml EE 133 23 DO le lt A da ds 133 AAA AO 134 RO A O A 134 23 5 9 open miput tile O 134 ERR LATE le EE 134 23D BE een le M E E E A A E A E E 134 23 6 AI
41. e If ID names one of the syntactic extensions chicken more macros chicken ffi macros then this extension will be loaded at compile time making the syntactic extensions available in compiled code If ID names one of the core library units shipped with CHICKEN or if the option uses ID has been passed to the compiler then a declare uses ID is generated e If ID names an installed extension with the syntax or require at runtime attribute then the equivalent of require for syntax ID is performed and code is emitted to require any needed run time requirements Otherwise require extension ID is equivalent to require ID To make long matters short just use require extension and it will normally figure everything out for dynamically loadable extensions and core library units ID should be a pure extension name and should not contain any path prefixes for example dir lib is illegal ID may also be a list that designates an extension specifier Currently the following extension specifiers are defined 9 Non standard macros and special forms 32 CHICKEN User s Manual The User s Manual e srfi NUMBER is required for SRFI 55 compatibility and is fully implemented e version ID NUMBER is equivalent to ID but checks at compile time whether the extension named ID is installed and whether its version is equal or higher than NUMBER NUMBER may be a string or a number the comparison is done lexicographically usin
42. fields s infix gt this is a string 1 2 3 string split fields s suffix gt this is a string 1 2 3 21 9 string match positions 120 CHICKEN User s Manual The User s Manual 21 13 string substitute procedure string substitute REGEXP SUBST STRING MODE Searches substrings in STRING that match REGEXP and substitutes them with the string SUBST The substitution can contain references to subexpressions in REGEXP with the NUM notation where NUM refers to the NUMth parenthesized expression The optional argument MODE defaults to 1 and specifies the number of the match to be substituted Any non numeric index specifies that all matches are to be substituted string substitute 0 9 eggs chicks NN or 99 chicks 2 NN Y naa T 2 NM 99 eggs or chicks 99 V d LO D O UN Q Note that a regular expression that matches an empty string will signal an error 21 14 string substitute procedure string substitute STRING SMAP MODE Substitutes elements of STRING with string substitute according to SMAP SMAP should be an association list where each element of the list is a pair of the form MATCH REPLACEMENT Every occurrence of the regular expression MATCH in STRING will be replaced by the string REPLACEMENT string substitute lt h1 gt Hello world lt h1 gt D A Za Z0 e 9 gt i EN gt Hello world 21 15 regexp escape pr
43. gt gc Zt 157812 7 gt While you might expect objects to be reclaimed and 1 2 3 is dead printed it won t happen the literal list gets held in the interpreter history because it is the result value of the set finalizer call Running this in a normal program will work fine When testing finalizers from the interpreter you might want to define a trivial macro such as define macro v x begin print x void and wrap calls to set finalizer init 38 8 Interpreter 38 8 1 Does CSI support history and autocompletion CSI doesn t support it natively but it can be activated with the http www call with current continuation org eggs readline html egg After installing the egg add the following to your CSirc or equivalent file require extension readline current input port make gnu readline port gnu history install file manager string append or getenv HOME cs Users of nix like systems including Cygwin may also want to check out rlwrap This program lets you wrap another process e g rLwrap csi with the readline library giving you history autocompletion and the ability to set the keystroke set Vi fans can get vi keystrokes by adding set editing mode vi to their inputrc file 38 8 2 Does code loaded with load run compiled or interpreted If you compile a file with a call to Load the code will be loaded at runtime and if the file loaded is a Scheme source code file instead o
44. information see SRFI 69 A setter for hash table ref is defined so set hash table ref HT KEY VAL is equivalent to 15 3 3 sprintf 93 CHICKEN User s Manual The User s Manual hash table set HT KEY VAL As an extension to SRFI 69 hash table update and hash table update default return the new value after applying the update procedure 15 4 1 hash table remove procedure hash table remove HASHTABLE PROC Calls PROC for all entries in HASHTABLE with the key and value of each entry If PROC returns true then that entry is removed 15 5 Queues 15 5 1 listqueue procedure list gt queue LIST Returns LIST converted into a queue where the first element of the list is the same as the first element of the queue The resulting queue may share memory with the list and the list should not be modified after this operation 15 5 2 make queue procedure make queue Returns a newly created queue 15 5 3 queue procedure queue X Returns t if X is a queue or f otherwise 15 5 4 queuelist procedure queue gt list QUEUE 15 4 Hash tables 94 CHICKEN User s Manual The User s Manual Returns QUEUE converted into a list where the first element of the list is the same as the first element of the queue The resulting list may share memory with the queue object and should not be modified 15 5 5 queue add procedure queue add QUEUE X Adds X to the rear of QUEUE 15 5 6 queue empty
45. library in your Setup script and install it along with the dynamically loadable extension The setup properties Static should contain the name of the object file or static library to be linked when CSC gets passed the static extensions option compile s 02 dl my ext scm dynamically loadable normal version compile c 02 d1 my ext unit my ext statically linkable version install extension my ext my ext so static my ext o Note the use of the unit option in the second compilation step static linking must use static library units chicken setup will perform platform dependent file extension translation for the file list but does currently not do that for the static extension property 35 8 Security 236 CHICKEN User s Manual The User s Manual To actually link with the static version of my ext do csc static extensions my program scm uses my ext The compiler will try to do the right thing but can not handle all extensions since the ability to statically link eggs is relatively new Eggs that support static linking are designated as being able to do so If you require a statically linkable version of an egg that has not been converted yet contact the extension author or the CHICKEN mailing list Previous Interface to external functions and variables Next Data representation 35 10 Linking extensions statically 237 36 Data representation Note In all cases below bits are nu
46. line 15 8 9 write line procedure read line PORT LIMIT procedure write line STRING PORT Line input and output PORT defaults to the value of current input port and current output port respectively If the optional argument LIMIT is given and not f then read line reads at most LIMIT characters per line read line returns a string without the terminating newline and write Lline adds a terminating newline before outputting 15 8 4 pretty print width 98 CHICKEN User s Manual The User s Manual 15 8 10 read lines procedure read lines PORT MAX Read MAX or fewer lines from PORT PORT defaults to the value of current input port PORT may optionally be a string naming a file Returns a list of strings each string representing a line read not including any line separation character s 15 8 11 read string 15 8 12 read string 15 8 13 write string procedure read string NUM PORT procedure read string NUM STRING PORT START procedure write string STRING NUM PORT Read or write NUM characters from to PORT which defaults to the value of current input port or current output port respectively If NUM is f or not given then all data up to the end of file is read or in the case of write string the whole string is written If no more input is available read string returns the empty string read string reads destructively into the given STRING argument but never m
47. moving arbitrary objects into static memory but care should be taken when mutating evicted data setting slots in evicted vector like objects to non evicted data is not allowed It is possible to set characters bytes in evicted strings or byte vectors though It is advisable not to evict ports because they might be mutated by certain file operations object evict is able to handle circular and shared structures but evicted symbols are no longer unique a fresh copy of the symbol is created so define x foo 26 3 2 extended procedure 180 CHICKEN User s Manual The User s Manual define y object evict foo y gt f00 eq x y gt JH define z object evict bar bar eq car z cadr z gt Ft The ALLOCATOR defaults to allocate 26 4 2 object evict to location procedure object evict to location X PTR LIMIT As object evict but moves the object at the address pointed to by the machine pointer PTR If the number of copied bytes exceeds the optional LIMIT then an error is signalled specifically a composite condition of types exn and evict The latter provides a Limit property which holds the exceeded limit Two values are returned the evicted object and a new pointer pointing to the first free address after the evicted object 26 4 3 object evicted procedure object evicted X Returns t if X is a non immediate evicted data object or f otherwise 26 4 4 object size procedure object size X
48. naturally rather simplistic Things like enabling dynamic loading estimating the optimal stack size and selecting supported features of the host system would need more configuration and build time support All this can be addressed using more elaborate build scripts makefiles or by using autoconf automake Note also that the size of the application can still be reduced by removing extras and eval and compiling hello scm with the explicit use option For more information study the CHICKEN source code and or get in contact with the author Previous index html 3 5 Distributing compiled C files 13 CHICKEN User s Manual The User s Manual Next Using the interpreter 3 5 Distributing compiled C files 14 4 Using the interpreter CHICKEN provides an interpreter named CSi for evaluating Scheme programs and expressions interactively 4 1 Interpreter command line format csi FILENAME OPTION where FILENAME specifies a file with Scheme source code If the extension of the source file is SCM it may be omitted The runtime options described in Compiler command line format are also available for the interpreter If the environment variable CSI OPTIONS is set to a list of options then these options are additionally passed to every direct or indirect invocation of CSi Please note that runtime options like can not be passed using this method The options recognized by the interpreter are Ignore everything on the command li
49. no access to anything created with def ine Use define for syntax instead 38 4 2 Why isn t load properly loading my library of macros During compile time macros are only available in the source file in which they are defined Files included via include are considered part of the containing file 38 4 3 Why is include unable to load my hygienic macros It is not sufficient for the included file to require the syntax case extension Call require extension syntax case before calling include 38 4 4 Why are macros not visible outside of the compilation unit in which they are defined Macros are defined during compile time so when a file has been compiled the definitions are gone An exception to this rule are macros defined with def ine macro which are also visible at run time i e in eval To use macros defined in other files use the include special form 38 3 2 How can I add compiled user passes 246 CHICKEN User s Manual The User s Manual 38 5 Warnings and errors 38 5 1 Why does my program crash when use callback functions from Scheme to C and back to Scheme again There are two reasons why code involving callbacks can crash out of no apparent reason 1 It is important to use foreign safe lambda foreign safe lambda for the C code that is to call back into Scheme If this is not done than sooner or later the available stack space will be exhausted 2 If the C code uses a large amount of stack storage or if Sche
50. of January 1970 UTC 23 16 7 timestring procedure time gt string VECTOR Converts the broken down time represented in the 10 element vector VECTOR into a string of the form Tue May 21 13 46 22 1991 23 16 2 local timeseconds 150 CHICKEN User s Manual The User s Manual 23 17 Raw exit 23 17 1 exit procedure _exit CODE Exits the current process without flushing any buffered output using the C function exit Note that the exit handLer is not called when this procedure is invoked The optional return code CODE defaults to 23 18 ERRNO values 23 18 1 errno perm 23 18 2 errno noent 23 18 3 errno srch 23 18 4 errno intr 23 18 5 errno io 23 18 6 errno noexec 23 18 7 errno badf 23 17 Raw exit 0 151 CHICKEN User s Manual The User s Manual 23 18 8 errno child 23 18 9 errno nomem 23 18 10 errno acces 23 18 11 errno fault 23 18 12 errno busy 23 18 13 errno notdir 23 18 14 errno isdir 23 18 15 errno inval 23 18 16 errno mfile 23 18 17 errno nospc 23 18 18 errno spipe 23 18 8 errno child 152 CHICKEN User s Manual The User s Manual 23 18 19 errno pipe 23 18 20 errno again 23 18 21 errno rofs 23 18 22 errno exist 23 18 23 errno wouldblock These variables contain error codes as returned by errno 23 19 Finding files 23 19 1 find files procedure find files DIRECTORY PREDICATE ACTION IDENTITY LIMIT Recursively traverses the contents
51. pointer object f is returned Otherwise an error is signalled 26 3 Extending procedures with data 26 3 1 extend procedure procedure extend procedure PROCEDURE X Returns a copy of the procedure PROCEDURE which contains an additional data slot initialized to X If PROCEDURE is already an extended procedure then its data slot is changed to contain X and the same procedure is returned 26 2 Tagged pointers 179 CHICKEN User s Manual The User s Manual 26 3 2 extended procedure procedure extended procedure PROCEDURE Returns t if PROCEDURE is an extended procedure or f otherwise 26 3 3 procedure data procedure procedure data PROCEDURE Returns the data object contained in the extended procedure PROCEDURE or f if it is not an extended procedure 26 3 4 set procedure data procedure set procedure data PROCEDURE X Changes the data object contained in the extended procedure PROCEDURE to X define foo letrec f lambda procedure data x x f set x extend procedure f 123 x foo gt 123 set procedure data foo hello foo gt hello 26 4 Data in unmanaged memory 26 4 1 object evict procedure object evict X ALLOCATOR Copies the object X recursively into the memory pointed to by the foreign pointer object returned by ALLOCATOR which should be a procedure of a single argument the number of bytes to allocate The freshly copied object is returned This facility allows
52. provided by the basic CHICKEN system to be built and installed separately The mechanism for loading compiled extensions is based on dynamically loadable code and as such is only available on systems on which loading compiled code at runtime is supported Currently these are most UNIX compatible platforms that provide the Libdl functionality like Linux Solaris BSD Mac OS X and Windows using Cygwin Note Extension may also be normal applications or shell scripts but are usually libraries chicken setup will download the source code for extension automatically from the canonical server at http www call with current continuation org eggs if the requested egg does not exist in the current directory Various command line options exist for customizing the process and or retrieving the egg from other locations or in other formats 35 2 Installing extensions To install an extension library run the chicken setup program with the extension name as argument The extension archive is downloaded its contents extracted and the contained setup script is executed This setup script is a normal Scheme source file which will be interpreted by chicken setup The complete language supported by CS1 is available and the library units srfi 1 regex utils posix tcp are loaded Additional libraries can be loaded at run time The setup script should perform all necessary steps to build the new library or application After a successful build the extension c
53. receives a single argument a string CLOSE is called when the port is closed and should be a procedure of no arguments FLUSH if provided is called for flushing the output port 15 8 3 pretty print procedure pretty print EXP PORT procedure pp EXP PORT Print expression nicely formatted PORT defaults to the value of current output port 15 7 2 randomize 97 CHICKEN User s Manual The User s Manual 15 8 4 pretty print width Parameter Specifies the maximal line width for pretty printing after which line wrap will occur 15 8 5 read byte 15 8 6 write byte procedure read byte PORT procedure write byte BYTE PORT Read write a byte to the port given in PORT which default to the values of Current input port and current output port respectively 15 8 7 read file procedure read file FILE OR PORT READER MAXCOUNT Returns a list containing all toplevel expressions read from the file or port FILE OR PORT If no argument is given input is read from the port that is the current value of current input port After all expressions are read and if the argument is a port then the port will not be closed The READER argument specifies the procedure used to read expressions from the given file or port and defaults to read The reader procedure will be called with a single argument an input port If MAXCOUNT is given then only up to MAXCOUNT expressions will be read in 15 8 8 read
54. ref procedure pointer u32 ref PTR Returns the unsigned 32 bit integer at the address designated by PTR 26 1 11 pointer offset 176 CHICKEN User s Manual The User s Manual 26 1 17 pointer s32 ref procedure pointer s32 ref PTR Returns the signed 32 bit integer at the address designated by PTR 26 1 18 pointer f32 ref procedure pointer f32 ref PTR Returns the 32 bit float at the address designated by PTR 26 1 19 pointer f64 ref procedure pointer f64 ref PTR Returns the 64 bit double at the address designated by PTR 26 1 20 pointer u8 set procedure pointer u8 set PTR N procedure set pointer u8 ref PTR N Stores the unsigned byte N at the address designated by PTR 26 1 21 pointer s8 set procedure pointer s8 set PTR N procedure set pointer s8 ref PTR N Stores the signed byte N at the address designated by PTR 26 1 22 pointer u16 set procedure pointer ul6 set PTR N procedure set pointer ul6 ref PTR N Stores the unsigned 16 bit integer N at the address designated by PTR 26 1 17 pointer s32 ref 177 CHICKEN User s Manual The User s Manual 26 1 23 pointer s16 set procedure pointer s16 set PTR N procedure set pointer s16 ref PTR N Stores the signed 16 bit integer N at the address designated by PTR 26 1 24 pointer u32 set procedure pointer u32 set PTR N procedure set pointer u32 ref PTR N Stores the unsigned 32 bit
55. require extension or require for syntax form then client code should perform an implicit require glass support at startup This can be conveniently packaged as an egg tar cfz glass egg glass setup glass scm glass support scm And now we use it chicken setup glass csi quiet 1 gt require extension glass loading usr local lib chicken 1 glass scm loading usr local lib chicken 1 glass support so 2 gt define foo glass lambda x y x y 3 gt glass lambda set foo y 99 4 gt foo 33 132 35 5 Examples for extensions 233 CHICKEN User s Manual The User s Manual 35 6 chicken setup reference Available options h help Show usage information and exit V version Display version and exit R repository PATHNAME When used without an argument the path of the extension repository is displayed on standard output When given an argument the repository pathname and the repository path parameter will be set to PATHNAME for all subsequent operations The default repository path is the installation library directory usually usr local lib chicken or if set the directory given in the environment variable CHICKEN_REPOSITORY PATHNAME should be an absolute pathname P program path PATHNAME When used without an argument the path for executables is displayed on standard output When given an argument the program path for installing executables and scripts will be set to PATHNAME for
56. the currently active read table with current read table 13 22 2 set read syntax 80 CHICKEN User s Manual The User s Manual 13 23 Property lists As in other Lisp dialects CHICKEN supports property lists associated with symbols Properties are accessible via a key that can be any kind of value but which will be compared using eq 13 23 1 get procedure get SYMBOL PROPERTY DEFAULT Returns the value stored under the key PROPERTY in the property list of SYMBOL If no such property is stored returns DEFAULT The DEFAULT is optional and defaults to f 13 23 2 put procedure put SYMBOL PROPERTY VALUE setter set get SYMBOL PROPERTY VALUE Stores VALUE under the key PROPERTY in the property list of SYMBOL replacing any previously stored value 13 23 3 remprop procedure remprop SYMBOL PROPERTY Deletes the first property matching the key PROPERTY in the property list of SYMBOL Returns t when a deletion performed and f otherwise 13 23 4 symbol plist procedure symbol plist SYMBOL setter set symbol plist SYMBOL LST Returns the property list of SYMBOL or sets it 13 23 5 get properties procedure get properties SYMBOL PROPERTIES Searches the property list of SYMBOL for the first property with a key in the list PROPERTIES Returns 3 values the matching property key value and the tail of property list after the matching property When no match found all values are f 13
57. the default the features srfi 0 srfi 2 srfi 6 srfi 8 srfi 9 and srfi 10 are defined When compiling code during compile time the feature compiling is registered When evaluating code in the interpreter csi the feature CSi is registered 13 3 3 rename file 63 CHICKEN User s Manual The User s Manual 13 5 1 features procedure features Returns a list of all registered features that will be accepted as valid feature identifiers by cond expand 13 5 2 feature procedure feature ID Returns t if all features with the given feature identifiers ID are registered 13 5 3 register feature procedure register feature FEATURE Register one or more features that will be accepted as valid feature identifiers by cond expand FEATURE may be a keyword string or symbol 13 5 4 unregister feature procedure unregister feature FEATURE Unregisters the specified feature identifiers FEATURE may be a keyword string or symbol 13 6 Keywords Keywords are special symbols prefixed with that evaluate to themselves Procedures can use keywords to accept optional named parameters in addition to normal required parameters Assignment to and bindings of keyword symbols is not allowed The parameter Keyword style and the compiler interpreter option keyword style can be used to allow an additional keyword syntax either compatible to Common LISP or to DSSSL 13 6 1 get keyword procedure get k
58. time to stdout Write compiled code to standard output instead of creating a C file unit NAME Compile this file as a library unit Equivalent to prelude declare unit NAME unsafe Disable runtime safety checks unsafe libraries Marks the generated file for being linked with the unsafe runtime system This should be used when generating shared object files that are to be loaded dynamically If the marker is present any attempt to load code compiled with this option will signal an error uses NAME Use definitions from the library unit NAME This is equivalent to prelude declare uses NAME Multiple arguments may be given separated by no usual integrations Specifies that standard procedures and certain internal procedures may be redefined and can not be inlined This is equivalent to declaring not usual integrations version Prints the version and some copyright information and exit the compiler verbose Prints progress information to standard output during compilation The environment variable CHICKEN OPTIONS can be set to a string with default command line options for the compiler 3 2 Runtime options After successful compilation a C source file is generated and can be compiled with a C compiler Executables generated with CHICKEN and the compiler itself accept a small set of runtime options Shows a list of the available runtime options and exits the program aNUMBER Specifies the length of the
59. time When encountered while compiling code and the situation specifier Load is not given then this form is ignored and an expression resulting into an unspecified value is compiled instead The following table should make this clearer In compiled code In interpreted code eval ignore evaluate compile evaluate at compile time ignore load compile as normal ignore The situation specifiers compile time and run time are also defined and have the same meaning as compile and Load respectively 9 7 5 include syntax include STRING Include toplevel expressions from the given source file in the currently compiled interpreted program If the included file has the extension SCm then it may be omitted The file is searched in the current directory and if not found in all directories specified in the include path option 9 7 6 nth value syntax nth value N EXP Returns the Nth value counting from zero of the values returned by expression EXP 9 7 7 time syntax time EXP1 Evaluates EXP1 and prints elapsed time and some values about GC use like time spent in major GCs number of minor and major GCs Previous Non standard read syntax Next Pattern matching 9 7 4 eval when 42 10 Pattern matching This description has been taken mostly from Andrew Wright s postscript document Pattern matching allows complicated control decisions based on data structure to be expressed in a concise manner Pattern ma
60. to the empty list e join r s t a b cd join p q join could be implemented as follows define join lstoflsts optional lst apply append intersperse lstoflists lst 15 1 11 shuffle procedure shuffle LIST Returns LIST with its elements sorted in a random order 15 1 12 tail procedure tail X LIST Returns true if X is one of the tails cdr s of LIST 15 2 String port extensions 15 2 1 call with input string procedure call with input string STRING PROC Calls the procedure PROC with a single argument that is a string input port with the contents of STRING 15 2 2 call with output string procedure call with output string PROC Calls the procedure PROC with a single argument that is a string output port Returns the accumulated output string 15 1 10 join 91 CHICKEN User s Manual The User s Manual 15 2 3 with input from string procedure with input from string STRING THUNK Call procedure THUNK with the current input port temporarily bound to an input string port with the contents of STRING 15 2 4 with output to string procedure with output to string THUNK Call procedure THUNK with the current output port temporarily bound to a string output port and return the accumulated output string 15 3 Formatted output 15 3 1 printf 15 3 2 fprintf 15 3 3 sprintf procedure fprintf PORT FORMATSTRING ARG procedure printf FORMATS
61. trace options SNUMBER Specifies stack size NUMBER Specifies symbol table size Enables garbage collection of unused symbols By default unused and unbound symbols are not garbage collected X Raises uncaught exceptions of separately spawned threads in primordial thread By default uncaught exceptions in separate threads are not handled unless the primordial one explicitly joins them When warnings are enabled the default and X is not given a warning will be shown though The argument values may be given in bytes in kilobytes suffixed with K or K in megabytes suffixed with M or m or in gigabytes suffixed with G or g Runtime options may be combined like dC but everything following a NUMBER argument is ignored So wh64m is OK but h64mw will not enable GC of unused symbols 3 3 Examples 3 3 Examples CHICKEN User s Manual The User s Manual 3 3 1 A simple example with one source file To compile a Scheme program assuming a UNIX like environment consisting of a single source file perform the following steps 3 3 1 1 Writing your source file In this example we will assume your source file is called foo scm 55 foo scm define fac n if zero n s n fac n 1 write fac 10 newline 3 3 1 2 Compiling your program Compile the file foo scm csc foo scm This will produce the foo executable ls foo foo scm 3 3 1 3 Running your program To run your newly c
62. variable is not accessible from outside of the current compilation unit it is declared static 32 2 let location syntax let location NAME TYPE INIT BODY Defines a lexically bound location 32 3 location syntax location NAME syntax location X This form returns a pointer object that contains the address of the variable NAME If the argument to location is not a location defined by define Location define external or Let Location then location X is essentially equivalent to make locative X See the manual chapter or Locatives for more information about locatives Note that Location X may be abbreviated as X define external foo int foreign lambda void c pointer int ip ip 123 Location foo foo This facility is especially useful in situations where a C function returns more than one result value gt 32 Locations 212 CHICKEN User s Manual The User s Manual include lt math h gt lt define modf foreign lambda double modf double c pointer double let location i double let f modf 1 99 location i print i i f f See location and c string for a tip on returning a C St ring type location returns a value of type C pointer when given the name of a callback procedure defined with define external Previous Callbacks Next Other support procedures 32 3 location 213 33 Other support procedures 33 1 argc
63. while interrupts are disabled This procedure returns X 13 11 4 set gc report procedure set gc report FLAG Print statistics after every GC depending on FLAG A value of t shows statistics after every major GC A true value different from t shows statistics after every minor GC f switches statistics off 13 12 Other control structures 13 11 Garbage collection 73 CHICKEN User s Manual The User s Manual 13 12 1 promise procedure promise X Returns t if X is a promise returned by de Lay or f otherwise 13 13 String utilities 13 13 1 reverse liststring procedure reverse list gt string LIST Returns a string with the characters in LIST in reverse order This is equivalent to List gt string reverse LIST but much more efficient 13 14 Generating uninterned symbols 13 14 1 gensym procedure gensym STRING OR SYMBOL Returns a newly created uninterned symbol If an argument is provided the new symbol is prefixed with that argument 13 14 2 stringuninterned symbol procedure string gt uninterned symbol STRING Returns a newly created unique symbol with the name STRING 13 15 Standard Input Output 13 12 1 promise 74 CHICKEN User s Manual The User s Manual 13 15 1 port procedure port X Returns t if X is a port object or f otherwise 13 15 2 print procedure print EXP1 Outputs the optional arguments EXP1 using display and writes a newline character
64. write prot execor prot none bitwise iored together FLAG should be one or more of the flags map fixed map shared map private map anonymous or map file FILENO should be the file descriptor of the mapped file The optional argument OFFSET gives the offset of the section of the file to be mapped and defaults to 0 This procedure returns an object representing the mapped file section The procedure move memo ry can be used to access the mapped memory 23 15 3 memory mapped file pointer procedure memory mapped file pointer MMAP Returns a machine pointer to the start of the memory region to which the file is mapped 23 14 2 setenv 148 CHICKEN User s Manual The User s Manual 23 15 4 unmap file from memory procedure unmap file from memory MMAP LEN Unmaps the section of a file mapped to memory using the C function munmap MMAP should be a mapped file as returned by the procedure map file to memory The optional argument LEN specifies the length of the section to be unmapped and defaults to the complete length given when the file was mapped 23 16 Date and time routines 23 16 1 secondslocal time procedure seconds gt local time SECONDS Breaks down the time value represented in SECONDS into a 10 element vector of the form seconds minutes hours mday month year wday yday dstflag timezone in the following format seconds 0 the number of seconds after the minute 0 59 minutes 1 the number of minutes af
65. x p block ref p 1 26 7 Low level data access 184 CHICKEN User s Manual The User s Manual define point x set p x block set p 1 x define point y p block ref p 2 define point y set p y block set p 1 y 26 7 5 move memory procedure move memory FROM TO BYTES FROM OFFSET TO OFFSET Copies BYTES bytes of memory from FROM to TO FROM and TO may be strings primitive byte vectors SRFI 4 byte vectors see Oref Unit srfi 4 memory mapped files foreign pointers as obtained from a call to foreign Lambda for example or locatives if BYTES is not given and the size of the source or destination operand is known then the maximal number of bytes will be copied Moving memory to the storage returned by locatives will cause havoc if the locative refers to containers of non immediate data like vectors or pairs The additional fourth and fifth argument specify starting offsets in bytes for the source and destination arguments 26 7 6 number of bytes procedure number of bytes BLOCK Returns the number of bytes that the object BLOCK contains BLOCK may be any non immediate value 26 7 7 number of slots procedure number of slots BLOCK Returns the number of slots that the object BLOCK contains BLOCK may be a vector record structure pair or symbol 26 7 8 record instance procedure record instance X Returns t if X is an instance of a record type See also make record instance
66. 154 SERENISSIMI 93 1541 Das ade TEME ii dido 94 AA O ERP on AEE TNA 94 IST ili EE 94 15 52 make quae LI EP 94 IS E 94 VDA EE E EE 94 UE EE Te ME 95 15 56 ET nl EE 95 US E EE NN 95 15 5 6 que ue last eegenen geen E 95 15 5 9 QUEME PEMOVE l ROS 95 15 5 10 queue push back 13 II netter e dinge ice e ERES caia oie gen 95 15 5 11 queue p shi back list 2er menester caian acts liceos 96 15 6 SOTME ee anu e ee a a E Ee aa a eE eae Ea aa eiae a eE Eae an baeten 96 LOL Tief ge opereres iege insi er ER E E wha A EE EE E tas EEES 96 1562 SOLE EE 96 156 3 SOME REENEN 96 15 27 Ratid Omi d dle e S etanan E EEEE EE A EEEN O EES 96 E Se 96 J572 Ee KEE 97 15 8 Input QUtpUt EXTENSIONS iirin rneer onie venrion EDan NEEE exh oa EERENS EEE EREE TERESE AEREE EO EEE R a i 97 EE ET EE 97 15 82 MAKE OUtPUl POT O 97 15 8 3 pretty prihL EE 97 15 8 4 prety primt With RN 98 US E 98 15 8 6 Write EE 98 15 8 7 read EE 98 15 8 8 re d lihe O 98 APRA e ee EE ee E E A ETE Pa PP ORTU 98 15 8 10 read lihe Skein a re iere ive aaa 99 EA ON 99 IS EE E 99 IEA E dene RN 99 15 8 14 Pead tOK EE 99 15 8 15 with error OUtpUt tO POTt eee ceseceseeceeeeeceeeeesaeceeaceceaeeceseeesaeeeeaaeceeaeceeaeecaeecueeeeaaeceaaeceeneeeses 99 J RTE HEET DOE toot tete rne eot ehe sea neto oh Lv esae aene eed re ERE Eee eee ern kel eek ERR REIR 100 15 8 1 7 wath output tO DOFL E 100 UE Be 100 IX MEDI EE 100
67. 186 CHICKEN User s Manual The User s Manual Changes the identity of the value of the car of each pair in ALIST to the value of the cdr Both values may not be immediate i e exact integers characters booleans or the empty list define x i used to be a string define y and now i am a vector object become list cons x y x gt and now i am a vector y gt and now i am a vector eq x y gt gt Note this operation invokes a major garbage collection The effect of using object become on evicted data see object evict is undefined 26 9 2 mutate procedure procedure mutate procedure OLD PROC Replaces the procedure OLD with the result of calling the one argument procedure PROC PROC will receive a copy of OLD that will be identical in behaviour to the result of PROC Replace arbitrary procedure with tracing one mutate procedure my proc lambda new lambda args printf s called with arguments s new args apply new args Previous Unit tcp Next Interface to external functions and variables 26 9 1 object become 187 27 Interface to external functions and variables e Accessing external objects e Foreign type specifiers e Embedding e Callbacks e Locations e Other support procedures e C interface Previous Supported language Next chicken setup 27 Interface to external functions and variables 188 28 Accessing external objects 28 1 foreign co
68. 2 3 begin is allowed in non toplevel contexts and evaluates to an unspecified value 4 2 5 Delayed expressions may return multiple values 5 2 2 CHICKEN extends standard semantics by allowing internal definitions everywhere and not only at the beginning of a body A set of internal definitions is equivalent to a Let rec form enclosing all following expressions in the body let foo 123 bar define foo 456 baz foo expands into let foo 123 bar letrec foo 456 baz foo 5 2 define with a single argument is allowed and initializes the toplevel or local binding to an unspecified value CHICKEN supports curried definitions where the variable name may also be a list specifying a name and a nested lambda list So define make adder x y x y 7 Extensions to the standard 25 CHICKEN User s Manual The User s Manual is equivalent to define make adder x lambda y x y 6 CHICKEN provides numerous non standard procedures See the manual sections on library units for more information 6 2 4 The special IEEE floating point numbers nan inf and inf are supported as is negative zero 6 3 4 User defined character names are supported See char name Characters can be given in hexadecimal notation using the AxXX syntax where XX specifies the character code Character codes above 255 are supported and can be read and are written using the AuXXXX and AUXXXXXXXX notations Non s
69. 2 4 let optionals syntax let optionals ARGS VAR1 DEFAULT1 RESTVAR BODY Binding constructs for optional procedure arguments ARGS should be a rest parameter taken from a lambda list Let optionals binds VAR1 to available arguments in parallel orto DEFAULT1 if not enough arguments were provided Let optionals binds VAR1 sequentially so every variable sees the previous ones If a single variable RESTVAR is given then it is bound to any remaining arguments otherwise it is an error if any excess arguments are provided let optionals one two a 1 b 2 c a list a b c gt one two one 9 3 Other binding forms 9 3 1 and let syntax and let BINDING EXP1 EXP2 SRFI 2 Bind sequentially and execute body BINDING can be a list of a variable and an expression a list with a single expression or a single variable If the value of an expression bound to a variable is f the and Letz form evaluates to f and the subsequent bindings and the body are not executed Otherwise the next binding is performed If all bindings expressions evaluate to a true result the body is executed normally and the result of the last expression is the result of the and Letz form See also the documentation for SREL2 9 3 2 rec syntax rec NAME EXPRESSION syntax rec NAME VARIABLE BODY Allows simple definition of recursive definitions rec NAME EXPRESSION is equivalent to Letrec
70. 23 5 6 file select 134 CHICKEN User s Manual The User s Manual 23 6 1 file access time 23 6 2 file change time 23 6 3 file modification time procedure file access time FILE procedure file change time FILE procedure file modification time FILE Returns time in seconds of the last access modification or change of FILE FILE may be a filename or a file descriptor If the file does not exist an error is signaled 23 6 4 file stat procedure file stat FILE LINK Returns a 13 element vector with the following contents inode number mode as with file permissions number of hard links uid of owner as with file owner gid of owner size as with file size and access change and modification time as with file access time file change time and file modification time device id device type for special file inode blocksize and blocks allocated On Windows systems the last 4 values are undefined If the optional argument LINK is given and not f then the file statistics vector will be resolved for symbolic links otherwise symbolic links are not resolved Note that for very large files the fi Le size value may be an inexact integer 23 6 5 file position procedure file position FILE Returns the current file position of FILE which should be a port or a file descriptor 23 6 6 file size procedure file size FILENAME Returns the size of the file designated by FILE FILE may be a filename or a f
71. 23 Property lists 81 CHICKEN User s Manual The User s Manual PROPERTIES may also be an atom in which case it is treated as a list of one element Previous Parameters Next Unit eval 13 23 5 get properties 82 14 Unit eval This unit has support for evaluation and macro handling This unit is used by default unless the program is compiled with the explicit use option 14 1 Loading code 14 1 1 load procedure load FILE EVALPROC Loads and evaluates expressions from the given source file which may be either a string or an input port Each expression read is passed to EVALPROC which defaults to eval On platforms that support it currently native Windows Linux ELF and Solaris Load can be used to load compiled programs cat x scm define hello print Hello CSC S X SCM csi q 1 gt load x so loading x so 2 gt hello Hello 3 gt The second argument to Load is ignored when loading compiled code If source code is loaded from a port then that port is closed after all expressions have been read Compiled code can be re loaded but care has to be taken if code from the replaced dynamically loaded module is still executing i e if an active continuation refers to compiled code in the old module Support for reloading compiled code dynamically is still experimental 14 1 2 load relative procedure load relative FILE EVALPROC Similar to Load but loads FILE relative
72. 26 ELE e 147 23 19 27 signal tStp EE 147 23 13 28 E Lt 147 ER 13229 tema Xop iii ia 147 AAA Le E 147 23 19 31 S1gnal Usrl ue ire reete t or tee er ones e ere e Ped e aede ee UHR Re edo Se EC ARR VAR Pu ded 147 23 13 32 si9gnal Usr2 O 147 ER E EE 147 2314 EnVarOmiMen t ACCESS seais Di da ret EE aee aros aia daa tai seu tasa n Ce dar 147 Z314leument envuonment nono tenete tenen n i ono no nonononenacanacanenos 147 DI MAD E 148 23 14 35 TEE 148 23 15 Memory Mapped WO iss ssstesssnsecessdendeesnascsnnadoadeessnadiecnsspeaiea esate eaten E AE ERNES E PERENE ETENEE AERE RAEES ba eaae 148 23 15 1 memory mapped tile eri edere eno Fere eee ep tetto Ie e e ee ev ae eae dde dav ea e Redes 148 23 152 E id e E ere dr OPE FORERO E REIR E EUR HEC Eee a RE LEER TEETH eds 148 23 15 3 memory mapped file pointer sss einen reete enne nns 148 23 15 4 unmap file from MeMOTY syrer s ii i s Ei iE EEEE ENRERE RERE 149 23 16 Date and time TQU INES cccccccccnononononononinananananananananananann ono nono nonennn nono nnnnnnononononononononononononononononananinaninananos 149 Ei Ee e Eileen 149 23 106 2 loCal tiMeSECONGS cuida ie lees 149 23 16 3 local timezone abbreviation cesses n eene nnne nennen eese enne en enn 150 29 16 Se 150 2316 5 e Ee EE 150 SS e Bet EE EE 150 23 VO TIMES AA AAA Eege 150 SN AA E O TOTO 151 DOM RE IS EE 151 23 18 ERRNO Values irc 151 AA PEL cs ege
73. 32 unsigned int32 esses eee enne enne enne 196 29 7 integer unsigned integer integer32 unsigned integer32 teeerg coococonnccnnnccnnocnnonnnnnnanonnnncnnnnn n 197 ere 197 VP ARIES sage aa 197 SHARE 197 DOME DO li A A A AA T 197 ARA Ee 197 29 13 nonnull scheMe POiNter eee ieir ani Ens E nei g ERE a EEE EREE ES T a Ee ri ek 198 E e EE 198 IAS 198 PALM ODO EE 198 29 17 nonnull blob E 198 29 18 u8vector ul6vector u32vector s8vector sl6vector s32vector f32vector f64vector 198 29 19 nonnull u8vector nonnull u16vector nonnull u32vector nonnull s8vector xvi CHICKEN User s Manual The User s Manual Chicken User s Manual 29 Foreign type specifiers nonnull s16vector nonnull s32vector nonnull f32vector nonnull f64vector 199 TU UR E 199 Eet EE TEE 199 29 22 nonnull C StEIDg A AA AAA AAA Re oae A E 199 29 23 nonnu ll si ned c stingf conc enne ener enne 199 e EE 199 29 25 TE EE 200 29 26 NOID A OO II E A 200 RSS bd d E EE 200 20 28 enim NAME iii a 200 29 29 c pointer TYPE EE 200 29 30 nonnull c pointer TYPE cscssccscstscescesvesessosdessca conssdestessicedensdcesnessautsssnscosanedsneacessdesvesedsacesen 200 29 ROLE TY NN EE 200 20 32 strict NAME E 201 RE OECD 201 29 34 mon NAME siria drid an diles 201 29 35 instance CNAME SC
74. 33 gt f 15 10 6 disjoin procedure disjoin PRED Returns a procedure that returns t if its argument satisfies any predicate PRED disjoin odd positive 32 gt t disjoin odd positive 32 gt f 15 10 7 each procedure each PROC Returns a procedure that applies PROC to its arguments and returns the result s of the last procedure application For example each pp eval is equivalent to Lambda args apply pp args apply eval args each PROC is equivalent to PROC and each is equivalent to noop 15 10 8 flip procedure flip PROC Returns a two argument procedure that calls PROC with its arguments swapped flip PROC lt gt lambda x y PROC y x 15 10 5 conjoin 104 CHICKEN User s Manual The User s Manual 15 10 9 identity procedure identity X Returns its sole argument X 15 10 10 project procedure project N Returns a procedure that returns its Nth argument starting from 0 15 10 11 list of procedure list of PRED Returns a procedure of one argument that returns t when applied to a list of elements that all satisfy the predicate procedure PRED or f otherwise list of even 1 2 3 gt f list of number 1 2 3 gt t 15 10 12 noop procedure noop X Ignores it s arguments does nothing and returns an unspecified value 15 10 13 o procedure o PROC A single value version of compose slightly
75. 6 3 Which non standard procedures are treated specially when the extended bindings Or usual integrations declaration or compiler option is used The following standard bindings are handled specially depending on optimization options and compiler settings quotient eq eqv equal apply c r values call with values list ref null Length not char string symbol vector pair procedure boolean number complex rational real exact inexact list eof object string ref string set vector ref vector set charz char char char char char numeric char alphabetic char whitespace char upper case char lower case char upcae char downcase list tail assv memv memq assoc member set car set cdr abs exp sin cos tan log asin acos atan sqrt zero positive negative vector length string length char gt integer integer gt char inexact gt exact gt lt gt lt for each map substring string append gcd lcm list exact gt inexact string gt number number gt string even odd remainder floor ceiling truncate round cons vector string string string ci make vector call with current continuation write char read string The following extended bindings are handled specially bitwise and bitwise ior bitwise xor bitwise not bit set add1 subl fx fx fx fx fxmod fx fx gt fx gt fixnum fxneg fxmax fxmin fxand fxior fxxor fxnot fxshl fxshr flonum fp fp fp fp atom fp fp gt fp gt fpneg fpmax fpmin arithmetic shift signu
76. CHICKEN deviations from the standard and extensions Interface to external functions and variables Accessing C and C code and data chicken setup Packaging and installing extension libraries Data representation How Scheme data is internally represented Bugs and limitations Yes there are some 1 The User s Manual CHICKEN User s Manual The User s Manual FAQ A list of Frequently Asked Questions about CHICKEN and their answers Acknowledgements A list of some of the people that have contributed to make CHICKEN what it is Bibliography Links to documents that may be of interest 1 The User s Manual 2 Basic mode of operation The compiler translates Scheme source code into fairly portable C that can be compiled and linked with most available C compilers CHICKEN supports the generation of executables and libraries linked either statically or dynamically Compiled Scheme code can be loaded dynamically or can be embedded in applications written in other languages Separate compilation of modules is fully supported The most portable way of creating separately linkable entities is supported by so called units A unit is a single compiled object module that contains a number of toplevel expressions that are executed either when the unit is the main unit or if the unit is used To use a unit the unit has to be declareed as used like this declare uses UNITNAME The toplevel expressions of used units are executed
77. CHICKEN User s Manual The User s Manual 9 2 Binding forms for optional arguments 9 2 1 optional syntax optional ARGS DEFAULT Use this form for procedures that take a single optional argument If ARGS is the empty list DEFAULT is evaluated and returned otherwise the first element of the list ARGS It is an error if ARGS contains more than one value define incr x i x optional i 1 incr 10 gt 11 incr 12 5 gt 17 9 2 2 case lambda syntax case lambda LAMBDA LIST1 EXP1 Expands into a lambda that invokes the body following the first matching lambda list define plus case lambda 0 x x x y x y x y z x y z args apply args plus gt 9 plus 1 gt 1 plus 1 2 3 gt 6 For more information see the documentation for SRFI 16 9 2 3 let optionals syntax let optionals ARGS VAR1 DEFAULT1 BODY Binding constructs for optional procedure arguments ARGS should be a rest parameter taken from a lambda list Let optionals binds VAR1 to available arguments in parallel orto DEFAULT1 if not enough arguments were provided Let optionals binds VAR1 sequentially so every variable sees the previous ones it is an error if any excess arguments are provided let optionals one two a 1 b 2 c 3 list a b c gt one two 3 9 2 Binding forms for optional arguments 34 CHICKEN User s Manual The User s Manual 9
78. CHICKEN User s Manual The User s Manual CHICKEN User s Manual The User s Manual Chicken User s Manual LT US ME ER RUE ERERE MERERI ELE EM MU MR ERN MEE IE LEE EP NUR 1 2 Basic mode OF OPE ai iia dia 3 USE cOn T Ue 4 3 1 Compiler command line Tomat 4 3 2 RUMUME OPUIONS sancionar censados 8 Ded Example ii A ii 9 3 3 1 A simple example with one source fie 10 3 3 2 An example with multiple Des eee 11 3 4 Extending the Compiler RR OS 12 3 5 Distributing compiled C TE 13 A 15 4 1 Interpreter command line Tomat 15 4 2 Writing Schem Scripts uinn ncis aai i a eiii 16 4 3 Tople Vel commnands O 17 4A toplevel COmmMand RN 18 Te 18 BR Ee lee 19 4 7 Auto completion and Cition ceeccceececssecessseeeeeceeaeeceneecaeeecaecesaaeceeaeeceaeeceaeesaeeseaaeceeaeceeneeeeaees 19 4 8 Accessing documentapon crono ron nn enne nien tenet nentes ernst nn sien tese ren tennis 19 A A a aaa 21 6 Deviations from the standard A a KDE ER 22 7 EXTENSIONS to Li SERDOATL EN 24 S Nonstandard road A E 28 8 1 Multiline Block Comment 28 8 2 EXpressiOn COMME EE 28 8 3 External Repr sentation E 28 5 4 Syntax EX PressiOM EE 28 8 5 Location EX TE EE 28 NA NI 29 8 7 Multiline S tring CONS LEE 29 8 8 Multiline String Constant with Embedded Expressions seen 29 EAT 30 8 10 Sharp Pretixed Symbol dr Eee Ee tere e ee REPE bes 30 Oe MMB AN AME
79. G tree rere tree eere evo Ut iia 209 30 22 CHICKEN 2lobal set eer tereti tuer pee epe de saute eet ep ee Innere 209 O 210 A 2 teer ote Error rr tor EE sole ce uasa leew evans va Lau DU GS DRY MERE DEAE ER DER UAR 210 312 Ee ee a o 0 EE EEEE E SEEE EE ALEEK EEEREN 211 313 ee Ee EE TE 211 xvii CHICKEN User s Manual The User s Manual Chicken User s Manual KA ENN 212 EPA AA SUV e vo cassavesis eis sinatiabebsdaaacheabasdvertaanata e e EEs 212 32 2 Ee re 212 32 3 LOCA e 212 O A E Sea a bu krs 214 See AL E 214 EE 215 SN SAVE EE 215 ENABLE IT TIU NIME 215 SE AV RTT TT PEE 215 SAAC make Characters EE 215 34 5 C SCHEME END OF USt nnn sehen nitent ne enean nenne 215 34 6 C word C SCHEME END OF FILE eee eee nmereenenne n nnr einen nete nn ne 215 34 7 C word SCHERMESSER 216 34 8C word C SCHEME TRUE 216 SE A 216 3410 ORT 216 34 IEC re RE 216 SA PAS EN 216 E RM TR 216 3414 C Hee Um 217 34 15 C t to DML dd aci aii 217 A e E 217 SZ IT ER EE EEN 217 A O m 217 Call tete ettet du mL EL OM RA 217 34 20 SIZBOE DISE EE 218 34 21 C SIZEOF SIRING eren ne enenenenn mnn ener nente nensis sitne te sns etes se tenens ese sterne 218 34 22 C SIZBOR VECTOR coli e des 218 34 23 C SIZEOF INTERNED SYMBOL eee n emen enn nenne eenen nnn n nes en enn nenne 218 34 24 C SIZEOE PAIR
80. GNNAME If NAME is a symbol then a C declaration will be generated that defines a C struct named struct NAME If NAME is a list then no struct declaration will be generated and FOREIGNNAME should name an existing C record type A foreign type specifier named NAME or TYPENAME will be defined as a pointer to the given C structure A SLOT definition should be a list of one of the following forms 28 4 define foreign type 190 CHICKEN User s Manual The User s Manual TYPE SLOTNAME or TYPE SLOTNAME SIZE The latter form defines an array of SIZE elements of the type TYPE embedded in the structure For every slot the following accessor procedures will be generated 28 6 1 TYPENAME SLOTNAME TYPENAME SLOTNAME FOREIGN RECORD POINTER INDEX A procedure of one argument a pointer to a C structure that returns the slot value of the slot SLOTNAME If a SIZE has been given in the slot definition then an additional argument INDEX is required that specifies the index of an array element 28 6 2 TYPENAME SLOTNAME set TYPENAME SLOTNAME set FOREIGN RECORD POINTER INXDEX VALUE A procedure of two arguments a pointer to a C structure and a value that sets the slot value of the slot SLOTNAME in the structure If a SIZE has been given in the slot definition then an additional argument INDEX is required for the array index If a slot type is of the form const then no setter procedure will be generated Slots of the types str
81. HEMECT ASS 201 29 36 instance ref CNAME SCHEMECL ASS 201 29 37 function RESULTTYPE ARGUMENTTYPE1 CALLCONY enne 201 29 38 MaDDIHpS chere t reae ne e eT re dia nan eee AAA AA EKE cet aenean 202 30 En etl oer Phat HEC PE PEOTI OOO RE EXE A LEE DOR haa nee 203 30 1 CHICKEN parse command line eese eene enne iian 203 30 2 CHICKEN imitialiZe cccsssscssccecssssscccccecossnscccescvssvssseeecevsessssatsessscssssnansescecsevsssrseseecsessnse 203 30 3 sie E e T T 203 SOA return to hOSt EN 204 30 5 CHICKEN Val idad ai eebe 204 SURE CHICKEN Vall n 204 30 7 CHICKEN v l e EE E 204 30 8 CHICKEN eval string to stong 204 30 9 CHICKEN apply erret ee e Yea eere Te ta daci n io 205 30 10 CHICKEN apply do string eicere ener roto nao e eue ne eee RENS UE Ree e Yan Eee ER a Ua ESO 205 30 11 CHICKEN r ad EE 205 30 12 CHICKEN To ld a a E E a cda 205 30 13 CHICKEN get rr r E 205 30 14 CHICKEN Jedi dt A A A A id 205 30 15 CHICKEN conmue coococonoconononnnnononononnnnonononononocononononnononononononononanonononananananananann nana tenete ne nana nnnnns 207 30 16 CHICKEN few g TE 208 30 17 CHICKEN delete TT EE 208 ALAS IATA PP E RO 208 30 19 CHICKEN 86 TOOL SOL eugene eneee eie Nan aie Pelea e E re in Er uae Ee adn ew ene tt odo 208 30 20 CHICKEN global look p entrer orit iio ener ha eren ie di ead 209 30 21 CHICKEN global rel e
82. HICKEN User s Manual The User s Manual 29 32 struct NAME A struct of the name NAME which should be a string Structs cannot be directly passed as arguments to foreign function neither can they be result values Pointers to structs are allowed though 29 33 template TYPE ARGTYPE A C template type For example vector lt int gt would be specified as template vector int Template types cannot be directly passed as arguments or returned as results 29 34 union NAME A union of the name NAME which should be a string Unions cannot be directly passed as arguments to foreign function neither can they be result values Pointers to unions are allowed though 29 35 instance CNAME SCHEMECLASS A pointer to a C class instance CNAME should designate the name of the C class and SCHEMECLASS should be the class that wraps the instance pointer Normally SCHEMECLASS should be a subclass of lt c object gt 29 36 instance ref CNAME SCHEMECLASS A reference to a C class instance 29 37 function RESULTTYPE ARGUMENTTYPEH CALLCONV A function pointer CALLCONV specifies an optional calling convention and should be a string The meaning of this string is entirely platform dependent The value f is also allowed and is passed as a NULL pointer 29 32 struct NAME 201 CHICKEN User s Manual The User s Manual 29 38 Mappings Foreign types are mapped to C types in the following manner bool
83. KEN User s Manual The User s Manual 24 3 1 create temporary file procedure create temporary file EXTENSION Creates an empty temporary file and returns its pathname If EXTENSION is not given then tmp is used If the environment variable TMPDIR TEMP or TMP is set then the pathname names a file in that directory 24 4 Deleting a file without signalling an error 24 4 1 delete file procedure delete file FILENAME If the file FILENAME exists it is deleted and t is returned If the file does not exist nothing happens and f is returned 24 5 Iterating over input lines and files 24 5 1 for each line procedure for each line PROCEDURE PORT Calls PROCEDURE for each line read from PORT which defaults to the value of current input port The argument passed to PROCEDURE is a string with the contents of the line excluding any line terminators When all input has been read from the port for each line returns some unspecified value 24 5 2 for each argv line procedure for each argv line PROCEDURE Opens each file listed on the command line in order passing one line at a time into PROCEDURE The filename is interpreted as current input port If no arguments are given on the command line it again uses the value of Current input port During execution of PROCEDURE the current input port will be correctly bound to the current input source This code will act as a simple Unix cat 1 command for e
84. Ke EE 51 RES RS DEE re 52 RRE interriipts En abled E 52 11 19 k ep shi dowed t actos eet trei RD da e er RR e RERO EUER REPRE E eR EE Prado 52 IPAE EE EE 52 11 21 tr e 52 Ne EE 53 1123 no bound checks rto D e tert ebay e di reed Eed vas oer eua seu ona EO edle tee ese Papa ba dada necesss 53 11 24 no proc du re checks eot ere ttt ire Ix RR EUR ER ER ERE CAR aeaiiai 53 TIA eene 53 L26 MUM DEP TEE 53 RES MAKE Tee TEE 53 11 28 r n trmie macros EE 54 11 29 standard bindings cotra Nr EEEO et ee e EBERT EEEE NEEE ERREEN ENEO EEEE DEENS 54 MRE rette ort teer deett e teen rre daa ere urea ree Se e ECCERR RE FO PM ERedues 54 REN seesi ieie ior i e EE E E A E EEE aE E EE 54 RRE RS E EE 54 1 33 MTS ANS E 55 MEAN EE 55 VD RTE 55 EA a BE DM EMEN MM EE MEME 56 PAI A tete Vere edo er eeh Pet nt teda eiie DU en ERE Ee RN de Fel duas 56 12 2 case sensitive cisco rre tao Dac dicas 56 UR eneen E ee 56 12 4 COMMANG liME aroUME E 56 12 5 current read table cococcconccccnnonocononononononinininanincnancnnananananano no nono nono ocn nono nannnno nono no nono oaia 57 PARTS AE o o E hee ko ee eer Eege 57 12 7 SE El E 57 Ree RE 57 12 9 1mplicit exat ha dl r EN 57 PARADAS nr oR EEE A E E E E R RE 57 TADA VEO ais AA A a 57 12 12 propran MAINS tot A AAA A Ati 58 IA RN 58 12 14 reset h ndler csssvaiscaievadedanswaswdvewecesarsnncnesdanseacesaces coves sedan ea prosa vraies terree eue eMe ee Ree
85. OB blob gt u32vector shared BLOB blob gt s32vector shared BLOB BLOB BLOB BLOB BLOB BLOB BLOB CHICKEN User s Manual The User s Manual procedure blob gt f32vector shared BLOB procedure blob gt f64vector shared BLOB Each of these procedures return a vector where the argument BLOB is taken as a packed representation of the contents of the vector The Shared variants return a vector that shares memory with the contents of the blob 17 34 subu8vector 17 35 subu16vector 17 36 subu32vector 17 37 subs8vector 17 38 subs16vector 17 39 subs32vector 17 40 subf32vector 17 41 subf64vector procedure subu8vector U8VECTOR FROM TO procedure subul6vector U16VECTOR FROM TO procedure subu32vector U32VECTOR FROM TO procedure subs8vector S8VECTOR FROM TO procedure subsl6vector S16VECTOR FROM TO procedure subs32vector S32VECTOR FROM TO procedure subf32vector F32VECTOR FROM TO procedure subf64vector F64VECTOR FROM TO 17 33 blobf64vector shared 112 CHICKEN User s Manual The User s Manual Creates a number vector of the same type as the argument vector with the elements at the positions FROM up to but not including TO SRFI 17 Setters for XXXvector ref are defined 17 42 read u8vector procedure read u8vector LENGTH PORT Reads LENGTH bytes from the PORT and returns a fresh u8vector or less if end of file is encountered PORT defaults to the value of Current input p
86. SRFI 4 number vectors 13 17 1 make blob procedure make blob SIZE Returns a blob object of SIZE bytes aligned on an 8 byte boundary uninitialized 13 17 2 blob procedure blob X Returns t if X is a blob object or f otherwise 13 17 3 blob size procedure blob size BLOB Returns the number of bytes in BLOB 13 17 4 blobstring procedure blob gt string BLOB Returns a string with the contents of BLOB 13 17 5 stringblob procedure string gt blob STRING Returns a blob with the contents of STRING 13 17 Blobs 76 CHICKEN User s Manual The User s Manual 13 17 6 blob procedure blob BLOB1 BLOB2 Returns t if the two argument blobs are of the same size and have the same content 13 18 Vectors 13 18 1 vector copy procedure vector copy VECTOR1 VECTOR2 COUNT Copies contents of VECTOR1 into VECTOR2 If the argument COUNT is given it specifies the maximal number of elements to be copied If not given the minimum of the lengths of the argument vectors is copied Exceptions exn bounds 13 18 2 vector resize procedure vector resize VECTOR N INIT Creates and returns a new vector with the contents of VECTOR and length N If N is greater than the original length of VECTOR then all additional items are initialized to INIT If INIT is not specified the contents are initialized to some unspecified value 13 19 The unspecified value 13 19 1 void procedure void
87. STNAME PORT The PORT can either be a string representation of an integer or a service name which is translated to an integer using the POSIX function getservbyname Note any I O on the ports returned will not block other running threads 25 5 tcp accept ready 170 CHICKEN User s Manual The User s Manual 25 9 tcp addresses procedure tcp addresses PORT Returns two values for the input or output port PORT which should be a port returned by either tcp accept or tcp connect the IP address of the local and the remote machine that are connected over the socket associated with PORT The returned addresses are strings in XXX XXX XXX XXX notation 25 10 tcp port numbers procedure tcp port numbers PORT Returns two values for the input or output port PORT which should be a port returned by either tcp accept or tcp connect the TCP port numbers of the local and the remote machine that are connected over the socket associated with PORT 25 11 tcp abandon port procedure tcp abandon port PORT Marks the socket port PORT as abandoned This is mainly useful to close down a port without breaking the connection 25 12 tcp buffer size parameter tcp buffer size Sets the size of the output buffer By default no output buffering for TCP output is done but to improve performance by minimizing the number of TCP packets buffering may be turned on by setting this parameter to an exact integer greater zero A buffer size of z
88. TH characters string chop one two three 4 gt one two thre e 15 8 16 with input from port 100 CHICKEN User s Manual The User s Manual 15 9 4 string chomp procedure string chomp STRING SUFFIX If STRING ends with SUFFIX then this procedure returns a copy of its first argument with the suffix removed otherwise returns STRING unchanged SUFFIX defaults to An 15 9 5 string compare3 procedure string compare3 STRING1 STRING2 procedure string compare3 ci STRING1 STRING2 Perform a three way comparison between the STRING1 and STRING2 returning either 1 if STRING is lexicographically less than STRING2 0 if it is equal or 1 if it s greater st ring compare3 ci performs a case insensitive comparison 15 9 6 string intersperse procedure string intersperse LIST STRING Returns a string that contains all strings in LIST concatenated together STRING is placed between each concatenated string and defaults to string intersperse one two three is equivalent to apply string append intersperse one two three 15 9 7 string split procedure string split STRING DELIMITER STRING KEEPEMPTY Split string into substrings separated by the given delimiters If no delimiters are specified a string comprising the tab newline and space characters is assumed If the parameter KEEPEMPTY is given and not f then empty substrings are retained I one two th
89. TRING ARG procedure sprintf FORMATSTRING ARG Simple formatted output to a given port fprintf the value of current output port printf or a string sprintf The FORMATSTRING can contain any sequence of characters There must be at least as many ARG arguments given as there are format directives that require an argument in FORMATSTRING Extra ARG arguments are ignored The character prefixes special formatting directives l d i write newline character N the same as S 15 2 3 with input from string 92 CHICKEN User s Manual The User s Manual write the next argument A display the next argument n skip all whitespace in the format string until the next non whitespace character B write the next argument as a binary number 0 write the next argument as an octal number X write the next argument as a hexadecimal number C write the next argument as a character display flush all pending output invoke formatted output routine recursively with the next two arguments as format string and list of parameters 15 3 4 format procedure format DESTINATION FORMATSTRING ARG The parameters FORMATSTRING and ARG are as for printf sprintf fprintf The optional DESTINATION when supplied performs a Sprintf fora f a printf fora t anda fprintf for an output port When missing a Sprint f is performed 15 4 Hash tables CHICKEN implements SRFI 69 For more
90. X system call kill SIGNAL defaults to the value of the variable signal term 23 8 8 process wait procedure process wait PID NOHANG Suspends the current process until the child process with the id PID has terminated using the UNIX system call waitpid If PID is not given then this procedure waits for any child process If NOHANG is given and not f then the current process is not suspended This procedure returns three values e PID or 0 if NOHANG is true and the child process has not terminated yet e t if the process exited normally or f otherwise e either the exit status if the process terminated normally or the signal number that terminated stopped the process 23 8 9 process procedure process COMMANDLINE procedure process COMMAND ARGUMENT LIST ENVIRONMENT LIST Creates a subprocess and returns three values an input port from which data written by the sub process can be read an output port from which any data written to will be received as input in the sub process and the process id of the started sub process Blocking reads and writes to or from the ports returned by process only block the current thread not other threads executing concurrently e The single parameter version passes the string COMMANDL INE to the host system s shell that is invoked as a subprocess The multiple parameter version directly invokes the COMMAND as a subprocess The ARGUMENT LIST is directly passed as is ENVIRONMENT
91. accessed through require extension will be searched and stored in the import table If a required extension does not provide explicit export information a exports file is searched as with used units After the analysis phase of the compiler referenced toplevel variables for which no assignment was found will generate a warning Also re assignments of imported variables will trigger a warning check syntax Aborts compilation process after macro expansion and syntax checks debug MODES Enables one or more compiler debugging modes MODES is a string of characters that select debugging information about the compiler that will be printed to standard output Show time needed for compilation show breakdown of time needed for each compiler pass show performed optimizations show invocation parameters 7 0 O et 3 Using the compiler 4 CHICKEN User s Manual The User s Manual show program size information and other statistics show node matching during simplification show execution of compiler sub passes show lambda lifting information show GC statistics during compilation print the line number database print every expression before macro expansion lists all unassigned global variable references display information about experimental features when printing nodes use node tree output show the real name mapping table show expressions after the secondary user pass show database before lambda lifting pass show expressions aft
92. ach argv line print 24 3 1 create temporary file 165 CHICKEN User s Manual The User s Manual 24 5 3 port for each procedure port for each FN THUNK Apply FN to successive results of calling the zero argument procedure THUNK until it returns eof discarding the results 24 5 4 port map procedure port map FN THUNK Apply FN to successive results of calling the zero argument procedure THUNK until it returns eof returning a list of the collected results 24 5 5 port fold procedure port map FN ACC THUNK Apply FN to successive results of calling the zero argument procedure THUNK passing the ACC value as the second argument The FN result becomes the new ACC value When THUNK returns eof the last FN result is returned 24 6 Executing shell commands with formatstring and error checking 24 6 1 system procedure system FORMATSTRING ARGUMENTI Similar to system sprintf FORMATSTRING ARGUMENT1 but signals an error if the invoked program should return a nonzero exit status 24 7 Reading a file s contents 24 5 3 port for each 166 CHICKEN User s Manual The User s Manual 24 7 1 read all procedure read all FILE OR PORT If FILE OR PORT is a string then this procedure returns the contents of the file as a string If FILE OR PORT is a port all remaining input is read and returned as a string The port is not closed If no argument is provided input will be read from the port that
93. ager string append or getenv HOME csi history More details are available in the egg s documentation 4 8 Accessing documentation You can access the manual directly from CSi using the man extension by Mario Domenech Goulart To enable it install the egg and put this in your CSi rc file use man man Load Then in CSi you can search for definitions using man search as in man search case 4 6 set describer 19 CHICKEN User s Manual The User s Manual Note that the search uses regular expressions To view the documentation for one entry from the manual use man help as in man help case lambda Note Currently the documentation provided by the man extension corresponds to Chicken s 2 429 one of the last releases whose documentation was in the texinfo format the format the man extension parses Previous Using the compiler Next Supported language 4 8 Accessing documentation 20 5 Supported language Deviations from the standard e Extensions to the standard e Non standard read syntax e Non standard macros and special forms e Pattern matching e Declarations e Parameters e Unit library basic Scheme definitions e Unit eval evaluation and macro handling e Unit extras useful utility definitions e Unit srfi 1 List Library e Unit srfi 4 Homogeneous numeric vectors e Unit srfi 13 String library e Unit srfi 14 character set library e Unit match pattern matching runtime
94. al compilation and linking options If compi le only is true then no linking step takes place If the keyword argument C is given and true then the code will be compiled in C mode 35 4 14 create directory procedure create directory PATH Creates the directory given in the string PATH with all parent directories as needed 35 4 15 installation prefix parameter installation prefix Holds the prefix under which CHICKEN executables and libraries have been installed either the value of the environment variable CHICKEN PREFIX or whatever prefix was specified at the time the system was built 35 4 16 program path parameter program path PATH Holds the path where executables are installed and defaults to either CHICKEN PREFIX bin ifthe environment variable CHICKEN PREFIX is set or the path where the CHICKEN binaries chicken csi etc are installed 35 4 17 setup root directory parameter setup root directory PATH Contains the path of the directory where chicken setup was invoked 35 4 18 setup build directory parameter setup build directory PATH 35 4 13 try compile 229 CHICKEN User s Manual The User s Manual Contains the path of the directory where the extension is built This is not necessarily identical to setup root directory 35 4 19 setup verbose flag parameter setup verbose flag BOOL Reflects the setting of the verbose option i e is t if verbose was given 35 4 20 setup
95. all subsequent operations PATHNAME should be an absolute pathname h host HOSTNAME PORT Specifies alternative host for downloading extensions optionally with a TCP port number which defaults to 80 u uninstall EXTENSION Removes all files that were installed for EXTENSION from the file system together with any metadata that has been stored l list NAME List all installed extensions or show extension information r run FILENAME Load and execute given file S script FILENAME Executes the given Scheme source file with all remaining arguments and exit The she bang shell script header is recognized so you can write Scheme scripts that use chicken setup just as with CS1 e eval EXPRESSION Evaluates the given expression s v verbose Display additional debug information k keep Keep temporary files and directories C csc option OPTION Passes OPTION as an extra argument to invocations of the compiler driver CSC this works only if CSC is invoked as run csc d dont ask Do not ask the user before trying to download required extensions n no install Do not install generated binaries and or support files any invocations of install program install extension or install script will be be no ops i docindex Displays the path to the index page of any installed extension documentation if the index page does not exist it is created t test EXTENSION return success if all given extensions are instal
96. ame of the currently compiled file Note that if you want to compile a file as a normal dynamically loadable extension library you should also pass the Shared option feature SYMBOL Registers SYMBOL to be a valid feature identifier for cond expand Multiple symbols may be given if comma separated fixnum arithmetic Equivalent to fixnum arithmetic declaration Assume all mathematical operations use small integer arguments heap size NUMBER Sets a fixed heap size of the generated executable to NUMBER bytes The parameter may be followed by a M m or K K suffix which stand for mega and kilobytes respectively The default heap size is 5 kilobytes Note that only half of it is in use at every given time heap initial size NUMBER Sets the size that the heap of the compiled application should have at startup time heap growth PERCENTAGE Sets the heap growth rate for the compiled program at compile time see hg heap shrinkage PERCENTAGE Sets the heap shrinkage rate for the compiled program at compile time see hs help Print a summary of available options and the format of the command line parameters and exit the compiler import FILENAME Read exports from linked or loaded libraries from given file See also check imports This is equivalent to declaring declare import FILENAME Implies check imports include path PATHNAME Specifies an additional search path for files included via the include special fo
97. an be installed by invoking one of the procedures install extension install programorinstall script These procedures will copy a number of given files into the extension repository or in the path where the CHICKEN executables are located in the case of executable programs or scripts Additionally the list of installed files and user defined metadata is stored in the repository If no extension name is given on the command line and if none of the options List version repository without argument program path without argument fetch fetch tree or docindex is given then all setup scripts in the current directory are processed 35 3 Creating extensions Extensions can be created by creating an optionally gzipped tar archive named EXTENSION egg containing all needed files plus a Setup script in the root directory After chicken setup has extracted the files the setup script will be invoked There are no additional constraints on the structure of the archive but the setup script has to be in the root path of the archive 35 chicken setup 224 CHICKEN User s Manual The User s Manual 35 4 Procedures and macros available in setup scripts 35 4 1 install extension install extension ID FILELIST INFOLIST Installs the extension library with the name ID All files given in the list of strings FILELIST will be copied to the extension repository It should be noted here that the extension id has to be identical to the
98. atch At least one subpattern must be present This pattern is often used as and x pat to bind x to to the entire value that matches pat cf as patterns in ML or Haskell or pat 1 pat n matches if any of the subpatterns match At least one subpattern must be present All subpatterns must bind the same set of pattern variables not pat 1 pat n matches if none of the subpatterns match At least one subpattern must be present The subpatterns may not bind any pattern variables predicate pat 1 pat n Inthis pattern predicate must be an expression evaluating to a single argument function This pattern matches if predicate applied to the corresponding value is true and the subpatterns pat 1 pat n all match The predicate should not have side effects as the code generated by the pattern matcher may invoke predicates repeatedly in any order The predicate expression is bound in the same scope as the match expression i e free variables in predicate are not bound by pattern variables set identifier matches anything and binds identifier to a procedure of one argument that mutates the corresponding field of the matching value This pattern must be nested within a pair vector box or structure pattern For example the expression define x list 1 list 2 3 match x set setit setit 4 mutates the cadadr of X to 4 so that x is 1 2 4 get identifier matches anything and binds identif
99. ated debug information 13 10 7 reset procedure reset Reset program Invokes reset handler 13 10 8 warning procedure warning STRING EXP Displays a warning message if warnings are enabled with enable warnings and continues execution 13 10 9 singlestep procedure singlestep THUNK Executes the code in the zero procedure THUNK in single stepping mode 13 10 4 print call chain 72 CHICKEN User s Manual The User s Manual 13 11 Garbage collection 13 11 1 gc procedure gc FLAG Invokes a garbage collection and returns the number of free bytes in the heap The flag specifies whether a minor f or major t GC is to be triggered If no argument is given t is assumed An explicit t argument will cause all pending finalizers to be executed 13 11 2 memory statistics procedure memory statistics Performs a major garbage collection and returns a three element vector containing the total heap size in bytes the number of bytes currently used and the size of the nursery the first heap generation Note that the actual heap is actually twice the size given in the heap size because CHICKEN uses a copying semi space collector 13 11 3 set finalizer procedure set finalizer X PROC Registers a procedure of one argument PROC that will be called as soon as the non immediate data object X is about to be garbage collected with that object as its argument Note that the finalizer will not be called
100. ation This file should be given in the file list passed to install extension and a link to it will be automatically included in the index page accessible via chicken setup docindex 35 4 1 5 examples extension property examples FILENAME Copies the given files into the examples directory which is usually prefix share chicken examples or make pathname chicken home examples Note that the files listed in this property should not be listed in the normal list of files to install passed to install extension This is the only exception other files that are installed in the repository must be given in the file list 35 4 1 6 exports extension property exports EXPORT Add export information to the generated extension information EXPORT may be a symbol naming an exported toplevel variable or a string designating a file with exported variables as generated by the emit exports option or the emit exports declaration specifier 35 4 1 7 static extension property static STRING If the extension also provides a static library then STRING should contain the name of that library Used by CSC when compiling with the static extensions option 35 4 1 8 static options extension property static options STRING Additional options that should be passed to the linker when linking with the static version of an extension see Static above Used by CSC when compiling with the static extensions option All other p
101. ble and new toplevel bindings may be introduced 6 6 The tilde character is automatically expanded in pathnames Additionally if a pathname starts with VARIABLE then the prefix is replaced by the value of the given environment variable 6 6 1 if the procedures current input port and current output port are called with an argument which should be a port then that argument is selected as the new current input and output port respectively The procedures open input file open output file with input from file with output to file call with input file and call with output file accept an optional second or third argument which should be one or more keywords if supplied These arguments specify the mode in which the file is opened Possible values are the keywords text binary or append 6 7 The exit procedure exits a program right away and does not invoke pending dynamic wind thunks Previous Deviations from the standard Next Non standard read syntax 7 Extensions to the standard 26 CHICKEN User s Manual The User s Manual 7 Extensions to the standard 27 8 Non standard read syntax 8 1 Multiline Block Comment A multiline block comment May be nested Implements SRFI 30 8 2 Expression Comment EXPRESSION Treats EXPRESSION as a comment 8 3 External Representation CONSTRUCTORNAME DATUM Allows user defined extension of external representations For more inf
102. buffer for recording a trace of the last invoked procedures Defaults to 16 b Enter a read eval print loop when an error is encountered B Sounds a bell ASCII 7 on every major garbage collection E 3 2 Runtime options 8 CHICKEN User s Manual The User s Manual Forces console mode Currently this is only used in the interpreter CSi to force output of the N gt prompt even if stdin is not a terminal for example if running in an emacs buffer under Windows d D W Prints some debug information at runtime Prints some more debug information at runtime FNUMBER Specifies the maximal number of currently pending finalizers before finalization is forced hNUMBER Specifies fixed heap size hg PERCENTAGE Sets the growth rate of the heap in percent If the heap is exhausted then it will grow by PERCENTAGE The default is 200 hi NUMBER Specifies the initial heap size hmNUMBER Specifies a maximal heap size The default is 2GB 15 hsPERCENTAGE Sets the shrink rate of the heap in percent If no more than a quarter of PERCENTAGE of the heap is used then it will shrink to PERCENTAGE The default is 50 Note If you want to make sure that the heap never shrinks specify a value of H this can be useful in situations where an optimal heap size is known in advance Disables detection of stack overflows at run time Writes trace output to stderr This option has no effect with in files compiled with the no
103. cally inserts callout items not defined here partial 21 4 regexp 118 CHICKEN User s Manual The User s Manual Partial match ok firstline An unanchored pattern is required to match before or at the first newline dupnames Names used to identify capturing subpatterns need not be unique newline cr Newline definition is wi newline lf Newline definition is wi newline crlf Newline definition is wn newline anycrlf Newline definition is any of r wl or r n newline any ewline definition is any Unicode newline sequence bsr anycrlf NR escape sequence matches only CR LF or CRLF bsr unicode RI escape sequence matches only Unicode newline sequence dfa shortest Currently unused dfa restart Currently unused 21 6 regexp procedure regexp X Returns t if X is a precompiled regular expression or f otherwise 21 7 regexp optimize procedure regexp optimize RX Perform available optimizations for the precompiled regular expression RX Returns t when optimization performed and f otherwise 21 8 string match 21 5 regexp 119 CHICKEN User s Manual The User s Manual 21 9 string match positions procedure string match REGEXP STRING START procedure string match positions REGEXP STRING START Matches the regular expression in REGEXP a string or a precompiled regular expression with STRING and returns either f if the match failed or a list of matching groups where the first eleme
104. certet rente Feet ye eu eerta tits 218 34 25 C SIZEOF ELONUNM nennen nenne enennnnas esse sii teta sa sas sesta sess se e setas esses se sese dada 218 34 26 SIZBOE POINTER eret S A cM UP 218 34 27 C SIZEOE LOCATIVE urere otro aeia oo E ete EE 218 34 28 C SIZEOF TAGGED POINTER eee eem AE EE sereni tenens 219 34 29 Character EE 219 FDA BOC KEE 219 34 3 eren EEN 219 34 32 OE LE 219 GR ER Tee COL EE 219 34 34 ee 219 34335 C EA EE 220 TULIO header Di A diia ida 220 34 37 C block em 220 3438 C U i ia 220 3439C u EE 220 S4AO C ata eu 220 CAE A 221 BAAD C MUS nana lia 221 34 43 rg 221 DAA A UU LLLI ILL LLLI 221 CHICKEN User s Manual The User s Manual Chicken User s Manual 34 C interface AR i estet eto ar Vo OR HORT TREEPOARR e Fee T aU rete En Ede b aee Ue saos ede cre ue PNE o ped 221 34 46 C pre iiiter e HE e RET FK ERE MARE ci D e EO RENE E PIRE HERR RES 222 RD REGI TV RECO IUIS EE 222 34 48 An example for simple calls to foreign code involving callbacke 222 SET 223 S NN 224 35 1 Ext tiSiOn HDA ES egene certo erae ose e Revo steta K EREE es KERNER RERNE KEN EKE ERNE REESE S 224 35 2 Installmg EE 224 35 3 Creating extenstOllS NN 224 35 4 Procedures and macros available in setup scripts oooooccccocccconcnoonanononcconcccnncnonnnonon nn nano cc nnnccnancnnns 225 35 4 AE E Ee TT TT 225 35 42 install propia EE 227 EE EE E 227 SD AGE TEE 227 DIA E 227 RERA TEI LEA E EE E A A T AE A A A
105. ching extensions Note that to use the macros in normal compiled code it is not required to declare this unit as used It is only necessary to do so if forms containing these macros are to be expanded at runtime Previous Unit srfi 14 Next Unit regex 20 Unit match 116 21 Unit regex This library unit provides support for regular expressions The regular expression package used is PCRE Perl Compatible Regular Expressions written by Philip Hazel See http www pcre org for information about the particular regexp flavor and extensions provided by this library To test that PCRE support has been built into Chicken properly try require regex test feature pcre gt t 21 1 grep procedure grep REGEX LIST Returns all items of LIST that match the regular expression REGEX This procedure could be defined as follows define grep regex lst filter Lambda x string search regex x lst 21 2 globregexp procedure glob gt regexp PATTERN Converts the file pattern PATTERN into a regular expression glob gt regexp foo gt ERAN TOO PATTERN should follow glob syntax Allowed wildcards are C C1 C2 C 21 3 glob procedure glob STRING Does the STRING have any glob wildcards A string without any glob wildcards does not meet the criteria even though it technically is a valid glob file pattern 21 Unit regex 117 CHICKEN User s Manual The User s
106. cifiers that should be used to speed up compiled files declaring standard bindings is mandatory since this enables most optimizations Even if some standard procedures should be redefined you can list untouched bindings in the declaration Declaring extended bindings lets the compiler choose faster versions of certain internal library functions This might give another speedup You can also use the the usual integrations declaration which is identical to declaring standard bindings and extended bindings note that usual integrations is set by default Declaring block tells the compiler that global procedures are not changed outside the current compilation unit this gives the compiler some more opportunities for optimization If no floating point arithmetic is required then declaring number type fixnum can give a big performance improvement because the compiler can now inline most arithmetic operations Declaring unsafe will switch off most safety checks If threads are not used you can declare disable interrupts You should always use maximum optimizations settings for your C compiler Good GCC compiler options on Pentium and compatible hardware are Os fomit frame pointer fno strict aliasing Some programs are very sensitive to the setting of the nursery the first heap generation You should experiment with different nursery settings either by compiling with the nursery option or by using the S runtime option 38
107. cks declaration specifier no procedure checks Disables checking of values in operator position for being of procedure type 11 25 post process declaration specifier post process STRING Arranges for the shell commands STRING to be invoked after the current file has been translated to C Any occurrences of the substring in the strings given for this declaration will be replaced by the pathname of the currently compiled file without the file extension This declaration will only work if the source file is compiled with the CSC compiler driver 11 26 number type 11 27 fixnum arithmetic declaration specifier number type TYPE declaration specifier fixnum arithmetic Declares that only numbers of the given type are used TYPE may be fixnum or generic which is the default 11 22 no argc checks 53 CHICKEN User s Manual The User s Manual 11 28 run time macros declaration specifier run time macros Equivalent to the compiler option of the same name macros defined in the compiled code are also made available at runtime 11 29 standard bindings declaration specifier standard bindings SYMBOL declaration specifier not standard bindings SYMBOL Declares that all given standard procedures or all if no symbols are specified are never globally redefined If not is specified then all but the given standard bindings are assumed to be never redefined 11 30 extended bindings declara
108. code will be executed in a primitive CPS context which means it will not actually return but call it s continuation on exit This means that code inside this form may allocate Scheme data on the C stack the nursery with C alloc see below If the RETURNTYPE is omitted it defaults to void You can return multiple values inside the body of the foreign primitive form by calling this C function C values N 2 C SCHEME UNDEFINED C k X1 where N is the number of values to be returned and X1 are the results which should be Scheme data objects When returning multiple values the return type should be omitted Previous Interface to external functions and variables Next Foreign type specifiers 28 9 foreign lambda 194 CHICKEN User s Manual The User s Manual 28 12 foreign primitive 195 29 Foreign type specifiers Here is a list of valid foreign type specifiers 29 1 scheme object An arbitrary Scheme data object immediate or non immediate 29 2 bool As argument any value f is false anything else is true As result anything different from 0 and the NULL pointer is t 29 3 byte unsigned byte A byte 29 4 char unsigned char A character 29 5 short unsigned short A short integer number 29 6 int unsigned int int32 unsigned int32 An small integer number in fixnum range at least 30 bit 29 Foreign type specifiers 196 CHICKEN User s Manual The User s Manual 29 7 integer unsig
109. d setuid set root directory chroot setenv setenv putenv sleep sleep system information uname terminal name ttyname terminal port isatty time gt string asctime unsetenv putenv unmap file from memory munmap user information getpwnam getpwuid utc time gt seconds timegm 23 24 Windows specific notes Use of UTF8 encoded strings is for pathnames is not supported Windows uses a 16 bit UNICODE encoding with special system calls for wide character support Only single byte string encoding can be used 23 24 Windows specific notes 159 CHICKEN User s Manual The User s Manual 23 24 1 Procedure Changes Exceptions to the above procedure definitions procedure create pipe MODE The optional parameter MODE default open binary open noinherit This can be open binary or open text optionally or ed with open noinherit procedure process wait PID NOHANG process wait always returns t for a terminated process and only the exit status is available Windows does not provide signals as an interprocess communication method procedure process execute PATHNAME ARGUMENT LIST ENVIRONMENT LIST EXACT F procedure process COMMAND ARGUMENT LIST ENVIRONMENT LIST EXACT FLAG procedure process COMMAND ARGUMENT LIST ENVIRONMENT LIST EXACT FLAG The optional parameter EXACT FLAG default f When f any argument string with embedded whitespace will be wrapped in quotes When
110. d library does nothing 14 1 5 set dynamic load mode procedure set dynamic load mode MODELIST On systems that support dynamic loading of compiled code via the dLopen 3 interface for example Linux and Solaris some options can be specified to fine tune the behaviour of the dynamic linker MODE should be a list of symbols or a single symbol taken from the following set local If Local is given then any C C symbols defined in the dynamically loaded file are not available for subsequently loaded files and libraries Use this if you have linked foreign code into your dynamically loadable file and if you don t want to export them for example because you want to load another file that defines the same symbols global The default is g Lobal which means all C C symbols are available to code loaded at a later stage now If now is specified all symbols are resolved immediately lazy Unresolved symbols are resolved as code from the file is executed This is the default 14 1 3 load noisily 84 CHICKEN User s Manual The User s Manual Note that this procedure does not control the way Scheme variables are handled this facility is mainly of interest when accessing foreign code 14 2 Read eval print loop 14 2 1 repl procedure repl Start a new read eval print loop Sets the reset handler so that any invocation of reset restarts the read eval print loop Also changes the current exception handler to display a message wri
111. d no nono nemen n cnn conoce nononocanenanonos 109 17 17 164 Vector blob Shared E 109 TELS DIODUS Ed iio 110 EA CN 110 EZODIODU EE 110 17 21 dee ie e ii ld 110 LER EPA EE 110 17 223 blobs Ae EE 110 CHICKEN User s Manual The User s Manual Chicken User s Manual 17 Unit srfi 4 17 24 DIODES QV PP O 110 17 25 DIODOA VECO E 111 17 26 blob Svector shared ii eee ev aes ces eua uae e saves dade dasa sadavanatavevntucetaanwaccdagecevacsonees 111 17 27 blobsSvector shated id A Ad buenos tegere Du eo e eae 111 17 28 blobulOvector shared ococccccccccccccococonocononinininoncncncanananananana nono conoce cnn nono nono nan nonononononecanananonos 111 17 29 blobsT6vectot sha ted nee cr m idas 111 17 30 blobu32vectot shared E 111 17 31 blobe ivectorisbared nono conoce cnn nn nano na nnc nono nono no EIEEE 111 17 32 blobf32vector shared 5 entere eo de rea severe vies dvvessasnsavadnsavavdeasheadarevansnaceventeacsoasdons 111 1 7 33 blobto4vector sh ated 12 a ds 111 17 34 SubuSVectoE a ieri tech AA sid ESAE DERE ERE ERR as 112 17 35 SubU LOVeCLOE er ois eterno tor ee ER Nee ede e exo vas ve ro Peu aeg ah EE E E reatu autera pese rn 112 LIES Te DUS IVECO e TT 112 EAE SHADES E TU IU T 112 17 38 subs ee EE 112 17 39 SUDSSZ2VECIOR EE 112 ASA TN 112 17 AV SUDIG4 Vecina ds 112 A E EE 113 1743 RER 113 17 44 Write UBVEC OL oooococcnnccononononononoconononononononononononinonononananannananananana no tenete seti
112. dard Input Output EE 74 IAS E oO ari 75 EN NN 75 UE e D e 75 13 16 User defined named characterg na nana nana nenne nenne nn 75 13 NG ENEE EE 75 EA ee 76 TST IE ESTEE TTD OM He 13172 uc EE eebe He KR Mee He 13 174 blobstring RN 76 LANA O 76 EIA e 71 TIAS e Te 71 IER EN re TT 13 182 Vectores nidad re re e PERS EYE Ree eR A eer EES desa TT 13 19 The unspecified value eI e eere ass TT 13 19 VVO t R TI 15 20 Continua e oon Ere ERE ERE t Mani ee E et Ee TT RSA 78 13 20 2 continuation Capture NN 78 13 20 COmtIMU LR 78 13 204 CONMMU AM ONO AL ers cec t svwetiaxvanncs RAN 78 13 20 5 re E E 78 A EE 79 EA NON 79 13 21 2 EE E 79 13 22 Reader extensions tpe reto aiii iia dias ai 79 13221 deste TEA EE 79 EPA A 79 CHICKEN User s Manual The User s Manual Chicken User s Manual 13 Unit library 13 22 3 setsharp read syntaxl EE 80 13 22 4 set parameterized read syntax sessi ennt sentent innen nns 80 UK Ee E EE 80 13 23 Property lists erint RO 81 ERNEUT c 81 3232 81 3 23 3 rempropl iiie A ave pee deans 81 13 23 4 SymbobLplist RO 81 1323 5 ET 81 ER EE 83 141 Loading E 83 EW ee RE 83 141 2 WO ad Peat VE 83 14 1 3 load TE 84 E VA TO APHID RA 84 14 1 5 set dynamic load mode sese eene eene enne nennen inen 84 14 2
113. dd 29 H setgray fill for Y for showpage EOF 23 4 Fifos 23 4 1 create fifo procedure create fifo FILENAME MODE Creates a FIFO with the name FILENAME and the permission bits MODE which defaults to procedure perm irwxu perm irwxg perm irwxo 23 4 2 fifo procedure fifo FILENAME Returns Zt if the file with the name FILENAME names a FIFO 23 5 File descriptors and low level UO 23 5 1 duplicate fileno procedure duplicate fileno OLD NEW If NEW is given then the file descriptor NEW is opened to access the file with the file descriptor OLD Otherwise a fresh file descriptor accessing the same file as OLD is returned 23 5 2 file close procedure file close FILENO Closes the input output file with the file descriptor FILENO 23 3 10 with output to pipe 132 CHICKEN User s Manual The User s Manual 23 5 3 file open procedure file open FILENAME FLAGS MODE Opens the file specified with the string FILENAME and open flags FLAGS using the C function open On success a file descriptor for the opened file is returned FLAGS should be a bitmask containing one or more of the open values ored together using bitwise ior or simply added together The optional MODE should be a bitmask composed of one or more permission values like pe rm irusr and is only relevant when a new file is created The default mode is perm irwxu perm irgrp perm iroth 23 5 4 file mkstemp procedure file mks
114. de syntax foreign code STRING Executes the embedded C C code STRING which should be a sequence of C statements which are executed and return an unspecified result foreign code doSomeInitStuff gt unspecified Code wrapped inside foreign code may not invoke callbacks into Scheme 28 2 foreign value syntax foreign value STRING TYPE Evaluates the embedded C C expression STRING returning a value of type given in the foreign type specifier TYPE print foreign value my version string c string 28 3 foreign declare syntax foreign declare STRING Include given strings verbatim into header of generated file 28 4 define foreign type syntax define foreign type NAME TYPE ARGCONVERT RETCONVERT Defines an alias for TYPE with the name NAME a symbol TYPE may be a type specifier or a string naming a C type The namespace of foreign type specifiers is separate from the normal Scheme namespace The optional arguments ARGCONVERT and RETCONVERT should evaluate to procedures that map argument and result values to a value that can be transformed to TYPE define foreign type char vector nonnull c string compose list gt string vector gt list compose list gt vector string gt list define strlen 28 Accessing external objects 189 CHICKEN User s Manual The User s Manual foreign lambda int strlen char vector strlen a Ab c gt 3 define memset fore
115. dvisable to develop and debug a program in safe mode without unsafe declarations and use this feature only if the application works properly 38 5 Warnings and errors 247 CHICKEN User s Manual The User s Manual 38 5 5 Why do I get a warning when I define a global variable named match Even when the match unit is not used the macros from that package are visible in the compiler The reason for this is that macros can not be accessed from library units only when explicitly evaluated in running code To speed up macro expansion time the compiler and the interpreter both already provide the compiled match macro definitions Macros shadowed lexically are no problem but global definitions of variables named identically to global macros are useless the macro definition shadows the global variable This problem can be solved using a different name or undefining the macro like this eval when compile eval undefine macro match 38 5 6 Why don t toplevel continuations captured in interpreted code work Consider the following piece of code define k call with current continuation lambda k k k k When compiled this will loop endlessly But when interpreted k k will return to the read eval print loop This happens because the continuation captured will eventually read the next toplevel expression from the standard input or an input file if loading from a file At the moment K was defined the next expression wa
116. e DEE rg 85 DAD EE 85 VAS MACOS EE 85 EW NEE een 85 E See e SE 85 14 3 3 MACrOEX PAN TE 85 l4 3A Ee D 86 14 3 5 utidebrthe THACEO EE 86 ERA A m 86 14 4 Loading extension libraries 7 eee ettet ricette ee tnter detenta eo eee eR an ee Leere eaa ease 86 14 4 T ere 86 14 4 2 extenslOn INTOTMAtION cccccccconcccncnonoconononononononinnncnnncnnncnnananananana no nono tenete e n n nro nono no nono nononananenenos 86 UE See 87 14 4 4 ee RE 87 E EU 87 UE WEE EE e E EE 87 UE W Bue CT ee 88 145 1 chicken LEE 88 EE 88 Ee EE 88 ES Did aaa 89 Be E EE EE 89 A EE 89 A e 89 E Ge et RE 89 DD VA ET 89 RS EES 90 IBIDEM EE 90 15 1 7 eu 90 REI m 90 15 1 9 1iterSDeESG i iere ertet RER CO e vtae ee edt te d e ens e E ee eege 90 IER OBL M 91 DS We TE Sh ftle ud ecc rea eere eoe TA 91 TEAM dia 91 vi CHICKEN User s Manual The User s Manual Chicken User s Manual 15 Unit extras 15 2 Siring Port extensi ns ae e eere eei et i EEN eeh EE genae eo ee Ee vated INVE ee nda E de Cube ore dU egets 91 15 2 1 Callswith mput Strin O 91 15 22 E Ee Ee 91 Luther OEI iieri A AAA A E 92 152 4 with outp t tO SETITg i rice eee nre ere tete tinto eene hne dae eee tin eie en edere ede bed cea tgae 92 1523 Rer GE Mer E 92 INIA O ERE pee trt oo electa eoe Vevey doce sea cea e e I eye ep ete dd epa Rue e ecd 92 T5 32 NM P 92 LESS RS Elo UL LL ERE c 92 ISA re 93
117. e and after invocation of chicken A program named CSC provides a much simpler interface to the Scheme and C compilers and linker Enter csc help on the command line for more information 3 1 Compiler command line format chicken FILENAME OPTION FILENAME is the complete pathname of the source file that is to be translated into C A filename argument of specifies that the source text should be read from standard input Note that the filename has to be the first argument to Chicken Possible options are analyze only Stop compilation after first analysis pass benchmark mode Equivalent to no trace no lambda info optimize level 3 fixnum arithmetic disable interrupts block lambda lift block Enable block compilation When this option is specified the compiler assumes that global variables are not modified outside this compilation unit Specifically toplevel bindings are not seen by eval and unused toplevel bindings are removed case insensitive Enables the reader to read symbols case insensitive The default is to read case sensitive in violation of R5RS This option registers the case insensitive feature identifier check imports Search for references to undefined global variables For each library unit accessed via declare uses the compiler will search a file named UNITNAME exports in the current include path and load its contents into the import table if found Also export information for extensions
118. e compile macro 35 5 Examples for extensions The simplest case is a single file that does not export any syntax For example riji MELLO ECN define hello name print Hello name We need a Setup script to build and install our nifty extension hello setup compile the code into a dynamically loadable shared object will generate hello so compile s hello scm Install as extension library install extension hello hello so After entering chicken setup hello at the shell prompt and in the same directory where the two files exist the file hello scm will be compiled into a dynamically loadable library If the compilation succeeds hel lo so will be stored in the repository together with a file named hello setup info containing an a list with metadata If no extension name is given to chicken setup it will simply execute the first file with the setup extension it can find Use it like any other CHICKEN extension csi q 1 gt require extension hello loading usr local lib chicken 1 hello so 2 gt hello me Hello me 3 gt Here we create a simple application ji 7 hello2 scm 35 4 24 host extension 231 CHICKEN User s Manual The User s Manual print Hello for each lambda x printf A vil command line arguments print We also need a setup script jis hello2 setup compile hello2 scm compile hello2 install program hel
119. e first heap generation of the generated executable to NUMBER bytes The parameter may be followed by a M m or K k suffix The default stack size depends on the target platform optimize leaf routines Enable leaf routine optimization optimize level LEVEL Enables certain sets of optimization options LEVEL should be an integer optimize level 0 does nothing optimize level 1 is equivalent to optimize leaf routines optimize level 2 is currently the same as optimize level 1 optimize level 3 is equivalent to optimize leaf routines unsafe output file FILENAME Specifies the pathname of the generated C file Default is FILENAME c postlude EXPRESSIONS Add EXPRESSIONS after all other toplevel expressions in the compiled file This option may be given multiple times Processing of this option takes place after processing of epi logue prelude EXPRESSIONS Add EXPRESSIONS before all other toplevel expressions in the compiled file This option may be given multiple times Processing of this option takes place before processing of prologue profile accumulate profile Instruments the source code to count procedure calls and execution times After the program terminates either via an explicit exit or implicitly profiling statistics are written to a file named PROFILE Each line of the generated file contains a list with the procedure name the number of calls and the time spent executing it Use the chicken profile program to displa
120. eally just a wrapper around alloca and can also be simulated by declaring a stack allocated array of C words 34 14 C flonum 217 CHICKEN User s Manual The User s Manual 34 20 C SIZEOF LIST C macro int C SIZEOF LIST int length 34 21 C SIZEOF STRING C macro int C SIZEOF STRING int Length 34 22 C SIZEOF VECTOR C macro int C SIZEOF VECTOR int Length 34 23 C SIZEOF INTERNED SYMBOL C macro int C SIZEOF INTERNED SYMBOL int length 34 24 C SIZEOF PAIR C macro int C SIZEOF PAIR 34 25 C SIZEOF FLONUM C macro int C SIZEOF FLONUM 34 26 C SIZEOF POINTER C macro int C SIZEOF POINTER 34 27 C SIZEOF LOCATIVE C macro int C SIZEOF LOCATIVE 34 20 C SIZEOF LIST 218 CHICKEN User s Manual The User s Manual 34 28 C SIZEOF TAGGED POINTER C macro int C SIZEOF TAGGED POINTER These are macros that return the size in words needed for a data object of a given type 34 29 C character code C macro int C character code C word character 34 30 C unfix C macro int C unfix C word fixnum 34 31 C flonum magnitude C macro double C flonum magnitude C word flonum 34 32 C c string C function char C c string C word string 34 33 C num to int C function int C num to int C word fixnum or flonum 34 34 C pointer address C function void C pointer address C word pointer These macros and functions can be used to convert Scheme data objects back to C data Note that C c
121. eep in mind that some operations such as string length are much more expensive in utf8 multibyte mode and should be used with care See the utf8 egg documentation for details 38 2 Platform specific 38 2 1 How do generate a DLL under MS Windows tm Use CSC in combination with the dll option C gt csc foo scm dll 38 2 2 How do generate a GUI application under Windows tm Invoke CSC with the windows option Or pass the DC_ WINDOWS GUI option to the C compiler and link with the GUI version of the runtime system that s Libchicken gui static lib The GUI runtime displays error messages in a message box and does some rudimentary command line parsing 38 2 3 Compiling very large files under Windows with the Microsoft C compiler fails with a message indicating insufficient heap space It seems that the Microsoft C compiler can only handle files up to a certain size and it doesn t utilize virtual memory as well as the GNU C compiler for example Try closing running applications If that fails try to break up the Scheme code into several library units 38 2 4 When I run csi inside an emacs buffer under Windows nothing happens Invoke CSi with the C runtime option Under Windows the interpreter thinks it is not running under control of a terminal and doesn t print the prompt and does not flush the output stream properly 38 2 5 load compiled code dynamically in a Windows GUI application and it crashes Code
122. ely 11 12 emit external prototypes first 51 CHICKEN User s Manual The User s Manual 11 17 inline limit declaration specifier inline limit THRESHOLD Sets the maximum size of procedures which may potentially be inlined The default threshold is 10 11 18 interrupts enabled declaration specifier interrupts enabled Enable timer interrupts checks in the compiled program the default 11 19 keep shadowed macros declaration specifier keep shadowed macros Normally when a toplevel variable is assigned or defined that has the same name as a macro the macro definition will be removed in addition to showing a warning This declaration will disable the removal of the macro 11 20 lambda lift declaration specifier lambda lift Enables lambda lifting equivalent to the Lambda Lift option 11 21 link options declaration specifier link options STRING Declares additional linker compiler options that are to be passed to the subsequent compilation pass that links the generated code into an executable or library This declaration will only work if the source file is compiled with the CSC compiler driver 11 17 inline limit 52 CHICKEN User s Manual The User s Manual 11 22 no argc checks declaration specifier no argc checks Disables argument count checking 11 23 no bound checks declaration specifier no bound checks Disables the bound checking of toplevel bindings 11 24 no procedure che
123. eneration then the garbage collector will remember to handle the data appropriately Assigning nursery pointers directly will otherwise result in lost data Note that no copying takes place at the moment when C mutate is called but later at the next minor garbage collection 34 43 C symbol value C macro C word C symbol value C word symbol Returns the global value of the variable with the name symbol If the variable is unbound C SCHEME UNBOUND is returned You can set a variable s value with C mutate amp C symbol value SYMBOL VALUE 34 44 C gc protect C function void C gc protect C word ptrs int n Registers n variables at address ptrs to be garbage collection roots The locations should not contain pointers to data allocated in the nursery only immediate values or pointers to heap data are valid Any assignment of potential nursery data into a root array should be done via C mutate The variables have to be initialized to sensible values before the next garbage collection starts when in doubt set all locations in ptrstoC SCHEME UNDEFINED C gc protect may not called before the runtime system has been initialized either by CHICKEN initialize CHICKEN run or CHICKEN invoke For a slightly simpler interface to creating and using GC roots see CHICKEN new gc root 34 45 C gc unprotect C function void C gc unprotect int n Removes the last n registered variables from the set of root variables 34 41 C make heade
124. er lambda lifting show unit information and syntax runtime requirements show source expressions show canonicalized expressions show expressions converted into CPS show database after each analysis pass show expressions after each optimization pass show expressions after each inlining pass show expressions after complete optimization show database after final analysis show expressions after closure conversion LO OO Y Ol UU BABUNA lt MPFOC2ZUOXCO5D3CcCOYywN debug level LEVEL Selects amount of debug information LEVEL should be an integer debug level 0 is equivalent to no trace no lambda info debug level 1 is equivalent to no trace debug level 2 does nothing the default disable interrupts Equivalent to the disable interrupts declaration No interrupt checks are generated for compiled programs disable compiler macros disable expansion of compiler macros disable stack overflow checks Disables detection of stack overflows This is equivalent to running the compiled executable with the 10 runtime option disable warning CLASS Disables specific class of warnings may be given multiple times The following classes are defined usage warnings related to command line arguments type warnings related to type conversion ext warnings related to extension libraries var warnings related to variable and syntax definitions and const warnings related to constant definitions syntax syntax related warnings redef warni
125. er s Manual The User s Manual 23 1 2 2 fileno stdout 23 1 2 3 fileno stderr 23 1 3 Open flags 23 1 3 1 open rdonly 23 1 3 2 open wronly 23 1 3 3 open rdwr 23 1 3 4 open read 23 1 3 5 open write 23 1 3 6 open creat 23 1 3 7 open append 23 1 3 8 open excl 23 1 3 9 open noctty 23 1 2 Standard I O file descriptors 126 CHICKEN User s Manual The User s Manual 23 1 3 10 open nonblock 23 1 3 11 open trunc 23 1 3 12 open sync 23 1 3 13 open fsync 23 1 3 14 open binary 23 1 3 15 open text 23 1 4 Permission bits 23 1 4 1 perm irusr 23 1 4 2 perm iwusr 23 1 4 3 perm ixusr 23 1 4 4 perm irgrp 23 1 4 5 perm iwgrp 23 1 3 Open flags 127 CHICKEN User s Manual The User s Manual 23 1 4 6 perm ixgrp 23 1 4 7 perm iroth 23 1 4 8 perm iwoth 23 1 4 9 perm ixoth 23 1 4 10 perm irwxu 23 1 4 11 perm irwxg 23 1 4 12 perm irwxo 23 1 4 13 perm isvtx 23 1 4 14 perm isuid 23 1 4 15 perm isgid 23 2 Directories 23 2 1 change directory procedure change directory NAME Changes the current working directory to NAME 23 1 4 Permission bits 128 CHICKEN User s Manual The User s Manual 23 2 2 current directory procedure current directory DIR Returns the name of the current working directory If the optional argument DIR is given then current directory DIR is equivalent to change directory DIR 23 2 3 create directory procedure create directo
126. erational garbage collection scheme is used in which short lived data structures are reclaimed extremely quickly e Moreover Call with current continuation is practically for free and CHICKEN does not suffer under any performance penalties if first class continuations are used in complex ways The generated C code is fully tail recursive Some of the features supported by CHICKEN e SRFIs 0 1 2 4 6 19 23 25 31 37 40 42 43 45 47 55 57 60 63 66 69 72 78 85 and 95 e Lightweight threads based on first class continuations e Pattern matching with Andrew Wright s match package e Record structures e Extended comment and string literal syntaxes e Libraries for regular expressions string handling e UNIX system calls and extended data structures e Create interpreted or compiled shell scripts written in Scheme for UNIX or Windows Compiled C files can be easily distributed e Allows the creation of fully self contained statically linked executables e On systems that support it compiled code can be loaded dynamically This manual is merely a reference for the CHICKEN system and assumes a working knowledge of Scheme The manual is split in the following sections Basic mode of operation Compiling Scheme files Using the compiler Explains how to use CHICKEN to compile programs and execute them Using the interpreter Invocation and usage of CSi the CHICKEN interpreter Supported language The language implemented by
127. erent a machine pointer object 29 14 c pointer An untyped operating system pointer or a locative The value f is also allowed and is passed as a NULL pointer If uses as the type of a return value a NULL pointer will be returned as f 29 15 nonnull c pointer As C pointer but guaranteed not to be f NULL 29 16 blob A blob object passed as a pointer to its contents Arguments of type b Lob may optionally be f which is passed as a NULL pointer This is not allowed as a return type 29 17 nonnull blob As blob but guaranteed not to be f 29 18 u8vector u16vector u32vector s8vector s16vector s32vector f32vector f64vector A SRFI 4 number vector object passed as a pointer to its contents These type specifiers are not allowed as return types 29 13 nonnull scheme pointer 198 CHICKEN User s Manual The User s Manual 29 19 nonnull u8vector nonnull u16vector nonnull u32vector nonnull s8vector nonnull s16vector nonnull s32vector nonnull f32vector nonnull f64vector As u8vector but guaranteed not to be f 29 20 c string A C string zero terminated The value f is also allowed and is passed as a NULL pointer If uses as the type of a return value a NULL pointer will be returned as f Note that the string is copied with a zero byte appended when passed as an argument to a foreign function Also a return value of this type is copied into garbage collected memory 29 21 nonnull c string As C Str
128. ero or f turns buffering off The setting of this parameter takes effect at the time when the I O ports for a particular socket are created i e when tcp connect or tcp accept is called Note that since output is not immediately written to the associated socket you may need to call flush output once you want the output to be transmitted Closing the output port will flush automatically 25 13 tcp read timeout parameter tcp read timeout Determines the timeout for TCP read operations in milliseconds A timeout of f disables timeout checking The default read timeout is 60000 i e 1 minute 25 9 tcp addresses 171 CHICKEN User s Manual The User s Manual 25 14 tcp write timeout parameter tcp write timeout Determines the timeout for TCP write operations in milliseconds A timeout of f disables timeout checking The default write timeout is 60000 i e 1 minute 25 15 tcp connect timeout parameter tcp connect timeout Determines the timeout for tcp connect operations in milliseconds A timeout of f disables timeout checking and is the default 25 16 tcp accept timeout parameter tcp accept timeout Determines the timeout for tcp accept operations in milliseconds A timeout of f disables timeout checking and is the default 25 17 Example A very simple example follows Say we have the two files cLient scm and server scm client scm declare uses tcp define values i o tcp connect localhost 4242
129. ery performed program analysis pass The procedure when defined will be called with seven arguments a symbol indicating the analysis pass the program database the current node graph a getter and a setter procedure which can be used to access and manipulate the program database which holds various information about the compiled program a pass iteration count and an analysis continuation flag The getter procedure should be called with two arguments a symbol representing the binding for which information should be retrieved and a symbol that specifies the database entry The current value of the database entry will be returned or HH if no such entry is available The setter procedure is called with three arguments the symbol and key and the new value The pass iteration count currently is meaningful only for the opt pass The analysis continuation flag will be f for the last opt pass For information about the contents of the program database contact the author 3 4 Extending the compiler 12 CHICKEN User s Manual The User s Manual Loaded code via the extend option has access to the library units extras srfi 1 srfi 4 utils regex and the pattern matching macros Multithreading is not available Note that the macroexpansion canonicalization phase of the compiler adds certain forms to the source program These extra expressions are not seen by user preprocessor pass but by user pass 3 5 Distributing compiled C files It is rela
130. ession NAME specifies the name of the external procedure and should be a string or a symbol 28 9 foreign lambda syntax foreign lambda RETURNTYPE ARGTYPE VARIABLE STRING 28 7 define foreign enum 193 CHICKEN User s Manual The User s Manual Similar to foreign lambda but instead of generating code to call an external function the body of the C procedure is directly given in STRING define my strlen foreign lambda int c string str feat Y nx C ratrturn MALL Str n C return n 0 while s int n my strlen one two three gt 13 For obscure technical reasons you should use the C_ return macro instead of the normal return statement to return a result from the foreign lambda body as some cleanup code has to be run before execution commences in the calling code 28 10 foreign safe lambda syntax foreign safe lambda RETURNTYPE NAME ARGTYPE This is similar to foreign Lambda but also allows the called function to call Scheme functions and allocate Scheme data objects See Callbacks 28 11 foreign safe lambda syntax foreign safe lambda RETURNTYPE ARGTYPE VARIABLE STRING This is similar to foreign lambda but also allows the called function to call Scheme functions and allocate Scheme data objects See Callbacks 28 12 foreign primitive syntax foreign primitive RETURNTYPE ARGTYPE VARIABLE STRING This is also similar to foreign Lambda but the
131. eyword KEYWORD ARGLIST THUNK Returns the argument from ARGLIST specified under the keyword KEYWORD If the keyword is not found then the zero argument procedure THUNK is invoked and the result value is returned If THUNK is not given f is returned 13 5 1 features 64 CHICKEN User s Manual The User s Manual define increase x args x get keyword amount args Lambda 1 increase 123 gt 124 increase 123 amount 10 gt 133 Note the KEYWORD may actually be any kind of object 13 6 2 keyword procedure keyword X Returns t if X is a keyword symbol or f otherwise 13 6 3 keywordstring procedure keyword gt string KEYWORD Transforms KEYWORD into a string 13 6 4 stringkeyword procedure string gt keyword STRING Returns a keyword with the name STRING 13 7 Exceptions CHICKEN implements the currently withdrawn SREL 12 exception system For more information see the SRFI 12 document 13 7 1 condition case syntax condition case EXPRESSION CLAUSE Evaluates EXPRESSION and handles any exceptions that are covered by CLAUSE where CLAUSE should be of the following form CLAUSE VARIABLE KIND BODY If provided VARIABLE will be bound to the signaled exception object BODY is executed when the exception is a property or composite condition with the kinds given KIND unevaluated If no clause 13 6 1 get keyword 65 CHICKEN User s Manual
132. f a shared object it will be interpreted even if the caller program is compiled 38 7 2 Why do finalizers not seem to work in simple cases in theinterpeter 252 CHICKEN User s Manual The User s Manual 38 9 Extensions 38 9 1 How can l install Chicken eggs to a non default location You can just set the CHICKEN REPOSITORY environment variable It should contain the path where you want eggs to be installed export CHICKEN REPOSITORY chicken chicken setup extensionname In order to make programs including csi see these eggs you should set this variable when you run them Alternatively you can call the repository path Scheme procedure before loading the eggs as in repository path home azul chicken use format modular Note however that using repository path as above hard codes the location of your eggs in your source files While this might not be an issue in your case it might be safe to keep this configuration outside of the source code that is specifying it as an environment variable to make it easier to maintain 38 9 2 Can l install chicken eggs as a non root user Yes just install them in a directory you can write Previous Bugs and limitations Next Acknowledgements 38 9 Extensions 253 39 Acknowledgements Many thanks to Nico Amtsberg William Annis Marc Baily Peter Barabas Jonah Beckford Arto Bendiken Peter Bex Jean Francois Bignolles Alaric Blagrave Snellpym Dave Bodenstab Fabian B
133. faster ol is equivalent to identity 15 11 Binary searching 15 10 9 identity 105 CHICKEN User s Manual The User s Manual 15 11 1 binary search procedure binary search SEQUENCE PROC Performs a binary search in SEQUENCE which should be a sorted list or vector PROC is called to compare items in the sequence should accept a single argument and return an exact integer zero if the searched value is equal to the current item negative if the searched value is less than the current item and positive otherwise Returns the index of the found value or f otherwise Previous Unit eval Next Unit srfi 1 15 11 1 binary search 106 16 Unit srfi 1 List library see the documentation for SRFI 1 Previous Unit extras Next Unit srfi 4 16 Unit srfi 1 107 17 Unit srfi 4 Homogeneous numeric vectors see the documentation for SREI 4 64 bit integer vectors U64vector and s64vector are not supported The basic constructor procedures for number vectors are extended to allow allocating the storage in non garbage collected memory 17 1 make XXXvector procedure make XXXvector SIZE INIT NONGC FINALIZE Creates a SRFI 4 homogenous number vector of length SIZE If INIT is given it specifies the initial value for each slot in the vector The optional arguments NONGC and FINALIZE define whether the vector should be allocated in a memory area not subject to garbage collection and whether the associated storage should be au
134. fined with de fine external before any other foreign declarations Equivalent to giving the emit external prototypes first option to the compiler 11 13 disable interrupts declaration specifier disable interrupts declaration specifier not interrupts enabled Disable timer interrupts checks in the compiled program Threads can not be preempted in main or library units that contain this declaration 11 14 disable warning declaration specifier disable warning CLASS Disable warnings of type CLASS equivalent to the disable warning CLASS compiler option 11 15 import declaration specifier import SYMBOL OR STRING Adds new imports to the list of externally available toplevel variables Arguments to this declaration may be either strings designating exports files without the file extension or symbols which directly designate imported variables 11 16 inline inline not inline inline IDENTIFIER not inline IDENTIFIER declaration specifier declaration specifier declaration specifier declaration specifier nnan If given without an identifier list inlining of known procedures is enabled this is equivalent to the inline compiler option When an identifier list is given then inlining is enabled only for the specified global procedures The negated forms not inline and not inline IDENTIFIER disable global inlining or inlining for the given global procedures only respectiv
135. fixed Symbol Bess Reads like a normal symbol 8 11 Bang NN Interpretation depends on the directly following characters Only the following are recognized Any other case results in a read error 8 11 1 Line Comment e If followed by whitespace or a slash then everything up the end of the current line is ignored 8 11 2 Eof Object e If followed by the character sequence eof then the self evaluating end of file object is returned 8 11 3 DSSSL Formal Parameter List Annotation e If followed by any of the character sequences Optional rest or key then a symbol with the same name and prefixed with is returned 8 11 4 Read Mark Invocation e Ifa read mark with the same name as the token is registered then its procedure is called and the result of the read mark procedure will be returned 8 9 Foreign Declare 30 CHICKEN User s Manual The User s Manual 8 12 Case Sensitive Expression CS Read the next expression in case sensitive mode regardless of the current global setting 8 13 Case Insensitive Expression Aci Read the next expression in case insensitive mode regardless of the current global setting 8 14 Conditional Expansion FEATURE EXPR Equivalent to cond expand FEATURE EXPR else Previous Extensions to the standard Next Non standard macros and special forms 8 12 Case Sensitive Expression 31 9 Non standard macros and special forms 9 1 Making extra libraries and extension
136. for each slot NAME STRUCT tests any object for being an instance of this structure Slots are accessed via NAME SLOTNAME STRUCT and updated using NAME SLOTNAME set STRUCT VALUE define record point x y define pl make point 123 456 point pl gt t point x pl gt 123 point y set pl 99 point y pl gt 99 9 5 1 select 39 CHICKEN User s Manual The User s Manual 9 6 2 define record printer syntax define record printer NAME RECORDVAR PORTVAR BODY syntax define record printer NAME PROCEDURE Defines a printing method for record of the type NAME by associating a procedure with the record type When a record of this type is written using display write or print then the procedure is called with two arguments the record to be printed and an output port define record foo x y zl define f make foo 1 2 3 define record printer foo x out fprintf out foo S S S foo x x foo y x foo z x define reader ctor foo make foo define s with output to string Lambda write f On A fan 7 7 s n gt TOO li Z 5 39 gt F S equal f with input from string s read gt t define record printer works also with SRFI 9 record types 9 6 3 define record type syntax define record type NAME CONSTRUCTOR TAG PREDICATE FIELD ACCESSOR MODIFIER SRFI 9 record types For more information see the documentation for SREL9
137. form SCHEMENAME REALTYPE SCHEME VALUE where REALTYPE designates the native type used The default enum specification is TYPENAME TYPENAME The SCHEME VALUE overrides the result of mapping from the native type When supplied the form is used unquoted otherwise the SCHEMENAME symbol is returned USE ALTASES is an optional boolean flag that determines whether an alias or the SCHEMENAME is used as the defined foreign variable name The default is FT Additionally two procedures are defined named SCHEMENAME number and number gt SCHEMENAME SCHEMENAME number takes one argument and converts a symbol or a list of symbols into its numeric value number gt SCHEMENAME takes one argument and converts a numeric value into its scheme value Note that the specification of a scheme value override SCHEME VALUE means the mapping may not be closed number gt SCHEMENAME SCHEMENAME gt number SCHEMENAME may not equal SCHEMENAME Here a heavily contrived example gt enum foo a foo 4 b foo c foo enum foo bar enum foo x printf sd n x return b foo lt define foreign enum foo enum foo a foo b foo c c foo define bar foreign lambda foo bar foo pp bar pp bar a foo pp bar b foo c 28 8 foreign lambda syntax foreign lambda RETURNTYPE NAME ARGTYPE Represents a binding to an external routine This form can be used in the position of an ordinary Lambda expr
138. g st ring gt See also set extension specifier When syntax extensions are loaded that redefine the global toplevel macro expander for example the syntax case extension then all remaining expression in the same toplevel form are still expanded with the old toplevel macro expander 9 1 2 define extension syntax define extension NAME CLAUSE This macro simplifies the task of writing extensions that can be linked both statically and dynamically If encountered in interpreted code or code that is compiled into a shared object specifically if compiled with the feature chicken compi Le shared done automatically by CSC when compiling with the shared or dynamic option then the code given by clauses of the form dynamic EXPRESSION are inserted into the output as a begin form If compiled statically specifically if the feature chicken compile shared has not been given then this form expands into the following declare unit NAME provide NAME and all clauses of the form static EXPRESSION all additionally inserted into the expansion As aconvenience the clause export IDENTIFIER is also allowed and is identical to declare export IDENTIFIER unless the define extension form occurs in interpreted code in with it is simply ignored Note that the compiler option extension NAME is equivalent to prefixing the compiled file with define extension NAME 9 1 1 require extension 33
139. gument at the same time that both the keyword and value arguments are added to the rest parameter list Note that for efficiency reasons the keyword parameter matching does nothing more than simply attempt to match with pairs that may exist in the remaining arguments Extra arguments that don t match are simply unused and forgotten if no rest parameter has been declared Because of this the caller of a procedure containing one or more keyword parameters cannot rely on any kind of system error to report 7 Extensions to the standard 24 CHICKEN User s Manual The User s Manual wrong keywords being passed in It shall be an error for an lt ident gt to appear more than once in a parameter list If there is no rest parameter and no keyword parameters in the parameter list then it shall be an error for any extra arguments to be passed to the procedure Example lambda x x 3 4 5 6 gt 3 45 6 lambda x y rest z z 3 45 6 gt 5 6 lambda x y optional z rest r key i j 1 list x y zi ij j 345 1 61 7 gt 3 45 i 6 j 1 4 1 6 set for unbound toplevel variables is allowed set PROCEDURE is supported as CHICKEN implements SRFI 17 4 2 1 The cond form supports SRFI 61 4 2 2 It is allowed for initialization values of bindings in a Let rec construct to refer to previous variables in the same set of bindings so letrec foo 123 bar foo bar is allowed and returns 123 4
140. h the code pointer as the first item C_8ALIGN_BIT Flag that specifies whether the data area of this block should be aligned on an 8 byte boundary floating point numbers for example The actual data follows immediately after the header Note that block addresses are always aligned to the native machine word boundary Scheme data objects map to blocks in the following manner pairs vector like object type bits C PAIR TYPE where the car and the cdr are contained in the first and second slots respectively vectors vector object type bits C VECTOR TYPE strings byte vector object type bits C STRING TYPE procedures special vector object type bits C CLOSURE TYPE The first slot contains a pointer to a compiled C function Any extra slots contain the free variables since a flat closure representation is used flonums a byte vector object type bits C FLONUM BITS Slots one and two or a single slot on 64 bit architectures contain a 64 bit floating point number in the representation used by the host systems C compiler symbols a vector object type bits C SYMBOL TYPE Slots one and two contain the toplevel variable value and the print name a string of the symbol respectively ports a special vector object type bits C PORT TYPE The first slot contains a pointer to a file stream if this is a file pointer or NULL if not The other slots contain housekeeping data used for this port structures a vector object ty
141. he following procedures make some struct C POINTER free some struct C POINTER some struct xcoord C POINTER gt NUMBER some struct ycoord C POINTER gt NUMBER some struct xcoord set C POINTER NUMBER some struct ycoord set C POINTER NUMBER 28 7 define foreign enum syntax define foreign enum TYPESPEC USE ALIASES ENUMSPEC Defines a foreign type as with define foreign type that maps the elements of a C C enum or a enum like list of constants to and from a set of symbols TYPESPEC specifies a foreign type that converts a symbol argument from the set ENUMSPEC into the appropriate enum value when passed as an argument to a foreign function A list of symbols passed as an argument will be combined using bitwise ior An empty list will be passed as 0 zero Results of the enum type are automatically converted into a scheme value note that combinations are not supported in this case 28 6 4 destructor 192 CHICKEN User s Manual The User s Manual TYPESPEC maybe a TYPENAME symbol or a list of the form SCHEMENAME REALTYPE DEFAULT SCHEME VALUE where REALTYPE designates the native type used The default type specification is TYPENAME TYPENAME The DEFAULT SCHEME VALUE overrides the default result of mapping from the native type i e when no such mapping exists When supplied the form is used unquoted otherwise the result is ENUMSPEC is a TYPENAME symbol or a list of the
142. heckug sees 166 DAG EE EE 166 24 7 Reading RE E 166 QA TA TEA E EE 167 DR FUNKY TE 167 24 8 1 OT 167 24 8 2 Make ConCatenated POrt 5 ettet Page bn E ERE CEDERE OPER REDE TERRE ERR dde 167 24 9 Miscellaneous Handy E 167 24 9 satt DEPRECATED da tl dida 167 24 9 2 unshift DERBRECATED no nono nano sn nn nn nn ono nono nonononacanananenos 168 2 Di A M Eon 169 25 tepli steier NN 169 e re EE I EA E E Ree tup EE ERE VAR eru ded 169 25 3 Bee 169 25 4 LCP ACCE EE 169 25 9 UCD ACCE dE EE 170 ASS ET 170 25 7 re EE E E E 170 25 8 tcp ConneGt oce tee Yee A tddi 170 25 0 NC 171 25 10 ee E EE 171 25 11 e EE O 171 22 12 eg EE EE 171 25 13 tcp read timeo t RO 171 25 12 ee Ee 172 25 15 TCP CONME CH MIME E 172 29 16 tcp actept tM COU EE 172 PN RN 172 PODES CIE m T 174 26 1 Foreign poltnt rs cocotte tort irae ete eee ue Ree ese ase de ERES SE SETS E Xue E RERO EE ege cues 174 26 1 1 addresspotntet tete E eee ue deed 174 QO eer EE 174 DO ER 174 26 AA null Pome TEE 174 26 15 NUN e NN 175 A NN 175 26 1 pointer iio ta 175 A oec ed eee HE EREECHEN 175 EE ere Tele 175 xiv CHICKEN User s Manual The User s Manual Chicken User s Manual 26 Unit lolevel XV CHICKEN User s Manual The User s Manual Chicken User s Manual 26 Unit lolevel 26 7 6 numbersof Dytes O 185 26 7 7 ernieren Ee E 185 26 7 8 TECOLG IMStANCE EE 185 20 1 9 TECOLEVECLOR E 185 26 8 Procedure call and
143. her Scheme implementatiON Po cooooccnnocinoninonccconoccnoncnnnncnnnnc nono cc cono ccnnccnnnnnos 241 38 1 2 What should I do if I find a bug oooonnccnnnnccnoncconncnononanonnccnnnnonnncnnnnncnnnc nano nc cnn ccnnccnnnnnss 241 XIX CHICKEN User s Manual The User s Manual Chicken User s Manual 38 FA 38 1 3 Why are values defined with define foreign variable or define constant or define inline not seen outside of the containing source file eeceeseceeseceeseceeeeeeeeeeeees 241 38 1 4 How does cond expand know which features are registered in used units 242 38 1 5 Why are constants defined by define constant not honoured in case constructs 242 38 1 6 How can I enable case sensitive reading writing in user code 242 38 1 7 How can I change match error control during compilation 242 38 1 8 Why doesn t CHICKEN support the full numeric tower by default 242 38 1 9 How can I specialize a generic function method to match instances of every e ENSIS MP Cer 243 38 1 10 Does CHICKEN support native threads ooooocnncccnnoninnocanonoccnnncnnnnncnnnannnoncnnnoconncccnnnnos 243 38 1 11 Does CHICKEN support Unicode onge 243 38 2 E ere EE 244 38 2 1 How do I generate a DLL under MS Windows tm sese 244 38 2 2 How do I generate a GUI application under Windows tm eeeeeeeee 244 38 2 3 Compiling
144. hy do finalizers not seem to work in simple cases in the terperter oooonocnnnncicnncccnnccccnnnnnnn 251 SSMUS NR O 252 38 8 1 Does CSI support history and autocompletion ooooonnccnonccinonocionanononononccnnnncnnnnnnnn nc nono conan cccnncn ns 252 38 8 2 Does code loaded with load run compiled or interprete coooonoccninncocnnccnoncccnonanonncnnnononanccnnncn ns 252 38 9 O NOEL TT 253 XX CHICKEN User s Manual The User s Manual Chicken User s Manual 38 FA 38 9 1 How can I install Chicken eggs to a non default location sese 253 38 9 2 Can I install chicken eggs as a non root user 2 eecceeecceceeeceseeceeaeceeneceeeeeceaeesaeceeaaeceaeeceeeeees 253 39 ACKNOW BOS CINE INS ida 254 LASCIA caia aa 256 xxi 1 The User s Manual This document describes version 3 0 0 CHICKEN is a compiler that translates Scheme source files into C which in turn can be fed to a C compiler to generate a standalone executable An interpreter is also available and can be used as a scripting environment or for testing programs before compilation This package is distributed under the BSD license and as such is free to use and modify The method of compilation and the design of the runtime system follow closely Henry Baker s CONS Should Not CONS Its Arguments Part II Cheney on the M T A paper and expose a number of interesting properties e Consing creation of data on the heap is relatively inexpensive because a gen
145. ializer gt if one was specified otherwise f The corresponding lt initializer gt is evaluated in an environment in which all previous parameters have been bound e If there is a rest parameter then it is bound to a list containing all the remaining arguments left over after the argument bindings with required parameters and optional parameters have been made e If key was specified in the parameter list there should be an even number of remaining arguments These are interpreted as a series of pairs where the first member of each pair is a keyword specifying the parameter name and the second member is the corresponding value If the same keyword occurs more than once in the list of arguments then the corresponding value of the first keyword is the binding value If there is no argument for a particular keyword parameter then the variable is bound to the result of evaluating lt initializer gt if one was specified otherwise f The corresponding lt initializer gt is evaluated in an environment in which all previous parameters have been bound Needing a special mention is the close relationship between the rest parameter and possible keyword parameters Declaring a rest parameter binds up all remaining arguments in a list as described above These same remaining arguments are also used for attempted matches with declared keyword parameters as described above in which case a matching keyword parameter binds to the corresponding value ar
146. ier to a procedure of zero arguments that accesses the corresponding field of the matching value This pattern is the complement to set As with set this pattern must be nested within a pair vector box or structure pattern Quasipatterns Quasiquote introduces a quasipattern in which identifiers are considered to be symbolic constants Like Scheme s quasiquote for data unquote and unquote splicing escape back to normal patterns 10 2 Patterns 46 CHICKEN User s Manual The User s Manual 10 3 Match Failure If no clause matches the value the default action is to invoke the procedure match error procedure with the value that did not match The default definition of match error procedure calls error with an appropriate message 1 gt match 1 2 2 Failed match Error no matching clause for 1 For most situations this behavior is adequate but it can be changed by altering the value of the parameter match error control procedure match error control match error control MODE Selects a mode that specifies how match macro forms are to be expanded With no argument this procedure returns the current mode A single argument specifies the new mode that decides what should happen if no match clause applies The following modes are supported Signal an error This is the default 1 error Signal an error and output the offending form 1 match Omits pair tests when the consequence is to fail in Ca
147. ifies the length of the portion to be locked and defaults to t which means the complete file File Lock returns a lock object 23 12 2 file lock blocking procedure file lock blocking PORT START LEN Similar to file Lock but if a lock is held on the file the current process blocks including all threads until the lock is released 23 12 3 file test lock procedure file test lock PORT START LEN Tests whether the file associated with PORT is locked for reading or writing according to whether PORT is an input or output port and returns either f or the process id of the locking process 23 12 4 file unlock procedure file unlock LOCK Unlocks the previously locked portion of a file given in LOCK 23 11 3 set process group id 143 CHICKEN User s Manual The User s Manual 23 13 Signal handling 23 13 1 set alarm procedure set alarm SECONDS Sets an internal timer to raise the Signal alrm after SECONDS are elapsed You can use the set signal handler procedure to write a handler for this signal 23 13 2 set signal handler procedure set signal handler SIGNUM PROC Establishes the procedure of one argument PROC as the handler for the signal with the code SIGNUM PROC is called with the signal number as its sole argument If the argument PROC is f then any signal handler will be removed Note that is is unspecified in which thread of execution the signal handler will be invoked 23 13 3
148. ign lambda char vector memset char vector char int memset 4 X 3 gt X X X Foreign type definitions are only visible in the compilation unit in which they are defined so use include to use the same definitions in multiple files 28 5 define foreign variable syntax define foreign variable NAME TYPE STRING Defines a foreign variable of name NAME a symbol STRING should be the real name of a foreign variable or parameterless macro If STRING is not given then the variable name NAME will be converted to a string and used instead All references and assignments via Set are modified to correctly convert values between Scheme and C representation This foreign variable can only be accessed in the current compilation unit but the name can be lexically shadowed Note that STRING can name an arbitrary C expression If no assignments are performed then STRING doesn t even have to specify an lvalue gt enum abc 3 def ghi lt define macro define simple foreign enum items begin G map match lambda name realname define foreign variable name int realname name define foreign variable name int items define simple foreign enum abc def ghi ghi gt 5 28 6 define foreign record syntax define foreign record NAME DECL SLOT Defines accessor procedures for a C structure definition NAME should either be a symbol or a list of the form TYPENAME FOREI
149. ile buffering mode 23 21 1 set buffering mode procedure set buffering mode PORT MODE BUFSIZE Sets the buffering mode for the file associated with PORT to MODE which should be one of the keywords full Line or none If BUFSIZE is specified it determines the size of the buffer to be used if any 23 22 Terminal ports 23 22 1 terminal name procedure terminal name PORT Returns the name of the terminal that is connected to PORT 23 20 Getting the hostname and system information 154 CHICKEN User s Manual The User s Manual 23 22 2 terminal port procedure terminal port PORT Returns t if PORT is connected to a terminal and f otherwise 23 23 How Scheme procedures relate to UNIX C functions change directory chdir change file mode chmod change file owner chown create directory mkdir create fifo mkfifo create pipe pipe create session setsid create symbolic link link current directory curdir current effective groupd id getegid current effective user id geteuid current group id getgid current parent id getppid current process id 23 22 2 terminal port 155 CHICKEN User s Manual The User s Manual getpid current user id getuid delete directory rmdir duplicate fileno dup dup2 _ exit _exit file close close file access time stat file change time stat file modification time stat file execute access access file open
150. ile descriptor If the file does not exist an error is signaled Note that for very large files file Size may return an inexact integer 23 6 1 file access time 135 CHICKEN User s Manual The User s Manual 23 6 7 regular file procedure regular file FILENAME Returns true if FILENAME names a regular file not a directory or symbolic link 23 6 8 file owner procedure file owner FILE Returns the user id of FILE FILE may be a filename or a file descriptor 23 6 9 file permissions procedure file permissions FILE Returns the permission bits for FILE You can test this value by performing bitwise operations on the result and the perm values FILE may be a filename or a file descriptor 23 6 10 file read access 23 6 11 file write access 23 6 12 file execute access procedure file read access FILENAME procedure file write access FILENAME procedure file execute access FILENAME These procedures return t if the current user has read write or execute permissions on the file named FILENAME 23 7 Changing file attributes 23 6 7 regular file 136 CHICKEN User s Manual The User s Manual 23 7 1 file truncate procedure file truncate FILE OFFSET Truncates the file FILE to the length OFFSET which should be an integer If the file size is smaller or equal to OFFSET then nothing is done FILE should be a filename or a file descriptor 23 7 2 set file position procedure set file p
151. in compiled code 14 5 System information 14 5 1 chicken home procedure chicken home Returns a string given the installation directory usually usr local share chicken on UNIX like systems As a last option if the environment variable CHICKEN PREFIX is set then chicken home will return CHICKEN PREFIX share 14 6 Eval 14 6 1 eval procedure eval EXP ENVIRONMENT Evaluates EXP and returns the result of the evaluation The second argument is optional and defaults to the value of interaction environment Previous Unit library Next Unit extras 14 4 6 set extension specifier 88 15 Unit extras This unit contains a collection of useful utility definitions This unit is used by default unless the program is compiled with the explicit use option 15 1 Lists 15 1 1 alist ref procedure alist ref KEY ALIST TEST DEFAULT Looks up KEY in ALIST using TEST as the comparison function or eqv if no test was given and returns the cdr of the found pair or DEFAULT which defaults to f 15 1 2 alist update procedure alist update KEY VALUE ALIST TEST If the list ALIST contains a pair of the form KEY X then this procedure replaces X with VALUE and returns ALIST If ALIST contains no such item then alist update returns KEY VALUE ALIST The optional argument TEST specifies the comparison procedure to search a matching pair in ALIST and defaults to eqv 15 1 3 atom procedure a
152. in the order in which the units appear in the uses declaration Units may be used multiple times and uses declarations may be circular the unit is initialized at most once To compile a file as a unit add a unit declaration declare unit UNITNAME When compiling different object modules make sure to have one main unit This unit is called initially and initializes all used units before executing its toplevel expressions The main unit has no unit declaration Another method of using definitions in separate source files is to include them This simply inserts the code in a given file into the current file include FILENAME Macro definitions are only available when processed by include or require for syntax Macro definitions in separate units are not available since they are defined at compile time i e the time when that other unit was compiled macros can optionally be available at runtime see def ine macro in Substitution forms and macros On platforms that support dynamic loading of compiled code Windows most ELF based systems like Linux or BSD MacOS X and others code can be compiled into a shared object dll so dylib and loaded dynamically into a running application Previous index html Next Using the compiler 2 Basic mode of operation 3 3 Using the compiler The interface to Chicken is intentionally simple System dependent makefiles shell scripts or batch files should perform any necessary steps befor
153. ing but guaranteed not to be f NULL 29 22 nonnull c string Similar to nonnull c string but if used as a result type the pointer returned by the foreign code will be freed using the C libraries free 1 after copying This type specifier is not valid as a result type for callbacks defined with define external 29 23 nonnull unsigned c string Same as C string but maps to the unsigned char C type 29 24 c string list Expects a pointer to a list of C strings teminated by a NULL pointer and returns a list of strings Only valid as a result type of non callback functions 29 19 nonnull u8vector nonnull ul6vector nonnull u32 vector nonnull s8vector nonnull s16vector nonnull 99vector n CHICKEN User s Manual The User s Manual 29 25 c string list Similar to cC string list but releases the storage of each string and the pointer array using f ree 1 29 26 void Specifies an undefined return value Not allowed as argument type 29 27 const TYPE The foreign type TYPE with an additional const specifier 29 28 enum NAME An enumeration type Handled internally as an integer 29 29 c pointer TYPE An operating system pointer or a locative to an object of TYPE 29 30 nonnull c pointer TYPE As C pointer TYPE but guaranteed not to be f NULL 29 31 ref TYPE A C reference type Reference types are handled the same way as pointers inside Scheme code 29 25 c string list 200 C
154. ing routines Olin Shivers implementation of Let optionals and reference implementations of SRFI 1 SRFI 13 and SRFI 14 Andrew Wilcox 39 Acknowledgements 254 CHICKEN User s Manual The User s Manual queues Andrew Wright pattern matcher http galinha ucpel tche br Alex Shinn scheme complete el emacs tab completion Previous FAQ Next Bibliography 39 Acknowledgements 255 40 Bibliography Henry Baker CONS Should Not CONS Its Arguments Part II Cheney on the M T A http home pipeline com hbaker1 CheneyMTA html Revised 5 Report on the Algorithmic Language Scheme http www schemers org Documents Standards R5RS Previous Acknowledgements 40 Bibliography 256
155. input ports PORT defaults to the value of current input port 13 2 6 set port name procedure set port name PORT STRING Sets the name of PORT to STRING 13 3 Files 13 3 1 delete file procedure delete file STRING Deletes the file with the pathname STRING If the file does not exist an error is signaled 13 3 2 file exists procedure file exists STRING Returns STRING if a file with the given pathname exists or f otherwise 13 2 4 port name 62 CHICKEN User s Manual The User s Manual 13 3 3 rename file procedure rename file OLD NEW Renames the file or directory with the pathname OLD to NEW If the operation does not succeed an error is signaled 13 4 String ports 13 4 1 get output string procedure get output string PORT Returns accumulated output of a port created with open output string 13 4 2 open input string procedure open input string STRING Returns a port for reading from STRING 13 4 3 open output string procedure open output string Returns a port for accumulating output in a string 13 5 Feature identifiers CHICKEN maintains a global list of features naming functionality available in the current system Additionally the cond expand form accesses this feature list to infer what features are provided Predefined features are chicken and the SRFIs Scheme Request For Implementation provided by the base system Srfi 23 srfi 30 srfi 39 If the eval unit is used
156. install flag parameter setup install flag BOOL Reflects the setting of the no install option i e is f if no install was given 35 4 21 required chicken version procedure required chicken version VERSION Signals an error if the version of CHICKEN that this script runs under is lexicographically less than VERSION the argument will be converted to a string first 35 4 22 required extension version procedure required extension version EXTENSION1 VERSIONI Checks whether the extensions EXTENSION1 are installed and at least of version VERSION1 The test is made by lexicographically comparing the string representations of the given version with the version of the installed extension If one of the listed extensions is not installed has no associated version information or is of a version older than the one specified 35 4 23 cross chicken procedure cross chicken Returns t if this system is configured for cross compilation or f otherwise 35 4 18 setup build directory 230 CHICKEN User s Manual The User s Manual 35 4 24 host extension parameter host extension For a cross compiling CHICKEN when compiling an extension then it should be built for the host environment as opposed to the target environment This parameter is controlled by the host extension command line option A setup script should perform the proper steps of compiling any code by passing host when invoking CSC or using th
157. integer N at the address designated by PTR 26 1 25 pointer s32 set procedure pointer s32 set PTR N procedure set pointer s32 ref PTR N Stores the 32 bit integer N at the address designated by PTR 26 1 26 pointer f32 set procedure pointer f32 set PTR N procedure set pointer f32 ref PTR N Stores the 32 bit floating point number N at the address designated by PTR 26 1 27 pointer f64 set procedure pointer f64 set PTR N procedure set pointer f64 ref PTR N Stores the 64 bit floating point number N at the address designated by PTR 26 1 28 align to word procedure align to word PTR OR INT Accepts either a machine pointer or an integer as argument and returns a new pointer or integer aligned to the native word size of the host platform 26 1 23 pointer s16 set 178 CHICKEN User s Manual The User s Manual 26 2 Tagged pointers Tagged pointers are foreign pointer objects with an extra tag object 26 2 1 tag pointer procedure tag pointer PTR TAG Creates a new tagged pointer object from the foreign pointer PTR with the tag TAG which may an arbitrary Scheme object 26 2 2 tagged pointer procedure tagged pointer X TAG Returns t if X is a tagged pointer object with the tag TAG using an eq comparison or f otherwise 26 2 3 pointer tag procedure pointer tag PTR If PTR is a tagged pointer object its tag is returned If PTR is a normal untagged foreign
158. ips hppa ultrasparc sparc ppc ppc64 ia64 x86 x86 64 unknown 13 8 9 on exit procedure on exit THUNK Schedules the zero argument procedures THUNK to be executed before the process exits either explicitly via exit or implicitly after execution of the last top level form Note that finalizers for unreferenced finalized data are run before exit procedures 13 8 10 software type procedure software type Returns a symbol specifying the operating system on which this process is currently running which is one of the following windows unix macos ecos unknown 13 8 11 software version procedure software version Returns a symbol specifying the operating system version on which this process is currently running which is one of the following 13 8 8 machine type 69 CHICKEN User s Manual The User s Manual Linux freebsd netbsd openbsd macosx hpux solaris sunos unknown 13 8 12 c runtime procedure c runtime Returns a symbol that designates what kind of C runtime library has been linked with this version of the Chicken libraries Possible return values are static dynamic or unknown On systems not compiled with the Microsoft C compiler C runtime always returns unknown 13 8 13 system procedure system STRING Execute shell command The functionality offered by this procedure depends on the capabilities of the host shell If the forking of a subprocess failed an exception is raised Otherwise
159. is the current value of current input port 24 8 Funky ports 24 8 1 make broadcast port procedure make broadcast port PORT Returns a custom output port that emits everything written into it to the ports given as PORT Closing the broadcast port does not close any of the argument ports 24 8 2 make concatenated port procedure make concatenated port PORT1 PORT2 Returns a custom input port that reads its input from PORT 1 until it is empty then from PORT2 and so on Closing the concatenated port does not close any of the argument ports 24 9 Miscellaneous handy things 24 9 1 shift DEPRECATED procedure shift LIST DEFAULT Returns the car of LIST or DEFAULT if LIST is empty and replaces the car of LIST with it s cadr and the cdr with the cddr If DEFAULT is not given and the list is empty f is returned An example might be clearer here define lst 1 2 3 shift lst gt 1 lst is now 2 3 The list must contain at least 2 elements 24 7 1 read all 167 CHICKEN User s Manual The User s Manual 24 9 2 unshift DEPRECATED procedure unshift X PAIR Sets the car of PAIR to X and the cdr to its cddr Returns PAIR define lst 2 unshift 99 lst lst is now 99 2 Previous Unit posix Next Unit tcp 24 9 2 unshift DEPRECATED 168 25 Unit tcp This unit provides basic facilities for communicating over TCP sockets The socket interface should be mostly compatible
160. it is not possible to access a toplevel binding with global ref or global set if it has been hidden in compiled code via declare hide orif the code has been compiled in block mode 26 6 3 global set procedure global set SYMBOL X procedure set global ref SYMBOL X Sets the global variable named SYMBOL to the value X 26 5 5 locative set 183 CHICKEN User s Manual The User s Manual 26 7 Low level data access 26 7 1 block ref procedure block ref BLOCK INDEX Returns the contents of the INDEXth slot of the object BLOCK BLOCK may be a vector record structure pair or symbol 26 7 2 block set procedure block set BLOCK INDEX X procedure set block ref BLOCK INDEX X Sets the contents of the INDEXth slot of the object BLOCK to the value of X BLOCK may be a vector record structure pair or symbol 26 7 3 object copy procedure object copy X Copies X recursively and returns the fresh copy Objects allocated in static memory are copied back into garbage collected storage 26 7 4 make record instance procedure make record instance SYMBOL ARG1 Returns a new instance of the record type SYMBOL with its slots initialized to ARG1 To illustrate define record point x y expands into something quite similar to begin define make point x y make record instance point x y define point x and record instance x eq point block ref x 0 define point
161. ituations machine byte order machine type software type software version where the actual feature identifier is platform dependent In addition the following feature identifiers may exist app Lyhook extraslot ptables dload For further information see the documentation for SRFI 0 9 7 3 ensure syntax ensure PREDICATE EXP ARGUMENTS Evaluates the expression EXP and applies the one argument procedure PREDICATE to the result If the predicate returns f an error is signaled otherwise the result of EXP is returned If compiled in unsafe mode either by specifying the unsafe compiler option or by declaring unsafe then this expression expands to an unspecified value If specified the optional ARGUMENTS are used as arguments to the invocation of the error signalling code as in error ARGUMENTS If no ARGUMENTS are given a generic error message is displayed with the offending value and PREDICATE expression 9 7 4 eval when syntax eval when SITUATION EXP Controls evaluation compilation of subforms SITUATION should be one of the symbols eval compile or Load When encountered in the evaluator and the situation specifier eval is not given then this form is not evaluated and an unspecified value is returned When encountered while compiling code and the situation 9 7 2 cond expand 41 CHICKEN User s Manual The User s Manual specifier compile is given then this form is evaluated at compile
162. l when like this eval when compile match error control unspecified 38 1 8 Why doesn t CHICKEN support the full numeric tower by default The short answer chicken setup numbers csi q 1 gt use numbers The long answer There are a number of reasons for this For most applications of Scheme fixnums exact word sized integers and flonums 64 bit floating point numbers are more than sufficient 38 1 4 How does cond expand know which features are registered in used units 242 CHICKEN User s Manual The User s Manual Interfacing to C is simpler Dispatching of arithmetic operations is more efficient There is an extension based on the GNU Multiprecision Package that implements most of the full numeric tower see http galinha ucpel tche br numbers 38 1 9 How can specialize a generic function method to match instances of every class Specializing a method on obj ect doesn t work on primitive data objects like numbers strings etc so for example define method foo x lt my class gt define method foo x lt object gt foo 123 will signal an error because to applicable method can be found To specialize a method for primitive objects use lt top gt define method foo x lt top gt 38 1 10 Does CHICKEN support native threads Currently native threads are not supported The runtime system is not reentrant and the garbage collection algorithm would
163. l cc Additionally the code generated to match a structure pattern like Foo pat 1 pat n refers to the name Foo This name also should not be shadowed Previous Non standard macros and special forms Next Declarations 10 5 Code Generation 48 11 Declarations 11 1 declare syntax declare DECLSPEC Process declaration specifiers Declarations always override any command line settings Declarations are valid for the whole compilation unit source file the position of the declaration in the source file can be arbitrary Declarations are ignored in the interpreter but not in code evaluated at compile time by eval when or in syntax extensions loaded via require extension or require for syntax DECLSPEC may be any of the following 11 2 always bound declaration specifier always bound SYMBOL Declares that the given variables are always bound and accesses to those have not to be checked 11 3 block declaration specifier block Assume global variables are never redefined This is the same as specifying the block option 11 4 block global 11 5 hide declaration specifier block global SYMBOL declaration specifier hide SYMBOL Declares that the toplevel bindings for SYMBOL should not be accessible from code in other compilation units or by eval Access to toplevel bindings declared as block global is also more efficient 11 Declarations 49 CHICKEN User s Manual The User s Man
164. ld be a symbol which when converted to a string represents a legal C identifier ARGUMENTTYPE1 and RETURNTYPE are foreign type specifiers for the argument variables VAR1 and the result respectively QUALIFIERS is an optional qualifier for the foreign procedure definition like stdcall define external foo c string x int string length x The second form of define external can be used to define variables that are accessible from foreign code It declares a global variable named by the symbol NAME that has the type TYPE INIT can be an arbitrary expression that is used to initialize the variable NAME is accessible from Scheme just like any other foreign variable defined by define foreign variable define external foo int 42 foreign lambda int C return foo gt 42 Note don t be tempted to assign strings or bytevectors to external variables Garbage collection moves those objects around so it is very bad idea to assign pointers to heap data If you have to do so then copy the data object into statically allocated memory for example by using obj ect evict Results of type scheme object returned by define external are always allocated in the secondary heap that is not in the stack 31 Callbacks 210 CHICKEN User s Manual The User s Manual 31 2 C callback C function C word C callback C word closure int argc This function can be used to invoke the Scheme procedure closure argc should con
165. ld return two values the source filename and the actual list of options where compiler switches have their leading hyphen removed and are converted to symbols Note that this parameter is invoked before processing of the extend option and so can only be changed in compiled user passes parameter user read pass Holds a procedure of three arguments The first argument is a list of strings with the code passed to the compiler via prelude options The second argument is a list of source files including any files specified by prologue and epilogue The third argument is a list of strings specified using postlude options The procedure should return a list of toplevel Scheme expressions parameter user preprocessor pass Holds a procedure of one argument This procedure is applied to each toplevel expression in the source file before macro expansion The result is macro expanded and compiled in place of the original expression parameter user pass Holds a procedure of one argument This procedure is applied to each toplevel expression after macro expansion The result of the procedure is then compiled in place of the original expression parameter user pass 2 Holds a procedure of three arguments which is called with the canonicalized node graph as its sole argument The result is ignored so this pass has to mutate the node structure to cause any effect parameter user post analysis pass Holds a procedure that will be called after ev
166. led ls EXTENSION List installed files for extension fetch tree 35 6 chicken setup reference 234 CHICKEN User s Manual The User s Manual Download and print the repository catalog create tree DIRECTORY Create a fresh minimal repository catalog and writes it to stdout t test If the extension sources contain a directory named tests and this directory includes a file named run scm then this file is executed with tests being the current working directory tree FILENAME Download and show the repository catalog svn URL Fetch extension from Subversion repository revision REV Specifies SVN revision to check out Local PATHNAME Fetch extension from local file destdir PATHNAME Specify alternative installation prefix for packaging host extension Compile extension in host mode sets the parameter host extension to f Ignore all following arguments Note that the options are processed exactly in the order in which they appear in the command line 35 7 Windows notes chicken setup works on Windows when compiled with Visual C but depends on the tar and gunzip tools to extract the contents of an egg The best way is to download an egg either manually or with chicken setup fetch and extract its contents with a separate program like winzip the CHICKEN REPOSITORY environment variable has to be set to a directory where your compiled extensions should be located The setup scripts will not always work under Windows a
167. lo2 hello2 name of the extension and files to be inst To use it just run chi cken setup in the same directory chicken setup Here we omit the extension name Now the program hello2 will be installed in the same location as the other CHICKEN tools like chicken csi etc which will normally be usr local bin Note that you need write permissions for those locations and may have to run chicken setup with administrative rights Uninstallation is just as easy chicken setup uninstall hello2 chicken setup provides a make macro so build operations can be of arbitrary complexity When running Chicken setup with an argument NAME for which no associated file NAME setup NAME egg or NAME scm exists will ask you to download the extension via HTTP from the default URL http www call with current continuation org eggs You can use the host option to specify an alternative source location Extensions that are required to compile and or use the requested extension are downloaded and installed automatically If the given extension name contains a path prefix and the host option is given then chicken setup can also download and install eggs from an arbitrary HTTP server Alternatively you can pass a full URL including the http prefix Note that no dependency checks are done when downloading eggs directly with the URL syntax Finally a somewhat more complex example We want to package a syntax extension with additional support
168. m flush output thread specific thread specific set not pair null list print print u8vector gt blob shared s8vector gt blob shared ul6vector gt blob shared sl6vector gt blob shared u32vector gt blob shared s32vector gt blob shared f32vector gt blob shared 38 6 2 How can I obtain faster executables 250 CHICKEN User s Manual The User s Manual f64vector gt blob shared block ref blob size u8vector length s8vector length ul6vector length s16vector length u32vector length s32vector length f32vector length f64vector length u8vector ref s8vector ref ul6vector ref sl6vector ref u32vector ref s32vector ref f32vector ref f64vector ref u8vector set s8vector set ul6vector set sl6vector set u32vector set s32vector set hash table ref block set number of slots first second third fourth null pointer pointer gt object make record instance locative ref locative set locative locative gt object identity cpu time error call cc any substring substring ci substring index substring index ci 38 6 4 Can I load compiled code at runtime Yes You can load compiled at code at runtime with Load just as well as you can load Scheme source code Compiled code will of course run faster To do this pass to Load a path for a shared object Use a form such as Load foo so and run CSC shared foo scm to produce f00 S0 from foo scm at which point foo scm will no longer be required 38 7 Garbage collection 38 7 1 Why does a loop
169. mation GROUP If GROUP specifies a valid group name or group id then this procedure returns a list of four values the group name the encrypted group password the group ID and a list of the names of all group members If no group with the given name or ID exists then f is returned 23 10 7 get groups procedure get groups Returns a list with the supplementary group IDs of the current user 23 11 Changing user amp group information 23 11 1 set groups procedure set groups GIDLIST Sets the supplementrary group IDs of the current user to the IDs given in the list GIDLIST Only the superuser may invoke this procedure 23 11 2 initialize groups procedure initialize groups USERNAME BASEGID Sets the supplementrary group IDs of the current user to the IDs from the user with name USERNAME a string including BASEGID Only the superuser may invoke this procedure 23 10 5 current effective group id 142 CHICKEN User s Manual The User s Manual 23 11 3 set process group id procedure set process group id PID PGID setter set process group id PID PGID Sets the process group ID of the process specifed by PID to PGID 23 12 Record locking 23 12 1 file lock procedure file lock PORT START LEN Locks the file associated with PORT for reading or writing according to whether PORT is an input or output port START specifies the starting position in the file to be locked and defaults to O LEN spec
170. may contain special characters if delimited with 2 3 The brackets andthe braces are provided as an alternative syntax for A number of reader extensions is provided See Non standard read syntax 4 Numerous non standard macros are provided See Non standard macros and special forms for more information 4 1 4 Extended DSSSL style lambda lists are supported DSSSL parameter lists are defined by the following grammar lt parameter list gt gt lt required parameter gt optional optional parameter rest lt rest parameter gt key lt keyword parameter gt lt required parameter gt gt lt ident gt lt optional parameter gt gt lt ident gt lt ident gt lt initializer gt lt rest parameter gt gt lt ident gt lt keyword parameter gt gt lt ident gt lt ident gt lt initializer gt lt initializer gt gt lt expr gt When a procedure is applied to a list of arguments the parameters and arguments are processed from left to right as follows e Required parameters are bound to successive arguments starting with the first argument It shall be an error if there are fewer arguments than required parameters e Next the optional parameters are bound with the remaining arguments If there are fewer arguments than optional parameters then the remaining optional parameters are bound to the result of the evaluation of their corresponding lt init
171. mbered starting at 1 and beginning with the lowest order bit There exist two different kinds of data objects in the CHICKEN system immediate and non immediate objects 36 1 Immediate objects Immediate objects are represented by a single machine word which is usually of 32 bits length or 64 bits on 64 bit architectures The immediate objects come in four different flavors fixnums that is small exact integers where bit 1 is set to 1 This gives fixnums a range of 31 bits for the actual numeric value 63 bits on 64 bit architectures characters where bits 1 4 are equal to C CHARACTER BITS The Unicode code point of the character is encoded in bits 9 to 32 booleans where bits 1 4 are equal to C BOOLEAN BITS Bit 5 is one for t and zero for tf other values the empty list the value of unbound identifiers the undefined value void and end of file Bits 1 4 are equal to C SPECIAL BITS bits 5 to 8 contain an identifying number for this type of object The following constants are defined C SCHEME END OF LIST C SCHEME UNDEFINED C SCHEME UNBOUND C SCHEME END OF FILE Collectively bits 1 and 2 are known as the immediate mark bits When bit 1 is set the object is a fixnum as described above and bit 2 is part of its value When bit 1 is clear but bit 2 is set it is an immediate object other than a fixnum If neither bit 1 nor bit 2 is set the object is non immediate as described below 36 2 Non immediate objects Non immedia
172. me to C to Scheme calls are nested deeply then the available nursery space on the stack will run low To avoid this it might be advisable to run the compiled code with a larger nursery setting i e run the code with S anda larger value than the default for example 300k or use the nursery compiler option Note that this can decrease runtime performance on some platforms 38 5 2 Why does the linker complain about a missing function _C_ toplevel This message indicates that your program uses a library unit but that the object file or library was not supplied to the linker If you have the unit foo which is contained in f 00 0 than you have to supply it to the linker like this assuming a GCC environment CSC program scm foo o o program 38 5 3 Why does the linker complain about a missing function _C_toplevel This means you have compiled a library unit as an application When a unit declaration as in declare unit is given then this file has a specially named toplevel entry procedure Just remove the declaration or compile this file to an object module and link it to your application code 38 5 4 Why does my program crash when compile a file with unsafe or unsafe declarations The compiler option unsafe or the declaration declare unsafe disable certain safety checks to improve performance so code that would normally trigger an error will work unexpectedly or even crash the running application It is a
173. name of the file implementing the extension The extension may load or include other files or may load other extensions at runtime specified by the require at runtime property FILELIST may be a filename a list of filenames or a list of pairs of the form SOURCE DEST if you want to copy into a particular sub directory the destination directory will be created as needed If DEST is a relative pathname lt it will be copied into the extension repository The optional argument INFOLIST should be an association list that maps symbols to values this list will be stored as ID setup info at the same location as the extension code Currently the following properties are used 35 4 1 1 syntax extension property syntax Marks the extension as syntax only No code is compiled the extension is intended as a file containing macros to be loaded at compile macro expansion time 35 4 1 2 require at runtime extension property require at runtime ID Specifies extensions that should be loaded via requi re at runtime This is mostly useful for syntax extensions that need additional support code at runtime 35 4 1 3 version extension property version STRING Specifies version string 35 4 Procedures and macros available in setup scripts 225 CHICKEN User s Manual The User s Manual 35 4 1 4 documentation extension property documentation FILENAME The filename of a HTML document containing extension specific document
174. nction void CHICKEN parse command line int argc char argv int heap Parse the programs command line contained in argc and argv and return the heap stack and symbol table limits given by runtime options of the form or choose default limits The library procedure argv can access the command line only if this function has been called by the containing application 30 2 CHICKEN initialize C function int CHICKEN initialize int heap int stack int symbols void to Initializes the Scheme execution context and memory heap holds the number of bytes that are to be allocated for the secondary heap Stack holds the number of bytes for the primary heap symbols contains the size of the symbol table Passing 0 to one or more of these parameters will select a default size toplevel should be a pointer to the toplevel entry point procedure You should pass C toplevel here In any subsequent call to CHICKEN run you can simply pass NULL Calling this function more than once has no effect If enough memory is available and initialization was successful then 1 is returned otherwise this function returns 0 30 3 CHICKEN run C function C word CHICKEN run void toplevel Starts the Scheme program Call this function once to execute all toplevel expressions in your compiled Scheme program If the runtime system was not initialized before then CHICKEN initialize is called with default sizes top Level is the toplevel entry point procedure y
175. nd the extensions may require libraries that are not provided for Windows or work differently Under these circumstances it is recommended to perform the required steps to build an extension manually The required UNIX tools are also available as Windows binaries Google or ask on the CHICKEN mailing list if you need help locating them 35 8 Security When extensions are downloaded and installed one is executing code from potentially compromised systems This applies also when chicken setup executes system tests for required extensions As the code has been retrieved over the network effectively untrusted code is going to be evaluated When chicken setup 1s run as root the whole system is at the mercy of the build instructions note that this is also the case every time you install software via sudo make install so this is not specific to the CHICKEN extension mechanism Security conscious users should never run Chicken setup as root A simple remedy is to set the environment variable CHICKEN REPOSITORY which will transparently place the repository at an arbitrary 35 7 Windows notes 235 CHICKEN User s Manual The User s Manual user selected location Alternatively obtain write execute access to the default location of the repository usually usr local lib chicken to avoid running as root 35 9 Other modes of installation It is possible to install extensions directly from a Subversion repository or from a local checkout by using
176. ne following this marker Runtime options are still recognized i case insensitive Enables the reader to read symbols case insensitive The default is to read case sensitive in violation of R5RS This option registers the Case insensitive feature identifier b batch Quit the interpreter after processing all command line options e eval EXPRESSIONS Evaluate EXPRESSIONS This option implies batch and quiet so no startup message will be printed and the interpreter exits after processing all eval options and or loading files given on the command line p print EXPRESSIONS Evaluate EXPRESSIONS and print the results of each expression using print Implies batch and quiet P pretty print EXPRESSIONS Evaluate EXPRESSIONS and print the results of each expression using pretty print Implies batch and quiet D feature SYMBOL Registers SYMBOL to be a valid feature identifier for cond expand and feature h help Write a summary of the available command line options to standard output and exit I include path PATHNAME Specifies an alternative search path for files included via the include special form This option may be given multiple times If the environment variable CHICKEN INCLUDE PATH is set it should contain a list of alternative include pathnames separated by k keyword style STYLE Enables alternative keyword syntax where STYLE may be either prefix as in Common Lisp or suffix as in DSSSL Any o
177. ned integer integer32 unsigned integer32 integer64 Either a fixnum or a flonum in the range of a unsigned machine int or with 32 64 bit width 29 8 long unsigned long Either a fixnum or a flonum in the range of a unsigned machine Jong or with 32 bit width 29 9 float double A floating point number If an exact integer is passed as an argument then it is automatically converted to a float 29 10 number A floating point number Similar to double but when used as a result type then either an exact integer or a floating point number is returned depending on whether the result fits into an exact integer or not 29 11 symbol A symbol which will be passed to foreign code as a zero terminated string When declared as the result of foreign code the result should be a string and a symbol with the same name will be interned in the symbol table and returned to the caller 29 12 scheme pointer An untyped pointer to the contents of a non immediate Scheme object not allowed as return type The value f is also allowed and is passed as a NULL pointer Don t confuse this type with C pointer which means something different a machine pointer object 29 7 integer unsigned integer integer32 unsigned integer32 integer64 197 CHICKEN User s Manual The User s Manual 29 13 nonnull scheme pointer As scheme pointer but guaranteed not to be f Don t confuse this type with nonnull c pointer which means something diff
178. new values of the parameter even the initial value are passed to this procedure The guard procedure should check the value and or convert it to an appropriate form 12 2 case sensitive If true then read reads symbols and identifiers in case sensitive mode and uppercase characters in symbols are printed escaped Defaults to t 12 3 dynamic load libraries A list of strings containing shared libraries that should be checked for explicitly loaded library units this facility is not available on all platforms See Load Library 12 4 command line arguments Contains the list of arguments passed to this program with the name of the program and any runtime options all options starting with removed 12 Parameters 56 CHICKEN User s Manual The User s Manual 12 5 current read table A read table object that holds read procedures for special non standard read syntax see set read syntax for more information 12 6 exit handler A procedure of a single optional argument When exit is called then this procedure will be invoked with the exit code as argument The default behavior is to terminate the program 12 7 eval handler A procedure of one or two arguments When eval is invoked it calls the value of this parameter with the same arguments The default behavior is to evaluate the argument expression and to ignore the second parameter 12 8 force finalizers If true force and execute all pending finalizers before exiti
179. ng SYMBOL PATTERN in the ENVIRONMENT on the current output port SYMBOL PATTERN A symbol string or regex When symbol or string substring matching is performed ENVIRONMENT An environment When missing the interaction environment is assumed 3t MACROS Keyword argument A boolean Include macro symbols When missing f is assumed 24 1 2 apropos list procedure apropos list SYMBOL PATTERN ENVIRONMENT MACROS Like apropos but returns a list of matching symbols 24 2 Pathname operations 24 2 1 absolute pathname procedure absolute pathname PATHNAME Returns t if the string PATHNAME names an absolute pathname and returns f otherwise 24 Unit utils 162 CHICKEN User s Manual The User s Manual 24 2 2 decompose pathname procedure decompose pathname PATHNAME Returns three values the directory filename and extension components of the file named by the string PATHNAME For any component that is not contained in PATHNAME f is returned 24 2 3 make pathname 24 2 4 make absolute pathname procedure make pathname DIRECTORY FILENAME EXTENSION SEPARATOR procedure make absolute pathname DIRECTORY FILENAME EXTENSION SEPARATOR Returns a string that names the file with the components DIRECTORY FILENAME and optionally EXTENSION with SEPARATOR being the directory separation indicator usually on UNIX systems and on Windows defaulting to whatever platform this is running on
180. ng the program either explicitly by exit or implicitly when the last toplevel expression has been executed Default is t 12 9 implicit exit handler A procedure of no arguments When the last toplevel expression of the program has executed then the value of this parameter is called The default behaviour is to invoke all pending finalizers 12 10 keyword style Enables alternative keyword syntax where STYLE may be either prefix as in Common Lisp or Suffix as in DSSSL Any other value disables the alternative syntaxes 12 11 load verbose A boolean indicating whether loading of source files compiled code if available and compiled libraries should display a message 12 5 current read table 57 CHICKEN User s Manual The User s Manual 12 12 program name The name of the currently executing program This is equivalent to car argv for compiled programs or the filename following the SCript option in interpreted scripts 12 13 repl prompt A procedure that should evaluate to a string that will be printed before reading interactive input from the user in a read eval print loop Defaults to Lambda N gt 12 14 reset handler A procedure of zero arguments that is called via reset The default behavior in compiled code is to invoke the value of exit handler The default behavior in the interpreter is to abort the current computation and to restart the read eval print loop Previous Declarations Next
181. ngs about redefinitions of standard or extended bi call warnings related to known procedure calls ffi warnings related to the foreign function interface dynamic 3 1 Compiler command line format 5 CHICKEN User s Manual The User s Manual This option should be used when compiling files intended to be loaded dynamically into a running Scheme program epilogue FILENAME Includes the file named FILENAME at the end of the compiled source file The include path is not searched This option may be given multiple times emit exports FILENAME Write exported toplevel variables to FILENAME emit external prototypes first Emit prototypes for callbacks defined with def ine external before any other foreign declarations This is sometimes useful when C C code embedded into the a Scheme program has to access the callbacks By default the prototypes are emitted after foreign declarations explicit use Disables automatic use of the units Library eval and extras Use this option if compiling a library unit instead of an application unit extend FILENAME Loads a Scheme source file or compiled Scheme program on systems that support it before compilation commences This feature can be used to extend the compiler This option may be given multiple times The file is also searched in the current include path and in the extension repository extension Mostly equivalent to prelude define extension lt NAME gt where lt NAME gt is the basen
182. nker complain about a missing function C toplevel 247 38 5 4 Why does my program crash when I compile a file with unsafe or unsafe declarations 247 38 5 5 Why do I get a warning when I define a global variable named match 248 38 5 6 Why don t toplevel continuations captured in interpreted code Work cooooconncnnincicnncccnnccccancnnns 248 38 5 7 Why does define reader ctor not work in my compiled program cooooccnnnccnnonininnnnnnnccnnnnonancn nn 248 38 5 8 Why do built in units such as srfi 1 srfi 18 and posix fail to load 249 38 5 9 How can I increase the size of the trace shown when runtime errors are detected 249 SIRO DISHES EI ODE CE titi 249 38 6 1 How can I obtain smaller executables nnn nennen nnne 249 38 6 2 How can I obtain faster executables ococccinnncncccococincnnanananannanananono non cnn cnn nnono conoce nonononocononanos 250 38 6 3 Which non standard procedures are treated specially when the extended bindings or usual integrations declaration or compiler option is USC cooooonoccconocaniccccnncccnnncconnncnnnanono conan ccnncccnnnno 250 38 6 4 Can I load compiled code at runtime 0 eee cccceeseeececeeeeesaeeeeaaeceeaeceeeeeceaeeeaecseaaeceaeeceeeeees 251 38 7 Garbage RT 251 38 7 1 Why does a loop that doesn t cons still trigger garbage collections 251 38 7 2 W
183. not seen outside of the containing source file Accesses to foreign variables are translated directly into C constructs that access the variable so the Scheme name given to that variable does only exist during compile time The same goes for constant and inline definitions The name is only there to tell the compiler that this reference is to be replaced with the actual value 38 FAQ 241 CHICKEN User s Manual The User s Manual 38 1 4 How does cond expand know which features are registered in used units Each unit used via declare uses is registered as a feature and so a symbol with the unit name can be tested by cond expand during macro expansion time Features registered using the register feature procedure are only available during run time of the compiled file You can use the eval when form to register features at compile time 38 1 5 Why are constants defined by define constant not honoured in case constructs case expands into a cascaded if expression where the first item in each arm is treated as a quoted list So the Case macro can not infer wether a symbol is to be treated as a constant name defined via define constant or a literal symbol 38 1 6 How can I enable case sensitive reading writing in user code To enable the read procedure to read symbols and identifiers case sensitive you can set the parameter case sensitivity to t 38 1 7 How can I change match error control during compilation Use eva
184. ns a NULL pointer or f otherwise 26 1 6 objectpointer procedure object gt pointer X Returns a pointer pointing to the Scheme object X which should be a non immediate object Note that data in the garbage collected heap moves during garbage collection 26 1 7 pointer procedure pointer X Returns t if X is a foreign pointer object and f otherwise 26 1 8 pointer procedure pointer PTR1 PTR2 Returns t if the pointer like objects PTR1 and PTR2 point to the same address 26 1 9 pointeraddress procedure pointer gt address PTR Returns the address to which the pointer PTR points 26 1 10 pointerobject procedure pointer gt object PTR Returns the Scheme object pointed to by the pointer PTR 26 1 5 null pointer 175 CHICKEN User s Manual The User s Manual 26 1 11 pointer offset procedure pointer offset PTR N Returns a new pointer representing the pointer PTR increased by N 26 1 12 pointer u8 ref procedure pointer u8 ref PTR Returns the unsigned byte at the address designated by PTR 26 1 13 pointer s8 ref procedure pointer s8 ref PTR Returns the signed byte at the address designated by PTR 26 1 14 pointer u16 ref procedure pointer ul6 ref PTR Returns the unsigned 16 bit integer at the address designated by PTR 26 1 15 pointer s16 ref procedure pointer s16 ref PTR Returns the signed 16 bit integer at the address designated by PTR 26 1 16 pointer u32
185. nt is the complete match If the optional argument START is supplied it specifies the starting position in STRING For each matching group the result list contains either f for a non matching but optional group a list of start and end position of the match in STRING in the case of string match positions or the matching substring in the case of string match Note that the exact string is matched For searching a pattern inside a string see below Note also that st ring match is implemented by calling st ring search with the regular expression wrapped in If invoked with a precompiled regular expression argument by using regexp string match is identical to string search 21 10 string search 21 11 string search positions procedure string search REGEXP STRING START RANGE procedure string search positions REGEXP STRING START RANGE Searches for the first match of the regular expression in REGEXP with STRING The search can be limited to RANGE characters 21 12 string split fields procedure string split fields REGEXP STRING MODE START Splits STRING into a list of fields according to MODE where MODE can be the keyword infix REGEXP matches field separator the keyword suf f ix REGEXP matches field terminator or t REGEXP matches field which is the default define s this is a string 1 2 3 string split fields s gt this is a string 1 2 3 string split
186. nt previously This for should only be used at top level 9 3 9 parameterize 37 CHICKEN User s Manual The User s Manual 9 4 2 define inline syntax define inline NAME VAR VAR BODY syntax define inline NAME EXP Defines an inline procedure Any occurrence of NAME will be replaced by EXP or Lambda VAR VAR BODY This is similar to a macro but variable names and scope will be correctly handled Inline substitutions take place after macro expansion EXP should be a lambda expression Any reference to NAME should appear textually after its definition Note that inline procedures are local to the current compilation unit and are not available outside of the source file in which they are defined Names of inline procedures still exist in the Scheme namespace and can be lexically shadowed This construct is equivalent to def ine when evaluated or interpreted Inline definitions should only appear at toplevel 9 4 3 define macro syntax define macro NAME VAR VAR EXP1 syntax define macro NAME lambda VAR VAR EXP1 syntax define macro NAME1 NAME2 Define a globally visible macro special form The macro is available as soon as it is defined i e it is registered at compile time If the file containing this definition invokes eval and the declaration run time macros or the command line option run time macros has been used then the macro is visible in evaluated expressions d
187. nt size Returns a textual description of the most recent error that occurred in executing embedded Scheme code 30 14 CHICKEN yield C macro int CHICKEN yield int status If threads have been spawned during earlier invocations of embedded Scheme code then this function will run the next scheduled thread for one complete time slice This is useful for example inside an idle handler in a GUI application with background Scheme threads Note that the s rf 1 18 library unit has to be linked in for this 30 9 CHICKEN apply 205 CHICKEN User s Manual The User s Manual An example cat x scm 121 X SCm define bar x gc x x define external baz int i double sqrt i return to host cat y c eames a mes include lt chicken h gt include lt assert h gt extern double baz int int main char buffer 256 int status C word val C SCHEME UNDEFINED C word data 1 data 0 aval CHICKEN run C toplevel status CHICKEN read bar 99 amp val assert status C gc protect data 1 printf data 08x n val status CHICKEN eval string to string bar buffer 255 assert status CHICKEN get error message buffer 255 printf ouch s n buffer status CHICKEN eval string to string bar 23 buffer 255 assert status printf gt s n buffer printf data 08x n val status CHICKEN eval to string val buffer 255 a
188. nual exn runtime Limit Signaled when an internal limit is exceeded like running out of memory exn match Signaled on errors raised by failed matches see the section on mat ch exn syntax Signaled on syntax errors exn breakpoint Signaled when a breakpoint is reached Notes e All error exceptions of the kind exn are non continuable e Error exceptions of the exn kind have additional arguments and Location properties that contain the arguments passed to the exception handler and the name of the procedure where the error occurred if available When the posix unit is available and used then a user interrupt signal int signals an exception of the kind user interrupt e the procedure condition property accessor accepts an optional third argument If the condition does not have a value for the desired property and if the optional argument is given no error is signaled and the accessor returns the third argument e In composite conditions all properties are currently collected in a single property list so in the case that to conditions have the same named property only one will be visible 13 8 Environment information and system interface 13 8 1 argv procedure argv Return a list of all supplied command line arguments The first item in the list is a string containing the name of the executing program The other items are the arguments passed to the application This list is freshly created on every in
189. ocedure regexp escape STRING Escapes all special characters in STRING with so that the string can be embedded into a regular expression regexp escape 0 9 4 y VANA TAZOQONN NS we VAN ENN VN H AN e I KANENN gt AAWL O S N AE a An AVAS 21 16 make anchored pattern procedure make anchored pattern REGEXP WITHOUT BOL WITHOUT EOL Makes an anchored pattern from REGEXP a string or a precompiled regular expression and returns the updated pattern When WITHOUT BOL is t the beginning of line anchor is not added When 21 13 string substitute 121 CHICKEN User s Manual The User s Manual WITHOUT EOL is t the end of line anchor is not added The WITHOUT BOL and WITHOUT EOL arguments are ignored for a precompiled regular expression Previous Unit match Next Unit srfi 18 21 16 make anchored pattern 122 22 Unit srfi 18 A simple multithreading package This threading package follows largely the specification of SRFI 18 For more information see the documentation for SRFI 18 Notes e thread start accepts a thunk a zero argument procedure as argument which is equivalent to thread start make thread THUNK e thread sleep accepts a seconds real number value in addition to a time object e When an uncaught exception i e an error is signalled in a thread other than the primordial thread and warnings are enabled see enable warnings then a warning message is written to the p
190. oehlke T Kurt Bond Ashley Bone Dominique Boucher Terence Brannon Roy Bryant Adam Buchbinder Hans Bulfone Category 5 Taylor Campbell Naruto Canada Esteban U Caamano Castro Franklin Chen Thomas Chust Gian Paolo Ciceri John Cowan Grzegorz Chrupa amp 322 a James Crippen Tollef Fog Heen Alejandro Forero Cuervo Linh Dang Brian Denheyer dgym Don Chris Double Jarod Eells Petter Egesund Steve Elkins Daniel B Faken Will Farr Graham Fawcett Marc Feeley Fizzie Kimura Fuyuki Tony Garnock Jones Martin Gasbichler Joey Gibson Stephen C Gilardi Joshua Griffith Johannes Groedem Damian Gryski Mario Domenech Goulart Andreas Gustafsson Sven Hartrumpf Jun ichiro itojun Hagino Ahdi Hargo Matthias Heiler Karl M Hegbloom William P Heinemann Bill Hoffman Bruce Hoult Hans Huebner Markus Huelsmann Goetz Isenmann Paulo Jabardo David Janssens Christian Jaeger Dale Jordan Valentin Kamyshenko Daishi Kato Peter Keller Brad Kind Ron Kneusel Matthias Koeppe Krysztof Kowa amp 322 czyk Andre Kuehne Todd R Kueny Sr Goran Krampe David Krentzlin Ben Kurtz Micky Latowicki John Lenz Kirill Lisovsky Juergen Lorenz Kon Lovett Dennis Marti Charles Martin Bob MclIsaac Alain Mellan Eric Merrit Perry Metzger Scott G Miller Mikael Bruce Mitchener Chris Moline Eric E Moore Julian Morrison Dan Muresan Lars Nilsson Ian Oversby o t Gene Pavlovsky Levi Pearson Nicolas Pelletier Carlos Pita Robin Lee Powell P
191. of DIRECTORY which should be a string and invokes the procedure ACTION for all files in which the procedure PREDICATE is true PREDICATE may me a procedure of one argument or a regular expression string ACTION should be a procedure of two arguments the currently encountered file and the result of the previous invocation of ACTION or if this is the first invocation the value of IDENTITY ACTION defaults to cons IDENTITY defaults to LIMIT should be a procedure of one argument that is called for each nested directory and which should return true if that directory is to be traversed recursively LIMIT may also be an exact integer that gives the maximum recursion depth For example a depth of H means that only files in the top level specified directory are to be traversed In this case all nested directories are ignored LIMIT may also be f the default which is equivalent to constantly t Note that ACTION is called with the full pathname of each file including the directory prefix 23 18 19 errno pipe 153 CHICKEN User s Manual The User s Manual 23 20 Getting the hostname and system information 23 20 1 get host name procedure get host name Returns the hostname of the machine that this process is running on 23 20 2 system information procedure system information Invokes the UNIX system call uname and returns a list of 5 values system name node name OS release OS version and machine 23 21 Setting the f
192. ompiled executable use foo 3628800 If you geta foo command not found error you might want to try with f o0 instead or in Unix machines modify your PATH environment variable to include your current directory 3 3 1 A simple example with one source file CHICKEN User s Manual The User s Manual 3 3 2 An example with multiple files If multiple bodies of Scheme code are to be combined into a single executable then we have to compile each file and link the resulting object files together with the runtime system Let s consider an example where your program consists of multiple source files 3 3 2 1 Writing your source files The declarations in these files specify which of the compiled files is the main module and which is the library module An executable can only have one main module since a program has only a single entry point In this case foo scm is the main module because it doesn t have a uni t declaration ez T EEN The declaration marks this source file as dependant on the symbols provided by the bar unit declare uses bar write fac 10 newline bar scm will be our library bar scm The declaration marks this source file as the bar unit The names of the units and your files don t need to match declare unit bar define fac n if zero n 1 n fac n 1 3 3 2 2 Compiling and running your program You should compile your two files with the following commands csc
193. oneesetoovessovevasevevassvaesbavatsavasusneanaeases 38 9 4 4 Tree 38 9 5 Conditional reg E 38 S RR E Let POP OP E N EE E E 39 VE E EE 39 VE 39 9 6 Record structures ia 39 9 6 Be Kee WEE 39 ENANOS ss sia geed iiiter tede teen de ettet re tbe Und dee ente Coe ee HR ED Ue EU pe rto de enean 40 A E 40 OF ET C a REST LR ee 40 MEE OL 40 EN BASIL RO IU NETT 41 EE 41 ARA NN 41 9 75 Ste 42 A O a e E a e a a a 42 S AO a ida O OEE E E 42 TU Pater rto DEDE uiae vr pir HIS EHFERHE EXER EVER DE EEERRE ERE RE HERE RU FEE E EREEE RE EREEEL E FIR HERE Ee EHE RE PERO AREE AREE RREN 43 10 1 Pattern Matching Expressions seses necir seie iieri enne iisi eased san ien iiei 43 LASS SE EE 45 10 3 Match ECHT iii ii A AAA A iaa 47 10 4 R cord Structures Pattern din adenda dias 47 HERB o SAEI CIO E 48 A 49 VD EE 49 NES 49 RR Beie 49 INE Bde E 49 RR e 49 CHICKEN User s Manual The User s Manual Chicken User s Manual 11 Declarations 11 6 bound to procedute ree eter re eerte eee cava reato tena ek ERR Freie e te Rete edu Ee ree CL eo deua 50 LUCO ele E 50 NEE EE 50 TD SO CONS tami EE 50 T1 TO E TE 50 11 11 emit exports icto eer eer rer e Pee PEL DR ER EEG ARE ORE RE e d EE E 50 11 12 mit external prototypes fTIrst EE 51 11 13 disable intetrrupts corem eere oret EE Eege de edd ged XR RS AERE diia 51 INEA nee tert ON 51 IN EEUU H 51 RBS
194. open file lock fentl file position ftell lseek file read read file read access access file select select file control fentl file stat 23 23 How Scheme procedures relate to UNIX C functions 156 CHICKEN User s Manual The User s Manual stat file test lock fentl file truncate truncate ftruncate file unlock fentl file write write file write access access get groups getgroups get host name gethostname initialize groups initgroups local time seconds mktime local timezone abbreviation localtime map file to memory mmap open input file fdopen open output file fdopen Open input pipe popen open output pipe popen port gt fileno fileno process execute 23 23 How Scheme procedures relate to UNIX C functions 157 CHICKEN User s Manual The User s Manual execvp process fork fork process group id getpgid process signal kill process wait waitpid close input pipe pclose close output pipe pclose read symbolic link readlink seconds gt lLocal time localtime seconds gt string ctime seconds gt utc time gmtime set alarm alarm set buffering mode setvbuf set file position fseek seek set groups setgroups set signal mask sigprocmask set group id setgid set process group id 23 23 How Scheme procedures relate to UNIX C functions 158 CHICKEN User s Manual The User s Manual setpgid set user i
195. ord consisting of three consecutive dots ie or two dots and an non negative integer eg 1 2 or three consecutive underscores ie L or two underscores and a non negative integer The keywords K and k are equivalent The keywords 0 and 0 are equivalent The next subsection describes the various patterns The match Lambda and match Lambda forms are convenient combinations of mat ch and Lambda and can be explained as follows match lambda pat body match lambda pat body Lambda x match x pat body Lambda x match x pat body 10 1 Pattern Matching Expressions 44 CHICKEN User s Manual The User s Manual where X is a unique variable The match Lambda form is convenient when defining a single argument function that immediately destructures its argument The match Lambda form constructs a function that accepts any number of arguments the patterns of match Lambda should be lists The match let match Let match Letrec and natch define forms generalize Scheme s Let let Letrec and define expressions to allow patterns in the binding position rather than just variables For example the following expression match let x y z list 1 2 3 body binds X to 1 y to 2 and Z to 3 in body These forms are convenient for destructuring the result of a function that returns multiple values as a list or vector As usual for Let rec and define patte
196. ore characters that would fit into STRING If START is given then the read characters are stored starting at that position read st ring returns the actual number of characters read 15 8 14 read token procedure read token PREDICATE PORT Reads characters from PORT which defaults to the value of current input port and calls the procedure PREDICATE with each character until PREDICATE returns false Returns a string with the accumulated characters 15 8 15 with error output to port procedure with error output to port PORT THUNK Call procedure THUNK with the current error output port temporarily bound to PORT 15 8 10 read lines 99 CHICKEN User s Manual The User s Manual 15 8 16 with input from port procedure with input from port PORT THUNK Call procedure THUNK with the current input port temporarily bound to PORT 15 8 17 with output to port procedure with output to port PORT THUNK Call procedure THUNK with the current output port temporarily bound to PORT 15 9 Strings 15 9 1 conc procedure conc X Returns a string with the string represenation of all arguments concatenated together CONC could be implemented as define conc args apply string append map gt string args 15 9 2 string procedure gt string X Returns a string representation of X 15 9 3 string chop procedure string chop STRING LENGTH Returns a list of substrings taken by chopping STRING every LENG
197. ormation see the documentation for SRFI 10 8 4 Syntax Expression EXPRESSION An abbreviation for Syntax EXPRESSION 8 5 Location Expression EXPRESSION An abbreviation for Location EXPRESSION 8 Non standard read syntax 28 CHICKEN User s Manual The User s Manual 8 6 Keyword SYMBOL Syntax for keywords Keywords are symbols that evaluate to themselves and as such don t have to be quoted 8 7 Multiline String Constant lt lt TAG Specifies a multiline string constant Anything up to a line equal to TAG or end of file will be returned as a single string define msg lt lt END Hello world she said END is equivalent to define msg Hello world she said 8 8 Multiline String Constant with Embedded Expressions lt TAG Similar to lt lt but allows substitution of embedded Scheme expressions prefixed with and optionally enclosed in curly brackets Two consecutive s are translated to a single define three 3 display lt HEOF This is a simple string with an embedded character and substituted expressions three 99 gt three 99 three is three EOF prints This is a simple string with an embedded character and substituted expressions three 99 gt 102 three is 3 8 6 Keyword 29 CHICKEN User s Manual The User s Manual 8 9 Foreign Declare gt dH Abbreviation for foreign declare 8 10 Sharp Pre
198. ort If LENGTH is f the vector will be filled completely until end of file is reached 17 43 read u8vector procedure read u8vector LENGTH U8VECTOR PORT START Reads LENGTH bytes from the PORT writing the read input into UBVECTOR beginning at START or 0 if not given PORT defaults to the value of current input port If LENGTH is f the vector will be filled completely until end of file is reached This procedure returns the number of bytes read 17 44 write u8vector procedure write u8vector U8VECTOR PORT START END Writes the bytes U8VECTOR between the indices START inclusive and END exclusive to PORT PORT defaults to the value of current output port Previous Unit srfi 1 Next Unit srfi 13 17 41 subf64vector 113 18 Unit srfi 13 String library see the documentation for SRFI 13 On systems that support dynamic loading the srfi 13 unit can be made available in the interpreter CSi by entering require extension srfi 13 Previous Unit srfi 4 Next Unit srfi 14 18 Unit srfi 13 114 19 Unit srfi 14 Character set library see the documentation for SREI 14 On systems that support dynamic loading the srfi 14 unit can be made available in the interpreter CSi by entering require extension srfi 14 This library provides only the Latin 1 character set Previous Unit srfi 13 Next Unit match 19 Unit srfi 14 115 20 Unit match The runtime support code for the Pattern Mat
199. ort that is the value of current error port e Blocking I O will block all threads except for some socket operations see the section about the tcp unit An exception is the read eval print loop on UNIX platforms waiting for input will not block other threads provided the current input port reads input from a console e It is generally not a good idea for one thread to call a continuation created by another thread if dynamic wind is involved e When more than one thread compete for the current time slice the thread that was waiting first will become the next runnable thread e The dynamic environment of a thread consists of the following state The current input output and error port The current exception handler 4 The values of all current parameters created by make parameter Any pending dynamic wind thunks The following procedures are provided in addition to the procedures defined in SRFI 18 22 1 thread signal procedure thread signal THREAD X This will cause THREAD to signal the condition X once it is scheduled for execution After signalling the condition the thread continues with its normal execution 22 2 thread quantum procedure thread quantum THREAD Returns the quantum of THREAD which is an exact integer specifying the approximate time slice of the thread in milliseconds 22 Unit srfi 18 123 CHICKEN User s Manual The User s Manual 22 3 thread quantum set procedure thread quantum
200. osition FILE POSITION WHENCE procedure set file position FILE POSITION Sets the current read write position of FILE to POSITION which should be an exact integer FILE should be a port or a file descriptor WHENCE specifies how the position is to interpreted and should be one of the values seek set seek cur and seek end It defaults to seek set Exceptions exn bounds exn i o file 23 7 3 change file mode procedure change file mode FILENAME MODE Changes the current file mode of the file named FILENAME to MODE using the chmod system call The perm variables contain the various permission bits and can be combinded with the bitwise ior procedure 23 7 4 change file owner procedure change file owner FILENAME UID GID Changes the owner information of the file named FILENAME to the user and group ids UID and GID which should be exact integers using the chown system call 23 8 Processes 23 8 1 current process id procedure current process id Returns the process ID of the current process 23 7 1 file truncate 137 CHICKEN User s Manual The User s Manual 23 8 2 parent process id procedure parent process id Returns the process ID of the parent of the current process 23 8 3 process group id procedure process group id PID Returns the process group ID of the process specified by PID 23 8 4 process execute procedure process execute PATHNAME ARGUMENT LIST ENVIRONMENT LIST
201. ou usually pass C toplevel here The result value is the continuation that can be used to re invoke the Scheme code from the point after it called return to host see below If you just need a Scheme interpreter you can also pass CHICKEN default toplevel as the toplevel procedure which just uses the default library units Once CHICKEN run has been called Scheme code is executing until all toplevel expressions have been evaluated or until return to host is called inside the Scheme program 30 Embedding 203 CHICKEN User s Manual The User s Manual 30 4 return to host procedure return to host Exits the Scheme code and returns to the invoking context that called CHICKEN_ run or CHICKEN continue After return to host has been executed and once CHICKEN run returns you can invoke callbacks which have been defined with def ine external The eval library unit also provides boilerplate callbacks that simplify invoking Scheme code embedded in a C or C application a lot 30 5 CHICKEN eval C macro int CHICKEN eval C word exp C word result Evaluates the Scheme object passed in exp writing the result value to result The return value is 1 if the operation succeeded or 0 if an error occurred Call CHICKEN get error message to obtain a description of the error 30 6 CHICKEN eval string C macro int CHICKEN eval string char str C word result Evaluates the Scheme expression passed in the string Str writing the result
202. pe bits C STRUCTURE TYPE The first slot contains a symbol that specifies the kind of structure this record is an instance of The other slots contain the actual record items pointers a special vector object type bits C POINTER TYPE The single slot contains a machine pointer tagged pointers similar to a pointer type bits C TAGGED POINTER TYPE but the object contains an additional slot with a tag an arbitrary data object that identifies the type of the pointer Data objects may be allocated outside of the garbage collected heap as long as their layout follows the above mentioned scheme But care has to be taken not to mutate these objects with heap data i e non immediate objects because this will confuse the garbage collector For more information see the header file chicken bh Previous chicken setup Next Bugs and limitations 36 2 Non immediate objects 239 37 Bugs and limitations Compiling large files takes too much time e If a known procedure has unused arguments but is always called without those parameters then the optimizer repairs the procedure in certain situations and removes the parameter from the lambda list e port position currently works only for input ports e Leaf routine optimization can theoretically result in code that thrashes if tight loops perform excessively many mutations Previous Data representation Next FAQ 37 Bugs and limitations 240 38 FAQ This is the list of Frequently
203. pectively procedure fx N1 N2 procedure fx N1 N2 procedure fx N1 N2 procedure fx N1 N2 procedure fxmod N1 N2 procedure fxneg N procedure fxmin N1 N2 procedure fxmax N1 N2 procedure fx N1 N2 procedure fx N1 N2 procedure fx N1 N2 procedure fx gt N1 N2 procedure fx N1 N2 procedure fxand N1 N2 procedure fxior N1 N2 procedure fxxor N1 N2 procedure fxnot N procedure fxshl N1 N2 procedure fxshr N1 N2 13 1 6 Arithmetic floating point operations In safe mode these procedures throw a type error with non float arguments except f Lonum which returns f In unsafe mode these procedures do not check their arguments A non flonum argument in unsafe mode can crash the system procedure flonum X procedure fp X Y procedure fp X Y procedure fp X Y procedure fp X Y procedure fpneg X procedure fpmin X Y procedure fpmax X Y procedure fp X Y procedure fp X Y procedure fp X Y procedure fp gt X Y procedure fp X Y 13 1 5 Arithmetic fixnum operations 60 CHICKEN User s Manual The User s Manual 13 1 7 signum procedure signum N Returns 1 if N is positive 1 if N is negative or 0 if N is zero Signum is exactness preserving 13 1 8 finite procedure finite N Returns f if N is negative or positive infinity and t otherwise 13 2 File Input Output 13 2 1 current outpu
204. port and invokes the current exception handler This conforms to SREL23 If LOCATION is given and a symbol it specifies the location the name of the procedure where the error occurred 13 10 3 get call chain procedure get call chain START THREAD Returns a list with the call history Backtrace information is only generated in code compiled without no trace and evaluated code If the optional argument START is given the backtrace starts at this offset i e when START is 1 the next to last trace entry is printed and so on If the optional argument THREAD is given then the call chain will only be constructed for calls performed by this thread 13 9 3 current seconds 71 CHICKEN User s Manual The User s Manual 13 10 4 print call chain procedure print call chain PORT START THREAD Prints a backtrace of the procedure call history to PORT which defaults to current output port 13 10 5 print error message procedure print error message EXN PORT STRING Prints an appropriate error message to PORT which defaults to the value of current output port for the object EXN EXN may be a condition a string or any other object If the optional argument STRING is given it is printed before the error message STRING defaults to Error 13 10 6 procedure information procedure procedure information PROC Returns an s expression with debug information for the procedure PROC or f if PROC has no associ
205. r 221 CHICKEN User s Manual The User s Manual 34 46 C pre gc hook C Variable void C pre gc hook int mode If not NULL the function pointed to by this variable will be called before each garbage collection with a flag indicating what kind of collection was performed either 0 for a minor collection or 2 for a resizing collection A resizing collection means a secondary collection that moves all live data into a enlarged or shrinked heap space Minor collections happen very frequently so the hook function should not consume too much time The hook function may not invoke Scheme callbacks Note that resizing collections may be nested in normal major collections 34 47 C post gc hook C Variable void C post gc hook int mode long ms If not NULL the function pointed to by this variable will be called after each garbage collection with a flag indicating what kind of collection was performed either O for a minor collection 1 for a major collection or 2 for a resizing collection Minor collections happen very frequently so the hook function should not consume too much time The hook function may not invoke Scheme callbacks The ms argument records the number of milliseconds required for the garbage collection if the collection was a major one For minor collections the value of the mS argument is undefined 34 48 An example for simple calls to foreign code involving callbacks cat foo scm gt extern int callout int in
206. r or Cdr rather than to signal an error 1 fail unspecified Non matching expressions will either fail in Car or Cdr or return an unspecified value This mode applies to files compiled with the unsafe option or declaration When an error is signalled the raised exception will be of kind exn match procedure match error procedure match error procedure PROCEDURE Sets or returns the procedure called upon a match error The procedure takes one argument the value which failed to match When the error control mode is match a second argument the source form of the match expression is available 10 4 Record Structures Pattern The pattern handles native record structures and SREL 9 records transparently Currently it is required that SREI 9 record predicates are named exactly like the record type name followed by a question mark character 10 3 Match Failure 47 CHICKEN User s Manual The User s Manual 10 5 Code Generation Pattern matching macros are compiled into i f expressions that decompose the value being matched with standard Scheme procedures and test the components with standard predicates Rebinding or lexically shadowing the names of any of these procedures will change the semantics of the match macros The names that should not be rebound or shadowed are null pair number string symbol boolean char procedure vector list equal car cdr cadr cdddr vector length vector ref reverse Length cal
207. racter an equal character s expression an equal s expression 10 Pattern matching 43 CHICKEN User s Manual The User s Manual pat 1 pat n a proper list of n elements pat 1 pat n pat n 1 a list of n or more elements pat 1 pat n pat n 1 k a proper list of n k or more elements 1 pat 1 pat n a vector of n elements pat 1 pat n pat n 1 k a vector of n k or more elements struct pat 1 pat n a structure field pat a field of a structure and pat 1 pat n if all of pat 1 through pat n match or pat 1 pat n if any of pat 1 through pat n match not pat 1 pat n if none of pat 1 through pat n match predicate pat 1 pat n if predicate true and pat 1 through pat n all matc set identifier anything and binds identifier as a setter get identifier anything and binds identifier as a getter gp a quasipattern qp itself the empty list Ft itself f itself string an equal string number an equal number character an equal character symbol an equal symbol qp 1 qp n a proper list of n elements qp 1 qp n qp n 1 a list of n or more elements qp 1 qp n qp n 1 k a proper list of n k or more elements qp 1 qp n a vector of n elements qp 1 qp n qp n 1 k a vector of n k or more elements pat a pattern pat a pattern spliced The notation k denotes a keyw
208. ree string split one two three gt string split foo bar baz t gt foo bar baz 15 9 4 string chomp 101 CHICKEN User s Manual The User s Manual 15 9 8 string translate procedure string translate STRING FROM TO Returns a fresh copy of STRING with characters matching FROM translated to TO If TO is omitted then matching characters are removed FROM and TO may be a character a string or a list If both FROM and TO are strings then the character at the same position in TO as the matching character in FROM is substituted 15 9 9 string translate procedure string translate STRING SMAP Substitutes elements of STRING according to SMAP SMAP should be an association list where each element of the list is a pair of the form MATCH REPLACEMENT Every occurrence of the string MATCH in STRING will be replaced by the string REPLACEMENT string translate lt hl gt this is a string lt h1 gt Lt gt this is a amp qu 15 9 10 substring procedure substring STRING1 STRING2 START1 START2 LENGTH procedure substring ci STRING1 STRING2 START1 START2 LENGTH Returns t if the strings STRING1 and STRING2 are equal or f otherwise The comparison starts at the positions START1 and START2 which default to 0 comparing LENGTH characters which defaults to the minimum of the remaining length of both strings 15 9 11 substring index
209. rfi 18 will silently fail This typically happens because the Chicken libraries have been installed in a non standard location such as your home directory The workaround is to explicitly tell the dynamic linker where to look for your libraries export DYLD LIBRARY PATH scheme chicken lib DYLD LIBRARY PATH Mac export LD LIBRARY PATH scheme chicken lib LD LIBRARY PATH SS Linux 38 5 9 How can increase the size of the trace shown when runtime errors are detected When a runtime error is detected Chicken will print the last entries from the trace of functions called unless your executable was compiled with the no trace option By default only 16 entries will be shown To increase this number pass the aN parameter to your executable 38 6 Optimizations 38 6 1 How can I obtain smaller executables If you don t need eval or the stuff in the extras library unit you can just use the Library unit declare uses library dilebley world n Don t forget to compile with the explicit use option Compiled with Visual C this generates an executable of around 240 kilobytes It is theoretically possible to compile something without the library but a program would have to implement quite a lot of support code on its own 38 5 7 Why does define reader ctor not work in my compiled program 249 CHICKEN User s Manual The User s Manual 38 6 2 How can obtain faster executables There are a number of declaration spe
210. rgs print Hi car args 0 csi ss hi scm you you csi q l l hi scm 2 gt main list ye all i ye all i k C ID E E VIP 3 gt 4 3 Toplevel commands The toplevel loop understands a number of special commands 32 Show summary of available toplevel commands J FILENAME Load files with given FILENAMEs In FILENAME Load files and print result s of each top level expression p EXP Pretty print evaluated expression EXP d EXP Describe result of evaluated expression EXP du EXP Dump contents of the result of evaluated expression EXP ur EXP N Dump N bytes of the result of evaluated expression EXP exn Describes the last exception that occurred and adds it to the result history it can be accessed using the notation 4 Quit the interpreter T Show system information S TEXT Execute shell command t EXP Evaluate form and print elapsed time A EXP Pretty print macroexpanded expression EXP the expression is not evaluated t SYMBOL Enables tracing of the toplevel procedures with the given names 1 gt fac 10 3628800 2 gt tr fac 3 gt fac 3 fac 3 fac 2 4 2 Writing Scheme scripts 17 CHICKEN User s Manual The User s Manual fac 1 fac 0 fac gt 1 fac gt 1 fac gt 2 fac gt 6 gt 6 4 gt utr fac 5 gt fac 3 gt 6 k tr SYMBOL Disables tracing of the given toplevel procedures br SYMBOL Se
211. rm This option may be given multiple times If the environment variable CHICKEN INCLUDE PATH is set it should contain a list of alternative include pathnames separated by inline Enable procedure inlining for known procedures of a size below the threshold which can be set through the inline Limit option inline limit THRESHOLD Sets the maximum size of a potentially inlinable procedure The default threshold is 10 keyword style STYLE 3 1 Compiler command line format 6 CHICKEN User s Manual The User s Manual Enables alternative keyword syntax where STYLE may be either prefix as in Common Lisp suffix as in DSSSL or none Any other value is ignored The default is suf fix keep shadowed macros Do not remove macro definitions with the same name as assigned toplevel variables the default is to remove the macro definition lambda lift Enable the optimization known as lambda lifting no lambda info Don t emit additional information for each Lambda expression currently the argument list after alpha conversion renaming no trace Disable generation of tracing information If a compiled executable should halt due to a runtime error then a list of the name and the line number if available of the last procedure calls is printed unless no trace is specified With this option the generated code is slightly faster no warnings Disable generation of compiler warnings nursery NUMBER stack size NUMBER Sets the size of th
212. rn variables bound by match letrec and match define should not be used in computing the bound value The match match Lambda and match Lambda forms allow the optional syntax gt identifier between the pattern and the body of a clause When the pattern match for such a clause succeeds the identifier is bound to a failure procedure of zero arguments within the body If this procedure is invoked it jumps back to the pattern matching expression and resumes the matching process as if the pattern had failed to match The body must not mutate the object being matched otherwise unpredictable behavior may result 10 2 Patterns identifier excluding the reserved names and or not set get and Kfor non negative integers K matches anything and binds a variable of this name to the matching value in the body _ matches anything without binding any variables t f string number character s expression These constant patterns match themselves i e the corresponding value must be equal to the pattern pat 1 pat n matches a proper list of n elements that match pat 1 through pat n pat 1 pat n pat n 1 matches a possibly improper list of at least n elements that ends in something matching pat n 1 pat 1 pat n pat n 1 matches a proper list of n or more elements where each element of the tail matches pat n 1 Each pattern variable in pat n 1 is bound to a list of the ma
213. roperties are currently ignored The FILELIST argument may also be a single string 35 4 1 install extension 226 CHICKEN User s Manual The User s Manual 35 4 2 install program procedure install program ID FILELIST INFOLIST Similar to install extension but installs an executable program in the executable path usually usr local bin 35 4 3 install script procedure install script ID FILELIST INFOLIST Similar to install program but additionally changes the file permissions of all files in FILELIST to executable for installing shell scripts 35 4 4 run syntax run FORM Runs the shell command FORM which is wrapped in an implicit quasiquote run csc is treated specially and passes V if verbose has been given to chicken setup and feature compiling extension options to the compiler 35 4 5 compile syntax compile FORM Equivalent to run csc FORM 35 4 6 make syntax make TARGET DEPENDENT COMMAND ARGUMENTS A make macro that executes the expressions COMMAND when any of the dependents DEPENDENT have changed to build TARGET This is the same as the make extension which is available separately For more information see make 35 4 7 patch procedure patch WHICH REGEX SUBST 35 4 2 install program 227 CHICKEN User s Manual The User s Manual Replaces all occurrences of the regular expression REGEX with the string SUBST in the file gi
214. rt 2 with input from string 1 2 f0f0f0 3 read gt 1 2 240 240 240 3 If CHAR OR SYMBOL is a symbol then a so called read mark handler is defined In that case the handler procedure will be called when a character sequence of the form SYMBOL is encountered You can undo special handling of read syntax by passing f as the second argument if the syntax was previously defined via set read syntax Note that all of CHICKEN s special non standard read syntax is handled directly by the reader To disable built in read syntax define a handler that triggers an error for example 13 22 3 set sharp read syntax procedure set sharp read syntax CHAR OR SYMBOL PROC Similar to set read syntax but allows defining new lt CHAR gt reader syntax If the first argument is a symbol then this procedure is equivalent to set read syntax 13 22 4 set parameterized read syntax procedure set parameterized read syntax CHAR OR SYMBOL PROC Similar to set sharp read syntax but intended for defining reader syntax of the form lt NUMBER gt lt CHAR gt The handler procedure PROC will be called with two arguments the input port and the number preceding the dispatching character If the first argument is a symbol then this procedure is equivalent to set read syntax 13 22 5 copy read table procedure copy read table READ TABLE Returns a copy of the given read table You can access
215. rue if the list or vector SEQUENCE is already sorted 15 7 Random numbers 15 7 1 random procedure random N Returns an exact random integer from 0 to N 1 15 5 11 queue push back list 96 CHICKEN User s Manual The User s Manual 15 7 2 randomize procedure randomize X Set random number seed If X is not supplied the current time is used On startup when the extras unit is initialized the random number generator is initialized with the current time 15 8 Input Output extensions 15 8 1 make input port procedure make input port READ READY CLOSE PEEK Returns a custom input port Common operations on this port are handled by the given parameters which should be procedures of no arguments READ is called when the next character is to be read and should return a character or eof READY is called when char ready is called on this port and should return t or f CLOSE is called when the port is closed PEEK is called when peek char is called on this port and should return a character or eof if the argument PEEK is not given then READ is used instead and the created port object handles peeking automatically by calling READ and buffering the character 15 8 2 make output port procedure make output port WRITE CLOSE FLUSH Returns a custom output port Common operations on this port are handled by the given parameters which should be procedures WRITE is called when output is sent to the port and
216. ry NAME Creates a directory with the pathname NAME 23 2 4 delete directory procedure delete directory NAME Deletes the directory with the pathname NAME The directory has to be empty 23 2 5 directory procedure directory PATHNAME SHOW DOTFILES Returns a list with all files that are contained in the directory with the name PATHNAME which defaults to the value of Current directory Files beginning with are included only if SHOW DOTFILES is given and not f 23 2 6 directory procedure directory NAME Returns t if there exists a file with the name NAME and if that file is a directory or f otherwise 23 2 7 glob procedure glob PATTERN1 Returns a list of the pathnames of all existing files matching PATTERN1 which should be strings containing the usual file patterns with matching zero or more characters and matching zero or one 23 2 2 current directory 129 CHICKEN User s Manual The User s Manual character 23 2 8 set root directory procedure set root directory STRING Sets the root directory for the current process to the path given in STRING using the chroot function If the current process has no root permissions the operation will fail 23 3 Pipes 23 3 1 call with input pipe 23 3 2 call with output pipe procedure call with input pipe CMDLINE PROC MODE procedure call with output pipe CMDLINE PROC MODE Call PROC with a single argument a inp
217. ry and so does only understand standard C library syntax for floating point constants 6 2 5 There is no built in support for rationals complex numbers or extended precision integers bignums The routines complex real and rational are identical to the standard procedure number The procedures numerator denominator rationalize make rectangular and make polar are not implemented Fixnums are limited to A 230 or A 262 on 64 bit hardware Support for extended numbers is available as a separate package provided the GNU multiprecision library is installed 6 2 6 The procedure st ring gt number does not obey read write invariance on inexact numbers 6 4 The maximum number of values that can be passed to continuations captured using call with current continuation is 120 6 5 Code evaluated in scheme report environment or null environment still sees non standard syntax 6 6 2 The procedure char ready always returns t for terminal ports The procedure read does not obey read write invariance on inexact numbers 6 Deviations from the standard 22 CHICKEN User s Manual The User s Manual 6 6 3 The procedures write and display do not obey read write invariance to inexact numbers 6 6 4 The transcript on and transcript off procedures are not implemented Previous Supported language Next Extensions to the standard 6 Deviations from the standard 23 7 Extensions to the standard 2 1 Identifiers
218. s k k But when k is invoked the next expression will be whatever follows after k k In other words invoking a captured continuation will not rewind the file position of the input source A solution is to wrap the whole code into a begin expression so all toplevel expressions will be loaded together 38 5 7 Why does define reader ctor not work in my compiled program The following piece of code does not work as expected eval when compile define reader ctor integer gt char integer gt char print integer gt char 33 The problem is that the compiler reads the complete source file before doing any processing on it so the sharp comma form is encountered before the reader ctor is defined A possible solution is to include the file containing the sharp comma form like this eval when compile define reader ctor integer gt char integer gt char include other file 38 5 5 Why do I get a warning when I define a global variable named match 248 CHICKEN User s Manual The User s Manual other file scm print integer gt char 33 38 5 8 Why do built in units such as srfi 1 srfi 18 and posix fail to load When you try to USE a built in unit such as srfi 18 you may get the following error 1 gt use srfi 18 loading library srfi 18 Error load library unable to load library srf gl on a Mac No such file or directory Another symptom is that require s
219. s available 9 1 1 require extension syntax require extension ID syntax use ID This form does all the necessary steps to make the libraries or extensions given in ID available It loads syntactic extensions if needed and generates code for loading linking with core library modules or separately installed extensions USE is just a shorter alias for require extension This implementation of require extension is compliant with SRFI 55 see the SRFI 55 document for more information During interpretation evaluation requi re extension performs one of the following If ID names a built in feature chicken srfi 0 srfi 2 srfi 6 srfi 8 srfi 9 srfi 10 srfi 17 srfi 23 srfi 30 srfi 39 srfi 55 then nothing is done e If ID names one of the syntactic extensions chicken more macros chicken ffi macros then this extension will be loaded e If ID names one of the core library units shipped with CHICKEN then a Load library ID will be performed e If ID names an installed extension with the syntax or require at runtime attribute then the equivalent of require for syntax ID is performed probably followed by require for any run time requirements Otherwise require extension ID is equivalent to require ID During compilation one of the following happens instead If ID names a built in feature chicken srfi 0 srfi 2 srfi 6 srfi 8 srfi 9 srfi 10 srfi 17 srfi 23 srfi 30 srfi 39 srfi 55 then nothing is done
220. s nano n aea neas asses assess neue 113 ISI SI AR M 114 CARNE SIE DRE 115 o E E TE E E 116 A A TOAT 117 PA E RE 117 E Ee EE 117 PA Wee 117 PA ATE CORD DEE 118 DUNE DICTUM 118 PT A RN 119 IMEEM 119 ENEE EE 119 21 9 string match posILORS eec oa ee Ere PE PRE E YRe dE cadence MERE ERREUR gas SEENEN EEN 120 21 l0 Eeer REL 120 21 11 strimig Search posItIONS 5 odor cree rra ne eae one E SERE ek ee Ee ETUR edd eege eege 120 E ee EE E 120 At Ee 121 21 14 ee EE 121 PA VS TE SEK E 121 21 16 make anchored patterhi eoe ioe reete ette evene etae ent s enne p re eee Poo de vio d eru otio 121 2 Uot IE RETE 123 PAS EDI EOE 123 22 2 ue E UE RE 123 22 3 Ee te 124 22 4 thread SuspeM EE 124 225 Me EE E 124 1X CHICKEN User s Manual The User s Manual Chicken User s Manual 22 Unit srfi 18 22 6 I CET EE EE 124 22 4 timermillis conds orit to c eerie to e oi d ia saunas das FU v TR E iaa 124 29 Lb ista 128 23 V COSS EE 125 23 1 1 File control Commande 125 23 1 2 Standard I O file descriptors 1 peccet a adidas 125 ZA ERAUSIBUECEREN 126 23 1 4 RETTEN 127 23 2 Rer 128 23 21 O EE 128 23 2 2 current dIrectOTy eroe eter suas evades AAA EEN 129 23 2 3 create dITectol y dees gedet e rettet eto d een PUE oi
221. set THREAD QUANTUM Sets the quantum of THREAD to QUANTUM 22 4 thread suspend procedure thread suspend THREAD Suspends the execution of THREAD until resumed 22 5 thread resume procedure thread resume THREAD Readies the suspended thread THREAD 22 6 thread wait for i o procedure thread wait for i o FD MODE Suspends the current thread until input MODE is input output MODE is output or both MODE is al 6D is available FD should be a file descriptor not a port open for input or output respectively 22 7 timemilliseconds procedure time gt milliseconds TIME Converts a time object as created via current time into an exact integer representing the number of milliseconds since process startup Previous Unit regex Next Unit posix 22 3 thread quantum set 124 23 Unit posix This unit provides services as used on many UNIX like systems Note that the following definitions are not all available on non UNIX systems like Windows See below for Windows specific notes This unit uses the regex scheduler extras and utils units All errors related to failing file operations will signal a condition of kind exn i o file 23 1 Constants 23 1 1 File control Commands 23 1 1 1 fcntl dupfd 23 1 1 2 fcntl getfd 23 1 1 3 fcntl setfd 23 1 1 4 fcntl getfl 23 1 1 5 fcntl setfl 23 1 2 Standard I O file descriptors 23 1 2 1 fileno stdin 23 Unit posix 125 CHICKEN Us
222. signal handler procedure signal handler SIGNUM Returns the signal handler for the code SIGNUM or f 23 13 4 set signal mask procedure set signal mask SIGLIST Sets the signal mask of the current process to block all signals given in the list SIGLIST Signals masked in that way will not be delivered to the current process 23 13 5 signal mask procedure signal mask Returns the signal mask of the current process 23 13 Signal handling 144 CHICKEN User s Manual The User s Manual 23 13 6 signal masked procedure signal masked SIGNUM Returns whether the signal for the code SIGNUM is currently masked 23 13 7 signal mask procedure signal mask SIGNUM Masks blocks the signal for the code SIGNUM 23 13 8 signal unmask procedure signal unmask SIGNUM Unmasks unblocks the signal for the code SIGNUM 23 13 9 signal term 23 13 10 signal kill 23 13 11 signal int 23 13 12 signal hup 23 13 13 signal fpe 23 13 14 signal ill 23 13 6 signal masked 145 CHICKEN User s Manual The User s Manual 23 13 15 signal segv 23 13 16 signal abrt 23 13 17 signal trap 23 13 18 signal quit 23 13 19 signal alrm 23 13 20 signal vtalrm 23 13 21 signal prof 23 13 22 signal io 23 13 23 signal urg 23 13 24 signal chld 23 13 25 signal cont 23 13 15 signal segv 146 CHICKEN User s Manual The User s Manual 23 13 26 signal stop 23 13 27 signal tstp 23 13 28
223. signal pipe 23 13 29 signal xcpu 23 13 30 signal xfsz 23 13 31 signal usr1 23 13 32 signal usr2 23 13 33 signal winch These variables contain signal codes for use with process Signal set signal handler signal handLler signal masked signal mask or Signal unmask 23 14 Environment access 23 14 1 current environment procedure current environment Returns a association list of the environment variables and their current values 23 13 26 signal stop 147 CHICKEN User s Manual The User s Manual 23 14 2 setenv procedure setenv VARIABLE VALUE Sets the environment variable named VARIABLE to VALUE Both arguments should be strings If the variable is not defined in the environment a new definition is created 23 14 3 unsetenv procedure unsetenv VARIABLE Removes the definition of the environment variable VARIABLE from the environment of the current process If the variable is not defined nothing happens 23 15 Memory mapped UO 23 15 1 memory mapped file pocedure memory mapped file X Returns t if X is an object representing a memory mapped file or f otherwise 23 15 2 map file to memory procedure map file to memory ADDRESS LEN PROTECTION FLAG FILENO OFFSET Maps a section of a file to memory using the C function mmap ADDRESS should be a foreign pointer object or f LEN specifies the size of the section to be mapped PROTECTION should be one or more of the flags prot read prot
224. spectively READFDLIST and WRITEFDLIST may also by file descriptors instead of lists In this case the returned values are booleans indicating whether input output is ready by t or f otherwise You can also pass f as 23 5 3 file open 133 CHICKEN User s Manual The User s Manual READFDLIST or WRITEFDLIST argument which is equivalent to 23 5 7 file write procedure file write FILENO BUFFER SIZE Writes the contents of the string or bytevector BUFFER into the file with the file descriptor FILENO If the optional argument SIZE is given then only the specified number of bytes are written 23 5 8 file control procedure file control FILENO COMMAND ARGUMENT Performs the fcntl operation COMMAND with the given FILENO and optional ARGUMENT The return value is meaningful depending on the COMMAND 23 5 9 open input file 23 5 10 open output file procedure open input file FILENO OPENMODE procedure open output file FILENO OPENMODE Opens file for the file descriptor FILENO for input or output and returns a port FILENO should be a positive exact integer OPENMODE specifies an additional mode for opening the file currently only the keyword append is supported which opens an output file for appending 23 5 11 portfileno procedure port gt fileno PORT If PORT is a file or tcp port then a file descriptor is returned for this port Otherwise an error is signaled 23 6 Retrieving file attributes
225. ssert status printf gt s n buffer printf gt g n baz 22 return 0 30 14 CHICKEN_yield 206 CHICKEN User s Manual The User s Manual CSC x scm y c embedded It is also possible to re enter the computation following the call to return to host by calling CHICKEN continue 30 15 CHICKEN continue C function C word CHICKEN continue C word k Re enters Scheme execution k is the continuation received from the previous invocation of CHICKEN run or CHICKEN continue When return to host is called again this function returns another continuation that can be used to restart again If you invoke callbacks prior to calling CHICKEN continue make sure that the continuation is not reclaimed by garbage collection This can be avoided by using C gc protect or gc roots Another example cat x scm require extension srfi 18 define m make mutex define t mutex lock m thread sleep 1 print thread name current thread mutex unlock m t thread start make thread t PING thread start make thread t PONG let loop return to host thread yield loop cat y c include lt chicken h gt int main C word k CHICKEN run C toplevel for k CHICKEN continue k return 0 30 15 CHICKEN continue 207 CHICKEN User s Manual The User s Manual CSC x scm y c embedded It is advisable not to mix repeated uses of CHICKEN continue re
226. string returns a pointer to the character buffer of the actual Scheme object and is not zero terminated 34 28 C SIZEOF TAGGED POINTER 219 CHICKEN User s Manual The User s Manual 34 35 C_header_size C macro int C header size C word x 34 36 C_header_bits C macro int C header bits C word x Return the number of elements and the type bits of the non immediate Scheme data object X 34 37 C_block_item C macro C word C block item C word x int index This macro can be used to access slots of the non immediate Scheme data object X index specifies the index of the slot to be fetched starting at O Pairs have 2 slots one for the car and one for the cdr Vectors have one slot for each element 34 38C u i car C macro C word C u i car C word x 34 39 C u i cdr C macro C word C u i cdr C word x Aliases for C block item x 0 andC block item x 1 respectively 34 40 C data pointer C macro void C data pointer C word x Returns a pointer to the data section of a non immediate Scheme object 34 35 C header size 220 CHICKEN User s Manual The User s Manual 34 41 C_make_header C macro C word C make header C word bits C word size A macro to build a Scheme object header from its bits and size parts 34 42 C_mutate C function C word C mutate C word slot C word val Assign the Scheme value val to the location specified by slot If the value points to data inside the nursery the first heap g
227. support e Unit regex regular expressions e Unit srfi 18 multithreading e Unit posix Unix like services e Unit utils Shell scripting and file operations e Unit tcp basic TCP sockets e Unit lolevel low level operations Previous Using the interpreter Next Interface to external functions and variables 5 Supported language 6 Deviations from the standard Identifiers are by default case sensitive see Compiler command line format 4 1 3 The maximal number of arguments that may be passed to a compiled procedure or macro is 120 A macro definition that has a single rest parameter can have any number of arguments If the Libf fi library is available on this platform and if it is installed then CHICKEN can take advantage of this See the README file for more details 4 2 2 Let rec does evaluate the initial values for the bound variables sequentially and not in parallel that is letrec x 1 y 2 cons x y is equivalent to let x void y void set x 1 set y 2 cons x y where R5RS requires let x void y void let tmp1 1 tmp2 2 set x tmpl set y tmp2 cons x y 4 3 syntax rules macros are not provided but available separately 6 1 equal compares all structured data recursively while R5RS specifies that eqv is used for data other than pairs strings and vectors 6 2 4 The runtime system uses the numerical string conversion routines of the underlying C libra
228. t int lt define callout foreign safe lambda int callout int int int define external callin scheme object xyz int print This is callin xyz 123 print callout 1 2 3 cat bar c include lt stdio h gt include chicken h extern int callout int int int extern int callin C word x int callout int x int y int z 34 46 C_pre_gc_hook 222 CHICKEN User s Manual The User s Manual C word ptr C alloc C SIZEOF LIST 3 C word lst printf This is callout d d Sd n x y Z lst C list amp ptr 3 C fix x C fix y C fix z return callin lst Note callin will have GC d the data in ptr csc Top sch bar c o foo foo This is callout 1 2 3 This is callin 1 2 3 123 34 49 Notes Scheme procedures can call C functions and C functions can call Scheme procedures but for every pending C stack frame the available size of the first heap generation the nursery will be decreased because the C stack is identical to the nursery On systems with a small nursery this might result in thrashing since the C code between the invocation of C from Scheme and the actual calling back to Scheme might build up several stack frames or allocates large amounts of stack data To prevent this it is advisable to increase the default nursery size either when compiling the file using the nursery option or when running the executable using the S runtime option
229. t port procedure current output port PORT Returns default output port If PORT is given then that port is selected as the new current output port Note that the default output port is not buffered Use http galinha ucpel tche br Unit posix Setting the file buffering modelset buf fering mode if you need a different behavior 13 2 2 current error port procedure current error port PORT Returns default error output port If PORT is given then that port is selected as the new current error output port Note that the default error output port is not buffered Use http galinha ucpel tche br Unit posix Setting the file buffering modelset buf fering mode if you need a different behavior 13 2 3 flush output procedure flush output PORT Write buffered output to the given output port PORT defaults to the value of Current output port 13 1 7 signum 61 CHICKEN User s Manual The User s Manual 13 2 4 port name procedure port name PORT Fetch filename from PORT This returns the filename that was used to open this file Returns a special tag string enclosed into parentheses for non file ports PORT defaults to the value of current input port 13 2 5 port position procedure port position PORT Returns the current position of PORT as two values row and column number If the port does not support such an operation an error is signaled This procedure is currently only available for
230. tain the number of arguments that are passed to the procedure on the temporary stack Values are put onto the temporary stack with the C save macro 31 3 C callback adjust stack C function void C callback adjust stack C word ptr int size The runtime system uses the stack as a special allocation area and internally holds pointers to estimated limits to distinguish between Scheme data objects inside the stack from objects outside of it If you invoke callbacks at wildly differing stack levels these limits may shift from invocation to invocation Callbacks defined with define external will perform appropriate adjustments automatically but if you invoke C callback manually you should performa C callback adjust stack to make sure the internal limits are set properly ptr should point to some data object on the stack and size is the number of words contained in the data object or some estimate The call will make sure the limits are adjusted so that the value pointed to by ptr is located in the stack Previous Embedding Next Locations 31 2 C callback 211 32 Locations It is also possible to define variables containing unboxed C data so called locations It should be noted that locations may only contain simple data that is everything that fits into a machine word and double precision floating point values 32 1 define location syntax define location NAME TYPE INIT Identical to define external NAME TYPE INIT but the
231. tandard characters names supported are tab Linefeed return alarm vtab nul page esc delete and backspace 6 3 5 CHICKEN supports special characters preceded with a backslash in quoted string constants V denotes the newline character V carriage return V backspace V TAB V vertical TAB Va alarm Y formfeed WXX a character with the code XX in hex and WXXXX and UXXXXXXXX a unicode character with the code XXXX The latter is encoded in UTF 8 format The third argument to subst ring is optional and defaults to the length of the string 6 4 force called with an argument that is not a promise returns that object unchanged Captured continuations can be safely invoked inside before and after thunks of a dynamic wind form and execute in the outer dynamic context of the dynamic wind form Implicit non multival continuations accept multiple values by discarding all but the first result Zero values result in the continuation receiving an unspecified value Note that this slight relaxation of the behaviour of returning mulitple values to non multival continuations does not apply to explicit continuations created with call with current continuation 6 5 The second argument to eval is optional and defaults to the value of interaction environment scheme report environment and nul l environment accept an optional 2nd parameter if not f which is the default toplevel bindings to standard procedures are muta
232. tching is found in several modern languages notably Standard ML Haskell and Miranda These syntactic extensions internally use the match library unit The basic form of pattern matching expression is match exp pat body where exp is an expression pat is a pattern and body is one or more expressions like the body of a lambda expression The match form matches its first subexpression against a sequence of patterns and branches to the body corresponding to the first pattern successfully matched For example the following code defines the usual map function define map Lambda f 1 match l 0 O0 x y cons f x map f y The first pattern matches the empty list The second pattern X y matches a pair binding X to the first component of the pair and y to the second component of the pair 10 1 Pattern Matching Expressions The complete syntax of the pattern matching expressions follows exp match exp clause match lambda clause match lambda clause match let pat exp body match letrec pat exp body match let var pat exp body match let pat exp body match define pat exp clause pat body pat gt identifier body pat identifier matches anything and binds identifier as a variab anything itself the empty list Ft itself f itself string an equal string number an equal number cha
233. tching values For example the expression match let x 1 y 21 z let binding values exp body binds binding to the list x y values to the list 1 2 and exp to z in the body of the match expression For the special case where pat n 1 is a pattern variable the list bound to that variable may share with the matched value pat 1 pat n pat n 1 This pattern means the same thing as the previous pattern pat 1 pat n pat n 1 k This pattern is similar to the previous pattern but the tail must be at least k elements long The pattern keywords and are equivalent 10 2 Patterns 45 CHICKEN User s Manual The User s Manual pat 1 pat n pat n 1 Kl This pattern means the same thing as the previous pattern pat 1 pat n matches a vector of length n whose elements match pat 1 through pat n Z pat 1 pat n pat n 1 matches a vector of length n or more where each element beyond n matches pat n 1 pat 1 pat n pat n 1 k matches a vector of length n k or more where each element beyond n matches pat n 1 struct pat 1 pat n matches a structure declared with def ine record or define record type field pat is intended for selecting a field from a structure field may be any expression it is applied to the value being matched and the result of this application is matched against pat and pat 1 pat n matches if all of the subpatterns m
234. te any arguments to the value of current error port and reset 14 3 Macros 14 3 1 get line number procedure get line number EXPR If EXPR is a pair with the car being a symbol and line number information is available for this expression then this procedure returns the associated line number If line number information is not available then f is returned Note that line number information for expressions is only available in the compiler 14 3 2 macro procedure macro SYMBOL Returns t if there exists a macro definition for SYMBOL 14 3 3 macroexpand procedure macroexpand X If X is a macro form expand the macro and repeat expansion until expression is a non macro form Returns the resulting expression 14 1 5 set dynamic load mode 85 CHICKEN User s Manual The User s Manual 14 3 4 macroexpand 1 procedure macroexpand 1 X If X is a macro form expand the macro Returns the resulting expression 14 3 5 undefine macro procedure undefine macro SYMBOL Remove the current macro definition of the macro named SYMBOL 14 3 6 syntax error procedure syntax error LOCATION MESSAGE ARGUMENT Signals an exception of the kind exn syntax Otherwise identical to error 14 4 Loading extension libraries This functionality is only available on platforms that support dynamic loading of compiled code Currently Linux BSD Solaris Windows with Cygwin and HP UX are supported 14 4 1 repositor
235. te objects are blocks of data represented by a pointer into the heap The pointer s immediate mark bits bits 1 and 2 must be zero to indicate the object is non immediate this guarantees the data block is aligned on a 4 byte boundary at minimum Alignment of data words is required on modern architectures anyway so we get the ability to distinguish between immediate and non immediate objects for free The first word of the data block contains a header which gives information about the type of the object The header has the size of a machine word usually 32 bits 64 bits on 64 bit architectures Bits 1 to 24 contain the length of the data object which is either the number of bytes in a string or byte vector or the the number of elements for a vector or for a structure type Bits 25 to 28 contain the type code of the object Bits 29 to 32 contain miscellaneous flags used for garbage collection or internal data type dispatching These flags are C_GC_FORWARDING BIT 36 Data representation 238 CHICKEN User s Manual The User s Manual Flag used for forwarding garbage collected object pointers C_BYTEBLOCK_BIT Flag that specifies whether this data object contains raw bytes a string or byte vector or pointers to other data objects C_SPECIALBLOCK_BIT Flag that specifies whether this object contains a special non object pointer value in its first slot An example for this kind of objects are closures which are a vector type object wit
236. temp TEMPLATE FILENAME Create a file based on the given TEMPLATE FILENAME in which the six last characters must be XXXXXX These will be replaced with a string that makes the filename unique The file descriptor of the created file and the generated filename is returned See the mkstemp 3 manual page for details on how this function works The template string given is not modified Example usage let values fd temp path file mkstemp tmp mytemporary let temp port open output file fd format temp port This file is A 5 temp path close output port temp port 23 5 5 file read procedure file read FILENO SIZE BUFFER Reads SIZE bytes from the file with the file descriptor FILENO If a string or bytevector is passed in the optional argument BUFFER then this string will be destructively modified to contain the read data This procedure returns a list with two values the buffer containing the data and the number of bytes read 23 5 6 file select procedure file select READFDLIST WRITEFDLIST TIMEOUT Waits until any of the file descriptors given in the lists READFDLIST and WRITEFDLIST is ready for input or output respectively If the optional argument T IMEOUT is given and not false then it should specify the number of seconds after which the wait is to be aborted the value may be a floating point number This procedure returns two values the lists of file descriptors ready for input and output re
237. ter the hour 0 59 hours 2 the number of hours past midnight 0 23 mday 3 the day of the month 1 31 month 4 the number of months since january 0 11 year 5 the number of years since 1900 wday 6 the number of days since Sunday 0 6 yday 7 the number of days since January 1 0 365 dstflag 8 a flag that is true if Daylight Saving Time is in effect at the time described timezone 9 the difference between UTC and the latest local standard time in seconds west of UTC 23 16 2 local timeseconds procedure local time gt seconds VECTOR 23 15 4 unmap file from memory 149 CHICKEN User s Manual The User s Manual Converts the ten element vector VECTOR representing the time value relative to the current timezone into the number of seconds since the first of January 1970 UTC 23 16 3 local timezone abbreviation procedure local timezone abbreviation Returns the abbreviation for the local timezone as a string 23 16 4 secondsstring procedure seconds gt string SECONDS Converts the local time represented in SECONDS into a string of the form Tue May 21 13 46 22 1991 23 16 5 secondsutc time procedure seconds gt utc time SECONDS Similar to seconds gt Local time but interpretes SECONDS as UTC time 23 16 6 utc timeseconds procedure utc time gt seconds VECTOR Converts the ten element vector VECTOR representing the UTC time value into the number of seconds since the first
238. that doesn t cons still trigger garbage collections Under CHICKENSs implementation policy tail recursion is achieved simply by avoiding to return from a function call Since the programs are CPS converted a continuous sequence of nested procedure calls is performed At some stage the stack space has to run out and the current procedure and its parameters including the current continuation are stored somewhere in the runtime system Now a minor garbage collection occurs and rescues all live data from the stack the first heap generation and moves it into the the second heap generation Then the stack is cleared using a Longjmp and execution can continue from the saved state With this method arbitrary recursion in tail or non tail position can happen provided the application doesn t run out of heap space The difference between a tail and a non tail call is that the tail call has no live data after it invokes its continuation and so the amount of heap space needed stays constant 38 7 2 Why do finalizers not seem to work in simple cases in the interpeter Consider the following interaction in CSI 1 gt define x 1 2 3 2 gt define yammer x print x is dead 3 gt set finalizer x yammer 1 2 3 38 6 3 Which non standard procedures are treated specially when theextended bindings or usual integratio d eclaratic CHICKEN User s Manual The User s Manual 4 gt gc t 157812 5 gt define x f 6
239. the Svn or Local options By using either the Svn client program which must be installed or file system operations all necessary files will be copied into the current directory creating a subdirectory named EXTENSIONNAME egg dir built and subsequently installed Dependency information which is necessary to ensure required extensions are also installed is downloaded automatically If you have no internet connection or don t want to connect you can also use a local file containing the necessary dependency information The fetch tree option retrieves the canonical repository file at http www call with current continuation org eggs repository writing it to stdout Redirecting this output into a file and passing the file via the t ree option to chicken setup allows you now to use the local repository file Retrieve complete extension repository big cd opt svn co https galinha ucpel tche br svn chicken eggs release 3 eggs Get your own copy of the repository file chicken setup fetch tree gt my repository file Now you can install eggs from your local checkout with full dependency tracking and without being connected to the internet cd tmp chicken setup local opt eggs tree my repository file opengl 35 10 Linking extensions statically The compiler and chicken setup support statically linked eggs The general approach is to generate an object file or static library in addition to the usual shared
240. the exact semantics of process spawn spawn overlay replaces the current process with the new one spawn wait suspends execution of the current process until the spawned process returns spawn nowait does the opposite spawn nowaito is identical according to the Microsoft documentation and runs the process asynchronously spawn detach runs the new process in the background without being attached to a console 23 24 4 process spawn procedure process spawn MODE COMMAND ARGUMENT LIST ENVIRONMENT LIST EXACT Creates and runs a new process with the given COMMAND filename and the optional ARGUMENT LIST and ENVIRONMENT LIST MODE specifies how exactly the process should be executed and must be one or more of the spawn flags defined above The EXACT FLAG default f controls quote wrapping of argument strings When t quote wrapping is not performed Returns e the exit status when synchronous e the PID when asynchronous e when failure Previous Unit srfi 18 Next Unit utils 23 24 3 Additional Definitions 161 24 Unit utils This unit contains file pathname oriented procedures apropos plus acts as a grab bag for procedures without a good home and which don t have to be available by default as compared to the extras unit This unit uses the extras and regex units 24 1 Environment Query 24 1 1 apropos procedure apropos SYMBOL PATTERN ENVIRONMENT MACROS Displays symbols amp type matchi
241. the return status of the subprocess is returned unaltered 13 9 Execution time 13 9 1 cpu time procedure cpu time Returns the used CPU time of the current process in milliseconds as two values the time spent in user code and the time spent in system code On platforms where user and system time can not be differentiated system time will be always be 0 13 9 2 current milliseconds procedure current milliseconds Returns the number of milliseconds since process or machine startup 13 8 11 software version 70 CHICKEN User s Manual The User s Manual 13 9 3 current seconds procedure current seconds Returns the number of seconds since midnight Jan 1 1970 13 9 4 current gc milliseconds procedure current gc milliseconds Returns the number of milliseconds spent in major garbage collections since the last call of current gc milliseconds and returns an exact integer 13 10 Interrupts and error handling 13 10 1 enable warnings procedure enable warnings BOOL Enables or disables warnings depending on wether BOOL is true or false If called with no arguments this procedure returns t if warnings are currently enabled or f otherwise Note that this is not a parameter The current state whether warnings are enabled or disabled is global and not thread local 13 10 2 error procedure error LOCATION STRING EXP Prints error message writes all extra arguments to the value of current error
242. ther value is ignored n no init Do not load initialization file If this option is not given and the file cSirc or HOME csirc exists then it is loaded before the read eval print loop commences W no warnings Disables any warnings that might be issued by the reader or evaluated code q quiet Do not print a startup message Also disables generation of call trace information for interpreted code s script PATHNAME 4 Using the interpreter 15 CHICKEN User s Manual The User s Manual This is equivalent to batch quiet no init PATHNAME Arguments following PATHNAME are available by using command Line arguments and are not processed as interpreter options Extra options in the environment variable CST OPTIONS are ignored ss PATHNAME The same as s PATHNAME but invokes the procedure main with the value of command line arguments as its single argument If the main procedure returns an integer result then the interpreter is terminated returning the integer as the status code back to the invoking process Any other result terminates the interpreter with a zero exit status R require extension NAME Equivalent to evaluating require extension NAME v version Write the banner with version information to standard output and exit 4 2 Writing Scheme scripts Since UNIX shells use the notation for starting scripts anything following the characters is ignored with the exception of the special symbols optional
243. tion specifier extended bindings SYMBOL declaration specifier not extended bindings SYMBOL Declares that all given non standard and CHICKEN specific procedures or all if no symbols are specified are never globally redefined If not is specified then all but the given extended bindings are assumed to be never redefined 11 31 usual integrations declaration specifier usual integrations SYMBOL declaration specifier not usual integrations SYMBOL Declares that all given standard and extended bindings or all if no symbols are specified are never globally redefined If not is specified then all but the given standard and extended bindings are assumed to be never redefined Note that this is the default behaviour unless the no uSual integrations option has been given 11 32 unit declaration specifier unit SYMBOL Specify compilation unit name if this is a library 11 28 run time macros 54 CHICKEN User s Manual The User s Manual 11 33 unsafe declaration specifier unsafe declaration specifier not safe Do not generate safety checks This is the same as specifying the unsafe option Also implies declare no bound checks no procedure checks no argc checks 11 34 unused declaration specifier unused SYMBOL Disables any warnings when the global variable SYMBOL is not defined but used or defined but never used and not exported 11 35 uses declaration specifier
244. tively easy to create distributions of Scheme projects that have been compiled to C The runtime system of CHICKEN consists of only two handcoded C files runtime c and chicken h plus the file chicken config h which is generated by the build process All other modules of the runtime system and the extension libraries are just compiled Scheme code The following example shows a minimal application which should run without changes on the most frequent operating systems like Windows Linux or FreeBSD Let s take a simple example hello scm print Hello world chicken hello scm optimize level 3 output file hello c Compiled to C we get hel lo c We need the files chicken hand runtime c which contain the basic runtime system plus the three basic library files Library c eval cand extras c which contain the same functionality as the library linked into a plain CHICKEN compiled application or which is available by default in the interpreter CSi cd tmp echo print Hello World hello scm cp CHICKEN BUILD runtime c cp CHICKEN BUILD Llibrary c cp CHICKEN BUILD eval c cp CHICKEN BUILD extras c gcc static 0s fomit frame pointer runtime c library c eval c extras c hello c o hello lm d o o o d i o d i Now we have all files together and can create an tarball containing all the files 9 6 tar cf hello tar Makefile hello c runtime c library c eval c extras c chicken gzip hello tar This is
245. to 0 26 5 2 make weak locative procedure make weak locative EXP INDEX Creates a weak locative Even though the locative refers to an element of a container object the container object will still be reclaimed by garbage collection if no other references to it exist 26 5 3 locative procedure locative X Returns t if X is a locative or f otherwise 26 5 4 locative ref procedure locative ref LOC Returns the element to which the locative LOC refers If the containing object has been reclaimed by garbage collection an error is signalled 26 4 6 object unevict 182 CHICKEN User s Manual The User s Manual 26 5 5 locative set procedure locative set LOC X procedure set locative ref LOC X Changes the element to which the locative LOC refers to X If the containing object has been reclaimed by garbage collection an error is signalled 26 5 6 locativeobject procedure locative gt object LOC Returns the object that contains the element referred to by LOC or f if the container has been reclaimed by garbage collection 26 6 Accessing toplevel variables 26 6 1 global bound procedure global bound SYMBOL Returns t if the global toplevel variable with the name SYMBOL is bound to a value or f otherwise 26 6 2 global ref procedure global ref SYMBOL Returns the value of the global variable SYMBOL If no variable under that name is bound an error is signalled Note that
246. to the one found in PLT Scheme This unit uses the extras unit All errors related to failing network operations will raise a condition of kind exn i o network 25 1 tcp listen procedure tcp listen TCPPORT BACKLOG HOST Creates and returns a TCP listener object that listens for connections on TCPPORT which should be an exact integer BACKLOG specifies the number of maximally pending connections and defaults to 4 If the optional argument HOST is given and not f then only incoming connections for the given host or IP are accepted 25 2 tcp listener procedure tcp listener X Returns t if X is a TCP listener object or f otherwise 25 3 tcp close procedure tcp close LISTENER Reclaims any resources associated with LISTENER 25 4 tcp accept procedure tcp accept LISTENER Waits until a connection is established on the port on which LISTENER is listening and returns two values an input and output port that can be used to communicate with the remote process The current value of tcp accept timeout is used to determine the maximal number of milliseconds if any to wait until a connection is established When a client connects any read and write operations on the returned ports will use the current values at the time of the connection of tcp read timeout and tcp write timeout respectively to determine the maximal number of milliseconds to wait for input output before a timeout error is signalled Note
247. to the path of the currently loaded file 14 Unit eval 83 CHICKEN User s Manual The User s Manual 14 1 3 load noisily procedure load noisily FILE key EVALUATOR TIME PRINTER As Load but the result s of each evaluated toplevel expression is written to standard output If EVALUATOR is given and not f then each expression is evaluated by calling this argument with the read expression as argument If TIME is given and not false then the execution time of each expression is shown as with the time macro If PRINTER is given and not false then each expression is printed before evaluation by applying the expression to the value of this argument which should be a one argument procedure See also the load verbose parameter 14 1 4 load library procedure load library UNIT LIBRARYFILE On platforms that support dynamic loading Load Library loads the compiled library unit UNIT which should be a symbol If the string LIBRARYFILE is given then the given shared library will be loaded and the toplevel code of the contained unit will be executed If no LIBRARYFILE argument is given then the following libraries are checked for the required unit e a file named UNIT so the files given in the parameter dynamic load libraries If the unit is not found an error is signaled When the library unit can be successfully loaded a feature identifier named UNIT is registered If the feature is already registered before loading the loa
248. to the port that is the value of current output port Returns void 13 15 3 print procedure print EXP1 Similar to print but does not output a terminating newline character and performs a f Lush output after writing its arguments 13 16 User defined named characters 13 16 1 char name procedure char name SYMBOL OR CHAR CHAR This procedure can be used to inquire about character names or to define new ones With a single argument the behavior is as follows If SYMBOL OR CHAR is a symbol then char name returns the character with this name or f if no character is defined under this name If SYMBOL OR CHAR is a character then the name of the character is returned as a symbol or f if the character has no associated name If the optional argument CHAR is provided then SYMBOL OR CHAR should be a symbol that will be the new name of the given character If multiple names designate the same character then the write will use the character name that was defined last char name space gt space char name space gt Space char name bell gt f char name integer gt char 7 gt f char name bell integer gt char 7 char name bell gt bell char gt integer char name bell 7 13 15 1 port 75 CHICKEN User s Manual The User s Manual 13 17 Blobs blobs are collections of unstructured bytes You can t do much with them but allow conversion to and from
249. tom X Returns t if X is not a pair This is identical to not pair from Unit srfi 1 but kept for historical reasons 15 1 4 rassoc procedure rassoc KEY LIST TEST Similar to ASSOC but compares KEY with the cdr of each pair in LIST using TEST as the comparison procedures which defaults to eqv 15 Unit extras 89 CHICKEN User s Manual The User s Manual 15 1 5 butlast procedure butlast LIST Returns a fresh list with all elements but the last of LIST 15 1 6 chop procedure chop LIST N Returns a new list of sublists where each sublist contains N elements of LIST If LIST has a length that is not a multiple of N then the last sublist contains the remaining elements 3 4 5 6 3 45 6 2 gt 1 2 cd abc d gt 15 1 7 compress procedure compress BLIST LIST Returns a new list with elements taken from LIST with corresponding true values in the list BLIST define nums 99 100 110 401 1234 compress map odd nums nums gt 99 401 15 1 8 flatten procedure flatten LIST1 Returns LIST1 concatenated together with nested lists removed flattened 15 1 9 intersperse procedure intersperse LIST X Returns a new list with X placed between each element 15 1 5 butlast 90 CHICKEN User s Manual The User s Manual 15 1 10 join procedure join LISTOFLISTS LIST Concatenates the lists in LISTOFLISTS with LIST placed between each sublist LIST defaults
250. tomatically freed using finalization when there are no references from Scheme variables and data NONGC defaults to f the vector will be located in normal garbage collected memory and FINALIZE defaults to t Note that the FINALIZE argument is only used when NONGC is true Additionally the following procedures are provided 17 2 u8vectorblob 17 3 s8vectorblob 17 4 u16vectorblob 17 5 s16vectorblob 17 6 u32vectorblob 17 Unit srfi 4 108 CHICKEN User s Manual The User s Manual 17 7 s32vectorblob 17 8 f32vectorblob 17 9 f64vectorblob 17 10 u8vectorblob shared 17 11 s8vectorblob shared 17 12 u16vectorblob shared 17 13 s16vectorblob shared 17 14 u32vectorblob shared 17 15 s32vectorblob shared 17 16 f82vectorblob shared 17 17 f64vectorblob shared u8vector gt blob U8VECTOR s8vector gt blob S8VECTOR ul6vector gt blob U16VECTOR sl6vector gt blob S16VECTOR procedure procedure procedure procedure D 17 7 s32vectorblob 109 CHICKEN User s Manual The User s Manual procedure u32vector gt blob U32VECTOR procedure s32vector gt blob S32VECTOR procedure f32vector gt blob F32VECTOR procedure f64vector gt blob F64VECTOR procedure u8vector gt blob shared U8VECTOR ul6vector gt blob shared sl6vector gt blob shared u32vector gt blob shared s32vector gt blob shared f32vector gt blob shared f64vector gt blob shared procedure procedure procedure
251. ts a breakpoint at the procedures named SYMBOL Breakpoint can also be trigged using the breakpoint procedure ubr SYMBOL Removes breakpoints Ke Continues execution from the last invoked breakpoint breakall Enable breakpoints for all threads this is the default breakonly THREAD Enable breakpoints only for the thread returned by the expression THREAD info Lists traced procedures and breakpoints Step EXPR Evaluates EXPR in single stepping mode On each procedure call you will be presented with a menu that allows stepping to the next call leaving single stepping mode or triggering a breakpoint Note that you will see some internal calls and unsafe or heavily optimized compiled code might not be stepped at all Single stepping mode is also possible by invoking the singlestep procedure You can define your own toplevel commands using the top Level command procedure 4 4 toplevel command procedure toplevel command SYMBOL PROC HELPSTRING Defines or redefines a toplevel interpreter command which can be invoked by entering SYMBOL PROC will be invoked when the command is entered and may read any required argument via read or read Line If the optional argument HELPSTRING is given it will be listed by the command 4 5 History access The interpreter toplevel accepts the special object INDEX which returns the result of entry number INDEX in the history list If the expression for that entry resulted in m
252. turn to host as in the example above with callbacks Once return to host is invoked the runtime system and any Scheme code executed prior to the invocation is initialized and can be conveniently used via callbacks A simpler interface For handling GC safe references to Scheme data are the so called gc roots 30 16 CHICKEN new gc root C function void CHICKEN new gc root Returns a pointer to a GC root which is an object that holds a reference to a Scheme value that will always be valid even after a garbage collection The content of the gc root is initialized to an unspecified value 30 17 CHICKEN delete gc root C function void CHICKEN delete gc root void root Deletes the gc root 30 18 CHICKEN gc root ref C macro C word CHICKEN gc root ref void root Returns the value stored in the gc root 30 19 CHICKEN gc root set C macro void CHICKEN gc root set void root C word value Sets the content of the GC root to a new value Sometimes it is handy to access global variables from C code 30 16 CHICKEN new gc root 208 CHICKEN User s Manual The User s Manual 30 20 CHICKEN_global_lookup C function void CHICKEN global lookup char name Returns a GC root that holds the global variable with the name name If no such variable exists NULL is returned 30 21 CHICKEN global ref C function C word CHICKEN global ref void global Returns the value of the global variable referenced by the GC root global
253. ual 11 6 bound to procedure declaration specifier bound to procedure SYMBOL Declares that the given identifiers are always bound to procedure values 11 7 c options declaration specifier c options STRING Declares additional C C compiler options that are to be passed to the subsequent compilation pass that translates C to machine code This declaration will only work if the source file is compiled with the CSC compiler driver 11 8 check c syntax declaration specifier check c syntax declaration specifier not check c syntax Enables or disables syntax checking of embedded C C code fragments Checking C syntax is the default 11 9 constant declaration specifier constant SYMBOL Declares the procedures with the names SYMBOL as constant that is as not having any side effects This can help the compiler to remove non side effecting expressions 11 10 export declaration specifier export SYMBOL The opposite of hide All given identifiers will be exported and all toplevel variables not listed will be hidden and not be accessible outside of this compilation unit 11 11 emit exports declaration specifier emit exports STRING Write exported toplevel variables to file with name STRING 11 6 bound to procedure 50 CHICKEN User s Manual The User s Manual 11 12 emit external prototypes first declaration specifier emit external prototypes first Emit prototypes for callbacks de
254. uct or union are accessed as pointers to the embedded struct or union and no setter will be generated Additionally special record declarations DECL may be given where each declaration consists of a list of the form KEYWORD ARGUMENT 1 The available declarations are 28 6 3 constructor constructor NAME Generate a constructor procedure with no arguments that has the name NAME a symbol that returns a pointer to a structure of this type The storage will be allocated with malloc 3 28 6 4 destructor destructor NAME 28 6 define foreign record 191 CHICKEN User s Manual The User s Manual Generate a destructor function with the name NAME that takes a pointer to a structure of this type as its single argument and releases the storage with f ree 3 If the argument is f the destructor procedure does nothing 28 6 5 rename rename EXPRESSION Evaluates EXPRESSION at compile macro expansion time and applies the result which should be a procedure to the string representation of the name of each accessor procedure generated Another or the same string should be returned which in turn is taken as the actual name of the accessor An example require for syntax srfi 13 define foreign record Some Struct rename compose string downcase cut string translate lt gt constructor make some struct destructor free some struct int xCoord int yCoord pt will generate t
255. ultiple values the first result or an unspecified value for no values is returned If no INDEX is given and if a whitespace or closing paranthesis character follows the then the result of the last expression is returned Note that the value returned is implicitly quoted 4 3 Toplevel commands 18 CHICKEN User s Manual The User s Manual 4 6 set describer procedure set describer TAG PROC Sets a custom description handler that invokes PROC when the d command is invoked with a record type object that has the type TAG a symbol PROC is called with two arguments the object to be described and an output port It should write a possibly useful textual description of the object to the passed output port For example 1 gt define record point x y 2 gt set describer point lambda pt o print a point with x point x pt and y point y pt 3 gt d make point 1 2 a point with x 1 and y 2 4 7 Auto completion and edition On platforms that support it it is possible to get auto completion of symbols history over different csi sessions and a more feature full editor for the expressions you type using the http www call with current continuation org eggs readline html egg by Tony Garnock Jones It is very useful for interactive use of csi To enable it install the egg and put this in your CSi rc file use readline regex current input port make gnu readline port gnu history install file man
256. upeno Davide Puricelli Doug Quale Eric Raible Ivan Raikov Joel Reymont Eric Rochester Andreas Rottman David Rush Lars Rustemeier Daniel Sadilek Oskar Schirmer Burton Samograd Reed Sheridan Ronald Schroeder Spencer Schumann Alex Shinn Ivan Shmakov Shmul Tony Sidaway Jeffrey B Siegal Andrey Sidorenko Michele Simionato Volker Stolz Jon Strait Dorai Sitaram Robert Skeels Jason Songhurst Clifford Stein Sunnan Zbigniew Szadkowski Rick Taube Mike Thomas Minh Thu Christian Tismer Andre van Tonder John Tobey Henrik Tramberend Vladimir Tsichevsky Neil van Dyke Sander Vesik Panagiotis Vossos Shawn Wagner Peter Wang Ed Watkeys Brad Watson Thomas Weidner Goeran Weinholt Matthew Welland Joerg Wittenberger Peter Wright Mark Wutka Richard Zidlicky and Houman Zolfaghari for bug fixes tips and suggestions CHICKEN uses the PCRE regular expression package http www pcre org which is written by Philip Hazel Special thanks to Brandon van Every for contributing the now defunct CMake support and for helping with Windows build issues Also special thanks to Benedikt Rosenau for his constant encouragement Thanks to Dunja Winkelmann for putting up with all of this CHICKEN contains code from several people Eli Barzilay some performance tweaks used in TinyCLOS Mikael Djurfeldt topological sort used by compiler Marc Feeley pretty printer Aubrey Jaffer implementation of dynamic wind Richard O Keefe sort
257. ure with input from pipe CMDLINE THUNK MODE procedure with output to pipe CMDLINE THUNK MODE Temporarily set the value of current input port current output port to a port for a pipe connected to the subprocess named in CMDLINE and call the procedure THUNK with no arguments After THUNK returns normally the pipe is closed and the standard input output port is restored to its previous value and any result values are returned with output to pipe I gs dNOPAUSE sDEVICE jpeg dBATCH sOutputFile signballs jpg g600x lambda print lt lt EOF TOPSC 1993 Creator HAYAKAWA Takashi lt XxXXXXXXX XX XXXXXX XX XX C neg d mul R rlineto E exp H cvx def repeat def T dup g gt r roll J ifelse H A copy z amp v4QX amp 93 r9AxYQOZomQalxS2w O amp vMYa43d6r93 rMYvx2dca D amp cj SnjSnj j 30 v amp 6 X amp 55SAxM1CD7AjYxTTd62rmxCnTdSSTOg amp 12wECST amp JOgGD1 amp xMO JOg 1 amp 544dC2Ac96ra m amp 3 23 3 5 create pipe 131 CHICKEN User s Manual The User s Manual F amp amp vGoGSnCTOg amp wDmlvGoS8wpn6wpS2wTCpS1Sd70v7Uk704Qkdw amp Mvlx1S70ZES3w J J Q amp 7185 Z amp lx1CS9d9nEA4 k amp X amp MY7 amp 1 J x amp jdnjdS3odS N amp mmx1C2wECc G amp 150Nx4 n amp 20 j amp 43r U amp 0777 82A4Y2A776ddT40S3oSnMVC00VVORRRA5E42063rNz amp v7UX amp UOzF F J amp 44ETCnVn a amp 1CDN Y amp O V1c amp j2AYdjmMdjjd o amp 1lr M T 0 4 3 r put T g T 9 g cvn cvi J g I I cvx forall moveto p floor w div S a
258. uring runtime The second possible syntax for def ine macro is allowed for portability purposes only In this case the second argument must be a lambda expression or a macro name Only global macros can be defined using this form define macro NAME1 NAME2 simply copies the macro definition from NAME2 to NAME 1 creating an alias Extended lambda list syntax optional etc can be used but note that arguments are source expressions and thus default values for optional or keyword arguments should take this into consideration 9 4 4 define for syntax syntax define for syntax NAME VAR VAR EXP1 syntax define for syntax NAME VALUE Defines the toplevel variable NAME at macro expansion time This can be helpful when you want to define support procedures for use in macro transformers for example 9 5 Conditional forms 9 4 2 define inline 38 CHICKEN User s Manual The User s Manual 9 5 1 select syntax select EXP KEY EXP1 else EXPn This is similar to Case but the keys are evaluated 9 5 2 unless syntax unless TEST EXP1 EXP2 Equivalent to if not TEST begin EXP1 EXP2 9 5 3 when syntax when TEST EXP1 EXP2 Equivalent to if TEST begin EXP1 EXP2 9 6 Record structures 9 6 1 define record syntax define record NAME SLOTNAME Defines a record type Call make NAME to create an instance of the structure with one initialization argument
259. ut or output port for a pipe connected to the subprocess named in CMDLINE If PROC returns normally the pipe is closed and any result values are returned 23 3 3 close input pipe 23 3 4 close output pipe procedure close input pipe PORT procedure close output pipe PORT Closes the pipe given in PORT and waits until the connected subprocess finishes The exit status code of the invoked process is returned 23 3 5 create pipe procedure create pipe 23 2 7 glob 130 CHICKEN User s Manual The User s Manual The fundamental pipe creation operator Calls the C function pipe and returns 2 values the file descriptors of the input and output ends of the pipe 23 3 6 open input pipe procedure open input pipe CMDLINE MODE Spawns a subprocess with the command line string CMDLINE and returns a port from which the output of the process can be read If MODE is specified it should be the keyword text the default or binary 23 3 7 open output pipe procedure open output pipe CMDLINE MODE Spawns a subprocess with the command line string CMDLINE and returns a port Anything written to that port is treated as the input for the process If MODE is specified it should be the keyword text the default or binary 23 3 8 pipe buf This variable contains the maximal number of bytes that can be written atomically into a pipe or FIFO 23 3 9 with input from pipe 23 3 10 with output to pipe proced
260. value to result 30 7 CHICKEN eval to string C macro int CHICKEN eval to string C word exp char result int size Evaluates the Scheme expression passed in exp writing a textual representation of the result into result Size should specify the maximal size of the result string 30 8 CHICKEN eval string to string C macro int CHICKEN eval string to string char str char result int size Evaluates the Scheme expression passed in the string Str writing a textual representation of the result into result size should specify the maximal size of the result string 30 4 return to host 204 CHICKEN User s Manual The User s Manual 30 9 CHICKEN_apply C macro int CHICKEN apply C word func C word args C word result Applies the procedure passed in func to the list of arguments args writing the result value to result 30 10 CHICKEN apply to string C macro int CHICKEN apply to string C word func C word args char result Applies the procedure passed in func to the list of arguments args writing a textual representation of the result into result 30 11 CHICKEN read C macro int CHICKEN read char str C word result Reads a Scheme object from the string st r writing the result value to result 30 12 CHICKEN load C macro int CHICKEN load char filename Loads the Scheme file filename either in source form or compiled 30 13 CHICKEN get error message C macro void CHICKEN get error message char result i
261. variable reference books 186 26 8 1 eertmpvalhd orocedure call bhandler nn nnnn conan cccnncnnns 186 26 8 2 onbound varable value snoeien inanin iE eE E E a aaie 186 PI BIET NN 186 AR A 186 26 0 2 TTT 187 27 Interface to external functions and Variables scccsssccccssssccsssscccssssccccssssccessssccecessccecscsccescssceecess 188 2 Accessing external OD GOES rr isaac SAn S ai 189 Se Ereegnes deed gue Ee EHE PEE Ra eue 189 PARQUET M M 189 28 3 Be EE 189 28 4 ASME FOTELSMALY PC va sins oi oio e GREEN dE GERE LFU RAP SERE ARE edad svat RUNE ESEE RSSa 189 28 5 defin foreipn variable reete aeree ettet ree tee iini a CERE Pk eee ee ERR eee edo 190 28 6 deline TorelgnsreCOEd eeu nes ert e eoe ee as ae bores i6 yo secet eae nut rena eua e aae ena keen ret RR nn 190 28 6 1 TYPENAME SLOTNAME rennen nnnenenenennnnnrnn nennen nnns esent nnne 191 J8p 2VRBENAME SLOTNAME sel 191 280 3 COM UC dia 191 285 0 4 d Str CLOF ca 191 ARS TAO 192 LA O 192 28 8 TOPS le EE 193 28 9 Tore EE le E EE 193 25 10 foreignzsafe lambda uiae tie eterne tet deret eet HE vienen de oed en tu eeuutoeddentenddeevieaiuratanie 194 28 11 toreign sate lambda ner ener REOR ERA AER ERA nega EE AER RAE ERE EA 194 PAS Crdinsa M a 194 PA 196 29 1 NN 196 AA 6101 0 EE 196 29 3 byte unsighed Dbyt cia A rece AAA lA AA 196 29 A char EE 196 AA e e E 196 29 6 int unsigned int int
262. ven in WHICH If WHICH is a string the file will be patched and overwritten If WHICH is a list of the form OLD NEW then a different file named NEW will be generated 35 4 8 copy file procedure copy file FROM TO Copies the file or directory recursively given in the string FROM to the destination file or directory TO 35 4 9 move file procedure move file FROM TO Moves the file or directory recursively given in the string FROM to the destination file or directory TO 35 4 10 remove file procedure remove file PATH Removes the file or directory given in the string PATH 35 4 11 find library procedure find library NAME PROC Returns t if the library named LibNAME Tal so unix or NAME Lib windows could be found by compiling and linking a test program PROC should be the name of a C function that must be provided by the library If no such library was found or the function could not be resolved f is returned 35 4 12 find header procedure find header NAME Returns t if a C include file with the given name is available or f otherwise 35 4 7 patch 228 CHICKEN User s Manual The User s Manual 35 4 13 try compile procedure try compile CODE key cc cflags ldflags compile only c Returns t if the C code in CODE compiles and links successfully or f otherwise The keyword parameters CC compiler name defaults to the C compiler used to build this system Cf Lags and Ldflags accept addition
263. very large files under Windows with the Microsoft C compiler fails with a message indicating insufficient heap epace ennt 244 38 2 4 When I run csi inside an emacs buffer under Windows nothing happens 244 38 2 5 I load compiled code dynamically in a Windows GUI application and it crashes 244 38 2 6 On Windows csc exe seems to be doing something wrong 245 38 2 7 On Windows source and or output filenames with embedded whitespace are not found 245 38 3 CUSLOMMZ AMON EE 245 38 3 1 How do I run custom startup code before the runtime system is invoked 245 38 3 2 How can I add compiled user po seeg ener 245 38 4 Compiled macros E 246 38 4 1 Why is define macro complaining about unbound vanables esses 246 38 4 2 Why isn t load properly loading my library of macros sese 246 38 4 3 Why is include unable to load my hygienic Macros ecoooocccconocnonanoonncconccnoneconnnannn nn nono conan ncnnncn ns 246 38 4 4 Why are macros not visible outside of the compilation unit in which they are defined 246 38 5 Warnings and eege eec eoe ein ero hot on ee cete ren LE ee eR e EE DRAN Co vae OERE eon Deme Fe dee eed reel npe Focus 247 38 5 1 Why does my program crash when I use callback functions from Scheme to C and back to SChEME APM RE 247 38 5 2 Why does the linker complain about a missing function C toplevel 247 38 5 3 Why does the li
264. vocation of argv It depends on the host shell whether arguments are expanded Cglobbed or not 13 8 2 exit procedure exit CODE Exit the running process and return exit code which defaults to 0 Invokes exit handler Note that pending dynamic wind thunks are not invoked when exiting your program in this way 13 7 2 breakpoint 67 CHICKEN User s Manual The User s Manual 13 8 3 build platform procedure build platform Returns a symbol specifying the toolset which has been used for building the executing system which is one of the following cygwin mingw32 gnu intel unknown 13 8 4 chicken version procedure chicken version FULL Returns a string containing the version number of the CHICKEN runtime system If the optional argument FULL is given and true then a full version string is returned 13 8 5 errno procedure errno Returns the error code of the last system call 13 8 6 getenv procedure getenv STRING Returns the value of the environment variable STRING or f if that variable is not defined 13 8 7 machine byte order procedure machine byte order Returns the symbol Litt le endian or big endian depending on the machine s byte order 13 8 3 build platform 68 CHICKEN User s Manual The User s Manual 13 8 8 machine type procedure machine type Returns a symbol specifying the processor on which this process is currently running which is one of the following alpha m
265. y path parameter repository path Contains a string naming the path to the extension repository which defaults to either the value of the environment variable CHICKEN REPOSITORY or the default library path usually usr local lib chicken on UNIX systems 14 4 2 extension information procedure extension information ID If an extension with the name ID is installed and if it has a setup information list registered in the extension repository then the info list is returned Otherwise extension information returns f 14 3 4 macroexpand 1 86 CHICKEN User s Manual The User s Manual 14 4 3 provide procedure provide ID Registers the extension IDs ID as loaded This is mainly intended to provide aliases for certain extension identifiers 14 4 4 provided procedure provided ID Returns t if the extension with the IDs ID are currently loaded or f otherwise 14 4 5 require procedure require ID procedure require for syntax ID If the extension library ID is not already loaded into the system then require will lookup the location of the shared extension library and load it If ID names a library unit of the base system then it is loaded via load library If no extension library is available for the given ID then an attempt is made to load the file ID so or ID SCm in that order from one of the following locations e the current include path which defaults to the pathnames given in
266. y the profiling information in a more user friendly form Enter chicken profile with no arguments at the command line to get a list of available options The accumulate profile option is similar to profile but the resulting profile information will be appended to any existing PROFILE file chicken profile will merge and sum up the accumulated timing information if several entries for the same procedure calls exist profile name FILENAME Specifies name of the generated profile information which defaults to PROFTLE Implies profile prologue FILENAME Includes the file named FILENAME at the start of the compiled source file The include path is not 3 1 Compiler command line format 7 CHICKEN User s Manual The User s Manual searched This option may be given multiple times quiet Disables output of compile information raw Disables the generation of any implicit code that uses the Scheme libraries that is all runtime system files besides runtime c and chicken h require extension NAME Loads the extension NAME before the compilation process commences This is identical to adding require extension NAME at the start of the compiled program If uses NAME is also given on the command line then any occurrences of require extension NAME are replaced with declare uses NAME Multiple names may be given and should be separated by run time macros Makes macros also available at run time By default macros are not available at run
267. yntax parameterize PARAMETER1 X1 BODY Binds the parameters PARAMETER1 dynamically to the values X1 during execution of BODY see also make parameter in Parameters Note that PARAMETER may be any expression that evaluates to a parameter procedure 9 3 10 receive syntax receive NAME1 NAMEn VALUEEXP BODY syntax receive VALUEEXP SRFI 8 Syntactic sugar for Call with values Binds variables to the result values of VALUEEXP and evaluates BODY The syntax receive VALUEEXP 1s equivalent to receive _ VALUEEXP 9 3 11 set values syntax set values NAME EXP Assigns the result values of expression EXP to multiple variables 9 4 Substitution forms and macros 9 4 1 define constant syntax define constant NAME CONST Define a variable with a constant value evaluated at compile time Any reference to such a constant should appear textually after its definition This construct is equivalent to define when evaluated or interpreted Constant definitions should only appear at toplevel Note that constants are local to the current compilation unit and are not available outside of the source file in which they are defined Names of constants still exist in the Scheme namespace and can be lexically shadowed If the value is mutable then the compiler is careful to preserve its identity CONST may be any constant expression and may also refer to constants defined via define consta
268. your code include chicken h extern void C toplevel C word C word C word C noret 38 3 2 How can add compiled user passes To add a compiled user pass instead of an interpreted one create a library unit and recompile the main unit of the compiler in the file chicken scm with an additional uses declaration Then link all compiler modules and your compiled extension to create a new version of the compiler like this assuming all sources are in the current directory cat userpass scm userpass scm My very own compiler pass declare unit userpass 38 2 6 On Windows csc exe seems to be doing something wrong 245 CHICKEN User s Manual The User s Manual Perhaps more user passes extensions are added let old user pass user pass Lambda x let x2 do something with x if old old x2 x2 csc C X userpass scm csc chicken scm c o chicken extended o uses userpass gcc chicken extended o support o easyffi o compiler o optimizer o batch drive backend o userpass o csc ldflags libs o chicken extended o d i d i C On platforms that support it Linux ELF Solaris Windows VC compiled code can be loaded via extend just like source files see Load in the User s Manual 38 4 Compiled macros 38 4 1 Why is define macro complaining about unbound variables Macro bodies that are defined and used in a compiled source file are evaluated during compilation and so have

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