1 Guile NEWS --- history of user-visible changes. -*- text -*-
2 Copyright (C) 1996, 1997 Free Software Foundation, Inc.
3 See the end for copying conditions.
5 Please send Guile bug reports to bug-guile@prep.ai.mit.edu.
9 [[trim out any sections we don't need]]
11 * Changes to the distribution
13 * Changes to the procedure for linking libguile with your programs
15 ** Like Guile 1.1, Guile 1.2 will now use the Rx regular expression
16 library, if it is installed on your system. When you are linking
17 libguile into your own programs, this means you will have to link
18 against -lguile, -lqt (if you configured Guile with thread support),
21 If you are using autoconf to generate configuration scripts for your
22 application, the following lines should suffice to add the appropriate
23 libraries to your link command:
25 ### Find Rx, quickthreads and libguile.
26 AC_CHECK_LIB(rx, main)
27 AC_CHECK_LIB(qt, main)
28 AC_CHECK_LIB(guile, scm_shell)
30 * Changes to Scheme functions and syntax
32 ** The #/ syntax for module names is depreciated, and will be removed
33 in a future version of Guile. Instead of
41 The latter syntax is more consistent with existing Lisp practice.
43 ** Guile now does fancier printing of structures. Structures are the
44 underlying implementation for records, which in turn are used to
45 implement modules, so all of these object now print differently and in
46 a more informative way.
48 The Scheme printer will examine the builtin variable
49 *struct-printer* whenever it needs to print a structure object. When
50 this variable is not `#f' it is deemed to be a procedure and will be
51 applied to the structure object and the output port. When
52 *struct-printer* is `#f' or the procedure return `#f' the structure
53 object will be printed in the boring #<struct 80458270> form.
55 This hook is used by some routines in ice-9/boot-9.scm to implement
56 type specific printing routines. Please read the comments there about
59 One of the more specific uses of structs are records. The printing
60 procedure that could be passed to MAKE-RECORD-TYPE is now actually
61 called. It should behave like a *struct-printer* procedure (described
64 ** Guile now supports a new R4RS-compliant syntax for keywords. A
65 token of the form #:NAME, where NAME has the same syntax as a Scheme
66 symbol, is the external representation of the keyword named NAME.
67 Keyword objects print using this syntax as well, so values containing
68 keyword objects can be read back into Guile. When used in an
69 expression, keywords are self-quoting objects.
71 Guile suports this read syntax, and uses this print syntax, regardless
72 of the current setting of the `keyword' read option. The `keyword'
73 read option only controls whether Guile recognizes the `:NAME' syntax,
74 which is incompatible with R4RS. (R4RS says such token represent
77 ** Guile has regular expression support again. Guile 1.0 included
78 functions for matching regular expressions, based on the Rx library.
79 In Guile 1.1, the Guile/Rx interface was removed to simplify the
80 distribution, and thus Guile had no regular expression support. Guile
81 1.2 now adds back the most commonly used functions, and supports all
82 of SCSH's regular expression functions. They are:
84 *** [[get docs from Tim?]]
86 * Changes to the gh_ interface
88 * Changes to the scm_ interface
90 * Changes to system call interfaces:
92 ** The value returned by `raise' is now unspecified. It throws an exception
95 ** A new procedure `sigaction' can be used to install signal handlers
97 (sigaction signum [action] [flags])
99 signum is the signal number, which can be specified using the value
102 If action is omitted, sigaction returns a pair: the CAR is the current
103 signal hander, which will be either an integer with the value SIG_DFL
104 (default action) or SIG_IGN (ignore), or the Scheme procedure which
105 handles the signal, or #f if a non-Scheme procedure handles the
106 signal. The CDR contains the current sigaction flags for the handler.
108 If action is provided, it is installed as the new handler for signum.
109 action can be a Scheme procedure taking one argument, or the value of
110 SIG_DFL (default action) or SIG_IGN (ignore), or #f to restore
111 whatever signal handler was installed before sigaction was first used.
112 Flags can optionally be specified for the new handler (SA_RESTART is
113 always used if the system provides it, so need not be specified.) The
114 return value is a pair with information about the old handler as
117 This interface does not provide access to the "signal blocking"
118 facility. Maybe this is not needed, since the thread support may
119 provide solutions to the problem of consistent access to data
123 Changes in Guile 1.1 (Fri May 16 1997):
125 * Changes to the distribution.
127 The Guile 1.0 distribution has been split up into several smaller
129 guile-core --- the Guile interpreter itself.
130 guile-tcltk --- the interface between the Guile interpreter and
131 Tcl/Tk; Tcl is an interpreter for a stringy language, and Tk
132 is a toolkit for building graphical user interfaces.
133 guile-rgx-ctax --- the interface between Guile and the Rx regular
134 expression matcher, and the translator for the Ctax
135 programming language. These are packaged together because the
136 Ctax translator uses Rx to parse Ctax source code.
138 This NEWS file describes the changes made to guile-core since the 1.0
141 We no longer distribute the documentation, since it was either out of
142 date, or incomplete. As soon as we have current documentation, we
145 * Changes to the stand-alone interpreter
147 ** guile now accepts command-line arguments compatible with SCSH, Olin
148 Shivers' Scheme Shell.
150 In general, arguments are evaluated from left to right, but there are
151 exceptions. The following switches stop argument processing, and
152 stash all remaining command-line arguments as the value returned by
153 the (command-line) function.
154 -s SCRIPT load Scheme source code from FILE, and exit
155 -c EXPR evalute Scheme expression EXPR, and exit
156 -- stop scanning arguments; run interactively
158 The switches below are processed as they are encountered.
159 -l FILE load Scheme source code from FILE
160 -e FUNCTION after reading script, apply FUNCTION to
161 command line arguments
162 -ds do -s script at this point
163 --emacs enable Emacs protocol (experimental)
164 -h, --help display this help and exit
165 -v, --version display version information and exit
166 \ read arguments from following script lines
168 So, for example, here is a Guile script named `ekko' (thanks, Olin)
169 which re-implements the traditional "echo" command:
171 #!/usr/local/bin/guile -s
174 (map (lambda (arg) (display arg) (display " "))
178 (main (command-line))
180 Suppose we invoke this script as follows:
182 ekko a speckled gecko
184 Through the magic of Unix script processing (triggered by the `#!'
185 token at the top of the file), /usr/local/bin/guile receives the
186 following list of command-line arguments:
188 ("-s" "./ekko" "a" "speckled" "gecko")
190 Unix inserts the name of the script after the argument specified on
191 the first line of the file (in this case, "-s"), and then follows that
192 with the arguments given to the script. Guile loads the script, which
193 defines the `main' function, and then applies it to the list of
194 remaining command-line arguments, ("a" "speckled" "gecko").
196 In Unix, the first line of a script file must take the following form:
198 #!INTERPRETER ARGUMENT
200 where INTERPRETER is the absolute filename of the interpreter
201 executable, and ARGUMENT is a single command-line argument to pass to
204 You may only pass one argument to the interpreter, and its length is
205 limited. These restrictions can be annoying to work around, so Guile
206 provides a general mechanism (borrowed from, and compatible with,
207 SCSH) for circumventing them.
209 If the ARGUMENT in a Guile script is a single backslash character,
210 `\', Guile will open the script file, parse arguments from its second
211 and subsequent lines, and replace the `\' with them. So, for example,
212 here is another implementation of the `ekko' script:
214 #!/usr/local/bin/guile \
218 (for-each (lambda (arg) (display arg) (display " "))
222 If the user invokes this script as follows:
224 ekko a speckled gecko
226 Unix expands this into
228 /usr/local/bin/guile \ ekko a speckled gecko
230 When Guile sees the `\' argument, it replaces it with the arguments
231 read from the second line of the script, producing:
233 /usr/local/bin/guile -e main -s ekko a speckled gecko
235 This tells Guile to load the `ekko' script, and apply the function
236 `main' to the argument list ("a" "speckled" "gecko").
238 Here is how Guile parses the command-line arguments:
239 - Each space character terminates an argument. This means that two
240 spaces in a row introduce an empty-string argument.
241 - The tab character is not permitted (unless you quote it with the
242 backslash character, as described below), to avoid confusion.
243 - The newline character terminates the sequence of arguments, and will
244 also terminate a final non-empty argument. (However, a newline
245 following a space will not introduce a final empty-string argument;
246 it only terminates the argument list.)
247 - The backslash character is the escape character. It escapes
248 backslash, space, tab, and newline. The ANSI C escape sequences
249 like \n and \t are also supported. These produce argument
250 constituents; the two-character combination \n doesn't act like a
251 terminating newline. The escape sequence \NNN for exactly three
252 octal digits reads as the character whose ASCII code is NNN. As
253 above, characters produced this way are argument constituents.
254 Backslash followed by other characters is not allowed.
256 * Changes to the procedure for linking libguile with your programs
258 ** Guile now builds and installs a shared guile library, if your
259 system support shared libraries. (It still builds a static library on
260 all systems.) Guile automatically detects whether your system
261 supports shared libraries. To prevent Guile from buildisg shared
262 libraries, pass the `--disable-shared' flag to the configure script.
264 Guile takes longer to compile when it builds shared libraries, because
265 it must compile every file twice --- once to produce position-
266 independent object code, and once to produce normal object code.
268 ** The libthreads library has been merged into libguile.
270 To link a program against Guile, you now need only link against
271 -lguile and -lqt; -lthreads is no longer needed. If you are using
272 autoconf to generate configuration scripts for your application, the
273 following lines should suffice to add the appropriate libraries to
276 ### Find quickthreads and libguile.
277 AC_CHECK_LIB(qt, main)
278 AC_CHECK_LIB(guile, scm_shell)
280 * Changes to Scheme functions
282 ** Guile Scheme's special syntax for keyword objects is now optional,
283 and disabled by default.
285 The syntax variation from R4RS made it difficult to port some
286 interesting packages to Guile. The routines which accepted keyword
287 arguments (mostly in the module system) have been modified to also
288 accept symbols whose names begin with `:'.
290 To change the keyword syntax, you must first import the (ice-9 debug)
292 (use-modules (ice-9 debug))
294 Then you can enable the keyword syntax as follows:
295 (read-set! keywords 'prefix)
297 To disable keyword syntax, do this:
298 (read-set! keywords #f)
300 ** Many more primitive functions accept shared substrings as
301 arguments. In the past, these functions required normal, mutable
302 strings as arguments, although they never made use of this
305 ** The uniform array functions now operate on byte vectors. These
306 functions are `array-fill!', `serial-array-copy!', `array-copy!',
307 `serial-array-map', `array-map', `array-for-each', and
310 ** The new functions `trace' and `untrace' implement simple debugging
311 support for Scheme functions.
313 The `trace' function accepts any number of procedures as arguments,
314 and tells the Guile interpreter to display each procedure's name and
315 arguments each time the procedure is invoked. When invoked with no
316 arguments, `trace' returns the list of procedures currently being
319 The `untrace' function accepts any number of procedures as arguments,
320 and tells the Guile interpreter not to trace them any more. When
321 invoked with no arguments, `untrace' untraces all curretly traced
324 The tracing in Guile has an advantage over most other systems: we
325 don't create new procedure objects, but mark the procedure objects
326 themselves. This means that anonymous and internal procedures can be
329 ** The function `assert-repl-prompt' has been renamed to
330 `set-repl-prompt!'. It takes one argument, PROMPT.
331 - If PROMPT is #f, the Guile read-eval-print loop will not prompt.
332 - If PROMPT is a string, we use it as a prompt.
333 - If PROMPT is a procedure accepting no arguments, we call it, and
334 display the result as a prompt.
335 - Otherwise, we display "> ".
337 ** The new function `eval-string' reads Scheme expressions from a
338 string and evaluates them, returning the value of the last expression
339 in the string. If the string contains no expressions, it returns an
342 ** The new function `thunk?' returns true iff its argument is a
343 procedure of zero arguments.
345 ** `defined?' is now a builtin function, instead of syntax. This
346 means that its argument should be quoted. It returns #t iff its
347 argument is bound in the current module.
349 ** The new syntax `use-modules' allows you to add new modules to your
350 environment without re-typing a complete `define-module' form. It
351 accepts any number of module names as arguments, and imports their
352 public bindings into the current module.
354 ** The new function (module-defined? NAME MODULE) returns true iff
355 NAME, a symbol, is defined in MODULE, a module object.
357 ** The new function `builtin-bindings' creates and returns a hash
358 table containing copies of all the root module's bindings.
360 ** The new function `builtin-weak-bindings' does the same as
361 `builtin-bindings', but creates a doubly-weak hash table.
363 ** The `equal?' function now considers variable objects to be
364 equivalent if they have the same name and the same value.
366 ** The new function `command-line' returns the command-line arguments
367 given to Guile, as a list of strings.
369 When using guile as a script interpreter, `command-line' returns the
370 script's arguments; those processed by the interpreter (like `-s' or
371 `-c') are omitted. (In other words, you get the normal, expected
372 behavior.) Any application that uses scm_shell to process its
373 command-line arguments gets this behavior as well.
375 ** The new function `load-user-init' looks for a file called `.guile'
376 in the user's home directory, and loads it if it exists. This is
377 mostly for use by the code generated by scm_compile_shell_switches,
378 but we thought it might also be useful in other circumstances.
380 ** The new function `log10' returns the base-10 logarithm of its
383 ** Changes to I/O functions
385 *** The functions `read', `primitive-load', `read-and-eval!', and
386 `primitive-load-path' no longer take optional arguments controlling
387 case insensitivity and a `#' parser.
389 Case sensitivity is now controlled by a read option called
390 `case-insensitive'. The user can add new `#' syntaxes with the
391 `read-hash-extend' function (see below).
393 *** The new function `read-hash-extend' allows the user to change the
394 syntax of Guile Scheme in a somewhat controlled way.
396 (read-hash-extend CHAR PROC)
397 When parsing S-expressions, if we read a `#' character followed by
398 the character CHAR, use PROC to parse an object from the stream.
399 If PROC is #f, remove any parsing procedure registered for CHAR.
401 The reader applies PROC to two arguments: CHAR and an input port.
403 *** The new functions read-delimited and read-delimited! provide a
404 general mechanism for doing delimited input on streams.
406 (read-delimited DELIMS [PORT HANDLE-DELIM])
407 Read until we encounter one of the characters in DELIMS (a string),
408 or end-of-file. PORT is the input port to read from; it defaults to
409 the current input port. The HANDLE-DELIM parameter determines how
410 the terminating character is handled; it should be one of the
413 'trim omit delimiter from result
414 'peek leave delimiter character in input stream
415 'concat append delimiter character to returned value
416 'split return a pair: (RESULT . TERMINATOR)
418 HANDLE-DELIM defaults to 'peek.
420 (read-delimited! DELIMS BUF [PORT HANDLE-DELIM START END])
421 A side-effecting variant of `read-delimited'.
423 The data is written into the string BUF at the indices in the
424 half-open interval [START, END); the default interval is the whole
425 string: START = 0 and END = (string-length BUF). The values of
426 START and END must specify a well-defined interval in BUF, i.e.
427 0 <= START <= END <= (string-length BUF).
429 It returns NBYTES, the number of bytes read. If the buffer filled
430 up without a delimiter character being found, it returns #f. If the
431 port is at EOF when the read starts, it returns the EOF object.
433 If an integer is returned (i.e., the read is successfully terminated
434 by reading a delimiter character), then the HANDLE-DELIM parameter
435 determines how to handle the terminating character. It is described
436 above, and defaults to 'peek.
438 (The descriptions of these functions were borrowed from the SCSH
439 manual, by Olin Shivers and Brian Carlstrom.)
441 *** The `%read-delimited!' function is the primitive used to implement
442 `read-delimited' and `read-delimited!'.
444 (%read-delimited! DELIMS BUF GOBBLE? [PORT START END])
446 This returns a pair of values: (TERMINATOR . NUM-READ).
447 - TERMINATOR describes why the read was terminated. If it is a
448 character or the eof object, then that is the value that terminated
449 the read. If it is #f, the function filled the buffer without finding
450 a delimiting character.
451 - NUM-READ is the number of characters read into BUF.
453 If the read is successfully terminated by reading a delimiter
454 character, then the gobble? parameter determines what to do with the
455 terminating character. If true, the character is removed from the
456 input stream; if false, the character is left in the input stream
457 where a subsequent read operation will retrieve it. In either case,
458 the character is also the first value returned by the procedure call.
460 (The descriptions of this function was borrowed from the SCSH manual,
461 by Olin Shivers and Brian Carlstrom.)
463 *** The `read-line' and `read-line!' functions have changed; they now
464 trim the terminator by default; previously they appended it to the
465 returned string. For the old behavior, use (read-line PORT 'concat).
467 *** The functions `uniform-array-read!' and `uniform-array-write!' now
468 take new optional START and END arguments, specifying the region of
469 the array to read and write.
471 *** The `ungetc-char-ready?' function has been removed. We feel it's
472 inappropriate for an interface to expose implementation details this
475 ** Changes to the Unix library and system call interface
477 *** The new fcntl function provides access to the Unix `fcntl' system
480 (fcntl PORT COMMAND VALUE)
481 Apply COMMAND to PORT's file descriptor, with VALUE as an argument.
482 Values for COMMAND are:
484 F_DUPFD duplicate a file descriptor
485 F_GETFD read the descriptor's close-on-exec flag
486 F_SETFD set the descriptor's close-on-exec flag to VALUE
487 F_GETFL read the descriptor's flags, as set on open
488 F_SETFL set the descriptor's flags, as set on open to VALUE
489 F_GETOWN return the process ID of a socket's owner, for SIGIO
490 F_SETOWN set the process that owns a socket to VALUE, for SIGIO
491 FD_CLOEXEC not sure what this is
493 For details, see the documentation for the fcntl system call.
495 *** The arguments to `select' have changed, for compatibility with
496 SCSH. The TIMEOUT parameter may now be non-integral, yielding the
497 expected behavior. The MILLISECONDS parameter has been changed to
498 MICROSECONDS, to more closely resemble the underlying system call.
499 The RVEC, WVEC, and EVEC arguments can now be vectors; the type of the
500 corresponding return set will be the same.
502 *** The arguments to the `mknod' system call have changed. They are
505 (mknod PATH TYPE PERMS DEV)
506 Create a new file (`node') in the file system. PATH is the name of
507 the file to create. TYPE is the kind of file to create; it should
508 be 'fifo, 'block-special, or 'char-special. PERMS specifies the
509 permission bits to give the newly created file. If TYPE is
510 'block-special or 'char-special, DEV specifies which device the
511 special file refers to; its interpretation depends on the kind of
512 special file being created.
514 *** The `fork' function has been renamed to `primitive-fork', to avoid
515 clashing with various SCSH forks.
517 *** The `recv' and `recvfrom' functions have been renamed to `recv!'
518 and `recvfrom!'. They no longer accept a size for a second argument;
519 you must pass a string to hold the received value. They no longer
520 return the buffer. Instead, `recv' returns the length of the message
521 received, and `recvfrom' returns a pair containing the packet's length
522 and originating address.
524 *** The file descriptor datatype has been removed, as have the
525 `read-fd', `write-fd', `close', `lseek', and `dup' functions.
526 We plan to replace these functions with a SCSH-compatible interface.
528 *** The `create' function has been removed; it's just a special case
531 *** There are new functions to break down process termination status
532 values. In the descriptions below, STATUS is a value returned by
535 (status:exit-val STATUS)
536 If the child process exited normally, this function returns the exit
537 code for the child process (i.e., the value passed to exit, or
538 returned from main). If the child process did not exit normally,
539 this function returns #f.
541 (status:stop-sig STATUS)
542 If the child process was suspended by a signal, this function
543 returns the signal that suspended the child. Otherwise, it returns
546 (status:term-sig STATUS)
547 If the child process terminated abnormally, this function returns
548 the signal that terminated the child. Otherwise, this function
551 POSIX promises that exactly one of these functions will return true on
552 a valid STATUS value.
554 These functions are compatible with SCSH.
556 *** There are new accessors and setters for the broken-out time vectors
557 returned by `localtime', `gmtime', and that ilk. They are:
559 Component Accessor Setter
560 ========================= ============ ============
561 seconds tm:sec set-tm:sec
562 minutes tm:min set-tm:min
563 hours tm:hour set-tm:hour
564 day of the month tm:mday set-tm:mday
565 month tm:mon set-tm:mon
566 year tm:year set-tm:year
567 day of the week tm:wday set-tm:wday
568 day in the year tm:yday set-tm:yday
569 daylight saving time tm:isdst set-tm:isdst
570 GMT offset, seconds tm:gmtoff set-tm:gmtoff
571 name of time zone tm:zone set-tm:zone
573 *** There are new accessors for the vectors returned by `uname',
574 describing the host system:
577 ============================================== ================
578 name of the operating system implementation utsname:sysname
579 network name of this machine utsname:nodename
580 release level of the operating system utsname:release
581 version level of the operating system utsname:version
582 machine hardware platform utsname:machine
584 *** There are new accessors for the vectors returned by `getpw',
585 `getpwnam', `getpwuid', and `getpwent', describing entries from the
586 system's user database:
589 ====================== =================
590 user name passwd:name
591 user password passwd:passwd
594 real name passwd:gecos
595 home directory passwd:dir
596 shell program passwd:shell
598 *** There are new accessors for the vectors returned by `getgr',
599 `getgrnam', `getgrgid', and `getgrent', describing entries from the
600 system's group database:
603 ======================= ============
604 group name group:name
605 group password group:passwd
607 group members group:mem
609 *** There are new accessors for the vectors returned by `gethost',
610 `gethostbyaddr', `gethostbyname', and `gethostent', describing
614 ========================= ===============
615 official name of host hostent:name
616 alias list hostent:aliases
617 host address type hostent:addrtype
618 length of address hostent:length
619 list of addresses hostent:addr-list
621 *** There are new accessors for the vectors returned by `getnet',
622 `getnetbyaddr', `getnetbyname', and `getnetent', describing internet
626 ========================= ===============
627 official name of net netent:name
628 alias list netent:aliases
629 net number type netent:addrtype
630 net number netent:net
632 *** There are new accessors for the vectors returned by `getproto',
633 `getprotobyname', `getprotobynumber', and `getprotoent', describing
637 ========================= ===============
638 official protocol name protoent:name
639 alias list protoent:aliases
640 protocol number protoent:proto
642 *** There are new accessors for the vectors returned by `getserv',
643 `getservbyname', `getservbyport', and `getservent', describing
647 ========================= ===============
648 official service name servent:name
649 alias list servent:aliases
650 port number servent:port
651 protocol to use servent:proto
653 *** There are new accessors for the sockaddr structures returned by
654 `accept', `getsockname', `getpeername', `recvfrom!':
657 ======================================== ===============
658 address format (`family') sockaddr:fam
659 path, for file domain addresses sockaddr:path
660 address, for internet domain addresses sockaddr:addr
661 TCP or UDP port, for internet sockaddr:port
663 *** The `getpwent', `getgrent', `gethostent', `getnetent',
664 `getprotoent', and `getservent' functions now return #f at the end of
665 the user database. (They used to throw an exception.)
667 Note that calling MUMBLEent function is equivalent to calling the
668 corresponding MUMBLE function with no arguments.
670 *** The `setpwent', `setgrent', `sethostent', `setnetent',
671 `setprotoent', and `setservent' routines now take no arguments.
673 *** The `gethost', `getproto', `getnet', and `getserv' functions now
674 provide more useful information when they throw an exception.
676 *** The `lnaof' function has been renamed to `inet-lnaof'.
678 *** Guile now claims to have the `current-time' feature.
680 *** The `mktime' function now takes an optional second argument ZONE,
681 giving the time zone to use for the conversion. ZONE should be a
682 string, in the same format as expected for the "TZ" environment variable.
684 *** The `strptime' function now returns a pair (TIME . COUNT), where
685 TIME is the parsed time as a vector, and COUNT is the number of
686 characters from the string left unparsed. This function used to
687 return the remaining characters as a string.
689 *** The `gettimeofday' function has replaced the old `time+ticks' function.
690 The return value is now (SECONDS . MICROSECONDS); the fractional
691 component is no longer expressed in "ticks".
693 *** The `ticks/sec' constant has been removed, in light of the above change.
695 * Changes to the gh_ interface
697 ** gh_eval_str() now returns an SCM object which is the result of the
700 ** gh_scm2str() now copies the Scheme data to a caller-provided C
703 ** gh_scm2newstr() now makes a C array, copies the Scheme data to it,
704 and returns the array
706 ** gh_scm2str0() is gone: there is no need to distinguish
707 null-terminated from non-null-terminated, since gh_scm2newstr() allows
708 the user to interpret the data both ways.
710 * Changes to the scm_ interface
712 ** The new function scm_symbol_value0 provides an easy way to get a
713 symbol's value from C code:
715 SCM scm_symbol_value0 (char *NAME)
716 Return the value of the symbol named by the null-terminated string
717 NAME in the current module. If the symbol named NAME is unbound in
718 the current module, return SCM_UNDEFINED.
720 ** The new function scm_sysintern0 creates new top-level variables,
721 without assigning them a value.
723 SCM scm_sysintern0 (char *NAME)
724 Create a new Scheme top-level variable named NAME. NAME is a
725 null-terminated string. Return the variable's value cell.
727 ** The function scm_internal_catch is the guts of catch. It handles
728 all the mechanics of setting up a catch target, invoking the catch
729 body, and perhaps invoking the handler if the body does a throw.
731 The function is designed to be usable from C code, but is general
732 enough to implement all the semantics Guile Scheme expects from throw.
734 TAG is the catch tag. Typically, this is a symbol, but this function
735 doesn't actually care about that.
737 BODY is a pointer to a C function which runs the body of the catch;
738 this is the code you can throw from. We call it like this:
739 BODY (BODY_DATA, JMPBUF)
741 BODY_DATA is just the BODY_DATA argument we received; we pass it
742 through to BODY as its first argument. The caller can make
743 BODY_DATA point to anything useful that BODY might need.
744 JMPBUF is the Scheme jmpbuf object corresponding to this catch,
745 which we have just created and initialized.
747 HANDLER is a pointer to a C function to deal with a throw to TAG,
748 should one occur. We call it like this:
749 HANDLER (HANDLER_DATA, THROWN_TAG, THROW_ARGS)
751 HANDLER_DATA is the HANDLER_DATA argument we recevied; it's the
752 same idea as BODY_DATA above.
753 THROWN_TAG is the tag that the user threw to; usually this is
754 TAG, but it could be something else if TAG was #t (i.e., a
755 catch-all), or the user threw to a jmpbuf.
756 THROW_ARGS is the list of arguments the user passed to the THROW
759 BODY_DATA is just a pointer we pass through to BODY. HANDLER_DATA
760 is just a pointer we pass through to HANDLER. We don't actually
761 use either of those pointers otherwise ourselves. The idea is
762 that, if our caller wants to communicate something to BODY or
763 HANDLER, it can pass a pointer to it as MUMBLE_DATA, which BODY and
764 HANDLER can then use. Think of it as a way to make BODY and
765 HANDLER closures, not just functions; MUMBLE_DATA points to the
768 Of course, it's up to the caller to make sure that any data a
769 MUMBLE_DATA needs is protected from GC. A common way to do this is
770 to make MUMBLE_DATA a pointer to data stored in an automatic
771 structure variable; since the collector must scan the stack for
772 references anyway, this assures that any references in MUMBLE_DATA
775 ** The new function scm_internal_lazy_catch is exactly like
776 scm_internal_catch, except:
778 - It does not unwind the stack (this is the major difference).
779 - If handler returns, its value is returned from the throw.
780 - BODY always receives #f as its JMPBUF argument (since there's no
781 jmpbuf associated with a lazy catch, because we don't unwind the
784 ** scm_body_thunk is a new body function you can pass to
785 scm_internal_catch if you want the body to be like Scheme's `catch'
786 --- a thunk, or a function of one argument if the tag is #f.
788 BODY_DATA is a pointer to a scm_body_thunk_data structure, which
789 contains the Scheme procedure to invoke as the body, and the tag
790 we're catching. If the tag is #f, then we pass JMPBUF (created by
791 scm_internal_catch) to the body procedure; otherwise, the body gets
794 ** scm_handle_by_proc is a new handler function you can pass to
795 scm_internal_catch if you want the handler to act like Scheme's catch
796 --- call a procedure with the tag and the throw arguments.
798 If the user does a throw to this catch, this function runs a handler
799 procedure written in Scheme. HANDLER_DATA is a pointer to an SCM
800 variable holding the Scheme procedure object to invoke. It ought to
801 be a pointer to an automatic variable (i.e., one living on the stack),
802 or the procedure object should be otherwise protected from GC.
804 ** scm_handle_by_message is a new handler function to use with
805 `scm_internal_catch' if you want Guile to print a message and die.
806 It's useful for dealing with throws to uncaught keys at the top level.
808 HANDLER_DATA, if non-zero, is assumed to be a char * pointing to a
809 message header to print; if zero, we use "guile" instead. That
810 text is followed by a colon, then the message described by ARGS.
812 ** The return type of scm_boot_guile is now void; the function does
813 not return a value, and indeed, never returns at all.
815 ** The new function scm_shell makes it easy for user applications to
816 process command-line arguments in a way that is compatible with the
817 stand-alone guile interpreter (which is in turn compatible with SCSH,
820 To use the scm_shell function, first initialize any guile modules
821 linked into your application, and then call scm_shell with the values
822 of ARGC and ARGV your `main' function received. scm_shell will adding
823 any SCSH-style meta-arguments from the top of the script file to the
824 argument vector, and then process the command-line arguments. This
825 generally means loading a script file or starting up an interactive
826 command interpreter. For details, see "Changes to the stand-alone
829 ** The new functions scm_get_meta_args and scm_count_argv help you
830 implement the SCSH-style meta-argument, `\'.
832 char **scm_get_meta_args (int ARGC, char **ARGV)
833 If the second element of ARGV is a string consisting of a single
834 backslash character (i.e. "\\" in Scheme notation), open the file
835 named by the following argument, parse arguments from it, and return
836 the spliced command line. The returned array is terminated by a
839 For details of argument parsing, see above, under "guile now accepts
840 command-line arguments compatible with SCSH..."
842 int scm_count_argv (char **ARGV)
843 Count the arguments in ARGV, assuming it is terminated by a null
846 For an example of how these functions might be used, see the source
847 code for the function scm_shell in libguile/script.c.
849 You will usually want to use scm_shell instead of calling this
852 ** The new function scm_compile_shell_switches turns an array of
853 command-line arguments into Scheme code to carry out the actions they
854 describe. Given ARGC and ARGV, it returns a Scheme expression to
855 evaluate, and calls scm_set_program_arguments to make any remaining
856 command-line arguments available to the Scheme code. For example,
857 given the following arguments:
859 -e main -s ekko a speckled gecko
861 scm_set_program_arguments will return the following expression:
863 (begin (load "ekko") (main (command-line)) (quit))
865 You will usually want to use scm_shell instead of calling this
868 ** The function scm_shell_usage prints a usage message appropriate for
869 an interpreter that uses scm_compile_shell_switches to handle its
870 command-line arguments.
872 void scm_shell_usage (int FATAL, char *MESSAGE)
873 Print a usage message to the standard error output. If MESSAGE is
874 non-zero, write it before the usage message, followed by a newline.
875 If FATAL is non-zero, exit the process, using FATAL as the
876 termination status. (If you want to be compatible with Guile,
877 always use 1 as the exit status when terminating due to command-line
880 You will usually want to use scm_shell instead of calling this
883 ** scm_eval_0str now returns SCM_UNSPECIFIED if the string contains no
884 expressions. It used to return SCM_EOL. Earth-shattering.
886 ** The macros for declaring scheme objects in C code have been
887 rearranged slightly. They are now:
889 SCM_SYMBOL (C_NAME, SCHEME_NAME)
890 Declare a static SCM variable named C_NAME, and initialize it to
891 point to the Scheme symbol whose name is SCHEME_NAME. C_NAME should
892 be a C identifier, and SCHEME_NAME should be a C string.
894 SCM_GLOBAL_SYMBOL (C_NAME, SCHEME_NAME)
895 Just like SCM_SYMBOL, but make C_NAME globally visible.
897 SCM_VCELL (C_NAME, SCHEME_NAME)
898 Create a global variable at the Scheme level named SCHEME_NAME.
899 Declare a static SCM variable named C_NAME, and initialize it to
900 point to the Scheme variable's value cell.
902 SCM_GLOBAL_VCELL (C_NAME, SCHEME_NAME)
903 Just like SCM_VCELL, but make C_NAME globally visible.
905 The `guile-snarf' script writes initialization code for these macros
906 to its standard output, given C source code as input.
908 The SCM_GLOBAL macro is gone.
910 ** The scm_read_line and scm_read_line_x functions have been replaced
911 by Scheme code based on the %read-delimited! procedure (known to C
912 code as scm_read_delimited_x). See its description above for more
915 ** The function scm_sys_open has been renamed to scm_open. It now
916 returns a port instead of an FD object.
918 * The dynamic linking support has changed. For more information, see
919 libguile/DYNAMIC-LINKING.
924 User-visible changes from Thursday, September 5, 1996 until Guile 1.0
927 * Changes to the 'guile' program:
929 ** Guile now loads some new files when it starts up. Guile first
930 searches the load path for init.scm, and loads it if found. Then, if
931 Guile is not being used to execute a script, and the user's home
932 directory contains a file named `.guile', Guile loads that.
934 ** You can now use Guile as a shell script interpreter.
936 To paraphrase the SCSH manual:
938 When Unix tries to execute an executable file whose first two
939 characters are the `#!', it treats the file not as machine code to
940 be directly executed by the native processor, but as source code
941 to be executed by some interpreter. The interpreter to use is
942 specified immediately after the #! sequence on the first line of
943 the source file. The kernel reads in the name of the interpreter,
944 and executes that instead. It passes the interpreter the source
945 filename as its first argument, with the original arguments
946 following. Consult the Unix man page for the `exec' system call
947 for more information.
949 Now you can use Guile as an interpreter, using a mechanism which is a
950 compatible subset of that provided by SCSH.
952 Guile now recognizes a '-s' command line switch, whose argument is the
953 name of a file of Scheme code to load. It also treats the two
954 characters `#!' as the start of a comment, terminated by `!#'. Thus,
955 to make a file of Scheme code directly executable by Unix, insert the
956 following two lines at the top of the file:
958 #!/usr/local/bin/guile -s
961 Guile treats the argument of the `-s' command-line switch as the name
962 of a file of Scheme code to load, and treats the sequence `#!' as the
963 start of a block comment, terminated by `!#'.
965 For example, here's a version of 'echo' written in Scheme:
967 #!/usr/local/bin/guile -s
969 (let loop ((args (cdr (program-arguments))))
973 (if (pair? (cdr args))
978 Why does `#!' start a block comment terminated by `!#', instead of the
979 end of the line? That is the notation SCSH uses, and although we
980 don't yet support the other SCSH features that motivate that choice,
981 we would like to be backward-compatible with any existing Guile
982 scripts once we do. Furthermore, if the path to Guile on your system
983 is too long for your kernel, you can start the script with this
987 exec /really/long/path/to/guile -s "$0" ${1+"$@"}
990 Note that some very old Unix systems don't support the `#!' syntax.
993 ** You can now run Guile without installing it.
995 Previous versions of the interactive Guile interpreter (`guile')
996 couldn't start up unless Guile's Scheme library had been installed;
997 they used the value of the environment variable `SCHEME_LOAD_PATH'
998 later on in the startup process, but not to find the startup code
999 itself. Now Guile uses `SCHEME_LOAD_PATH' in all searches for Scheme
1002 To run Guile without installing it, build it in the normal way, and
1003 then set the environment variable `SCHEME_LOAD_PATH' to a
1004 colon-separated list of directories, including the top-level directory
1005 of the Guile sources. For example, if you unpacked Guile so that the
1006 full filename of this NEWS file is /home/jimb/guile-1.0b3/NEWS, then
1009 export SCHEME_LOAD_PATH=/home/jimb/my-scheme:/home/jimb/guile-1.0b3
1012 ** Guile's read-eval-print loop no longer prints #<unspecified>
1013 results. If the user wants to see this, she can evaluate the
1014 expression (assert-repl-print-unspecified #t), perhaps in her startup
1017 ** Guile no longer shows backtraces by default when an error occurs;
1018 however, it does display a message saying how to get one, and how to
1019 request that they be displayed by default. After an error, evaluate
1021 to see a backtrace, and
1022 (debug-enable 'backtrace)
1023 to see them by default.
1027 * Changes to Guile Scheme:
1029 ** Guile now distinguishes between #f and the empty list.
1031 This is for compatibility with the IEEE standard, the (possibly)
1032 upcoming Revised^5 Report on Scheme, and many extant Scheme
1035 Guile used to have #f and '() denote the same object, to make Scheme's
1036 type system more compatible with Emacs Lisp's. However, the change
1037 caused too much trouble for Scheme programmers, and we found another
1038 way to reconcile Emacs Lisp with Scheme that didn't require this.
1041 ** Guile's delq, delv, delete functions, and their destructive
1042 counterparts, delq!, delv!, and delete!, now remove all matching
1043 elements from the list, not just the first. This matches the behavior
1044 of the corresponding Emacs Lisp functions, and (I believe) the Maclisp
1045 functions which inspired them.
1047 I recognize that this change may break code in subtle ways, but it
1048 seems best to make the change before the FSF's first Guile release,
1052 ** The compiled-library-path function has been deleted from libguile.
1054 ** The facilities for loading Scheme source files have changed.
1056 *** The variable %load-path now tells Guile which directories to search
1057 for Scheme code. Its value is a list of strings, each of which names
1060 *** The variable %load-extensions now tells Guile which extensions to
1061 try appending to a filename when searching the load path. Its value
1062 is a list of strings. Its default value is ("" ".scm").
1064 *** (%search-load-path FILENAME) searches the directories listed in the
1065 value of the %load-path variable for a Scheme file named FILENAME,
1066 with all the extensions listed in %load-extensions. If it finds a
1067 match, then it returns its full filename. If FILENAME is absolute, it
1068 returns it unchanged. Otherwise, it returns #f.
1070 %search-load-path will not return matches that refer to directories.
1072 *** (primitive-load FILENAME :optional CASE-INSENSITIVE-P SHARP)
1073 uses %seach-load-path to find a file named FILENAME, and loads it if
1074 it finds it. If it can't read FILENAME for any reason, it throws an
1077 The arguments CASE-INSENSITIVE-P and SHARP are interpreted as by the
1080 *** load uses the same searching semantics as primitive-load.
1082 *** The functions %try-load, try-load-with-path, %load, load-with-path,
1083 basic-try-load-with-path, basic-load-with-path, try-load-module-with-
1084 path, and load-module-with-path have been deleted. The functions
1085 above should serve their purposes.
1087 *** If the value of the variable %load-hook is a procedure,
1088 `primitive-load' applies its value to the name of the file being
1089 loaded (without the load path directory name prepended). If its value
1090 is #f, it is ignored. Otherwise, an error occurs.
1092 This is mostly useful for printing load notification messages.
1095 ** The function `eval!' is no longer accessible from the scheme level.
1096 We can't allow operations which introduce glocs into the scheme level,
1097 because Guile's type system can't handle these as data. Use `eval' or
1098 `read-and-eval!' (see below) as replacement.
1100 ** The new function read-and-eval! reads an expression from PORT,
1101 evaluates it, and returns the result. This is more efficient than
1102 simply calling `read' and `eval', since it is not necessary to make a
1103 copy of the expression for the evaluator to munge.
1105 Its optional arguments CASE_INSENSITIVE_P and SHARP are interpreted as
1106 for the `read' function.
1109 ** The function `int?' has been removed; its definition was identical
1110 to that of `integer?'.
1112 ** The functions `<?', `<?', `<=?', `=?', `>?', and `>=?'. Code should
1113 use the R4RS names for these functions.
1115 ** The function object-properties no longer returns the hash handle;
1116 it simply returns the object's property list.
1118 ** Many functions have been changed to throw errors, instead of
1119 returning #f on failure. The point of providing exception handling in
1120 the language is to simplify the logic of user code, but this is less
1121 useful if Guile's primitives don't throw exceptions.
1123 ** The function `fileno' has been renamed from `%fileno'.
1125 ** The function primitive-mode->fdes returns #t or #f now, not 1 or 0.
1128 * Changes to Guile's C interface:
1130 ** The library's initialization procedure has been simplified.
1131 scm_boot_guile now has the prototype:
1133 void scm_boot_guile (int ARGC,
1135 void (*main_func) (),
1138 scm_boot_guile calls MAIN_FUNC, passing it CLOSURE, ARGC, and ARGV.
1139 MAIN_FUNC should do all the work of the program (initializing other
1140 packages, reading user input, etc.) before returning. When MAIN_FUNC
1141 returns, call exit (0); this function never returns. If you want some
1142 other exit value, MAIN_FUNC may call exit itself.
1144 scm_boot_guile arranges for program-arguments to return the strings
1145 given by ARGC and ARGV. If MAIN_FUNC modifies ARGC/ARGV, should call
1146 scm_set_program_arguments with the final list, so Scheme code will
1147 know which arguments have been processed.
1149 scm_boot_guile establishes a catch-all catch handler which prints an
1150 error message and exits the process. This means that Guile exits in a
1151 coherent way when system errors occur and the user isn't prepared to
1152 handle it. If the user doesn't like this behavior, they can establish
1153 their own universal catcher in MAIN_FUNC to shadow this one.
1155 Why must the caller do all the real work from MAIN_FUNC? The garbage
1156 collector assumes that all local variables of type SCM will be above
1157 scm_boot_guile's stack frame on the stack. If you try to manipulate
1158 SCM values after this function returns, it's the luck of the draw
1159 whether the GC will be able to find the objects you allocate. So,
1160 scm_boot_guile function exits, rather than returning, to discourage
1161 people from making that mistake.
1163 The IN, OUT, and ERR arguments were removed; there are other
1164 convenient ways to override these when desired.
1166 The RESULT argument was deleted; this function should never return.
1168 The BOOT_CMD argument was deleted; the MAIN_FUNC argument is more
1172 ** Guile's header files should no longer conflict with your system's
1175 In order to compile code which #included <libguile.h>, previous
1176 versions of Guile required you to add a directory containing all the
1177 Guile header files to your #include path. This was a problem, since
1178 Guile's header files have names which conflict with many systems'
1181 Now only <libguile.h> need appear in your #include path; you must
1182 refer to all Guile's other header files as <libguile/mumble.h>.
1183 Guile's installation procedure puts libguile.h in $(includedir), and
1184 the rest in $(includedir)/libguile.
1187 ** Two new C functions, scm_protect_object and scm_unprotect_object,
1188 have been added to the Guile library.
1190 scm_protect_object (OBJ) protects OBJ from the garbage collector.
1191 OBJ will not be freed, even if all other references are dropped,
1192 until someone does scm_unprotect_object (OBJ). Both functions
1195 Note that calls to scm_protect_object do not nest. You can call
1196 scm_protect_object any number of times on a given object, and the
1197 next call to scm_unprotect_object will unprotect it completely.
1199 Basically, scm_protect_object and scm_unprotect_object just
1200 maintain a list of references to things. Since the GC knows about
1201 this list, all objects it mentions stay alive. scm_protect_object
1202 adds its argument to the list; scm_unprotect_object remove its
1203 argument from the list.
1206 ** scm_eval_0str now returns the value of the last expression
1209 ** The new function scm_read_0str reads an s-expression from a
1210 null-terminated string, and returns it.
1212 ** The new function `scm_stdio_to_port' converts a STDIO file pointer
1213 to a Scheme port object.
1215 ** The new function `scm_set_program_arguments' allows C code to set
1216 the value teruturned by the Scheme `program-arguments' function.
1221 * Guile no longer includes sophisticated Tcl/Tk support.
1223 The old Tcl/Tk support was unsatisfying to us, because it required the
1224 user to link against the Tcl library, as well as Tk and Guile. The
1225 interface was also un-lispy, in that it preserved Tcl/Tk's practice of
1226 referring to widgets by names, rather than exporting widgets to Scheme
1227 code as a special datatype.
1229 In the Usenix Tk Developer's Workshop held in July 1996, the Tcl/Tk
1230 maintainers described some very interesting changes in progress to the
1231 Tcl/Tk internals, which would facilitate clean interfaces between lone
1232 Tk and other interpreters --- even for garbage-collected languages
1233 like Scheme. They expected the new Tk to be publicly available in the
1236 Since it seems that Guile might soon have a new, cleaner interface to
1237 lone Tk, and that the old Guile/Tk glue code would probably need to be
1238 completely rewritten, we (Jim Blandy and Richard Stallman) have
1239 decided not to support the old code. We'll spend the time instead on
1240 a good interface to the newer Tk, as soon as it is available.
1242 Until then, gtcltk-lib provides trivial, low-maintenance functionality.
1245 Copyright information:
1247 Copyright (C) 1996,1997 Free Software Foundation, Inc.
1249 Permission is granted to anyone to make or distribute verbatim copies
1250 of this document as received, in any medium, provided that the
1251 copyright notice and this permission notice are preserved,
1252 thus giving the recipient permission to redistribute in turn.
1254 Permission is granted to distribute modified versions
1255 of this document, or of portions of it,
1256 under the above conditions, provided also that they
1257 carry prominent notices stating who last changed them.
1262 paragraph-separate: "[
\f]*$"