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@gnu.org.
7 Changes since Guile 1.2:
9 * Changes to the distribution
11 ** We renamed the SCHEME_LOAD_PATH environment variable to GUILE_LOAD_PATH.
12 To avoid conflicts, programs should name environment variables after
13 themselves, except when there's a common practice establishing some
16 For now, Guile supports both GUILE_LOAD_PATH and SCHEME_LOAD_PATH,
17 giving the former precedence, and printing a warning message if the
18 latter is set. Guile 1.4 will not recognize SCHEME_LOAD_PATH at all.
20 ** The header files related to multi-byte characters have been removed.
21 They were: libguile/extchrs.h and libguile/mbstrings.h. Any C code
22 which referred to these explicitly will probably need to be rewritten,
23 since the support for the variant string types has been removed; see
26 ** The header files append.h and sequences.h have been removed. These
27 files implemented non-R4RS operations which would encourage
28 non-portable programming style and less easy-to-read code.
30 * Changes to the stand-alone interpreter
32 ** New procedures have been added to implement a "batch mode":
34 *** Function: batch-mode?
36 Returns a boolean indicating whether the interpreter is in batch
39 *** Function: set-batch-mode?! ARG
41 If ARG is true, switches the interpreter to batch mode. The `#f'
42 case has not been implemented.
44 ** Guile now provides full command-line editing, when run interactively.
45 To use this feature, you must have the readline library installed.
46 The Guile build process will notice it, and automatically include
49 The readline library is available via anonymous FTP from any GNU
50 mirror site; the canonical location is "ftp://prep.ai.mit.edu/pub/gnu".
52 ** the-last-stack is now a fluid.
54 * Changes to the procedure for linking libguile with your programs
56 ** You can now use the `guile-config' utility to build programs that use Guile.
58 Guile now includes a command-line utility called `guile-config', which
59 can provide information about how to compile and link programs that
62 *** `guile-config compile' prints any C compiler flags needed to use Guile.
63 You should include this command's output on the command line you use
64 to compile C or C++ code that #includes the Guile header files. It's
65 usually just a `-I' flag to help the compiler find the Guile headers.
68 *** `guile-config link' prints any linker flags necessary to link with Guile.
70 This command writes to its standard output a list of flags which you
71 must pass to the linker to link your code against the Guile library.
72 The flags include '-lguile' itself, any other libraries the Guile
73 library depends upon, and any `-L' flags needed to help the linker
76 For example, here is a Makefile rule that builds a program named 'foo'
77 from the object files ${FOO_OBJECTS}, and links them against Guile:
80 ${CC} ${CFLAGS} ${FOO_OBJECTS} `guile-config link` -o foo
82 Previous Guile releases recommended that you use autoconf to detect
83 which of a predefined set of libraries were present on your system.
84 It is more robust to use `guile-config', since it records exactly which
85 libraries the installed Guile library requires.
87 This was originally called `build-guile', but was renamed to
88 `guile-config' before Guile 1.3 was released, to be consistent with
89 the analogous script for the GTK+ GUI toolkit, which is called
93 ** Use the GUILE_FLAGS macro in your configure.in file to find Guile.
95 If you are using the GNU autoconf package to configure your program,
96 you can use the GUILE_FLAGS autoconf macro to call `guile-config'
97 (described above) and gather the necessary values for use in your
100 The GUILE_FLAGS macro expands to configure script code which runs the
101 `guile-config' script, to find out where Guile's header files and
102 libraries are installed. It sets two variables, marked for
103 substitution, as by AC_SUBST.
105 GUILE_CFLAGS --- flags to pass to a C or C++ compiler to build
106 code that uses Guile header files. This is almost always just a
109 GUILE_LDFLAGS --- flags to pass to the linker to link a
110 program against Guile. This includes `-lguile' for the Guile
111 library itself, any libraries that Guile itself requires (like
112 -lqthreads), and so on. It may also include a -L flag to tell the
113 compiler where to find the libraries.
115 GUILE_FLAGS is defined in the file guile.m4, in the top-level
116 directory of the Guile distribution. You can copy it into your
117 package's aclocal.m4 file, and then use it in your configure.in file.
119 If you are using the `aclocal' program, distributed with GNU automake,
120 to maintain your aclocal.m4 file, the Guile installation process
121 installs guile.m4 where aclocal will find it. All you need to do is
122 use GUILE_FLAGS in your configure.in file, and then run `aclocal';
123 this will copy the definition of GUILE_FLAGS into your aclocal.m4
127 * Changes to Scheme functions and syntax
129 ** Multi-byte strings have been removed, as have multi-byte and wide
130 ports. We felt that these were the wrong approach to
131 internationalization support.
133 ** New function: readline [PROMPT]
134 Read a line from the terminal, and allow the user to edit it,
135 prompting with PROMPT. READLINE provides a large set of Emacs-like
136 editing commands, lets the user recall previously typed lines, and
137 works on almost every kind of terminal, including dumb terminals.
139 READLINE assumes that the cursor is at the beginning of the line when
140 it is invoked. Thus, you can't print a prompt yourself, and then call
141 READLINE; you need to package up your prompt as a string, pass it to
142 the function, and let READLINE print the prompt itself. This is
143 because READLINE needs to know the prompt's screen width.
145 For Guile to provide this function, you must have the readline library
146 installed on your system.
148 See also ADD-HISTORY function.
150 ** New function: add-history STRING
151 Add STRING as the most recent line in the history used by the READLINE
152 command. READLINE does not add lines to the history itself; you must
153 call ADD-HISTORY to make previous input available to the user.
155 ** New module (ice-9 getopt-gnu-style): Parse command-line arguments.
157 This module provides some simple argument parsing. It exports one
160 Function: getopt-gnu-style ARG-LS
161 Parse a list of program arguments into an alist of option
164 Each item in the list of program arguments is examined to see if
165 it meets the syntax of a GNU long-named option. An argument like
166 `--MUMBLE' produces an element of the form (MUMBLE . #t) in the
167 returned alist, where MUMBLE is a keyword object with the same
168 name as the argument. An argument like `--MUMBLE=FROB' produces
169 an element of the form (MUMBLE . FROB), where FROB is a string.
171 As a special case, the returned alist also contains a pair whose
172 car is the symbol `rest'. The cdr of this pair is a list
173 containing all the items in the argument list that are not options
174 of the form mentioned above.
176 The argument `--' is treated specially: all items in the argument
177 list appearing after such an argument are not examined, and are
178 returned in the special `rest' list.
180 This function does not parse normal single-character switches.
181 You will need to parse them out of the `rest' list yourself.
183 ** macro-eval! is removed. Use local-eval instead.
185 ** Some magic has been added to the printer to better handle user
186 written printing routines (like record printers, closure printers).
188 The problem is that these user written routines must have access to
189 the current `print-state' to be able to handle fancy things like
190 detection of circular references. These print-states have to be
191 passed to the builtin printing routines (display, write, etc) to
192 properly continue the print chain.
194 We didn't want to change all existing print code so that it
195 explicitely passes thru a print state in addition to a port. Instead,
196 we extented the possible values that the builtin printing routines
197 accept as a `port'. In addition to a normal port, they now also take
198 a pair of a normal port and a print-state. Printing will go to the
199 port and the print-state will be used to control the detection of
200 circular references, etc. If the builtin function does not care for a
201 print-state, it is simply ignored.
203 User written callbacks are now called with such a pair as their
204 `port', but because every function now accepts this pair as a PORT
205 argument, you don't have to worry about that. In fact, it is probably
206 safest to not check for these pairs.
208 However, it is sometimes necessary to continue a print chain on a
209 different port, for example to get a intermediate string
210 representation of the printed value, mangle that string somehow, and
211 then to finally print the mangled string. Use the new function
213 inherit-print-state OLD-PORT NEW-PORT
215 for this. It constructs a new `port' that prints to NEW-PORT but
216 inherits the print-state of OLD-PORT.
218 ** struct-vtable-offset renamed to vtable-offset-user
220 ** New constants: vtable-index-layout, vtable-index-vtable, vtable-index-printer
222 ** There is now a fourth (optional) argument to make-vtable-vtable and
223 make-struct when constructing new types (vtables). This argument
224 initializes field vtable-index-printer of the vtable.
226 ** The detection of circular references has been extended to structs.
227 That is, a structure that -- in the process of being printed -- prints
228 itself does not lead to infinite recursion.
230 ** There is now some basic support for fluids. Please read
231 "libguile/fluid.h" to find out more. It is accessible from Scheme with
232 the following functions and macros:
236 Create a new fluid object. Fluids are not special variables or
237 some other extension to the semantics of Scheme, but rather
238 ordinary Scheme objects. You can store them into variables (that
239 are still lexically scoped, of course) or into any other place you
240 like. Every fluid has a initial value of `#f'.
244 Test whether OBJ is a fluid.
246 Function: fluid-ref FLUID
247 Function: fluid-set! FLUID VAL
249 Access/modify the fluid FLUID. Modifications are only visible
250 within the current dynamic root (that includes threads).
252 Function: with-fluids* FLUIDS VALUES THUNK
254 FLUIDS is a list of fluids and VALUES a corresponding list of
255 values for these fluids. Before THUNK gets called the values are
256 installed in the fluids and the old values of the fluids are
257 saved in the VALUES list. When the flow of control leaves THUNK
258 or reenters it, the values get swapped again. You might think of
259 this as a `safe-fluid-excursion'. Note that the VALUES list is
260 modified by `with-fluids*'.
262 Macro: with-fluids ((FLUID VALUE) ...) FORM ...
264 The same as `with-fluids*' but with a different syntax. It looks
265 just like `let', but both FLUID and VALUE are evaluated. Remember,
266 fluids are not special variables but ordinary objects. FLUID
267 should evaluate to a fluid.
269 ** Changes to system call interfaces:
271 *** close-port, close-input-port and close-output-port now return a
272 boolean instead of an `unspecified' object. #t means that the port
273 was successfully closed, while #f means it was already closed. It is
274 also now possible for these procedures to raise an exception if an
275 error occurs (some errors from write can be delayed until close.)
277 *** the first argument to chmod, fcntl, ftell and fseek can now be a
280 *** the third argument to fcntl is now optional.
282 *** the first argument to chown can now be a file descriptor or a port.
284 *** the argument to stat can now be a port.
286 *** The following new procedures have been added (most use scsh
289 *** procedure: close PORT/FD
290 Similar to close-port (*note close-port: Closing Ports.), but also
291 works on file descriptors. A side effect of closing a file
292 descriptor is that any ports using that file descriptor are moved
293 to a different file descriptor and have their revealed counts set
296 *** procedure: port->fdes PORT
297 Returns the integer file descriptor underlying PORT. As a side
298 effect the revealed count of PORT is incremented.
300 *** procedure: fdes->ports FDES
301 Returns a list of existing ports which have FDES as an underlying
302 file descriptor, without changing their revealed counts.
304 *** procedure: fdes->inport FDES
305 Returns an existing input port which has FDES as its underlying
306 file descriptor, if one exists, and increments its revealed count.
307 Otherwise, returns a new input port with a revealed count of 1.
309 *** procedure: fdes->outport FDES
310 Returns an existing output port which has FDES as its underlying
311 file descriptor, if one exists, and increments its revealed count.
312 Otherwise, returns a new output port with a revealed count of 1.
314 The next group of procedures perform a `dup2' system call, if NEWFD
315 (an integer) is supplied, otherwise a `dup'. The file descriptor to be
316 duplicated can be supplied as an integer or contained in a port. The
317 type of value returned varies depending on which procedure is used.
319 All procedures also have the side effect when performing `dup2' that
320 any ports using NEWFD are moved to a different file descriptor and have
321 their revealed counts set to zero.
323 *** procedure: dup->fdes PORT/FD [NEWFD]
324 Returns an integer file descriptor.
326 *** procedure: dup->inport PORT/FD [NEWFD]
327 Returns a new input port using the new file descriptor.
329 *** procedure: dup->outport PORT/FD [NEWFD]
330 Returns a new output port using the new file descriptor.
332 *** procedure: dup PORT/FD [NEWFD]
333 Returns a new port if PORT/FD is a port, with the same mode as the
334 supplied port, otherwise returns an integer file descriptor.
336 *** procedure: dup->port PORT/FD MODE [NEWFD]
337 Returns a new port using the new file descriptor. MODE supplies a
338 mode string for the port (*note open-file: File Ports.).
340 *** procedure: setenv NAME VALUE
341 Modifies the environment of the current process, which is also the
342 default environment inherited by child processes.
344 If VALUE is `#f', then NAME is removed from the environment.
345 Otherwise, the string NAME=VALUE is added to the environment,
346 replacing any existing string with name matching NAME.
348 The return value is unspecified.
350 *** procedure: truncate-file OBJ SIZE
351 Truncates the file referred to by OBJ to at most SIZE bytes. OBJ
352 can be a string containing a file name or an integer file
353 descriptor or port open for output on the file. The underlying
354 system calls are `truncate' and `ftruncate'.
356 The return value is unspecified.
358 *** procedure: setvbuf PORT MODE [SIZE]
359 Set the buffering mode for PORT. MODE can be:
367 block buffered, using a newly allocated buffer of SIZE bytes.
368 However if SIZE is zero or unspecified, the port will be made
371 This procedure should not be used after I/O has been performed with
374 Ports are usually block buffered by default, with a default buffer
375 size. Procedures e.g., *Note open-file: File Ports, which accept a
376 mode string allow `0' to be added to request an unbuffered port.
378 *** procedure: fsync PORT/FD
379 Copies any unwritten data for the specified output file descriptor
380 to disk. If PORT/FD is a port, its buffer is flushed before the
381 underlying file descriptor is fsync'd. The return value is
384 *** procedure: open-fdes PATH FLAGS [MODES]
385 Similar to `open' but returns a file descriptor instead of a port.
387 *** procedure: execle PATH ENV [ARG] ...
388 Similar to `execl', but the environment of the new process is
389 specified by ENV, which must be a list of strings as returned by
390 the `environ' procedure.
392 This procedure is currently implemented using the `execve' system
393 call, but we call it `execle' because of its Scheme calling
396 *** procedure: strerror ERRNO
397 Returns the Unix error message corresponding to ERRNO, an integer.
399 *** procedure: primitive-exit [STATUS]
400 Terminate the current process without unwinding the Scheme stack.
401 This is would typically be useful after a fork. The exit status
402 is STATUS if supplied, otherwise zero.
405 Returns an object with information about real and processor time.
406 The following procedures accept such an object as an argument and
407 return a selected component:
410 The current real time, expressed as time units relative to an
414 The CPU time units used by the calling process.
417 The CPU time units used by the system on behalf of the
421 The CPU time units used by terminated child processes of the
422 calling process, whose status has been collected (e.g., using
426 Similarly, the CPU times units used by the system on behalf of
427 terminated child processes.
429 ** Removed: list-length
430 ** Removed: list-append, list-append!
431 ** Removed: list-reverse, list-reverse!
433 ** array-map renamed to array-map!
435 ** serial-array-map renamed to serial-array-map!
437 ** catch doesn't take #f as first argument any longer
439 Previously, it was possible to pass #f instead of a key to `catch'.
440 That would cause `catch' to pass a jump buffer object to the procedure
441 passed as second argument. The procedure could then use this jump
442 buffer objekt as an argument to throw.
444 This mechanism has been removed since its utility doesn't motivate the
445 extra complexity it introduces.
447 * Changes to the gh_ interface
449 ** The gh_enter function now takes care of loading the Guile startup files.
450 gh_enter works by calling scm_boot_guile; see the remarks below.
452 ** Function: void gh_write (SCM x)
454 Write the printed representation of the scheme object x to the current
455 output port. Corresponds to the scheme level `write'.
457 ** gh_list_length renamed to gh_length.
459 ** vector handling routines
461 Several major changes. In particular, gh_vector() now resembles
462 (vector ...) (with a caveat -- see manual), and gh_make_vector() now
463 exists and behaves like (make-vector ...). gh_vset() and gh_vref()
464 have been renamed gh_vector_set_x() and gh_vector_ref(). Some missing
465 vector-related gh_ functions have been implemented.
467 ** pair and list routines
469 Implemented several of the R4RS pair and list functions that were
472 ** gh_scm2doubles, gh_doubles2scm, gh_doubles2dvect
474 New function. Converts double arrays back and forth between Scheme
477 * Changes to the scm_ interface
479 ** The function scm_boot_guile now takes care of loading the startup files.
481 Guile's primary initialization function, scm_boot_guile, now takes
482 care of loading `boot-9.scm', in the `ice-9' module, to initialize
483 Guile, define the module system, and put together some standard
484 bindings. It also loads `init.scm', which is intended to hold
485 site-specific initialization code.
487 Since Guile cannot operate properly until boot-9.scm is loaded, there
488 is no reason to separate loading boot-9.scm from Guile's other
489 initialization processes.
491 This job used to be done by scm_compile_shell_switches, which didn't
492 make much sense; in particular, it meant that people using Guile for
493 non-shell-like applications had to jump through hoops to get Guile
494 initialized properly.
496 ** The function scm_compile_shell_switches no longer loads the startup files.
497 Now, Guile always loads the startup files, whenever it is initialized;
498 see the notes above for scm_boot_guile and scm_load_startup_files.
500 ** Function: scm_load_startup_files
501 This new function takes care of loading Guile's initialization file
502 (`boot-9.scm'), and the site initialization file, `init.scm'. Since
503 this is always called by the Guile initialization process, it's
504 probably not too useful to call this yourself, but it's there anyway.
506 ** The semantics of smob marking have changed slightly.
508 The smob marking function (the `mark' member of the scm_smobfuns
509 structure) is no longer responsible for setting the mark bit on the
510 smob. The generic smob handling code in the garbage collector will
511 set this bit. The mark function need only ensure that any other
512 objects the smob refers to get marked.
514 Note that this change means that the smob's GC8MARK bit is typically
515 already set upon entry to the mark function. Thus, marking functions
516 which look like this:
519 if (SCM_GC8MARKP (ptr))
521 SCM_SETGC8MARK (ptr);
522 ... mark objects to which the smob refers ...
525 are now incorrect, since they will return early, and fail to mark any
526 other objects the smob refers to. Some code in the Guile library used
530 ** Function: int scm_internal_select (int fds,
534 struct timeval *timeout);
536 This is a replacement for the `select' function provided by the OS.
537 It enables I/O blocking and sleeping to happen for one cooperative
538 thread without blocking other threads. It also avoids busy-loops in
539 these situations. It is intended that all I/O blocking and sleeping
540 will finally go through this function. Currently, this function is
541 only available on systems providing `gettimeofday' and `select'.
543 ** Function: SCM scm_internal_stack_catch (SCM tag,
544 scm_catch_body_t body,
546 scm_catch_handler_t handler,
549 A new sibling to the other two C level `catch' functions
550 scm_internal_catch and scm_internal_lazy_catch. Use it if you want
551 the stack to be saved automatically into the variable `the-last-stack'
552 (scm_the_last_stack_var) on error. This is necessary if you want to
553 use advanced error reporting, such as calling scm_display_error and
554 scm_display_backtrace. (They both take a stack object as argument.)
556 ** Function: SCM scm_spawn_thread (scm_catch_body_t body,
558 scm_catch_handler_t handler,
561 Spawns a new thread. It does a job similar to
562 scm_call_with_new_thread but takes arguments more suitable when
563 spawning threads from application C code.
565 ** The hook scm_error_callback has been removed. It was originally
566 intended as a way for the user to install his own error handler. But
567 that method works badly since it intervenes between throw and catch,
568 thereby changing the semantics of expressions like (catch #t ...).
569 The correct way to do it is to use one of the C level catch functions
570 in throw.c: scm_internal_catch/lazy_catch/stack_catch.
572 ** Removed functions:
574 scm_obj_length, scm_list_length, scm_list_append, scm_list_append_x,
575 scm_list_reverse, scm_list_reverse_x
577 ** New macros: SCM_LISTn where n is one of the integers 0-9.
579 These can be used for pretty list creation from C. The idea is taken
580 from Erick Gallesio's STk.
582 ** scm_array_map renamed to scm_array_map_x
584 ** mbstrings are now removed
586 This means that the type codes scm_tc7_mb_string and
587 scm_tc7_mb_substring has been removed.
589 ** The macros SCM_TYP7D and SCM_TYP7SD has been removed.
591 ** The macro SCM_TYP7S has taken the role of the old SCM_TYP7D
593 SCM_TYP7S now masks away the bit which distinguishes substrings from
596 ** All genio functions changed names and interfaces; new functions are
597 scm_putc, scm_puts, scm_lfwrite, scm_getc, scm_ungetc, and
600 ** scm_catch_body_t: Backward incompatible change!
602 Body functions to scm_internal_catch and friends do not any longer
603 take a second argument. This is because it is no longer possible to
604 pass a #f arg to catch.
607 Changes in Guile 1.2 (released Tuesday, June 24 1997):
609 * Changes to the distribution
611 ** Nightly snapshots are now available from ftp.red-bean.com.
612 The old server, ftp.cyclic.com, has been relinquished to its rightful
615 Nightly snapshots of the Guile development sources are now available via
616 anonymous FTP from ftp.red-bean.com, as /pub/guile/guile-snap.tar.gz.
618 Via the web, that's: ftp://ftp.red-bean.com/pub/guile/guile-snap.tar.gz
619 For getit, that's: ftp.red-bean.com:/pub/guile/guile-snap.tar.gz
621 ** To run Guile without installing it, the procedure has changed a bit.
623 If you used a separate build directory to compile Guile, you'll need
624 to include the build directory in SCHEME_LOAD_PATH, as well as the
625 source directory. See the `INSTALL' file for examples.
627 * Changes to the procedure for linking libguile with your programs
629 ** The standard Guile load path for Scheme code now includes
630 $(datadir)/guile (usually /usr/local/share/guile). This means that
631 you can install your own Scheme files there, and Guile will find them.
632 (Previous versions of Guile only checked a directory whose name
633 contained the Guile version number, so you had to re-install or move
634 your Scheme sources each time you installed a fresh version of Guile.)
636 The load path also includes $(datadir)/guile/site; we recommend
637 putting individual Scheme files there. If you want to install a
638 package with multiple source files, create a directory for them under
641 ** Guile 1.2 will now use the Rx regular expression library, if it is
642 installed on your system. When you are linking libguile into your own
643 programs, this means you will have to link against -lguile, -lqt (if
644 you configured Guile with thread support), and -lrx.
646 If you are using autoconf to generate configuration scripts for your
647 application, the following lines should suffice to add the appropriate
648 libraries to your link command:
650 ### Find Rx, quickthreads and libguile.
651 AC_CHECK_LIB(rx, main)
652 AC_CHECK_LIB(qt, main)
653 AC_CHECK_LIB(guile, scm_shell)
655 The Guile 1.2 distribution does not contain sources for the Rx
656 library, as Guile 1.0 did. If you want to use Rx, you'll need to
657 retrieve it from a GNU FTP site and install it separately.
659 * Changes to Scheme functions and syntax
661 ** The dynamic linking features of Guile are now enabled by default.
662 You can disable them by giving the `--disable-dynamic-linking' option
665 (dynamic-link FILENAME)
667 Find the object file denoted by FILENAME (a string) and link it
668 into the running Guile application. When everything works out,
669 return a Scheme object suitable for representing the linked object
670 file. Otherwise an error is thrown. How object files are
671 searched is system dependent.
673 (dynamic-object? VAL)
675 Determine whether VAL represents a dynamically linked object file.
677 (dynamic-unlink DYNOBJ)
679 Unlink the indicated object file from the application. DYNOBJ
680 should be one of the values returned by `dynamic-link'.
682 (dynamic-func FUNCTION DYNOBJ)
684 Search the C function indicated by FUNCTION (a string or symbol)
685 in DYNOBJ and return some Scheme object that can later be used
686 with `dynamic-call' to actually call this function. Right now,
687 these Scheme objects are formed by casting the address of the
688 function to `long' and converting this number to its Scheme
691 (dynamic-call FUNCTION DYNOBJ)
693 Call the C function indicated by FUNCTION and DYNOBJ. The
694 function is passed no arguments and its return value is ignored.
695 When FUNCTION is something returned by `dynamic-func', call that
696 function and ignore DYNOBJ. When FUNCTION is a string (or symbol,
697 etc.), look it up in DYNOBJ; this is equivalent to
699 (dynamic-call (dynamic-func FUNCTION DYNOBJ) #f)
701 Interrupts are deferred while the C function is executing (with
702 SCM_DEFER_INTS/SCM_ALLOW_INTS).
704 (dynamic-args-call FUNCTION DYNOBJ ARGS)
706 Call the C function indicated by FUNCTION and DYNOBJ, but pass it
707 some arguments and return its return value. The C function is
708 expected to take two arguments and return an `int', just like
711 int c_func (int argc, char **argv);
713 ARGS must be a list of strings and is converted into an array of
714 `char *'. The array is passed in ARGV and its size in ARGC. The
715 return value is converted to a Scheme number and returned from the
716 call to `dynamic-args-call'.
718 When dynamic linking is disabled or not supported on your system,
719 the above functions throw errors, but they are still available.
721 Here is a small example that works on GNU/Linux:
723 (define libc-obj (dynamic-link "libc.so"))
724 (dynamic-args-call 'rand libc-obj '())
726 See the file `libguile/DYNAMIC-LINKING' for additional comments.
728 ** The #/ syntax for module names is depreciated, and will be removed
729 in a future version of Guile. Instead of
737 The latter syntax is more consistent with existing Lisp practice.
739 ** Guile now does fancier printing of structures. Structures are the
740 underlying implementation for records, which in turn are used to
741 implement modules, so all of these object now print differently and in
742 a more informative way.
744 The Scheme printer will examine the builtin variable *struct-printer*
745 whenever it needs to print a structure object. When this variable is
746 not `#f' it is deemed to be a procedure and will be applied to the
747 structure object and the output port. When *struct-printer* is `#f'
748 or the procedure return `#f' the structure object will be printed in
749 the boring #<struct 80458270> form.
751 This hook is used by some routines in ice-9/boot-9.scm to implement
752 type specific printing routines. Please read the comments there about
755 One of the more specific uses of structs are records. The printing
756 procedure that could be passed to MAKE-RECORD-TYPE is now actually
757 called. It should behave like a *struct-printer* procedure (described
760 ** Guile now supports a new R4RS-compliant syntax for keywords. A
761 token of the form #:NAME, where NAME has the same syntax as a Scheme
762 symbol, is the external representation of the keyword named NAME.
763 Keyword objects print using this syntax as well, so values containing
764 keyword objects can be read back into Guile. When used in an
765 expression, keywords are self-quoting objects.
767 Guile suports this read syntax, and uses this print syntax, regardless
768 of the current setting of the `keyword' read option. The `keyword'
769 read option only controls whether Guile recognizes the `:NAME' syntax,
770 which is incompatible with R4RS. (R4RS says such token represent
773 ** Guile has regular expression support again. Guile 1.0 included
774 functions for matching regular expressions, based on the Rx library.
775 In Guile 1.1, the Guile/Rx interface was removed to simplify the
776 distribution, and thus Guile had no regular expression support. Guile
777 1.2 again supports the most commonly used functions, and supports all
778 of SCSH's regular expression functions.
780 If your system does not include a POSIX regular expression library,
781 and you have not linked Guile with a third-party regexp library such as
782 Rx, these functions will not be available. You can tell whether your
783 Guile installation includes regular expression support by checking
784 whether the `*features*' list includes the `regex' symbol.
788 By default, Guile supports POSIX extended regular expressions. That
789 means that the characters `(', `)', `+' and `?' are special, and must
790 be escaped if you wish to match the literal characters.
792 This regular expression interface was modeled after that implemented
793 by SCSH, the Scheme Shell. It is intended to be upwardly compatible
794 with SCSH regular expressions.
796 **** Function: string-match PATTERN STR [START]
797 Compile the string PATTERN into a regular expression and compare
798 it with STR. The optional numeric argument START specifies the
799 position of STR at which to begin matching.
801 `string-match' returns a "match structure" which describes what,
802 if anything, was matched by the regular expression. *Note Match
803 Structures::. If STR does not match PATTERN at all,
804 `string-match' returns `#f'.
806 Each time `string-match' is called, it must compile its PATTERN
807 argument into a regular expression structure. This operation is
808 expensive, which makes `string-match' inefficient if the same regular
809 expression is used several times (for example, in a loop). For better
810 performance, you can compile a regular expression in advance and then
811 match strings against the compiled regexp.
813 **** Function: make-regexp STR [FLAGS]
814 Compile the regular expression described by STR, and return the
815 compiled regexp structure. If STR does not describe a legal
816 regular expression, `make-regexp' throws a
817 `regular-expression-syntax' error.
819 FLAGS may be the bitwise-or of one or more of the following:
821 **** Constant: regexp/extended
822 Use POSIX Extended Regular Expression syntax when interpreting
823 STR. If not set, POSIX Basic Regular Expression syntax is used.
824 If the FLAGS argument is omitted, we assume regexp/extended.
826 **** Constant: regexp/icase
827 Do not differentiate case. Subsequent searches using the
828 returned regular expression will be case insensitive.
830 **** Constant: regexp/newline
831 Match-any-character operators don't match a newline.
833 A non-matching list ([^...]) not containing a newline matches a
836 Match-beginning-of-line operator (^) matches the empty string
837 immediately after a newline, regardless of whether the FLAGS
838 passed to regexp-exec contain regexp/notbol.
840 Match-end-of-line operator ($) matches the empty string
841 immediately before a newline, regardless of whether the FLAGS
842 passed to regexp-exec contain regexp/noteol.
844 **** Function: regexp-exec REGEXP STR [START [FLAGS]]
845 Match the compiled regular expression REGEXP against `str'. If
846 the optional integer START argument is provided, begin matching
847 from that position in the string. Return a match structure
848 describing the results of the match, or `#f' if no match could be
851 FLAGS may be the bitwise-or of one or more of the following:
853 **** Constant: regexp/notbol
854 The match-beginning-of-line operator always fails to match (but
855 see the compilation flag regexp/newline above) This flag may be
856 used when different portions of a string are passed to
857 regexp-exec and the beginning of the string should not be
858 interpreted as the beginning of the line.
860 **** Constant: regexp/noteol
861 The match-end-of-line operator always fails to match (but see the
862 compilation flag regexp/newline above)
864 **** Function: regexp? OBJ
865 Return `#t' if OBJ is a compiled regular expression, or `#f'
868 Regular expressions are commonly used to find patterns in one string
869 and replace them with the contents of another string.
871 **** Function: regexp-substitute PORT MATCH [ITEM...]
872 Write to the output port PORT selected contents of the match
873 structure MATCH. Each ITEM specifies what should be written, and
874 may be one of the following arguments:
876 * A string. String arguments are written out verbatim.
878 * An integer. The submatch with that number is written.
880 * The symbol `pre'. The portion of the matched string preceding
881 the regexp match is written.
883 * The symbol `post'. The portion of the matched string
884 following the regexp match is written.
886 PORT may be `#f', in which case nothing is written; instead,
887 `regexp-substitute' constructs a string from the specified ITEMs
890 **** Function: regexp-substitute/global PORT REGEXP TARGET [ITEM...]
891 Similar to `regexp-substitute', but can be used to perform global
892 substitutions on STR. Instead of taking a match structure as an
893 argument, `regexp-substitute/global' takes two string arguments: a
894 REGEXP string describing a regular expression, and a TARGET string
895 which should be matched against this regular expression.
897 Each ITEM behaves as in REGEXP-SUBSTITUTE, with the following
900 * A function may be supplied. When this function is called, it
901 will be passed one argument: a match structure for a given
902 regular expression match. It should return a string to be
905 * The `post' symbol causes `regexp-substitute/global' to recurse
906 on the unmatched portion of STR. This *must* be supplied in
907 order to perform global search-and-replace on STR; if it is
908 not present among the ITEMs, then `regexp-substitute/global'
909 will return after processing a single match.
913 A "match structure" is the object returned by `string-match' and
914 `regexp-exec'. It describes which portion of a string, if any, matched
915 the given regular expression. Match structures include: a reference to
916 the string that was checked for matches; the starting and ending
917 positions of the regexp match; and, if the regexp included any
918 parenthesized subexpressions, the starting and ending positions of each
921 In each of the regexp match functions described below, the `match'
922 argument must be a match structure returned by a previous call to
923 `string-match' or `regexp-exec'. Most of these functions return some
924 information about the original target string that was matched against a
925 regular expression; we will call that string TARGET for easy reference.
927 **** Function: regexp-match? OBJ
928 Return `#t' if OBJ is a match structure returned by a previous
929 call to `regexp-exec', or `#f' otherwise.
931 **** Function: match:substring MATCH [N]
932 Return the portion of TARGET matched by subexpression number N.
933 Submatch 0 (the default) represents the entire regexp match. If
934 the regular expression as a whole matched, but the subexpression
935 number N did not match, return `#f'.
937 **** Function: match:start MATCH [N]
938 Return the starting position of submatch number N.
940 **** Function: match:end MATCH [N]
941 Return the ending position of submatch number N.
943 **** Function: match:prefix MATCH
944 Return the unmatched portion of TARGET preceding the regexp match.
946 **** Function: match:suffix MATCH
947 Return the unmatched portion of TARGET following the regexp match.
949 **** Function: match:count MATCH
950 Return the number of parenthesized subexpressions from MATCH.
951 Note that the entire regular expression match itself counts as a
952 subexpression, and failed submatches are included in the count.
954 **** Function: match:string MATCH
955 Return the original TARGET string.
957 *** Backslash Escapes
959 Sometimes you will want a regexp to match characters like `*' or `$'
960 exactly. For example, to check whether a particular string represents
961 a menu entry from an Info node, it would be useful to match it against
962 a regexp like `^* [^:]*::'. However, this won't work; because the
963 asterisk is a metacharacter, it won't match the `*' at the beginning of
964 the string. In this case, we want to make the first asterisk un-magic.
966 You can do this by preceding the metacharacter with a backslash
967 character `\'. (This is also called "quoting" the metacharacter, and
968 is known as a "backslash escape".) When Guile sees a backslash in a
969 regular expression, it considers the following glyph to be an ordinary
970 character, no matter what special meaning it would ordinarily have.
971 Therefore, we can make the above example work by changing the regexp to
972 `^\* [^:]*::'. The `\*' sequence tells the regular expression engine
973 to match only a single asterisk in the target string.
975 Since the backslash is itself a metacharacter, you may force a
976 regexp to match a backslash in the target string by preceding the
977 backslash with itself. For example, to find variable references in a
978 TeX program, you might want to find occurrences of the string `\let\'
979 followed by any number of alphabetic characters. The regular expression
980 `\\let\\[A-Za-z]*' would do this: the double backslashes in the regexp
981 each match a single backslash in the target string.
983 **** Function: regexp-quote STR
984 Quote each special character found in STR with a backslash, and
985 return the resulting string.
987 *Very important:* Using backslash escapes in Guile source code (as
988 in Emacs Lisp or C) can be tricky, because the backslash character has
989 special meaning for the Guile reader. For example, if Guile encounters
990 the character sequence `\n' in the middle of a string while processing
991 Scheme code, it replaces those characters with a newline character.
992 Similarly, the character sequence `\t' is replaced by a horizontal tab.
993 Several of these "escape sequences" are processed by the Guile reader
994 before your code is executed. Unrecognized escape sequences are
995 ignored: if the characters `\*' appear in a string, they will be
996 translated to the single character `*'.
998 This translation is obviously undesirable for regular expressions,
999 since we want to be able to include backslashes in a string in order to
1000 escape regexp metacharacters. Therefore, to make sure that a backslash
1001 is preserved in a string in your Guile program, you must use *two*
1002 consecutive backslashes:
1004 (define Info-menu-entry-pattern (make-regexp "^\\* [^:]*"))
1006 The string in this example is preprocessed by the Guile reader before
1007 any code is executed. The resulting argument to `make-regexp' is the
1008 string `^\* [^:]*', which is what we really want.
1010 This also means that in order to write a regular expression that
1011 matches a single backslash character, the regular expression string in
1012 the source code must include *four* backslashes. Each consecutive pair
1013 of backslashes gets translated by the Guile reader to a single
1014 backslash, and the resulting double-backslash is interpreted by the
1015 regexp engine as matching a single backslash character. Hence:
1017 (define tex-variable-pattern (make-regexp "\\\\let\\\\=[A-Za-z]*"))
1019 The reason for the unwieldiness of this syntax is historical. Both
1020 regular expression pattern matchers and Unix string processing systems
1021 have traditionally used backslashes with the special meanings described
1022 above. The POSIX regular expression specification and ANSI C standard
1023 both require these semantics. Attempting to abandon either convention
1024 would cause other kinds of compatibility problems, possibly more severe
1025 ones. Therefore, without extending the Scheme reader to support
1026 strings with different quoting conventions (an ungainly and confusing
1027 extension when implemented in other languages), we must adhere to this
1028 cumbersome escape syntax.
1030 * Changes to the gh_ interface
1032 * Changes to the scm_ interface
1034 * Changes to system call interfaces:
1036 ** The value returned by `raise' is now unspecified. It throws an exception
1039 *** A new procedure `sigaction' can be used to install signal handlers
1041 (sigaction signum [action] [flags])
1043 signum is the signal number, which can be specified using the value
1046 If action is omitted, sigaction returns a pair: the CAR is the current
1047 signal hander, which will be either an integer with the value SIG_DFL
1048 (default action) or SIG_IGN (ignore), or the Scheme procedure which
1049 handles the signal, or #f if a non-Scheme procedure handles the
1050 signal. The CDR contains the current sigaction flags for the handler.
1052 If action is provided, it is installed as the new handler for signum.
1053 action can be a Scheme procedure taking one argument, or the value of
1054 SIG_DFL (default action) or SIG_IGN (ignore), or #f to restore
1055 whatever signal handler was installed before sigaction was first used.
1056 Flags can optionally be specified for the new handler (SA_RESTART is
1057 always used if the system provides it, so need not be specified.) The
1058 return value is a pair with information about the old handler as
1061 This interface does not provide access to the "signal blocking"
1062 facility. Maybe this is not needed, since the thread support may
1063 provide solutions to the problem of consistent access to data
1066 *** A new procedure `flush-all-ports' is equivalent to running
1067 `force-output' on every port open for output.
1069 ** Guile now provides information on how it was built, via the new
1070 global variable, %guile-build-info. This variable records the values
1071 of the standard GNU makefile directory variables as an assocation
1072 list, mapping variable names (symbols) onto directory paths (strings).
1073 For example, to find out where the Guile link libraries were
1074 installed, you can say:
1076 guile -c "(display (assq-ref %guile-build-info 'libdir)) (newline)"
1079 * Changes to the scm_ interface
1081 ** The new function scm_handle_by_message_noexit is just like the
1082 existing scm_handle_by_message function, except that it doesn't call
1083 exit to terminate the process. Instead, it prints a message and just
1084 returns #f. This might be a more appropriate catch-all handler for
1085 new dynamic roots and threads.
1088 Changes in Guile 1.1 (released Friday, May 16 1997):
1090 * Changes to the distribution.
1092 The Guile 1.0 distribution has been split up into several smaller
1094 guile-core --- the Guile interpreter itself.
1095 guile-tcltk --- the interface between the Guile interpreter and
1096 Tcl/Tk; Tcl is an interpreter for a stringy language, and Tk
1097 is a toolkit for building graphical user interfaces.
1098 guile-rgx-ctax --- the interface between Guile and the Rx regular
1099 expression matcher, and the translator for the Ctax
1100 programming language. These are packaged together because the
1101 Ctax translator uses Rx to parse Ctax source code.
1103 This NEWS file describes the changes made to guile-core since the 1.0
1106 We no longer distribute the documentation, since it was either out of
1107 date, or incomplete. As soon as we have current documentation, we
1112 * Changes to the stand-alone interpreter
1114 ** guile now accepts command-line arguments compatible with SCSH, Olin
1115 Shivers' Scheme Shell.
1117 In general, arguments are evaluated from left to right, but there are
1118 exceptions. The following switches stop argument processing, and
1119 stash all remaining command-line arguments as the value returned by
1120 the (command-line) function.
1121 -s SCRIPT load Scheme source code from FILE, and exit
1122 -c EXPR evalute Scheme expression EXPR, and exit
1123 -- stop scanning arguments; run interactively
1125 The switches below are processed as they are encountered.
1126 -l FILE load Scheme source code from FILE
1127 -e FUNCTION after reading script, apply FUNCTION to
1128 command line arguments
1129 -ds do -s script at this point
1130 --emacs enable Emacs protocol (experimental)
1131 -h, --help display this help and exit
1132 -v, --version display version information and exit
1133 \ read arguments from following script lines
1135 So, for example, here is a Guile script named `ekko' (thanks, Olin)
1136 which re-implements the traditional "echo" command:
1138 #!/usr/local/bin/guile -s
1141 (map (lambda (arg) (display arg) (display " "))
1145 (main (command-line))
1147 Suppose we invoke this script as follows:
1149 ekko a speckled gecko
1151 Through the magic of Unix script processing (triggered by the `#!'
1152 token at the top of the file), /usr/local/bin/guile receives the
1153 following list of command-line arguments:
1155 ("-s" "./ekko" "a" "speckled" "gecko")
1157 Unix inserts the name of the script after the argument specified on
1158 the first line of the file (in this case, "-s"), and then follows that
1159 with the arguments given to the script. Guile loads the script, which
1160 defines the `main' function, and then applies it to the list of
1161 remaining command-line arguments, ("a" "speckled" "gecko").
1163 In Unix, the first line of a script file must take the following form:
1165 #!INTERPRETER ARGUMENT
1167 where INTERPRETER is the absolute filename of the interpreter
1168 executable, and ARGUMENT is a single command-line argument to pass to
1171 You may only pass one argument to the interpreter, and its length is
1172 limited. These restrictions can be annoying to work around, so Guile
1173 provides a general mechanism (borrowed from, and compatible with,
1174 SCSH) for circumventing them.
1176 If the ARGUMENT in a Guile script is a single backslash character,
1177 `\', Guile will open the script file, parse arguments from its second
1178 and subsequent lines, and replace the `\' with them. So, for example,
1179 here is another implementation of the `ekko' script:
1181 #!/usr/local/bin/guile \
1185 (for-each (lambda (arg) (display arg) (display " "))
1189 If the user invokes this script as follows:
1191 ekko a speckled gecko
1193 Unix expands this into
1195 /usr/local/bin/guile \ ekko a speckled gecko
1197 When Guile sees the `\' argument, it replaces it with the arguments
1198 read from the second line of the script, producing:
1200 /usr/local/bin/guile -e main -s ekko a speckled gecko
1202 This tells Guile to load the `ekko' script, and apply the function
1203 `main' to the argument list ("a" "speckled" "gecko").
1205 Here is how Guile parses the command-line arguments:
1206 - Each space character terminates an argument. This means that two
1207 spaces in a row introduce an empty-string argument.
1208 - The tab character is not permitted (unless you quote it with the
1209 backslash character, as described below), to avoid confusion.
1210 - The newline character terminates the sequence of arguments, and will
1211 also terminate a final non-empty argument. (However, a newline
1212 following a space will not introduce a final empty-string argument;
1213 it only terminates the argument list.)
1214 - The backslash character is the escape character. It escapes
1215 backslash, space, tab, and newline. The ANSI C escape sequences
1216 like \n and \t are also supported. These produce argument
1217 constituents; the two-character combination \n doesn't act like a
1218 terminating newline. The escape sequence \NNN for exactly three
1219 octal digits reads as the character whose ASCII code is NNN. As
1220 above, characters produced this way are argument constituents.
1221 Backslash followed by other characters is not allowed.
1223 * Changes to the procedure for linking libguile with your programs
1225 ** Guile now builds and installs a shared guile library, if your
1226 system support shared libraries. (It still builds a static library on
1227 all systems.) Guile automatically detects whether your system
1228 supports shared libraries. To prevent Guile from buildisg shared
1229 libraries, pass the `--disable-shared' flag to the configure script.
1231 Guile takes longer to compile when it builds shared libraries, because
1232 it must compile every file twice --- once to produce position-
1233 independent object code, and once to produce normal object code.
1235 ** The libthreads library has been merged into libguile.
1237 To link a program against Guile, you now need only link against
1238 -lguile and -lqt; -lthreads is no longer needed. If you are using
1239 autoconf to generate configuration scripts for your application, the
1240 following lines should suffice to add the appropriate libraries to
1243 ### Find quickthreads and libguile.
1244 AC_CHECK_LIB(qt, main)
1245 AC_CHECK_LIB(guile, scm_shell)
1247 * Changes to Scheme functions
1249 ** Guile Scheme's special syntax for keyword objects is now optional,
1250 and disabled by default.
1252 The syntax variation from R4RS made it difficult to port some
1253 interesting packages to Guile. The routines which accepted keyword
1254 arguments (mostly in the module system) have been modified to also
1255 accept symbols whose names begin with `:'.
1257 To change the keyword syntax, you must first import the (ice-9 debug)
1259 (use-modules (ice-9 debug))
1261 Then you can enable the keyword syntax as follows:
1262 (read-set! keywords 'prefix)
1264 To disable keyword syntax, do this:
1265 (read-set! keywords #f)
1267 ** Many more primitive functions accept shared substrings as
1268 arguments. In the past, these functions required normal, mutable
1269 strings as arguments, although they never made use of this
1272 ** The uniform array functions now operate on byte vectors. These
1273 functions are `array-fill!', `serial-array-copy!', `array-copy!',
1274 `serial-array-map', `array-map', `array-for-each', and
1277 ** The new functions `trace' and `untrace' implement simple debugging
1278 support for Scheme functions.
1280 The `trace' function accepts any number of procedures as arguments,
1281 and tells the Guile interpreter to display each procedure's name and
1282 arguments each time the procedure is invoked. When invoked with no
1283 arguments, `trace' returns the list of procedures currently being
1286 The `untrace' function accepts any number of procedures as arguments,
1287 and tells the Guile interpreter not to trace them any more. When
1288 invoked with no arguments, `untrace' untraces all curretly traced
1291 The tracing in Guile has an advantage over most other systems: we
1292 don't create new procedure objects, but mark the procedure objects
1293 themselves. This means that anonymous and internal procedures can be
1296 ** The function `assert-repl-prompt' has been renamed to
1297 `set-repl-prompt!'. It takes one argument, PROMPT.
1298 - If PROMPT is #f, the Guile read-eval-print loop will not prompt.
1299 - If PROMPT is a string, we use it as a prompt.
1300 - If PROMPT is a procedure accepting no arguments, we call it, and
1301 display the result as a prompt.
1302 - Otherwise, we display "> ".
1304 ** The new function `eval-string' reads Scheme expressions from a
1305 string and evaluates them, returning the value of the last expression
1306 in the string. If the string contains no expressions, it returns an
1309 ** The new function `thunk?' returns true iff its argument is a
1310 procedure of zero arguments.
1312 ** `defined?' is now a builtin function, instead of syntax. This
1313 means that its argument should be quoted. It returns #t iff its
1314 argument is bound in the current module.
1316 ** The new syntax `use-modules' allows you to add new modules to your
1317 environment without re-typing a complete `define-module' form. It
1318 accepts any number of module names as arguments, and imports their
1319 public bindings into the current module.
1321 ** The new function (module-defined? NAME MODULE) returns true iff
1322 NAME, a symbol, is defined in MODULE, a module object.
1324 ** The new function `builtin-bindings' creates and returns a hash
1325 table containing copies of all the root module's bindings.
1327 ** The new function `builtin-weak-bindings' does the same as
1328 `builtin-bindings', but creates a doubly-weak hash table.
1330 ** The `equal?' function now considers variable objects to be
1331 equivalent if they have the same name and the same value.
1333 ** The new function `command-line' returns the command-line arguments
1334 given to Guile, as a list of strings.
1336 When using guile as a script interpreter, `command-line' returns the
1337 script's arguments; those processed by the interpreter (like `-s' or
1338 `-c') are omitted. (In other words, you get the normal, expected
1339 behavior.) Any application that uses scm_shell to process its
1340 command-line arguments gets this behavior as well.
1342 ** The new function `load-user-init' looks for a file called `.guile'
1343 in the user's home directory, and loads it if it exists. This is
1344 mostly for use by the code generated by scm_compile_shell_switches,
1345 but we thought it might also be useful in other circumstances.
1347 ** The new function `log10' returns the base-10 logarithm of its
1350 ** Changes to I/O functions
1352 *** The functions `read', `primitive-load', `read-and-eval!', and
1353 `primitive-load-path' no longer take optional arguments controlling
1354 case insensitivity and a `#' parser.
1356 Case sensitivity is now controlled by a read option called
1357 `case-insensitive'. The user can add new `#' syntaxes with the
1358 `read-hash-extend' function (see below).
1360 *** The new function `read-hash-extend' allows the user to change the
1361 syntax of Guile Scheme in a somewhat controlled way.
1363 (read-hash-extend CHAR PROC)
1364 When parsing S-expressions, if we read a `#' character followed by
1365 the character CHAR, use PROC to parse an object from the stream.
1366 If PROC is #f, remove any parsing procedure registered for CHAR.
1368 The reader applies PROC to two arguments: CHAR and an input port.
1370 *** The new functions read-delimited and read-delimited! provide a
1371 general mechanism for doing delimited input on streams.
1373 (read-delimited DELIMS [PORT HANDLE-DELIM])
1374 Read until we encounter one of the characters in DELIMS (a string),
1375 or end-of-file. PORT is the input port to read from; it defaults to
1376 the current input port. The HANDLE-DELIM parameter determines how
1377 the terminating character is handled; it should be one of the
1380 'trim omit delimiter from result
1381 'peek leave delimiter character in input stream
1382 'concat append delimiter character to returned value
1383 'split return a pair: (RESULT . TERMINATOR)
1385 HANDLE-DELIM defaults to 'peek.
1387 (read-delimited! DELIMS BUF [PORT HANDLE-DELIM START END])
1388 A side-effecting variant of `read-delimited'.
1390 The data is written into the string BUF at the indices in the
1391 half-open interval [START, END); the default interval is the whole
1392 string: START = 0 and END = (string-length BUF). The values of
1393 START and END must specify a well-defined interval in BUF, i.e.
1394 0 <= START <= END <= (string-length BUF).
1396 It returns NBYTES, the number of bytes read. If the buffer filled
1397 up without a delimiter character being found, it returns #f. If the
1398 port is at EOF when the read starts, it returns the EOF object.
1400 If an integer is returned (i.e., the read is successfully terminated
1401 by reading a delimiter character), then the HANDLE-DELIM parameter
1402 determines how to handle the terminating character. It is described
1403 above, and defaults to 'peek.
1405 (The descriptions of these functions were borrowed from the SCSH
1406 manual, by Olin Shivers and Brian Carlstrom.)
1408 *** The `%read-delimited!' function is the primitive used to implement
1409 `read-delimited' and `read-delimited!'.
1411 (%read-delimited! DELIMS BUF GOBBLE? [PORT START END])
1413 This returns a pair of values: (TERMINATOR . NUM-READ).
1414 - TERMINATOR describes why the read was terminated. If it is a
1415 character or the eof object, then that is the value that terminated
1416 the read. If it is #f, the function filled the buffer without finding
1417 a delimiting character.
1418 - NUM-READ is the number of characters read into BUF.
1420 If the read is successfully terminated by reading a delimiter
1421 character, then the gobble? parameter determines what to do with the
1422 terminating character. If true, the character is removed from the
1423 input stream; if false, the character is left in the input stream
1424 where a subsequent read operation will retrieve it. In either case,
1425 the character is also the first value returned by the procedure call.
1427 (The descriptions of this function was borrowed from the SCSH manual,
1428 by Olin Shivers and Brian Carlstrom.)
1430 *** The `read-line' and `read-line!' functions have changed; they now
1431 trim the terminator by default; previously they appended it to the
1432 returned string. For the old behavior, use (read-line PORT 'concat).
1434 *** The functions `uniform-array-read!' and `uniform-array-write!' now
1435 take new optional START and END arguments, specifying the region of
1436 the array to read and write.
1438 *** The `ungetc-char-ready?' function has been removed. We feel it's
1439 inappropriate for an interface to expose implementation details this
1442 ** Changes to the Unix library and system call interface
1444 *** The new fcntl function provides access to the Unix `fcntl' system
1447 (fcntl PORT COMMAND VALUE)
1448 Apply COMMAND to PORT's file descriptor, with VALUE as an argument.
1449 Values for COMMAND are:
1451 F_DUPFD duplicate a file descriptor
1452 F_GETFD read the descriptor's close-on-exec flag
1453 F_SETFD set the descriptor's close-on-exec flag to VALUE
1454 F_GETFL read the descriptor's flags, as set on open
1455 F_SETFL set the descriptor's flags, as set on open to VALUE
1456 F_GETOWN return the process ID of a socket's owner, for SIGIO
1457 F_SETOWN set the process that owns a socket to VALUE, for SIGIO
1458 FD_CLOEXEC not sure what this is
1460 For details, see the documentation for the fcntl system call.
1462 *** The arguments to `select' have changed, for compatibility with
1463 SCSH. The TIMEOUT parameter may now be non-integral, yielding the
1464 expected behavior. The MILLISECONDS parameter has been changed to
1465 MICROSECONDS, to more closely resemble the underlying system call.
1466 The RVEC, WVEC, and EVEC arguments can now be vectors; the type of the
1467 corresponding return set will be the same.
1469 *** The arguments to the `mknod' system call have changed. They are
1472 (mknod PATH TYPE PERMS DEV)
1473 Create a new file (`node') in the file system. PATH is the name of
1474 the file to create. TYPE is the kind of file to create; it should
1475 be 'fifo, 'block-special, or 'char-special. PERMS specifies the
1476 permission bits to give the newly created file. If TYPE is
1477 'block-special or 'char-special, DEV specifies which device the
1478 special file refers to; its interpretation depends on the kind of
1479 special file being created.
1481 *** The `fork' function has been renamed to `primitive-fork', to avoid
1482 clashing with various SCSH forks.
1484 *** The `recv' and `recvfrom' functions have been renamed to `recv!'
1485 and `recvfrom!'. They no longer accept a size for a second argument;
1486 you must pass a string to hold the received value. They no longer
1487 return the buffer. Instead, `recv' returns the length of the message
1488 received, and `recvfrom' returns a pair containing the packet's length
1489 and originating address.
1491 *** The file descriptor datatype has been removed, as have the
1492 `read-fd', `write-fd', `close', `lseek', and `dup' functions.
1493 We plan to replace these functions with a SCSH-compatible interface.
1495 *** The `create' function has been removed; it's just a special case
1498 *** There are new functions to break down process termination status
1499 values. In the descriptions below, STATUS is a value returned by
1502 (status:exit-val STATUS)
1503 If the child process exited normally, this function returns the exit
1504 code for the child process (i.e., the value passed to exit, or
1505 returned from main). If the child process did not exit normally,
1506 this function returns #f.
1508 (status:stop-sig STATUS)
1509 If the child process was suspended by a signal, this function
1510 returns the signal that suspended the child. Otherwise, it returns
1513 (status:term-sig STATUS)
1514 If the child process terminated abnormally, this function returns
1515 the signal that terminated the child. Otherwise, this function
1518 POSIX promises that exactly one of these functions will return true on
1519 a valid STATUS value.
1521 These functions are compatible with SCSH.
1523 *** There are new accessors and setters for the broken-out time vectors
1524 returned by `localtime', `gmtime', and that ilk. They are:
1526 Component Accessor Setter
1527 ========================= ============ ============
1528 seconds tm:sec set-tm:sec
1529 minutes tm:min set-tm:min
1530 hours tm:hour set-tm:hour
1531 day of the month tm:mday set-tm:mday
1532 month tm:mon set-tm:mon
1533 year tm:year set-tm:year
1534 day of the week tm:wday set-tm:wday
1535 day in the year tm:yday set-tm:yday
1536 daylight saving time tm:isdst set-tm:isdst
1537 GMT offset, seconds tm:gmtoff set-tm:gmtoff
1538 name of time zone tm:zone set-tm:zone
1540 *** There are new accessors for the vectors returned by `uname',
1541 describing the host system:
1544 ============================================== ================
1545 name of the operating system implementation utsname:sysname
1546 network name of this machine utsname:nodename
1547 release level of the operating system utsname:release
1548 version level of the operating system utsname:version
1549 machine hardware platform utsname:machine
1551 *** There are new accessors for the vectors returned by `getpw',
1552 `getpwnam', `getpwuid', and `getpwent', describing entries from the
1553 system's user database:
1556 ====================== =================
1557 user name passwd:name
1558 user password passwd:passwd
1561 real name passwd:gecos
1562 home directory passwd:dir
1563 shell program passwd:shell
1565 *** There are new accessors for the vectors returned by `getgr',
1566 `getgrnam', `getgrgid', and `getgrent', describing entries from the
1567 system's group database:
1570 ======================= ============
1571 group name group:name
1572 group password group:passwd
1574 group members group:mem
1576 *** There are new accessors for the vectors returned by `gethost',
1577 `gethostbyaddr', `gethostbyname', and `gethostent', describing
1581 ========================= ===============
1582 official name of host hostent:name
1583 alias list hostent:aliases
1584 host address type hostent:addrtype
1585 length of address hostent:length
1586 list of addresses hostent:addr-list
1588 *** There are new accessors for the vectors returned by `getnet',
1589 `getnetbyaddr', `getnetbyname', and `getnetent', describing internet
1593 ========================= ===============
1594 official name of net netent:name
1595 alias list netent:aliases
1596 net number type netent:addrtype
1597 net number netent:net
1599 *** There are new accessors for the vectors returned by `getproto',
1600 `getprotobyname', `getprotobynumber', and `getprotoent', describing
1604 ========================= ===============
1605 official protocol name protoent:name
1606 alias list protoent:aliases
1607 protocol number protoent:proto
1609 *** There are new accessors for the vectors returned by `getserv',
1610 `getservbyname', `getservbyport', and `getservent', describing
1614 ========================= ===============
1615 official service name servent:name
1616 alias list servent:aliases
1617 port number servent:port
1618 protocol to use servent:proto
1620 *** There are new accessors for the sockaddr structures returned by
1621 `accept', `getsockname', `getpeername', `recvfrom!':
1624 ======================================== ===============
1625 address format (`family') sockaddr:fam
1626 path, for file domain addresses sockaddr:path
1627 address, for internet domain addresses sockaddr:addr
1628 TCP or UDP port, for internet sockaddr:port
1630 *** The `getpwent', `getgrent', `gethostent', `getnetent',
1631 `getprotoent', and `getservent' functions now return #f at the end of
1632 the user database. (They used to throw an exception.)
1634 Note that calling MUMBLEent function is equivalent to calling the
1635 corresponding MUMBLE function with no arguments.
1637 *** The `setpwent', `setgrent', `sethostent', `setnetent',
1638 `setprotoent', and `setservent' routines now take no arguments.
1640 *** The `gethost', `getproto', `getnet', and `getserv' functions now
1641 provide more useful information when they throw an exception.
1643 *** The `lnaof' function has been renamed to `inet-lnaof'.
1645 *** Guile now claims to have the `current-time' feature.
1647 *** The `mktime' function now takes an optional second argument ZONE,
1648 giving the time zone to use for the conversion. ZONE should be a
1649 string, in the same format as expected for the "TZ" environment variable.
1651 *** The `strptime' function now returns a pair (TIME . COUNT), where
1652 TIME is the parsed time as a vector, and COUNT is the number of
1653 characters from the string left unparsed. This function used to
1654 return the remaining characters as a string.
1656 *** The `gettimeofday' function has replaced the old `time+ticks' function.
1657 The return value is now (SECONDS . MICROSECONDS); the fractional
1658 component is no longer expressed in "ticks".
1660 *** The `ticks/sec' constant has been removed, in light of the above change.
1662 * Changes to the gh_ interface
1664 ** gh_eval_str() now returns an SCM object which is the result of the
1667 ** gh_scm2str() now copies the Scheme data to a caller-provided C
1670 ** gh_scm2newstr() now makes a C array, copies the Scheme data to it,
1671 and returns the array
1673 ** gh_scm2str0() is gone: there is no need to distinguish
1674 null-terminated from non-null-terminated, since gh_scm2newstr() allows
1675 the user to interpret the data both ways.
1677 * Changes to the scm_ interface
1679 ** The new function scm_symbol_value0 provides an easy way to get a
1680 symbol's value from C code:
1682 SCM scm_symbol_value0 (char *NAME)
1683 Return the value of the symbol named by the null-terminated string
1684 NAME in the current module. If the symbol named NAME is unbound in
1685 the current module, return SCM_UNDEFINED.
1687 ** The new function scm_sysintern0 creates new top-level variables,
1688 without assigning them a value.
1690 SCM scm_sysintern0 (char *NAME)
1691 Create a new Scheme top-level variable named NAME. NAME is a
1692 null-terminated string. Return the variable's value cell.
1694 ** The function scm_internal_catch is the guts of catch. It handles
1695 all the mechanics of setting up a catch target, invoking the catch
1696 body, and perhaps invoking the handler if the body does a throw.
1698 The function is designed to be usable from C code, but is general
1699 enough to implement all the semantics Guile Scheme expects from throw.
1701 TAG is the catch tag. Typically, this is a symbol, but this function
1702 doesn't actually care about that.
1704 BODY is a pointer to a C function which runs the body of the catch;
1705 this is the code you can throw from. We call it like this:
1706 BODY (BODY_DATA, JMPBUF)
1708 BODY_DATA is just the BODY_DATA argument we received; we pass it
1709 through to BODY as its first argument. The caller can make
1710 BODY_DATA point to anything useful that BODY might need.
1711 JMPBUF is the Scheme jmpbuf object corresponding to this catch,
1712 which we have just created and initialized.
1714 HANDLER is a pointer to a C function to deal with a throw to TAG,
1715 should one occur. We call it like this:
1716 HANDLER (HANDLER_DATA, THROWN_TAG, THROW_ARGS)
1718 HANDLER_DATA is the HANDLER_DATA argument we recevied; it's the
1719 same idea as BODY_DATA above.
1720 THROWN_TAG is the tag that the user threw to; usually this is
1721 TAG, but it could be something else if TAG was #t (i.e., a
1722 catch-all), or the user threw to a jmpbuf.
1723 THROW_ARGS is the list of arguments the user passed to the THROW
1726 BODY_DATA is just a pointer we pass through to BODY. HANDLER_DATA
1727 is just a pointer we pass through to HANDLER. We don't actually
1728 use either of those pointers otherwise ourselves. The idea is
1729 that, if our caller wants to communicate something to BODY or
1730 HANDLER, it can pass a pointer to it as MUMBLE_DATA, which BODY and
1731 HANDLER can then use. Think of it as a way to make BODY and
1732 HANDLER closures, not just functions; MUMBLE_DATA points to the
1735 Of course, it's up to the caller to make sure that any data a
1736 MUMBLE_DATA needs is protected from GC. A common way to do this is
1737 to make MUMBLE_DATA a pointer to data stored in an automatic
1738 structure variable; since the collector must scan the stack for
1739 references anyway, this assures that any references in MUMBLE_DATA
1742 ** The new function scm_internal_lazy_catch is exactly like
1743 scm_internal_catch, except:
1745 - It does not unwind the stack (this is the major difference).
1746 - If handler returns, its value is returned from the throw.
1747 - BODY always receives #f as its JMPBUF argument (since there's no
1748 jmpbuf associated with a lazy catch, because we don't unwind the
1751 ** scm_body_thunk is a new body function you can pass to
1752 scm_internal_catch if you want the body to be like Scheme's `catch'
1753 --- a thunk, or a function of one argument if the tag is #f.
1755 BODY_DATA is a pointer to a scm_body_thunk_data structure, which
1756 contains the Scheme procedure to invoke as the body, and the tag
1757 we're catching. If the tag is #f, then we pass JMPBUF (created by
1758 scm_internal_catch) to the body procedure; otherwise, the body gets
1761 ** scm_handle_by_proc is a new handler function you can pass to
1762 scm_internal_catch if you want the handler to act like Scheme's catch
1763 --- call a procedure with the tag and the throw arguments.
1765 If the user does a throw to this catch, this function runs a handler
1766 procedure written in Scheme. HANDLER_DATA is a pointer to an SCM
1767 variable holding the Scheme procedure object to invoke. It ought to
1768 be a pointer to an automatic variable (i.e., one living on the stack),
1769 or the procedure object should be otherwise protected from GC.
1771 ** scm_handle_by_message is a new handler function to use with
1772 `scm_internal_catch' if you want Guile to print a message and die.
1773 It's useful for dealing with throws to uncaught keys at the top level.
1775 HANDLER_DATA, if non-zero, is assumed to be a char * pointing to a
1776 message header to print; if zero, we use "guile" instead. That
1777 text is followed by a colon, then the message described by ARGS.
1779 ** The return type of scm_boot_guile is now void; the function does
1780 not return a value, and indeed, never returns at all.
1782 ** The new function scm_shell makes it easy for user applications to
1783 process command-line arguments in a way that is compatible with the
1784 stand-alone guile interpreter (which is in turn compatible with SCSH,
1787 To use the scm_shell function, first initialize any guile modules
1788 linked into your application, and then call scm_shell with the values
1789 of ARGC and ARGV your `main' function received. scm_shell will add
1790 any SCSH-style meta-arguments from the top of the script file to the
1791 argument vector, and then process the command-line arguments. This
1792 generally means loading a script file or starting up an interactive
1793 command interpreter. For details, see "Changes to the stand-alone
1796 ** The new functions scm_get_meta_args and scm_count_argv help you
1797 implement the SCSH-style meta-argument, `\'.
1799 char **scm_get_meta_args (int ARGC, char **ARGV)
1800 If the second element of ARGV is a string consisting of a single
1801 backslash character (i.e. "\\" in Scheme notation), open the file
1802 named by the following argument, parse arguments from it, and return
1803 the spliced command line. The returned array is terminated by a
1806 For details of argument parsing, see above, under "guile now accepts
1807 command-line arguments compatible with SCSH..."
1809 int scm_count_argv (char **ARGV)
1810 Count the arguments in ARGV, assuming it is terminated by a null
1813 For an example of how these functions might be used, see the source
1814 code for the function scm_shell in libguile/script.c.
1816 You will usually want to use scm_shell instead of calling this
1819 ** The new function scm_compile_shell_switches turns an array of
1820 command-line arguments into Scheme code to carry out the actions they
1821 describe. Given ARGC and ARGV, it returns a Scheme expression to
1822 evaluate, and calls scm_set_program_arguments to make any remaining
1823 command-line arguments available to the Scheme code. For example,
1824 given the following arguments:
1826 -e main -s ekko a speckled gecko
1828 scm_set_program_arguments will return the following expression:
1830 (begin (load "ekko") (main (command-line)) (quit))
1832 You will usually want to use scm_shell instead of calling this
1835 ** The function scm_shell_usage prints a usage message appropriate for
1836 an interpreter that uses scm_compile_shell_switches to handle its
1837 command-line arguments.
1839 void scm_shell_usage (int FATAL, char *MESSAGE)
1840 Print a usage message to the standard error output. If MESSAGE is
1841 non-zero, write it before the usage message, followed by a newline.
1842 If FATAL is non-zero, exit the process, using FATAL as the
1843 termination status. (If you want to be compatible with Guile,
1844 always use 1 as the exit status when terminating due to command-line
1847 You will usually want to use scm_shell instead of calling this
1850 ** scm_eval_0str now returns SCM_UNSPECIFIED if the string contains no
1851 expressions. It used to return SCM_EOL. Earth-shattering.
1853 ** The macros for declaring scheme objects in C code have been
1854 rearranged slightly. They are now:
1856 SCM_SYMBOL (C_NAME, SCHEME_NAME)
1857 Declare a static SCM variable named C_NAME, and initialize it to
1858 point to the Scheme symbol whose name is SCHEME_NAME. C_NAME should
1859 be a C identifier, and SCHEME_NAME should be a C string.
1861 SCM_GLOBAL_SYMBOL (C_NAME, SCHEME_NAME)
1862 Just like SCM_SYMBOL, but make C_NAME globally visible.
1864 SCM_VCELL (C_NAME, SCHEME_NAME)
1865 Create a global variable at the Scheme level named SCHEME_NAME.
1866 Declare a static SCM variable named C_NAME, and initialize it to
1867 point to the Scheme variable's value cell.
1869 SCM_GLOBAL_VCELL (C_NAME, SCHEME_NAME)
1870 Just like SCM_VCELL, but make C_NAME globally visible.
1872 The `guile-snarf' script writes initialization code for these macros
1873 to its standard output, given C source code as input.
1875 The SCM_GLOBAL macro is gone.
1877 ** The scm_read_line and scm_read_line_x functions have been replaced
1878 by Scheme code based on the %read-delimited! procedure (known to C
1879 code as scm_read_delimited_x). See its description above for more
1882 ** The function scm_sys_open has been renamed to scm_open. It now
1883 returns a port instead of an FD object.
1885 * The dynamic linking support has changed. For more information, see
1886 libguile/DYNAMIC-LINKING.
1891 User-visible changes from Thursday, September 5, 1996 until Guile 1.0
1894 * Changes to the 'guile' program:
1896 ** Guile now loads some new files when it starts up. Guile first
1897 searches the load path for init.scm, and loads it if found. Then, if
1898 Guile is not being used to execute a script, and the user's home
1899 directory contains a file named `.guile', Guile loads that.
1901 ** You can now use Guile as a shell script interpreter.
1903 To paraphrase the SCSH manual:
1905 When Unix tries to execute an executable file whose first two
1906 characters are the `#!', it treats the file not as machine code to
1907 be directly executed by the native processor, but as source code
1908 to be executed by some interpreter. The interpreter to use is
1909 specified immediately after the #! sequence on the first line of
1910 the source file. The kernel reads in the name of the interpreter,
1911 and executes that instead. It passes the interpreter the source
1912 filename as its first argument, with the original arguments
1913 following. Consult the Unix man page for the `exec' system call
1914 for more information.
1916 Now you can use Guile as an interpreter, using a mechanism which is a
1917 compatible subset of that provided by SCSH.
1919 Guile now recognizes a '-s' command line switch, whose argument is the
1920 name of a file of Scheme code to load. It also treats the two
1921 characters `#!' as the start of a comment, terminated by `!#'. Thus,
1922 to make a file of Scheme code directly executable by Unix, insert the
1923 following two lines at the top of the file:
1925 #!/usr/local/bin/guile -s
1928 Guile treats the argument of the `-s' command-line switch as the name
1929 of a file of Scheme code to load, and treats the sequence `#!' as the
1930 start of a block comment, terminated by `!#'.
1932 For example, here's a version of 'echo' written in Scheme:
1934 #!/usr/local/bin/guile -s
1936 (let loop ((args (cdr (program-arguments))))
1939 (display (car args))
1940 (if (pair? (cdr args))
1942 (loop (cdr args)))))
1945 Why does `#!' start a block comment terminated by `!#', instead of the
1946 end of the line? That is the notation SCSH uses, and although we
1947 don't yet support the other SCSH features that motivate that choice,
1948 we would like to be backward-compatible with any existing Guile
1949 scripts once we do. Furthermore, if the path to Guile on your system
1950 is too long for your kernel, you can start the script with this
1954 exec /really/long/path/to/guile -s "$0" ${1+"$@"}
1957 Note that some very old Unix systems don't support the `#!' syntax.
1960 ** You can now run Guile without installing it.
1962 Previous versions of the interactive Guile interpreter (`guile')
1963 couldn't start up unless Guile's Scheme library had been installed;
1964 they used the value of the environment variable `SCHEME_LOAD_PATH'
1965 later on in the startup process, but not to find the startup code
1966 itself. Now Guile uses `SCHEME_LOAD_PATH' in all searches for Scheme
1969 To run Guile without installing it, build it in the normal way, and
1970 then set the environment variable `SCHEME_LOAD_PATH' to a
1971 colon-separated list of directories, including the top-level directory
1972 of the Guile sources. For example, if you unpacked Guile so that the
1973 full filename of this NEWS file is /home/jimb/guile-1.0b3/NEWS, then
1976 export SCHEME_LOAD_PATH=/home/jimb/my-scheme:/home/jimb/guile-1.0b3
1979 ** Guile's read-eval-print loop no longer prints #<unspecified>
1980 results. If the user wants to see this, she can evaluate the
1981 expression (assert-repl-print-unspecified #t), perhaps in her startup
1984 ** Guile no longer shows backtraces by default when an error occurs;
1985 however, it does display a message saying how to get one, and how to
1986 request that they be displayed by default. After an error, evaluate
1988 to see a backtrace, and
1989 (debug-enable 'backtrace)
1990 to see them by default.
1994 * Changes to Guile Scheme:
1996 ** Guile now distinguishes between #f and the empty list.
1998 This is for compatibility with the IEEE standard, the (possibly)
1999 upcoming Revised^5 Report on Scheme, and many extant Scheme
2002 Guile used to have #f and '() denote the same object, to make Scheme's
2003 type system more compatible with Emacs Lisp's. However, the change
2004 caused too much trouble for Scheme programmers, and we found another
2005 way to reconcile Emacs Lisp with Scheme that didn't require this.
2008 ** Guile's delq, delv, delete functions, and their destructive
2009 counterparts, delq!, delv!, and delete!, now remove all matching
2010 elements from the list, not just the first. This matches the behavior
2011 of the corresponding Emacs Lisp functions, and (I believe) the Maclisp
2012 functions which inspired them.
2014 I recognize that this change may break code in subtle ways, but it
2015 seems best to make the change before the FSF's first Guile release,
2019 ** The compiled-library-path function has been deleted from libguile.
2021 ** The facilities for loading Scheme source files have changed.
2023 *** The variable %load-path now tells Guile which directories to search
2024 for Scheme code. Its value is a list of strings, each of which names
2027 *** The variable %load-extensions now tells Guile which extensions to
2028 try appending to a filename when searching the load path. Its value
2029 is a list of strings. Its default value is ("" ".scm").
2031 *** (%search-load-path FILENAME) searches the directories listed in the
2032 value of the %load-path variable for a Scheme file named FILENAME,
2033 with all the extensions listed in %load-extensions. If it finds a
2034 match, then it returns its full filename. If FILENAME is absolute, it
2035 returns it unchanged. Otherwise, it returns #f.
2037 %search-load-path will not return matches that refer to directories.
2039 *** (primitive-load FILENAME :optional CASE-INSENSITIVE-P SHARP)
2040 uses %seach-load-path to find a file named FILENAME, and loads it if
2041 it finds it. If it can't read FILENAME for any reason, it throws an
2044 The arguments CASE-INSENSITIVE-P and SHARP are interpreted as by the
2047 *** load uses the same searching semantics as primitive-load.
2049 *** The functions %try-load, try-load-with-path, %load, load-with-path,
2050 basic-try-load-with-path, basic-load-with-path, try-load-module-with-
2051 path, and load-module-with-path have been deleted. The functions
2052 above should serve their purposes.
2054 *** If the value of the variable %load-hook is a procedure,
2055 `primitive-load' applies its value to the name of the file being
2056 loaded (without the load path directory name prepended). If its value
2057 is #f, it is ignored. Otherwise, an error occurs.
2059 This is mostly useful for printing load notification messages.
2062 ** The function `eval!' is no longer accessible from the scheme level.
2063 We can't allow operations which introduce glocs into the scheme level,
2064 because Guile's type system can't handle these as data. Use `eval' or
2065 `read-and-eval!' (see below) as replacement.
2067 ** The new function read-and-eval! reads an expression from PORT,
2068 evaluates it, and returns the result. This is more efficient than
2069 simply calling `read' and `eval', since it is not necessary to make a
2070 copy of the expression for the evaluator to munge.
2072 Its optional arguments CASE_INSENSITIVE_P and SHARP are interpreted as
2073 for the `read' function.
2076 ** The function `int?' has been removed; its definition was identical
2077 to that of `integer?'.
2079 ** The functions `<?', `<?', `<=?', `=?', `>?', and `>=?'. Code should
2080 use the R4RS names for these functions.
2082 ** The function object-properties no longer returns the hash handle;
2083 it simply returns the object's property list.
2085 ** Many functions have been changed to throw errors, instead of
2086 returning #f on failure. The point of providing exception handling in
2087 the language is to simplify the logic of user code, but this is less
2088 useful if Guile's primitives don't throw exceptions.
2090 ** The function `fileno' has been renamed from `%fileno'.
2092 ** The function primitive-mode->fdes returns #t or #f now, not 1 or 0.
2095 * Changes to Guile's C interface:
2097 ** The library's initialization procedure has been simplified.
2098 scm_boot_guile now has the prototype:
2100 void scm_boot_guile (int ARGC,
2102 void (*main_func) (),
2105 scm_boot_guile calls MAIN_FUNC, passing it CLOSURE, ARGC, and ARGV.
2106 MAIN_FUNC should do all the work of the program (initializing other
2107 packages, reading user input, etc.) before returning. When MAIN_FUNC
2108 returns, call exit (0); this function never returns. If you want some
2109 other exit value, MAIN_FUNC may call exit itself.
2111 scm_boot_guile arranges for program-arguments to return the strings
2112 given by ARGC and ARGV. If MAIN_FUNC modifies ARGC/ARGV, should call
2113 scm_set_program_arguments with the final list, so Scheme code will
2114 know which arguments have been processed.
2116 scm_boot_guile establishes a catch-all catch handler which prints an
2117 error message and exits the process. This means that Guile exits in a
2118 coherent way when system errors occur and the user isn't prepared to
2119 handle it. If the user doesn't like this behavior, they can establish
2120 their own universal catcher in MAIN_FUNC to shadow this one.
2122 Why must the caller do all the real work from MAIN_FUNC? The garbage
2123 collector assumes that all local variables of type SCM will be above
2124 scm_boot_guile's stack frame on the stack. If you try to manipulate
2125 SCM values after this function returns, it's the luck of the draw
2126 whether the GC will be able to find the objects you allocate. So,
2127 scm_boot_guile function exits, rather than returning, to discourage
2128 people from making that mistake.
2130 The IN, OUT, and ERR arguments were removed; there are other
2131 convenient ways to override these when desired.
2133 The RESULT argument was deleted; this function should never return.
2135 The BOOT_CMD argument was deleted; the MAIN_FUNC argument is more
2139 ** Guile's header files should no longer conflict with your system's
2142 In order to compile code which #included <libguile.h>, previous
2143 versions of Guile required you to add a directory containing all the
2144 Guile header files to your #include path. This was a problem, since
2145 Guile's header files have names which conflict with many systems'
2148 Now only <libguile.h> need appear in your #include path; you must
2149 refer to all Guile's other header files as <libguile/mumble.h>.
2150 Guile's installation procedure puts libguile.h in $(includedir), and
2151 the rest in $(includedir)/libguile.
2154 ** Two new C functions, scm_protect_object and scm_unprotect_object,
2155 have been added to the Guile library.
2157 scm_protect_object (OBJ) protects OBJ from the garbage collector.
2158 OBJ will not be freed, even if all other references are dropped,
2159 until someone does scm_unprotect_object (OBJ). Both functions
2162 Note that calls to scm_protect_object do not nest. You can call
2163 scm_protect_object any number of times on a given object, and the
2164 next call to scm_unprotect_object will unprotect it completely.
2166 Basically, scm_protect_object and scm_unprotect_object just
2167 maintain a list of references to things. Since the GC knows about
2168 this list, all objects it mentions stay alive. scm_protect_object
2169 adds its argument to the list; scm_unprotect_object remove its
2170 argument from the list.
2173 ** scm_eval_0str now returns the value of the last expression
2176 ** The new function scm_read_0str reads an s-expression from a
2177 null-terminated string, and returns it.
2179 ** The new function `scm_stdio_to_port' converts a STDIO file pointer
2180 to a Scheme port object.
2182 ** The new function `scm_set_program_arguments' allows C code to set
2183 the value teruturned by the Scheme `program-arguments' function.
2188 * Guile no longer includes sophisticated Tcl/Tk support.
2190 The old Tcl/Tk support was unsatisfying to us, because it required the
2191 user to link against the Tcl library, as well as Tk and Guile. The
2192 interface was also un-lispy, in that it preserved Tcl/Tk's practice of
2193 referring to widgets by names, rather than exporting widgets to Scheme
2194 code as a special datatype.
2196 In the Usenix Tk Developer's Workshop held in July 1996, the Tcl/Tk
2197 maintainers described some very interesting changes in progress to the
2198 Tcl/Tk internals, which would facilitate clean interfaces between lone
2199 Tk and other interpreters --- even for garbage-collected languages
2200 like Scheme. They expected the new Tk to be publicly available in the
2203 Since it seems that Guile might soon have a new, cleaner interface to
2204 lone Tk, and that the old Guile/Tk glue code would probably need to be
2205 completely rewritten, we (Jim Blandy and Richard Stallman) have
2206 decided not to support the old code. We'll spend the time instead on
2207 a good interface to the newer Tk, as soon as it is available.
2209 Until then, gtcltk-lib provides trivial, low-maintenance functionality.
2212 Copyright information:
2214 Copyright (C) 1996,1997 Free Software Foundation, Inc.
2216 Permission is granted to anyone to make or distribute verbatim copies
2217 of this document as received, in any medium, provided that the
2218 copyright notice and this permission notice are preserved,
2219 thus giving the recipient permission to redistribute in turn.
2221 Permission is granted to distribute modified versions
2222 of this document, or of portions of it,
2223 under the above conditions, provided also that they
2224 carry prominent notices stating who last changed them.
2229 paragraph-separate: "[
\f]*$"