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[bpt/guile.git] / NEWS
1 Guile NEWS --- history of user-visible changes.
2 Copyright (C) 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004 Free Software Foundation, Inc.
3 See the end for copying conditions.
4
5 Please send Guile bug reports to bug-guile@gnu.org.
6
7 Each release reports the NEWS in the following sections:
8
9 * Changes to the distribution
10 * Changes to the stand-alone interpreter
11 * Changes to Scheme functions and syntax
12 * Changes to the C interface
13
14 \f
15 Changes since the 1.6.x series:
16
17 * Changes to the distribution
18
19 ** Guile is now licensed with the GNU Lesser General Public License.
20
21 ** The manual is now licensed with the GNU Free Documentation License.
22
23 ** Guile now requires GNU MP (http://swox.com/gmp).
24
25 Guile now uses the GNU MP library for arbitrary precision arithmetic.
26
27 ** Guile now has separate private and public configuration headers.
28
29 That is, things like HAVE_STRING_H no longer leak from Guile's
30 headers.
31
32 ** Guile now provides and uses an "effective" version number.
33
34 Guile now provides scm_effective_version and effective-version
35 functions which return the "effective" version number. This is just
36 the normal full version string without the final micro-version number,
37 so the current effective-version is "1.7". The effective version
38 should remain unchanged during a stable series, and should be used for
39 items like the versioned share directory name
40 i.e. /usr/share/guile/1.7.
41
42 Providing an unchanging version number during a stable release for
43 things like the versioned share directory can be particularly
44 important for Guile "add-on" packages, since it provides a directory
45 that they can install to that won't be changed out from under them
46 with each micro release during a stable series.
47
48 ** Thread implementation has changed.
49
50 When you configure "--with-threads=null", you will get the usual
51 threading API (call-with-new-thread, make-mutex, etc), but you can't
52 actually create new threads. Also, "--with-threads=no" is now
53 equivalent to "--with-threads=null". This means that the thread API
54 is always present, although you might not be able to create new
55 threads.
56
57 When you configure "--with-threads=pthreads" or "--with-threads=yes",
58 you will get threads that are implemented with the portable POSIX
59 threads. These threads can run concurrently (unlike the previous
60 "coop" thread implementation), but need to cooperate for things like
61 the GC. See the manual for details. [XXX - write this.]
62
63 The default is "pthreads", unless your platform doesn't have pthreads,
64 in which case "null" threads are used.
65
66 ** New module (ice-9 serialize):
67
68 (serialize FORM1 ...) and (parallelize FORM1 ...) are useful when
69 you don't trust the thread safety of most of your program, but
70 where you have some section(s) of code which you consider can run
71 in parallel to other sections.
72
73 ### move rest to manual
74
75 They "flag" (with dynamic extent) sections of code to be of
76 "serial" or "parallel" nature and have the single effect of
77 preventing a serial section from being run in parallel with any
78 serial section (including itself).
79
80 Both serialize and parallelize can be nested. If so, the
81 inner-most construct is in effect.
82
83 NOTE 1: A serial section can run in parallel with a parallel
84 section.
85
86 NOTE 2: If a serial section S is "interrupted" by a parallel
87 section P in the following manner: S = S1 P S2, S2 is not
88 guaranteed to be resumed by the same thread that previously
89 executed S1.
90
91 WARNING: Spawning new threads within a serial section have
92 undefined effects. It is OK, though, to spawn threads in unflagged
93 sections of code where neither serialize or parallelize is in
94 effect.
95
96 A typical usage is when Guile is used as scripting language in some
97 application doing heavy computations. If each thread is
98 encapsulated with a serialize form, you can then put a parallelize
99 form around the code performing the heavy computations (typically a
100 C code primitive), enabling the computations to run in parallel
101 while the scripting code runs single-threadedly.
102
103 ** New module (srfi srfi-26)
104
105 This is an implementation of SRFI-26.
106
107 ** New module (srfi srfi-31)
108
109 This is an implementation of SRFI-31 which provides a special form
110 `rec' for recursive evaluation.
111
112 ** The modules (srfi srfi-13), (srfi srfi-14) and (srfi srfi-4) have
113 been merged with the core, making their functionality always
114 available.
115
116 The modules are still available, tho, and you could use them together
117 with a renaming import, for example.
118
119 ** Guile no longer includes its own version of libltdl.
120
121 The official version is good enough now.
122
123 ** The --enable-htmldoc option has been removed from 'configure'.
124
125 Support for translating the documentation into HTML is now always
126 provided. Use 'make html'.
127
128 * Changes to the stand-alone interpreter
129
130 ** New command line option `-L'.
131
132 This option adds a directory to the front of the load path.
133
134 ** New command line option `--no-debug'.
135
136 Specifying `--no-debug' on the command line will keep the debugging
137 evaluator turned off, even for interactive sessions.
138
139 ** User-init file ~/.guile is now loaded with the debugging evaluator.
140
141 Previously, the normal evaluator would have been used. Using the
142 debugging evaluator gives better error messages.
143
144 ** The '-e' option now 'read's its argument.
145
146 This is to allow the new '(@ MODULE-NAME VARIABLE-NAME)' construct to
147 be used with '-e'. For example, you can now write a script like
148
149 #! /bin/sh
150 exec guile -e '(@ (demo) main)' -s "$0" "$@"
151 !#
152
153 (define-module (demo)
154 :export (main))
155
156 (define (main args)
157 (format #t "Demo: ~a~%" args))
158
159
160 * Changes to Scheme functions and syntax
161
162 ** The uniform vector and array support has been overhauled.
163
164 It now complies with SRFI-4 and the weird prototype based uniform
165 array creation has been deprecated. See the manual for more details.
166
167 One non-compatible change is that characters can no longer be stored
168 into byte arrays.
169
170 ** There is now support for copy-on-write substrings, mutation-sharing
171 substrings and read-only strings.
172
173 Three new procedures are related to this: substring/shared,
174 substring/copy, and substring/read-only. See the manual for more
175 information.
176
177 ** Backtraces will now highlight the value that caused the error.
178
179 By default, these values are enclosed in "{...}", such as in this
180 example:
181
182 guile> (car 'a)
183
184 Backtrace:
185 In current input:
186 1: 0* [car {a}]
187
188 <unnamed port>:1:1: In procedure car in expression (car (quote a)):
189 <unnamed port>:1:1: Wrong type (expecting pair): a
190 ABORT: (wrong-type-arg)
191
192 The prefix and suffix used for highlighting can be set via the two new
193 printer options 'highlight-prefix' and 'highlight-suffix'. For
194 example, putting this into ~/.guile will output the bad value in bold
195 on an ANSI terminal:
196
197 (print-set! highlight-prefix "\x1b[1m")
198 (print-set! highlight-suffix "\x1b[22m")
199
200
201 ** 'gettext' support for internationalization has been added.
202
203 See the manual for details.
204
205 ** New syntax '@' and '@@':
206
207 You can now directly refer to variables exported from a module by
208 writing
209
210 (@ MODULE-NAME VARIABLE-NAME)
211
212 For example (@ (ice-9 pretty-print) pretty-print) will directly access
213 the pretty-print variable exported from the (ice-9 pretty-print)
214 module. You don't need to 'use' that module first. You can also use
215 '@' as a target of 'set!', as in (set! (@ mod var) val).
216
217 The related syntax (@@ MODULE-NAME VARIABLE-NAME) works just like '@',
218 but it can also access variables that have not been exported. It is
219 intended only for kluges and temporary fixes and for debugging, not
220 for ordinary code.
221
222 ** Keyword syntax has been made more disciplined.
223
224 Previously, the name of a keyword was read as a 'token' but printed as
225 a symbol. Now, it is read as a general Scheme datum which must be a
226 symbol.
227
228 Previously:
229
230 guile> #:12
231 #:#{12}#
232 guile> #:#{12}#
233 #:#{\#{12}\#}#
234 guile> #:(a b c)
235 #:#{}#
236 ERROR: In expression (a b c):
237 Unbound variable: a
238 guile> #: foo
239 #:#{}#
240 ERROR: Unbound variable: foo
241
242 Now:
243
244 guile> #:12
245 ERROR: Wrong type (expecting symbol): 12
246 guile> #:#{12}#
247 #:#{12}#
248 guile> #:(a b c)
249 ERROR: Wrong type (expecting symbol): (a b c)
250 guile> #: foo
251 #:foo
252
253 ** 'while' now provides 'break' and 'continue'
254
255 break and continue were previously bound in a while loop, but not
256 documented, and continue didn't quite work properly. The undocumented
257 parameter to break which gave a return value for the while has been
258 dropped.
259
260 ** 'call-with-current-continuation' is now also available under the name
261 'call/cc'.
262
263 ** The module system now checks for duplicate bindings.
264
265 The module system now can check for name conflicts among imported
266 bindings.
267
268 The behavior can be controlled by specifying one or more 'duplicates'
269 handlers. For example, to make Guile return an error for every name
270 collision, write:
271
272 (define-module (foo)
273 :use-module (bar)
274 :use-module (baz)
275 :duplicates check)
276
277 The new default behavior of the module system when a name collision
278 has been detected is to
279
280 1. Give priority to bindings marked as a replacement.
281 2. Issue a warning (different warning if overriding core binding).
282 3. Give priority to the last encountered binding (this corresponds to
283 the old behavior).
284
285 If you want the old behavior back without replacements or warnings you
286 can add the line:
287
288 (default-duplicate-binding-handler 'last)
289
290 to your .guile init file.
291
292 ### move rest to manual
293
294 The syntax for the :duplicates option is:
295
296 :duplicates HANDLER-NAME | (HANDLER1-NAME HANDLER2-NAME ...)
297
298 Specifying multiple handlers is useful since some handlers (such as
299 replace) can defer conflict resolution to others. Each handler is
300 tried until a binding is selected.
301
302 Currently available duplicates handlers are:
303
304 check report an error for bindings with a common name
305 warn issue a warning for bindings with a common name
306 replace replace bindings which have an imported replacement
307 warn-override-core issue a warning for imports which override core bindings
308 and accept the override
309 first select the first encountered binding (override)
310 last select the last encountered binding (override)
311
312 These two are provided by the (oop goops) module:
313
314 merge-generics merge generic functions with a common name
315 into an <extended-generic>
316 merge-accessors merge accessors with a common name
317
318 The default duplicates handler is:
319
320 (replace warn-override-core warn last)
321
322 A recommended handler (which is likely to correspond to future Guile
323 behavior) can be installed with:
324
325 (default-duplicate-binding-handler '(replace warn-override-core check))
326
327 ** New define-module option: :replace
328
329 :replace works as :export, but, in addition, marks the binding as a
330 replacement.
331
332 A typical example is `format' in (ice-9 format) which is a replacement
333 for the core binding `format'.
334
335 ** Adding prefixes to imported bindings in the module system
336
337 There is now a new :use-module option :prefix. It can be used to add
338 a prefix to all imported bindings.
339
340 (define-module (foo)
341 :use-module ((bar) :prefix bar:))
342
343 will import all bindings exported from bar, but rename them by adding
344 the prefix `bar:'.
345
346 ** Conflicting generic functions can be automatically merged.
347
348 When two imported bindings conflict and they are both generic
349 functions, the two functions can now be merged automatically. This is
350 activated with the 'duplicates' handler 'merge-generics'.
351
352 ### move the rest to the manual
353
354 It is sometimes tempting to use GOOPS accessors with short names.
355 For example, it is tempting to use the name `x' for the x-coordinate
356 in vector packages.
357
358 Assume that we work with a graphical package which needs to use two
359 independent vector packages for 2D and 3D vectors respectively. If
360 both packages export `x' we will encounter a name collision.
361
362 This can now be resolved automagically with the duplicates handler
363 `merge-generics' which gives the module system license to merge all
364 generic functions sharing a common name:
365
366 (define-module (math 2D-vectors)
367 :use-module (oop goops)
368 :export (x y ...))
369
370 (define-module (math 3D-vectors)
371 :use-module (oop goops)
372 :export (x y z ...))
373
374 (define-module (my-module)
375 :use-module (math 2D-vectors)
376 :use-module (math 3D-vectors)
377 :duplicates merge-generics)
378
379 x in (my-module) will now share methods with x in both imported
380 modules.
381
382 There will, in fact, now be three distinct generic functions named
383 `x': x in (2D-vectors), x in (3D-vectors), and x in (my-module). The
384 last function will be an <extended-generic>, extending the previous
385 two functions.
386
387 Let's call the imported generic functions the "ancestor functions". x
388 in (my-module) is, in turn, a "descendant function" of the imported
389 functions, extending its ancestors.
390
391 For any generic function G, the applicable methods are selected from
392 the union of the methods of the descendant functions, the methods of G
393 itself and the methods of the ancestor functions.
394
395 This, ancestor functions share methods with their descendants and vice
396 versa. This implies that x in (math 2D-vectors) can will share the
397 methods of x in (my-module) and vice versa, while x in (math 2D-vectors)
398 doesn't share the methods of x in (math 3D-vectors), thus preserving
399 modularity.
400
401 Sharing is dynamic, so that adding new methods to a descendant implies
402 adding it to the ancestor.
403
404 If duplicates checking is desired in the above example, the following
405 form of the :duplicates option can be used instead:
406
407 :duplicates (merge-generics check)
408
409 ** New function: effective-version
410
411 Returns the "effective" version number. This is just the normal full
412 version string without the final micro-version number. See "Changes
413 to the distribution" above.
414
415 ** New feature, 'futures': future, make-future, future-ref
416
417 Futures are like promises, but begin execution immediately in a new
418 thread. See the "Futures" section in the reference manual.
419
420 ** New threading functions: parallel, letpar, par-map, and friends
421
422 These are convenient ways to run calculations in parallel in new
423 threads. See "Parallel forms" in the manual for details.
424
425 ** Fair mutexes and condition variables
426
427 Fair mutexes and condition variables have been added. The fairness
428 means that scheduling is arranged to give as equal time shares as
429 possible and that threads are awakened in a first-in-first-out
430 manner. This is not guaranteed with standard mutexes and condition
431 variables.
432
433 In addition, fair mutexes are recursive. Locking a fair mutex that
434 you have already locked will succeed. Every call to lock-mutex must
435 be matched with a call to unlock-mutex. Only the last call to
436 unlock-mutex will actually unlock the mutex.
437
438 A fair condition variable must be used together with a fair mutex,
439 just as a standard condition variable must be used together with a
440 standard mutex.
441
442 *** New functions: make-fair-mutex, make-fair-condition-variable'
443
444 Make a new fair mutex and a new fair condition variable respectively.
445
446 ** New function 'try-mutex'.
447
448 This function will attempt to lock a mutex but will return immediately
449 instead if blocking and indicate failure.
450
451 ** Waiting on a condition variable can have a timeout.
452
453 The funtion 'wait-condition-variable' now takes a third, optional
454 argument that specifies the point in time where the waiting should be
455 aborted.
456
457 ** New function 'broadcast-condition-variable'.
458
459 ** New functions 'all-threads' and 'current-thread'.
460
461 ** Signals and system asyncs work better with threads.
462
463 The function 'sigaction' now takes a fourth, optional, argument that
464 specifies the thread that the handler should run in. When the
465 argument is omitted, the handler will run in the thread that called
466 'sigaction'.
467
468 Likewise, 'system-async-mark' takes a second, optional, argument that
469 specifies the thread that the async should run in. When it is
470 omitted, the async will run in the thread that called
471 'system-async-mark'.
472
473 C code can use the new functions scm_sigaction_for_thread and
474 scm_system_async_mark_for_thread to pass the new thread argument.
475
476 ** The function 'system-async' is deprecated.
477
478 You can now pass any zero-argument procedure to 'system-async-mark'.
479 The function 'system-async' will just return its argument unchanged
480 now.
481
482 ** New functions 'call-with-blocked-asyncs' and
483 'call-with-unblocked-asyncs'
484
485 The expression (call-with-blocked-asyncs PROC) will call PROC and will
486 block execution of system asyncs for the current thread by one level
487 while PROC runs. Likewise, call-with-unblocked-asyncs will call a
488 procedure and will unblock the execution of system asyncs by one
489 level for the current thread.
490
491 Only system asyncs are affected by these functions.
492
493 ** The functions 'mask-signals' and 'unmask-signals' are deprecated.
494
495 Use 'call-with-blocked-asyncs' or 'call-with-unblocked-asyncs'
496 instead. Those functions are easier to use correctly and can be
497 nested.
498
499 ** New function 'unsetenv'.
500
501 ** New macro 'define-syntax-public'.
502
503 It works like 'define-syntax' and also exports the defined macro (but
504 only on top-level).
505
506 ** There is support for Infinity and NaNs.
507
508 Following PLT Scheme, Guile can now work with infinite numbers, and
509 'not-a-numbers'.
510
511 There is new syntax for numbers: "+inf.0" (infinity), "-inf.0"
512 (negative infinity), "+nan.0" (not-a-number), and "-nan.0" (same as
513 "+nan.0"). These numbers are inexact and have no exact counterpart.
514
515 Dividing by an inexact zero returns +inf.0 or -inf.0, depending on the
516 sign of the dividend. The infinities are integers, and they answer #t
517 for both 'even?' and 'odd?'. The +nan.0 value is not an integer and is
518 not '=' to itself, but '+nan.0' is 'eqv?' to itself.
519
520 For example
521
522 (/ 1 0.0)
523 => +inf.0
524
525 (/ 0 0.0)
526 => +nan.0
527
528 (/ 0)
529 ERROR: Numerical overflow
530
531 Two new predicates 'inf?' and 'nan?' can be used to test for the
532 special values.
533
534 ** Inexact zero can have a sign.
535
536 Guile can now distinguish between plus and minus inexact zero, if your
537 platform supports this, too. The two zeros are equal according to
538 '=', but not according to 'eqv?'. For example
539
540 (- 0.0)
541 => -0.0
542
543 (= 0.0 (- 0.0))
544 => #t
545
546 (eqv? 0.0 (- 0.0))
547 => #f
548
549 ** Guile now has exact rationals.
550
551 Guile can now represent fractions such as 1/3 exactly. Computing with
552 them is also done exactly, of course:
553
554 (* 1/3 3/2)
555 => 1/2
556
557 ** 'floor', 'ceiling', 'round' and 'truncate' now return exact numbers
558 for exact arguments.
559
560 For example: (floor 2) now returns an exact 2 where in the past it
561 returned an inexact 2.0. Likewise, (floor 5/4) returns an exact 1.
562
563 ** inexact->exact no longer returns only integers.
564
565 Without exact rationals, the closest exact number was always an
566 integer, but now inexact->exact returns the fraction that is exactly
567 equal to a floating point number. For example:
568
569 (inexact->exact 1.234)
570 => 694680242521899/562949953421312
571
572 When you want the old behavior, use 'round' explicitely:
573
574 (inexact->exact (round 1.234))
575 => 1
576
577 ** New function 'rationalize'.
578
579 This function finds a simple fraction that is close to a given real
580 number. For example (and compare with inexact->exact above):
581
582 (rationalize (inexact->exact 1.234) 1/2000)
583 => 58/47
584
585 Note that, as required by R5RS, rationalize returns only then an exact
586 result when both its arguments are exact.
587
588 ** 'odd?' and 'even?' work also for inexact integers.
589
590 Previously, (odd? 1.0) would signal an error since only exact integers
591 were recognized as integers. Now (odd? 1.0) returns #t, (odd? 2.0)
592 returns #f and (odd? 1.5) signals an error.
593
594 ** Guile now has uninterned symbols.
595
596 The new function 'make-symbol' will return an uninterned symbol. This
597 is a symbol that is unique and is guaranteed to remain unique.
598 However, uninterned symbols can not yet be read back in.
599
600 Use the new function 'symbol-interned?' to check whether a symbol is
601 interned or not.
602
603 ** pretty-print has more options.
604
605 The function pretty-print from the (ice-9 pretty-print) module can now
606 also be invoked with keyword arguments that control things like
607 maximum output width. See the manual for details.
608
609 ** Variables have no longer a special behavior for `equal?'.
610
611 Previously, comparing two variables with `equal?' would recursivly
612 compare their values. This is no longer done. Variables are now only
613 `equal?' if they are `eq?'.
614
615 ** `(begin)' is now valid.
616
617 You can now use an empty `begin' form. It will yield #<unspecified>
618 when evaluated and simply be ignored in a definition context.
619
620 ** Deprecated: procedure->macro
621
622 Change your code to use 'define-macro' or r5rs macros. Also, be aware
623 that macro expansion will not be done during evaluation, but prior to
624 evaluation.
625
626 ** Soft ports now allow a `char-ready?' procedure
627
628 The vector argument to `make-soft-port' can now have a length of
629 either 5 or 6. (Previously the length had to be 5.) The optional 6th
630 element is interpreted as an `input-waiting' thunk -- i.e. a thunk
631 that returns the number of characters that can be read immediately
632 without the soft port blocking.
633
634 ** New debugging feature: breakpoints.
635
636 Guile now has breakpoints. For details see the `Debugging Features'
637 chapter in the reference manual.
638
639 ** Deprecated: undefine
640
641 There is no replacement for undefine.
642
643 * The functions make-keyword-from-dash-symbol and keyword-dash-symbol
644 have been discouraged.
645
646 They are relics from a time where a keyword like #:foo was used
647 directly as a Tcl option "-foo" and thus keywords were internally
648 stored as a symbol with a starting dash. We now store a symbol
649 without the dash.
650
651 Use symbol->keyword and keyword->symbol instead.
652
653
654 * Changes to the C interface
655
656 ** There is the new notion of 'discouraged' features.
657
658 This is a milder form of deprecation.
659
660 Things that are discouraged should not be used in new code, but it is
661 OK to leave them in old code for now. When a discouraged feature is
662 used, no warning message is printed like there is for 'deprecated'
663 features. Also, things that are merely discouraged are nevertheless
664 implemented efficiently, while deprecated features can be very slow.
665
666 You can omit discouraged features from libguile by configuring it with
667 the '--disable-discouraged' option.
668
669 ** A new family of functions for converting between C values and
670 Scheme values has been added.
671
672 These functions follow a common naming scheme and are designed to be
673 easier to use, thread-safe and more future-proof than the older
674 alternatives.
675
676 - int scm_is_* (...)
677
678 These are predicates that return a C boolean: 1 or 0. Instead of
679 SCM_NFALSEP, you can now use scm_is_true, for example.
680
681 - <type> scm_to_<type> (SCM val, ...)
682
683 These are functions that convert a Scheme value into an appropriate
684 C value. For example, you can use scm_to_int to safely convert from
685 a SCM to an int.
686
687 - SCM scm_from_<type>) (<type> val, ...)
688
689 These functions convert from a C type to a SCM value; for example,
690 scm_from_int for ints.
691
692 There is a huge number of these functions, for numbers, strings,
693 symbols, vectors, etc. They are documented in the reference manual in
694 the API section together with the types that they apply to.
695
696 ** New functions for dealing with complex numbers in C have been added.
697
698 The new functions are scm_c_make_rectangular, scm_c_make_polar,
699 scm_c_real_part, scm_c_imag_part, scm_c_magnitude and scm_c_angle.
700 They work like scm_make_rectangular etc but take or return doubles
701 directly.
702
703 ** The function scm_make_complex has been discouraged.
704
705 Use scm_c_make_rectangular instead.
706
707 ** The INUM macros have been deprecated.
708
709 A lot of code uses these macros to do general integer conversions,
710 although the macros only work correctly with fixnums. Use the
711 following alternatives.
712
713 SCM_INUMP -> scm_is_integer or similar
714 SCM_NINUMP -> !scm_is_integer or similar
715 SCM_MAKINUM -> scm_from_int or similar
716 SCM_INUM -> scm_to_int or similar
717
718 SCM_VALIDATE_INUM_* -> Do not use these; scm_to_int, etc. will
719 do the validating for you.
720
721 ** The scm_num2<type> and scm_<type>2num functions and scm_make_real
722 have been discouraged.
723
724 Use the newer scm_to_<type> and scm_from_<type> functions instead for
725 new code. The functions have been discouraged since they don't fit
726 the naming scheme.
727
728 ** The 'boolean' macros SCM_FALSEP etc have been discouraged.
729
730 They have strange names, especially SCM_NFALSEP, and SCM_BOOLP
731 evaluates its argument twice. Use scm_is_true, etc. instead for new
732 code.
733
734 ** The macro SCM_EQ_P has been discouraged.
735
736 Use scm_is_eq for new code, which fits better into the naming
737 conventions.
738
739 ** The macros SCM_CONSP, SCM_NCONSP, SCM_NULLP, and SCM_NNULLP have
740 been discouraged.
741
742 Use the function scm_is_pair or scm_is_null instead.
743
744 ** The functions scm_round and scm_truncate have been deprecated and
745 are now available as scm_c_round and scm_c_truncate, respectively.
746
747 These functions occupy the names that scm_round_number and
748 scm_truncate_number should have.
749
750 ** The functions scm_c_string2str, scm_c_substring2str, and
751 scm_c_symbol2str have been deprecated.
752
753 Use scm_to_locale_stringbuf or similar instead, maybe together with
754 scm_substring.
755
756 ** New functions scm_c_make_string, scm_c_string_length,
757 scm_c_string_ref, scm_c_string_set_x, scm_c_substring,
758 scm_c_substring_shared, scm_c_substring_copy.
759
760 These are like scm_make_string, scm_length, etc. but are slightly
761 easier to use from C.
762
763 ** The macros SCM_STRINGP, SCM_STRING_CHARS, SCM_STRING_LENGTH,
764 SCM_SYMBOL_CHARS, and SCM_SYMBOL_LENGTH have been deprecated.
765
766 They export too many assumptions about the implementation of strings
767 and symbols that are no longer true in the presence of
768 mutation-sharing substrings and when Guile switches to some form of
769 Unicode.
770
771 When working with strings, it is often best to use the normal string
772 functions provided by Guile, such as scm_c_string_ref,
773 scm_c_string_set_x, scm_string_append, etc. Be sure to look in the
774 manual since many more such functions are now provided than
775 previously.
776
777 When you want to convert a SCM string to a C string, use the
778 scm_to_locale_string function or similar instead. For symbols, use
779 scm_symbol_to_string and then work with that string. Because of the
780 new string representation, scm_symbol_to_string does not need to copy
781 and is thus quite efficient.
782
783 ** Some string, symbol and keyword functions have been discouraged.
784
785 They don't fit into the uniform naming scheme and are not explicit
786 about the character encoding.
787
788 Replace according to the following table:
789
790 scm_allocate_string -> scm_c_make_string
791 scm_take_str -> scm_take_locale_stringn
792 scm_take0str -> scm_take_locale_string
793 scm_mem2string -> scm_from_locale_stringn
794 scm_str2string -> scm_from_locale_string
795 scm_makfrom0str -> scm_from_locale_string
796 scm_mem2symbol -> scm_from_locale_symboln
797 scm_mem2uninterned_symbol -> scm_from_locale_stringn + scm_make_symbol
798 scm_str2symbol -> scm_from_locale_symbol
799
800 SCM_SYMBOL_HASH -> scm_hashq
801 SCM_SYMBOL_INTERNED_P -> scm_symbol_interned_p
802
803 scm_c_make_keyword -> scm_from_locale_keyword
804
805 ** The functions scm_keyword_to_symbol and sym_symbol_to_keyword are
806 now also available to C code.
807
808 ** SCM_KEYWORDP and SCM_KEYWORDSYM have been deprecated.
809
810 Use scm_is_keyword and scm_keyword_to_symbol instead, but note that
811 the latter returns the true name of the keyword, not the 'dash name',
812 as SCM_KEYWORDSYM used to do.
813
814 ** SCM_CELL_WORD_LOC has been deprecated.
815
816 Use the new macro SCM_CELL_OBJECT_LOC instead, which returns a pointer
817 to a SCM, as opposed to a pointer to a scm_t_bits.
818
819 This was done to allow the correct use of pointers into the Scheme
820 heap. Previously, the heap words were of type scm_t_bits and local
821 variables and function arguments were of type SCM, making it
822 non-standards-conformant to have a pointer that can point to both.
823
824 ** New macros SCM_SMOB_DATA_2, SCM_SMOB_DATA_3, etc.
825
826 These macros should be used instead of SCM_CELL_WORD_2/3 to access the
827 second and third words of double smobs. Likewise for
828 SCM_SET_SMOB_DATA_2 and SCM_SET_SMOB_DATA_3.
829
830 Also, there is SCM_SMOB_FLAGS and SCM_SET_SMOB_FLAGS that should be
831 used to get and set the 16 exra bits in the zeroth word of a smob.
832
833 And finally, there is SCM_SMOB_OBJECT and SCM_SMOB_SET_OBJECT for
834 accesing the first immediate word of a smob as a SCM value, and there
835 is SCM_SMOB_OBJECT_LOC for getting a pointer to the first immediate
836 smob word. Like wise for SCM_SMOB_OBJECT_2, etc.
837
838 ** New way to deal with non-local exits and re-entries.
839
840 There is a new set of functions that essentially do what
841 scm_internal_dynamic_wind does, but in a way that is more convenient
842 for C code in some situations. Here is a quick example of how to
843 prevent a potential memory leak:
844
845 void
846 foo ()
847 {
848 char *mem;
849
850 scm_frame_begin (0);
851
852 mem = scm_malloc (100);
853 scm_frame_unwind_handler (free, mem, SCM_F_WIND_EXPLICITELY);
854
855 /* MEM would leak if BAR throws an error.
856 SCM_FRAME_UNWIND_HANDLER frees it nevertheless.
857 */
858
859 bar ();
860
861 scm_frame_end ();
862
863 /* Because of SCM_F_WIND_EXPLICITELY, MEM will be freed by
864 SCM_FRAME_END as well.
865 */
866 }
867
868 For full documentation, see the node "Frames" in the manual.
869
870 ** New function scm_frame_free
871
872 This function calls 'free' on a given pointer when a frame is left.
873 Thus the call to scm_frame_unwind_handler above could be replaced with
874 simply scm_frame_free (mem).
875
876 ** New way to block and unblock asyncs
877
878 In addition to scm_c_call_with_blocked_asyncs you can now also use
879 scm_frame_block_asyncs in a 'frame' (see above). Likewise for
880 scm_c_call_with_unblocked_asyncs and scm_frame_unblock_asyncs.
881
882 ** New way to temporarily set the current input, output or error ports
883
884 C code can now use scm_frame_current_<foo>_port in a 'frame' (see
885 above). <foo> is one of "input", "output" or "error".
886
887 ** New way to temporarily set fluids
888
889 C code can now use scm_frame_fluid in a 'frame' (see
890 above) to temporarily set the value of a fluid.
891
892 ** New types scm_t_intmax and scm_t_uintmax.
893
894 On platforms that have them, these types are identical to intmax_t and
895 uintmax_t, respectively. On other platforms, they are identical to
896 the largest integer types that Guile knows about.
897
898 ** The functions scm_unmemocopy and scm_unmemoize have been removed.
899
900 You should not have used them.
901
902 ** Many public #defines with generic names have been made private.
903
904 #defines with generic names like HAVE_FOO or SIZEOF_FOO have been made
905 private or renamed with a more suitable public name.
906
907 ** The macro SCM_TYP16S has been deprecated.
908
909 This macro is not intended for public use.
910
911 ** The macro SCM_SLOPPY_INEXACTP has been deprecated.
912
913 Use scm_is_true (scm_inexact_p (...)) instead.
914
915 ** The macro SCM_SLOPPY_REALP has been deprecated.
916
917 Use scm_is_real instead.
918
919 ** The macro SCM_SLOPPY_COMPLEXP has been deprecated.
920
921 Use scm_is_complex instead.
922
923 ** Some preprocessor defines have been deprecated.
924
925 These defines indicated whether a certain feature was present in Guile
926 or not. Going forward, assume that the features are always present.
927
928 The macros are: USE_THREADS, GUILE_ISELECT, READER_EXTENSIONS,
929 DEBUG_EXTENSIONS, DYNAMIC_LINKING.
930
931 The following macros have been removed completely: MEMOIZE_LOCALS,
932 SCM_RECKLESS, SCM_CAUTIOUS.
933
934 ** The preprocessor define STACK_DIRECTION has been deprecated.
935
936 There should be no need to know about the stack direction for ordinary
937 programs.
938
939 ** New function: scm_effective_version
940
941 Returns the "effective" version number. This is just the normal full
942 version string without the final micro-version number. See "Changes
943 to the distribution" above.
944
945 ** The function scm_call_with_new_thread has a new prototype.
946
947 Instead of taking a list with the thunk and handler, these two
948 arguments are now passed directly:
949
950 SCM scm_call_with_new_thread (SCM thunk, SCM handler);
951
952 This is an incompatible change.
953
954 ** The value 'scm_mask_ints' is no longer writable.
955
956 Previously, you could set scm_mask_ints directly. This is no longer
957 possible. Use scm_c_call_with_blocked_asyncs and
958 scm_c_call_with_unblocked_asyncs instead.
959
960 ** New functions scm_c_call_with_blocked_asyncs and
961 scm_c_call_with_unblocked_asyncs
962
963 Like scm_call_with_blocked_asyncs etc. but for C functions.
964
965 ** New snarfer macro SCM_DEFINE_PUBLIC.
966
967 This is like SCM_DEFINE, but also calls scm_c_export for the defined
968 function in the init section.
969
970 ** The snarfer macro SCM_SNARF_INIT is now officially supported.
971
972 ** New macros SCM_VECTOR_REF and SCM_VECTOR_SET.
973
974 Use these in preference to SCM_VELTS.
975
976 ** The SCM_VELTS macros now returns a read-only vector. For writing,
977 use the new macros SCM_WRITABLE_VELTS or SCM_VECTOR_SET. The use of
978 SCM_WRITABLE_VELTS is discouraged, though.
979
980 ** Garbage collector rewrite.
981
982 The garbage collector is cleaned up a lot, and now uses lazy
983 sweeping. This is reflected in the output of (gc-stats); since cells
984 are being freed when they are allocated, the cells-allocated field
985 stays roughly constant.
986
987 For malloc related triggers, the behavior is changed. It uses the same
988 heuristic as the cell-triggered collections. It may be tuned with the
989 environment variables GUILE_MIN_YIELD_MALLOC. This is the percentage
990 for minimum yield of malloc related triggers. The default is 40.
991 GUILE_INIT_MALLOC_LIMIT sets the initial trigger for doing a GC. The
992 default is 200 kb.
993
994 Debugging operations for the freelist have been deprecated, along with
995 the C variables that control garbage collection. The environment
996 variables GUILE_MAX_SEGMENT_SIZE, GUILE_INIT_SEGMENT_SIZE_2,
997 GUILE_INIT_SEGMENT_SIZE_1, and GUILE_MIN_YIELD_2 should be used.
998
999 ** The function scm_definedp has been renamed to scm_defined_p
1000
1001 The name scm_definedp is deprecated.
1002
1003 ** The struct scm_cell type has been renamed to scm_t_cell
1004
1005 This is in accordance to Guile's naming scheme for types. Note that
1006 the name scm_cell is now used for a function that allocates and
1007 initializes a new cell (see below).
1008
1009 ** New functions for memory management
1010
1011 A new set of functions for memory management has been added since the
1012 old way (scm_must_malloc, scm_must_free, etc) was error prone and
1013 indeed, Guile itself contained some long standing bugs that could
1014 cause aborts in long running programs.
1015
1016 The new functions are more symmetrical and do not need cooperation
1017 from smob free routines, among other improvements.
1018
1019 The new functions are scm_malloc, scm_realloc, scm_calloc, scm_strdup,
1020 scm_strndup, scm_gc_malloc, scm_gc_calloc, scm_gc_realloc,
1021 scm_gc_free, scm_gc_register_collectable_memory, and
1022 scm_gc_unregister_collectable_memory. Refer to the manual for more
1023 details and for upgrading instructions.
1024
1025 The old functions for memory management have been deprecated. They
1026 are: scm_must_malloc, scm_must_realloc, scm_must_free,
1027 scm_must_strdup, scm_must_strndup, scm_done_malloc, scm_done_free.
1028
1029 ** Declarations of exported features are marked with SCM_API.
1030
1031 Every declaration of a feature that belongs to the exported Guile API
1032 has been marked by adding the macro "SCM_API" to the start of the
1033 declaration. This macro can expand into different things, the most
1034 common of which is just "extern" for Unix platforms. On Win32, it can
1035 be used to control which symbols are exported from a DLL.
1036
1037 If you `#define SCM_IMPORT' before including <libguile.h>, SCM_API
1038 will expand into "__declspec (dllimport) extern", which is needed for
1039 linking to the Guile DLL in Windows.
1040
1041 There are also SCM_RL_IMPORT, SCM_SRFI1314_IMPORT, and
1042 SCM_SRFI4_IMPORT, for the corresponding libraries.
1043
1044 ** SCM_NEWCELL and SCM_NEWCELL2 have been deprecated.
1045
1046 Use the new functions scm_cell and scm_double_cell instead. The old
1047 macros had problems because with them allocation and initialization
1048 was separated and the GC could sometimes observe half initialized
1049 cells. Only careful coding by the user of SCM_NEWCELL and
1050 SCM_NEWCELL2 could make this safe and efficient.
1051
1052 ** CHECK_ENTRY, CHECK_APPLY and CHECK_EXIT have been deprecated.
1053
1054 Use the variables scm_check_entry_p, scm_check_apply_p and scm_check_exit_p
1055 instead.
1056
1057 ** SRCBRKP has been deprecated.
1058
1059 Use scm_c_source_property_breakpoint_p instead.
1060
1061 ** Deprecated: scm_makmacro
1062
1063 Change your code to use either scm_makmmacro or to define macros in
1064 Scheme, using 'define-macro'.
1065
1066 ** New function scm_c_port_for_each.
1067
1068 This function is like scm_port_for_each but takes a pointer to a C
1069 function as the callback instead of a SCM value.
1070
1071 ** Many definitions have been removed that were previously deprecated.
1072
1073 scm_lisp_nil, scm_lisp_t, s_nil_ify, scm_m_nil_ify, s_t_ify,
1074 scm_m_t_ify, s_0_cond, scm_m_0_cond, s_0_ify, scm_m_0_ify, s_1_ify,
1075 scm_m_1_ify, scm_debug_newcell, scm_debug_newcell2,
1076 scm_tc16_allocated, SCM_SET_SYMBOL_HASH, SCM_IM_NIL_IFY, SCM_IM_T_IFY,
1077 SCM_IM_0_COND, SCM_IM_0_IFY, SCM_IM_1_IFY, SCM_GC_SET_ALLOCATED,
1078 scm_debug_newcell, scm_debug_newcell2, SCM_HUP_SIGNAL, SCM_INT_SIGNAL,
1079 SCM_FPE_SIGNAL, SCM_BUS_SIGNAL, SCM_SEGV_SIGNAL, SCM_ALRM_SIGNAL,
1080 SCM_GC_SIGNAL, SCM_TICK_SIGNAL, SCM_SIG_ORD, SCM_ORD_SIG,
1081 SCM_NUM_SIGS, scm_top_level_lookup_closure_var,
1082 *top-level-lookup-closure*, scm_system_transformer, scm_eval_3,
1083 scm_eval2, root_module_lookup_closure, SCM_SLOPPY_STRINGP,
1084 SCM_RWSTRINGP, scm_read_only_string_p, scm_make_shared_substring,
1085 scm_tc7_substring, sym_huh, SCM_VARVCELL, SCM_UDVARIABLEP,
1086 SCM_DEFVARIABLEP, scm_mkbig, scm_big2inum, scm_adjbig, scm_normbig,
1087 scm_copybig, scm_2ulong2big, scm_dbl2big, scm_big2dbl, SCM_FIXNUM_BIT,
1088 SCM_SETCHARS, SCM_SLOPPY_SUBSTRP, SCM_SUBSTR_STR, SCM_SUBSTR_OFFSET,
1089 SCM_LENGTH_MAX, SCM_SETLENGTH, SCM_ROSTRINGP, SCM_ROLENGTH,
1090 SCM_ROCHARS, SCM_ROUCHARS, SCM_SUBSTRP, SCM_COERCE_SUBSTR,
1091 scm_sym2vcell, scm_intern, scm_intern0, scm_sysintern, scm_sysintern0,
1092 scm_sysintern0_no_module_lookup, scm_init_symbols_deprecated,
1093 scm_vector_set_length_x, scm_contregs, scm_debug_info,
1094 scm_debug_frame, SCM_DSIDEVAL, SCM_CONST_LONG, SCM_VCELL,
1095 SCM_GLOBAL_VCELL, SCM_VCELL_INIT, SCM_GLOBAL_VCELL_INIT,
1096 SCM_HUGE_LENGTH, SCM_VALIDATE_STRINGORSUBSTR, SCM_VALIDATE_ROSTRING,
1097 SCM_VALIDATE_ROSTRING_COPY, SCM_VALIDATE_NULLORROSTRING_COPY,
1098 SCM_VALIDATE_RWSTRING, DIGITS, scm_small_istr2int, scm_istr2int,
1099 scm_istr2flo, scm_istring2number, scm_istr2int, scm_istr2flo,
1100 scm_istring2number, scm_vtable_index_vcell, scm_si_vcell, SCM_ECONSP,
1101 SCM_NECONSP, SCM_GLOC_VAR, SCM_GLOC_VAL, SCM_GLOC_SET_VAL,
1102 SCM_GLOC_VAL_LOC, scm_make_gloc, scm_gloc_p, scm_tc16_variable,
1103 SCM_CHARS, SCM_LENGTH, SCM_SET_STRING_CHARS, SCM_SET_STRING_LENGTH.
1104
1105 \f
1106 Changes since Guile 1.4:
1107
1108 * Changes to the distribution
1109
1110 ** A top-level TODO file is included.
1111
1112 ** Guile now uses a versioning scheme similar to that of the Linux kernel.
1113
1114 Guile now always uses three numbers to represent the version,
1115 i.e. "1.6.5". The first number, 1, is the major version number, the
1116 second number, 6, is the minor version number, and the third number,
1117 5, is the micro version number. Changes in major version number
1118 indicate major changes in Guile.
1119
1120 Minor version numbers that are even denote stable releases, and odd
1121 minor version numbers denote development versions (which may be
1122 unstable). The micro version number indicates a minor sub-revision of
1123 a given MAJOR.MINOR release.
1124
1125 In keeping with the new scheme, (minor-version) and scm_minor_version
1126 no longer return everything but the major version number. They now
1127 just return the minor version number. Two new functions
1128 (micro-version) and scm_micro_version have been added to report the
1129 micro version number.
1130
1131 In addition, ./GUILE-VERSION now defines GUILE_MICRO_VERSION.
1132
1133 ** New preprocessor definitions are available for checking versions.
1134
1135 version.h now #defines SCM_MAJOR_VERSION, SCM_MINOR_VERSION, and
1136 SCM_MICRO_VERSION to the appropriate integer values.
1137
1138 ** Guile now actively warns about deprecated features.
1139
1140 The new configure option `--enable-deprecated=LEVEL' and the
1141 environment variable GUILE_WARN_DEPRECATED control this mechanism.
1142 See INSTALL and README for more information.
1143
1144 ** Guile is much more likely to work on 64-bit architectures.
1145
1146 Guile now compiles and passes "make check" with only two UNRESOLVED GC
1147 cases on Alpha and ia64 based machines now. Thanks to John Goerzen
1148 for the use of a test machine, and thanks to Stefan Jahn for ia64
1149 patches.
1150
1151 ** New functions: setitimer and getitimer.
1152
1153 These implement a fairly direct interface to the libc functions of the
1154 same name.
1155
1156 ** The #. reader extension is now disabled by default.
1157
1158 For safety reasons, #. evaluation is disabled by default. To
1159 re-enable it, set the fluid read-eval? to #t. For example:
1160
1161 (fluid-set! read-eval? #t)
1162
1163 but make sure you realize the potential security risks involved. With
1164 read-eval? enabled, reading a data file from an untrusted source can
1165 be dangerous.
1166
1167 ** New SRFI modules have been added:
1168
1169 SRFI-0 `cond-expand' is now supported in Guile, without requiring
1170 using a module.
1171
1172 (srfi srfi-1) is a library containing many useful pair- and list-processing
1173 procedures.
1174
1175 (srfi srfi-2) exports and-let*.
1176
1177 (srfi srfi-4) implements homogeneous numeric vector datatypes.
1178
1179 (srfi srfi-6) is a dummy module for now, since guile already provides
1180 all of the srfi-6 procedures by default: open-input-string,
1181 open-output-string, get-output-string.
1182
1183 (srfi srfi-8) exports receive.
1184
1185 (srfi srfi-9) exports define-record-type.
1186
1187 (srfi srfi-10) exports define-reader-ctor and implements the reader
1188 extension #,().
1189
1190 (srfi srfi-11) exports let-values and let*-values.
1191
1192 (srfi srfi-13) implements the SRFI String Library.
1193
1194 (srfi srfi-14) implements the SRFI Character-Set Library.
1195
1196 (srfi srfi-17) implements setter and getter-with-setter and redefines
1197 some accessor procedures as procedures with getters. (such as car,
1198 cdr, vector-ref etc.)
1199
1200 (srfi srfi-19) implements the SRFI Time/Date Library.
1201
1202 ** New scripts / "executable modules"
1203
1204 Subdirectory "scripts" contains Scheme modules that are packaged to
1205 also be executable as scripts. At this time, these scripts are available:
1206
1207 display-commentary
1208 doc-snarf
1209 generate-autoload
1210 punify
1211 read-scheme-source
1212 use2dot
1213
1214 See README there for more info.
1215
1216 These scripts can be invoked from the shell with the new program
1217 "guile-tools", which keeps track of installation directory for you.
1218 For example:
1219
1220 $ guile-tools display-commentary srfi/*.scm
1221
1222 guile-tools is copied to the standard $bindir on "make install".
1223
1224 ** New module (ice-9 stack-catch):
1225
1226 stack-catch is like catch, but saves the current state of the stack in
1227 the fluid the-last-stack. This fluid can be useful when using the
1228 debugger and when re-throwing an error.
1229
1230 ** The module (ice-9 and-let*) has been renamed to (ice-9 and-let-star)
1231
1232 This has been done to prevent problems on lesser operating systems
1233 that can't tolerate `*'s in file names. The exported macro continues
1234 to be named `and-let*', of course.
1235
1236 On systems that support it, there is also a compatibility module named
1237 (ice-9 and-let*). It will go away in the next release.
1238
1239 ** New modules (oop goops) etc.:
1240
1241 (oop goops)
1242 (oop goops describe)
1243 (oop goops save)
1244 (oop goops active-slot)
1245 (oop goops composite-slot)
1246
1247 The Guile Object Oriented Programming System (GOOPS) has been
1248 integrated into Guile. For further information, consult the GOOPS
1249 manual and tutorial in the `doc' directory.
1250
1251 ** New module (ice-9 rdelim).
1252
1253 This exports the following procedures which were previously defined
1254 in the default environment:
1255
1256 read-line read-line! read-delimited read-delimited! %read-delimited!
1257 %read-line write-line
1258
1259 For backwards compatibility the definitions are still imported into the
1260 default environment in this version of Guile. However you should add:
1261
1262 (use-modules (ice-9 rdelim))
1263
1264 to any program which uses the definitions, since this may change in
1265 future.
1266
1267 Alternatively, if guile-scsh is installed, the (scsh rdelim) module
1268 can be used for similar functionality.
1269
1270 ** New module (ice-9 rw)
1271
1272 This is a subset of the (scsh rw) module from guile-scsh. Currently
1273 it defines two procedures:
1274
1275 *** New function: read-string!/partial str [port_or_fdes [start [end]]]
1276
1277 Read characters from a port or file descriptor into a string STR.
1278 A port must have an underlying file descriptor -- a so-called
1279 fport. This procedure is scsh-compatible and can efficiently read
1280 large strings.
1281
1282 *** New function: write-string/partial str [port_or_fdes [start [end]]]
1283
1284 Write characters from a string STR to a port or file descriptor.
1285 A port must have an underlying file descriptor -- a so-called
1286 fport. This procedure is mostly compatible and can efficiently
1287 write large strings.
1288
1289 ** New module (ice-9 match)
1290
1291 This module includes Andrew K. Wright's pattern matcher. See
1292 ice-9/match.scm for brief description or
1293
1294 http://www.star-lab.com/wright/code.html
1295
1296 for complete documentation.
1297
1298 ** New module (ice-9 buffered-input)
1299
1300 This module provides procedures to construct an input port from an
1301 underlying source of input that reads and returns its input in chunks.
1302 The underlying input source is a Scheme procedure, specified by the
1303 caller, which the port invokes whenever it needs more input.
1304
1305 This is useful when building an input port whose back end is Readline
1306 or a UI element such as the GtkEntry widget.
1307
1308 ** Documentation
1309
1310 The reference and tutorial documentation that was previously
1311 distributed separately, as `guile-doc', is now included in the core
1312 Guile distribution. The documentation consists of the following
1313 manuals.
1314
1315 - The Guile Tutorial (guile-tut.texi) contains a tutorial introduction
1316 to using Guile.
1317
1318 - The Guile Reference Manual (guile.texi) contains (or is intended to
1319 contain) reference documentation on all aspects of Guile.
1320
1321 - The GOOPS Manual (goops.texi) contains both tutorial-style and
1322 reference documentation for using GOOPS, Guile's Object Oriented
1323 Programming System.
1324
1325 - The Revised^5 Report on the Algorithmic Language Scheme
1326 (r5rs.texi).
1327
1328 See the README file in the `doc' directory for more details.
1329
1330 ** There are a couple of examples in the examples/ directory now.
1331
1332 * Changes to the stand-alone interpreter
1333
1334 ** New command line option `--use-srfi'
1335
1336 Using this option, SRFI modules can be loaded on startup and be
1337 available right from the beginning. This makes programming portable
1338 Scheme programs easier.
1339
1340 The option `--use-srfi' expects a comma-separated list of numbers,
1341 each representing a SRFI number to be loaded into the interpreter
1342 before starting evaluating a script file or the REPL. Additionally,
1343 the feature identifier for the loaded SRFIs is recognized by
1344 `cond-expand' when using this option.
1345
1346 Example:
1347 $ guile --use-srfi=8,13
1348 guile> (receive (x z) (values 1 2) (+ 1 2))
1349 3
1350 guile> (string-pad "bla" 20)
1351 " bla"
1352
1353 ** Guile now always starts up in the `(guile-user)' module.
1354
1355 Previously, scripts executed via the `-s' option would run in the
1356 `(guile)' module and the repl would run in the `(guile-user)' module.
1357 Now every user action takes place in the `(guile-user)' module by
1358 default.
1359
1360 * Changes to Scheme functions and syntax
1361
1362 ** Character classifiers work for non-ASCII characters.
1363
1364 The predicates `char-alphabetic?', `char-numeric?',
1365 `char-whitespace?', `char-lower?', `char-upper?' and `char-is-both?'
1366 no longer check whether their arguments are ASCII characters.
1367 Previously, a character would only be considered alphabetic when it
1368 was also ASCII, for example.
1369
1370 ** Previously deprecated Scheme functions have been removed:
1371
1372 tag - no replacement.
1373 fseek - replaced by seek.
1374 list* - replaced by cons*.
1375
1376 ** It's now possible to create modules with controlled environments
1377
1378 Example:
1379
1380 (use-modules (ice-9 safe))
1381 (define m (make-safe-module))
1382 ;;; m will now be a module containing only a safe subset of R5RS
1383 (eval '(+ 1 2) m) --> 3
1384 (eval 'load m) --> ERROR: Unbound variable: load
1385
1386 ** Evaluation of "()", the empty list, is now an error.
1387
1388 Previously, the expression "()" evaluated to the empty list. This has
1389 been changed to signal a "missing expression" error. The correct way
1390 to write the empty list as a literal constant is to use quote: "'()".
1391
1392 ** New concept of `Guile Extensions'.
1393
1394 A Guile Extension is just a ordinary shared library that can be linked
1395 at run-time. We found it advantageous to give this simple concept a
1396 dedicated name to distinguish the issues related to shared libraries
1397 from the issues related to the module system.
1398
1399 *** New function: load-extension
1400
1401 Executing (load-extension lib init) is mostly equivalent to
1402
1403 (dynamic-call init (dynamic-link lib))
1404
1405 except when scm_register_extension has been called previously.
1406 Whenever appropriate, you should use `load-extension' instead of
1407 dynamic-link and dynamic-call.
1408
1409 *** New C function: scm_c_register_extension
1410
1411 This function registers a initialization function for use by
1412 `load-extension'. Use it when you don't want specific extensions to
1413 be loaded as shared libraries (for example on platforms that don't
1414 support dynamic linking).
1415
1416 ** Auto-loading of compiled-code modules is deprecated.
1417
1418 Guile used to be able to automatically find and link a shared
1419 library to satisfy requests for a module. For example, the module
1420 `(foo bar)' could be implemented by placing a shared library named
1421 "foo/libbar.so" (or with a different extension) in a directory on the
1422 load path of Guile.
1423
1424 This has been found to be too tricky, and is no longer supported. The
1425 shared libraries are now called "extensions". You should now write a
1426 small Scheme file that calls `load-extension' to load the shared
1427 library and initialize it explicitely.
1428
1429 The shared libraries themselves should be installed in the usual
1430 places for shared libraries, with names like "libguile-foo-bar".
1431
1432 For example, place this into a file "foo/bar.scm"
1433
1434 (define-module (foo bar))
1435
1436 (load-extension "libguile-foo-bar" "foobar_init")
1437
1438 ** Backward incompatible change: eval EXP ENVIRONMENT-SPECIFIER
1439
1440 `eval' is now R5RS, that is it takes two arguments.
1441 The second argument is an environment specifier, i.e. either
1442
1443 (scheme-report-environment 5)
1444 (null-environment 5)
1445 (interaction-environment)
1446
1447 or
1448
1449 any module.
1450
1451 ** The module system has been made more disciplined.
1452
1453 The function `eval' will save and restore the current module around
1454 the evaluation of the specified expression. While this expression is
1455 evaluated, `(current-module)' will now return the right module, which
1456 is the module specified as the second argument to `eval'.
1457
1458 A consequence of this change is that `eval' is not particularly
1459 useful when you want allow the evaluated code to change what module is
1460 designated as the current module and have this change persist from one
1461 call to `eval' to the next. The read-eval-print-loop is an example
1462 where `eval' is now inadequate. To compensate, there is a new
1463 function `primitive-eval' that does not take a module specifier and
1464 that does not save/restore the current module. You should use this
1465 function together with `set-current-module', `current-module', etc
1466 when you want to have more control over the state that is carried from
1467 one eval to the next.
1468
1469 Additionally, it has been made sure that forms that are evaluated at
1470 the top level are always evaluated with respect to the current module.
1471 Previously, subforms of top-level forms such as `begin', `case',
1472 etc. did not respect changes to the current module although these
1473 subforms are at the top-level as well.
1474
1475 To prevent strange behavior, the forms `define-module',
1476 `use-modules', `use-syntax', and `export' have been restricted to only
1477 work on the top level. The forms `define-public' and
1478 `defmacro-public' only export the new binding on the top level. They
1479 behave just like `define' and `defmacro', respectively, when they are
1480 used in a lexical environment.
1481
1482 Also, `export' will no longer silently re-export bindings imported
1483 from a used module. It will emit a `deprecation' warning and will
1484 cease to perform any re-export in the next version. If you actually
1485 want to re-export bindings, use the new `re-export' in place of
1486 `export'. The new `re-export' will not make copies of variables when
1487 rexporting them, as `export' did wrongly.
1488
1489 ** Module system now allows selection and renaming of imported bindings
1490
1491 Previously, when using `use-modules' or the `#:use-module' clause in
1492 the `define-module' form, all the bindings (association of symbols to
1493 values) for imported modules were added to the "current module" on an
1494 as-is basis. This has been changed to allow finer control through two
1495 new facilities: selection and renaming.
1496
1497 You can now select which of the imported module's bindings are to be
1498 visible in the current module by using the `:select' clause. This
1499 clause also can be used to rename individual bindings. For example:
1500
1501 ;; import all bindings no questions asked
1502 (use-modules (ice-9 common-list))
1503
1504 ;; import four bindings, renaming two of them;
1505 ;; the current module sees: every some zonk-y zonk-n
1506 (use-modules ((ice-9 common-list)
1507 :select (every some
1508 (remove-if . zonk-y)
1509 (remove-if-not . zonk-n))))
1510
1511 You can also programmatically rename all selected bindings using the
1512 `:renamer' clause, which specifies a proc that takes a symbol and
1513 returns another symbol. Because it is common practice to use a prefix,
1514 we now provide the convenience procedure `symbol-prefix-proc'. For
1515 example:
1516
1517 ;; import four bindings, renaming two of them specifically,
1518 ;; and all four w/ prefix "CL:";
1519 ;; the current module sees: CL:every CL:some CL:zonk-y CL:zonk-n
1520 (use-modules ((ice-9 common-list)
1521 :select (every some
1522 (remove-if . zonk-y)
1523 (remove-if-not . zonk-n))
1524 :renamer (symbol-prefix-proc 'CL:)))
1525
1526 ;; import four bindings, renaming two of them specifically,
1527 ;; and all four by upcasing.
1528 ;; the current module sees: EVERY SOME ZONK-Y ZONK-N
1529 (define (upcase-symbol sym)
1530 (string->symbol (string-upcase (symbol->string sym))))
1531
1532 (use-modules ((ice-9 common-list)
1533 :select (every some
1534 (remove-if . zonk-y)
1535 (remove-if-not . zonk-n))
1536 :renamer upcase-symbol))
1537
1538 Note that programmatic renaming is done *after* individual renaming.
1539 Also, the above examples show `use-modules', but the same facilities are
1540 available for the `#:use-module' clause of `define-module'.
1541
1542 See manual for more info.
1543
1544 ** The semantics of guardians have changed.
1545
1546 The changes are for the most part compatible. An important criterion
1547 was to keep the typical usage of guardians as simple as before, but to
1548 make the semantics safer and (as a result) more useful.
1549
1550 *** All objects returned from guardians are now properly alive.
1551
1552 It is now guaranteed that any object referenced by an object returned
1553 from a guardian is alive. It's now impossible for a guardian to
1554 return a "contained" object before its "containing" object.
1555
1556 One incompatible (but probably not very important) change resulting
1557 from this is that it is no longer possible to guard objects that
1558 indirectly reference themselves (i.e. are parts of cycles). If you do
1559 so accidentally, you'll get a warning.
1560
1561 *** There are now two types of guardians: greedy and sharing.
1562
1563 If you call (make-guardian #t) or just (make-guardian), you'll get a
1564 greedy guardian, and for (make-guardian #f) a sharing guardian.
1565
1566 Greedy guardians are the default because they are more "defensive".
1567 You can only greedily guard an object once. If you guard an object
1568 more than once, once in a greedy guardian and the rest of times in
1569 sharing guardians, then it is guaranteed that the object won't be
1570 returned from sharing guardians as long as it is greedily guarded
1571 and/or alive.
1572
1573 Guardians returned by calls to `make-guardian' can now take one more
1574 optional parameter, which says whether to throw an error in case an
1575 attempt is made to greedily guard an object that is already greedily
1576 guarded. The default is true, i.e. throw an error. If the parameter
1577 is false, the guardian invocation returns #t if guarding was
1578 successful and #f if it wasn't.
1579
1580 Also, since greedy guarding is, in effect, a side-effecting operation
1581 on objects, a new function is introduced: `destroy-guardian!'.
1582 Invoking this function on a guardian renders it unoperative and, if
1583 the guardian is greedy, clears the "greedily guarded" property of the
1584 objects that were guarded by it, thus undoing the side effect.
1585
1586 Note that all this hair is hardly very important, since guardian
1587 objects are usually permanent.
1588
1589 ** Continuations created by call-with-current-continuation now accept
1590 any number of arguments, as required by R5RS.
1591
1592 ** New function `issue-deprecation-warning'
1593
1594 This function is used to display the deprecation messages that are
1595 controlled by GUILE_WARN_DEPRECATION as explained in the README.
1596
1597 (define (id x)
1598 (issue-deprecation-warning "`id' is deprecated. Use `identity' instead.")
1599 (identity x))
1600
1601 guile> (id 1)
1602 ;; `id' is deprecated. Use `identity' instead.
1603 1
1604 guile> (id 1)
1605 1
1606
1607 ** New syntax `begin-deprecated'
1608
1609 When deprecated features are included (as determined by the configure
1610 option --enable-deprecated), `begin-deprecated' is identical to
1611 `begin'. When deprecated features are excluded, it always evaluates
1612 to `#f', ignoring the body forms.
1613
1614 ** New function `make-object-property'
1615
1616 This function returns a new `procedure with setter' P that can be used
1617 to attach a property to objects. When calling P as
1618
1619 (set! (P obj) val)
1620
1621 where `obj' is any kind of object, it attaches `val' to `obj' in such
1622 a way that it can be retrieved by calling P as
1623
1624 (P obj)
1625
1626 This function will replace procedure properties, symbol properties and
1627 source properties eventually.
1628
1629 ** Module (ice-9 optargs) now uses keywords instead of `#&'.
1630
1631 Instead of #&optional, #&key, etc you should now use #:optional,
1632 #:key, etc. Since #:optional is a keyword, you can write it as just
1633 :optional when (read-set! keywords 'prefix) is active.
1634
1635 The old reader syntax `#&' is still supported, but deprecated. It
1636 will be removed in the next release.
1637
1638 ** New define-module option: pure
1639
1640 Tells the module system not to include any bindings from the root
1641 module.
1642
1643 Example:
1644
1645 (define-module (totally-empty-module)
1646 :pure)
1647
1648 ** New define-module option: export NAME1 ...
1649
1650 Export names NAME1 ...
1651
1652 This option is required if you want to be able to export bindings from
1653 a module which doesn't import one of `define-public' or `export'.
1654
1655 Example:
1656
1657 (define-module (foo)
1658 :pure
1659 :use-module (ice-9 r5rs)
1660 :export (bar))
1661
1662 ;;; Note that we're pure R5RS below this point!
1663
1664 (define (bar)
1665 ...)
1666
1667 ** New function: object->string OBJ
1668
1669 Return a Scheme string obtained by printing a given object.
1670
1671 ** New function: port? X
1672
1673 Returns a boolean indicating whether X is a port. Equivalent to
1674 `(or (input-port? X) (output-port? X))'.
1675
1676 ** New function: file-port?
1677
1678 Determines whether a given object is a port that is related to a file.
1679
1680 ** New function: port-for-each proc
1681
1682 Apply PROC to each port in the Guile port table in turn. The return
1683 value is unspecified. More specifically, PROC is applied exactly once
1684 to every port that exists in the system at the time PORT-FOR-EACH is
1685 invoked. Changes to the port table while PORT-FOR-EACH is running
1686 have no effect as far as PORT-FOR-EACH is concerned.
1687
1688 ** New function: dup2 oldfd newfd
1689
1690 A simple wrapper for the `dup2' system call. Copies the file
1691 descriptor OLDFD to descriptor number NEWFD, replacing the
1692 previous meaning of NEWFD. Both OLDFD and NEWFD must be integers.
1693 Unlike for dup->fdes or primitive-move->fdes, no attempt is made
1694 to move away ports which are using NEWFD. The return value is
1695 unspecified.
1696
1697 ** New function: close-fdes fd
1698
1699 A simple wrapper for the `close' system call. Close file
1700 descriptor FD, which must be an integer. Unlike close (*note
1701 close: Ports and File Descriptors.), the file descriptor will be
1702 closed even if a port is using it. The return value is
1703 unspecified.
1704
1705 ** New function: crypt password salt
1706
1707 Encrypts `password' using the standard unix password encryption
1708 algorithm.
1709
1710 ** New function: chroot path
1711
1712 Change the root directory of the running process to `path'.
1713
1714 ** New functions: getlogin, cuserid
1715
1716 Return the login name or the user name of the current effective user
1717 id, respectively.
1718
1719 ** New functions: getpriority which who, setpriority which who prio
1720
1721 Get or set the priority of the running process.
1722
1723 ** New function: getpass prompt
1724
1725 Read a password from the terminal, first displaying `prompt' and
1726 disabling echoing.
1727
1728 ** New function: flock file operation
1729
1730 Set/remove an advisory shared or exclusive lock on `file'.
1731
1732 ** New functions: sethostname name, gethostname
1733
1734 Set or get the hostname of the machine the current process is running
1735 on.
1736
1737 ** New function: mkstemp! tmpl
1738
1739 mkstemp creates a new unique file in the file system and returns a
1740 new buffered port open for reading and writing to the file. TMPL
1741 is a string specifying where the file should be created: it must
1742 end with `XXXXXX' and will be changed in place to return the name
1743 of the temporary file.
1744
1745 ** New function: open-input-string string
1746
1747 Return an input string port which delivers the characters from
1748 `string'. This procedure, together with `open-output-string' and
1749 `get-output-string' implements SRFI-6.
1750
1751 ** New function: open-output-string
1752
1753 Return an output string port which collects all data written to it.
1754 The data can then be retrieved by `get-output-string'.
1755
1756 ** New function: get-output-string
1757
1758 Return the contents of an output string port.
1759
1760 ** New function: identity
1761
1762 Return the argument.
1763
1764 ** socket, connect, accept etc., now have support for IPv6. IPv6 addresses
1765 are represented in Scheme as integers with normal host byte ordering.
1766
1767 ** New function: inet-pton family address
1768
1769 Convert a printable string network address into an integer. Note that
1770 unlike the C version of this function, the result is an integer with
1771 normal host byte ordering. FAMILY can be `AF_INET' or `AF_INET6'.
1772 e.g.,
1773
1774 (inet-pton AF_INET "127.0.0.1") => 2130706433
1775 (inet-pton AF_INET6 "::1") => 1
1776
1777 ** New function: inet-ntop family address
1778
1779 Convert an integer network address into a printable string. Note that
1780 unlike the C version of this function, the input is an integer with
1781 normal host byte ordering. FAMILY can be `AF_INET' or `AF_INET6'.
1782 e.g.,
1783
1784 (inet-ntop AF_INET 2130706433) => "127.0.0.1"
1785 (inet-ntop AF_INET6 (- (expt 2 128) 1)) =>
1786 ffff:ffff:ffff:ffff:ffff:ffff:ffff:ffff
1787
1788 ** Deprecated: id
1789
1790 Use `identity' instead.
1791
1792 ** Deprecated: -1+
1793
1794 Use `1-' instead.
1795
1796 ** Deprecated: return-it
1797
1798 Do without it.
1799
1800 ** Deprecated: string-character-length
1801
1802 Use `string-length' instead.
1803
1804 ** Deprecated: flags
1805
1806 Use `logior' instead.
1807
1808 ** Deprecated: close-all-ports-except.
1809
1810 This was intended for closing ports in a child process after a fork,
1811 but it has the undesirable side effect of flushing buffers.
1812 port-for-each is more flexible.
1813
1814 ** The (ice-9 popen) module now attempts to set up file descriptors in
1815 the child process from the current Scheme ports, instead of using the
1816 current values of file descriptors 0, 1, and 2 in the parent process.
1817
1818 ** Removed function: builtin-weak-bindings
1819
1820 There is no such concept as a weak binding any more.
1821
1822 ** Removed constants: bignum-radix, scm-line-incrementors
1823
1824 ** define-method: New syntax mandatory.
1825
1826 The new method syntax is now mandatory:
1827
1828 (define-method (NAME ARG-SPEC ...) BODY ...)
1829 (define-method (NAME ARG-SPEC ... . REST-ARG) BODY ...)
1830
1831 ARG-SPEC ::= ARG-NAME | (ARG-NAME TYPE)
1832 REST-ARG ::= ARG-NAME
1833
1834 If you have old code using the old syntax, import
1835 (oop goops old-define-method) before (oop goops) as in:
1836
1837 (use-modules (oop goops old-define-method) (oop goops))
1838
1839 ** Deprecated function: builtin-variable
1840 Removed function: builtin-bindings
1841
1842 There is no longer a distinction between builtin or other variables.
1843 Use module system operations for all variables.
1844
1845 ** Lazy-catch handlers are no longer allowed to return.
1846
1847 That is, a call to `throw', `error', etc is now guaranteed to not
1848 return.
1849
1850 ** Bugfixes for (ice-9 getopt-long)
1851
1852 This module is now tested using test-suite/tests/getopt-long.test.
1853 The following bugs have been fixed:
1854
1855 *** Parsing for options that are specified to have `optional' args now checks
1856 if the next element is an option instead of unconditionally taking it as the
1857 option arg.
1858
1859 *** An error is now thrown for `--opt=val' when the option description
1860 does not specify `(value #t)' or `(value optional)'. This condition used to
1861 be accepted w/o error, contrary to the documentation.
1862
1863 *** The error message for unrecognized options is now more informative.
1864 It used to be "not a record", an artifact of the implementation.
1865
1866 *** The error message for `--opt' terminating the arg list (no value), when
1867 `(value #t)' is specified, is now more informative. It used to be "not enough
1868 args".
1869
1870 *** "Clumped" single-char args now preserve trailing string, use it as arg.
1871 The expansion used to be like so:
1872
1873 ("-abc5d" "--xyz") => ("-a" "-b" "-c" "--xyz")
1874
1875 Note that the "5d" is dropped. Now it is like so:
1876
1877 ("-abc5d" "--xyz") => ("-a" "-b" "-c" "5d" "--xyz")
1878
1879 This enables single-char options to have adjoining arguments as long as their
1880 constituent characters are not potential single-char options.
1881
1882 ** (ice-9 session) procedure `arity' now works with (ice-9 optargs) `lambda*'
1883
1884 The `lambda*' and derivative forms in (ice-9 optargs) now set a procedure
1885 property `arglist', which can be retrieved by `arity'. The result is that
1886 `arity' can give more detailed information than before:
1887
1888 Before:
1889
1890 guile> (use-modules (ice-9 optargs))
1891 guile> (define* (foo #:optional a b c) a)
1892 guile> (arity foo)
1893 0 or more arguments in `lambda*:G0'.
1894
1895 After:
1896
1897 guile> (arity foo)
1898 3 optional arguments: `a', `b' and `c'.
1899 guile> (define* (bar a b #:key c d #:allow-other-keys) a)
1900 guile> (arity bar)
1901 2 required arguments: `a' and `b', 2 keyword arguments: `c'
1902 and `d', other keywords allowed.
1903 guile> (define* (baz a b #:optional c #:rest r) a)
1904 guile> (arity baz)
1905 2 required arguments: `a' and `b', 1 optional argument: `c',
1906 the rest in `r'.
1907
1908 * Changes to the C interface
1909
1910 ** Types have been renamed from scm_*_t to scm_t_*.
1911
1912 This has been done for POSIX sake. It reserves identifiers ending
1913 with "_t". What a concept.
1914
1915 The old names are still available with status `deprecated'.
1916
1917 ** scm_t_bits (former scm_bits_t) is now a unsigned type.
1918
1919 ** Deprecated features have been removed.
1920
1921 *** Macros removed
1922
1923 SCM_INPORTP, SCM_OUTPORTP SCM_ICHRP, SCM_ICHR, SCM_MAKICHR
1924 SCM_SETJMPBUF SCM_NSTRINGP SCM_NRWSTRINGP SCM_NVECTORP SCM_DOUBLE_CELLP
1925
1926 *** C Functions removed
1927
1928 scm_sysmissing scm_tag scm_tc16_flo scm_tc_flo
1929 scm_fseek - replaced by scm_seek.
1930 gc-thunk - replaced by after-gc-hook.
1931 gh_int2scmb - replaced by gh_bool2scm.
1932 scm_tc_dblr - replaced by scm_tc16_real.
1933 scm_tc_dblc - replaced by scm_tc16_complex.
1934 scm_list_star - replaced by scm_cons_star.
1935
1936 ** Deprecated: scm_makfromstr
1937
1938 Use scm_mem2string instead.
1939
1940 ** Deprecated: scm_make_shared_substring
1941
1942 Explicit shared substrings will disappear from Guile.
1943
1944 Instead, "normal" strings will be implemented using sharing
1945 internally, combined with a copy-on-write strategy.
1946
1947 ** Deprecated: scm_read_only_string_p
1948
1949 The concept of read-only strings will disappear in next release of
1950 Guile.
1951
1952 ** Deprecated: scm_sloppy_memq, scm_sloppy_memv, scm_sloppy_member
1953
1954 Instead, use scm_c_memq or scm_memq, scm_memv, scm_member.
1955
1956 ** New functions: scm_call_0, scm_call_1, scm_call_2, scm_call_3
1957
1958 Call a procedure with the indicated number of arguments. See "Fly
1959 Evaluation" in the manual.
1960
1961 ** New functions: scm_apply_0, scm_apply_1, scm_apply_2, scm_apply_3
1962
1963 Call a procedure with the indicated number of arguments and a list of
1964 further arguments. See "Fly Evaluation" in the manual.
1965
1966 ** New functions: scm_list_1, scm_list_2, scm_list_3, scm_list_4, scm_list_5
1967
1968 Create a list of the given number of elements. See "List
1969 Constructors" in the manual.
1970
1971 ** Renamed function: scm_listify has been replaced by scm_list_n.
1972
1973 ** Deprecated macros: SCM_LIST0, SCM_LIST1, SCM_LIST2, SCM_LIST3, SCM_LIST4,
1974 SCM_LIST5, SCM_LIST6, SCM_LIST7, SCM_LIST8, SCM_LIST9.
1975
1976 Use functions scm_list_N instead.
1977
1978 ** New function: scm_c_read (SCM port, void *buffer, scm_sizet size)
1979
1980 Used by an application to read arbitrary number of bytes from a port.
1981 Same semantics as libc read, except that scm_c_read only returns less
1982 than SIZE bytes if at end-of-file.
1983
1984 Warning: Doesn't update port line and column counts!
1985
1986 ** New function: scm_c_write (SCM port, const void *ptr, scm_sizet size)
1987
1988 Used by an application to write arbitrary number of bytes to an SCM
1989 port. Similar semantics as libc write. However, unlike libc
1990 write, scm_c_write writes the requested number of bytes and has no
1991 return value.
1992
1993 Warning: Doesn't update port line and column counts!
1994
1995 ** New function: scm_init_guile ()
1996
1997 In contrast to scm_boot_guile, scm_init_guile will return normally
1998 after initializing Guile. It is not available on all systems, tho.
1999
2000 ** New functions: scm_str2symbol, scm_mem2symbol
2001
2002 The function scm_str2symbol takes a const char* pointing to a zero-terminated
2003 field of characters and creates a scheme symbol object from that C string.
2004 The function scm_mem2symbol takes a const char* and a number of characters and
2005 creates a symbol from the characters in that memory area.
2006
2007 ** New functions: scm_primitive_make_property
2008 scm_primitive_property_ref
2009 scm_primitive_property_set_x
2010 scm_primitive_property_del_x
2011
2012 These functions implement a new way to deal with object properties.
2013 See libguile/properties.c for their documentation.
2014
2015 ** New function: scm_done_free (long size)
2016
2017 This function is the inverse of scm_done_malloc. Use it to report the
2018 amount of smob memory you free. The previous method, which involved
2019 calling scm_done_malloc with negative argument, was somewhat
2020 unintuitive (and is still available, of course).
2021
2022 ** New function: scm_c_memq (SCM obj, SCM list)
2023
2024 This function provides a fast C level alternative for scm_memq for the case
2025 that the list parameter is known to be a proper list. The function is a
2026 replacement for scm_sloppy_memq, but is stricter in its requirements on its
2027 list input parameter, since for anything else but a proper list the function's
2028 behaviour is undefined - it may even crash or loop endlessly. Further, for
2029 the case that the object is not found in the list, scm_c_memq returns #f which
2030 is similar to scm_memq, but different from scm_sloppy_memq's behaviour.
2031
2032 ** New functions: scm_remember_upto_here_1, scm_remember_upto_here_2,
2033 scm_remember_upto_here
2034
2035 These functions replace the function scm_remember.
2036
2037 ** Deprecated function: scm_remember
2038
2039 Use one of the new functions scm_remember_upto_here_1,
2040 scm_remember_upto_here_2 or scm_remember_upto_here instead.
2041
2042 ** New function: scm_allocate_string
2043
2044 This function replaces the function scm_makstr.
2045
2046 ** Deprecated function: scm_makstr
2047
2048 Use the new function scm_allocate_string instead.
2049
2050 ** New global variable scm_gc_running_p introduced.
2051
2052 Use this variable to find out if garbage collection is being executed. Up to
2053 now applications have used scm_gc_heap_lock to test if garbage collection was
2054 running, which also works because of the fact that up to know only the garbage
2055 collector has set this variable. But, this is an implementation detail that
2056 may change. Further, scm_gc_heap_lock is not set throughout gc, thus the use
2057 of this variable is (and has been) not fully safe anyway.
2058
2059 ** New macros: SCM_BITVECTOR_MAX_LENGTH, SCM_UVECTOR_MAX_LENGTH
2060
2061 Use these instead of SCM_LENGTH_MAX.
2062
2063 ** New macros: SCM_CONTINUATION_LENGTH, SCM_CCLO_LENGTH, SCM_STACK_LENGTH,
2064 SCM_STRING_LENGTH, SCM_SYMBOL_LENGTH, SCM_UVECTOR_LENGTH,
2065 SCM_BITVECTOR_LENGTH, SCM_VECTOR_LENGTH.
2066
2067 Use these instead of SCM_LENGTH.
2068
2069 ** New macros: SCM_SET_CONTINUATION_LENGTH, SCM_SET_STRING_LENGTH,
2070 SCM_SET_SYMBOL_LENGTH, SCM_SET_VECTOR_LENGTH, SCM_SET_UVECTOR_LENGTH,
2071 SCM_SET_BITVECTOR_LENGTH
2072
2073 Use these instead of SCM_SETLENGTH
2074
2075 ** New macros: SCM_STRING_CHARS, SCM_SYMBOL_CHARS, SCM_CCLO_BASE,
2076 SCM_VECTOR_BASE, SCM_UVECTOR_BASE, SCM_BITVECTOR_BASE, SCM_COMPLEX_MEM,
2077 SCM_ARRAY_MEM
2078
2079 Use these instead of SCM_CHARS, SCM_UCHARS, SCM_ROCHARS, SCM_ROUCHARS or
2080 SCM_VELTS.
2081
2082 ** New macros: SCM_SET_BIGNUM_BASE, SCM_SET_STRING_CHARS,
2083 SCM_SET_SYMBOL_CHARS, SCM_SET_UVECTOR_BASE, SCM_SET_BITVECTOR_BASE,
2084 SCM_SET_VECTOR_BASE
2085
2086 Use these instead of SCM_SETCHARS.
2087
2088 ** New macro: SCM_BITVECTOR_P
2089
2090 ** New macro: SCM_STRING_COERCE_0TERMINATION_X
2091
2092 Use instead of SCM_COERCE_SUBSTR.
2093
2094 ** New macros: SCM_DIR_OPEN_P, SCM_DIR_FLAG_OPEN
2095
2096 For directory objects, use these instead of SCM_OPDIRP and SCM_OPN.
2097
2098 ** Deprecated macros: SCM_OUTOFRANGE, SCM_NALLOC, SCM_HUP_SIGNAL,
2099 SCM_INT_SIGNAL, SCM_FPE_SIGNAL, SCM_BUS_SIGNAL, SCM_SEGV_SIGNAL,
2100 SCM_ALRM_SIGNAL, SCM_GC_SIGNAL, SCM_TICK_SIGNAL, SCM_SIG_ORD,
2101 SCM_ORD_SIG, SCM_NUM_SIGS, SCM_SYMBOL_SLOTS, SCM_SLOTS, SCM_SLOPPY_STRINGP,
2102 SCM_VALIDATE_STRINGORSUBSTR, SCM_FREEP, SCM_NFREEP, SCM_CHARS, SCM_UCHARS,
2103 SCM_VALIDATE_ROSTRING, SCM_VALIDATE_ROSTRING_COPY,
2104 SCM_VALIDATE_NULLORROSTRING_COPY, SCM_ROLENGTH, SCM_LENGTH, SCM_HUGE_LENGTH,
2105 SCM_SUBSTRP, SCM_SUBSTR_STR, SCM_SUBSTR_OFFSET, SCM_COERCE_SUBSTR,
2106 SCM_ROSTRINGP, SCM_RWSTRINGP, SCM_VALIDATE_RWSTRING, SCM_ROCHARS,
2107 SCM_ROUCHARS, SCM_SETLENGTH, SCM_SETCHARS, SCM_LENGTH_MAX, SCM_GC8MARKP,
2108 SCM_SETGC8MARK, SCM_CLRGC8MARK, SCM_GCTYP16, SCM_GCCDR, SCM_SUBR_DOC,
2109 SCM_OPDIRP, SCM_VALIDATE_OPDIR, SCM_WTA, RETURN_SCM_WTA, SCM_CONST_LONG,
2110 SCM_WNA, SCM_FUNC_NAME, SCM_VALIDATE_NUMBER_COPY,
2111 SCM_VALIDATE_NUMBER_DEF_COPY, SCM_SLOPPY_CONSP, SCM_SLOPPY_NCONSP,
2112 SCM_SETAND_CDR, SCM_SETOR_CDR, SCM_SETAND_CAR, SCM_SETOR_CAR
2113
2114 Use SCM_ASSERT_RANGE or SCM_VALIDATE_XXX_RANGE instead of SCM_OUTOFRANGE.
2115 Use scm_memory_error instead of SCM_NALLOC.
2116 Use SCM_STRINGP instead of SCM_SLOPPY_STRINGP.
2117 Use SCM_VALIDATE_STRING instead of SCM_VALIDATE_STRINGORSUBSTR.
2118 Use SCM_FREE_CELL_P instead of SCM_FREEP/SCM_NFREEP
2119 Use a type specific accessor macro instead of SCM_CHARS/SCM_UCHARS.
2120 Use a type specific accessor instead of SCM(_|_RO|_HUGE_)LENGTH.
2121 Use SCM_VALIDATE_(SYMBOL|STRING) instead of SCM_VALIDATE_ROSTRING.
2122 Use SCM_STRING_COERCE_0TERMINATION_X instead of SCM_COERCE_SUBSTR.
2123 Use SCM_STRINGP or SCM_SYMBOLP instead of SCM_ROSTRINGP.
2124 Use SCM_STRINGP instead of SCM_RWSTRINGP.
2125 Use SCM_VALIDATE_STRING instead of SCM_VALIDATE_RWSTRING.
2126 Use SCM_STRING_CHARS instead of SCM_ROCHARS.
2127 Use SCM_STRING_UCHARS instead of SCM_ROUCHARS.
2128 Use a type specific setter macro instead of SCM_SETLENGTH.
2129 Use a type specific setter macro instead of SCM_SETCHARS.
2130 Use a type specific length macro instead of SCM_LENGTH_MAX.
2131 Use SCM_GCMARKP instead of SCM_GC8MARKP.
2132 Use SCM_SETGCMARK instead of SCM_SETGC8MARK.
2133 Use SCM_CLRGCMARK instead of SCM_CLRGC8MARK.
2134 Use SCM_TYP16 instead of SCM_GCTYP16.
2135 Use SCM_CDR instead of SCM_GCCDR.
2136 Use SCM_DIR_OPEN_P instead of SCM_OPDIRP.
2137 Use SCM_MISC_ERROR or SCM_WRONG_TYPE_ARG instead of SCM_WTA.
2138 Use SCM_MISC_ERROR or SCM_WRONG_TYPE_ARG instead of RETURN_SCM_WTA.
2139 Use SCM_VCELL_INIT instead of SCM_CONST_LONG.
2140 Use SCM_WRONG_NUM_ARGS instead of SCM_WNA.
2141 Use SCM_CONSP instead of SCM_SLOPPY_CONSP.
2142 Use !SCM_CONSP instead of SCM_SLOPPY_NCONSP.
2143
2144 ** Removed function: scm_struct_init
2145
2146 ** Removed variable: scm_symhash_dim
2147
2148 ** Renamed function: scm_make_cont has been replaced by
2149 scm_make_continuation, which has a different interface.
2150
2151 ** Deprecated function: scm_call_catching_errors
2152
2153 Use scm_catch or scm_lazy_catch from throw.[ch] instead.
2154
2155 ** Deprecated function: scm_strhash
2156
2157 Use scm_string_hash instead.
2158
2159 ** Deprecated function: scm_vector_set_length_x
2160
2161 Instead, create a fresh vector of the desired size and copy the contents.
2162
2163 ** scm_gensym has changed prototype
2164
2165 scm_gensym now only takes one argument.
2166
2167 ** Deprecated type tags: scm_tc7_ssymbol, scm_tc7_msymbol, scm_tcs_symbols,
2168 scm_tc7_lvector
2169
2170 There is now only a single symbol type scm_tc7_symbol.
2171 The tag scm_tc7_lvector was not used anyway.
2172
2173 ** Deprecated function: scm_make_smob_type_mfpe, scm_set_smob_mfpe.
2174
2175 Use scm_make_smob_type and scm_set_smob_XXX instead.
2176
2177 ** New function scm_set_smob_apply.
2178
2179 This can be used to set an apply function to a smob type.
2180
2181 ** Deprecated function: scm_strprint_obj
2182
2183 Use scm_object_to_string instead.
2184
2185 ** Deprecated function: scm_wta
2186
2187 Use scm_wrong_type_arg, or another appropriate error signalling function
2188 instead.
2189
2190 ** Explicit support for obarrays has been deprecated.
2191
2192 Use `scm_str2symbol' and the generic hashtable functions instead.
2193
2194 ** The concept of `vcells' has been deprecated.
2195
2196 The data type `variable' is now used exclusively. `Vcells' have been
2197 a low-level concept so you are likely not affected by this change.
2198
2199 *** Deprecated functions: scm_sym2vcell, scm_sysintern,
2200 scm_sysintern0, scm_symbol_value0, scm_intern, scm_intern0.
2201
2202 Use scm_c_define or scm_c_lookup instead, as appropriate.
2203
2204 *** New functions: scm_c_module_lookup, scm_c_lookup,
2205 scm_c_module_define, scm_c_define, scm_module_lookup, scm_lookup,
2206 scm_module_define, scm_define.
2207
2208 These functions work with variables instead of with vcells.
2209
2210 ** New functions for creating and defining `subr's and `gsubr's.
2211
2212 The new functions more clearly distinguish between creating a subr (or
2213 gsubr) object and adding it to the current module.
2214
2215 These new functions are available: scm_c_make_subr, scm_c_define_subr,
2216 scm_c_make_subr_with_generic, scm_c_define_subr_with_generic,
2217 scm_c_make_gsubr, scm_c_define_gsubr, scm_c_make_gsubr_with_generic,
2218 scm_c_define_gsubr_with_generic.
2219
2220 ** Deprecated functions: scm_make_subr, scm_make_subr_opt,
2221 scm_make_subr_with_generic, scm_make_gsubr,
2222 scm_make_gsubr_with_generic.
2223
2224 Use the new ones from above instead.
2225
2226 ** C interface to the module system has changed.
2227
2228 While we suggest that you avoid as many explicit module system
2229 operations from C as possible for the time being, the C interface has
2230 been made more similar to the high-level Scheme module system.
2231
2232 *** New functions: scm_c_define_module, scm_c_use_module,
2233 scm_c_export, scm_c_resolve_module.
2234
2235 They mostly work like their Scheme namesakes. scm_c_define_module
2236 takes a function that is called a context where the new module is
2237 current.
2238
2239 *** Deprecated functions: scm_the_root_module, scm_make_module,
2240 scm_ensure_user_module, scm_load_scheme_module.
2241
2242 Use the new functions instead.
2243
2244 ** Renamed function: scm_internal_with_fluids becomes
2245 scm_c_with_fluids.
2246
2247 scm_internal_with_fluids is available as a deprecated function.
2248
2249 ** New function: scm_c_with_fluid.
2250
2251 Just like scm_c_with_fluids, but takes one fluid and one value instead
2252 of lists of same.
2253
2254 ** Deprecated typedefs: long_long, ulong_long.
2255
2256 They are of questionable utility and they pollute the global
2257 namespace.
2258
2259 ** Deprecated typedef: scm_sizet
2260
2261 It is of questionable utility now that Guile requires ANSI C, and is
2262 oddly named.
2263
2264 ** Deprecated typedefs: scm_port_rw_active, scm_port,
2265 scm_ptob_descriptor, scm_debug_info, scm_debug_frame, scm_fport,
2266 scm_option, scm_rstate, scm_rng, scm_array, scm_array_dim.
2267
2268 Made more compliant with the naming policy by adding a _t at the end.
2269
2270 ** Deprecated functions: scm_mkbig, scm_big2num, scm_adjbig,
2271 scm_normbig, scm_copybig, scm_2ulong2big, scm_dbl2big, scm_big2dbl
2272
2273 With the exception of the mysterious scm_2ulong2big, they are still
2274 available under new names (scm_i_mkbig etc). These functions are not
2275 intended to be used in user code. You should avoid dealing with
2276 bignums directly, and should deal with numbers in general (which can
2277 be bignums).
2278
2279 ** Change in behavior: scm_num2long, scm_num2ulong
2280
2281 The scm_num2[u]long functions don't any longer accept an inexact
2282 argument. This change in behavior is motivated by concordance with
2283 R5RS: It is more common that a primitive doesn't want to accept an
2284 inexact for an exact.
2285
2286 ** New functions: scm_short2num, scm_ushort2num, scm_int2num,
2287 scm_uint2num, scm_size2num, scm_ptrdiff2num, scm_num2short,
2288 scm_num2ushort, scm_num2int, scm_num2uint, scm_num2ptrdiff,
2289 scm_num2size.
2290
2291 These are conversion functions between the various ANSI C integral
2292 types and Scheme numbers. NOTE: The scm_num2xxx functions don't
2293 accept an inexact argument.
2294
2295 ** New functions: scm_float2num, scm_double2num,
2296 scm_num2float, scm_num2double.
2297
2298 These are conversion functions between the two ANSI C float types and
2299 Scheme numbers.
2300
2301 ** New number validation macros:
2302 SCM_NUM2{SIZE,PTRDIFF,SHORT,USHORT,INT,UINT}[_DEF]
2303
2304 See above.
2305
2306 ** New functions: scm_gc_protect_object, scm_gc_unprotect_object
2307
2308 These are just nicer-named old scm_protect_object and
2309 scm_unprotect_object.
2310
2311 ** Deprecated functions: scm_protect_object, scm_unprotect_object
2312
2313 ** New functions: scm_gc_[un]register_root, scm_gc_[un]register_roots
2314
2315 These functions can be used to register pointers to locations that
2316 hold SCM values.
2317
2318 ** Deprecated function: scm_create_hook.
2319
2320 Its sins are: misleading name, non-modularity and lack of general
2321 usefulness.
2322
2323 \f
2324 Changes since Guile 1.3.4:
2325
2326 * Changes to the distribution
2327
2328 ** Trees from nightly snapshots and CVS now require you to run autogen.sh.
2329
2330 We've changed the way we handle generated files in the Guile source
2331 repository. As a result, the procedure for building trees obtained
2332 from the nightly FTP snapshots or via CVS has changed:
2333 - You must have appropriate versions of autoconf, automake, and
2334 libtool installed on your system. See README for info on how to
2335 obtain these programs.
2336 - Before configuring the tree, you must first run the script
2337 `autogen.sh' at the top of the source tree.
2338
2339 The Guile repository used to contain not only source files, written by
2340 humans, but also some generated files, like configure scripts and
2341 Makefile.in files. Even though the contents of these files could be
2342 derived mechanically from other files present, we thought it would
2343 make the tree easier to build if we checked them into CVS.
2344
2345 However, this approach means that minor differences between
2346 developer's installed tools and habits affected the whole team.
2347 So we have removed the generated files from the repository, and
2348 added the autogen.sh script, which will reconstruct them
2349 appropriately.
2350
2351
2352 ** configure now has experimental options to remove support for certain
2353 features:
2354
2355 --disable-arrays omit array and uniform array support
2356 --disable-posix omit posix interfaces
2357 --disable-networking omit networking interfaces
2358 --disable-regex omit regular expression interfaces
2359
2360 These are likely to become separate modules some day.
2361
2362 ** New configure option --enable-debug-freelist
2363
2364 This enables a debugging version of SCM_NEWCELL(), and also registers
2365 an extra primitive, the setter `gc-set-debug-check-freelist!'.
2366
2367 Configure with the --enable-debug-freelist option to enable
2368 the gc-set-debug-check-freelist! primitive, and then use:
2369
2370 (gc-set-debug-check-freelist! #t) # turn on checking of the freelist
2371 (gc-set-debug-check-freelist! #f) # turn off checking
2372
2373 Checking of the freelist forces a traversal of the freelist and
2374 a garbage collection before each allocation of a cell. This can
2375 slow down the interpreter dramatically, so the setter should be used to
2376 turn on this extra processing only when necessary.
2377
2378 ** New configure option --enable-debug-malloc
2379
2380 Include code for debugging of calls to scm_must_malloc/realloc/free.
2381
2382 Checks that
2383
2384 1. objects freed by scm_must_free has been mallocated by scm_must_malloc
2385 2. objects reallocated by scm_must_realloc has been allocated by
2386 scm_must_malloc
2387 3. reallocated objects are reallocated with the same what string
2388
2389 But, most importantly, it records the number of allocated objects of
2390 each kind. This is useful when searching for memory leaks.
2391
2392 A Guile compiled with this option provides the primitive
2393 `malloc-stats' which returns an alist with pairs of kind and the
2394 number of objects of that kind.
2395
2396 ** All includes are now referenced relative to the root directory
2397
2398 Since some users have had problems with mixups between Guile and
2399 system headers, we have decided to always refer to Guile headers via
2400 their parent directories. This essentially creates a "private name
2401 space" for Guile headers. This means that the compiler only is given
2402 -I options for the root build and root source directory.
2403
2404 ** Header files kw.h and genio.h have been removed.
2405
2406 ** The module (ice-9 getopt-gnu-style) has been removed.
2407
2408 ** New module (ice-9 documentation)
2409
2410 Implements the interface to documentation strings associated with
2411 objects.
2412
2413 ** New module (ice-9 time)
2414
2415 Provides a macro `time', which displays execution time of a given form.
2416
2417 ** New module (ice-9 history)
2418
2419 Loading this module enables value history in the repl.
2420
2421 * Changes to the stand-alone interpreter
2422
2423 ** New command line option --debug
2424
2425 Start Guile with debugging evaluator and backtraces enabled.
2426
2427 This is useful when debugging your .guile init file or scripts.
2428
2429 ** New help facility
2430
2431 Usage: (help NAME) gives documentation about objects named NAME (a symbol)
2432 (help REGEXP) ditto for objects with names matching REGEXP (a string)
2433 (help 'NAME) gives documentation for NAME, even if it is not an object
2434 (help ,EXPR) gives documentation for object returned by EXPR
2435 (help (my module)) gives module commentary for `(my module)'
2436 (help) gives this text
2437
2438 `help' searches among bindings exported from loaded modules, while
2439 `apropos' searches among bindings visible from the "current" module.
2440
2441 Examples: (help help)
2442 (help cons)
2443 (help "output-string")
2444
2445 ** `help' and `apropos' now prints full module names
2446
2447 ** Dynamic linking now uses libltdl from the libtool package.
2448
2449 The old system dependent code for doing dynamic linking has been
2450 replaced with calls to the libltdl functions which do all the hairy
2451 details for us.
2452
2453 The major improvement is that you can now directly pass libtool
2454 library names like "libfoo.la" to `dynamic-link' and `dynamic-link'
2455 will be able to do the best shared library job you can get, via
2456 libltdl.
2457
2458 The way dynamic libraries are found has changed and is not really
2459 portable across platforms, probably. It is therefore recommended to
2460 use absolute filenames when possible.
2461
2462 If you pass a filename without an extension to `dynamic-link', it will
2463 try a few appropriate ones. Thus, the most platform ignorant way is
2464 to specify a name like "libfoo", without any directories and
2465 extensions.
2466
2467 ** Guile COOP threads are now compatible with LinuxThreads
2468
2469 Previously, COOP threading wasn't possible in applications linked with
2470 Linux POSIX threads due to their use of the stack pointer to find the
2471 thread context. This has now been fixed with a workaround which uses
2472 the pthreads to allocate the stack.
2473
2474 ** New primitives: `pkgdata-dir', `site-dir', `library-dir'
2475
2476 ** Positions of erring expression in scripts
2477
2478 With version 1.3.4, the location of the erring expression in Guile
2479 scipts is no longer automatically reported. (This should have been
2480 documented before the 1.3.4 release.)
2481
2482 You can get this information by enabling recording of positions of
2483 source expressions and running the debugging evaluator. Put this at
2484 the top of your script (or in your "site" file):
2485
2486 (read-enable 'positions)
2487 (debug-enable 'debug)
2488
2489 ** Backtraces in scripts
2490
2491 It is now possible to get backtraces in scripts.
2492
2493 Put
2494
2495 (debug-enable 'debug 'backtrace)
2496
2497 at the top of the script.
2498
2499 (The first options enables the debugging evaluator.
2500 The second enables backtraces.)
2501
2502 ** Part of module system symbol lookup now implemented in C
2503
2504 The eval closure of most modules is now implemented in C. Since this
2505 was one of the bottlenecks for loading speed, Guile now loads code
2506 substantially faster than before.
2507
2508 ** Attempting to get the value of an unbound variable now produces
2509 an exception with a key of 'unbound-variable instead of 'misc-error.
2510
2511 ** The initial default output port is now unbuffered if it's using a
2512 tty device. Previously in this situation it was line-buffered.
2513
2514 ** New hook: after-gc-hook
2515
2516 after-gc-hook takes over the role of gc-thunk. This hook is run at
2517 the first SCM_TICK after a GC. (Thus, the code is run at the same
2518 point during evaluation as signal handlers.)
2519
2520 Note that this hook should be used only for diagnostic and debugging
2521 purposes. It is not certain that it will continue to be well-defined
2522 when this hook is run in the future.
2523
2524 C programmers: Note the new C level hooks scm_before_gc_c_hook,
2525 scm_before_sweep_c_hook, scm_after_gc_c_hook.
2526
2527 ** Improvements to garbage collector
2528
2529 Guile 1.4 has a new policy for triggering heap allocation and
2530 determining the sizes of heap segments. It fixes a number of problems
2531 in the old GC.
2532
2533 1. The new policy can handle two separate pools of cells
2534 (2-word/4-word) better. (The old policy would run wild, allocating
2535 more and more memory for certain programs.)
2536
2537 2. The old code would sometimes allocate far too much heap so that the
2538 Guile process became gigantic. The new code avoids this.
2539
2540 3. The old code would sometimes allocate too little so that few cells
2541 were freed at GC so that, in turn, too much time was spent in GC.
2542
2543 4. The old code would often trigger heap allocation several times in a
2544 row. (The new scheme predicts how large the segments needs to be
2545 in order not to need further allocation.)
2546
2547 All in all, the new GC policy will make larger applications more
2548 efficient.
2549
2550 The new GC scheme also is prepared for POSIX threading. Threads can
2551 allocate private pools of cells ("clusters") with just a single
2552 function call. Allocation of single cells from such a cluster can
2553 then proceed without any need of inter-thread synchronization.
2554
2555 ** New environment variables controlling GC parameters
2556
2557 GUILE_MAX_SEGMENT_SIZE Maximal segment size
2558 (default = 2097000)
2559
2560 Allocation of 2-word cell heaps:
2561
2562 GUILE_INIT_SEGMENT_SIZE_1 Size of initial heap segment in bytes
2563 (default = 360000)
2564
2565 GUILE_MIN_YIELD_1 Minimum number of freed cells at each
2566 GC in percent of total heap size
2567 (default = 40)
2568
2569 Allocation of 4-word cell heaps
2570 (used for real numbers and misc other objects):
2571
2572 GUILE_INIT_SEGMENT_SIZE_2, GUILE_MIN_YIELD_2
2573
2574 (See entry "Way for application to customize GC parameters" under
2575 section "Changes to the scm_ interface" below.)
2576
2577 ** Guile now implements reals using 4-word cells
2578
2579 This speeds up computation with reals. (They were earlier allocated
2580 with `malloc'.) There is still some room for optimizations, however.
2581
2582 ** Some further steps toward POSIX thread support have been taken
2583
2584 *** Guile's critical sections (SCM_DEFER/ALLOW_INTS)
2585 don't have much effect any longer, and many of them will be removed in
2586 next release.
2587
2588 *** Signals
2589 are only handled at the top of the evaluator loop, immediately after
2590 I/O, and in scm_equalp.
2591
2592 *** The GC can allocate thread private pools of pairs.
2593
2594 * Changes to Scheme functions and syntax
2595
2596 ** close-input-port and close-output-port are now R5RS
2597
2598 These procedures have been turned into primitives and have R5RS behaviour.
2599
2600 ** New procedure: simple-format PORT MESSAGE ARG1 ...
2601
2602 (ice-9 boot) makes `format' an alias for `simple-format' until possibly
2603 extended by the more sophisticated version in (ice-9 format)
2604
2605 (simple-format port message . args)
2606 Write MESSAGE to DESTINATION, defaulting to `current-output-port'.
2607 MESSAGE can contain ~A (was %s) and ~S (was %S) escapes. When printed,
2608 the escapes are replaced with corresponding members of ARGS:
2609 ~A formats using `display' and ~S formats using `write'.
2610 If DESTINATION is #t, then use the `current-output-port',
2611 if DESTINATION is #f, then return a string containing the formatted text.
2612 Does not add a trailing newline."
2613
2614 ** string-ref: the second argument is no longer optional.
2615
2616 ** string, list->string: no longer accept strings in their arguments,
2617 only characters, for compatibility with R5RS.
2618
2619 ** New procedure: port-closed? PORT
2620 Returns #t if PORT is closed or #f if it is open.
2621
2622 ** Deprecated: list*
2623
2624 The list* functionality is now provided by cons* (SRFI-1 compliant)
2625
2626 ** New procedure: cons* ARG1 ARG2 ... ARGn
2627
2628 Like `list', but the last arg provides the tail of the constructed list,
2629 returning (cons ARG1 (cons ARG2 (cons ... ARGn))).
2630
2631 Requires at least one argument. If given one argument, that argument
2632 is returned as result.
2633
2634 This function is called `list*' in some other Schemes and in Common LISP.
2635
2636 ** Removed deprecated: serial-map, serial-array-copy!, serial-array-map!
2637
2638 ** New procedure: object-documentation OBJECT
2639
2640 Returns the documentation string associated with OBJECT. The
2641 procedure uses a caching mechanism so that subsequent lookups are
2642 faster.
2643
2644 Exported by (ice-9 documentation).
2645
2646 ** module-name now returns full names of modules
2647
2648 Previously, only the last part of the name was returned (`session' for
2649 `(ice-9 session)'). Ex: `(ice-9 session)'.
2650
2651 * Changes to the gh_ interface
2652
2653 ** Deprecated: gh_int2scmb
2654
2655 Use gh_bool2scm instead.
2656
2657 * Changes to the scm_ interface
2658
2659 ** Guile primitives now carry docstrings!
2660
2661 Thanks to Greg Badros!
2662
2663 ** Guile primitives are defined in a new way: SCM_DEFINE/SCM_DEFINE1/SCM_PROC
2664
2665 Now Guile primitives are defined using the SCM_DEFINE/SCM_DEFINE1/SCM_PROC
2666 macros and must contain a docstring that is extracted into foo.doc using a new
2667 guile-doc-snarf script (that uses guile-doc-snarf.awk).
2668
2669 However, a major overhaul of these macros is scheduled for the next release of
2670 guile.
2671
2672 ** Guile primitives use a new technique for validation of arguments
2673
2674 SCM_VALIDATE_* macros are defined to ease the redundancy and improve
2675 the readability of argument checking.
2676
2677 ** All (nearly?) K&R prototypes for functions replaced with ANSI C equivalents.
2678
2679 ** New macros: SCM_PACK, SCM_UNPACK
2680
2681 Compose/decompose an SCM value.
2682
2683 The SCM type is now treated as an abstract data type and may be defined as a
2684 long, a void* or as a struct, depending on the architecture and compile time
2685 options. This makes it easier to find several types of bugs, for example when
2686 SCM values are treated as integers without conversion. Values of the SCM type
2687 should be treated as "atomic" values. These macros are used when
2688 composing/decomposing an SCM value, either because you want to access
2689 individual bits, or because you want to treat it as an integer value.
2690
2691 E.g., in order to set bit 7 in an SCM value x, use the expression
2692
2693 SCM_PACK (SCM_UNPACK (x) | 0x80)
2694
2695 ** The name property of hooks is deprecated.
2696 Thus, the use of SCM_HOOK_NAME and scm_make_hook_with_name is deprecated.
2697
2698 You can emulate this feature by using object properties.
2699
2700 ** Deprecated macros: SCM_INPORTP, SCM_OUTPORTP, SCM_CRDY, SCM_ICHRP,
2701 SCM_ICHR, SCM_MAKICHR, SCM_SETJMPBUF, SCM_NSTRINGP, SCM_NRWSTRINGP,
2702 SCM_NVECTORP
2703
2704 These macros will be removed in a future release of Guile.
2705
2706 ** The following types, functions and macros from numbers.h are deprecated:
2707 scm_dblproc, SCM_UNEGFIXABLE, SCM_FLOBUFLEN, SCM_INEXP, SCM_CPLXP, SCM_REAL,
2708 SCM_IMAG, SCM_REALPART, scm_makdbl, SCM_SINGP, SCM_NUM2DBL, SCM_NO_BIGDIG
2709
2710 ** Port internals: the rw_random variable in the scm_port structure
2711 must be set to non-zero in any random access port. In recent Guile
2712 releases it was only set for bidirectional random-access ports.
2713
2714 ** Port internals: the seek ptob procedure is now responsible for
2715 resetting the buffers if required. The change was made so that in the
2716 special case of reading the current position (i.e., seek p 0 SEEK_CUR)
2717 the fport and strport ptobs can avoid resetting the buffers,
2718 in particular to avoid discarding unread chars. An existing port
2719 type can be fixed by adding something like the following to the
2720 beginning of the ptob seek procedure:
2721
2722 if (pt->rw_active == SCM_PORT_READ)
2723 scm_end_input (object);
2724 else if (pt->rw_active == SCM_PORT_WRITE)
2725 ptob->flush (object);
2726
2727 although to actually avoid resetting the buffers and discard unread
2728 chars requires further hacking that depends on the characteristics
2729 of the ptob.
2730
2731 ** Deprecated functions: scm_fseek, scm_tag
2732
2733 These functions are no longer used and will be removed in a future version.
2734
2735 ** The scm_sysmissing procedure is no longer used in libguile.
2736 Unless it turns out to be unexpectedly useful to somebody, it will be
2737 removed in a future version.
2738
2739 ** The format of error message strings has changed
2740
2741 The two C procedures: scm_display_error and scm_error, as well as the
2742 primitive `scm-error', now use scm_simple_format to do their work.
2743 This means that the message strings of all code must be updated to use
2744 ~A where %s was used before, and ~S where %S was used before.
2745
2746 During the period when there still are a lot of old Guiles out there,
2747 you might want to support both old and new versions of Guile.
2748
2749 There are basically two methods to achieve this. Both methods use
2750 autoconf. Put
2751
2752 AC_CHECK_FUNCS(scm_simple_format)
2753
2754 in your configure.in.
2755
2756 Method 1: Use the string concatenation features of ANSI C's
2757 preprocessor.
2758
2759 In C:
2760
2761 #ifdef HAVE_SCM_SIMPLE_FORMAT
2762 #define FMT_S "~S"
2763 #else
2764 #define FMT_S "%S"
2765 #endif
2766
2767 Then represent each of your error messages using a preprocessor macro:
2768
2769 #define E_SPIDER_ERROR "There's a spider in your " ## FMT_S ## "!!!"
2770
2771 In Scheme:
2772
2773 (define fmt-s (if (defined? 'simple-format) "~S" "%S"))
2774 (define make-message string-append)
2775
2776 (define e-spider-error (make-message "There's a spider in your " fmt-s "!!!"))
2777
2778 Method 2: Use the oldfmt function found in doc/oldfmt.c.
2779
2780 In C:
2781
2782 scm_misc_error ("picnic", scm_c_oldfmt0 ("There's a spider in your ~S!!!"),
2783 ...);
2784
2785 In Scheme:
2786
2787 (scm-error 'misc-error "picnic" (oldfmt "There's a spider in your ~S!!!")
2788 ...)
2789
2790
2791 ** Deprecated: coop_mutex_init, coop_condition_variable_init
2792
2793 Don't use the functions coop_mutex_init and
2794 coop_condition_variable_init. They will change.
2795
2796 Use scm_mutex_init and scm_cond_init instead.
2797
2798 ** New function: int scm_cond_timedwait (scm_cond_t *COND, scm_mutex_t *MUTEX, const struct timespec *ABSTIME)
2799 `scm_cond_timedwait' atomically unlocks MUTEX and waits on
2800 COND, as `scm_cond_wait' does, but it also bounds the duration
2801 of the wait. If COND has not been signaled before time ABSTIME,
2802 the mutex MUTEX is re-acquired and `scm_cond_timedwait'
2803 returns the error code `ETIMEDOUT'.
2804
2805 The ABSTIME parameter specifies an absolute time, with the same
2806 origin as `time' and `gettimeofday': an ABSTIME of 0 corresponds
2807 to 00:00:00 GMT, January 1, 1970.
2808
2809 ** New function: scm_cond_broadcast (scm_cond_t *COND)
2810 `scm_cond_broadcast' restarts all the threads that are waiting
2811 on the condition variable COND. Nothing happens if no threads are
2812 waiting on COND.
2813
2814 ** New function: scm_key_create (scm_key_t *KEY, void (*destr_function) (void *))
2815 `scm_key_create' allocates a new TSD key. The key is stored in
2816 the location pointed to by KEY. There is no limit on the number
2817 of keys allocated at a given time. The value initially associated
2818 with the returned key is `NULL' in all currently executing threads.
2819
2820 The DESTR_FUNCTION argument, if not `NULL', specifies a destructor
2821 function associated with the key. When a thread terminates,
2822 DESTR_FUNCTION is called on the value associated with the key in
2823 that thread. The DESTR_FUNCTION is not called if a key is deleted
2824 with `scm_key_delete' or a value is changed with
2825 `scm_setspecific'. The order in which destructor functions are
2826 called at thread termination time is unspecified.
2827
2828 Destructors are not yet implemented.
2829
2830 ** New function: scm_setspecific (scm_key_t KEY, const void *POINTER)
2831 `scm_setspecific' changes the value associated with KEY in the
2832 calling thread, storing the given POINTER instead.
2833
2834 ** New function: scm_getspecific (scm_key_t KEY)
2835 `scm_getspecific' returns the value currently associated with
2836 KEY in the calling thread.
2837
2838 ** New function: scm_key_delete (scm_key_t KEY)
2839 `scm_key_delete' deallocates a TSD key. It does not check
2840 whether non-`NULL' values are associated with that key in the
2841 currently executing threads, nor call the destructor function
2842 associated with the key.
2843
2844 ** New function: scm_c_hook_init (scm_c_hook_t *HOOK, void *HOOK_DATA, scm_c_hook_type_t TYPE)
2845
2846 Initialize a C level hook HOOK with associated HOOK_DATA and type
2847 TYPE. (See scm_c_hook_run ().)
2848
2849 ** New function: scm_c_hook_add (scm_c_hook_t *HOOK, scm_c_hook_function_t FUNC, void *FUNC_DATA, int APPENDP)
2850
2851 Add hook function FUNC with associated FUNC_DATA to HOOK. If APPENDP
2852 is true, add it last, otherwise first. The same FUNC can be added
2853 multiple times if FUNC_DATA differ and vice versa.
2854
2855 ** New function: scm_c_hook_remove (scm_c_hook_t *HOOK, scm_c_hook_function_t FUNC, void *FUNC_DATA)
2856
2857 Remove hook function FUNC with associated FUNC_DATA from HOOK. A
2858 function is only removed if both FUNC and FUNC_DATA matches.
2859
2860 ** New function: void *scm_c_hook_run (scm_c_hook_t *HOOK, void *DATA)
2861
2862 Run hook HOOK passing DATA to the hook functions.
2863
2864 If TYPE is SCM_C_HOOK_NORMAL, all hook functions are run. The value
2865 returned is undefined.
2866
2867 If TYPE is SCM_C_HOOK_OR, hook functions are run until a function
2868 returns a non-NULL value. This value is returned as the result of
2869 scm_c_hook_run. If all functions return NULL, NULL is returned.
2870
2871 If TYPE is SCM_C_HOOK_AND, hook functions are run until a function
2872 returns a NULL value, and NULL is returned. If all functions returns
2873 a non-NULL value, the last value is returned.
2874
2875 ** New C level GC hooks
2876
2877 Five new C level hooks has been added to the garbage collector.
2878
2879 scm_before_gc_c_hook
2880 scm_after_gc_c_hook
2881
2882 are run before locking and after unlocking the heap. The system is
2883 thus in a mode where evaluation can take place. (Except that
2884 scm_before_gc_c_hook must not allocate new cells.)
2885
2886 scm_before_mark_c_hook
2887 scm_before_sweep_c_hook
2888 scm_after_sweep_c_hook
2889
2890 are run when the heap is locked. These are intended for extension of
2891 the GC in a modular fashion. Examples are the weaks and guardians
2892 modules.
2893
2894 ** Way for application to customize GC parameters
2895
2896 The application can set up other default values for the GC heap
2897 allocation parameters
2898
2899 GUILE_INIT_HEAP_SIZE_1, GUILE_MIN_YIELD_1,
2900 GUILE_INIT_HEAP_SIZE_2, GUILE_MIN_YIELD_2,
2901 GUILE_MAX_SEGMENT_SIZE,
2902
2903 by setting
2904
2905 scm_default_init_heap_size_1, scm_default_min_yield_1,
2906 scm_default_init_heap_size_2, scm_default_min_yield_2,
2907 scm_default_max_segment_size
2908
2909 respectively before callong scm_boot_guile.
2910
2911 (See entry "New environment variables ..." in section
2912 "Changes to the stand-alone interpreter" above.)
2913
2914 ** scm_protect_object/scm_unprotect_object now nest
2915
2916 This means that you can call scm_protect_object multiple times on an
2917 object and count on the object being protected until
2918 scm_unprotect_object has been call the same number of times.
2919
2920 The functions also have better time complexity.
2921
2922 Still, it is usually possible to structure the application in a way
2923 that you don't need to use these functions. For example, if you use a
2924 protected standard Guile list to keep track of live objects rather
2925 than some custom data type, objects will die a natural death when they
2926 are no longer needed.
2927
2928 ** Deprecated type tags: scm_tc16_flo, scm_tc_flo, scm_tc_dblr, scm_tc_dblc
2929
2930 Guile does not provide the float representation for inexact real numbers any
2931 more. Now, only doubles are used to represent inexact real numbers. Further,
2932 the tag names scm_tc_dblr and scm_tc_dblc have been changed to scm_tc16_real
2933 and scm_tc16_complex, respectively.
2934
2935 ** Removed deprecated type scm_smobfuns
2936
2937 ** Removed deprecated function scm_newsmob
2938
2939 ** Warning: scm_make_smob_type_mfpe might become deprecated in a future release
2940
2941 There is an ongoing discussion among the developers whether to
2942 deprecate `scm_make_smob_type_mfpe' or not. Please use the current
2943 standard interface (scm_make_smob_type, scm_set_smob_XXX) in new code
2944 until this issue has been settled.
2945
2946 ** Removed deprecated type tag scm_tc16_kw
2947
2948 ** Added type tag scm_tc16_keyword
2949
2950 (This was introduced already in release 1.3.4 but was not documented
2951 until now.)
2952
2953 ** gdb_print now prints "*** Guile not initialized ***" until Guile initialized
2954
2955 * Changes to system call interfaces:
2956
2957 ** The "select" procedure now tests port buffers for the ability to
2958 provide input or accept output. Previously only the underlying file
2959 descriptors were checked.
2960
2961 ** New variable PIPE_BUF: the maximum number of bytes that can be
2962 atomically written to a pipe.
2963
2964 ** If a facility is not available on the system when Guile is
2965 compiled, the corresponding primitive procedure will not be defined.
2966 Previously it would have been defined but would throw a system-error
2967 exception if called. Exception handlers which catch this case may
2968 need minor modification: an error will be thrown with key
2969 'unbound-variable instead of 'system-error. Alternatively it's
2970 now possible to use `defined?' to check whether the facility is
2971 available.
2972
2973 ** Procedures which depend on the timezone should now give the correct
2974 result on systems which cache the TZ environment variable, even if TZ
2975 is changed without calling tzset.
2976
2977 * Changes to the networking interfaces:
2978
2979 ** New functions: htons, ntohs, htonl, ntohl: for converting short and
2980 long integers between network and host format. For now, it's not
2981 particularly convenient to do this kind of thing, but consider:
2982
2983 (define write-network-long
2984 (lambda (value port)
2985 (let ((v (make-uniform-vector 1 1 0)))
2986 (uniform-vector-set! v 0 (htonl value))
2987 (uniform-vector-write v port))))
2988
2989 (define read-network-long
2990 (lambda (port)
2991 (let ((v (make-uniform-vector 1 1 0)))
2992 (uniform-vector-read! v port)
2993 (ntohl (uniform-vector-ref v 0)))))
2994
2995 ** If inet-aton fails, it now throws an error with key 'misc-error
2996 instead of 'system-error, since errno is not relevant.
2997
2998 ** Certain gethostbyname/gethostbyaddr failures now throw errors with
2999 specific keys instead of 'system-error. The latter is inappropriate
3000 since errno will not have been set. The keys are:
3001 'host-not-found, 'try-again, 'no-recovery and 'no-data.
3002
3003 ** sethostent, setnetent, setprotoent, setservent: now take an
3004 optional argument STAYOPEN, which specifies whether the database
3005 remains open after a database entry is accessed randomly (e.g., using
3006 gethostbyname for the hosts database.) The default is #f. Previously
3007 #t was always used.
3008
3009 \f
3010 Changes since Guile 1.3.2:
3011
3012 * Changes to the stand-alone interpreter
3013
3014 ** Debugger
3015
3016 An initial version of the Guile debugger written by Chris Hanson has
3017 been added. The debugger is still under development but is included
3018 in the distribution anyway since it is already quite useful.
3019
3020 Type
3021
3022 (debug)
3023
3024 after an error to enter the debugger. Type `help' inside the debugger
3025 for a description of available commands.
3026
3027 If you prefer to have stack frames numbered and printed in
3028 anti-chronological order and prefer up in the stack to be down on the
3029 screen as is the case in gdb, you can put
3030
3031 (debug-enable 'backwards)
3032
3033 in your .guile startup file. (However, this means that Guile can't
3034 use indentation to indicate stack level.)
3035
3036 The debugger is autoloaded into Guile at the first use.
3037
3038 ** Further enhancements to backtraces
3039
3040 There is a new debug option `width' which controls the maximum width
3041 on the screen of printed stack frames. Fancy printing parameters
3042 ("level" and "length" as in Common LISP) are adaptively adjusted for
3043 each stack frame to give maximum information while still fitting
3044 within the bounds. If the stack frame can't be made to fit by
3045 adjusting parameters, it is simply cut off at the end. This is marked
3046 with a `$'.
3047
3048 ** Some modules are now only loaded when the repl is started
3049
3050 The modules (ice-9 debug), (ice-9 session), (ice-9 threads) and (ice-9
3051 regex) are now loaded into (guile-user) only if the repl has been
3052 started. The effect is that the startup time for scripts has been
3053 reduced to 30% of what it was previously.
3054
3055 Correctly written scripts load the modules they require at the top of
3056 the file and should not be affected by this change.
3057
3058 ** Hooks are now represented as smobs
3059
3060 * Changes to Scheme functions and syntax
3061
3062 ** Readline support has changed again.
3063
3064 The old (readline-activator) module is gone. Use (ice-9 readline)
3065 instead, which now contains all readline functionality. So the code
3066 to activate readline is now
3067
3068 (use-modules (ice-9 readline))
3069 (activate-readline)
3070
3071 This should work at any time, including from the guile prompt.
3072
3073 To avoid confusion about the terms of Guile's license, please only
3074 enable readline for your personal use; please don't make it the
3075 default for others. Here is why we make this rather odd-sounding
3076 request:
3077
3078 Guile is normally licensed under a weakened form of the GNU General
3079 Public License, which allows you to link code with Guile without
3080 placing that code under the GPL. This exception is important to some
3081 people.
3082
3083 However, since readline is distributed under the GNU General Public
3084 License, when you link Guile with readline, either statically or
3085 dynamically, you effectively change Guile's license to the strict GPL.
3086 Whenever you link any strictly GPL'd code into Guile, uses of Guile
3087 which are normally permitted become forbidden. This is a rather
3088 non-obvious consequence of the licensing terms.
3089
3090 So, to make sure things remain clear, please let people choose for
3091 themselves whether to link GPL'd libraries like readline with Guile.
3092
3093 ** regexp-substitute/global has changed slightly, but incompatibly.
3094
3095 If you include a function in the item list, the string of the match
3096 object it receives is the same string passed to
3097 regexp-substitute/global, not some suffix of that string.
3098 Correspondingly, the match's positions are relative to the entire
3099 string, not the suffix.
3100
3101 If the regexp can match the empty string, the way matches are chosen
3102 from the string has changed. regexp-substitute/global recognizes the
3103 same set of matches that list-matches does; see below.
3104
3105 ** New function: list-matches REGEXP STRING [FLAGS]
3106
3107 Return a list of match objects, one for every non-overlapping, maximal
3108 match of REGEXP in STRING. The matches appear in left-to-right order.
3109 list-matches only reports matches of the empty string if there are no
3110 other matches which begin on, end at, or include the empty match's
3111 position.
3112
3113 If present, FLAGS is passed as the FLAGS argument to regexp-exec.
3114
3115 ** New function: fold-matches REGEXP STRING INIT PROC [FLAGS]
3116
3117 For each match of REGEXP in STRING, apply PROC to the match object,
3118 and the last value PROC returned, or INIT for the first call. Return
3119 the last value returned by PROC. We apply PROC to the matches as they
3120 appear from left to right.
3121
3122 This function recognizes matches according to the same criteria as
3123 list-matches.
3124
3125 Thus, you could define list-matches like this:
3126
3127 (define (list-matches regexp string . flags)
3128 (reverse! (apply fold-matches regexp string '() cons flags)))
3129
3130 If present, FLAGS is passed as the FLAGS argument to regexp-exec.
3131
3132 ** Hooks
3133
3134 *** New function: hook? OBJ
3135
3136 Return #t if OBJ is a hook, otherwise #f.
3137
3138 *** New function: make-hook-with-name NAME [ARITY]
3139
3140 Return a hook with name NAME and arity ARITY. The default value for
3141 ARITY is 0. The only effect of NAME is that it will appear when the
3142 hook object is printed to ease debugging.
3143
3144 *** New function: hook-empty? HOOK
3145
3146 Return #t if HOOK doesn't contain any procedures, otherwise #f.
3147
3148 *** New function: hook->list HOOK
3149
3150 Return a list of the procedures that are called when run-hook is
3151 applied to HOOK.
3152
3153 ** `map' signals an error if its argument lists are not all the same length.
3154
3155 This is the behavior required by R5RS, so this change is really a bug
3156 fix. But it seems to affect a lot of people's code, so we're
3157 mentioning it here anyway.
3158
3159 ** Print-state handling has been made more transparent
3160
3161 Under certain circumstances, ports are represented as a port with an
3162 associated print state. Earlier, this pair was represented as a pair
3163 (see "Some magic has been added to the printer" below). It is now
3164 indistinguishable (almost; see `get-print-state') from a port on the
3165 user level.
3166
3167 *** New function: port-with-print-state OUTPUT-PORT PRINT-STATE
3168
3169 Return a new port with the associated print state PRINT-STATE.
3170
3171 *** New function: get-print-state OUTPUT-PORT
3172
3173 Return the print state associated with this port if it exists,
3174 otherwise return #f.
3175
3176 *** New function: directory-stream? OBJECT
3177
3178 Returns true iff OBJECT is a directory stream --- the sort of object
3179 returned by `opendir'.
3180
3181 ** New function: using-readline?
3182
3183 Return #t if readline is in use in the current repl.
3184
3185 ** structs will be removed in 1.4
3186
3187 Structs will be replaced in Guile 1.4. We will merge GOOPS into Guile
3188 and use GOOPS objects as the fundamental record type.
3189
3190 * Changes to the scm_ interface
3191
3192 ** structs will be removed in 1.4
3193
3194 The entire current struct interface (struct.c, struct.h) will be
3195 replaced in Guile 1.4. We will merge GOOPS into libguile and use
3196 GOOPS objects as the fundamental record type.
3197
3198 ** The internal representation of subr's has changed
3199
3200 Instead of giving a hint to the subr name, the CAR field of the subr
3201 now contains an index to a subr entry in scm_subr_table.
3202
3203 *** New variable: scm_subr_table
3204
3205 An array of subr entries. A subr entry contains the name, properties
3206 and documentation associated with the subr. The properties and
3207 documentation slots are not yet used.
3208
3209 ** A new scheme for "forwarding" calls to a builtin to a generic function
3210
3211 It is now possible to extend the functionality of some Guile
3212 primitives by letting them defer a call to a GOOPS generic function on
3213 argument mismatch. This means that there is no loss of efficiency in
3214 normal evaluation.
3215
3216 Example:
3217
3218 (use-modules (oop goops)) ; Must be GOOPS version 0.2.
3219 (define-method + ((x <string>) (y <string>))
3220 (string-append x y))
3221
3222 + will still be as efficient as usual in numerical calculations, but
3223 can also be used for concatenating strings.
3224
3225 Who will be the first one to extend Guile's numerical tower to
3226 rationals? :) [OK, there a few other things to fix before this can
3227 be made in a clean way.]
3228
3229 *** New snarf macros for defining primitives: SCM_GPROC, SCM_GPROC1
3230
3231 New macro: SCM_GPROC (CNAME, SNAME, REQ, OPT, VAR, CFUNC, GENERIC)
3232
3233 New macro: SCM_GPROC1 (CNAME, SNAME, TYPE, CFUNC, GENERIC)
3234
3235 These do the same job as SCM_PROC and SCM_PROC1, but they also define
3236 a variable GENERIC which can be used by the dispatch macros below.
3237
3238 [This is experimental code which may change soon.]
3239
3240 *** New macros for forwarding control to a generic on arg type error
3241
3242 New macro: SCM_WTA_DISPATCH_1 (GENERIC, ARG1, POS, SUBR)
3243
3244 New macro: SCM_WTA_DISPATCH_2 (GENERIC, ARG1, ARG2, POS, SUBR)
3245
3246 These correspond to the scm_wta function call, and have the same
3247 behaviour until the user has called the GOOPS primitive
3248 `enable-primitive-generic!'. After that, these macros will apply the
3249 generic function GENERIC to the argument(s) instead of calling
3250 scm_wta.
3251
3252 [This is experimental code which may change soon.]
3253
3254 *** New macros for argument testing with generic dispatch
3255
3256 New macro: SCM_GASSERT1 (COND, GENERIC, ARG1, POS, SUBR)
3257
3258 New macro: SCM_GASSERT2 (COND, GENERIC, ARG1, ARG2, POS, SUBR)
3259
3260 These correspond to the SCM_ASSERT macro, but will defer control to
3261 GENERIC on error after `enable-primitive-generic!' has been called.
3262
3263 [This is experimental code which may change soon.]
3264
3265 ** New function: SCM scm_eval_body (SCM body, SCM env)
3266
3267 Evaluates the body of a special form.
3268
3269 ** The internal representation of struct's has changed
3270
3271 Previously, four slots were allocated for the procedure(s) of entities
3272 and operators. The motivation for this representation had to do with
3273 the structure of the evaluator, the wish to support tail-recursive
3274 generic functions, and efficiency. Since the generic function
3275 dispatch mechanism has changed, there is no longer a need for such an
3276 expensive representation, and the representation has been simplified.
3277
3278 This should not make any difference for most users.
3279
3280 ** GOOPS support has been cleaned up.
3281
3282 Some code has been moved from eval.c to objects.c and code in both of
3283 these compilation units has been cleaned up and better structured.
3284
3285 *** New functions for applying generic functions
3286
3287 New function: SCM scm_apply_generic (GENERIC, ARGS)
3288 New function: SCM scm_call_generic_0 (GENERIC)
3289 New function: SCM scm_call_generic_1 (GENERIC, ARG1)
3290 New function: SCM scm_call_generic_2 (GENERIC, ARG1, ARG2)
3291 New function: SCM scm_call_generic_3 (GENERIC, ARG1, ARG2, ARG3)
3292
3293 ** Deprecated function: scm_make_named_hook
3294
3295 It is now replaced by:
3296
3297 ** New function: SCM scm_create_hook (const char *name, int arity)
3298
3299 Creates a hook in the same way as make-hook above but also
3300 binds a variable named NAME to it.
3301
3302 This is the typical way of creating a hook from C code.
3303
3304 Currently, the variable is created in the "current" module.
3305 This might change when we get the new module system.
3306
3307 [The behaviour is identical to scm_make_named_hook.]
3308
3309
3310 \f
3311 Changes since Guile 1.3:
3312
3313 * Changes to mailing lists
3314
3315 ** Some of the Guile mailing lists have moved to sourceware.cygnus.com.
3316
3317 See the README file to find current addresses for all the Guile
3318 mailing lists.
3319
3320 * Changes to the distribution
3321
3322 ** Readline support is no longer included with Guile by default.
3323
3324 Based on the different license terms of Guile and Readline, we
3325 concluded that Guile should not *by default* cause the linking of
3326 Readline into an application program. Readline support is now offered
3327 as a separate module, which is linked into an application only when
3328 you explicitly specify it.
3329
3330 Although Guile is GNU software, its distribution terms add a special
3331 exception to the usual GNU General Public License (GPL). Guile's
3332 license includes a clause that allows you to link Guile with non-free
3333 programs. We add this exception so as not to put Guile at a
3334 disadvantage vis-a-vis other extensibility packages that support other
3335 languages.
3336
3337 In contrast, the GNU Readline library is distributed under the GNU
3338 General Public License pure and simple. This means that you may not
3339 link Readline, even dynamically, into an application unless it is
3340 distributed under a free software license that is compatible the GPL.
3341
3342 Because of this difference in distribution terms, an application that
3343 can use Guile may not be able to use Readline. Now users will be
3344 explicitly offered two independent decisions about the use of these
3345 two packages.
3346
3347 You can activate the readline support by issuing
3348
3349 (use-modules (readline-activator))
3350 (activate-readline)
3351
3352 from your ".guile" file, for example.
3353
3354 * Changes to the stand-alone interpreter
3355
3356 ** All builtins now print as primitives.
3357 Previously builtin procedures not belonging to the fundamental subr
3358 types printed as #<compiled closure #<primitive-procedure gsubr-apply>>.
3359 Now, they print as #<primitive-procedure NAME>.
3360
3361 ** Backtraces slightly more intelligible.
3362 gsubr-apply and macro transformer application frames no longer appear
3363 in backtraces.
3364
3365 * Changes to Scheme functions and syntax
3366
3367 ** Guile now correctly handles internal defines by rewriting them into
3368 their equivalent letrec. Previously, internal defines would
3369 incrementally add to the innermost environment, without checking
3370 whether the restrictions specified in RnRS were met. This lead to the
3371 correct behaviour when these restriction actually were met, but didn't
3372 catch all illegal uses. Such an illegal use could lead to crashes of
3373 the Guile interpreter or or other unwanted results. An example of
3374 incorrect internal defines that made Guile behave erratically:
3375
3376 (let ()
3377 (define a 1)
3378 (define (b) a)
3379 (define c (1+ (b)))
3380 (define d 3)
3381
3382 (b))
3383
3384 => 2
3385
3386 The problem with this example is that the definition of `c' uses the
3387 value of `b' directly. This confuses the meoization machine of Guile
3388 so that the second call of `b' (this time in a larger environment that
3389 also contains bindings for `c' and `d') refers to the binding of `c'
3390 instead of `a'. You could also make Guile crash with a variation on
3391 this theme:
3392
3393 (define (foo flag)
3394 (define a 1)
3395 (define (b flag) (if flag a 1))
3396 (define c (1+ (b flag)))
3397 (define d 3)
3398
3399 (b #t))
3400
3401 (foo #f)
3402 (foo #t)
3403
3404 From now on, Guile will issue an `Unbound variable: b' error message
3405 for both examples.
3406
3407 ** Hooks
3408
3409 A hook contains a list of functions which should be called on
3410 particular occasions in an existing program. Hooks are used for
3411 customization.
3412
3413 A window manager might have a hook before-window-map-hook. The window
3414 manager uses the function run-hooks to call all functions stored in
3415 before-window-map-hook each time a window is mapped. The user can
3416 store functions in the hook using add-hook!.
3417
3418 In Guile, hooks are first class objects.
3419
3420 *** New function: make-hook [N_ARGS]
3421
3422 Return a hook for hook functions which can take N_ARGS arguments.
3423 The default value for N_ARGS is 0.
3424
3425 (See also scm_make_named_hook below.)
3426
3427 *** New function: add-hook! HOOK PROC [APPEND_P]
3428
3429 Put PROC at the beginning of the list of functions stored in HOOK.
3430 If APPEND_P is supplied, and non-false, put PROC at the end instead.
3431
3432 PROC must be able to take the number of arguments specified when the
3433 hook was created.
3434
3435 If PROC already exists in HOOK, then remove it first.
3436
3437 *** New function: remove-hook! HOOK PROC
3438
3439 Remove PROC from the list of functions in HOOK.
3440
3441 *** New function: reset-hook! HOOK
3442
3443 Clear the list of hook functions stored in HOOK.
3444
3445 *** New function: run-hook HOOK ARG1 ...
3446
3447 Run all hook functions stored in HOOK with arguments ARG1 ... .
3448 The number of arguments supplied must correspond to the number given
3449 when the hook was created.
3450
3451 ** The function `dynamic-link' now takes optional keyword arguments.
3452 The only keyword argument that is currently defined is `:global
3453 BOOL'. With it, you can control whether the shared library will be
3454 linked in global mode or not. In global mode, the symbols from the
3455 linked library can be used to resolve references from other
3456 dynamically linked libraries. In non-global mode, the linked
3457 library is essentially invisible and can only be accessed via
3458 `dynamic-func', etc. The default is now to link in global mode.
3459 Previously, the default has been non-global mode.
3460
3461 The `#:global' keyword is only effective on platforms that support
3462 the dlopen family of functions.
3463
3464 ** New function `provided?'
3465
3466 - Function: provided? FEATURE
3467 Return true iff FEATURE is supported by this installation of
3468 Guile. FEATURE must be a symbol naming a feature; the global
3469 variable `*features*' is a list of available features.
3470
3471 ** Changes to the module (ice-9 expect):
3472
3473 *** The expect-strings macro now matches `$' in a regular expression
3474 only at a line-break or end-of-file by default. Previously it would
3475 match the end of the string accumulated so far. The old behaviour
3476 can be obtained by setting the variable `expect-strings-exec-flags'
3477 to 0.
3478
3479 *** The expect-strings macro now uses a variable `expect-strings-exec-flags'
3480 for the regexp-exec flags. If `regexp/noteol' is included, then `$'
3481 in a regular expression will still match before a line-break or
3482 end-of-file. The default is `regexp/noteol'.
3483
3484 *** The expect-strings macro now uses a variable
3485 `expect-strings-compile-flags' for the flags to be supplied to
3486 `make-regexp'. The default is `regexp/newline', which was previously
3487 hard-coded.
3488
3489 *** The expect macro now supplies two arguments to a match procedure:
3490 the current accumulated string and a flag to indicate whether
3491 end-of-file has been reached. Previously only the string was supplied.
3492 If end-of-file is reached, the match procedure will be called an
3493 additional time with the same accumulated string as the previous call
3494 but with the flag set.
3495
3496 ** New module (ice-9 format), implementing the Common Lisp `format' function.
3497
3498 This code, and the documentation for it that appears here, was
3499 borrowed from SLIB, with minor adaptations for Guile.
3500
3501 - Function: format DESTINATION FORMAT-STRING . ARGUMENTS
3502 An almost complete implementation of Common LISP format description
3503 according to the CL reference book `Common LISP' from Guy L.
3504 Steele, Digital Press. Backward compatible to most of the
3505 available Scheme format implementations.
3506
3507 Returns `#t', `#f' or a string; has side effect of printing
3508 according to FORMAT-STRING. If DESTINATION is `#t', the output is
3509 to the current output port and `#t' is returned. If DESTINATION
3510 is `#f', a formatted string is returned as the result of the call.
3511 NEW: If DESTINATION is a string, DESTINATION is regarded as the
3512 format string; FORMAT-STRING is then the first argument and the
3513 output is returned as a string. If DESTINATION is a number, the
3514 output is to the current error port if available by the
3515 implementation. Otherwise DESTINATION must be an output port and
3516 `#t' is returned.
3517
3518 FORMAT-STRING must be a string. In case of a formatting error
3519 format returns `#f' and prints a message on the current output or
3520 error port. Characters are output as if the string were output by
3521 the `display' function with the exception of those prefixed by a
3522 tilde (~). For a detailed description of the FORMAT-STRING syntax
3523 please consult a Common LISP format reference manual. For a test
3524 suite to verify this format implementation load `formatst.scm'.
3525 Please send bug reports to `lutzeb@cs.tu-berlin.de'.
3526
3527 Note: `format' is not reentrant, i.e. only one `format'-call may
3528 be executed at a time.
3529
3530
3531 *** Format Specification (Format version 3.0)
3532
3533 Please consult a Common LISP format reference manual for a detailed
3534 description of the format string syntax. For a demonstration of the
3535 implemented directives see `formatst.scm'.
3536
3537 This implementation supports directive parameters and modifiers (`:'
3538 and `@' characters). Multiple parameters must be separated by a comma
3539 (`,'). Parameters can be numerical parameters (positive or negative),
3540 character parameters (prefixed by a quote character (`''), variable
3541 parameters (`v'), number of rest arguments parameter (`#'), empty and
3542 default parameters. Directive characters are case independent. The
3543 general form of a directive is:
3544
3545 DIRECTIVE ::= ~{DIRECTIVE-PARAMETER,}[:][@]DIRECTIVE-CHARACTER
3546
3547 DIRECTIVE-PARAMETER ::= [ [-|+]{0-9}+ | 'CHARACTER | v | # ]
3548
3549 *** Implemented CL Format Control Directives
3550
3551 Documentation syntax: Uppercase characters represent the
3552 corresponding control directive characters. Lowercase characters
3553 represent control directive parameter descriptions.
3554
3555 `~A'
3556 Any (print as `display' does).
3557 `~@A'
3558 left pad.
3559
3560 `~MINCOL,COLINC,MINPAD,PADCHARA'
3561 full padding.
3562
3563 `~S'
3564 S-expression (print as `write' does).
3565 `~@S'
3566 left pad.
3567
3568 `~MINCOL,COLINC,MINPAD,PADCHARS'
3569 full padding.
3570
3571 `~D'
3572 Decimal.
3573 `~@D'
3574 print number sign always.
3575
3576 `~:D'
3577 print comma separated.
3578
3579 `~MINCOL,PADCHAR,COMMACHARD'
3580 padding.
3581
3582 `~X'
3583 Hexadecimal.
3584 `~@X'
3585 print number sign always.
3586
3587 `~:X'
3588 print comma separated.
3589
3590 `~MINCOL,PADCHAR,COMMACHARX'
3591 padding.
3592
3593 `~O'
3594 Octal.
3595 `~@O'
3596 print number sign always.
3597
3598 `~:O'
3599 print comma separated.
3600
3601 `~MINCOL,PADCHAR,COMMACHARO'
3602 padding.
3603
3604 `~B'
3605 Binary.
3606 `~@B'
3607 print number sign always.
3608
3609 `~:B'
3610 print comma separated.
3611
3612 `~MINCOL,PADCHAR,COMMACHARB'
3613 padding.
3614
3615 `~NR'
3616 Radix N.
3617 `~N,MINCOL,PADCHAR,COMMACHARR'
3618 padding.
3619
3620 `~@R'
3621 print a number as a Roman numeral.
3622
3623 `~:@R'
3624 print a number as an "old fashioned" Roman numeral.
3625
3626 `~:R'
3627 print a number as an ordinal English number.
3628
3629 `~:@R'
3630 print a number as a cardinal English number.
3631
3632 `~P'
3633 Plural.
3634 `~@P'
3635 prints `y' and `ies'.
3636
3637 `~:P'
3638 as `~P but jumps 1 argument backward.'
3639
3640 `~:@P'
3641 as `~@P but jumps 1 argument backward.'
3642
3643 `~C'
3644 Character.
3645 `~@C'
3646 prints a character as the reader can understand it (i.e. `#\'
3647 prefixing).
3648
3649 `~:C'
3650 prints a character as emacs does (eg. `^C' for ASCII 03).
3651
3652 `~F'
3653 Fixed-format floating-point (prints a flonum like MMM.NNN).
3654 `~WIDTH,DIGITS,SCALE,OVERFLOWCHAR,PADCHARF'
3655 `~@F'
3656 If the number is positive a plus sign is printed.
3657
3658 `~E'
3659 Exponential floating-point (prints a flonum like MMM.NNN`E'EE).
3660 `~WIDTH,DIGITS,EXPONENTDIGITS,SCALE,OVERFLOWCHAR,PADCHAR,EXPONENTCHARE'
3661 `~@E'
3662 If the number is positive a plus sign is printed.
3663
3664 `~G'
3665 General floating-point (prints a flonum either fixed or
3666 exponential).
3667 `~WIDTH,DIGITS,EXPONENTDIGITS,SCALE,OVERFLOWCHAR,PADCHAR,EXPONENTCHARG'
3668 `~@G'
3669 If the number is positive a plus sign is printed.
3670
3671 `~$'
3672 Dollars floating-point (prints a flonum in fixed with signs
3673 separated).
3674 `~DIGITS,SCALE,WIDTH,PADCHAR$'
3675 `~@$'
3676 If the number is positive a plus sign is printed.
3677
3678 `~:@$'
3679 A sign is always printed and appears before the padding.
3680
3681 `~:$'
3682 The sign appears before the padding.
3683
3684 `~%'
3685 Newline.
3686 `~N%'
3687 print N newlines.
3688
3689 `~&'
3690 print newline if not at the beginning of the output line.
3691 `~N&'
3692 prints `~&' and then N-1 newlines.
3693
3694 `~|'
3695 Page Separator.
3696 `~N|'
3697 print N page separators.
3698
3699 `~~'
3700 Tilde.
3701 `~N~'
3702 print N tildes.
3703
3704 `~'<newline>
3705 Continuation Line.
3706 `~:'<newline>
3707 newline is ignored, white space left.
3708
3709 `~@'<newline>
3710 newline is left, white space ignored.
3711
3712 `~T'
3713 Tabulation.
3714 `~@T'
3715 relative tabulation.
3716
3717 `~COLNUM,COLINCT'
3718 full tabulation.
3719
3720 `~?'
3721 Indirection (expects indirect arguments as a list).
3722 `~@?'
3723 extracts indirect arguments from format arguments.
3724
3725 `~(STR~)'
3726 Case conversion (converts by `string-downcase').
3727 `~:(STR~)'
3728 converts by `string-capitalize'.
3729
3730 `~@(STR~)'
3731 converts by `string-capitalize-first'.
3732
3733 `~:@(STR~)'
3734 converts by `string-upcase'.
3735
3736 `~*'
3737 Argument Jumping (jumps 1 argument forward).
3738 `~N*'
3739 jumps N arguments forward.
3740
3741 `~:*'
3742 jumps 1 argument backward.
3743
3744 `~N:*'
3745 jumps N arguments backward.
3746
3747 `~@*'
3748 jumps to the 0th argument.
3749
3750 `~N@*'
3751 jumps to the Nth argument (beginning from 0)
3752
3753 `~[STR0~;STR1~;...~;STRN~]'
3754 Conditional Expression (numerical clause conditional).
3755 `~N['
3756 take argument from N.
3757
3758 `~@['
3759 true test conditional.
3760
3761 `~:['
3762 if-else-then conditional.
3763
3764 `~;'
3765 clause separator.
3766
3767 `~:;'
3768 default clause follows.
3769
3770 `~{STR~}'
3771 Iteration (args come from the next argument (a list)).
3772 `~N{'
3773 at most N iterations.
3774
3775 `~:{'
3776 args from next arg (a list of lists).
3777
3778 `~@{'
3779 args from the rest of arguments.
3780
3781 `~:@{'
3782 args from the rest args (lists).
3783
3784 `~^'
3785 Up and out.
3786 `~N^'
3787 aborts if N = 0
3788
3789 `~N,M^'
3790 aborts if N = M
3791
3792 `~N,M,K^'
3793 aborts if N <= M <= K
3794
3795 *** Not Implemented CL Format Control Directives
3796
3797 `~:A'
3798 print `#f' as an empty list (see below).
3799
3800 `~:S'
3801 print `#f' as an empty list (see below).
3802
3803 `~<~>'
3804 Justification.
3805
3806 `~:^'
3807 (sorry I don't understand its semantics completely)
3808
3809 *** Extended, Replaced and Additional Control Directives
3810
3811 `~MINCOL,PADCHAR,COMMACHAR,COMMAWIDTHD'
3812 `~MINCOL,PADCHAR,COMMACHAR,COMMAWIDTHX'
3813 `~MINCOL,PADCHAR,COMMACHAR,COMMAWIDTHO'
3814 `~MINCOL,PADCHAR,COMMACHAR,COMMAWIDTHB'
3815 `~N,MINCOL,PADCHAR,COMMACHAR,COMMAWIDTHR'
3816 COMMAWIDTH is the number of characters between two comma
3817 characters.
3818
3819 `~I'
3820 print a R4RS complex number as `~F~@Fi' with passed parameters for
3821 `~F'.
3822
3823 `~Y'
3824 Pretty print formatting of an argument for scheme code lists.
3825
3826 `~K'
3827 Same as `~?.'
3828
3829 `~!'
3830 Flushes the output if format DESTINATION is a port.
3831
3832 `~_'
3833 Print a `#\space' character
3834 `~N_'
3835 print N `#\space' characters.
3836
3837 `~/'
3838 Print a `#\tab' character
3839 `~N/'
3840 print N `#\tab' characters.
3841
3842 `~NC'
3843 Takes N as an integer representation for a character. No arguments
3844 are consumed. N is converted to a character by `integer->char'. N
3845 must be a positive decimal number.
3846
3847 `~:S'
3848 Print out readproof. Prints out internal objects represented as
3849 `#<...>' as strings `"#<...>"' so that the format output can always
3850 be processed by `read'.
3851
3852 `~:A'
3853 Print out readproof. Prints out internal objects represented as
3854 `#<...>' as strings `"#<...>"' so that the format output can always
3855 be processed by `read'.
3856
3857 `~Q'
3858 Prints information and a copyright notice on the format
3859 implementation.
3860 `~:Q'
3861 prints format version.
3862
3863 `~F, ~E, ~G, ~$'
3864 may also print number strings, i.e. passing a number as a string
3865 and format it accordingly.
3866
3867 *** Configuration Variables
3868
3869 The format module exports some configuration variables to suit the
3870 systems and users needs. There should be no modification necessary for
3871 the configuration that comes with Guile. Format detects automatically
3872 if the running scheme system implements floating point numbers and
3873 complex numbers.
3874
3875 format:symbol-case-conv
3876 Symbols are converted by `symbol->string' so the case type of the
3877 printed symbols is implementation dependent.
3878 `format:symbol-case-conv' is a one arg closure which is either
3879 `#f' (no conversion), `string-upcase', `string-downcase' or
3880 `string-capitalize'. (default `#f')
3881
3882 format:iobj-case-conv
3883 As FORMAT:SYMBOL-CASE-CONV but applies for the representation of
3884 implementation internal objects. (default `#f')
3885
3886 format:expch
3887 The character prefixing the exponent value in `~E' printing.
3888 (default `#\E')
3889
3890 *** Compatibility With Other Format Implementations
3891
3892 SLIB format 2.x:
3893 See `format.doc'.
3894
3895 SLIB format 1.4:
3896 Downward compatible except for padding support and `~A', `~S',
3897 `~P', `~X' uppercase printing. SLIB format 1.4 uses C-style
3898 `printf' padding support which is completely replaced by the CL
3899 `format' padding style.
3900
3901 MIT C-Scheme 7.1:
3902 Downward compatible except for `~', which is not documented
3903 (ignores all characters inside the format string up to a newline
3904 character). (7.1 implements `~a', `~s', ~NEWLINE, `~~', `~%',
3905 numerical and variable parameters and `:/@' modifiers in the CL
3906 sense).
3907
3908 Elk 1.5/2.0:
3909 Downward compatible except for `~A' and `~S' which print in
3910 uppercase. (Elk implements `~a', `~s', `~~', and `~%' (no
3911 directive parameters or modifiers)).
3912
3913 Scheme->C 01nov91:
3914 Downward compatible except for an optional destination parameter:
3915 S2C accepts a format call without a destination which returns a
3916 formatted string. This is equivalent to a #f destination in S2C.
3917 (S2C implements `~a', `~s', `~c', `~%', and `~~' (no directive
3918 parameters or modifiers)).
3919
3920
3921 ** Changes to string-handling functions.
3922
3923 These functions were added to support the (ice-9 format) module, above.
3924
3925 *** New function: string-upcase STRING
3926 *** New function: string-downcase STRING
3927
3928 These are non-destructive versions of the existing string-upcase! and
3929 string-downcase! functions.
3930
3931 *** New function: string-capitalize! STRING
3932 *** New function: string-capitalize STRING
3933
3934 These functions convert the first letter of each word in the string to
3935 upper case. Thus:
3936
3937 (string-capitalize "howdy there")
3938 => "Howdy There"
3939
3940 As with the other functions, string-capitalize! modifies the string in
3941 place, while string-capitalize returns a modified copy of its argument.
3942
3943 *** New function: string-ci->symbol STRING
3944
3945 Return a symbol whose name is STRING, but having the same case as if
3946 the symbol had be read by `read'.
3947
3948 Guile can be configured to be sensitive or insensitive to case
3949 differences in Scheme identifiers. If Guile is case-insensitive, all
3950 symbols are converted to lower case on input. The `string-ci->symbol'
3951 function returns a symbol whose name in STRING, transformed as Guile
3952 would if STRING were input.
3953
3954 *** New function: substring-move! STRING1 START END STRING2 START
3955
3956 Copy the substring of STRING1 from START (inclusive) to END
3957 (exclusive) to STRING2 at START. STRING1 and STRING2 may be the same
3958 string, and the source and destination areas may overlap; in all
3959 cases, the function behaves as if all the characters were copied
3960 simultanously.
3961
3962 *** Extended functions: substring-move-left! substring-move-right!
3963
3964 These functions now correctly copy arbitrarily overlapping substrings;
3965 they are both synonyms for substring-move!.
3966
3967
3968 ** New module (ice-9 getopt-long), with the function `getopt-long'.
3969
3970 getopt-long is a function for parsing command-line arguments in a
3971 manner consistent with other GNU programs.
3972
3973 (getopt-long ARGS GRAMMAR)
3974 Parse the arguments ARGS according to the argument list grammar GRAMMAR.
3975
3976 ARGS should be a list of strings. Its first element should be the
3977 name of the program; subsequent elements should be the arguments
3978 that were passed to the program on the command line. The
3979 `program-arguments' procedure returns a list of this form.
3980
3981 GRAMMAR is a list of the form:
3982 ((OPTION (PROPERTY VALUE) ...) ...)
3983
3984 Each OPTION should be a symbol. `getopt-long' will accept a
3985 command-line option named `--OPTION'.
3986 Each option can have the following (PROPERTY VALUE) pairs:
3987
3988 (single-char CHAR) --- Accept `-CHAR' as a single-character
3989 equivalent to `--OPTION'. This is how to specify traditional
3990 Unix-style flags.
3991 (required? BOOL) --- If BOOL is true, the option is required.
3992 getopt-long will raise an error if it is not found in ARGS.
3993 (value BOOL) --- If BOOL is #t, the option accepts a value; if
3994 it is #f, it does not; and if it is the symbol
3995 `optional', the option may appear in ARGS with or
3996 without a value.
3997 (predicate FUNC) --- If the option accepts a value (i.e. you
3998 specified `(value #t)' for this option), then getopt
3999 will apply FUNC to the value, and throw an exception
4000 if it returns #f. FUNC should be a procedure which
4001 accepts a string and returns a boolean value; you may
4002 need to use quasiquotes to get it into GRAMMAR.
4003
4004 The (PROPERTY VALUE) pairs may occur in any order, but each
4005 property may occur only once. By default, options do not have
4006 single-character equivalents, are not required, and do not take
4007 values.
4008
4009 In ARGS, single-character options may be combined, in the usual
4010 Unix fashion: ("-x" "-y") is equivalent to ("-xy"). If an option
4011 accepts values, then it must be the last option in the
4012 combination; the value is the next argument. So, for example, using
4013 the following grammar:
4014 ((apples (single-char #\a))
4015 (blimps (single-char #\b) (value #t))
4016 (catalexis (single-char #\c) (value #t)))
4017 the following argument lists would be acceptable:
4018 ("-a" "-b" "bang" "-c" "couth") ("bang" and "couth" are the values
4019 for "blimps" and "catalexis")
4020 ("-ab" "bang" "-c" "couth") (same)
4021 ("-ac" "couth" "-b" "bang") (same)
4022 ("-abc" "couth" "bang") (an error, since `-b' is not the
4023 last option in its combination)
4024
4025 If an option's value is optional, then `getopt-long' decides
4026 whether it has a value by looking at what follows it in ARGS. If
4027 the next element is a string, and it does not appear to be an
4028 option itself, then that string is the option's value.
4029
4030 The value of a long option can appear as the next element in ARGS,
4031 or it can follow the option name, separated by an `=' character.
4032 Thus, using the same grammar as above, the following argument lists
4033 are equivalent:
4034 ("--apples" "Braeburn" "--blimps" "Goodyear")
4035 ("--apples=Braeburn" "--blimps" "Goodyear")
4036 ("--blimps" "Goodyear" "--apples=Braeburn")
4037
4038 If the option "--" appears in ARGS, argument parsing stops there;
4039 subsequent arguments are returned as ordinary arguments, even if
4040 they resemble options. So, in the argument list:
4041 ("--apples" "Granny Smith" "--" "--blimp" "Goodyear")
4042 `getopt-long' will recognize the `apples' option as having the
4043 value "Granny Smith", but it will not recognize the `blimp'
4044 option; it will return the strings "--blimp" and "Goodyear" as
4045 ordinary argument strings.
4046
4047 The `getopt-long' function returns the parsed argument list as an
4048 assocation list, mapping option names --- the symbols from GRAMMAR
4049 --- onto their values, or #t if the option does not accept a value.
4050 Unused options do not appear in the alist.
4051
4052 All arguments that are not the value of any option are returned
4053 as a list, associated with the empty list.
4054
4055 `getopt-long' throws an exception if:
4056 - it finds an unrecognized option in ARGS
4057 - a required option is omitted
4058 - an option that requires an argument doesn't get one
4059 - an option that doesn't accept an argument does get one (this can
4060 only happen using the long option `--opt=value' syntax)
4061 - an option predicate fails
4062
4063 So, for example:
4064
4065 (define grammar
4066 `((lockfile-dir (required? #t)
4067 (value #t)
4068 (single-char #\k)
4069 (predicate ,file-is-directory?))
4070 (verbose (required? #f)
4071 (single-char #\v)
4072 (value #f))
4073 (x-includes (single-char #\x))
4074 (rnet-server (single-char #\y)
4075 (predicate ,string?))))
4076
4077 (getopt-long '("my-prog" "-vk" "/tmp" "foo1" "--x-includes=/usr/include"
4078 "--rnet-server=lamprod" "--" "-fred" "foo2" "foo3")
4079 grammar)
4080 => ((() "foo1" "-fred" "foo2" "foo3")
4081 (rnet-server . "lamprod")
4082 (x-includes . "/usr/include")
4083 (lockfile-dir . "/tmp")
4084 (verbose . #t))
4085
4086 ** The (ice-9 getopt-gnu-style) module is obsolete; use (ice-9 getopt-long).
4087
4088 It will be removed in a few releases.
4089
4090 ** New syntax: lambda*
4091 ** New syntax: define*
4092 ** New syntax: define*-public
4093 ** New syntax: defmacro*
4094 ** New syntax: defmacro*-public
4095 Guile now supports optional arguments.
4096
4097 `lambda*', `define*', `define*-public', `defmacro*' and
4098 `defmacro*-public' are identical to the non-* versions except that
4099 they use an extended type of parameter list that has the following BNF
4100 syntax (parentheses are literal, square brackets indicate grouping,
4101 and `*', `+' and `?' have the usual meaning):
4102
4103 ext-param-list ::= ( [identifier]* [#&optional [ext-var-decl]+]?
4104 [#&key [ext-var-decl]+ [#&allow-other-keys]?]?
4105 [[#&rest identifier]|[. identifier]]? ) | [identifier]
4106
4107 ext-var-decl ::= identifier | ( identifier expression )
4108
4109 The semantics are best illustrated with the following documentation
4110 and examples for `lambda*':
4111
4112 lambda* args . body
4113 lambda extended for optional and keyword arguments
4114
4115 lambda* creates a procedure that takes optional arguments. These
4116 are specified by putting them inside brackets at the end of the
4117 paramater list, but before any dotted rest argument. For example,
4118 (lambda* (a b #&optional c d . e) '())
4119 creates a procedure with fixed arguments a and b, optional arguments c
4120 and d, and rest argument e. If the optional arguments are omitted
4121 in a call, the variables for them are unbound in the procedure. This
4122 can be checked with the bound? macro.
4123
4124 lambda* can also take keyword arguments. For example, a procedure
4125 defined like this:
4126 (lambda* (#&key xyzzy larch) '())
4127 can be called with any of the argument lists (#:xyzzy 11)
4128 (#:larch 13) (#:larch 42 #:xyzzy 19) (). Whichever arguments
4129 are given as keywords are bound to values.
4130
4131 Optional and keyword arguments can also be given default values
4132 which they take on when they are not present in a call, by giving a
4133 two-item list in place of an optional argument, for example in:
4134 (lambda* (foo #&optional (bar 42) #&key (baz 73)) (list foo bar baz))
4135 foo is a fixed argument, bar is an optional argument with default
4136 value 42, and baz is a keyword argument with default value 73.
4137 Default value expressions are not evaluated unless they are needed
4138 and until the procedure is called.
4139
4140 lambda* now supports two more special parameter list keywords.
4141
4142 lambda*-defined procedures now throw an error by default if a
4143 keyword other than one of those specified is found in the actual
4144 passed arguments. However, specifying #&allow-other-keys
4145 immediately after the kyword argument declarations restores the
4146 previous behavior of ignoring unknown keywords. lambda* also now
4147 guarantees that if the same keyword is passed more than once, the
4148 last one passed is the one that takes effect. For example,
4149 ((lambda* (#&key (heads 0) (tails 0)) (display (list heads tails)))
4150 #:heads 37 #:tails 42 #:heads 99)
4151 would result in (99 47) being displayed.
4152
4153 #&rest is also now provided as a synonym for the dotted syntax rest
4154 argument. The argument lists (a . b) and (a #&rest b) are equivalent in
4155 all respects to lambda*. This is provided for more similarity to DSSSL,
4156 MIT-Scheme and Kawa among others, as well as for refugees from other
4157 Lisp dialects.
4158
4159 Further documentation may be found in the optargs.scm file itself.
4160
4161 The optional argument module also exports the macros `let-optional',
4162 `let-optional*', `let-keywords', `let-keywords*' and `bound?'. These
4163 are not documented here because they may be removed in the future, but
4164 full documentation is still available in optargs.scm.
4165
4166 ** New syntax: and-let*
4167 Guile now supports the `and-let*' form, described in the draft SRFI-2.
4168
4169 Syntax: (land* (<clause> ...) <body> ...)
4170 Each <clause> should have one of the following forms:
4171 (<variable> <expression>)
4172 (<expression>)
4173 <bound-variable>
4174 Each <variable> or <bound-variable> should be an identifier. Each
4175 <expression> should be a valid expression. The <body> should be a
4176 possibly empty sequence of expressions, like the <body> of a
4177 lambda form.
4178
4179 Semantics: A LAND* expression is evaluated by evaluating the
4180 <expression> or <bound-variable> of each of the <clause>s from
4181 left to right. The value of the first <expression> or
4182 <bound-variable> that evaluates to a false value is returned; the
4183 remaining <expression>s and <bound-variable>s are not evaluated.
4184 The <body> forms are evaluated iff all the <expression>s and
4185 <bound-variable>s evaluate to true values.
4186
4187 The <expression>s and the <body> are evaluated in an environment
4188 binding each <variable> of the preceding (<variable> <expression>)
4189 clauses to the value of the <expression>. Later bindings
4190 shadow earlier bindings.
4191
4192 Guile's and-let* macro was contributed by Michael Livshin.
4193
4194 ** New sorting functions
4195
4196 *** New function: sorted? SEQUENCE LESS?
4197 Returns `#t' when the sequence argument is in non-decreasing order
4198 according to LESS? (that is, there is no adjacent pair `... x y
4199 ...' for which `(less? y x)').
4200
4201 Returns `#f' when the sequence contains at least one out-of-order
4202 pair. It is an error if the sequence is neither a list nor a
4203 vector.
4204
4205 *** New function: merge LIST1 LIST2 LESS?
4206 LIST1 and LIST2 are sorted lists.
4207 Returns the sorted list of all elements in LIST1 and LIST2.
4208
4209 Assume that the elements a and b1 in LIST1 and b2 in LIST2 are "equal"
4210 in the sense that (LESS? x y) --> #f for x, y in {a, b1, b2},
4211 and that a < b1 in LIST1. Then a < b1 < b2 in the result.
4212 (Here "<" should read "comes before".)
4213
4214 *** New procedure: merge! LIST1 LIST2 LESS?
4215 Merges two lists, re-using the pairs of LIST1 and LIST2 to build
4216 the result. If the code is compiled, and LESS? constructs no new
4217 pairs, no pairs at all will be allocated. The first pair of the
4218 result will be either the first pair of LIST1 or the first pair of
4219 LIST2.
4220
4221 *** New function: sort SEQUENCE LESS?
4222 Accepts either a list or a vector, and returns a new sequence
4223 which is sorted. The new sequence is the same type as the input.
4224 Always `(sorted? (sort sequence less?) less?)'. The original
4225 sequence is not altered in any way. The new sequence shares its
4226 elements with the old one; no elements are copied.
4227
4228 *** New procedure: sort! SEQUENCE LESS
4229 Returns its sorted result in the original boxes. No new storage is
4230 allocated at all. Proper usage: (set! slist (sort! slist <))
4231
4232 *** New function: stable-sort SEQUENCE LESS?
4233 Similar to `sort' but stable. That is, if "equal" elements are
4234 ordered a < b in the original sequence, they will have the same order
4235 in the result.
4236
4237 *** New function: stable-sort! SEQUENCE LESS?
4238 Similar to `sort!' but stable.
4239 Uses temporary storage when sorting vectors.
4240
4241 *** New functions: sort-list, sort-list!
4242 Added for compatibility with scsh.
4243
4244 ** New built-in random number support
4245
4246 *** New function: random N [STATE]
4247 Accepts a positive integer or real N and returns a number of the
4248 same type between zero (inclusive) and N (exclusive). The values
4249 returned have a uniform distribution.
4250
4251 The optional argument STATE must be of the type produced by
4252 `copy-random-state' or `seed->random-state'. It defaults to the value
4253 of the variable `*random-state*'. This object is used to maintain the
4254 state of the pseudo-random-number generator and is altered as a side
4255 effect of the `random' operation.
4256
4257 *** New variable: *random-state*
4258 Holds a data structure that encodes the internal state of the
4259 random-number generator that `random' uses by default. The nature
4260 of this data structure is implementation-dependent. It may be
4261 printed out and successfully read back in, but may or may not
4262 function correctly as a random-number state object in another
4263 implementation.
4264
4265 *** New function: copy-random-state [STATE]
4266 Returns a new object of type suitable for use as the value of the
4267 variable `*random-state*' and as a second argument to `random'.
4268 If argument STATE is given, a copy of it is returned. Otherwise a
4269 copy of `*random-state*' is returned.
4270
4271 *** New function: seed->random-state SEED
4272 Returns a new object of type suitable for use as the value of the
4273 variable `*random-state*' and as a second argument to `random'.
4274 SEED is a string or a number. A new state is generated and
4275 initialized using SEED.
4276
4277 *** New function: random:uniform [STATE]
4278 Returns an uniformly distributed inexact real random number in the
4279 range between 0 and 1.
4280
4281 *** New procedure: random:solid-sphere! VECT [STATE]
4282 Fills VECT with inexact real random numbers the sum of whose
4283 squares is less than 1.0. Thinking of VECT as coordinates in
4284 space of dimension N = `(vector-length VECT)', the coordinates are
4285 uniformly distributed within the unit N-shere. The sum of the
4286 squares of the numbers is returned. VECT can be either a vector
4287 or a uniform vector of doubles.
4288
4289 *** New procedure: random:hollow-sphere! VECT [STATE]
4290 Fills VECT with inexact real random numbers the sum of whose squares
4291 is equal to 1.0. Thinking of VECT as coordinates in space of
4292 dimension n = `(vector-length VECT)', the coordinates are uniformly
4293 distributed over the surface of the unit n-shere. VECT can be either
4294 a vector or a uniform vector of doubles.
4295
4296 *** New function: random:normal [STATE]
4297 Returns an inexact real in a normal distribution with mean 0 and
4298 standard deviation 1. For a normal distribution with mean M and
4299 standard deviation D use `(+ M (* D (random:normal)))'.
4300
4301 *** New procedure: random:normal-vector! VECT [STATE]
4302 Fills VECT with inexact real random numbers which are independent and
4303 standard normally distributed (i.e., with mean 0 and variance 1).
4304 VECT can be either a vector or a uniform vector of doubles.
4305
4306 *** New function: random:exp STATE
4307 Returns an inexact real in an exponential distribution with mean 1.
4308 For an exponential distribution with mean U use (* U (random:exp)).
4309
4310 ** The range of logand, logior, logxor, logtest, and logbit? have changed.
4311
4312 These functions now operate on numbers in the range of a C unsigned
4313 long.
4314
4315 These functions used to operate on numbers in the range of a C signed
4316 long; however, this seems inappropriate, because Guile integers don't
4317 overflow.
4318
4319 ** New function: make-guardian
4320 This is an implementation of guardians as described in
4321 R. Kent Dybvig, Carl Bruggeman, and David Eby (1993) "Guardians in a
4322 Generation-Based Garbage Collector" ACM SIGPLAN Conference on
4323 Programming Language Design and Implementation, June 1993
4324 ftp://ftp.cs.indiana.edu/pub/scheme-repository/doc/pubs/guardians.ps.gz
4325
4326 ** New functions: delq1!, delv1!, delete1!
4327 These procedures behave similar to delq! and friends but delete only
4328 one object if at all.
4329
4330 ** New function: unread-string STRING PORT
4331 Unread STRING to PORT, that is, push it back onto the port so that
4332 next read operation will work on the pushed back characters.
4333
4334 ** unread-char can now be called multiple times
4335 If unread-char is called multiple times, the unread characters will be
4336 read again in last-in first-out order.
4337
4338 ** the procedures uniform-array-read! and uniform-array-write! now
4339 work on any kind of port, not just ports which are open on a file.
4340
4341 ** Now 'l' in a port mode requests line buffering.
4342
4343 ** The procedure truncate-file now works on string ports as well
4344 as file ports. If the size argument is omitted, the current
4345 file position is used.
4346
4347 ** new procedure: seek PORT/FDES OFFSET WHENCE
4348 The arguments are the same as for the old fseek procedure, but it
4349 works on string ports as well as random-access file ports.
4350
4351 ** the fseek procedure now works on string ports, since it has been
4352 redefined using seek.
4353
4354 ** the setvbuf procedure now uses a default size if mode is _IOFBF and
4355 size is not supplied.
4356
4357 ** the newline procedure no longer flushes the port if it's not
4358 line-buffered: previously it did if it was the current output port.
4359
4360 ** open-pipe and close-pipe are no longer primitive procedures, but
4361 an emulation can be obtained using `(use-modules (ice-9 popen))'.
4362
4363 ** the freopen procedure has been removed.
4364
4365 ** new procedure: drain-input PORT
4366 Drains PORT's read buffers (including any pushed-back characters)
4367 and returns the contents as a single string.
4368
4369 ** New function: map-in-order PROC LIST1 LIST2 ...
4370 Version of `map' which guarantees that the procedure is applied to the
4371 lists in serial order.
4372
4373 ** Renamed `serial-array-copy!' and `serial-array-map!' to
4374 `array-copy-in-order!' and `array-map-in-order!'. The old names are
4375 now obsolete and will go away in release 1.5.
4376
4377 ** New syntax: collect BODY1 ...
4378 Version of `begin' which returns a list of the results of the body
4379 forms instead of the result of the last body form. In contrast to
4380 `begin', `collect' allows an empty body.
4381
4382 ** New functions: read-history FILENAME, write-history FILENAME
4383 Read/write command line history from/to file. Returns #t on success
4384 and #f if an error occured.
4385
4386 ** `ls' and `lls' in module (ice-9 ls) now handle no arguments.
4387
4388 These procedures return a list of definitions available in the specified
4389 argument, a relative module reference. In the case of no argument,
4390 `(current-module)' is now consulted for definitions to return, instead
4391 of simply returning #f, the former behavior.
4392
4393 ** The #/ syntax for lists is no longer supported.
4394
4395 Earlier versions of Scheme accepted this syntax, but printed a
4396 warning.
4397
4398 ** Guile no longer consults the SCHEME_LOAD_PATH environment variable.
4399
4400 Instead, you should set GUILE_LOAD_PATH to tell Guile where to find
4401 modules.
4402
4403 * Changes to the gh_ interface
4404
4405 ** gh_scm2doubles
4406
4407 Now takes a second argument which is the result array. If this
4408 pointer is NULL, a new array is malloced (the old behaviour).
4409
4410 ** gh_chars2byvect, gh_shorts2svect, gh_floats2fvect, gh_scm2chars,
4411 gh_scm2shorts, gh_scm2longs, gh_scm2floats
4412
4413 New functions.
4414
4415 * Changes to the scm_ interface
4416
4417 ** Function: scm_make_named_hook (char* name, int n_args)
4418
4419 Creates a hook in the same way as make-hook above but also
4420 binds a variable named NAME to it.
4421
4422 This is the typical way of creating a hook from C code.
4423
4424 Currently, the variable is created in the "current" module. This
4425 might change when we get the new module system.
4426
4427 ** The smob interface
4428
4429 The interface for creating smobs has changed. For documentation, see
4430 data-rep.info (made from guile-core/doc/data-rep.texi).
4431
4432 *** Deprecated function: SCM scm_newsmob (scm_smobfuns *)
4433
4434 >>> This function will be removed in 1.3.4. <<<
4435
4436 It is replaced by:
4437
4438 *** Function: SCM scm_make_smob_type (const char *name, scm_sizet size)
4439 This function adds a new smob type, named NAME, with instance size
4440 SIZE to the system. The return value is a tag that is used in
4441 creating instances of the type. If SIZE is 0, then no memory will
4442 be allocated when instances of the smob are created, and nothing
4443 will be freed by the default free function.
4444
4445 *** Function: void scm_set_smob_mark (long tc, SCM (*mark) (SCM))
4446 This function sets the smob marking procedure for the smob type
4447 specified by the tag TC. TC is the tag returned by
4448 `scm_make_smob_type'.
4449
4450 *** Function: void scm_set_smob_free (long tc, SCM (*mark) (SCM))
4451 This function sets the smob freeing procedure for the smob type
4452 specified by the tag TC. TC is the tag returned by
4453 `scm_make_smob_type'.
4454
4455 *** Function: void scm_set_smob_print (tc, print)
4456
4457 - Function: void scm_set_smob_print (long tc,
4458 scm_sizet (*print) (SCM,
4459 SCM,
4460 scm_print_state *))
4461
4462 This function sets the smob printing procedure for the smob type
4463 specified by the tag TC. TC is the tag returned by
4464 `scm_make_smob_type'.
4465
4466 *** Function: void scm_set_smob_equalp (long tc, SCM (*equalp) (SCM, SCM))
4467 This function sets the smob equality-testing predicate for the
4468 smob type specified by the tag TC. TC is the tag returned by
4469 `scm_make_smob_type'.
4470
4471 *** Macro: void SCM_NEWSMOB (SCM var, long tc, void *data)
4472 Make VALUE contain a smob instance of the type with type code TC and
4473 smob data DATA. VALUE must be previously declared as C type `SCM'.
4474
4475 *** Macro: fn_returns SCM_RETURN_NEWSMOB (long tc, void *data)
4476 This macro expands to a block of code that creates a smob instance
4477 of the type with type code TC and smob data DATA, and returns that
4478 `SCM' value. It should be the last piece of code in a block.
4479
4480 ** The interfaces for using I/O ports and implementing port types
4481 (ptobs) have changed significantly. The new interface is based on
4482 shared access to buffers and a new set of ptob procedures.
4483
4484 *** scm_newptob has been removed
4485
4486 It is replaced by:
4487
4488 *** Function: SCM scm_make_port_type (type_name, fill_buffer, write_flush)
4489
4490 - Function: SCM scm_make_port_type (char *type_name,
4491 int (*fill_buffer) (SCM port),
4492 void (*write_flush) (SCM port));
4493
4494 Similarly to the new smob interface, there is a set of function
4495 setters by which the user can customize the behaviour of his port
4496 type. See ports.h (scm_set_port_XXX).
4497
4498 ** scm_strport_to_string: New function: creates a new string from
4499 a string port's buffer.
4500
4501 ** Plug in interface for random number generators
4502 The variable `scm_the_rng' in random.c contains a value and three
4503 function pointers which together define the current random number
4504 generator being used by the Scheme level interface and the random
4505 number library functions.
4506
4507 The user is free to replace the default generator with the generator
4508 of his own choice.
4509
4510 *** Variable: size_t scm_the_rng.rstate_size
4511 The size of the random state type used by the current RNG
4512 measured in chars.
4513
4514 *** Function: unsigned long scm_the_rng.random_bits (scm_rstate *STATE)
4515 Given the random STATE, return 32 random bits.
4516
4517 *** Function: void scm_the_rng.init_rstate (scm_rstate *STATE, chars *S, int N)
4518 Seed random state STATE using string S of length N.
4519
4520 *** Function: scm_rstate *scm_the_rng.copy_rstate (scm_rstate *STATE)
4521 Given random state STATE, return a malloced copy.
4522
4523 ** Default RNG
4524 The default RNG is the MWC (Multiply With Carry) random number
4525 generator described by George Marsaglia at the Department of
4526 Statistics and Supercomputer Computations Research Institute, The
4527 Florida State University (http://stat.fsu.edu/~geo).
4528
4529 It uses 64 bits, has a period of 4578426017172946943 (4.6e18), and
4530 passes all tests in the DIEHARD test suite
4531 (http://stat.fsu.edu/~geo/diehard.html). The generation of 32 bits
4532 costs one multiply and one add on platforms which either supports long
4533 longs (gcc does this on most systems) or have 64 bit longs. The cost
4534 is four multiply on other systems but this can be optimized by writing
4535 scm_i_uniform32 in assembler.
4536
4537 These functions are provided through the scm_the_rng interface for use
4538 by libguile and the application.
4539
4540 *** Function: unsigned long scm_i_uniform32 (scm_i_rstate *STATE)
4541 Given the random STATE, return 32 random bits.
4542 Don't use this function directly. Instead go through the plugin
4543 interface (see "Plug in interface" above).
4544
4545 *** Function: void scm_i_init_rstate (scm_i_rstate *STATE, char *SEED, int N)
4546 Initialize STATE using SEED of length N.
4547
4548 *** Function: scm_i_rstate *scm_i_copy_rstate (scm_i_rstate *STATE)
4549 Return a malloc:ed copy of STATE. This function can easily be re-used
4550 in the interfaces to other RNGs.
4551
4552 ** Random number library functions
4553 These functions use the current RNG through the scm_the_rng interface.
4554 It might be a good idea to use these functions from your C code so
4555 that only one random generator is used by all code in your program.
4556
4557 The default random state is stored in:
4558
4559 *** Variable: SCM scm_var_random_state
4560 Contains the vcell of the Scheme variable "*random-state*" which is
4561 used as default state by all random number functions in the Scheme
4562 level interface.
4563
4564 Example:
4565
4566 double x = scm_c_uniform01 (SCM_RSTATE (SCM_CDR (scm_var_random_state)));
4567
4568 *** Function: scm_rstate *scm_c_default_rstate (void)
4569 This is a convenience function which returns the value of
4570 scm_var_random_state. An error message is generated if this value
4571 isn't a random state.
4572
4573 *** Function: scm_rstate *scm_c_make_rstate (char *SEED, int LENGTH)
4574 Make a new random state from the string SEED of length LENGTH.
4575
4576 It is generally not a good idea to use multiple random states in a
4577 program. While subsequent random numbers generated from one random
4578 state are guaranteed to be reasonably independent, there is no such
4579 guarantee for numbers generated from different random states.
4580
4581 *** Macro: unsigned long scm_c_uniform32 (scm_rstate *STATE)
4582 Return 32 random bits.
4583
4584 *** Function: double scm_c_uniform01 (scm_rstate *STATE)
4585 Return a sample from the uniform(0,1) distribution.
4586
4587 *** Function: double scm_c_normal01 (scm_rstate *STATE)
4588 Return a sample from the normal(0,1) distribution.
4589
4590 *** Function: double scm_c_exp1 (scm_rstate *STATE)
4591 Return a sample from the exp(1) distribution.
4592
4593 *** Function: unsigned long scm_c_random (scm_rstate *STATE, unsigned long M)
4594 Return a sample from the discrete uniform(0,M) distribution.
4595
4596 *** Function: SCM scm_c_random_bignum (scm_rstate *STATE, SCM M)
4597 Return a sample from the discrete uniform(0,M) distribution.
4598 M must be a bignum object. The returned value may be an INUM.
4599
4600
4601 \f
4602 Changes in Guile 1.3 (released Monday, October 19, 1998):
4603
4604 * Changes to the distribution
4605
4606 ** We renamed the SCHEME_LOAD_PATH environment variable to GUILE_LOAD_PATH.
4607 To avoid conflicts, programs should name environment variables after
4608 themselves, except when there's a common practice establishing some
4609 other convention.
4610
4611 For now, Guile supports both GUILE_LOAD_PATH and SCHEME_LOAD_PATH,
4612 giving the former precedence, and printing a warning message if the
4613 latter is set. Guile 1.4 will not recognize SCHEME_LOAD_PATH at all.
4614
4615 ** The header files related to multi-byte characters have been removed.
4616 They were: libguile/extchrs.h and libguile/mbstrings.h. Any C code
4617 which referred to these explicitly will probably need to be rewritten,
4618 since the support for the variant string types has been removed; see
4619 below.
4620
4621 ** The header files append.h and sequences.h have been removed. These
4622 files implemented non-R4RS operations which would encourage
4623 non-portable programming style and less easy-to-read code.
4624
4625 * Changes to the stand-alone interpreter
4626
4627 ** New procedures have been added to implement a "batch mode":
4628
4629 *** Function: batch-mode?
4630
4631 Returns a boolean indicating whether the interpreter is in batch
4632 mode.
4633
4634 *** Function: set-batch-mode?! ARG
4635
4636 If ARG is true, switches the interpreter to batch mode. The `#f'
4637 case has not been implemented.
4638
4639 ** Guile now provides full command-line editing, when run interactively.
4640 To use this feature, you must have the readline library installed.
4641 The Guile build process will notice it, and automatically include
4642 support for it.
4643
4644 The readline library is available via anonymous FTP from any GNU
4645 mirror site; the canonical location is "ftp://prep.ai.mit.edu/pub/gnu".
4646
4647 ** the-last-stack is now a fluid.
4648
4649 * Changes to the procedure for linking libguile with your programs
4650
4651 ** You can now use the `guile-config' utility to build programs that use Guile.
4652
4653 Guile now includes a command-line utility called `guile-config', which
4654 can provide information about how to compile and link programs that
4655 use Guile.
4656
4657 *** `guile-config compile' prints any C compiler flags needed to use Guile.
4658 You should include this command's output on the command line you use
4659 to compile C or C++ code that #includes the Guile header files. It's
4660 usually just a `-I' flag to help the compiler find the Guile headers.
4661
4662
4663 *** `guile-config link' prints any linker flags necessary to link with Guile.
4664
4665 This command writes to its standard output a list of flags which you
4666 must pass to the linker to link your code against the Guile library.
4667 The flags include '-lguile' itself, any other libraries the Guile
4668 library depends upon, and any `-L' flags needed to help the linker
4669 find those libraries.
4670
4671 For example, here is a Makefile rule that builds a program named 'foo'
4672 from the object files ${FOO_OBJECTS}, and links them against Guile:
4673
4674 foo: ${FOO_OBJECTS}
4675 ${CC} ${CFLAGS} ${FOO_OBJECTS} `guile-config link` -o foo
4676
4677 Previous Guile releases recommended that you use autoconf to detect
4678 which of a predefined set of libraries were present on your system.
4679 It is more robust to use `guile-config', since it records exactly which
4680 libraries the installed Guile library requires.
4681
4682 This was originally called `build-guile', but was renamed to
4683 `guile-config' before Guile 1.3 was released, to be consistent with
4684 the analogous script for the GTK+ GUI toolkit, which is called
4685 `gtk-config'.
4686
4687
4688 ** Use the GUILE_FLAGS macro in your configure.in file to find Guile.
4689
4690 If you are using the GNU autoconf package to configure your program,
4691 you can use the GUILE_FLAGS autoconf macro to call `guile-config'
4692 (described above) and gather the necessary values for use in your
4693 Makefiles.
4694
4695 The GUILE_FLAGS macro expands to configure script code which runs the
4696 `guile-config' script, to find out where Guile's header files and
4697 libraries are installed. It sets two variables, marked for
4698 substitution, as by AC_SUBST.
4699
4700 GUILE_CFLAGS --- flags to pass to a C or C++ compiler to build
4701 code that uses Guile header files. This is almost always just a
4702 -I flag.
4703
4704 GUILE_LDFLAGS --- flags to pass to the linker to link a
4705 program against Guile. This includes `-lguile' for the Guile
4706 library itself, any libraries that Guile itself requires (like
4707 -lqthreads), and so on. It may also include a -L flag to tell the
4708 compiler where to find the libraries.
4709
4710 GUILE_FLAGS is defined in the file guile.m4, in the top-level
4711 directory of the Guile distribution. You can copy it into your
4712 package's aclocal.m4 file, and then use it in your configure.in file.
4713
4714 If you are using the `aclocal' program, distributed with GNU automake,
4715 to maintain your aclocal.m4 file, the Guile installation process
4716 installs guile.m4 where aclocal will find it. All you need to do is
4717 use GUILE_FLAGS in your configure.in file, and then run `aclocal';
4718 this will copy the definition of GUILE_FLAGS into your aclocal.m4
4719 file.
4720
4721
4722 * Changes to Scheme functions and syntax
4723
4724 ** Multi-byte strings have been removed, as have multi-byte and wide
4725 ports. We felt that these were the wrong approach to
4726 internationalization support.
4727
4728 ** New function: readline [PROMPT]
4729 Read a line from the terminal, and allow the user to edit it,
4730 prompting with PROMPT. READLINE provides a large set of Emacs-like
4731 editing commands, lets the user recall previously typed lines, and
4732 works on almost every kind of terminal, including dumb terminals.
4733
4734 READLINE assumes that the cursor is at the beginning of the line when
4735 it is invoked. Thus, you can't print a prompt yourself, and then call
4736 READLINE; you need to package up your prompt as a string, pass it to
4737 the function, and let READLINE print the prompt itself. This is
4738 because READLINE needs to know the prompt's screen width.
4739
4740 For Guile to provide this function, you must have the readline
4741 library, version 2.1 or later, installed on your system. Readline is
4742 available via anonymous FTP from prep.ai.mit.edu in pub/gnu, or from
4743 any GNU mirror site.
4744
4745 See also ADD-HISTORY function.
4746
4747 ** New function: add-history STRING
4748 Add STRING as the most recent line in the history used by the READLINE
4749 command. READLINE does not add lines to the history itself; you must
4750 call ADD-HISTORY to make previous input available to the user.
4751
4752 ** The behavior of the read-line function has changed.
4753
4754 This function now uses standard C library functions to read the line,
4755 for speed. This means that it doesn not respect the value of
4756 scm-line-incrementors; it assumes that lines are delimited with
4757 #\newline.
4758
4759 (Note that this is read-line, the function that reads a line of text
4760 from a port, not readline, the function that reads a line from a
4761 terminal, providing full editing capabilities.)
4762
4763 ** New module (ice-9 getopt-gnu-style): Parse command-line arguments.
4764
4765 This module provides some simple argument parsing. It exports one
4766 function:
4767
4768 Function: getopt-gnu-style ARG-LS
4769 Parse a list of program arguments into an alist of option
4770 descriptions.
4771
4772 Each item in the list of program arguments is examined to see if
4773 it meets the syntax of a GNU long-named option. An argument like
4774 `--MUMBLE' produces an element of the form (MUMBLE . #t) in the
4775 returned alist, where MUMBLE is a keyword object with the same
4776 name as the argument. An argument like `--MUMBLE=FROB' produces
4777 an element of the form (MUMBLE . FROB), where FROB is a string.
4778
4779 As a special case, the returned alist also contains a pair whose
4780 car is the symbol `rest'. The cdr of this pair is a list
4781 containing all the items in the argument list that are not options
4782 of the form mentioned above.
4783
4784 The argument `--' is treated specially: all items in the argument
4785 list appearing after such an argument are not examined, and are
4786 returned in the special `rest' list.
4787
4788 This function does not parse normal single-character switches.
4789 You will need to parse them out of the `rest' list yourself.
4790
4791 ** The read syntax for byte vectors and short vectors has changed.
4792
4793 Instead of #bytes(...), write #y(...).
4794
4795 Instead of #short(...), write #h(...).
4796
4797 This may seem nutty, but, like the other uniform vectors, byte vectors
4798 and short vectors want to have the same print and read syntax (and,
4799 more basic, want to have read syntax!). Changing the read syntax to
4800 use multiple characters after the hash sign breaks with the
4801 conventions used in R5RS and the conventions used for the other
4802 uniform vectors. It also introduces complexity in the current reader,
4803 both on the C and Scheme levels. (The Right solution is probably to
4804 change the syntax and prototypes for uniform vectors entirely.)
4805
4806
4807 ** The new module (ice-9 session) provides useful interactive functions.
4808
4809 *** New procedure: (apropos REGEXP OPTION ...)
4810
4811 Display a list of top-level variables whose names match REGEXP, and
4812 the modules they are imported from. Each OPTION should be one of the
4813 following symbols:
4814
4815 value --- Show the value of each matching variable.
4816 shadow --- Show bindings shadowed by subsequently imported modules.
4817 full --- Same as both `shadow' and `value'.
4818
4819 For example:
4820
4821 guile> (apropos "trace" 'full)
4822 debug: trace #<procedure trace args>
4823 debug: untrace #<procedure untrace args>
4824 the-scm-module: display-backtrace #<compiled-closure #<primitive-procedure gsubr-apply>>
4825 the-scm-module: before-backtrace-hook ()
4826 the-scm-module: backtrace #<primitive-procedure backtrace>
4827 the-scm-module: after-backtrace-hook ()
4828 the-scm-module: has-shown-backtrace-hint? #f
4829 guile>
4830
4831 ** There are new functions and syntax for working with macros.
4832
4833 Guile implements macros as a special object type. Any variable whose
4834 top-level binding is a macro object acts as a macro. The macro object
4835 specifies how the expression should be transformed before evaluation.
4836
4837 *** Macro objects now print in a reasonable way, resembling procedures.
4838
4839 *** New function: (macro? OBJ)
4840 True iff OBJ is a macro object.
4841
4842 *** New function: (primitive-macro? OBJ)
4843 Like (macro? OBJ), but true only if OBJ is one of the Guile primitive
4844 macro transformers, implemented in eval.c rather than Scheme code.
4845
4846 Why do we have this function?
4847 - For symmetry with procedure? and primitive-procedure?,
4848 - to allow custom print procedures to tell whether a macro is
4849 primitive, and display it differently, and
4850 - to allow compilers and user-written evaluators to distinguish
4851 builtin special forms from user-defined ones, which could be
4852 compiled.
4853
4854 *** New function: (macro-type OBJ)
4855 Return a value indicating what kind of macro OBJ is. Possible return
4856 values are:
4857
4858 The symbol `syntax' --- a macro created by procedure->syntax.
4859 The symbol `macro' --- a macro created by procedure->macro.
4860 The symbol `macro!' --- a macro created by procedure->memoizing-macro.
4861 The boolean #f --- if OBJ is not a macro object.
4862
4863 *** New function: (macro-name MACRO)
4864 Return the name of the macro object MACRO's procedure, as returned by
4865 procedure-name.
4866
4867 *** New function: (macro-transformer MACRO)
4868 Return the transformer procedure for MACRO.
4869
4870 *** New syntax: (use-syntax MODULE ... TRANSFORMER)
4871
4872 Specify a new macro expander to use in the current module. Each
4873 MODULE is a module name, with the same meaning as in the `use-modules'
4874 form; each named module's exported bindings are added to the current
4875 top-level environment. TRANSFORMER is an expression evaluated in the
4876 resulting environment which must yield a procedure to use as the
4877 module's eval transformer: every expression evaluated in this module
4878 is passed to this function, and the result passed to the Guile
4879 interpreter.
4880
4881 *** macro-eval! is removed. Use local-eval instead.
4882
4883 ** Some magic has been added to the printer to better handle user
4884 written printing routines (like record printers, closure printers).
4885
4886 The problem is that these user written routines must have access to
4887 the current `print-state' to be able to handle fancy things like
4888 detection of circular references. These print-states have to be
4889 passed to the builtin printing routines (display, write, etc) to
4890 properly continue the print chain.
4891
4892 We didn't want to change all existing print code so that it
4893 explicitly passes thru a print state in addition to a port. Instead,
4894 we extented the possible values that the builtin printing routines
4895 accept as a `port'. In addition to a normal port, they now also take
4896 a pair of a normal port and a print-state. Printing will go to the
4897 port and the print-state will be used to control the detection of
4898 circular references, etc. If the builtin function does not care for a
4899 print-state, it is simply ignored.
4900
4901 User written callbacks are now called with such a pair as their
4902 `port', but because every function now accepts this pair as a PORT
4903 argument, you don't have to worry about that. In fact, it is probably
4904 safest to not check for these pairs.
4905
4906 However, it is sometimes necessary to continue a print chain on a
4907 different port, for example to get a intermediate string
4908 representation of the printed value, mangle that string somehow, and
4909 then to finally print the mangled string. Use the new function
4910
4911 inherit-print-state OLD-PORT NEW-PORT
4912
4913 for this. It constructs a new `port' that prints to NEW-PORT but
4914 inherits the print-state of OLD-PORT.
4915
4916 ** struct-vtable-offset renamed to vtable-offset-user
4917
4918 ** New constants: vtable-index-layout, vtable-index-vtable, vtable-index-printer
4919
4920 ** There is now a third optional argument to make-vtable-vtable
4921 (and fourth to make-struct) when constructing new types (vtables).
4922 This argument initializes field vtable-index-printer of the vtable.
4923
4924 ** The detection of circular references has been extended to structs.
4925 That is, a structure that -- in the process of being printed -- prints
4926 itself does not lead to infinite recursion.
4927
4928 ** There is now some basic support for fluids. Please read
4929 "libguile/fluid.h" to find out more. It is accessible from Scheme with
4930 the following functions and macros:
4931
4932 Function: make-fluid
4933
4934 Create a new fluid object. Fluids are not special variables or
4935 some other extension to the semantics of Scheme, but rather
4936 ordinary Scheme objects. You can store them into variables (that
4937 are still lexically scoped, of course) or into any other place you
4938 like. Every fluid has a initial value of `#f'.
4939
4940 Function: fluid? OBJ
4941
4942 Test whether OBJ is a fluid.
4943
4944 Function: fluid-ref FLUID
4945 Function: fluid-set! FLUID VAL
4946
4947 Access/modify the fluid FLUID. Modifications are only visible
4948 within the current dynamic root (that includes threads).
4949
4950 Function: with-fluids* FLUIDS VALUES THUNK
4951
4952 FLUIDS is a list of fluids and VALUES a corresponding list of
4953 values for these fluids. Before THUNK gets called the values are
4954 installed in the fluids and the old values of the fluids are
4955 saved in the VALUES list. When the flow of control leaves THUNK
4956 or reenters it, the values get swapped again. You might think of
4957 this as a `safe-fluid-excursion'. Note that the VALUES list is
4958 modified by `with-fluids*'.
4959
4960 Macro: with-fluids ((FLUID VALUE) ...) FORM ...
4961
4962 The same as `with-fluids*' but with a different syntax. It looks
4963 just like `let', but both FLUID and VALUE are evaluated. Remember,
4964 fluids are not special variables but ordinary objects. FLUID
4965 should evaluate to a fluid.
4966
4967 ** Changes to system call interfaces:
4968
4969 *** close-port, close-input-port and close-output-port now return a
4970 boolean instead of an `unspecified' object. #t means that the port
4971 was successfully closed, while #f means it was already closed. It is
4972 also now possible for these procedures to raise an exception if an
4973 error occurs (some errors from write can be delayed until close.)
4974
4975 *** the first argument to chmod, fcntl, ftell and fseek can now be a
4976 file descriptor.
4977
4978 *** the third argument to fcntl is now optional.
4979
4980 *** the first argument to chown can now be a file descriptor or a port.
4981
4982 *** the argument to stat can now be a port.
4983
4984 *** The following new procedures have been added (most use scsh
4985 interfaces):
4986
4987 *** procedure: close PORT/FD
4988 Similar to close-port (*note close-port: Closing Ports.), but also
4989 works on file descriptors. A side effect of closing a file
4990 descriptor is that any ports using that file descriptor are moved
4991 to a different file descriptor and have their revealed counts set
4992 to zero.
4993
4994 *** procedure: port->fdes PORT
4995 Returns the integer file descriptor underlying PORT. As a side
4996 effect the revealed count of PORT is incremented.
4997
4998 *** procedure: fdes->ports FDES
4999 Returns a list of existing ports which have FDES as an underlying
5000 file descriptor, without changing their revealed counts.
5001
5002 *** procedure: fdes->inport FDES
5003 Returns an existing input port which has FDES as its underlying
5004 file descriptor, if one exists, and increments its revealed count.
5005 Otherwise, returns a new input port with a revealed count of 1.
5006
5007 *** procedure: fdes->outport FDES
5008 Returns an existing output port which has FDES as its underlying
5009 file descriptor, if one exists, and increments its revealed count.
5010 Otherwise, returns a new output port with a revealed count of 1.
5011
5012 The next group of procedures perform a `dup2' system call, if NEWFD
5013 (an integer) is supplied, otherwise a `dup'. The file descriptor to be
5014 duplicated can be supplied as an integer or contained in a port. The
5015 type of value returned varies depending on which procedure is used.
5016
5017 All procedures also have the side effect when performing `dup2' that
5018 any ports using NEWFD are moved to a different file descriptor and have
5019 their revealed counts set to zero.
5020
5021 *** procedure: dup->fdes PORT/FD [NEWFD]
5022 Returns an integer file descriptor.
5023
5024 *** procedure: dup->inport PORT/FD [NEWFD]
5025 Returns a new input port using the new file descriptor.
5026
5027 *** procedure: dup->outport PORT/FD [NEWFD]
5028 Returns a new output port using the new file descriptor.
5029
5030 *** procedure: dup PORT/FD [NEWFD]
5031 Returns a new port if PORT/FD is a port, with the same mode as the
5032 supplied port, otherwise returns an integer file descriptor.
5033
5034 *** procedure: dup->port PORT/FD MODE [NEWFD]
5035 Returns a new port using the new file descriptor. MODE supplies a
5036 mode string for the port (*note open-file: File Ports.).
5037
5038 *** procedure: setenv NAME VALUE
5039 Modifies the environment of the current process, which is also the
5040 default environment inherited by child processes.
5041
5042 If VALUE is `#f', then NAME is removed from the environment.
5043 Otherwise, the string NAME=VALUE is added to the environment,
5044 replacing any existing string with name matching NAME.
5045
5046 The return value is unspecified.
5047
5048 *** procedure: truncate-file OBJ SIZE
5049 Truncates the file referred to by OBJ to at most SIZE bytes. OBJ
5050 can be a string containing a file name or an integer file
5051 descriptor or port open for output on the file. The underlying
5052 system calls are `truncate' and `ftruncate'.
5053
5054 The return value is unspecified.
5055
5056 *** procedure: setvbuf PORT MODE [SIZE]
5057 Set the buffering mode for PORT. MODE can be:
5058 `_IONBF'
5059 non-buffered
5060
5061 `_IOLBF'
5062 line buffered
5063
5064 `_IOFBF'
5065 block buffered, using a newly allocated buffer of SIZE bytes.
5066 However if SIZE is zero or unspecified, the port will be made
5067 non-buffered.
5068
5069 This procedure should not be used after I/O has been performed with
5070 the port.
5071
5072 Ports are usually block buffered by default, with a default buffer
5073 size. Procedures e.g., *Note open-file: File Ports, which accept a
5074 mode string allow `0' to be added to request an unbuffered port.
5075
5076 *** procedure: fsync PORT/FD
5077 Copies any unwritten data for the specified output file descriptor
5078 to disk. If PORT/FD is a port, its buffer is flushed before the
5079 underlying file descriptor is fsync'd. The return value is
5080 unspecified.
5081
5082 *** procedure: open-fdes PATH FLAGS [MODES]
5083 Similar to `open' but returns a file descriptor instead of a port.
5084
5085 *** procedure: execle PATH ENV [ARG] ...
5086 Similar to `execl', but the environment of the new process is
5087 specified by ENV, which must be a list of strings as returned by
5088 the `environ' procedure.
5089
5090 This procedure is currently implemented using the `execve' system
5091 call, but we call it `execle' because of its Scheme calling
5092 interface.
5093
5094 *** procedure: strerror ERRNO
5095 Returns the Unix error message corresponding to ERRNO, an integer.
5096
5097 *** procedure: primitive-exit [STATUS]
5098 Terminate the current process without unwinding the Scheme stack.
5099 This is would typically be useful after a fork. The exit status
5100 is STATUS if supplied, otherwise zero.
5101
5102 *** procedure: times
5103 Returns an object with information about real and processor time.
5104 The following procedures accept such an object as an argument and
5105 return a selected component:
5106
5107 `tms:clock'
5108 The current real time, expressed as time units relative to an
5109 arbitrary base.
5110
5111 `tms:utime'
5112 The CPU time units used by the calling process.
5113
5114 `tms:stime'
5115 The CPU time units used by the system on behalf of the
5116 calling process.
5117
5118 `tms:cutime'
5119 The CPU time units used by terminated child processes of the
5120 calling process, whose status has been collected (e.g., using
5121 `waitpid').
5122
5123 `tms:cstime'
5124 Similarly, the CPU times units used by the system on behalf of
5125 terminated child processes.
5126
5127 ** Removed: list-length
5128 ** Removed: list-append, list-append!
5129 ** Removed: list-reverse, list-reverse!
5130
5131 ** array-map renamed to array-map!
5132
5133 ** serial-array-map renamed to serial-array-map!
5134
5135 ** catch doesn't take #f as first argument any longer
5136
5137 Previously, it was possible to pass #f instead of a key to `catch'.
5138 That would cause `catch' to pass a jump buffer object to the procedure
5139 passed as second argument. The procedure could then use this jump
5140 buffer objekt as an argument to throw.
5141
5142 This mechanism has been removed since its utility doesn't motivate the
5143 extra complexity it introduces.
5144
5145 ** The `#/' notation for lists now provokes a warning message from Guile.
5146 This syntax will be removed from Guile in the near future.
5147
5148 To disable the warning message, set the GUILE_HUSH environment
5149 variable to any non-empty value.
5150
5151 ** The newline character now prints as `#\newline', following the
5152 normal Scheme notation, not `#\nl'.
5153
5154 * Changes to the gh_ interface
5155
5156 ** The gh_enter function now takes care of loading the Guile startup files.
5157 gh_enter works by calling scm_boot_guile; see the remarks below.
5158
5159 ** Function: void gh_write (SCM x)
5160
5161 Write the printed representation of the scheme object x to the current
5162 output port. Corresponds to the scheme level `write'.
5163
5164 ** gh_list_length renamed to gh_length.
5165
5166 ** vector handling routines
5167
5168 Several major changes. In particular, gh_vector() now resembles
5169 (vector ...) (with a caveat -- see manual), and gh_make_vector() now
5170 exists and behaves like (make-vector ...). gh_vset() and gh_vref()
5171 have been renamed gh_vector_set_x() and gh_vector_ref(). Some missing
5172 vector-related gh_ functions have been implemented.
5173
5174 ** pair and list routines
5175
5176 Implemented several of the R4RS pair and list functions that were
5177 missing.
5178
5179 ** gh_scm2doubles, gh_doubles2scm, gh_doubles2dvect
5180
5181 New function. Converts double arrays back and forth between Scheme
5182 and C.
5183
5184 * Changes to the scm_ interface
5185
5186 ** The function scm_boot_guile now takes care of loading the startup files.
5187
5188 Guile's primary initialization function, scm_boot_guile, now takes
5189 care of loading `boot-9.scm', in the `ice-9' module, to initialize
5190 Guile, define the module system, and put together some standard
5191 bindings. It also loads `init.scm', which is intended to hold
5192 site-specific initialization code.
5193
5194 Since Guile cannot operate properly until boot-9.scm is loaded, there
5195 is no reason to separate loading boot-9.scm from Guile's other
5196 initialization processes.
5197
5198 This job used to be done by scm_compile_shell_switches, which didn't
5199 make much sense; in particular, it meant that people using Guile for
5200 non-shell-like applications had to jump through hoops to get Guile
5201 initialized properly.
5202
5203 ** The function scm_compile_shell_switches no longer loads the startup files.
5204 Now, Guile always loads the startup files, whenever it is initialized;
5205 see the notes above for scm_boot_guile and scm_load_startup_files.
5206
5207 ** Function: scm_load_startup_files
5208 This new function takes care of loading Guile's initialization file
5209 (`boot-9.scm'), and the site initialization file, `init.scm'. Since
5210 this is always called by the Guile initialization process, it's
5211 probably not too useful to call this yourself, but it's there anyway.
5212
5213 ** The semantics of smob marking have changed slightly.
5214
5215 The smob marking function (the `mark' member of the scm_smobfuns
5216 structure) is no longer responsible for setting the mark bit on the
5217 smob. The generic smob handling code in the garbage collector will
5218 set this bit. The mark function need only ensure that any other
5219 objects the smob refers to get marked.
5220
5221 Note that this change means that the smob's GC8MARK bit is typically
5222 already set upon entry to the mark function. Thus, marking functions
5223 which look like this:
5224
5225 {
5226 if (SCM_GC8MARKP (ptr))
5227 return SCM_BOOL_F;
5228 SCM_SETGC8MARK (ptr);
5229 ... mark objects to which the smob refers ...
5230 }
5231
5232 are now incorrect, since they will return early, and fail to mark any
5233 other objects the smob refers to. Some code in the Guile library used
5234 to work this way.
5235
5236 ** The semantics of the I/O port functions in scm_ptobfuns have changed.
5237
5238 If you have implemented your own I/O port type, by writing the
5239 functions required by the scm_ptobfuns and then calling scm_newptob,
5240 you will need to change your functions slightly.
5241
5242 The functions in a scm_ptobfuns structure now expect the port itself
5243 as their argument; they used to expect the `stream' member of the
5244 port's scm_port_table structure. This allows functions in an
5245 scm_ptobfuns structure to easily access the port's cell (and any flags
5246 it its CAR), and the port's scm_port_table structure.
5247
5248 Guile now passes the I/O port itself as the `port' argument in the
5249 following scm_ptobfuns functions:
5250
5251 int (*free) (SCM port);
5252 int (*fputc) (int, SCM port);
5253 int (*fputs) (char *, SCM port);
5254 scm_sizet (*fwrite) SCM_P ((char *ptr,
5255 scm_sizet size,
5256 scm_sizet nitems,
5257 SCM port));
5258 int (*fflush) (SCM port);
5259 int (*fgetc) (SCM port);
5260 int (*fclose) (SCM port);
5261
5262 The interfaces to the `mark', `print', `equalp', and `fgets' methods
5263 are unchanged.
5264
5265 If you have existing code which defines its own port types, it is easy
5266 to convert your code to the new interface; simply apply SCM_STREAM to
5267 the port argument to yield the value you code used to expect.
5268
5269 Note that since both the port and the stream have the same type in the
5270 C code --- they are both SCM values --- the C compiler will not remind
5271 you if you forget to update your scm_ptobfuns functions.
5272
5273
5274 ** Function: int scm_internal_select (int fds,
5275 SELECT_TYPE *rfds,
5276 SELECT_TYPE *wfds,
5277 SELECT_TYPE *efds,
5278 struct timeval *timeout);
5279
5280 This is a replacement for the `select' function provided by the OS.
5281 It enables I/O blocking and sleeping to happen for one cooperative
5282 thread without blocking other threads. It also avoids busy-loops in
5283 these situations. It is intended that all I/O blocking and sleeping
5284 will finally go through this function. Currently, this function is
5285 only available on systems providing `gettimeofday' and `select'.
5286
5287 ** Function: SCM scm_internal_stack_catch (SCM tag,
5288 scm_catch_body_t body,
5289 void *body_data,
5290 scm_catch_handler_t handler,
5291 void *handler_data)
5292
5293 A new sibling to the other two C level `catch' functions
5294 scm_internal_catch and scm_internal_lazy_catch. Use it if you want
5295 the stack to be saved automatically into the variable `the-last-stack'
5296 (scm_the_last_stack_var) on error. This is necessary if you want to
5297 use advanced error reporting, such as calling scm_display_error and
5298 scm_display_backtrace. (They both take a stack object as argument.)
5299
5300 ** Function: SCM scm_spawn_thread (scm_catch_body_t body,
5301 void *body_data,
5302 scm_catch_handler_t handler,
5303 void *handler_data)
5304
5305 Spawns a new thread. It does a job similar to
5306 scm_call_with_new_thread but takes arguments more suitable when
5307 spawning threads from application C code.
5308
5309 ** The hook scm_error_callback has been removed. It was originally
5310 intended as a way for the user to install his own error handler. But
5311 that method works badly since it intervenes between throw and catch,
5312 thereby changing the semantics of expressions like (catch #t ...).
5313 The correct way to do it is to use one of the C level catch functions
5314 in throw.c: scm_internal_catch/lazy_catch/stack_catch.
5315
5316 ** Removed functions:
5317
5318 scm_obj_length, scm_list_length, scm_list_append, scm_list_append_x,
5319 scm_list_reverse, scm_list_reverse_x
5320
5321 ** New macros: SCM_LISTn where n is one of the integers 0-9.
5322
5323 These can be used for pretty list creation from C. The idea is taken
5324 from Erick Gallesio's STk.
5325
5326 ** scm_array_map renamed to scm_array_map_x
5327
5328 ** mbstrings are now removed
5329
5330 This means that the type codes scm_tc7_mb_string and
5331 scm_tc7_mb_substring has been removed.
5332
5333 ** scm_gen_putc, scm_gen_puts, scm_gen_write, and scm_gen_getc have changed.
5334
5335 Since we no longer support multi-byte strings, these I/O functions
5336 have been simplified, and renamed. Here are their old names, and
5337 their new names and arguments:
5338
5339 scm_gen_putc -> void scm_putc (int c, SCM port);
5340 scm_gen_puts -> void scm_puts (char *s, SCM port);
5341 scm_gen_write -> void scm_lfwrite (char *ptr, scm_sizet size, SCM port);
5342 scm_gen_getc -> void scm_getc (SCM port);
5343
5344
5345 ** The macros SCM_TYP7D and SCM_TYP7SD has been removed.
5346
5347 ** The macro SCM_TYP7S has taken the role of the old SCM_TYP7D
5348
5349 SCM_TYP7S now masks away the bit which distinguishes substrings from
5350 strings.
5351
5352 ** scm_catch_body_t: Backward incompatible change!
5353
5354 Body functions to scm_internal_catch and friends do not any longer
5355 take a second argument. This is because it is no longer possible to
5356 pass a #f arg to catch.
5357
5358 ** Calls to scm_protect_object and scm_unprotect now nest properly.
5359
5360 The function scm_protect_object protects its argument from being freed
5361 by the garbage collector. scm_unprotect_object removes that
5362 protection.
5363
5364 These functions now nest properly. That is, for every object O, there
5365 is a counter which scm_protect_object(O) increments and
5366 scm_unprotect_object(O) decrements, if the counter is greater than
5367 zero. Every object's counter is zero when it is first created. If an
5368 object's counter is greater than zero, the garbage collector will not
5369 reclaim its storage.
5370
5371 This allows you to use scm_protect_object in your code without
5372 worrying that some other function you call will call
5373 scm_unprotect_object, and allow it to be freed. Assuming that the
5374 functions you call are well-behaved, and unprotect only those objects
5375 they protect, you can follow the same rule and have confidence that
5376 objects will be freed only at appropriate times.
5377
5378 \f
5379 Changes in Guile 1.2 (released Tuesday, June 24 1997):
5380
5381 * Changes to the distribution
5382
5383 ** Nightly snapshots are now available from ftp.red-bean.com.
5384 The old server, ftp.cyclic.com, has been relinquished to its rightful
5385 owner.
5386
5387 Nightly snapshots of the Guile development sources are now available via
5388 anonymous FTP from ftp.red-bean.com, as /pub/guile/guile-snap.tar.gz.
5389
5390 Via the web, that's: ftp://ftp.red-bean.com/pub/guile/guile-snap.tar.gz
5391 For getit, that's: ftp.red-bean.com:/pub/guile/guile-snap.tar.gz
5392
5393 ** To run Guile without installing it, the procedure has changed a bit.
5394
5395 If you used a separate build directory to compile Guile, you'll need
5396 to include the build directory in SCHEME_LOAD_PATH, as well as the
5397 source directory. See the `INSTALL' file for examples.
5398
5399 * Changes to the procedure for linking libguile with your programs
5400
5401 ** The standard Guile load path for Scheme code now includes
5402 $(datadir)/guile (usually /usr/local/share/guile). This means that
5403 you can install your own Scheme files there, and Guile will find them.
5404 (Previous versions of Guile only checked a directory whose name
5405 contained the Guile version number, so you had to re-install or move
5406 your Scheme sources each time you installed a fresh version of Guile.)
5407
5408 The load path also includes $(datadir)/guile/site; we recommend
5409 putting individual Scheme files there. If you want to install a
5410 package with multiple source files, create a directory for them under
5411 $(datadir)/guile.
5412
5413 ** Guile 1.2 will now use the Rx regular expression library, if it is
5414 installed on your system. When you are linking libguile into your own
5415 programs, this means you will have to link against -lguile, -lqt (if
5416 you configured Guile with thread support), and -lrx.
5417
5418 If you are using autoconf to generate configuration scripts for your
5419 application, the following lines should suffice to add the appropriate
5420 libraries to your link command:
5421
5422 ### Find Rx, quickthreads and libguile.
5423 AC_CHECK_LIB(rx, main)
5424 AC_CHECK_LIB(qt, main)
5425 AC_CHECK_LIB(guile, scm_shell)
5426
5427 The Guile 1.2 distribution does not contain sources for the Rx
5428 library, as Guile 1.0 did. If you want to use Rx, you'll need to
5429 retrieve it from a GNU FTP site and install it separately.
5430
5431 * Changes to Scheme functions and syntax
5432
5433 ** The dynamic linking features of Guile are now enabled by default.
5434 You can disable them by giving the `--disable-dynamic-linking' option
5435 to configure.
5436
5437 (dynamic-link FILENAME)
5438
5439 Find the object file denoted by FILENAME (a string) and link it
5440 into the running Guile application. When everything works out,
5441 return a Scheme object suitable for representing the linked object
5442 file. Otherwise an error is thrown. How object files are
5443 searched is system dependent.
5444
5445 (dynamic-object? VAL)
5446
5447 Determine whether VAL represents a dynamically linked object file.
5448
5449 (dynamic-unlink DYNOBJ)
5450
5451 Unlink the indicated object file from the application. DYNOBJ
5452 should be one of the values returned by `dynamic-link'.
5453
5454 (dynamic-func FUNCTION DYNOBJ)
5455
5456 Search the C function indicated by FUNCTION (a string or symbol)
5457 in DYNOBJ and return some Scheme object that can later be used
5458 with `dynamic-call' to actually call this function. Right now,
5459 these Scheme objects are formed by casting the address of the
5460 function to `long' and converting this number to its Scheme
5461 representation.
5462
5463 (dynamic-call FUNCTION DYNOBJ)
5464
5465 Call the C function indicated by FUNCTION and DYNOBJ. The
5466 function is passed no arguments and its return value is ignored.
5467 When FUNCTION is something returned by `dynamic-func', call that
5468 function and ignore DYNOBJ. When FUNCTION is a string (or symbol,
5469 etc.), look it up in DYNOBJ; this is equivalent to
5470
5471 (dynamic-call (dynamic-func FUNCTION DYNOBJ) #f)
5472
5473 Interrupts are deferred while the C function is executing (with
5474 SCM_DEFER_INTS/SCM_ALLOW_INTS).
5475
5476 (dynamic-args-call FUNCTION DYNOBJ ARGS)
5477
5478 Call the C function indicated by FUNCTION and DYNOBJ, but pass it
5479 some arguments and return its return value. The C function is
5480 expected to take two arguments and return an `int', just like
5481 `main':
5482
5483 int c_func (int argc, char **argv);
5484
5485 ARGS must be a list of strings and is converted into an array of
5486 `char *'. The array is passed in ARGV and its size in ARGC. The
5487 return value is converted to a Scheme number and returned from the
5488 call to `dynamic-args-call'.
5489
5490 When dynamic linking is disabled or not supported on your system,
5491 the above functions throw errors, but they are still available.
5492
5493 Here is a small example that works on GNU/Linux:
5494
5495 (define libc-obj (dynamic-link "libc.so"))
5496 (dynamic-args-call 'rand libc-obj '())
5497
5498 See the file `libguile/DYNAMIC-LINKING' for additional comments.
5499
5500 ** The #/ syntax for module names is depreciated, and will be removed
5501 in a future version of Guile. Instead of
5502
5503 #/foo/bar/baz
5504
5505 instead write
5506
5507 (foo bar baz)
5508
5509 The latter syntax is more consistent with existing Lisp practice.
5510
5511 ** Guile now does fancier printing of structures. Structures are the
5512 underlying implementation for records, which in turn are used to
5513 implement modules, so all of these object now print differently and in
5514 a more informative way.
5515
5516 The Scheme printer will examine the builtin variable *struct-printer*
5517 whenever it needs to print a structure object. When this variable is
5518 not `#f' it is deemed to be a procedure and will be applied to the
5519 structure object and the output port. When *struct-printer* is `#f'
5520 or the procedure return `#f' the structure object will be printed in
5521 the boring #<struct 80458270> form.
5522
5523 This hook is used by some routines in ice-9/boot-9.scm to implement
5524 type specific printing routines. Please read the comments there about
5525 "printing structs".
5526
5527 One of the more specific uses of structs are records. The printing
5528 procedure that could be passed to MAKE-RECORD-TYPE is now actually
5529 called. It should behave like a *struct-printer* procedure (described
5530 above).
5531
5532 ** Guile now supports a new R4RS-compliant syntax for keywords. A
5533 token of the form #:NAME, where NAME has the same syntax as a Scheme
5534 symbol, is the external representation of the keyword named NAME.
5535 Keyword objects print using this syntax as well, so values containing
5536 keyword objects can be read back into Guile. When used in an
5537 expression, keywords are self-quoting objects.
5538
5539 Guile suports this read syntax, and uses this print syntax, regardless
5540 of the current setting of the `keyword' read option. The `keyword'
5541 read option only controls whether Guile recognizes the `:NAME' syntax,
5542 which is incompatible with R4RS. (R4RS says such token represent
5543 symbols.)
5544
5545 ** Guile has regular expression support again. Guile 1.0 included
5546 functions for matching regular expressions, based on the Rx library.
5547 In Guile 1.1, the Guile/Rx interface was removed to simplify the
5548 distribution, and thus Guile had no regular expression support. Guile
5549 1.2 again supports the most commonly used functions, and supports all
5550 of SCSH's regular expression functions.
5551
5552 If your system does not include a POSIX regular expression library,
5553 and you have not linked Guile with a third-party regexp library such as
5554 Rx, these functions will not be available. You can tell whether your
5555 Guile installation includes regular expression support by checking
5556 whether the `*features*' list includes the `regex' symbol.
5557
5558 *** regexp functions
5559
5560 By default, Guile supports POSIX extended regular expressions. That
5561 means that the characters `(', `)', `+' and `?' are special, and must
5562 be escaped if you wish to match the literal characters.
5563
5564 This regular expression interface was modeled after that implemented
5565 by SCSH, the Scheme Shell. It is intended to be upwardly compatible
5566 with SCSH regular expressions.
5567
5568 **** Function: string-match PATTERN STR [START]
5569 Compile the string PATTERN into a regular expression and compare
5570 it with STR. The optional numeric argument START specifies the
5571 position of STR at which to begin matching.
5572
5573 `string-match' returns a "match structure" which describes what,
5574 if anything, was matched by the regular expression. *Note Match
5575 Structures::. If STR does not match PATTERN at all,
5576 `string-match' returns `#f'.
5577
5578 Each time `string-match' is called, it must compile its PATTERN
5579 argument into a regular expression structure. This operation is
5580 expensive, which makes `string-match' inefficient if the same regular
5581 expression is used several times (for example, in a loop). For better
5582 performance, you can compile a regular expression in advance and then
5583 match strings against the compiled regexp.
5584
5585 **** Function: make-regexp STR [FLAGS]
5586 Compile the regular expression described by STR, and return the
5587 compiled regexp structure. If STR does not describe a legal
5588 regular expression, `make-regexp' throws a
5589 `regular-expression-syntax' error.
5590
5591 FLAGS may be the bitwise-or of one or more of the following:
5592
5593 **** Constant: regexp/extended
5594 Use POSIX Extended Regular Expression syntax when interpreting
5595 STR. If not set, POSIX Basic Regular Expression syntax is used.
5596 If the FLAGS argument is omitted, we assume regexp/extended.
5597
5598 **** Constant: regexp/icase
5599 Do not differentiate case. Subsequent searches using the
5600 returned regular expression will be case insensitive.
5601
5602 **** Constant: regexp/newline
5603 Match-any-character operators don't match a newline.
5604
5605 A non-matching list ([^...]) not containing a newline matches a
5606 newline.
5607
5608 Match-beginning-of-line operator (^) matches the empty string
5609 immediately after a newline, regardless of whether the FLAGS
5610 passed to regexp-exec contain regexp/notbol.
5611
5612 Match-end-of-line operator ($) matches the empty string
5613 immediately before a newline, regardless of whether the FLAGS
5614 passed to regexp-exec contain regexp/noteol.
5615
5616 **** Function: regexp-exec REGEXP STR [START [FLAGS]]
5617 Match the compiled regular expression REGEXP against `str'. If
5618 the optional integer START argument is provided, begin matching
5619 from that position in the string. Return a match structure
5620 describing the results of the match, or `#f' if no match could be
5621 found.
5622
5623 FLAGS may be the bitwise-or of one or more of the following:
5624
5625 **** Constant: regexp/notbol
5626 The match-beginning-of-line operator always fails to match (but
5627 see the compilation flag regexp/newline above) This flag may be
5628 used when different portions of a string are passed to
5629 regexp-exec and the beginning of the string should not be
5630 interpreted as the beginning of the line.
5631
5632 **** Constant: regexp/noteol
5633 The match-end-of-line operator always fails to match (but see the
5634 compilation flag regexp/newline above)
5635
5636 **** Function: regexp? OBJ
5637 Return `#t' if OBJ is a compiled regular expression, or `#f'
5638 otherwise.
5639
5640 Regular expressions are commonly used to find patterns in one string
5641 and replace them with the contents of another string.
5642
5643 **** Function: regexp-substitute PORT MATCH [ITEM...]
5644 Write to the output port PORT selected contents of the match
5645 structure MATCH. Each ITEM specifies what should be written, and
5646 may be one of the following arguments:
5647
5648 * A string. String arguments are written out verbatim.
5649
5650 * An integer. The submatch with that number is written.
5651
5652 * The symbol `pre'. The portion of the matched string preceding
5653 the regexp match is written.
5654
5655 * The symbol `post'. The portion of the matched string
5656 following the regexp match is written.
5657
5658 PORT may be `#f', in which case nothing is written; instead,
5659 `regexp-substitute' constructs a string from the specified ITEMs
5660 and returns that.
5661
5662 **** Function: regexp-substitute/global PORT REGEXP TARGET [ITEM...]
5663 Similar to `regexp-substitute', but can be used to perform global
5664 substitutions on STR. Instead of taking a match structure as an
5665 argument, `regexp-substitute/global' takes two string arguments: a
5666 REGEXP string describing a regular expression, and a TARGET string
5667 which should be matched against this regular expression.
5668
5669 Each ITEM behaves as in REGEXP-SUBSTITUTE, with the following
5670 exceptions:
5671
5672 * A function may be supplied. When this function is called, it
5673 will be passed one argument: a match structure for a given
5674 regular expression match. It should return a string to be
5675 written out to PORT.
5676
5677 * The `post' symbol causes `regexp-substitute/global' to recurse
5678 on the unmatched portion of STR. This *must* be supplied in
5679 order to perform global search-and-replace on STR; if it is
5680 not present among the ITEMs, then `regexp-substitute/global'
5681 will return after processing a single match.
5682
5683 *** Match Structures
5684
5685 A "match structure" is the object returned by `string-match' and
5686 `regexp-exec'. It describes which portion of a string, if any, matched
5687 the given regular expression. Match structures include: a reference to
5688 the string that was checked for matches; the starting and ending
5689 positions of the regexp match; and, if the regexp included any
5690 parenthesized subexpressions, the starting and ending positions of each
5691 submatch.
5692
5693 In each of the regexp match functions described below, the `match'
5694 argument must be a match structure returned by a previous call to
5695 `string-match' or `regexp-exec'. Most of these functions return some
5696 information about the original target string that was matched against a
5697 regular expression; we will call that string TARGET for easy reference.
5698
5699 **** Function: regexp-match? OBJ
5700 Return `#t' if OBJ is a match structure returned by a previous
5701 call to `regexp-exec', or `#f' otherwise.
5702
5703 **** Function: match:substring MATCH [N]
5704 Return the portion of TARGET matched by subexpression number N.
5705 Submatch 0 (the default) represents the entire regexp match. If
5706 the regular expression as a whole matched, but the subexpression
5707 number N did not match, return `#f'.
5708
5709 **** Function: match:start MATCH [N]
5710 Return the starting position of submatch number N.
5711
5712 **** Function: match:end MATCH [N]
5713 Return the ending position of submatch number N.
5714
5715 **** Function: match:prefix MATCH
5716 Return the unmatched portion of TARGET preceding the regexp match.
5717
5718 **** Function: match:suffix MATCH
5719 Return the unmatched portion of TARGET following the regexp match.
5720
5721 **** Function: match:count MATCH
5722 Return the number of parenthesized subexpressions from MATCH.
5723 Note that the entire regular expression match itself counts as a
5724 subexpression, and failed submatches are included in the count.
5725
5726 **** Function: match:string MATCH
5727 Return the original TARGET string.
5728
5729 *** Backslash Escapes
5730
5731 Sometimes you will want a regexp to match characters like `*' or `$'
5732 exactly. For example, to check whether a particular string represents
5733 a menu entry from an Info node, it would be useful to match it against
5734 a regexp like `^* [^:]*::'. However, this won't work; because the
5735 asterisk is a metacharacter, it won't match the `*' at the beginning of
5736 the string. In this case, we want to make the first asterisk un-magic.
5737
5738 You can do this by preceding the metacharacter with a backslash
5739 character `\'. (This is also called "quoting" the metacharacter, and
5740 is known as a "backslash escape".) When Guile sees a backslash in a
5741 regular expression, it considers the following glyph to be an ordinary
5742 character, no matter what special meaning it would ordinarily have.
5743 Therefore, we can make the above example work by changing the regexp to
5744 `^\* [^:]*::'. The `\*' sequence tells the regular expression engine
5745 to match only a single asterisk in the target string.
5746
5747 Since the backslash is itself a metacharacter, you may force a
5748 regexp to match a backslash in the target string by preceding the
5749 backslash with itself. For example, to find variable references in a
5750 TeX program, you might want to find occurrences of the string `\let\'
5751 followed by any number of alphabetic characters. The regular expression
5752 `\\let\\[A-Za-z]*' would do this: the double backslashes in the regexp
5753 each match a single backslash in the target string.
5754
5755 **** Function: regexp-quote STR
5756 Quote each special character found in STR with a backslash, and
5757 return the resulting string.
5758
5759 *Very important:* Using backslash escapes in Guile source code (as
5760 in Emacs Lisp or C) can be tricky, because the backslash character has
5761 special meaning for the Guile reader. For example, if Guile encounters
5762 the character sequence `\n' in the middle of a string while processing
5763 Scheme code, it replaces those characters with a newline character.
5764 Similarly, the character sequence `\t' is replaced by a horizontal tab.
5765 Several of these "escape sequences" are processed by the Guile reader
5766 before your code is executed. Unrecognized escape sequences are
5767 ignored: if the characters `\*' appear in a string, they will be
5768 translated to the single character `*'.
5769
5770 This translation is obviously undesirable for regular expressions,
5771 since we want to be able to include backslashes in a string in order to
5772 escape regexp metacharacters. Therefore, to make sure that a backslash
5773 is preserved in a string in your Guile program, you must use *two*
5774 consecutive backslashes:
5775
5776 (define Info-menu-entry-pattern (make-regexp "^\\* [^:]*"))
5777
5778 The string in this example is preprocessed by the Guile reader before
5779 any code is executed. The resulting argument to `make-regexp' is the
5780 string `^\* [^:]*', which is what we really want.
5781
5782 This also means that in order to write a regular expression that
5783 matches a single backslash character, the regular expression string in
5784 the source code must include *four* backslashes. Each consecutive pair
5785 of backslashes gets translated by the Guile reader to a single
5786 backslash, and the resulting double-backslash is interpreted by the
5787 regexp engine as matching a single backslash character. Hence:
5788
5789 (define tex-variable-pattern (make-regexp "\\\\let\\\\=[A-Za-z]*"))
5790
5791 The reason for the unwieldiness of this syntax is historical. Both
5792 regular expression pattern matchers and Unix string processing systems
5793 have traditionally used backslashes with the special meanings described
5794 above. The POSIX regular expression specification and ANSI C standard
5795 both require these semantics. Attempting to abandon either convention
5796 would cause other kinds of compatibility problems, possibly more severe
5797 ones. Therefore, without extending the Scheme reader to support
5798 strings with different quoting conventions (an ungainly and confusing
5799 extension when implemented in other languages), we must adhere to this
5800 cumbersome escape syntax.
5801
5802 * Changes to the gh_ interface
5803
5804 * Changes to the scm_ interface
5805
5806 * Changes to system call interfaces:
5807
5808 ** The value returned by `raise' is now unspecified. It throws an exception
5809 if an error occurs.
5810
5811 *** A new procedure `sigaction' can be used to install signal handlers
5812
5813 (sigaction signum [action] [flags])
5814
5815 signum is the signal number, which can be specified using the value
5816 of SIGINT etc.
5817
5818 If action is omitted, sigaction returns a pair: the CAR is the current
5819 signal hander, which will be either an integer with the value SIG_DFL
5820 (default action) or SIG_IGN (ignore), or the Scheme procedure which
5821 handles the signal, or #f if a non-Scheme procedure handles the
5822 signal. The CDR contains the current sigaction flags for the handler.
5823
5824 If action is provided, it is installed as the new handler for signum.
5825 action can be a Scheme procedure taking one argument, or the value of
5826 SIG_DFL (default action) or SIG_IGN (ignore), or #f to restore
5827 whatever signal handler was installed before sigaction was first used.
5828 Flags can optionally be specified for the new handler (SA_RESTART is
5829 always used if the system provides it, so need not be specified.) The
5830 return value is a pair with information about the old handler as
5831 described above.
5832
5833 This interface does not provide access to the "signal blocking"
5834 facility. Maybe this is not needed, since the thread support may
5835 provide solutions to the problem of consistent access to data
5836 structures.
5837
5838 *** A new procedure `flush-all-ports' is equivalent to running
5839 `force-output' on every port open for output.
5840
5841 ** Guile now provides information on how it was built, via the new
5842 global variable, %guile-build-info. This variable records the values
5843 of the standard GNU makefile directory variables as an assocation
5844 list, mapping variable names (symbols) onto directory paths (strings).
5845 For example, to find out where the Guile link libraries were
5846 installed, you can say:
5847
5848 guile -c "(display (assq-ref %guile-build-info 'libdir)) (newline)"
5849
5850
5851 * Changes to the scm_ interface
5852
5853 ** The new function scm_handle_by_message_noexit is just like the
5854 existing scm_handle_by_message function, except that it doesn't call
5855 exit to terminate the process. Instead, it prints a message and just
5856 returns #f. This might be a more appropriate catch-all handler for
5857 new dynamic roots and threads.
5858
5859 \f
5860 Changes in Guile 1.1 (released Friday, May 16 1997):
5861
5862 * Changes to the distribution.
5863
5864 The Guile 1.0 distribution has been split up into several smaller
5865 pieces:
5866 guile-core --- the Guile interpreter itself.
5867 guile-tcltk --- the interface between the Guile interpreter and
5868 Tcl/Tk; Tcl is an interpreter for a stringy language, and Tk
5869 is a toolkit for building graphical user interfaces.
5870 guile-rgx-ctax --- the interface between Guile and the Rx regular
5871 expression matcher, and the translator for the Ctax
5872 programming language. These are packaged together because the
5873 Ctax translator uses Rx to parse Ctax source code.
5874
5875 This NEWS file describes the changes made to guile-core since the 1.0
5876 release.
5877
5878 We no longer distribute the documentation, since it was either out of
5879 date, or incomplete. As soon as we have current documentation, we
5880 will distribute it.
5881
5882
5883
5884 * Changes to the stand-alone interpreter
5885
5886 ** guile now accepts command-line arguments compatible with SCSH, Olin
5887 Shivers' Scheme Shell.
5888
5889 In general, arguments are evaluated from left to right, but there are
5890 exceptions. The following switches stop argument processing, and
5891 stash all remaining command-line arguments as the value returned by
5892 the (command-line) function.
5893 -s SCRIPT load Scheme source code from FILE, and exit
5894 -c EXPR evalute Scheme expression EXPR, and exit
5895 -- stop scanning arguments; run interactively
5896
5897 The switches below are processed as they are encountered.
5898 -l FILE load Scheme source code from FILE
5899 -e FUNCTION after reading script, apply FUNCTION to
5900 command line arguments
5901 -ds do -s script at this point
5902 --emacs enable Emacs protocol (experimental)
5903 -h, --help display this help and exit
5904 -v, --version display version information and exit
5905 \ read arguments from following script lines
5906
5907 So, for example, here is a Guile script named `ekko' (thanks, Olin)
5908 which re-implements the traditional "echo" command:
5909
5910 #!/usr/local/bin/guile -s
5911 !#
5912 (define (main args)
5913 (map (lambda (arg) (display arg) (display " "))
5914 (cdr args))
5915 (newline))
5916
5917 (main (command-line))
5918
5919 Suppose we invoke this script as follows:
5920
5921 ekko a speckled gecko
5922
5923 Through the magic of Unix script processing (triggered by the `#!'
5924 token at the top of the file), /usr/local/bin/guile receives the
5925 following list of command-line arguments:
5926
5927 ("-s" "./ekko" "a" "speckled" "gecko")
5928
5929 Unix inserts the name of the script after the argument specified on
5930 the first line of the file (in this case, "-s"), and then follows that
5931 with the arguments given to the script. Guile loads the script, which
5932 defines the `main' function, and then applies it to the list of
5933 remaining command-line arguments, ("a" "speckled" "gecko").
5934
5935 In Unix, the first line of a script file must take the following form:
5936
5937 #!INTERPRETER ARGUMENT
5938
5939 where INTERPRETER is the absolute filename of the interpreter
5940 executable, and ARGUMENT is a single command-line argument to pass to
5941 the interpreter.
5942
5943 You may only pass one argument to the interpreter, and its length is
5944 limited. These restrictions can be annoying to work around, so Guile
5945 provides a general mechanism (borrowed from, and compatible with,
5946 SCSH) for circumventing them.
5947
5948 If the ARGUMENT in a Guile script is a single backslash character,
5949 `\', Guile will open the script file, parse arguments from its second
5950 and subsequent lines, and replace the `\' with them. So, for example,
5951 here is another implementation of the `ekko' script:
5952
5953 #!/usr/local/bin/guile \
5954 -e main -s
5955 !#
5956 (define (main args)
5957 (for-each (lambda (arg) (display arg) (display " "))
5958 (cdr args))
5959 (newline))
5960
5961 If the user invokes this script as follows:
5962
5963 ekko a speckled gecko
5964
5965 Unix expands this into
5966
5967 /usr/local/bin/guile \ ekko a speckled gecko
5968
5969 When Guile sees the `\' argument, it replaces it with the arguments
5970 read from the second line of the script, producing:
5971
5972 /usr/local/bin/guile -e main -s ekko a speckled gecko
5973
5974 This tells Guile to load the `ekko' script, and apply the function
5975 `main' to the argument list ("a" "speckled" "gecko").
5976
5977 Here is how Guile parses the command-line arguments:
5978 - Each space character terminates an argument. This means that two
5979 spaces in a row introduce an empty-string argument.
5980 - The tab character is not permitted (unless you quote it with the
5981 backslash character, as described below), to avoid confusion.
5982 - The newline character terminates the sequence of arguments, and will
5983 also terminate a final non-empty argument. (However, a newline
5984 following a space will not introduce a final empty-string argument;
5985 it only terminates the argument list.)
5986 - The backslash character is the escape character. It escapes
5987 backslash, space, tab, and newline. The ANSI C escape sequences
5988 like \n and \t are also supported. These produce argument
5989 constituents; the two-character combination \n doesn't act like a
5990 terminating newline. The escape sequence \NNN for exactly three
5991 octal digits reads as the character whose ASCII code is NNN. As
5992 above, characters produced this way are argument constituents.
5993 Backslash followed by other characters is not allowed.
5994
5995 * Changes to the procedure for linking libguile with your programs
5996
5997 ** Guile now builds and installs a shared guile library, if your
5998 system support shared libraries. (It still builds a static library on
5999 all systems.) Guile automatically detects whether your system
6000 supports shared libraries. To prevent Guile from buildisg shared
6001 libraries, pass the `--disable-shared' flag to the configure script.
6002
6003 Guile takes longer to compile when it builds shared libraries, because
6004 it must compile every file twice --- once to produce position-
6005 independent object code, and once to produce normal object code.
6006
6007 ** The libthreads library has been merged into libguile.
6008
6009 To link a program against Guile, you now need only link against
6010 -lguile and -lqt; -lthreads is no longer needed. If you are using
6011 autoconf to generate configuration scripts for your application, the
6012 following lines should suffice to add the appropriate libraries to
6013 your link command:
6014
6015 ### Find quickthreads and libguile.
6016 AC_CHECK_LIB(qt, main)
6017 AC_CHECK_LIB(guile, scm_shell)
6018
6019 * Changes to Scheme functions
6020
6021 ** Guile Scheme's special syntax for keyword objects is now optional,
6022 and disabled by default.
6023
6024 The syntax variation from R4RS made it difficult to port some
6025 interesting packages to Guile. The routines which accepted keyword
6026 arguments (mostly in the module system) have been modified to also
6027 accept symbols whose names begin with `:'.
6028
6029 To change the keyword syntax, you must first import the (ice-9 debug)
6030 module:
6031 (use-modules (ice-9 debug))
6032
6033 Then you can enable the keyword syntax as follows:
6034 (read-set! keywords 'prefix)
6035
6036 To disable keyword syntax, do this:
6037 (read-set! keywords #f)
6038
6039 ** Many more primitive functions accept shared substrings as
6040 arguments. In the past, these functions required normal, mutable
6041 strings as arguments, although they never made use of this
6042 restriction.
6043
6044 ** The uniform array functions now operate on byte vectors. These
6045 functions are `array-fill!', `serial-array-copy!', `array-copy!',
6046 `serial-array-map', `array-map', `array-for-each', and
6047 `array-index-map!'.
6048
6049 ** The new functions `trace' and `untrace' implement simple debugging
6050 support for Scheme functions.
6051
6052 The `trace' function accepts any number of procedures as arguments,
6053 and tells the Guile interpreter to display each procedure's name and
6054 arguments each time the procedure is invoked. When invoked with no
6055 arguments, `trace' returns the list of procedures currently being
6056 traced.
6057
6058 The `untrace' function accepts any number of procedures as arguments,
6059 and tells the Guile interpreter not to trace them any more. When
6060 invoked with no arguments, `untrace' untraces all curretly traced
6061 procedures.
6062
6063 The tracing in Guile has an advantage over most other systems: we
6064 don't create new procedure objects, but mark the procedure objects
6065 themselves. This means that anonymous and internal procedures can be
6066 traced.
6067
6068 ** The function `assert-repl-prompt' has been renamed to
6069 `set-repl-prompt!'. It takes one argument, PROMPT.
6070 - If PROMPT is #f, the Guile read-eval-print loop will not prompt.
6071 - If PROMPT is a string, we use it as a prompt.
6072 - If PROMPT is a procedure accepting no arguments, we call it, and
6073 display the result as a prompt.
6074 - Otherwise, we display "> ".
6075
6076 ** The new function `eval-string' reads Scheme expressions from a
6077 string and evaluates them, returning the value of the last expression
6078 in the string. If the string contains no expressions, it returns an
6079 unspecified value.
6080
6081 ** The new function `thunk?' returns true iff its argument is a
6082 procedure of zero arguments.
6083
6084 ** `defined?' is now a builtin function, instead of syntax. This
6085 means that its argument should be quoted. It returns #t iff its
6086 argument is bound in the current module.
6087
6088 ** The new syntax `use-modules' allows you to add new modules to your
6089 environment without re-typing a complete `define-module' form. It
6090 accepts any number of module names as arguments, and imports their
6091 public bindings into the current module.
6092
6093 ** The new function (module-defined? NAME MODULE) returns true iff
6094 NAME, a symbol, is defined in MODULE, a module object.
6095
6096 ** The new function `builtin-bindings' creates and returns a hash
6097 table containing copies of all the root module's bindings.
6098
6099 ** The new function `builtin-weak-bindings' does the same as
6100 `builtin-bindings', but creates a doubly-weak hash table.
6101
6102 ** The `equal?' function now considers variable objects to be
6103 equivalent if they have the same name and the same value.
6104
6105 ** The new function `command-line' returns the command-line arguments
6106 given to Guile, as a list of strings.
6107
6108 When using guile as a script interpreter, `command-line' returns the
6109 script's arguments; those processed by the interpreter (like `-s' or
6110 `-c') are omitted. (In other words, you get the normal, expected
6111 behavior.) Any application that uses scm_shell to process its
6112 command-line arguments gets this behavior as well.
6113
6114 ** The new function `load-user-init' looks for a file called `.guile'
6115 in the user's home directory, and loads it if it exists. This is
6116 mostly for use by the code generated by scm_compile_shell_switches,
6117 but we thought it might also be useful in other circumstances.
6118
6119 ** The new function `log10' returns the base-10 logarithm of its
6120 argument.
6121
6122 ** Changes to I/O functions
6123
6124 *** The functions `read', `primitive-load', `read-and-eval!', and
6125 `primitive-load-path' no longer take optional arguments controlling
6126 case insensitivity and a `#' parser.
6127
6128 Case sensitivity is now controlled by a read option called
6129 `case-insensitive'. The user can add new `#' syntaxes with the
6130 `read-hash-extend' function (see below).
6131
6132 *** The new function `read-hash-extend' allows the user to change the
6133 syntax of Guile Scheme in a somewhat controlled way.
6134
6135 (read-hash-extend CHAR PROC)
6136 When parsing S-expressions, if we read a `#' character followed by
6137 the character CHAR, use PROC to parse an object from the stream.
6138 If PROC is #f, remove any parsing procedure registered for CHAR.
6139
6140 The reader applies PROC to two arguments: CHAR and an input port.
6141
6142 *** The new functions read-delimited and read-delimited! provide a
6143 general mechanism for doing delimited input on streams.
6144
6145 (read-delimited DELIMS [PORT HANDLE-DELIM])
6146 Read until we encounter one of the characters in DELIMS (a string),
6147 or end-of-file. PORT is the input port to read from; it defaults to
6148 the current input port. The HANDLE-DELIM parameter determines how
6149 the terminating character is handled; it should be one of the
6150 following symbols:
6151
6152 'trim omit delimiter from result
6153 'peek leave delimiter character in input stream
6154 'concat append delimiter character to returned value
6155 'split return a pair: (RESULT . TERMINATOR)
6156
6157 HANDLE-DELIM defaults to 'peek.
6158
6159 (read-delimited! DELIMS BUF [PORT HANDLE-DELIM START END])
6160 A side-effecting variant of `read-delimited'.
6161
6162 The data is written into the string BUF at the indices in the
6163 half-open interval [START, END); the default interval is the whole
6164 string: START = 0 and END = (string-length BUF). The values of
6165 START and END must specify a well-defined interval in BUF, i.e.
6166 0 <= START <= END <= (string-length BUF).
6167
6168 It returns NBYTES, the number of bytes read. If the buffer filled
6169 up without a delimiter character being found, it returns #f. If the
6170 port is at EOF when the read starts, it returns the EOF object.
6171
6172 If an integer is returned (i.e., the read is successfully terminated
6173 by reading a delimiter character), then the HANDLE-DELIM parameter
6174 determines how to handle the terminating character. It is described
6175 above, and defaults to 'peek.
6176
6177 (The descriptions of these functions were borrowed from the SCSH
6178 manual, by Olin Shivers and Brian Carlstrom.)
6179
6180 *** The `%read-delimited!' function is the primitive used to implement
6181 `read-delimited' and `read-delimited!'.
6182
6183 (%read-delimited! DELIMS BUF GOBBLE? [PORT START END])
6184
6185 This returns a pair of values: (TERMINATOR . NUM-READ).
6186 - TERMINATOR describes why the read was terminated. If it is a
6187 character or the eof object, then that is the value that terminated
6188 the read. If it is #f, the function filled the buffer without finding
6189 a delimiting character.
6190 - NUM-READ is the number of characters read into BUF.
6191
6192 If the read is successfully terminated by reading a delimiter
6193 character, then the gobble? parameter determines what to do with the
6194 terminating character. If true, the character is removed from the
6195 input stream; if false, the character is left in the input stream
6196 where a subsequent read operation will retrieve it. In either case,
6197 the character is also the first value returned by the procedure call.
6198
6199 (The descriptions of this function was borrowed from the SCSH manual,
6200 by Olin Shivers and Brian Carlstrom.)
6201
6202 *** The `read-line' and `read-line!' functions have changed; they now
6203 trim the terminator by default; previously they appended it to the
6204 returned string. For the old behavior, use (read-line PORT 'concat).
6205
6206 *** The functions `uniform-array-read!' and `uniform-array-write!' now
6207 take new optional START and END arguments, specifying the region of
6208 the array to read and write.
6209
6210 *** The `ungetc-char-ready?' function has been removed. We feel it's
6211 inappropriate for an interface to expose implementation details this
6212 way.
6213
6214 ** Changes to the Unix library and system call interface
6215
6216 *** The new fcntl function provides access to the Unix `fcntl' system
6217 call.
6218
6219 (fcntl PORT COMMAND VALUE)
6220 Apply COMMAND to PORT's file descriptor, with VALUE as an argument.
6221 Values for COMMAND are:
6222
6223 F_DUPFD duplicate a file descriptor
6224 F_GETFD read the descriptor's close-on-exec flag
6225 F_SETFD set the descriptor's close-on-exec flag to VALUE
6226 F_GETFL read the descriptor's flags, as set on open
6227 F_SETFL set the descriptor's flags, as set on open to VALUE
6228 F_GETOWN return the process ID of a socket's owner, for SIGIO
6229 F_SETOWN set the process that owns a socket to VALUE, for SIGIO
6230 FD_CLOEXEC not sure what this is
6231
6232 For details, see the documentation for the fcntl system call.
6233
6234 *** The arguments to `select' have changed, for compatibility with
6235 SCSH. The TIMEOUT parameter may now be non-integral, yielding the
6236 expected behavior. The MILLISECONDS parameter has been changed to
6237 MICROSECONDS, to more closely resemble the underlying system call.
6238 The RVEC, WVEC, and EVEC arguments can now be vectors; the type of the
6239 corresponding return set will be the same.
6240
6241 *** The arguments to the `mknod' system call have changed. They are
6242 now:
6243
6244 (mknod PATH TYPE PERMS DEV)
6245 Create a new file (`node') in the file system. PATH is the name of
6246 the file to create. TYPE is the kind of file to create; it should
6247 be 'fifo, 'block-special, or 'char-special. PERMS specifies the
6248 permission bits to give the newly created file. If TYPE is
6249 'block-special or 'char-special, DEV specifies which device the
6250 special file refers to; its interpretation depends on the kind of
6251 special file being created.
6252
6253 *** The `fork' function has been renamed to `primitive-fork', to avoid
6254 clashing with various SCSH forks.
6255
6256 *** The `recv' and `recvfrom' functions have been renamed to `recv!'
6257 and `recvfrom!'. They no longer accept a size for a second argument;
6258 you must pass a string to hold the received value. They no longer
6259 return the buffer. Instead, `recv' returns the length of the message
6260 received, and `recvfrom' returns a pair containing the packet's length
6261 and originating address.
6262
6263 *** The file descriptor datatype has been removed, as have the
6264 `read-fd', `write-fd', `close', `lseek', and `dup' functions.
6265 We plan to replace these functions with a SCSH-compatible interface.
6266
6267 *** The `create' function has been removed; it's just a special case
6268 of `open'.
6269
6270 *** There are new functions to break down process termination status
6271 values. In the descriptions below, STATUS is a value returned by
6272 `waitpid'.
6273
6274 (status:exit-val STATUS)
6275 If the child process exited normally, this function returns the exit
6276 code for the child process (i.e., the value passed to exit, or
6277 returned from main). If the child process did not exit normally,
6278 this function returns #f.
6279
6280 (status:stop-sig STATUS)
6281 If the child process was suspended by a signal, this function
6282 returns the signal that suspended the child. Otherwise, it returns
6283 #f.
6284
6285 (status:term-sig STATUS)
6286 If the child process terminated abnormally, this function returns
6287 the signal that terminated the child. Otherwise, this function
6288 returns false.
6289
6290 POSIX promises that exactly one of these functions will return true on
6291 a valid STATUS value.
6292
6293 These functions are compatible with SCSH.
6294
6295 *** There are new accessors and setters for the broken-out time vectors
6296 returned by `localtime', `gmtime', and that ilk. They are:
6297
6298 Component Accessor Setter
6299 ========================= ============ ============
6300 seconds tm:sec set-tm:sec
6301 minutes tm:min set-tm:min
6302 hours tm:hour set-tm:hour
6303 day of the month tm:mday set-tm:mday
6304 month tm:mon set-tm:mon
6305 year tm:year set-tm:year
6306 day of the week tm:wday set-tm:wday
6307 day in the year tm:yday set-tm:yday
6308 daylight saving time tm:isdst set-tm:isdst
6309 GMT offset, seconds tm:gmtoff set-tm:gmtoff
6310 name of time zone tm:zone set-tm:zone
6311
6312 *** There are new accessors for the vectors returned by `uname',
6313 describing the host system:
6314
6315 Component Accessor
6316 ============================================== ================
6317 name of the operating system implementation utsname:sysname
6318 network name of this machine utsname:nodename
6319 release level of the operating system utsname:release
6320 version level of the operating system utsname:version
6321 machine hardware platform utsname:machine
6322
6323 *** There are new accessors for the vectors returned by `getpw',
6324 `getpwnam', `getpwuid', and `getpwent', describing entries from the
6325 system's user database:
6326
6327 Component Accessor
6328 ====================== =================
6329 user name passwd:name
6330 user password passwd:passwd
6331 user id passwd:uid
6332 group id passwd:gid
6333 real name passwd:gecos
6334 home directory passwd:dir
6335 shell program passwd:shell
6336
6337 *** There are new accessors for the vectors returned by `getgr',
6338 `getgrnam', `getgrgid', and `getgrent', describing entries from the
6339 system's group database:
6340
6341 Component Accessor
6342 ======================= ============
6343 group name group:name
6344 group password group:passwd
6345 group id group:gid
6346 group members group:mem
6347
6348 *** There are new accessors for the vectors returned by `gethost',
6349 `gethostbyaddr', `gethostbyname', and `gethostent', describing
6350 internet hosts:
6351
6352 Component Accessor
6353 ========================= ===============
6354 official name of host hostent:name
6355 alias list hostent:aliases
6356 host address type hostent:addrtype
6357 length of address hostent:length
6358 list of addresses hostent:addr-list
6359
6360 *** There are new accessors for the vectors returned by `getnet',
6361 `getnetbyaddr', `getnetbyname', and `getnetent', describing internet
6362 networks:
6363
6364 Component Accessor
6365 ========================= ===============
6366 official name of net netent:name
6367 alias list netent:aliases
6368 net number type netent:addrtype
6369 net number netent:net
6370
6371 *** There are new accessors for the vectors returned by `getproto',
6372 `getprotobyname', `getprotobynumber', and `getprotoent', describing
6373 internet protocols:
6374
6375 Component Accessor
6376 ========================= ===============
6377 official protocol name protoent:name
6378 alias list protoent:aliases
6379 protocol number protoent:proto
6380
6381 *** There are new accessors for the vectors returned by `getserv',
6382 `getservbyname', `getservbyport', and `getservent', describing
6383 internet protocols:
6384
6385 Component Accessor
6386 ========================= ===============
6387 official service name servent:name
6388 alias list servent:aliases
6389 port number servent:port
6390 protocol to use servent:proto
6391
6392 *** There are new accessors for the sockaddr structures returned by
6393 `accept', `getsockname', `getpeername', `recvfrom!':
6394
6395 Component Accessor
6396 ======================================== ===============
6397 address format (`family') sockaddr:fam
6398 path, for file domain addresses sockaddr:path
6399 address, for internet domain addresses sockaddr:addr
6400 TCP or UDP port, for internet sockaddr:port
6401
6402 *** The `getpwent', `getgrent', `gethostent', `getnetent',
6403 `getprotoent', and `getservent' functions now return #f at the end of
6404 the user database. (They used to throw an exception.)
6405
6406 Note that calling MUMBLEent function is equivalent to calling the
6407 corresponding MUMBLE function with no arguments.
6408
6409 *** The `setpwent', `setgrent', `sethostent', `setnetent',
6410 `setprotoent', and `setservent' routines now take no arguments.
6411
6412 *** The `gethost', `getproto', `getnet', and `getserv' functions now
6413 provide more useful information when they throw an exception.
6414
6415 *** The `lnaof' function has been renamed to `inet-lnaof'.
6416
6417 *** Guile now claims to have the `current-time' feature.
6418
6419 *** The `mktime' function now takes an optional second argument ZONE,
6420 giving the time zone to use for the conversion. ZONE should be a
6421 string, in the same format as expected for the "TZ" environment variable.
6422
6423 *** The `strptime' function now returns a pair (TIME . COUNT), where
6424 TIME is the parsed time as a vector, and COUNT is the number of
6425 characters from the string left unparsed. This function used to
6426 return the remaining characters as a string.
6427
6428 *** The `gettimeofday' function has replaced the old `time+ticks' function.
6429 The return value is now (SECONDS . MICROSECONDS); the fractional
6430 component is no longer expressed in "ticks".
6431
6432 *** The `ticks/sec' constant has been removed, in light of the above change.
6433
6434 * Changes to the gh_ interface
6435
6436 ** gh_eval_str() now returns an SCM object which is the result of the
6437 evaluation
6438
6439 ** gh_scm2str() now copies the Scheme data to a caller-provided C
6440 array
6441
6442 ** gh_scm2newstr() now makes a C array, copies the Scheme data to it,
6443 and returns the array
6444
6445 ** gh_scm2str0() is gone: there is no need to distinguish
6446 null-terminated from non-null-terminated, since gh_scm2newstr() allows
6447 the user to interpret the data both ways.
6448
6449 * Changes to the scm_ interface
6450
6451 ** The new function scm_symbol_value0 provides an easy way to get a
6452 symbol's value from C code:
6453
6454 SCM scm_symbol_value0 (char *NAME)
6455 Return the value of the symbol named by the null-terminated string
6456 NAME in the current module. If the symbol named NAME is unbound in
6457 the current module, return SCM_UNDEFINED.
6458
6459 ** The new function scm_sysintern0 creates new top-level variables,
6460 without assigning them a value.
6461
6462 SCM scm_sysintern0 (char *NAME)
6463 Create a new Scheme top-level variable named NAME. NAME is a
6464 null-terminated string. Return the variable's value cell.
6465
6466 ** The function scm_internal_catch is the guts of catch. It handles
6467 all the mechanics of setting up a catch target, invoking the catch
6468 body, and perhaps invoking the handler if the body does a throw.
6469
6470 The function is designed to be usable from C code, but is general
6471 enough to implement all the semantics Guile Scheme expects from throw.
6472
6473 TAG is the catch tag. Typically, this is a symbol, but this function
6474 doesn't actually care about that.
6475
6476 BODY is a pointer to a C function which runs the body of the catch;
6477 this is the code you can throw from. We call it like this:
6478 BODY (BODY_DATA, JMPBUF)
6479 where:
6480 BODY_DATA is just the BODY_DATA argument we received; we pass it
6481 through to BODY as its first argument. The caller can make
6482 BODY_DATA point to anything useful that BODY might need.
6483 JMPBUF is the Scheme jmpbuf object corresponding to this catch,
6484 which we have just created and initialized.
6485
6486 HANDLER is a pointer to a C function to deal with a throw to TAG,
6487 should one occur. We call it like this:
6488 HANDLER (HANDLER_DATA, THROWN_TAG, THROW_ARGS)
6489 where
6490 HANDLER_DATA is the HANDLER_DATA argument we recevied; it's the
6491 same idea as BODY_DATA above.
6492 THROWN_TAG is the tag that the user threw to; usually this is
6493 TAG, but it could be something else if TAG was #t (i.e., a
6494 catch-all), or the user threw to a jmpbuf.
6495 THROW_ARGS is the list of arguments the user passed to the THROW
6496 function.
6497
6498 BODY_DATA is just a pointer we pass through to BODY. HANDLER_DATA
6499 is just a pointer we pass through to HANDLER. We don't actually
6500 use either of those pointers otherwise ourselves. The idea is
6501 that, if our caller wants to communicate something to BODY or
6502 HANDLER, it can pass a pointer to it as MUMBLE_DATA, which BODY and
6503 HANDLER can then use. Think of it as a way to make BODY and
6504 HANDLER closures, not just functions; MUMBLE_DATA points to the
6505 enclosed variables.
6506
6507 Of course, it's up to the caller to make sure that any data a
6508 MUMBLE_DATA needs is protected from GC. A common way to do this is
6509 to make MUMBLE_DATA a pointer to data stored in an automatic
6510 structure variable; since the collector must scan the stack for
6511 references anyway, this assures that any references in MUMBLE_DATA
6512 will be found.
6513
6514 ** The new function scm_internal_lazy_catch is exactly like
6515 scm_internal_catch, except:
6516
6517 - It does not unwind the stack (this is the major difference).
6518 - If handler returns, its value is returned from the throw.
6519 - BODY always receives #f as its JMPBUF argument (since there's no
6520 jmpbuf associated with a lazy catch, because we don't unwind the
6521 stack.)
6522
6523 ** scm_body_thunk is a new body function you can pass to
6524 scm_internal_catch if you want the body to be like Scheme's `catch'
6525 --- a thunk, or a function of one argument if the tag is #f.
6526
6527 BODY_DATA is a pointer to a scm_body_thunk_data structure, which
6528 contains the Scheme procedure to invoke as the body, and the tag
6529 we're catching. If the tag is #f, then we pass JMPBUF (created by
6530 scm_internal_catch) to the body procedure; otherwise, the body gets
6531 no arguments.
6532
6533 ** scm_handle_by_proc is a new handler function you can pass to
6534 scm_internal_catch if you want the handler to act like Scheme's catch
6535 --- call a procedure with the tag and the throw arguments.
6536
6537 If the user does a throw to this catch, this function runs a handler
6538 procedure written in Scheme. HANDLER_DATA is a pointer to an SCM
6539 variable holding the Scheme procedure object to invoke. It ought to
6540 be a pointer to an automatic variable (i.e., one living on the stack),
6541 or the procedure object should be otherwise protected from GC.
6542
6543 ** scm_handle_by_message is a new handler function to use with
6544 `scm_internal_catch' if you want Guile to print a message and die.
6545 It's useful for dealing with throws to uncaught keys at the top level.
6546
6547 HANDLER_DATA, if non-zero, is assumed to be a char * pointing to a
6548 message header to print; if zero, we use "guile" instead. That
6549 text is followed by a colon, then the message described by ARGS.
6550
6551 ** The return type of scm_boot_guile is now void; the function does
6552 not return a value, and indeed, never returns at all.
6553
6554 ** The new function scm_shell makes it easy for user applications to
6555 process command-line arguments in a way that is compatible with the
6556 stand-alone guile interpreter (which is in turn compatible with SCSH,
6557 the Scheme shell).
6558
6559 To use the scm_shell function, first initialize any guile modules
6560 linked into your application, and then call scm_shell with the values
6561 of ARGC and ARGV your `main' function received. scm_shell will add
6562 any SCSH-style meta-arguments from the top of the script file to the
6563 argument vector, and then process the command-line arguments. This
6564 generally means loading a script file or starting up an interactive
6565 command interpreter. For details, see "Changes to the stand-alone
6566 interpreter" above.
6567
6568 ** The new functions scm_get_meta_args and scm_count_argv help you
6569 implement the SCSH-style meta-argument, `\'.
6570
6571 char **scm_get_meta_args (int ARGC, char **ARGV)
6572 If the second element of ARGV is a string consisting of a single
6573 backslash character (i.e. "\\" in Scheme notation), open the file
6574 named by the following argument, parse arguments from it, and return
6575 the spliced command line. The returned array is terminated by a
6576 null pointer.
6577
6578 For details of argument parsing, see above, under "guile now accepts
6579 command-line arguments compatible with SCSH..."
6580
6581 int scm_count_argv (char **ARGV)
6582 Count the arguments in ARGV, assuming it is terminated by a null
6583 pointer.
6584
6585 For an example of how these functions might be used, see the source
6586 code for the function scm_shell in libguile/script.c.
6587
6588 You will usually want to use scm_shell instead of calling this
6589 function yourself.
6590
6591 ** The new function scm_compile_shell_switches turns an array of
6592 command-line arguments into Scheme code to carry out the actions they
6593 describe. Given ARGC and ARGV, it returns a Scheme expression to
6594 evaluate, and calls scm_set_program_arguments to make any remaining
6595 command-line arguments available to the Scheme code. For example,
6596 given the following arguments:
6597
6598 -e main -s ekko a speckled gecko
6599
6600 scm_set_program_arguments will return the following expression:
6601
6602 (begin (load "ekko") (main (command-line)) (quit))
6603
6604 You will usually want to use scm_shell instead of calling this
6605 function yourself.
6606
6607 ** The function scm_shell_usage prints a usage message appropriate for
6608 an interpreter that uses scm_compile_shell_switches to handle its
6609 command-line arguments.
6610
6611 void scm_shell_usage (int FATAL, char *MESSAGE)
6612 Print a usage message to the standard error output. If MESSAGE is
6613 non-zero, write it before the usage message, followed by a newline.
6614 If FATAL is non-zero, exit the process, using FATAL as the
6615 termination status. (If you want to be compatible with Guile,
6616 always use 1 as the exit status when terminating due to command-line
6617 usage problems.)
6618
6619 You will usually want to use scm_shell instead of calling this
6620 function yourself.
6621
6622 ** scm_eval_0str now returns SCM_UNSPECIFIED if the string contains no
6623 expressions. It used to return SCM_EOL. Earth-shattering.
6624
6625 ** The macros for declaring scheme objects in C code have been
6626 rearranged slightly. They are now:
6627
6628 SCM_SYMBOL (C_NAME, SCHEME_NAME)
6629 Declare a static SCM variable named C_NAME, and initialize it to
6630 point to the Scheme symbol whose name is SCHEME_NAME. C_NAME should
6631 be a C identifier, and SCHEME_NAME should be a C string.
6632
6633 SCM_GLOBAL_SYMBOL (C_NAME, SCHEME_NAME)
6634 Just like SCM_SYMBOL, but make C_NAME globally visible.
6635
6636 SCM_VCELL (C_NAME, SCHEME_NAME)
6637 Create a global variable at the Scheme level named SCHEME_NAME.
6638 Declare a static SCM variable named C_NAME, and initialize it to
6639 point to the Scheme variable's value cell.
6640
6641 SCM_GLOBAL_VCELL (C_NAME, SCHEME_NAME)
6642 Just like SCM_VCELL, but make C_NAME globally visible.
6643
6644 The `guile-snarf' script writes initialization code for these macros
6645 to its standard output, given C source code as input.
6646
6647 The SCM_GLOBAL macro is gone.
6648
6649 ** The scm_read_line and scm_read_line_x functions have been replaced
6650 by Scheme code based on the %read-delimited! procedure (known to C
6651 code as scm_read_delimited_x). See its description above for more
6652 information.
6653
6654 ** The function scm_sys_open has been renamed to scm_open. It now
6655 returns a port instead of an FD object.
6656
6657 * The dynamic linking support has changed. For more information, see
6658 libguile/DYNAMIC-LINKING.
6659
6660 \f
6661 Guile 1.0b3
6662
6663 User-visible changes from Thursday, September 5, 1996 until Guile 1.0
6664 (Sun 5 Jan 1997):
6665
6666 * Changes to the 'guile' program:
6667
6668 ** Guile now loads some new files when it starts up. Guile first
6669 searches the load path for init.scm, and loads it if found. Then, if
6670 Guile is not being used to execute a script, and the user's home
6671 directory contains a file named `.guile', Guile loads that.
6672
6673 ** You can now use Guile as a shell script interpreter.
6674
6675 To paraphrase the SCSH manual:
6676
6677 When Unix tries to execute an executable file whose first two
6678 characters are the `#!', it treats the file not as machine code to
6679 be directly executed by the native processor, but as source code
6680 to be executed by some interpreter. The interpreter to use is
6681 specified immediately after the #! sequence on the first line of
6682 the source file. The kernel reads in the name of the interpreter,
6683 and executes that instead. It passes the interpreter the source
6684 filename as its first argument, with the original arguments
6685 following. Consult the Unix man page for the `exec' system call
6686 for more information.
6687
6688 Now you can use Guile as an interpreter, using a mechanism which is a
6689 compatible subset of that provided by SCSH.
6690
6691 Guile now recognizes a '-s' command line switch, whose argument is the
6692 name of a file of Scheme code to load. It also treats the two
6693 characters `#!' as the start of a comment, terminated by `!#'. Thus,
6694 to make a file of Scheme code directly executable by Unix, insert the
6695 following two lines at the top of the file:
6696
6697 #!/usr/local/bin/guile -s
6698 !#
6699
6700 Guile treats the argument of the `-s' command-line switch as the name
6701 of a file of Scheme code to load, and treats the sequence `#!' as the
6702 start of a block comment, terminated by `!#'.
6703
6704 For example, here's a version of 'echo' written in Scheme:
6705
6706 #!/usr/local/bin/guile -s
6707 !#
6708 (let loop ((args (cdr (program-arguments))))
6709 (if (pair? args)
6710 (begin
6711 (display (car args))
6712 (if (pair? (cdr args))
6713 (display " "))
6714 (loop (cdr args)))))
6715 (newline)
6716
6717 Why does `#!' start a block comment terminated by `!#', instead of the
6718 end of the line? That is the notation SCSH uses, and although we
6719 don't yet support the other SCSH features that motivate that choice,
6720 we would like to be backward-compatible with any existing Guile
6721 scripts once we do. Furthermore, if the path to Guile on your system
6722 is too long for your kernel, you can start the script with this
6723 horrible hack:
6724
6725 #!/bin/sh
6726 exec /really/long/path/to/guile -s "$0" ${1+"$@"}
6727 !#
6728
6729 Note that some very old Unix systems don't support the `#!' syntax.
6730
6731
6732 ** You can now run Guile without installing it.
6733
6734 Previous versions of the interactive Guile interpreter (`guile')
6735 couldn't start up unless Guile's Scheme library had been installed;
6736 they used the value of the environment variable `SCHEME_LOAD_PATH'
6737 later on in the startup process, but not to find the startup code
6738 itself. Now Guile uses `SCHEME_LOAD_PATH' in all searches for Scheme
6739 code.
6740
6741 To run Guile without installing it, build it in the normal way, and
6742 then set the environment variable `SCHEME_LOAD_PATH' to a
6743 colon-separated list of directories, including the top-level directory
6744 of the Guile sources. For example, if you unpacked Guile so that the
6745 full filename of this NEWS file is /home/jimb/guile-1.0b3/NEWS, then
6746 you might say
6747
6748 export SCHEME_LOAD_PATH=/home/jimb/my-scheme:/home/jimb/guile-1.0b3
6749
6750
6751 ** Guile's read-eval-print loop no longer prints #<unspecified>
6752 results. If the user wants to see this, she can evaluate the
6753 expression (assert-repl-print-unspecified #t), perhaps in her startup
6754 file.
6755
6756 ** Guile no longer shows backtraces by default when an error occurs;
6757 however, it does display a message saying how to get one, and how to
6758 request that they be displayed by default. After an error, evaluate
6759 (backtrace)
6760 to see a backtrace, and
6761 (debug-enable 'backtrace)
6762 to see them by default.
6763
6764
6765
6766 * Changes to Guile Scheme:
6767
6768 ** Guile now distinguishes between #f and the empty list.
6769
6770 This is for compatibility with the IEEE standard, the (possibly)
6771 upcoming Revised^5 Report on Scheme, and many extant Scheme
6772 implementations.
6773
6774 Guile used to have #f and '() denote the same object, to make Scheme's
6775 type system more compatible with Emacs Lisp's. However, the change
6776 caused too much trouble for Scheme programmers, and we found another
6777 way to reconcile Emacs Lisp with Scheme that didn't require this.
6778
6779
6780 ** Guile's delq, delv, delete functions, and their destructive
6781 counterparts, delq!, delv!, and delete!, now remove all matching
6782 elements from the list, not just the first. This matches the behavior
6783 of the corresponding Emacs Lisp functions, and (I believe) the Maclisp
6784 functions which inspired them.
6785
6786 I recognize that this change may break code in subtle ways, but it
6787 seems best to make the change before the FSF's first Guile release,
6788 rather than after.
6789
6790
6791 ** The compiled-library-path function has been deleted from libguile.
6792
6793 ** The facilities for loading Scheme source files have changed.
6794
6795 *** The variable %load-path now tells Guile which directories to search
6796 for Scheme code. Its value is a list of strings, each of which names
6797 a directory.
6798
6799 *** The variable %load-extensions now tells Guile which extensions to
6800 try appending to a filename when searching the load path. Its value
6801 is a list of strings. Its default value is ("" ".scm").
6802
6803 *** (%search-load-path FILENAME) searches the directories listed in the
6804 value of the %load-path variable for a Scheme file named FILENAME,
6805 with all the extensions listed in %load-extensions. If it finds a
6806 match, then it returns its full filename. If FILENAME is absolute, it
6807 returns it unchanged. Otherwise, it returns #f.
6808
6809 %search-load-path will not return matches that refer to directories.
6810
6811 *** (primitive-load FILENAME :optional CASE-INSENSITIVE-P SHARP)
6812 uses %seach-load-path to find a file named FILENAME, and loads it if
6813 it finds it. If it can't read FILENAME for any reason, it throws an
6814 error.
6815
6816 The arguments CASE-INSENSITIVE-P and SHARP are interpreted as by the
6817 `read' function.
6818
6819 *** load uses the same searching semantics as primitive-load.
6820
6821 *** The functions %try-load, try-load-with-path, %load, load-with-path,
6822 basic-try-load-with-path, basic-load-with-path, try-load-module-with-
6823 path, and load-module-with-path have been deleted. The functions
6824 above should serve their purposes.
6825
6826 *** If the value of the variable %load-hook is a procedure,
6827 `primitive-load' applies its value to the name of the file being
6828 loaded (without the load path directory name prepended). If its value
6829 is #f, it is ignored. Otherwise, an error occurs.
6830
6831 This is mostly useful for printing load notification messages.
6832
6833
6834 ** The function `eval!' is no longer accessible from the scheme level.
6835 We can't allow operations which introduce glocs into the scheme level,
6836 because Guile's type system can't handle these as data. Use `eval' or
6837 `read-and-eval!' (see below) as replacement.
6838
6839 ** The new function read-and-eval! reads an expression from PORT,
6840 evaluates it, and returns the result. This is more efficient than
6841 simply calling `read' and `eval', since it is not necessary to make a
6842 copy of the expression for the evaluator to munge.
6843
6844 Its optional arguments CASE_INSENSITIVE_P and SHARP are interpreted as
6845 for the `read' function.
6846
6847
6848 ** The function `int?' has been removed; its definition was identical
6849 to that of `integer?'.
6850
6851 ** The functions `<?', `<?', `<=?', `=?', `>?', and `>=?'. Code should
6852 use the R4RS names for these functions.
6853
6854 ** The function object-properties no longer returns the hash handle;
6855 it simply returns the object's property list.
6856
6857 ** Many functions have been changed to throw errors, instead of
6858 returning #f on failure. The point of providing exception handling in
6859 the language is to simplify the logic of user code, but this is less
6860 useful if Guile's primitives don't throw exceptions.
6861
6862 ** The function `fileno' has been renamed from `%fileno'.
6863
6864 ** The function primitive-mode->fdes returns #t or #f now, not 1 or 0.
6865
6866
6867 * Changes to Guile's C interface:
6868
6869 ** The library's initialization procedure has been simplified.
6870 scm_boot_guile now has the prototype:
6871
6872 void scm_boot_guile (int ARGC,
6873 char **ARGV,
6874 void (*main_func) (),
6875 void *closure);
6876
6877 scm_boot_guile calls MAIN_FUNC, passing it CLOSURE, ARGC, and ARGV.
6878 MAIN_FUNC should do all the work of the program (initializing other
6879 packages, reading user input, etc.) before returning. When MAIN_FUNC
6880 returns, call exit (0); this function never returns. If you want some
6881 other exit value, MAIN_FUNC may call exit itself.
6882
6883 scm_boot_guile arranges for program-arguments to return the strings
6884 given by ARGC and ARGV. If MAIN_FUNC modifies ARGC/ARGV, should call
6885 scm_set_program_arguments with the final list, so Scheme code will
6886 know which arguments have been processed.
6887
6888 scm_boot_guile establishes a catch-all catch handler which prints an
6889 error message and exits the process. This means that Guile exits in a
6890 coherent way when system errors occur and the user isn't prepared to
6891 handle it. If the user doesn't like this behavior, they can establish
6892 their own universal catcher in MAIN_FUNC to shadow this one.
6893
6894 Why must the caller do all the real work from MAIN_FUNC? The garbage
6895 collector assumes that all local variables of type SCM will be above
6896 scm_boot_guile's stack frame on the stack. If you try to manipulate
6897 SCM values after this function returns, it's the luck of the draw
6898 whether the GC will be able to find the objects you allocate. So,
6899 scm_boot_guile function exits, rather than returning, to discourage
6900 people from making that mistake.
6901
6902 The IN, OUT, and ERR arguments were removed; there are other
6903 convenient ways to override these when desired.
6904
6905 The RESULT argument was deleted; this function should never return.
6906
6907 The BOOT_CMD argument was deleted; the MAIN_FUNC argument is more
6908 general.
6909
6910
6911 ** Guile's header files should no longer conflict with your system's
6912 header files.
6913
6914 In order to compile code which #included <libguile.h>, previous
6915 versions of Guile required you to add a directory containing all the
6916 Guile header files to your #include path. This was a problem, since
6917 Guile's header files have names which conflict with many systems'
6918 header files.
6919
6920 Now only <libguile.h> need appear in your #include path; you must
6921 refer to all Guile's other header files as <libguile/mumble.h>.
6922 Guile's installation procedure puts libguile.h in $(includedir), and
6923 the rest in $(includedir)/libguile.
6924
6925
6926 ** Two new C functions, scm_protect_object and scm_unprotect_object,
6927 have been added to the Guile library.
6928
6929 scm_protect_object (OBJ) protects OBJ from the garbage collector.
6930 OBJ will not be freed, even if all other references are dropped,
6931 until someone does scm_unprotect_object (OBJ). Both functions
6932 return OBJ.
6933
6934 Note that calls to scm_protect_object do not nest. You can call
6935 scm_protect_object any number of times on a given object, and the
6936 next call to scm_unprotect_object will unprotect it completely.
6937
6938 Basically, scm_protect_object and scm_unprotect_object just
6939 maintain a list of references to things. Since the GC knows about
6940 this list, all objects it mentions stay alive. scm_protect_object
6941 adds its argument to the list; scm_unprotect_object remove its
6942 argument from the list.
6943
6944
6945 ** scm_eval_0str now returns the value of the last expression
6946 evaluated.
6947
6948 ** The new function scm_read_0str reads an s-expression from a
6949 null-terminated string, and returns it.
6950
6951 ** The new function `scm_stdio_to_port' converts a STDIO file pointer
6952 to a Scheme port object.
6953
6954 ** The new function `scm_set_program_arguments' allows C code to set
6955 the value returned by the Scheme `program-arguments' function.
6956
6957 \f
6958 Older changes:
6959
6960 * Guile no longer includes sophisticated Tcl/Tk support.
6961
6962 The old Tcl/Tk support was unsatisfying to us, because it required the
6963 user to link against the Tcl library, as well as Tk and Guile. The
6964 interface was also un-lispy, in that it preserved Tcl/Tk's practice of
6965 referring to widgets by names, rather than exporting widgets to Scheme
6966 code as a special datatype.
6967
6968 In the Usenix Tk Developer's Workshop held in July 1996, the Tcl/Tk
6969 maintainers described some very interesting changes in progress to the
6970 Tcl/Tk internals, which would facilitate clean interfaces between lone
6971 Tk and other interpreters --- even for garbage-collected languages
6972 like Scheme. They expected the new Tk to be publicly available in the
6973 fall of 1996.
6974
6975 Since it seems that Guile might soon have a new, cleaner interface to
6976 lone Tk, and that the old Guile/Tk glue code would probably need to be
6977 completely rewritten, we (Jim Blandy and Richard Stallman) have
6978 decided not to support the old code. We'll spend the time instead on
6979 a good interface to the newer Tk, as soon as it is available.
6980
6981 Until then, gtcltk-lib provides trivial, low-maintenance functionality.
6982
6983 \f
6984 Copyright information:
6985
6986 Copyright (C) 1996, 1997, 1998, 1999, 2000, 2001 Free Software Foundation, Inc.
6987
6988 Permission is granted to anyone to make or distribute verbatim copies
6989 of this document as received, in any medium, provided that the
6990 copyright notice and this permission notice are preserved,
6991 thus giving the recipient permission to redistribute in turn.
6992
6993 Permission is granted to distribute modified versions
6994 of this document, or of portions of it,
6995 under the above conditions, provided also that they
6996 carry prominent notices stating who last changed them.
6997
6998 \f
6999 Local variables:
7000 mode: outline
7001 paragraph-separate: "[ \f]*$"
7002 end: