1 Guile NEWS --- history of user-visible changes. -*- text -*-
2 Copyright (C) 1996, 1997, 1998, 1999 Free Software Foundation, Inc.
3 See the end for copying conditions.
5 Please send Guile bug reports to bug-guile@gnu.org.
7 Changes since Guile 1.3.2:
9 * Changes to Scheme functions and syntax
11 ** Print-state handling has been made more transparent
13 Under certain circumstances, ports are represented as a port with an
14 associated print state. Earlier, this pair was represented as a pair
15 (see "Some magic has been added to the printer" below). It is now
16 indistinguishable (almost; see `get-print-state') from a port on the
19 *** New function: port-with-print-state OUTPUT-PORT PRINT-STATE
21 Return a new port with the associated print state PRINT-STATE.
23 *** New function: get-print-state OUTPUT-PORT
25 Return the print state associated with this port if it exists,
29 Changes since Guile 1.3:
31 * Changes to mailing lists
33 ** Some of the Guile mailing lists have moved to sourceware.cygnus.com.
35 See the README file to find current addresses for all the Guile
38 * Changes to the distribution
40 ** Readline support is no longer included with Guile by default.
42 Based on the different license terms of Guile and Readline, we
43 concluded that Guile should not *by default* cause the linking of
44 Readline into an application program. Readline support is now offered
45 as a separate module, which is linked into an application only when
46 you explicitly specify it.
48 Although Guile is GNU software, its distribution terms add a special
49 exception to the usual GNU General Public License (GPL). Guile's
50 license includes a clause that allows you to link Guile with non-free
51 programs. We add this exception so as not to put Guile at a
52 disadvantage vis-a-vis other extensibility packages that support other
55 In contrast, the GNU Readline library is distributed under the GNU
56 General Public License pure and simple. This means that you may not
57 link Readline, even dynamically, into an application unless it is
58 distributed under a free software license that is compatible the GPL.
60 Because of this difference in distribution terms, an application that
61 can use Guile may not be able to use Readline. Now users will be
62 explicitly offered two independent decisions about the use of these
65 You can activate the readline support by issuing
67 (use-modules (readline-activator))
70 from your ".guile" file, for example.
72 * Changes to the stand-alone interpreter
74 ** All builtins now print as primitives.
75 Previously builtin procedures not belonging to the fundamental subr
76 types printed as #<compiled closure #<primitive-procedure gsubr-apply>>.
77 Now, they print as #<primitive-procedure NAME>.
79 ** Backtraces slightly more intelligible.
80 gsubr-apply and macro transformer application frames no longer appear
83 * Changes to Scheme functions and syntax
85 ** Guile now correctly handles internal defines by rewriting them into
86 their equivalent letrec. Previously, internal defines would
87 incrementally add to the innermost environment, without checking
88 whether the restrictions specified in RnRS were met. This lead to the
89 correct behaviour when these restriction actually were met, but didn't
90 catch all illegal uses. Such an illegal use could lead to crashes of
91 the Guile interpreter or or other unwanted results. An example of
92 incorrect internal defines that made Guile behave erratically:
104 The problem with this example is that the definition of `c' uses the
105 value of `b' directly. This confuses the meoization machine of Guile
106 so that the second call of `b' (this time in a larger environment that
107 also contains bindings for `c' and `d') refers to the binding of `c'
108 instead of `a'. You could also make Guile crash with a variation on
113 (define (b flag) (if flag a 1))
114 (define c (1+ (b flag)))
122 From now on, Guile will issue an `Unbound variable: b' error message
127 A hook contains a list of functions which should be called on
128 particular occasions in an existing program. Hooks are used for
131 A window manager might have a hook before-window-map-hook. The window
132 manager uses the function run-hooks to call all functions stored in
133 before-window-map-hook each time a window is mapped. The user can
134 store functions in the hook using add-hook!.
136 In Guile, hooks are first class objects.
138 *** New function: make-hook [N_ARGS]
140 Return a hook for hook functions which can take N_ARGS arguments.
141 The default value for N_ARGS is 0.
143 (See also scm_make_named_hook below.)
145 *** New function: add-hook! HOOK PROC [APPEND_P]
147 Put PROC at the beginning of the list of functions stored in HOOK.
148 If APPEND_P is supplied, and non-false, put PROC at the end instead.
150 PROC must be able to take the number of arguments specified when the
153 If PROC already exists in HOOK, then remove it first.
155 *** New function: remove-hook! HOOK PROC
157 Remove PROC from the list of functions in HOOK.
159 *** New function: reset-hook! HOOK
161 Clear the list of hook functions stored in HOOK.
163 *** New function: run-hook HOOK ARG1 ...
165 Run all hook functions stored in HOOK with arguments ARG1 ... .
166 The number of arguments supplied must correspond to the number given
167 when the hook was created.
169 ** The function `dynamic-link' now takes optional keyword arguments.
170 The only keyword argument that is currently defined is `:global
171 BOOL'. With it, you can control whether the shared library will be
172 linked in global mode or not. In global mode, the symbols from the
173 linked library can be used to resolve references from other
174 dynamically linked libraries. In non-global mode, the linked
175 library is essentially invisible and can only be accessed via
176 `dynamic-func', etc. The default is now to link in global mode.
177 Previously, the default has been non-global mode.
179 The `#:global' keyword is only effective on platforms that support
180 the dlopen family of functions.
182 ** New function `provided?'
184 - Function: provided? FEATURE
185 Return true iff FEATURE is supported by this installation of
186 Guile. FEATURE must be a symbol naming a feature; the global
187 variable `*features*' is a list of available features.
189 ** Changes to the module (ice-9 expect):
191 *** The expect-strings macro now matches `$' in a regular expression
192 only at a line-break or end-of-file by default. Previously it would
193 match the end of the string accumulated so far. The old behaviour
194 can be obtained by setting the variable `expect-strings-exec-flags'
197 *** The expect-strings macro now uses a variable `expect-strings-exec-flags'
198 for the regexp-exec flags. If `regexp/noteol' is included, then `$'
199 in a regular expression will still match before a line-break or
200 end-of-file. The default is `regexp/noteol'.
202 *** The expect-strings macro now uses a variable
203 `expect-strings-compile-flags' for the flags to be supplied to
204 `make-regexp'. The default is `regexp/newline', which was previously
207 *** The expect macro now supplies two arguments to a match procedure:
208 the current accumulated string and a flag to indicate whether
209 end-of-file has been reached. Previously only the string was supplied.
210 If end-of-file is reached, the match procedure will be called an
211 additional time with the same accumulated string as the previous call
212 but with the flag set.
214 ** New module (ice-9 format), implementing the Common Lisp `format' function.
216 This code, and the documentation for it that appears here, was
217 borrowed from SLIB, with minor adaptations for Guile.
219 - Function: format DESTINATION FORMAT-STRING . ARGUMENTS
220 An almost complete implementation of Common LISP format description
221 according to the CL reference book `Common LISP' from Guy L.
222 Steele, Digital Press. Backward compatible to most of the
223 available Scheme format implementations.
225 Returns `#t', `#f' or a string; has side effect of printing
226 according to FORMAT-STRING. If DESTINATION is `#t', the output is
227 to the current output port and `#t' is returned. If DESTINATION
228 is `#f', a formatted string is returned as the result of the call.
229 NEW: If DESTINATION is a string, DESTINATION is regarded as the
230 format string; FORMAT-STRING is then the first argument and the
231 output is returned as a string. If DESTINATION is a number, the
232 output is to the current error port if available by the
233 implementation. Otherwise DESTINATION must be an output port and
236 FORMAT-STRING must be a string. In case of a formatting error
237 format returns `#f' and prints a message on the current output or
238 error port. Characters are output as if the string were output by
239 the `display' function with the exception of those prefixed by a
240 tilde (~). For a detailed description of the FORMAT-STRING syntax
241 please consult a Common LISP format reference manual. For a test
242 suite to verify this format implementation load `formatst.scm'.
243 Please send bug reports to `lutzeb@cs.tu-berlin.de'.
245 Note: `format' is not reentrant, i.e. only one `format'-call may
246 be executed at a time.
249 *** Format Specification (Format version 3.0)
251 Please consult a Common LISP format reference manual for a detailed
252 description of the format string syntax. For a demonstration of the
253 implemented directives see `formatst.scm'.
255 This implementation supports directive parameters and modifiers (`:'
256 and `@' characters). Multiple parameters must be separated by a comma
257 (`,'). Parameters can be numerical parameters (positive or negative),
258 character parameters (prefixed by a quote character (`''), variable
259 parameters (`v'), number of rest arguments parameter (`#'), empty and
260 default parameters. Directive characters are case independent. The
261 general form of a directive is:
263 DIRECTIVE ::= ~{DIRECTIVE-PARAMETER,}[:][@]DIRECTIVE-CHARACTER
265 DIRECTIVE-PARAMETER ::= [ [-|+]{0-9}+ | 'CHARACTER | v | # ]
267 *** Implemented CL Format Control Directives
269 Documentation syntax: Uppercase characters represent the
270 corresponding control directive characters. Lowercase characters
271 represent control directive parameter descriptions.
274 Any (print as `display' does).
278 `~MINCOL,COLINC,MINPAD,PADCHARA'
282 S-expression (print as `write' does).
286 `~MINCOL,COLINC,MINPAD,PADCHARS'
292 print number sign always.
295 print comma separated.
297 `~MINCOL,PADCHAR,COMMACHARD'
303 print number sign always.
306 print comma separated.
308 `~MINCOL,PADCHAR,COMMACHARX'
314 print number sign always.
317 print comma separated.
319 `~MINCOL,PADCHAR,COMMACHARO'
325 print number sign always.
328 print comma separated.
330 `~MINCOL,PADCHAR,COMMACHARB'
335 `~N,MINCOL,PADCHAR,COMMACHARR'
339 print a number as a Roman numeral.
342 print a number as an "old fashioned" Roman numeral.
345 print a number as an ordinal English number.
348 print a number as a cardinal English number.
353 prints `y' and `ies'.
356 as `~P but jumps 1 argument backward.'
359 as `~@P but jumps 1 argument backward.'
364 prints a character as the reader can understand it (i.e. `#\'
368 prints a character as emacs does (eg. `^C' for ASCII 03).
371 Fixed-format floating-point (prints a flonum like MMM.NNN).
372 `~WIDTH,DIGITS,SCALE,OVERFLOWCHAR,PADCHARF'
374 If the number is positive a plus sign is printed.
377 Exponential floating-point (prints a flonum like MMM.NNN`E'EE).
378 `~WIDTH,DIGITS,EXPONENTDIGITS,SCALE,OVERFLOWCHAR,PADCHAR,EXPONENTCHARE'
380 If the number is positive a plus sign is printed.
383 General floating-point (prints a flonum either fixed or
385 `~WIDTH,DIGITS,EXPONENTDIGITS,SCALE,OVERFLOWCHAR,PADCHAR,EXPONENTCHARG'
387 If the number is positive a plus sign is printed.
390 Dollars floating-point (prints a flonum in fixed with signs
392 `~DIGITS,SCALE,WIDTH,PADCHAR$'
394 If the number is positive a plus sign is printed.
397 A sign is always printed and appears before the padding.
400 The sign appears before the padding.
408 print newline if not at the beginning of the output line.
410 prints `~&' and then N-1 newlines.
415 print N page separators.
425 newline is ignored, white space left.
428 newline is left, white space ignored.
439 Indirection (expects indirect arguments as a list).
441 extracts indirect arguments from format arguments.
444 Case conversion (converts by `string-downcase').
446 converts by `string-capitalize'.
449 converts by `string-capitalize-first'.
452 converts by `string-upcase'.
455 Argument Jumping (jumps 1 argument forward).
457 jumps N arguments forward.
460 jumps 1 argument backward.
463 jumps N arguments backward.
466 jumps to the 0th argument.
469 jumps to the Nth argument (beginning from 0)
471 `~[STR0~;STR1~;...~;STRN~]'
472 Conditional Expression (numerical clause conditional).
474 take argument from N.
477 true test conditional.
480 if-else-then conditional.
486 default clause follows.
489 Iteration (args come from the next argument (a list)).
491 at most N iterations.
494 args from next arg (a list of lists).
497 args from the rest of arguments.
500 args from the rest args (lists).
511 aborts if N <= M <= K
513 *** Not Implemented CL Format Control Directives
516 print `#f' as an empty list (see below).
519 print `#f' as an empty list (see below).
525 (sorry I don't understand its semantics completely)
527 *** Extended, Replaced and Additional Control Directives
529 `~MINCOL,PADCHAR,COMMACHAR,COMMAWIDTHD'
530 `~MINCOL,PADCHAR,COMMACHAR,COMMAWIDTHX'
531 `~MINCOL,PADCHAR,COMMACHAR,COMMAWIDTHO'
532 `~MINCOL,PADCHAR,COMMACHAR,COMMAWIDTHB'
533 `~N,MINCOL,PADCHAR,COMMACHAR,COMMAWIDTHR'
534 COMMAWIDTH is the number of characters between two comma
538 print a R4RS complex number as `~F~@Fi' with passed parameters for
542 Pretty print formatting of an argument for scheme code lists.
548 Flushes the output if format DESTINATION is a port.
551 Print a `#\space' character
553 print N `#\space' characters.
556 Print a `#\tab' character
558 print N `#\tab' characters.
561 Takes N as an integer representation for a character. No arguments
562 are consumed. N is converted to a character by `integer->char'. N
563 must be a positive decimal number.
566 Print out readproof. Prints out internal objects represented as
567 `#<...>' as strings `"#<...>"' so that the format output can always
568 be processed by `read'.
571 Print out readproof. Prints out internal objects represented as
572 `#<...>' as strings `"#<...>"' so that the format output can always
573 be processed by `read'.
576 Prints information and a copyright notice on the format
579 prints format version.
582 may also print number strings, i.e. passing a number as a string
583 and format it accordingly.
585 *** Configuration Variables
587 The format module exports some configuration variables to suit the
588 systems and users needs. There should be no modification necessary for
589 the configuration that comes with Guile. Format detects automatically
590 if the running scheme system implements floating point numbers and
593 format:symbol-case-conv
594 Symbols are converted by `symbol->string' so the case type of the
595 printed symbols is implementation dependent.
596 `format:symbol-case-conv' is a one arg closure which is either
597 `#f' (no conversion), `string-upcase', `string-downcase' or
598 `string-capitalize'. (default `#f')
600 format:iobj-case-conv
601 As FORMAT:SYMBOL-CASE-CONV but applies for the representation of
602 implementation internal objects. (default `#f')
605 The character prefixing the exponent value in `~E' printing.
608 *** Compatibility With Other Format Implementations
614 Downward compatible except for padding support and `~A', `~S',
615 `~P', `~X' uppercase printing. SLIB format 1.4 uses C-style
616 `printf' padding support which is completely replaced by the CL
617 `format' padding style.
620 Downward compatible except for `~', which is not documented
621 (ignores all characters inside the format string up to a newline
622 character). (7.1 implements `~a', `~s', ~NEWLINE, `~~', `~%',
623 numerical and variable parameters and `:/@' modifiers in the CL
627 Downward compatible except for `~A' and `~S' which print in
628 uppercase. (Elk implements `~a', `~s', `~~', and `~%' (no
629 directive parameters or modifiers)).
632 Downward compatible except for an optional destination parameter:
633 S2C accepts a format call without a destination which returns a
634 formatted string. This is equivalent to a #f destination in S2C.
635 (S2C implements `~a', `~s', `~c', `~%', and `~~' (no directive
636 parameters or modifiers)).
639 ** Changes to string-handling functions.
641 These functions were added to support the (ice-9 format) module, above.
643 *** New function: string-upcase STRING
644 *** New function: string-downcase STRING
646 These are non-destructive versions of the existing string-upcase! and
647 string-downcase! functions.
649 *** New function: string-capitalize! STRING
650 *** New function: string-capitalize STRING
652 These functions convert the first letter of each word in the string to
655 (string-capitalize "howdy there")
658 As with the other functions, string-capitalize! modifies the string in
659 place, while string-capitalize returns a modified copy of its argument.
661 *** New function: string-ci->symbol STRING
663 Return a symbol whose name is STRING, but having the same case as if
664 the symbol had be read by `read'.
666 Guile can be configured to be sensitive or insensitive to case
667 differences in Scheme identifiers. If Guile is case-insensitive, all
668 symbols are converted to lower case on input. The `string-ci->symbol'
669 function returns a symbol whose name in STRING, transformed as Guile
670 would if STRING were input.
672 *** New function: substring-move! STRING1 START END STRING2 START
674 Copy the substring of STRING1 from START (inclusive) to END
675 (exclusive) to STRING2 at START. STRING1 and STRING2 may be the same
676 string, and the source and destination areas may overlap; in all
677 cases, the function behaves as if all the characters were copied
680 *** Extended functions: substring-move-left! substring-move-right!
682 These functions now correctly copy arbitrarily overlapping substrings;
683 they are both synonyms for substring-move!.
686 ** New module (ice-9 getopt-long), with the function `getopt-long'.
688 getopt-long is a function for parsing command-line arguments in a
689 manner consistent with other GNU programs.
691 (getopt-long ARGS GRAMMAR)
692 Parse the arguments ARGS according to the argument list grammar GRAMMAR.
694 ARGS should be a list of strings. Its first element should be the
695 name of the program; subsequent elements should be the arguments
696 that were passed to the program on the command line. The
697 `program-arguments' procedure returns a list of this form.
699 GRAMMAR is a list of the form:
700 ((OPTION (PROPERTY VALUE) ...) ...)
702 Each OPTION should be a symbol. `getopt-long' will accept a
703 command-line option named `--OPTION'.
704 Each option can have the following (PROPERTY VALUE) pairs:
706 (single-char CHAR) --- Accept `-CHAR' as a single-character
707 equivalent to `--OPTION'. This is how to specify traditional
709 (required? BOOL) --- If BOOL is true, the option is required.
710 getopt-long will raise an error if it is not found in ARGS.
711 (value BOOL) --- If BOOL is #t, the option accepts a value; if
712 it is #f, it does not; and if it is the symbol
713 `optional', the option may appear in ARGS with or
715 (predicate FUNC) --- If the option accepts a value (i.e. you
716 specified `(value #t)' for this option), then getopt
717 will apply FUNC to the value, and throw an exception
718 if it returns #f. FUNC should be a procedure which
719 accepts a string and returns a boolean value; you may
720 need to use quasiquotes to get it into GRAMMAR.
722 The (PROPERTY VALUE) pairs may occur in any order, but each
723 property may occur only once. By default, options do not have
724 single-character equivalents, are not required, and do not take
727 In ARGS, single-character options may be combined, in the usual
728 Unix fashion: ("-x" "-y") is equivalent to ("-xy"). If an option
729 accepts values, then it must be the last option in the
730 combination; the value is the next argument. So, for example, using
731 the following grammar:
732 ((apples (single-char #\a))
733 (blimps (single-char #\b) (value #t))
734 (catalexis (single-char #\c) (value #t)))
735 the following argument lists would be acceptable:
736 ("-a" "-b" "bang" "-c" "couth") ("bang" and "couth" are the values
737 for "blimps" and "catalexis")
738 ("-ab" "bang" "-c" "couth") (same)
739 ("-ac" "couth" "-b" "bang") (same)
740 ("-abc" "couth" "bang") (an error, since `-b' is not the
741 last option in its combination)
743 If an option's value is optional, then `getopt-long' decides
744 whether it has a value by looking at what follows it in ARGS. If
745 the next element is a string, and it does not appear to be an
746 option itself, then that string is the option's value.
748 The value of a long option can appear as the next element in ARGS,
749 or it can follow the option name, separated by an `=' character.
750 Thus, using the same grammar as above, the following argument lists
752 ("--apples" "Braeburn" "--blimps" "Goodyear")
753 ("--apples=Braeburn" "--blimps" "Goodyear")
754 ("--blimps" "Goodyear" "--apples=Braeburn")
756 If the option "--" appears in ARGS, argument parsing stops there;
757 subsequent arguments are returned as ordinary arguments, even if
758 they resemble options. So, in the argument list:
759 ("--apples" "Granny Smith" "--" "--blimp" "Goodyear")
760 `getopt-long' will recognize the `apples' option as having the
761 value "Granny Smith", but it will not recognize the `blimp'
762 option; it will return the strings "--blimp" and "Goodyear" as
763 ordinary argument strings.
765 The `getopt-long' function returns the parsed argument list as an
766 assocation list, mapping option names --- the symbols from GRAMMAR
767 --- onto their values, or #t if the option does not accept a value.
768 Unused options do not appear in the alist.
770 All arguments that are not the value of any option are returned
771 as a list, associated with the empty list.
773 `getopt-long' throws an exception if:
774 - it finds an unrecognized option in ARGS
775 - a required option is omitted
776 - an option that requires an argument doesn't get one
777 - an option that doesn't accept an argument does get one (this can
778 only happen using the long option `--opt=value' syntax)
779 - an option predicate fails
784 `((lockfile-dir (required? #t)
787 (predicate ,file-is-directory?))
788 (verbose (required? #f)
791 (x-includes (single-char #\x))
792 (rnet-server (single-char #\y)
793 (predicate ,string?))))
795 (getopt-long '("my-prog" "-vk" "/tmp" "foo1" "--x-includes=/usr/include"
796 "--rnet-server=lamprod" "--" "-fred" "foo2" "foo3")
798 => ((() "foo1" "-fred" "foo2" "foo3")
799 (rnet-server . "lamprod")
800 (x-includes . "/usr/include")
801 (lockfile-dir . "/tmp")
804 ** The (ice-9 getopt-gnu-style) module is obsolete; use (ice-9 getopt-long).
806 It will be removed in a few releases.
808 ** New syntax: lambda*
809 ** New syntax: define*
810 ** New syntax: define*-public
811 ** New syntax: defmacro*
812 ** New syntax: defmacro*-public
813 Guile now supports optional arguments.
815 `lambda*', `define*', `define*-public', `defmacro*' and
816 `defmacro*-public' are identical to the non-* versions except that
817 they use an extended type of parameter list that has the following BNF
818 syntax (parentheses are literal, square brackets indicate grouping,
819 and `*', `+' and `?' have the usual meaning):
821 ext-param-list ::= ( [identifier]* [#&optional [ext-var-decl]+]?
822 [#&key [ext-var-decl]+ [#&allow-other-keys]?]?
823 [[#&rest identifier]|[. identifier]]? ) | [identifier]
825 ext-var-decl ::= identifier | ( identifier expression )
827 The semantics are best illustrated with the following documentation
828 and examples for `lambda*':
831 lambda extended for optional and keyword arguments
833 lambda* creates a procedure that takes optional arguments. These
834 are specified by putting them inside brackets at the end of the
835 paramater list, but before any dotted rest argument. For example,
836 (lambda* (a b #&optional c d . e) '())
837 creates a procedure with fixed arguments a and b, optional arguments c
838 and d, and rest argument e. If the optional arguments are omitted
839 in a call, the variables for them are unbound in the procedure. This
840 can be checked with the bound? macro.
842 lambda* can also take keyword arguments. For example, a procedure
844 (lambda* (#&key xyzzy larch) '())
845 can be called with any of the argument lists (#:xyzzy 11)
846 (#:larch 13) (#:larch 42 #:xyzzy 19) (). Whichever arguments
847 are given as keywords are bound to values.
849 Optional and keyword arguments can also be given default values
850 which they take on when they are not present in a call, by giving a
851 two-item list in place of an optional argument, for example in:
852 (lambda* (foo #&optional (bar 42) #&key (baz 73)) (list foo bar baz))
853 foo is a fixed argument, bar is an optional argument with default
854 value 42, and baz is a keyword argument with default value 73.
855 Default value expressions are not evaluated unless they are needed
856 and until the procedure is called.
858 lambda* now supports two more special parameter list keywords.
860 lambda*-defined procedures now throw an error by default if a
861 keyword other than one of those specified is found in the actual
862 passed arguments. However, specifying #&allow-other-keys
863 immediately after the kyword argument declarations restores the
864 previous behavior of ignoring unknown keywords. lambda* also now
865 guarantees that if the same keyword is passed more than once, the
866 last one passed is the one that takes effect. For example,
867 ((lambda* (#&key (heads 0) (tails 0)) (display (list heads tails)))
868 #:heads 37 #:tails 42 #:heads 99)
869 would result in (99 47) being displayed.
871 #&rest is also now provided as a synonym for the dotted syntax rest
872 argument. The argument lists (a . b) and (a #&rest b) are equivalent in
873 all respects to lambda*. This is provided for more similarity to DSSSL,
874 MIT-Scheme and Kawa among others, as well as for refugees from other
877 Further documentation may be found in the optargs.scm file itself.
879 The optional argument module also exports the macros `let-optional',
880 `let-optional*', `let-keywords', `let-keywords*' and `bound?'. These
881 are not documented here because they may be removed in the future, but
882 full documentation is still available in optargs.scm.
884 ** New syntax: and-let*
885 Guile now supports the `and-let*' form, described in the draft SRFI-2.
887 Syntax: (land* (<clause> ...) <body> ...)
888 Each <clause> should have one of the following forms:
889 (<variable> <expression>)
892 Each <variable> or <bound-variable> should be an identifier. Each
893 <expression> should be a valid expression. The <body> should be a
894 possibly empty sequence of expressions, like the <body> of a
897 Semantics: A LAND* expression is evaluated by evaluating the
898 <expression> or <bound-variable> of each of the <clause>s from
899 left to right. The value of the first <expression> or
900 <bound-variable> that evaluates to a false value is returned; the
901 remaining <expression>s and <bound-variable>s are not evaluated.
902 The <body> forms are evaluated iff all the <expression>s and
903 <bound-variable>s evaluate to true values.
905 The <expression>s and the <body> are evaluated in an environment
906 binding each <variable> of the preceding (<variable> <expression>)
907 clauses to the value of the <expression>. Later bindings
908 shadow earlier bindings.
910 Guile's and-let* macro was contributed by Michael Livshin.
912 ** New sorting functions
914 *** New function: sorted? SEQUENCE LESS?
915 Returns `#t' when the sequence argument is in non-decreasing order
916 according to LESS? (that is, there is no adjacent pair `... x y
917 ...' for which `(less? y x)').
919 Returns `#f' when the sequence contains at least one out-of-order
920 pair. It is an error if the sequence is neither a list nor a
923 *** New function: merge LIST1 LIST2 LESS?
924 LIST1 and LIST2 are sorted lists.
925 Returns the sorted list of all elements in LIST1 and LIST2.
927 Assume that the elements a and b1 in LIST1 and b2 in LIST2 are "equal"
928 in the sense that (LESS? x y) --> #f for x, y in {a, b1, b2},
929 and that a < b1 in LIST1. Then a < b1 < b2 in the result.
930 (Here "<" should read "comes before".)
932 *** New procedure: merge! LIST1 LIST2 LESS?
933 Merges two lists, re-using the pairs of LIST1 and LIST2 to build
934 the result. If the code is compiled, and LESS? constructs no new
935 pairs, no pairs at all will be allocated. The first pair of the
936 result will be either the first pair of LIST1 or the first pair of
939 *** New function: sort SEQUENCE LESS?
940 Accepts either a list or a vector, and returns a new sequence
941 which is sorted. The new sequence is the same type as the input.
942 Always `(sorted? (sort sequence less?) less?)'. The original
943 sequence is not altered in any way. The new sequence shares its
944 elements with the old one; no elements are copied.
946 *** New procedure: sort! SEQUENCE LESS
947 Returns its sorted result in the original boxes. No new storage is
948 allocated at all. Proper usage: (set! slist (sort! slist <))
950 *** New function: stable-sort SEQUENCE LESS?
951 Similar to `sort' but stable. That is, if "equal" elements are
952 ordered a < b in the original sequence, they will have the same order
955 *** New function: stable-sort! SEQUENCE LESS?
956 Similar to `sort!' but stable.
957 Uses temporary storage when sorting vectors.
959 *** New functions: sort-list, sort-list!
960 Added for compatibility with scsh.
962 ** New built-in random number support
964 *** New function: random N [STATE]
965 Accepts a positive integer or real N and returns a number of the
966 same type between zero (inclusive) and N (exclusive). The values
967 returned have a uniform distribution.
969 The optional argument STATE must be of the type produced by
970 `copy-random-state' or `seed->random-state'. It defaults to the value
971 of the variable `*random-state*'. This object is used to maintain the
972 state of the pseudo-random-number generator and is altered as a side
973 effect of the `random' operation.
975 *** New variable: *random-state*
976 Holds a data structure that encodes the internal state of the
977 random-number generator that `random' uses by default. The nature
978 of this data structure is implementation-dependent. It may be
979 printed out and successfully read back in, but may or may not
980 function correctly as a random-number state object in another
983 *** New function: copy-random-state [STATE]
984 Returns a new object of type suitable for use as the value of the
985 variable `*random-state*' and as a second argument to `random'.
986 If argument STATE is given, a copy of it is returned. Otherwise a
987 copy of `*random-state*' is returned.
989 *** New function: seed->random-state SEED
990 Returns a new object of type suitable for use as the value of the
991 variable `*random-state*' and as a second argument to `random'.
992 SEED is a string or a number. A new state is generated and
993 initialized using SEED.
995 *** New function: random:uniform [STATE]
996 Returns an uniformly distributed inexact real random number in the
997 range between 0 and 1.
999 *** New procedure: random:solid-sphere! VECT [STATE]
1000 Fills VECT with inexact real random numbers the sum of whose
1001 squares is less than 1.0. Thinking of VECT as coordinates in
1002 space of dimension N = `(vector-length VECT)', the coordinates are
1003 uniformly distributed within the unit N-shere. The sum of the
1004 squares of the numbers is returned. VECT can be either a vector
1005 or a uniform vector of doubles.
1007 *** New procedure: random:hollow-sphere! VECT [STATE]
1008 Fills VECT with inexact real random numbers the sum of whose squares
1009 is equal to 1.0. Thinking of VECT as coordinates in space of
1010 dimension n = `(vector-length VECT)', the coordinates are uniformly
1011 distributed over the surface of the unit n-shere. VECT can be either
1012 a vector or a uniform vector of doubles.
1014 *** New function: random:normal [STATE]
1015 Returns an inexact real in a normal distribution with mean 0 and
1016 standard deviation 1. For a normal distribution with mean M and
1017 standard deviation D use `(+ M (* D (random:normal)))'.
1019 *** New procedure: random:normal-vector! VECT [STATE]
1020 Fills VECT with inexact real random numbers which are independent and
1021 standard normally distributed (i.e., with mean 0 and variance 1).
1022 VECT can be either a vector or a uniform vector of doubles.
1024 *** New function: random:exp STATE
1025 Returns an inexact real in an exponential distribution with mean 1.
1026 For an exponential distribution with mean U use (* U (random:exp)).
1028 ** The range of logand, logior, logxor, logtest, and logbit? have changed.
1030 These functions now operate on numbers in the range of a C unsigned
1033 These functions used to operate on numbers in the range of a C signed
1034 long; however, this seems inappropriate, because Guile integers don't
1037 ** New function: make-guardian
1038 This is an implementation of guardians as described in
1039 R. Kent Dybvig, Carl Bruggeman, and David Eby (1993) "Guardians in a
1040 Generation-Based Garbage Collector" ACM SIGPLAN Conference on
1041 Programming Language Design and Implementation, June 1993
1042 ftp://ftp.cs.indiana.edu/pub/scheme-repository/doc/pubs/guardians.ps.gz
1044 ** New functions: delq1!, delv1!, delete1!
1045 These procedures behave similar to delq! and friends but delete only
1046 one object if at all.
1048 ** New function: unread-string STRING PORT
1049 Unread STRING to PORT, that is, push it back onto the port so that
1050 next read operation will work on the pushed back characters.
1052 ** unread-char can now be called multiple times
1053 If unread-char is called multiple times, the unread characters will be
1054 read again in last-in first-out order.
1056 ** the procedures uniform-array-read! and uniform-array-write! now
1057 work on any kind of port, not just ports which are open on a file.
1059 ** now 'l' in a port mode requests line buffering.
1061 ** The procedure truncate-file now works on string ports as well
1062 as file ports. If the size argument is omitted, the current
1063 file position is used.
1065 ** new procedure: seek PORT/FDES OFFSET WHENCE
1066 The arguments are the same as for the old fseek procedure, but it
1067 works on string ports as well as random-access file ports.
1069 ** the fseek procedure now works on string ports, since it has been
1070 redefined using seek.
1072 ** the setvbuf procedure now uses a default size if mode is _IOFBF and
1073 size is not supplied.
1075 ** the newline procedure no longer flushes the port if it's not
1076 line-buffered: previously it did if it was the current output port.
1078 ** open-pipe and close-pipe are no longer primitive procedures, but
1079 an emulation can be obtained using `(use-modules (ice-9 popen))'.
1081 ** the freopen procedure has been removed.
1083 ** new procedure: drain-input PORT
1084 Drains PORT's read buffers (including any pushed-back characters)
1085 and returns the contents as a single string.
1087 ** New function: map-in-order PROC LIST1 LIST2 ...
1088 Version of `map' which guarantees that the procedure is applied to the
1089 lists in serial order.
1091 ** Renamed `serial-array-copy!' and `serial-array-map!' to
1092 `array-copy-in-order!' and `array-map-in-order!'. The old names are
1093 now obsolete and will go away in release 1.5.
1095 ** New syntax: collect BODY1 ...
1096 Version of `begin' which returns a list of the results of the body
1097 forms instead of the result of the last body form. In contrast to
1098 `begin', `collect' allows an empty body.
1100 ** New functions: read-history FILENAME, write-history FILENAME
1101 Read/write command line history from/to file. Returns #t on success
1102 and #f if an error occured.
1104 ** `ls' and `lls' in module (ice-9 ls) now handle no arguments.
1106 These procedures return a list of definitions available in the specified
1107 argument, a relative module reference. In the case of no argument,
1108 `(current-module)' is now consulted for definitions to return, instead
1109 of simply returning #f, the former behavior.
1111 ** The #/ syntax for lists is no longer supported.
1113 Earlier versions of Scheme accepted this syntax, but printed a
1116 ** Guile no longer consults the SCHEME_LOAD_PATH environment variable.
1118 Instead, you should set GUILE_LOAD_PATH to tell Guile where to find
1121 * Changes to the gh_ interface
1125 Now takes a second argument which is the result array. If this
1126 pointer is NULL, a new array is malloced (the old behaviour).
1128 ** gh_chars2byvect, gh_shorts2svect, gh_floats2fvect, gh_scm2chars,
1129 gh_scm2shorts, gh_scm2longs, gh_scm2floats
1133 * Changes to the scm_ interface
1135 ** Function: scm_make_named_hook (char* name, int n_args)
1137 Creates a hook in the same way as make-hook above but also
1138 binds a variable named NAME to it.
1140 This is the typical way of creating a hook from C code.
1142 Currently, the variable is created in the root module. This will
1143 change when we get the new module system.
1145 ** The smob interface
1147 The interface for creating smobs has changed. For documentation, see
1148 data-rep.info (made from guile-core/doc/data-rep.texi).
1150 *** Deprecated function: SCM scm_newsmob (scm_smobfuns *)
1152 >>> This function will be removed in 1.3.4. <<<
1156 *** Function: SCM scm_make_smob_type (const char *name, scm_sizet size)
1157 This function adds a new smob type, named NAME, with instance size
1158 SIZE to the system. The return value is a tag that is used in
1159 creating instances of the type. If SIZE is 0, then no memory will
1160 be allocated when instances of the smob are created, and nothing
1161 will be freed by the default free function.
1163 *** Function: void scm_set_smob_mark (long tc, SCM (*mark) (SCM))
1164 This function sets the smob marking procedure for the smob type
1165 specified by the tag TC. TC is the tag returned by
1166 `scm_make_smob_type'.
1168 *** Function: void scm_set_smob_free (long tc, SCM (*mark) (SCM))
1169 This function sets the smob freeing procedure for the smob type
1170 specified by the tag TC. TC is the tag returned by
1171 `scm_make_smob_type'.
1173 *** Function: void scm_set_smob_print (tc, print)
1175 - Function: void scm_set_smob_print (long tc,
1176 scm_sizet (*print) (SCM,
1180 This function sets the smob printing procedure for the smob type
1181 specified by the tag TC. TC is the tag returned by
1182 `scm_make_smob_type'.
1184 *** Function: void scm_set_smob_equalp (long tc, SCM (*equalp) (SCM, SCM))
1185 This function sets the smob equality-testing predicate for the
1186 smob type specified by the tag TC. TC is the tag returned by
1187 `scm_make_smob_type'.
1189 *** Macro: void SCM_NEWSMOB (SCM var, long tc, void *data)
1190 Make VALUE contain a smob instance of the type with type code TC and
1191 smob data DATA. VALUE must be previously declared as C type `SCM'.
1193 *** Macro: fn_returns SCM_RETURN_NEWSMOB (long tc, void *data)
1194 This macro expands to a block of code that creates a smob instance
1195 of the type with type code TC and smob data DATA, and returns that
1196 `SCM' value. It should be the last piece of code in a block.
1198 ** The interfaces for using I/O ports and implementing port types
1199 (ptobs) have changed significantly. The new interface is based on
1200 shared access to buffers and a new set of ptob procedures.
1202 *** scm_newptob has been removed
1206 *** Function: SCM scm_make_port_type (type_name, fill_buffer, write_flush)
1208 - Function: SCM scm_make_port_type (char *type_name,
1209 int (*fill_buffer) (SCM port),
1210 void (*write_flush) (SCM port));
1212 Similarly to the new smob interface, there is a set of function
1213 setters by which the user can customize the behaviour of his port
1214 type. See ports.h (scm_set_port_XXX).
1216 ** scm_strport_to_string: New function: creates a new string from
1217 a string port's buffer.
1219 ** Plug in interface for random number generators
1220 The variable `scm_the_rng' in random.c contains a value and three
1221 function pointers which together define the current random number
1222 generator being used by the Scheme level interface and the random
1223 number library functions.
1225 The user is free to replace the default generator with the generator
1228 *** Variable: size_t scm_the_rng.rstate_size
1229 The size of the random state type used by the current RNG
1232 *** Function: unsigned long scm_the_rng.random_bits (scm_rstate *STATE)
1233 Given the random STATE, return 32 random bits.
1235 *** Function: void scm_the_rng.init_rstate (scm_rstate *STATE, chars *S, int N)
1236 Seed random state STATE using string S of length N.
1238 *** Function: scm_rstate *scm_the_rng.copy_rstate (scm_rstate *STATE)
1239 Given random state STATE, return a malloced copy.
1242 The default RNG is the MWC (Multiply With Carry) random number
1243 generator described by George Marsaglia at the Department of
1244 Statistics and Supercomputer Computations Research Institute, The
1245 Florida State University (http://stat.fsu.edu/~geo).
1247 It uses 64 bits, has a period of 4578426017172946943 (4.6e18), and
1248 passes all tests in the DIEHARD test suite
1249 (http://stat.fsu.edu/~geo/diehard.html). The generation of 32 bits
1250 costs one multiply and one add on platforms which either supports long
1251 longs (gcc does this on most systems) or have 64 bit longs. The cost
1252 is four multiply on other systems but this can be optimized by writing
1253 scm_i_uniform32 in assembler.
1255 These functions are provided through the scm_the_rng interface for use
1256 by libguile and the application.
1258 *** Function: unsigned long scm_i_uniform32 (scm_i_rstate *STATE)
1259 Given the random STATE, return 32 random bits.
1260 Don't use this function directly. Instead go through the plugin
1261 interface (see "Plug in interface" above).
1263 *** Function: void scm_i_init_rstate (scm_i_rstate *STATE, char *SEED, int N)
1264 Initialize STATE using SEED of length N.
1266 *** Function: scm_i_rstate *scm_i_copy_rstate (scm_i_rstate *STATE)
1267 Return a malloc:ed copy of STATE. This function can easily be re-used
1268 in the interfaces to other RNGs.
1270 ** Random number library functions
1271 These functions use the current RNG through the scm_the_rng interface.
1272 It might be a good idea to use these functions from your C code so
1273 that only one random generator is used by all code in your program.
1275 The default random state is stored in:
1277 *** Variable: SCM scm_var_random_state
1278 Contains the vcell of the Scheme variable "*random-state*" which is
1279 used as default state by all random number functions in the Scheme
1284 double x = scm_c_uniform01 (SCM_RSTATE (SCM_CDR (scm_var_random_state)));
1286 *** Function: scm_rstate *scm_c_default_rstate (void)
1287 This is a convenience function which returns the value of
1288 scm_var_random_state. An error message is generated if this value
1289 isn't a random state.
1291 *** Function: scm_rstate *scm_c_make_rstate (char *SEED, int LENGTH)
1292 Make a new random state from the string SEED of length LENGTH.
1294 It is generally not a good idea to use multiple random states in a
1295 program. While subsequent random numbers generated from one random
1296 state are guaranteed to be reasonably independent, there is no such
1297 guarantee for numbers generated from different random states.
1299 *** Macro: unsigned long scm_c_uniform32 (scm_rstate *STATE)
1300 Return 32 random bits.
1302 *** Function: double scm_c_uniform01 (scm_rstate *STATE)
1303 Return a sample from the uniform(0,1) distribution.
1305 *** Function: double scm_c_normal01 (scm_rstate *STATE)
1306 Return a sample from the normal(0,1) distribution.
1308 *** Function: double scm_c_exp1 (scm_rstate *STATE)
1309 Return a sample from the exp(1) distribution.
1311 *** Function: unsigned long scm_c_random (scm_rstate *STATE, unsigned long M)
1312 Return a sample from the discrete uniform(0,M) distribution.
1314 *** Function: SCM scm_c_random_bignum (scm_rstate *STATE, SCM M)
1315 Return a sample from the discrete uniform(0,M) distribution.
1316 M must be a bignum object. The returned value may be an INUM.
1320 Changes in Guile 1.3 (released Monday, October 19, 1998):
1322 * Changes to the distribution
1324 ** We renamed the SCHEME_LOAD_PATH environment variable to GUILE_LOAD_PATH.
1325 To avoid conflicts, programs should name environment variables after
1326 themselves, except when there's a common practice establishing some
1329 For now, Guile supports both GUILE_LOAD_PATH and SCHEME_LOAD_PATH,
1330 giving the former precedence, and printing a warning message if the
1331 latter is set. Guile 1.4 will not recognize SCHEME_LOAD_PATH at all.
1333 ** The header files related to multi-byte characters have been removed.
1334 They were: libguile/extchrs.h and libguile/mbstrings.h. Any C code
1335 which referred to these explicitly will probably need to be rewritten,
1336 since the support for the variant string types has been removed; see
1339 ** The header files append.h and sequences.h have been removed. These
1340 files implemented non-R4RS operations which would encourage
1341 non-portable programming style and less easy-to-read code.
1343 * Changes to the stand-alone interpreter
1345 ** New procedures have been added to implement a "batch mode":
1347 *** Function: batch-mode?
1349 Returns a boolean indicating whether the interpreter is in batch
1352 *** Function: set-batch-mode?! ARG
1354 If ARG is true, switches the interpreter to batch mode. The `#f'
1355 case has not been implemented.
1357 ** Guile now provides full command-line editing, when run interactively.
1358 To use this feature, you must have the readline library installed.
1359 The Guile build process will notice it, and automatically include
1362 The readline library is available via anonymous FTP from any GNU
1363 mirror site; the canonical location is "ftp://prep.ai.mit.edu/pub/gnu".
1365 ** the-last-stack is now a fluid.
1367 * Changes to the procedure for linking libguile with your programs
1369 ** You can now use the `guile-config' utility to build programs that use Guile.
1371 Guile now includes a command-line utility called `guile-config', which
1372 can provide information about how to compile and link programs that
1375 *** `guile-config compile' prints any C compiler flags needed to use Guile.
1376 You should include this command's output on the command line you use
1377 to compile C or C++ code that #includes the Guile header files. It's
1378 usually just a `-I' flag to help the compiler find the Guile headers.
1381 *** `guile-config link' prints any linker flags necessary to link with Guile.
1383 This command writes to its standard output a list of flags which you
1384 must pass to the linker to link your code against the Guile library.
1385 The flags include '-lguile' itself, any other libraries the Guile
1386 library depends upon, and any `-L' flags needed to help the linker
1387 find those libraries.
1389 For example, here is a Makefile rule that builds a program named 'foo'
1390 from the object files ${FOO_OBJECTS}, and links them against Guile:
1393 ${CC} ${CFLAGS} ${FOO_OBJECTS} `guile-config link` -o foo
1395 Previous Guile releases recommended that you use autoconf to detect
1396 which of a predefined set of libraries were present on your system.
1397 It is more robust to use `guile-config', since it records exactly which
1398 libraries the installed Guile library requires.
1400 This was originally called `build-guile', but was renamed to
1401 `guile-config' before Guile 1.3 was released, to be consistent with
1402 the analogous script for the GTK+ GUI toolkit, which is called
1406 ** Use the GUILE_FLAGS macro in your configure.in file to find Guile.
1408 If you are using the GNU autoconf package to configure your program,
1409 you can use the GUILE_FLAGS autoconf macro to call `guile-config'
1410 (described above) and gather the necessary values for use in your
1413 The GUILE_FLAGS macro expands to configure script code which runs the
1414 `guile-config' script, to find out where Guile's header files and
1415 libraries are installed. It sets two variables, marked for
1416 substitution, as by AC_SUBST.
1418 GUILE_CFLAGS --- flags to pass to a C or C++ compiler to build
1419 code that uses Guile header files. This is almost always just a
1422 GUILE_LDFLAGS --- flags to pass to the linker to link a
1423 program against Guile. This includes `-lguile' for the Guile
1424 library itself, any libraries that Guile itself requires (like
1425 -lqthreads), and so on. It may also include a -L flag to tell the
1426 compiler where to find the libraries.
1428 GUILE_FLAGS is defined in the file guile.m4, in the top-level
1429 directory of the Guile distribution. You can copy it into your
1430 package's aclocal.m4 file, and then use it in your configure.in file.
1432 If you are using the `aclocal' program, distributed with GNU automake,
1433 to maintain your aclocal.m4 file, the Guile installation process
1434 installs guile.m4 where aclocal will find it. All you need to do is
1435 use GUILE_FLAGS in your configure.in file, and then run `aclocal';
1436 this will copy the definition of GUILE_FLAGS into your aclocal.m4
1440 * Changes to Scheme functions and syntax
1442 ** Multi-byte strings have been removed, as have multi-byte and wide
1443 ports. We felt that these were the wrong approach to
1444 internationalization support.
1446 ** New function: readline [PROMPT]
1447 Read a line from the terminal, and allow the user to edit it,
1448 prompting with PROMPT. READLINE provides a large set of Emacs-like
1449 editing commands, lets the user recall previously typed lines, and
1450 works on almost every kind of terminal, including dumb terminals.
1452 READLINE assumes that the cursor is at the beginning of the line when
1453 it is invoked. Thus, you can't print a prompt yourself, and then call
1454 READLINE; you need to package up your prompt as a string, pass it to
1455 the function, and let READLINE print the prompt itself. This is
1456 because READLINE needs to know the prompt's screen width.
1458 For Guile to provide this function, you must have the readline
1459 library, version 2.1 or later, installed on your system. Readline is
1460 available via anonymous FTP from prep.ai.mit.edu in pub/gnu, or from
1461 any GNU mirror site.
1463 See also ADD-HISTORY function.
1465 ** New function: add-history STRING
1466 Add STRING as the most recent line in the history used by the READLINE
1467 command. READLINE does not add lines to the history itself; you must
1468 call ADD-HISTORY to make previous input available to the user.
1470 ** The behavior of the read-line function has changed.
1472 This function now uses standard C library functions to read the line,
1473 for speed. This means that it doesn not respect the value of
1474 scm-line-incrementors; it assumes that lines are delimited with
1477 (Note that this is read-line, the function that reads a line of text
1478 from a port, not readline, the function that reads a line from a
1479 terminal, providing full editing capabilities.)
1481 ** New module (ice-9 getopt-gnu-style): Parse command-line arguments.
1483 This module provides some simple argument parsing. It exports one
1486 Function: getopt-gnu-style ARG-LS
1487 Parse a list of program arguments into an alist of option
1490 Each item in the list of program arguments is examined to see if
1491 it meets the syntax of a GNU long-named option. An argument like
1492 `--MUMBLE' produces an element of the form (MUMBLE . #t) in the
1493 returned alist, where MUMBLE is a keyword object with the same
1494 name as the argument. An argument like `--MUMBLE=FROB' produces
1495 an element of the form (MUMBLE . FROB), where FROB is a string.
1497 As a special case, the returned alist also contains a pair whose
1498 car is the symbol `rest'. The cdr of this pair is a list
1499 containing all the items in the argument list that are not options
1500 of the form mentioned above.
1502 The argument `--' is treated specially: all items in the argument
1503 list appearing after such an argument are not examined, and are
1504 returned in the special `rest' list.
1506 This function does not parse normal single-character switches.
1507 You will need to parse them out of the `rest' list yourself.
1509 ** The read syntax for byte vectors and short vectors has changed.
1511 Instead of #bytes(...), write #y(...).
1513 Instead of #short(...), write #h(...).
1515 This may seem nutty, but, like the other uniform vectors, byte vectors
1516 and short vectors want to have the same print and read syntax (and,
1517 more basic, want to have read syntax!). Changing the read syntax to
1518 use multiple characters after the hash sign breaks with the
1519 conventions used in R5RS and the conventions used for the other
1520 uniform vectors. It also introduces complexity in the current reader,
1521 both on the C and Scheme levels. (The Right solution is probably to
1522 change the syntax and prototypes for uniform vectors entirely.)
1525 ** The new module (ice-9 session) provides useful interactive functions.
1527 *** New procedure: (apropos REGEXP OPTION ...)
1529 Display a list of top-level variables whose names match REGEXP, and
1530 the modules they are imported from. Each OPTION should be one of the
1533 value --- Show the value of each matching variable.
1534 shadow --- Show bindings shadowed by subsequently imported modules.
1535 full --- Same as both `shadow' and `value'.
1539 guile> (apropos "trace" 'full)
1540 debug: trace #<procedure trace args>
1541 debug: untrace #<procedure untrace args>
1542 the-scm-module: display-backtrace #<compiled-closure #<primitive-procedure gsubr-apply>>
1543 the-scm-module: before-backtrace-hook ()
1544 the-scm-module: backtrace #<primitive-procedure backtrace>
1545 the-scm-module: after-backtrace-hook ()
1546 the-scm-module: has-shown-backtrace-hint? #f
1549 ** There are new functions and syntax for working with macros.
1551 Guile implements macros as a special object type. Any variable whose
1552 top-level binding is a macro object acts as a macro. The macro object
1553 specifies how the expression should be transformed before evaluation.
1555 *** Macro objects now print in a reasonable way, resembling procedures.
1557 *** New function: (macro? OBJ)
1558 True iff OBJ is a macro object.
1560 *** New function: (primitive-macro? OBJ)
1561 Like (macro? OBJ), but true only if OBJ is one of the Guile primitive
1562 macro transformers, implemented in eval.c rather than Scheme code.
1564 Why do we have this function?
1565 - For symmetry with procedure? and primitive-procedure?,
1566 - to allow custom print procedures to tell whether a macro is
1567 primitive, and display it differently, and
1568 - to allow compilers and user-written evaluators to distinguish
1569 builtin special forms from user-defined ones, which could be
1572 *** New function: (macro-type OBJ)
1573 Return a value indicating what kind of macro OBJ is. Possible return
1576 The symbol `syntax' --- a macro created by procedure->syntax.
1577 The symbol `macro' --- a macro created by procedure->macro.
1578 The symbol `macro!' --- a macro created by procedure->memoizing-macro.
1579 The boolean #f --- if OBJ is not a macro object.
1581 *** New function: (macro-name MACRO)
1582 Return the name of the macro object MACRO's procedure, as returned by
1585 *** New function: (macro-transformer MACRO)
1586 Return the transformer procedure for MACRO.
1588 *** New syntax: (use-syntax MODULE ... TRANSFORMER)
1590 Specify a new macro expander to use in the current module. Each
1591 MODULE is a module name, with the same meaning as in the `use-modules'
1592 form; each named module's exported bindings are added to the current
1593 top-level environment. TRANSFORMER is an expression evaluated in the
1594 resulting environment which must yield a procedure to use as the
1595 module's eval transformer: every expression evaluated in this module
1596 is passed to this function, and the result passed to the Guile
1599 *** macro-eval! is removed. Use local-eval instead.
1601 ** Some magic has been added to the printer to better handle user
1602 written printing routines (like record printers, closure printers).
1604 The problem is that these user written routines must have access to
1605 the current `print-state' to be able to handle fancy things like
1606 detection of circular references. These print-states have to be
1607 passed to the builtin printing routines (display, write, etc) to
1608 properly continue the print chain.
1610 We didn't want to change all existing print code so that it
1611 explicitly passes thru a print state in addition to a port. Instead,
1612 we extented the possible values that the builtin printing routines
1613 accept as a `port'. In addition to a normal port, they now also take
1614 a pair of a normal port and a print-state. Printing will go to the
1615 port and the print-state will be used to control the detection of
1616 circular references, etc. If the builtin function does not care for a
1617 print-state, it is simply ignored.
1619 User written callbacks are now called with such a pair as their
1620 `port', but because every function now accepts this pair as a PORT
1621 argument, you don't have to worry about that. In fact, it is probably
1622 safest to not check for these pairs.
1624 However, it is sometimes necessary to continue a print chain on a
1625 different port, for example to get a intermediate string
1626 representation of the printed value, mangle that string somehow, and
1627 then to finally print the mangled string. Use the new function
1629 inherit-print-state OLD-PORT NEW-PORT
1631 for this. It constructs a new `port' that prints to NEW-PORT but
1632 inherits the print-state of OLD-PORT.
1634 ** struct-vtable-offset renamed to vtable-offset-user
1636 ** New constants: vtable-index-layout, vtable-index-vtable, vtable-index-printer
1638 ** There is now a fourth (optional) argument to make-vtable-vtable and
1639 make-struct when constructing new types (vtables). This argument
1640 initializes field vtable-index-printer of the vtable.
1642 ** The detection of circular references has been extended to structs.
1643 That is, a structure that -- in the process of being printed -- prints
1644 itself does not lead to infinite recursion.
1646 ** There is now some basic support for fluids. Please read
1647 "libguile/fluid.h" to find out more. It is accessible from Scheme with
1648 the following functions and macros:
1650 Function: make-fluid
1652 Create a new fluid object. Fluids are not special variables or
1653 some other extension to the semantics of Scheme, but rather
1654 ordinary Scheme objects. You can store them into variables (that
1655 are still lexically scoped, of course) or into any other place you
1656 like. Every fluid has a initial value of `#f'.
1658 Function: fluid? OBJ
1660 Test whether OBJ is a fluid.
1662 Function: fluid-ref FLUID
1663 Function: fluid-set! FLUID VAL
1665 Access/modify the fluid FLUID. Modifications are only visible
1666 within the current dynamic root (that includes threads).
1668 Function: with-fluids* FLUIDS VALUES THUNK
1670 FLUIDS is a list of fluids and VALUES a corresponding list of
1671 values for these fluids. Before THUNK gets called the values are
1672 installed in the fluids and the old values of the fluids are
1673 saved in the VALUES list. When the flow of control leaves THUNK
1674 or reenters it, the values get swapped again. You might think of
1675 this as a `safe-fluid-excursion'. Note that the VALUES list is
1676 modified by `with-fluids*'.
1678 Macro: with-fluids ((FLUID VALUE) ...) FORM ...
1680 The same as `with-fluids*' but with a different syntax. It looks
1681 just like `let', but both FLUID and VALUE are evaluated. Remember,
1682 fluids are not special variables but ordinary objects. FLUID
1683 should evaluate to a fluid.
1685 ** Changes to system call interfaces:
1687 *** close-port, close-input-port and close-output-port now return a
1688 boolean instead of an `unspecified' object. #t means that the port
1689 was successfully closed, while #f means it was already closed. It is
1690 also now possible for these procedures to raise an exception if an
1691 error occurs (some errors from write can be delayed until close.)
1693 *** the first argument to chmod, fcntl, ftell and fseek can now be a
1696 *** the third argument to fcntl is now optional.
1698 *** the first argument to chown can now be a file descriptor or a port.
1700 *** the argument to stat can now be a port.
1702 *** The following new procedures have been added (most use scsh
1705 *** procedure: close PORT/FD
1706 Similar to close-port (*note close-port: Closing Ports.), but also
1707 works on file descriptors. A side effect of closing a file
1708 descriptor is that any ports using that file descriptor are moved
1709 to a different file descriptor and have their revealed counts set
1712 *** procedure: port->fdes PORT
1713 Returns the integer file descriptor underlying PORT. As a side
1714 effect the revealed count of PORT is incremented.
1716 *** procedure: fdes->ports FDES
1717 Returns a list of existing ports which have FDES as an underlying
1718 file descriptor, without changing their revealed counts.
1720 *** procedure: fdes->inport FDES
1721 Returns an existing input port which has FDES as its underlying
1722 file descriptor, if one exists, and increments its revealed count.
1723 Otherwise, returns a new input port with a revealed count of 1.
1725 *** procedure: fdes->outport FDES
1726 Returns an existing output port which has FDES as its underlying
1727 file descriptor, if one exists, and increments its revealed count.
1728 Otherwise, returns a new output port with a revealed count of 1.
1730 The next group of procedures perform a `dup2' system call, if NEWFD
1731 (an integer) is supplied, otherwise a `dup'. The file descriptor to be
1732 duplicated can be supplied as an integer or contained in a port. The
1733 type of value returned varies depending on which procedure is used.
1735 All procedures also have the side effect when performing `dup2' that
1736 any ports using NEWFD are moved to a different file descriptor and have
1737 their revealed counts set to zero.
1739 *** procedure: dup->fdes PORT/FD [NEWFD]
1740 Returns an integer file descriptor.
1742 *** procedure: dup->inport PORT/FD [NEWFD]
1743 Returns a new input port using the new file descriptor.
1745 *** procedure: dup->outport PORT/FD [NEWFD]
1746 Returns a new output port using the new file descriptor.
1748 *** procedure: dup PORT/FD [NEWFD]
1749 Returns a new port if PORT/FD is a port, with the same mode as the
1750 supplied port, otherwise returns an integer file descriptor.
1752 *** procedure: dup->port PORT/FD MODE [NEWFD]
1753 Returns a new port using the new file descriptor. MODE supplies a
1754 mode string for the port (*note open-file: File Ports.).
1756 *** procedure: setenv NAME VALUE
1757 Modifies the environment of the current process, which is also the
1758 default environment inherited by child processes.
1760 If VALUE is `#f', then NAME is removed from the environment.
1761 Otherwise, the string NAME=VALUE is added to the environment,
1762 replacing any existing string with name matching NAME.
1764 The return value is unspecified.
1766 *** procedure: truncate-file OBJ SIZE
1767 Truncates the file referred to by OBJ to at most SIZE bytes. OBJ
1768 can be a string containing a file name or an integer file
1769 descriptor or port open for output on the file. The underlying
1770 system calls are `truncate' and `ftruncate'.
1772 The return value is unspecified.
1774 *** procedure: setvbuf PORT MODE [SIZE]
1775 Set the buffering mode for PORT. MODE can be:
1783 block buffered, using a newly allocated buffer of SIZE bytes.
1784 However if SIZE is zero or unspecified, the port will be made
1787 This procedure should not be used after I/O has been performed with
1790 Ports are usually block buffered by default, with a default buffer
1791 size. Procedures e.g., *Note open-file: File Ports, which accept a
1792 mode string allow `0' to be added to request an unbuffered port.
1794 *** procedure: fsync PORT/FD
1795 Copies any unwritten data for the specified output file descriptor
1796 to disk. If PORT/FD is a port, its buffer is flushed before the
1797 underlying file descriptor is fsync'd. The return value is
1800 *** procedure: open-fdes PATH FLAGS [MODES]
1801 Similar to `open' but returns a file descriptor instead of a port.
1803 *** procedure: execle PATH ENV [ARG] ...
1804 Similar to `execl', but the environment of the new process is
1805 specified by ENV, which must be a list of strings as returned by
1806 the `environ' procedure.
1808 This procedure is currently implemented using the `execve' system
1809 call, but we call it `execle' because of its Scheme calling
1812 *** procedure: strerror ERRNO
1813 Returns the Unix error message corresponding to ERRNO, an integer.
1815 *** procedure: primitive-exit [STATUS]
1816 Terminate the current process without unwinding the Scheme stack.
1817 This is would typically be useful after a fork. The exit status
1818 is STATUS if supplied, otherwise zero.
1820 *** procedure: times
1821 Returns an object with information about real and processor time.
1822 The following procedures accept such an object as an argument and
1823 return a selected component:
1826 The current real time, expressed as time units relative to an
1830 The CPU time units used by the calling process.
1833 The CPU time units used by the system on behalf of the
1837 The CPU time units used by terminated child processes of the
1838 calling process, whose status has been collected (e.g., using
1842 Similarly, the CPU times units used by the system on behalf of
1843 terminated child processes.
1845 ** Removed: list-length
1846 ** Removed: list-append, list-append!
1847 ** Removed: list-reverse, list-reverse!
1849 ** array-map renamed to array-map!
1851 ** serial-array-map renamed to serial-array-map!
1853 ** catch doesn't take #f as first argument any longer
1855 Previously, it was possible to pass #f instead of a key to `catch'.
1856 That would cause `catch' to pass a jump buffer object to the procedure
1857 passed as second argument. The procedure could then use this jump
1858 buffer objekt as an argument to throw.
1860 This mechanism has been removed since its utility doesn't motivate the
1861 extra complexity it introduces.
1863 ** The `#/' notation for lists now provokes a warning message from Guile.
1864 This syntax will be removed from Guile in the near future.
1866 To disable the warning message, set the GUILE_HUSH environment
1867 variable to any non-empty value.
1869 ** The newline character now prints as `#\newline', following the
1870 normal Scheme notation, not `#\nl'.
1872 * Changes to the gh_ interface
1874 ** The gh_enter function now takes care of loading the Guile startup files.
1875 gh_enter works by calling scm_boot_guile; see the remarks below.
1877 ** Function: void gh_write (SCM x)
1879 Write the printed representation of the scheme object x to the current
1880 output port. Corresponds to the scheme level `write'.
1882 ** gh_list_length renamed to gh_length.
1884 ** vector handling routines
1886 Several major changes. In particular, gh_vector() now resembles
1887 (vector ...) (with a caveat -- see manual), and gh_make_vector() now
1888 exists and behaves like (make-vector ...). gh_vset() and gh_vref()
1889 have been renamed gh_vector_set_x() and gh_vector_ref(). Some missing
1890 vector-related gh_ functions have been implemented.
1892 ** pair and list routines
1894 Implemented several of the R4RS pair and list functions that were
1897 ** gh_scm2doubles, gh_doubles2scm, gh_doubles2dvect
1899 New function. Converts double arrays back and forth between Scheme
1902 * Changes to the scm_ interface
1904 ** The function scm_boot_guile now takes care of loading the startup files.
1906 Guile's primary initialization function, scm_boot_guile, now takes
1907 care of loading `boot-9.scm', in the `ice-9' module, to initialize
1908 Guile, define the module system, and put together some standard
1909 bindings. It also loads `init.scm', which is intended to hold
1910 site-specific initialization code.
1912 Since Guile cannot operate properly until boot-9.scm is loaded, there
1913 is no reason to separate loading boot-9.scm from Guile's other
1914 initialization processes.
1916 This job used to be done by scm_compile_shell_switches, which didn't
1917 make much sense; in particular, it meant that people using Guile for
1918 non-shell-like applications had to jump through hoops to get Guile
1919 initialized properly.
1921 ** The function scm_compile_shell_switches no longer loads the startup files.
1922 Now, Guile always loads the startup files, whenever it is initialized;
1923 see the notes above for scm_boot_guile and scm_load_startup_files.
1925 ** Function: scm_load_startup_files
1926 This new function takes care of loading Guile's initialization file
1927 (`boot-9.scm'), and the site initialization file, `init.scm'. Since
1928 this is always called by the Guile initialization process, it's
1929 probably not too useful to call this yourself, but it's there anyway.
1931 ** The semantics of smob marking have changed slightly.
1933 The smob marking function (the `mark' member of the scm_smobfuns
1934 structure) is no longer responsible for setting the mark bit on the
1935 smob. The generic smob handling code in the garbage collector will
1936 set this bit. The mark function need only ensure that any other
1937 objects the smob refers to get marked.
1939 Note that this change means that the smob's GC8MARK bit is typically
1940 already set upon entry to the mark function. Thus, marking functions
1941 which look like this:
1944 if (SCM_GC8MARKP (ptr))
1946 SCM_SETGC8MARK (ptr);
1947 ... mark objects to which the smob refers ...
1950 are now incorrect, since they will return early, and fail to mark any
1951 other objects the smob refers to. Some code in the Guile library used
1954 ** The semantics of the I/O port functions in scm_ptobfuns have changed.
1956 If you have implemented your own I/O port type, by writing the
1957 functions required by the scm_ptobfuns and then calling scm_newptob,
1958 you will need to change your functions slightly.
1960 The functions in a scm_ptobfuns structure now expect the port itself
1961 as their argument; they used to expect the `stream' member of the
1962 port's scm_port_table structure. This allows functions in an
1963 scm_ptobfuns structure to easily access the port's cell (and any flags
1964 it its CAR), and the port's scm_port_table structure.
1966 Guile now passes the I/O port itself as the `port' argument in the
1967 following scm_ptobfuns functions:
1969 int (*free) (SCM port);
1970 int (*fputc) (int, SCM port);
1971 int (*fputs) (char *, SCM port);
1972 scm_sizet (*fwrite) SCM_P ((char *ptr,
1976 int (*fflush) (SCM port);
1977 int (*fgetc) (SCM port);
1978 int (*fclose) (SCM port);
1980 The interfaces to the `mark', `print', `equalp', and `fgets' methods
1983 If you have existing code which defines its own port types, it is easy
1984 to convert your code to the new interface; simply apply SCM_STREAM to
1985 the port argument to yield the value you code used to expect.
1987 Note that since both the port and the stream have the same type in the
1988 C code --- they are both SCM values --- the C compiler will not remind
1989 you if you forget to update your scm_ptobfuns functions.
1992 ** Function: int scm_internal_select (int fds,
1996 struct timeval *timeout);
1998 This is a replacement for the `select' function provided by the OS.
1999 It enables I/O blocking and sleeping to happen for one cooperative
2000 thread without blocking other threads. It also avoids busy-loops in
2001 these situations. It is intended that all I/O blocking and sleeping
2002 will finally go through this function. Currently, this function is
2003 only available on systems providing `gettimeofday' and `select'.
2005 ** Function: SCM scm_internal_stack_catch (SCM tag,
2006 scm_catch_body_t body,
2008 scm_catch_handler_t handler,
2011 A new sibling to the other two C level `catch' functions
2012 scm_internal_catch and scm_internal_lazy_catch. Use it if you want
2013 the stack to be saved automatically into the variable `the-last-stack'
2014 (scm_the_last_stack_var) on error. This is necessary if you want to
2015 use advanced error reporting, such as calling scm_display_error and
2016 scm_display_backtrace. (They both take a stack object as argument.)
2018 ** Function: SCM scm_spawn_thread (scm_catch_body_t body,
2020 scm_catch_handler_t handler,
2023 Spawns a new thread. It does a job similar to
2024 scm_call_with_new_thread but takes arguments more suitable when
2025 spawning threads from application C code.
2027 ** The hook scm_error_callback has been removed. It was originally
2028 intended as a way for the user to install his own error handler. But
2029 that method works badly since it intervenes between throw and catch,
2030 thereby changing the semantics of expressions like (catch #t ...).
2031 The correct way to do it is to use one of the C level catch functions
2032 in throw.c: scm_internal_catch/lazy_catch/stack_catch.
2034 ** Removed functions:
2036 scm_obj_length, scm_list_length, scm_list_append, scm_list_append_x,
2037 scm_list_reverse, scm_list_reverse_x
2039 ** New macros: SCM_LISTn where n is one of the integers 0-9.
2041 These can be used for pretty list creation from C. The idea is taken
2042 from Erick Gallesio's STk.
2044 ** scm_array_map renamed to scm_array_map_x
2046 ** mbstrings are now removed
2048 This means that the type codes scm_tc7_mb_string and
2049 scm_tc7_mb_substring has been removed.
2051 ** scm_gen_putc, scm_gen_puts, scm_gen_write, and scm_gen_getc have changed.
2053 Since we no longer support multi-byte strings, these I/O functions
2054 have been simplified, and renamed. Here are their old names, and
2055 their new names and arguments:
2057 scm_gen_putc -> void scm_putc (int c, SCM port);
2058 scm_gen_puts -> void scm_puts (char *s, SCM port);
2059 scm_gen_write -> void scm_lfwrite (char *ptr, scm_sizet size, SCM port);
2060 scm_gen_getc -> void scm_getc (SCM port);
2063 ** The macros SCM_TYP7D and SCM_TYP7SD has been removed.
2065 ** The macro SCM_TYP7S has taken the role of the old SCM_TYP7D
2067 SCM_TYP7S now masks away the bit which distinguishes substrings from
2070 ** scm_catch_body_t: Backward incompatible change!
2072 Body functions to scm_internal_catch and friends do not any longer
2073 take a second argument. This is because it is no longer possible to
2074 pass a #f arg to catch.
2076 ** Calls to scm_protect_object and scm_unprotect now nest properly.
2078 The function scm_protect_object protects its argument from being freed
2079 by the garbage collector. scm_unprotect_object removes that
2082 These functions now nest properly. That is, for every object O, there
2083 is a counter which scm_protect_object(O) increments and
2084 scm_unprotect_object(O) decrements, if the counter is greater than
2085 zero. Every object's counter is zero when it is first created. If an
2086 object's counter is greater than zero, the garbage collector will not
2087 reclaim its storage.
2089 This allows you to use scm_protect_object in your code without
2090 worrying that some other function you call will call
2091 scm_unprotect_object, and allow it to be freed. Assuming that the
2092 functions you call are well-behaved, and unprotect only those objects
2093 they protect, you can follow the same rule and have confidence that
2094 objects will be freed only at appropriate times.
2097 Changes in Guile 1.2 (released Tuesday, June 24 1997):
2099 * Changes to the distribution
2101 ** Nightly snapshots are now available from ftp.red-bean.com.
2102 The old server, ftp.cyclic.com, has been relinquished to its rightful
2105 Nightly snapshots of the Guile development sources are now available via
2106 anonymous FTP from ftp.red-bean.com, as /pub/guile/guile-snap.tar.gz.
2108 Via the web, that's: ftp://ftp.red-bean.com/pub/guile/guile-snap.tar.gz
2109 For getit, that's: ftp.red-bean.com:/pub/guile/guile-snap.tar.gz
2111 ** To run Guile without installing it, the procedure has changed a bit.
2113 If you used a separate build directory to compile Guile, you'll need
2114 to include the build directory in SCHEME_LOAD_PATH, as well as the
2115 source directory. See the `INSTALL' file for examples.
2117 * Changes to the procedure for linking libguile with your programs
2119 ** The standard Guile load path for Scheme code now includes
2120 $(datadir)/guile (usually /usr/local/share/guile). This means that
2121 you can install your own Scheme files there, and Guile will find them.
2122 (Previous versions of Guile only checked a directory whose name
2123 contained the Guile version number, so you had to re-install or move
2124 your Scheme sources each time you installed a fresh version of Guile.)
2126 The load path also includes $(datadir)/guile/site; we recommend
2127 putting individual Scheme files there. If you want to install a
2128 package with multiple source files, create a directory for them under
2131 ** Guile 1.2 will now use the Rx regular expression library, if it is
2132 installed on your system. When you are linking libguile into your own
2133 programs, this means you will have to link against -lguile, -lqt (if
2134 you configured Guile with thread support), and -lrx.
2136 If you are using autoconf to generate configuration scripts for your
2137 application, the following lines should suffice to add the appropriate
2138 libraries to your link command:
2140 ### Find Rx, quickthreads and libguile.
2141 AC_CHECK_LIB(rx, main)
2142 AC_CHECK_LIB(qt, main)
2143 AC_CHECK_LIB(guile, scm_shell)
2145 The Guile 1.2 distribution does not contain sources for the Rx
2146 library, as Guile 1.0 did. If you want to use Rx, you'll need to
2147 retrieve it from a GNU FTP site and install it separately.
2149 * Changes to Scheme functions and syntax
2151 ** The dynamic linking features of Guile are now enabled by default.
2152 You can disable them by giving the `--disable-dynamic-linking' option
2155 (dynamic-link FILENAME)
2157 Find the object file denoted by FILENAME (a string) and link it
2158 into the running Guile application. When everything works out,
2159 return a Scheme object suitable for representing the linked object
2160 file. Otherwise an error is thrown. How object files are
2161 searched is system dependent.
2163 (dynamic-object? VAL)
2165 Determine whether VAL represents a dynamically linked object file.
2167 (dynamic-unlink DYNOBJ)
2169 Unlink the indicated object file from the application. DYNOBJ
2170 should be one of the values returned by `dynamic-link'.
2172 (dynamic-func FUNCTION DYNOBJ)
2174 Search the C function indicated by FUNCTION (a string or symbol)
2175 in DYNOBJ and return some Scheme object that can later be used
2176 with `dynamic-call' to actually call this function. Right now,
2177 these Scheme objects are formed by casting the address of the
2178 function to `long' and converting this number to its Scheme
2181 (dynamic-call FUNCTION DYNOBJ)
2183 Call the C function indicated by FUNCTION and DYNOBJ. The
2184 function is passed no arguments and its return value is ignored.
2185 When FUNCTION is something returned by `dynamic-func', call that
2186 function and ignore DYNOBJ. When FUNCTION is a string (or symbol,
2187 etc.), look it up in DYNOBJ; this is equivalent to
2189 (dynamic-call (dynamic-func FUNCTION DYNOBJ) #f)
2191 Interrupts are deferred while the C function is executing (with
2192 SCM_DEFER_INTS/SCM_ALLOW_INTS).
2194 (dynamic-args-call FUNCTION DYNOBJ ARGS)
2196 Call the C function indicated by FUNCTION and DYNOBJ, but pass it
2197 some arguments and return its return value. The C function is
2198 expected to take two arguments and return an `int', just like
2201 int c_func (int argc, char **argv);
2203 ARGS must be a list of strings and is converted into an array of
2204 `char *'. The array is passed in ARGV and its size in ARGC. The
2205 return value is converted to a Scheme number and returned from the
2206 call to `dynamic-args-call'.
2208 When dynamic linking is disabled or not supported on your system,
2209 the above functions throw errors, but they are still available.
2211 Here is a small example that works on GNU/Linux:
2213 (define libc-obj (dynamic-link "libc.so"))
2214 (dynamic-args-call 'rand libc-obj '())
2216 See the file `libguile/DYNAMIC-LINKING' for additional comments.
2218 ** The #/ syntax for module names is depreciated, and will be removed
2219 in a future version of Guile. Instead of
2227 The latter syntax is more consistent with existing Lisp practice.
2229 ** Guile now does fancier printing of structures. Structures are the
2230 underlying implementation for records, which in turn are used to
2231 implement modules, so all of these object now print differently and in
2232 a more informative way.
2234 The Scheme printer will examine the builtin variable *struct-printer*
2235 whenever it needs to print a structure object. When this variable is
2236 not `#f' it is deemed to be a procedure and will be applied to the
2237 structure object and the output port. When *struct-printer* is `#f'
2238 or the procedure return `#f' the structure object will be printed in
2239 the boring #<struct 80458270> form.
2241 This hook is used by some routines in ice-9/boot-9.scm to implement
2242 type specific printing routines. Please read the comments there about
2245 One of the more specific uses of structs are records. The printing
2246 procedure that could be passed to MAKE-RECORD-TYPE is now actually
2247 called. It should behave like a *struct-printer* procedure (described
2250 ** Guile now supports a new R4RS-compliant syntax for keywords. A
2251 token of the form #:NAME, where NAME has the same syntax as a Scheme
2252 symbol, is the external representation of the keyword named NAME.
2253 Keyword objects print using this syntax as well, so values containing
2254 keyword objects can be read back into Guile. When used in an
2255 expression, keywords are self-quoting objects.
2257 Guile suports this read syntax, and uses this print syntax, regardless
2258 of the current setting of the `keyword' read option. The `keyword'
2259 read option only controls whether Guile recognizes the `:NAME' syntax,
2260 which is incompatible with R4RS. (R4RS says such token represent
2263 ** Guile has regular expression support again. Guile 1.0 included
2264 functions for matching regular expressions, based on the Rx library.
2265 In Guile 1.1, the Guile/Rx interface was removed to simplify the
2266 distribution, and thus Guile had no regular expression support. Guile
2267 1.2 again supports the most commonly used functions, and supports all
2268 of SCSH's regular expression functions.
2270 If your system does not include a POSIX regular expression library,
2271 and you have not linked Guile with a third-party regexp library such as
2272 Rx, these functions will not be available. You can tell whether your
2273 Guile installation includes regular expression support by checking
2274 whether the `*features*' list includes the `regex' symbol.
2276 *** regexp functions
2278 By default, Guile supports POSIX extended regular expressions. That
2279 means that the characters `(', `)', `+' and `?' are special, and must
2280 be escaped if you wish to match the literal characters.
2282 This regular expression interface was modeled after that implemented
2283 by SCSH, the Scheme Shell. It is intended to be upwardly compatible
2284 with SCSH regular expressions.
2286 **** Function: string-match PATTERN STR [START]
2287 Compile the string PATTERN into a regular expression and compare
2288 it with STR. The optional numeric argument START specifies the
2289 position of STR at which to begin matching.
2291 `string-match' returns a "match structure" which describes what,
2292 if anything, was matched by the regular expression. *Note Match
2293 Structures::. If STR does not match PATTERN at all,
2294 `string-match' returns `#f'.
2296 Each time `string-match' is called, it must compile its PATTERN
2297 argument into a regular expression structure. This operation is
2298 expensive, which makes `string-match' inefficient if the same regular
2299 expression is used several times (for example, in a loop). For better
2300 performance, you can compile a regular expression in advance and then
2301 match strings against the compiled regexp.
2303 **** Function: make-regexp STR [FLAGS]
2304 Compile the regular expression described by STR, and return the
2305 compiled regexp structure. If STR does not describe a legal
2306 regular expression, `make-regexp' throws a
2307 `regular-expression-syntax' error.
2309 FLAGS may be the bitwise-or of one or more of the following:
2311 **** Constant: regexp/extended
2312 Use POSIX Extended Regular Expression syntax when interpreting
2313 STR. If not set, POSIX Basic Regular Expression syntax is used.
2314 If the FLAGS argument is omitted, we assume regexp/extended.
2316 **** Constant: regexp/icase
2317 Do not differentiate case. Subsequent searches using the
2318 returned regular expression will be case insensitive.
2320 **** Constant: regexp/newline
2321 Match-any-character operators don't match a newline.
2323 A non-matching list ([^...]) not containing a newline matches a
2326 Match-beginning-of-line operator (^) matches the empty string
2327 immediately after a newline, regardless of whether the FLAGS
2328 passed to regexp-exec contain regexp/notbol.
2330 Match-end-of-line operator ($) matches the empty string
2331 immediately before a newline, regardless of whether the FLAGS
2332 passed to regexp-exec contain regexp/noteol.
2334 **** Function: regexp-exec REGEXP STR [START [FLAGS]]
2335 Match the compiled regular expression REGEXP against `str'. If
2336 the optional integer START argument is provided, begin matching
2337 from that position in the string. Return a match structure
2338 describing the results of the match, or `#f' if no match could be
2341 FLAGS may be the bitwise-or of one or more of the following:
2343 **** Constant: regexp/notbol
2344 The match-beginning-of-line operator always fails to match (but
2345 see the compilation flag regexp/newline above) This flag may be
2346 used when different portions of a string are passed to
2347 regexp-exec and the beginning of the string should not be
2348 interpreted as the beginning of the line.
2350 **** Constant: regexp/noteol
2351 The match-end-of-line operator always fails to match (but see the
2352 compilation flag regexp/newline above)
2354 **** Function: regexp? OBJ
2355 Return `#t' if OBJ is a compiled regular expression, or `#f'
2358 Regular expressions are commonly used to find patterns in one string
2359 and replace them with the contents of another string.
2361 **** Function: regexp-substitute PORT MATCH [ITEM...]
2362 Write to the output port PORT selected contents of the match
2363 structure MATCH. Each ITEM specifies what should be written, and
2364 may be one of the following arguments:
2366 * A string. String arguments are written out verbatim.
2368 * An integer. The submatch with that number is written.
2370 * The symbol `pre'. The portion of the matched string preceding
2371 the regexp match is written.
2373 * The symbol `post'. The portion of the matched string
2374 following the regexp match is written.
2376 PORT may be `#f', in which case nothing is written; instead,
2377 `regexp-substitute' constructs a string from the specified ITEMs
2380 **** Function: regexp-substitute/global PORT REGEXP TARGET [ITEM...]
2381 Similar to `regexp-substitute', but can be used to perform global
2382 substitutions on STR. Instead of taking a match structure as an
2383 argument, `regexp-substitute/global' takes two string arguments: a
2384 REGEXP string describing a regular expression, and a TARGET string
2385 which should be matched against this regular expression.
2387 Each ITEM behaves as in REGEXP-SUBSTITUTE, with the following
2390 * A function may be supplied. When this function is called, it
2391 will be passed one argument: a match structure for a given
2392 regular expression match. It should return a string to be
2393 written out to PORT.
2395 * The `post' symbol causes `regexp-substitute/global' to recurse
2396 on the unmatched portion of STR. This *must* be supplied in
2397 order to perform global search-and-replace on STR; if it is
2398 not present among the ITEMs, then `regexp-substitute/global'
2399 will return after processing a single match.
2401 *** Match Structures
2403 A "match structure" is the object returned by `string-match' and
2404 `regexp-exec'. It describes which portion of a string, if any, matched
2405 the given regular expression. Match structures include: a reference to
2406 the string that was checked for matches; the starting and ending
2407 positions of the regexp match; and, if the regexp included any
2408 parenthesized subexpressions, the starting and ending positions of each
2411 In each of the regexp match functions described below, the `match'
2412 argument must be a match structure returned by a previous call to
2413 `string-match' or `regexp-exec'. Most of these functions return some
2414 information about the original target string that was matched against a
2415 regular expression; we will call that string TARGET for easy reference.
2417 **** Function: regexp-match? OBJ
2418 Return `#t' if OBJ is a match structure returned by a previous
2419 call to `regexp-exec', or `#f' otherwise.
2421 **** Function: match:substring MATCH [N]
2422 Return the portion of TARGET matched by subexpression number N.
2423 Submatch 0 (the default) represents the entire regexp match. If
2424 the regular expression as a whole matched, but the subexpression
2425 number N did not match, return `#f'.
2427 **** Function: match:start MATCH [N]
2428 Return the starting position of submatch number N.
2430 **** Function: match:end MATCH [N]
2431 Return the ending position of submatch number N.
2433 **** Function: match:prefix MATCH
2434 Return the unmatched portion of TARGET preceding the regexp match.
2436 **** Function: match:suffix MATCH
2437 Return the unmatched portion of TARGET following the regexp match.
2439 **** Function: match:count MATCH
2440 Return the number of parenthesized subexpressions from MATCH.
2441 Note that the entire regular expression match itself counts as a
2442 subexpression, and failed submatches are included in the count.
2444 **** Function: match:string MATCH
2445 Return the original TARGET string.
2447 *** Backslash Escapes
2449 Sometimes you will want a regexp to match characters like `*' or `$'
2450 exactly. For example, to check whether a particular string represents
2451 a menu entry from an Info node, it would be useful to match it against
2452 a regexp like `^* [^:]*::'. However, this won't work; because the
2453 asterisk is a metacharacter, it won't match the `*' at the beginning of
2454 the string. In this case, we want to make the first asterisk un-magic.
2456 You can do this by preceding the metacharacter with a backslash
2457 character `\'. (This is also called "quoting" the metacharacter, and
2458 is known as a "backslash escape".) When Guile sees a backslash in a
2459 regular expression, it considers the following glyph to be an ordinary
2460 character, no matter what special meaning it would ordinarily have.
2461 Therefore, we can make the above example work by changing the regexp to
2462 `^\* [^:]*::'. The `\*' sequence tells the regular expression engine
2463 to match only a single asterisk in the target string.
2465 Since the backslash is itself a metacharacter, you may force a
2466 regexp to match a backslash in the target string by preceding the
2467 backslash with itself. For example, to find variable references in a
2468 TeX program, you might want to find occurrences of the string `\let\'
2469 followed by any number of alphabetic characters. The regular expression
2470 `\\let\\[A-Za-z]*' would do this: the double backslashes in the regexp
2471 each match a single backslash in the target string.
2473 **** Function: regexp-quote STR
2474 Quote each special character found in STR with a backslash, and
2475 return the resulting string.
2477 *Very important:* Using backslash escapes in Guile source code (as
2478 in Emacs Lisp or C) can be tricky, because the backslash character has
2479 special meaning for the Guile reader. For example, if Guile encounters
2480 the character sequence `\n' in the middle of a string while processing
2481 Scheme code, it replaces those characters with a newline character.
2482 Similarly, the character sequence `\t' is replaced by a horizontal tab.
2483 Several of these "escape sequences" are processed by the Guile reader
2484 before your code is executed. Unrecognized escape sequences are
2485 ignored: if the characters `\*' appear in a string, they will be
2486 translated to the single character `*'.
2488 This translation is obviously undesirable for regular expressions,
2489 since we want to be able to include backslashes in a string in order to
2490 escape regexp metacharacters. Therefore, to make sure that a backslash
2491 is preserved in a string in your Guile program, you must use *two*
2492 consecutive backslashes:
2494 (define Info-menu-entry-pattern (make-regexp "^\\* [^:]*"))
2496 The string in this example is preprocessed by the Guile reader before
2497 any code is executed. The resulting argument to `make-regexp' is the
2498 string `^\* [^:]*', which is what we really want.
2500 This also means that in order to write a regular expression that
2501 matches a single backslash character, the regular expression string in
2502 the source code must include *four* backslashes. Each consecutive pair
2503 of backslashes gets translated by the Guile reader to a single
2504 backslash, and the resulting double-backslash is interpreted by the
2505 regexp engine as matching a single backslash character. Hence:
2507 (define tex-variable-pattern (make-regexp "\\\\let\\\\=[A-Za-z]*"))
2509 The reason for the unwieldiness of this syntax is historical. Both
2510 regular expression pattern matchers and Unix string processing systems
2511 have traditionally used backslashes with the special meanings described
2512 above. The POSIX regular expression specification and ANSI C standard
2513 both require these semantics. Attempting to abandon either convention
2514 would cause other kinds of compatibility problems, possibly more severe
2515 ones. Therefore, without extending the Scheme reader to support
2516 strings with different quoting conventions (an ungainly and confusing
2517 extension when implemented in other languages), we must adhere to this
2518 cumbersome escape syntax.
2520 * Changes to the gh_ interface
2522 * Changes to the scm_ interface
2524 * Changes to system call interfaces:
2526 ** The value returned by `raise' is now unspecified. It throws an exception
2529 *** A new procedure `sigaction' can be used to install signal handlers
2531 (sigaction signum [action] [flags])
2533 signum is the signal number, which can be specified using the value
2536 If action is omitted, sigaction returns a pair: the CAR is the current
2537 signal hander, which will be either an integer with the value SIG_DFL
2538 (default action) or SIG_IGN (ignore), or the Scheme procedure which
2539 handles the signal, or #f if a non-Scheme procedure handles the
2540 signal. The CDR contains the current sigaction flags for the handler.
2542 If action is provided, it is installed as the new handler for signum.
2543 action can be a Scheme procedure taking one argument, or the value of
2544 SIG_DFL (default action) or SIG_IGN (ignore), or #f to restore
2545 whatever signal handler was installed before sigaction was first used.
2546 Flags can optionally be specified for the new handler (SA_RESTART is
2547 always used if the system provides it, so need not be specified.) The
2548 return value is a pair with information about the old handler as
2551 This interface does not provide access to the "signal blocking"
2552 facility. Maybe this is not needed, since the thread support may
2553 provide solutions to the problem of consistent access to data
2556 *** A new procedure `flush-all-ports' is equivalent to running
2557 `force-output' on every port open for output.
2559 ** Guile now provides information on how it was built, via the new
2560 global variable, %guile-build-info. This variable records the values
2561 of the standard GNU makefile directory variables as an assocation
2562 list, mapping variable names (symbols) onto directory paths (strings).
2563 For example, to find out where the Guile link libraries were
2564 installed, you can say:
2566 guile -c "(display (assq-ref %guile-build-info 'libdir)) (newline)"
2569 * Changes to the scm_ interface
2571 ** The new function scm_handle_by_message_noexit is just like the
2572 existing scm_handle_by_message function, except that it doesn't call
2573 exit to terminate the process. Instead, it prints a message and just
2574 returns #f. This might be a more appropriate catch-all handler for
2575 new dynamic roots and threads.
2578 Changes in Guile 1.1 (released Friday, May 16 1997):
2580 * Changes to the distribution.
2582 The Guile 1.0 distribution has been split up into several smaller
2584 guile-core --- the Guile interpreter itself.
2585 guile-tcltk --- the interface between the Guile interpreter and
2586 Tcl/Tk; Tcl is an interpreter for a stringy language, and Tk
2587 is a toolkit for building graphical user interfaces.
2588 guile-rgx-ctax --- the interface between Guile and the Rx regular
2589 expression matcher, and the translator for the Ctax
2590 programming language. These are packaged together because the
2591 Ctax translator uses Rx to parse Ctax source code.
2593 This NEWS file describes the changes made to guile-core since the 1.0
2596 We no longer distribute the documentation, since it was either out of
2597 date, or incomplete. As soon as we have current documentation, we
2602 * Changes to the stand-alone interpreter
2604 ** guile now accepts command-line arguments compatible with SCSH, Olin
2605 Shivers' Scheme Shell.
2607 In general, arguments are evaluated from left to right, but there are
2608 exceptions. The following switches stop argument processing, and
2609 stash all remaining command-line arguments as the value returned by
2610 the (command-line) function.
2611 -s SCRIPT load Scheme source code from FILE, and exit
2612 -c EXPR evalute Scheme expression EXPR, and exit
2613 -- stop scanning arguments; run interactively
2615 The switches below are processed as they are encountered.
2616 -l FILE load Scheme source code from FILE
2617 -e FUNCTION after reading script, apply FUNCTION to
2618 command line arguments
2619 -ds do -s script at this point
2620 --emacs enable Emacs protocol (experimental)
2621 -h, --help display this help and exit
2622 -v, --version display version information and exit
2623 \ read arguments from following script lines
2625 So, for example, here is a Guile script named `ekko' (thanks, Olin)
2626 which re-implements the traditional "echo" command:
2628 #!/usr/local/bin/guile -s
2631 (map (lambda (arg) (display arg) (display " "))
2635 (main (command-line))
2637 Suppose we invoke this script as follows:
2639 ekko a speckled gecko
2641 Through the magic of Unix script processing (triggered by the `#!'
2642 token at the top of the file), /usr/local/bin/guile receives the
2643 following list of command-line arguments:
2645 ("-s" "./ekko" "a" "speckled" "gecko")
2647 Unix inserts the name of the script after the argument specified on
2648 the first line of the file (in this case, "-s"), and then follows that
2649 with the arguments given to the script. Guile loads the script, which
2650 defines the `main' function, and then applies it to the list of
2651 remaining command-line arguments, ("a" "speckled" "gecko").
2653 In Unix, the first line of a script file must take the following form:
2655 #!INTERPRETER ARGUMENT
2657 where INTERPRETER is the absolute filename of the interpreter
2658 executable, and ARGUMENT is a single command-line argument to pass to
2661 You may only pass one argument to the interpreter, and its length is
2662 limited. These restrictions can be annoying to work around, so Guile
2663 provides a general mechanism (borrowed from, and compatible with,
2664 SCSH) for circumventing them.
2666 If the ARGUMENT in a Guile script is a single backslash character,
2667 `\', Guile will open the script file, parse arguments from its second
2668 and subsequent lines, and replace the `\' with them. So, for example,
2669 here is another implementation of the `ekko' script:
2671 #!/usr/local/bin/guile \
2675 (for-each (lambda (arg) (display arg) (display " "))
2679 If the user invokes this script as follows:
2681 ekko a speckled gecko
2683 Unix expands this into
2685 /usr/local/bin/guile \ ekko a speckled gecko
2687 When Guile sees the `\' argument, it replaces it with the arguments
2688 read from the second line of the script, producing:
2690 /usr/local/bin/guile -e main -s ekko a speckled gecko
2692 This tells Guile to load the `ekko' script, and apply the function
2693 `main' to the argument list ("a" "speckled" "gecko").
2695 Here is how Guile parses the command-line arguments:
2696 - Each space character terminates an argument. This means that two
2697 spaces in a row introduce an empty-string argument.
2698 - The tab character is not permitted (unless you quote it with the
2699 backslash character, as described below), to avoid confusion.
2700 - The newline character terminates the sequence of arguments, and will
2701 also terminate a final non-empty argument. (However, a newline
2702 following a space will not introduce a final empty-string argument;
2703 it only terminates the argument list.)
2704 - The backslash character is the escape character. It escapes
2705 backslash, space, tab, and newline. The ANSI C escape sequences
2706 like \n and \t are also supported. These produce argument
2707 constituents; the two-character combination \n doesn't act like a
2708 terminating newline. The escape sequence \NNN for exactly three
2709 octal digits reads as the character whose ASCII code is NNN. As
2710 above, characters produced this way are argument constituents.
2711 Backslash followed by other characters is not allowed.
2713 * Changes to the procedure for linking libguile with your programs
2715 ** Guile now builds and installs a shared guile library, if your
2716 system support shared libraries. (It still builds a static library on
2717 all systems.) Guile automatically detects whether your system
2718 supports shared libraries. To prevent Guile from buildisg shared
2719 libraries, pass the `--disable-shared' flag to the configure script.
2721 Guile takes longer to compile when it builds shared libraries, because
2722 it must compile every file twice --- once to produce position-
2723 independent object code, and once to produce normal object code.
2725 ** The libthreads library has been merged into libguile.
2727 To link a program against Guile, you now need only link against
2728 -lguile and -lqt; -lthreads is no longer needed. If you are using
2729 autoconf to generate configuration scripts for your application, the
2730 following lines should suffice to add the appropriate libraries to
2733 ### Find quickthreads and libguile.
2734 AC_CHECK_LIB(qt, main)
2735 AC_CHECK_LIB(guile, scm_shell)
2737 * Changes to Scheme functions
2739 ** Guile Scheme's special syntax for keyword objects is now optional,
2740 and disabled by default.
2742 The syntax variation from R4RS made it difficult to port some
2743 interesting packages to Guile. The routines which accepted keyword
2744 arguments (mostly in the module system) have been modified to also
2745 accept symbols whose names begin with `:'.
2747 To change the keyword syntax, you must first import the (ice-9 debug)
2749 (use-modules (ice-9 debug))
2751 Then you can enable the keyword syntax as follows:
2752 (read-set! keywords 'prefix)
2754 To disable keyword syntax, do this:
2755 (read-set! keywords #f)
2757 ** Many more primitive functions accept shared substrings as
2758 arguments. In the past, these functions required normal, mutable
2759 strings as arguments, although they never made use of this
2762 ** The uniform array functions now operate on byte vectors. These
2763 functions are `array-fill!', `serial-array-copy!', `array-copy!',
2764 `serial-array-map', `array-map', `array-for-each', and
2767 ** The new functions `trace' and `untrace' implement simple debugging
2768 support for Scheme functions.
2770 The `trace' function accepts any number of procedures as arguments,
2771 and tells the Guile interpreter to display each procedure's name and
2772 arguments each time the procedure is invoked. When invoked with no
2773 arguments, `trace' returns the list of procedures currently being
2776 The `untrace' function accepts any number of procedures as arguments,
2777 and tells the Guile interpreter not to trace them any more. When
2778 invoked with no arguments, `untrace' untraces all curretly traced
2781 The tracing in Guile has an advantage over most other systems: we
2782 don't create new procedure objects, but mark the procedure objects
2783 themselves. This means that anonymous and internal procedures can be
2786 ** The function `assert-repl-prompt' has been renamed to
2787 `set-repl-prompt!'. It takes one argument, PROMPT.
2788 - If PROMPT is #f, the Guile read-eval-print loop will not prompt.
2789 - If PROMPT is a string, we use it as a prompt.
2790 - If PROMPT is a procedure accepting no arguments, we call it, and
2791 display the result as a prompt.
2792 - Otherwise, we display "> ".
2794 ** The new function `eval-string' reads Scheme expressions from a
2795 string and evaluates them, returning the value of the last expression
2796 in the string. If the string contains no expressions, it returns an
2799 ** The new function `thunk?' returns true iff its argument is a
2800 procedure of zero arguments.
2802 ** `defined?' is now a builtin function, instead of syntax. This
2803 means that its argument should be quoted. It returns #t iff its
2804 argument is bound in the current module.
2806 ** The new syntax `use-modules' allows you to add new modules to your
2807 environment without re-typing a complete `define-module' form. It
2808 accepts any number of module names as arguments, and imports their
2809 public bindings into the current module.
2811 ** The new function (module-defined? NAME MODULE) returns true iff
2812 NAME, a symbol, is defined in MODULE, a module object.
2814 ** The new function `builtin-bindings' creates and returns a hash
2815 table containing copies of all the root module's bindings.
2817 ** The new function `builtin-weak-bindings' does the same as
2818 `builtin-bindings', but creates a doubly-weak hash table.
2820 ** The `equal?' function now considers variable objects to be
2821 equivalent if they have the same name and the same value.
2823 ** The new function `command-line' returns the command-line arguments
2824 given to Guile, as a list of strings.
2826 When using guile as a script interpreter, `command-line' returns the
2827 script's arguments; those processed by the interpreter (like `-s' or
2828 `-c') are omitted. (In other words, you get the normal, expected
2829 behavior.) Any application that uses scm_shell to process its
2830 command-line arguments gets this behavior as well.
2832 ** The new function `load-user-init' looks for a file called `.guile'
2833 in the user's home directory, and loads it if it exists. This is
2834 mostly for use by the code generated by scm_compile_shell_switches,
2835 but we thought it might also be useful in other circumstances.
2837 ** The new function `log10' returns the base-10 logarithm of its
2840 ** Changes to I/O functions
2842 *** The functions `read', `primitive-load', `read-and-eval!', and
2843 `primitive-load-path' no longer take optional arguments controlling
2844 case insensitivity and a `#' parser.
2846 Case sensitivity is now controlled by a read option called
2847 `case-insensitive'. The user can add new `#' syntaxes with the
2848 `read-hash-extend' function (see below).
2850 *** The new function `read-hash-extend' allows the user to change the
2851 syntax of Guile Scheme in a somewhat controlled way.
2853 (read-hash-extend CHAR PROC)
2854 When parsing S-expressions, if we read a `#' character followed by
2855 the character CHAR, use PROC to parse an object from the stream.
2856 If PROC is #f, remove any parsing procedure registered for CHAR.
2858 The reader applies PROC to two arguments: CHAR and an input port.
2860 *** The new functions read-delimited and read-delimited! provide a
2861 general mechanism for doing delimited input on streams.
2863 (read-delimited DELIMS [PORT HANDLE-DELIM])
2864 Read until we encounter one of the characters in DELIMS (a string),
2865 or end-of-file. PORT is the input port to read from; it defaults to
2866 the current input port. The HANDLE-DELIM parameter determines how
2867 the terminating character is handled; it should be one of the
2870 'trim omit delimiter from result
2871 'peek leave delimiter character in input stream
2872 'concat append delimiter character to returned value
2873 'split return a pair: (RESULT . TERMINATOR)
2875 HANDLE-DELIM defaults to 'peek.
2877 (read-delimited! DELIMS BUF [PORT HANDLE-DELIM START END])
2878 A side-effecting variant of `read-delimited'.
2880 The data is written into the string BUF at the indices in the
2881 half-open interval [START, END); the default interval is the whole
2882 string: START = 0 and END = (string-length BUF). The values of
2883 START and END must specify a well-defined interval in BUF, i.e.
2884 0 <= START <= END <= (string-length BUF).
2886 It returns NBYTES, the number of bytes read. If the buffer filled
2887 up without a delimiter character being found, it returns #f. If the
2888 port is at EOF when the read starts, it returns the EOF object.
2890 If an integer is returned (i.e., the read is successfully terminated
2891 by reading a delimiter character), then the HANDLE-DELIM parameter
2892 determines how to handle the terminating character. It is described
2893 above, and defaults to 'peek.
2895 (The descriptions of these functions were borrowed from the SCSH
2896 manual, by Olin Shivers and Brian Carlstrom.)
2898 *** The `%read-delimited!' function is the primitive used to implement
2899 `read-delimited' and `read-delimited!'.
2901 (%read-delimited! DELIMS BUF GOBBLE? [PORT START END])
2903 This returns a pair of values: (TERMINATOR . NUM-READ).
2904 - TERMINATOR describes why the read was terminated. If it is a
2905 character or the eof object, then that is the value that terminated
2906 the read. If it is #f, the function filled the buffer without finding
2907 a delimiting character.
2908 - NUM-READ is the number of characters read into BUF.
2910 If the read is successfully terminated by reading a delimiter
2911 character, then the gobble? parameter determines what to do with the
2912 terminating character. If true, the character is removed from the
2913 input stream; if false, the character is left in the input stream
2914 where a subsequent read operation will retrieve it. In either case,
2915 the character is also the first value returned by the procedure call.
2917 (The descriptions of this function was borrowed from the SCSH manual,
2918 by Olin Shivers and Brian Carlstrom.)
2920 *** The `read-line' and `read-line!' functions have changed; they now
2921 trim the terminator by default; previously they appended it to the
2922 returned string. For the old behavior, use (read-line PORT 'concat).
2924 *** The functions `uniform-array-read!' and `uniform-array-write!' now
2925 take new optional START and END arguments, specifying the region of
2926 the array to read and write.
2928 *** The `ungetc-char-ready?' function has been removed. We feel it's
2929 inappropriate for an interface to expose implementation details this
2932 ** Changes to the Unix library and system call interface
2934 *** The new fcntl function provides access to the Unix `fcntl' system
2937 (fcntl PORT COMMAND VALUE)
2938 Apply COMMAND to PORT's file descriptor, with VALUE as an argument.
2939 Values for COMMAND are:
2941 F_DUPFD duplicate a file descriptor
2942 F_GETFD read the descriptor's close-on-exec flag
2943 F_SETFD set the descriptor's close-on-exec flag to VALUE
2944 F_GETFL read the descriptor's flags, as set on open
2945 F_SETFL set the descriptor's flags, as set on open to VALUE
2946 F_GETOWN return the process ID of a socket's owner, for SIGIO
2947 F_SETOWN set the process that owns a socket to VALUE, for SIGIO
2948 FD_CLOEXEC not sure what this is
2950 For details, see the documentation for the fcntl system call.
2952 *** The arguments to `select' have changed, for compatibility with
2953 SCSH. The TIMEOUT parameter may now be non-integral, yielding the
2954 expected behavior. The MILLISECONDS parameter has been changed to
2955 MICROSECONDS, to more closely resemble the underlying system call.
2956 The RVEC, WVEC, and EVEC arguments can now be vectors; the type of the
2957 corresponding return set will be the same.
2959 *** The arguments to the `mknod' system call have changed. They are
2962 (mknod PATH TYPE PERMS DEV)
2963 Create a new file (`node') in the file system. PATH is the name of
2964 the file to create. TYPE is the kind of file to create; it should
2965 be 'fifo, 'block-special, or 'char-special. PERMS specifies the
2966 permission bits to give the newly created file. If TYPE is
2967 'block-special or 'char-special, DEV specifies which device the
2968 special file refers to; its interpretation depends on the kind of
2969 special file being created.
2971 *** The `fork' function has been renamed to `primitive-fork', to avoid
2972 clashing with various SCSH forks.
2974 *** The `recv' and `recvfrom' functions have been renamed to `recv!'
2975 and `recvfrom!'. They no longer accept a size for a second argument;
2976 you must pass a string to hold the received value. They no longer
2977 return the buffer. Instead, `recv' returns the length of the message
2978 received, and `recvfrom' returns a pair containing the packet's length
2979 and originating address.
2981 *** The file descriptor datatype has been removed, as have the
2982 `read-fd', `write-fd', `close', `lseek', and `dup' functions.
2983 We plan to replace these functions with a SCSH-compatible interface.
2985 *** The `create' function has been removed; it's just a special case
2988 *** There are new functions to break down process termination status
2989 values. In the descriptions below, STATUS is a value returned by
2992 (status:exit-val STATUS)
2993 If the child process exited normally, this function returns the exit
2994 code for the child process (i.e., the value passed to exit, or
2995 returned from main). If the child process did not exit normally,
2996 this function returns #f.
2998 (status:stop-sig STATUS)
2999 If the child process was suspended by a signal, this function
3000 returns the signal that suspended the child. Otherwise, it returns
3003 (status:term-sig STATUS)
3004 If the child process terminated abnormally, this function returns
3005 the signal that terminated the child. Otherwise, this function
3008 POSIX promises that exactly one of these functions will return true on
3009 a valid STATUS value.
3011 These functions are compatible with SCSH.
3013 *** There are new accessors and setters for the broken-out time vectors
3014 returned by `localtime', `gmtime', and that ilk. They are:
3016 Component Accessor Setter
3017 ========================= ============ ============
3018 seconds tm:sec set-tm:sec
3019 minutes tm:min set-tm:min
3020 hours tm:hour set-tm:hour
3021 day of the month tm:mday set-tm:mday
3022 month tm:mon set-tm:mon
3023 year tm:year set-tm:year
3024 day of the week tm:wday set-tm:wday
3025 day in the year tm:yday set-tm:yday
3026 daylight saving time tm:isdst set-tm:isdst
3027 GMT offset, seconds tm:gmtoff set-tm:gmtoff
3028 name of time zone tm:zone set-tm:zone
3030 *** There are new accessors for the vectors returned by `uname',
3031 describing the host system:
3034 ============================================== ================
3035 name of the operating system implementation utsname:sysname
3036 network name of this machine utsname:nodename
3037 release level of the operating system utsname:release
3038 version level of the operating system utsname:version
3039 machine hardware platform utsname:machine
3041 *** There are new accessors for the vectors returned by `getpw',
3042 `getpwnam', `getpwuid', and `getpwent', describing entries from the
3043 system's user database:
3046 ====================== =================
3047 user name passwd:name
3048 user password passwd:passwd
3051 real name passwd:gecos
3052 home directory passwd:dir
3053 shell program passwd:shell
3055 *** There are new accessors for the vectors returned by `getgr',
3056 `getgrnam', `getgrgid', and `getgrent', describing entries from the
3057 system's group database:
3060 ======================= ============
3061 group name group:name
3062 group password group:passwd
3064 group members group:mem
3066 *** There are new accessors for the vectors returned by `gethost',
3067 `gethostbyaddr', `gethostbyname', and `gethostent', describing
3071 ========================= ===============
3072 official name of host hostent:name
3073 alias list hostent:aliases
3074 host address type hostent:addrtype
3075 length of address hostent:length
3076 list of addresses hostent:addr-list
3078 *** There are new accessors for the vectors returned by `getnet',
3079 `getnetbyaddr', `getnetbyname', and `getnetent', describing internet
3083 ========================= ===============
3084 official name of net netent:name
3085 alias list netent:aliases
3086 net number type netent:addrtype
3087 net number netent:net
3089 *** There are new accessors for the vectors returned by `getproto',
3090 `getprotobyname', `getprotobynumber', and `getprotoent', describing
3094 ========================= ===============
3095 official protocol name protoent:name
3096 alias list protoent:aliases
3097 protocol number protoent:proto
3099 *** There are new accessors for the vectors returned by `getserv',
3100 `getservbyname', `getservbyport', and `getservent', describing
3104 ========================= ===============
3105 official service name servent:name
3106 alias list servent:aliases
3107 port number servent:port
3108 protocol to use servent:proto
3110 *** There are new accessors for the sockaddr structures returned by
3111 `accept', `getsockname', `getpeername', `recvfrom!':
3114 ======================================== ===============
3115 address format (`family') sockaddr:fam
3116 path, for file domain addresses sockaddr:path
3117 address, for internet domain addresses sockaddr:addr
3118 TCP or UDP port, for internet sockaddr:port
3120 *** The `getpwent', `getgrent', `gethostent', `getnetent',
3121 `getprotoent', and `getservent' functions now return #f at the end of
3122 the user database. (They used to throw an exception.)
3124 Note that calling MUMBLEent function is equivalent to calling the
3125 corresponding MUMBLE function with no arguments.
3127 *** The `setpwent', `setgrent', `sethostent', `setnetent',
3128 `setprotoent', and `setservent' routines now take no arguments.
3130 *** The `gethost', `getproto', `getnet', and `getserv' functions now
3131 provide more useful information when they throw an exception.
3133 *** The `lnaof' function has been renamed to `inet-lnaof'.
3135 *** Guile now claims to have the `current-time' feature.
3137 *** The `mktime' function now takes an optional second argument ZONE,
3138 giving the time zone to use for the conversion. ZONE should be a
3139 string, in the same format as expected for the "TZ" environment variable.
3141 *** The `strptime' function now returns a pair (TIME . COUNT), where
3142 TIME is the parsed time as a vector, and COUNT is the number of
3143 characters from the string left unparsed. This function used to
3144 return the remaining characters as a string.
3146 *** The `gettimeofday' function has replaced the old `time+ticks' function.
3147 The return value is now (SECONDS . MICROSECONDS); the fractional
3148 component is no longer expressed in "ticks".
3150 *** The `ticks/sec' constant has been removed, in light of the above change.
3152 * Changes to the gh_ interface
3154 ** gh_eval_str() now returns an SCM object which is the result of the
3157 ** gh_scm2str() now copies the Scheme data to a caller-provided C
3160 ** gh_scm2newstr() now makes a C array, copies the Scheme data to it,
3161 and returns the array
3163 ** gh_scm2str0() is gone: there is no need to distinguish
3164 null-terminated from non-null-terminated, since gh_scm2newstr() allows
3165 the user to interpret the data both ways.
3167 * Changes to the scm_ interface
3169 ** The new function scm_symbol_value0 provides an easy way to get a
3170 symbol's value from C code:
3172 SCM scm_symbol_value0 (char *NAME)
3173 Return the value of the symbol named by the null-terminated string
3174 NAME in the current module. If the symbol named NAME is unbound in
3175 the current module, return SCM_UNDEFINED.
3177 ** The new function scm_sysintern0 creates new top-level variables,
3178 without assigning them a value.
3180 SCM scm_sysintern0 (char *NAME)
3181 Create a new Scheme top-level variable named NAME. NAME is a
3182 null-terminated string. Return the variable's value cell.
3184 ** The function scm_internal_catch is the guts of catch. It handles
3185 all the mechanics of setting up a catch target, invoking the catch
3186 body, and perhaps invoking the handler if the body does a throw.
3188 The function is designed to be usable from C code, but is general
3189 enough to implement all the semantics Guile Scheme expects from throw.
3191 TAG is the catch tag. Typically, this is a symbol, but this function
3192 doesn't actually care about that.
3194 BODY is a pointer to a C function which runs the body of the catch;
3195 this is the code you can throw from. We call it like this:
3196 BODY (BODY_DATA, JMPBUF)
3198 BODY_DATA is just the BODY_DATA argument we received; we pass it
3199 through to BODY as its first argument. The caller can make
3200 BODY_DATA point to anything useful that BODY might need.
3201 JMPBUF is the Scheme jmpbuf object corresponding to this catch,
3202 which we have just created and initialized.
3204 HANDLER is a pointer to a C function to deal with a throw to TAG,
3205 should one occur. We call it like this:
3206 HANDLER (HANDLER_DATA, THROWN_TAG, THROW_ARGS)
3208 HANDLER_DATA is the HANDLER_DATA argument we recevied; it's the
3209 same idea as BODY_DATA above.
3210 THROWN_TAG is the tag that the user threw to; usually this is
3211 TAG, but it could be something else if TAG was #t (i.e., a
3212 catch-all), or the user threw to a jmpbuf.
3213 THROW_ARGS is the list of arguments the user passed to the THROW
3216 BODY_DATA is just a pointer we pass through to BODY. HANDLER_DATA
3217 is just a pointer we pass through to HANDLER. We don't actually
3218 use either of those pointers otherwise ourselves. The idea is
3219 that, if our caller wants to communicate something to BODY or
3220 HANDLER, it can pass a pointer to it as MUMBLE_DATA, which BODY and
3221 HANDLER can then use. Think of it as a way to make BODY and
3222 HANDLER closures, not just functions; MUMBLE_DATA points to the
3225 Of course, it's up to the caller to make sure that any data a
3226 MUMBLE_DATA needs is protected from GC. A common way to do this is
3227 to make MUMBLE_DATA a pointer to data stored in an automatic
3228 structure variable; since the collector must scan the stack for
3229 references anyway, this assures that any references in MUMBLE_DATA
3232 ** The new function scm_internal_lazy_catch is exactly like
3233 scm_internal_catch, except:
3235 - It does not unwind the stack (this is the major difference).
3236 - If handler returns, its value is returned from the throw.
3237 - BODY always receives #f as its JMPBUF argument (since there's no
3238 jmpbuf associated with a lazy catch, because we don't unwind the
3241 ** scm_body_thunk is a new body function you can pass to
3242 scm_internal_catch if you want the body to be like Scheme's `catch'
3243 --- a thunk, or a function of one argument if the tag is #f.
3245 BODY_DATA is a pointer to a scm_body_thunk_data structure, which
3246 contains the Scheme procedure to invoke as the body, and the tag
3247 we're catching. If the tag is #f, then we pass JMPBUF (created by
3248 scm_internal_catch) to the body procedure; otherwise, the body gets
3251 ** scm_handle_by_proc is a new handler function you can pass to
3252 scm_internal_catch if you want the handler to act like Scheme's catch
3253 --- call a procedure with the tag and the throw arguments.
3255 If the user does a throw to this catch, this function runs a handler
3256 procedure written in Scheme. HANDLER_DATA is a pointer to an SCM
3257 variable holding the Scheme procedure object to invoke. It ought to
3258 be a pointer to an automatic variable (i.e., one living on the stack),
3259 or the procedure object should be otherwise protected from GC.
3261 ** scm_handle_by_message is a new handler function to use with
3262 `scm_internal_catch' if you want Guile to print a message and die.
3263 It's useful for dealing with throws to uncaught keys at the top level.
3265 HANDLER_DATA, if non-zero, is assumed to be a char * pointing to a
3266 message header to print; if zero, we use "guile" instead. That
3267 text is followed by a colon, then the message described by ARGS.
3269 ** The return type of scm_boot_guile is now void; the function does
3270 not return a value, and indeed, never returns at all.
3272 ** The new function scm_shell makes it easy for user applications to
3273 process command-line arguments in a way that is compatible with the
3274 stand-alone guile interpreter (which is in turn compatible with SCSH,
3277 To use the scm_shell function, first initialize any guile modules
3278 linked into your application, and then call scm_shell with the values
3279 of ARGC and ARGV your `main' function received. scm_shell will add
3280 any SCSH-style meta-arguments from the top of the script file to the
3281 argument vector, and then process the command-line arguments. This
3282 generally means loading a script file or starting up an interactive
3283 command interpreter. For details, see "Changes to the stand-alone
3286 ** The new functions scm_get_meta_args and scm_count_argv help you
3287 implement the SCSH-style meta-argument, `\'.
3289 char **scm_get_meta_args (int ARGC, char **ARGV)
3290 If the second element of ARGV is a string consisting of a single
3291 backslash character (i.e. "\\" in Scheme notation), open the file
3292 named by the following argument, parse arguments from it, and return
3293 the spliced command line. The returned array is terminated by a
3296 For details of argument parsing, see above, under "guile now accepts
3297 command-line arguments compatible with SCSH..."
3299 int scm_count_argv (char **ARGV)
3300 Count the arguments in ARGV, assuming it is terminated by a null
3303 For an example of how these functions might be used, see the source
3304 code for the function scm_shell in libguile/script.c.
3306 You will usually want to use scm_shell instead of calling this
3309 ** The new function scm_compile_shell_switches turns an array of
3310 command-line arguments into Scheme code to carry out the actions they
3311 describe. Given ARGC and ARGV, it returns a Scheme expression to
3312 evaluate, and calls scm_set_program_arguments to make any remaining
3313 command-line arguments available to the Scheme code. For example,
3314 given the following arguments:
3316 -e main -s ekko a speckled gecko
3318 scm_set_program_arguments will return the following expression:
3320 (begin (load "ekko") (main (command-line)) (quit))
3322 You will usually want to use scm_shell instead of calling this
3325 ** The function scm_shell_usage prints a usage message appropriate for
3326 an interpreter that uses scm_compile_shell_switches to handle its
3327 command-line arguments.
3329 void scm_shell_usage (int FATAL, char *MESSAGE)
3330 Print a usage message to the standard error output. If MESSAGE is
3331 non-zero, write it before the usage message, followed by a newline.
3332 If FATAL is non-zero, exit the process, using FATAL as the
3333 termination status. (If you want to be compatible with Guile,
3334 always use 1 as the exit status when terminating due to command-line
3337 You will usually want to use scm_shell instead of calling this
3340 ** scm_eval_0str now returns SCM_UNSPECIFIED if the string contains no
3341 expressions. It used to return SCM_EOL. Earth-shattering.
3343 ** The macros for declaring scheme objects in C code have been
3344 rearranged slightly. They are now:
3346 SCM_SYMBOL (C_NAME, SCHEME_NAME)
3347 Declare a static SCM variable named C_NAME, and initialize it to
3348 point to the Scheme symbol whose name is SCHEME_NAME. C_NAME should
3349 be a C identifier, and SCHEME_NAME should be a C string.
3351 SCM_GLOBAL_SYMBOL (C_NAME, SCHEME_NAME)
3352 Just like SCM_SYMBOL, but make C_NAME globally visible.
3354 SCM_VCELL (C_NAME, SCHEME_NAME)
3355 Create a global variable at the Scheme level named SCHEME_NAME.
3356 Declare a static SCM variable named C_NAME, and initialize it to
3357 point to the Scheme variable's value cell.
3359 SCM_GLOBAL_VCELL (C_NAME, SCHEME_NAME)
3360 Just like SCM_VCELL, but make C_NAME globally visible.
3362 The `guile-snarf' script writes initialization code for these macros
3363 to its standard output, given C source code as input.
3365 The SCM_GLOBAL macro is gone.
3367 ** The scm_read_line and scm_read_line_x functions have been replaced
3368 by Scheme code based on the %read-delimited! procedure (known to C
3369 code as scm_read_delimited_x). See its description above for more
3372 ** The function scm_sys_open has been renamed to scm_open. It now
3373 returns a port instead of an FD object.
3375 * The dynamic linking support has changed. For more information, see
3376 libguile/DYNAMIC-LINKING.
3381 User-visible changes from Thursday, September 5, 1996 until Guile 1.0
3384 * Changes to the 'guile' program:
3386 ** Guile now loads some new files when it starts up. Guile first
3387 searches the load path for init.scm, and loads it if found. Then, if
3388 Guile is not being used to execute a script, and the user's home
3389 directory contains a file named `.guile', Guile loads that.
3391 ** You can now use Guile as a shell script interpreter.
3393 To paraphrase the SCSH manual:
3395 When Unix tries to execute an executable file whose first two
3396 characters are the `#!', it treats the file not as machine code to
3397 be directly executed by the native processor, but as source code
3398 to be executed by some interpreter. The interpreter to use is
3399 specified immediately after the #! sequence on the first line of
3400 the source file. The kernel reads in the name of the interpreter,
3401 and executes that instead. It passes the interpreter the source
3402 filename as its first argument, with the original arguments
3403 following. Consult the Unix man page for the `exec' system call
3404 for more information.
3406 Now you can use Guile as an interpreter, using a mechanism which is a
3407 compatible subset of that provided by SCSH.
3409 Guile now recognizes a '-s' command line switch, whose argument is the
3410 name of a file of Scheme code to load. It also treats the two
3411 characters `#!' as the start of a comment, terminated by `!#'. Thus,
3412 to make a file of Scheme code directly executable by Unix, insert the
3413 following two lines at the top of the file:
3415 #!/usr/local/bin/guile -s
3418 Guile treats the argument of the `-s' command-line switch as the name
3419 of a file of Scheme code to load, and treats the sequence `#!' as the
3420 start of a block comment, terminated by `!#'.
3422 For example, here's a version of 'echo' written in Scheme:
3424 #!/usr/local/bin/guile -s
3426 (let loop ((args (cdr (program-arguments))))
3429 (display (car args))
3430 (if (pair? (cdr args))
3432 (loop (cdr args)))))
3435 Why does `#!' start a block comment terminated by `!#', instead of the
3436 end of the line? That is the notation SCSH uses, and although we
3437 don't yet support the other SCSH features that motivate that choice,
3438 we would like to be backward-compatible with any existing Guile
3439 scripts once we do. Furthermore, if the path to Guile on your system
3440 is too long for your kernel, you can start the script with this
3444 exec /really/long/path/to/guile -s "$0" ${1+"$@"}
3447 Note that some very old Unix systems don't support the `#!' syntax.
3450 ** You can now run Guile without installing it.
3452 Previous versions of the interactive Guile interpreter (`guile')
3453 couldn't start up unless Guile's Scheme library had been installed;
3454 they used the value of the environment variable `SCHEME_LOAD_PATH'
3455 later on in the startup process, but not to find the startup code
3456 itself. Now Guile uses `SCHEME_LOAD_PATH' in all searches for Scheme
3459 To run Guile without installing it, build it in the normal way, and
3460 then set the environment variable `SCHEME_LOAD_PATH' to a
3461 colon-separated list of directories, including the top-level directory
3462 of the Guile sources. For example, if you unpacked Guile so that the
3463 full filename of this NEWS file is /home/jimb/guile-1.0b3/NEWS, then
3466 export SCHEME_LOAD_PATH=/home/jimb/my-scheme:/home/jimb/guile-1.0b3
3469 ** Guile's read-eval-print loop no longer prints #<unspecified>
3470 results. If the user wants to see this, she can evaluate the
3471 expression (assert-repl-print-unspecified #t), perhaps in her startup
3474 ** Guile no longer shows backtraces by default when an error occurs;
3475 however, it does display a message saying how to get one, and how to
3476 request that they be displayed by default. After an error, evaluate
3478 to see a backtrace, and
3479 (debug-enable 'backtrace)
3480 to see them by default.
3484 * Changes to Guile Scheme:
3486 ** Guile now distinguishes between #f and the empty list.
3488 This is for compatibility with the IEEE standard, the (possibly)
3489 upcoming Revised^5 Report on Scheme, and many extant Scheme
3492 Guile used to have #f and '() denote the same object, to make Scheme's
3493 type system more compatible with Emacs Lisp's. However, the change
3494 caused too much trouble for Scheme programmers, and we found another
3495 way to reconcile Emacs Lisp with Scheme that didn't require this.
3498 ** Guile's delq, delv, delete functions, and their destructive
3499 counterparts, delq!, delv!, and delete!, now remove all matching
3500 elements from the list, not just the first. This matches the behavior
3501 of the corresponding Emacs Lisp functions, and (I believe) the Maclisp
3502 functions which inspired them.
3504 I recognize that this change may break code in subtle ways, but it
3505 seems best to make the change before the FSF's first Guile release,
3509 ** The compiled-library-path function has been deleted from libguile.
3511 ** The facilities for loading Scheme source files have changed.
3513 *** The variable %load-path now tells Guile which directories to search
3514 for Scheme code. Its value is a list of strings, each of which names
3517 *** The variable %load-extensions now tells Guile which extensions to
3518 try appending to a filename when searching the load path. Its value
3519 is a list of strings. Its default value is ("" ".scm").
3521 *** (%search-load-path FILENAME) searches the directories listed in the
3522 value of the %load-path variable for a Scheme file named FILENAME,
3523 with all the extensions listed in %load-extensions. If it finds a
3524 match, then it returns its full filename. If FILENAME is absolute, it
3525 returns it unchanged. Otherwise, it returns #f.
3527 %search-load-path will not return matches that refer to directories.
3529 *** (primitive-load FILENAME :optional CASE-INSENSITIVE-P SHARP)
3530 uses %seach-load-path to find a file named FILENAME, and loads it if
3531 it finds it. If it can't read FILENAME for any reason, it throws an
3534 The arguments CASE-INSENSITIVE-P and SHARP are interpreted as by the
3537 *** load uses the same searching semantics as primitive-load.
3539 *** The functions %try-load, try-load-with-path, %load, load-with-path,
3540 basic-try-load-with-path, basic-load-with-path, try-load-module-with-
3541 path, and load-module-with-path have been deleted. The functions
3542 above should serve their purposes.
3544 *** If the value of the variable %load-hook is a procedure,
3545 `primitive-load' applies its value to the name of the file being
3546 loaded (without the load path directory name prepended). If its value
3547 is #f, it is ignored. Otherwise, an error occurs.
3549 This is mostly useful for printing load notification messages.
3552 ** The function `eval!' is no longer accessible from the scheme level.
3553 We can't allow operations which introduce glocs into the scheme level,
3554 because Guile's type system can't handle these as data. Use `eval' or
3555 `read-and-eval!' (see below) as replacement.
3557 ** The new function read-and-eval! reads an expression from PORT,
3558 evaluates it, and returns the result. This is more efficient than
3559 simply calling `read' and `eval', since it is not necessary to make a
3560 copy of the expression for the evaluator to munge.
3562 Its optional arguments CASE_INSENSITIVE_P and SHARP are interpreted as
3563 for the `read' function.
3566 ** The function `int?' has been removed; its definition was identical
3567 to that of `integer?'.
3569 ** The functions `<?', `<?', `<=?', `=?', `>?', and `>=?'. Code should
3570 use the R4RS names for these functions.
3572 ** The function object-properties no longer returns the hash handle;
3573 it simply returns the object's property list.
3575 ** Many functions have been changed to throw errors, instead of
3576 returning #f on failure. The point of providing exception handling in
3577 the language is to simplify the logic of user code, but this is less
3578 useful if Guile's primitives don't throw exceptions.
3580 ** The function `fileno' has been renamed from `%fileno'.
3582 ** The function primitive-mode->fdes returns #t or #f now, not 1 or 0.
3585 * Changes to Guile's C interface:
3587 ** The library's initialization procedure has been simplified.
3588 scm_boot_guile now has the prototype:
3590 void scm_boot_guile (int ARGC,
3592 void (*main_func) (),
3595 scm_boot_guile calls MAIN_FUNC, passing it CLOSURE, ARGC, and ARGV.
3596 MAIN_FUNC should do all the work of the program (initializing other
3597 packages, reading user input, etc.) before returning. When MAIN_FUNC
3598 returns, call exit (0); this function never returns. If you want some
3599 other exit value, MAIN_FUNC may call exit itself.
3601 scm_boot_guile arranges for program-arguments to return the strings
3602 given by ARGC and ARGV. If MAIN_FUNC modifies ARGC/ARGV, should call
3603 scm_set_program_arguments with the final list, so Scheme code will
3604 know which arguments have been processed.
3606 scm_boot_guile establishes a catch-all catch handler which prints an
3607 error message and exits the process. This means that Guile exits in a
3608 coherent way when system errors occur and the user isn't prepared to
3609 handle it. If the user doesn't like this behavior, they can establish
3610 their own universal catcher in MAIN_FUNC to shadow this one.
3612 Why must the caller do all the real work from MAIN_FUNC? The garbage
3613 collector assumes that all local variables of type SCM will be above
3614 scm_boot_guile's stack frame on the stack. If you try to manipulate
3615 SCM values after this function returns, it's the luck of the draw
3616 whether the GC will be able to find the objects you allocate. So,
3617 scm_boot_guile function exits, rather than returning, to discourage
3618 people from making that mistake.
3620 The IN, OUT, and ERR arguments were removed; there are other
3621 convenient ways to override these when desired.
3623 The RESULT argument was deleted; this function should never return.
3625 The BOOT_CMD argument was deleted; the MAIN_FUNC argument is more
3629 ** Guile's header files should no longer conflict with your system's
3632 In order to compile code which #included <libguile.h>, previous
3633 versions of Guile required you to add a directory containing all the
3634 Guile header files to your #include path. This was a problem, since
3635 Guile's header files have names which conflict with many systems'
3638 Now only <libguile.h> need appear in your #include path; you must
3639 refer to all Guile's other header files as <libguile/mumble.h>.
3640 Guile's installation procedure puts libguile.h in $(includedir), and
3641 the rest in $(includedir)/libguile.
3644 ** Two new C functions, scm_protect_object and scm_unprotect_object,
3645 have been added to the Guile library.
3647 scm_protect_object (OBJ) protects OBJ from the garbage collector.
3648 OBJ will not be freed, even if all other references are dropped,
3649 until someone does scm_unprotect_object (OBJ). Both functions
3652 Note that calls to scm_protect_object do not nest. You can call
3653 scm_protect_object any number of times on a given object, and the
3654 next call to scm_unprotect_object will unprotect it completely.
3656 Basically, scm_protect_object and scm_unprotect_object just
3657 maintain a list of references to things. Since the GC knows about
3658 this list, all objects it mentions stay alive. scm_protect_object
3659 adds its argument to the list; scm_unprotect_object remove its
3660 argument from the list.
3663 ** scm_eval_0str now returns the value of the last expression
3666 ** The new function scm_read_0str reads an s-expression from a
3667 null-terminated string, and returns it.
3669 ** The new function `scm_stdio_to_port' converts a STDIO file pointer
3670 to a Scheme port object.
3672 ** The new function `scm_set_program_arguments' allows C code to set
3673 the value returned by the Scheme `program-arguments' function.
3678 * Guile no longer includes sophisticated Tcl/Tk support.
3680 The old Tcl/Tk support was unsatisfying to us, because it required the
3681 user to link against the Tcl library, as well as Tk and Guile. The
3682 interface was also un-lispy, in that it preserved Tcl/Tk's practice of
3683 referring to widgets by names, rather than exporting widgets to Scheme
3684 code as a special datatype.
3686 In the Usenix Tk Developer's Workshop held in July 1996, the Tcl/Tk
3687 maintainers described some very interesting changes in progress to the
3688 Tcl/Tk internals, which would facilitate clean interfaces between lone
3689 Tk and other interpreters --- even for garbage-collected languages
3690 like Scheme. They expected the new Tk to be publicly available in the
3693 Since it seems that Guile might soon have a new, cleaner interface to
3694 lone Tk, and that the old Guile/Tk glue code would probably need to be
3695 completely rewritten, we (Jim Blandy and Richard Stallman) have
3696 decided not to support the old code. We'll spend the time instead on
3697 a good interface to the newer Tk, as soon as it is available.
3699 Until then, gtcltk-lib provides trivial, low-maintenance functionality.
3702 Copyright information:
3704 Copyright (C) 1996,1997 Free Software Foundation, Inc.
3706 Permission is granted to anyone to make or distribute verbatim copies
3707 of this document as received, in any medium, provided that the
3708 copyright notice and this permission notice are preserved,
3709 thus giving the recipient permission to redistribute in turn.
3711 Permission is granted to distribute modified versions
3712 of this document, or of portions of it,
3713 under the above conditions, provided also that they
3714 carry prominent notices stating who last changed them.
3719 paragraph-separate: "[
\f]*$"