1 Guile NEWS --- history of user-visible changes. -*- text -*-
2 Copyright (C) 1996, 1997 Free Software Foundation, Inc.
3 See the end for copying conditions.
5 Please send Guile bug reports to bug-guile@prep.ai.mit.edu.
7 Changes since Guile 1.2:
9 * Changes to the distribution
11 ** libguile/append.h, libguile/append.c, libguile/extchrs.h,
12 libguile/extchrs.c, libguile/mbstrings.h libguile/mbstrings.c,
13 libguile/sequences.h, libguile/sequences.c removed.
15 * Changes to the stand-alone interpreter
17 ** New procedures have been added to implement a "batch mode":
19 *** Function: batch-mode?
21 Returns a boolean indicating whether the interpreter is in batch
24 *** Function: set-batch-mode?! ARG
26 If ARG is true, switches the interpreter to batch mode. The `#f'
27 case has not been implemented.
29 ** Guile now provides full command-line editing, when run interactively.
30 To use this feature, you must have the readline library installed.
31 The Guile build process will notice it, and automatically include
34 The readline library is available via anonymous FTP from any GNU
35 mirror site; the canonical location is "ftp://prep.ai.mit.edu/pub/gnu".
37 * Changes to the procedure for linking libguile with your programs
39 ** You can now use the 'build-guile' utility to link against Guile.
41 Guile now includes a command-line utility called 'build-guile', which
42 writes to its standard output a list of flags which you must pass to
43 the linker to link against the Guile library. The flags include
46 This is necessary because the Guile library may depend on other
47 libraries for networking functions, thread support, and so on. To
48 link your program against libguile, you must link against these
49 libraries as well. The exact set of libraries depends on the type of
50 system you are running, and what you have installed on it. The
51 'build-guile' command uses information recorded in libguile itself to
52 determine which libraries you must link against.
54 For example, here is a Makefile rule that builds a program named 'foo'
55 from the object files ${FOO_OBJECTS}, and links them against Guile:
58 ${CC} ${CFLAGS} ${FOO_OBJECTS} `build-guile link` -o foo
61 * Changes to Scheme functions and syntax
63 ** Multi-byte strings have been removed, as have multi-byte and wide
66 ** New function: readline [PROMPT]
67 Read a line from the terminal, and allow the user to edit it,
68 prompting with PROMPT. READLINE provides a large set of Emacs-like
69 editing commands, lets the user recall previously typed lines, and
70 works on almost every kind of terminal, including dumb terminals.
72 READLINE assumes that the cursor is at the beginning of the line when
73 it is invoked. Thus, you can't print a prompt yourself, and then call
74 READLINE; you need to package up your prompt as a string, pass it to
75 the function, and let READLINE print the prompt itself. This is
76 because READLINE needs to know the prompt's screen width.
78 For Guile to provide this function, you must have the readline library
79 installed on your system.
81 See also ADD-HISTORY function.
83 ** New function: add-history STRING
84 Add STRING as the most recent line in the history used by the READLINE
85 command. READLINE does not add lines to the history itself; you must
86 call ADD-HISTORY to make previous input available to the user.
88 ** Some magic has been added to the printer to better handle user
89 written printing routines (like record printers, closure printers).
91 The problem is that these user written routines must have access to
92 the current `prine-state' to be able to handle fancy things like
93 detection of circular references. These print-states have to be
94 passed to the builtin printing routines (display, write, etc) to
95 properly continue the print chain.
97 We didn't want to change all existing print code so that it
98 explicitely passes thru a print state in addition to a port. Instead,
99 we extented the possible values that the builtin printing routines
100 accept as a `port'. In addition to a normal port, they now also take
101 a pair of a normal port and a print-state. Printing will go to the
102 port and the print-state will be used to control the detection of
103 circular references, etc. If the builtin function does not care for a
104 print-state, it is simply ignored.
106 User written callbacks are now called with such a pair as their
107 `port', but because every function now accepts this pair as a PORT
108 argument, you don't have to worry about that. In fact, it is probably
109 safest to not check for these pairs.
111 However, it is sometimes necessary to continue a print chain on a
112 different port, for example to get a intermediate string
113 representation of the printed value, mangle that string somehow, and
114 then to finally print the mangled string. Use the new function
116 inherit-print-state OLD-PORT NEW-PORT
118 for this. It constructs a new `port' that prints to NEW-PORT but
119 inherits the print-state of OLD-PORT.
121 ** struct-vtable-offset renamed to vtable-offset-user
123 ** New constants: vtable-index-layout, vtable-index-vtable, vtable-index-printer
125 ** There is now a fourth (optional) argument to make-vtable-vtable and
126 make-struct when constructing new types (vtables). This argument
127 initializes field vtable-index-printer of the vtable.
129 ** The detection of circular references has been extended to structs.
130 That is, a structure that -- in the process of being printed -- prints
131 itself does not lead to infinite recursion.
133 ** There is now some basic support for fluids. Please read
134 "libguile/fluid.h" to find out more. It is accessible from Scheme with
135 the following functions and macros:
139 Create a new fluid object. Fluids are not special variables or
140 some other extension to the semantics of Scheme, but rather
141 ordinary Scheme objects. You can store them into variables (that
142 are still lexically scoped, of course) or into any other place you
143 like. Every fluid has a initial value of `#f'.
147 Test whether OBJ is a fluid.
149 Function: fluid-ref FLUID
150 Function: fluid-set! FLUID VAL
152 Access/modify the fluid FLUID. Modifications are only visible
153 within the current dynamic root (that includes threads).
155 Function: with-fluids* FLUIDS VALUES THUNK
157 FLUIDS is a list of fluids and VALUES a corresponding list of
158 values for these fluids. Before THUNK gets called the values are
159 installed in the fluids and the old values of the fluids are
160 saved in the VALUES list. When the flow of control leaves THUNK
161 or reenters it, the values get swapped again. You might think of
162 this as a `safe-fluid-excursion'. Note that the VALUES list is
163 modified by `with-fluids*'.
165 Macro: with-fluids ((FLUID VALUE) ...) FORM ...
167 The same as `with-fluids*' but with a different syntax. It looks
168 just like `let', but both FLUID and VALUE are evaluated. Remember,
169 fluids are not special variables but ordinary objects. FLUID
170 should evaluate to a fluid.
172 ** Removed procedures:
174 list-length, list-append, list-append!, list-reverse, list-reverse!
176 ** array-map renamed to array-map!
178 ** serial-array-map renamed to serial-array-map!
180 * Changes to system call interfaces:
182 ** close-port, close-input-port and close-output-port now return a
183 boolean instead of an `unspecified' object. #t means that the port
184 was successfully closed, while #f means it was already closed. It is
185 also now possible for these procedures to raise an exception if an
186 error occurs (some errors from write can be delayed until close.)
188 ** the first argument to chmod, fcntl, ftell and fseek can now be a
191 ** the third argument to fcntl is now optional.
193 ** the first argument to chown can now be a file descriptor or a port.
195 ** the argument to stat can now be a port.
197 ** The following new procedures have been added (most use scsh
200 ** procedure: close PORT/FD
201 Similar to close-port (*note close-port: Closing Ports.), but also
202 works on file descriptors. A side effect of closing a file
203 descriptor is that any ports using that file descriptor are moved
204 to a different file descriptor and have their revealed counts set
207 ** procedure: port->fdes PORT
208 Returns the integer file descriptor underlying PORT. As a side
209 effect the revealed count of PORT is incremented.
211 ** procedure: fdes->ports FDES
212 Returns a list of existing ports which have FDES as an underlying
213 file descriptor, without changing their revealed counts.
215 ** procedure: fdes->inport FDES
216 Returns an existing input port which has FDES as its underlying
217 file descriptor, if one exists, and increments its revealed count.
218 Otherwise, returns a new input port with a revealed count of 1.
220 ** procedure: fdes->outport FDES
221 Returns an existing output port which has FDES as its underlying
222 file descriptor, if one exists, and increments its revealed count.
223 Otherwise, returns a new output port with a revealed count of 1.
225 The next group of procedures perform a `dup2' system call, if NEWFD
226 (an integer) is supplied, otherwise a `dup'. The file descriptor to be
227 duplicated can be supplied as an integer or contained in a port. The
228 type of value returned varies depending on which procedure is used.
230 All procedures also have the side effect when performing `dup2' that
231 any ports using NEWFD are moved to a different file descriptor and have
232 their revealed counts set to zero.
234 ** procedure: dup->fdes PORT/FD [NEWFD]
235 Returns an integer file descriptor.
237 ** procedure: dup->inport PORT/FD [NEWFD]
238 Returns a new input port using the new file descriptor.
240 ** procedure: dup->outport PORT/FD [NEWFD]
241 Returns a new output port using the new file descriptor.
243 ** procedure: dup PORT/FD [NEWFD]
244 Returns a new port if PORT/FD is a port, with the same mode as the
245 supplied port, otherwise returns an integer file descriptor.
247 ** procedure: dup->port PORT/FD MODE [NEWFD]
248 Returns a new port using the new file descriptor. MODE supplies a
249 mode string for the port (*note open-file: File Ports.).
251 ** procedure: setenv NAME VALUE
252 Modifies the environment of the current process, which is also the
253 default environment inherited by child processes.
255 If VALUE is `#f', then NAME is removed from the environment.
256 Otherwise, the string NAME=VALUE is added to the environment,
257 replacing any existing string with name matching NAME.
259 The return value is unspecified.
261 ** procedure: truncate-file OBJ SIZE
262 Truncates the file referred to by OBJ to at most SIZE bytes. OBJ
263 can be a string containing a file name or an integer file
264 descriptor or port open for output on the file. The underlying
265 system calls are `truncate' and `ftruncate'.
267 The return value is unspecified.
269 ** procedure: setvbuf PORT MODE [SIZE]
270 Set the buffering mode for PORT. MODE can be:
278 block buffered, using a newly allocated buffer of SIZE bytes.
279 However if SIZE is zero or unspecified, the port will be made
282 This procedure should not be used after I/O has been performed with
285 Ports are usually block buffered by default, with a default buffer
286 size. Procedures e.g., *Note open-file: File Ports, which accept a
287 mode string allow `0' to be added to request an unbuffered port.
289 ** procedure: fsync PORT/FD
290 Copies any unwritten data for the specified output file descriptor
291 to disk. If PORT/FD is a port, its buffer is flushed before the
292 underlying file descriptor is fsync'd. The return value is
295 ** procedure: open-fdes PATH FLAGS [MODES]
296 Similar to `open' but returns a file descriptor instead of a port.
298 ** procedure: execle PATH ENV [ARG] ...
299 Similar to `execl', but the environment of the new process is
300 specified by ENV, which must be a list of strings as returned by
301 the `environ' procedure.
303 This procedure is currently implemented using the `execve' system
304 call, but we call it `execle' because of its Scheme calling
307 ** procedure: strerror ERRNO
308 Returns the Unix error message corresponding to ERRNO, an integer.
310 ** procedure: primitive-exit [STATUS]
311 Terminate the current process without unwinding the Scheme stack.
312 This is would typically be useful after a fork. The exit status
313 is STATUS if supplied, otherwise zero.
316 Returns an object with information about real and processor time.
317 The following procedures accept such an object as an argument and
318 return a selected component:
321 The current real time, expressed as time units relative to an
325 The CPU time units used by the calling process.
328 The CPU time units used by the system on behalf of the
332 The CPU time units used by terminated child processes of the
333 calling process, whose status has been collected (e.g., using
337 Similarly, the CPU times units used by the system on behalf of
338 terminated child processes.
340 * Changes to the gh_ interface
342 ** Function: void gh_write (SCM x)
344 Write the printed representation of the scheme object x to the current
345 output port. Corresponds to the scheme level `write'.
347 ** gh_list_length renamed to gh_length.
349 ** vector handling routines
351 Several major changes. In particular, gh_vector() now resembles
352 (vector ...) (with a caveat -- see manual), and gh_make_vector() now
353 exists and behaves like (make-vector ...). gh_vset() and gh_vref()
354 have been renamed gh_vector_set_x() and gh_vector_ref(). Some missing
355 vector-related gh_ functions have been implemented.
357 ** pair and list routines
359 Implemented several of the R4RS pair and list functions that were
362 * Changes to the scm_ interface
364 ** Function: SCM scm_internal_stack_catch (SCM tag,
365 scm_catch_body_t body,
367 scm_catch_handler_t handler,
370 A new sibling to the other two C level `catch' functions
371 scm_internal_catch and scm_internal_lazy_catch. Use it if you want
372 the stack to be saved automatically into the variable `the-last-stack'
373 (scm_the_last_stack_var) on error. This is necessary if you want to
374 use advanced error reporting, such as calling scm_display_error and
375 scm_display_backtrace. (They both take a stack object as argument.)
377 ** The hook scm_error_callback has been removed. It was originally
378 intended as a way for the user to install his own error handler. But
379 that method works badly since it intervenes between throw and catch,
380 thereby changing the semantics of expressions like (catch #t ...).
381 The correct way to do it is to use one of the C level catch functions
382 in throw.c: scm_internal_catch/lazy_catch/stack_catch.
384 ** Removed functions:
386 scm_obj_length, scm_list_length, scm_list_append, scm_list_append_x,
387 scm_list_reverse, scm_list_reverse_x
389 ** New macros: SCM_LISTn where n is one of the integers 0-9.
391 These can be used for pretty list creation from C. The idea is taken
392 from Erick Gallesio's STk.
394 ** scm_array_map renamed to scm_array_map_x
396 ** mbstrings are now removed
398 This means that the type codes scm_tc7_mb_string and
399 scm_tc7_mb_substring has been removed.
401 ** The macros SCM_TYP7D and SCM_TYP7SD has been removed.
403 ** The macro SCM_TYP7S has taken the role of the old SCM_TYP7D
405 SCM_TYP7S now masks away the bit which distinguishes substrings from
408 ** All genio functions changed names and interfaces; new functions are
409 scm_putc, scm_puts, scm_lfwrite, scm_getc, scm_ungetc, and
413 Changes in Guile 1.2 (released Tuesday, June 24 1997):
415 * Changes to the distribution
417 ** Nightly snapshots are now available from ftp.red-bean.com.
418 The old server, ftp.cyclic.com, has been relinquished to its rightful
421 Nightly snapshots of the Guile development sources are now available via
422 anonymous FTP from ftp.red-bean.com, as /pub/guile/guile-snap.tar.gz.
424 Via the web, that's: ftp://ftp.red-bean.com/pub/guile/guile-snap.tar.gz
425 For getit, that's: ftp.red-bean.com:/pub/guile/guile-snap.tar.gz
427 ** To run Guile without installing it, the procedure has changed a bit.
429 If you used a separate build directory to compile Guile, you'll need
430 to include the build directory in SCHEME_LOAD_PATH, as well as the
431 source directory. See the `INSTALL' file for examples.
433 * Changes to the procedure for linking libguile with your programs
435 ** The standard Guile load path for Scheme code now includes
436 $(datadir)/guile (usually /usr/local/share/guile). This means that
437 you can install your own Scheme files there, and Guile will find them.
438 (Previous versions of Guile only checked a directory whose name
439 contained the Guile version number, so you had to re-install or move
440 your Scheme sources each time you installed a fresh version of Guile.)
442 The load path also includes $(datadir)/guile/site; we recommend
443 putting individual Scheme files there. If you want to install a
444 package with multiple source files, create a directory for them under
447 ** Guile 1.2 will now use the Rx regular expression library, if it is
448 installed on your system. When you are linking libguile into your own
449 programs, this means you will have to link against -lguile, -lqt (if
450 you configured Guile with thread support), and -lrx.
452 If you are using autoconf to generate configuration scripts for your
453 application, the following lines should suffice to add the appropriate
454 libraries to your link command:
456 ### Find Rx, quickthreads and libguile.
457 AC_CHECK_LIB(rx, main)
458 AC_CHECK_LIB(qt, main)
459 AC_CHECK_LIB(guile, scm_shell)
461 The Guile 1.2 distribution does not contain sources for the Rx
462 library, as Guile 1.0 did. If you want to use Rx, you'll need to
463 retrieve it from a GNU FTP site and install it separately.
465 * Changes to Scheme functions and syntax
467 ** The dynamic linking features of Guile are now enabled by default.
468 You can disable them by giving the `--disable-dynamic-linking' option
471 (dynamic-link FILENAME)
473 Find the object file denoted by FILENAME (a string) and link it
474 into the running Guile application. When everything works out,
475 return a Scheme object suitable for representing the linked object
476 file. Otherwise an error is thrown. How object files are
477 searched is system dependent.
479 (dynamic-object? VAL)
481 Determine whether VAL represents a dynamically linked object file.
483 (dynamic-unlink DYNOBJ)
485 Unlink the indicated object file from the application. DYNOBJ
486 should be one of the values returned by `dynamic-link'.
488 (dynamic-func FUNCTION DYNOBJ)
490 Search the C function indicated by FUNCTION (a string or symbol)
491 in DYNOBJ and return some Scheme object that can later be used
492 with `dynamic-call' to actually call this function. Right now,
493 these Scheme objects are formed by casting the address of the
494 function to `long' and converting this number to its Scheme
497 (dynamic-call FUNCTION DYNOBJ)
499 Call the C function indicated by FUNCTION and DYNOBJ. The
500 function is passed no arguments and its return value is ignored.
501 When FUNCTION is something returned by `dynamic-func', call that
502 function and ignore DYNOBJ. When FUNCTION is a string (or symbol,
503 etc.), look it up in DYNOBJ; this is equivalent to
505 (dynamic-call (dynamic-func FUNCTION DYNOBJ) #f)
507 Interrupts are deferred while the C function is executing (with
508 SCM_DEFER_INTS/SCM_ALLOW_INTS).
510 (dynamic-args-call FUNCTION DYNOBJ ARGS)
512 Call the C function indicated by FUNCTION and DYNOBJ, but pass it
513 some arguments and return its return value. The C function is
514 expected to take two arguments and return an `int', just like
517 int c_func (int argc, char **argv);
519 ARGS must be a list of strings and is converted into an array of
520 `char *'. The array is passed in ARGV and its size in ARGC. The
521 return value is converted to a Scheme number and returned from the
522 call to `dynamic-args-call'.
524 When dynamic linking is disabled or not supported on your system,
525 the above functions throw errors, but they are still available.
527 Here is a small example that works on GNU/Linux:
529 (define libc-obj (dynamic-link "libc.so"))
530 (dynamic-args-call 'rand libc-obj '())
532 See the file `libguile/DYNAMIC-LINKING' for additional comments.
534 ** The #/ syntax for module names is depreciated, and will be removed
535 in a future version of Guile. Instead of
543 The latter syntax is more consistent with existing Lisp practice.
545 ** Guile now does fancier printing of structures. Structures are the
546 underlying implementation for records, which in turn are used to
547 implement modules, so all of these object now print differently and in
548 a more informative way.
550 The Scheme printer will examine the builtin variable *struct-printer*
551 whenever it needs to print a structure object. When this variable is
552 not `#f' it is deemed to be a procedure and will be applied to the
553 structure object and the output port. When *struct-printer* is `#f'
554 or the procedure return `#f' the structure object will be printed in
555 the boring #<struct 80458270> form.
557 This hook is used by some routines in ice-9/boot-9.scm to implement
558 type specific printing routines. Please read the comments there about
561 One of the more specific uses of structs are records. The printing
562 procedure that could be passed to MAKE-RECORD-TYPE is now actually
563 called. It should behave like a *struct-printer* procedure (described
566 ** Guile now supports a new R4RS-compliant syntax for keywords. A
567 token of the form #:NAME, where NAME has the same syntax as a Scheme
568 symbol, is the external representation of the keyword named NAME.
569 Keyword objects print using this syntax as well, so values containing
570 keyword objects can be read back into Guile. When used in an
571 expression, keywords are self-quoting objects.
573 Guile suports this read syntax, and uses this print syntax, regardless
574 of the current setting of the `keyword' read option. The `keyword'
575 read option only controls whether Guile recognizes the `:NAME' syntax,
576 which is incompatible with R4RS. (R4RS says such token represent
579 ** Guile has regular expression support again. Guile 1.0 included
580 functions for matching regular expressions, based on the Rx library.
581 In Guile 1.1, the Guile/Rx interface was removed to simplify the
582 distribution, and thus Guile had no regular expression support. Guile
583 1.2 again supports the most commonly used functions, and supports all
584 of SCSH's regular expression functions.
586 If your system does not include a POSIX regular expression library,
587 and you have not linked Guile with a third-party regexp library such as
588 Rx, these functions will not be available. You can tell whether your
589 Guile installation includes regular expression support by checking
590 whether the `*features*' list includes the `regex' symbol.
594 By default, Guile supports POSIX extended regular expressions. That
595 means that the characters `(', `)', `+' and `?' are special, and must
596 be escaped if you wish to match the literal characters.
598 This regular expression interface was modeled after that implemented
599 by SCSH, the Scheme Shell. It is intended to be upwardly compatible
600 with SCSH regular expressions.
602 **** Function: string-match PATTERN STR [START]
603 Compile the string PATTERN into a regular expression and compare
604 it with STR. The optional numeric argument START specifies the
605 position of STR at which to begin matching.
607 `string-match' returns a "match structure" which describes what,
608 if anything, was matched by the regular expression. *Note Match
609 Structures::. If STR does not match PATTERN at all,
610 `string-match' returns `#f'.
612 Each time `string-match' is called, it must compile its PATTERN
613 argument into a regular expression structure. This operation is
614 expensive, which makes `string-match' inefficient if the same regular
615 expression is used several times (for example, in a loop). For better
616 performance, you can compile a regular expression in advance and then
617 match strings against the compiled regexp.
619 **** Function: make-regexp STR [FLAGS]
620 Compile the regular expression described by STR, and return the
621 compiled regexp structure. If STR does not describe a legal
622 regular expression, `make-regexp' throws a
623 `regular-expression-syntax' error.
625 FLAGS may be the bitwise-or of one or more of the following:
627 **** Constant: regexp/extended
628 Use POSIX Extended Regular Expression syntax when interpreting
629 STR. If not set, POSIX Basic Regular Expression syntax is used.
630 If the FLAGS argument is omitted, we assume regexp/extended.
632 **** Constant: regexp/icase
633 Do not differentiate case. Subsequent searches using the
634 returned regular expression will be case insensitive.
636 **** Constant: regexp/newline
637 Match-any-character operators don't match a newline.
639 A non-matching list ([^...]) not containing a newline matches a
642 Match-beginning-of-line operator (^) matches the empty string
643 immediately after a newline, regardless of whether the FLAGS
644 passed to regexp-exec contain regexp/notbol.
646 Match-end-of-line operator ($) matches the empty string
647 immediately before a newline, regardless of whether the FLAGS
648 passed to regexp-exec contain regexp/noteol.
650 **** Function: regexp-exec REGEXP STR [START [FLAGS]]
651 Match the compiled regular expression REGEXP against `str'. If
652 the optional integer START argument is provided, begin matching
653 from that position in the string. Return a match structure
654 describing the results of the match, or `#f' if no match could be
657 FLAGS may be the bitwise-or of one or more of the following:
659 **** Constant: regexp/notbol
660 The match-beginning-of-line operator always fails to match (but
661 see the compilation flag regexp/newline above) This flag may be
662 used when different portions of a string are passed to
663 regexp-exec and the beginning of the string should not be
664 interpreted as the beginning of the line.
666 **** Constant: regexp/noteol
667 The match-end-of-line operator always fails to match (but see the
668 compilation flag regexp/newline above)
670 **** Function: regexp? OBJ
671 Return `#t' if OBJ is a compiled regular expression, or `#f'
674 Regular expressions are commonly used to find patterns in one string
675 and replace them with the contents of another string.
677 **** Function: regexp-substitute PORT MATCH [ITEM...]
678 Write to the output port PORT selected contents of the match
679 structure MATCH. Each ITEM specifies what should be written, and
680 may be one of the following arguments:
682 * A string. String arguments are written out verbatim.
684 * An integer. The submatch with that number is written.
686 * The symbol `pre'. The portion of the matched string preceding
687 the regexp match is written.
689 * The symbol `post'. The portion of the matched string
690 following the regexp match is written.
692 PORT may be `#f', in which case nothing is written; instead,
693 `regexp-substitute' constructs a string from the specified ITEMs
696 **** Function: regexp-substitute/global PORT REGEXP TARGET [ITEM...]
697 Similar to `regexp-substitute', but can be used to perform global
698 substitutions on STR. Instead of taking a match structure as an
699 argument, `regexp-substitute/global' takes two string arguments: a
700 REGEXP string describing a regular expression, and a TARGET string
701 which should be matched against this regular expression.
703 Each ITEM behaves as in REGEXP-SUBSTITUTE, with the following
706 * A function may be supplied. When this function is called, it
707 will be passed one argument: a match structure for a given
708 regular expression match. It should return a string to be
711 * The `post' symbol causes `regexp-substitute/global' to recurse
712 on the unmatched portion of STR. This *must* be supplied in
713 order to perform global search-and-replace on STR; if it is
714 not present among the ITEMs, then `regexp-substitute/global'
715 will return after processing a single match.
719 A "match structure" is the object returned by `string-match' and
720 `regexp-exec'. It describes which portion of a string, if any, matched
721 the given regular expression. Match structures include: a reference to
722 the string that was checked for matches; the starting and ending
723 positions of the regexp match; and, if the regexp included any
724 parenthesized subexpressions, the starting and ending positions of each
727 In each of the regexp match functions described below, the `match'
728 argument must be a match structure returned by a previous call to
729 `string-match' or `regexp-exec'. Most of these functions return some
730 information about the original target string that was matched against a
731 regular expression; we will call that string TARGET for easy reference.
733 **** Function: regexp-match? OBJ
734 Return `#t' if OBJ is a match structure returned by a previous
735 call to `regexp-exec', or `#f' otherwise.
737 **** Function: match:substring MATCH [N]
738 Return the portion of TARGET matched by subexpression number N.
739 Submatch 0 (the default) represents the entire regexp match. If
740 the regular expression as a whole matched, but the subexpression
741 number N did not match, return `#f'.
743 **** Function: match:start MATCH [N]
744 Return the starting position of submatch number N.
746 **** Function: match:end MATCH [N]
747 Return the ending position of submatch number N.
749 **** Function: match:prefix MATCH
750 Return the unmatched portion of TARGET preceding the regexp match.
752 **** Function: match:suffix MATCH
753 Return the unmatched portion of TARGET following the regexp match.
755 **** Function: match:count MATCH
756 Return the number of parenthesized subexpressions from MATCH.
757 Note that the entire regular expression match itself counts as a
758 subexpression, and failed submatches are included in the count.
760 **** Function: match:string MATCH
761 Return the original TARGET string.
763 *** Backslash Escapes
765 Sometimes you will want a regexp to match characters like `*' or `$'
766 exactly. For example, to check whether a particular string represents
767 a menu entry from an Info node, it would be useful to match it against
768 a regexp like `^* [^:]*::'. However, this won't work; because the
769 asterisk is a metacharacter, it won't match the `*' at the beginning of
770 the string. In this case, we want to make the first asterisk un-magic.
772 You can do this by preceding the metacharacter with a backslash
773 character `\'. (This is also called "quoting" the metacharacter, and
774 is known as a "backslash escape".) When Guile sees a backslash in a
775 regular expression, it considers the following glyph to be an ordinary
776 character, no matter what special meaning it would ordinarily have.
777 Therefore, we can make the above example work by changing the regexp to
778 `^\* [^:]*::'. The `\*' sequence tells the regular expression engine
779 to match only a single asterisk in the target string.
781 Since the backslash is itself a metacharacter, you may force a
782 regexp to match a backslash in the target string by preceding the
783 backslash with itself. For example, to find variable references in a
784 TeX program, you might want to find occurrences of the string `\let\'
785 followed by any number of alphabetic characters. The regular expression
786 `\\let\\[A-Za-z]*' would do this: the double backslashes in the regexp
787 each match a single backslash in the target string.
789 **** Function: regexp-quote STR
790 Quote each special character found in STR with a backslash, and
791 return the resulting string.
793 *Very important:* Using backslash escapes in Guile source code (as
794 in Emacs Lisp or C) can be tricky, because the backslash character has
795 special meaning for the Guile reader. For example, if Guile encounters
796 the character sequence `\n' in the middle of a string while processing
797 Scheme code, it replaces those characters with a newline character.
798 Similarly, the character sequence `\t' is replaced by a horizontal tab.
799 Several of these "escape sequences" are processed by the Guile reader
800 before your code is executed. Unrecognized escape sequences are
801 ignored: if the characters `\*' appear in a string, they will be
802 translated to the single character `*'.
804 This translation is obviously undesirable for regular expressions,
805 since we want to be able to include backslashes in a string in order to
806 escape regexp metacharacters. Therefore, to make sure that a backslash
807 is preserved in a string in your Guile program, you must use *two*
808 consecutive backslashes:
810 (define Info-menu-entry-pattern (make-regexp "^\\* [^:]*"))
812 The string in this example is preprocessed by the Guile reader before
813 any code is executed. The resulting argument to `make-regexp' is the
814 string `^\* [^:]*', which is what we really want.
816 This also means that in order to write a regular expression that
817 matches a single backslash character, the regular expression string in
818 the source code must include *four* backslashes. Each consecutive pair
819 of backslashes gets translated by the Guile reader to a single
820 backslash, and the resulting double-backslash is interpreted by the
821 regexp engine as matching a single backslash character. Hence:
823 (define tex-variable-pattern (make-regexp "\\\\let\\\\=[A-Za-z]*"))
825 The reason for the unwieldiness of this syntax is historical. Both
826 regular expression pattern matchers and Unix string processing systems
827 have traditionally used backslashes with the special meanings described
828 above. The POSIX regular expression specification and ANSI C standard
829 both require these semantics. Attempting to abandon either convention
830 would cause other kinds of compatibility problems, possibly more severe
831 ones. Therefore, without extending the Scheme reader to support
832 strings with different quoting conventions (an ungainly and confusing
833 extension when implemented in other languages), we must adhere to this
834 cumbersome escape syntax.
836 * Changes to the gh_ interface
838 * Changes to the scm_ interface
840 * Changes to system call interfaces:
842 ** The value returned by `raise' is now unspecified. It throws an exception
845 *** A new procedure `sigaction' can be used to install signal handlers
847 (sigaction signum [action] [flags])
849 signum is the signal number, which can be specified using the value
852 If action is omitted, sigaction returns a pair: the CAR is the current
853 signal hander, which will be either an integer with the value SIG_DFL
854 (default action) or SIG_IGN (ignore), or the Scheme procedure which
855 handles the signal, or #f if a non-Scheme procedure handles the
856 signal. The CDR contains the current sigaction flags for the handler.
858 If action is provided, it is installed as the new handler for signum.
859 action can be a Scheme procedure taking one argument, or the value of
860 SIG_DFL (default action) or SIG_IGN (ignore), or #f to restore
861 whatever signal handler was installed before sigaction was first used.
862 Flags can optionally be specified for the new handler (SA_RESTART is
863 always used if the system provides it, so need not be specified.) The
864 return value is a pair with information about the old handler as
867 This interface does not provide access to the "signal blocking"
868 facility. Maybe this is not needed, since the thread support may
869 provide solutions to the problem of consistent access to data
872 *** A new procedure `flush-all-ports' is equivalent to running
873 `force-output' on every port open for output.
875 ** Guile now provides information on how it was built, via the new
876 global variable, %guile-build-info. This variable records the values
877 of the standard GNU makefile directory variables as an assocation
878 list, mapping variable names (symbols) onto directory paths (strings).
879 For example, to find out where the Guile link libraries were
880 installed, you can say:
882 guile -c "(display (assq-ref %guile-build-info 'libdir)) (newline)"
885 * Changes to the scm_ interface
887 ** The new function scm_handle_by_message_noexit is just like the
888 existing scm_handle_by_message function, except that it doesn't call
889 exit to terminate the process. Instead, it prints a message and just
890 returns #f. This might be a more appropriate catch-all handler for
891 new dynamic roots and threads.
894 Changes in Guile 1.1 (released Friday, May 16 1997):
896 * Changes to the distribution.
898 The Guile 1.0 distribution has been split up into several smaller
900 guile-core --- the Guile interpreter itself.
901 guile-tcltk --- the interface between the Guile interpreter and
902 Tcl/Tk; Tcl is an interpreter for a stringy language, and Tk
903 is a toolkit for building graphical user interfaces.
904 guile-rgx-ctax --- the interface between Guile and the Rx regular
905 expression matcher, and the translator for the Ctax
906 programming language. These are packaged together because the
907 Ctax translator uses Rx to parse Ctax source code.
909 This NEWS file describes the changes made to guile-core since the 1.0
912 We no longer distribute the documentation, since it was either out of
913 date, or incomplete. As soon as we have current documentation, we
918 * Changes to the stand-alone interpreter
920 ** guile now accepts command-line arguments compatible with SCSH, Olin
921 Shivers' Scheme Shell.
923 In general, arguments are evaluated from left to right, but there are
924 exceptions. The following switches stop argument processing, and
925 stash all remaining command-line arguments as the value returned by
926 the (command-line) function.
927 -s SCRIPT load Scheme source code from FILE, and exit
928 -c EXPR evalute Scheme expression EXPR, and exit
929 -- stop scanning arguments; run interactively
931 The switches below are processed as they are encountered.
932 -l FILE load Scheme source code from FILE
933 -e FUNCTION after reading script, apply FUNCTION to
934 command line arguments
935 -ds do -s script at this point
936 --emacs enable Emacs protocol (experimental)
937 -h, --help display this help and exit
938 -v, --version display version information and exit
939 \ read arguments from following script lines
941 So, for example, here is a Guile script named `ekko' (thanks, Olin)
942 which re-implements the traditional "echo" command:
944 #!/usr/local/bin/guile -s
947 (map (lambda (arg) (display arg) (display " "))
951 (main (command-line))
953 Suppose we invoke this script as follows:
955 ekko a speckled gecko
957 Through the magic of Unix script processing (triggered by the `#!'
958 token at the top of the file), /usr/local/bin/guile receives the
959 following list of command-line arguments:
961 ("-s" "./ekko" "a" "speckled" "gecko")
963 Unix inserts the name of the script after the argument specified on
964 the first line of the file (in this case, "-s"), and then follows that
965 with the arguments given to the script. Guile loads the script, which
966 defines the `main' function, and then applies it to the list of
967 remaining command-line arguments, ("a" "speckled" "gecko").
969 In Unix, the first line of a script file must take the following form:
971 #!INTERPRETER ARGUMENT
973 where INTERPRETER is the absolute filename of the interpreter
974 executable, and ARGUMENT is a single command-line argument to pass to
977 You may only pass one argument to the interpreter, and its length is
978 limited. These restrictions can be annoying to work around, so Guile
979 provides a general mechanism (borrowed from, and compatible with,
980 SCSH) for circumventing them.
982 If the ARGUMENT in a Guile script is a single backslash character,
983 `\', Guile will open the script file, parse arguments from its second
984 and subsequent lines, and replace the `\' with them. So, for example,
985 here is another implementation of the `ekko' script:
987 #!/usr/local/bin/guile \
991 (for-each (lambda (arg) (display arg) (display " "))
995 If the user invokes this script as follows:
997 ekko a speckled gecko
999 Unix expands this into
1001 /usr/local/bin/guile \ ekko a speckled gecko
1003 When Guile sees the `\' argument, it replaces it with the arguments
1004 read from the second line of the script, producing:
1006 /usr/local/bin/guile -e main -s ekko a speckled gecko
1008 This tells Guile to load the `ekko' script, and apply the function
1009 `main' to the argument list ("a" "speckled" "gecko").
1011 Here is how Guile parses the command-line arguments:
1012 - Each space character terminates an argument. This means that two
1013 spaces in a row introduce an empty-string argument.
1014 - The tab character is not permitted (unless you quote it with the
1015 backslash character, as described below), to avoid confusion.
1016 - The newline character terminates the sequence of arguments, and will
1017 also terminate a final non-empty argument. (However, a newline
1018 following a space will not introduce a final empty-string argument;
1019 it only terminates the argument list.)
1020 - The backslash character is the escape character. It escapes
1021 backslash, space, tab, and newline. The ANSI C escape sequences
1022 like \n and \t are also supported. These produce argument
1023 constituents; the two-character combination \n doesn't act like a
1024 terminating newline. The escape sequence \NNN for exactly three
1025 octal digits reads as the character whose ASCII code is NNN. As
1026 above, characters produced this way are argument constituents.
1027 Backslash followed by other characters is not allowed.
1029 * Changes to the procedure for linking libguile with your programs
1031 ** Guile now builds and installs a shared guile library, if your
1032 system support shared libraries. (It still builds a static library on
1033 all systems.) Guile automatically detects whether your system
1034 supports shared libraries. To prevent Guile from buildisg shared
1035 libraries, pass the `--disable-shared' flag to the configure script.
1037 Guile takes longer to compile when it builds shared libraries, because
1038 it must compile every file twice --- once to produce position-
1039 independent object code, and once to produce normal object code.
1041 ** The libthreads library has been merged into libguile.
1043 To link a program against Guile, you now need only link against
1044 -lguile and -lqt; -lthreads is no longer needed. If you are using
1045 autoconf to generate configuration scripts for your application, the
1046 following lines should suffice to add the appropriate libraries to
1049 ### Find quickthreads and libguile.
1050 AC_CHECK_LIB(qt, main)
1051 AC_CHECK_LIB(guile, scm_shell)
1053 * Changes to Scheme functions
1055 ** Guile Scheme's special syntax for keyword objects is now optional,
1056 and disabled by default.
1058 The syntax variation from R4RS made it difficult to port some
1059 interesting packages to Guile. The routines which accepted keyword
1060 arguments (mostly in the module system) have been modified to also
1061 accept symbols whose names begin with `:'.
1063 To change the keyword syntax, you must first import the (ice-9 debug)
1065 (use-modules (ice-9 debug))
1067 Then you can enable the keyword syntax as follows:
1068 (read-set! keywords 'prefix)
1070 To disable keyword syntax, do this:
1071 (read-set! keywords #f)
1073 ** Many more primitive functions accept shared substrings as
1074 arguments. In the past, these functions required normal, mutable
1075 strings as arguments, although they never made use of this
1078 ** The uniform array functions now operate on byte vectors. These
1079 functions are `array-fill!', `serial-array-copy!', `array-copy!',
1080 `serial-array-map', `array-map', `array-for-each', and
1083 ** The new functions `trace' and `untrace' implement simple debugging
1084 support for Scheme functions.
1086 The `trace' function accepts any number of procedures as arguments,
1087 and tells the Guile interpreter to display each procedure's name and
1088 arguments each time the procedure is invoked. When invoked with no
1089 arguments, `trace' returns the list of procedures currently being
1092 The `untrace' function accepts any number of procedures as arguments,
1093 and tells the Guile interpreter not to trace them any more. When
1094 invoked with no arguments, `untrace' untraces all curretly traced
1097 The tracing in Guile has an advantage over most other systems: we
1098 don't create new procedure objects, but mark the procedure objects
1099 themselves. This means that anonymous and internal procedures can be
1102 ** The function `assert-repl-prompt' has been renamed to
1103 `set-repl-prompt!'. It takes one argument, PROMPT.
1104 - If PROMPT is #f, the Guile read-eval-print loop will not prompt.
1105 - If PROMPT is a string, we use it as a prompt.
1106 - If PROMPT is a procedure accepting no arguments, we call it, and
1107 display the result as a prompt.
1108 - Otherwise, we display "> ".
1110 ** The new function `eval-string' reads Scheme expressions from a
1111 string and evaluates them, returning the value of the last expression
1112 in the string. If the string contains no expressions, it returns an
1115 ** The new function `thunk?' returns true iff its argument is a
1116 procedure of zero arguments.
1118 ** `defined?' is now a builtin function, instead of syntax. This
1119 means that its argument should be quoted. It returns #t iff its
1120 argument is bound in the current module.
1122 ** The new syntax `use-modules' allows you to add new modules to your
1123 environment without re-typing a complete `define-module' form. It
1124 accepts any number of module names as arguments, and imports their
1125 public bindings into the current module.
1127 ** The new function (module-defined? NAME MODULE) returns true iff
1128 NAME, a symbol, is defined in MODULE, a module object.
1130 ** The new function `builtin-bindings' creates and returns a hash
1131 table containing copies of all the root module's bindings.
1133 ** The new function `builtin-weak-bindings' does the same as
1134 `builtin-bindings', but creates a doubly-weak hash table.
1136 ** The `equal?' function now considers variable objects to be
1137 equivalent if they have the same name and the same value.
1139 ** The new function `command-line' returns the command-line arguments
1140 given to Guile, as a list of strings.
1142 When using guile as a script interpreter, `command-line' returns the
1143 script's arguments; those processed by the interpreter (like `-s' or
1144 `-c') are omitted. (In other words, you get the normal, expected
1145 behavior.) Any application that uses scm_shell to process its
1146 command-line arguments gets this behavior as well.
1148 ** The new function `load-user-init' looks for a file called `.guile'
1149 in the user's home directory, and loads it if it exists. This is
1150 mostly for use by the code generated by scm_compile_shell_switches,
1151 but we thought it might also be useful in other circumstances.
1153 ** The new function `log10' returns the base-10 logarithm of its
1156 ** Changes to I/O functions
1158 *** The functions `read', `primitive-load', `read-and-eval!', and
1159 `primitive-load-path' no longer take optional arguments controlling
1160 case insensitivity and a `#' parser.
1162 Case sensitivity is now controlled by a read option called
1163 `case-insensitive'. The user can add new `#' syntaxes with the
1164 `read-hash-extend' function (see below).
1166 *** The new function `read-hash-extend' allows the user to change the
1167 syntax of Guile Scheme in a somewhat controlled way.
1169 (read-hash-extend CHAR PROC)
1170 When parsing S-expressions, if we read a `#' character followed by
1171 the character CHAR, use PROC to parse an object from the stream.
1172 If PROC is #f, remove any parsing procedure registered for CHAR.
1174 The reader applies PROC to two arguments: CHAR and an input port.
1176 *** The new functions read-delimited and read-delimited! provide a
1177 general mechanism for doing delimited input on streams.
1179 (read-delimited DELIMS [PORT HANDLE-DELIM])
1180 Read until we encounter one of the characters in DELIMS (a string),
1181 or end-of-file. PORT is the input port to read from; it defaults to
1182 the current input port. The HANDLE-DELIM parameter determines how
1183 the terminating character is handled; it should be one of the
1186 'trim omit delimiter from result
1187 'peek leave delimiter character in input stream
1188 'concat append delimiter character to returned value
1189 'split return a pair: (RESULT . TERMINATOR)
1191 HANDLE-DELIM defaults to 'peek.
1193 (read-delimited! DELIMS BUF [PORT HANDLE-DELIM START END])
1194 A side-effecting variant of `read-delimited'.
1196 The data is written into the string BUF at the indices in the
1197 half-open interval [START, END); the default interval is the whole
1198 string: START = 0 and END = (string-length BUF). The values of
1199 START and END must specify a well-defined interval in BUF, i.e.
1200 0 <= START <= END <= (string-length BUF).
1202 It returns NBYTES, the number of bytes read. If the buffer filled
1203 up without a delimiter character being found, it returns #f. If the
1204 port is at EOF when the read starts, it returns the EOF object.
1206 If an integer is returned (i.e., the read is successfully terminated
1207 by reading a delimiter character), then the HANDLE-DELIM parameter
1208 determines how to handle the terminating character. It is described
1209 above, and defaults to 'peek.
1211 (The descriptions of these functions were borrowed from the SCSH
1212 manual, by Olin Shivers and Brian Carlstrom.)
1214 *** The `%read-delimited!' function is the primitive used to implement
1215 `read-delimited' and `read-delimited!'.
1217 (%read-delimited! DELIMS BUF GOBBLE? [PORT START END])
1219 This returns a pair of values: (TERMINATOR . NUM-READ).
1220 - TERMINATOR describes why the read was terminated. If it is a
1221 character or the eof object, then that is the value that terminated
1222 the read. If it is #f, the function filled the buffer without finding
1223 a delimiting character.
1224 - NUM-READ is the number of characters read into BUF.
1226 If the read is successfully terminated by reading a delimiter
1227 character, then the gobble? parameter determines what to do with the
1228 terminating character. If true, the character is removed from the
1229 input stream; if false, the character is left in the input stream
1230 where a subsequent read operation will retrieve it. In either case,
1231 the character is also the first value returned by the procedure call.
1233 (The descriptions of this function was borrowed from the SCSH manual,
1234 by Olin Shivers and Brian Carlstrom.)
1236 *** The `read-line' and `read-line!' functions have changed; they now
1237 trim the terminator by default; previously they appended it to the
1238 returned string. For the old behavior, use (read-line PORT 'concat).
1240 *** The functions `uniform-array-read!' and `uniform-array-write!' now
1241 take new optional START and END arguments, specifying the region of
1242 the array to read and write.
1244 *** The `ungetc-char-ready?' function has been removed. We feel it's
1245 inappropriate for an interface to expose implementation details this
1248 ** Changes to the Unix library and system call interface
1250 *** The new fcntl function provides access to the Unix `fcntl' system
1253 (fcntl PORT COMMAND VALUE)
1254 Apply COMMAND to PORT's file descriptor, with VALUE as an argument.
1255 Values for COMMAND are:
1257 F_DUPFD duplicate a file descriptor
1258 F_GETFD read the descriptor's close-on-exec flag
1259 F_SETFD set the descriptor's close-on-exec flag to VALUE
1260 F_GETFL read the descriptor's flags, as set on open
1261 F_SETFL set the descriptor's flags, as set on open to VALUE
1262 F_GETOWN return the process ID of a socket's owner, for SIGIO
1263 F_SETOWN set the process that owns a socket to VALUE, for SIGIO
1264 FD_CLOEXEC not sure what this is
1266 For details, see the documentation for the fcntl system call.
1268 *** The arguments to `select' have changed, for compatibility with
1269 SCSH. The TIMEOUT parameter may now be non-integral, yielding the
1270 expected behavior. The MILLISECONDS parameter has been changed to
1271 MICROSECONDS, to more closely resemble the underlying system call.
1272 The RVEC, WVEC, and EVEC arguments can now be vectors; the type of the
1273 corresponding return set will be the same.
1275 *** The arguments to the `mknod' system call have changed. They are
1278 (mknod PATH TYPE PERMS DEV)
1279 Create a new file (`node') in the file system. PATH is the name of
1280 the file to create. TYPE is the kind of file to create; it should
1281 be 'fifo, 'block-special, or 'char-special. PERMS specifies the
1282 permission bits to give the newly created file. If TYPE is
1283 'block-special or 'char-special, DEV specifies which device the
1284 special file refers to; its interpretation depends on the kind of
1285 special file being created.
1287 *** The `fork' function has been renamed to `primitive-fork', to avoid
1288 clashing with various SCSH forks.
1290 *** The `recv' and `recvfrom' functions have been renamed to `recv!'
1291 and `recvfrom!'. They no longer accept a size for a second argument;
1292 you must pass a string to hold the received value. They no longer
1293 return the buffer. Instead, `recv' returns the length of the message
1294 received, and `recvfrom' returns a pair containing the packet's length
1295 and originating address.
1297 *** The file descriptor datatype has been removed, as have the
1298 `read-fd', `write-fd', `close', `lseek', and `dup' functions.
1299 We plan to replace these functions with a SCSH-compatible interface.
1301 *** The `create' function has been removed; it's just a special case
1304 *** There are new functions to break down process termination status
1305 values. In the descriptions below, STATUS is a value returned by
1308 (status:exit-val STATUS)
1309 If the child process exited normally, this function returns the exit
1310 code for the child process (i.e., the value passed to exit, or
1311 returned from main). If the child process did not exit normally,
1312 this function returns #f.
1314 (status:stop-sig STATUS)
1315 If the child process was suspended by a signal, this function
1316 returns the signal that suspended the child. Otherwise, it returns
1319 (status:term-sig STATUS)
1320 If the child process terminated abnormally, this function returns
1321 the signal that terminated the child. Otherwise, this function
1324 POSIX promises that exactly one of these functions will return true on
1325 a valid STATUS value.
1327 These functions are compatible with SCSH.
1329 *** There are new accessors and setters for the broken-out time vectors
1330 returned by `localtime', `gmtime', and that ilk. They are:
1332 Component Accessor Setter
1333 ========================= ============ ============
1334 seconds tm:sec set-tm:sec
1335 minutes tm:min set-tm:min
1336 hours tm:hour set-tm:hour
1337 day of the month tm:mday set-tm:mday
1338 month tm:mon set-tm:mon
1339 year tm:year set-tm:year
1340 day of the week tm:wday set-tm:wday
1341 day in the year tm:yday set-tm:yday
1342 daylight saving time tm:isdst set-tm:isdst
1343 GMT offset, seconds tm:gmtoff set-tm:gmtoff
1344 name of time zone tm:zone set-tm:zone
1346 *** There are new accessors for the vectors returned by `uname',
1347 describing the host system:
1350 ============================================== ================
1351 name of the operating system implementation utsname:sysname
1352 network name of this machine utsname:nodename
1353 release level of the operating system utsname:release
1354 version level of the operating system utsname:version
1355 machine hardware platform utsname:machine
1357 *** There are new accessors for the vectors returned by `getpw',
1358 `getpwnam', `getpwuid', and `getpwent', describing entries from the
1359 system's user database:
1362 ====================== =================
1363 user name passwd:name
1364 user password passwd:passwd
1367 real name passwd:gecos
1368 home directory passwd:dir
1369 shell program passwd:shell
1371 *** There are new accessors for the vectors returned by `getgr',
1372 `getgrnam', `getgrgid', and `getgrent', describing entries from the
1373 system's group database:
1376 ======================= ============
1377 group name group:name
1378 group password group:passwd
1380 group members group:mem
1382 *** There are new accessors for the vectors returned by `gethost',
1383 `gethostbyaddr', `gethostbyname', and `gethostent', describing
1387 ========================= ===============
1388 official name of host hostent:name
1389 alias list hostent:aliases
1390 host address type hostent:addrtype
1391 length of address hostent:length
1392 list of addresses hostent:addr-list
1394 *** There are new accessors for the vectors returned by `getnet',
1395 `getnetbyaddr', `getnetbyname', and `getnetent', describing internet
1399 ========================= ===============
1400 official name of net netent:name
1401 alias list netent:aliases
1402 net number type netent:addrtype
1403 net number netent:net
1405 *** There are new accessors for the vectors returned by `getproto',
1406 `getprotobyname', `getprotobynumber', and `getprotoent', describing
1410 ========================= ===============
1411 official protocol name protoent:name
1412 alias list protoent:aliases
1413 protocol number protoent:proto
1415 *** There are new accessors for the vectors returned by `getserv',
1416 `getservbyname', `getservbyport', and `getservent', describing
1420 ========================= ===============
1421 official service name servent:name
1422 alias list servent:aliases
1423 port number servent:port
1424 protocol to use servent:proto
1426 *** There are new accessors for the sockaddr structures returned by
1427 `accept', `getsockname', `getpeername', `recvfrom!':
1430 ======================================== ===============
1431 address format (`family') sockaddr:fam
1432 path, for file domain addresses sockaddr:path
1433 address, for internet domain addresses sockaddr:addr
1434 TCP or UDP port, for internet sockaddr:port
1436 *** The `getpwent', `getgrent', `gethostent', `getnetent',
1437 `getprotoent', and `getservent' functions now return #f at the end of
1438 the user database. (They used to throw an exception.)
1440 Note that calling MUMBLEent function is equivalent to calling the
1441 corresponding MUMBLE function with no arguments.
1443 *** The `setpwent', `setgrent', `sethostent', `setnetent',
1444 `setprotoent', and `setservent' routines now take no arguments.
1446 *** The `gethost', `getproto', `getnet', and `getserv' functions now
1447 provide more useful information when they throw an exception.
1449 *** The `lnaof' function has been renamed to `inet-lnaof'.
1451 *** Guile now claims to have the `current-time' feature.
1453 *** The `mktime' function now takes an optional second argument ZONE,
1454 giving the time zone to use for the conversion. ZONE should be a
1455 string, in the same format as expected for the "TZ" environment variable.
1457 *** The `strptime' function now returns a pair (TIME . COUNT), where
1458 TIME is the parsed time as a vector, and COUNT is the number of
1459 characters from the string left unparsed. This function used to
1460 return the remaining characters as a string.
1462 *** The `gettimeofday' function has replaced the old `time+ticks' function.
1463 The return value is now (SECONDS . MICROSECONDS); the fractional
1464 component is no longer expressed in "ticks".
1466 *** The `ticks/sec' constant has been removed, in light of the above change.
1468 * Changes to the gh_ interface
1470 ** gh_eval_str() now returns an SCM object which is the result of the
1473 ** gh_scm2str() now copies the Scheme data to a caller-provided C
1476 ** gh_scm2newstr() now makes a C array, copies the Scheme data to it,
1477 and returns the array
1479 ** gh_scm2str0() is gone: there is no need to distinguish
1480 null-terminated from non-null-terminated, since gh_scm2newstr() allows
1481 the user to interpret the data both ways.
1483 * Changes to the scm_ interface
1485 ** The new function scm_symbol_value0 provides an easy way to get a
1486 symbol's value from C code:
1488 SCM scm_symbol_value0 (char *NAME)
1489 Return the value of the symbol named by the null-terminated string
1490 NAME in the current module. If the symbol named NAME is unbound in
1491 the current module, return SCM_UNDEFINED.
1493 ** The new function scm_sysintern0 creates new top-level variables,
1494 without assigning them a value.
1496 SCM scm_sysintern0 (char *NAME)
1497 Create a new Scheme top-level variable named NAME. NAME is a
1498 null-terminated string. Return the variable's value cell.
1500 ** The function scm_internal_catch is the guts of catch. It handles
1501 all the mechanics of setting up a catch target, invoking the catch
1502 body, and perhaps invoking the handler if the body does a throw.
1504 The function is designed to be usable from C code, but is general
1505 enough to implement all the semantics Guile Scheme expects from throw.
1507 TAG is the catch tag. Typically, this is a symbol, but this function
1508 doesn't actually care about that.
1510 BODY is a pointer to a C function which runs the body of the catch;
1511 this is the code you can throw from. We call it like this:
1512 BODY (BODY_DATA, JMPBUF)
1514 BODY_DATA is just the BODY_DATA argument we received; we pass it
1515 through to BODY as its first argument. The caller can make
1516 BODY_DATA point to anything useful that BODY might need.
1517 JMPBUF is the Scheme jmpbuf object corresponding to this catch,
1518 which we have just created and initialized.
1520 HANDLER is a pointer to a C function to deal with a throw to TAG,
1521 should one occur. We call it like this:
1522 HANDLER (HANDLER_DATA, THROWN_TAG, THROW_ARGS)
1524 HANDLER_DATA is the HANDLER_DATA argument we recevied; it's the
1525 same idea as BODY_DATA above.
1526 THROWN_TAG is the tag that the user threw to; usually this is
1527 TAG, but it could be something else if TAG was #t (i.e., a
1528 catch-all), or the user threw to a jmpbuf.
1529 THROW_ARGS is the list of arguments the user passed to the THROW
1532 BODY_DATA is just a pointer we pass through to BODY. HANDLER_DATA
1533 is just a pointer we pass through to HANDLER. We don't actually
1534 use either of those pointers otherwise ourselves. The idea is
1535 that, if our caller wants to communicate something to BODY or
1536 HANDLER, it can pass a pointer to it as MUMBLE_DATA, which BODY and
1537 HANDLER can then use. Think of it as a way to make BODY and
1538 HANDLER closures, not just functions; MUMBLE_DATA points to the
1541 Of course, it's up to the caller to make sure that any data a
1542 MUMBLE_DATA needs is protected from GC. A common way to do this is
1543 to make MUMBLE_DATA a pointer to data stored in an automatic
1544 structure variable; since the collector must scan the stack for
1545 references anyway, this assures that any references in MUMBLE_DATA
1548 ** The new function scm_internal_lazy_catch is exactly like
1549 scm_internal_catch, except:
1551 - It does not unwind the stack (this is the major difference).
1552 - If handler returns, its value is returned from the throw.
1553 - BODY always receives #f as its JMPBUF argument (since there's no
1554 jmpbuf associated with a lazy catch, because we don't unwind the
1557 ** scm_body_thunk is a new body function you can pass to
1558 scm_internal_catch if you want the body to be like Scheme's `catch'
1559 --- a thunk, or a function of one argument if the tag is #f.
1561 BODY_DATA is a pointer to a scm_body_thunk_data structure, which
1562 contains the Scheme procedure to invoke as the body, and the tag
1563 we're catching. If the tag is #f, then we pass JMPBUF (created by
1564 scm_internal_catch) to the body procedure; otherwise, the body gets
1567 ** scm_handle_by_proc is a new handler function you can pass to
1568 scm_internal_catch if you want the handler to act like Scheme's catch
1569 --- call a procedure with the tag and the throw arguments.
1571 If the user does a throw to this catch, this function runs a handler
1572 procedure written in Scheme. HANDLER_DATA is a pointer to an SCM
1573 variable holding the Scheme procedure object to invoke. It ought to
1574 be a pointer to an automatic variable (i.e., one living on the stack),
1575 or the procedure object should be otherwise protected from GC.
1577 ** scm_handle_by_message is a new handler function to use with
1578 `scm_internal_catch' if you want Guile to print a message and die.
1579 It's useful for dealing with throws to uncaught keys at the top level.
1581 HANDLER_DATA, if non-zero, is assumed to be a char * pointing to a
1582 message header to print; if zero, we use "guile" instead. That
1583 text is followed by a colon, then the message described by ARGS.
1585 ** The return type of scm_boot_guile is now void; the function does
1586 not return a value, and indeed, never returns at all.
1588 ** The new function scm_shell makes it easy for user applications to
1589 process command-line arguments in a way that is compatible with the
1590 stand-alone guile interpreter (which is in turn compatible with SCSH,
1593 To use the scm_shell function, first initialize any guile modules
1594 linked into your application, and then call scm_shell with the values
1595 of ARGC and ARGV your `main' function received. scm_shell will add
1596 any SCSH-style meta-arguments from the top of the script file to the
1597 argument vector, and then process the command-line arguments. This
1598 generally means loading a script file or starting up an interactive
1599 command interpreter. For details, see "Changes to the stand-alone
1602 ** The new functions scm_get_meta_args and scm_count_argv help you
1603 implement the SCSH-style meta-argument, `\'.
1605 char **scm_get_meta_args (int ARGC, char **ARGV)
1606 If the second element of ARGV is a string consisting of a single
1607 backslash character (i.e. "\\" in Scheme notation), open the file
1608 named by the following argument, parse arguments from it, and return
1609 the spliced command line. The returned array is terminated by a
1612 For details of argument parsing, see above, under "guile now accepts
1613 command-line arguments compatible with SCSH..."
1615 int scm_count_argv (char **ARGV)
1616 Count the arguments in ARGV, assuming it is terminated by a null
1619 For an example of how these functions might be used, see the source
1620 code for the function scm_shell in libguile/script.c.
1622 You will usually want to use scm_shell instead of calling this
1625 ** The new function scm_compile_shell_switches turns an array of
1626 command-line arguments into Scheme code to carry out the actions they
1627 describe. Given ARGC and ARGV, it returns a Scheme expression to
1628 evaluate, and calls scm_set_program_arguments to make any remaining
1629 command-line arguments available to the Scheme code. For example,
1630 given the following arguments:
1632 -e main -s ekko a speckled gecko
1634 scm_set_program_arguments will return the following expression:
1636 (begin (load "ekko") (main (command-line)) (quit))
1638 You will usually want to use scm_shell instead of calling this
1641 ** The function scm_shell_usage prints a usage message appropriate for
1642 an interpreter that uses scm_compile_shell_switches to handle its
1643 command-line arguments.
1645 void scm_shell_usage (int FATAL, char *MESSAGE)
1646 Print a usage message to the standard error output. If MESSAGE is
1647 non-zero, write it before the usage message, followed by a newline.
1648 If FATAL is non-zero, exit the process, using FATAL as the
1649 termination status. (If you want to be compatible with Guile,
1650 always use 1 as the exit status when terminating due to command-line
1653 You will usually want to use scm_shell instead of calling this
1656 ** scm_eval_0str now returns SCM_UNSPECIFIED if the string contains no
1657 expressions. It used to return SCM_EOL. Earth-shattering.
1659 ** The macros for declaring scheme objects in C code have been
1660 rearranged slightly. They are now:
1662 SCM_SYMBOL (C_NAME, SCHEME_NAME)
1663 Declare a static SCM variable named C_NAME, and initialize it to
1664 point to the Scheme symbol whose name is SCHEME_NAME. C_NAME should
1665 be a C identifier, and SCHEME_NAME should be a C string.
1667 SCM_GLOBAL_SYMBOL (C_NAME, SCHEME_NAME)
1668 Just like SCM_SYMBOL, but make C_NAME globally visible.
1670 SCM_VCELL (C_NAME, SCHEME_NAME)
1671 Create a global variable at the Scheme level named SCHEME_NAME.
1672 Declare a static SCM variable named C_NAME, and initialize it to
1673 point to the Scheme variable's value cell.
1675 SCM_GLOBAL_VCELL (C_NAME, SCHEME_NAME)
1676 Just like SCM_VCELL, but make C_NAME globally visible.
1678 The `guile-snarf' script writes initialization code for these macros
1679 to its standard output, given C source code as input.
1681 The SCM_GLOBAL macro is gone.
1683 ** The scm_read_line and scm_read_line_x functions have been replaced
1684 by Scheme code based on the %read-delimited! procedure (known to C
1685 code as scm_read_delimited_x). See its description above for more
1688 ** The function scm_sys_open has been renamed to scm_open. It now
1689 returns a port instead of an FD object.
1691 * The dynamic linking support has changed. For more information, see
1692 libguile/DYNAMIC-LINKING.
1697 User-visible changes from Thursday, September 5, 1996 until Guile 1.0
1700 * Changes to the 'guile' program:
1702 ** Guile now loads some new files when it starts up. Guile first
1703 searches the load path for init.scm, and loads it if found. Then, if
1704 Guile is not being used to execute a script, and the user's home
1705 directory contains a file named `.guile', Guile loads that.
1707 ** You can now use Guile as a shell script interpreter.
1709 To paraphrase the SCSH manual:
1711 When Unix tries to execute an executable file whose first two
1712 characters are the `#!', it treats the file not as machine code to
1713 be directly executed by the native processor, but as source code
1714 to be executed by some interpreter. The interpreter to use is
1715 specified immediately after the #! sequence on the first line of
1716 the source file. The kernel reads in the name of the interpreter,
1717 and executes that instead. It passes the interpreter the source
1718 filename as its first argument, with the original arguments
1719 following. Consult the Unix man page for the `exec' system call
1720 for more information.
1722 Now you can use Guile as an interpreter, using a mechanism which is a
1723 compatible subset of that provided by SCSH.
1725 Guile now recognizes a '-s' command line switch, whose argument is the
1726 name of a file of Scheme code to load. It also treats the two
1727 characters `#!' as the start of a comment, terminated by `!#'. Thus,
1728 to make a file of Scheme code directly executable by Unix, insert the
1729 following two lines at the top of the file:
1731 #!/usr/local/bin/guile -s
1734 Guile treats the argument of the `-s' command-line switch as the name
1735 of a file of Scheme code to load, and treats the sequence `#!' as the
1736 start of a block comment, terminated by `!#'.
1738 For example, here's a version of 'echo' written in Scheme:
1740 #!/usr/local/bin/guile -s
1742 (let loop ((args (cdr (program-arguments))))
1745 (display (car args))
1746 (if (pair? (cdr args))
1748 (loop (cdr args)))))
1751 Why does `#!' start a block comment terminated by `!#', instead of the
1752 end of the line? That is the notation SCSH uses, and although we
1753 don't yet support the other SCSH features that motivate that choice,
1754 we would like to be backward-compatible with any existing Guile
1755 scripts once we do. Furthermore, if the path to Guile on your system
1756 is too long for your kernel, you can start the script with this
1760 exec /really/long/path/to/guile -s "$0" ${1+"$@"}
1763 Note that some very old Unix systems don't support the `#!' syntax.
1766 ** You can now run Guile without installing it.
1768 Previous versions of the interactive Guile interpreter (`guile')
1769 couldn't start up unless Guile's Scheme library had been installed;
1770 they used the value of the environment variable `SCHEME_LOAD_PATH'
1771 later on in the startup process, but not to find the startup code
1772 itself. Now Guile uses `SCHEME_LOAD_PATH' in all searches for Scheme
1775 To run Guile without installing it, build it in the normal way, and
1776 then set the environment variable `SCHEME_LOAD_PATH' to a
1777 colon-separated list of directories, including the top-level directory
1778 of the Guile sources. For example, if you unpacked Guile so that the
1779 full filename of this NEWS file is /home/jimb/guile-1.0b3/NEWS, then
1782 export SCHEME_LOAD_PATH=/home/jimb/my-scheme:/home/jimb/guile-1.0b3
1785 ** Guile's read-eval-print loop no longer prints #<unspecified>
1786 results. If the user wants to see this, she can evaluate the
1787 expression (assert-repl-print-unspecified #t), perhaps in her startup
1790 ** Guile no longer shows backtraces by default when an error occurs;
1791 however, it does display a message saying how to get one, and how to
1792 request that they be displayed by default. After an error, evaluate
1794 to see a backtrace, and
1795 (debug-enable 'backtrace)
1796 to see them by default.
1800 * Changes to Guile Scheme:
1802 ** Guile now distinguishes between #f and the empty list.
1804 This is for compatibility with the IEEE standard, the (possibly)
1805 upcoming Revised^5 Report on Scheme, and many extant Scheme
1808 Guile used to have #f and '() denote the same object, to make Scheme's
1809 type system more compatible with Emacs Lisp's. However, the change
1810 caused too much trouble for Scheme programmers, and we found another
1811 way to reconcile Emacs Lisp with Scheme that didn't require this.
1814 ** Guile's delq, delv, delete functions, and their destructive
1815 counterparts, delq!, delv!, and delete!, now remove all matching
1816 elements from the list, not just the first. This matches the behavior
1817 of the corresponding Emacs Lisp functions, and (I believe) the Maclisp
1818 functions which inspired them.
1820 I recognize that this change may break code in subtle ways, but it
1821 seems best to make the change before the FSF's first Guile release,
1825 ** The compiled-library-path function has been deleted from libguile.
1827 ** The facilities for loading Scheme source files have changed.
1829 *** The variable %load-path now tells Guile which directories to search
1830 for Scheme code. Its value is a list of strings, each of which names
1833 *** The variable %load-extensions now tells Guile which extensions to
1834 try appending to a filename when searching the load path. Its value
1835 is a list of strings. Its default value is ("" ".scm").
1837 *** (%search-load-path FILENAME) searches the directories listed in the
1838 value of the %load-path variable for a Scheme file named FILENAME,
1839 with all the extensions listed in %load-extensions. If it finds a
1840 match, then it returns its full filename. If FILENAME is absolute, it
1841 returns it unchanged. Otherwise, it returns #f.
1843 %search-load-path will not return matches that refer to directories.
1845 *** (primitive-load FILENAME :optional CASE-INSENSITIVE-P SHARP)
1846 uses %seach-load-path to find a file named FILENAME, and loads it if
1847 it finds it. If it can't read FILENAME for any reason, it throws an
1850 The arguments CASE-INSENSITIVE-P and SHARP are interpreted as by the
1853 *** load uses the same searching semantics as primitive-load.
1855 *** The functions %try-load, try-load-with-path, %load, load-with-path,
1856 basic-try-load-with-path, basic-load-with-path, try-load-module-with-
1857 path, and load-module-with-path have been deleted. The functions
1858 above should serve their purposes.
1860 *** If the value of the variable %load-hook is a procedure,
1861 `primitive-load' applies its value to the name of the file being
1862 loaded (without the load path directory name prepended). If its value
1863 is #f, it is ignored. Otherwise, an error occurs.
1865 This is mostly useful for printing load notification messages.
1868 ** The function `eval!' is no longer accessible from the scheme level.
1869 We can't allow operations which introduce glocs into the scheme level,
1870 because Guile's type system can't handle these as data. Use `eval' or
1871 `read-and-eval!' (see below) as replacement.
1873 ** The new function read-and-eval! reads an expression from PORT,
1874 evaluates it, and returns the result. This is more efficient than
1875 simply calling `read' and `eval', since it is not necessary to make a
1876 copy of the expression for the evaluator to munge.
1878 Its optional arguments CASE_INSENSITIVE_P and SHARP are interpreted as
1879 for the `read' function.
1882 ** The function `int?' has been removed; its definition was identical
1883 to that of `integer?'.
1885 ** The functions `<?', `<?', `<=?', `=?', `>?', and `>=?'. Code should
1886 use the R4RS names for these functions.
1888 ** The function object-properties no longer returns the hash handle;
1889 it simply returns the object's property list.
1891 ** Many functions have been changed to throw errors, instead of
1892 returning #f on failure. The point of providing exception handling in
1893 the language is to simplify the logic of user code, but this is less
1894 useful if Guile's primitives don't throw exceptions.
1896 ** The function `fileno' has been renamed from `%fileno'.
1898 ** The function primitive-mode->fdes returns #t or #f now, not 1 or 0.
1901 * Changes to Guile's C interface:
1903 ** The library's initialization procedure has been simplified.
1904 scm_boot_guile now has the prototype:
1906 void scm_boot_guile (int ARGC,
1908 void (*main_func) (),
1911 scm_boot_guile calls MAIN_FUNC, passing it CLOSURE, ARGC, and ARGV.
1912 MAIN_FUNC should do all the work of the program (initializing other
1913 packages, reading user input, etc.) before returning. When MAIN_FUNC
1914 returns, call exit (0); this function never returns. If you want some
1915 other exit value, MAIN_FUNC may call exit itself.
1917 scm_boot_guile arranges for program-arguments to return the strings
1918 given by ARGC and ARGV. If MAIN_FUNC modifies ARGC/ARGV, should call
1919 scm_set_program_arguments with the final list, so Scheme code will
1920 know which arguments have been processed.
1922 scm_boot_guile establishes a catch-all catch handler which prints an
1923 error message and exits the process. This means that Guile exits in a
1924 coherent way when system errors occur and the user isn't prepared to
1925 handle it. If the user doesn't like this behavior, they can establish
1926 their own universal catcher in MAIN_FUNC to shadow this one.
1928 Why must the caller do all the real work from MAIN_FUNC? The garbage
1929 collector assumes that all local variables of type SCM will be above
1930 scm_boot_guile's stack frame on the stack. If you try to manipulate
1931 SCM values after this function returns, it's the luck of the draw
1932 whether the GC will be able to find the objects you allocate. So,
1933 scm_boot_guile function exits, rather than returning, to discourage
1934 people from making that mistake.
1936 The IN, OUT, and ERR arguments were removed; there are other
1937 convenient ways to override these when desired.
1939 The RESULT argument was deleted; this function should never return.
1941 The BOOT_CMD argument was deleted; the MAIN_FUNC argument is more
1945 ** Guile's header files should no longer conflict with your system's
1948 In order to compile code which #included <libguile.h>, previous
1949 versions of Guile required you to add a directory containing all the
1950 Guile header files to your #include path. This was a problem, since
1951 Guile's header files have names which conflict with many systems'
1954 Now only <libguile.h> need appear in your #include path; you must
1955 refer to all Guile's other header files as <libguile/mumble.h>.
1956 Guile's installation procedure puts libguile.h in $(includedir), and
1957 the rest in $(includedir)/libguile.
1960 ** Two new C functions, scm_protect_object and scm_unprotect_object,
1961 have been added to the Guile library.
1963 scm_protect_object (OBJ) protects OBJ from the garbage collector.
1964 OBJ will not be freed, even if all other references are dropped,
1965 until someone does scm_unprotect_object (OBJ). Both functions
1968 Note that calls to scm_protect_object do not nest. You can call
1969 scm_protect_object any number of times on a given object, and the
1970 next call to scm_unprotect_object will unprotect it completely.
1972 Basically, scm_protect_object and scm_unprotect_object just
1973 maintain a list of references to things. Since the GC knows about
1974 this list, all objects it mentions stay alive. scm_protect_object
1975 adds its argument to the list; scm_unprotect_object remove its
1976 argument from the list.
1979 ** scm_eval_0str now returns the value of the last expression
1982 ** The new function scm_read_0str reads an s-expression from a
1983 null-terminated string, and returns it.
1985 ** The new function `scm_stdio_to_port' converts a STDIO file pointer
1986 to a Scheme port object.
1988 ** The new function `scm_set_program_arguments' allows C code to set
1989 the value teruturned by the Scheme `program-arguments' function.
1994 * Guile no longer includes sophisticated Tcl/Tk support.
1996 The old Tcl/Tk support was unsatisfying to us, because it required the
1997 user to link against the Tcl library, as well as Tk and Guile. The
1998 interface was also un-lispy, in that it preserved Tcl/Tk's practice of
1999 referring to widgets by names, rather than exporting widgets to Scheme
2000 code as a special datatype.
2002 In the Usenix Tk Developer's Workshop held in July 1996, the Tcl/Tk
2003 maintainers described some very interesting changes in progress to the
2004 Tcl/Tk internals, which would facilitate clean interfaces between lone
2005 Tk and other interpreters --- even for garbage-collected languages
2006 like Scheme. They expected the new Tk to be publicly available in the
2009 Since it seems that Guile might soon have a new, cleaner interface to
2010 lone Tk, and that the old Guile/Tk glue code would probably need to be
2011 completely rewritten, we (Jim Blandy and Richard Stallman) have
2012 decided not to support the old code. We'll spend the time instead on
2013 a good interface to the newer Tk, as soon as it is available.
2015 Until then, gtcltk-lib provides trivial, low-maintenance functionality.
2018 Copyright information:
2020 Copyright (C) 1996,1997 Free Software Foundation, Inc.
2022 Permission is granted to anyone to make or distribute verbatim copies
2023 of this document as received, in any medium, provided that the
2024 copyright notice and this permission notice are preserved,
2025 thus giving the recipient permission to redistribute in turn.
2027 Permission is granted to distribute modified versions
2028 of this document, or of portions of it,
2029 under the above conditions, provided also that they
2030 carry prominent notices stating who last changed them.
2035 paragraph-separate: "[
\f]*$"