1 Guile NEWS --- history of user-visible changes. -*- text -*-
2 Copyright (C) 1996, 1997, 1998 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:
9 * Changes to the stand-alone interpreter
11 ** New options interface: readline-options,
12 readline-enable, readline-disable, readline-set!
14 ** Command line history is now restored from and saved to file
16 If readline is used and the readline option `history-file' is enabled,
17 the command line history is read from file when the interpreter is
18 entered, and written to file on exit. The filename used can be
19 specified with the environment variable GUILE_HISTORY. Default file
20 name is "$HOME/.guile_history". Nothing special happens if errors
21 occur during read or write.
23 ** Command line history length can now be customized.
24 Command line history length is now controlled by the readline option
25 `history-length'. Default is 200 lines.
27 ** All builtins now print as primitives.
28 Previously builtin procedures not belonging to the fundamental subr
29 types printed as #<compiled closure #<primitive-procedure gsubr-apply>>.
30 Now, they print as #<primitive-procedure NAME>.
32 ** Backtraces slightly more intelligible.
33 gsubr-apply and macro transformer application frames no longer appear
36 * Changes to Scheme functions and syntax
38 ** New functions: delq1!, delv1!, delete1!
39 These procedures behave similar to delq! and friends but delete only
42 ** New function: unread-string STRING PORT
43 Unread STRING to PORT, that is, push it back onto the port so that
44 next read operation will work on the pushed back characters.
46 ** unread-char can now be called multiple times
47 If unread-char is called multiple times, the unread characters will be
48 read again in last-in first-out order.
50 ** New function: serial-map PROC LIST1 LIST2 ...
51 Version of `map' which guarantees that the procedure is applied to the
52 lists in serial order.
54 ** New syntax: sequence->list BODY1 ...
55 Version of `begin' which returns a list of the results of the body
56 forms instead of the result of the last body form. In contrast to
57 `begin', sequence->list allows an empty body.
59 ** New functions: read-history FILENAME, write-history FILENAME
60 Read/write command line history from/to file. Returns #t on success
61 and #f if an error occured.
63 * Changes to the gh_ interface
67 Now takes a second argument which is the result array. If this
68 pointer is NULL, a new array is malloced (the old behaviour).
70 ** gh_chars2byvect, gh_shorts2svect, gh_floats2fvect, gh_scm2chars,
71 gh_scm2shorts, gh_scm2longs, gh_scm2floats
76 Changes in Guile 1.3 (released Monday, October 19, 1998):
78 * Changes to the distribution
80 ** We renamed the SCHEME_LOAD_PATH environment variable to GUILE_LOAD_PATH.
81 To avoid conflicts, programs should name environment variables after
82 themselves, except when there's a common practice establishing some
85 For now, Guile supports both GUILE_LOAD_PATH and SCHEME_LOAD_PATH,
86 giving the former precedence, and printing a warning message if the
87 latter is set. Guile 1.4 will not recognize SCHEME_LOAD_PATH at all.
89 ** The header files related to multi-byte characters have been removed.
90 They were: libguile/extchrs.h and libguile/mbstrings.h. Any C code
91 which referred to these explicitly will probably need to be rewritten,
92 since the support for the variant string types has been removed; see
95 ** The header files append.h and sequences.h have been removed. These
96 files implemented non-R4RS operations which would encourage
97 non-portable programming style and less easy-to-read code.
99 * Changes to the stand-alone interpreter
101 ** New procedures have been added to implement a "batch mode":
103 *** Function: batch-mode?
105 Returns a boolean indicating whether the interpreter is in batch
108 *** Function: set-batch-mode?! ARG
110 If ARG is true, switches the interpreter to batch mode. The `#f'
111 case has not been implemented.
113 ** Guile now provides full command-line editing, when run interactively.
114 To use this feature, you must have the readline library installed.
115 The Guile build process will notice it, and automatically include
118 The readline library is available via anonymous FTP from any GNU
119 mirror site; the canonical location is "ftp://prep.ai.mit.edu/pub/gnu".
121 ** the-last-stack is now a fluid.
123 * Changes to the procedure for linking libguile with your programs
125 ** You can now use the `guile-config' utility to build programs that use Guile.
127 Guile now includes a command-line utility called `guile-config', which
128 can provide information about how to compile and link programs that
131 *** `guile-config compile' prints any C compiler flags needed to use Guile.
132 You should include this command's output on the command line you use
133 to compile C or C++ code that #includes the Guile header files. It's
134 usually just a `-I' flag to help the compiler find the Guile headers.
137 *** `guile-config link' prints any linker flags necessary to link with Guile.
139 This command writes to its standard output a list of flags which you
140 must pass to the linker to link your code against the Guile library.
141 The flags include '-lguile' itself, any other libraries the Guile
142 library depends upon, and any `-L' flags needed to help the linker
143 find those libraries.
145 For example, here is a Makefile rule that builds a program named 'foo'
146 from the object files ${FOO_OBJECTS}, and links them against Guile:
149 ${CC} ${CFLAGS} ${FOO_OBJECTS} `guile-config link` -o foo
151 Previous Guile releases recommended that you use autoconf to detect
152 which of a predefined set of libraries were present on your system.
153 It is more robust to use `guile-config', since it records exactly which
154 libraries the installed Guile library requires.
156 This was originally called `build-guile', but was renamed to
157 `guile-config' before Guile 1.3 was released, to be consistent with
158 the analogous script for the GTK+ GUI toolkit, which is called
162 ** Use the GUILE_FLAGS macro in your configure.in file to find Guile.
164 If you are using the GNU autoconf package to configure your program,
165 you can use the GUILE_FLAGS autoconf macro to call `guile-config'
166 (described above) and gather the necessary values for use in your
169 The GUILE_FLAGS macro expands to configure script code which runs the
170 `guile-config' script, to find out where Guile's header files and
171 libraries are installed. It sets two variables, marked for
172 substitution, as by AC_SUBST.
174 GUILE_CFLAGS --- flags to pass to a C or C++ compiler to build
175 code that uses Guile header files. This is almost always just a
178 GUILE_LDFLAGS --- flags to pass to the linker to link a
179 program against Guile. This includes `-lguile' for the Guile
180 library itself, any libraries that Guile itself requires (like
181 -lqthreads), and so on. It may also include a -L flag to tell the
182 compiler where to find the libraries.
184 GUILE_FLAGS is defined in the file guile.m4, in the top-level
185 directory of the Guile distribution. You can copy it into your
186 package's aclocal.m4 file, and then use it in your configure.in file.
188 If you are using the `aclocal' program, distributed with GNU automake,
189 to maintain your aclocal.m4 file, the Guile installation process
190 installs guile.m4 where aclocal will find it. All you need to do is
191 use GUILE_FLAGS in your configure.in file, and then run `aclocal';
192 this will copy the definition of GUILE_FLAGS into your aclocal.m4
196 * Changes to Scheme functions and syntax
198 ** Multi-byte strings have been removed, as have multi-byte and wide
199 ports. We felt that these were the wrong approach to
200 internationalization support.
202 ** New function: readline [PROMPT]
203 Read a line from the terminal, and allow the user to edit it,
204 prompting with PROMPT. READLINE provides a large set of Emacs-like
205 editing commands, lets the user recall previously typed lines, and
206 works on almost every kind of terminal, including dumb terminals.
208 READLINE assumes that the cursor is at the beginning of the line when
209 it is invoked. Thus, you can't print a prompt yourself, and then call
210 READLINE; you need to package up your prompt as a string, pass it to
211 the function, and let READLINE print the prompt itself. This is
212 because READLINE needs to know the prompt's screen width.
214 For Guile to provide this function, you must have the readline
215 library, version 2.1 or later, installed on your system. Readline is
216 available via anonymous FTP from prep.ai.mit.edu in pub/gnu, or from
219 See also ADD-HISTORY function.
221 ** New function: add-history STRING
222 Add STRING as the most recent line in the history used by the READLINE
223 command. READLINE does not add lines to the history itself; you must
224 call ADD-HISTORY to make previous input available to the user.
226 ** The behavior of the read-line function has changed.
228 This function now uses standard C library functions to read the line,
229 for speed. This means that it doesn not respect the value of
230 scm-line-incrementors; it assumes that lines are delimited with
233 (Note that this is read-line, the function that reads a line of text
234 from a port, not readline, the function that reads a line from a
235 terminal, providing full editing capabilities.)
237 ** New module (ice-9 getopt-gnu-style): Parse command-line arguments.
239 This module provides some simple argument parsing. It exports one
242 Function: getopt-gnu-style ARG-LS
243 Parse a list of program arguments into an alist of option
246 Each item in the list of program arguments is examined to see if
247 it meets the syntax of a GNU long-named option. An argument like
248 `--MUMBLE' produces an element of the form (MUMBLE . #t) in the
249 returned alist, where MUMBLE is a keyword object with the same
250 name as the argument. An argument like `--MUMBLE=FROB' produces
251 an element of the form (MUMBLE . FROB), where FROB is a string.
253 As a special case, the returned alist also contains a pair whose
254 car is the symbol `rest'. The cdr of this pair is a list
255 containing all the items in the argument list that are not options
256 of the form mentioned above.
258 The argument `--' is treated specially: all items in the argument
259 list appearing after such an argument are not examined, and are
260 returned in the special `rest' list.
262 This function does not parse normal single-character switches.
263 You will need to parse them out of the `rest' list yourself.
265 ** The read syntax for byte vectors and short vectors has changed.
267 Instead of #bytes(...), write #y(...).
269 Instead of #short(...), write #h(...).
271 This may seem nutty, but, like the other uniform vectors, byte vectors
272 and short vectors want to have the same print and read syntax (and,
273 more basic, want to have read syntax!). Changing the read syntax to
274 use multiple characters after the hash sign breaks with the
275 conventions used in R5RS and the conventions used for the other
276 uniform vectors. It also introduces complexity in the current reader,
277 both on the C and Scheme levels. (The Right solution is probably to
278 change the syntax and prototypes for uniform vectors entirely.)
281 ** The new module (ice-9 session) provides useful interactive functions.
283 *** New procedure: (apropos REGEXP OPTION ...)
285 Display a list of top-level variables whose names match REGEXP, and
286 the modules they are imported from. Each OPTION should be one of the
289 value --- Show the value of each matching variable.
290 shadow --- Show bindings shadowed by subsequently imported modules.
291 full --- Same as both `shadow' and `value'.
295 guile> (apropos "trace" 'full)
296 debug: trace #<procedure trace args>
297 debug: untrace #<procedure untrace args>
298 the-scm-module: display-backtrace #<compiled-closure #<primitive-procedure gsubr-apply>>
299 the-scm-module: before-backtrace-hook ()
300 the-scm-module: backtrace #<primitive-procedure backtrace>
301 the-scm-module: after-backtrace-hook ()
302 the-scm-module: has-shown-backtrace-hint? #f
305 ** There are new functions and syntax for working with macros.
307 Guile implements macros as a special object type. Any variable whose
308 top-level binding is a macro object acts as a macro. The macro object
309 specifies how the expression should be transformed before evaluation.
311 *** Macro objects now print in a reasonable way, resembling procedures.
313 *** New function: (macro? OBJ)
314 True iff OBJ is a macro object.
316 *** New function: (primitive-macro? OBJ)
317 Like (macro? OBJ), but true only if OBJ is one of the Guile primitive
318 macro transformers, implemented in eval.c rather than Scheme code.
320 Why do we have this function?
321 - For symmetry with procedure? and primitive-procedure?,
322 - to allow custom print procedures to tell whether a macro is
323 primitive, and display it differently, and
324 - to allow compilers and user-written evaluators to distinguish
325 builtin special forms from user-defined ones, which could be
328 *** New function: (macro-type OBJ)
329 Return a value indicating what kind of macro OBJ is. Possible return
332 The symbol `syntax' --- a macro created by procedure->syntax.
333 The symbol `macro' --- a macro created by procedure->macro.
334 The symbol `macro!' --- a macro created by procedure->memoizing-macro.
335 The boolean #f --- if OBJ is not a macro object.
337 *** New function: (macro-name MACRO)
338 Return the name of the macro object MACRO's procedure, as returned by
341 *** New function: (macro-transformer MACRO)
342 Return the transformer procedure for MACRO.
344 *** New syntax: (use-syntax MODULE ... TRANSFORMER)
346 Specify a new macro expander to use in the current module. Each
347 MODULE is a module name, with the same meaning as in the `use-modules'
348 form; each named module's exported bindings are added to the current
349 top-level environment. TRANSFORMER is an expression evaluated in the
350 resulting environment which must yield a procedure to use as the
351 module's eval transformer: every expression evaluated in this module
352 is passed to this function, and the result passed to the Guile
355 *** macro-eval! is removed. Use local-eval instead.
357 ** Some magic has been added to the printer to better handle user
358 written printing routines (like record printers, closure printers).
360 The problem is that these user written routines must have access to
361 the current `print-state' to be able to handle fancy things like
362 detection of circular references. These print-states have to be
363 passed to the builtin printing routines (display, write, etc) to
364 properly continue the print chain.
366 We didn't want to change all existing print code so that it
367 explicitly passes thru a print state in addition to a port. Instead,
368 we extented the possible values that the builtin printing routines
369 accept as a `port'. In addition to a normal port, they now also take
370 a pair of a normal port and a print-state. Printing will go to the
371 port and the print-state will be used to control the detection of
372 circular references, etc. If the builtin function does not care for a
373 print-state, it is simply ignored.
375 User written callbacks are now called with such a pair as their
376 `port', but because every function now accepts this pair as a PORT
377 argument, you don't have to worry about that. In fact, it is probably
378 safest to not check for these pairs.
380 However, it is sometimes necessary to continue a print chain on a
381 different port, for example to get a intermediate string
382 representation of the printed value, mangle that string somehow, and
383 then to finally print the mangled string. Use the new function
385 inherit-print-state OLD-PORT NEW-PORT
387 for this. It constructs a new `port' that prints to NEW-PORT but
388 inherits the print-state of OLD-PORT.
390 ** struct-vtable-offset renamed to vtable-offset-user
392 ** New constants: vtable-index-layout, vtable-index-vtable, vtable-index-printer
394 ** There is now a fourth (optional) argument to make-vtable-vtable and
395 make-struct when constructing new types (vtables). This argument
396 initializes field vtable-index-printer of the vtable.
398 ** The detection of circular references has been extended to structs.
399 That is, a structure that -- in the process of being printed -- prints
400 itself does not lead to infinite recursion.
402 ** There is now some basic support for fluids. Please read
403 "libguile/fluid.h" to find out more. It is accessible from Scheme with
404 the following functions and macros:
408 Create a new fluid object. Fluids are not special variables or
409 some other extension to the semantics of Scheme, but rather
410 ordinary Scheme objects. You can store them into variables (that
411 are still lexically scoped, of course) or into any other place you
412 like. Every fluid has a initial value of `#f'.
416 Test whether OBJ is a fluid.
418 Function: fluid-ref FLUID
419 Function: fluid-set! FLUID VAL
421 Access/modify the fluid FLUID. Modifications are only visible
422 within the current dynamic root (that includes threads).
424 Function: with-fluids* FLUIDS VALUES THUNK
426 FLUIDS is a list of fluids and VALUES a corresponding list of
427 values for these fluids. Before THUNK gets called the values are
428 installed in the fluids and the old values of the fluids are
429 saved in the VALUES list. When the flow of control leaves THUNK
430 or reenters it, the values get swapped again. You might think of
431 this as a `safe-fluid-excursion'. Note that the VALUES list is
432 modified by `with-fluids*'.
434 Macro: with-fluids ((FLUID VALUE) ...) FORM ...
436 The same as `with-fluids*' but with a different syntax. It looks
437 just like `let', but both FLUID and VALUE are evaluated. Remember,
438 fluids are not special variables but ordinary objects. FLUID
439 should evaluate to a fluid.
441 ** Changes to system call interfaces:
443 *** close-port, close-input-port and close-output-port now return a
444 boolean instead of an `unspecified' object. #t means that the port
445 was successfully closed, while #f means it was already closed. It is
446 also now possible for these procedures to raise an exception if an
447 error occurs (some errors from write can be delayed until close.)
449 *** the first argument to chmod, fcntl, ftell and fseek can now be a
452 *** the third argument to fcntl is now optional.
454 *** the first argument to chown can now be a file descriptor or a port.
456 *** the argument to stat can now be a port.
458 *** The following new procedures have been added (most use scsh
461 *** procedure: close PORT/FD
462 Similar to close-port (*note close-port: Closing Ports.), but also
463 works on file descriptors. A side effect of closing a file
464 descriptor is that any ports using that file descriptor are moved
465 to a different file descriptor and have their revealed counts set
468 *** procedure: port->fdes PORT
469 Returns the integer file descriptor underlying PORT. As a side
470 effect the revealed count of PORT is incremented.
472 *** procedure: fdes->ports FDES
473 Returns a list of existing ports which have FDES as an underlying
474 file descriptor, without changing their revealed counts.
476 *** procedure: fdes->inport FDES
477 Returns an existing input port which has FDES as its underlying
478 file descriptor, if one exists, and increments its revealed count.
479 Otherwise, returns a new input port with a revealed count of 1.
481 *** procedure: fdes->outport FDES
482 Returns an existing output port which has FDES as its underlying
483 file descriptor, if one exists, and increments its revealed count.
484 Otherwise, returns a new output port with a revealed count of 1.
486 The next group of procedures perform a `dup2' system call, if NEWFD
487 (an integer) is supplied, otherwise a `dup'. The file descriptor to be
488 duplicated can be supplied as an integer or contained in a port. The
489 type of value returned varies depending on which procedure is used.
491 All procedures also have the side effect when performing `dup2' that
492 any ports using NEWFD are moved to a different file descriptor and have
493 their revealed counts set to zero.
495 *** procedure: dup->fdes PORT/FD [NEWFD]
496 Returns an integer file descriptor.
498 *** procedure: dup->inport PORT/FD [NEWFD]
499 Returns a new input port using the new file descriptor.
501 *** procedure: dup->outport PORT/FD [NEWFD]
502 Returns a new output port using the new file descriptor.
504 *** procedure: dup PORT/FD [NEWFD]
505 Returns a new port if PORT/FD is a port, with the same mode as the
506 supplied port, otherwise returns an integer file descriptor.
508 *** procedure: dup->port PORT/FD MODE [NEWFD]
509 Returns a new port using the new file descriptor. MODE supplies a
510 mode string for the port (*note open-file: File Ports.).
512 *** procedure: setenv NAME VALUE
513 Modifies the environment of the current process, which is also the
514 default environment inherited by child processes.
516 If VALUE is `#f', then NAME is removed from the environment.
517 Otherwise, the string NAME=VALUE is added to the environment,
518 replacing any existing string with name matching NAME.
520 The return value is unspecified.
522 *** procedure: truncate-file OBJ SIZE
523 Truncates the file referred to by OBJ to at most SIZE bytes. OBJ
524 can be a string containing a file name or an integer file
525 descriptor or port open for output on the file. The underlying
526 system calls are `truncate' and `ftruncate'.
528 The return value is unspecified.
530 *** procedure: setvbuf PORT MODE [SIZE]
531 Set the buffering mode for PORT. MODE can be:
539 block buffered, using a newly allocated buffer of SIZE bytes.
540 However if SIZE is zero or unspecified, the port will be made
543 This procedure should not be used after I/O has been performed with
546 Ports are usually block buffered by default, with a default buffer
547 size. Procedures e.g., *Note open-file: File Ports, which accept a
548 mode string allow `0' to be added to request an unbuffered port.
550 *** procedure: fsync PORT/FD
551 Copies any unwritten data for the specified output file descriptor
552 to disk. If PORT/FD is a port, its buffer is flushed before the
553 underlying file descriptor is fsync'd. The return value is
556 *** procedure: open-fdes PATH FLAGS [MODES]
557 Similar to `open' but returns a file descriptor instead of a port.
559 *** procedure: execle PATH ENV [ARG] ...
560 Similar to `execl', but the environment of the new process is
561 specified by ENV, which must be a list of strings as returned by
562 the `environ' procedure.
564 This procedure is currently implemented using the `execve' system
565 call, but we call it `execle' because of its Scheme calling
568 *** procedure: strerror ERRNO
569 Returns the Unix error message corresponding to ERRNO, an integer.
571 *** procedure: primitive-exit [STATUS]
572 Terminate the current process without unwinding the Scheme stack.
573 This is would typically be useful after a fork. The exit status
574 is STATUS if supplied, otherwise zero.
577 Returns an object with information about real and processor time.
578 The following procedures accept such an object as an argument and
579 return a selected component:
582 The current real time, expressed as time units relative to an
586 The CPU time units used by the calling process.
589 The CPU time units used by the system on behalf of the
593 The CPU time units used by terminated child processes of the
594 calling process, whose status has been collected (e.g., using
598 Similarly, the CPU times units used by the system on behalf of
599 terminated child processes.
601 ** Removed: list-length
602 ** Removed: list-append, list-append!
603 ** Removed: list-reverse, list-reverse!
605 ** array-map renamed to array-map!
607 ** serial-array-map renamed to serial-array-map!
609 ** catch doesn't take #f as first argument any longer
611 Previously, it was possible to pass #f instead of a key to `catch'.
612 That would cause `catch' to pass a jump buffer object to the procedure
613 passed as second argument. The procedure could then use this jump
614 buffer objekt as an argument to throw.
616 This mechanism has been removed since its utility doesn't motivate the
617 extra complexity it introduces.
619 ** The `#/' notation for lists now provokes a warning message from Guile.
620 This syntax will be removed from Guile in the near future.
622 To disable the warning message, set the GUILE_HUSH environment
623 variable to any non-empty value.
625 ** The newline character now prints as `#\newline', following the
626 normal Scheme notation, not `#\nl'.
628 * Changes to the gh_ interface
630 ** The gh_enter function now takes care of loading the Guile startup files.
631 gh_enter works by calling scm_boot_guile; see the remarks below.
633 ** Function: void gh_write (SCM x)
635 Write the printed representation of the scheme object x to the current
636 output port. Corresponds to the scheme level `write'.
638 ** gh_list_length renamed to gh_length.
640 ** vector handling routines
642 Several major changes. In particular, gh_vector() now resembles
643 (vector ...) (with a caveat -- see manual), and gh_make_vector() now
644 exists and behaves like (make-vector ...). gh_vset() and gh_vref()
645 have been renamed gh_vector_set_x() and gh_vector_ref(). Some missing
646 vector-related gh_ functions have been implemented.
648 ** pair and list routines
650 Implemented several of the R4RS pair and list functions that were
653 ** gh_scm2doubles, gh_doubles2scm, gh_doubles2dvect
655 New function. Converts double arrays back and forth between Scheme
658 * Changes to the scm_ interface
660 ** The function scm_boot_guile now takes care of loading the startup files.
662 Guile's primary initialization function, scm_boot_guile, now takes
663 care of loading `boot-9.scm', in the `ice-9' module, to initialize
664 Guile, define the module system, and put together some standard
665 bindings. It also loads `init.scm', which is intended to hold
666 site-specific initialization code.
668 Since Guile cannot operate properly until boot-9.scm is loaded, there
669 is no reason to separate loading boot-9.scm from Guile's other
670 initialization processes.
672 This job used to be done by scm_compile_shell_switches, which didn't
673 make much sense; in particular, it meant that people using Guile for
674 non-shell-like applications had to jump through hoops to get Guile
675 initialized properly.
677 ** The function scm_compile_shell_switches no longer loads the startup files.
678 Now, Guile always loads the startup files, whenever it is initialized;
679 see the notes above for scm_boot_guile and scm_load_startup_files.
681 ** Function: scm_load_startup_files
682 This new function takes care of loading Guile's initialization file
683 (`boot-9.scm'), and the site initialization file, `init.scm'. Since
684 this is always called by the Guile initialization process, it's
685 probably not too useful to call this yourself, but it's there anyway.
687 ** The semantics of smob marking have changed slightly.
689 The smob marking function (the `mark' member of the scm_smobfuns
690 structure) is no longer responsible for setting the mark bit on the
691 smob. The generic smob handling code in the garbage collector will
692 set this bit. The mark function need only ensure that any other
693 objects the smob refers to get marked.
695 Note that this change means that the smob's GC8MARK bit is typically
696 already set upon entry to the mark function. Thus, marking functions
697 which look like this:
700 if (SCM_GC8MARKP (ptr))
702 SCM_SETGC8MARK (ptr);
703 ... mark objects to which the smob refers ...
706 are now incorrect, since they will return early, and fail to mark any
707 other objects the smob refers to. Some code in the Guile library used
710 ** The semantics of the I/O port functions in scm_ptobfuns have changed.
712 If you have implemented your own I/O port type, by writing the
713 functions required by the scm_ptobfuns and then calling scm_newptob,
714 you will need to change your functions slightly.
716 The functions in a scm_ptobfuns structure now expect the port itself
717 as their argument; they used to expect the `stream' member of the
718 port's scm_port_table structure. This allows functions in an
719 scm_ptobfuns structure to easily access the port's cell (and any flags
720 it its CAR), and the port's scm_port_table structure.
722 Guile now passes the I/O port itself as the `port' argument in the
723 following scm_ptobfuns functions:
725 int (*free) (SCM port);
726 int (*fputc) (int, SCM port);
727 int (*fputs) (char *, SCM port);
728 scm_sizet (*fwrite) SCM_P ((char *ptr,
732 int (*fflush) (SCM port);
733 int (*fgetc) (SCM port);
734 int (*fclose) (SCM port);
736 The interfaces to the `mark', `print', `equalp', and `fgets' methods
739 If you have existing code which defines its own port types, it is easy
740 to convert your code to the new interface; simply apply SCM_STREAM to
741 the port argument to yield the value you code used to expect.
743 Note that since both the port and the stream have the same type in the
744 C code --- they are both SCM values --- the C compiler will not remind
745 you if you forget to update your scm_ptobfuns functions.
748 ** Function: int scm_internal_select (int fds,
752 struct timeval *timeout);
754 This is a replacement for the `select' function provided by the OS.
755 It enables I/O blocking and sleeping to happen for one cooperative
756 thread without blocking other threads. It also avoids busy-loops in
757 these situations. It is intended that all I/O blocking and sleeping
758 will finally go through this function. Currently, this function is
759 only available on systems providing `gettimeofday' and `select'.
761 ** Function: SCM scm_internal_stack_catch (SCM tag,
762 scm_catch_body_t body,
764 scm_catch_handler_t handler,
767 A new sibling to the other two C level `catch' functions
768 scm_internal_catch and scm_internal_lazy_catch. Use it if you want
769 the stack to be saved automatically into the variable `the-last-stack'
770 (scm_the_last_stack_var) on error. This is necessary if you want to
771 use advanced error reporting, such as calling scm_display_error and
772 scm_display_backtrace. (They both take a stack object as argument.)
774 ** Function: SCM scm_spawn_thread (scm_catch_body_t body,
776 scm_catch_handler_t handler,
779 Spawns a new thread. It does a job similar to
780 scm_call_with_new_thread but takes arguments more suitable when
781 spawning threads from application C code.
783 ** The hook scm_error_callback has been removed. It was originally
784 intended as a way for the user to install his own error handler. But
785 that method works badly since it intervenes between throw and catch,
786 thereby changing the semantics of expressions like (catch #t ...).
787 The correct way to do it is to use one of the C level catch functions
788 in throw.c: scm_internal_catch/lazy_catch/stack_catch.
790 ** Removed functions:
792 scm_obj_length, scm_list_length, scm_list_append, scm_list_append_x,
793 scm_list_reverse, scm_list_reverse_x
795 ** New macros: SCM_LISTn where n is one of the integers 0-9.
797 These can be used for pretty list creation from C. The idea is taken
798 from Erick Gallesio's STk.
800 ** scm_array_map renamed to scm_array_map_x
802 ** mbstrings are now removed
804 This means that the type codes scm_tc7_mb_string and
805 scm_tc7_mb_substring has been removed.
807 ** scm_gen_putc, scm_gen_puts, scm_gen_write, and scm_gen_getc have changed.
809 Since we no longer support multi-byte strings, these I/O functions
810 have been simplified, and renamed. Here are their old names, and
811 their new names and arguments:
813 scm_gen_putc -> void scm_putc (int c, SCM port);
814 scm_gen_puts -> void scm_puts (char *s, SCM port);
815 scm_gen_write -> void scm_lfwrite (char *ptr, scm_sizet size, SCM port);
816 scm_gen_getc -> void scm_getc (SCM port);
819 ** The macros SCM_TYP7D and SCM_TYP7SD has been removed.
821 ** The macro SCM_TYP7S has taken the role of the old SCM_TYP7D
823 SCM_TYP7S now masks away the bit which distinguishes substrings from
826 ** scm_catch_body_t: Backward incompatible change!
828 Body functions to scm_internal_catch and friends do not any longer
829 take a second argument. This is because it is no longer possible to
830 pass a #f arg to catch.
832 ** Calls to scm_protect_object and scm_unprotect now nest properly.
834 The function scm_protect_object protects its argument from being freed
835 by the garbage collector. scm_unprotect_object removes that
838 These functions now nest properly. That is, for every object O, there
839 is a counter which scm_protect_object(O) increments and
840 scm_unprotect_object(O) decrements, if the counter is greater than
841 zero. Every object's counter is zero when it is first created. If an
842 object's counter is greater than zero, the garbage collector will not
845 This allows you to use scm_protect_object in your code without
846 worrying that some other function you call will call
847 scm_unprotect_object, and allow it to be freed. Assuming that the
848 functions you call are well-behaved, and unprotect only those objects
849 they protect, you can follow the same rule and have confidence that
850 objects will be freed only at appropriate times.
853 Changes in Guile 1.2 (released Tuesday, June 24 1997):
855 * Changes to the distribution
857 ** Nightly snapshots are now available from ftp.red-bean.com.
858 The old server, ftp.cyclic.com, has been relinquished to its rightful
861 Nightly snapshots of the Guile development sources are now available via
862 anonymous FTP from ftp.red-bean.com, as /pub/guile/guile-snap.tar.gz.
864 Via the web, that's: ftp://ftp.red-bean.com/pub/guile/guile-snap.tar.gz
865 For getit, that's: ftp.red-bean.com:/pub/guile/guile-snap.tar.gz
867 ** To run Guile without installing it, the procedure has changed a bit.
869 If you used a separate build directory to compile Guile, you'll need
870 to include the build directory in SCHEME_LOAD_PATH, as well as the
871 source directory. See the `INSTALL' file for examples.
873 * Changes to the procedure for linking libguile with your programs
875 ** The standard Guile load path for Scheme code now includes
876 $(datadir)/guile (usually /usr/local/share/guile). This means that
877 you can install your own Scheme files there, and Guile will find them.
878 (Previous versions of Guile only checked a directory whose name
879 contained the Guile version number, so you had to re-install or move
880 your Scheme sources each time you installed a fresh version of Guile.)
882 The load path also includes $(datadir)/guile/site; we recommend
883 putting individual Scheme files there. If you want to install a
884 package with multiple source files, create a directory for them under
887 ** Guile 1.2 will now use the Rx regular expression library, if it is
888 installed on your system. When you are linking libguile into your own
889 programs, this means you will have to link against -lguile, -lqt (if
890 you configured Guile with thread support), and -lrx.
892 If you are using autoconf to generate configuration scripts for your
893 application, the following lines should suffice to add the appropriate
894 libraries to your link command:
896 ### Find Rx, quickthreads and libguile.
897 AC_CHECK_LIB(rx, main)
898 AC_CHECK_LIB(qt, main)
899 AC_CHECK_LIB(guile, scm_shell)
901 The Guile 1.2 distribution does not contain sources for the Rx
902 library, as Guile 1.0 did. If you want to use Rx, you'll need to
903 retrieve it from a GNU FTP site and install it separately.
905 * Changes to Scheme functions and syntax
907 ** The dynamic linking features of Guile are now enabled by default.
908 You can disable them by giving the `--disable-dynamic-linking' option
911 (dynamic-link FILENAME)
913 Find the object file denoted by FILENAME (a string) and link it
914 into the running Guile application. When everything works out,
915 return a Scheme object suitable for representing the linked object
916 file. Otherwise an error is thrown. How object files are
917 searched is system dependent.
919 (dynamic-object? VAL)
921 Determine whether VAL represents a dynamically linked object file.
923 (dynamic-unlink DYNOBJ)
925 Unlink the indicated object file from the application. DYNOBJ
926 should be one of the values returned by `dynamic-link'.
928 (dynamic-func FUNCTION DYNOBJ)
930 Search the C function indicated by FUNCTION (a string or symbol)
931 in DYNOBJ and return some Scheme object that can later be used
932 with `dynamic-call' to actually call this function. Right now,
933 these Scheme objects are formed by casting the address of the
934 function to `long' and converting this number to its Scheme
937 (dynamic-call FUNCTION DYNOBJ)
939 Call the C function indicated by FUNCTION and DYNOBJ. The
940 function is passed no arguments and its return value is ignored.
941 When FUNCTION is something returned by `dynamic-func', call that
942 function and ignore DYNOBJ. When FUNCTION is a string (or symbol,
943 etc.), look it up in DYNOBJ; this is equivalent to
945 (dynamic-call (dynamic-func FUNCTION DYNOBJ) #f)
947 Interrupts are deferred while the C function is executing (with
948 SCM_DEFER_INTS/SCM_ALLOW_INTS).
950 (dynamic-args-call FUNCTION DYNOBJ ARGS)
952 Call the C function indicated by FUNCTION and DYNOBJ, but pass it
953 some arguments and return its return value. The C function is
954 expected to take two arguments and return an `int', just like
957 int c_func (int argc, char **argv);
959 ARGS must be a list of strings and is converted into an array of
960 `char *'. The array is passed in ARGV and its size in ARGC. The
961 return value is converted to a Scheme number and returned from the
962 call to `dynamic-args-call'.
964 When dynamic linking is disabled or not supported on your system,
965 the above functions throw errors, but they are still available.
967 Here is a small example that works on GNU/Linux:
969 (define libc-obj (dynamic-link "libc.so"))
970 (dynamic-args-call 'rand libc-obj '())
972 See the file `libguile/DYNAMIC-LINKING' for additional comments.
974 ** The #/ syntax for module names is depreciated, and will be removed
975 in a future version of Guile. Instead of
983 The latter syntax is more consistent with existing Lisp practice.
985 ** Guile now does fancier printing of structures. Structures are the
986 underlying implementation for records, which in turn are used to
987 implement modules, so all of these object now print differently and in
988 a more informative way.
990 The Scheme printer will examine the builtin variable *struct-printer*
991 whenever it needs to print a structure object. When this variable is
992 not `#f' it is deemed to be a procedure and will be applied to the
993 structure object and the output port. When *struct-printer* is `#f'
994 or the procedure return `#f' the structure object will be printed in
995 the boring #<struct 80458270> form.
997 This hook is used by some routines in ice-9/boot-9.scm to implement
998 type specific printing routines. Please read the comments there about
1001 One of the more specific uses of structs are records. The printing
1002 procedure that could be passed to MAKE-RECORD-TYPE is now actually
1003 called. It should behave like a *struct-printer* procedure (described
1006 ** Guile now supports a new R4RS-compliant syntax for keywords. A
1007 token of the form #:NAME, where NAME has the same syntax as a Scheme
1008 symbol, is the external representation of the keyword named NAME.
1009 Keyword objects print using this syntax as well, so values containing
1010 keyword objects can be read back into Guile. When used in an
1011 expression, keywords are self-quoting objects.
1013 Guile suports this read syntax, and uses this print syntax, regardless
1014 of the current setting of the `keyword' read option. The `keyword'
1015 read option only controls whether Guile recognizes the `:NAME' syntax,
1016 which is incompatible with R4RS. (R4RS says such token represent
1019 ** Guile has regular expression support again. Guile 1.0 included
1020 functions for matching regular expressions, based on the Rx library.
1021 In Guile 1.1, the Guile/Rx interface was removed to simplify the
1022 distribution, and thus Guile had no regular expression support. Guile
1023 1.2 again supports the most commonly used functions, and supports all
1024 of SCSH's regular expression functions.
1026 If your system does not include a POSIX regular expression library,
1027 and you have not linked Guile with a third-party regexp library such as
1028 Rx, these functions will not be available. You can tell whether your
1029 Guile installation includes regular expression support by checking
1030 whether the `*features*' list includes the `regex' symbol.
1032 *** regexp functions
1034 By default, Guile supports POSIX extended regular expressions. That
1035 means that the characters `(', `)', `+' and `?' are special, and must
1036 be escaped if you wish to match the literal characters.
1038 This regular expression interface was modeled after that implemented
1039 by SCSH, the Scheme Shell. It is intended to be upwardly compatible
1040 with SCSH regular expressions.
1042 **** Function: string-match PATTERN STR [START]
1043 Compile the string PATTERN into a regular expression and compare
1044 it with STR. The optional numeric argument START specifies the
1045 position of STR at which to begin matching.
1047 `string-match' returns a "match structure" which describes what,
1048 if anything, was matched by the regular expression. *Note Match
1049 Structures::. If STR does not match PATTERN at all,
1050 `string-match' returns `#f'.
1052 Each time `string-match' is called, it must compile its PATTERN
1053 argument into a regular expression structure. This operation is
1054 expensive, which makes `string-match' inefficient if the same regular
1055 expression is used several times (for example, in a loop). For better
1056 performance, you can compile a regular expression in advance and then
1057 match strings against the compiled regexp.
1059 **** Function: make-regexp STR [FLAGS]
1060 Compile the regular expression described by STR, and return the
1061 compiled regexp structure. If STR does not describe a legal
1062 regular expression, `make-regexp' throws a
1063 `regular-expression-syntax' error.
1065 FLAGS may be the bitwise-or of one or more of the following:
1067 **** Constant: regexp/extended
1068 Use POSIX Extended Regular Expression syntax when interpreting
1069 STR. If not set, POSIX Basic Regular Expression syntax is used.
1070 If the FLAGS argument is omitted, we assume regexp/extended.
1072 **** Constant: regexp/icase
1073 Do not differentiate case. Subsequent searches using the
1074 returned regular expression will be case insensitive.
1076 **** Constant: regexp/newline
1077 Match-any-character operators don't match a newline.
1079 A non-matching list ([^...]) not containing a newline matches a
1082 Match-beginning-of-line operator (^) matches the empty string
1083 immediately after a newline, regardless of whether the FLAGS
1084 passed to regexp-exec contain regexp/notbol.
1086 Match-end-of-line operator ($) matches the empty string
1087 immediately before a newline, regardless of whether the FLAGS
1088 passed to regexp-exec contain regexp/noteol.
1090 **** Function: regexp-exec REGEXP STR [START [FLAGS]]
1091 Match the compiled regular expression REGEXP against `str'. If
1092 the optional integer START argument is provided, begin matching
1093 from that position in the string. Return a match structure
1094 describing the results of the match, or `#f' if no match could be
1097 FLAGS may be the bitwise-or of one or more of the following:
1099 **** Constant: regexp/notbol
1100 The match-beginning-of-line operator always fails to match (but
1101 see the compilation flag regexp/newline above) This flag may be
1102 used when different portions of a string are passed to
1103 regexp-exec and the beginning of the string should not be
1104 interpreted as the beginning of the line.
1106 **** Constant: regexp/noteol
1107 The match-end-of-line operator always fails to match (but see the
1108 compilation flag regexp/newline above)
1110 **** Function: regexp? OBJ
1111 Return `#t' if OBJ is a compiled regular expression, or `#f'
1114 Regular expressions are commonly used to find patterns in one string
1115 and replace them with the contents of another string.
1117 **** Function: regexp-substitute PORT MATCH [ITEM...]
1118 Write to the output port PORT selected contents of the match
1119 structure MATCH. Each ITEM specifies what should be written, and
1120 may be one of the following arguments:
1122 * A string. String arguments are written out verbatim.
1124 * An integer. The submatch with that number is written.
1126 * The symbol `pre'. The portion of the matched string preceding
1127 the regexp match is written.
1129 * The symbol `post'. The portion of the matched string
1130 following the regexp match is written.
1132 PORT may be `#f', in which case nothing is written; instead,
1133 `regexp-substitute' constructs a string from the specified ITEMs
1136 **** Function: regexp-substitute/global PORT REGEXP TARGET [ITEM...]
1137 Similar to `regexp-substitute', but can be used to perform global
1138 substitutions on STR. Instead of taking a match structure as an
1139 argument, `regexp-substitute/global' takes two string arguments: a
1140 REGEXP string describing a regular expression, and a TARGET string
1141 which should be matched against this regular expression.
1143 Each ITEM behaves as in REGEXP-SUBSTITUTE, with the following
1146 * A function may be supplied. When this function is called, it
1147 will be passed one argument: a match structure for a given
1148 regular expression match. It should return a string to be
1149 written out to PORT.
1151 * The `post' symbol causes `regexp-substitute/global' to recurse
1152 on the unmatched portion of STR. This *must* be supplied in
1153 order to perform global search-and-replace on STR; if it is
1154 not present among the ITEMs, then `regexp-substitute/global'
1155 will return after processing a single match.
1157 *** Match Structures
1159 A "match structure" is the object returned by `string-match' and
1160 `regexp-exec'. It describes which portion of a string, if any, matched
1161 the given regular expression. Match structures include: a reference to
1162 the string that was checked for matches; the starting and ending
1163 positions of the regexp match; and, if the regexp included any
1164 parenthesized subexpressions, the starting and ending positions of each
1167 In each of the regexp match functions described below, the `match'
1168 argument must be a match structure returned by a previous call to
1169 `string-match' or `regexp-exec'. Most of these functions return some
1170 information about the original target string that was matched against a
1171 regular expression; we will call that string TARGET for easy reference.
1173 **** Function: regexp-match? OBJ
1174 Return `#t' if OBJ is a match structure returned by a previous
1175 call to `regexp-exec', or `#f' otherwise.
1177 **** Function: match:substring MATCH [N]
1178 Return the portion of TARGET matched by subexpression number N.
1179 Submatch 0 (the default) represents the entire regexp match. If
1180 the regular expression as a whole matched, but the subexpression
1181 number N did not match, return `#f'.
1183 **** Function: match:start MATCH [N]
1184 Return the starting position of submatch number N.
1186 **** Function: match:end MATCH [N]
1187 Return the ending position of submatch number N.
1189 **** Function: match:prefix MATCH
1190 Return the unmatched portion of TARGET preceding the regexp match.
1192 **** Function: match:suffix MATCH
1193 Return the unmatched portion of TARGET following the regexp match.
1195 **** Function: match:count MATCH
1196 Return the number of parenthesized subexpressions from MATCH.
1197 Note that the entire regular expression match itself counts as a
1198 subexpression, and failed submatches are included in the count.
1200 **** Function: match:string MATCH
1201 Return the original TARGET string.
1203 *** Backslash Escapes
1205 Sometimes you will want a regexp to match characters like `*' or `$'
1206 exactly. For example, to check whether a particular string represents
1207 a menu entry from an Info node, it would be useful to match it against
1208 a regexp like `^* [^:]*::'. However, this won't work; because the
1209 asterisk is a metacharacter, it won't match the `*' at the beginning of
1210 the string. In this case, we want to make the first asterisk un-magic.
1212 You can do this by preceding the metacharacter with a backslash
1213 character `\'. (This is also called "quoting" the metacharacter, and
1214 is known as a "backslash escape".) When Guile sees a backslash in a
1215 regular expression, it considers the following glyph to be an ordinary
1216 character, no matter what special meaning it would ordinarily have.
1217 Therefore, we can make the above example work by changing the regexp to
1218 `^\* [^:]*::'. The `\*' sequence tells the regular expression engine
1219 to match only a single asterisk in the target string.
1221 Since the backslash is itself a metacharacter, you may force a
1222 regexp to match a backslash in the target string by preceding the
1223 backslash with itself. For example, to find variable references in a
1224 TeX program, you might want to find occurrences of the string `\let\'
1225 followed by any number of alphabetic characters. The regular expression
1226 `\\let\\[A-Za-z]*' would do this: the double backslashes in the regexp
1227 each match a single backslash in the target string.
1229 **** Function: regexp-quote STR
1230 Quote each special character found in STR with a backslash, and
1231 return the resulting string.
1233 *Very important:* Using backslash escapes in Guile source code (as
1234 in Emacs Lisp or C) can be tricky, because the backslash character has
1235 special meaning for the Guile reader. For example, if Guile encounters
1236 the character sequence `\n' in the middle of a string while processing
1237 Scheme code, it replaces those characters with a newline character.
1238 Similarly, the character sequence `\t' is replaced by a horizontal tab.
1239 Several of these "escape sequences" are processed by the Guile reader
1240 before your code is executed. Unrecognized escape sequences are
1241 ignored: if the characters `\*' appear in a string, they will be
1242 translated to the single character `*'.
1244 This translation is obviously undesirable for regular expressions,
1245 since we want to be able to include backslashes in a string in order to
1246 escape regexp metacharacters. Therefore, to make sure that a backslash
1247 is preserved in a string in your Guile program, you must use *two*
1248 consecutive backslashes:
1250 (define Info-menu-entry-pattern (make-regexp "^\\* [^:]*"))
1252 The string in this example is preprocessed by the Guile reader before
1253 any code is executed. The resulting argument to `make-regexp' is the
1254 string `^\* [^:]*', which is what we really want.
1256 This also means that in order to write a regular expression that
1257 matches a single backslash character, the regular expression string in
1258 the source code must include *four* backslashes. Each consecutive pair
1259 of backslashes gets translated by the Guile reader to a single
1260 backslash, and the resulting double-backslash is interpreted by the
1261 regexp engine as matching a single backslash character. Hence:
1263 (define tex-variable-pattern (make-regexp "\\\\let\\\\=[A-Za-z]*"))
1265 The reason for the unwieldiness of this syntax is historical. Both
1266 regular expression pattern matchers and Unix string processing systems
1267 have traditionally used backslashes with the special meanings described
1268 above. The POSIX regular expression specification and ANSI C standard
1269 both require these semantics. Attempting to abandon either convention
1270 would cause other kinds of compatibility problems, possibly more severe
1271 ones. Therefore, without extending the Scheme reader to support
1272 strings with different quoting conventions (an ungainly and confusing
1273 extension when implemented in other languages), we must adhere to this
1274 cumbersome escape syntax.
1276 * Changes to the gh_ interface
1278 * Changes to the scm_ interface
1280 * Changes to system call interfaces:
1282 ** The value returned by `raise' is now unspecified. It throws an exception
1285 *** A new procedure `sigaction' can be used to install signal handlers
1287 (sigaction signum [action] [flags])
1289 signum is the signal number, which can be specified using the value
1292 If action is omitted, sigaction returns a pair: the CAR is the current
1293 signal hander, which will be either an integer with the value SIG_DFL
1294 (default action) or SIG_IGN (ignore), or the Scheme procedure which
1295 handles the signal, or #f if a non-Scheme procedure handles the
1296 signal. The CDR contains the current sigaction flags for the handler.
1298 If action is provided, it is installed as the new handler for signum.
1299 action can be a Scheme procedure taking one argument, or the value of
1300 SIG_DFL (default action) or SIG_IGN (ignore), or #f to restore
1301 whatever signal handler was installed before sigaction was first used.
1302 Flags can optionally be specified for the new handler (SA_RESTART is
1303 always used if the system provides it, so need not be specified.) The
1304 return value is a pair with information about the old handler as
1307 This interface does not provide access to the "signal blocking"
1308 facility. Maybe this is not needed, since the thread support may
1309 provide solutions to the problem of consistent access to data
1312 *** A new procedure `flush-all-ports' is equivalent to running
1313 `force-output' on every port open for output.
1315 ** Guile now provides information on how it was built, via the new
1316 global variable, %guile-build-info. This variable records the values
1317 of the standard GNU makefile directory variables as an assocation
1318 list, mapping variable names (symbols) onto directory paths (strings).
1319 For example, to find out where the Guile link libraries were
1320 installed, you can say:
1322 guile -c "(display (assq-ref %guile-build-info 'libdir)) (newline)"
1325 * Changes to the scm_ interface
1327 ** The new function scm_handle_by_message_noexit is just like the
1328 existing scm_handle_by_message function, except that it doesn't call
1329 exit to terminate the process. Instead, it prints a message and just
1330 returns #f. This might be a more appropriate catch-all handler for
1331 new dynamic roots and threads.
1334 Changes in Guile 1.1 (released Friday, May 16 1997):
1336 * Changes to the distribution.
1338 The Guile 1.0 distribution has been split up into several smaller
1340 guile-core --- the Guile interpreter itself.
1341 guile-tcltk --- the interface between the Guile interpreter and
1342 Tcl/Tk; Tcl is an interpreter for a stringy language, and Tk
1343 is a toolkit for building graphical user interfaces.
1344 guile-rgx-ctax --- the interface between Guile and the Rx regular
1345 expression matcher, and the translator for the Ctax
1346 programming language. These are packaged together because the
1347 Ctax translator uses Rx to parse Ctax source code.
1349 This NEWS file describes the changes made to guile-core since the 1.0
1352 We no longer distribute the documentation, since it was either out of
1353 date, or incomplete. As soon as we have current documentation, we
1358 * Changes to the stand-alone interpreter
1360 ** guile now accepts command-line arguments compatible with SCSH, Olin
1361 Shivers' Scheme Shell.
1363 In general, arguments are evaluated from left to right, but there are
1364 exceptions. The following switches stop argument processing, and
1365 stash all remaining command-line arguments as the value returned by
1366 the (command-line) function.
1367 -s SCRIPT load Scheme source code from FILE, and exit
1368 -c EXPR evalute Scheme expression EXPR, and exit
1369 -- stop scanning arguments; run interactively
1371 The switches below are processed as they are encountered.
1372 -l FILE load Scheme source code from FILE
1373 -e FUNCTION after reading script, apply FUNCTION to
1374 command line arguments
1375 -ds do -s script at this point
1376 --emacs enable Emacs protocol (experimental)
1377 -h, --help display this help and exit
1378 -v, --version display version information and exit
1379 \ read arguments from following script lines
1381 So, for example, here is a Guile script named `ekko' (thanks, Olin)
1382 which re-implements the traditional "echo" command:
1384 #!/usr/local/bin/guile -s
1387 (map (lambda (arg) (display arg) (display " "))
1391 (main (command-line))
1393 Suppose we invoke this script as follows:
1395 ekko a speckled gecko
1397 Through the magic of Unix script processing (triggered by the `#!'
1398 token at the top of the file), /usr/local/bin/guile receives the
1399 following list of command-line arguments:
1401 ("-s" "./ekko" "a" "speckled" "gecko")
1403 Unix inserts the name of the script after the argument specified on
1404 the first line of the file (in this case, "-s"), and then follows that
1405 with the arguments given to the script. Guile loads the script, which
1406 defines the `main' function, and then applies it to the list of
1407 remaining command-line arguments, ("a" "speckled" "gecko").
1409 In Unix, the first line of a script file must take the following form:
1411 #!INTERPRETER ARGUMENT
1413 where INTERPRETER is the absolute filename of the interpreter
1414 executable, and ARGUMENT is a single command-line argument to pass to
1417 You may only pass one argument to the interpreter, and its length is
1418 limited. These restrictions can be annoying to work around, so Guile
1419 provides a general mechanism (borrowed from, and compatible with,
1420 SCSH) for circumventing them.
1422 If the ARGUMENT in a Guile script is a single backslash character,
1423 `\', Guile will open the script file, parse arguments from its second
1424 and subsequent lines, and replace the `\' with them. So, for example,
1425 here is another implementation of the `ekko' script:
1427 #!/usr/local/bin/guile \
1431 (for-each (lambda (arg) (display arg) (display " "))
1435 If the user invokes this script as follows:
1437 ekko a speckled gecko
1439 Unix expands this into
1441 /usr/local/bin/guile \ ekko a speckled gecko
1443 When Guile sees the `\' argument, it replaces it with the arguments
1444 read from the second line of the script, producing:
1446 /usr/local/bin/guile -e main -s ekko a speckled gecko
1448 This tells Guile to load the `ekko' script, and apply the function
1449 `main' to the argument list ("a" "speckled" "gecko").
1451 Here is how Guile parses the command-line arguments:
1452 - Each space character terminates an argument. This means that two
1453 spaces in a row introduce an empty-string argument.
1454 - The tab character is not permitted (unless you quote it with the
1455 backslash character, as described below), to avoid confusion.
1456 - The newline character terminates the sequence of arguments, and will
1457 also terminate a final non-empty argument. (However, a newline
1458 following a space will not introduce a final empty-string argument;
1459 it only terminates the argument list.)
1460 - The backslash character is the escape character. It escapes
1461 backslash, space, tab, and newline. The ANSI C escape sequences
1462 like \n and \t are also supported. These produce argument
1463 constituents; the two-character combination \n doesn't act like a
1464 terminating newline. The escape sequence \NNN for exactly three
1465 octal digits reads as the character whose ASCII code is NNN. As
1466 above, characters produced this way are argument constituents.
1467 Backslash followed by other characters is not allowed.
1469 * Changes to the procedure for linking libguile with your programs
1471 ** Guile now builds and installs a shared guile library, if your
1472 system support shared libraries. (It still builds a static library on
1473 all systems.) Guile automatically detects whether your system
1474 supports shared libraries. To prevent Guile from buildisg shared
1475 libraries, pass the `--disable-shared' flag to the configure script.
1477 Guile takes longer to compile when it builds shared libraries, because
1478 it must compile every file twice --- once to produce position-
1479 independent object code, and once to produce normal object code.
1481 ** The libthreads library has been merged into libguile.
1483 To link a program against Guile, you now need only link against
1484 -lguile and -lqt; -lthreads is no longer needed. If you are using
1485 autoconf to generate configuration scripts for your application, the
1486 following lines should suffice to add the appropriate libraries to
1489 ### Find quickthreads and libguile.
1490 AC_CHECK_LIB(qt, main)
1491 AC_CHECK_LIB(guile, scm_shell)
1493 * Changes to Scheme functions
1495 ** Guile Scheme's special syntax for keyword objects is now optional,
1496 and disabled by default.
1498 The syntax variation from R4RS made it difficult to port some
1499 interesting packages to Guile. The routines which accepted keyword
1500 arguments (mostly in the module system) have been modified to also
1501 accept symbols whose names begin with `:'.
1503 To change the keyword syntax, you must first import the (ice-9 debug)
1505 (use-modules (ice-9 debug))
1507 Then you can enable the keyword syntax as follows:
1508 (read-set! keywords 'prefix)
1510 To disable keyword syntax, do this:
1511 (read-set! keywords #f)
1513 ** Many more primitive functions accept shared substrings as
1514 arguments. In the past, these functions required normal, mutable
1515 strings as arguments, although they never made use of this
1518 ** The uniform array functions now operate on byte vectors. These
1519 functions are `array-fill!', `serial-array-copy!', `array-copy!',
1520 `serial-array-map', `array-map', `array-for-each', and
1523 ** The new functions `trace' and `untrace' implement simple debugging
1524 support for Scheme functions.
1526 The `trace' function accepts any number of procedures as arguments,
1527 and tells the Guile interpreter to display each procedure's name and
1528 arguments each time the procedure is invoked. When invoked with no
1529 arguments, `trace' returns the list of procedures currently being
1532 The `untrace' function accepts any number of procedures as arguments,
1533 and tells the Guile interpreter not to trace them any more. When
1534 invoked with no arguments, `untrace' untraces all curretly traced
1537 The tracing in Guile has an advantage over most other systems: we
1538 don't create new procedure objects, but mark the procedure objects
1539 themselves. This means that anonymous and internal procedures can be
1542 ** The function `assert-repl-prompt' has been renamed to
1543 `set-repl-prompt!'. It takes one argument, PROMPT.
1544 - If PROMPT is #f, the Guile read-eval-print loop will not prompt.
1545 - If PROMPT is a string, we use it as a prompt.
1546 - If PROMPT is a procedure accepting no arguments, we call it, and
1547 display the result as a prompt.
1548 - Otherwise, we display "> ".
1550 ** The new function `eval-string' reads Scheme expressions from a
1551 string and evaluates them, returning the value of the last expression
1552 in the string. If the string contains no expressions, it returns an
1555 ** The new function `thunk?' returns true iff its argument is a
1556 procedure of zero arguments.
1558 ** `defined?' is now a builtin function, instead of syntax. This
1559 means that its argument should be quoted. It returns #t iff its
1560 argument is bound in the current module.
1562 ** The new syntax `use-modules' allows you to add new modules to your
1563 environment without re-typing a complete `define-module' form. It
1564 accepts any number of module names as arguments, and imports their
1565 public bindings into the current module.
1567 ** The new function (module-defined? NAME MODULE) returns true iff
1568 NAME, a symbol, is defined in MODULE, a module object.
1570 ** The new function `builtin-bindings' creates and returns a hash
1571 table containing copies of all the root module's bindings.
1573 ** The new function `builtin-weak-bindings' does the same as
1574 `builtin-bindings', but creates a doubly-weak hash table.
1576 ** The `equal?' function now considers variable objects to be
1577 equivalent if they have the same name and the same value.
1579 ** The new function `command-line' returns the command-line arguments
1580 given to Guile, as a list of strings.
1582 When using guile as a script interpreter, `command-line' returns the
1583 script's arguments; those processed by the interpreter (like `-s' or
1584 `-c') are omitted. (In other words, you get the normal, expected
1585 behavior.) Any application that uses scm_shell to process its
1586 command-line arguments gets this behavior as well.
1588 ** The new function `load-user-init' looks for a file called `.guile'
1589 in the user's home directory, and loads it if it exists. This is
1590 mostly for use by the code generated by scm_compile_shell_switches,
1591 but we thought it might also be useful in other circumstances.
1593 ** The new function `log10' returns the base-10 logarithm of its
1596 ** Changes to I/O functions
1598 *** The functions `read', `primitive-load', `read-and-eval!', and
1599 `primitive-load-path' no longer take optional arguments controlling
1600 case insensitivity and a `#' parser.
1602 Case sensitivity is now controlled by a read option called
1603 `case-insensitive'. The user can add new `#' syntaxes with the
1604 `read-hash-extend' function (see below).
1606 *** The new function `read-hash-extend' allows the user to change the
1607 syntax of Guile Scheme in a somewhat controlled way.
1609 (read-hash-extend CHAR PROC)
1610 When parsing S-expressions, if we read a `#' character followed by
1611 the character CHAR, use PROC to parse an object from the stream.
1612 If PROC is #f, remove any parsing procedure registered for CHAR.
1614 The reader applies PROC to two arguments: CHAR and an input port.
1616 *** The new functions read-delimited and read-delimited! provide a
1617 general mechanism for doing delimited input on streams.
1619 (read-delimited DELIMS [PORT HANDLE-DELIM])
1620 Read until we encounter one of the characters in DELIMS (a string),
1621 or end-of-file. PORT is the input port to read from; it defaults to
1622 the current input port. The HANDLE-DELIM parameter determines how
1623 the terminating character is handled; it should be one of the
1626 'trim omit delimiter from result
1627 'peek leave delimiter character in input stream
1628 'concat append delimiter character to returned value
1629 'split return a pair: (RESULT . TERMINATOR)
1631 HANDLE-DELIM defaults to 'peek.
1633 (read-delimited! DELIMS BUF [PORT HANDLE-DELIM START END])
1634 A side-effecting variant of `read-delimited'.
1636 The data is written into the string BUF at the indices in the
1637 half-open interval [START, END); the default interval is the whole
1638 string: START = 0 and END = (string-length BUF). The values of
1639 START and END must specify a well-defined interval in BUF, i.e.
1640 0 <= START <= END <= (string-length BUF).
1642 It returns NBYTES, the number of bytes read. If the buffer filled
1643 up without a delimiter character being found, it returns #f. If the
1644 port is at EOF when the read starts, it returns the EOF object.
1646 If an integer is returned (i.e., the read is successfully terminated
1647 by reading a delimiter character), then the HANDLE-DELIM parameter
1648 determines how to handle the terminating character. It is described
1649 above, and defaults to 'peek.
1651 (The descriptions of these functions were borrowed from the SCSH
1652 manual, by Olin Shivers and Brian Carlstrom.)
1654 *** The `%read-delimited!' function is the primitive used to implement
1655 `read-delimited' and `read-delimited!'.
1657 (%read-delimited! DELIMS BUF GOBBLE? [PORT START END])
1659 This returns a pair of values: (TERMINATOR . NUM-READ).
1660 - TERMINATOR describes why the read was terminated. If it is a
1661 character or the eof object, then that is the value that terminated
1662 the read. If it is #f, the function filled the buffer without finding
1663 a delimiting character.
1664 - NUM-READ is the number of characters read into BUF.
1666 If the read is successfully terminated by reading a delimiter
1667 character, then the gobble? parameter determines what to do with the
1668 terminating character. If true, the character is removed from the
1669 input stream; if false, the character is left in the input stream
1670 where a subsequent read operation will retrieve it. In either case,
1671 the character is also the first value returned by the procedure call.
1673 (The descriptions of this function was borrowed from the SCSH manual,
1674 by Olin Shivers and Brian Carlstrom.)
1676 *** The `read-line' and `read-line!' functions have changed; they now
1677 trim the terminator by default; previously they appended it to the
1678 returned string. For the old behavior, use (read-line PORT 'concat).
1680 *** The functions `uniform-array-read!' and `uniform-array-write!' now
1681 take new optional START and END arguments, specifying the region of
1682 the array to read and write.
1684 *** The `ungetc-char-ready?' function has been removed. We feel it's
1685 inappropriate for an interface to expose implementation details this
1688 ** Changes to the Unix library and system call interface
1690 *** The new fcntl function provides access to the Unix `fcntl' system
1693 (fcntl PORT COMMAND VALUE)
1694 Apply COMMAND to PORT's file descriptor, with VALUE as an argument.
1695 Values for COMMAND are:
1697 F_DUPFD duplicate a file descriptor
1698 F_GETFD read the descriptor's close-on-exec flag
1699 F_SETFD set the descriptor's close-on-exec flag to VALUE
1700 F_GETFL read the descriptor's flags, as set on open
1701 F_SETFL set the descriptor's flags, as set on open to VALUE
1702 F_GETOWN return the process ID of a socket's owner, for SIGIO
1703 F_SETOWN set the process that owns a socket to VALUE, for SIGIO
1704 FD_CLOEXEC not sure what this is
1706 For details, see the documentation for the fcntl system call.
1708 *** The arguments to `select' have changed, for compatibility with
1709 SCSH. The TIMEOUT parameter may now be non-integral, yielding the
1710 expected behavior. The MILLISECONDS parameter has been changed to
1711 MICROSECONDS, to more closely resemble the underlying system call.
1712 The RVEC, WVEC, and EVEC arguments can now be vectors; the type of the
1713 corresponding return set will be the same.
1715 *** The arguments to the `mknod' system call have changed. They are
1718 (mknod PATH TYPE PERMS DEV)
1719 Create a new file (`node') in the file system. PATH is the name of
1720 the file to create. TYPE is the kind of file to create; it should
1721 be 'fifo, 'block-special, or 'char-special. PERMS specifies the
1722 permission bits to give the newly created file. If TYPE is
1723 'block-special or 'char-special, DEV specifies which device the
1724 special file refers to; its interpretation depends on the kind of
1725 special file being created.
1727 *** The `fork' function has been renamed to `primitive-fork', to avoid
1728 clashing with various SCSH forks.
1730 *** The `recv' and `recvfrom' functions have been renamed to `recv!'
1731 and `recvfrom!'. They no longer accept a size for a second argument;
1732 you must pass a string to hold the received value. They no longer
1733 return the buffer. Instead, `recv' returns the length of the message
1734 received, and `recvfrom' returns a pair containing the packet's length
1735 and originating address.
1737 *** The file descriptor datatype has been removed, as have the
1738 `read-fd', `write-fd', `close', `lseek', and `dup' functions.
1739 We plan to replace these functions with a SCSH-compatible interface.
1741 *** The `create' function has been removed; it's just a special case
1744 *** There are new functions to break down process termination status
1745 values. In the descriptions below, STATUS is a value returned by
1748 (status:exit-val STATUS)
1749 If the child process exited normally, this function returns the exit
1750 code for the child process (i.e., the value passed to exit, or
1751 returned from main). If the child process did not exit normally,
1752 this function returns #f.
1754 (status:stop-sig STATUS)
1755 If the child process was suspended by a signal, this function
1756 returns the signal that suspended the child. Otherwise, it returns
1759 (status:term-sig STATUS)
1760 If the child process terminated abnormally, this function returns
1761 the signal that terminated the child. Otherwise, this function
1764 POSIX promises that exactly one of these functions will return true on
1765 a valid STATUS value.
1767 These functions are compatible with SCSH.
1769 *** There are new accessors and setters for the broken-out time vectors
1770 returned by `localtime', `gmtime', and that ilk. They are:
1772 Component Accessor Setter
1773 ========================= ============ ============
1774 seconds tm:sec set-tm:sec
1775 minutes tm:min set-tm:min
1776 hours tm:hour set-tm:hour
1777 day of the month tm:mday set-tm:mday
1778 month tm:mon set-tm:mon
1779 year tm:year set-tm:year
1780 day of the week tm:wday set-tm:wday
1781 day in the year tm:yday set-tm:yday
1782 daylight saving time tm:isdst set-tm:isdst
1783 GMT offset, seconds tm:gmtoff set-tm:gmtoff
1784 name of time zone tm:zone set-tm:zone
1786 *** There are new accessors for the vectors returned by `uname',
1787 describing the host system:
1790 ============================================== ================
1791 name of the operating system implementation utsname:sysname
1792 network name of this machine utsname:nodename
1793 release level of the operating system utsname:release
1794 version level of the operating system utsname:version
1795 machine hardware platform utsname:machine
1797 *** There are new accessors for the vectors returned by `getpw',
1798 `getpwnam', `getpwuid', and `getpwent', describing entries from the
1799 system's user database:
1802 ====================== =================
1803 user name passwd:name
1804 user password passwd:passwd
1807 real name passwd:gecos
1808 home directory passwd:dir
1809 shell program passwd:shell
1811 *** There are new accessors for the vectors returned by `getgr',
1812 `getgrnam', `getgrgid', and `getgrent', describing entries from the
1813 system's group database:
1816 ======================= ============
1817 group name group:name
1818 group password group:passwd
1820 group members group:mem
1822 *** There are new accessors for the vectors returned by `gethost',
1823 `gethostbyaddr', `gethostbyname', and `gethostent', describing
1827 ========================= ===============
1828 official name of host hostent:name
1829 alias list hostent:aliases
1830 host address type hostent:addrtype
1831 length of address hostent:length
1832 list of addresses hostent:addr-list
1834 *** There are new accessors for the vectors returned by `getnet',
1835 `getnetbyaddr', `getnetbyname', and `getnetent', describing internet
1839 ========================= ===============
1840 official name of net netent:name
1841 alias list netent:aliases
1842 net number type netent:addrtype
1843 net number netent:net
1845 *** There are new accessors for the vectors returned by `getproto',
1846 `getprotobyname', `getprotobynumber', and `getprotoent', describing
1850 ========================= ===============
1851 official protocol name protoent:name
1852 alias list protoent:aliases
1853 protocol number protoent:proto
1855 *** There are new accessors for the vectors returned by `getserv',
1856 `getservbyname', `getservbyport', and `getservent', describing
1860 ========================= ===============
1861 official service name servent:name
1862 alias list servent:aliases
1863 port number servent:port
1864 protocol to use servent:proto
1866 *** There are new accessors for the sockaddr structures returned by
1867 `accept', `getsockname', `getpeername', `recvfrom!':
1870 ======================================== ===============
1871 address format (`family') sockaddr:fam
1872 path, for file domain addresses sockaddr:path
1873 address, for internet domain addresses sockaddr:addr
1874 TCP or UDP port, for internet sockaddr:port
1876 *** The `getpwent', `getgrent', `gethostent', `getnetent',
1877 `getprotoent', and `getservent' functions now return #f at the end of
1878 the user database. (They used to throw an exception.)
1880 Note that calling MUMBLEent function is equivalent to calling the
1881 corresponding MUMBLE function with no arguments.
1883 *** The `setpwent', `setgrent', `sethostent', `setnetent',
1884 `setprotoent', and `setservent' routines now take no arguments.
1886 *** The `gethost', `getproto', `getnet', and `getserv' functions now
1887 provide more useful information when they throw an exception.
1889 *** The `lnaof' function has been renamed to `inet-lnaof'.
1891 *** Guile now claims to have the `current-time' feature.
1893 *** The `mktime' function now takes an optional second argument ZONE,
1894 giving the time zone to use for the conversion. ZONE should be a
1895 string, in the same format as expected for the "TZ" environment variable.
1897 *** The `strptime' function now returns a pair (TIME . COUNT), where
1898 TIME is the parsed time as a vector, and COUNT is the number of
1899 characters from the string left unparsed. This function used to
1900 return the remaining characters as a string.
1902 *** The `gettimeofday' function has replaced the old `time+ticks' function.
1903 The return value is now (SECONDS . MICROSECONDS); the fractional
1904 component is no longer expressed in "ticks".
1906 *** The `ticks/sec' constant has been removed, in light of the above change.
1908 * Changes to the gh_ interface
1910 ** gh_eval_str() now returns an SCM object which is the result of the
1913 ** gh_scm2str() now copies the Scheme data to a caller-provided C
1916 ** gh_scm2newstr() now makes a C array, copies the Scheme data to it,
1917 and returns the array
1919 ** gh_scm2str0() is gone: there is no need to distinguish
1920 null-terminated from non-null-terminated, since gh_scm2newstr() allows
1921 the user to interpret the data both ways.
1923 * Changes to the scm_ interface
1925 ** The new function scm_symbol_value0 provides an easy way to get a
1926 symbol's value from C code:
1928 SCM scm_symbol_value0 (char *NAME)
1929 Return the value of the symbol named by the null-terminated string
1930 NAME in the current module. If the symbol named NAME is unbound in
1931 the current module, return SCM_UNDEFINED.
1933 ** The new function scm_sysintern0 creates new top-level variables,
1934 without assigning them a value.
1936 SCM scm_sysintern0 (char *NAME)
1937 Create a new Scheme top-level variable named NAME. NAME is a
1938 null-terminated string. Return the variable's value cell.
1940 ** The function scm_internal_catch is the guts of catch. It handles
1941 all the mechanics of setting up a catch target, invoking the catch
1942 body, and perhaps invoking the handler if the body does a throw.
1944 The function is designed to be usable from C code, but is general
1945 enough to implement all the semantics Guile Scheme expects from throw.
1947 TAG is the catch tag. Typically, this is a symbol, but this function
1948 doesn't actually care about that.
1950 BODY is a pointer to a C function which runs the body of the catch;
1951 this is the code you can throw from. We call it like this:
1952 BODY (BODY_DATA, JMPBUF)
1954 BODY_DATA is just the BODY_DATA argument we received; we pass it
1955 through to BODY as its first argument. The caller can make
1956 BODY_DATA point to anything useful that BODY might need.
1957 JMPBUF is the Scheme jmpbuf object corresponding to this catch,
1958 which we have just created and initialized.
1960 HANDLER is a pointer to a C function to deal with a throw to TAG,
1961 should one occur. We call it like this:
1962 HANDLER (HANDLER_DATA, THROWN_TAG, THROW_ARGS)
1964 HANDLER_DATA is the HANDLER_DATA argument we recevied; it's the
1965 same idea as BODY_DATA above.
1966 THROWN_TAG is the tag that the user threw to; usually this is
1967 TAG, but it could be something else if TAG was #t (i.e., a
1968 catch-all), or the user threw to a jmpbuf.
1969 THROW_ARGS is the list of arguments the user passed to the THROW
1972 BODY_DATA is just a pointer we pass through to BODY. HANDLER_DATA
1973 is just a pointer we pass through to HANDLER. We don't actually
1974 use either of those pointers otherwise ourselves. The idea is
1975 that, if our caller wants to communicate something to BODY or
1976 HANDLER, it can pass a pointer to it as MUMBLE_DATA, which BODY and
1977 HANDLER can then use. Think of it as a way to make BODY and
1978 HANDLER closures, not just functions; MUMBLE_DATA points to the
1981 Of course, it's up to the caller to make sure that any data a
1982 MUMBLE_DATA needs is protected from GC. A common way to do this is
1983 to make MUMBLE_DATA a pointer to data stored in an automatic
1984 structure variable; since the collector must scan the stack for
1985 references anyway, this assures that any references in MUMBLE_DATA
1988 ** The new function scm_internal_lazy_catch is exactly like
1989 scm_internal_catch, except:
1991 - It does not unwind the stack (this is the major difference).
1992 - If handler returns, its value is returned from the throw.
1993 - BODY always receives #f as its JMPBUF argument (since there's no
1994 jmpbuf associated with a lazy catch, because we don't unwind the
1997 ** scm_body_thunk is a new body function you can pass to
1998 scm_internal_catch if you want the body to be like Scheme's `catch'
1999 --- a thunk, or a function of one argument if the tag is #f.
2001 BODY_DATA is a pointer to a scm_body_thunk_data structure, which
2002 contains the Scheme procedure to invoke as the body, and the tag
2003 we're catching. If the tag is #f, then we pass JMPBUF (created by
2004 scm_internal_catch) to the body procedure; otherwise, the body gets
2007 ** scm_handle_by_proc is a new handler function you can pass to
2008 scm_internal_catch if you want the handler to act like Scheme's catch
2009 --- call a procedure with the tag and the throw arguments.
2011 If the user does a throw to this catch, this function runs a handler
2012 procedure written in Scheme. HANDLER_DATA is a pointer to an SCM
2013 variable holding the Scheme procedure object to invoke. It ought to
2014 be a pointer to an automatic variable (i.e., one living on the stack),
2015 or the procedure object should be otherwise protected from GC.
2017 ** scm_handle_by_message is a new handler function to use with
2018 `scm_internal_catch' if you want Guile to print a message and die.
2019 It's useful for dealing with throws to uncaught keys at the top level.
2021 HANDLER_DATA, if non-zero, is assumed to be a char * pointing to a
2022 message header to print; if zero, we use "guile" instead. That
2023 text is followed by a colon, then the message described by ARGS.
2025 ** The return type of scm_boot_guile is now void; the function does
2026 not return a value, and indeed, never returns at all.
2028 ** The new function scm_shell makes it easy for user applications to
2029 process command-line arguments in a way that is compatible with the
2030 stand-alone guile interpreter (which is in turn compatible with SCSH,
2033 To use the scm_shell function, first initialize any guile modules
2034 linked into your application, and then call scm_shell with the values
2035 of ARGC and ARGV your `main' function received. scm_shell will add
2036 any SCSH-style meta-arguments from the top of the script file to the
2037 argument vector, and then process the command-line arguments. This
2038 generally means loading a script file or starting up an interactive
2039 command interpreter. For details, see "Changes to the stand-alone
2042 ** The new functions scm_get_meta_args and scm_count_argv help you
2043 implement the SCSH-style meta-argument, `\'.
2045 char **scm_get_meta_args (int ARGC, char **ARGV)
2046 If the second element of ARGV is a string consisting of a single
2047 backslash character (i.e. "\\" in Scheme notation), open the file
2048 named by the following argument, parse arguments from it, and return
2049 the spliced command line. The returned array is terminated by a
2052 For details of argument parsing, see above, under "guile now accepts
2053 command-line arguments compatible with SCSH..."
2055 int scm_count_argv (char **ARGV)
2056 Count the arguments in ARGV, assuming it is terminated by a null
2059 For an example of how these functions might be used, see the source
2060 code for the function scm_shell in libguile/script.c.
2062 You will usually want to use scm_shell instead of calling this
2065 ** The new function scm_compile_shell_switches turns an array of
2066 command-line arguments into Scheme code to carry out the actions they
2067 describe. Given ARGC and ARGV, it returns a Scheme expression to
2068 evaluate, and calls scm_set_program_arguments to make any remaining
2069 command-line arguments available to the Scheme code. For example,
2070 given the following arguments:
2072 -e main -s ekko a speckled gecko
2074 scm_set_program_arguments will return the following expression:
2076 (begin (load "ekko") (main (command-line)) (quit))
2078 You will usually want to use scm_shell instead of calling this
2081 ** The function scm_shell_usage prints a usage message appropriate for
2082 an interpreter that uses scm_compile_shell_switches to handle its
2083 command-line arguments.
2085 void scm_shell_usage (int FATAL, char *MESSAGE)
2086 Print a usage message to the standard error output. If MESSAGE is
2087 non-zero, write it before the usage message, followed by a newline.
2088 If FATAL is non-zero, exit the process, using FATAL as the
2089 termination status. (If you want to be compatible with Guile,
2090 always use 1 as the exit status when terminating due to command-line
2093 You will usually want to use scm_shell instead of calling this
2096 ** scm_eval_0str now returns SCM_UNSPECIFIED if the string contains no
2097 expressions. It used to return SCM_EOL. Earth-shattering.
2099 ** The macros for declaring scheme objects in C code have been
2100 rearranged slightly. They are now:
2102 SCM_SYMBOL (C_NAME, SCHEME_NAME)
2103 Declare a static SCM variable named C_NAME, and initialize it to
2104 point to the Scheme symbol whose name is SCHEME_NAME. C_NAME should
2105 be a C identifier, and SCHEME_NAME should be a C string.
2107 SCM_GLOBAL_SYMBOL (C_NAME, SCHEME_NAME)
2108 Just like SCM_SYMBOL, but make C_NAME globally visible.
2110 SCM_VCELL (C_NAME, SCHEME_NAME)
2111 Create a global variable at the Scheme level named SCHEME_NAME.
2112 Declare a static SCM variable named C_NAME, and initialize it to
2113 point to the Scheme variable's value cell.
2115 SCM_GLOBAL_VCELL (C_NAME, SCHEME_NAME)
2116 Just like SCM_VCELL, but make C_NAME globally visible.
2118 The `guile-snarf' script writes initialization code for these macros
2119 to its standard output, given C source code as input.
2121 The SCM_GLOBAL macro is gone.
2123 ** The scm_read_line and scm_read_line_x functions have been replaced
2124 by Scheme code based on the %read-delimited! procedure (known to C
2125 code as scm_read_delimited_x). See its description above for more
2128 ** The function scm_sys_open has been renamed to scm_open. It now
2129 returns a port instead of an FD object.
2131 * The dynamic linking support has changed. For more information, see
2132 libguile/DYNAMIC-LINKING.
2137 User-visible changes from Thursday, September 5, 1996 until Guile 1.0
2140 * Changes to the 'guile' program:
2142 ** Guile now loads some new files when it starts up. Guile first
2143 searches the load path for init.scm, and loads it if found. Then, if
2144 Guile is not being used to execute a script, and the user's home
2145 directory contains a file named `.guile', Guile loads that.
2147 ** You can now use Guile as a shell script interpreter.
2149 To paraphrase the SCSH manual:
2151 When Unix tries to execute an executable file whose first two
2152 characters are the `#!', it treats the file not as machine code to
2153 be directly executed by the native processor, but as source code
2154 to be executed by some interpreter. The interpreter to use is
2155 specified immediately after the #! sequence on the first line of
2156 the source file. The kernel reads in the name of the interpreter,
2157 and executes that instead. It passes the interpreter the source
2158 filename as its first argument, with the original arguments
2159 following. Consult the Unix man page for the `exec' system call
2160 for more information.
2162 Now you can use Guile as an interpreter, using a mechanism which is a
2163 compatible subset of that provided by SCSH.
2165 Guile now recognizes a '-s' command line switch, whose argument is the
2166 name of a file of Scheme code to load. It also treats the two
2167 characters `#!' as the start of a comment, terminated by `!#'. Thus,
2168 to make a file of Scheme code directly executable by Unix, insert the
2169 following two lines at the top of the file:
2171 #!/usr/local/bin/guile -s
2174 Guile treats the argument of the `-s' command-line switch as the name
2175 of a file of Scheme code to load, and treats the sequence `#!' as the
2176 start of a block comment, terminated by `!#'.
2178 For example, here's a version of 'echo' written in Scheme:
2180 #!/usr/local/bin/guile -s
2182 (let loop ((args (cdr (program-arguments))))
2185 (display (car args))
2186 (if (pair? (cdr args))
2188 (loop (cdr args)))))
2191 Why does `#!' start a block comment terminated by `!#', instead of the
2192 end of the line? That is the notation SCSH uses, and although we
2193 don't yet support the other SCSH features that motivate that choice,
2194 we would like to be backward-compatible with any existing Guile
2195 scripts once we do. Furthermore, if the path to Guile on your system
2196 is too long for your kernel, you can start the script with this
2200 exec /really/long/path/to/guile -s "$0" ${1+"$@"}
2203 Note that some very old Unix systems don't support the `#!' syntax.
2206 ** You can now run Guile without installing it.
2208 Previous versions of the interactive Guile interpreter (`guile')
2209 couldn't start up unless Guile's Scheme library had been installed;
2210 they used the value of the environment variable `SCHEME_LOAD_PATH'
2211 later on in the startup process, but not to find the startup code
2212 itself. Now Guile uses `SCHEME_LOAD_PATH' in all searches for Scheme
2215 To run Guile without installing it, build it in the normal way, and
2216 then set the environment variable `SCHEME_LOAD_PATH' to a
2217 colon-separated list of directories, including the top-level directory
2218 of the Guile sources. For example, if you unpacked Guile so that the
2219 full filename of this NEWS file is /home/jimb/guile-1.0b3/NEWS, then
2222 export SCHEME_LOAD_PATH=/home/jimb/my-scheme:/home/jimb/guile-1.0b3
2225 ** Guile's read-eval-print loop no longer prints #<unspecified>
2226 results. If the user wants to see this, she can evaluate the
2227 expression (assert-repl-print-unspecified #t), perhaps in her startup
2230 ** Guile no longer shows backtraces by default when an error occurs;
2231 however, it does display a message saying how to get one, and how to
2232 request that they be displayed by default. After an error, evaluate
2234 to see a backtrace, and
2235 (debug-enable 'backtrace)
2236 to see them by default.
2240 * Changes to Guile Scheme:
2242 ** Guile now distinguishes between #f and the empty list.
2244 This is for compatibility with the IEEE standard, the (possibly)
2245 upcoming Revised^5 Report on Scheme, and many extant Scheme
2248 Guile used to have #f and '() denote the same object, to make Scheme's
2249 type system more compatible with Emacs Lisp's. However, the change
2250 caused too much trouble for Scheme programmers, and we found another
2251 way to reconcile Emacs Lisp with Scheme that didn't require this.
2254 ** Guile's delq, delv, delete functions, and their destructive
2255 counterparts, delq!, delv!, and delete!, now remove all matching
2256 elements from the list, not just the first. This matches the behavior
2257 of the corresponding Emacs Lisp functions, and (I believe) the Maclisp
2258 functions which inspired them.
2260 I recognize that this change may break code in subtle ways, but it
2261 seems best to make the change before the FSF's first Guile release,
2265 ** The compiled-library-path function has been deleted from libguile.
2267 ** The facilities for loading Scheme source files have changed.
2269 *** The variable %load-path now tells Guile which directories to search
2270 for Scheme code. Its value is a list of strings, each of which names
2273 *** The variable %load-extensions now tells Guile which extensions to
2274 try appending to a filename when searching the load path. Its value
2275 is a list of strings. Its default value is ("" ".scm").
2277 *** (%search-load-path FILENAME) searches the directories listed in the
2278 value of the %load-path variable for a Scheme file named FILENAME,
2279 with all the extensions listed in %load-extensions. If it finds a
2280 match, then it returns its full filename. If FILENAME is absolute, it
2281 returns it unchanged. Otherwise, it returns #f.
2283 %search-load-path will not return matches that refer to directories.
2285 *** (primitive-load FILENAME :optional CASE-INSENSITIVE-P SHARP)
2286 uses %seach-load-path to find a file named FILENAME, and loads it if
2287 it finds it. If it can't read FILENAME for any reason, it throws an
2290 The arguments CASE-INSENSITIVE-P and SHARP are interpreted as by the
2293 *** load uses the same searching semantics as primitive-load.
2295 *** The functions %try-load, try-load-with-path, %load, load-with-path,
2296 basic-try-load-with-path, basic-load-with-path, try-load-module-with-
2297 path, and load-module-with-path have been deleted. The functions
2298 above should serve their purposes.
2300 *** If the value of the variable %load-hook is a procedure,
2301 `primitive-load' applies its value to the name of the file being
2302 loaded (without the load path directory name prepended). If its value
2303 is #f, it is ignored. Otherwise, an error occurs.
2305 This is mostly useful for printing load notification messages.
2308 ** The function `eval!' is no longer accessible from the scheme level.
2309 We can't allow operations which introduce glocs into the scheme level,
2310 because Guile's type system can't handle these as data. Use `eval' or
2311 `read-and-eval!' (see below) as replacement.
2313 ** The new function read-and-eval! reads an expression from PORT,
2314 evaluates it, and returns the result. This is more efficient than
2315 simply calling `read' and `eval', since it is not necessary to make a
2316 copy of the expression for the evaluator to munge.
2318 Its optional arguments CASE_INSENSITIVE_P and SHARP are interpreted as
2319 for the `read' function.
2322 ** The function `int?' has been removed; its definition was identical
2323 to that of `integer?'.
2325 ** The functions `<?', `<?', `<=?', `=?', `>?', and `>=?'. Code should
2326 use the R4RS names for these functions.
2328 ** The function object-properties no longer returns the hash handle;
2329 it simply returns the object's property list.
2331 ** Many functions have been changed to throw errors, instead of
2332 returning #f on failure. The point of providing exception handling in
2333 the language is to simplify the logic of user code, but this is less
2334 useful if Guile's primitives don't throw exceptions.
2336 ** The function `fileno' has been renamed from `%fileno'.
2338 ** The function primitive-mode->fdes returns #t or #f now, not 1 or 0.
2341 * Changes to Guile's C interface:
2343 ** The library's initialization procedure has been simplified.
2344 scm_boot_guile now has the prototype:
2346 void scm_boot_guile (int ARGC,
2348 void (*main_func) (),
2351 scm_boot_guile calls MAIN_FUNC, passing it CLOSURE, ARGC, and ARGV.
2352 MAIN_FUNC should do all the work of the program (initializing other
2353 packages, reading user input, etc.) before returning. When MAIN_FUNC
2354 returns, call exit (0); this function never returns. If you want some
2355 other exit value, MAIN_FUNC may call exit itself.
2357 scm_boot_guile arranges for program-arguments to return the strings
2358 given by ARGC and ARGV. If MAIN_FUNC modifies ARGC/ARGV, should call
2359 scm_set_program_arguments with the final list, so Scheme code will
2360 know which arguments have been processed.
2362 scm_boot_guile establishes a catch-all catch handler which prints an
2363 error message and exits the process. This means that Guile exits in a
2364 coherent way when system errors occur and the user isn't prepared to
2365 handle it. If the user doesn't like this behavior, they can establish
2366 their own universal catcher in MAIN_FUNC to shadow this one.
2368 Why must the caller do all the real work from MAIN_FUNC? The garbage
2369 collector assumes that all local variables of type SCM will be above
2370 scm_boot_guile's stack frame on the stack. If you try to manipulate
2371 SCM values after this function returns, it's the luck of the draw
2372 whether the GC will be able to find the objects you allocate. So,
2373 scm_boot_guile function exits, rather than returning, to discourage
2374 people from making that mistake.
2376 The IN, OUT, and ERR arguments were removed; there are other
2377 convenient ways to override these when desired.
2379 The RESULT argument was deleted; this function should never return.
2381 The BOOT_CMD argument was deleted; the MAIN_FUNC argument is more
2385 ** Guile's header files should no longer conflict with your system's
2388 In order to compile code which #included <libguile.h>, previous
2389 versions of Guile required you to add a directory containing all the
2390 Guile header files to your #include path. This was a problem, since
2391 Guile's header files have names which conflict with many systems'
2394 Now only <libguile.h> need appear in your #include path; you must
2395 refer to all Guile's other header files as <libguile/mumble.h>.
2396 Guile's installation procedure puts libguile.h in $(includedir), and
2397 the rest in $(includedir)/libguile.
2400 ** Two new C functions, scm_protect_object and scm_unprotect_object,
2401 have been added to the Guile library.
2403 scm_protect_object (OBJ) protects OBJ from the garbage collector.
2404 OBJ will not be freed, even if all other references are dropped,
2405 until someone does scm_unprotect_object (OBJ). Both functions
2408 Note that calls to scm_protect_object do not nest. You can call
2409 scm_protect_object any number of times on a given object, and the
2410 next call to scm_unprotect_object will unprotect it completely.
2412 Basically, scm_protect_object and scm_unprotect_object just
2413 maintain a list of references to things. Since the GC knows about
2414 this list, all objects it mentions stay alive. scm_protect_object
2415 adds its argument to the list; scm_unprotect_object remove its
2416 argument from the list.
2419 ** scm_eval_0str now returns the value of the last expression
2422 ** The new function scm_read_0str reads an s-expression from a
2423 null-terminated string, and returns it.
2425 ** The new function `scm_stdio_to_port' converts a STDIO file pointer
2426 to a Scheme port object.
2428 ** The new function `scm_set_program_arguments' allows C code to set
2429 the value returned by the Scheme `program-arguments' function.
2434 * Guile no longer includes sophisticated Tcl/Tk support.
2436 The old Tcl/Tk support was unsatisfying to us, because it required the
2437 user to link against the Tcl library, as well as Tk and Guile. The
2438 interface was also un-lispy, in that it preserved Tcl/Tk's practice of
2439 referring to widgets by names, rather than exporting widgets to Scheme
2440 code as a special datatype.
2442 In the Usenix Tk Developer's Workshop held in July 1996, the Tcl/Tk
2443 maintainers described some very interesting changes in progress to the
2444 Tcl/Tk internals, which would facilitate clean interfaces between lone
2445 Tk and other interpreters --- even for garbage-collected languages
2446 like Scheme. They expected the new Tk to be publicly available in the
2449 Since it seems that Guile might soon have a new, cleaner interface to
2450 lone Tk, and that the old Guile/Tk glue code would probably need to be
2451 completely rewritten, we (Jim Blandy and Richard Stallman) have
2452 decided not to support the old code. We'll spend the time instead on
2453 a good interface to the newer Tk, as soon as it is available.
2455 Until then, gtcltk-lib provides trivial, low-maintenance functionality.
2458 Copyright information:
2460 Copyright (C) 1996,1997 Free Software Foundation, Inc.
2462 Permission is granted to anyone to make or distribute verbatim copies
2463 of this document as received, in any medium, provided that the
2464 copyright notice and this permission notice are preserved,
2465 thus giving the recipient permission to redistribute in turn.
2467 Permission is granted to distribute modified versions
2468 of this document, or of portions of it,
2469 under the above conditions, provided also that they
2470 carry prominent notices stating who last changed them.
2475 paragraph-separate: "[
\f]*$"