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1 | Guile NEWS --- history of user-visible changes. -*- text -*- |
2 | Copyright (C) 1996, 1997 Free Software Foundation, Inc. | |
5c54da76 JB |
3 | See the end for copying conditions. |
4 | ||
e1b6c710 | 5 | Please send Guile bug reports to bug-guile@gnu.org. |
5c54da76 | 6 | \f |
c484bf7f JB |
7 | Changes since Guile 1.2: |
8 | ||
9 | * Changes to the distribution | |
10 | ||
e2d6569c JB |
11 | ** We renamed the SCHEME_LOAD_PATH environment variable to GUILE_LOAD_PATH. |
12 | To avoid conflicts, programs should name environment variables after | |
13 | themselves, except when there's a common practice establishing some | |
14 | other convention. | |
15 | ||
16 | For now, Guile supports both GUILE_LOAD_PATH and SCHEME_LOAD_PATH, | |
17 | giving the former precedence, and printing a warning message if the | |
18 | latter is set. Guile 1.4 will not recognize SCHEME_LOAD_PATH at all. | |
19 | ||
20 | ** The header files related to multi-byte characters have been removed. | |
21 | They were: libguile/extchrs.h and libguile/mbstrings.h. Any C code | |
22 | which referred to these explicitly will probably need to be rewritten, | |
23 | since the support for the variant string types has been removed; see | |
24 | below. | |
25 | ||
26 | ** The header files append.h and sequences.h have been removed. These | |
27 | files implemented non-R4RS operations which would encourage | |
28 | non-portable programming style and less easy-to-read code. | |
3a97e020 | 29 | |
c484bf7f JB |
30 | * Changes to the stand-alone interpreter |
31 | ||
2e368582 | 32 | ** New procedures have been added to implement a "batch mode": |
ec4ab4fd | 33 | |
2e368582 | 34 | *** Function: batch-mode? |
ec4ab4fd GH |
35 | |
36 | Returns a boolean indicating whether the interpreter is in batch | |
37 | mode. | |
38 | ||
2e368582 | 39 | *** Function: set-batch-mode?! ARG |
ec4ab4fd GH |
40 | |
41 | If ARG is true, switches the interpreter to batch mode. The `#f' | |
42 | case has not been implemented. | |
43 | ||
2e368582 JB |
44 | ** Guile now provides full command-line editing, when run interactively. |
45 | To use this feature, you must have the readline library installed. | |
46 | The Guile build process will notice it, and automatically include | |
47 | support for it. | |
48 | ||
49 | The readline library is available via anonymous FTP from any GNU | |
50 | mirror site; the canonical location is "ftp://prep.ai.mit.edu/pub/gnu". | |
51 | ||
a5d6d578 MD |
52 | ** the-last-stack is now a fluid. |
53 | ||
c484bf7f JB |
54 | * Changes to the procedure for linking libguile with your programs |
55 | ||
2e368582 JB |
56 | ** You can now use the 'build-guile' utility to link against Guile. |
57 | ||
58 | Guile now includes a command-line utility called 'build-guile', which | |
59 | writes to its standard output a list of flags which you must pass to | |
60 | the linker to link against the Guile library. The flags include | |
e2d6569c JB |
61 | '-lguile' itself, and any other libraries the Guile library depends |
62 | upon. | |
2e368582 JB |
63 | |
64 | For example, here is a Makefile rule that builds a program named 'foo' | |
65 | from the object files ${FOO_OBJECTS}, and links them against Guile: | |
66 | ||
67 | foo: ${FOO_OBJECTS} | |
68 | ${CC} ${CFLAGS} ${FOO_OBJECTS} `build-guile link` -o foo | |
69 | ||
e2d6569c JB |
70 | Previous Guile releases recommended that you use autoconf to detect |
71 | which of a predefined set of libraries were present on your system. | |
72 | It is more robust to use build-guile, since it records exactly which | |
73 | libraries the installed Guile library requires. | |
74 | ||
2e368582 | 75 | |
c484bf7f | 76 | * Changes to Scheme functions and syntax |
7ad3c1e7 | 77 | |
02755d59 | 78 | ** Multi-byte strings have been removed, as have multi-byte and wide |
e2d6569c JB |
79 | ports. We felt that these were the wrong approach to |
80 | internationalization support. | |
02755d59 | 81 | |
2e368582 JB |
82 | ** New function: readline [PROMPT] |
83 | Read a line from the terminal, and allow the user to edit it, | |
84 | prompting with PROMPT. READLINE provides a large set of Emacs-like | |
85 | editing commands, lets the user recall previously typed lines, and | |
86 | works on almost every kind of terminal, including dumb terminals. | |
87 | ||
88 | READLINE assumes that the cursor is at the beginning of the line when | |
89 | it is invoked. Thus, you can't print a prompt yourself, and then call | |
90 | READLINE; you need to package up your prompt as a string, pass it to | |
91 | the function, and let READLINE print the prompt itself. This is | |
92 | because READLINE needs to know the prompt's screen width. | |
93 | ||
94 | For Guile to provide this function, you must have the readline library | |
95 | installed on your system. | |
96 | ||
97 | See also ADD-HISTORY function. | |
98 | ||
99 | ** New function: add-history STRING | |
100 | Add STRING as the most recent line in the history used by the READLINE | |
101 | command. READLINE does not add lines to the history itself; you must | |
102 | call ADD-HISTORY to make previous input available to the user. | |
103 | ||
29521173 MD |
104 | ** macro-eval! is removed. Use local-eval instead. |
105 | ||
8d9dcb3c MV |
106 | ** Some magic has been added to the printer to better handle user |
107 | written printing routines (like record printers, closure printers). | |
108 | ||
109 | The problem is that these user written routines must have access to | |
7fbd77df | 110 | the current `print-state' to be able to handle fancy things like |
8d9dcb3c MV |
111 | detection of circular references. These print-states have to be |
112 | passed to the builtin printing routines (display, write, etc) to | |
113 | properly continue the print chain. | |
114 | ||
115 | We didn't want to change all existing print code so that it | |
116 | explicitely passes thru a print state in addition to a port. Instead, | |
117 | we extented the possible values that the builtin printing routines | |
118 | accept as a `port'. In addition to a normal port, they now also take | |
119 | a pair of a normal port and a print-state. Printing will go to the | |
120 | port and the print-state will be used to control the detection of | |
121 | circular references, etc. If the builtin function does not care for a | |
122 | print-state, it is simply ignored. | |
123 | ||
124 | User written callbacks are now called with such a pair as their | |
125 | `port', but because every function now accepts this pair as a PORT | |
126 | argument, you don't have to worry about that. In fact, it is probably | |
127 | safest to not check for these pairs. | |
128 | ||
129 | However, it is sometimes necessary to continue a print chain on a | |
130 | different port, for example to get a intermediate string | |
131 | representation of the printed value, mangle that string somehow, and | |
132 | then to finally print the mangled string. Use the new function | |
133 | ||
134 | inherit-print-state OLD-PORT NEW-PORT | |
135 | ||
136 | for this. It constructs a new `port' that prints to NEW-PORT but | |
137 | inherits the print-state of OLD-PORT. | |
138 | ||
ef1ea498 MD |
139 | ** struct-vtable-offset renamed to vtable-offset-user |
140 | ||
141 | ** New constants: vtable-index-layout, vtable-index-vtable, vtable-index-printer | |
142 | ||
143 | ** There is now a fourth (optional) argument to make-vtable-vtable and | |
144 | make-struct when constructing new types (vtables). This argument | |
145 | initializes field vtable-index-printer of the vtable. | |
146 | ||
4851dc57 MV |
147 | ** The detection of circular references has been extended to structs. |
148 | That is, a structure that -- in the process of being printed -- prints | |
149 | itself does not lead to infinite recursion. | |
150 | ||
151 | ** There is now some basic support for fluids. Please read | |
152 | "libguile/fluid.h" to find out more. It is accessible from Scheme with | |
153 | the following functions and macros: | |
154 | ||
9c3fb66f MV |
155 | Function: make-fluid |
156 | ||
157 | Create a new fluid object. Fluids are not special variables or | |
158 | some other extension to the semantics of Scheme, but rather | |
159 | ordinary Scheme objects. You can store them into variables (that | |
160 | are still lexically scoped, of course) or into any other place you | |
161 | like. Every fluid has a initial value of `#f'. | |
04c76b58 | 162 | |
9c3fb66f | 163 | Function: fluid? OBJ |
04c76b58 | 164 | |
9c3fb66f | 165 | Test whether OBJ is a fluid. |
04c76b58 | 166 | |
9c3fb66f MV |
167 | Function: fluid-ref FLUID |
168 | Function: fluid-set! FLUID VAL | |
04c76b58 MV |
169 | |
170 | Access/modify the fluid FLUID. Modifications are only visible | |
171 | within the current dynamic root (that includes threads). | |
172 | ||
9c3fb66f MV |
173 | Function: with-fluids* FLUIDS VALUES THUNK |
174 | ||
175 | FLUIDS is a list of fluids and VALUES a corresponding list of | |
176 | values for these fluids. Before THUNK gets called the values are | |
177 | installed in the fluids and the old values of the fluids are | |
178 | saved in the VALUES list. When the flow of control leaves THUNK | |
179 | or reenters it, the values get swapped again. You might think of | |
180 | this as a `safe-fluid-excursion'. Note that the VALUES list is | |
181 | modified by `with-fluids*'. | |
182 | ||
183 | Macro: with-fluids ((FLUID VALUE) ...) FORM ... | |
184 | ||
185 | The same as `with-fluids*' but with a different syntax. It looks | |
186 | just like `let', but both FLUID and VALUE are evaluated. Remember, | |
187 | fluids are not special variables but ordinary objects. FLUID | |
188 | should evaluate to a fluid. | |
04c76b58 | 189 | |
e2d6569c | 190 | ** Changes to system call interfaces: |
64d01d13 | 191 | |
e2d6569c | 192 | *** close-port, close-input-port and close-output-port now return a |
64d01d13 GH |
193 | boolean instead of an `unspecified' object. #t means that the port |
194 | was successfully closed, while #f means it was already closed. It is | |
195 | also now possible for these procedures to raise an exception if an | |
196 | error occurs (some errors from write can be delayed until close.) | |
197 | ||
e2d6569c | 198 | *** the first argument to chmod, fcntl, ftell and fseek can now be a |
6afcd3b2 GH |
199 | file descriptor. |
200 | ||
e2d6569c | 201 | *** the third argument to fcntl is now optional. |
6afcd3b2 | 202 | |
e2d6569c | 203 | *** the first argument to chown can now be a file descriptor or a port. |
6afcd3b2 | 204 | |
e2d6569c | 205 | *** the argument to stat can now be a port. |
6afcd3b2 | 206 | |
e2d6569c | 207 | *** The following new procedures have been added (most use scsh |
64d01d13 GH |
208 | interfaces): |
209 | ||
e2d6569c | 210 | *** procedure: close PORT/FD |
ec4ab4fd GH |
211 | Similar to close-port (*note close-port: Closing Ports.), but also |
212 | works on file descriptors. A side effect of closing a file | |
213 | descriptor is that any ports using that file descriptor are moved | |
214 | to a different file descriptor and have their revealed counts set | |
215 | to zero. | |
216 | ||
e2d6569c | 217 | *** procedure: port->fdes PORT |
ec4ab4fd GH |
218 | Returns the integer file descriptor underlying PORT. As a side |
219 | effect the revealed count of PORT is incremented. | |
220 | ||
e2d6569c | 221 | *** procedure: fdes->ports FDES |
ec4ab4fd GH |
222 | Returns a list of existing ports which have FDES as an underlying |
223 | file descriptor, without changing their revealed counts. | |
224 | ||
e2d6569c | 225 | *** procedure: fdes->inport FDES |
ec4ab4fd GH |
226 | Returns an existing input port which has FDES as its underlying |
227 | file descriptor, if one exists, and increments its revealed count. | |
228 | Otherwise, returns a new input port with a revealed count of 1. | |
229 | ||
e2d6569c | 230 | *** procedure: fdes->outport FDES |
ec4ab4fd GH |
231 | Returns an existing output port which has FDES as its underlying |
232 | file descriptor, if one exists, and increments its revealed count. | |
233 | Otherwise, returns a new output port with a revealed count of 1. | |
234 | ||
235 | The next group of procedures perform a `dup2' system call, if NEWFD | |
236 | (an integer) is supplied, otherwise a `dup'. The file descriptor to be | |
237 | duplicated can be supplied as an integer or contained in a port. The | |
64d01d13 GH |
238 | type of value returned varies depending on which procedure is used. |
239 | ||
ec4ab4fd GH |
240 | All procedures also have the side effect when performing `dup2' that |
241 | any ports using NEWFD are moved to a different file descriptor and have | |
64d01d13 GH |
242 | their revealed counts set to zero. |
243 | ||
e2d6569c | 244 | *** procedure: dup->fdes PORT/FD [NEWFD] |
ec4ab4fd | 245 | Returns an integer file descriptor. |
64d01d13 | 246 | |
e2d6569c | 247 | *** procedure: dup->inport PORT/FD [NEWFD] |
ec4ab4fd | 248 | Returns a new input port using the new file descriptor. |
64d01d13 | 249 | |
e2d6569c | 250 | *** procedure: dup->outport PORT/FD [NEWFD] |
ec4ab4fd | 251 | Returns a new output port using the new file descriptor. |
64d01d13 | 252 | |
e2d6569c | 253 | *** procedure: dup PORT/FD [NEWFD] |
ec4ab4fd GH |
254 | Returns a new port if PORT/FD is a port, with the same mode as the |
255 | supplied port, otherwise returns an integer file descriptor. | |
64d01d13 | 256 | |
e2d6569c | 257 | *** procedure: dup->port PORT/FD MODE [NEWFD] |
ec4ab4fd GH |
258 | Returns a new port using the new file descriptor. MODE supplies a |
259 | mode string for the port (*note open-file: File Ports.). | |
64d01d13 | 260 | |
e2d6569c | 261 | *** procedure: setenv NAME VALUE |
ec4ab4fd GH |
262 | Modifies the environment of the current process, which is also the |
263 | default environment inherited by child processes. | |
64d01d13 | 264 | |
ec4ab4fd GH |
265 | If VALUE is `#f', then NAME is removed from the environment. |
266 | Otherwise, the string NAME=VALUE is added to the environment, | |
267 | replacing any existing string with name matching NAME. | |
64d01d13 | 268 | |
ec4ab4fd | 269 | The return value is unspecified. |
956055a9 | 270 | |
e2d6569c | 271 | *** procedure: truncate-file OBJ SIZE |
6afcd3b2 GH |
272 | Truncates the file referred to by OBJ to at most SIZE bytes. OBJ |
273 | can be a string containing a file name or an integer file | |
274 | descriptor or port open for output on the file. The underlying | |
275 | system calls are `truncate' and `ftruncate'. | |
276 | ||
277 | The return value is unspecified. | |
278 | ||
e2d6569c | 279 | *** procedure: setvbuf PORT MODE [SIZE] |
7a6f1ffa GH |
280 | Set the buffering mode for PORT. MODE can be: |
281 | `_IONBF' | |
282 | non-buffered | |
283 | ||
284 | `_IOLBF' | |
285 | line buffered | |
286 | ||
287 | `_IOFBF' | |
288 | block buffered, using a newly allocated buffer of SIZE bytes. | |
289 | However if SIZE is zero or unspecified, the port will be made | |
290 | non-buffered. | |
291 | ||
292 | This procedure should not be used after I/O has been performed with | |
293 | the port. | |
294 | ||
295 | Ports are usually block buffered by default, with a default buffer | |
296 | size. Procedures e.g., *Note open-file: File Ports, which accept a | |
297 | mode string allow `0' to be added to request an unbuffered port. | |
298 | ||
e2d6569c | 299 | *** procedure: fsync PORT/FD |
6afcd3b2 GH |
300 | Copies any unwritten data for the specified output file descriptor |
301 | to disk. If PORT/FD is a port, its buffer is flushed before the | |
302 | underlying file descriptor is fsync'd. The return value is | |
303 | unspecified. | |
304 | ||
e2d6569c | 305 | *** procedure: open-fdes PATH FLAGS [MODES] |
6afcd3b2 GH |
306 | Similar to `open' but returns a file descriptor instead of a port. |
307 | ||
e2d6569c | 308 | *** procedure: execle PATH ENV [ARG] ... |
6afcd3b2 GH |
309 | Similar to `execl', but the environment of the new process is |
310 | specified by ENV, which must be a list of strings as returned by | |
311 | the `environ' procedure. | |
312 | ||
313 | This procedure is currently implemented using the `execve' system | |
314 | call, but we call it `execle' because of its Scheme calling | |
315 | interface. | |
316 | ||
e2d6569c | 317 | *** procedure: strerror ERRNO |
ec4ab4fd GH |
318 | Returns the Unix error message corresponding to ERRNO, an integer. |
319 | ||
e2d6569c | 320 | *** procedure: primitive-exit [STATUS] |
6afcd3b2 GH |
321 | Terminate the current process without unwinding the Scheme stack. |
322 | This is would typically be useful after a fork. The exit status | |
323 | is STATUS if supplied, otherwise zero. | |
324 | ||
e2d6569c | 325 | *** procedure: times |
6afcd3b2 GH |
326 | Returns an object with information about real and processor time. |
327 | The following procedures accept such an object as an argument and | |
328 | return a selected component: | |
329 | ||
330 | `tms:clock' | |
331 | The current real time, expressed as time units relative to an | |
332 | arbitrary base. | |
333 | ||
334 | `tms:utime' | |
335 | The CPU time units used by the calling process. | |
336 | ||
337 | `tms:stime' | |
338 | The CPU time units used by the system on behalf of the | |
339 | calling process. | |
340 | ||
341 | `tms:cutime' | |
342 | The CPU time units used by terminated child processes of the | |
343 | calling process, whose status has been collected (e.g., using | |
344 | `waitpid'). | |
345 | ||
346 | `tms:cstime' | |
347 | Similarly, the CPU times units used by the system on behalf of | |
348 | terminated child processes. | |
7ad3c1e7 | 349 | |
e2d6569c JB |
350 | ** Removed: list-length |
351 | ** Removed: list-append, list-append! | |
352 | ** Removed: list-reverse, list-reverse! | |
353 | ||
354 | ** array-map renamed to array-map! | |
355 | ||
356 | ** serial-array-map renamed to serial-array-map! | |
357 | ||
660f41fa MD |
358 | ** catch doesn't take #f as first argument any longer |
359 | ||
360 | Previously, it was possible to pass #f instead of a key to `catch'. | |
361 | That would cause `catch' to pass a jump buffer object to the procedure | |
362 | passed as second argument. The procedure could then use this jump | |
363 | buffer objekt as an argument to throw. | |
364 | ||
365 | This mechanism has been removed since its utility doesn't motivate the | |
366 | extra complexity it introduces. | |
367 | ||
c484bf7f JB |
368 | * Changes to the gh_ interface |
369 | ||
5424b4f7 MD |
370 | ** Function: void gh_write (SCM x) |
371 | ||
372 | Write the printed representation of the scheme object x to the current | |
373 | output port. Corresponds to the scheme level `write'. | |
374 | ||
3a97e020 MD |
375 | ** gh_list_length renamed to gh_length. |
376 | ||
8d6787b6 MG |
377 | ** vector handling routines |
378 | ||
379 | Several major changes. In particular, gh_vector() now resembles | |
380 | (vector ...) (with a caveat -- see manual), and gh_make_vector() now | |
956328d2 MG |
381 | exists and behaves like (make-vector ...). gh_vset() and gh_vref() |
382 | have been renamed gh_vector_set_x() and gh_vector_ref(). Some missing | |
8d6787b6 MG |
383 | vector-related gh_ functions have been implemented. |
384 | ||
7fee59bd MG |
385 | ** pair and list routines |
386 | ||
387 | Implemented several of the R4RS pair and list functions that were | |
388 | missing. | |
389 | ||
171422a9 MD |
390 | ** gh_scm2doubles, gh_doubles2scm, gh_doubles2dvect |
391 | ||
392 | New function. Converts double arrays back and forth between Scheme | |
393 | and C. | |
394 | ||
c484bf7f JB |
395 | * Changes to the scm_ interface |
396 | ||
87148d9e JB |
397 | ** The semantics of smob marking have changed slightly. |
398 | ||
399 | The smob marking function (the `mark' member of the scm_smobfuns | |
400 | structure) is no longer responsible for setting the mark bit on the | |
401 | smob. The generic smob handling code in the garbage collector will | |
402 | set this bit. The mark function need only ensure that any other | |
403 | objects the smob refers to get marked. | |
404 | ||
405 | Note that this change means that the smob's GC8MARK bit is typically | |
406 | already set upon entry to the mark function. Thus, marking functions | |
407 | which look like this: | |
408 | ||
409 | { | |
410 | if (SCM_GC8MARKP (ptr)) | |
411 | return SCM_BOOL_F; | |
412 | SCM_SETGC8MARK (ptr); | |
413 | ... mark objects to which the smob refers ... | |
414 | } | |
415 | ||
416 | are now incorrect, since they will return early, and fail to mark any | |
417 | other objects the smob refers to. Some code in the Guile library used | |
418 | to work this way. | |
419 | ||
420 | ||
933a7411 MD |
421 | ** Function: int scm_internal_select (int fds, |
422 | SELECT_TYPE *rfds, | |
423 | SELECT_TYPE *wfds, | |
424 | SELECT_TYPE *efds, | |
425 | struct timeval *timeout); | |
426 | ||
427 | This is a replacement for the `select' function provided by the OS. | |
428 | It enables I/O blocking and sleeping to happen for one cooperative | |
429 | thread without blocking other threads. It also avoids busy-loops in | |
430 | these situations. It is intended that all I/O blocking and sleeping | |
431 | will finally go through this function. Currently, this function is | |
432 | only available on systems providing `gettimeofday' and `select'. | |
433 | ||
5424b4f7 MD |
434 | ** Function: SCM scm_internal_stack_catch (SCM tag, |
435 | scm_catch_body_t body, | |
436 | void *body_data, | |
437 | scm_catch_handler_t handler, | |
438 | void *handler_data) | |
439 | ||
440 | A new sibling to the other two C level `catch' functions | |
441 | scm_internal_catch and scm_internal_lazy_catch. Use it if you want | |
442 | the stack to be saved automatically into the variable `the-last-stack' | |
443 | (scm_the_last_stack_var) on error. This is necessary if you want to | |
444 | use advanced error reporting, such as calling scm_display_error and | |
445 | scm_display_backtrace. (They both take a stack object as argument.) | |
446 | ||
df366c26 MD |
447 | ** Function: SCM scm_spawn_thread (scm_catch_body_t body, |
448 | void *body_data, | |
449 | scm_catch_handler_t handler, | |
450 | void *handler_data) | |
451 | ||
452 | Spawns a new thread. It does a job similar to | |
453 | scm_call_with_new_thread but takes arguments more suitable when | |
454 | spawning threads from application C code. | |
455 | ||
88482b31 MD |
456 | ** The hook scm_error_callback has been removed. It was originally |
457 | intended as a way for the user to install his own error handler. But | |
458 | that method works badly since it intervenes between throw and catch, | |
459 | thereby changing the semantics of expressions like (catch #t ...). | |
460 | The correct way to do it is to use one of the C level catch functions | |
461 | in throw.c: scm_internal_catch/lazy_catch/stack_catch. | |
462 | ||
3a97e020 MD |
463 | ** Removed functions: |
464 | ||
465 | scm_obj_length, scm_list_length, scm_list_append, scm_list_append_x, | |
466 | scm_list_reverse, scm_list_reverse_x | |
467 | ||
468 | ** New macros: SCM_LISTn where n is one of the integers 0-9. | |
469 | ||
470 | These can be used for pretty list creation from C. The idea is taken | |
471 | from Erick Gallesio's STk. | |
472 | ||
298aa6e3 MD |
473 | ** scm_array_map renamed to scm_array_map_x |
474 | ||
527da704 MD |
475 | ** mbstrings are now removed |
476 | ||
477 | This means that the type codes scm_tc7_mb_string and | |
478 | scm_tc7_mb_substring has been removed. | |
479 | ||
480 | ** The macros SCM_TYP7D and SCM_TYP7SD has been removed. | |
481 | ||
482 | ** The macro SCM_TYP7S has taken the role of the old SCM_TYP7D | |
483 | ||
484 | SCM_TYP7S now masks away the bit which distinguishes substrings from | |
485 | strings. | |
486 | ||
02755d59 TT |
487 | ** All genio functions changed names and interfaces; new functions are |
488 | scm_putc, scm_puts, scm_lfwrite, scm_getc, scm_ungetc, and | |
489 | scm_do_read_line. | |
490 | ||
660f41fa MD |
491 | ** scm_catch_body_t: Backward incompatible change! |
492 | ||
493 | Body functions to scm_internal_catch and friends do not any longer | |
494 | take a second argument. This is because it is no longer possible to | |
495 | pass a #f arg to catch. | |
496 | ||
c484bf7f JB |
497 | \f |
498 | Changes in Guile 1.2 (released Tuesday, June 24 1997): | |
cf78e9e8 | 499 | |
737c9113 JB |
500 | * Changes to the distribution |
501 | ||
832b09ed JB |
502 | ** Nightly snapshots are now available from ftp.red-bean.com. |
503 | The old server, ftp.cyclic.com, has been relinquished to its rightful | |
504 | owner. | |
505 | ||
506 | Nightly snapshots of the Guile development sources are now available via | |
507 | anonymous FTP from ftp.red-bean.com, as /pub/guile/guile-snap.tar.gz. | |
508 | ||
509 | Via the web, that's: ftp://ftp.red-bean.com/pub/guile/guile-snap.tar.gz | |
510 | For getit, that's: ftp.red-bean.com:/pub/guile/guile-snap.tar.gz | |
511 | ||
0fcab5ed JB |
512 | ** To run Guile without installing it, the procedure has changed a bit. |
513 | ||
514 | If you used a separate build directory to compile Guile, you'll need | |
515 | to include the build directory in SCHEME_LOAD_PATH, as well as the | |
516 | source directory. See the `INSTALL' file for examples. | |
517 | ||
737c9113 JB |
518 | * Changes to the procedure for linking libguile with your programs |
519 | ||
94982a4e JB |
520 | ** The standard Guile load path for Scheme code now includes |
521 | $(datadir)/guile (usually /usr/local/share/guile). This means that | |
522 | you can install your own Scheme files there, and Guile will find them. | |
523 | (Previous versions of Guile only checked a directory whose name | |
524 | contained the Guile version number, so you had to re-install or move | |
525 | your Scheme sources each time you installed a fresh version of Guile.) | |
526 | ||
527 | The load path also includes $(datadir)/guile/site; we recommend | |
528 | putting individual Scheme files there. If you want to install a | |
529 | package with multiple source files, create a directory for them under | |
530 | $(datadir)/guile. | |
531 | ||
532 | ** Guile 1.2 will now use the Rx regular expression library, if it is | |
533 | installed on your system. When you are linking libguile into your own | |
534 | programs, this means you will have to link against -lguile, -lqt (if | |
535 | you configured Guile with thread support), and -lrx. | |
27590f82 JB |
536 | |
537 | If you are using autoconf to generate configuration scripts for your | |
538 | application, the following lines should suffice to add the appropriate | |
539 | libraries to your link command: | |
540 | ||
541 | ### Find Rx, quickthreads and libguile. | |
542 | AC_CHECK_LIB(rx, main) | |
543 | AC_CHECK_LIB(qt, main) | |
544 | AC_CHECK_LIB(guile, scm_shell) | |
545 | ||
94982a4e JB |
546 | The Guile 1.2 distribution does not contain sources for the Rx |
547 | library, as Guile 1.0 did. If you want to use Rx, you'll need to | |
548 | retrieve it from a GNU FTP site and install it separately. | |
549 | ||
b83b8bee JB |
550 | * Changes to Scheme functions and syntax |
551 | ||
e035e7e6 MV |
552 | ** The dynamic linking features of Guile are now enabled by default. |
553 | You can disable them by giving the `--disable-dynamic-linking' option | |
554 | to configure. | |
555 | ||
e035e7e6 MV |
556 | (dynamic-link FILENAME) |
557 | ||
558 | Find the object file denoted by FILENAME (a string) and link it | |
559 | into the running Guile application. When everything works out, | |
560 | return a Scheme object suitable for representing the linked object | |
561 | file. Otherwise an error is thrown. How object files are | |
562 | searched is system dependent. | |
563 | ||
564 | (dynamic-object? VAL) | |
565 | ||
566 | Determine whether VAL represents a dynamically linked object file. | |
567 | ||
568 | (dynamic-unlink DYNOBJ) | |
569 | ||
570 | Unlink the indicated object file from the application. DYNOBJ | |
571 | should be one of the values returned by `dynamic-link'. | |
572 | ||
573 | (dynamic-func FUNCTION DYNOBJ) | |
574 | ||
575 | Search the C function indicated by FUNCTION (a string or symbol) | |
576 | in DYNOBJ and return some Scheme object that can later be used | |
577 | with `dynamic-call' to actually call this function. Right now, | |
578 | these Scheme objects are formed by casting the address of the | |
579 | function to `long' and converting this number to its Scheme | |
580 | representation. | |
581 | ||
582 | (dynamic-call FUNCTION DYNOBJ) | |
583 | ||
584 | Call the C function indicated by FUNCTION and DYNOBJ. The | |
585 | function is passed no arguments and its return value is ignored. | |
586 | When FUNCTION is something returned by `dynamic-func', call that | |
587 | function and ignore DYNOBJ. When FUNCTION is a string (or symbol, | |
588 | etc.), look it up in DYNOBJ; this is equivalent to | |
589 | ||
590 | (dynamic-call (dynamic-func FUNCTION DYNOBJ) #f) | |
591 | ||
592 | Interrupts are deferred while the C function is executing (with | |
593 | SCM_DEFER_INTS/SCM_ALLOW_INTS). | |
594 | ||
595 | (dynamic-args-call FUNCTION DYNOBJ ARGS) | |
596 | ||
597 | Call the C function indicated by FUNCTION and DYNOBJ, but pass it | |
598 | some arguments and return its return value. The C function is | |
599 | expected to take two arguments and return an `int', just like | |
600 | `main': | |
601 | ||
602 | int c_func (int argc, char **argv); | |
603 | ||
604 | ARGS must be a list of strings and is converted into an array of | |
605 | `char *'. The array is passed in ARGV and its size in ARGC. The | |
606 | return value is converted to a Scheme number and returned from the | |
607 | call to `dynamic-args-call'. | |
608 | ||
0fcab5ed JB |
609 | When dynamic linking is disabled or not supported on your system, |
610 | the above functions throw errors, but they are still available. | |
611 | ||
e035e7e6 MV |
612 | Here is a small example that works on GNU/Linux: |
613 | ||
614 | (define libc-obj (dynamic-link "libc.so")) | |
615 | (dynamic-args-call 'rand libc-obj '()) | |
616 | ||
617 | See the file `libguile/DYNAMIC-LINKING' for additional comments. | |
618 | ||
27590f82 JB |
619 | ** The #/ syntax for module names is depreciated, and will be removed |
620 | in a future version of Guile. Instead of | |
621 | ||
622 | #/foo/bar/baz | |
623 | ||
624 | instead write | |
625 | ||
626 | (foo bar baz) | |
627 | ||
628 | The latter syntax is more consistent with existing Lisp practice. | |
629 | ||
5dade857 MV |
630 | ** Guile now does fancier printing of structures. Structures are the |
631 | underlying implementation for records, which in turn are used to | |
632 | implement modules, so all of these object now print differently and in | |
633 | a more informative way. | |
634 | ||
161029df JB |
635 | The Scheme printer will examine the builtin variable *struct-printer* |
636 | whenever it needs to print a structure object. When this variable is | |
637 | not `#f' it is deemed to be a procedure and will be applied to the | |
638 | structure object and the output port. When *struct-printer* is `#f' | |
639 | or the procedure return `#f' the structure object will be printed in | |
640 | the boring #<struct 80458270> form. | |
5dade857 MV |
641 | |
642 | This hook is used by some routines in ice-9/boot-9.scm to implement | |
643 | type specific printing routines. Please read the comments there about | |
644 | "printing structs". | |
645 | ||
646 | One of the more specific uses of structs are records. The printing | |
647 | procedure that could be passed to MAKE-RECORD-TYPE is now actually | |
648 | called. It should behave like a *struct-printer* procedure (described | |
649 | above). | |
650 | ||
b83b8bee JB |
651 | ** Guile now supports a new R4RS-compliant syntax for keywords. A |
652 | token of the form #:NAME, where NAME has the same syntax as a Scheme | |
653 | symbol, is the external representation of the keyword named NAME. | |
654 | Keyword objects print using this syntax as well, so values containing | |
1e5afba0 JB |
655 | keyword objects can be read back into Guile. When used in an |
656 | expression, keywords are self-quoting objects. | |
b83b8bee JB |
657 | |
658 | Guile suports this read syntax, and uses this print syntax, regardless | |
659 | of the current setting of the `keyword' read option. The `keyword' | |
660 | read option only controls whether Guile recognizes the `:NAME' syntax, | |
661 | which is incompatible with R4RS. (R4RS says such token represent | |
662 | symbols.) | |
737c9113 JB |
663 | |
664 | ** Guile has regular expression support again. Guile 1.0 included | |
665 | functions for matching regular expressions, based on the Rx library. | |
666 | In Guile 1.1, the Guile/Rx interface was removed to simplify the | |
667 | distribution, and thus Guile had no regular expression support. Guile | |
94982a4e JB |
668 | 1.2 again supports the most commonly used functions, and supports all |
669 | of SCSH's regular expression functions. | |
2409cdfa | 670 | |
94982a4e JB |
671 | If your system does not include a POSIX regular expression library, |
672 | and you have not linked Guile with a third-party regexp library such as | |
673 | Rx, these functions will not be available. You can tell whether your | |
674 | Guile installation includes regular expression support by checking | |
675 | whether the `*features*' list includes the `regex' symbol. | |
737c9113 | 676 | |
94982a4e | 677 | *** regexp functions |
161029df | 678 | |
94982a4e JB |
679 | By default, Guile supports POSIX extended regular expressions. That |
680 | means that the characters `(', `)', `+' and `?' are special, and must | |
681 | be escaped if you wish to match the literal characters. | |
e1a191a8 | 682 | |
94982a4e JB |
683 | This regular expression interface was modeled after that implemented |
684 | by SCSH, the Scheme Shell. It is intended to be upwardly compatible | |
685 | with SCSH regular expressions. | |
686 | ||
687 | **** Function: string-match PATTERN STR [START] | |
688 | Compile the string PATTERN into a regular expression and compare | |
689 | it with STR. The optional numeric argument START specifies the | |
690 | position of STR at which to begin matching. | |
691 | ||
692 | `string-match' returns a "match structure" which describes what, | |
693 | if anything, was matched by the regular expression. *Note Match | |
694 | Structures::. If STR does not match PATTERN at all, | |
695 | `string-match' returns `#f'. | |
696 | ||
697 | Each time `string-match' is called, it must compile its PATTERN | |
698 | argument into a regular expression structure. This operation is | |
699 | expensive, which makes `string-match' inefficient if the same regular | |
700 | expression is used several times (for example, in a loop). For better | |
701 | performance, you can compile a regular expression in advance and then | |
702 | match strings against the compiled regexp. | |
703 | ||
704 | **** Function: make-regexp STR [FLAGS] | |
705 | Compile the regular expression described by STR, and return the | |
706 | compiled regexp structure. If STR does not describe a legal | |
707 | regular expression, `make-regexp' throws a | |
708 | `regular-expression-syntax' error. | |
709 | ||
710 | FLAGS may be the bitwise-or of one or more of the following: | |
711 | ||
712 | **** Constant: regexp/extended | |
713 | Use POSIX Extended Regular Expression syntax when interpreting | |
714 | STR. If not set, POSIX Basic Regular Expression syntax is used. | |
715 | If the FLAGS argument is omitted, we assume regexp/extended. | |
716 | ||
717 | **** Constant: regexp/icase | |
718 | Do not differentiate case. Subsequent searches using the | |
719 | returned regular expression will be case insensitive. | |
720 | ||
721 | **** Constant: regexp/newline | |
722 | Match-any-character operators don't match a newline. | |
723 | ||
724 | A non-matching list ([^...]) not containing a newline matches a | |
725 | newline. | |
726 | ||
727 | Match-beginning-of-line operator (^) matches the empty string | |
728 | immediately after a newline, regardless of whether the FLAGS | |
729 | passed to regexp-exec contain regexp/notbol. | |
730 | ||
731 | Match-end-of-line operator ($) matches the empty string | |
732 | immediately before a newline, regardless of whether the FLAGS | |
733 | passed to regexp-exec contain regexp/noteol. | |
734 | ||
735 | **** Function: regexp-exec REGEXP STR [START [FLAGS]] | |
736 | Match the compiled regular expression REGEXP against `str'. If | |
737 | the optional integer START argument is provided, begin matching | |
738 | from that position in the string. Return a match structure | |
739 | describing the results of the match, or `#f' if no match could be | |
740 | found. | |
741 | ||
742 | FLAGS may be the bitwise-or of one or more of the following: | |
743 | ||
744 | **** Constant: regexp/notbol | |
745 | The match-beginning-of-line operator always fails to match (but | |
746 | see the compilation flag regexp/newline above) This flag may be | |
747 | used when different portions of a string are passed to | |
748 | regexp-exec and the beginning of the string should not be | |
749 | interpreted as the beginning of the line. | |
750 | ||
751 | **** Constant: regexp/noteol | |
752 | The match-end-of-line operator always fails to match (but see the | |
753 | compilation flag regexp/newline above) | |
754 | ||
755 | **** Function: regexp? OBJ | |
756 | Return `#t' if OBJ is a compiled regular expression, or `#f' | |
757 | otherwise. | |
758 | ||
759 | Regular expressions are commonly used to find patterns in one string | |
760 | and replace them with the contents of another string. | |
761 | ||
762 | **** Function: regexp-substitute PORT MATCH [ITEM...] | |
763 | Write to the output port PORT selected contents of the match | |
764 | structure MATCH. Each ITEM specifies what should be written, and | |
765 | may be one of the following arguments: | |
766 | ||
767 | * A string. String arguments are written out verbatim. | |
768 | ||
769 | * An integer. The submatch with that number is written. | |
770 | ||
771 | * The symbol `pre'. The portion of the matched string preceding | |
772 | the regexp match is written. | |
773 | ||
774 | * The symbol `post'. The portion of the matched string | |
775 | following the regexp match is written. | |
776 | ||
777 | PORT may be `#f', in which case nothing is written; instead, | |
778 | `regexp-substitute' constructs a string from the specified ITEMs | |
779 | and returns that. | |
780 | ||
781 | **** Function: regexp-substitute/global PORT REGEXP TARGET [ITEM...] | |
782 | Similar to `regexp-substitute', but can be used to perform global | |
783 | substitutions on STR. Instead of taking a match structure as an | |
784 | argument, `regexp-substitute/global' takes two string arguments: a | |
785 | REGEXP string describing a regular expression, and a TARGET string | |
786 | which should be matched against this regular expression. | |
787 | ||
788 | Each ITEM behaves as in REGEXP-SUBSTITUTE, with the following | |
789 | exceptions: | |
790 | ||
791 | * A function may be supplied. When this function is called, it | |
792 | will be passed one argument: a match structure for a given | |
793 | regular expression match. It should return a string to be | |
794 | written out to PORT. | |
795 | ||
796 | * The `post' symbol causes `regexp-substitute/global' to recurse | |
797 | on the unmatched portion of STR. This *must* be supplied in | |
798 | order to perform global search-and-replace on STR; if it is | |
799 | not present among the ITEMs, then `regexp-substitute/global' | |
800 | will return after processing a single match. | |
801 | ||
802 | *** Match Structures | |
803 | ||
804 | A "match structure" is the object returned by `string-match' and | |
805 | `regexp-exec'. It describes which portion of a string, if any, matched | |
806 | the given regular expression. Match structures include: a reference to | |
807 | the string that was checked for matches; the starting and ending | |
808 | positions of the regexp match; and, if the regexp included any | |
809 | parenthesized subexpressions, the starting and ending positions of each | |
810 | submatch. | |
811 | ||
812 | In each of the regexp match functions described below, the `match' | |
813 | argument must be a match structure returned by a previous call to | |
814 | `string-match' or `regexp-exec'. Most of these functions return some | |
815 | information about the original target string that was matched against a | |
816 | regular expression; we will call that string TARGET for easy reference. | |
817 | ||
818 | **** Function: regexp-match? OBJ | |
819 | Return `#t' if OBJ is a match structure returned by a previous | |
820 | call to `regexp-exec', or `#f' otherwise. | |
821 | ||
822 | **** Function: match:substring MATCH [N] | |
823 | Return the portion of TARGET matched by subexpression number N. | |
824 | Submatch 0 (the default) represents the entire regexp match. If | |
825 | the regular expression as a whole matched, but the subexpression | |
826 | number N did not match, return `#f'. | |
827 | ||
828 | **** Function: match:start MATCH [N] | |
829 | Return the starting position of submatch number N. | |
830 | ||
831 | **** Function: match:end MATCH [N] | |
832 | Return the ending position of submatch number N. | |
833 | ||
834 | **** Function: match:prefix MATCH | |
835 | Return the unmatched portion of TARGET preceding the regexp match. | |
836 | ||
837 | **** Function: match:suffix MATCH | |
838 | Return the unmatched portion of TARGET following the regexp match. | |
839 | ||
840 | **** Function: match:count MATCH | |
841 | Return the number of parenthesized subexpressions from MATCH. | |
842 | Note that the entire regular expression match itself counts as a | |
843 | subexpression, and failed submatches are included in the count. | |
844 | ||
845 | **** Function: match:string MATCH | |
846 | Return the original TARGET string. | |
847 | ||
848 | *** Backslash Escapes | |
849 | ||
850 | Sometimes you will want a regexp to match characters like `*' or `$' | |
851 | exactly. For example, to check whether a particular string represents | |
852 | a menu entry from an Info node, it would be useful to match it against | |
853 | a regexp like `^* [^:]*::'. However, this won't work; because the | |
854 | asterisk is a metacharacter, it won't match the `*' at the beginning of | |
855 | the string. In this case, we want to make the first asterisk un-magic. | |
856 | ||
857 | You can do this by preceding the metacharacter with a backslash | |
858 | character `\'. (This is also called "quoting" the metacharacter, and | |
859 | is known as a "backslash escape".) When Guile sees a backslash in a | |
860 | regular expression, it considers the following glyph to be an ordinary | |
861 | character, no matter what special meaning it would ordinarily have. | |
862 | Therefore, we can make the above example work by changing the regexp to | |
863 | `^\* [^:]*::'. The `\*' sequence tells the regular expression engine | |
864 | to match only a single asterisk in the target string. | |
865 | ||
866 | Since the backslash is itself a metacharacter, you may force a | |
867 | regexp to match a backslash in the target string by preceding the | |
868 | backslash with itself. For example, to find variable references in a | |
869 | TeX program, you might want to find occurrences of the string `\let\' | |
870 | followed by any number of alphabetic characters. The regular expression | |
871 | `\\let\\[A-Za-z]*' would do this: the double backslashes in the regexp | |
872 | each match a single backslash in the target string. | |
873 | ||
874 | **** Function: regexp-quote STR | |
875 | Quote each special character found in STR with a backslash, and | |
876 | return the resulting string. | |
877 | ||
878 | *Very important:* Using backslash escapes in Guile source code (as | |
879 | in Emacs Lisp or C) can be tricky, because the backslash character has | |
880 | special meaning for the Guile reader. For example, if Guile encounters | |
881 | the character sequence `\n' in the middle of a string while processing | |
882 | Scheme code, it replaces those characters with a newline character. | |
883 | Similarly, the character sequence `\t' is replaced by a horizontal tab. | |
884 | Several of these "escape sequences" are processed by the Guile reader | |
885 | before your code is executed. Unrecognized escape sequences are | |
886 | ignored: if the characters `\*' appear in a string, they will be | |
887 | translated to the single character `*'. | |
888 | ||
889 | This translation is obviously undesirable for regular expressions, | |
890 | since we want to be able to include backslashes in a string in order to | |
891 | escape regexp metacharacters. Therefore, to make sure that a backslash | |
892 | is preserved in a string in your Guile program, you must use *two* | |
893 | consecutive backslashes: | |
894 | ||
895 | (define Info-menu-entry-pattern (make-regexp "^\\* [^:]*")) | |
896 | ||
897 | The string in this example is preprocessed by the Guile reader before | |
898 | any code is executed. The resulting argument to `make-regexp' is the | |
899 | string `^\* [^:]*', which is what we really want. | |
900 | ||
901 | This also means that in order to write a regular expression that | |
902 | matches a single backslash character, the regular expression string in | |
903 | the source code must include *four* backslashes. Each consecutive pair | |
904 | of backslashes gets translated by the Guile reader to a single | |
905 | backslash, and the resulting double-backslash is interpreted by the | |
906 | regexp engine as matching a single backslash character. Hence: | |
907 | ||
908 | (define tex-variable-pattern (make-regexp "\\\\let\\\\=[A-Za-z]*")) | |
909 | ||
910 | The reason for the unwieldiness of this syntax is historical. Both | |
911 | regular expression pattern matchers and Unix string processing systems | |
912 | have traditionally used backslashes with the special meanings described | |
913 | above. The POSIX regular expression specification and ANSI C standard | |
914 | both require these semantics. Attempting to abandon either convention | |
915 | would cause other kinds of compatibility problems, possibly more severe | |
916 | ones. Therefore, without extending the Scheme reader to support | |
917 | strings with different quoting conventions (an ungainly and confusing | |
918 | extension when implemented in other languages), we must adhere to this | |
919 | cumbersome escape syntax. | |
920 | ||
7ad3c1e7 GH |
921 | * Changes to the gh_ interface |
922 | ||
923 | * Changes to the scm_ interface | |
924 | ||
925 | * Changes to system call interfaces: | |
94982a4e | 926 | |
7ad3c1e7 | 927 | ** The value returned by `raise' is now unspecified. It throws an exception |
e1a191a8 GH |
928 | if an error occurs. |
929 | ||
94982a4e | 930 | *** A new procedure `sigaction' can be used to install signal handlers |
115b09a5 GH |
931 | |
932 | (sigaction signum [action] [flags]) | |
933 | ||
934 | signum is the signal number, which can be specified using the value | |
935 | of SIGINT etc. | |
936 | ||
937 | If action is omitted, sigaction returns a pair: the CAR is the current | |
938 | signal hander, which will be either an integer with the value SIG_DFL | |
939 | (default action) or SIG_IGN (ignore), or the Scheme procedure which | |
940 | handles the signal, or #f if a non-Scheme procedure handles the | |
941 | signal. The CDR contains the current sigaction flags for the handler. | |
942 | ||
943 | If action is provided, it is installed as the new handler for signum. | |
944 | action can be a Scheme procedure taking one argument, or the value of | |
945 | SIG_DFL (default action) or SIG_IGN (ignore), or #f to restore | |
946 | whatever signal handler was installed before sigaction was first used. | |
947 | Flags can optionally be specified for the new handler (SA_RESTART is | |
948 | always used if the system provides it, so need not be specified.) The | |
949 | return value is a pair with information about the old handler as | |
950 | described above. | |
951 | ||
952 | This interface does not provide access to the "signal blocking" | |
953 | facility. Maybe this is not needed, since the thread support may | |
954 | provide solutions to the problem of consistent access to data | |
955 | structures. | |
e1a191a8 | 956 | |
94982a4e | 957 | *** A new procedure `flush-all-ports' is equivalent to running |
89ea5b7c GH |
958 | `force-output' on every port open for output. |
959 | ||
94982a4e JB |
960 | ** Guile now provides information on how it was built, via the new |
961 | global variable, %guile-build-info. This variable records the values | |
962 | of the standard GNU makefile directory variables as an assocation | |
963 | list, mapping variable names (symbols) onto directory paths (strings). | |
964 | For example, to find out where the Guile link libraries were | |
965 | installed, you can say: | |
966 | ||
967 | guile -c "(display (assq-ref %guile-build-info 'libdir)) (newline)" | |
968 | ||
969 | ||
970 | * Changes to the scm_ interface | |
971 | ||
972 | ** The new function scm_handle_by_message_noexit is just like the | |
973 | existing scm_handle_by_message function, except that it doesn't call | |
974 | exit to terminate the process. Instead, it prints a message and just | |
975 | returns #f. This might be a more appropriate catch-all handler for | |
976 | new dynamic roots and threads. | |
977 | ||
cf78e9e8 | 978 | \f |
c484bf7f | 979 | Changes in Guile 1.1 (released Friday, May 16 1997): |
f3b1485f JB |
980 | |
981 | * Changes to the distribution. | |
982 | ||
983 | The Guile 1.0 distribution has been split up into several smaller | |
984 | pieces: | |
985 | guile-core --- the Guile interpreter itself. | |
986 | guile-tcltk --- the interface between the Guile interpreter and | |
987 | Tcl/Tk; Tcl is an interpreter for a stringy language, and Tk | |
988 | is a toolkit for building graphical user interfaces. | |
989 | guile-rgx-ctax --- the interface between Guile and the Rx regular | |
990 | expression matcher, and the translator for the Ctax | |
991 | programming language. These are packaged together because the | |
992 | Ctax translator uses Rx to parse Ctax source code. | |
993 | ||
095936d2 JB |
994 | This NEWS file describes the changes made to guile-core since the 1.0 |
995 | release. | |
996 | ||
48d224d7 JB |
997 | We no longer distribute the documentation, since it was either out of |
998 | date, or incomplete. As soon as we have current documentation, we | |
999 | will distribute it. | |
1000 | ||
0fcab5ed JB |
1001 | |
1002 | ||
f3b1485f JB |
1003 | * Changes to the stand-alone interpreter |
1004 | ||
48d224d7 JB |
1005 | ** guile now accepts command-line arguments compatible with SCSH, Olin |
1006 | Shivers' Scheme Shell. | |
1007 | ||
1008 | In general, arguments are evaluated from left to right, but there are | |
1009 | exceptions. The following switches stop argument processing, and | |
1010 | stash all remaining command-line arguments as the value returned by | |
1011 | the (command-line) function. | |
1012 | -s SCRIPT load Scheme source code from FILE, and exit | |
1013 | -c EXPR evalute Scheme expression EXPR, and exit | |
1014 | -- stop scanning arguments; run interactively | |
1015 | ||
1016 | The switches below are processed as they are encountered. | |
1017 | -l FILE load Scheme source code from FILE | |
1018 | -e FUNCTION after reading script, apply FUNCTION to | |
1019 | command line arguments | |
1020 | -ds do -s script at this point | |
1021 | --emacs enable Emacs protocol (experimental) | |
1022 | -h, --help display this help and exit | |
1023 | -v, --version display version information and exit | |
1024 | \ read arguments from following script lines | |
1025 | ||
1026 | So, for example, here is a Guile script named `ekko' (thanks, Olin) | |
1027 | which re-implements the traditional "echo" command: | |
1028 | ||
1029 | #!/usr/local/bin/guile -s | |
1030 | !# | |
1031 | (define (main args) | |
1032 | (map (lambda (arg) (display arg) (display " ")) | |
1033 | (cdr args)) | |
1034 | (newline)) | |
1035 | ||
1036 | (main (command-line)) | |
1037 | ||
1038 | Suppose we invoke this script as follows: | |
1039 | ||
1040 | ekko a speckled gecko | |
1041 | ||
1042 | Through the magic of Unix script processing (triggered by the `#!' | |
1043 | token at the top of the file), /usr/local/bin/guile receives the | |
1044 | following list of command-line arguments: | |
1045 | ||
1046 | ("-s" "./ekko" "a" "speckled" "gecko") | |
1047 | ||
1048 | Unix inserts the name of the script after the argument specified on | |
1049 | the first line of the file (in this case, "-s"), and then follows that | |
1050 | with the arguments given to the script. Guile loads the script, which | |
1051 | defines the `main' function, and then applies it to the list of | |
1052 | remaining command-line arguments, ("a" "speckled" "gecko"). | |
1053 | ||
095936d2 JB |
1054 | In Unix, the first line of a script file must take the following form: |
1055 | ||
1056 | #!INTERPRETER ARGUMENT | |
1057 | ||
1058 | where INTERPRETER is the absolute filename of the interpreter | |
1059 | executable, and ARGUMENT is a single command-line argument to pass to | |
1060 | the interpreter. | |
1061 | ||
1062 | You may only pass one argument to the interpreter, and its length is | |
1063 | limited. These restrictions can be annoying to work around, so Guile | |
1064 | provides a general mechanism (borrowed from, and compatible with, | |
1065 | SCSH) for circumventing them. | |
1066 | ||
1067 | If the ARGUMENT in a Guile script is a single backslash character, | |
1068 | `\', Guile will open the script file, parse arguments from its second | |
1069 | and subsequent lines, and replace the `\' with them. So, for example, | |
1070 | here is another implementation of the `ekko' script: | |
1071 | ||
1072 | #!/usr/local/bin/guile \ | |
1073 | -e main -s | |
1074 | !# | |
1075 | (define (main args) | |
1076 | (for-each (lambda (arg) (display arg) (display " ")) | |
1077 | (cdr args)) | |
1078 | (newline)) | |
1079 | ||
1080 | If the user invokes this script as follows: | |
1081 | ||
1082 | ekko a speckled gecko | |
1083 | ||
1084 | Unix expands this into | |
1085 | ||
1086 | /usr/local/bin/guile \ ekko a speckled gecko | |
1087 | ||
1088 | When Guile sees the `\' argument, it replaces it with the arguments | |
1089 | read from the second line of the script, producing: | |
1090 | ||
1091 | /usr/local/bin/guile -e main -s ekko a speckled gecko | |
1092 | ||
1093 | This tells Guile to load the `ekko' script, and apply the function | |
1094 | `main' to the argument list ("a" "speckled" "gecko"). | |
1095 | ||
1096 | Here is how Guile parses the command-line arguments: | |
1097 | - Each space character terminates an argument. This means that two | |
1098 | spaces in a row introduce an empty-string argument. | |
1099 | - The tab character is not permitted (unless you quote it with the | |
1100 | backslash character, as described below), to avoid confusion. | |
1101 | - The newline character terminates the sequence of arguments, and will | |
1102 | also terminate a final non-empty argument. (However, a newline | |
1103 | following a space will not introduce a final empty-string argument; | |
1104 | it only terminates the argument list.) | |
1105 | - The backslash character is the escape character. It escapes | |
1106 | backslash, space, tab, and newline. The ANSI C escape sequences | |
1107 | like \n and \t are also supported. These produce argument | |
1108 | constituents; the two-character combination \n doesn't act like a | |
1109 | terminating newline. The escape sequence \NNN for exactly three | |
1110 | octal digits reads as the character whose ASCII code is NNN. As | |
1111 | above, characters produced this way are argument constituents. | |
1112 | Backslash followed by other characters is not allowed. | |
1113 | ||
48d224d7 JB |
1114 | * Changes to the procedure for linking libguile with your programs |
1115 | ||
1116 | ** Guile now builds and installs a shared guile library, if your | |
1117 | system support shared libraries. (It still builds a static library on | |
1118 | all systems.) Guile automatically detects whether your system | |
1119 | supports shared libraries. To prevent Guile from buildisg shared | |
1120 | libraries, pass the `--disable-shared' flag to the configure script. | |
1121 | ||
1122 | Guile takes longer to compile when it builds shared libraries, because | |
1123 | it must compile every file twice --- once to produce position- | |
1124 | independent object code, and once to produce normal object code. | |
1125 | ||
1126 | ** The libthreads library has been merged into libguile. | |
1127 | ||
1128 | To link a program against Guile, you now need only link against | |
1129 | -lguile and -lqt; -lthreads is no longer needed. If you are using | |
1130 | autoconf to generate configuration scripts for your application, the | |
1131 | following lines should suffice to add the appropriate libraries to | |
1132 | your link command: | |
1133 | ||
1134 | ### Find quickthreads and libguile. | |
1135 | AC_CHECK_LIB(qt, main) | |
1136 | AC_CHECK_LIB(guile, scm_shell) | |
f3b1485f JB |
1137 | |
1138 | * Changes to Scheme functions | |
1139 | ||
095936d2 JB |
1140 | ** Guile Scheme's special syntax for keyword objects is now optional, |
1141 | and disabled by default. | |
1142 | ||
1143 | The syntax variation from R4RS made it difficult to port some | |
1144 | interesting packages to Guile. The routines which accepted keyword | |
1145 | arguments (mostly in the module system) have been modified to also | |
1146 | accept symbols whose names begin with `:'. | |
1147 | ||
1148 | To change the keyword syntax, you must first import the (ice-9 debug) | |
1149 | module: | |
1150 | (use-modules (ice-9 debug)) | |
1151 | ||
1152 | Then you can enable the keyword syntax as follows: | |
1153 | (read-set! keywords 'prefix) | |
1154 | ||
1155 | To disable keyword syntax, do this: | |
1156 | (read-set! keywords #f) | |
1157 | ||
1158 | ** Many more primitive functions accept shared substrings as | |
1159 | arguments. In the past, these functions required normal, mutable | |
1160 | strings as arguments, although they never made use of this | |
1161 | restriction. | |
1162 | ||
1163 | ** The uniform array functions now operate on byte vectors. These | |
1164 | functions are `array-fill!', `serial-array-copy!', `array-copy!', | |
1165 | `serial-array-map', `array-map', `array-for-each', and | |
1166 | `array-index-map!'. | |
1167 | ||
1168 | ** The new functions `trace' and `untrace' implement simple debugging | |
1169 | support for Scheme functions. | |
1170 | ||
1171 | The `trace' function accepts any number of procedures as arguments, | |
1172 | and tells the Guile interpreter to display each procedure's name and | |
1173 | arguments each time the procedure is invoked. When invoked with no | |
1174 | arguments, `trace' returns the list of procedures currently being | |
1175 | traced. | |
1176 | ||
1177 | The `untrace' function accepts any number of procedures as arguments, | |
1178 | and tells the Guile interpreter not to trace them any more. When | |
1179 | invoked with no arguments, `untrace' untraces all curretly traced | |
1180 | procedures. | |
1181 | ||
1182 | The tracing in Guile has an advantage over most other systems: we | |
1183 | don't create new procedure objects, but mark the procedure objects | |
1184 | themselves. This means that anonymous and internal procedures can be | |
1185 | traced. | |
1186 | ||
1187 | ** The function `assert-repl-prompt' has been renamed to | |
1188 | `set-repl-prompt!'. It takes one argument, PROMPT. | |
1189 | - If PROMPT is #f, the Guile read-eval-print loop will not prompt. | |
1190 | - If PROMPT is a string, we use it as a prompt. | |
1191 | - If PROMPT is a procedure accepting no arguments, we call it, and | |
1192 | display the result as a prompt. | |
1193 | - Otherwise, we display "> ". | |
1194 | ||
1195 | ** The new function `eval-string' reads Scheme expressions from a | |
1196 | string and evaluates them, returning the value of the last expression | |
1197 | in the string. If the string contains no expressions, it returns an | |
1198 | unspecified value. | |
1199 | ||
1200 | ** The new function `thunk?' returns true iff its argument is a | |
1201 | procedure of zero arguments. | |
1202 | ||
1203 | ** `defined?' is now a builtin function, instead of syntax. This | |
1204 | means that its argument should be quoted. It returns #t iff its | |
1205 | argument is bound in the current module. | |
1206 | ||
1207 | ** The new syntax `use-modules' allows you to add new modules to your | |
1208 | environment without re-typing a complete `define-module' form. It | |
1209 | accepts any number of module names as arguments, and imports their | |
1210 | public bindings into the current module. | |
1211 | ||
1212 | ** The new function (module-defined? NAME MODULE) returns true iff | |
1213 | NAME, a symbol, is defined in MODULE, a module object. | |
1214 | ||
1215 | ** The new function `builtin-bindings' creates and returns a hash | |
1216 | table containing copies of all the root module's bindings. | |
1217 | ||
1218 | ** The new function `builtin-weak-bindings' does the same as | |
1219 | `builtin-bindings', but creates a doubly-weak hash table. | |
1220 | ||
1221 | ** The `equal?' function now considers variable objects to be | |
1222 | equivalent if they have the same name and the same value. | |
1223 | ||
1224 | ** The new function `command-line' returns the command-line arguments | |
1225 | given to Guile, as a list of strings. | |
1226 | ||
1227 | When using guile as a script interpreter, `command-line' returns the | |
1228 | script's arguments; those processed by the interpreter (like `-s' or | |
1229 | `-c') are omitted. (In other words, you get the normal, expected | |
1230 | behavior.) Any application that uses scm_shell to process its | |
1231 | command-line arguments gets this behavior as well. | |
1232 | ||
1233 | ** The new function `load-user-init' looks for a file called `.guile' | |
1234 | in the user's home directory, and loads it if it exists. This is | |
1235 | mostly for use by the code generated by scm_compile_shell_switches, | |
1236 | but we thought it might also be useful in other circumstances. | |
1237 | ||
1238 | ** The new function `log10' returns the base-10 logarithm of its | |
1239 | argument. | |
1240 | ||
1241 | ** Changes to I/O functions | |
1242 | ||
1243 | *** The functions `read', `primitive-load', `read-and-eval!', and | |
1244 | `primitive-load-path' no longer take optional arguments controlling | |
1245 | case insensitivity and a `#' parser. | |
1246 | ||
1247 | Case sensitivity is now controlled by a read option called | |
1248 | `case-insensitive'. The user can add new `#' syntaxes with the | |
1249 | `read-hash-extend' function (see below). | |
1250 | ||
1251 | *** The new function `read-hash-extend' allows the user to change the | |
1252 | syntax of Guile Scheme in a somewhat controlled way. | |
1253 | ||
1254 | (read-hash-extend CHAR PROC) | |
1255 | When parsing S-expressions, if we read a `#' character followed by | |
1256 | the character CHAR, use PROC to parse an object from the stream. | |
1257 | If PROC is #f, remove any parsing procedure registered for CHAR. | |
1258 | ||
1259 | The reader applies PROC to two arguments: CHAR and an input port. | |
1260 | ||
1261 | *** The new functions read-delimited and read-delimited! provide a | |
1262 | general mechanism for doing delimited input on streams. | |
1263 | ||
1264 | (read-delimited DELIMS [PORT HANDLE-DELIM]) | |
1265 | Read until we encounter one of the characters in DELIMS (a string), | |
1266 | or end-of-file. PORT is the input port to read from; it defaults to | |
1267 | the current input port. The HANDLE-DELIM parameter determines how | |
1268 | the terminating character is handled; it should be one of the | |
1269 | following symbols: | |
1270 | ||
1271 | 'trim omit delimiter from result | |
1272 | 'peek leave delimiter character in input stream | |
1273 | 'concat append delimiter character to returned value | |
1274 | 'split return a pair: (RESULT . TERMINATOR) | |
1275 | ||
1276 | HANDLE-DELIM defaults to 'peek. | |
1277 | ||
1278 | (read-delimited! DELIMS BUF [PORT HANDLE-DELIM START END]) | |
1279 | A side-effecting variant of `read-delimited'. | |
1280 | ||
1281 | The data is written into the string BUF at the indices in the | |
1282 | half-open interval [START, END); the default interval is the whole | |
1283 | string: START = 0 and END = (string-length BUF). The values of | |
1284 | START and END must specify a well-defined interval in BUF, i.e. | |
1285 | 0 <= START <= END <= (string-length BUF). | |
1286 | ||
1287 | It returns NBYTES, the number of bytes read. If the buffer filled | |
1288 | up without a delimiter character being found, it returns #f. If the | |
1289 | port is at EOF when the read starts, it returns the EOF object. | |
1290 | ||
1291 | If an integer is returned (i.e., the read is successfully terminated | |
1292 | by reading a delimiter character), then the HANDLE-DELIM parameter | |
1293 | determines how to handle the terminating character. It is described | |
1294 | above, and defaults to 'peek. | |
1295 | ||
1296 | (The descriptions of these functions were borrowed from the SCSH | |
1297 | manual, by Olin Shivers and Brian Carlstrom.) | |
1298 | ||
1299 | *** The `%read-delimited!' function is the primitive used to implement | |
1300 | `read-delimited' and `read-delimited!'. | |
1301 | ||
1302 | (%read-delimited! DELIMS BUF GOBBLE? [PORT START END]) | |
1303 | ||
1304 | This returns a pair of values: (TERMINATOR . NUM-READ). | |
1305 | - TERMINATOR describes why the read was terminated. If it is a | |
1306 | character or the eof object, then that is the value that terminated | |
1307 | the read. If it is #f, the function filled the buffer without finding | |
1308 | a delimiting character. | |
1309 | - NUM-READ is the number of characters read into BUF. | |
1310 | ||
1311 | If the read is successfully terminated by reading a delimiter | |
1312 | character, then the gobble? parameter determines what to do with the | |
1313 | terminating character. If true, the character is removed from the | |
1314 | input stream; if false, the character is left in the input stream | |
1315 | where a subsequent read operation will retrieve it. In either case, | |
1316 | the character is also the first value returned by the procedure call. | |
1317 | ||
1318 | (The descriptions of this function was borrowed from the SCSH manual, | |
1319 | by Olin Shivers and Brian Carlstrom.) | |
1320 | ||
1321 | *** The `read-line' and `read-line!' functions have changed; they now | |
1322 | trim the terminator by default; previously they appended it to the | |
1323 | returned string. For the old behavior, use (read-line PORT 'concat). | |
1324 | ||
1325 | *** The functions `uniform-array-read!' and `uniform-array-write!' now | |
1326 | take new optional START and END arguments, specifying the region of | |
1327 | the array to read and write. | |
1328 | ||
f348c807 JB |
1329 | *** The `ungetc-char-ready?' function has been removed. We feel it's |
1330 | inappropriate for an interface to expose implementation details this | |
1331 | way. | |
095936d2 JB |
1332 | |
1333 | ** Changes to the Unix library and system call interface | |
1334 | ||
1335 | *** The new fcntl function provides access to the Unix `fcntl' system | |
1336 | call. | |
1337 | ||
1338 | (fcntl PORT COMMAND VALUE) | |
1339 | Apply COMMAND to PORT's file descriptor, with VALUE as an argument. | |
1340 | Values for COMMAND are: | |
1341 | ||
1342 | F_DUPFD duplicate a file descriptor | |
1343 | F_GETFD read the descriptor's close-on-exec flag | |
1344 | F_SETFD set the descriptor's close-on-exec flag to VALUE | |
1345 | F_GETFL read the descriptor's flags, as set on open | |
1346 | F_SETFL set the descriptor's flags, as set on open to VALUE | |
1347 | F_GETOWN return the process ID of a socket's owner, for SIGIO | |
1348 | F_SETOWN set the process that owns a socket to VALUE, for SIGIO | |
1349 | FD_CLOEXEC not sure what this is | |
1350 | ||
1351 | For details, see the documentation for the fcntl system call. | |
1352 | ||
1353 | *** The arguments to `select' have changed, for compatibility with | |
1354 | SCSH. The TIMEOUT parameter may now be non-integral, yielding the | |
1355 | expected behavior. The MILLISECONDS parameter has been changed to | |
1356 | MICROSECONDS, to more closely resemble the underlying system call. | |
1357 | The RVEC, WVEC, and EVEC arguments can now be vectors; the type of the | |
1358 | corresponding return set will be the same. | |
1359 | ||
1360 | *** The arguments to the `mknod' system call have changed. They are | |
1361 | now: | |
1362 | ||
1363 | (mknod PATH TYPE PERMS DEV) | |
1364 | Create a new file (`node') in the file system. PATH is the name of | |
1365 | the file to create. TYPE is the kind of file to create; it should | |
1366 | be 'fifo, 'block-special, or 'char-special. PERMS specifies the | |
1367 | permission bits to give the newly created file. If TYPE is | |
1368 | 'block-special or 'char-special, DEV specifies which device the | |
1369 | special file refers to; its interpretation depends on the kind of | |
1370 | special file being created. | |
1371 | ||
1372 | *** The `fork' function has been renamed to `primitive-fork', to avoid | |
1373 | clashing with various SCSH forks. | |
1374 | ||
1375 | *** The `recv' and `recvfrom' functions have been renamed to `recv!' | |
1376 | and `recvfrom!'. They no longer accept a size for a second argument; | |
1377 | you must pass a string to hold the received value. They no longer | |
1378 | return the buffer. Instead, `recv' returns the length of the message | |
1379 | received, and `recvfrom' returns a pair containing the packet's length | |
1380 | and originating address. | |
1381 | ||
1382 | *** The file descriptor datatype has been removed, as have the | |
1383 | `read-fd', `write-fd', `close', `lseek', and `dup' functions. | |
1384 | We plan to replace these functions with a SCSH-compatible interface. | |
1385 | ||
1386 | *** The `create' function has been removed; it's just a special case | |
1387 | of `open'. | |
1388 | ||
1389 | *** There are new functions to break down process termination status | |
1390 | values. In the descriptions below, STATUS is a value returned by | |
1391 | `waitpid'. | |
1392 | ||
1393 | (status:exit-val STATUS) | |
1394 | If the child process exited normally, this function returns the exit | |
1395 | code for the child process (i.e., the value passed to exit, or | |
1396 | returned from main). If the child process did not exit normally, | |
1397 | this function returns #f. | |
1398 | ||
1399 | (status:stop-sig STATUS) | |
1400 | If the child process was suspended by a signal, this function | |
1401 | returns the signal that suspended the child. Otherwise, it returns | |
1402 | #f. | |
1403 | ||
1404 | (status:term-sig STATUS) | |
1405 | If the child process terminated abnormally, this function returns | |
1406 | the signal that terminated the child. Otherwise, this function | |
1407 | returns false. | |
1408 | ||
1409 | POSIX promises that exactly one of these functions will return true on | |
1410 | a valid STATUS value. | |
1411 | ||
1412 | These functions are compatible with SCSH. | |
1413 | ||
1414 | *** There are new accessors and setters for the broken-out time vectors | |
48d224d7 JB |
1415 | returned by `localtime', `gmtime', and that ilk. They are: |
1416 | ||
1417 | Component Accessor Setter | |
1418 | ========================= ============ ============ | |
1419 | seconds tm:sec set-tm:sec | |
1420 | minutes tm:min set-tm:min | |
1421 | hours tm:hour set-tm:hour | |
1422 | day of the month tm:mday set-tm:mday | |
1423 | month tm:mon set-tm:mon | |
1424 | year tm:year set-tm:year | |
1425 | day of the week tm:wday set-tm:wday | |
1426 | day in the year tm:yday set-tm:yday | |
1427 | daylight saving time tm:isdst set-tm:isdst | |
1428 | GMT offset, seconds tm:gmtoff set-tm:gmtoff | |
1429 | name of time zone tm:zone set-tm:zone | |
1430 | ||
095936d2 JB |
1431 | *** There are new accessors for the vectors returned by `uname', |
1432 | describing the host system: | |
48d224d7 JB |
1433 | |
1434 | Component Accessor | |
1435 | ============================================== ================ | |
1436 | name of the operating system implementation utsname:sysname | |
1437 | network name of this machine utsname:nodename | |
1438 | release level of the operating system utsname:release | |
1439 | version level of the operating system utsname:version | |
1440 | machine hardware platform utsname:machine | |
1441 | ||
095936d2 JB |
1442 | *** There are new accessors for the vectors returned by `getpw', |
1443 | `getpwnam', `getpwuid', and `getpwent', describing entries from the | |
1444 | system's user database: | |
1445 | ||
1446 | Component Accessor | |
1447 | ====================== ================= | |
1448 | user name passwd:name | |
1449 | user password passwd:passwd | |
1450 | user id passwd:uid | |
1451 | group id passwd:gid | |
1452 | real name passwd:gecos | |
1453 | home directory passwd:dir | |
1454 | shell program passwd:shell | |
1455 | ||
1456 | *** There are new accessors for the vectors returned by `getgr', | |
1457 | `getgrnam', `getgrgid', and `getgrent', describing entries from the | |
1458 | system's group database: | |
1459 | ||
1460 | Component Accessor | |
1461 | ======================= ============ | |
1462 | group name group:name | |
1463 | group password group:passwd | |
1464 | group id group:gid | |
1465 | group members group:mem | |
1466 | ||
1467 | *** There are new accessors for the vectors returned by `gethost', | |
1468 | `gethostbyaddr', `gethostbyname', and `gethostent', describing | |
1469 | internet hosts: | |
1470 | ||
1471 | Component Accessor | |
1472 | ========================= =============== | |
1473 | official name of host hostent:name | |
1474 | alias list hostent:aliases | |
1475 | host address type hostent:addrtype | |
1476 | length of address hostent:length | |
1477 | list of addresses hostent:addr-list | |
1478 | ||
1479 | *** There are new accessors for the vectors returned by `getnet', | |
1480 | `getnetbyaddr', `getnetbyname', and `getnetent', describing internet | |
1481 | networks: | |
1482 | ||
1483 | Component Accessor | |
1484 | ========================= =============== | |
1485 | official name of net netent:name | |
1486 | alias list netent:aliases | |
1487 | net number type netent:addrtype | |
1488 | net number netent:net | |
1489 | ||
1490 | *** There are new accessors for the vectors returned by `getproto', | |
1491 | `getprotobyname', `getprotobynumber', and `getprotoent', describing | |
1492 | internet protocols: | |
1493 | ||
1494 | Component Accessor | |
1495 | ========================= =============== | |
1496 | official protocol name protoent:name | |
1497 | alias list protoent:aliases | |
1498 | protocol number protoent:proto | |
1499 | ||
1500 | *** There are new accessors for the vectors returned by `getserv', | |
1501 | `getservbyname', `getservbyport', and `getservent', describing | |
1502 | internet protocols: | |
1503 | ||
1504 | Component Accessor | |
1505 | ========================= =============== | |
1506 | official service name servent:name | |
1507 | alias list servent:aliases | |
1508 | port number servent:port | |
1509 | protocol to use servent:proto | |
1510 | ||
1511 | *** There are new accessors for the sockaddr structures returned by | |
1512 | `accept', `getsockname', `getpeername', `recvfrom!': | |
1513 | ||
1514 | Component Accessor | |
1515 | ======================================== =============== | |
1516 | address format (`family') sockaddr:fam | |
1517 | path, for file domain addresses sockaddr:path | |
1518 | address, for internet domain addresses sockaddr:addr | |
1519 | TCP or UDP port, for internet sockaddr:port | |
1520 | ||
1521 | *** The `getpwent', `getgrent', `gethostent', `getnetent', | |
1522 | `getprotoent', and `getservent' functions now return #f at the end of | |
1523 | the user database. (They used to throw an exception.) | |
1524 | ||
1525 | Note that calling MUMBLEent function is equivalent to calling the | |
1526 | corresponding MUMBLE function with no arguments. | |
1527 | ||
1528 | *** The `setpwent', `setgrent', `sethostent', `setnetent', | |
1529 | `setprotoent', and `setservent' routines now take no arguments. | |
1530 | ||
1531 | *** The `gethost', `getproto', `getnet', and `getserv' functions now | |
1532 | provide more useful information when they throw an exception. | |
1533 | ||
1534 | *** The `lnaof' function has been renamed to `inet-lnaof'. | |
1535 | ||
1536 | *** Guile now claims to have the `current-time' feature. | |
1537 | ||
1538 | *** The `mktime' function now takes an optional second argument ZONE, | |
1539 | giving the time zone to use for the conversion. ZONE should be a | |
1540 | string, in the same format as expected for the "TZ" environment variable. | |
1541 | ||
1542 | *** The `strptime' function now returns a pair (TIME . COUNT), where | |
1543 | TIME is the parsed time as a vector, and COUNT is the number of | |
1544 | characters from the string left unparsed. This function used to | |
1545 | return the remaining characters as a string. | |
1546 | ||
1547 | *** The `gettimeofday' function has replaced the old `time+ticks' function. | |
1548 | The return value is now (SECONDS . MICROSECONDS); the fractional | |
1549 | component is no longer expressed in "ticks". | |
1550 | ||
1551 | *** The `ticks/sec' constant has been removed, in light of the above change. | |
6685dc83 | 1552 | |
ea00ecba MG |
1553 | * Changes to the gh_ interface |
1554 | ||
1555 | ** gh_eval_str() now returns an SCM object which is the result of the | |
1556 | evaluation | |
1557 | ||
aaef0d2a MG |
1558 | ** gh_scm2str() now copies the Scheme data to a caller-provided C |
1559 | array | |
1560 | ||
1561 | ** gh_scm2newstr() now makes a C array, copies the Scheme data to it, | |
1562 | and returns the array | |
1563 | ||
1564 | ** gh_scm2str0() is gone: there is no need to distinguish | |
1565 | null-terminated from non-null-terminated, since gh_scm2newstr() allows | |
1566 | the user to interpret the data both ways. | |
1567 | ||
f3b1485f JB |
1568 | * Changes to the scm_ interface |
1569 | ||
095936d2 JB |
1570 | ** The new function scm_symbol_value0 provides an easy way to get a |
1571 | symbol's value from C code: | |
1572 | ||
1573 | SCM scm_symbol_value0 (char *NAME) | |
1574 | Return the value of the symbol named by the null-terminated string | |
1575 | NAME in the current module. If the symbol named NAME is unbound in | |
1576 | the current module, return SCM_UNDEFINED. | |
1577 | ||
1578 | ** The new function scm_sysintern0 creates new top-level variables, | |
1579 | without assigning them a value. | |
1580 | ||
1581 | SCM scm_sysintern0 (char *NAME) | |
1582 | Create a new Scheme top-level variable named NAME. NAME is a | |
1583 | null-terminated string. Return the variable's value cell. | |
1584 | ||
1585 | ** The function scm_internal_catch is the guts of catch. It handles | |
1586 | all the mechanics of setting up a catch target, invoking the catch | |
1587 | body, and perhaps invoking the handler if the body does a throw. | |
1588 | ||
1589 | The function is designed to be usable from C code, but is general | |
1590 | enough to implement all the semantics Guile Scheme expects from throw. | |
1591 | ||
1592 | TAG is the catch tag. Typically, this is a symbol, but this function | |
1593 | doesn't actually care about that. | |
1594 | ||
1595 | BODY is a pointer to a C function which runs the body of the catch; | |
1596 | this is the code you can throw from. We call it like this: | |
1597 | BODY (BODY_DATA, JMPBUF) | |
1598 | where: | |
1599 | BODY_DATA is just the BODY_DATA argument we received; we pass it | |
1600 | through to BODY as its first argument. The caller can make | |
1601 | BODY_DATA point to anything useful that BODY might need. | |
1602 | JMPBUF is the Scheme jmpbuf object corresponding to this catch, | |
1603 | which we have just created and initialized. | |
1604 | ||
1605 | HANDLER is a pointer to a C function to deal with a throw to TAG, | |
1606 | should one occur. We call it like this: | |
1607 | HANDLER (HANDLER_DATA, THROWN_TAG, THROW_ARGS) | |
1608 | where | |
1609 | HANDLER_DATA is the HANDLER_DATA argument we recevied; it's the | |
1610 | same idea as BODY_DATA above. | |
1611 | THROWN_TAG is the tag that the user threw to; usually this is | |
1612 | TAG, but it could be something else if TAG was #t (i.e., a | |
1613 | catch-all), or the user threw to a jmpbuf. | |
1614 | THROW_ARGS is the list of arguments the user passed to the THROW | |
1615 | function. | |
1616 | ||
1617 | BODY_DATA is just a pointer we pass through to BODY. HANDLER_DATA | |
1618 | is just a pointer we pass through to HANDLER. We don't actually | |
1619 | use either of those pointers otherwise ourselves. The idea is | |
1620 | that, if our caller wants to communicate something to BODY or | |
1621 | HANDLER, it can pass a pointer to it as MUMBLE_DATA, which BODY and | |
1622 | HANDLER can then use. Think of it as a way to make BODY and | |
1623 | HANDLER closures, not just functions; MUMBLE_DATA points to the | |
1624 | enclosed variables. | |
1625 | ||
1626 | Of course, it's up to the caller to make sure that any data a | |
1627 | MUMBLE_DATA needs is protected from GC. A common way to do this is | |
1628 | to make MUMBLE_DATA a pointer to data stored in an automatic | |
1629 | structure variable; since the collector must scan the stack for | |
1630 | references anyway, this assures that any references in MUMBLE_DATA | |
1631 | will be found. | |
1632 | ||
1633 | ** The new function scm_internal_lazy_catch is exactly like | |
1634 | scm_internal_catch, except: | |
1635 | ||
1636 | - It does not unwind the stack (this is the major difference). | |
1637 | - If handler returns, its value is returned from the throw. | |
1638 | - BODY always receives #f as its JMPBUF argument (since there's no | |
1639 | jmpbuf associated with a lazy catch, because we don't unwind the | |
1640 | stack.) | |
1641 | ||
1642 | ** scm_body_thunk is a new body function you can pass to | |
1643 | scm_internal_catch if you want the body to be like Scheme's `catch' | |
1644 | --- a thunk, or a function of one argument if the tag is #f. | |
1645 | ||
1646 | BODY_DATA is a pointer to a scm_body_thunk_data structure, which | |
1647 | contains the Scheme procedure to invoke as the body, and the tag | |
1648 | we're catching. If the tag is #f, then we pass JMPBUF (created by | |
1649 | scm_internal_catch) to the body procedure; otherwise, the body gets | |
1650 | no arguments. | |
1651 | ||
1652 | ** scm_handle_by_proc is a new handler function you can pass to | |
1653 | scm_internal_catch if you want the handler to act like Scheme's catch | |
1654 | --- call a procedure with the tag and the throw arguments. | |
1655 | ||
1656 | If the user does a throw to this catch, this function runs a handler | |
1657 | procedure written in Scheme. HANDLER_DATA is a pointer to an SCM | |
1658 | variable holding the Scheme procedure object to invoke. It ought to | |
1659 | be a pointer to an automatic variable (i.e., one living on the stack), | |
1660 | or the procedure object should be otherwise protected from GC. | |
1661 | ||
1662 | ** scm_handle_by_message is a new handler function to use with | |
1663 | `scm_internal_catch' if you want Guile to print a message and die. | |
1664 | It's useful for dealing with throws to uncaught keys at the top level. | |
1665 | ||
1666 | HANDLER_DATA, if non-zero, is assumed to be a char * pointing to a | |
1667 | message header to print; if zero, we use "guile" instead. That | |
1668 | text is followed by a colon, then the message described by ARGS. | |
1669 | ||
1670 | ** The return type of scm_boot_guile is now void; the function does | |
1671 | not return a value, and indeed, never returns at all. | |
1672 | ||
f3b1485f JB |
1673 | ** The new function scm_shell makes it easy for user applications to |
1674 | process command-line arguments in a way that is compatible with the | |
1675 | stand-alone guile interpreter (which is in turn compatible with SCSH, | |
1676 | the Scheme shell). | |
1677 | ||
1678 | To use the scm_shell function, first initialize any guile modules | |
1679 | linked into your application, and then call scm_shell with the values | |
7ed46dc8 | 1680 | of ARGC and ARGV your `main' function received. scm_shell will add |
f3b1485f JB |
1681 | any SCSH-style meta-arguments from the top of the script file to the |
1682 | argument vector, and then process the command-line arguments. This | |
1683 | generally means loading a script file or starting up an interactive | |
1684 | command interpreter. For details, see "Changes to the stand-alone | |
1685 | interpreter" above. | |
1686 | ||
095936d2 JB |
1687 | ** The new functions scm_get_meta_args and scm_count_argv help you |
1688 | implement the SCSH-style meta-argument, `\'. | |
1689 | ||
1690 | char **scm_get_meta_args (int ARGC, char **ARGV) | |
1691 | If the second element of ARGV is a string consisting of a single | |
1692 | backslash character (i.e. "\\" in Scheme notation), open the file | |
1693 | named by the following argument, parse arguments from it, and return | |
1694 | the spliced command line. The returned array is terminated by a | |
1695 | null pointer. | |
1696 | ||
1697 | For details of argument parsing, see above, under "guile now accepts | |
1698 | command-line arguments compatible with SCSH..." | |
1699 | ||
1700 | int scm_count_argv (char **ARGV) | |
1701 | Count the arguments in ARGV, assuming it is terminated by a null | |
1702 | pointer. | |
1703 | ||
1704 | For an example of how these functions might be used, see the source | |
1705 | code for the function scm_shell in libguile/script.c. | |
1706 | ||
1707 | You will usually want to use scm_shell instead of calling this | |
1708 | function yourself. | |
1709 | ||
1710 | ** The new function scm_compile_shell_switches turns an array of | |
1711 | command-line arguments into Scheme code to carry out the actions they | |
1712 | describe. Given ARGC and ARGV, it returns a Scheme expression to | |
1713 | evaluate, and calls scm_set_program_arguments to make any remaining | |
1714 | command-line arguments available to the Scheme code. For example, | |
1715 | given the following arguments: | |
1716 | ||
1717 | -e main -s ekko a speckled gecko | |
1718 | ||
1719 | scm_set_program_arguments will return the following expression: | |
1720 | ||
1721 | (begin (load "ekko") (main (command-line)) (quit)) | |
1722 | ||
1723 | You will usually want to use scm_shell instead of calling this | |
1724 | function yourself. | |
1725 | ||
1726 | ** The function scm_shell_usage prints a usage message appropriate for | |
1727 | an interpreter that uses scm_compile_shell_switches to handle its | |
1728 | command-line arguments. | |
1729 | ||
1730 | void scm_shell_usage (int FATAL, char *MESSAGE) | |
1731 | Print a usage message to the standard error output. If MESSAGE is | |
1732 | non-zero, write it before the usage message, followed by a newline. | |
1733 | If FATAL is non-zero, exit the process, using FATAL as the | |
1734 | termination status. (If you want to be compatible with Guile, | |
1735 | always use 1 as the exit status when terminating due to command-line | |
1736 | usage problems.) | |
1737 | ||
1738 | You will usually want to use scm_shell instead of calling this | |
1739 | function yourself. | |
48d224d7 JB |
1740 | |
1741 | ** scm_eval_0str now returns SCM_UNSPECIFIED if the string contains no | |
095936d2 JB |
1742 | expressions. It used to return SCM_EOL. Earth-shattering. |
1743 | ||
1744 | ** The macros for declaring scheme objects in C code have been | |
1745 | rearranged slightly. They are now: | |
1746 | ||
1747 | SCM_SYMBOL (C_NAME, SCHEME_NAME) | |
1748 | Declare a static SCM variable named C_NAME, and initialize it to | |
1749 | point to the Scheme symbol whose name is SCHEME_NAME. C_NAME should | |
1750 | be a C identifier, and SCHEME_NAME should be a C string. | |
1751 | ||
1752 | SCM_GLOBAL_SYMBOL (C_NAME, SCHEME_NAME) | |
1753 | Just like SCM_SYMBOL, but make C_NAME globally visible. | |
1754 | ||
1755 | SCM_VCELL (C_NAME, SCHEME_NAME) | |
1756 | Create a global variable at the Scheme level named SCHEME_NAME. | |
1757 | Declare a static SCM variable named C_NAME, and initialize it to | |
1758 | point to the Scheme variable's value cell. | |
1759 | ||
1760 | SCM_GLOBAL_VCELL (C_NAME, SCHEME_NAME) | |
1761 | Just like SCM_VCELL, but make C_NAME globally visible. | |
1762 | ||
1763 | The `guile-snarf' script writes initialization code for these macros | |
1764 | to its standard output, given C source code as input. | |
1765 | ||
1766 | The SCM_GLOBAL macro is gone. | |
1767 | ||
1768 | ** The scm_read_line and scm_read_line_x functions have been replaced | |
1769 | by Scheme code based on the %read-delimited! procedure (known to C | |
1770 | code as scm_read_delimited_x). See its description above for more | |
1771 | information. | |
48d224d7 | 1772 | |
095936d2 JB |
1773 | ** The function scm_sys_open has been renamed to scm_open. It now |
1774 | returns a port instead of an FD object. | |
ea00ecba | 1775 | |
095936d2 JB |
1776 | * The dynamic linking support has changed. For more information, see |
1777 | libguile/DYNAMIC-LINKING. | |
ea00ecba | 1778 | |
f7b47737 JB |
1779 | \f |
1780 | Guile 1.0b3 | |
3065a62a | 1781 | |
f3b1485f JB |
1782 | User-visible changes from Thursday, September 5, 1996 until Guile 1.0 |
1783 | (Sun 5 Jan 1997): | |
3065a62a | 1784 | |
4b521edb | 1785 | * Changes to the 'guile' program: |
3065a62a | 1786 | |
4b521edb JB |
1787 | ** Guile now loads some new files when it starts up. Guile first |
1788 | searches the load path for init.scm, and loads it if found. Then, if | |
1789 | Guile is not being used to execute a script, and the user's home | |
1790 | directory contains a file named `.guile', Guile loads that. | |
c6486f8a | 1791 | |
4b521edb | 1792 | ** You can now use Guile as a shell script interpreter. |
3065a62a JB |
1793 | |
1794 | To paraphrase the SCSH manual: | |
1795 | ||
1796 | When Unix tries to execute an executable file whose first two | |
1797 | characters are the `#!', it treats the file not as machine code to | |
1798 | be directly executed by the native processor, but as source code | |
1799 | to be executed by some interpreter. The interpreter to use is | |
1800 | specified immediately after the #! sequence on the first line of | |
1801 | the source file. The kernel reads in the name of the interpreter, | |
1802 | and executes that instead. It passes the interpreter the source | |
1803 | filename as its first argument, with the original arguments | |
1804 | following. Consult the Unix man page for the `exec' system call | |
1805 | for more information. | |
1806 | ||
1a1945be JB |
1807 | Now you can use Guile as an interpreter, using a mechanism which is a |
1808 | compatible subset of that provided by SCSH. | |
1809 | ||
3065a62a JB |
1810 | Guile now recognizes a '-s' command line switch, whose argument is the |
1811 | name of a file of Scheme code to load. It also treats the two | |
1812 | characters `#!' as the start of a comment, terminated by `!#'. Thus, | |
1813 | to make a file of Scheme code directly executable by Unix, insert the | |
1814 | following two lines at the top of the file: | |
1815 | ||
1816 | #!/usr/local/bin/guile -s | |
1817 | !# | |
1818 | ||
1819 | Guile treats the argument of the `-s' command-line switch as the name | |
1820 | of a file of Scheme code to load, and treats the sequence `#!' as the | |
1821 | start of a block comment, terminated by `!#'. | |
1822 | ||
1823 | For example, here's a version of 'echo' written in Scheme: | |
1824 | ||
1825 | #!/usr/local/bin/guile -s | |
1826 | !# | |
1827 | (let loop ((args (cdr (program-arguments)))) | |
1828 | (if (pair? args) | |
1829 | (begin | |
1830 | (display (car args)) | |
1831 | (if (pair? (cdr args)) | |
1832 | (display " ")) | |
1833 | (loop (cdr args))))) | |
1834 | (newline) | |
1835 | ||
1836 | Why does `#!' start a block comment terminated by `!#', instead of the | |
1837 | end of the line? That is the notation SCSH uses, and although we | |
1838 | don't yet support the other SCSH features that motivate that choice, | |
1839 | we would like to be backward-compatible with any existing Guile | |
3763761c JB |
1840 | scripts once we do. Furthermore, if the path to Guile on your system |
1841 | is too long for your kernel, you can start the script with this | |
1842 | horrible hack: | |
1843 | ||
1844 | #!/bin/sh | |
1845 | exec /really/long/path/to/guile -s "$0" ${1+"$@"} | |
1846 | !# | |
3065a62a JB |
1847 | |
1848 | Note that some very old Unix systems don't support the `#!' syntax. | |
1849 | ||
c6486f8a | 1850 | |
4b521edb | 1851 | ** You can now run Guile without installing it. |
6685dc83 JB |
1852 | |
1853 | Previous versions of the interactive Guile interpreter (`guile') | |
1854 | couldn't start up unless Guile's Scheme library had been installed; | |
1855 | they used the value of the environment variable `SCHEME_LOAD_PATH' | |
1856 | later on in the startup process, but not to find the startup code | |
1857 | itself. Now Guile uses `SCHEME_LOAD_PATH' in all searches for Scheme | |
1858 | code. | |
1859 | ||
1860 | To run Guile without installing it, build it in the normal way, and | |
1861 | then set the environment variable `SCHEME_LOAD_PATH' to a | |
1862 | colon-separated list of directories, including the top-level directory | |
1863 | of the Guile sources. For example, if you unpacked Guile so that the | |
1864 | full filename of this NEWS file is /home/jimb/guile-1.0b3/NEWS, then | |
1865 | you might say | |
1866 | ||
1867 | export SCHEME_LOAD_PATH=/home/jimb/my-scheme:/home/jimb/guile-1.0b3 | |
1868 | ||
c6486f8a | 1869 | |
4b521edb JB |
1870 | ** Guile's read-eval-print loop no longer prints #<unspecified> |
1871 | results. If the user wants to see this, she can evaluate the | |
1872 | expression (assert-repl-print-unspecified #t), perhaps in her startup | |
48d224d7 | 1873 | file. |
6685dc83 | 1874 | |
4b521edb JB |
1875 | ** Guile no longer shows backtraces by default when an error occurs; |
1876 | however, it does display a message saying how to get one, and how to | |
1877 | request that they be displayed by default. After an error, evaluate | |
1878 | (backtrace) | |
1879 | to see a backtrace, and | |
1880 | (debug-enable 'backtrace) | |
1881 | to see them by default. | |
6685dc83 | 1882 | |
6685dc83 | 1883 | |
d9fb83d9 | 1884 | |
4b521edb JB |
1885 | * Changes to Guile Scheme: |
1886 | ||
1887 | ** Guile now distinguishes between #f and the empty list. | |
1888 | ||
1889 | This is for compatibility with the IEEE standard, the (possibly) | |
1890 | upcoming Revised^5 Report on Scheme, and many extant Scheme | |
1891 | implementations. | |
1892 | ||
1893 | Guile used to have #f and '() denote the same object, to make Scheme's | |
1894 | type system more compatible with Emacs Lisp's. However, the change | |
1895 | caused too much trouble for Scheme programmers, and we found another | |
1896 | way to reconcile Emacs Lisp with Scheme that didn't require this. | |
1897 | ||
1898 | ||
1899 | ** Guile's delq, delv, delete functions, and their destructive | |
c6486f8a JB |
1900 | counterparts, delq!, delv!, and delete!, now remove all matching |
1901 | elements from the list, not just the first. This matches the behavior | |
1902 | of the corresponding Emacs Lisp functions, and (I believe) the Maclisp | |
1903 | functions which inspired them. | |
1904 | ||
1905 | I recognize that this change may break code in subtle ways, but it | |
1906 | seems best to make the change before the FSF's first Guile release, | |
1907 | rather than after. | |
1908 | ||
1909 | ||
4b521edb | 1910 | ** The compiled-library-path function has been deleted from libguile. |
6685dc83 | 1911 | |
4b521edb | 1912 | ** The facilities for loading Scheme source files have changed. |
c6486f8a | 1913 | |
4b521edb | 1914 | *** The variable %load-path now tells Guile which directories to search |
6685dc83 JB |
1915 | for Scheme code. Its value is a list of strings, each of which names |
1916 | a directory. | |
1917 | ||
4b521edb JB |
1918 | *** The variable %load-extensions now tells Guile which extensions to |
1919 | try appending to a filename when searching the load path. Its value | |
1920 | is a list of strings. Its default value is ("" ".scm"). | |
1921 | ||
1922 | *** (%search-load-path FILENAME) searches the directories listed in the | |
1923 | value of the %load-path variable for a Scheme file named FILENAME, | |
1924 | with all the extensions listed in %load-extensions. If it finds a | |
1925 | match, then it returns its full filename. If FILENAME is absolute, it | |
1926 | returns it unchanged. Otherwise, it returns #f. | |
6685dc83 | 1927 | |
4b521edb JB |
1928 | %search-load-path will not return matches that refer to directories. |
1929 | ||
1930 | *** (primitive-load FILENAME :optional CASE-INSENSITIVE-P SHARP) | |
1931 | uses %seach-load-path to find a file named FILENAME, and loads it if | |
1932 | it finds it. If it can't read FILENAME for any reason, it throws an | |
1933 | error. | |
6685dc83 JB |
1934 | |
1935 | The arguments CASE-INSENSITIVE-P and SHARP are interpreted as by the | |
4b521edb JB |
1936 | `read' function. |
1937 | ||
1938 | *** load uses the same searching semantics as primitive-load. | |
1939 | ||
1940 | *** The functions %try-load, try-load-with-path, %load, load-with-path, | |
1941 | basic-try-load-with-path, basic-load-with-path, try-load-module-with- | |
1942 | path, and load-module-with-path have been deleted. The functions | |
1943 | above should serve their purposes. | |
1944 | ||
1945 | *** If the value of the variable %load-hook is a procedure, | |
1946 | `primitive-load' applies its value to the name of the file being | |
1947 | loaded (without the load path directory name prepended). If its value | |
1948 | is #f, it is ignored. Otherwise, an error occurs. | |
1949 | ||
1950 | This is mostly useful for printing load notification messages. | |
1951 | ||
1952 | ||
1953 | ** The function `eval!' is no longer accessible from the scheme level. | |
1954 | We can't allow operations which introduce glocs into the scheme level, | |
1955 | because Guile's type system can't handle these as data. Use `eval' or | |
1956 | `read-and-eval!' (see below) as replacement. | |
1957 | ||
1958 | ** The new function read-and-eval! reads an expression from PORT, | |
1959 | evaluates it, and returns the result. This is more efficient than | |
1960 | simply calling `read' and `eval', since it is not necessary to make a | |
1961 | copy of the expression for the evaluator to munge. | |
1962 | ||
1963 | Its optional arguments CASE_INSENSITIVE_P and SHARP are interpreted as | |
1964 | for the `read' function. | |
1965 | ||
1966 | ||
1967 | ** The function `int?' has been removed; its definition was identical | |
1968 | to that of `integer?'. | |
1969 | ||
1970 | ** The functions `<?', `<?', `<=?', `=?', `>?', and `>=?'. Code should | |
1971 | use the R4RS names for these functions. | |
1972 | ||
1973 | ** The function object-properties no longer returns the hash handle; | |
1974 | it simply returns the object's property list. | |
1975 | ||
1976 | ** Many functions have been changed to throw errors, instead of | |
1977 | returning #f on failure. The point of providing exception handling in | |
1978 | the language is to simplify the logic of user code, but this is less | |
1979 | useful if Guile's primitives don't throw exceptions. | |
1980 | ||
1981 | ** The function `fileno' has been renamed from `%fileno'. | |
1982 | ||
1983 | ** The function primitive-mode->fdes returns #t or #f now, not 1 or 0. | |
1984 | ||
1985 | ||
1986 | * Changes to Guile's C interface: | |
1987 | ||
1988 | ** The library's initialization procedure has been simplified. | |
1989 | scm_boot_guile now has the prototype: | |
1990 | ||
1991 | void scm_boot_guile (int ARGC, | |
1992 | char **ARGV, | |
1993 | void (*main_func) (), | |
1994 | void *closure); | |
1995 | ||
1996 | scm_boot_guile calls MAIN_FUNC, passing it CLOSURE, ARGC, and ARGV. | |
1997 | MAIN_FUNC should do all the work of the program (initializing other | |
1998 | packages, reading user input, etc.) before returning. When MAIN_FUNC | |
1999 | returns, call exit (0); this function never returns. If you want some | |
2000 | other exit value, MAIN_FUNC may call exit itself. | |
2001 | ||
2002 | scm_boot_guile arranges for program-arguments to return the strings | |
2003 | given by ARGC and ARGV. If MAIN_FUNC modifies ARGC/ARGV, should call | |
2004 | scm_set_program_arguments with the final list, so Scheme code will | |
2005 | know which arguments have been processed. | |
2006 | ||
2007 | scm_boot_guile establishes a catch-all catch handler which prints an | |
2008 | error message and exits the process. This means that Guile exits in a | |
2009 | coherent way when system errors occur and the user isn't prepared to | |
2010 | handle it. If the user doesn't like this behavior, they can establish | |
2011 | their own universal catcher in MAIN_FUNC to shadow this one. | |
2012 | ||
2013 | Why must the caller do all the real work from MAIN_FUNC? The garbage | |
2014 | collector assumes that all local variables of type SCM will be above | |
2015 | scm_boot_guile's stack frame on the stack. If you try to manipulate | |
2016 | SCM values after this function returns, it's the luck of the draw | |
2017 | whether the GC will be able to find the objects you allocate. So, | |
2018 | scm_boot_guile function exits, rather than returning, to discourage | |
2019 | people from making that mistake. | |
2020 | ||
2021 | The IN, OUT, and ERR arguments were removed; there are other | |
2022 | convenient ways to override these when desired. | |
2023 | ||
2024 | The RESULT argument was deleted; this function should never return. | |
2025 | ||
2026 | The BOOT_CMD argument was deleted; the MAIN_FUNC argument is more | |
2027 | general. | |
2028 | ||
2029 | ||
2030 | ** Guile's header files should no longer conflict with your system's | |
2031 | header files. | |
2032 | ||
2033 | In order to compile code which #included <libguile.h>, previous | |
2034 | versions of Guile required you to add a directory containing all the | |
2035 | Guile header files to your #include path. This was a problem, since | |
2036 | Guile's header files have names which conflict with many systems' | |
2037 | header files. | |
2038 | ||
2039 | Now only <libguile.h> need appear in your #include path; you must | |
2040 | refer to all Guile's other header files as <libguile/mumble.h>. | |
2041 | Guile's installation procedure puts libguile.h in $(includedir), and | |
2042 | the rest in $(includedir)/libguile. | |
2043 | ||
2044 | ||
2045 | ** Two new C functions, scm_protect_object and scm_unprotect_object, | |
2046 | have been added to the Guile library. | |
2047 | ||
2048 | scm_protect_object (OBJ) protects OBJ from the garbage collector. | |
2049 | OBJ will not be freed, even if all other references are dropped, | |
2050 | until someone does scm_unprotect_object (OBJ). Both functions | |
2051 | return OBJ. | |
2052 | ||
2053 | Note that calls to scm_protect_object do not nest. You can call | |
2054 | scm_protect_object any number of times on a given object, and the | |
2055 | next call to scm_unprotect_object will unprotect it completely. | |
2056 | ||
2057 | Basically, scm_protect_object and scm_unprotect_object just | |
2058 | maintain a list of references to things. Since the GC knows about | |
2059 | this list, all objects it mentions stay alive. scm_protect_object | |
2060 | adds its argument to the list; scm_unprotect_object remove its | |
2061 | argument from the list. | |
2062 | ||
2063 | ||
2064 | ** scm_eval_0str now returns the value of the last expression | |
2065 | evaluated. | |
2066 | ||
2067 | ** The new function scm_read_0str reads an s-expression from a | |
2068 | null-terminated string, and returns it. | |
2069 | ||
2070 | ** The new function `scm_stdio_to_port' converts a STDIO file pointer | |
2071 | to a Scheme port object. | |
2072 | ||
2073 | ** The new function `scm_set_program_arguments' allows C code to set | |
2074 | the value teruturned by the Scheme `program-arguments' function. | |
6685dc83 | 2075 | |
6685dc83 | 2076 | \f |
1a1945be JB |
2077 | Older changes: |
2078 | ||
2079 | * Guile no longer includes sophisticated Tcl/Tk support. | |
2080 | ||
2081 | The old Tcl/Tk support was unsatisfying to us, because it required the | |
2082 | user to link against the Tcl library, as well as Tk and Guile. The | |
2083 | interface was also un-lispy, in that it preserved Tcl/Tk's practice of | |
2084 | referring to widgets by names, rather than exporting widgets to Scheme | |
2085 | code as a special datatype. | |
2086 | ||
2087 | In the Usenix Tk Developer's Workshop held in July 1996, the Tcl/Tk | |
2088 | maintainers described some very interesting changes in progress to the | |
2089 | Tcl/Tk internals, which would facilitate clean interfaces between lone | |
2090 | Tk and other interpreters --- even for garbage-collected languages | |
2091 | like Scheme. They expected the new Tk to be publicly available in the | |
2092 | fall of 1996. | |
2093 | ||
2094 | Since it seems that Guile might soon have a new, cleaner interface to | |
2095 | lone Tk, and that the old Guile/Tk glue code would probably need to be | |
2096 | completely rewritten, we (Jim Blandy and Richard Stallman) have | |
2097 | decided not to support the old code. We'll spend the time instead on | |
2098 | a good interface to the newer Tk, as soon as it is available. | |
5c54da76 | 2099 | |
8512dea6 | 2100 | Until then, gtcltk-lib provides trivial, low-maintenance functionality. |
deb95d71 | 2101 | |
5c54da76 JB |
2102 | \f |
2103 | Copyright information: | |
2104 | ||
ea00ecba | 2105 | Copyright (C) 1996,1997 Free Software Foundation, Inc. |
5c54da76 JB |
2106 | |
2107 | Permission is granted to anyone to make or distribute verbatim copies | |
2108 | of this document as received, in any medium, provided that the | |
2109 | copyright notice and this permission notice are preserved, | |
2110 | thus giving the recipient permission to redistribute in turn. | |
2111 | ||
2112 | Permission is granted to distribute modified versions | |
2113 | of this document, or of portions of it, | |
2114 | under the above conditions, provided also that they | |
2115 | carry prominent notices stating who last changed them. | |
2116 | ||
48d224d7 JB |
2117 | \f |
2118 | Local variables: | |
2119 | mode: outline | |
2120 | paragraph-separate: "[ \f]*$" | |
2121 | end: | |
2122 |