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1 | /* Copyright (C) 1999, 2000 Free Software Foundation, Inc. |
2 | * | |
3 | * This program is free software; you can redistribute it and/or modify | |
4 | * it under the terms of the GNU General Public License as published by | |
5 | * the Free Software Foundation; either version 2, or (at your option) | |
6 | * any later version. | |
7 | * | |
8 | * This program is distributed in the hope that it will be useful, | |
9 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
10 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
11 | * GNU General Public License for more details. | |
12 | * | |
13 | * You should have received a copy of the GNU General Public License | |
14 | * along with this software; see the file COPYING. If not, write to | |
15 | * the Free Software Foundation, Inc., 59 Temple Place, Suite 330, | |
16 | * Boston, MA 02111-1307 USA | |
17 | * | |
18 | * As a special exception, the Free Software Foundation gives permission | |
19 | * for additional uses of the text contained in its release of GUILE. | |
20 | * | |
21 | * The exception is that, if you link the GUILE library with other files | |
22 | * to produce an executable, this does not by itself cause the | |
23 | * resulting executable to be covered by the GNU General Public License. | |
24 | * Your use of that executable is in no way restricted on account of | |
25 | * linking the GUILE library code into it. | |
26 | * | |
27 | * This exception does not however invalidate any other reasons why | |
28 | * the executable file might be covered by the GNU General Public License. | |
29 | * | |
30 | * This exception applies only to the code released by the | |
31 | * Free Software Foundation under the name GUILE. If you copy | |
32 | * code from other Free Software Foundation releases into a copy of | |
33 | * GUILE, as the General Public License permits, the exception does | |
34 | * not apply to the code that you add in this way. To avoid misleading | |
35 | * anyone as to the status of such modified files, you must delete | |
36 | * this exception notice from them. | |
37 | * | |
38 | * If you write modifications of your own for GUILE, it is your choice | |
39 | * whether to permit this exception to apply to your modifications. | |
40 | * If you do not wish that, delete this exception notice. */ | |
41 | ||
42 | \f | |
43 | ||
44 | #include "libguile/_scm.h" | |
45 | #include "libguile/alist.h" | |
46 | #include "libguile/eval.h" | |
47 | #include "libguile/gh.h" | |
48 | #include "libguile/hash.h" | |
49 | #include "libguile/ports.h" | |
50 | #include "libguile/smob.h" | |
51 | #include "libguile/symbols.h" | |
52 | #include "libguile/vectors.h" | |
53 | #include "libguile/weaks.h" | |
54 | ||
55 | #include "libguile/environments.h" | |
56 | ||
57 | \f | |
58 | ||
59 | long scm_tc16_environment; | |
60 | long scm_tc16_observer; | |
61 | ||
62 | \f | |
63 | ||
64 | /* error conditions */ | |
65 | ||
66 | /* | |
67 | * Throw an error if symbol is not bound in environment func | |
68 | */ | |
69 | void | |
70 | scm_error_environment_unbound (const char *func, SCM env, SCM symbol) | |
71 | { | |
72 | /* Dirk:FIXME:: Should throw an environment:unbound type error */ | |
73 | char error[] = "Symbol `~A' not bound in environment `~A'."; | |
74 | SCM arguments = scm_cons2 (symbol, env, SCM_EOL); | |
75 | scm_misc_error (func, error, arguments); | |
76 | } | |
77 | ||
78 | ||
79 | /* | |
80 | * Throw an error if func tried to create (define) or remove | |
81 | * (undefine) a new binding for symbol in env | |
82 | */ | |
83 | void | |
84 | scm_error_environment_immutable_binding (const char *func, SCM env, SCM symbol) | |
85 | { | |
86 | /* Dirk:FIXME:: Should throw an environment:immutable-binding type error */ | |
87 | char error[] = "Immutable binding in environment ~A (symbol: `~A')."; | |
88 | SCM arguments = scm_cons2 (env, symbol, SCM_EOL); | |
89 | scm_misc_error (func, error, arguments); | |
90 | } | |
91 | ||
92 | ||
93 | /* | |
94 | * Throw an error if func tried to change an immutable location. | |
95 | */ | |
96 | void | |
97 | scm_error_environment_immutable_location (const char *func, SCM env, SCM symbol) | |
98 | { | |
99 | /* Dirk:FIXME:: Should throw an environment:immutable-location type error */ | |
100 | char error[] = "Immutable location in environment `~A' (symbol: `~A')."; | |
101 | SCM arguments = scm_cons2 (env, symbol, SCM_EOL); | |
102 | scm_misc_error (func, error, arguments); | |
103 | } | |
104 | ||
105 | \f | |
106 | ||
107 | /* generic environments */ | |
108 | ||
109 | ||
110 | /* Create an environment for the given type. Dereferencing type twice must | |
111 | * deliver the initialized set of environment functions. Thus, type will | |
112 | * also determine the signature of the underlying environment implementation. | |
113 | * Dereferencing type once will typically deliver the data fields used by the | |
114 | * underlying environment implementation. | |
115 | */ | |
116 | SCM | |
117 | scm_make_environment (void *type) | |
118 | { | |
119 | SCM env; | |
120 | ||
121 | SCM_NEWCELL (env); | |
122 | SCM_SET_CELL_WORD_1 (env, type); | |
123 | SCM_SET_CELL_TYPE (env, scm_tc16_environment); | |
124 | ||
125 | return env; | |
126 | } | |
127 | ||
128 | ||
129 | SCM_DEFINE (scm_environment_p, "environment?", 1, 0, 0, | |
130 | (SCM obj), | |
131 | "Return #t if OBJ is an environment, or #f otherwise.") | |
132 | #define FUNC_NAME s_scm_environment_p | |
133 | { | |
134 | return SCM_BOOL (SCM_ENVIRONMENT_P (obj)); | |
135 | } | |
136 | #undef FUNC_NAME | |
137 | ||
138 | ||
139 | SCM_DEFINE (scm_environment_bound_p, "environment-bound?", 2, 0, 0, | |
140 | (SCM env, SCM sym), | |
141 | "Return #t if SYM is bound in ENV, or #f otherwise.") | |
142 | #define FUNC_NAME s_scm_environment_bound_p | |
143 | { | |
144 | SCM_ASSERT (SCM_ENVIRONMENT_P (env), env, SCM_ARG1, FUNC_NAME); | |
145 | SCM_ASSERT (SCM_SYMBOLP (sym), sym, SCM_ARG2, FUNC_NAME); | |
146 | ||
147 | return SCM_BOOL (SCM_ENVIRONMENT_BOUND_P (env, sym)); | |
148 | } | |
149 | #undef FUNC_NAME | |
150 | ||
151 | ||
152 | SCM_DEFINE (scm_environment_ref, "environment-ref", 2, 0, 0, | |
153 | (SCM env, SCM sym), | |
154 | "Return the value of the location bound to SYM in ENV.\n" | |
155 | "If SYM is unbound in ENV, signal an environment:unbound\n" | |
156 | "error.") | |
157 | #define FUNC_NAME s_scm_environment_ref | |
158 | { | |
159 | SCM val; | |
160 | ||
161 | SCM_ASSERT (SCM_ENVIRONMENT_P (env), env, SCM_ARG1, FUNC_NAME); | |
162 | SCM_ASSERT (SCM_SYMBOLP (sym), sym, SCM_ARG2, FUNC_NAME); | |
163 | ||
164 | val = SCM_ENVIRONMENT_REF (env, sym); | |
165 | ||
166 | if (!SCM_UNBNDP (val)) | |
167 | return val; | |
168 | else | |
169 | scm_error_environment_unbound (FUNC_NAME, env, sym); | |
170 | } | |
171 | #undef FUNC_NAME | |
172 | ||
173 | ||
174 | /* This C function is identical to environment-ref, except that if symbol is | |
175 | * unbound in env, it returns the value SCM_UNDEFINED, instead of signalling | |
176 | * an error. | |
177 | */ | |
178 | SCM | |
179 | scm_c_environment_ref (SCM env, SCM sym) | |
180 | { | |
181 | SCM_ASSERT (SCM_ENVIRONMENT_P (env), env, SCM_ARG1, "scm_c_environment_ref"); | |
182 | SCM_ASSERT (SCM_SYMBOLP (sym), sym, SCM_ARG2, "scm_c_environment_ref"); | |
183 | return SCM_ENVIRONMENT_REF (env, sym); | |
184 | } | |
185 | ||
186 | ||
187 | static SCM | |
188 | environment_default_folder (SCM proc, SCM symbol, SCM value, SCM tail) | |
189 | { | |
190 | return gh_call3 (proc, symbol, value, tail); | |
191 | } | |
192 | ||
193 | ||
194 | SCM_DEFINE (scm_environment_fold, "environment-fold", 3, 0, 0, | |
195 | (SCM env, SCM proc, SCM init), | |
196 | "Iterate over all the bindings in ENV, accumulating some value.\n" | |
197 | "For each binding in ENV, apply PROC to the symbol bound, its\n" | |
198 | "value, and the result from the previous application of PROC.\n" | |
199 | "Use INIT as PROC's third argument the first time PROC is\n" | |
200 | "applied.\n" | |
201 | "If ENV contains no bindings, this function simply returns INIT.\n" | |
202 | "If ENV binds the symbol sym1 to the value val1, sym2 to val2,\n" | |
203 | "and so on, then this procedure computes:\n" | |
204 | " (proc sym1 val1\n" | |
205 | " (proc sym2 val2\n" | |
206 | " ...\n" | |
207 | " (proc symn valn\n" | |
208 | " init)))\n" | |
209 | "Each binding in ENV will be processed exactly once.\n" | |
210 | "environment-fold makes no guarantees about the order in which\n" | |
211 | "the bindings are processed.\n" | |
212 | "Here is a function which, given an environment, constructs an\n" | |
213 | "association list representing that environment's bindings,\n" | |
214 | "using environment-fold:\n" | |
215 | " (define (environment->alist env)\n" | |
216 | " (environment-fold env\n" | |
217 | " (lambda (sym val tail)\n" | |
218 | " (cons (cons sym val) tail))\n" | |
219 | " '()))") | |
220 | #define FUNC_NAME s_scm_environment_fold | |
221 | { | |
222 | SCM_ASSERT (SCM_ENVIRONMENT_P (env), env, SCM_ARG1, FUNC_NAME); | |
223 | SCM_ASSERT (SCM_EQ_P (scm_procedure_p (proc), SCM_BOOL_T), | |
224 | proc, SCM_ARG2, FUNC_NAME); | |
225 | ||
226 | return SCM_ENVIRONMENT_FOLD (env, environment_default_folder, proc, init); | |
227 | } | |
228 | #undef FUNC_NAME | |
229 | ||
230 | ||
231 | /* This is the C-level analog of environment-fold. For each binding in ENV, | |
232 | * make the call: | |
233 | * (*proc) (data, symbol, value, previous) | |
234 | * where previous is the value returned from the last call to *PROC, or INIT | |
235 | * for the first call. If ENV contains no bindings, return INIT. | |
236 | */ | |
237 | SCM | |
238 | scm_c_environment_fold (SCM env, scm_environment_folder proc, SCM data, SCM init) | |
239 | { | |
240 | SCM_ASSERT (SCM_ENVIRONMENT_P (env), env, SCM_ARG1, "scm_c_environment_fold"); | |
241 | ||
242 | return SCM_ENVIRONMENT_FOLD (env, proc, data, init); | |
243 | } | |
244 | ||
245 | ||
246 | SCM_DEFINE (scm_environment_define, "environment-define", 3, 0, 0, | |
247 | (SCM env, SCM sym, SCM val), | |
248 | "Bind SYM to a new location containing VAL in ENV. If SYM is\n" | |
249 | "already bound to another location in ENV and the binding is\n" | |
250 | "mutable, that binding is replaced. The new binding and\n" | |
251 | "location are both mutable. The return value is unspecified.\n" | |
252 | "If SYM is already bound in ENV, and the binding is immutable,\n" | |
253 | "signal an environment:immutable-binding error.") | |
254 | #define FUNC_NAME s_scm_environment_define | |
255 | { | |
256 | SCM status; | |
257 | ||
258 | SCM_ASSERT (SCM_ENVIRONMENT_P (env), env, SCM_ARG1, FUNC_NAME); | |
259 | SCM_ASSERT (SCM_SYMBOLP (sym), sym, SCM_ARG2, FUNC_NAME); | |
260 | ||
261 | status = SCM_ENVIRONMENT_DEFINE (env, sym, val); | |
262 | ||
263 | if (SCM_EQ_P (status, SCM_ENVIRONMENT_SUCCESS)) | |
264 | return SCM_UNSPECIFIED; | |
265 | else if (SCM_EQ_P (status, SCM_ENVIRONMENT_BINDING_IMMUTABLE)) | |
266 | scm_error_environment_immutable_binding (FUNC_NAME, env, sym); | |
267 | else | |
268 | abort(); | |
269 | } | |
270 | #undef FUNC_NAME | |
271 | ||
272 | ||
273 | SCM_DEFINE (scm_environment_undefine, "environment-undefine", 2, 0, 0, | |
274 | (SCM env, SCM sym), | |
275 | "Remove any binding for SYM from ENV. If SYM is unbound in ENV,\n" | |
276 | "do nothing. The return value is unspecified.\n" | |
277 | "If SYM is already bound in ENV, and the binding is immutable,\n" | |
278 | "signal an environment:immutable-binding error.") | |
279 | #define FUNC_NAME s_scm_environment_undefine | |
280 | { | |
281 | SCM status; | |
282 | ||
283 | SCM_ASSERT(SCM_ENVIRONMENT_P(env), env, SCM_ARG1, FUNC_NAME); | |
284 | SCM_ASSERT(SCM_SYMBOLP(sym), sym, SCM_ARG2, FUNC_NAME); | |
285 | ||
286 | status = SCM_ENVIRONMENT_UNDEFINE (env, sym); | |
287 | ||
288 | if (SCM_EQ_P (status, SCM_ENVIRONMENT_SUCCESS)) | |
289 | return SCM_UNSPECIFIED; | |
290 | else if (SCM_EQ_P (status, SCM_ENVIRONMENT_BINDING_IMMUTABLE)) | |
291 | scm_error_environment_immutable_binding (FUNC_NAME, env, sym); | |
292 | else | |
293 | abort(); | |
294 | } | |
295 | #undef FUNC_NAME | |
296 | ||
297 | ||
298 | SCM_DEFINE (scm_environment_set_x, "environment-set!", 3, 0, 0, | |
299 | (SCM env, SCM sym, SCM val), | |
300 | "If ENV binds SYM to some location, change that location's\n" | |
301 | "value to VAL. The return value is unspecified.\n" | |
302 | "If SYM is not bound in ENV, signal an environment:unbound\n" | |
303 | "error. If ENV binds SYM to an immutable location, signal an\n" | |
304 | "environment:immutable-location error.") | |
305 | #define FUNC_NAME s_scm_environment_set_x | |
306 | { | |
307 | SCM status; | |
308 | ||
309 | SCM_ASSERT (SCM_ENVIRONMENT_P (env), env, SCM_ARG1, FUNC_NAME); | |
310 | SCM_ASSERT (SCM_SYMBOLP (sym), sym, SCM_ARG2, FUNC_NAME); | |
311 | ||
312 | status = SCM_ENVIRONMENT_SET (env, sym, val); | |
313 | ||
314 | if (SCM_EQ_P (status, SCM_ENVIRONMENT_SUCCESS)) | |
315 | return SCM_UNSPECIFIED; | |
316 | else if (SCM_UNBNDP (status)) | |
317 | scm_error_environment_unbound (FUNC_NAME, env, sym); | |
318 | else if (SCM_EQ_P (status, SCM_ENVIRONMENT_LOCATION_IMMUTABLE)) | |
319 | scm_error_environment_immutable_binding (FUNC_NAME, env, sym); | |
320 | else | |
321 | abort(); | |
322 | } | |
323 | #undef FUNC_NAME | |
324 | ||
325 | ||
326 | SCM_DEFINE (scm_environment_cell, "environment-cell", 3, 0, 0, | |
327 | (SCM env, SCM sym, SCM for_write), | |
328 | "Return the value cell which ENV binds to SYM, or #f if the\n" | |
329 | "binding does not live in a value cell.\n" | |
330 | "The argument FOR-WRITE indicates whether the caller intends\n" | |
331 | "to modify the variable's value by mutating the value cell. If\n" | |
332 | "the variable is immutable, then environment-cell signals an\n" | |
333 | "environment:immutable-location error.\n" | |
334 | "If SYM is unbound in ENV, signal an environment:unbound error.\n" | |
335 | "If you use this function, you should consider using\n" | |
336 | "environment-observe, to be notified when SYM gets re-bound to\n" | |
337 | "a new value cell, or becomes undefined.") | |
338 | #define FUNC_NAME s_scm_environment_cell | |
339 | { | |
340 | SCM location; | |
341 | ||
342 | SCM_ASSERT (SCM_ENVIRONMENT_P (env), env, SCM_ARG1, FUNC_NAME); | |
343 | SCM_ASSERT (SCM_SYMBOLP (sym), sym, SCM_ARG2, FUNC_NAME); | |
344 | SCM_ASSERT (SCM_BOOLP (for_write), for_write, SCM_ARG3, FUNC_NAME); | |
345 | ||
346 | location = SCM_ENVIRONMENT_CELL (env, sym, !SCM_FALSEP (for_write)); | |
347 | if (!SCM_IMP (location)) | |
348 | return location; | |
349 | else if (SCM_UNBNDP (location)) | |
350 | scm_error_environment_unbound (FUNC_NAME, env, sym); | |
351 | else if (SCM_EQ_P (location, SCM_ENVIRONMENT_LOCATION_IMMUTABLE)) | |
352 | scm_error_environment_immutable_location (FUNC_NAME, env, sym); | |
353 | else /* no cell */ | |
354 | return location; | |
355 | } | |
356 | #undef FUNC_NAME | |
357 | ||
358 | ||
359 | /* This C function is identical to environment-cell, with the following | |
360 | * exceptions: If symbol is unbound in env, it returns the value | |
361 | * SCM_UNDEFINED, instead of signalling an error. If symbol is bound to an | |
362 | * immutable location but the cell is requested for write, the value | |
363 | * SCM_ENVIRONMENT_LOCATION_IMMUTABLE is returned. | |
364 | */ | |
365 | SCM | |
366 | scm_c_environment_cell(SCM env, SCM sym, int for_write) | |
367 | { | |
368 | SCM_ASSERT (SCM_ENVIRONMENT_P (env), env, SCM_ARG1, "scm_c_environment_cell"); | |
369 | SCM_ASSERT (SCM_SYMBOLP (sym), sym, SCM_ARG2, "scm_c_environment_cell"); | |
370 | ||
371 | return SCM_ENVIRONMENT_CELL (env, sym, for_write); | |
372 | } | |
373 | ||
374 | ||
375 | static void | |
376 | environment_default_observer (SCM env, SCM proc) | |
377 | { | |
378 | gh_call1 (proc, env); | |
379 | } | |
380 | ||
381 | ||
382 | SCM_DEFINE (scm_environment_observe, "environment-observe", 2, 0, 0, | |
383 | (SCM env, SCM proc), | |
384 | "Whenever ENV's bindings change, apply PROC to ENV.\n" | |
385 | "This function returns an object, token, which you can pass to\n" | |
386 | "environment-unobserve to remove PROC from the set of\n" | |
387 | "procedures observing ENV. The type and value of token is\n" | |
388 | "unspecified.") | |
389 | #define FUNC_NAME s_scm_environment_observe | |
390 | { | |
391 | SCM_ASSERT (SCM_ENVIRONMENT_P (env), env, SCM_ARG1, FUNC_NAME); | |
392 | ||
393 | return SCM_ENVIRONMENT_OBSERVE (env, environment_default_observer, proc, 0); | |
394 | } | |
395 | #undef FUNC_NAME | |
396 | ||
397 | ||
398 | SCM_DEFINE (scm_environment_observe_weak, "environment-observe-weak", 2, 0, 0, | |
399 | (SCM env, SCM proc), | |
400 | "This function is the same as environment-observe, except that\n" | |
401 | "the reference ENV retains to PROC is a weak reference. This\n" | |
402 | "means that, if there are no other live, non-weak references\n" | |
403 | "to PROC, it will be garbage-collected, and dropped from ENV's\n" | |
404 | "list of observing procedures.") | |
405 | #define FUNC_NAME s_scm_environment_observe_weak | |
406 | { | |
407 | SCM_ASSERT (SCM_ENVIRONMENT_P (env), env, SCM_ARG1, FUNC_NAME); | |
408 | ||
409 | return SCM_ENVIRONMENT_OBSERVE (env, environment_default_observer, proc, 1); | |
410 | } | |
411 | #undef FUNC_NAME | |
412 | ||
413 | ||
414 | /* This is the C-level analog of the Scheme functions environment-observe and | |
415 | * environment-observe-weak. Whenever env's bindings change, call the | |
416 | * function proc, passing it env and data. If weak_p is non-zero, env will | |
417 | * retain only a weak reference to data, and if data is garbage collected, the | |
418 | * entire observation will be dropped. This function returns a token, with | |
419 | * the same meaning as those returned by environment-observe and | |
420 | * environment-observe-weak. | |
421 | */ | |
422 | SCM | |
423 | scm_c_environment_observe (SCM env, scm_environment_observer proc, SCM data, int weak_p) | |
424 | #define FUNC_NAME "scm_c_environment_observe" | |
425 | { | |
426 | SCM_ASSERT (SCM_ENVIRONMENT_P (env), env, SCM_ARG1, FUNC_NAME); | |
427 | ||
428 | return SCM_ENVIRONMENT_OBSERVE (env, proc, data, weak_p); | |
429 | } | |
430 | #undef FUNC_NAME | |
431 | ||
432 | ||
433 | SCM_DEFINE (scm_environment_unobserve, "environment-unobserve", 1, 0, 0, | |
434 | (SCM token), | |
435 | "Cancel the observation request which returned the value\n" | |
436 | "TOKEN. The return value is unspecified.\n" | |
437 | "If a call (environment-observe env proc) returns token, then\n" | |
438 | "the call (environment-unobserve token) will cause proc to no\n" | |
439 | "longer be called when env's bindings change.") | |
440 | #define FUNC_NAME s_scm_environment_unobserve | |
441 | { | |
442 | SCM env; | |
443 | ||
444 | SCM_ASSERT (SCM_OBSERVER_P (token), token, SCM_ARG1, FUNC_NAME); | |
445 | ||
446 | env = SCM_OBSERVER_ENVIRONMENT (token); | |
447 | SCM_ENVIRONMENT_UNOBSERVE (env, token); | |
448 | ||
449 | return SCM_UNSPECIFIED; | |
450 | } | |
451 | #undef FUNC_NAME | |
452 | ||
453 | ||
454 | static SCM | |
455 | mark_environment (SCM env) | |
456 | { | |
457 | return (*(SCM_ENVIRONMENT_FUNCS (env)->mark)) (env); | |
458 | } | |
459 | ||
460 | ||
461 | static scm_sizet | |
462 | free_environment (SCM env) | |
463 | { | |
464 | return (*(SCM_ENVIRONMENT_FUNCS (env)->free)) (env); | |
465 | } | |
466 | ||
467 | ||
468 | static int | |
469 | print_environment (SCM env, SCM port, scm_print_state *pstate) | |
470 | { | |
471 | return (*(SCM_ENVIRONMENT_FUNCS (env)->print)) (env, port, pstate); | |
472 | } | |
473 | ||
474 | \f | |
475 | ||
476 | /* observers */ | |
477 | ||
478 | static SCM | |
479 | mark_observer (SCM observer) | |
480 | { | |
481 | scm_gc_mark (SCM_OBSERVER_ENVIRONMENT (observer)); | |
482 | scm_gc_mark (SCM_OBSERVER_DATA (observer)); | |
483 | return SCM_BOOL_F; | |
484 | } | |
485 | ||
486 | ||
487 | static scm_sizet | |
488 | free_observer (SCM observer_smob) | |
489 | { | |
490 | return 0; | |
491 | } | |
492 | ||
493 | ||
494 | static int | |
495 | print_observer (SCM type, SCM port, scm_print_state *pstate) | |
496 | { | |
497 | SCM address = scm_ulong2num (SCM_UNPACK (type)); | |
498 | SCM base16 = scm_number_to_string (address, SCM_MAKINUM (16)); | |
499 | ||
500 | scm_puts ("#<observer ", port); | |
86c991c2 | 501 | scm_puts (SCM_STRING_CHARS (base16), port); |
5d3e2388 DH |
502 | scm_puts (">", port); |
503 | ||
504 | return 1; | |
505 | } | |
506 | ||
507 | \f | |
508 | ||
509 | /* obarrays | |
510 | * | |
511 | * Obarrays form the basic lookup tables used to implement most of guile's | |
512 | * built-in environment types. An obarray is implemented as a hash table with | |
513 | * symbols as keys. The content of the data depends on the environment type. | |
514 | */ | |
515 | ||
516 | ||
517 | /* | |
a2d47b23 DH |
518 | * Enter symbol into obarray. The symbol must not already exist in obarray. |
519 | * The freshly generated (symbol . data) cell is returned. | |
5d3e2388 DH |
520 | */ |
521 | static SCM | |
522 | obarray_enter (SCM obarray, SCM symbol, SCM data) | |
523 | { | |
bfa974f0 | 524 | scm_sizet hash = SCM_SYMBOL_HASH (symbol) % SCM_VECTOR_LENGTH (obarray); |
5d3e2388 DH |
525 | SCM entry = scm_cons (symbol, data); |
526 | SCM slot = scm_cons (entry, SCM_VELTS (obarray)[hash]); | |
527 | SCM_VELTS (obarray)[hash] = slot; | |
528 | ||
529 | return entry; | |
530 | } | |
531 | ||
532 | ||
a2d47b23 DH |
533 | /* |
534 | * Enter symbol into obarray. An existing entry for symbol is replaced. If | |
535 | * an entry existed, the old (symbol . data) cell is returned, #f otherwise. | |
536 | */ | |
537 | static SCM | |
538 | obarray_replace (SCM obarray, SCM symbol, SCM data) | |
539 | { | |
bfa974f0 | 540 | scm_sizet hash = SCM_SYMBOL_HASH (symbol) % SCM_VECTOR_LENGTH (obarray); |
a2d47b23 DH |
541 | SCM new_entry = scm_cons (symbol, data); |
542 | SCM lsym; | |
543 | SCM slot; | |
544 | ||
545 | for (lsym = SCM_VELTS (obarray)[hash]; !SCM_NULLP (lsym); lsym = SCM_CDR (lsym)) | |
546 | { | |
547 | SCM old_entry = SCM_CAR (lsym); | |
548 | if (SCM_CAR (old_entry) == symbol) | |
549 | { | |
550 | SCM_SETCAR (lsym, new_entry); | |
551 | return old_entry; | |
552 | } | |
553 | } | |
554 | ||
555 | slot = scm_cons (new_entry, SCM_VELTS (obarray)[hash]); | |
556 | SCM_VELTS (obarray)[hash] = slot; | |
557 | ||
558 | return SCM_BOOL_F; | |
559 | } | |
560 | ||
561 | ||
5d3e2388 DH |
562 | /* |
563 | * Look up symbol in obarray | |
564 | */ | |
565 | static SCM | |
566 | obarray_retrieve (SCM obarray, SCM sym) | |
567 | { | |
bfa974f0 | 568 | scm_sizet hash = SCM_SYMBOL_HASH (sym) % SCM_VECTOR_LENGTH (obarray); |
5d3e2388 DH |
569 | SCM lsym; |
570 | ||
571 | for (lsym = SCM_VELTS (obarray)[hash]; !SCM_NULLP (lsym); lsym = SCM_CDR (lsym)) | |
572 | { | |
573 | SCM entry = SCM_CAR (lsym); | |
574 | if (SCM_CAR (entry) == sym) | |
575 | return entry; | |
576 | } | |
577 | ||
578 | return SCM_UNDEFINED; | |
579 | } | |
580 | ||
581 | ||
582 | /* | |
a2d47b23 DH |
583 | * Remove entry from obarray. If the symbol was found and removed, the old |
584 | * (symbol . data) cell is returned, #f otherwise. | |
5d3e2388 DH |
585 | */ |
586 | static SCM | |
587 | obarray_remove (SCM obarray, SCM sym) | |
588 | { | |
bfa974f0 | 589 | scm_sizet hash = SCM_SYMBOL_HASH (sym) % SCM_VECTOR_LENGTH (obarray); |
5d3e2388 DH |
590 | SCM lsym; |
591 | SCM *lsymp; | |
592 | ||
593 | /* Dirk:FIXME:: gc problem due to use of &SCM_VELTS[hash] */ | |
594 | for (lsym = *(lsymp = &SCM_VELTS (obarray)[hash]); | |
595 | !SCM_NULLP (lsym); | |
596 | lsym = *(lsymp = SCM_CDRLOC (lsym))) | |
597 | { | |
598 | SCM entry = SCM_CAR (lsym); | |
599 | if (SCM_CAR (entry) == sym) | |
600 | { | |
601 | *lsymp = SCM_CDR (lsym); | |
602 | return entry; | |
603 | } | |
604 | } | |
605 | return SCM_BOOL_F; | |
606 | } | |
607 | ||
608 | ||
609 | static void | |
610 | obarray_remove_all (SCM obarray) | |
611 | { | |
bfa974f0 | 612 | scm_sizet size = SCM_VECTOR_LENGTH (obarray); |
5d3e2388 DH |
613 | scm_sizet i; |
614 | ||
615 | for (i = 0; i < size; i++) | |
616 | { | |
617 | SCM_VELTS (obarray)[i] = SCM_EOL; | |
618 | } | |
619 | } | |
620 | ||
621 | \f | |
622 | ||
623 | /* core environments base | |
624 | * | |
625 | * This struct and the corresponding functions form a base class for guile's | |
626 | * built-in environment types. | |
627 | */ | |
628 | ||
629 | ||
630 | struct core_environments_base { | |
631 | struct scm_environment_funcs *funcs; | |
632 | ||
633 | SCM observers; | |
634 | SCM weak_observers; | |
635 | }; | |
636 | ||
637 | ||
638 | #define CORE_ENVIRONMENTS_BASE(env) \ | |
639 | ((struct core_environments_base *) SCM_CELL_WORD_1 (env)) | |
640 | #define CORE_ENVIRONMENT_OBSERVERS(env) \ | |
641 | (CORE_ENVIRONMENTS_BASE (env)->observers) | |
642 | #define SCM_SET_CORE_ENVIRONMENT_OBSERVERS(env, v) \ | |
643 | (CORE_ENVIRONMENT_OBSERVERS (env) = (v)) | |
644 | #define CORE_ENVIRONMENT_WEAK_OBSERVER_VECTOR(env) \ | |
645 | (CORE_ENVIRONMENTS_BASE (env)->weak_observers) | |
646 | #define CORE_ENVIRONMENT_WEAK_OBSERVERS(env) \ | |
647 | (SCM_VELTS (CORE_ENVIRONMENT_WEAK_OBSERVER_VECTOR (env)) [0]) | |
648 | #define SCM_SET_CORE_ENVIRONMENT_WEAK_OBSERVERS(env, v) \ | |
649 | (SCM_VELTS (CORE_ENVIRONMENT_WEAK_OBSERVER_VECTOR (env)) [0] = (v)) | |
650 | ||
651 | \f | |
652 | ||
653 | static SCM | |
654 | core_environments_observe (SCM env, scm_environment_observer proc, SCM data, int weak_p) | |
655 | { | |
656 | SCM observer; | |
657 | ||
658 | SCM_NEWCELL2 (observer); | |
659 | SCM_SET_CELL_OBJECT_1 (observer, env); | |
660 | SCM_SET_CELL_OBJECT_2 (observer, data); | |
661 | SCM_SET_CELL_WORD_3 (observer, proc); | |
662 | SCM_SET_CELL_TYPE (observer, scm_tc16_observer); | |
663 | ||
664 | if (!weak_p) | |
665 | { | |
666 | SCM observers = CORE_ENVIRONMENT_OBSERVERS (env); | |
667 | SCM new_observers = scm_cons (observer, observers); | |
668 | SCM_SET_CORE_ENVIRONMENT_OBSERVERS (env, new_observers); | |
669 | } | |
670 | else | |
671 | { | |
672 | SCM observers = CORE_ENVIRONMENT_WEAK_OBSERVERS (env); | |
673 | SCM new_observers = scm_acons (SCM_BOOL_F, observer, observers); | |
674 | SCM_SET_CORE_ENVIRONMENT_WEAK_OBSERVERS (env, new_observers); | |
675 | } | |
676 | ||
677 | return observer; | |
678 | } | |
679 | ||
680 | ||
681 | static void | |
682 | core_environments_unobserve (SCM env, SCM observer) | |
683 | { | |
684 | unsigned int handling_weaks; | |
685 | for (handling_weaks = 0; handling_weaks <= 1; ++handling_weaks) | |
686 | { | |
687 | SCM l = handling_weaks | |
688 | ? CORE_ENVIRONMENT_WEAK_OBSERVERS (env) | |
689 | : CORE_ENVIRONMENT_OBSERVERS (env); | |
690 | ||
691 | if (!SCM_NULLP (l)) | |
692 | { | |
693 | SCM rest = SCM_CDR (l); | |
694 | SCM first = handling_weaks | |
695 | ? SCM_CDAR (l) | |
696 | : SCM_CAR (l); | |
697 | ||
698 | if (SCM_EQ_P (first, observer)) | |
699 | { | |
700 | /* Remove the first observer */ | |
701 | handling_weaks | |
702 | ? SCM_SET_CORE_ENVIRONMENT_WEAK_OBSERVERS (env, rest) | |
703 | : SCM_SET_CORE_ENVIRONMENT_OBSERVERS (env, rest); | |
704 | return; | |
705 | } | |
706 | ||
707 | do { | |
708 | SCM rest = SCM_CDR (l); | |
709 | ||
710 | if (!SCM_NULLP (rest)) | |
711 | { | |
712 | SCM next = handling_weaks | |
713 | ? SCM_CDAR (l) | |
714 | : SCM_CAR (l); | |
715 | ||
716 | if (SCM_EQ_P (next, observer)) | |
717 | { | |
718 | SCM_SETCDR (l, SCM_CDR (rest)); | |
719 | return; | |
720 | } | |
721 | } | |
722 | ||
723 | l = rest; | |
724 | } while (!SCM_NULLP (l)); | |
725 | } | |
726 | } | |
727 | ||
728 | /* Dirk:FIXME:: What to do now, since the observer is not found? */ | |
729 | } | |
730 | ||
731 | ||
732 | static SCM | |
733 | core_environments_mark (SCM env) | |
734 | { | |
735 | scm_gc_mark (CORE_ENVIRONMENT_OBSERVERS (env)); | |
736 | return CORE_ENVIRONMENT_WEAK_OBSERVER_VECTOR (env); | |
737 | } | |
738 | ||
739 | ||
740 | static void | |
741 | core_environments_finalize (SCM env) | |
742 | { | |
743 | } | |
744 | ||
745 | ||
746 | static void | |
747 | core_environments_preinit (struct core_environments_base *body) | |
748 | { | |
749 | body->funcs = NULL; | |
750 | body->observers = SCM_BOOL_F; | |
751 | body->weak_observers = SCM_BOOL_F; | |
752 | } | |
753 | ||
754 | ||
755 | static void | |
756 | core_environments_init (struct core_environments_base *body, | |
757 | struct scm_environment_funcs *funcs) | |
758 | { | |
759 | body->funcs = funcs; | |
760 | body->observers = SCM_EOL; | |
761 | body->weak_observers = scm_make_weak_value_hash_table (SCM_MAKINUM (1)); | |
762 | } | |
763 | ||
764 | ||
765 | /* Tell all observers to clear their caches. | |
766 | * | |
767 | * Environments have to be informed about changes in the following cases: | |
768 | * - The observed env has a new binding. This must be always reported. | |
769 | * - The observed env has dropped a binding. This must be always reported. | |
770 | * - A binding in the observed environment has changed. This must only be | |
771 | * reported, if there is a chance that the binding is being cached outside. | |
772 | * However, this potential optimization is not performed currently. | |
773 | * | |
774 | * Errors that occur while the observers are called are accumulated and | |
775 | * signalled as one single error message to the caller. | |
776 | */ | |
777 | ||
778 | struct update_data | |
779 | { | |
780 | SCM observer; | |
781 | SCM environment; | |
782 | }; | |
783 | ||
784 | ||
785 | static SCM | |
786 | update_catch_body (void *ptr) | |
787 | { | |
788 | struct update_data *data = (struct update_data *) ptr; | |
789 | SCM observer = data->observer; | |
790 | ||
791 | (*SCM_OBSERVER_PROC (observer)) | |
792 | (data->environment, SCM_OBSERVER_DATA (observer)); | |
793 | ||
794 | return SCM_UNDEFINED; | |
795 | } | |
796 | ||
797 | ||
798 | static SCM | |
799 | update_catch_handler (void *ptr, SCM tag, SCM args) | |
800 | { | |
801 | struct update_data *data = (struct update_data *) ptr; | |
802 | SCM observer = data->observer; | |
803 | SCM message = scm_makfrom0str ("Observer `~A' signals `~A' error: ~S"); | |
804 | ||
805 | return scm_cons (message, scm_listify (observer, tag, args, SCM_UNDEFINED)); | |
806 | } | |
807 | ||
808 | ||
809 | static void | |
810 | core_environments_broadcast (SCM env) | |
811 | #define FUNC_NAME "core_environments_broadcast" | |
812 | { | |
813 | unsigned int handling_weaks; | |
814 | SCM errors = SCM_EOL; | |
815 | ||
816 | for (handling_weaks = 0; handling_weaks <= 1; ++handling_weaks) | |
817 | { | |
818 | SCM observers = handling_weaks | |
819 | ? CORE_ENVIRONMENT_WEAK_OBSERVERS (env) | |
820 | : CORE_ENVIRONMENT_OBSERVERS (env); | |
821 | ||
822 | for (; !SCM_NULLP (observers); observers = SCM_CDR (observers)) | |
823 | { | |
824 | struct update_data data; | |
825 | SCM observer = handling_weaks | |
826 | ? SCM_CDAR (observers) | |
827 | : SCM_CAR (observers); | |
828 | SCM error; | |
829 | ||
830 | data.observer = observer; | |
831 | data.environment = env; | |
832 | ||
833 | error = scm_internal_catch (SCM_BOOL_T, | |
834 | update_catch_body, &data, | |
835 | update_catch_handler, &data); | |
836 | ||
837 | if (!SCM_UNBNDP (error)) | |
838 | errors = scm_cons (error, errors); | |
839 | } | |
840 | } | |
841 | ||
842 | if (!SCM_NULLP (errors)) | |
843 | { | |
844 | /* Dirk:FIXME:: As soon as scm_misc_error is fixed to handle the name | |
845 | * parameter correctly it should not be necessary any more to also pass | |
846 | * namestr in order to get the desired information from the error | |
847 | * message. | |
848 | */ | |
849 | SCM ordered_errors = scm_reverse (errors); | |
850 | scm_misc_error | |
851 | (FUNC_NAME, | |
852 | "Observers of `~A' have signalled the following errors: ~S", | |
853 | scm_cons2 (env, ordered_errors, SCM_EOL)); | |
854 | } | |
855 | } | |
856 | #undef FUNC_NAME | |
857 | ||
858 | \f | |
859 | ||
860 | /* leaf environments | |
861 | * | |
862 | * A leaf environment is simply a mutable set of definitions. A leaf | |
863 | * environment supports no operations beyond the common set. | |
864 | * | |
865 | * Implementation: The obarray of the leaf environment holds (symbol . value) | |
866 | * pairs. No further information is necessary, since all bindings and | |
867 | * locations in a leaf environment are mutable. | |
868 | */ | |
869 | ||
870 | ||
871 | struct leaf_environment { | |
872 | struct core_environments_base base; | |
873 | ||
874 | SCM obarray; | |
875 | }; | |
876 | ||
877 | ||
878 | #define LEAF_ENVIRONMENT(env) \ | |
879 | ((struct leaf_environment *) SCM_CELL_WORD_1 (env)) | |
880 | ||
881 | \f | |
882 | ||
883 | static SCM | |
884 | leaf_environment_ref (SCM env, SCM sym) | |
885 | { | |
886 | SCM obarray = LEAF_ENVIRONMENT (env)->obarray; | |
887 | SCM binding = obarray_retrieve (obarray, sym); | |
888 | return SCM_UNBNDP (binding) ? binding : SCM_CDR (binding); | |
889 | } | |
890 | ||
891 | ||
892 | static SCM | |
893 | leaf_environment_fold (SCM env, scm_environment_folder proc, SCM data, SCM init) | |
894 | { | |
895 | scm_sizet i; | |
896 | SCM result = init; | |
897 | SCM obarray = LEAF_ENVIRONMENT (env)->obarray; | |
898 | ||
bfa974f0 | 899 | for (i = 0; i < SCM_VECTOR_LENGTH (obarray); i++) |
5d3e2388 DH |
900 | { |
901 | SCM l; | |
902 | for (l = SCM_VELTS (obarray)[i]; !SCM_NULLP (l); l = SCM_CDR (l)) | |
903 | { | |
904 | SCM binding = SCM_CAR (l); | |
905 | SCM symbol = SCM_CAR (binding); | |
906 | SCM value = SCM_CDR (binding); | |
907 | result = (*proc) (data, symbol, value, result); | |
908 | } | |
909 | } | |
910 | return result; | |
911 | } | |
912 | ||
913 | ||
914 | static SCM | |
915 | leaf_environment_define (SCM env, SCM sym, SCM val) | |
916 | #define FUNC_NAME "leaf_environment_define" | |
917 | { | |
918 | SCM obarray = LEAF_ENVIRONMENT (env)->obarray; | |
5d3e2388 | 919 | |
a2d47b23 | 920 | obarray_replace (obarray, sym, val); |
5d3e2388 DH |
921 | core_environments_broadcast (env); |
922 | ||
923 | return SCM_ENVIRONMENT_SUCCESS; | |
924 | } | |
925 | #undef FUNC_NAME | |
926 | ||
927 | ||
928 | static SCM | |
929 | leaf_environment_undefine (SCM env, SCM sym) | |
930 | #define FUNC_NAME "leaf_environment_undefine" | |
931 | { | |
932 | SCM obarray = LEAF_ENVIRONMENT (env)->obarray; | |
a2d47b23 | 933 | SCM removed = obarray_remove (obarray, sym); |
5d3e2388 | 934 | |
a2d47b23 DH |
935 | if (!SCM_FALSEP (removed)) |
936 | core_environments_broadcast (env); | |
5d3e2388 DH |
937 | |
938 | return SCM_ENVIRONMENT_SUCCESS; | |
939 | } | |
940 | #undef FUNC_NAME | |
941 | ||
942 | ||
943 | static SCM | |
944 | leaf_environment_set_x (SCM env, SCM sym, SCM val) | |
945 | #define FUNC_NAME "leaf_environment_set_x" | |
946 | { | |
947 | SCM obarray = LEAF_ENVIRONMENT (env)->obarray; | |
948 | SCM binding = obarray_retrieve (obarray, sym); | |
949 | ||
950 | if (!SCM_UNBNDP (binding)) | |
951 | { | |
952 | SCM_SETCDR (binding, val); | |
953 | return SCM_ENVIRONMENT_SUCCESS; | |
954 | } | |
955 | else | |
956 | { | |
957 | return SCM_UNDEFINED; | |
958 | } | |
959 | } | |
960 | #undef FUNC_NAME | |
961 | ||
962 | ||
963 | static SCM | |
964 | leaf_environment_cell(SCM env, SCM sym, int for_write) | |
965 | { | |
966 | SCM obarray = LEAF_ENVIRONMENT (env)->obarray; | |
967 | SCM binding = obarray_retrieve (obarray, sym); | |
968 | return binding; | |
969 | } | |
970 | ||
971 | ||
972 | static SCM | |
973 | mark_leaf_environment (SCM env) | |
974 | { | |
975 | scm_gc_mark (LEAF_ENVIRONMENT (env)->obarray); | |
976 | return core_environments_mark (env); | |
977 | } | |
978 | ||
979 | ||
980 | static scm_sizet | |
981 | free_leaf_environment (SCM env) | |
982 | { | |
983 | core_environments_finalize (env); | |
984 | ||
985 | free (LEAF_ENVIRONMENT (env)); | |
986 | return sizeof (struct leaf_environment); | |
987 | } | |
988 | ||
989 | ||
990 | static int | |
991 | print_leaf_environment (SCM type, SCM port, scm_print_state *pstate) | |
992 | { | |
993 | SCM address = scm_ulong2num (SCM_UNPACK (type)); | |
994 | SCM base16 = scm_number_to_string (address, SCM_MAKINUM (16)); | |
995 | ||
996 | scm_puts ("#<leaf environment ", port); | |
86c991c2 | 997 | scm_puts (SCM_STRING_CHARS (base16), port); |
5d3e2388 DH |
998 | scm_puts (">", port); |
999 | ||
1000 | return 1; | |
1001 | } | |
1002 | ||
1003 | ||
1004 | static struct scm_environment_funcs leaf_environment_funcs = { | |
1005 | leaf_environment_ref, | |
1006 | leaf_environment_fold, | |
1007 | leaf_environment_define, | |
1008 | leaf_environment_undefine, | |
1009 | leaf_environment_set_x, | |
1010 | leaf_environment_cell, | |
1011 | core_environments_observe, | |
1012 | core_environments_unobserve, | |
1013 | mark_leaf_environment, | |
1014 | free_leaf_environment, | |
1015 | print_leaf_environment | |
1016 | }; | |
1017 | ||
1018 | ||
1019 | void *scm_type_leaf_environment = &leaf_environment_funcs; | |
1020 | ||
1021 | ||
1022 | SCM_DEFINE (scm_make_leaf_environment, "make-leaf-environment", 0, 0, 0, | |
1023 | (), | |
1024 | "Create a new leaf environment, containing no bindings.\n" | |
1025 | "All bindings and locations created in the new environment\n" | |
1026 | "will be mutable.") | |
1027 | #define FUNC_NAME s_scm_make_leaf_environment | |
1028 | { | |
1029 | scm_sizet size = sizeof (struct leaf_environment); | |
1030 | struct leaf_environment *body = scm_must_malloc (size, FUNC_NAME); | |
1031 | SCM env; | |
1032 | ||
1033 | core_environments_preinit (&body->base); | |
1034 | body->obarray = SCM_BOOL_F; | |
1035 | ||
1036 | env = scm_make_environment (body); | |
1037 | ||
1038 | core_environments_init (&body->base, &leaf_environment_funcs); | |
1039 | body->obarray = scm_make_vector (SCM_MAKINUM (scm_symhash_dim), SCM_EOL); | |
1040 | ||
1041 | return env; | |
1042 | } | |
1043 | #undef FUNC_NAME | |
1044 | ||
1045 | ||
1046 | SCM_DEFINE (scm_leaf_environment_p, "leaf-environment?", 1, 0, 0, | |
1047 | (SCM object), | |
1048 | "Return #t if object is a leaf environment, or #f otherwise.") | |
1049 | #define FUNC_NAME s_scm_leaf_environment_p | |
1050 | { | |
1051 | return SCM_BOOL (SCM_LEAF_ENVIRONMENT_P (object)); | |
1052 | } | |
1053 | #undef FUNC_NAME | |
1054 | ||
1055 | \f | |
1056 | ||
1057 | /* eval environments | |
1058 | * | |
1059 | * A module's source code refers to definitions imported from other modules, | |
1060 | * and definitions made within itself. An eval environment combines two | |
1061 | * environments -- a local environment and an imported environment -- to | |
1062 | * produce a new environment in which both sorts of references can be | |
1063 | * resolved. | |
1064 | * | |
1065 | * Implementation: The obarray of the eval environment is used to cache | |
1066 | * entries from the local and imported environments such that in most of the | |
1067 | * cases only a single lookup is necessary. Since for neither the local nor | |
1068 | * the imported environment it is known, what kind of environment they form, | |
1069 | * the most general case is assumed. Therefore, entries in the obarray take | |
1070 | * one of the following forms: | |
1071 | * | |
1072 | * 1) (<symbol> location mutability . source-env), where mutability indicates | |
1073 | * one of the following states: IMMUTABLE if the location is known to be | |
1074 | * immutable, MUTABLE if the location is known to be mutable, UNKNOWN if | |
1075 | * the location has only been requested for non modifying accesses. | |
1076 | * | |
1077 | * 2) (symbol . source-env) if the symbol has a binding in the source-env, but | |
1078 | * if the source-env can't provide a cell for the binding. Thus, for every | |
1079 | * access, the source-env has to be contacted directly. | |
1080 | */ | |
1081 | ||
1082 | ||
1083 | struct eval_environment { | |
1084 | struct core_environments_base base; | |
1085 | ||
1086 | SCM obarray; | |
1087 | ||
1088 | SCM imported; | |
1089 | SCM imported_observer; | |
1090 | SCM local; | |
1091 | SCM local_observer; | |
1092 | }; | |
1093 | ||
1094 | ||
1095 | #define EVAL_ENVIRONMENT(env) \ | |
1096 | ((struct eval_environment *) SCM_CELL_WORD_1 (env)) | |
1097 | ||
1098 | #define IMMUTABLE SCM_MAKINUM (0) | |
1099 | #define MUTABLE SCM_MAKINUM (1) | |
1100 | #define UNKNOWN SCM_MAKINUM (2) | |
1101 | ||
1102 | #define CACHED_LOCATION(x) SCM_CAR (x) | |
1103 | #define CACHED_MUTABILITY(x) SCM_CADR (x) | |
1104 | #define SET_CACHED_MUTABILITY(x, v) SCM_SETCAR (SCM_CDR (x), (v)) | |
1105 | #define CACHED_SOURCE_ENVIRONMENT(x) SCM_CDDR (x) | |
1106 | ||
1107 | \f | |
1108 | ||
1109 | /* eval_environment_lookup will report one of the following distinct results: | |
1110 | * a) (<object> . value) if a cell could be obtained. | |
1111 | * b) <environment> if the environment has to be contacted directly. | |
1112 | * c) IMMUTABLE if an immutable cell was requested for write. | |
1113 | * d) SCM_UNDEFINED if there is no binding for the symbol. | |
1114 | */ | |
1115 | static SCM | |
1116 | eval_environment_lookup (SCM env, SCM sym, int for_write) | |
1117 | { | |
1118 | SCM obarray = EVAL_ENVIRONMENT (env)->obarray; | |
1119 | SCM binding = obarray_retrieve (obarray, sym); | |
1120 | ||
1121 | if (!SCM_UNBNDP (binding)) | |
1122 | { | |
1123 | /* The obarray holds an entry for the symbol. */ | |
1124 | ||
1125 | SCM entry = SCM_CDR (binding); | |
1126 | ||
1127 | if (SCM_CONSP (entry)) | |
1128 | { | |
1129 | /* The entry in the obarray is a cached location. */ | |
1130 | ||
1131 | SCM location = CACHED_LOCATION (entry); | |
1132 | SCM mutability; | |
1133 | ||
1134 | if (!for_write) | |
1135 | return location; | |
1136 | ||
1137 | mutability = CACHED_MUTABILITY (entry); | |
1138 | if (SCM_EQ_P (mutability, MUTABLE)) | |
1139 | return location; | |
1140 | ||
1141 | if (SCM_EQ_P (mutability, UNKNOWN)) | |
1142 | { | |
1143 | SCM source_env = CACHED_SOURCE_ENVIRONMENT (entry); | |
1144 | SCM location = SCM_ENVIRONMENT_CELL (source_env, sym, 1); | |
1145 | ||
1146 | if (SCM_CONSP (location)) | |
1147 | { | |
1148 | SET_CACHED_MUTABILITY (entry, MUTABLE); | |
1149 | return location; | |
1150 | } | |
1151 | else /* IMMUTABLE */ | |
1152 | { | |
1153 | SET_CACHED_MUTABILITY (entry, IMMUTABLE); | |
1154 | return IMMUTABLE; | |
1155 | } | |
1156 | } | |
1157 | ||
1158 | return IMMUTABLE; | |
1159 | } | |
1160 | else | |
1161 | { | |
1162 | /* The obarray entry is an environment */ | |
1163 | ||
1164 | return entry; | |
1165 | } | |
1166 | } | |
1167 | else | |
1168 | { | |
1169 | /* There is no entry for the symbol in the obarray. This can either | |
1170 | * mean that there has not been a request for the symbol yet, or that | |
1171 | * the symbol is really undefined. We are looking for the symbol in | |
1172 | * both the local and the imported environment. If we find a binding, a | |
1173 | * cached entry is created. | |
1174 | */ | |
1175 | ||
1176 | struct eval_environment *body = EVAL_ENVIRONMENT (env); | |
1177 | unsigned int handling_import; | |
1178 | ||
1179 | for (handling_import = 0; handling_import <= 1; ++handling_import) | |
1180 | { | |
1181 | SCM source_env = handling_import ? body->imported : body->local; | |
1182 | SCM location = SCM_ENVIRONMENT_CELL (source_env, sym, for_write); | |
1183 | ||
1184 | if (!SCM_UNBNDP (location)) | |
1185 | { | |
1186 | if (SCM_CONSP (location)) | |
1187 | { | |
1188 | SCM mutability = for_write ? MUTABLE : UNKNOWN; | |
1189 | SCM entry = scm_cons2 (location, mutability, source_env); | |
1190 | obarray_enter (obarray, sym, entry); | |
1191 | return location; | |
1192 | } | |
1193 | else if (SCM_EQ_P (location, SCM_ENVIRONMENT_LOCATION_NO_CELL)) | |
1194 | { | |
1195 | obarray_enter (obarray, sym, source_env); | |
1196 | return source_env; | |
1197 | } | |
1198 | else | |
1199 | { | |
1200 | return IMMUTABLE; | |
1201 | } | |
1202 | } | |
1203 | } | |
1204 | ||
1205 | return SCM_UNDEFINED; | |
1206 | } | |
1207 | } | |
1208 | ||
1209 | ||
1210 | static SCM | |
1211 | eval_environment_ref (SCM env, SCM sym) | |
1212 | #define FUNC_NAME "eval_environment_ref" | |
1213 | { | |
1214 | SCM location = eval_environment_lookup (env, sym, 0); | |
1215 | ||
1216 | if (SCM_CONSP (location)) | |
1217 | return SCM_CDR (location); | |
1218 | else if (!SCM_UNBNDP (location)) | |
1219 | return SCM_ENVIRONMENT_REF (location, sym); | |
1220 | else | |
1221 | return SCM_UNDEFINED; | |
1222 | } | |
1223 | #undef FUNC_NAME | |
1224 | ||
1225 | ||
1226 | static SCM | |
1227 | eval_environment_folder (SCM extended_data, SCM symbol, SCM value, SCM tail) | |
1228 | { | |
1229 | SCM local = SCM_CAR (extended_data); | |
1230 | ||
1231 | if (!SCM_ENVIRONMENT_BOUND_P (local, symbol)) | |
1232 | { | |
1233 | SCM proc_as_nr = SCM_CADR (extended_data); | |
1234 | unsigned long int proc_as_ul = scm_num2ulong (proc_as_nr, NULL, NULL); | |
1235 | scm_environment_folder proc = (scm_environment_folder) proc_as_ul; | |
1236 | SCM data = SCM_CDDR (extended_data); | |
1237 | ||
1238 | return (*proc) (data, symbol, value, tail); | |
1239 | } | |
1240 | else | |
1241 | { | |
1242 | return tail; | |
1243 | } | |
1244 | } | |
1245 | ||
1246 | ||
1247 | static SCM | |
1248 | eval_environment_fold (SCM env, scm_environment_folder proc, SCM data, SCM init) | |
1249 | { | |
1250 | SCM local = EVAL_ENVIRONMENT (env)->local; | |
1251 | SCM imported = EVAL_ENVIRONMENT (env)->imported; | |
1252 | SCM proc_as_nr = scm_ulong2num ((unsigned long int) proc); | |
1253 | SCM extended_data = scm_cons2 (local, proc_as_nr, data); | |
1254 | SCM tmp_result = scm_c_environment_fold (imported, eval_environment_folder, extended_data, init); | |
1255 | ||
1256 | return scm_c_environment_fold (local, proc, data, tmp_result); | |
1257 | } | |
1258 | ||
1259 | ||
1260 | static SCM | |
1261 | eval_environment_define (SCM env, SCM sym, SCM val) | |
1262 | #define FUNC_NAME "eval_environment_define" | |
1263 | { | |
1264 | SCM local = EVAL_ENVIRONMENT (env)->local; | |
1265 | return SCM_ENVIRONMENT_DEFINE (local, sym, val); | |
1266 | } | |
1267 | #undef FUNC_NAME | |
1268 | ||
1269 | ||
1270 | static SCM | |
1271 | eval_environment_undefine (SCM env, SCM sym) | |
1272 | #define FUNC_NAME "eval_environment_undefine" | |
1273 | { | |
1274 | SCM local = EVAL_ENVIRONMENT (env)->local; | |
1275 | return SCM_ENVIRONMENT_UNDEFINE (local, sym); | |
1276 | } | |
1277 | #undef FUNC_NAME | |
1278 | ||
1279 | ||
1280 | static SCM | |
1281 | eval_environment_set_x (SCM env, SCM sym, SCM val) | |
1282 | #define FUNC_NAME "eval_environment_set_x" | |
1283 | { | |
1284 | SCM location = eval_environment_lookup (env, sym, 1); | |
1285 | ||
1286 | if (SCM_CONSP (location)) | |
1287 | { | |
1288 | SCM_SETCDR (location, val); | |
1289 | return SCM_ENVIRONMENT_SUCCESS; | |
1290 | } | |
1291 | else if (SCM_ENVIRONMENT_P (location)) | |
1292 | { | |
1293 | return SCM_ENVIRONMENT_SET (location, sym, val); | |
1294 | } | |
1295 | else if (SCM_EQ_P (location, IMMUTABLE)) | |
1296 | { | |
1297 | return SCM_ENVIRONMENT_LOCATION_IMMUTABLE; | |
1298 | } | |
1299 | else | |
1300 | { | |
1301 | return SCM_UNDEFINED; | |
1302 | } | |
1303 | } | |
1304 | #undef FUNC_NAME | |
1305 | ||
1306 | ||
1307 | static SCM | |
1308 | eval_environment_cell (SCM env, SCM sym, int for_write) | |
1309 | #define FUNC_NAME "eval_environment_cell" | |
1310 | { | |
1311 | SCM location = eval_environment_lookup (env, sym, for_write); | |
1312 | ||
1313 | if (SCM_CONSP (location)) | |
1314 | return location; | |
1315 | else if (SCM_ENVIRONMENT_P (location)) | |
1316 | return SCM_ENVIRONMENT_LOCATION_NO_CELL; | |
1317 | else if (SCM_EQ_P (location, IMMUTABLE)) | |
1318 | return SCM_ENVIRONMENT_LOCATION_IMMUTABLE; | |
1319 | else | |
1320 | return SCM_UNDEFINED; | |
1321 | } | |
1322 | #undef FUNC_NAME | |
1323 | ||
1324 | ||
1325 | static SCM | |
1326 | mark_eval_environment (SCM env) | |
1327 | { | |
1328 | struct eval_environment *body = EVAL_ENVIRONMENT (env); | |
1329 | ||
1330 | scm_gc_mark (body->obarray); | |
1331 | scm_gc_mark (body->imported); | |
1332 | scm_gc_mark (body->imported_observer); | |
1333 | scm_gc_mark (body->local); | |
1334 | scm_gc_mark (body->local_observer); | |
1335 | ||
1336 | return core_environments_mark (env); | |
1337 | } | |
1338 | ||
1339 | ||
1340 | static scm_sizet | |
1341 | free_eval_environment (SCM env) | |
1342 | { | |
1343 | core_environments_finalize (env); | |
1344 | ||
1345 | free (EVAL_ENVIRONMENT (env)); | |
1346 | return sizeof (struct eval_environment); | |
1347 | } | |
1348 | ||
1349 | ||
1350 | static int | |
1351 | print_eval_environment (SCM type, SCM port, scm_print_state *pstate) | |
1352 | { | |
1353 | SCM address = scm_ulong2num (SCM_UNPACK (type)); | |
1354 | SCM base16 = scm_number_to_string (address, SCM_MAKINUM (16)); | |
1355 | ||
1356 | scm_puts ("#<eval environment ", port); | |
86c991c2 | 1357 | scm_puts (SCM_STRING_CHARS (base16), port); |
5d3e2388 DH |
1358 | scm_puts (">", port); |
1359 | ||
1360 | return 1; | |
1361 | } | |
1362 | ||
1363 | ||
1364 | static struct scm_environment_funcs eval_environment_funcs = { | |
1365 | eval_environment_ref, | |
1366 | eval_environment_fold, | |
1367 | eval_environment_define, | |
1368 | eval_environment_undefine, | |
1369 | eval_environment_set_x, | |
1370 | eval_environment_cell, | |
1371 | core_environments_observe, | |
1372 | core_environments_unobserve, | |
1373 | mark_eval_environment, | |
1374 | free_eval_environment, | |
1375 | print_eval_environment | |
1376 | }; | |
1377 | ||
1378 | ||
1379 | void *scm_type_eval_environment = &eval_environment_funcs; | |
1380 | ||
1381 | ||
1382 | static void | |
1383 | eval_environment_observer (SCM caller, SCM eval_env) | |
1384 | { | |
1385 | SCM obarray = EVAL_ENVIRONMENT (eval_env)->obarray; | |
1386 | ||
1387 | obarray_remove_all (obarray); | |
1388 | core_environments_broadcast (eval_env); | |
1389 | } | |
1390 | ||
1391 | ||
1392 | SCM_DEFINE (scm_make_eval_environment, "make-eval-environment", 2, 0, 0, | |
1393 | (SCM local, SCM imported), | |
1394 | "Return a new environment object eval whose bindings are the\n" | |
1395 | "union of the bindings in the environments local and imported,\n" | |
1396 | "with bindings from local taking precedence. Definitions made\n" | |
1397 | "in eval are placed in local.\n" | |
1398 | "Applying environment-define or environment-undefine to eval\n" | |
1399 | "has the same effect as applying the procedure to local.\n" | |
1400 | "Note that eval incorporates local and imported by reference:\n" | |
1401 | "If, after creating eval, the program changes the bindings of\n" | |
1402 | "local or imported, those changes will be visible in eval.\n" | |
1403 | "Since most Scheme evaluation takes place in eval environments,\n" | |
1404 | "they transparenty cache the bindings received from local and\n" | |
1405 | "imported. Thus, the first time the program looks up a symbol\n" | |
1406 | "in eval, eval may make calls to local or imported to find\n" | |
1407 | "their bindings, but subsequent references to that symbol will\n" | |
1408 | "be as fast as references to bindings in finite environments.\n" | |
1409 | "In typical use, local will be a finite environment, and\n" | |
1410 | "imported will be an import environment") | |
1411 | #define FUNC_NAME s_scm_make_eval_environment | |
1412 | { | |
1413 | SCM env; | |
1414 | struct eval_environment *body; | |
1415 | ||
1416 | SCM_ASSERT (SCM_ENVIRONMENT_P (local), local, SCM_ARG1, FUNC_NAME); | |
1417 | SCM_ASSERT (SCM_ENVIRONMENT_P (imported), imported, SCM_ARG2, FUNC_NAME); | |
1418 | ||
1419 | body = scm_must_malloc (sizeof (struct eval_environment), FUNC_NAME); | |
1420 | ||
1421 | core_environments_preinit (&body->base); | |
1422 | body->obarray = SCM_BOOL_F; | |
1423 | body->imported = SCM_BOOL_F; | |
1424 | body->imported_observer = SCM_BOOL_F; | |
1425 | body->local = SCM_BOOL_F; | |
1426 | body->local_observer = SCM_BOOL_F; | |
1427 | ||
1428 | env = scm_make_environment (body); | |
1429 | ||
1430 | core_environments_init (&body->base, &eval_environment_funcs); | |
1431 | body->obarray = scm_make_vector (SCM_MAKINUM (scm_symhash_dim), SCM_EOL); | |
1432 | body->imported = imported; | |
1433 | body->imported_observer | |
1434 | = SCM_ENVIRONMENT_OBSERVE (imported, eval_environment_observer, env, 1); | |
1435 | body->local = local; | |
1436 | body->local_observer | |
1437 | = SCM_ENVIRONMENT_OBSERVE (local, eval_environment_observer, env, 1); | |
1438 | ||
1439 | return env; | |
1440 | } | |
1441 | #undef FUNC_NAME | |
1442 | ||
1443 | ||
1444 | SCM_DEFINE (scm_eval_environment_p, "eval-environment?", 1, 0, 0, | |
1445 | (SCM object), | |
1446 | "Return #t if object is an eval environment, or #f otherwise.") | |
1447 | #define FUNC_NAME s_scm_eval_environment_p | |
1448 | { | |
1449 | return SCM_BOOL (SCM_EVAL_ENVIRONMENT_P (object)); | |
1450 | } | |
1451 | #undef FUNC_NAME | |
1452 | ||
1453 | ||
1454 | SCM_DEFINE (scm_eval_environment_local, "eval-environment-local", 1, 0, 0, | |
1455 | (SCM env), | |
1456 | "Return the local environment of eval environment env.") | |
1457 | #define FUNC_NAME s_scm_eval_environment_local | |
1458 | { | |
1459 | SCM_ASSERT (SCM_EVAL_ENVIRONMENT_P (env), env, SCM_ARG1, FUNC_NAME); | |
1460 | ||
1461 | return EVAL_ENVIRONMENT (env)->local; | |
1462 | } | |
1463 | #undef FUNC_NAME | |
1464 | ||
1465 | ||
1466 | SCM_DEFINE (scm_eval_environment_set_local_x, "eval-environment-set-local!", 2, 0, 0, | |
1467 | (SCM env, SCM local), | |
1468 | "Change env's local environment to LOCAL.") | |
1469 | #define FUNC_NAME s_scm_eval_environment_set_local_x | |
1470 | { | |
1471 | struct eval_environment *body; | |
1472 | ||
1473 | SCM_ASSERT (SCM_EVAL_ENVIRONMENT_P (env), env, SCM_ARG1, FUNC_NAME); | |
1474 | SCM_ASSERT (SCM_ENVIRONMENT_P (local), local, SCM_ARG2, FUNC_NAME); | |
1475 | ||
1476 | body = EVAL_ENVIRONMENT (env); | |
1477 | ||
1478 | obarray_remove_all (body->obarray); | |
1479 | SCM_ENVIRONMENT_UNOBSERVE (body->local, body->local_observer); | |
1480 | ||
1481 | body->local = local; | |
1482 | body->local_observer | |
1483 | = SCM_ENVIRONMENT_OBSERVE (local, eval_environment_observer, env, 1); | |
1484 | ||
1485 | core_environments_broadcast (env); | |
1486 | ||
1487 | return SCM_UNSPECIFIED; | |
1488 | } | |
1489 | #undef FUNC_NAME | |
1490 | ||
1491 | ||
1492 | SCM_DEFINE (scm_eval_environment_imported, "eval-environment-imported", 1, 0, 0, | |
1493 | (SCM env), | |
1494 | "Return the imported environment of eval environment env.") | |
1495 | #define FUNC_NAME s_scm_eval_environment_imported | |
1496 | { | |
1497 | SCM_ASSERT (SCM_EVAL_ENVIRONMENT_P (env), env, SCM_ARG1, FUNC_NAME); | |
1498 | ||
1499 | return EVAL_ENVIRONMENT (env)->imported; | |
1500 | } | |
1501 | #undef FUNC_NAME | |
1502 | ||
1503 | ||
1504 | SCM_DEFINE (scm_eval_environment_set_imported_x, "eval-environment-set-imported!", 2, 0, 0, | |
1505 | (SCM env, SCM imported), | |
1506 | "Change env's imported environment to IMPORTED.") | |
1507 | #define FUNC_NAME s_scm_eval_environment_set_imported_x | |
1508 | { | |
1509 | struct eval_environment *body; | |
1510 | ||
1511 | SCM_ASSERT (SCM_EVAL_ENVIRONMENT_P (env), env, SCM_ARG1, FUNC_NAME); | |
1512 | SCM_ASSERT (SCM_ENVIRONMENT_P (imported), imported, SCM_ARG2, FUNC_NAME); | |
1513 | ||
1514 | body = EVAL_ENVIRONMENT (env); | |
1515 | ||
1516 | obarray_remove_all (body->obarray); | |
1517 | SCM_ENVIRONMENT_UNOBSERVE (body->imported, body->imported_observer); | |
1518 | ||
1519 | body->imported = imported; | |
1520 | body->imported_observer | |
1521 | = SCM_ENVIRONMENT_OBSERVE (imported, eval_environment_observer, env, 1); | |
1522 | ||
1523 | core_environments_broadcast (env); | |
1524 | ||
1525 | return SCM_UNSPECIFIED; | |
1526 | } | |
1527 | #undef FUNC_NAME | |
1528 | ||
1529 | \f | |
1530 | ||
1531 | /* import environments | |
1532 | * | |
1533 | * An import environment combines the bindings of a set of argument | |
1534 | * environments, and checks for naming clashes. | |
1535 | * | |
1536 | * Implementation: The import environment does no caching at all. For every | |
1537 | * access, the list of imported environments is scanned. | |
1538 | */ | |
1539 | ||
1540 | ||
1541 | struct import_environment { | |
1542 | struct core_environments_base base; | |
1543 | ||
1544 | SCM imports; | |
1545 | SCM import_observers; | |
1546 | ||
1547 | SCM conflict_proc; | |
1548 | }; | |
1549 | ||
1550 | ||
1551 | #define IMPORT_ENVIRONMENT(env) \ | |
1552 | ((struct import_environment *) SCM_CELL_WORD_1 (env)) | |
1553 | ||
1554 | \f | |
1555 | ||
1556 | /* Lookup will report one of the following distinct results: | |
1557 | * a) <environment> if only environment binds the symbol. | |
1558 | * b) (env-1 env-2 ...) for conflicting bindings in env-1, ... | |
1559 | * c) SCM_UNDEFINED if there is no binding for the symbol. | |
1560 | */ | |
1561 | static SCM | |
1562 | import_environment_lookup (SCM env, SCM sym) | |
1563 | { | |
1564 | SCM imports = IMPORT_ENVIRONMENT (env)->imports; | |
1565 | SCM result = SCM_UNDEFINED; | |
1566 | SCM l; | |
1567 | ||
1568 | for (l = imports; !SCM_NULLP (l); l = SCM_CDR (l)) | |
1569 | { | |
1570 | SCM imported = SCM_CAR (l); | |
1571 | ||
1572 | if (SCM_ENVIRONMENT_BOUND_P (imported, sym)) | |
1573 | { | |
1574 | if (SCM_UNBNDP (result)) | |
1575 | result = imported; | |
1576 | else if (SCM_CONSP (result)) | |
1577 | result = scm_cons (imported, result); | |
1578 | else | |
1579 | result = scm_cons2 (imported, result, SCM_EOL); | |
1580 | } | |
1581 | } | |
1582 | ||
1583 | if (SCM_CONSP (result)) | |
1584 | return scm_reverse (result); | |
1585 | else | |
1586 | return result; | |
1587 | } | |
1588 | ||
1589 | ||
1590 | static SCM | |
1591 | import_environment_conflict (SCM env, SCM sym, SCM imports) | |
1592 | { | |
1593 | SCM conflict_proc = IMPORT_ENVIRONMENT (env)->conflict_proc; | |
1594 | SCM args = scm_cons2 (env, sym, scm_cons (imports, SCM_EOL)); | |
1595 | ||
1596 | return scm_apply (conflict_proc, args, SCM_EOL); | |
1597 | } | |
1598 | ||
1599 | ||
1600 | static SCM | |
1601 | import_environment_ref (SCM env, SCM sym) | |
1602 | #define FUNC_NAME "import_environment_ref" | |
1603 | { | |
1604 | SCM owner = import_environment_lookup (env, sym); | |
1605 | ||
1606 | if (SCM_UNBNDP (owner)) | |
1607 | { | |
1608 | return SCM_UNDEFINED; | |
1609 | } | |
1610 | else if (SCM_CONSP (owner)) | |
1611 | { | |
1612 | SCM resolve = import_environment_conflict (env, sym, owner); | |
1613 | ||
1614 | if (SCM_ENVIRONMENT_P (resolve)) | |
1615 | return SCM_ENVIRONMENT_REF (resolve, sym); | |
1616 | else | |
1617 | return SCM_UNSPECIFIED; | |
1618 | } | |
1619 | else | |
1620 | { | |
1621 | return SCM_ENVIRONMENT_REF (owner, sym); | |
1622 | } | |
1623 | } | |
1624 | #undef FUNC_NAME | |
1625 | ||
1626 | ||
1627 | static SCM | |
1628 | import_environment_folder (SCM extended_data, SCM symbol, SCM value, SCM tail) | |
1629 | #define FUNC_NAME "import_environment_fold" | |
1630 | { | |
1631 | SCM import_env = SCM_CAR (extended_data); | |
1632 | SCM imported_env = SCM_CADR (extended_data); | |
1633 | SCM owner = import_environment_lookup (import_env, symbol); | |
1634 | SCM proc_as_nr = SCM_CADDR (extended_data); | |
1635 | unsigned long int proc_as_ul = scm_num2ulong (proc_as_nr, NULL, NULL); | |
1636 | scm_environment_folder proc = (scm_environment_folder) proc_as_ul; | |
1637 | SCM data = SCM_CDDDR (extended_data); | |
1638 | ||
1639 | if (SCM_CONSP (owner) && SCM_EQ_P (SCM_CAR (owner), imported_env)) | |
1640 | owner = import_environment_conflict (import_env, symbol, owner); | |
1641 | ||
1642 | if (SCM_ENVIRONMENT_P (owner)) | |
1643 | return (*proc) (data, symbol, value, tail); | |
1644 | else /* unresolved conflict */ | |
1645 | return (*proc) (data, symbol, SCM_UNSPECIFIED, tail); | |
1646 | } | |
1647 | #undef FUNC_NAME | |
1648 | ||
1649 | ||
1650 | static SCM | |
1651 | import_environment_fold (SCM env, scm_environment_folder proc, SCM data, SCM init) | |
1652 | { | |
1653 | SCM proc_as_nr = scm_ulong2num ((unsigned long int) proc); | |
1654 | SCM result = init; | |
1655 | SCM l; | |
1656 | ||
1657 | for (l = IMPORT_ENVIRONMENT (env)->imports; !SCM_NULLP (l); l = SCM_CDR (l)) | |
1658 | { | |
1659 | SCM imported_env = SCM_CAR (l); | |
1660 | SCM extended_data = scm_cons (env, scm_cons2 (imported_env, proc_as_nr, data)); | |
1661 | ||
1662 | result = scm_c_environment_fold (imported_env, import_environment_folder, extended_data, result); | |
1663 | } | |
1664 | ||
1665 | return result; | |
1666 | } | |
1667 | ||
1668 | ||
1669 | static SCM | |
1670 | import_environment_define (SCM env, SCM sym, SCM val) | |
1671 | #define FUNC_NAME "import_environment_define" | |
1672 | { | |
1673 | return SCM_ENVIRONMENT_BINDING_IMMUTABLE; | |
1674 | } | |
1675 | #undef FUNC_NAME | |
1676 | ||
1677 | ||
1678 | static SCM | |
1679 | import_environment_undefine (SCM env, SCM sym) | |
1680 | #define FUNC_NAME "import_environment_undefine" | |
1681 | { | |
1682 | return SCM_ENVIRONMENT_BINDING_IMMUTABLE; | |
1683 | } | |
1684 | #undef FUNC_NAME | |
1685 | ||
1686 | ||
1687 | static SCM | |
1688 | import_environment_set_x (SCM env, SCM sym, SCM val) | |
1689 | #define FUNC_NAME "import_environment_set_x" | |
1690 | { | |
1691 | SCM owner = import_environment_lookup (env, sym); | |
1692 | ||
1693 | if (SCM_UNBNDP (owner)) | |
1694 | { | |
1695 | return SCM_UNDEFINED; | |
1696 | } | |
1697 | else if (SCM_CONSP (owner)) | |
1698 | { | |
1699 | SCM resolve = import_environment_conflict (env, sym, owner); | |
1700 | ||
1701 | if (SCM_ENVIRONMENT_P (resolve)) | |
1702 | return SCM_ENVIRONMENT_SET (resolve, sym, val); | |
1703 | else | |
1704 | return SCM_ENVIRONMENT_LOCATION_IMMUTABLE; | |
1705 | } | |
1706 | else | |
1707 | { | |
1708 | return SCM_ENVIRONMENT_SET (owner, sym, val); | |
1709 | } | |
1710 | } | |
1711 | #undef FUNC_NAME | |
1712 | ||
1713 | ||
1714 | static SCM | |
1715 | import_environment_cell (SCM env, SCM sym, int for_write) | |
1716 | #define FUNC_NAME "import_environment_cell" | |
1717 | { | |
1718 | SCM owner = import_environment_lookup (env, sym); | |
1719 | ||
1720 | if (SCM_UNBNDP (owner)) | |
1721 | { | |
1722 | return SCM_UNDEFINED; | |
1723 | } | |
1724 | else if (SCM_CONSP (owner)) | |
1725 | { | |
1726 | SCM resolve = import_environment_conflict (env, sym, owner); | |
1727 | ||
1728 | if (SCM_ENVIRONMENT_P (resolve)) | |
1729 | return SCM_ENVIRONMENT_CELL (resolve, sym, for_write); | |
1730 | else | |
1731 | return SCM_ENVIRONMENT_LOCATION_NO_CELL; | |
1732 | } | |
1733 | else | |
1734 | { | |
1735 | return SCM_ENVIRONMENT_CELL (owner, sym, for_write); | |
1736 | } | |
1737 | } | |
1738 | #undef FUNC_NAME | |
1739 | ||
1740 | ||
1741 | static SCM | |
1742 | mark_import_environment (SCM env) | |
1743 | { | |
1744 | scm_gc_mark (IMPORT_ENVIRONMENT (env)->imports); | |
1745 | scm_gc_mark (IMPORT_ENVIRONMENT (env)->import_observers); | |
1746 | scm_gc_mark (IMPORT_ENVIRONMENT (env)->conflict_proc); | |
1747 | return core_environments_mark (env); | |
1748 | } | |
1749 | ||
1750 | ||
1751 | static scm_sizet | |
1752 | free_import_environment (SCM env) | |
1753 | { | |
1754 | core_environments_finalize (env); | |
1755 | ||
1756 | free (IMPORT_ENVIRONMENT (env)); | |
1757 | return sizeof (struct import_environment); | |
1758 | } | |
1759 | ||
1760 | ||
1761 | static int | |
1762 | print_import_environment (SCM type, SCM port, scm_print_state *pstate) | |
1763 | { | |
1764 | SCM address = scm_ulong2num (SCM_UNPACK (type)); | |
1765 | SCM base16 = scm_number_to_string (address, SCM_MAKINUM (16)); | |
1766 | ||
1767 | scm_puts ("#<import environment ", port); | |
86c991c2 | 1768 | scm_puts (SCM_STRING_CHARS (base16), port); |
5d3e2388 DH |
1769 | scm_puts (">", port); |
1770 | ||
1771 | return 1; | |
1772 | } | |
1773 | ||
1774 | ||
1775 | static struct scm_environment_funcs import_environment_funcs = { | |
1776 | import_environment_ref, | |
1777 | import_environment_fold, | |
1778 | import_environment_define, | |
1779 | import_environment_undefine, | |
1780 | import_environment_set_x, | |
1781 | import_environment_cell, | |
1782 | core_environments_observe, | |
1783 | core_environments_unobserve, | |
1784 | mark_import_environment, | |
1785 | free_import_environment, | |
1786 | print_import_environment | |
1787 | }; | |
1788 | ||
1789 | ||
1790 | void *scm_type_import_environment = &import_environment_funcs; | |
1791 | ||
1792 | ||
1793 | static void | |
1794 | import_environment_observer (SCM caller, SCM import_env) | |
1795 | { | |
1796 | core_environments_broadcast (import_env); | |
1797 | } | |
1798 | ||
1799 | ||
1800 | SCM_DEFINE (scm_make_import_environment, "make-import-environment", 2, 0, 0, | |
1801 | (SCM imports, SCM conflict_proc), | |
1802 | "Return a new environment imp whose bindings are the union of\n" | |
1803 | "the bindings from the environments in imports; imports must\n" | |
1804 | "be a list of environments. That is, imp binds symbol to\n" | |
1805 | "location when some element of imports does.\n" | |
1806 | "If two different elements of imports have a binding for the\n" | |
1807 | "same symbol, the conflict-proc is called with the following\n" | |
1808 | "parameters: the import environment, the symbol and the list\n" | |
1809 | "of the imported environments that bind the symbol. If the\n" | |
1810 | "conflict-proc returns an environment env, the conflict is\n" | |
1811 | "considered as resolved and the binding from env is used. If\n" | |
1812 | "the conflict-proc returns some non-environment object, the\n" | |
1813 | "conflict is considered unresolved and the symbol is treated\n" | |
1814 | "as unspecified in the import environment.\n" | |
1815 | "The checking for conflicts may be performed lazily, i. e. at\m" | |
1816 | "the moment when a value or binding for a certain symbol is\n" | |
1817 | "requested instead of the moment when the environment is\n" | |
1818 | "created or the bindings of the imports change.\n" | |
1819 | "All bindings in imp are immutable. If you apply\n" | |
1820 | "environment-define or environment-undefine to imp, Guile\n" | |
1821 | "will signal an environment:immutable-binding error. However,\n" | |
1822 | "notice that the set of bindings in imp may still change, if\n" | |
1823 | "one of its imported environments changes.") | |
1824 | #define FUNC_NAME s_scm_make_import_environment | |
1825 | { | |
1826 | scm_sizet size = sizeof (struct import_environment); | |
1827 | struct import_environment *body = scm_must_malloc (size, FUNC_NAME); | |
1828 | SCM env; | |
1829 | ||
1830 | core_environments_preinit (&body->base); | |
1831 | body->imports = SCM_BOOL_F; | |
1832 | body->import_observers = SCM_BOOL_F; | |
1833 | body->conflict_proc = SCM_BOOL_F; | |
1834 | ||
1835 | env = scm_make_environment (body); | |
1836 | ||
1837 | core_environments_init (&body->base, &import_environment_funcs); | |
1838 | body->imports = SCM_EOL; | |
1839 | body->import_observers = SCM_EOL; | |
1840 | body->conflict_proc = conflict_proc; | |
1841 | ||
1842 | scm_import_environment_set_imports_x (env, imports); | |
1843 | ||
1844 | return env; | |
1845 | } | |
1846 | #undef FUNC_NAME | |
1847 | ||
1848 | ||
1849 | SCM_DEFINE (scm_import_environment_p, "import-environment?", 1, 0, 0, | |
1850 | (SCM object), | |
1851 | "Return #t if object is an import environment, or #f otherwise.") | |
1852 | #define FUNC_NAME s_scm_import_environment_p | |
1853 | { | |
1854 | return SCM_BOOL (SCM_IMPORT_ENVIRONMENT_P (object)); | |
1855 | } | |
1856 | #undef FUNC_NAME | |
1857 | ||
1858 | ||
1859 | SCM_DEFINE (scm_import_environment_imports, "import-environment-imports", 1, 0, 0, | |
1860 | (SCM env), | |
1861 | "Return the list of environments imported by the import environment env.") | |
1862 | #define FUNC_NAME s_scm_import_environment_imports | |
1863 | { | |
1864 | SCM_ASSERT (SCM_IMPORT_ENVIRONMENT_P (env), env, SCM_ARG1, FUNC_NAME); | |
1865 | ||
1866 | return IMPORT_ENVIRONMENT (env)->imports; | |
1867 | } | |
1868 | #undef FUNC_NAME | |
1869 | ||
1870 | ||
1871 | SCM_DEFINE (scm_import_environment_set_imports_x, "import-environment-set-imports!", 2, 0, 0, | |
1872 | (SCM env, SCM imports), | |
1873 | "Change env's list of imported environments to imports, and check for conflicts.") | |
1874 | #define FUNC_NAME s_scm_import_environment_set_imports_x | |
1875 | { | |
1876 | struct import_environment *body = IMPORT_ENVIRONMENT (env); | |
1877 | SCM import_observers = SCM_EOL; | |
1878 | SCM l; | |
1879 | ||
1880 | SCM_ASSERT (SCM_IMPORT_ENVIRONMENT_P (env), env, SCM_ARG1, FUNC_NAME); | |
1881 | for (l = imports; SCM_CONSP (l); l = SCM_CDR (l)) | |
1882 | { | |
1883 | SCM obj = SCM_CAR (l); | |
1884 | SCM_ASSERT (SCM_ENVIRONMENT_P (obj), imports, SCM_ARG1, FUNC_NAME); | |
1885 | } | |
1886 | SCM_ASSERT (SCM_NULLP (l), imports, SCM_ARG1, FUNC_NAME); | |
1887 | ||
1888 | for (l = body->import_observers; !SCM_NULLP (l); l = SCM_CDR (l)) | |
1889 | { | |
1890 | SCM obs = SCM_CAR (l); | |
1891 | SCM_ENVIRONMENT_UNOBSERVE (env, obs); | |
1892 | } | |
1893 | ||
1894 | for (l = imports; !SCM_NULLP (l); l = SCM_CDR (l)) | |
1895 | { | |
1896 | SCM imp = SCM_CAR (l); | |
1897 | SCM obs = SCM_ENVIRONMENT_OBSERVE (imp, import_environment_observer, env, 1); | |
1898 | import_observers = scm_cons (obs, import_observers); | |
1899 | } | |
1900 | ||
1901 | body->imports = imports; | |
1902 | body->import_observers = import_observers; | |
1903 | ||
1904 | return SCM_UNSPECIFIED; | |
1905 | } | |
1906 | #undef FUNC_NAME | |
1907 | ||
1908 | \f | |
1909 | ||
1910 | /* export environments | |
1911 | * | |
1912 | * An export environment restricts an environment to a specified set of | |
1913 | * bindings. | |
1914 | * | |
1915 | * Implementation: The export environment does no caching at all. For every | |
1916 | * access, the signature is scanned. The signature that is stored internally | |
1917 | * is an alist of pairs (symbol . (mutability)). | |
1918 | */ | |
1919 | ||
1920 | ||
1921 | struct export_environment { | |
1922 | struct core_environments_base base; | |
1923 | ||
1924 | SCM private; | |
1925 | SCM private_observer; | |
1926 | ||
1927 | SCM signature; | |
1928 | }; | |
1929 | ||
1930 | ||
1931 | #define EXPORT_ENVIRONMENT(env) \ | |
1932 | ((struct export_environment *) SCM_CELL_WORD_1 (env)) | |
1933 | ||
1934 | ||
1935 | SCM_SYMBOL (symbol_immutable_location, "immutable-location"); | |
1936 | SCM_SYMBOL (symbol_mutable_location, "mutable-location"); | |
1937 | ||
1938 | \f | |
1939 | ||
1940 | static SCM | |
1941 | export_environment_ref (SCM env, SCM sym) | |
1942 | #define FUNC_NAME "export_environment_ref" | |
1943 | { | |
1944 | struct export_environment *body = EXPORT_ENVIRONMENT (env); | |
1945 | SCM entry = scm_assq (sym, body->signature); | |
1946 | ||
1947 | if (SCM_FALSEP (entry)) | |
1948 | return SCM_UNDEFINED; | |
1949 | else | |
1950 | return SCM_ENVIRONMENT_REF (body->private, sym); | |
1951 | } | |
1952 | #undef FUNC_NAME | |
1953 | ||
1954 | ||
1955 | static SCM | |
1956 | export_environment_fold (SCM env, scm_environment_folder proc, SCM data, SCM init) | |
1957 | { | |
1958 | struct export_environment *body = EXPORT_ENVIRONMENT (env); | |
1959 | SCM result = init; | |
1960 | SCM l; | |
1961 | ||
1962 | for (l = body->signature; !SCM_NULLP (l); l = SCM_CDR (l)) | |
1963 | { | |
1964 | SCM symbol = SCM_CAR (l); | |
1965 | SCM value = SCM_ENVIRONMENT_REF (body->private, symbol); | |
1966 | if (!SCM_UNBNDP (value)) | |
1967 | result = (*proc) (data, symbol, value, result); | |
1968 | } | |
1969 | return result; | |
1970 | } | |
1971 | ||
1972 | ||
1973 | static SCM | |
1974 | export_environment_define (SCM env, SCM sym, SCM val) | |
1975 | #define FUNC_NAME "export_environment_define" | |
1976 | { | |
1977 | return SCM_ENVIRONMENT_BINDING_IMMUTABLE; | |
1978 | } | |
1979 | #undef FUNC_NAME | |
1980 | ||
1981 | ||
1982 | static SCM | |
1983 | export_environment_undefine (SCM env, SCM sym) | |
1984 | #define FUNC_NAME "export_environment_undefine" | |
1985 | { | |
1986 | return SCM_ENVIRONMENT_BINDING_IMMUTABLE; | |
1987 | } | |
1988 | #undef FUNC_NAME | |
1989 | ||
1990 | ||
1991 | static SCM | |
1992 | export_environment_set_x (SCM env, SCM sym, SCM val) | |
1993 | #define FUNC_NAME "export_environment_set_x" | |
1994 | { | |
1995 | struct export_environment *body = EXPORT_ENVIRONMENT (env); | |
1996 | SCM entry = scm_assq (sym, body->signature); | |
1997 | ||
1998 | if (SCM_FALSEP (entry)) | |
1999 | { | |
2000 | return SCM_UNDEFINED; | |
2001 | } | |
2002 | else | |
2003 | { | |
2004 | if (SCM_EQ_P (SCM_CADR (entry), symbol_mutable_location)) | |
2005 | return SCM_ENVIRONMENT_SET (body->private, sym, val); | |
2006 | else | |
2007 | return SCM_ENVIRONMENT_LOCATION_IMMUTABLE; | |
2008 | } | |
2009 | } | |
2010 | #undef FUNC_NAME | |
2011 | ||
2012 | ||
2013 | static SCM | |
2014 | export_environment_cell (SCM env, SCM sym, int for_write) | |
2015 | #define FUNC_NAME "export_environment_cell" | |
2016 | { | |
2017 | struct export_environment *body = EXPORT_ENVIRONMENT (env); | |
2018 | SCM entry = scm_assq (sym, body->signature); | |
2019 | ||
2020 | if (SCM_FALSEP (entry)) | |
2021 | { | |
2022 | return SCM_UNDEFINED; | |
2023 | } | |
2024 | else | |
2025 | { | |
2026 | if (!for_write || SCM_EQ_P (SCM_CADR (entry), symbol_mutable_location)) | |
2027 | return SCM_ENVIRONMENT_CELL (body->private, sym, for_write); | |
2028 | else | |
2029 | return SCM_ENVIRONMENT_LOCATION_IMMUTABLE; | |
2030 | } | |
2031 | } | |
2032 | #undef FUNC_NAME | |
2033 | ||
2034 | ||
2035 | static SCM | |
2036 | mark_export_environment (SCM env) | |
2037 | { | |
2038 | struct export_environment *body = EXPORT_ENVIRONMENT (env); | |
2039 | ||
2040 | scm_gc_mark (body->private); | |
2041 | scm_gc_mark (body->private_observer); | |
2042 | scm_gc_mark (body->signature); | |
2043 | ||
2044 | return core_environments_mark (env); | |
2045 | } | |
2046 | ||
2047 | ||
2048 | static scm_sizet | |
2049 | free_export_environment (SCM env) | |
2050 | { | |
2051 | core_environments_finalize (env); | |
2052 | ||
2053 | free (EXPORT_ENVIRONMENT (env)); | |
2054 | return sizeof (struct export_environment); | |
2055 | } | |
2056 | ||
2057 | ||
2058 | static int | |
2059 | print_export_environment (SCM type, SCM port, scm_print_state *pstate) | |
2060 | { | |
2061 | SCM address = scm_ulong2num (SCM_UNPACK (type)); | |
2062 | SCM base16 = scm_number_to_string (address, SCM_MAKINUM (16)); | |
2063 | ||
2064 | scm_puts ("#<export environment ", port); | |
86c991c2 | 2065 | scm_puts (SCM_STRING_CHARS (base16), port); |
5d3e2388 DH |
2066 | scm_puts (">", port); |
2067 | ||
2068 | return 1; | |
2069 | } | |
2070 | ||
2071 | ||
2072 | static struct scm_environment_funcs export_environment_funcs = { | |
2073 | export_environment_ref, | |
2074 | export_environment_fold, | |
2075 | export_environment_define, | |
2076 | export_environment_undefine, | |
2077 | export_environment_set_x, | |
2078 | export_environment_cell, | |
2079 | core_environments_observe, | |
2080 | core_environments_unobserve, | |
2081 | mark_export_environment, | |
2082 | free_export_environment, | |
2083 | print_export_environment | |
2084 | }; | |
2085 | ||
2086 | ||
2087 | void *scm_type_export_environment = &export_environment_funcs; | |
2088 | ||
2089 | ||
2090 | static void | |
2091 | export_environment_observer (SCM caller, SCM export_env) | |
2092 | { | |
2093 | core_environments_broadcast (export_env); | |
2094 | } | |
2095 | ||
2096 | ||
2097 | SCM_DEFINE (scm_make_export_environment, "make-export-environment", 2, 0, 0, | |
2098 | (SCM private, SCM signature), | |
2099 | "Return a new environment exp containing only those bindings\n" | |
2100 | "in private whose symbols are present in signature. The\n" | |
2101 | "private argument must be an environment.\n\n" | |
2102 | "The environment exp binds symbol to location when env does,\n" | |
2103 | "and symbol is exported by signature.\n\n" | |
2104 | "Signature is a list specifying which of the bindings in\n" | |
2105 | "private should be visible in exp. Each element of signature\n" | |
2106 | "should be a list of the form:\n" | |
2107 | " (symbol attribute ...)\n" | |
2108 | "where each attribute is one of the following:\n" | |
2109 | "* the symbol mutable-location exp should treat the location\n" | |
2110 | " bound to symbol as mutable. That is, exp will pass calls\n" | |
2111 | " to env-set! or environment-cell directly through to\n" | |
2112 | " private.\n" | |
2113 | "* the symbol immutable-location exp should treat the\n" | |
2114 | " location bound to symbol as immutable. If the program\n" | |
2115 | " applies environment-set! to exp and symbol, or calls\n" | |
2116 | " environment-cell to obtain a writable value cell,\n" | |
2117 | " environment-set! will signal an\n" | |
2118 | " environment:immutable-location error. Note that, even if\n" | |
2119 | " an export environment treats a location as immutable, the\n" | |
2120 | " underlying environment may treat it as mutable, so its\n" | |
2121 | " value may change.\n" | |
2122 | "It is an error for an element of signature to specify both\n" | |
2123 | "mutable-location and immutable-location. If neither is\n" | |
2124 | "specified, immutable-location is assumed.\n\n" | |
2125 | "As a special case, if an element of signature is a lone\n" | |
2126 | "symbol sym, it is equivalent to an element of the form\n" | |
2127 | "(sym).\n\n" | |
2128 | "All bindings in exp are immutable. If you apply\n" | |
2129 | "environment-define or environment-undefine to exp, Guile\n" | |
2130 | "will signal an environment:immutable-binding error. However,\n" | |
2131 | "notice that the set of bindings in exp may still change, if\n" | |
2132 | "the bindings in private change.") | |
2133 | #define FUNC_NAME s_scm_make_export_environment | |
2134 | { | |
2135 | scm_sizet size; | |
2136 | struct export_environment *body; | |
2137 | SCM env; | |
2138 | ||
2139 | SCM_ASSERT (SCM_ENVIRONMENT_P (private), private, SCM_ARG1, FUNC_NAME); | |
2140 | ||
2141 | size = sizeof (struct export_environment); | |
2142 | body = scm_must_malloc (size, FUNC_NAME); | |
2143 | ||
2144 | core_environments_preinit (&body->base); | |
2145 | body->private = SCM_BOOL_F; | |
2146 | body->private_observer = SCM_BOOL_F; | |
2147 | body->signature = SCM_BOOL_F; | |
2148 | ||
2149 | env = scm_make_environment (body); | |
2150 | ||
2151 | core_environments_init (&body->base, &export_environment_funcs); | |
2152 | body->private = private; | |
2153 | body->private_observer | |
2154 | = SCM_ENVIRONMENT_OBSERVE (private, export_environment_observer, env, 1); | |
2155 | body->signature = SCM_EOL; | |
2156 | ||
2157 | scm_export_environment_set_signature_x (env, signature); | |
2158 | ||
2159 | return env; | |
2160 | } | |
2161 | #undef FUNC_NAME | |
2162 | ||
2163 | ||
2164 | SCM_DEFINE (scm_export_environment_p, "export-environment?", 1, 0, 0, | |
2165 | (SCM object), | |
2166 | "Return #t if object is an export environment, or #f otherwise.") | |
2167 | #define FUNC_NAME s_scm_export_environment_p | |
2168 | { | |
2169 | return SCM_BOOL (SCM_EXPORT_ENVIRONMENT_P (object)); | |
2170 | } | |
2171 | #undef FUNC_NAME | |
2172 | ||
2173 | ||
2174 | SCM_DEFINE (scm_export_environment_private, "export-environment-private", 1, 0, 0, | |
2175 | (SCM env), | |
2176 | "Return the private environment of export environment env.") | |
2177 | #define FUNC_NAME s_scm_export_environment_private | |
2178 | { | |
2179 | SCM_ASSERT (SCM_EXPORT_ENVIRONMENT_P (env), env, SCM_ARG1, FUNC_NAME); | |
2180 | ||
2181 | return EXPORT_ENVIRONMENT (env)->private; | |
2182 | } | |
2183 | #undef FUNC_NAME | |
2184 | ||
2185 | ||
2186 | SCM_DEFINE (scm_export_environment_set_private_x, "export-environment-set-private!", 2, 0, 0, | |
2187 | (SCM env, SCM private), | |
2188 | "Change the private environment of export environment env.") | |
2189 | #define FUNC_NAME s_scm_export_environment_set_private_x | |
2190 | { | |
2191 | struct export_environment *body; | |
2192 | ||
2193 | SCM_ASSERT (SCM_EXPORT_ENVIRONMENT_P (env), env, SCM_ARG1, FUNC_NAME); | |
2194 | SCM_ASSERT (SCM_ENVIRONMENT_P (private), private, SCM_ARG2, FUNC_NAME); | |
2195 | ||
2196 | body = EXPORT_ENVIRONMENT (env); | |
2197 | SCM_ENVIRONMENT_UNOBSERVE (private, body->private_observer); | |
2198 | ||
2199 | body->private = private; | |
2200 | body->private_observer | |
2201 | = SCM_ENVIRONMENT_OBSERVE (private, export_environment_observer, env, 1); | |
2202 | ||
2203 | return SCM_UNSPECIFIED; | |
2204 | } | |
2205 | #undef FUNC_NAME | |
2206 | ||
2207 | ||
2208 | SCM_DEFINE (scm_export_environment_signature, "export-environment-signature", 1, 0, 0, | |
2209 | (SCM env), | |
2210 | "Return the signature of export environment env.") | |
2211 | #define FUNC_NAME s_scm_export_environment_signature | |
2212 | { | |
2213 | SCM_ASSERT (SCM_EXPORT_ENVIRONMENT_P (env), env, SCM_ARG1, FUNC_NAME); | |
2214 | ||
2215 | return EXPORT_ENVIRONMENT (env)->signature; | |
2216 | } | |
2217 | #undef FUNC_NAME | |
2218 | ||
2219 | ||
2220 | static SCM | |
2221 | export_environment_parse_signature (SCM signature, const char* caller) | |
2222 | { | |
2223 | SCM result = SCM_EOL; | |
2224 | SCM l; | |
2225 | ||
2226 | for (l = signature; SCM_CONSP (l); l = SCM_CDR (l)) | |
2227 | { | |
2228 | SCM entry = SCM_CAR (l); | |
2229 | ||
2230 | if (SCM_SYMBOLP (entry)) | |
2231 | { | |
2232 | SCM new_entry = scm_cons2 (entry, symbol_immutable_location, SCM_EOL); | |
2233 | result = scm_cons (new_entry, result); | |
2234 | } | |
2235 | else | |
2236 | { | |
2237 | SCM sym; | |
2238 | SCM new_entry; | |
2239 | int immutable = 0; | |
2240 | int mutable = 0; | |
2241 | SCM mutability; | |
2242 | SCM l2; | |
2243 | ||
2244 | SCM_ASSERT (SCM_CONSP (entry), entry, SCM_ARGn, caller); | |
2245 | SCM_ASSERT (SCM_SYMBOLP (SCM_CAR (entry)), entry, SCM_ARGn, caller); | |
2246 | ||
2247 | sym = SCM_CAR (entry); | |
2248 | ||
2249 | for (l2 = SCM_CDR (entry); SCM_CONSP (l2); l2 = SCM_CDR (l2)) | |
2250 | { | |
2251 | SCM attribute = SCM_CAR (l2); | |
2252 | if (SCM_EQ_P (attribute, symbol_immutable_location)) | |
2253 | immutable = 1; | |
2254 | else if (SCM_EQ_P (attribute, symbol_mutable_location)) | |
2255 | mutable = 1; | |
2256 | else | |
2257 | SCM_ASSERT (0, entry, SCM_ARGn, caller); | |
2258 | } | |
2259 | SCM_ASSERT (SCM_NULLP (l2), entry, SCM_ARGn, caller); | |
2260 | SCM_ASSERT (!mutable || !immutable, entry, SCM_ARGn, caller); | |
2261 | ||
2262 | if (!mutable && !immutable) | |
2263 | immutable = 1; | |
2264 | ||
2265 | mutability = mutable ? symbol_mutable_location : symbol_immutable_location; | |
2266 | new_entry = scm_cons2 (sym, mutability, SCM_EOL); | |
2267 | result = scm_cons (new_entry, result); | |
2268 | } | |
2269 | } | |
2270 | SCM_ASSERT (SCM_NULLP (l), signature, SCM_ARGn, caller); | |
2271 | ||
2272 | /* Dirk:FIXME:: Now we know that signature is syntactically correct. There | |
2273 | * are, however, no checks for symbols entered twice with contradicting | |
2274 | * mutabilities. It would be nice, to implement this test, to be able to | |
2275 | * call the sort functions conveniently from C. | |
2276 | */ | |
2277 | ||
2278 | return scm_reverse (result); | |
2279 | } | |
2280 | ||
2281 | ||
2282 | SCM_DEFINE (scm_export_environment_set_signature_x, "export-environment-set-signature!", 2, 0, 0, | |
2283 | (SCM env, SCM signature), | |
2284 | "Change the signature of export environment env.") | |
2285 | #define FUNC_NAME s_scm_export_environment_set_signature_x | |
2286 | { | |
2287 | SCM parsed_sig; | |
2288 | ||
2289 | SCM_ASSERT (SCM_EXPORT_ENVIRONMENT_P (env), env, SCM_ARG1, FUNC_NAME); | |
2290 | parsed_sig = export_environment_parse_signature (signature, FUNC_NAME); | |
2291 | ||
2292 | EXPORT_ENVIRONMENT (env)->signature = parsed_sig; | |
2293 | ||
2294 | return SCM_UNSPECIFIED; | |
2295 | } | |
2296 | #undef FUNC_NAME | |
2297 | ||
2298 | \f | |
2299 | ||
2300 | void | |
2301 | scm_environments_prehistory () | |
2302 | { | |
2303 | /* create environment smob */ | |
2304 | scm_tc16_environment = scm_make_smob_type ("environment", 0); | |
2305 | scm_set_smob_mark (scm_tc16_environment, mark_environment); | |
2306 | scm_set_smob_free (scm_tc16_environment, free_environment); | |
2307 | scm_set_smob_print (scm_tc16_environment, print_environment); | |
2308 | ||
2309 | /* create observer smob */ | |
2310 | scm_tc16_observer = scm_make_smob_type ("observer", 0); | |
2311 | scm_set_smob_mark (scm_tc16_observer, mark_observer); | |
2312 | scm_set_smob_free (scm_tc16_observer, free_observer); | |
2313 | scm_set_smob_print (scm_tc16_observer, print_observer); | |
2314 | } | |
2315 | ||
2316 | ||
2317 | void | |
2318 | scm_init_environments () | |
2319 | { | |
480a873c | 2320 | #include "libguile/environments.x" |
5d3e2388 DH |
2321 | } |
2322 | ||
2323 | ||
2324 | /* | |
2325 | Local Variables: | |
2326 | c-file-style: "gnu" | |
2327 | End: | |
2328 | */ |