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e4b265d8 | 1 | /* Copyright (C) 1999,2000,2001 Free Software Foundation, Inc. |
5d3e2388 DH |
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 | ||
92c2555f MV |
59 | scm_t_bits scm_tc16_environment; |
60 | scm_t_bits scm_tc16_observer; | |
93d40df2 | 61 | #define DEFAULT_OBARRAY_SIZE 137 |
5d3e2388 | 62 | |
de42a0ee DH |
63 | SCM scm_system_environment; |
64 | ||
5d3e2388 DH |
65 | \f |
66 | ||
67 | /* error conditions */ | |
68 | ||
69 | /* | |
70 | * Throw an error if symbol is not bound in environment func | |
71 | */ | |
72 | void | |
73 | scm_error_environment_unbound (const char *func, SCM env, SCM symbol) | |
74 | { | |
75 | /* Dirk:FIXME:: Should throw an environment:unbound type error */ | |
76 | char error[] = "Symbol `~A' not bound in environment `~A'."; | |
77 | SCM arguments = scm_cons2 (symbol, env, SCM_EOL); | |
78 | scm_misc_error (func, error, arguments); | |
79 | } | |
80 | ||
81 | ||
82 | /* | |
83 | * Throw an error if func tried to create (define) or remove | |
84 | * (undefine) a new binding for symbol in env | |
85 | */ | |
86 | void | |
87 | scm_error_environment_immutable_binding (const char *func, SCM env, SCM symbol) | |
88 | { | |
89 | /* Dirk:FIXME:: Should throw an environment:immutable-binding type error */ | |
90 | char error[] = "Immutable binding in environment ~A (symbol: `~A')."; | |
91 | SCM arguments = scm_cons2 (env, symbol, SCM_EOL); | |
92 | scm_misc_error (func, error, arguments); | |
93 | } | |
94 | ||
95 | ||
96 | /* | |
97 | * Throw an error if func tried to change an immutable location. | |
98 | */ | |
99 | void | |
100 | scm_error_environment_immutable_location (const char *func, SCM env, SCM symbol) | |
101 | { | |
102 | /* Dirk:FIXME:: Should throw an environment:immutable-location type error */ | |
103 | char error[] = "Immutable location in environment `~A' (symbol: `~A')."; | |
104 | SCM arguments = scm_cons2 (env, symbol, SCM_EOL); | |
105 | scm_misc_error (func, error, arguments); | |
106 | } | |
107 | ||
108 | \f | |
109 | ||
110 | /* generic environments */ | |
111 | ||
112 | ||
113 | /* Create an environment for the given type. Dereferencing type twice must | |
114 | * deliver the initialized set of environment functions. Thus, type will | |
115 | * also determine the signature of the underlying environment implementation. | |
116 | * Dereferencing type once will typically deliver the data fields used by the | |
117 | * underlying environment implementation. | |
118 | */ | |
119 | SCM | |
120 | scm_make_environment (void *type) | |
121 | { | |
228a24ef | 122 | return scm_cell (scm_tc16_environment, (scm_t_bits) type); |
5d3e2388 DH |
123 | } |
124 | ||
125 | ||
126 | SCM_DEFINE (scm_environment_p, "environment?", 1, 0, 0, | |
127 | (SCM obj), | |
0fb104ed MG |
128 | "Return @code{#t} if @var{obj} is an environment, or @code{#f}\n" |
129 | "otherwise.") | |
5d3e2388 DH |
130 | #define FUNC_NAME s_scm_environment_p |
131 | { | |
132 | return SCM_BOOL (SCM_ENVIRONMENT_P (obj)); | |
133 | } | |
134 | #undef FUNC_NAME | |
135 | ||
136 | ||
137 | SCM_DEFINE (scm_environment_bound_p, "environment-bound?", 2, 0, 0, | |
138 | (SCM env, SCM sym), | |
0fb104ed MG |
139 | "Return @code{#t} if @var{sym} is bound in @var{env}, or\n" |
140 | "@code{#f} otherwise.") | |
5d3e2388 DH |
141 | #define FUNC_NAME s_scm_environment_bound_p |
142 | { | |
143 | SCM_ASSERT (SCM_ENVIRONMENT_P (env), env, SCM_ARG1, FUNC_NAME); | |
144 | SCM_ASSERT (SCM_SYMBOLP (sym), sym, SCM_ARG2, FUNC_NAME); | |
145 | ||
146 | return SCM_BOOL (SCM_ENVIRONMENT_BOUND_P (env, sym)); | |
147 | } | |
148 | #undef FUNC_NAME | |
149 | ||
150 | ||
151 | SCM_DEFINE (scm_environment_ref, "environment-ref", 2, 0, 0, | |
152 | (SCM env, SCM sym), | |
0fb104ed MG |
153 | "Return the value of the location bound to @var{sym} in\n" |
154 | "@var{env}. If @var{sym} is unbound in @var{env}, signal an\n" | |
155 | "@code{environment:unbound} error.") | |
5d3e2388 DH |
156 | #define FUNC_NAME s_scm_environment_ref |
157 | { | |
158 | SCM val; | |
159 | ||
160 | SCM_ASSERT (SCM_ENVIRONMENT_P (env), env, SCM_ARG1, FUNC_NAME); | |
161 | SCM_ASSERT (SCM_SYMBOLP (sym), sym, SCM_ARG2, FUNC_NAME); | |
162 | ||
163 | val = SCM_ENVIRONMENT_REF (env, sym); | |
164 | ||
165 | if (!SCM_UNBNDP (val)) | |
166 | return val; | |
167 | else | |
168 | scm_error_environment_unbound (FUNC_NAME, env, sym); | |
169 | } | |
170 | #undef FUNC_NAME | |
171 | ||
172 | ||
173 | /* This C function is identical to environment-ref, except that if symbol is | |
174 | * unbound in env, it returns the value SCM_UNDEFINED, instead of signalling | |
175 | * an error. | |
176 | */ | |
177 | SCM | |
178 | scm_c_environment_ref (SCM env, SCM sym) | |
179 | { | |
180 | SCM_ASSERT (SCM_ENVIRONMENT_P (env), env, SCM_ARG1, "scm_c_environment_ref"); | |
181 | SCM_ASSERT (SCM_SYMBOLP (sym), sym, SCM_ARG2, "scm_c_environment_ref"); | |
182 | return SCM_ENVIRONMENT_REF (env, sym); | |
183 | } | |
184 | ||
185 | ||
186 | static SCM | |
187 | environment_default_folder (SCM proc, SCM symbol, SCM value, SCM tail) | |
188 | { | |
189 | return gh_call3 (proc, symbol, value, tail); | |
190 | } | |
191 | ||
192 | ||
193 | SCM_DEFINE (scm_environment_fold, "environment-fold", 3, 0, 0, | |
194 | (SCM env, SCM proc, SCM init), | |
0fb104ed MG |
195 | "Iterate over all the bindings in @var{env}, accumulating some\n" |
196 | "value.\n" | |
197 | "For each binding in @var{env}, apply @var{proc} to the symbol\n" | |
198 | "bound, its value, and the result from the previous application\n" | |
199 | "of @var{proc}.\n" | |
200 | "Use @var{init} as @var{proc}'s third argument the first time\n" | |
201 | "@var{proc} is applied.\n" | |
202 | "If @var{env} contains no bindings, this function simply returns\n" | |
203 | "@var{init}.\n" | |
204 | "If @var{env} binds the symbol sym1 to the value val1, sym2 to\n" | |
205 | "val2, and so on, then this procedure computes:\n" | |
1e6808ea | 206 | "@lisp\n" |
5d3e2388 DH |
207 | " (proc sym1 val1\n" |
208 | " (proc sym2 val2\n" | |
209 | " ...\n" | |
210 | " (proc symn valn\n" | |
211 | " init)))\n" | |
1e6808ea | 212 | "@end lisp\n" |
0fb104ed MG |
213 | "Each binding in @var{env} will be processed exactly once.\n" |
214 | "@code{environment-fold} makes no guarantees about the order in\n" | |
215 | "which the bindings are processed.\n" | |
5d3e2388 DH |
216 | "Here is a function which, given an environment, constructs an\n" |
217 | "association list representing that environment's bindings,\n" | |
218 | "using environment-fold:\n" | |
1e6808ea | 219 | "@lisp\n" |
5d3e2388 DH |
220 | " (define (environment->alist env)\n" |
221 | " (environment-fold env\n" | |
222 | " (lambda (sym val tail)\n" | |
223 | " (cons (cons sym val) tail))\n" | |
0fb104ed | 224 | " '()))\n" |
1e6808ea | 225 | "@end lisp") |
5d3e2388 DH |
226 | #define FUNC_NAME s_scm_environment_fold |
227 | { | |
228 | SCM_ASSERT (SCM_ENVIRONMENT_P (env), env, SCM_ARG1, FUNC_NAME); | |
229 | SCM_ASSERT (SCM_EQ_P (scm_procedure_p (proc), SCM_BOOL_T), | |
230 | proc, SCM_ARG2, FUNC_NAME); | |
231 | ||
232 | return SCM_ENVIRONMENT_FOLD (env, environment_default_folder, proc, init); | |
233 | } | |
234 | #undef FUNC_NAME | |
235 | ||
236 | ||
237 | /* This is the C-level analog of environment-fold. For each binding in ENV, | |
238 | * make the call: | |
239 | * (*proc) (data, symbol, value, previous) | |
240 | * where previous is the value returned from the last call to *PROC, or INIT | |
241 | * for the first call. If ENV contains no bindings, return INIT. | |
242 | */ | |
243 | SCM | |
244 | scm_c_environment_fold (SCM env, scm_environment_folder proc, SCM data, SCM init) | |
245 | { | |
246 | SCM_ASSERT (SCM_ENVIRONMENT_P (env), env, SCM_ARG1, "scm_c_environment_fold"); | |
247 | ||
248 | return SCM_ENVIRONMENT_FOLD (env, proc, data, init); | |
249 | } | |
250 | ||
251 | ||
252 | SCM_DEFINE (scm_environment_define, "environment-define", 3, 0, 0, | |
253 | (SCM env, SCM sym, SCM val), | |
0fb104ed MG |
254 | "Bind @var{sym} to a new location containing @var{val} in\n" |
255 | "@var{env}. If @var{sym} is already bound to another location\n" | |
256 | "in @var{env} and the binding is mutable, that binding is\n" | |
257 | "replaced. The new binding and location are both mutable. The\n" | |
258 | "return value is unspecified.\n" | |
259 | "If @var{sym} is already bound in @var{env}, and the binding is\n" | |
260 | "immutable, signal an @code{environment:immutable-binding} error.") | |
5d3e2388 DH |
261 | #define FUNC_NAME s_scm_environment_define |
262 | { | |
263 | SCM status; | |
264 | ||
265 | SCM_ASSERT (SCM_ENVIRONMENT_P (env), env, SCM_ARG1, FUNC_NAME); | |
266 | SCM_ASSERT (SCM_SYMBOLP (sym), sym, SCM_ARG2, FUNC_NAME); | |
267 | ||
268 | status = SCM_ENVIRONMENT_DEFINE (env, sym, val); | |
269 | ||
270 | if (SCM_EQ_P (status, SCM_ENVIRONMENT_SUCCESS)) | |
271 | return SCM_UNSPECIFIED; | |
272 | else if (SCM_EQ_P (status, SCM_ENVIRONMENT_BINDING_IMMUTABLE)) | |
273 | scm_error_environment_immutable_binding (FUNC_NAME, env, sym); | |
274 | else | |
275 | abort(); | |
276 | } | |
277 | #undef FUNC_NAME | |
278 | ||
279 | ||
280 | SCM_DEFINE (scm_environment_undefine, "environment-undefine", 2, 0, 0, | |
281 | (SCM env, SCM sym), | |
0fb104ed MG |
282 | "Remove any binding for @var{sym} from @var{env}. If @var{sym}\n" |
283 | "is unbound in @var{env}, do nothing. The return value is\n" | |
284 | "unspecified.\n" | |
285 | "If @var{sym} is already bound in @var{env}, and the binding is\n" | |
286 | "immutable, signal an @code{environment:immutable-binding} error.") | |
5d3e2388 DH |
287 | #define FUNC_NAME s_scm_environment_undefine |
288 | { | |
289 | SCM status; | |
290 | ||
291 | SCM_ASSERT(SCM_ENVIRONMENT_P(env), env, SCM_ARG1, FUNC_NAME); | |
292 | SCM_ASSERT(SCM_SYMBOLP(sym), sym, SCM_ARG2, FUNC_NAME); | |
293 | ||
294 | status = SCM_ENVIRONMENT_UNDEFINE (env, sym); | |
295 | ||
296 | if (SCM_EQ_P (status, SCM_ENVIRONMENT_SUCCESS)) | |
297 | return SCM_UNSPECIFIED; | |
298 | else if (SCM_EQ_P (status, SCM_ENVIRONMENT_BINDING_IMMUTABLE)) | |
299 | scm_error_environment_immutable_binding (FUNC_NAME, env, sym); | |
300 | else | |
301 | abort(); | |
302 | } | |
303 | #undef FUNC_NAME | |
304 | ||
305 | ||
306 | SCM_DEFINE (scm_environment_set_x, "environment-set!", 3, 0, 0, | |
307 | (SCM env, SCM sym, SCM val), | |
0fb104ed MG |
308 | "If @var{env} binds @var{sym} to some location, change that\n" |
309 | "location's value to @var{val}. The return value is\n" | |
310 | "unspecified.\n" | |
311 | "If @var{sym} is not bound in @var{env}, signal an\n" | |
312 | "@code{environment:unbound} error. If @var{env} binds @var{sym}\n" | |
313 | "to an immutable location, signal an\n" | |
314 | "@code{environment:immutable-location} error.") | |
5d3e2388 DH |
315 | #define FUNC_NAME s_scm_environment_set_x |
316 | { | |
317 | SCM status; | |
318 | ||
319 | SCM_ASSERT (SCM_ENVIRONMENT_P (env), env, SCM_ARG1, FUNC_NAME); | |
320 | SCM_ASSERT (SCM_SYMBOLP (sym), sym, SCM_ARG2, FUNC_NAME); | |
321 | ||
322 | status = SCM_ENVIRONMENT_SET (env, sym, val); | |
323 | ||
324 | if (SCM_EQ_P (status, SCM_ENVIRONMENT_SUCCESS)) | |
325 | return SCM_UNSPECIFIED; | |
326 | else if (SCM_UNBNDP (status)) | |
327 | scm_error_environment_unbound (FUNC_NAME, env, sym); | |
328 | else if (SCM_EQ_P (status, SCM_ENVIRONMENT_LOCATION_IMMUTABLE)) | |
329 | scm_error_environment_immutable_binding (FUNC_NAME, env, sym); | |
330 | else | |
331 | abort(); | |
332 | } | |
333 | #undef FUNC_NAME | |
334 | ||
335 | ||
336 | SCM_DEFINE (scm_environment_cell, "environment-cell", 3, 0, 0, | |
337 | (SCM env, SCM sym, SCM for_write), | |
0fb104ed MG |
338 | "Return the value cell which @var{env} binds to @var{sym}, or\n" |
339 | "@code{#f} if the binding does not live in a value cell.\n" | |
340 | "The argument @var{for-write} indicates whether the caller\n" | |
341 | "intends to modify the variable's value by mutating the value\n" | |
342 | "cell. If the variable is immutable, then\n" | |
343 | "@code{environment-cell} signals an\n" | |
344 | "@code{environment:immutable-location} error.\n" | |
345 | "If @var{sym} is unbound in @var{env}, signal an\n" | |
346 | "@code{environment:unbound} error.\n" | |
5d3e2388 | 347 | "If you use this function, you should consider using\n" |
0fb104ed MG |
348 | "@code{environment-observe}, to be notified when @var{sym} gets\n" |
349 | "re-bound to a new value cell, or becomes undefined.") | |
5d3e2388 DH |
350 | #define FUNC_NAME s_scm_environment_cell |
351 | { | |
352 | SCM location; | |
353 | ||
354 | SCM_ASSERT (SCM_ENVIRONMENT_P (env), env, SCM_ARG1, FUNC_NAME); | |
355 | SCM_ASSERT (SCM_SYMBOLP (sym), sym, SCM_ARG2, FUNC_NAME); | |
356 | SCM_ASSERT (SCM_BOOLP (for_write), for_write, SCM_ARG3, FUNC_NAME); | |
357 | ||
358 | location = SCM_ENVIRONMENT_CELL (env, sym, !SCM_FALSEP (for_write)); | |
359 | if (!SCM_IMP (location)) | |
360 | return location; | |
361 | else if (SCM_UNBNDP (location)) | |
362 | scm_error_environment_unbound (FUNC_NAME, env, sym); | |
363 | else if (SCM_EQ_P (location, SCM_ENVIRONMENT_LOCATION_IMMUTABLE)) | |
364 | scm_error_environment_immutable_location (FUNC_NAME, env, sym); | |
365 | else /* no cell */ | |
366 | return location; | |
367 | } | |
368 | #undef FUNC_NAME | |
369 | ||
370 | ||
371 | /* This C function is identical to environment-cell, with the following | |
372 | * exceptions: If symbol is unbound in env, it returns the value | |
373 | * SCM_UNDEFINED, instead of signalling an error. If symbol is bound to an | |
374 | * immutable location but the cell is requested for write, the value | |
375 | * SCM_ENVIRONMENT_LOCATION_IMMUTABLE is returned. | |
376 | */ | |
377 | SCM | |
378 | scm_c_environment_cell(SCM env, SCM sym, int for_write) | |
379 | { | |
380 | SCM_ASSERT (SCM_ENVIRONMENT_P (env), env, SCM_ARG1, "scm_c_environment_cell"); | |
381 | SCM_ASSERT (SCM_SYMBOLP (sym), sym, SCM_ARG2, "scm_c_environment_cell"); | |
382 | ||
383 | return SCM_ENVIRONMENT_CELL (env, sym, for_write); | |
384 | } | |
385 | ||
386 | ||
387 | static void | |
388 | environment_default_observer (SCM env, SCM proc) | |
389 | { | |
390 | gh_call1 (proc, env); | |
391 | } | |
392 | ||
393 | ||
394 | SCM_DEFINE (scm_environment_observe, "environment-observe", 2, 0, 0, | |
395 | (SCM env, SCM proc), | |
0fb104ed MG |
396 | "Whenever @var{env}'s bindings change, apply @var{proc} to\n" |
397 | "@var{env}.\n" | |
5d3e2388 | 398 | "This function returns an object, token, which you can pass to\n" |
0fb104ed MG |
399 | "@code{environment-unobserve} to remove @var{proc} from the set\n" |
400 | "of procedures observing @var{env}. The type and value of\n" | |
401 | "token is unspecified.") | |
5d3e2388 DH |
402 | #define FUNC_NAME s_scm_environment_observe |
403 | { | |
404 | SCM_ASSERT (SCM_ENVIRONMENT_P (env), env, SCM_ARG1, FUNC_NAME); | |
405 | ||
406 | return SCM_ENVIRONMENT_OBSERVE (env, environment_default_observer, proc, 0); | |
407 | } | |
408 | #undef FUNC_NAME | |
409 | ||
410 | ||
411 | SCM_DEFINE (scm_environment_observe_weak, "environment-observe-weak", 2, 0, 0, | |
412 | (SCM env, SCM proc), | |
413 | "This function is the same as environment-observe, except that\n" | |
0fb104ed MG |
414 | "the reference @var{env} retains to @var{proc} is a weak\n" |
415 | "reference. This means that, if there are no other live,\n" | |
416 | "non-weak references to @var{proc}, it will be\n" | |
417 | "garbage-collected, and dropped from @var{env}'s\n" | |
5d3e2388 DH |
418 | "list of observing procedures.") |
419 | #define FUNC_NAME s_scm_environment_observe_weak | |
420 | { | |
421 | SCM_ASSERT (SCM_ENVIRONMENT_P (env), env, SCM_ARG1, FUNC_NAME); | |
422 | ||
423 | return SCM_ENVIRONMENT_OBSERVE (env, environment_default_observer, proc, 1); | |
424 | } | |
425 | #undef FUNC_NAME | |
426 | ||
427 | ||
428 | /* This is the C-level analog of the Scheme functions environment-observe and | |
429 | * environment-observe-weak. Whenever env's bindings change, call the | |
430 | * function proc, passing it env and data. If weak_p is non-zero, env will | |
431 | * retain only a weak reference to data, and if data is garbage collected, the | |
432 | * entire observation will be dropped. This function returns a token, with | |
433 | * the same meaning as those returned by environment-observe and | |
434 | * environment-observe-weak. | |
435 | */ | |
436 | SCM | |
437 | scm_c_environment_observe (SCM env, scm_environment_observer proc, SCM data, int weak_p) | |
438 | #define FUNC_NAME "scm_c_environment_observe" | |
439 | { | |
440 | SCM_ASSERT (SCM_ENVIRONMENT_P (env), env, SCM_ARG1, FUNC_NAME); | |
441 | ||
442 | return SCM_ENVIRONMENT_OBSERVE (env, proc, data, weak_p); | |
443 | } | |
444 | #undef FUNC_NAME | |
445 | ||
446 | ||
447 | SCM_DEFINE (scm_environment_unobserve, "environment-unobserve", 1, 0, 0, | |
448 | (SCM token), | |
449 | "Cancel the observation request which returned the value\n" | |
0fb104ed MG |
450 | "@var{token}. The return value is unspecified.\n" |
451 | "If a call @code{(environment-observe env proc)} returns\n" | |
452 | "@var{token}, then the call @code{(environment-unobserve token)}\n" | |
453 | "will cause @var{proc} to no longer be called when @var{env}'s\n" | |
454 | "bindings change.") | |
5d3e2388 DH |
455 | #define FUNC_NAME s_scm_environment_unobserve |
456 | { | |
457 | SCM env; | |
458 | ||
459 | SCM_ASSERT (SCM_OBSERVER_P (token), token, SCM_ARG1, FUNC_NAME); | |
460 | ||
461 | env = SCM_OBSERVER_ENVIRONMENT (token); | |
462 | SCM_ENVIRONMENT_UNOBSERVE (env, token); | |
463 | ||
464 | return SCM_UNSPECIFIED; | |
465 | } | |
466 | #undef FUNC_NAME | |
467 | ||
468 | ||
469 | static SCM | |
e841c3e0 | 470 | environment_mark (SCM env) |
5d3e2388 DH |
471 | { |
472 | return (*(SCM_ENVIRONMENT_FUNCS (env)->mark)) (env); | |
473 | } | |
474 | ||
475 | ||
1be6b49c | 476 | static size_t |
e841c3e0 | 477 | environment_free (SCM env) |
5d3e2388 | 478 | { |
4c9419ac MV |
479 | (*(SCM_ENVIRONMENT_FUNCS (env)->free)) (env); |
480 | return 0; | |
5d3e2388 DH |
481 | } |
482 | ||
483 | ||
484 | static int | |
e841c3e0 | 485 | environment_print (SCM env, SCM port, scm_print_state *pstate) |
5d3e2388 DH |
486 | { |
487 | return (*(SCM_ENVIRONMENT_FUNCS (env)->print)) (env, port, pstate); | |
488 | } | |
489 | ||
490 | \f | |
491 | ||
492 | /* observers */ | |
493 | ||
494 | static SCM | |
e841c3e0 | 495 | observer_mark (SCM observer) |
5d3e2388 DH |
496 | { |
497 | scm_gc_mark (SCM_OBSERVER_ENVIRONMENT (observer)); | |
498 | scm_gc_mark (SCM_OBSERVER_DATA (observer)); | |
499 | return SCM_BOOL_F; | |
500 | } | |
501 | ||
502 | ||
5d3e2388 | 503 | static int |
e81d98ec | 504 | observer_print (SCM type, SCM port, scm_print_state *pstate SCM_UNUSED) |
5d3e2388 | 505 | { |
c014a02e | 506 | SCM address = scm_ulong2num (SCM_UNPACK (type)); |
5d3e2388 DH |
507 | SCM base16 = scm_number_to_string (address, SCM_MAKINUM (16)); |
508 | ||
509 | scm_puts ("#<observer ", port); | |
86c991c2 | 510 | scm_puts (SCM_STRING_CHARS (base16), port); |
5d3e2388 DH |
511 | scm_puts (">", port); |
512 | ||
513 | return 1; | |
514 | } | |
515 | ||
516 | \f | |
517 | ||
518 | /* obarrays | |
519 | * | |
520 | * Obarrays form the basic lookup tables used to implement most of guile's | |
521 | * built-in environment types. An obarray is implemented as a hash table with | |
522 | * symbols as keys. The content of the data depends on the environment type. | |
523 | */ | |
524 | ||
525 | ||
526 | /* | |
a2d47b23 DH |
527 | * Enter symbol into obarray. The symbol must not already exist in obarray. |
528 | * The freshly generated (symbol . data) cell is returned. | |
5d3e2388 DH |
529 | */ |
530 | static SCM | |
531 | obarray_enter (SCM obarray, SCM symbol, SCM data) | |
532 | { | |
1be6b49c | 533 | size_t hash = SCM_SYMBOL_HASH (symbol) % SCM_VECTOR_LENGTH (obarray); |
5d3e2388 DH |
534 | SCM entry = scm_cons (symbol, data); |
535 | SCM slot = scm_cons (entry, SCM_VELTS (obarray)[hash]); | |
34d19ef6 | 536 | SCM_VECTOR_SET (obarray, hash, slot); |
5d3e2388 DH |
537 | |
538 | return entry; | |
539 | } | |
540 | ||
541 | ||
a2d47b23 DH |
542 | /* |
543 | * Enter symbol into obarray. An existing entry for symbol is replaced. If | |
544 | * an entry existed, the old (symbol . data) cell is returned, #f otherwise. | |
545 | */ | |
546 | static SCM | |
547 | obarray_replace (SCM obarray, SCM symbol, SCM data) | |
548 | { | |
1be6b49c | 549 | size_t hash = SCM_SYMBOL_HASH (symbol) % SCM_VECTOR_LENGTH (obarray); |
a2d47b23 DH |
550 | SCM new_entry = scm_cons (symbol, data); |
551 | SCM lsym; | |
552 | SCM slot; | |
553 | ||
554 | for (lsym = SCM_VELTS (obarray)[hash]; !SCM_NULLP (lsym); lsym = SCM_CDR (lsym)) | |
555 | { | |
556 | SCM old_entry = SCM_CAR (lsym); | |
66460dfb | 557 | if (SCM_EQ_P (SCM_CAR (old_entry), symbol)) |
a2d47b23 DH |
558 | { |
559 | SCM_SETCAR (lsym, new_entry); | |
560 | return old_entry; | |
561 | } | |
562 | } | |
563 | ||
564 | slot = scm_cons (new_entry, SCM_VELTS (obarray)[hash]); | |
34d19ef6 | 565 | SCM_VECTOR_SET (obarray, hash, slot); |
a2d47b23 DH |
566 | |
567 | return SCM_BOOL_F; | |
568 | } | |
569 | ||
570 | ||
5d3e2388 DH |
571 | /* |
572 | * Look up symbol in obarray | |
573 | */ | |
574 | static SCM | |
575 | obarray_retrieve (SCM obarray, SCM sym) | |
576 | { | |
1be6b49c | 577 | size_t hash = SCM_SYMBOL_HASH (sym) % SCM_VECTOR_LENGTH (obarray); |
5d3e2388 DH |
578 | SCM lsym; |
579 | ||
580 | for (lsym = SCM_VELTS (obarray)[hash]; !SCM_NULLP (lsym); lsym = SCM_CDR (lsym)) | |
581 | { | |
582 | SCM entry = SCM_CAR (lsym); | |
66460dfb | 583 | if (SCM_EQ_P (SCM_CAR (entry), sym)) |
5d3e2388 DH |
584 | return entry; |
585 | } | |
586 | ||
587 | return SCM_UNDEFINED; | |
588 | } | |
589 | ||
34d19ef6 HWN |
590 | /* |
591 | Remove first occurance of KEY from (cdr ALIST), | |
592 | return (KEY . VAL) if found, otherwise return #f | |
593 | ||
594 | PRECONDITION: | |
595 | ||
596 | length (ALIST) >= 1 | |
597 | */ | |
598 | static | |
599 | SCM | |
600 | remove_key_from_alist (SCM alist, SCM key) | |
601 | { | |
602 | SCM cell_cdr = alist; | |
603 | alist =SCM_CDR (alist); | |
604 | ||
605 | /* | |
606 | inv: cdr(cell_cdr) == alist | |
607 | */ | |
608 | while (!SCM_NULLP (alist)) | |
609 | { | |
610 | if (SCM_EQ_P(SCM_CAAR (alist), key)) | |
611 | { | |
612 | SCM entry = SCM_CAR(alist); | |
613 | SCM_SETCDR(cell_cdr, SCM_CDR (alist)); | |
614 | ||
615 | return entry; | |
616 | } | |
617 | else | |
618 | { | |
619 | cell_cdr = SCM_CDR (cell_cdr); | |
620 | } | |
621 | ||
622 | if (!SCM_NULLP(alist)) | |
623 | alist = SCM_CDR (alist); | |
624 | } | |
625 | ||
626 | return SCM_BOOL_F; | |
627 | } | |
628 | ||
629 | ||
5d3e2388 DH |
630 | |
631 | /* | |
a2d47b23 DH |
632 | * Remove entry from obarray. If the symbol was found and removed, the old |
633 | * (symbol . data) cell is returned, #f otherwise. | |
5d3e2388 DH |
634 | */ |
635 | static SCM | |
636 | obarray_remove (SCM obarray, SCM sym) | |
637 | { | |
1be6b49c | 638 | size_t hash = SCM_SYMBOL_HASH (sym) % SCM_VECTOR_LENGTH (obarray); |
34d19ef6 HWN |
639 | SCM table_entry = SCM_VELTS (obarray)[hash]; |
640 | ||
641 | if (SCM_NULLP(table_entry)) | |
642 | return SCM_BOOL_F; | |
5d3e2388 | 643 | |
34d19ef6 | 644 | if (SCM_EQ_P (SCM_CAAR (table_entry), sym)) |
5d3e2388 | 645 | { |
34d19ef6 HWN |
646 | SCM_VECTOR_SET (obarray, hash, SCM_CDR(table_entry)); |
647 | return SCM_CAR(table_entry); | |
648 | } | |
649 | else | |
650 | { | |
651 | return remove_key_from_alist (table_entry, sym); | |
5d3e2388 | 652 | } |
5d3e2388 DH |
653 | } |
654 | ||
655 | ||
656 | static void | |
657 | obarray_remove_all (SCM obarray) | |
658 | { | |
1be6b49c ML |
659 | size_t size = SCM_VECTOR_LENGTH (obarray); |
660 | size_t i; | |
5d3e2388 DH |
661 | |
662 | for (i = 0; i < size; i++) | |
663 | { | |
34d19ef6 | 664 | SCM_VECTOR_SET (obarray, i, SCM_EOL); |
5d3e2388 DH |
665 | } |
666 | } | |
667 | ||
668 | \f | |
669 | ||
670 | /* core environments base | |
671 | * | |
672 | * This struct and the corresponding functions form a base class for guile's | |
673 | * built-in environment types. | |
674 | */ | |
675 | ||
676 | ||
677 | struct core_environments_base { | |
678 | struct scm_environment_funcs *funcs; | |
679 | ||
680 | SCM observers; | |
681 | SCM weak_observers; | |
682 | }; | |
683 | ||
684 | ||
685 | #define CORE_ENVIRONMENTS_BASE(env) \ | |
686 | ((struct core_environments_base *) SCM_CELL_WORD_1 (env)) | |
687 | #define CORE_ENVIRONMENT_OBSERVERS(env) \ | |
688 | (CORE_ENVIRONMENTS_BASE (env)->observers) | |
689 | #define SCM_SET_CORE_ENVIRONMENT_OBSERVERS(env, v) \ | |
690 | (CORE_ENVIRONMENT_OBSERVERS (env) = (v)) | |
691 | #define CORE_ENVIRONMENT_WEAK_OBSERVER_VECTOR(env) \ | |
692 | (CORE_ENVIRONMENTS_BASE (env)->weak_observers) | |
693 | #define CORE_ENVIRONMENT_WEAK_OBSERVERS(env) \ | |
694 | (SCM_VELTS (CORE_ENVIRONMENT_WEAK_OBSERVER_VECTOR (env)) [0]) | |
695 | #define SCM_SET_CORE_ENVIRONMENT_WEAK_OBSERVERS(env, v) \ | |
34d19ef6 | 696 | (SCM_VECTOR_SET (CORE_ENVIRONMENT_WEAK_OBSERVER_VECTOR (env), 0, (v))) |
5d3e2388 DH |
697 | |
698 | \f | |
699 | ||
700 | static SCM | |
701 | core_environments_observe (SCM env, scm_environment_observer proc, SCM data, int weak_p) | |
702 | { | |
228a24ef DH |
703 | SCM observer = scm_double_cell (scm_tc16_observer, |
704 | SCM_UNPACK (env), | |
705 | SCM_UNPACK (data), | |
706 | (scm_t_bits) proc); | |
5d3e2388 DH |
707 | |
708 | if (!weak_p) | |
709 | { | |
710 | SCM observers = CORE_ENVIRONMENT_OBSERVERS (env); | |
711 | SCM new_observers = scm_cons (observer, observers); | |
712 | SCM_SET_CORE_ENVIRONMENT_OBSERVERS (env, new_observers); | |
713 | } | |
714 | else | |
715 | { | |
716 | SCM observers = CORE_ENVIRONMENT_WEAK_OBSERVERS (env); | |
717 | SCM new_observers = scm_acons (SCM_BOOL_F, observer, observers); | |
718 | SCM_SET_CORE_ENVIRONMENT_WEAK_OBSERVERS (env, new_observers); | |
719 | } | |
720 | ||
721 | return observer; | |
722 | } | |
723 | ||
724 | ||
725 | static void | |
726 | core_environments_unobserve (SCM env, SCM observer) | |
727 | { | |
728 | unsigned int handling_weaks; | |
729 | for (handling_weaks = 0; handling_weaks <= 1; ++handling_weaks) | |
730 | { | |
731 | SCM l = handling_weaks | |
732 | ? CORE_ENVIRONMENT_WEAK_OBSERVERS (env) | |
733 | : CORE_ENVIRONMENT_OBSERVERS (env); | |
734 | ||
735 | if (!SCM_NULLP (l)) | |
736 | { | |
737 | SCM rest = SCM_CDR (l); | |
738 | SCM first = handling_weaks | |
739 | ? SCM_CDAR (l) | |
740 | : SCM_CAR (l); | |
741 | ||
742 | if (SCM_EQ_P (first, observer)) | |
743 | { | |
744 | /* Remove the first observer */ | |
745 | handling_weaks | |
746 | ? SCM_SET_CORE_ENVIRONMENT_WEAK_OBSERVERS (env, rest) | |
747 | : SCM_SET_CORE_ENVIRONMENT_OBSERVERS (env, rest); | |
748 | return; | |
749 | } | |
750 | ||
751 | do { | |
752 | SCM rest = SCM_CDR (l); | |
753 | ||
754 | if (!SCM_NULLP (rest)) | |
755 | { | |
756 | SCM next = handling_weaks | |
757 | ? SCM_CDAR (l) | |
758 | : SCM_CAR (l); | |
759 | ||
760 | if (SCM_EQ_P (next, observer)) | |
761 | { | |
762 | SCM_SETCDR (l, SCM_CDR (rest)); | |
763 | return; | |
764 | } | |
765 | } | |
766 | ||
767 | l = rest; | |
768 | } while (!SCM_NULLP (l)); | |
769 | } | |
770 | } | |
771 | ||
772 | /* Dirk:FIXME:: What to do now, since the observer is not found? */ | |
773 | } | |
774 | ||
775 | ||
776 | static SCM | |
777 | core_environments_mark (SCM env) | |
778 | { | |
779 | scm_gc_mark (CORE_ENVIRONMENT_OBSERVERS (env)); | |
780 | return CORE_ENVIRONMENT_WEAK_OBSERVER_VECTOR (env); | |
781 | } | |
782 | ||
783 | ||
784 | static void | |
e81d98ec | 785 | core_environments_finalize (SCM env SCM_UNUSED) |
5d3e2388 DH |
786 | { |
787 | } | |
788 | ||
789 | ||
790 | static void | |
791 | core_environments_preinit (struct core_environments_base *body) | |
792 | { | |
793 | body->funcs = NULL; | |
794 | body->observers = SCM_BOOL_F; | |
795 | body->weak_observers = SCM_BOOL_F; | |
796 | } | |
797 | ||
798 | ||
799 | static void | |
800 | core_environments_init (struct core_environments_base *body, | |
801 | struct scm_environment_funcs *funcs) | |
802 | { | |
803 | body->funcs = funcs; | |
804 | body->observers = SCM_EOL; | |
805 | body->weak_observers = scm_make_weak_value_hash_table (SCM_MAKINUM (1)); | |
806 | } | |
807 | ||
808 | ||
809 | /* Tell all observers to clear their caches. | |
810 | * | |
811 | * Environments have to be informed about changes in the following cases: | |
812 | * - The observed env has a new binding. This must be always reported. | |
813 | * - The observed env has dropped a binding. This must be always reported. | |
814 | * - A binding in the observed environment has changed. This must only be | |
815 | * reported, if there is a chance that the binding is being cached outside. | |
816 | * However, this potential optimization is not performed currently. | |
817 | * | |
818 | * Errors that occur while the observers are called are accumulated and | |
819 | * signalled as one single error message to the caller. | |
820 | */ | |
821 | ||
822 | struct update_data | |
823 | { | |
824 | SCM observer; | |
825 | SCM environment; | |
826 | }; | |
827 | ||
828 | ||
829 | static SCM | |
830 | update_catch_body (void *ptr) | |
831 | { | |
832 | struct update_data *data = (struct update_data *) ptr; | |
833 | SCM observer = data->observer; | |
834 | ||
835 | (*SCM_OBSERVER_PROC (observer)) | |
836 | (data->environment, SCM_OBSERVER_DATA (observer)); | |
837 | ||
838 | return SCM_UNDEFINED; | |
839 | } | |
840 | ||
841 | ||
842 | static SCM | |
843 | update_catch_handler (void *ptr, SCM tag, SCM args) | |
844 | { | |
845 | struct update_data *data = (struct update_data *) ptr; | |
846 | SCM observer = data->observer; | |
847 | SCM message = scm_makfrom0str ("Observer `~A' signals `~A' error: ~S"); | |
848 | ||
1afff620 | 849 | return scm_cons (message, scm_list_3 (observer, tag, args)); |
5d3e2388 DH |
850 | } |
851 | ||
852 | ||
853 | static void | |
854 | core_environments_broadcast (SCM env) | |
855 | #define FUNC_NAME "core_environments_broadcast" | |
856 | { | |
857 | unsigned int handling_weaks; | |
858 | SCM errors = SCM_EOL; | |
859 | ||
860 | for (handling_weaks = 0; handling_weaks <= 1; ++handling_weaks) | |
861 | { | |
862 | SCM observers = handling_weaks | |
863 | ? CORE_ENVIRONMENT_WEAK_OBSERVERS (env) | |
864 | : CORE_ENVIRONMENT_OBSERVERS (env); | |
865 | ||
866 | for (; !SCM_NULLP (observers); observers = SCM_CDR (observers)) | |
867 | { | |
868 | struct update_data data; | |
869 | SCM observer = handling_weaks | |
870 | ? SCM_CDAR (observers) | |
871 | : SCM_CAR (observers); | |
872 | SCM error; | |
873 | ||
874 | data.observer = observer; | |
875 | data.environment = env; | |
876 | ||
877 | error = scm_internal_catch (SCM_BOOL_T, | |
878 | update_catch_body, &data, | |
879 | update_catch_handler, &data); | |
880 | ||
881 | if (!SCM_UNBNDP (error)) | |
882 | errors = scm_cons (error, errors); | |
883 | } | |
884 | } | |
885 | ||
886 | if (!SCM_NULLP (errors)) | |
887 | { | |
888 | /* Dirk:FIXME:: As soon as scm_misc_error is fixed to handle the name | |
889 | * parameter correctly it should not be necessary any more to also pass | |
890 | * namestr in order to get the desired information from the error | |
891 | * message. | |
892 | */ | |
893 | SCM ordered_errors = scm_reverse (errors); | |
894 | scm_misc_error | |
895 | (FUNC_NAME, | |
896 | "Observers of `~A' have signalled the following errors: ~S", | |
897 | scm_cons2 (env, ordered_errors, SCM_EOL)); | |
898 | } | |
899 | } | |
900 | #undef FUNC_NAME | |
901 | ||
902 | \f | |
903 | ||
904 | /* leaf environments | |
905 | * | |
906 | * A leaf environment is simply a mutable set of definitions. A leaf | |
907 | * environment supports no operations beyond the common set. | |
908 | * | |
909 | * Implementation: The obarray of the leaf environment holds (symbol . value) | |
910 | * pairs. No further information is necessary, since all bindings and | |
911 | * locations in a leaf environment are mutable. | |
912 | */ | |
913 | ||
914 | ||
915 | struct leaf_environment { | |
916 | struct core_environments_base base; | |
917 | ||
918 | SCM obarray; | |
919 | }; | |
920 | ||
921 | ||
922 | #define LEAF_ENVIRONMENT(env) \ | |
923 | ((struct leaf_environment *) SCM_CELL_WORD_1 (env)) | |
924 | ||
925 | \f | |
926 | ||
927 | static SCM | |
928 | leaf_environment_ref (SCM env, SCM sym) | |
929 | { | |
930 | SCM obarray = LEAF_ENVIRONMENT (env)->obarray; | |
931 | SCM binding = obarray_retrieve (obarray, sym); | |
932 | return SCM_UNBNDP (binding) ? binding : SCM_CDR (binding); | |
933 | } | |
934 | ||
935 | ||
936 | static SCM | |
937 | leaf_environment_fold (SCM env, scm_environment_folder proc, SCM data, SCM init) | |
938 | { | |
1be6b49c | 939 | size_t i; |
5d3e2388 DH |
940 | SCM result = init; |
941 | SCM obarray = LEAF_ENVIRONMENT (env)->obarray; | |
942 | ||
bfa974f0 | 943 | for (i = 0; i < SCM_VECTOR_LENGTH (obarray); i++) |
5d3e2388 DH |
944 | { |
945 | SCM l; | |
946 | for (l = SCM_VELTS (obarray)[i]; !SCM_NULLP (l); l = SCM_CDR (l)) | |
947 | { | |
948 | SCM binding = SCM_CAR (l); | |
949 | SCM symbol = SCM_CAR (binding); | |
950 | SCM value = SCM_CDR (binding); | |
951 | result = (*proc) (data, symbol, value, result); | |
952 | } | |
953 | } | |
954 | return result; | |
955 | } | |
956 | ||
957 | ||
958 | static SCM | |
959 | leaf_environment_define (SCM env, SCM sym, SCM val) | |
960 | #define FUNC_NAME "leaf_environment_define" | |
961 | { | |
962 | SCM obarray = LEAF_ENVIRONMENT (env)->obarray; | |
5d3e2388 | 963 | |
a2d47b23 | 964 | obarray_replace (obarray, sym, val); |
5d3e2388 DH |
965 | core_environments_broadcast (env); |
966 | ||
967 | return SCM_ENVIRONMENT_SUCCESS; | |
968 | } | |
969 | #undef FUNC_NAME | |
970 | ||
971 | ||
972 | static SCM | |
973 | leaf_environment_undefine (SCM env, SCM sym) | |
974 | #define FUNC_NAME "leaf_environment_undefine" | |
975 | { | |
976 | SCM obarray = LEAF_ENVIRONMENT (env)->obarray; | |
a2d47b23 | 977 | SCM removed = obarray_remove (obarray, sym); |
5d3e2388 | 978 | |
a2d47b23 DH |
979 | if (!SCM_FALSEP (removed)) |
980 | core_environments_broadcast (env); | |
5d3e2388 DH |
981 | |
982 | return SCM_ENVIRONMENT_SUCCESS; | |
983 | } | |
984 | #undef FUNC_NAME | |
985 | ||
986 | ||
987 | static SCM | |
988 | leaf_environment_set_x (SCM env, SCM sym, SCM val) | |
989 | #define FUNC_NAME "leaf_environment_set_x" | |
990 | { | |
991 | SCM obarray = LEAF_ENVIRONMENT (env)->obarray; | |
992 | SCM binding = obarray_retrieve (obarray, sym); | |
993 | ||
994 | if (!SCM_UNBNDP (binding)) | |
995 | { | |
996 | SCM_SETCDR (binding, val); | |
997 | return SCM_ENVIRONMENT_SUCCESS; | |
998 | } | |
999 | else | |
1000 | { | |
1001 | return SCM_UNDEFINED; | |
1002 | } | |
1003 | } | |
1004 | #undef FUNC_NAME | |
1005 | ||
1006 | ||
1007 | static SCM | |
e81d98ec | 1008 | leaf_environment_cell (SCM env, SCM sym, int for_write SCM_UNUSED) |
5d3e2388 DH |
1009 | { |
1010 | SCM obarray = LEAF_ENVIRONMENT (env)->obarray; | |
1011 | SCM binding = obarray_retrieve (obarray, sym); | |
1012 | return binding; | |
1013 | } | |
1014 | ||
1015 | ||
1016 | static SCM | |
e841c3e0 | 1017 | leaf_environment_mark (SCM env) |
5d3e2388 DH |
1018 | { |
1019 | scm_gc_mark (LEAF_ENVIRONMENT (env)->obarray); | |
1020 | return core_environments_mark (env); | |
1021 | } | |
1022 | ||
1023 | ||
4c9419ac | 1024 | static void |
e841c3e0 | 1025 | leaf_environment_free (SCM env) |
5d3e2388 DH |
1026 | { |
1027 | core_environments_finalize (env); | |
4c9419ac MV |
1028 | scm_gc_free (LEAF_ENVIRONMENT (env), sizeof (struct leaf_environment), |
1029 | "leaf environment"); | |
5d3e2388 DH |
1030 | } |
1031 | ||
1032 | ||
1033 | static int | |
e81d98ec | 1034 | leaf_environment_print (SCM type, SCM port, scm_print_state *pstate SCM_UNUSED) |
5d3e2388 | 1035 | { |
c014a02e | 1036 | SCM address = scm_ulong2num (SCM_UNPACK (type)); |
5d3e2388 DH |
1037 | SCM base16 = scm_number_to_string (address, SCM_MAKINUM (16)); |
1038 | ||
1039 | scm_puts ("#<leaf environment ", port); | |
86c991c2 | 1040 | scm_puts (SCM_STRING_CHARS (base16), port); |
5d3e2388 DH |
1041 | scm_puts (">", port); |
1042 | ||
1043 | return 1; | |
1044 | } | |
1045 | ||
1046 | ||
1047 | static struct scm_environment_funcs leaf_environment_funcs = { | |
1048 | leaf_environment_ref, | |
1049 | leaf_environment_fold, | |
1050 | leaf_environment_define, | |
1051 | leaf_environment_undefine, | |
1052 | leaf_environment_set_x, | |
1053 | leaf_environment_cell, | |
1054 | core_environments_observe, | |
1055 | core_environments_unobserve, | |
e841c3e0 KN |
1056 | leaf_environment_mark, |
1057 | leaf_environment_free, | |
1058 | leaf_environment_print | |
5d3e2388 DH |
1059 | }; |
1060 | ||
1061 | ||
1062 | void *scm_type_leaf_environment = &leaf_environment_funcs; | |
1063 | ||
1064 | ||
1065 | SCM_DEFINE (scm_make_leaf_environment, "make-leaf-environment", 0, 0, 0, | |
1066 | (), | |
1067 | "Create a new leaf environment, containing no bindings.\n" | |
1068 | "All bindings and locations created in the new environment\n" | |
1069 | "will be mutable.") | |
1070 | #define FUNC_NAME s_scm_make_leaf_environment | |
1071 | { | |
1be6b49c | 1072 | size_t size = sizeof (struct leaf_environment); |
4c9419ac | 1073 | struct leaf_environment *body = scm_gc_malloc (size, "leaf environment"); |
5d3e2388 DH |
1074 | SCM env; |
1075 | ||
1076 | core_environments_preinit (&body->base); | |
1077 | body->obarray = SCM_BOOL_F; | |
1078 | ||
1079 | env = scm_make_environment (body); | |
1080 | ||
1081 | core_environments_init (&body->base, &leaf_environment_funcs); | |
00ffa0e7 | 1082 | body->obarray = scm_c_make_hash_table (DEFAULT_OBARRAY_SIZE); |
5d3e2388 DH |
1083 | |
1084 | return env; | |
1085 | } | |
1086 | #undef FUNC_NAME | |
1087 | ||
1088 | ||
1089 | SCM_DEFINE (scm_leaf_environment_p, "leaf-environment?", 1, 0, 0, | |
1090 | (SCM object), | |
0fb104ed MG |
1091 | "Return @code{#t} if object is a leaf environment, or @code{#f}\n" |
1092 | "otherwise.") | |
5d3e2388 DH |
1093 | #define FUNC_NAME s_scm_leaf_environment_p |
1094 | { | |
1095 | return SCM_BOOL (SCM_LEAF_ENVIRONMENT_P (object)); | |
1096 | } | |
1097 | #undef FUNC_NAME | |
1098 | ||
1099 | \f | |
1100 | ||
1101 | /* eval environments | |
1102 | * | |
1103 | * A module's source code refers to definitions imported from other modules, | |
1104 | * and definitions made within itself. An eval environment combines two | |
1105 | * environments -- a local environment and an imported environment -- to | |
1106 | * produce a new environment in which both sorts of references can be | |
1107 | * resolved. | |
1108 | * | |
1109 | * Implementation: The obarray of the eval environment is used to cache | |
1110 | * entries from the local and imported environments such that in most of the | |
1111 | * cases only a single lookup is necessary. Since for neither the local nor | |
1112 | * the imported environment it is known, what kind of environment they form, | |
1113 | * the most general case is assumed. Therefore, entries in the obarray take | |
1114 | * one of the following forms: | |
1115 | * | |
1116 | * 1) (<symbol> location mutability . source-env), where mutability indicates | |
1117 | * one of the following states: IMMUTABLE if the location is known to be | |
1118 | * immutable, MUTABLE if the location is known to be mutable, UNKNOWN if | |
1119 | * the location has only been requested for non modifying accesses. | |
1120 | * | |
1121 | * 2) (symbol . source-env) if the symbol has a binding in the source-env, but | |
1122 | * if the source-env can't provide a cell for the binding. Thus, for every | |
1123 | * access, the source-env has to be contacted directly. | |
1124 | */ | |
1125 | ||
1126 | ||
1127 | struct eval_environment { | |
1128 | struct core_environments_base base; | |
1129 | ||
1130 | SCM obarray; | |
1131 | ||
1132 | SCM imported; | |
1133 | SCM imported_observer; | |
1134 | SCM local; | |
1135 | SCM local_observer; | |
1136 | }; | |
1137 | ||
1138 | ||
1139 | #define EVAL_ENVIRONMENT(env) \ | |
1140 | ((struct eval_environment *) SCM_CELL_WORD_1 (env)) | |
1141 | ||
1142 | #define IMMUTABLE SCM_MAKINUM (0) | |
1143 | #define MUTABLE SCM_MAKINUM (1) | |
1144 | #define UNKNOWN SCM_MAKINUM (2) | |
1145 | ||
1146 | #define CACHED_LOCATION(x) SCM_CAR (x) | |
1147 | #define CACHED_MUTABILITY(x) SCM_CADR (x) | |
1148 | #define SET_CACHED_MUTABILITY(x, v) SCM_SETCAR (SCM_CDR (x), (v)) | |
1149 | #define CACHED_SOURCE_ENVIRONMENT(x) SCM_CDDR (x) | |
1150 | ||
1151 | \f | |
1152 | ||
1153 | /* eval_environment_lookup will report one of the following distinct results: | |
1154 | * a) (<object> . value) if a cell could be obtained. | |
1155 | * b) <environment> if the environment has to be contacted directly. | |
1156 | * c) IMMUTABLE if an immutable cell was requested for write. | |
1157 | * d) SCM_UNDEFINED if there is no binding for the symbol. | |
1158 | */ | |
1159 | static SCM | |
1160 | eval_environment_lookup (SCM env, SCM sym, int for_write) | |
1161 | { | |
1162 | SCM obarray = EVAL_ENVIRONMENT (env)->obarray; | |
1163 | SCM binding = obarray_retrieve (obarray, sym); | |
1164 | ||
1165 | if (!SCM_UNBNDP (binding)) | |
1166 | { | |
1167 | /* The obarray holds an entry for the symbol. */ | |
1168 | ||
1169 | SCM entry = SCM_CDR (binding); | |
1170 | ||
1171 | if (SCM_CONSP (entry)) | |
1172 | { | |
1173 | /* The entry in the obarray is a cached location. */ | |
1174 | ||
1175 | SCM location = CACHED_LOCATION (entry); | |
1176 | SCM mutability; | |
1177 | ||
1178 | if (!for_write) | |
1179 | return location; | |
1180 | ||
1181 | mutability = CACHED_MUTABILITY (entry); | |
1182 | if (SCM_EQ_P (mutability, MUTABLE)) | |
1183 | return location; | |
1184 | ||
1185 | if (SCM_EQ_P (mutability, UNKNOWN)) | |
1186 | { | |
1187 | SCM source_env = CACHED_SOURCE_ENVIRONMENT (entry); | |
1188 | SCM location = SCM_ENVIRONMENT_CELL (source_env, sym, 1); | |
1189 | ||
1190 | if (SCM_CONSP (location)) | |
1191 | { | |
1192 | SET_CACHED_MUTABILITY (entry, MUTABLE); | |
1193 | return location; | |
1194 | } | |
1195 | else /* IMMUTABLE */ | |
1196 | { | |
1197 | SET_CACHED_MUTABILITY (entry, IMMUTABLE); | |
1198 | return IMMUTABLE; | |
1199 | } | |
1200 | } | |
1201 | ||
1202 | return IMMUTABLE; | |
1203 | } | |
1204 | else | |
1205 | { | |
1206 | /* The obarray entry is an environment */ | |
1207 | ||
1208 | return entry; | |
1209 | } | |
1210 | } | |
1211 | else | |
1212 | { | |
1213 | /* There is no entry for the symbol in the obarray. This can either | |
1214 | * mean that there has not been a request for the symbol yet, or that | |
1215 | * the symbol is really undefined. We are looking for the symbol in | |
1216 | * both the local and the imported environment. If we find a binding, a | |
1217 | * cached entry is created. | |
1218 | */ | |
1219 | ||
1220 | struct eval_environment *body = EVAL_ENVIRONMENT (env); | |
1221 | unsigned int handling_import; | |
1222 | ||
1223 | for (handling_import = 0; handling_import <= 1; ++handling_import) | |
1224 | { | |
1225 | SCM source_env = handling_import ? body->imported : body->local; | |
1226 | SCM location = SCM_ENVIRONMENT_CELL (source_env, sym, for_write); | |
1227 | ||
1228 | if (!SCM_UNBNDP (location)) | |
1229 | { | |
1230 | if (SCM_CONSP (location)) | |
1231 | { | |
1232 | SCM mutability = for_write ? MUTABLE : UNKNOWN; | |
1233 | SCM entry = scm_cons2 (location, mutability, source_env); | |
1234 | obarray_enter (obarray, sym, entry); | |
1235 | return location; | |
1236 | } | |
1237 | else if (SCM_EQ_P (location, SCM_ENVIRONMENT_LOCATION_NO_CELL)) | |
1238 | { | |
1239 | obarray_enter (obarray, sym, source_env); | |
1240 | return source_env; | |
1241 | } | |
1242 | else | |
1243 | { | |
1244 | return IMMUTABLE; | |
1245 | } | |
1246 | } | |
1247 | } | |
1248 | ||
1249 | return SCM_UNDEFINED; | |
1250 | } | |
1251 | } | |
1252 | ||
1253 | ||
1254 | static SCM | |
1255 | eval_environment_ref (SCM env, SCM sym) | |
1256 | #define FUNC_NAME "eval_environment_ref" | |
1257 | { | |
1258 | SCM location = eval_environment_lookup (env, sym, 0); | |
1259 | ||
1260 | if (SCM_CONSP (location)) | |
1261 | return SCM_CDR (location); | |
1262 | else if (!SCM_UNBNDP (location)) | |
1263 | return SCM_ENVIRONMENT_REF (location, sym); | |
1264 | else | |
1265 | return SCM_UNDEFINED; | |
1266 | } | |
1267 | #undef FUNC_NAME | |
1268 | ||
1269 | ||
1270 | static SCM | |
1271 | eval_environment_folder (SCM extended_data, SCM symbol, SCM value, SCM tail) | |
1272 | { | |
1273 | SCM local = SCM_CAR (extended_data); | |
1274 | ||
1275 | if (!SCM_ENVIRONMENT_BOUND_P (local, symbol)) | |
1276 | { | |
1277 | SCM proc_as_nr = SCM_CADR (extended_data); | |
c014a02e | 1278 | unsigned long int proc_as_ul = scm_num2ulong (proc_as_nr, 0, NULL); |
5d3e2388 DH |
1279 | scm_environment_folder proc = (scm_environment_folder) proc_as_ul; |
1280 | SCM data = SCM_CDDR (extended_data); | |
1281 | ||
1282 | return (*proc) (data, symbol, value, tail); | |
1283 | } | |
1284 | else | |
1285 | { | |
1286 | return tail; | |
1287 | } | |
1288 | } | |
1289 | ||
1290 | ||
1291 | static SCM | |
1292 | eval_environment_fold (SCM env, scm_environment_folder proc, SCM data, SCM init) | |
1293 | { | |
1294 | SCM local = EVAL_ENVIRONMENT (env)->local; | |
1295 | SCM imported = EVAL_ENVIRONMENT (env)->imported; | |
c014a02e | 1296 | SCM proc_as_nr = scm_ulong2num ((unsigned long int) proc); |
5d3e2388 DH |
1297 | SCM extended_data = scm_cons2 (local, proc_as_nr, data); |
1298 | SCM tmp_result = scm_c_environment_fold (imported, eval_environment_folder, extended_data, init); | |
1299 | ||
1300 | return scm_c_environment_fold (local, proc, data, tmp_result); | |
1301 | } | |
1302 | ||
1303 | ||
1304 | static SCM | |
1305 | eval_environment_define (SCM env, SCM sym, SCM val) | |
1306 | #define FUNC_NAME "eval_environment_define" | |
1307 | { | |
1308 | SCM local = EVAL_ENVIRONMENT (env)->local; | |
1309 | return SCM_ENVIRONMENT_DEFINE (local, sym, val); | |
1310 | } | |
1311 | #undef FUNC_NAME | |
1312 | ||
1313 | ||
1314 | static SCM | |
1315 | eval_environment_undefine (SCM env, SCM sym) | |
1316 | #define FUNC_NAME "eval_environment_undefine" | |
1317 | { | |
1318 | SCM local = EVAL_ENVIRONMENT (env)->local; | |
1319 | return SCM_ENVIRONMENT_UNDEFINE (local, sym); | |
1320 | } | |
1321 | #undef FUNC_NAME | |
1322 | ||
1323 | ||
1324 | static SCM | |
1325 | eval_environment_set_x (SCM env, SCM sym, SCM val) | |
1326 | #define FUNC_NAME "eval_environment_set_x" | |
1327 | { | |
1328 | SCM location = eval_environment_lookup (env, sym, 1); | |
1329 | ||
1330 | if (SCM_CONSP (location)) | |
1331 | { | |
1332 | SCM_SETCDR (location, val); | |
1333 | return SCM_ENVIRONMENT_SUCCESS; | |
1334 | } | |
1335 | else if (SCM_ENVIRONMENT_P (location)) | |
1336 | { | |
1337 | return SCM_ENVIRONMENT_SET (location, sym, val); | |
1338 | } | |
1339 | else if (SCM_EQ_P (location, IMMUTABLE)) | |
1340 | { | |
1341 | return SCM_ENVIRONMENT_LOCATION_IMMUTABLE; | |
1342 | } | |
1343 | else | |
1344 | { | |
1345 | return SCM_UNDEFINED; | |
1346 | } | |
1347 | } | |
1348 | #undef FUNC_NAME | |
1349 | ||
1350 | ||
1351 | static SCM | |
1352 | eval_environment_cell (SCM env, SCM sym, int for_write) | |
1353 | #define FUNC_NAME "eval_environment_cell" | |
1354 | { | |
1355 | SCM location = eval_environment_lookup (env, sym, for_write); | |
1356 | ||
1357 | if (SCM_CONSP (location)) | |
1358 | return location; | |
1359 | else if (SCM_ENVIRONMENT_P (location)) | |
1360 | return SCM_ENVIRONMENT_LOCATION_NO_CELL; | |
1361 | else if (SCM_EQ_P (location, IMMUTABLE)) | |
1362 | return SCM_ENVIRONMENT_LOCATION_IMMUTABLE; | |
1363 | else | |
1364 | return SCM_UNDEFINED; | |
1365 | } | |
1366 | #undef FUNC_NAME | |
1367 | ||
1368 | ||
1369 | static SCM | |
e841c3e0 | 1370 | eval_environment_mark (SCM env) |
5d3e2388 DH |
1371 | { |
1372 | struct eval_environment *body = EVAL_ENVIRONMENT (env); | |
1373 | ||
1374 | scm_gc_mark (body->obarray); | |
1375 | scm_gc_mark (body->imported); | |
1376 | scm_gc_mark (body->imported_observer); | |
1377 | scm_gc_mark (body->local); | |
1378 | scm_gc_mark (body->local_observer); | |
1379 | ||
1380 | return core_environments_mark (env); | |
1381 | } | |
1382 | ||
1383 | ||
4c9419ac | 1384 | static void |
e841c3e0 | 1385 | eval_environment_free (SCM env) |
5d3e2388 DH |
1386 | { |
1387 | core_environments_finalize (env); | |
4c9419ac MV |
1388 | scm_gc_free (EVAL_ENVIRONMENT (env), sizeof (struct eval_environment), |
1389 | "eval environment"); | |
5d3e2388 DH |
1390 | } |
1391 | ||
1392 | ||
1393 | static int | |
e81d98ec | 1394 | eval_environment_print (SCM type, SCM port, scm_print_state *pstate SCM_UNUSED) |
5d3e2388 | 1395 | { |
c014a02e | 1396 | SCM address = scm_ulong2num (SCM_UNPACK (type)); |
5d3e2388 DH |
1397 | SCM base16 = scm_number_to_string (address, SCM_MAKINUM (16)); |
1398 | ||
1399 | scm_puts ("#<eval environment ", port); | |
86c991c2 | 1400 | scm_puts (SCM_STRING_CHARS (base16), port); |
5d3e2388 DH |
1401 | scm_puts (">", port); |
1402 | ||
1403 | return 1; | |
1404 | } | |
1405 | ||
1406 | ||
1407 | static struct scm_environment_funcs eval_environment_funcs = { | |
1408 | eval_environment_ref, | |
1409 | eval_environment_fold, | |
1410 | eval_environment_define, | |
1411 | eval_environment_undefine, | |
1412 | eval_environment_set_x, | |
1413 | eval_environment_cell, | |
1414 | core_environments_observe, | |
1415 | core_environments_unobserve, | |
e841c3e0 KN |
1416 | eval_environment_mark, |
1417 | eval_environment_free, | |
1418 | eval_environment_print | |
5d3e2388 DH |
1419 | }; |
1420 | ||
1421 | ||
1422 | void *scm_type_eval_environment = &eval_environment_funcs; | |
1423 | ||
1424 | ||
1425 | static void | |
e81d98ec | 1426 | eval_environment_observer (SCM caller SCM_UNUSED, SCM eval_env) |
5d3e2388 DH |
1427 | { |
1428 | SCM obarray = EVAL_ENVIRONMENT (eval_env)->obarray; | |
1429 | ||
1430 | obarray_remove_all (obarray); | |
1431 | core_environments_broadcast (eval_env); | |
1432 | } | |
1433 | ||
1434 | ||
1435 | SCM_DEFINE (scm_make_eval_environment, "make-eval-environment", 2, 0, 0, | |
1436 | (SCM local, SCM imported), | |
1437 | "Return a new environment object eval whose bindings are the\n" | |
0fb104ed MG |
1438 | "union of the bindings in the environments @var{local} and\n" |
1439 | "@var{imported}, with bindings from @var{local} taking\n" | |
1440 | "precedence. Definitions made in eval are placed in @var{local}.\n" | |
1441 | "Applying @code{environment-define} or\n" | |
1442 | "@code{environment-undefine} to eval has the same effect as\n" | |
1443 | "applying the procedure to @var{local}.\n" | |
1444 | "Note that eval incorporates @var{local} and @var{imported} by\n" | |
1445 | "reference:\n" | |
5d3e2388 | 1446 | "If, after creating eval, the program changes the bindings of\n" |
0fb104ed MG |
1447 | "@var{local} or @var{imported}, those changes will be visible\n" |
1448 | "in eval.\n" | |
5d3e2388 | 1449 | "Since most Scheme evaluation takes place in eval environments,\n" |
0fb104ed MG |
1450 | "they transparently cache the bindings received from @var{local}\n" |
1451 | "and @var{imported}. Thus, the first time the program looks up\n" | |
1452 | "a symbol in eval, eval may make calls to @var{local} or\n" | |
1453 | "@var{imported} to find their bindings, but subsequent\n" | |
1454 | "references to that symbol will be as fast as references to\n" | |
1455 | "bindings in finite environments.\n" | |
1456 | "In typical use, @var{local} will be a finite environment, and\n" | |
1457 | "@var{imported} will be an import environment") | |
5d3e2388 DH |
1458 | #define FUNC_NAME s_scm_make_eval_environment |
1459 | { | |
1460 | SCM env; | |
1461 | struct eval_environment *body; | |
1462 | ||
1463 | SCM_ASSERT (SCM_ENVIRONMENT_P (local), local, SCM_ARG1, FUNC_NAME); | |
1464 | SCM_ASSERT (SCM_ENVIRONMENT_P (imported), imported, SCM_ARG2, FUNC_NAME); | |
1465 | ||
4c9419ac | 1466 | body = scm_gc_malloc (sizeof (struct eval_environment), "eval environment"); |
5d3e2388 DH |
1467 | |
1468 | core_environments_preinit (&body->base); | |
1469 | body->obarray = SCM_BOOL_F; | |
1470 | body->imported = SCM_BOOL_F; | |
1471 | body->imported_observer = SCM_BOOL_F; | |
1472 | body->local = SCM_BOOL_F; | |
1473 | body->local_observer = SCM_BOOL_F; | |
1474 | ||
1475 | env = scm_make_environment (body); | |
1476 | ||
1477 | core_environments_init (&body->base, &eval_environment_funcs); | |
00ffa0e7 | 1478 | body->obarray = scm_c_make_hash_table (DEFAULT_OBARRAY_SIZE); |
5d3e2388 DH |
1479 | body->imported = imported; |
1480 | body->imported_observer | |
1481 | = SCM_ENVIRONMENT_OBSERVE (imported, eval_environment_observer, env, 1); | |
1482 | body->local = local; | |
1483 | body->local_observer | |
1484 | = SCM_ENVIRONMENT_OBSERVE (local, eval_environment_observer, env, 1); | |
1485 | ||
1486 | return env; | |
1487 | } | |
1488 | #undef FUNC_NAME | |
1489 | ||
1490 | ||
1491 | SCM_DEFINE (scm_eval_environment_p, "eval-environment?", 1, 0, 0, | |
1492 | (SCM object), | |
0fb104ed MG |
1493 | "Return @code{#t} if object is an eval environment, or @code{#f}\n" |
1494 | "otherwise.") | |
5d3e2388 DH |
1495 | #define FUNC_NAME s_scm_eval_environment_p |
1496 | { | |
1497 | return SCM_BOOL (SCM_EVAL_ENVIRONMENT_P (object)); | |
1498 | } | |
1499 | #undef FUNC_NAME | |
1500 | ||
1501 | ||
1502 | SCM_DEFINE (scm_eval_environment_local, "eval-environment-local", 1, 0, 0, | |
1503 | (SCM env), | |
0fb104ed | 1504 | "Return the local environment of eval environment @var{env}.") |
5d3e2388 DH |
1505 | #define FUNC_NAME s_scm_eval_environment_local |
1506 | { | |
1507 | SCM_ASSERT (SCM_EVAL_ENVIRONMENT_P (env), env, SCM_ARG1, FUNC_NAME); | |
1508 | ||
1509 | return EVAL_ENVIRONMENT (env)->local; | |
1510 | } | |
1511 | #undef FUNC_NAME | |
1512 | ||
1513 | ||
1514 | SCM_DEFINE (scm_eval_environment_set_local_x, "eval-environment-set-local!", 2, 0, 0, | |
1515 | (SCM env, SCM local), | |
0fb104ed | 1516 | "Change @var{env}'s local environment to @var{local}.") |
5d3e2388 DH |
1517 | #define FUNC_NAME s_scm_eval_environment_set_local_x |
1518 | { | |
1519 | struct eval_environment *body; | |
1520 | ||
1521 | SCM_ASSERT (SCM_EVAL_ENVIRONMENT_P (env), env, SCM_ARG1, FUNC_NAME); | |
1522 | SCM_ASSERT (SCM_ENVIRONMENT_P (local), local, SCM_ARG2, FUNC_NAME); | |
1523 | ||
1524 | body = EVAL_ENVIRONMENT (env); | |
1525 | ||
1526 | obarray_remove_all (body->obarray); | |
1527 | SCM_ENVIRONMENT_UNOBSERVE (body->local, body->local_observer); | |
1528 | ||
1529 | body->local = local; | |
1530 | body->local_observer | |
1531 | = SCM_ENVIRONMENT_OBSERVE (local, eval_environment_observer, env, 1); | |
1532 | ||
1533 | core_environments_broadcast (env); | |
1534 | ||
1535 | return SCM_UNSPECIFIED; | |
1536 | } | |
1537 | #undef FUNC_NAME | |
1538 | ||
1539 | ||
1540 | SCM_DEFINE (scm_eval_environment_imported, "eval-environment-imported", 1, 0, 0, | |
1541 | (SCM env), | |
0fb104ed | 1542 | "Return the imported environment of eval environment @var{env}.") |
5d3e2388 DH |
1543 | #define FUNC_NAME s_scm_eval_environment_imported |
1544 | { | |
1545 | SCM_ASSERT (SCM_EVAL_ENVIRONMENT_P (env), env, SCM_ARG1, FUNC_NAME); | |
1546 | ||
1547 | return EVAL_ENVIRONMENT (env)->imported; | |
1548 | } | |
1549 | #undef FUNC_NAME | |
1550 | ||
1551 | ||
1552 | SCM_DEFINE (scm_eval_environment_set_imported_x, "eval-environment-set-imported!", 2, 0, 0, | |
1553 | (SCM env, SCM imported), | |
0fb104ed | 1554 | "Change @var{env}'s imported environment to @var{imported}.") |
5d3e2388 DH |
1555 | #define FUNC_NAME s_scm_eval_environment_set_imported_x |
1556 | { | |
1557 | struct eval_environment *body; | |
1558 | ||
1559 | SCM_ASSERT (SCM_EVAL_ENVIRONMENT_P (env), env, SCM_ARG1, FUNC_NAME); | |
1560 | SCM_ASSERT (SCM_ENVIRONMENT_P (imported), imported, SCM_ARG2, FUNC_NAME); | |
1561 | ||
1562 | body = EVAL_ENVIRONMENT (env); | |
1563 | ||
1564 | obarray_remove_all (body->obarray); | |
1565 | SCM_ENVIRONMENT_UNOBSERVE (body->imported, body->imported_observer); | |
1566 | ||
1567 | body->imported = imported; | |
1568 | body->imported_observer | |
1569 | = SCM_ENVIRONMENT_OBSERVE (imported, eval_environment_observer, env, 1); | |
1570 | ||
1571 | core_environments_broadcast (env); | |
1572 | ||
1573 | return SCM_UNSPECIFIED; | |
1574 | } | |
1575 | #undef FUNC_NAME | |
1576 | ||
1577 | \f | |
1578 | ||
1579 | /* import environments | |
1580 | * | |
1581 | * An import environment combines the bindings of a set of argument | |
1582 | * environments, and checks for naming clashes. | |
1583 | * | |
1584 | * Implementation: The import environment does no caching at all. For every | |
1585 | * access, the list of imported environments is scanned. | |
1586 | */ | |
1587 | ||
1588 | ||
1589 | struct import_environment { | |
1590 | struct core_environments_base base; | |
1591 | ||
1592 | SCM imports; | |
1593 | SCM import_observers; | |
1594 | ||
1595 | SCM conflict_proc; | |
1596 | }; | |
1597 | ||
1598 | ||
1599 | #define IMPORT_ENVIRONMENT(env) \ | |
1600 | ((struct import_environment *) SCM_CELL_WORD_1 (env)) | |
1601 | ||
1602 | \f | |
1603 | ||
1604 | /* Lookup will report one of the following distinct results: | |
1605 | * a) <environment> if only environment binds the symbol. | |
1606 | * b) (env-1 env-2 ...) for conflicting bindings in env-1, ... | |
1607 | * c) SCM_UNDEFINED if there is no binding for the symbol. | |
1608 | */ | |
1609 | static SCM | |
1610 | import_environment_lookup (SCM env, SCM sym) | |
1611 | { | |
1612 | SCM imports = IMPORT_ENVIRONMENT (env)->imports; | |
1613 | SCM result = SCM_UNDEFINED; | |
1614 | SCM l; | |
1615 | ||
1616 | for (l = imports; !SCM_NULLP (l); l = SCM_CDR (l)) | |
1617 | { | |
1618 | SCM imported = SCM_CAR (l); | |
1619 | ||
1620 | if (SCM_ENVIRONMENT_BOUND_P (imported, sym)) | |
1621 | { | |
1622 | if (SCM_UNBNDP (result)) | |
1623 | result = imported; | |
1624 | else if (SCM_CONSP (result)) | |
1625 | result = scm_cons (imported, result); | |
1626 | else | |
1627 | result = scm_cons2 (imported, result, SCM_EOL); | |
1628 | } | |
1629 | } | |
1630 | ||
1631 | if (SCM_CONSP (result)) | |
1632 | return scm_reverse (result); | |
1633 | else | |
1634 | return result; | |
1635 | } | |
1636 | ||
1637 | ||
1638 | static SCM | |
1639 | import_environment_conflict (SCM env, SCM sym, SCM imports) | |
1640 | { | |
1641 | SCM conflict_proc = IMPORT_ENVIRONMENT (env)->conflict_proc; | |
1642 | SCM args = scm_cons2 (env, sym, scm_cons (imports, SCM_EOL)); | |
1643 | ||
fdc28395 | 1644 | return scm_apply_0 (conflict_proc, args); |
5d3e2388 DH |
1645 | } |
1646 | ||
1647 | ||
1648 | static SCM | |
1649 | import_environment_ref (SCM env, SCM sym) | |
1650 | #define FUNC_NAME "import_environment_ref" | |
1651 | { | |
1652 | SCM owner = import_environment_lookup (env, sym); | |
1653 | ||
1654 | if (SCM_UNBNDP (owner)) | |
1655 | { | |
1656 | return SCM_UNDEFINED; | |
1657 | } | |
1658 | else if (SCM_CONSP (owner)) | |
1659 | { | |
1660 | SCM resolve = import_environment_conflict (env, sym, owner); | |
1661 | ||
1662 | if (SCM_ENVIRONMENT_P (resolve)) | |
1663 | return SCM_ENVIRONMENT_REF (resolve, sym); | |
1664 | else | |
1665 | return SCM_UNSPECIFIED; | |
1666 | } | |
1667 | else | |
1668 | { | |
1669 | return SCM_ENVIRONMENT_REF (owner, sym); | |
1670 | } | |
1671 | } | |
1672 | #undef FUNC_NAME | |
1673 | ||
1674 | ||
1675 | static SCM | |
1676 | import_environment_folder (SCM extended_data, SCM symbol, SCM value, SCM tail) | |
1677 | #define FUNC_NAME "import_environment_fold" | |
1678 | { | |
1679 | SCM import_env = SCM_CAR (extended_data); | |
1680 | SCM imported_env = SCM_CADR (extended_data); | |
1681 | SCM owner = import_environment_lookup (import_env, symbol); | |
1682 | SCM proc_as_nr = SCM_CADDR (extended_data); | |
c014a02e | 1683 | unsigned long int proc_as_ul = scm_num2ulong (proc_as_nr, 0, NULL); |
5d3e2388 DH |
1684 | scm_environment_folder proc = (scm_environment_folder) proc_as_ul; |
1685 | SCM data = SCM_CDDDR (extended_data); | |
1686 | ||
1687 | if (SCM_CONSP (owner) && SCM_EQ_P (SCM_CAR (owner), imported_env)) | |
1688 | owner = import_environment_conflict (import_env, symbol, owner); | |
1689 | ||
1690 | if (SCM_ENVIRONMENT_P (owner)) | |
1691 | return (*proc) (data, symbol, value, tail); | |
1692 | else /* unresolved conflict */ | |
1693 | return (*proc) (data, symbol, SCM_UNSPECIFIED, tail); | |
1694 | } | |
1695 | #undef FUNC_NAME | |
1696 | ||
1697 | ||
1698 | static SCM | |
1699 | import_environment_fold (SCM env, scm_environment_folder proc, SCM data, SCM init) | |
1700 | { | |
c014a02e | 1701 | SCM proc_as_nr = scm_ulong2num ((unsigned long int) proc); |
5d3e2388 DH |
1702 | SCM result = init; |
1703 | SCM l; | |
1704 | ||
1705 | for (l = IMPORT_ENVIRONMENT (env)->imports; !SCM_NULLP (l); l = SCM_CDR (l)) | |
1706 | { | |
1707 | SCM imported_env = SCM_CAR (l); | |
1708 | SCM extended_data = scm_cons (env, scm_cons2 (imported_env, proc_as_nr, data)); | |
1709 | ||
1710 | result = scm_c_environment_fold (imported_env, import_environment_folder, extended_data, result); | |
1711 | } | |
1712 | ||
1713 | return result; | |
1714 | } | |
1715 | ||
1716 | ||
1717 | static SCM | |
e81d98ec DH |
1718 | import_environment_define (SCM env SCM_UNUSED, |
1719 | SCM sym SCM_UNUSED, | |
1720 | SCM val SCM_UNUSED) | |
5d3e2388 DH |
1721 | #define FUNC_NAME "import_environment_define" |
1722 | { | |
1723 | return SCM_ENVIRONMENT_BINDING_IMMUTABLE; | |
1724 | } | |
1725 | #undef FUNC_NAME | |
1726 | ||
1727 | ||
1728 | static SCM | |
e81d98ec DH |
1729 | import_environment_undefine (SCM env SCM_UNUSED, |
1730 | SCM sym SCM_UNUSED) | |
5d3e2388 DH |
1731 | #define FUNC_NAME "import_environment_undefine" |
1732 | { | |
1733 | return SCM_ENVIRONMENT_BINDING_IMMUTABLE; | |
1734 | } | |
1735 | #undef FUNC_NAME | |
1736 | ||
1737 | ||
1738 | static SCM | |
1739 | import_environment_set_x (SCM env, SCM sym, SCM val) | |
1740 | #define FUNC_NAME "import_environment_set_x" | |
1741 | { | |
1742 | SCM owner = import_environment_lookup (env, sym); | |
1743 | ||
1744 | if (SCM_UNBNDP (owner)) | |
1745 | { | |
1746 | return SCM_UNDEFINED; | |
1747 | } | |
1748 | else if (SCM_CONSP (owner)) | |
1749 | { | |
1750 | SCM resolve = import_environment_conflict (env, sym, owner); | |
1751 | ||
1752 | if (SCM_ENVIRONMENT_P (resolve)) | |
1753 | return SCM_ENVIRONMENT_SET (resolve, sym, val); | |
1754 | else | |
1755 | return SCM_ENVIRONMENT_LOCATION_IMMUTABLE; | |
1756 | } | |
1757 | else | |
1758 | { | |
1759 | return SCM_ENVIRONMENT_SET (owner, sym, val); | |
1760 | } | |
1761 | } | |
1762 | #undef FUNC_NAME | |
1763 | ||
1764 | ||
1765 | static SCM | |
1766 | import_environment_cell (SCM env, SCM sym, int for_write) | |
1767 | #define FUNC_NAME "import_environment_cell" | |
1768 | { | |
1769 | SCM owner = import_environment_lookup (env, sym); | |
1770 | ||
1771 | if (SCM_UNBNDP (owner)) | |
1772 | { | |
1773 | return SCM_UNDEFINED; | |
1774 | } | |
1775 | else if (SCM_CONSP (owner)) | |
1776 | { | |
1777 | SCM resolve = import_environment_conflict (env, sym, owner); | |
1778 | ||
1779 | if (SCM_ENVIRONMENT_P (resolve)) | |
1780 | return SCM_ENVIRONMENT_CELL (resolve, sym, for_write); | |
1781 | else | |
1782 | return SCM_ENVIRONMENT_LOCATION_NO_CELL; | |
1783 | } | |
1784 | else | |
1785 | { | |
1786 | return SCM_ENVIRONMENT_CELL (owner, sym, for_write); | |
1787 | } | |
1788 | } | |
1789 | #undef FUNC_NAME | |
1790 | ||
1791 | ||
1792 | static SCM | |
e841c3e0 | 1793 | import_environment_mark (SCM env) |
5d3e2388 DH |
1794 | { |
1795 | scm_gc_mark (IMPORT_ENVIRONMENT (env)->imports); | |
1796 | scm_gc_mark (IMPORT_ENVIRONMENT (env)->import_observers); | |
1797 | scm_gc_mark (IMPORT_ENVIRONMENT (env)->conflict_proc); | |
1798 | return core_environments_mark (env); | |
1799 | } | |
1800 | ||
1801 | ||
4c9419ac | 1802 | static void |
e841c3e0 | 1803 | import_environment_free (SCM env) |
5d3e2388 DH |
1804 | { |
1805 | core_environments_finalize (env); | |
4c9419ac MV |
1806 | scm_gc_free (IMPORT_ENVIRONMENT (env), sizeof (struct import_environment), |
1807 | "import environment"); | |
5d3e2388 DH |
1808 | } |
1809 | ||
1810 | ||
1811 | static int | |
e81d98ec DH |
1812 | import_environment_print (SCM type, SCM port, |
1813 | scm_print_state *pstate SCM_UNUSED) | |
5d3e2388 | 1814 | { |
c014a02e | 1815 | SCM address = scm_ulong2num (SCM_UNPACK (type)); |
5d3e2388 DH |
1816 | SCM base16 = scm_number_to_string (address, SCM_MAKINUM (16)); |
1817 | ||
1818 | scm_puts ("#<import environment ", port); | |
86c991c2 | 1819 | scm_puts (SCM_STRING_CHARS (base16), port); |
5d3e2388 DH |
1820 | scm_puts (">", port); |
1821 | ||
1822 | return 1; | |
1823 | } | |
1824 | ||
1825 | ||
1826 | static struct scm_environment_funcs import_environment_funcs = { | |
1827 | import_environment_ref, | |
1828 | import_environment_fold, | |
1829 | import_environment_define, | |
1830 | import_environment_undefine, | |
1831 | import_environment_set_x, | |
1832 | import_environment_cell, | |
1833 | core_environments_observe, | |
1834 | core_environments_unobserve, | |
e841c3e0 KN |
1835 | import_environment_mark, |
1836 | import_environment_free, | |
1837 | import_environment_print | |
5d3e2388 DH |
1838 | }; |
1839 | ||
1840 | ||
1841 | void *scm_type_import_environment = &import_environment_funcs; | |
1842 | ||
1843 | ||
1844 | static void | |
e81d98ec | 1845 | import_environment_observer (SCM caller SCM_UNUSED, SCM import_env) |
5d3e2388 DH |
1846 | { |
1847 | core_environments_broadcast (import_env); | |
1848 | } | |
1849 | ||
1850 | ||
1851 | SCM_DEFINE (scm_make_import_environment, "make-import-environment", 2, 0, 0, | |
1852 | (SCM imports, SCM conflict_proc), | |
0fb104ed MG |
1853 | "Return a new environment @var{imp} whose bindings are the union\n" |
1854 | "of the bindings from the environments in @var{imports};\n" | |
1855 | "@var{imports} must be a list of environments. That is,\n" | |
1856 | "@var{imp} binds a symbol to a location when some element of\n" | |
1857 | "@var{imports} does.\n" | |
1858 | "If two different elements of @var{imports} have a binding for\n" | |
1859 | "the same symbol, the @var{conflict-proc} is called with the\n" | |
1860 | "following parameters: the import environment, the symbol and\n" | |
1861 | "the list of the imported environments that bind the symbol.\n" | |
1862 | "If the @var{conflict-proc} returns an environment @var{env},\n" | |
1863 | "the conflict is considered as resolved and the binding from\n" | |
1864 | "@var{env} is used. If the @var{conflict-proc} returns some\n" | |
1865 | "non-environment object, the conflict is considered unresolved\n" | |
1866 | "and the symbol is treated as unspecified in the import\n" | |
1867 | "environment.\n" | |
1868 | "The checking for conflicts may be performed lazily, i. e. at\n" | |
5d3e2388 DH |
1869 | "the moment when a value or binding for a certain symbol is\n" |
1870 | "requested instead of the moment when the environment is\n" | |
1871 | "created or the bindings of the imports change.\n" | |
0fb104ed MG |
1872 | "All bindings in @var{imp} are immutable. If you apply\n" |
1873 | "@code{environment-define} or @code{environment-undefine} to\n" | |
1874 | "@var{imp}, Guile will signal an\n" | |
1875 | " @code{environment:immutable-binding} error. However,\n" | |
1876 | "notice that the set of bindings in @var{imp} may still change,\n" | |
1877 | "if one of its imported environments changes.") | |
5d3e2388 DH |
1878 | #define FUNC_NAME s_scm_make_import_environment |
1879 | { | |
1be6b49c | 1880 | size_t size = sizeof (struct import_environment); |
4c9419ac | 1881 | struct import_environment *body = scm_gc_malloc (size, "import environment"); |
5d3e2388 DH |
1882 | SCM env; |
1883 | ||
1884 | core_environments_preinit (&body->base); | |
1885 | body->imports = SCM_BOOL_F; | |
1886 | body->import_observers = SCM_BOOL_F; | |
1887 | body->conflict_proc = SCM_BOOL_F; | |
1888 | ||
1889 | env = scm_make_environment (body); | |
1890 | ||
1891 | core_environments_init (&body->base, &import_environment_funcs); | |
1892 | body->imports = SCM_EOL; | |
1893 | body->import_observers = SCM_EOL; | |
1894 | body->conflict_proc = conflict_proc; | |
1895 | ||
1896 | scm_import_environment_set_imports_x (env, imports); | |
1897 | ||
1898 | return env; | |
1899 | } | |
1900 | #undef FUNC_NAME | |
1901 | ||
1902 | ||
1903 | SCM_DEFINE (scm_import_environment_p, "import-environment?", 1, 0, 0, | |
1904 | (SCM object), | |
0fb104ed MG |
1905 | "Return @code{#t} if object is an import environment, or\n" |
1906 | "@code{#f} otherwise.") | |
5d3e2388 DH |
1907 | #define FUNC_NAME s_scm_import_environment_p |
1908 | { | |
1909 | return SCM_BOOL (SCM_IMPORT_ENVIRONMENT_P (object)); | |
1910 | } | |
1911 | #undef FUNC_NAME | |
1912 | ||
1913 | ||
1914 | SCM_DEFINE (scm_import_environment_imports, "import-environment-imports", 1, 0, 0, | |
1915 | (SCM env), | |
0fb104ed MG |
1916 | "Return the list of environments imported by the import\n" |
1917 | "environment @var{env}.") | |
5d3e2388 DH |
1918 | #define FUNC_NAME s_scm_import_environment_imports |
1919 | { | |
1920 | SCM_ASSERT (SCM_IMPORT_ENVIRONMENT_P (env), env, SCM_ARG1, FUNC_NAME); | |
1921 | ||
1922 | return IMPORT_ENVIRONMENT (env)->imports; | |
1923 | } | |
1924 | #undef FUNC_NAME | |
1925 | ||
1926 | ||
1927 | SCM_DEFINE (scm_import_environment_set_imports_x, "import-environment-set-imports!", 2, 0, 0, | |
1928 | (SCM env, SCM imports), | |
0fb104ed MG |
1929 | "Change @var{env}'s list of imported environments to\n" |
1930 | "@var{imports}, and check for conflicts.") | |
5d3e2388 DH |
1931 | #define FUNC_NAME s_scm_import_environment_set_imports_x |
1932 | { | |
1933 | struct import_environment *body = IMPORT_ENVIRONMENT (env); | |
1934 | SCM import_observers = SCM_EOL; | |
1935 | SCM l; | |
1936 | ||
1937 | SCM_ASSERT (SCM_IMPORT_ENVIRONMENT_P (env), env, SCM_ARG1, FUNC_NAME); | |
1938 | for (l = imports; SCM_CONSP (l); l = SCM_CDR (l)) | |
1939 | { | |
1940 | SCM obj = SCM_CAR (l); | |
dd85ce47 | 1941 | SCM_ASSERT (SCM_ENVIRONMENT_P (obj), imports, SCM_ARG2, FUNC_NAME); |
5d3e2388 | 1942 | } |
dd85ce47 | 1943 | SCM_ASSERT (SCM_NULLP (l), imports, SCM_ARG2, FUNC_NAME); |
5d3e2388 DH |
1944 | |
1945 | for (l = body->import_observers; !SCM_NULLP (l); l = SCM_CDR (l)) | |
1946 | { | |
1947 | SCM obs = SCM_CAR (l); | |
1948 | SCM_ENVIRONMENT_UNOBSERVE (env, obs); | |
1949 | } | |
1950 | ||
1951 | for (l = imports; !SCM_NULLP (l); l = SCM_CDR (l)) | |
1952 | { | |
1953 | SCM imp = SCM_CAR (l); | |
1954 | SCM obs = SCM_ENVIRONMENT_OBSERVE (imp, import_environment_observer, env, 1); | |
1955 | import_observers = scm_cons (obs, import_observers); | |
1956 | } | |
1957 | ||
1958 | body->imports = imports; | |
1959 | body->import_observers = import_observers; | |
1960 | ||
1961 | return SCM_UNSPECIFIED; | |
1962 | } | |
1963 | #undef FUNC_NAME | |
1964 | ||
1965 | \f | |
1966 | ||
1967 | /* export environments | |
1968 | * | |
1969 | * An export environment restricts an environment to a specified set of | |
1970 | * bindings. | |
1971 | * | |
1972 | * Implementation: The export environment does no caching at all. For every | |
1973 | * access, the signature is scanned. The signature that is stored internally | |
1974 | * is an alist of pairs (symbol . (mutability)). | |
1975 | */ | |
1976 | ||
1977 | ||
1978 | struct export_environment { | |
1979 | struct core_environments_base base; | |
1980 | ||
1981 | SCM private; | |
1982 | SCM private_observer; | |
1983 | ||
1984 | SCM signature; | |
1985 | }; | |
1986 | ||
1987 | ||
1988 | #define EXPORT_ENVIRONMENT(env) \ | |
1989 | ((struct export_environment *) SCM_CELL_WORD_1 (env)) | |
1990 | ||
1991 | ||
1992 | SCM_SYMBOL (symbol_immutable_location, "immutable-location"); | |
1993 | SCM_SYMBOL (symbol_mutable_location, "mutable-location"); | |
1994 | ||
1995 | \f | |
1996 | ||
1997 | static SCM | |
1998 | export_environment_ref (SCM env, SCM sym) | |
1999 | #define FUNC_NAME "export_environment_ref" | |
2000 | { | |
2001 | struct export_environment *body = EXPORT_ENVIRONMENT (env); | |
2002 | SCM entry = scm_assq (sym, body->signature); | |
2003 | ||
2004 | if (SCM_FALSEP (entry)) | |
2005 | return SCM_UNDEFINED; | |
2006 | else | |
2007 | return SCM_ENVIRONMENT_REF (body->private, sym); | |
2008 | } | |
2009 | #undef FUNC_NAME | |
2010 | ||
2011 | ||
2012 | static SCM | |
2013 | export_environment_fold (SCM env, scm_environment_folder proc, SCM data, SCM init) | |
2014 | { | |
2015 | struct export_environment *body = EXPORT_ENVIRONMENT (env); | |
2016 | SCM result = init; | |
2017 | SCM l; | |
2018 | ||
2019 | for (l = body->signature; !SCM_NULLP (l); l = SCM_CDR (l)) | |
2020 | { | |
2021 | SCM symbol = SCM_CAR (l); | |
2022 | SCM value = SCM_ENVIRONMENT_REF (body->private, symbol); | |
2023 | if (!SCM_UNBNDP (value)) | |
2024 | result = (*proc) (data, symbol, value, result); | |
2025 | } | |
2026 | return result; | |
2027 | } | |
2028 | ||
2029 | ||
2030 | static SCM | |
e81d98ec DH |
2031 | export_environment_define (SCM env SCM_UNUSED, |
2032 | SCM sym SCM_UNUSED, | |
2033 | SCM val SCM_UNUSED) | |
5d3e2388 DH |
2034 | #define FUNC_NAME "export_environment_define" |
2035 | { | |
2036 | return SCM_ENVIRONMENT_BINDING_IMMUTABLE; | |
2037 | } | |
2038 | #undef FUNC_NAME | |
2039 | ||
2040 | ||
2041 | static SCM | |
e81d98ec | 2042 | export_environment_undefine (SCM env SCM_UNUSED, SCM sym SCM_UNUSED) |
5d3e2388 DH |
2043 | #define FUNC_NAME "export_environment_undefine" |
2044 | { | |
2045 | return SCM_ENVIRONMENT_BINDING_IMMUTABLE; | |
2046 | } | |
2047 | #undef FUNC_NAME | |
2048 | ||
2049 | ||
2050 | static SCM | |
2051 | export_environment_set_x (SCM env, SCM sym, SCM val) | |
2052 | #define FUNC_NAME "export_environment_set_x" | |
2053 | { | |
2054 | struct export_environment *body = EXPORT_ENVIRONMENT (env); | |
2055 | SCM entry = scm_assq (sym, body->signature); | |
2056 | ||
2057 | if (SCM_FALSEP (entry)) | |
2058 | { | |
2059 | return SCM_UNDEFINED; | |
2060 | } | |
2061 | else | |
2062 | { | |
2063 | if (SCM_EQ_P (SCM_CADR (entry), symbol_mutable_location)) | |
2064 | return SCM_ENVIRONMENT_SET (body->private, sym, val); | |
2065 | else | |
2066 | return SCM_ENVIRONMENT_LOCATION_IMMUTABLE; | |
2067 | } | |
2068 | } | |
2069 | #undef FUNC_NAME | |
2070 | ||
2071 | ||
2072 | static SCM | |
2073 | export_environment_cell (SCM env, SCM sym, int for_write) | |
2074 | #define FUNC_NAME "export_environment_cell" | |
2075 | { | |
2076 | struct export_environment *body = EXPORT_ENVIRONMENT (env); | |
2077 | SCM entry = scm_assq (sym, body->signature); | |
2078 | ||
2079 | if (SCM_FALSEP (entry)) | |
2080 | { | |
2081 | return SCM_UNDEFINED; | |
2082 | } | |
2083 | else | |
2084 | { | |
2085 | if (!for_write || SCM_EQ_P (SCM_CADR (entry), symbol_mutable_location)) | |
2086 | return SCM_ENVIRONMENT_CELL (body->private, sym, for_write); | |
2087 | else | |
2088 | return SCM_ENVIRONMENT_LOCATION_IMMUTABLE; | |
2089 | } | |
2090 | } | |
2091 | #undef FUNC_NAME | |
2092 | ||
2093 | ||
2094 | static SCM | |
e841c3e0 | 2095 | export_environment_mark (SCM env) |
5d3e2388 DH |
2096 | { |
2097 | struct export_environment *body = EXPORT_ENVIRONMENT (env); | |
2098 | ||
2099 | scm_gc_mark (body->private); | |
2100 | scm_gc_mark (body->private_observer); | |
2101 | scm_gc_mark (body->signature); | |
2102 | ||
2103 | return core_environments_mark (env); | |
2104 | } | |
2105 | ||
2106 | ||
4c9419ac | 2107 | static void |
e841c3e0 | 2108 | export_environment_free (SCM env) |
5d3e2388 DH |
2109 | { |
2110 | core_environments_finalize (env); | |
4c9419ac MV |
2111 | scm_gc_free (EXPORT_ENVIRONMENT (env), sizeof (struct export_environment), |
2112 | "export environment"); | |
5d3e2388 DH |
2113 | } |
2114 | ||
2115 | ||
2116 | static int | |
e81d98ec DH |
2117 | export_environment_print (SCM type, SCM port, |
2118 | scm_print_state *pstate SCM_UNUSED) | |
5d3e2388 | 2119 | { |
c014a02e | 2120 | SCM address = scm_ulong2num (SCM_UNPACK (type)); |
5d3e2388 DH |
2121 | SCM base16 = scm_number_to_string (address, SCM_MAKINUM (16)); |
2122 | ||
2123 | scm_puts ("#<export environment ", port); | |
86c991c2 | 2124 | scm_puts (SCM_STRING_CHARS (base16), port); |
5d3e2388 DH |
2125 | scm_puts (">", port); |
2126 | ||
2127 | return 1; | |
2128 | } | |
2129 | ||
2130 | ||
2131 | static struct scm_environment_funcs export_environment_funcs = { | |
2132 | export_environment_ref, | |
2133 | export_environment_fold, | |
2134 | export_environment_define, | |
2135 | export_environment_undefine, | |
2136 | export_environment_set_x, | |
2137 | export_environment_cell, | |
2138 | core_environments_observe, | |
2139 | core_environments_unobserve, | |
e841c3e0 KN |
2140 | export_environment_mark, |
2141 | export_environment_free, | |
2142 | export_environment_print | |
5d3e2388 DH |
2143 | }; |
2144 | ||
2145 | ||
2146 | void *scm_type_export_environment = &export_environment_funcs; | |
2147 | ||
2148 | ||
2149 | static void | |
e81d98ec | 2150 | export_environment_observer (SCM caller SCM_UNUSED, SCM export_env) |
5d3e2388 DH |
2151 | { |
2152 | core_environments_broadcast (export_env); | |
2153 | } | |
2154 | ||
2155 | ||
2156 | SCM_DEFINE (scm_make_export_environment, "make-export-environment", 2, 0, 0, | |
2157 | (SCM private, SCM signature), | |
0fb104ed MG |
2158 | "Return a new environment @var{exp} containing only those\n" |
2159 | "bindings in private whose symbols are present in\n" | |
2160 | "@var{signature}. The @var{private} argument must be an\n" | |
2161 | "environment.\n\n" | |
2162 | "The environment @var{exp} binds symbol to location when\n" | |
2163 | "@var{env} does, and symbol is exported by @var{signature}.\n\n" | |
2164 | "@var{signature} is a list specifying which of the bindings in\n" | |
2165 | "@var{private} should be visible in @var{exp}. Each element of\n" | |
2166 | "@var{signature} should be a list of the form:\n" | |
5d3e2388 DH |
2167 | " (symbol attribute ...)\n" |
2168 | "where each attribute is one of the following:\n" | |
0fb104ed MG |
2169 | "@table @asis\n" |
2170 | "@item the symbol @code{mutable-location}\n" | |
2171 | " @var{exp} should treat the\n" | |
2172 | " location bound to symbol as mutable. That is, @var{exp}\n" | |
2173 | " will pass calls to @code{environment-set!} or\n" | |
2174 | " @code{environment-cell} directly through to private.\n" | |
2175 | "@item the symbol @code{immutable-location}\n" | |
2176 | " @var{exp} should treat\n" | |
2177 | " the location bound to symbol as immutable. If the program\n" | |
2178 | " applies @code{environment-set!} to @var{exp} and symbol, or\n" | |
2179 | " calls @code{environment-cell} to obtain a writable value\n" | |
2180 | " cell, @code{environment-set!} will signal an\n" | |
2181 | " @code{environment:immutable-location} error. Note that, even\n" | |
2182 | " if an export environment treats a location as immutable, the\n" | |
5d3e2388 DH |
2183 | " underlying environment may treat it as mutable, so its\n" |
2184 | " value may change.\n" | |
0fb104ed | 2185 | "@end table\n" |
5d3e2388 | 2186 | "It is an error for an element of signature to specify both\n" |
0fb104ed MG |
2187 | "@code{mutable-location} and @code{immutable-location}. If\n" |
2188 | "neither is specified, @code{immutable-location} is assumed.\n\n" | |
5d3e2388 | 2189 | "As a special case, if an element of signature is a lone\n" |
0fb104ed MG |
2190 | "symbol @var{sym}, it is equivalent to an element of the form\n" |
2191 | "@code{(sym)}.\n\n" | |
2192 | "All bindings in @var{exp} are immutable. If you apply\n" | |
2193 | "@code{environment-define} or @code{environment-undefine} to\n" | |
2194 | "@var{exp}, Guile will signal an\n" | |
2195 | "@code{environment:immutable-binding} error. However,\n" | |
2196 | "notice that the set of bindings in @var{exp} may still change,\n" | |
2197 | "if the bindings in private change.") | |
5d3e2388 DH |
2198 | #define FUNC_NAME s_scm_make_export_environment |
2199 | { | |
1be6b49c | 2200 | size_t size; |
5d3e2388 DH |
2201 | struct export_environment *body; |
2202 | SCM env; | |
2203 | ||
2204 | SCM_ASSERT (SCM_ENVIRONMENT_P (private), private, SCM_ARG1, FUNC_NAME); | |
2205 | ||
2206 | size = sizeof (struct export_environment); | |
4c9419ac | 2207 | body = scm_gc_malloc (size, "export environment"); |
5d3e2388 DH |
2208 | |
2209 | core_environments_preinit (&body->base); | |
2210 | body->private = SCM_BOOL_F; | |
2211 | body->private_observer = SCM_BOOL_F; | |
2212 | body->signature = SCM_BOOL_F; | |
2213 | ||
2214 | env = scm_make_environment (body); | |
2215 | ||
2216 | core_environments_init (&body->base, &export_environment_funcs); | |
2217 | body->private = private; | |
2218 | body->private_observer | |
2219 | = SCM_ENVIRONMENT_OBSERVE (private, export_environment_observer, env, 1); | |
2220 | body->signature = SCM_EOL; | |
2221 | ||
2222 | scm_export_environment_set_signature_x (env, signature); | |
2223 | ||
2224 | return env; | |
2225 | } | |
2226 | #undef FUNC_NAME | |
2227 | ||
2228 | ||
2229 | SCM_DEFINE (scm_export_environment_p, "export-environment?", 1, 0, 0, | |
2230 | (SCM object), | |
0fb104ed MG |
2231 | "Return @code{#t} if object is an export environment, or\n" |
2232 | "@code{#f} otherwise.") | |
5d3e2388 DH |
2233 | #define FUNC_NAME s_scm_export_environment_p |
2234 | { | |
2235 | return SCM_BOOL (SCM_EXPORT_ENVIRONMENT_P (object)); | |
2236 | } | |
2237 | #undef FUNC_NAME | |
2238 | ||
2239 | ||
2240 | SCM_DEFINE (scm_export_environment_private, "export-environment-private", 1, 0, 0, | |
2241 | (SCM env), | |
0fb104ed | 2242 | "Return the private environment of export environment @var{env}.") |
5d3e2388 DH |
2243 | #define FUNC_NAME s_scm_export_environment_private |
2244 | { | |
2245 | SCM_ASSERT (SCM_EXPORT_ENVIRONMENT_P (env), env, SCM_ARG1, FUNC_NAME); | |
2246 | ||
2247 | return EXPORT_ENVIRONMENT (env)->private; | |
2248 | } | |
2249 | #undef FUNC_NAME | |
2250 | ||
2251 | ||
2252 | SCM_DEFINE (scm_export_environment_set_private_x, "export-environment-set-private!", 2, 0, 0, | |
2253 | (SCM env, SCM private), | |
0fb104ed | 2254 | "Change the private environment of export environment @var{env}.") |
5d3e2388 DH |
2255 | #define FUNC_NAME s_scm_export_environment_set_private_x |
2256 | { | |
2257 | struct export_environment *body; | |
2258 | ||
2259 | SCM_ASSERT (SCM_EXPORT_ENVIRONMENT_P (env), env, SCM_ARG1, FUNC_NAME); | |
2260 | SCM_ASSERT (SCM_ENVIRONMENT_P (private), private, SCM_ARG2, FUNC_NAME); | |
2261 | ||
2262 | body = EXPORT_ENVIRONMENT (env); | |
2263 | SCM_ENVIRONMENT_UNOBSERVE (private, body->private_observer); | |
2264 | ||
2265 | body->private = private; | |
2266 | body->private_observer | |
2267 | = SCM_ENVIRONMENT_OBSERVE (private, export_environment_observer, env, 1); | |
2268 | ||
2269 | return SCM_UNSPECIFIED; | |
2270 | } | |
2271 | #undef FUNC_NAME | |
2272 | ||
2273 | ||
2274 | SCM_DEFINE (scm_export_environment_signature, "export-environment-signature", 1, 0, 0, | |
2275 | (SCM env), | |
0fb104ed | 2276 | "Return the signature of export environment @var{env}.") |
5d3e2388 DH |
2277 | #define FUNC_NAME s_scm_export_environment_signature |
2278 | { | |
2279 | SCM_ASSERT (SCM_EXPORT_ENVIRONMENT_P (env), env, SCM_ARG1, FUNC_NAME); | |
2280 | ||
2281 | return EXPORT_ENVIRONMENT (env)->signature; | |
2282 | } | |
2283 | #undef FUNC_NAME | |
2284 | ||
2285 | ||
2286 | static SCM | |
2287 | export_environment_parse_signature (SCM signature, const char* caller) | |
2288 | { | |
2289 | SCM result = SCM_EOL; | |
2290 | SCM l; | |
2291 | ||
2292 | for (l = signature; SCM_CONSP (l); l = SCM_CDR (l)) | |
2293 | { | |
2294 | SCM entry = SCM_CAR (l); | |
2295 | ||
2296 | if (SCM_SYMBOLP (entry)) | |
2297 | { | |
2298 | SCM new_entry = scm_cons2 (entry, symbol_immutable_location, SCM_EOL); | |
2299 | result = scm_cons (new_entry, result); | |
2300 | } | |
2301 | else | |
2302 | { | |
2303 | SCM sym; | |
2304 | SCM new_entry; | |
2305 | int immutable = 0; | |
2306 | int mutable = 0; | |
2307 | SCM mutability; | |
2308 | SCM l2; | |
2309 | ||
2310 | SCM_ASSERT (SCM_CONSP (entry), entry, SCM_ARGn, caller); | |
2311 | SCM_ASSERT (SCM_SYMBOLP (SCM_CAR (entry)), entry, SCM_ARGn, caller); | |
2312 | ||
2313 | sym = SCM_CAR (entry); | |
2314 | ||
2315 | for (l2 = SCM_CDR (entry); SCM_CONSP (l2); l2 = SCM_CDR (l2)) | |
2316 | { | |
2317 | SCM attribute = SCM_CAR (l2); | |
2318 | if (SCM_EQ_P (attribute, symbol_immutable_location)) | |
2319 | immutable = 1; | |
2320 | else if (SCM_EQ_P (attribute, symbol_mutable_location)) | |
2321 | mutable = 1; | |
2322 | else | |
2323 | SCM_ASSERT (0, entry, SCM_ARGn, caller); | |
2324 | } | |
2325 | SCM_ASSERT (SCM_NULLP (l2), entry, SCM_ARGn, caller); | |
2326 | SCM_ASSERT (!mutable || !immutable, entry, SCM_ARGn, caller); | |
2327 | ||
2328 | if (!mutable && !immutable) | |
2329 | immutable = 1; | |
2330 | ||
2331 | mutability = mutable ? symbol_mutable_location : symbol_immutable_location; | |
2332 | new_entry = scm_cons2 (sym, mutability, SCM_EOL); | |
2333 | result = scm_cons (new_entry, result); | |
2334 | } | |
2335 | } | |
2336 | SCM_ASSERT (SCM_NULLP (l), signature, SCM_ARGn, caller); | |
2337 | ||
2338 | /* Dirk:FIXME:: Now we know that signature is syntactically correct. There | |
2339 | * are, however, no checks for symbols entered twice with contradicting | |
2340 | * mutabilities. It would be nice, to implement this test, to be able to | |
2341 | * call the sort functions conveniently from C. | |
2342 | */ | |
2343 | ||
2344 | return scm_reverse (result); | |
2345 | } | |
2346 | ||
2347 | ||
2348 | SCM_DEFINE (scm_export_environment_set_signature_x, "export-environment-set-signature!", 2, 0, 0, | |
2349 | (SCM env, SCM signature), | |
0fb104ed | 2350 | "Change the signature of export environment @var{env}.") |
5d3e2388 DH |
2351 | #define FUNC_NAME s_scm_export_environment_set_signature_x |
2352 | { | |
2353 | SCM parsed_sig; | |
2354 | ||
2355 | SCM_ASSERT (SCM_EXPORT_ENVIRONMENT_P (env), env, SCM_ARG1, FUNC_NAME); | |
2356 | parsed_sig = export_environment_parse_signature (signature, FUNC_NAME); | |
2357 | ||
2358 | EXPORT_ENVIRONMENT (env)->signature = parsed_sig; | |
2359 | ||
2360 | return SCM_UNSPECIFIED; | |
2361 | } | |
2362 | #undef FUNC_NAME | |
2363 | ||
2364 | \f | |
2365 | ||
2366 | void | |
2367 | scm_environments_prehistory () | |
2368 | { | |
2369 | /* create environment smob */ | |
2370 | scm_tc16_environment = scm_make_smob_type ("environment", 0); | |
e841c3e0 KN |
2371 | scm_set_smob_mark (scm_tc16_environment, environment_mark); |
2372 | scm_set_smob_free (scm_tc16_environment, environment_free); | |
2373 | scm_set_smob_print (scm_tc16_environment, environment_print); | |
5d3e2388 DH |
2374 | |
2375 | /* create observer smob */ | |
2376 | scm_tc16_observer = scm_make_smob_type ("observer", 0); | |
e841c3e0 KN |
2377 | scm_set_smob_mark (scm_tc16_observer, observer_mark); |
2378 | scm_set_smob_print (scm_tc16_observer, observer_print); | |
de42a0ee DH |
2379 | |
2380 | /* create system environment */ | |
2381 | scm_system_environment = scm_make_leaf_environment (); | |
2382 | scm_permanent_object (scm_system_environment); | |
5d3e2388 DH |
2383 | } |
2384 | ||
2385 | ||
2386 | void | |
2387 | scm_init_environments () | |
2388 | { | |
480a873c | 2389 | #include "libguile/environments.x" |
5d3e2388 DH |
2390 | } |
2391 | ||
2392 | ||
2393 | /* | |
2394 | Local Variables: | |
2395 | c-file-style: "gnu" | |
2396 | End: | |
2397 | */ |