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c35738c1 | 1 | /* Copyright (C) 1999,2000,2001, 2003 Free Software Foundation, Inc. |
5d3e2388 | 2 | * |
73be1d9e MV |
3 | * This library is free software; you can redistribute it and/or |
4 | * modify it under the terms of the GNU Lesser General Public | |
5 | * License as published by the Free Software Foundation; either | |
6 | * version 2.1 of the License, or (at your option) any later version. | |
5d3e2388 | 7 | * |
73be1d9e | 8 | * This library is distributed in the hope that it will be useful, |
5d3e2388 | 9 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
73be1d9e MV |
10 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
11 | * Lesser General Public License for more details. | |
5d3e2388 | 12 | * |
73be1d9e MV |
13 | * You should have received a copy of the GNU Lesser General Public |
14 | * License along with this library; if not, write to the Free Software | |
15 | * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA | |
16 | */ | |
5d3e2388 DH |
17 | |
18 | \f | |
19 | ||
20 | #include "libguile/_scm.h" | |
21 | #include "libguile/alist.h" | |
22 | #include "libguile/eval.h" | |
23 | #include "libguile/gh.h" | |
24 | #include "libguile/hash.h" | |
35060ae9 | 25 | #include "libguile/list.h" |
5d3e2388 DH |
26 | #include "libguile/ports.h" |
27 | #include "libguile/smob.h" | |
28 | #include "libguile/symbols.h" | |
29 | #include "libguile/vectors.h" | |
30 | #include "libguile/weaks.h" | |
31 | ||
32 | #include "libguile/environments.h" | |
33 | ||
34 | \f | |
35 | ||
92c2555f MV |
36 | scm_t_bits scm_tc16_environment; |
37 | scm_t_bits scm_tc16_observer; | |
231a4ea8 | 38 | #define DEFAULT_OBARRAY_SIZE 31 |
5d3e2388 | 39 | |
de42a0ee DH |
40 | SCM scm_system_environment; |
41 | ||
5d3e2388 DH |
42 | \f |
43 | ||
44 | /* error conditions */ | |
45 | ||
46 | /* | |
47 | * Throw an error if symbol is not bound in environment func | |
48 | */ | |
49 | void | |
50 | scm_error_environment_unbound (const char *func, SCM env, SCM symbol) | |
51 | { | |
52 | /* Dirk:FIXME:: Should throw an environment:unbound type error */ | |
53 | char error[] = "Symbol `~A' not bound in environment `~A'."; | |
54 | SCM arguments = scm_cons2 (symbol, env, SCM_EOL); | |
55 | scm_misc_error (func, error, arguments); | |
56 | } | |
57 | ||
58 | ||
59 | /* | |
60 | * Throw an error if func tried to create (define) or remove | |
61 | * (undefine) a new binding for symbol in env | |
62 | */ | |
63 | void | |
64 | scm_error_environment_immutable_binding (const char *func, SCM env, SCM symbol) | |
65 | { | |
66 | /* Dirk:FIXME:: Should throw an environment:immutable-binding type error */ | |
67 | char error[] = "Immutable binding in environment ~A (symbol: `~A')."; | |
68 | SCM arguments = scm_cons2 (env, symbol, SCM_EOL); | |
69 | scm_misc_error (func, error, arguments); | |
70 | } | |
71 | ||
72 | ||
73 | /* | |
74 | * Throw an error if func tried to change an immutable location. | |
75 | */ | |
76 | void | |
77 | scm_error_environment_immutable_location (const char *func, SCM env, SCM symbol) | |
78 | { | |
79 | /* Dirk:FIXME:: Should throw an environment:immutable-location type error */ | |
80 | char error[] = "Immutable location in environment `~A' (symbol: `~A')."; | |
81 | SCM arguments = scm_cons2 (env, symbol, SCM_EOL); | |
82 | scm_misc_error (func, error, arguments); | |
83 | } | |
84 | ||
85 | \f | |
86 | ||
87 | /* generic environments */ | |
88 | ||
89 | ||
90 | /* Create an environment for the given type. Dereferencing type twice must | |
91 | * deliver the initialized set of environment functions. Thus, type will | |
92 | * also determine the signature of the underlying environment implementation. | |
93 | * Dereferencing type once will typically deliver the data fields used by the | |
94 | * underlying environment implementation. | |
95 | */ | |
96 | SCM | |
97 | scm_make_environment (void *type) | |
98 | { | |
228a24ef | 99 | return scm_cell (scm_tc16_environment, (scm_t_bits) type); |
5d3e2388 DH |
100 | } |
101 | ||
102 | ||
103 | SCM_DEFINE (scm_environment_p, "environment?", 1, 0, 0, | |
104 | (SCM obj), | |
0fb104ed MG |
105 | "Return @code{#t} if @var{obj} is an environment, or @code{#f}\n" |
106 | "otherwise.") | |
5d3e2388 DH |
107 | #define FUNC_NAME s_scm_environment_p |
108 | { | |
7888309b | 109 | return scm_from_bool (SCM_ENVIRONMENT_P (obj)); |
5d3e2388 DH |
110 | } |
111 | #undef FUNC_NAME | |
112 | ||
113 | ||
114 | SCM_DEFINE (scm_environment_bound_p, "environment-bound?", 2, 0, 0, | |
115 | (SCM env, SCM sym), | |
0fb104ed MG |
116 | "Return @code{#t} if @var{sym} is bound in @var{env}, or\n" |
117 | "@code{#f} otherwise.") | |
5d3e2388 DH |
118 | #define FUNC_NAME s_scm_environment_bound_p |
119 | { | |
120 | SCM_ASSERT (SCM_ENVIRONMENT_P (env), env, SCM_ARG1, FUNC_NAME); | |
121 | SCM_ASSERT (SCM_SYMBOLP (sym), sym, SCM_ARG2, FUNC_NAME); | |
122 | ||
7888309b | 123 | return scm_from_bool (SCM_ENVIRONMENT_BOUND_P (env, sym)); |
5d3e2388 DH |
124 | } |
125 | #undef FUNC_NAME | |
126 | ||
127 | ||
128 | SCM_DEFINE (scm_environment_ref, "environment-ref", 2, 0, 0, | |
129 | (SCM env, SCM sym), | |
0fb104ed MG |
130 | "Return the value of the location bound to @var{sym} in\n" |
131 | "@var{env}. If @var{sym} is unbound in @var{env}, signal an\n" | |
132 | "@code{environment:unbound} error.") | |
5d3e2388 DH |
133 | #define FUNC_NAME s_scm_environment_ref |
134 | { | |
135 | SCM val; | |
136 | ||
137 | SCM_ASSERT (SCM_ENVIRONMENT_P (env), env, SCM_ARG1, FUNC_NAME); | |
138 | SCM_ASSERT (SCM_SYMBOLP (sym), sym, SCM_ARG2, FUNC_NAME); | |
139 | ||
140 | val = SCM_ENVIRONMENT_REF (env, sym); | |
141 | ||
142 | if (!SCM_UNBNDP (val)) | |
143 | return val; | |
144 | else | |
145 | scm_error_environment_unbound (FUNC_NAME, env, sym); | |
146 | } | |
147 | #undef FUNC_NAME | |
148 | ||
149 | ||
150 | /* This C function is identical to environment-ref, except that if symbol is | |
151 | * unbound in env, it returns the value SCM_UNDEFINED, instead of signalling | |
152 | * an error. | |
153 | */ | |
154 | SCM | |
155 | scm_c_environment_ref (SCM env, SCM sym) | |
156 | { | |
157 | SCM_ASSERT (SCM_ENVIRONMENT_P (env), env, SCM_ARG1, "scm_c_environment_ref"); | |
158 | SCM_ASSERT (SCM_SYMBOLP (sym), sym, SCM_ARG2, "scm_c_environment_ref"); | |
159 | return SCM_ENVIRONMENT_REF (env, sym); | |
160 | } | |
161 | ||
162 | ||
163 | static SCM | |
164 | environment_default_folder (SCM proc, SCM symbol, SCM value, SCM tail) | |
165 | { | |
166 | return gh_call3 (proc, symbol, value, tail); | |
167 | } | |
168 | ||
169 | ||
170 | SCM_DEFINE (scm_environment_fold, "environment-fold", 3, 0, 0, | |
171 | (SCM env, SCM proc, SCM init), | |
0fb104ed MG |
172 | "Iterate over all the bindings in @var{env}, accumulating some\n" |
173 | "value.\n" | |
174 | "For each binding in @var{env}, apply @var{proc} to the symbol\n" | |
175 | "bound, its value, and the result from the previous application\n" | |
176 | "of @var{proc}.\n" | |
177 | "Use @var{init} as @var{proc}'s third argument the first time\n" | |
178 | "@var{proc} is applied.\n" | |
179 | "If @var{env} contains no bindings, this function simply returns\n" | |
180 | "@var{init}.\n" | |
181 | "If @var{env} binds the symbol sym1 to the value val1, sym2 to\n" | |
182 | "val2, and so on, then this procedure computes:\n" | |
1e6808ea | 183 | "@lisp\n" |
5d3e2388 DH |
184 | " (proc sym1 val1\n" |
185 | " (proc sym2 val2\n" | |
186 | " ...\n" | |
187 | " (proc symn valn\n" | |
188 | " init)))\n" | |
1e6808ea | 189 | "@end lisp\n" |
0fb104ed MG |
190 | "Each binding in @var{env} will be processed exactly once.\n" |
191 | "@code{environment-fold} makes no guarantees about the order in\n" | |
192 | "which the bindings are processed.\n" | |
5d3e2388 DH |
193 | "Here is a function which, given an environment, constructs an\n" |
194 | "association list representing that environment's bindings,\n" | |
195 | "using environment-fold:\n" | |
1e6808ea | 196 | "@lisp\n" |
5d3e2388 DH |
197 | " (define (environment->alist env)\n" |
198 | " (environment-fold env\n" | |
199 | " (lambda (sym val tail)\n" | |
200 | " (cons (cons sym val) tail))\n" | |
0fb104ed | 201 | " '()))\n" |
1e6808ea | 202 | "@end lisp") |
5d3e2388 DH |
203 | #define FUNC_NAME s_scm_environment_fold |
204 | { | |
205 | SCM_ASSERT (SCM_ENVIRONMENT_P (env), env, SCM_ARG1, FUNC_NAME); | |
206 | SCM_ASSERT (SCM_EQ_P (scm_procedure_p (proc), SCM_BOOL_T), | |
207 | proc, SCM_ARG2, FUNC_NAME); | |
208 | ||
209 | return SCM_ENVIRONMENT_FOLD (env, environment_default_folder, proc, init); | |
210 | } | |
211 | #undef FUNC_NAME | |
212 | ||
213 | ||
214 | /* This is the C-level analog of environment-fold. For each binding in ENV, | |
215 | * make the call: | |
216 | * (*proc) (data, symbol, value, previous) | |
217 | * where previous is the value returned from the last call to *PROC, or INIT | |
218 | * for the first call. If ENV contains no bindings, return INIT. | |
219 | */ | |
220 | SCM | |
221 | scm_c_environment_fold (SCM env, scm_environment_folder proc, SCM data, SCM init) | |
222 | { | |
223 | SCM_ASSERT (SCM_ENVIRONMENT_P (env), env, SCM_ARG1, "scm_c_environment_fold"); | |
224 | ||
225 | return SCM_ENVIRONMENT_FOLD (env, proc, data, init); | |
226 | } | |
227 | ||
228 | ||
229 | SCM_DEFINE (scm_environment_define, "environment-define", 3, 0, 0, | |
230 | (SCM env, SCM sym, SCM val), | |
0fb104ed MG |
231 | "Bind @var{sym} to a new location containing @var{val} in\n" |
232 | "@var{env}. If @var{sym} is already bound to another location\n" | |
233 | "in @var{env} and the binding is mutable, that binding is\n" | |
234 | "replaced. The new binding and location are both mutable. The\n" | |
235 | "return value is unspecified.\n" | |
236 | "If @var{sym} is already bound in @var{env}, and the binding is\n" | |
237 | "immutable, signal an @code{environment:immutable-binding} error.") | |
5d3e2388 DH |
238 | #define FUNC_NAME s_scm_environment_define |
239 | { | |
240 | SCM status; | |
241 | ||
242 | SCM_ASSERT (SCM_ENVIRONMENT_P (env), env, SCM_ARG1, FUNC_NAME); | |
243 | SCM_ASSERT (SCM_SYMBOLP (sym), sym, SCM_ARG2, FUNC_NAME); | |
244 | ||
245 | status = SCM_ENVIRONMENT_DEFINE (env, sym, val); | |
246 | ||
247 | if (SCM_EQ_P (status, SCM_ENVIRONMENT_SUCCESS)) | |
248 | return SCM_UNSPECIFIED; | |
249 | else if (SCM_EQ_P (status, SCM_ENVIRONMENT_BINDING_IMMUTABLE)) | |
250 | scm_error_environment_immutable_binding (FUNC_NAME, env, sym); | |
251 | else | |
252 | abort(); | |
253 | } | |
254 | #undef FUNC_NAME | |
255 | ||
256 | ||
257 | SCM_DEFINE (scm_environment_undefine, "environment-undefine", 2, 0, 0, | |
258 | (SCM env, SCM sym), | |
0fb104ed MG |
259 | "Remove any binding for @var{sym} from @var{env}. If @var{sym}\n" |
260 | "is unbound in @var{env}, do nothing. The return value is\n" | |
261 | "unspecified.\n" | |
262 | "If @var{sym} is already bound in @var{env}, and the binding is\n" | |
263 | "immutable, signal an @code{environment:immutable-binding} error.") | |
5d3e2388 DH |
264 | #define FUNC_NAME s_scm_environment_undefine |
265 | { | |
266 | SCM status; | |
267 | ||
268 | SCM_ASSERT(SCM_ENVIRONMENT_P(env), env, SCM_ARG1, FUNC_NAME); | |
269 | SCM_ASSERT(SCM_SYMBOLP(sym), sym, SCM_ARG2, FUNC_NAME); | |
270 | ||
271 | status = SCM_ENVIRONMENT_UNDEFINE (env, sym); | |
272 | ||
273 | if (SCM_EQ_P (status, SCM_ENVIRONMENT_SUCCESS)) | |
274 | return SCM_UNSPECIFIED; | |
275 | else if (SCM_EQ_P (status, SCM_ENVIRONMENT_BINDING_IMMUTABLE)) | |
276 | scm_error_environment_immutable_binding (FUNC_NAME, env, sym); | |
277 | else | |
278 | abort(); | |
279 | } | |
280 | #undef FUNC_NAME | |
281 | ||
282 | ||
283 | SCM_DEFINE (scm_environment_set_x, "environment-set!", 3, 0, 0, | |
284 | (SCM env, SCM sym, SCM val), | |
0fb104ed MG |
285 | "If @var{env} binds @var{sym} to some location, change that\n" |
286 | "location's value to @var{val}. The return value is\n" | |
287 | "unspecified.\n" | |
288 | "If @var{sym} is not bound in @var{env}, signal an\n" | |
289 | "@code{environment:unbound} error. If @var{env} binds @var{sym}\n" | |
290 | "to an immutable location, signal an\n" | |
291 | "@code{environment:immutable-location} error.") | |
5d3e2388 DH |
292 | #define FUNC_NAME s_scm_environment_set_x |
293 | { | |
294 | SCM status; | |
295 | ||
296 | SCM_ASSERT (SCM_ENVIRONMENT_P (env), env, SCM_ARG1, FUNC_NAME); | |
297 | SCM_ASSERT (SCM_SYMBOLP (sym), sym, SCM_ARG2, FUNC_NAME); | |
298 | ||
299 | status = SCM_ENVIRONMENT_SET (env, sym, val); | |
300 | ||
301 | if (SCM_EQ_P (status, SCM_ENVIRONMENT_SUCCESS)) | |
302 | return SCM_UNSPECIFIED; | |
303 | else if (SCM_UNBNDP (status)) | |
304 | scm_error_environment_unbound (FUNC_NAME, env, sym); | |
305 | else if (SCM_EQ_P (status, SCM_ENVIRONMENT_LOCATION_IMMUTABLE)) | |
306 | scm_error_environment_immutable_binding (FUNC_NAME, env, sym); | |
307 | else | |
308 | abort(); | |
309 | } | |
310 | #undef FUNC_NAME | |
311 | ||
312 | ||
313 | SCM_DEFINE (scm_environment_cell, "environment-cell", 3, 0, 0, | |
314 | (SCM env, SCM sym, SCM for_write), | |
0fb104ed MG |
315 | "Return the value cell which @var{env} binds to @var{sym}, or\n" |
316 | "@code{#f} if the binding does not live in a value cell.\n" | |
317 | "The argument @var{for-write} indicates whether the caller\n" | |
318 | "intends to modify the variable's value by mutating the value\n" | |
319 | "cell. If the variable is immutable, then\n" | |
320 | "@code{environment-cell} signals an\n" | |
321 | "@code{environment:immutable-location} error.\n" | |
322 | "If @var{sym} is unbound in @var{env}, signal an\n" | |
323 | "@code{environment:unbound} error.\n" | |
5d3e2388 | 324 | "If you use this function, you should consider using\n" |
0fb104ed MG |
325 | "@code{environment-observe}, to be notified when @var{sym} gets\n" |
326 | "re-bound to a new value cell, or becomes undefined.") | |
5d3e2388 DH |
327 | #define FUNC_NAME s_scm_environment_cell |
328 | { | |
329 | SCM location; | |
330 | ||
331 | SCM_ASSERT (SCM_ENVIRONMENT_P (env), env, SCM_ARG1, FUNC_NAME); | |
332 | SCM_ASSERT (SCM_SYMBOLP (sym), sym, SCM_ARG2, FUNC_NAME); | |
7888309b | 333 | SCM_ASSERT (scm_is_bool (for_write), for_write, SCM_ARG3, FUNC_NAME); |
5d3e2388 | 334 | |
7888309b | 335 | location = SCM_ENVIRONMENT_CELL (env, sym, scm_is_true (for_write)); |
5d3e2388 DH |
336 | if (!SCM_IMP (location)) |
337 | return location; | |
338 | else if (SCM_UNBNDP (location)) | |
339 | scm_error_environment_unbound (FUNC_NAME, env, sym); | |
340 | else if (SCM_EQ_P (location, SCM_ENVIRONMENT_LOCATION_IMMUTABLE)) | |
341 | scm_error_environment_immutable_location (FUNC_NAME, env, sym); | |
342 | else /* no cell */ | |
343 | return location; | |
344 | } | |
345 | #undef FUNC_NAME | |
346 | ||
347 | ||
348 | /* This C function is identical to environment-cell, with the following | |
349 | * exceptions: If symbol is unbound in env, it returns the value | |
350 | * SCM_UNDEFINED, instead of signalling an error. If symbol is bound to an | |
351 | * immutable location but the cell is requested for write, the value | |
352 | * SCM_ENVIRONMENT_LOCATION_IMMUTABLE is returned. | |
353 | */ | |
354 | SCM | |
355 | scm_c_environment_cell(SCM env, SCM sym, int for_write) | |
356 | { | |
357 | SCM_ASSERT (SCM_ENVIRONMENT_P (env), env, SCM_ARG1, "scm_c_environment_cell"); | |
358 | SCM_ASSERT (SCM_SYMBOLP (sym), sym, SCM_ARG2, "scm_c_environment_cell"); | |
359 | ||
360 | return SCM_ENVIRONMENT_CELL (env, sym, for_write); | |
361 | } | |
362 | ||
363 | ||
364 | static void | |
365 | environment_default_observer (SCM env, SCM proc) | |
366 | { | |
367 | gh_call1 (proc, env); | |
368 | } | |
369 | ||
370 | ||
371 | SCM_DEFINE (scm_environment_observe, "environment-observe", 2, 0, 0, | |
372 | (SCM env, SCM proc), | |
0fb104ed MG |
373 | "Whenever @var{env}'s bindings change, apply @var{proc} to\n" |
374 | "@var{env}.\n" | |
5d3e2388 | 375 | "This function returns an object, token, which you can pass to\n" |
0fb104ed MG |
376 | "@code{environment-unobserve} to remove @var{proc} from the set\n" |
377 | "of procedures observing @var{env}. The type and value of\n" | |
378 | "token is unspecified.") | |
5d3e2388 DH |
379 | #define FUNC_NAME s_scm_environment_observe |
380 | { | |
381 | SCM_ASSERT (SCM_ENVIRONMENT_P (env), env, SCM_ARG1, FUNC_NAME); | |
382 | ||
383 | return SCM_ENVIRONMENT_OBSERVE (env, environment_default_observer, proc, 0); | |
384 | } | |
385 | #undef FUNC_NAME | |
386 | ||
387 | ||
388 | SCM_DEFINE (scm_environment_observe_weak, "environment-observe-weak", 2, 0, 0, | |
389 | (SCM env, SCM proc), | |
390 | "This function is the same as environment-observe, except that\n" | |
0fb104ed MG |
391 | "the reference @var{env} retains to @var{proc} is a weak\n" |
392 | "reference. This means that, if there are no other live,\n" | |
393 | "non-weak references to @var{proc}, it will be\n" | |
394 | "garbage-collected, and dropped from @var{env}'s\n" | |
5d3e2388 DH |
395 | "list of observing procedures.") |
396 | #define FUNC_NAME s_scm_environment_observe_weak | |
397 | { | |
398 | SCM_ASSERT (SCM_ENVIRONMENT_P (env), env, SCM_ARG1, FUNC_NAME); | |
399 | ||
400 | return SCM_ENVIRONMENT_OBSERVE (env, environment_default_observer, proc, 1); | |
401 | } | |
402 | #undef FUNC_NAME | |
403 | ||
404 | ||
405 | /* This is the C-level analog of the Scheme functions environment-observe and | |
406 | * environment-observe-weak. Whenever env's bindings change, call the | |
407 | * function proc, passing it env and data. If weak_p is non-zero, env will | |
408 | * retain only a weak reference to data, and if data is garbage collected, the | |
409 | * entire observation will be dropped. This function returns a token, with | |
410 | * the same meaning as those returned by environment-observe and | |
411 | * environment-observe-weak. | |
412 | */ | |
413 | SCM | |
414 | scm_c_environment_observe (SCM env, scm_environment_observer proc, SCM data, int weak_p) | |
415 | #define FUNC_NAME "scm_c_environment_observe" | |
416 | { | |
417 | SCM_ASSERT (SCM_ENVIRONMENT_P (env), env, SCM_ARG1, FUNC_NAME); | |
418 | ||
419 | return SCM_ENVIRONMENT_OBSERVE (env, proc, data, weak_p); | |
420 | } | |
421 | #undef FUNC_NAME | |
422 | ||
423 | ||
424 | SCM_DEFINE (scm_environment_unobserve, "environment-unobserve", 1, 0, 0, | |
425 | (SCM token), | |
426 | "Cancel the observation request which returned the value\n" | |
0fb104ed MG |
427 | "@var{token}. The return value is unspecified.\n" |
428 | "If a call @code{(environment-observe env proc)} returns\n" | |
429 | "@var{token}, then the call @code{(environment-unobserve token)}\n" | |
430 | "will cause @var{proc} to no longer be called when @var{env}'s\n" | |
431 | "bindings change.") | |
5d3e2388 DH |
432 | #define FUNC_NAME s_scm_environment_unobserve |
433 | { | |
434 | SCM env; | |
435 | ||
436 | SCM_ASSERT (SCM_OBSERVER_P (token), token, SCM_ARG1, FUNC_NAME); | |
437 | ||
438 | env = SCM_OBSERVER_ENVIRONMENT (token); | |
439 | SCM_ENVIRONMENT_UNOBSERVE (env, token); | |
440 | ||
441 | return SCM_UNSPECIFIED; | |
442 | } | |
443 | #undef FUNC_NAME | |
444 | ||
445 | ||
446 | static SCM | |
e841c3e0 | 447 | environment_mark (SCM env) |
5d3e2388 DH |
448 | { |
449 | return (*(SCM_ENVIRONMENT_FUNCS (env)->mark)) (env); | |
450 | } | |
451 | ||
452 | ||
1be6b49c | 453 | static size_t |
e841c3e0 | 454 | environment_free (SCM env) |
5d3e2388 | 455 | { |
4c9419ac MV |
456 | (*(SCM_ENVIRONMENT_FUNCS (env)->free)) (env); |
457 | return 0; | |
5d3e2388 DH |
458 | } |
459 | ||
460 | ||
461 | static int | |
e841c3e0 | 462 | environment_print (SCM env, SCM port, scm_print_state *pstate) |
5d3e2388 DH |
463 | { |
464 | return (*(SCM_ENVIRONMENT_FUNCS (env)->print)) (env, port, pstate); | |
465 | } | |
466 | ||
467 | \f | |
468 | ||
469 | /* observers */ | |
470 | ||
471 | static SCM | |
e841c3e0 | 472 | observer_mark (SCM observer) |
5d3e2388 DH |
473 | { |
474 | scm_gc_mark (SCM_OBSERVER_ENVIRONMENT (observer)); | |
475 | scm_gc_mark (SCM_OBSERVER_DATA (observer)); | |
476 | return SCM_BOOL_F; | |
477 | } | |
478 | ||
479 | ||
5d3e2388 | 480 | static int |
e81d98ec | 481 | observer_print (SCM type, SCM port, scm_print_state *pstate SCM_UNUSED) |
5d3e2388 | 482 | { |
c014a02e | 483 | SCM address = scm_ulong2num (SCM_UNPACK (type)); |
5d3e2388 DH |
484 | SCM base16 = scm_number_to_string (address, SCM_MAKINUM (16)); |
485 | ||
486 | scm_puts ("#<observer ", port); | |
86c991c2 | 487 | scm_puts (SCM_STRING_CHARS (base16), port); |
5d3e2388 DH |
488 | scm_puts (">", port); |
489 | ||
490 | return 1; | |
491 | } | |
492 | ||
493 | \f | |
494 | ||
495 | /* obarrays | |
496 | * | |
497 | * Obarrays form the basic lookup tables used to implement most of guile's | |
498 | * built-in environment types. An obarray is implemented as a hash table with | |
499 | * symbols as keys. The content of the data depends on the environment type. | |
500 | */ | |
501 | ||
502 | ||
503 | /* | |
a2d47b23 DH |
504 | * Enter symbol into obarray. The symbol must not already exist in obarray. |
505 | * The freshly generated (symbol . data) cell is returned. | |
5d3e2388 DH |
506 | */ |
507 | static SCM | |
508 | obarray_enter (SCM obarray, SCM symbol, SCM data) | |
509 | { | |
c35738c1 | 510 | size_t hash = SCM_SYMBOL_HASH (symbol) % SCM_HASHTABLE_N_BUCKETS (obarray); |
5d3e2388 | 511 | SCM entry = scm_cons (symbol, data); |
c35738c1 MD |
512 | SCM slot = scm_cons (entry, SCM_HASHTABLE_BUCKETS (obarray)[hash]); |
513 | SCM_SET_HASHTABLE_BUCKET (obarray, hash, slot); | |
514 | if (SCM_HASHTABLE_N_ITEMS (obarray) > SCM_HASHTABLE_UPPER (obarray)) | |
515 | scm_i_rehash (obarray, scm_i_hash_symbol, 0, "obarray_enter"); | |
5d3e2388 DH |
516 | |
517 | return entry; | |
518 | } | |
519 | ||
520 | ||
a2d47b23 DH |
521 | /* |
522 | * Enter symbol into obarray. An existing entry for symbol is replaced. If | |
523 | * an entry existed, the old (symbol . data) cell is returned, #f otherwise. | |
524 | */ | |
525 | static SCM | |
526 | obarray_replace (SCM obarray, SCM symbol, SCM data) | |
527 | { | |
c35738c1 | 528 | size_t hash = SCM_SYMBOL_HASH (symbol) % SCM_HASHTABLE_N_BUCKETS (obarray); |
a2d47b23 DH |
529 | SCM new_entry = scm_cons (symbol, data); |
530 | SCM lsym; | |
531 | SCM slot; | |
532 | ||
c35738c1 MD |
533 | for (lsym = SCM_HASHTABLE_BUCKETS (obarray)[hash]; |
534 | !SCM_NULLP (lsym); | |
535 | lsym = SCM_CDR (lsym)) | |
a2d47b23 DH |
536 | { |
537 | SCM old_entry = SCM_CAR (lsym); | |
66460dfb | 538 | if (SCM_EQ_P (SCM_CAR (old_entry), symbol)) |
a2d47b23 DH |
539 | { |
540 | SCM_SETCAR (lsym, new_entry); | |
541 | return old_entry; | |
542 | } | |
543 | } | |
544 | ||
c35738c1 MD |
545 | slot = scm_cons (new_entry, SCM_HASHTABLE_BUCKETS (obarray)[hash]); |
546 | SCM_SET_HASHTABLE_BUCKET (obarray, hash, slot); | |
547 | if (SCM_HASHTABLE_N_ITEMS (obarray) > SCM_HASHTABLE_UPPER (obarray)) | |
548 | scm_i_rehash (obarray, scm_i_hash_symbol, 0, "obarray_replace"); | |
a2d47b23 DH |
549 | |
550 | return SCM_BOOL_F; | |
551 | } | |
552 | ||
553 | ||
5d3e2388 DH |
554 | /* |
555 | * Look up symbol in obarray | |
556 | */ | |
557 | static SCM | |
558 | obarray_retrieve (SCM obarray, SCM sym) | |
559 | { | |
c35738c1 | 560 | size_t hash = SCM_SYMBOL_HASH (sym) % SCM_HASHTABLE_N_BUCKETS (obarray); |
5d3e2388 DH |
561 | SCM lsym; |
562 | ||
c35738c1 MD |
563 | for (lsym = SCM_HASHTABLE_BUCKETS (obarray)[hash]; |
564 | !SCM_NULLP (lsym); | |
565 | lsym = SCM_CDR (lsym)) | |
5d3e2388 DH |
566 | { |
567 | SCM entry = SCM_CAR (lsym); | |
66460dfb | 568 | if (SCM_EQ_P (SCM_CAR (entry), sym)) |
5d3e2388 DH |
569 | return entry; |
570 | } | |
571 | ||
572 | return SCM_UNDEFINED; | |
573 | } | |
574 | ||
575 | ||
576 | /* | |
a2d47b23 DH |
577 | * Remove entry from obarray. If the symbol was found and removed, the old |
578 | * (symbol . data) cell is returned, #f otherwise. | |
5d3e2388 DH |
579 | */ |
580 | static SCM | |
581 | obarray_remove (SCM obarray, SCM sym) | |
582 | { | |
c35738c1 MD |
583 | size_t hash = SCM_SYMBOL_HASH (sym) % SCM_HASHTABLE_N_BUCKETS (obarray); |
584 | SCM table_entry = SCM_HASHTABLE_BUCKETS (obarray)[hash]; | |
35060ae9 | 585 | SCM handle = scm_sloppy_assq (sym, table_entry); |
34d19ef6 | 586 | |
35060ae9 | 587 | if (SCM_CONSP (handle)) |
34d19ef6 | 588 | { |
35060ae9 | 589 | SCM new_table_entry = scm_delq1_x (handle, table_entry); |
c35738c1 MD |
590 | SCM_SET_HASHTABLE_BUCKET (obarray, hash, new_table_entry); |
591 | SCM_HASHTABLE_DECREMENT (obarray); | |
5d3e2388 | 592 | } |
35060ae9 DH |
593 | |
594 | return handle; | |
5d3e2388 DH |
595 | } |
596 | ||
597 | ||
598 | static void | |
599 | obarray_remove_all (SCM obarray) | |
600 | { | |
c35738c1 | 601 | size_t size = SCM_HASHTABLE_N_BUCKETS (obarray); |
1be6b49c | 602 | size_t i; |
5d3e2388 DH |
603 | |
604 | for (i = 0; i < size; i++) | |
605 | { | |
c35738c1 | 606 | SCM_SET_HASHTABLE_BUCKET (obarray, i, SCM_EOL); |
5d3e2388 | 607 | } |
c35738c1 | 608 | SCM_SET_HASHTABLE_N_ITEMS (obarray, 0); |
5d3e2388 DH |
609 | } |
610 | ||
611 | \f | |
612 | ||
613 | /* core environments base | |
614 | * | |
615 | * This struct and the corresponding functions form a base class for guile's | |
616 | * built-in environment types. | |
617 | */ | |
618 | ||
619 | ||
620 | struct core_environments_base { | |
621 | struct scm_environment_funcs *funcs; | |
622 | ||
623 | SCM observers; | |
624 | SCM weak_observers; | |
625 | }; | |
626 | ||
627 | ||
628 | #define CORE_ENVIRONMENTS_BASE(env) \ | |
629 | ((struct core_environments_base *) SCM_CELL_WORD_1 (env)) | |
630 | #define CORE_ENVIRONMENT_OBSERVERS(env) \ | |
631 | (CORE_ENVIRONMENTS_BASE (env)->observers) | |
632 | #define SCM_SET_CORE_ENVIRONMENT_OBSERVERS(env, v) \ | |
633 | (CORE_ENVIRONMENT_OBSERVERS (env) = (v)) | |
634 | #define CORE_ENVIRONMENT_WEAK_OBSERVER_VECTOR(env) \ | |
635 | (CORE_ENVIRONMENTS_BASE (env)->weak_observers) | |
636 | #define CORE_ENVIRONMENT_WEAK_OBSERVERS(env) \ | |
637 | (SCM_VELTS (CORE_ENVIRONMENT_WEAK_OBSERVER_VECTOR (env)) [0]) | |
638 | #define SCM_SET_CORE_ENVIRONMENT_WEAK_OBSERVERS(env, v) \ | |
34d19ef6 | 639 | (SCM_VECTOR_SET (CORE_ENVIRONMENT_WEAK_OBSERVER_VECTOR (env), 0, (v))) |
5d3e2388 DH |
640 | |
641 | \f | |
642 | ||
643 | static SCM | |
644 | core_environments_observe (SCM env, scm_environment_observer proc, SCM data, int weak_p) | |
645 | { | |
228a24ef DH |
646 | SCM observer = scm_double_cell (scm_tc16_observer, |
647 | SCM_UNPACK (env), | |
648 | SCM_UNPACK (data), | |
649 | (scm_t_bits) proc); | |
5d3e2388 DH |
650 | |
651 | if (!weak_p) | |
652 | { | |
653 | SCM observers = CORE_ENVIRONMENT_OBSERVERS (env); | |
654 | SCM new_observers = scm_cons (observer, observers); | |
655 | SCM_SET_CORE_ENVIRONMENT_OBSERVERS (env, new_observers); | |
656 | } | |
657 | else | |
658 | { | |
659 | SCM observers = CORE_ENVIRONMENT_WEAK_OBSERVERS (env); | |
660 | SCM new_observers = scm_acons (SCM_BOOL_F, observer, observers); | |
661 | SCM_SET_CORE_ENVIRONMENT_WEAK_OBSERVERS (env, new_observers); | |
662 | } | |
663 | ||
664 | return observer; | |
665 | } | |
666 | ||
667 | ||
668 | static void | |
669 | core_environments_unobserve (SCM env, SCM observer) | |
670 | { | |
671 | unsigned int handling_weaks; | |
672 | for (handling_weaks = 0; handling_weaks <= 1; ++handling_weaks) | |
673 | { | |
674 | SCM l = handling_weaks | |
675 | ? CORE_ENVIRONMENT_WEAK_OBSERVERS (env) | |
676 | : CORE_ENVIRONMENT_OBSERVERS (env); | |
677 | ||
678 | if (!SCM_NULLP (l)) | |
679 | { | |
680 | SCM rest = SCM_CDR (l); | |
681 | SCM first = handling_weaks | |
682 | ? SCM_CDAR (l) | |
683 | : SCM_CAR (l); | |
684 | ||
685 | if (SCM_EQ_P (first, observer)) | |
686 | { | |
687 | /* Remove the first observer */ | |
688 | handling_weaks | |
689 | ? SCM_SET_CORE_ENVIRONMENT_WEAK_OBSERVERS (env, rest) | |
690 | : SCM_SET_CORE_ENVIRONMENT_OBSERVERS (env, rest); | |
691 | return; | |
692 | } | |
693 | ||
694 | do { | |
695 | SCM rest = SCM_CDR (l); | |
696 | ||
697 | if (!SCM_NULLP (rest)) | |
698 | { | |
699 | SCM next = handling_weaks | |
700 | ? SCM_CDAR (l) | |
701 | : SCM_CAR (l); | |
702 | ||
703 | if (SCM_EQ_P (next, observer)) | |
704 | { | |
705 | SCM_SETCDR (l, SCM_CDR (rest)); | |
706 | return; | |
707 | } | |
708 | } | |
709 | ||
710 | l = rest; | |
711 | } while (!SCM_NULLP (l)); | |
712 | } | |
713 | } | |
714 | ||
715 | /* Dirk:FIXME:: What to do now, since the observer is not found? */ | |
716 | } | |
717 | ||
718 | ||
719 | static SCM | |
720 | core_environments_mark (SCM env) | |
721 | { | |
722 | scm_gc_mark (CORE_ENVIRONMENT_OBSERVERS (env)); | |
723 | return CORE_ENVIRONMENT_WEAK_OBSERVER_VECTOR (env); | |
724 | } | |
725 | ||
726 | ||
727 | static void | |
e81d98ec | 728 | core_environments_finalize (SCM env SCM_UNUSED) |
5d3e2388 DH |
729 | { |
730 | } | |
731 | ||
732 | ||
733 | static void | |
734 | core_environments_preinit (struct core_environments_base *body) | |
735 | { | |
736 | body->funcs = NULL; | |
737 | body->observers = SCM_BOOL_F; | |
738 | body->weak_observers = SCM_BOOL_F; | |
739 | } | |
740 | ||
741 | ||
742 | static void | |
743 | core_environments_init (struct core_environments_base *body, | |
744 | struct scm_environment_funcs *funcs) | |
745 | { | |
746 | body->funcs = funcs; | |
747 | body->observers = SCM_EOL; | |
c35738c1 | 748 | body->weak_observers = scm_make_weak_value_alist_vector (SCM_MAKINUM (1)); |
5d3e2388 DH |
749 | } |
750 | ||
751 | ||
752 | /* Tell all observers to clear their caches. | |
753 | * | |
754 | * Environments have to be informed about changes in the following cases: | |
755 | * - The observed env has a new binding. This must be always reported. | |
756 | * - The observed env has dropped a binding. This must be always reported. | |
757 | * - A binding in the observed environment has changed. This must only be | |
758 | * reported, if there is a chance that the binding is being cached outside. | |
759 | * However, this potential optimization is not performed currently. | |
760 | * | |
761 | * Errors that occur while the observers are called are accumulated and | |
762 | * signalled as one single error message to the caller. | |
763 | */ | |
764 | ||
765 | struct update_data | |
766 | { | |
767 | SCM observer; | |
768 | SCM environment; | |
769 | }; | |
770 | ||
771 | ||
772 | static SCM | |
773 | update_catch_body (void *ptr) | |
774 | { | |
775 | struct update_data *data = (struct update_data *) ptr; | |
776 | SCM observer = data->observer; | |
777 | ||
778 | (*SCM_OBSERVER_PROC (observer)) | |
779 | (data->environment, SCM_OBSERVER_DATA (observer)); | |
780 | ||
781 | return SCM_UNDEFINED; | |
782 | } | |
783 | ||
784 | ||
785 | static SCM | |
786 | update_catch_handler (void *ptr, SCM tag, SCM args) | |
787 | { | |
788 | struct update_data *data = (struct update_data *) ptr; | |
789 | SCM observer = data->observer; | |
790 | SCM message = scm_makfrom0str ("Observer `~A' signals `~A' error: ~S"); | |
791 | ||
1afff620 | 792 | return scm_cons (message, scm_list_3 (observer, tag, args)); |
5d3e2388 DH |
793 | } |
794 | ||
795 | ||
796 | static void | |
797 | core_environments_broadcast (SCM env) | |
798 | #define FUNC_NAME "core_environments_broadcast" | |
799 | { | |
800 | unsigned int handling_weaks; | |
801 | SCM errors = SCM_EOL; | |
802 | ||
803 | for (handling_weaks = 0; handling_weaks <= 1; ++handling_weaks) | |
804 | { | |
805 | SCM observers = handling_weaks | |
806 | ? CORE_ENVIRONMENT_WEAK_OBSERVERS (env) | |
807 | : CORE_ENVIRONMENT_OBSERVERS (env); | |
808 | ||
809 | for (; !SCM_NULLP (observers); observers = SCM_CDR (observers)) | |
810 | { | |
811 | struct update_data data; | |
812 | SCM observer = handling_weaks | |
813 | ? SCM_CDAR (observers) | |
814 | : SCM_CAR (observers); | |
815 | SCM error; | |
816 | ||
817 | data.observer = observer; | |
818 | data.environment = env; | |
819 | ||
820 | error = scm_internal_catch (SCM_BOOL_T, | |
821 | update_catch_body, &data, | |
822 | update_catch_handler, &data); | |
823 | ||
824 | if (!SCM_UNBNDP (error)) | |
825 | errors = scm_cons (error, errors); | |
826 | } | |
827 | } | |
828 | ||
829 | if (!SCM_NULLP (errors)) | |
830 | { | |
831 | /* Dirk:FIXME:: As soon as scm_misc_error is fixed to handle the name | |
832 | * parameter correctly it should not be necessary any more to also pass | |
833 | * namestr in order to get the desired information from the error | |
834 | * message. | |
835 | */ | |
836 | SCM ordered_errors = scm_reverse (errors); | |
837 | scm_misc_error | |
838 | (FUNC_NAME, | |
839 | "Observers of `~A' have signalled the following errors: ~S", | |
840 | scm_cons2 (env, ordered_errors, SCM_EOL)); | |
841 | } | |
842 | } | |
843 | #undef FUNC_NAME | |
844 | ||
845 | \f | |
846 | ||
847 | /* leaf environments | |
848 | * | |
849 | * A leaf environment is simply a mutable set of definitions. A leaf | |
850 | * environment supports no operations beyond the common set. | |
851 | * | |
852 | * Implementation: The obarray of the leaf environment holds (symbol . value) | |
853 | * pairs. No further information is necessary, since all bindings and | |
854 | * locations in a leaf environment are mutable. | |
855 | */ | |
856 | ||
857 | ||
858 | struct leaf_environment { | |
859 | struct core_environments_base base; | |
860 | ||
861 | SCM obarray; | |
862 | }; | |
863 | ||
864 | ||
865 | #define LEAF_ENVIRONMENT(env) \ | |
866 | ((struct leaf_environment *) SCM_CELL_WORD_1 (env)) | |
867 | ||
868 | \f | |
869 | ||
870 | static SCM | |
871 | leaf_environment_ref (SCM env, SCM sym) | |
872 | { | |
873 | SCM obarray = LEAF_ENVIRONMENT (env)->obarray; | |
874 | SCM binding = obarray_retrieve (obarray, sym); | |
875 | return SCM_UNBNDP (binding) ? binding : SCM_CDR (binding); | |
876 | } | |
877 | ||
878 | ||
879 | static SCM | |
880 | leaf_environment_fold (SCM env, scm_environment_folder proc, SCM data, SCM init) | |
881 | { | |
1be6b49c | 882 | size_t i; |
5d3e2388 DH |
883 | SCM result = init; |
884 | SCM obarray = LEAF_ENVIRONMENT (env)->obarray; | |
885 | ||
c35738c1 | 886 | for (i = 0; i < SCM_HASHTABLE_N_BUCKETS (obarray); i++) |
5d3e2388 DH |
887 | { |
888 | SCM l; | |
c35738c1 MD |
889 | for (l = SCM_HASHTABLE_BUCKETS (obarray)[i]; |
890 | !SCM_NULLP (l); | |
891 | l = SCM_CDR (l)) | |
5d3e2388 DH |
892 | { |
893 | SCM binding = SCM_CAR (l); | |
894 | SCM symbol = SCM_CAR (binding); | |
895 | SCM value = SCM_CDR (binding); | |
896 | result = (*proc) (data, symbol, value, result); | |
897 | } | |
898 | } | |
899 | return result; | |
900 | } | |
901 | ||
902 | ||
903 | static SCM | |
904 | leaf_environment_define (SCM env, SCM sym, SCM val) | |
905 | #define FUNC_NAME "leaf_environment_define" | |
906 | { | |
907 | SCM obarray = LEAF_ENVIRONMENT (env)->obarray; | |
5d3e2388 | 908 | |
a2d47b23 | 909 | obarray_replace (obarray, sym, val); |
5d3e2388 DH |
910 | core_environments_broadcast (env); |
911 | ||
912 | return SCM_ENVIRONMENT_SUCCESS; | |
913 | } | |
914 | #undef FUNC_NAME | |
915 | ||
916 | ||
917 | static SCM | |
918 | leaf_environment_undefine (SCM env, SCM sym) | |
919 | #define FUNC_NAME "leaf_environment_undefine" | |
920 | { | |
921 | SCM obarray = LEAF_ENVIRONMENT (env)->obarray; | |
a2d47b23 | 922 | SCM removed = obarray_remove (obarray, sym); |
5d3e2388 | 923 | |
7888309b | 924 | if (scm_is_true (removed)) |
a2d47b23 | 925 | core_environments_broadcast (env); |
5d3e2388 DH |
926 | |
927 | return SCM_ENVIRONMENT_SUCCESS; | |
928 | } | |
929 | #undef FUNC_NAME | |
930 | ||
931 | ||
932 | static SCM | |
933 | leaf_environment_set_x (SCM env, SCM sym, SCM val) | |
934 | #define FUNC_NAME "leaf_environment_set_x" | |
935 | { | |
936 | SCM obarray = LEAF_ENVIRONMENT (env)->obarray; | |
937 | SCM binding = obarray_retrieve (obarray, sym); | |
938 | ||
939 | if (!SCM_UNBNDP (binding)) | |
940 | { | |
941 | SCM_SETCDR (binding, val); | |
942 | return SCM_ENVIRONMENT_SUCCESS; | |
943 | } | |
944 | else | |
945 | { | |
946 | return SCM_UNDEFINED; | |
947 | } | |
948 | } | |
949 | #undef FUNC_NAME | |
950 | ||
951 | ||
952 | static SCM | |
e81d98ec | 953 | leaf_environment_cell (SCM env, SCM sym, int for_write SCM_UNUSED) |
5d3e2388 DH |
954 | { |
955 | SCM obarray = LEAF_ENVIRONMENT (env)->obarray; | |
956 | SCM binding = obarray_retrieve (obarray, sym); | |
957 | return binding; | |
958 | } | |
959 | ||
960 | ||
961 | static SCM | |
e841c3e0 | 962 | leaf_environment_mark (SCM env) |
5d3e2388 DH |
963 | { |
964 | scm_gc_mark (LEAF_ENVIRONMENT (env)->obarray); | |
965 | return core_environments_mark (env); | |
966 | } | |
967 | ||
968 | ||
4c9419ac | 969 | static void |
e841c3e0 | 970 | leaf_environment_free (SCM env) |
5d3e2388 DH |
971 | { |
972 | core_environments_finalize (env); | |
4c9419ac MV |
973 | scm_gc_free (LEAF_ENVIRONMENT (env), sizeof (struct leaf_environment), |
974 | "leaf environment"); | |
5d3e2388 DH |
975 | } |
976 | ||
977 | ||
978 | static int | |
e81d98ec | 979 | leaf_environment_print (SCM type, SCM port, scm_print_state *pstate SCM_UNUSED) |
5d3e2388 | 980 | { |
c014a02e | 981 | SCM address = scm_ulong2num (SCM_UNPACK (type)); |
5d3e2388 DH |
982 | SCM base16 = scm_number_to_string (address, SCM_MAKINUM (16)); |
983 | ||
984 | scm_puts ("#<leaf environment ", port); | |
86c991c2 | 985 | scm_puts (SCM_STRING_CHARS (base16), port); |
5d3e2388 DH |
986 | scm_puts (">", port); |
987 | ||
988 | return 1; | |
989 | } | |
990 | ||
991 | ||
992 | static struct scm_environment_funcs leaf_environment_funcs = { | |
993 | leaf_environment_ref, | |
994 | leaf_environment_fold, | |
995 | leaf_environment_define, | |
996 | leaf_environment_undefine, | |
997 | leaf_environment_set_x, | |
998 | leaf_environment_cell, | |
999 | core_environments_observe, | |
1000 | core_environments_unobserve, | |
e841c3e0 KN |
1001 | leaf_environment_mark, |
1002 | leaf_environment_free, | |
1003 | leaf_environment_print | |
5d3e2388 DH |
1004 | }; |
1005 | ||
1006 | ||
1007 | void *scm_type_leaf_environment = &leaf_environment_funcs; | |
1008 | ||
1009 | ||
1010 | SCM_DEFINE (scm_make_leaf_environment, "make-leaf-environment", 0, 0, 0, | |
1011 | (), | |
1012 | "Create a new leaf environment, containing no bindings.\n" | |
1013 | "All bindings and locations created in the new environment\n" | |
1014 | "will be mutable.") | |
1015 | #define FUNC_NAME s_scm_make_leaf_environment | |
1016 | { | |
1be6b49c | 1017 | size_t size = sizeof (struct leaf_environment); |
4c9419ac | 1018 | struct leaf_environment *body = scm_gc_malloc (size, "leaf environment"); |
5d3e2388 DH |
1019 | SCM env; |
1020 | ||
1021 | core_environments_preinit (&body->base); | |
1022 | body->obarray = SCM_BOOL_F; | |
1023 | ||
1024 | env = scm_make_environment (body); | |
1025 | ||
1026 | core_environments_init (&body->base, &leaf_environment_funcs); | |
00ffa0e7 | 1027 | body->obarray = scm_c_make_hash_table (DEFAULT_OBARRAY_SIZE); |
5d3e2388 DH |
1028 | |
1029 | return env; | |
1030 | } | |
1031 | #undef FUNC_NAME | |
1032 | ||
1033 | ||
1034 | SCM_DEFINE (scm_leaf_environment_p, "leaf-environment?", 1, 0, 0, | |
1035 | (SCM object), | |
0fb104ed MG |
1036 | "Return @code{#t} if object is a leaf environment, or @code{#f}\n" |
1037 | "otherwise.") | |
5d3e2388 DH |
1038 | #define FUNC_NAME s_scm_leaf_environment_p |
1039 | { | |
7888309b | 1040 | return scm_from_bool (SCM_LEAF_ENVIRONMENT_P (object)); |
5d3e2388 DH |
1041 | } |
1042 | #undef FUNC_NAME | |
1043 | ||
1044 | \f | |
1045 | ||
1046 | /* eval environments | |
1047 | * | |
1048 | * A module's source code refers to definitions imported from other modules, | |
1049 | * and definitions made within itself. An eval environment combines two | |
1050 | * environments -- a local environment and an imported environment -- to | |
1051 | * produce a new environment in which both sorts of references can be | |
1052 | * resolved. | |
1053 | * | |
1054 | * Implementation: The obarray of the eval environment is used to cache | |
1055 | * entries from the local and imported environments such that in most of the | |
1056 | * cases only a single lookup is necessary. Since for neither the local nor | |
1057 | * the imported environment it is known, what kind of environment they form, | |
1058 | * the most general case is assumed. Therefore, entries in the obarray take | |
1059 | * one of the following forms: | |
1060 | * | |
1061 | * 1) (<symbol> location mutability . source-env), where mutability indicates | |
1062 | * one of the following states: IMMUTABLE if the location is known to be | |
1063 | * immutable, MUTABLE if the location is known to be mutable, UNKNOWN if | |
1064 | * the location has only been requested for non modifying accesses. | |
1065 | * | |
1066 | * 2) (symbol . source-env) if the symbol has a binding in the source-env, but | |
1067 | * if the source-env can't provide a cell for the binding. Thus, for every | |
1068 | * access, the source-env has to be contacted directly. | |
1069 | */ | |
1070 | ||
1071 | ||
1072 | struct eval_environment { | |
1073 | struct core_environments_base base; | |
1074 | ||
1075 | SCM obarray; | |
1076 | ||
1077 | SCM imported; | |
1078 | SCM imported_observer; | |
1079 | SCM local; | |
1080 | SCM local_observer; | |
1081 | }; | |
1082 | ||
1083 | ||
1084 | #define EVAL_ENVIRONMENT(env) \ | |
1085 | ((struct eval_environment *) SCM_CELL_WORD_1 (env)) | |
1086 | ||
1087 | #define IMMUTABLE SCM_MAKINUM (0) | |
1088 | #define MUTABLE SCM_MAKINUM (1) | |
1089 | #define UNKNOWN SCM_MAKINUM (2) | |
1090 | ||
1091 | #define CACHED_LOCATION(x) SCM_CAR (x) | |
1092 | #define CACHED_MUTABILITY(x) SCM_CADR (x) | |
1093 | #define SET_CACHED_MUTABILITY(x, v) SCM_SETCAR (SCM_CDR (x), (v)) | |
1094 | #define CACHED_SOURCE_ENVIRONMENT(x) SCM_CDDR (x) | |
1095 | ||
1096 | \f | |
1097 | ||
1098 | /* eval_environment_lookup will report one of the following distinct results: | |
1099 | * a) (<object> . value) if a cell could be obtained. | |
1100 | * b) <environment> if the environment has to be contacted directly. | |
1101 | * c) IMMUTABLE if an immutable cell was requested for write. | |
1102 | * d) SCM_UNDEFINED if there is no binding for the symbol. | |
1103 | */ | |
1104 | static SCM | |
1105 | eval_environment_lookup (SCM env, SCM sym, int for_write) | |
1106 | { | |
1107 | SCM obarray = EVAL_ENVIRONMENT (env)->obarray; | |
1108 | SCM binding = obarray_retrieve (obarray, sym); | |
1109 | ||
1110 | if (!SCM_UNBNDP (binding)) | |
1111 | { | |
1112 | /* The obarray holds an entry for the symbol. */ | |
1113 | ||
1114 | SCM entry = SCM_CDR (binding); | |
1115 | ||
1116 | if (SCM_CONSP (entry)) | |
1117 | { | |
1118 | /* The entry in the obarray is a cached location. */ | |
1119 | ||
1120 | SCM location = CACHED_LOCATION (entry); | |
1121 | SCM mutability; | |
1122 | ||
1123 | if (!for_write) | |
1124 | return location; | |
1125 | ||
1126 | mutability = CACHED_MUTABILITY (entry); | |
1127 | if (SCM_EQ_P (mutability, MUTABLE)) | |
1128 | return location; | |
1129 | ||
1130 | if (SCM_EQ_P (mutability, UNKNOWN)) | |
1131 | { | |
1132 | SCM source_env = CACHED_SOURCE_ENVIRONMENT (entry); | |
1133 | SCM location = SCM_ENVIRONMENT_CELL (source_env, sym, 1); | |
1134 | ||
1135 | if (SCM_CONSP (location)) | |
1136 | { | |
1137 | SET_CACHED_MUTABILITY (entry, MUTABLE); | |
1138 | return location; | |
1139 | } | |
1140 | else /* IMMUTABLE */ | |
1141 | { | |
1142 | SET_CACHED_MUTABILITY (entry, IMMUTABLE); | |
1143 | return IMMUTABLE; | |
1144 | } | |
1145 | } | |
1146 | ||
1147 | return IMMUTABLE; | |
1148 | } | |
1149 | else | |
1150 | { | |
1151 | /* The obarray entry is an environment */ | |
1152 | ||
1153 | return entry; | |
1154 | } | |
1155 | } | |
1156 | else | |
1157 | { | |
1158 | /* There is no entry for the symbol in the obarray. This can either | |
1159 | * mean that there has not been a request for the symbol yet, or that | |
1160 | * the symbol is really undefined. We are looking for the symbol in | |
1161 | * both the local and the imported environment. If we find a binding, a | |
1162 | * cached entry is created. | |
1163 | */ | |
1164 | ||
1165 | struct eval_environment *body = EVAL_ENVIRONMENT (env); | |
1166 | unsigned int handling_import; | |
1167 | ||
1168 | for (handling_import = 0; handling_import <= 1; ++handling_import) | |
1169 | { | |
1170 | SCM source_env = handling_import ? body->imported : body->local; | |
1171 | SCM location = SCM_ENVIRONMENT_CELL (source_env, sym, for_write); | |
1172 | ||
1173 | if (!SCM_UNBNDP (location)) | |
1174 | { | |
1175 | if (SCM_CONSP (location)) | |
1176 | { | |
1177 | SCM mutability = for_write ? MUTABLE : UNKNOWN; | |
1178 | SCM entry = scm_cons2 (location, mutability, source_env); | |
1179 | obarray_enter (obarray, sym, entry); | |
1180 | return location; | |
1181 | } | |
1182 | else if (SCM_EQ_P (location, SCM_ENVIRONMENT_LOCATION_NO_CELL)) | |
1183 | { | |
1184 | obarray_enter (obarray, sym, source_env); | |
1185 | return source_env; | |
1186 | } | |
1187 | else | |
1188 | { | |
1189 | return IMMUTABLE; | |
1190 | } | |
1191 | } | |
1192 | } | |
1193 | ||
1194 | return SCM_UNDEFINED; | |
1195 | } | |
1196 | } | |
1197 | ||
1198 | ||
1199 | static SCM | |
1200 | eval_environment_ref (SCM env, SCM sym) | |
1201 | #define FUNC_NAME "eval_environment_ref" | |
1202 | { | |
1203 | SCM location = eval_environment_lookup (env, sym, 0); | |
1204 | ||
1205 | if (SCM_CONSP (location)) | |
1206 | return SCM_CDR (location); | |
1207 | else if (!SCM_UNBNDP (location)) | |
1208 | return SCM_ENVIRONMENT_REF (location, sym); | |
1209 | else | |
1210 | return SCM_UNDEFINED; | |
1211 | } | |
1212 | #undef FUNC_NAME | |
1213 | ||
1214 | ||
1215 | static SCM | |
1216 | eval_environment_folder (SCM extended_data, SCM symbol, SCM value, SCM tail) | |
1217 | { | |
1218 | SCM local = SCM_CAR (extended_data); | |
1219 | ||
1220 | if (!SCM_ENVIRONMENT_BOUND_P (local, symbol)) | |
1221 | { | |
1222 | SCM proc_as_nr = SCM_CADR (extended_data); | |
c014a02e | 1223 | unsigned long int proc_as_ul = scm_num2ulong (proc_as_nr, 0, NULL); |
5d3e2388 DH |
1224 | scm_environment_folder proc = (scm_environment_folder) proc_as_ul; |
1225 | SCM data = SCM_CDDR (extended_data); | |
1226 | ||
1227 | return (*proc) (data, symbol, value, tail); | |
1228 | } | |
1229 | else | |
1230 | { | |
1231 | return tail; | |
1232 | } | |
1233 | } | |
1234 | ||
1235 | ||
1236 | static SCM | |
1237 | eval_environment_fold (SCM env, scm_environment_folder proc, SCM data, SCM init) | |
1238 | { | |
1239 | SCM local = EVAL_ENVIRONMENT (env)->local; | |
1240 | SCM imported = EVAL_ENVIRONMENT (env)->imported; | |
c014a02e | 1241 | SCM proc_as_nr = scm_ulong2num ((unsigned long int) proc); |
5d3e2388 DH |
1242 | SCM extended_data = scm_cons2 (local, proc_as_nr, data); |
1243 | SCM tmp_result = scm_c_environment_fold (imported, eval_environment_folder, extended_data, init); | |
1244 | ||
1245 | return scm_c_environment_fold (local, proc, data, tmp_result); | |
1246 | } | |
1247 | ||
1248 | ||
1249 | static SCM | |
1250 | eval_environment_define (SCM env, SCM sym, SCM val) | |
1251 | #define FUNC_NAME "eval_environment_define" | |
1252 | { | |
1253 | SCM local = EVAL_ENVIRONMENT (env)->local; | |
1254 | return SCM_ENVIRONMENT_DEFINE (local, sym, val); | |
1255 | } | |
1256 | #undef FUNC_NAME | |
1257 | ||
1258 | ||
1259 | static SCM | |
1260 | eval_environment_undefine (SCM env, SCM sym) | |
1261 | #define FUNC_NAME "eval_environment_undefine" | |
1262 | { | |
1263 | SCM local = EVAL_ENVIRONMENT (env)->local; | |
1264 | return SCM_ENVIRONMENT_UNDEFINE (local, sym); | |
1265 | } | |
1266 | #undef FUNC_NAME | |
1267 | ||
1268 | ||
1269 | static SCM | |
1270 | eval_environment_set_x (SCM env, SCM sym, SCM val) | |
1271 | #define FUNC_NAME "eval_environment_set_x" | |
1272 | { | |
1273 | SCM location = eval_environment_lookup (env, sym, 1); | |
1274 | ||
1275 | if (SCM_CONSP (location)) | |
1276 | { | |
1277 | SCM_SETCDR (location, val); | |
1278 | return SCM_ENVIRONMENT_SUCCESS; | |
1279 | } | |
1280 | else if (SCM_ENVIRONMENT_P (location)) | |
1281 | { | |
1282 | return SCM_ENVIRONMENT_SET (location, sym, val); | |
1283 | } | |
1284 | else if (SCM_EQ_P (location, IMMUTABLE)) | |
1285 | { | |
1286 | return SCM_ENVIRONMENT_LOCATION_IMMUTABLE; | |
1287 | } | |
1288 | else | |
1289 | { | |
1290 | return SCM_UNDEFINED; | |
1291 | } | |
1292 | } | |
1293 | #undef FUNC_NAME | |
1294 | ||
1295 | ||
1296 | static SCM | |
1297 | eval_environment_cell (SCM env, SCM sym, int for_write) | |
1298 | #define FUNC_NAME "eval_environment_cell" | |
1299 | { | |
1300 | SCM location = eval_environment_lookup (env, sym, for_write); | |
1301 | ||
1302 | if (SCM_CONSP (location)) | |
1303 | return location; | |
1304 | else if (SCM_ENVIRONMENT_P (location)) | |
1305 | return SCM_ENVIRONMENT_LOCATION_NO_CELL; | |
1306 | else if (SCM_EQ_P (location, IMMUTABLE)) | |
1307 | return SCM_ENVIRONMENT_LOCATION_IMMUTABLE; | |
1308 | else | |
1309 | return SCM_UNDEFINED; | |
1310 | } | |
1311 | #undef FUNC_NAME | |
1312 | ||
1313 | ||
1314 | static SCM | |
e841c3e0 | 1315 | eval_environment_mark (SCM env) |
5d3e2388 DH |
1316 | { |
1317 | struct eval_environment *body = EVAL_ENVIRONMENT (env); | |
1318 | ||
1319 | scm_gc_mark (body->obarray); | |
1320 | scm_gc_mark (body->imported); | |
1321 | scm_gc_mark (body->imported_observer); | |
1322 | scm_gc_mark (body->local); | |
1323 | scm_gc_mark (body->local_observer); | |
1324 | ||
1325 | return core_environments_mark (env); | |
1326 | } | |
1327 | ||
1328 | ||
4c9419ac | 1329 | static void |
e841c3e0 | 1330 | eval_environment_free (SCM env) |
5d3e2388 DH |
1331 | { |
1332 | core_environments_finalize (env); | |
4c9419ac MV |
1333 | scm_gc_free (EVAL_ENVIRONMENT (env), sizeof (struct eval_environment), |
1334 | "eval environment"); | |
5d3e2388 DH |
1335 | } |
1336 | ||
1337 | ||
1338 | static int | |
e81d98ec | 1339 | eval_environment_print (SCM type, SCM port, scm_print_state *pstate SCM_UNUSED) |
5d3e2388 | 1340 | { |
c014a02e | 1341 | SCM address = scm_ulong2num (SCM_UNPACK (type)); |
5d3e2388 DH |
1342 | SCM base16 = scm_number_to_string (address, SCM_MAKINUM (16)); |
1343 | ||
1344 | scm_puts ("#<eval environment ", port); | |
86c991c2 | 1345 | scm_puts (SCM_STRING_CHARS (base16), port); |
5d3e2388 DH |
1346 | scm_puts (">", port); |
1347 | ||
1348 | return 1; | |
1349 | } | |
1350 | ||
1351 | ||
1352 | static struct scm_environment_funcs eval_environment_funcs = { | |
1353 | eval_environment_ref, | |
1354 | eval_environment_fold, | |
1355 | eval_environment_define, | |
1356 | eval_environment_undefine, | |
1357 | eval_environment_set_x, | |
1358 | eval_environment_cell, | |
1359 | core_environments_observe, | |
1360 | core_environments_unobserve, | |
e841c3e0 KN |
1361 | eval_environment_mark, |
1362 | eval_environment_free, | |
1363 | eval_environment_print | |
5d3e2388 DH |
1364 | }; |
1365 | ||
1366 | ||
1367 | void *scm_type_eval_environment = &eval_environment_funcs; | |
1368 | ||
1369 | ||
1370 | static void | |
e81d98ec | 1371 | eval_environment_observer (SCM caller SCM_UNUSED, SCM eval_env) |
5d3e2388 DH |
1372 | { |
1373 | SCM obarray = EVAL_ENVIRONMENT (eval_env)->obarray; | |
1374 | ||
1375 | obarray_remove_all (obarray); | |
1376 | core_environments_broadcast (eval_env); | |
1377 | } | |
1378 | ||
1379 | ||
1380 | SCM_DEFINE (scm_make_eval_environment, "make-eval-environment", 2, 0, 0, | |
1381 | (SCM local, SCM imported), | |
1382 | "Return a new environment object eval whose bindings are the\n" | |
0fb104ed MG |
1383 | "union of the bindings in the environments @var{local} and\n" |
1384 | "@var{imported}, with bindings from @var{local} taking\n" | |
1385 | "precedence. Definitions made in eval are placed in @var{local}.\n" | |
1386 | "Applying @code{environment-define} or\n" | |
1387 | "@code{environment-undefine} to eval has the same effect as\n" | |
1388 | "applying the procedure to @var{local}.\n" | |
1389 | "Note that eval incorporates @var{local} and @var{imported} by\n" | |
1390 | "reference:\n" | |
5d3e2388 | 1391 | "If, after creating eval, the program changes the bindings of\n" |
0fb104ed MG |
1392 | "@var{local} or @var{imported}, those changes will be visible\n" |
1393 | "in eval.\n" | |
5d3e2388 | 1394 | "Since most Scheme evaluation takes place in eval environments,\n" |
0fb104ed MG |
1395 | "they transparently cache the bindings received from @var{local}\n" |
1396 | "and @var{imported}. Thus, the first time the program looks up\n" | |
1397 | "a symbol in eval, eval may make calls to @var{local} or\n" | |
1398 | "@var{imported} to find their bindings, but subsequent\n" | |
1399 | "references to that symbol will be as fast as references to\n" | |
1400 | "bindings in finite environments.\n" | |
1401 | "In typical use, @var{local} will be a finite environment, and\n" | |
1402 | "@var{imported} will be an import environment") | |
5d3e2388 DH |
1403 | #define FUNC_NAME s_scm_make_eval_environment |
1404 | { | |
1405 | SCM env; | |
1406 | struct eval_environment *body; | |
1407 | ||
1408 | SCM_ASSERT (SCM_ENVIRONMENT_P (local), local, SCM_ARG1, FUNC_NAME); | |
1409 | SCM_ASSERT (SCM_ENVIRONMENT_P (imported), imported, SCM_ARG2, FUNC_NAME); | |
1410 | ||
4c9419ac | 1411 | body = scm_gc_malloc (sizeof (struct eval_environment), "eval environment"); |
5d3e2388 DH |
1412 | |
1413 | core_environments_preinit (&body->base); | |
1414 | body->obarray = SCM_BOOL_F; | |
1415 | body->imported = SCM_BOOL_F; | |
1416 | body->imported_observer = SCM_BOOL_F; | |
1417 | body->local = SCM_BOOL_F; | |
1418 | body->local_observer = SCM_BOOL_F; | |
1419 | ||
1420 | env = scm_make_environment (body); | |
1421 | ||
1422 | core_environments_init (&body->base, &eval_environment_funcs); | |
00ffa0e7 | 1423 | body->obarray = scm_c_make_hash_table (DEFAULT_OBARRAY_SIZE); |
5d3e2388 DH |
1424 | body->imported = imported; |
1425 | body->imported_observer | |
1426 | = SCM_ENVIRONMENT_OBSERVE (imported, eval_environment_observer, env, 1); | |
1427 | body->local = local; | |
1428 | body->local_observer | |
1429 | = SCM_ENVIRONMENT_OBSERVE (local, eval_environment_observer, env, 1); | |
1430 | ||
1431 | return env; | |
1432 | } | |
1433 | #undef FUNC_NAME | |
1434 | ||
1435 | ||
1436 | SCM_DEFINE (scm_eval_environment_p, "eval-environment?", 1, 0, 0, | |
1437 | (SCM object), | |
0fb104ed MG |
1438 | "Return @code{#t} if object is an eval environment, or @code{#f}\n" |
1439 | "otherwise.") | |
5d3e2388 DH |
1440 | #define FUNC_NAME s_scm_eval_environment_p |
1441 | { | |
7888309b | 1442 | return scm_from_bool (SCM_EVAL_ENVIRONMENT_P (object)); |
5d3e2388 DH |
1443 | } |
1444 | #undef FUNC_NAME | |
1445 | ||
1446 | ||
1447 | SCM_DEFINE (scm_eval_environment_local, "eval-environment-local", 1, 0, 0, | |
1448 | (SCM env), | |
0fb104ed | 1449 | "Return the local environment of eval environment @var{env}.") |
5d3e2388 DH |
1450 | #define FUNC_NAME s_scm_eval_environment_local |
1451 | { | |
1452 | SCM_ASSERT (SCM_EVAL_ENVIRONMENT_P (env), env, SCM_ARG1, FUNC_NAME); | |
1453 | ||
1454 | return EVAL_ENVIRONMENT (env)->local; | |
1455 | } | |
1456 | #undef FUNC_NAME | |
1457 | ||
1458 | ||
1459 | SCM_DEFINE (scm_eval_environment_set_local_x, "eval-environment-set-local!", 2, 0, 0, | |
1460 | (SCM env, SCM local), | |
0fb104ed | 1461 | "Change @var{env}'s local environment to @var{local}.") |
5d3e2388 DH |
1462 | #define FUNC_NAME s_scm_eval_environment_set_local_x |
1463 | { | |
1464 | struct eval_environment *body; | |
1465 | ||
1466 | SCM_ASSERT (SCM_EVAL_ENVIRONMENT_P (env), env, SCM_ARG1, FUNC_NAME); | |
1467 | SCM_ASSERT (SCM_ENVIRONMENT_P (local), local, SCM_ARG2, FUNC_NAME); | |
1468 | ||
1469 | body = EVAL_ENVIRONMENT (env); | |
1470 | ||
1471 | obarray_remove_all (body->obarray); | |
1472 | SCM_ENVIRONMENT_UNOBSERVE (body->local, body->local_observer); | |
1473 | ||
1474 | body->local = local; | |
1475 | body->local_observer | |
1476 | = SCM_ENVIRONMENT_OBSERVE (local, eval_environment_observer, env, 1); | |
1477 | ||
1478 | core_environments_broadcast (env); | |
1479 | ||
1480 | return SCM_UNSPECIFIED; | |
1481 | } | |
1482 | #undef FUNC_NAME | |
1483 | ||
1484 | ||
1485 | SCM_DEFINE (scm_eval_environment_imported, "eval-environment-imported", 1, 0, 0, | |
1486 | (SCM env), | |
0fb104ed | 1487 | "Return the imported environment of eval environment @var{env}.") |
5d3e2388 DH |
1488 | #define FUNC_NAME s_scm_eval_environment_imported |
1489 | { | |
1490 | SCM_ASSERT (SCM_EVAL_ENVIRONMENT_P (env), env, SCM_ARG1, FUNC_NAME); | |
1491 | ||
1492 | return EVAL_ENVIRONMENT (env)->imported; | |
1493 | } | |
1494 | #undef FUNC_NAME | |
1495 | ||
1496 | ||
1497 | SCM_DEFINE (scm_eval_environment_set_imported_x, "eval-environment-set-imported!", 2, 0, 0, | |
1498 | (SCM env, SCM imported), | |
0fb104ed | 1499 | "Change @var{env}'s imported environment to @var{imported}.") |
5d3e2388 DH |
1500 | #define FUNC_NAME s_scm_eval_environment_set_imported_x |
1501 | { | |
1502 | struct eval_environment *body; | |
1503 | ||
1504 | SCM_ASSERT (SCM_EVAL_ENVIRONMENT_P (env), env, SCM_ARG1, FUNC_NAME); | |
1505 | SCM_ASSERT (SCM_ENVIRONMENT_P (imported), imported, SCM_ARG2, FUNC_NAME); | |
1506 | ||
1507 | body = EVAL_ENVIRONMENT (env); | |
1508 | ||
1509 | obarray_remove_all (body->obarray); | |
1510 | SCM_ENVIRONMENT_UNOBSERVE (body->imported, body->imported_observer); | |
1511 | ||
1512 | body->imported = imported; | |
1513 | body->imported_observer | |
1514 | = SCM_ENVIRONMENT_OBSERVE (imported, eval_environment_observer, env, 1); | |
1515 | ||
1516 | core_environments_broadcast (env); | |
1517 | ||
1518 | return SCM_UNSPECIFIED; | |
1519 | } | |
1520 | #undef FUNC_NAME | |
1521 | ||
1522 | \f | |
1523 | ||
1524 | /* import environments | |
1525 | * | |
1526 | * An import environment combines the bindings of a set of argument | |
1527 | * environments, and checks for naming clashes. | |
1528 | * | |
1529 | * Implementation: The import environment does no caching at all. For every | |
1530 | * access, the list of imported environments is scanned. | |
1531 | */ | |
1532 | ||
1533 | ||
1534 | struct import_environment { | |
1535 | struct core_environments_base base; | |
1536 | ||
1537 | SCM imports; | |
1538 | SCM import_observers; | |
1539 | ||
1540 | SCM conflict_proc; | |
1541 | }; | |
1542 | ||
1543 | ||
1544 | #define IMPORT_ENVIRONMENT(env) \ | |
1545 | ((struct import_environment *) SCM_CELL_WORD_1 (env)) | |
1546 | ||
1547 | \f | |
1548 | ||
1549 | /* Lookup will report one of the following distinct results: | |
1550 | * a) <environment> if only environment binds the symbol. | |
1551 | * b) (env-1 env-2 ...) for conflicting bindings in env-1, ... | |
1552 | * c) SCM_UNDEFINED if there is no binding for the symbol. | |
1553 | */ | |
1554 | static SCM | |
1555 | import_environment_lookup (SCM env, SCM sym) | |
1556 | { | |
1557 | SCM imports = IMPORT_ENVIRONMENT (env)->imports; | |
1558 | SCM result = SCM_UNDEFINED; | |
1559 | SCM l; | |
1560 | ||
1561 | for (l = imports; !SCM_NULLP (l); l = SCM_CDR (l)) | |
1562 | { | |
1563 | SCM imported = SCM_CAR (l); | |
1564 | ||
1565 | if (SCM_ENVIRONMENT_BOUND_P (imported, sym)) | |
1566 | { | |
1567 | if (SCM_UNBNDP (result)) | |
1568 | result = imported; | |
1569 | else if (SCM_CONSP (result)) | |
1570 | result = scm_cons (imported, result); | |
1571 | else | |
1572 | result = scm_cons2 (imported, result, SCM_EOL); | |
1573 | } | |
1574 | } | |
1575 | ||
1576 | if (SCM_CONSP (result)) | |
1577 | return scm_reverse (result); | |
1578 | else | |
1579 | return result; | |
1580 | } | |
1581 | ||
1582 | ||
1583 | static SCM | |
1584 | import_environment_conflict (SCM env, SCM sym, SCM imports) | |
1585 | { | |
1586 | SCM conflict_proc = IMPORT_ENVIRONMENT (env)->conflict_proc; | |
1587 | SCM args = scm_cons2 (env, sym, scm_cons (imports, SCM_EOL)); | |
1588 | ||
fdc28395 | 1589 | return scm_apply_0 (conflict_proc, args); |
5d3e2388 DH |
1590 | } |
1591 | ||
1592 | ||
1593 | static SCM | |
1594 | import_environment_ref (SCM env, SCM sym) | |
1595 | #define FUNC_NAME "import_environment_ref" | |
1596 | { | |
1597 | SCM owner = import_environment_lookup (env, sym); | |
1598 | ||
1599 | if (SCM_UNBNDP (owner)) | |
1600 | { | |
1601 | return SCM_UNDEFINED; | |
1602 | } | |
1603 | else if (SCM_CONSP (owner)) | |
1604 | { | |
1605 | SCM resolve = import_environment_conflict (env, sym, owner); | |
1606 | ||
1607 | if (SCM_ENVIRONMENT_P (resolve)) | |
1608 | return SCM_ENVIRONMENT_REF (resolve, sym); | |
1609 | else | |
1610 | return SCM_UNSPECIFIED; | |
1611 | } | |
1612 | else | |
1613 | { | |
1614 | return SCM_ENVIRONMENT_REF (owner, sym); | |
1615 | } | |
1616 | } | |
1617 | #undef FUNC_NAME | |
1618 | ||
1619 | ||
1620 | static SCM | |
1621 | import_environment_folder (SCM extended_data, SCM symbol, SCM value, SCM tail) | |
1622 | #define FUNC_NAME "import_environment_fold" | |
1623 | { | |
1624 | SCM import_env = SCM_CAR (extended_data); | |
1625 | SCM imported_env = SCM_CADR (extended_data); | |
1626 | SCM owner = import_environment_lookup (import_env, symbol); | |
1627 | SCM proc_as_nr = SCM_CADDR (extended_data); | |
c014a02e | 1628 | unsigned long int proc_as_ul = scm_num2ulong (proc_as_nr, 0, NULL); |
5d3e2388 DH |
1629 | scm_environment_folder proc = (scm_environment_folder) proc_as_ul; |
1630 | SCM data = SCM_CDDDR (extended_data); | |
1631 | ||
1632 | if (SCM_CONSP (owner) && SCM_EQ_P (SCM_CAR (owner), imported_env)) | |
1633 | owner = import_environment_conflict (import_env, symbol, owner); | |
1634 | ||
1635 | if (SCM_ENVIRONMENT_P (owner)) | |
1636 | return (*proc) (data, symbol, value, tail); | |
1637 | else /* unresolved conflict */ | |
1638 | return (*proc) (data, symbol, SCM_UNSPECIFIED, tail); | |
1639 | } | |
1640 | #undef FUNC_NAME | |
1641 | ||
1642 | ||
1643 | static SCM | |
1644 | import_environment_fold (SCM env, scm_environment_folder proc, SCM data, SCM init) | |
1645 | { | |
c014a02e | 1646 | SCM proc_as_nr = scm_ulong2num ((unsigned long int) proc); |
5d3e2388 DH |
1647 | SCM result = init; |
1648 | SCM l; | |
1649 | ||
1650 | for (l = IMPORT_ENVIRONMENT (env)->imports; !SCM_NULLP (l); l = SCM_CDR (l)) | |
1651 | { | |
1652 | SCM imported_env = SCM_CAR (l); | |
1653 | SCM extended_data = scm_cons (env, scm_cons2 (imported_env, proc_as_nr, data)); | |
1654 | ||
1655 | result = scm_c_environment_fold (imported_env, import_environment_folder, extended_data, result); | |
1656 | } | |
1657 | ||
1658 | return result; | |
1659 | } | |
1660 | ||
1661 | ||
1662 | static SCM | |
e81d98ec DH |
1663 | import_environment_define (SCM env SCM_UNUSED, |
1664 | SCM sym SCM_UNUSED, | |
1665 | SCM val SCM_UNUSED) | |
5d3e2388 DH |
1666 | #define FUNC_NAME "import_environment_define" |
1667 | { | |
1668 | return SCM_ENVIRONMENT_BINDING_IMMUTABLE; | |
1669 | } | |
1670 | #undef FUNC_NAME | |
1671 | ||
1672 | ||
1673 | static SCM | |
e81d98ec DH |
1674 | import_environment_undefine (SCM env SCM_UNUSED, |
1675 | SCM sym SCM_UNUSED) | |
5d3e2388 DH |
1676 | #define FUNC_NAME "import_environment_undefine" |
1677 | { | |
1678 | return SCM_ENVIRONMENT_BINDING_IMMUTABLE; | |
1679 | } | |
1680 | #undef FUNC_NAME | |
1681 | ||
1682 | ||
1683 | static SCM | |
1684 | import_environment_set_x (SCM env, SCM sym, SCM val) | |
1685 | #define FUNC_NAME "import_environment_set_x" | |
1686 | { | |
1687 | SCM owner = import_environment_lookup (env, sym); | |
1688 | ||
1689 | if (SCM_UNBNDP (owner)) | |
1690 | { | |
1691 | return SCM_UNDEFINED; | |
1692 | } | |
1693 | else if (SCM_CONSP (owner)) | |
1694 | { | |
1695 | SCM resolve = import_environment_conflict (env, sym, owner); | |
1696 | ||
1697 | if (SCM_ENVIRONMENT_P (resolve)) | |
1698 | return SCM_ENVIRONMENT_SET (resolve, sym, val); | |
1699 | else | |
1700 | return SCM_ENVIRONMENT_LOCATION_IMMUTABLE; | |
1701 | } | |
1702 | else | |
1703 | { | |
1704 | return SCM_ENVIRONMENT_SET (owner, sym, val); | |
1705 | } | |
1706 | } | |
1707 | #undef FUNC_NAME | |
1708 | ||
1709 | ||
1710 | static SCM | |
1711 | import_environment_cell (SCM env, SCM sym, int for_write) | |
1712 | #define FUNC_NAME "import_environment_cell" | |
1713 | { | |
1714 | SCM owner = import_environment_lookup (env, sym); | |
1715 | ||
1716 | if (SCM_UNBNDP (owner)) | |
1717 | { | |
1718 | return SCM_UNDEFINED; | |
1719 | } | |
1720 | else if (SCM_CONSP (owner)) | |
1721 | { | |
1722 | SCM resolve = import_environment_conflict (env, sym, owner); | |
1723 | ||
1724 | if (SCM_ENVIRONMENT_P (resolve)) | |
1725 | return SCM_ENVIRONMENT_CELL (resolve, sym, for_write); | |
1726 | else | |
1727 | return SCM_ENVIRONMENT_LOCATION_NO_CELL; | |
1728 | } | |
1729 | else | |
1730 | { | |
1731 | return SCM_ENVIRONMENT_CELL (owner, sym, for_write); | |
1732 | } | |
1733 | } | |
1734 | #undef FUNC_NAME | |
1735 | ||
1736 | ||
1737 | static SCM | |
e841c3e0 | 1738 | import_environment_mark (SCM env) |
5d3e2388 DH |
1739 | { |
1740 | scm_gc_mark (IMPORT_ENVIRONMENT (env)->imports); | |
1741 | scm_gc_mark (IMPORT_ENVIRONMENT (env)->import_observers); | |
1742 | scm_gc_mark (IMPORT_ENVIRONMENT (env)->conflict_proc); | |
1743 | return core_environments_mark (env); | |
1744 | } | |
1745 | ||
1746 | ||
4c9419ac | 1747 | static void |
e841c3e0 | 1748 | import_environment_free (SCM env) |
5d3e2388 DH |
1749 | { |
1750 | core_environments_finalize (env); | |
4c9419ac MV |
1751 | scm_gc_free (IMPORT_ENVIRONMENT (env), sizeof (struct import_environment), |
1752 | "import environment"); | |
5d3e2388 DH |
1753 | } |
1754 | ||
1755 | ||
1756 | static int | |
e81d98ec DH |
1757 | import_environment_print (SCM type, SCM port, |
1758 | scm_print_state *pstate SCM_UNUSED) | |
5d3e2388 | 1759 | { |
c014a02e | 1760 | SCM address = scm_ulong2num (SCM_UNPACK (type)); |
5d3e2388 DH |
1761 | SCM base16 = scm_number_to_string (address, SCM_MAKINUM (16)); |
1762 | ||
1763 | scm_puts ("#<import environment ", port); | |
86c991c2 | 1764 | scm_puts (SCM_STRING_CHARS (base16), port); |
5d3e2388 DH |
1765 | scm_puts (">", port); |
1766 | ||
1767 | return 1; | |
1768 | } | |
1769 | ||
1770 | ||
1771 | static struct scm_environment_funcs import_environment_funcs = { | |
1772 | import_environment_ref, | |
1773 | import_environment_fold, | |
1774 | import_environment_define, | |
1775 | import_environment_undefine, | |
1776 | import_environment_set_x, | |
1777 | import_environment_cell, | |
1778 | core_environments_observe, | |
1779 | core_environments_unobserve, | |
e841c3e0 KN |
1780 | import_environment_mark, |
1781 | import_environment_free, | |
1782 | import_environment_print | |
5d3e2388 DH |
1783 | }; |
1784 | ||
1785 | ||
1786 | void *scm_type_import_environment = &import_environment_funcs; | |
1787 | ||
1788 | ||
1789 | static void | |
e81d98ec | 1790 | import_environment_observer (SCM caller SCM_UNUSED, SCM import_env) |
5d3e2388 DH |
1791 | { |
1792 | core_environments_broadcast (import_env); | |
1793 | } | |
1794 | ||
1795 | ||
1796 | SCM_DEFINE (scm_make_import_environment, "make-import-environment", 2, 0, 0, | |
1797 | (SCM imports, SCM conflict_proc), | |
0fb104ed MG |
1798 | "Return a new environment @var{imp} whose bindings are the union\n" |
1799 | "of the bindings from the environments in @var{imports};\n" | |
1800 | "@var{imports} must be a list of environments. That is,\n" | |
1801 | "@var{imp} binds a symbol to a location when some element of\n" | |
1802 | "@var{imports} does.\n" | |
1803 | "If two different elements of @var{imports} have a binding for\n" | |
1804 | "the same symbol, the @var{conflict-proc} is called with the\n" | |
1805 | "following parameters: the import environment, the symbol and\n" | |
1806 | "the list of the imported environments that bind the symbol.\n" | |
1807 | "If the @var{conflict-proc} returns an environment @var{env},\n" | |
1808 | "the conflict is considered as resolved and the binding from\n" | |
1809 | "@var{env} is used. If the @var{conflict-proc} returns some\n" | |
1810 | "non-environment object, the conflict is considered unresolved\n" | |
1811 | "and the symbol is treated as unspecified in the import\n" | |
1812 | "environment.\n" | |
1813 | "The checking for conflicts may be performed lazily, i. e. at\n" | |
5d3e2388 DH |
1814 | "the moment when a value or binding for a certain symbol is\n" |
1815 | "requested instead of the moment when the environment is\n" | |
1816 | "created or the bindings of the imports change.\n" | |
0fb104ed MG |
1817 | "All bindings in @var{imp} are immutable. If you apply\n" |
1818 | "@code{environment-define} or @code{environment-undefine} to\n" | |
1819 | "@var{imp}, Guile will signal an\n" | |
1820 | " @code{environment:immutable-binding} error. However,\n" | |
1821 | "notice that the set of bindings in @var{imp} may still change,\n" | |
1822 | "if one of its imported environments changes.") | |
5d3e2388 DH |
1823 | #define FUNC_NAME s_scm_make_import_environment |
1824 | { | |
1be6b49c | 1825 | size_t size = sizeof (struct import_environment); |
4c9419ac | 1826 | struct import_environment *body = scm_gc_malloc (size, "import environment"); |
5d3e2388 DH |
1827 | SCM env; |
1828 | ||
1829 | core_environments_preinit (&body->base); | |
1830 | body->imports = SCM_BOOL_F; | |
1831 | body->import_observers = SCM_BOOL_F; | |
1832 | body->conflict_proc = SCM_BOOL_F; | |
1833 | ||
1834 | env = scm_make_environment (body); | |
1835 | ||
1836 | core_environments_init (&body->base, &import_environment_funcs); | |
1837 | body->imports = SCM_EOL; | |
1838 | body->import_observers = SCM_EOL; | |
1839 | body->conflict_proc = conflict_proc; | |
1840 | ||
1841 | scm_import_environment_set_imports_x (env, imports); | |
1842 | ||
1843 | return env; | |
1844 | } | |
1845 | #undef FUNC_NAME | |
1846 | ||
1847 | ||
1848 | SCM_DEFINE (scm_import_environment_p, "import-environment?", 1, 0, 0, | |
1849 | (SCM object), | |
0fb104ed MG |
1850 | "Return @code{#t} if object is an import environment, or\n" |
1851 | "@code{#f} otherwise.") | |
5d3e2388 DH |
1852 | #define FUNC_NAME s_scm_import_environment_p |
1853 | { | |
7888309b | 1854 | return scm_from_bool (SCM_IMPORT_ENVIRONMENT_P (object)); |
5d3e2388 DH |
1855 | } |
1856 | #undef FUNC_NAME | |
1857 | ||
1858 | ||
1859 | SCM_DEFINE (scm_import_environment_imports, "import-environment-imports", 1, 0, 0, | |
1860 | (SCM env), | |
0fb104ed MG |
1861 | "Return the list of environments imported by the import\n" |
1862 | "environment @var{env}.") | |
5d3e2388 DH |
1863 | #define FUNC_NAME s_scm_import_environment_imports |
1864 | { | |
1865 | SCM_ASSERT (SCM_IMPORT_ENVIRONMENT_P (env), env, SCM_ARG1, FUNC_NAME); | |
1866 | ||
1867 | return IMPORT_ENVIRONMENT (env)->imports; | |
1868 | } | |
1869 | #undef FUNC_NAME | |
1870 | ||
1871 | ||
1872 | SCM_DEFINE (scm_import_environment_set_imports_x, "import-environment-set-imports!", 2, 0, 0, | |
1873 | (SCM env, SCM imports), | |
0fb104ed MG |
1874 | "Change @var{env}'s list of imported environments to\n" |
1875 | "@var{imports}, and check for conflicts.") | |
5d3e2388 DH |
1876 | #define FUNC_NAME s_scm_import_environment_set_imports_x |
1877 | { | |
1878 | struct import_environment *body = IMPORT_ENVIRONMENT (env); | |
1879 | SCM import_observers = SCM_EOL; | |
1880 | SCM l; | |
1881 | ||
1882 | SCM_ASSERT (SCM_IMPORT_ENVIRONMENT_P (env), env, SCM_ARG1, FUNC_NAME); | |
1883 | for (l = imports; SCM_CONSP (l); l = SCM_CDR (l)) | |
1884 | { | |
1885 | SCM obj = SCM_CAR (l); | |
dd85ce47 | 1886 | SCM_ASSERT (SCM_ENVIRONMENT_P (obj), imports, SCM_ARG2, FUNC_NAME); |
5d3e2388 | 1887 | } |
dd85ce47 | 1888 | SCM_ASSERT (SCM_NULLP (l), imports, SCM_ARG2, FUNC_NAME); |
5d3e2388 DH |
1889 | |
1890 | for (l = body->import_observers; !SCM_NULLP (l); l = SCM_CDR (l)) | |
1891 | { | |
1892 | SCM obs = SCM_CAR (l); | |
1893 | SCM_ENVIRONMENT_UNOBSERVE (env, obs); | |
1894 | } | |
1895 | ||
1896 | for (l = imports; !SCM_NULLP (l); l = SCM_CDR (l)) | |
1897 | { | |
1898 | SCM imp = SCM_CAR (l); | |
1899 | SCM obs = SCM_ENVIRONMENT_OBSERVE (imp, import_environment_observer, env, 1); | |
1900 | import_observers = scm_cons (obs, import_observers); | |
1901 | } | |
1902 | ||
1903 | body->imports = imports; | |
1904 | body->import_observers = import_observers; | |
1905 | ||
1906 | return SCM_UNSPECIFIED; | |
1907 | } | |
1908 | #undef FUNC_NAME | |
1909 | ||
1910 | \f | |
1911 | ||
1912 | /* export environments | |
1913 | * | |
1914 | * An export environment restricts an environment to a specified set of | |
1915 | * bindings. | |
1916 | * | |
1917 | * Implementation: The export environment does no caching at all. For every | |
1918 | * access, the signature is scanned. The signature that is stored internally | |
1919 | * is an alist of pairs (symbol . (mutability)). | |
1920 | */ | |
1921 | ||
1922 | ||
1923 | struct export_environment { | |
1924 | struct core_environments_base base; | |
1925 | ||
1926 | SCM private; | |
1927 | SCM private_observer; | |
1928 | ||
1929 | SCM signature; | |
1930 | }; | |
1931 | ||
1932 | ||
1933 | #define EXPORT_ENVIRONMENT(env) \ | |
1934 | ((struct export_environment *) SCM_CELL_WORD_1 (env)) | |
1935 | ||
1936 | ||
1937 | SCM_SYMBOL (symbol_immutable_location, "immutable-location"); | |
1938 | SCM_SYMBOL (symbol_mutable_location, "mutable-location"); | |
1939 | ||
1940 | \f | |
1941 | ||
1942 | static SCM | |
1943 | export_environment_ref (SCM env, SCM sym) | |
1944 | #define FUNC_NAME "export_environment_ref" | |
1945 | { | |
1946 | struct export_environment *body = EXPORT_ENVIRONMENT (env); | |
1947 | SCM entry = scm_assq (sym, body->signature); | |
1948 | ||
7888309b | 1949 | if (scm_is_false (entry)) |
5d3e2388 DH |
1950 | return SCM_UNDEFINED; |
1951 | else | |
1952 | return SCM_ENVIRONMENT_REF (body->private, sym); | |
1953 | } | |
1954 | #undef FUNC_NAME | |
1955 | ||
1956 | ||
1957 | static SCM | |
1958 | export_environment_fold (SCM env, scm_environment_folder proc, SCM data, SCM init) | |
1959 | { | |
1960 | struct export_environment *body = EXPORT_ENVIRONMENT (env); | |
1961 | SCM result = init; | |
1962 | SCM l; | |
1963 | ||
1964 | for (l = body->signature; !SCM_NULLP (l); l = SCM_CDR (l)) | |
1965 | { | |
1966 | SCM symbol = SCM_CAR (l); | |
1967 | SCM value = SCM_ENVIRONMENT_REF (body->private, symbol); | |
1968 | if (!SCM_UNBNDP (value)) | |
1969 | result = (*proc) (data, symbol, value, result); | |
1970 | } | |
1971 | return result; | |
1972 | } | |
1973 | ||
1974 | ||
1975 | static SCM | |
e81d98ec DH |
1976 | export_environment_define (SCM env SCM_UNUSED, |
1977 | SCM sym SCM_UNUSED, | |
1978 | SCM val SCM_UNUSED) | |
5d3e2388 DH |
1979 | #define FUNC_NAME "export_environment_define" |
1980 | { | |
1981 | return SCM_ENVIRONMENT_BINDING_IMMUTABLE; | |
1982 | } | |
1983 | #undef FUNC_NAME | |
1984 | ||
1985 | ||
1986 | static SCM | |
e81d98ec | 1987 | export_environment_undefine (SCM env SCM_UNUSED, SCM sym SCM_UNUSED) |
5d3e2388 DH |
1988 | #define FUNC_NAME "export_environment_undefine" |
1989 | { | |
1990 | return SCM_ENVIRONMENT_BINDING_IMMUTABLE; | |
1991 | } | |
1992 | #undef FUNC_NAME | |
1993 | ||
1994 | ||
1995 | static SCM | |
1996 | export_environment_set_x (SCM env, SCM sym, SCM val) | |
1997 | #define FUNC_NAME "export_environment_set_x" | |
1998 | { | |
1999 | struct export_environment *body = EXPORT_ENVIRONMENT (env); | |
2000 | SCM entry = scm_assq (sym, body->signature); | |
2001 | ||
7888309b | 2002 | if (scm_is_false (entry)) |
5d3e2388 DH |
2003 | { |
2004 | return SCM_UNDEFINED; | |
2005 | } | |
2006 | else | |
2007 | { | |
2008 | if (SCM_EQ_P (SCM_CADR (entry), symbol_mutable_location)) | |
2009 | return SCM_ENVIRONMENT_SET (body->private, sym, val); | |
2010 | else | |
2011 | return SCM_ENVIRONMENT_LOCATION_IMMUTABLE; | |
2012 | } | |
2013 | } | |
2014 | #undef FUNC_NAME | |
2015 | ||
2016 | ||
2017 | static SCM | |
2018 | export_environment_cell (SCM env, SCM sym, int for_write) | |
2019 | #define FUNC_NAME "export_environment_cell" | |
2020 | { | |
2021 | struct export_environment *body = EXPORT_ENVIRONMENT (env); | |
2022 | SCM entry = scm_assq (sym, body->signature); | |
2023 | ||
7888309b | 2024 | if (scm_is_false (entry)) |
5d3e2388 DH |
2025 | { |
2026 | return SCM_UNDEFINED; | |
2027 | } | |
2028 | else | |
2029 | { | |
2030 | if (!for_write || SCM_EQ_P (SCM_CADR (entry), symbol_mutable_location)) | |
2031 | return SCM_ENVIRONMENT_CELL (body->private, sym, for_write); | |
2032 | else | |
2033 | return SCM_ENVIRONMENT_LOCATION_IMMUTABLE; | |
2034 | } | |
2035 | } | |
2036 | #undef FUNC_NAME | |
2037 | ||
2038 | ||
2039 | static SCM | |
e841c3e0 | 2040 | export_environment_mark (SCM env) |
5d3e2388 DH |
2041 | { |
2042 | struct export_environment *body = EXPORT_ENVIRONMENT (env); | |
2043 | ||
2044 | scm_gc_mark (body->private); | |
2045 | scm_gc_mark (body->private_observer); | |
2046 | scm_gc_mark (body->signature); | |
2047 | ||
2048 | return core_environments_mark (env); | |
2049 | } | |
2050 | ||
2051 | ||
4c9419ac | 2052 | static void |
e841c3e0 | 2053 | export_environment_free (SCM env) |
5d3e2388 DH |
2054 | { |
2055 | core_environments_finalize (env); | |
4c9419ac MV |
2056 | scm_gc_free (EXPORT_ENVIRONMENT (env), sizeof (struct export_environment), |
2057 | "export environment"); | |
5d3e2388 DH |
2058 | } |
2059 | ||
2060 | ||
2061 | static int | |
e81d98ec DH |
2062 | export_environment_print (SCM type, SCM port, |
2063 | scm_print_state *pstate SCM_UNUSED) | |
5d3e2388 | 2064 | { |
c014a02e | 2065 | SCM address = scm_ulong2num (SCM_UNPACK (type)); |
5d3e2388 DH |
2066 | SCM base16 = scm_number_to_string (address, SCM_MAKINUM (16)); |
2067 | ||
2068 | scm_puts ("#<export environment ", port); | |
86c991c2 | 2069 | scm_puts (SCM_STRING_CHARS (base16), port); |
5d3e2388 DH |
2070 | scm_puts (">", port); |
2071 | ||
2072 | return 1; | |
2073 | } | |
2074 | ||
2075 | ||
2076 | static struct scm_environment_funcs export_environment_funcs = { | |
2077 | export_environment_ref, | |
2078 | export_environment_fold, | |
2079 | export_environment_define, | |
2080 | export_environment_undefine, | |
2081 | export_environment_set_x, | |
2082 | export_environment_cell, | |
2083 | core_environments_observe, | |
2084 | core_environments_unobserve, | |
e841c3e0 KN |
2085 | export_environment_mark, |
2086 | export_environment_free, | |
2087 | export_environment_print | |
5d3e2388 DH |
2088 | }; |
2089 | ||
2090 | ||
2091 | void *scm_type_export_environment = &export_environment_funcs; | |
2092 | ||
2093 | ||
2094 | static void | |
e81d98ec | 2095 | export_environment_observer (SCM caller SCM_UNUSED, SCM export_env) |
5d3e2388 DH |
2096 | { |
2097 | core_environments_broadcast (export_env); | |
2098 | } | |
2099 | ||
2100 | ||
2101 | SCM_DEFINE (scm_make_export_environment, "make-export-environment", 2, 0, 0, | |
2102 | (SCM private, SCM signature), | |
0fb104ed MG |
2103 | "Return a new environment @var{exp} containing only those\n" |
2104 | "bindings in private whose symbols are present in\n" | |
2105 | "@var{signature}. The @var{private} argument must be an\n" | |
2106 | "environment.\n\n" | |
2107 | "The environment @var{exp} binds symbol to location when\n" | |
2108 | "@var{env} does, and symbol is exported by @var{signature}.\n\n" | |
2109 | "@var{signature} is a list specifying which of the bindings in\n" | |
2110 | "@var{private} should be visible in @var{exp}. Each element of\n" | |
2111 | "@var{signature} should be a list of the form:\n" | |
5d3e2388 DH |
2112 | " (symbol attribute ...)\n" |
2113 | "where each attribute is one of the following:\n" | |
0fb104ed MG |
2114 | "@table @asis\n" |
2115 | "@item the symbol @code{mutable-location}\n" | |
2116 | " @var{exp} should treat the\n" | |
2117 | " location bound to symbol as mutable. That is, @var{exp}\n" | |
2118 | " will pass calls to @code{environment-set!} or\n" | |
2119 | " @code{environment-cell} directly through to private.\n" | |
2120 | "@item the symbol @code{immutable-location}\n" | |
2121 | " @var{exp} should treat\n" | |
2122 | " the location bound to symbol as immutable. If the program\n" | |
2123 | " applies @code{environment-set!} to @var{exp} and symbol, or\n" | |
2124 | " calls @code{environment-cell} to obtain a writable value\n" | |
2125 | " cell, @code{environment-set!} will signal an\n" | |
2126 | " @code{environment:immutable-location} error. Note that, even\n" | |
2127 | " if an export environment treats a location as immutable, the\n" | |
5d3e2388 DH |
2128 | " underlying environment may treat it as mutable, so its\n" |
2129 | " value may change.\n" | |
0fb104ed | 2130 | "@end table\n" |
5d3e2388 | 2131 | "It is an error for an element of signature to specify both\n" |
0fb104ed MG |
2132 | "@code{mutable-location} and @code{immutable-location}. If\n" |
2133 | "neither is specified, @code{immutable-location} is assumed.\n\n" | |
5d3e2388 | 2134 | "As a special case, if an element of signature is a lone\n" |
0fb104ed MG |
2135 | "symbol @var{sym}, it is equivalent to an element of the form\n" |
2136 | "@code{(sym)}.\n\n" | |
2137 | "All bindings in @var{exp} are immutable. If you apply\n" | |
2138 | "@code{environment-define} or @code{environment-undefine} to\n" | |
2139 | "@var{exp}, Guile will signal an\n" | |
2140 | "@code{environment:immutable-binding} error. However,\n" | |
2141 | "notice that the set of bindings in @var{exp} may still change,\n" | |
2142 | "if the bindings in private change.") | |
5d3e2388 DH |
2143 | #define FUNC_NAME s_scm_make_export_environment |
2144 | { | |
1be6b49c | 2145 | size_t size; |
5d3e2388 DH |
2146 | struct export_environment *body; |
2147 | SCM env; | |
2148 | ||
2149 | SCM_ASSERT (SCM_ENVIRONMENT_P (private), private, SCM_ARG1, FUNC_NAME); | |
2150 | ||
2151 | size = sizeof (struct export_environment); | |
4c9419ac | 2152 | body = scm_gc_malloc (size, "export environment"); |
5d3e2388 DH |
2153 | |
2154 | core_environments_preinit (&body->base); | |
2155 | body->private = SCM_BOOL_F; | |
2156 | body->private_observer = SCM_BOOL_F; | |
2157 | body->signature = SCM_BOOL_F; | |
2158 | ||
2159 | env = scm_make_environment (body); | |
2160 | ||
2161 | core_environments_init (&body->base, &export_environment_funcs); | |
2162 | body->private = private; | |
2163 | body->private_observer | |
2164 | = SCM_ENVIRONMENT_OBSERVE (private, export_environment_observer, env, 1); | |
2165 | body->signature = SCM_EOL; | |
2166 | ||
2167 | scm_export_environment_set_signature_x (env, signature); | |
2168 | ||
2169 | return env; | |
2170 | } | |
2171 | #undef FUNC_NAME | |
2172 | ||
2173 | ||
2174 | SCM_DEFINE (scm_export_environment_p, "export-environment?", 1, 0, 0, | |
2175 | (SCM object), | |
0fb104ed MG |
2176 | "Return @code{#t} if object is an export environment, or\n" |
2177 | "@code{#f} otherwise.") | |
5d3e2388 DH |
2178 | #define FUNC_NAME s_scm_export_environment_p |
2179 | { | |
7888309b | 2180 | return scm_from_bool (SCM_EXPORT_ENVIRONMENT_P (object)); |
5d3e2388 DH |
2181 | } |
2182 | #undef FUNC_NAME | |
2183 | ||
2184 | ||
2185 | SCM_DEFINE (scm_export_environment_private, "export-environment-private", 1, 0, 0, | |
2186 | (SCM env), | |
0fb104ed | 2187 | "Return the private environment of export environment @var{env}.") |
5d3e2388 DH |
2188 | #define FUNC_NAME s_scm_export_environment_private |
2189 | { | |
2190 | SCM_ASSERT (SCM_EXPORT_ENVIRONMENT_P (env), env, SCM_ARG1, FUNC_NAME); | |
2191 | ||
2192 | return EXPORT_ENVIRONMENT (env)->private; | |
2193 | } | |
2194 | #undef FUNC_NAME | |
2195 | ||
2196 | ||
2197 | SCM_DEFINE (scm_export_environment_set_private_x, "export-environment-set-private!", 2, 0, 0, | |
2198 | (SCM env, SCM private), | |
0fb104ed | 2199 | "Change the private environment of export environment @var{env}.") |
5d3e2388 DH |
2200 | #define FUNC_NAME s_scm_export_environment_set_private_x |
2201 | { | |
2202 | struct export_environment *body; | |
2203 | ||
2204 | SCM_ASSERT (SCM_EXPORT_ENVIRONMENT_P (env), env, SCM_ARG1, FUNC_NAME); | |
2205 | SCM_ASSERT (SCM_ENVIRONMENT_P (private), private, SCM_ARG2, FUNC_NAME); | |
2206 | ||
2207 | body = EXPORT_ENVIRONMENT (env); | |
2208 | SCM_ENVIRONMENT_UNOBSERVE (private, body->private_observer); | |
2209 | ||
2210 | body->private = private; | |
2211 | body->private_observer | |
2212 | = SCM_ENVIRONMENT_OBSERVE (private, export_environment_observer, env, 1); | |
2213 | ||
2214 | return SCM_UNSPECIFIED; | |
2215 | } | |
2216 | #undef FUNC_NAME | |
2217 | ||
2218 | ||
2219 | SCM_DEFINE (scm_export_environment_signature, "export-environment-signature", 1, 0, 0, | |
2220 | (SCM env), | |
0fb104ed | 2221 | "Return the signature of export environment @var{env}.") |
5d3e2388 DH |
2222 | #define FUNC_NAME s_scm_export_environment_signature |
2223 | { | |
2224 | SCM_ASSERT (SCM_EXPORT_ENVIRONMENT_P (env), env, SCM_ARG1, FUNC_NAME); | |
2225 | ||
2226 | return EXPORT_ENVIRONMENT (env)->signature; | |
2227 | } | |
2228 | #undef FUNC_NAME | |
2229 | ||
2230 | ||
2231 | static SCM | |
2232 | export_environment_parse_signature (SCM signature, const char* caller) | |
2233 | { | |
2234 | SCM result = SCM_EOL; | |
2235 | SCM l; | |
2236 | ||
2237 | for (l = signature; SCM_CONSP (l); l = SCM_CDR (l)) | |
2238 | { | |
2239 | SCM entry = SCM_CAR (l); | |
2240 | ||
2241 | if (SCM_SYMBOLP (entry)) | |
2242 | { | |
2243 | SCM new_entry = scm_cons2 (entry, symbol_immutable_location, SCM_EOL); | |
2244 | result = scm_cons (new_entry, result); | |
2245 | } | |
2246 | else | |
2247 | { | |
2248 | SCM sym; | |
2249 | SCM new_entry; | |
2250 | int immutable = 0; | |
2251 | int mutable = 0; | |
2252 | SCM mutability; | |
2253 | SCM l2; | |
2254 | ||
2255 | SCM_ASSERT (SCM_CONSP (entry), entry, SCM_ARGn, caller); | |
2256 | SCM_ASSERT (SCM_SYMBOLP (SCM_CAR (entry)), entry, SCM_ARGn, caller); | |
2257 | ||
2258 | sym = SCM_CAR (entry); | |
2259 | ||
2260 | for (l2 = SCM_CDR (entry); SCM_CONSP (l2); l2 = SCM_CDR (l2)) | |
2261 | { | |
2262 | SCM attribute = SCM_CAR (l2); | |
2263 | if (SCM_EQ_P (attribute, symbol_immutable_location)) | |
2264 | immutable = 1; | |
2265 | else if (SCM_EQ_P (attribute, symbol_mutable_location)) | |
2266 | mutable = 1; | |
2267 | else | |
2268 | SCM_ASSERT (0, entry, SCM_ARGn, caller); | |
2269 | } | |
2270 | SCM_ASSERT (SCM_NULLP (l2), entry, SCM_ARGn, caller); | |
2271 | SCM_ASSERT (!mutable || !immutable, entry, SCM_ARGn, caller); | |
2272 | ||
2273 | if (!mutable && !immutable) | |
2274 | immutable = 1; | |
2275 | ||
2276 | mutability = mutable ? symbol_mutable_location : symbol_immutable_location; | |
2277 | new_entry = scm_cons2 (sym, mutability, SCM_EOL); | |
2278 | result = scm_cons (new_entry, result); | |
2279 | } | |
2280 | } | |
2281 | SCM_ASSERT (SCM_NULLP (l), signature, SCM_ARGn, caller); | |
2282 | ||
2283 | /* Dirk:FIXME:: Now we know that signature is syntactically correct. There | |
2284 | * are, however, no checks for symbols entered twice with contradicting | |
2285 | * mutabilities. It would be nice, to implement this test, to be able to | |
2286 | * call the sort functions conveniently from C. | |
2287 | */ | |
2288 | ||
2289 | return scm_reverse (result); | |
2290 | } | |
2291 | ||
2292 | ||
2293 | SCM_DEFINE (scm_export_environment_set_signature_x, "export-environment-set-signature!", 2, 0, 0, | |
2294 | (SCM env, SCM signature), | |
0fb104ed | 2295 | "Change the signature of export environment @var{env}.") |
5d3e2388 DH |
2296 | #define FUNC_NAME s_scm_export_environment_set_signature_x |
2297 | { | |
2298 | SCM parsed_sig; | |
2299 | ||
2300 | SCM_ASSERT (SCM_EXPORT_ENVIRONMENT_P (env), env, SCM_ARG1, FUNC_NAME); | |
2301 | parsed_sig = export_environment_parse_signature (signature, FUNC_NAME); | |
2302 | ||
2303 | EXPORT_ENVIRONMENT (env)->signature = parsed_sig; | |
2304 | ||
2305 | return SCM_UNSPECIFIED; | |
2306 | } | |
2307 | #undef FUNC_NAME | |
2308 | ||
2309 | \f | |
2310 | ||
2311 | void | |
2312 | scm_environments_prehistory () | |
2313 | { | |
2314 | /* create environment smob */ | |
2315 | scm_tc16_environment = scm_make_smob_type ("environment", 0); | |
e841c3e0 KN |
2316 | scm_set_smob_mark (scm_tc16_environment, environment_mark); |
2317 | scm_set_smob_free (scm_tc16_environment, environment_free); | |
2318 | scm_set_smob_print (scm_tc16_environment, environment_print); | |
5d3e2388 DH |
2319 | |
2320 | /* create observer smob */ | |
2321 | scm_tc16_observer = scm_make_smob_type ("observer", 0); | |
e841c3e0 KN |
2322 | scm_set_smob_mark (scm_tc16_observer, observer_mark); |
2323 | scm_set_smob_print (scm_tc16_observer, observer_print); | |
de42a0ee DH |
2324 | |
2325 | /* create system environment */ | |
2326 | scm_system_environment = scm_make_leaf_environment (); | |
2327 | scm_permanent_object (scm_system_environment); | |
5d3e2388 DH |
2328 | } |
2329 | ||
2330 | ||
2331 | void | |
2332 | scm_init_environments () | |
2333 | { | |
480a873c | 2334 | #include "libguile/environments.x" |
5d3e2388 DH |
2335 | } |
2336 | ||
2337 | ||
2338 | /* | |
2339 | Local Variables: | |
2340 | c-file-style: "gnu" | |
2341 | End: | |
2342 | */ |