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dbb605f5 | 1 | /* Copyright (C) 1999,2000,2001, 2003, 2006, 2008 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 | |
92205699 | 15 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
73be1d9e | 16 | */ |
5d3e2388 DH |
17 | |
18 | \f | |
dbb605f5 LC |
19 | #ifdef HAVE_CONFIG_H |
20 | # include <config.h> | |
21 | #endif | |
5d3e2388 DH |
22 | |
23 | #include "libguile/_scm.h" | |
24 | #include "libguile/alist.h" | |
25 | #include "libguile/eval.h" | |
26 | #include "libguile/gh.h" | |
27 | #include "libguile/hash.h" | |
35060ae9 | 28 | #include "libguile/list.h" |
5d3e2388 DH |
29 | #include "libguile/ports.h" |
30 | #include "libguile/smob.h" | |
31 | #include "libguile/symbols.h" | |
32 | #include "libguile/vectors.h" | |
33 | #include "libguile/weaks.h" | |
34 | ||
35 | #include "libguile/environments.h" | |
36 | ||
37 | \f | |
38 | ||
92c2555f MV |
39 | scm_t_bits scm_tc16_environment; |
40 | scm_t_bits scm_tc16_observer; | |
231a4ea8 | 41 | #define DEFAULT_OBARRAY_SIZE 31 |
5d3e2388 | 42 | |
de42a0ee DH |
43 | SCM scm_system_environment; |
44 | ||
5d3e2388 DH |
45 | \f |
46 | ||
47 | /* error conditions */ | |
48 | ||
49 | /* | |
50 | * Throw an error if symbol is not bound in environment func | |
51 | */ | |
52 | void | |
53 | scm_error_environment_unbound (const char *func, SCM env, SCM symbol) | |
54 | { | |
55 | /* Dirk:FIXME:: Should throw an environment:unbound type error */ | |
56 | char error[] = "Symbol `~A' not bound in environment `~A'."; | |
57 | SCM arguments = scm_cons2 (symbol, env, SCM_EOL); | |
58 | scm_misc_error (func, error, arguments); | |
59 | } | |
60 | ||
61 | ||
62 | /* | |
63 | * Throw an error if func tried to create (define) or remove | |
64 | * (undefine) a new binding for symbol in env | |
65 | */ | |
66 | void | |
67 | scm_error_environment_immutable_binding (const char *func, SCM env, SCM symbol) | |
68 | { | |
69 | /* Dirk:FIXME:: Should throw an environment:immutable-binding type error */ | |
70 | char error[] = "Immutable binding in environment ~A (symbol: `~A')."; | |
71 | SCM arguments = scm_cons2 (env, symbol, SCM_EOL); | |
72 | scm_misc_error (func, error, arguments); | |
73 | } | |
74 | ||
75 | ||
76 | /* | |
77 | * Throw an error if func tried to change an immutable location. | |
78 | */ | |
79 | void | |
80 | scm_error_environment_immutable_location (const char *func, SCM env, SCM symbol) | |
81 | { | |
82 | /* Dirk:FIXME:: Should throw an environment:immutable-location type error */ | |
83 | char error[] = "Immutable location in environment `~A' (symbol: `~A')."; | |
84 | SCM arguments = scm_cons2 (env, symbol, SCM_EOL); | |
85 | scm_misc_error (func, error, arguments); | |
86 | } | |
87 | ||
88 | \f | |
89 | ||
90 | /* generic environments */ | |
91 | ||
92 | ||
93 | /* Create an environment for the given type. Dereferencing type twice must | |
94 | * deliver the initialized set of environment functions. Thus, type will | |
95 | * also determine the signature of the underlying environment implementation. | |
96 | * Dereferencing type once will typically deliver the data fields used by the | |
97 | * underlying environment implementation. | |
98 | */ | |
99 | SCM | |
100 | scm_make_environment (void *type) | |
101 | { | |
228a24ef | 102 | return scm_cell (scm_tc16_environment, (scm_t_bits) type); |
5d3e2388 DH |
103 | } |
104 | ||
105 | ||
106 | SCM_DEFINE (scm_environment_p, "environment?", 1, 0, 0, | |
107 | (SCM obj), | |
0fb104ed MG |
108 | "Return @code{#t} if @var{obj} is an environment, or @code{#f}\n" |
109 | "otherwise.") | |
5d3e2388 DH |
110 | #define FUNC_NAME s_scm_environment_p |
111 | { | |
7888309b | 112 | return scm_from_bool (SCM_ENVIRONMENT_P (obj)); |
5d3e2388 DH |
113 | } |
114 | #undef FUNC_NAME | |
115 | ||
116 | ||
117 | SCM_DEFINE (scm_environment_bound_p, "environment-bound?", 2, 0, 0, | |
118 | (SCM env, SCM sym), | |
0fb104ed MG |
119 | "Return @code{#t} if @var{sym} is bound in @var{env}, or\n" |
120 | "@code{#f} otherwise.") | |
5d3e2388 DH |
121 | #define FUNC_NAME s_scm_environment_bound_p |
122 | { | |
123 | SCM_ASSERT (SCM_ENVIRONMENT_P (env), env, SCM_ARG1, FUNC_NAME); | |
cc95e00a | 124 | SCM_ASSERT (scm_is_symbol (sym), sym, SCM_ARG2, FUNC_NAME); |
5d3e2388 | 125 | |
7888309b | 126 | return scm_from_bool (SCM_ENVIRONMENT_BOUND_P (env, sym)); |
5d3e2388 DH |
127 | } |
128 | #undef FUNC_NAME | |
129 | ||
130 | ||
131 | SCM_DEFINE (scm_environment_ref, "environment-ref", 2, 0, 0, | |
132 | (SCM env, SCM sym), | |
0fb104ed MG |
133 | "Return the value of the location bound to @var{sym} in\n" |
134 | "@var{env}. If @var{sym} is unbound in @var{env}, signal an\n" | |
135 | "@code{environment:unbound} error.") | |
5d3e2388 DH |
136 | #define FUNC_NAME s_scm_environment_ref |
137 | { | |
138 | SCM val; | |
139 | ||
140 | SCM_ASSERT (SCM_ENVIRONMENT_P (env), env, SCM_ARG1, FUNC_NAME); | |
cc95e00a | 141 | SCM_ASSERT (scm_is_symbol (sym), sym, SCM_ARG2, FUNC_NAME); |
5d3e2388 DH |
142 | |
143 | val = SCM_ENVIRONMENT_REF (env, sym); | |
144 | ||
145 | if (!SCM_UNBNDP (val)) | |
146 | return val; | |
147 | else | |
148 | scm_error_environment_unbound (FUNC_NAME, env, sym); | |
149 | } | |
150 | #undef FUNC_NAME | |
151 | ||
152 | ||
153 | /* This C function is identical to environment-ref, except that if symbol is | |
154 | * unbound in env, it returns the value SCM_UNDEFINED, instead of signalling | |
155 | * an error. | |
156 | */ | |
157 | SCM | |
158 | scm_c_environment_ref (SCM env, SCM sym) | |
159 | { | |
160 | SCM_ASSERT (SCM_ENVIRONMENT_P (env), env, SCM_ARG1, "scm_c_environment_ref"); | |
cc95e00a | 161 | SCM_ASSERT (scm_is_symbol (sym), sym, SCM_ARG2, "scm_c_environment_ref"); |
5d3e2388 DH |
162 | return SCM_ENVIRONMENT_REF (env, sym); |
163 | } | |
164 | ||
165 | ||
166 | static SCM | |
167 | environment_default_folder (SCM proc, SCM symbol, SCM value, SCM tail) | |
168 | { | |
9b26d381 | 169 | return scm_call_3 (proc, symbol, value, tail); |
5d3e2388 DH |
170 | } |
171 | ||
172 | ||
173 | SCM_DEFINE (scm_environment_fold, "environment-fold", 3, 0, 0, | |
174 | (SCM env, SCM proc, SCM init), | |
0fb104ed MG |
175 | "Iterate over all the bindings in @var{env}, accumulating some\n" |
176 | "value.\n" | |
177 | "For each binding in @var{env}, apply @var{proc} to the symbol\n" | |
178 | "bound, its value, and the result from the previous application\n" | |
179 | "of @var{proc}.\n" | |
180 | "Use @var{init} as @var{proc}'s third argument the first time\n" | |
181 | "@var{proc} is applied.\n" | |
182 | "If @var{env} contains no bindings, this function simply returns\n" | |
183 | "@var{init}.\n" | |
184 | "If @var{env} binds the symbol sym1 to the value val1, sym2 to\n" | |
185 | "val2, and so on, then this procedure computes:\n" | |
1e6808ea | 186 | "@lisp\n" |
5d3e2388 DH |
187 | " (proc sym1 val1\n" |
188 | " (proc sym2 val2\n" | |
189 | " ...\n" | |
190 | " (proc symn valn\n" | |
191 | " init)))\n" | |
1e6808ea | 192 | "@end lisp\n" |
0fb104ed MG |
193 | "Each binding in @var{env} will be processed exactly once.\n" |
194 | "@code{environment-fold} makes no guarantees about the order in\n" | |
195 | "which the bindings are processed.\n" | |
5d3e2388 DH |
196 | "Here is a function which, given an environment, constructs an\n" |
197 | "association list representing that environment's bindings,\n" | |
198 | "using environment-fold:\n" | |
1e6808ea | 199 | "@lisp\n" |
5d3e2388 DH |
200 | " (define (environment->alist env)\n" |
201 | " (environment-fold env\n" | |
202 | " (lambda (sym val tail)\n" | |
203 | " (cons (cons sym val) tail))\n" | |
0fb104ed | 204 | " '()))\n" |
1e6808ea | 205 | "@end lisp") |
5d3e2388 DH |
206 | #define FUNC_NAME s_scm_environment_fold |
207 | { | |
208 | SCM_ASSERT (SCM_ENVIRONMENT_P (env), env, SCM_ARG1, FUNC_NAME); | |
bc36d050 | 209 | SCM_ASSERT (scm_is_true (scm_procedure_p (proc)), |
5d3e2388 DH |
210 | proc, SCM_ARG2, FUNC_NAME); |
211 | ||
212 | return SCM_ENVIRONMENT_FOLD (env, environment_default_folder, proc, init); | |
213 | } | |
214 | #undef FUNC_NAME | |
215 | ||
216 | ||
217 | /* This is the C-level analog of environment-fold. For each binding in ENV, | |
218 | * make the call: | |
219 | * (*proc) (data, symbol, value, previous) | |
220 | * where previous is the value returned from the last call to *PROC, or INIT | |
221 | * for the first call. If ENV contains no bindings, return INIT. | |
222 | */ | |
223 | SCM | |
224 | scm_c_environment_fold (SCM env, scm_environment_folder proc, SCM data, SCM init) | |
225 | { | |
226 | SCM_ASSERT (SCM_ENVIRONMENT_P (env), env, SCM_ARG1, "scm_c_environment_fold"); | |
227 | ||
228 | return SCM_ENVIRONMENT_FOLD (env, proc, data, init); | |
229 | } | |
230 | ||
231 | ||
232 | SCM_DEFINE (scm_environment_define, "environment-define", 3, 0, 0, | |
233 | (SCM env, SCM sym, SCM val), | |
0fb104ed MG |
234 | "Bind @var{sym} to a new location containing @var{val} in\n" |
235 | "@var{env}. If @var{sym} is already bound to another location\n" | |
236 | "in @var{env} and the binding is mutable, that binding is\n" | |
237 | "replaced. The new binding and location are both mutable. The\n" | |
238 | "return value is unspecified.\n" | |
239 | "If @var{sym} is already bound in @var{env}, and the binding is\n" | |
240 | "immutable, signal an @code{environment:immutable-binding} error.") | |
5d3e2388 DH |
241 | #define FUNC_NAME s_scm_environment_define |
242 | { | |
243 | SCM status; | |
244 | ||
245 | SCM_ASSERT (SCM_ENVIRONMENT_P (env), env, SCM_ARG1, FUNC_NAME); | |
cc95e00a | 246 | SCM_ASSERT (scm_is_symbol (sym), sym, SCM_ARG2, FUNC_NAME); |
5d3e2388 DH |
247 | |
248 | status = SCM_ENVIRONMENT_DEFINE (env, sym, val); | |
249 | ||
bc36d050 | 250 | if (scm_is_eq (status, SCM_ENVIRONMENT_SUCCESS)) |
5d3e2388 | 251 | return SCM_UNSPECIFIED; |
bc36d050 | 252 | else if (scm_is_eq (status, SCM_ENVIRONMENT_BINDING_IMMUTABLE)) |
5d3e2388 DH |
253 | scm_error_environment_immutable_binding (FUNC_NAME, env, sym); |
254 | else | |
255 | abort(); | |
256 | } | |
257 | #undef FUNC_NAME | |
258 | ||
259 | ||
260 | SCM_DEFINE (scm_environment_undefine, "environment-undefine", 2, 0, 0, | |
261 | (SCM env, SCM sym), | |
0fb104ed MG |
262 | "Remove any binding for @var{sym} from @var{env}. If @var{sym}\n" |
263 | "is unbound in @var{env}, do nothing. The return value is\n" | |
264 | "unspecified.\n" | |
265 | "If @var{sym} is already bound in @var{env}, and the binding is\n" | |
266 | "immutable, signal an @code{environment:immutable-binding} error.") | |
5d3e2388 DH |
267 | #define FUNC_NAME s_scm_environment_undefine |
268 | { | |
269 | SCM status; | |
270 | ||
271 | SCM_ASSERT(SCM_ENVIRONMENT_P(env), env, SCM_ARG1, FUNC_NAME); | |
cc95e00a | 272 | SCM_ASSERT(scm_is_symbol(sym), sym, SCM_ARG2, FUNC_NAME); |
5d3e2388 DH |
273 | |
274 | status = SCM_ENVIRONMENT_UNDEFINE (env, sym); | |
275 | ||
bc36d050 | 276 | if (scm_is_eq (status, SCM_ENVIRONMENT_SUCCESS)) |
5d3e2388 | 277 | return SCM_UNSPECIFIED; |
bc36d050 | 278 | else if (scm_is_eq (status, SCM_ENVIRONMENT_BINDING_IMMUTABLE)) |
5d3e2388 DH |
279 | scm_error_environment_immutable_binding (FUNC_NAME, env, sym); |
280 | else | |
281 | abort(); | |
282 | } | |
283 | #undef FUNC_NAME | |
284 | ||
285 | ||
286 | SCM_DEFINE (scm_environment_set_x, "environment-set!", 3, 0, 0, | |
287 | (SCM env, SCM sym, SCM val), | |
0fb104ed MG |
288 | "If @var{env} binds @var{sym} to some location, change that\n" |
289 | "location's value to @var{val}. The return value is\n" | |
290 | "unspecified.\n" | |
291 | "If @var{sym} is not bound in @var{env}, signal an\n" | |
292 | "@code{environment:unbound} error. If @var{env} binds @var{sym}\n" | |
293 | "to an immutable location, signal an\n" | |
294 | "@code{environment:immutable-location} error.") | |
5d3e2388 DH |
295 | #define FUNC_NAME s_scm_environment_set_x |
296 | { | |
297 | SCM status; | |
298 | ||
299 | SCM_ASSERT (SCM_ENVIRONMENT_P (env), env, SCM_ARG1, FUNC_NAME); | |
cc95e00a | 300 | SCM_ASSERT (scm_is_symbol (sym), sym, SCM_ARG2, FUNC_NAME); |
5d3e2388 DH |
301 | |
302 | status = SCM_ENVIRONMENT_SET (env, sym, val); | |
303 | ||
bc36d050 | 304 | if (scm_is_eq (status, SCM_ENVIRONMENT_SUCCESS)) |
5d3e2388 DH |
305 | return SCM_UNSPECIFIED; |
306 | else if (SCM_UNBNDP (status)) | |
307 | scm_error_environment_unbound (FUNC_NAME, env, sym); | |
bc36d050 | 308 | else if (scm_is_eq (status, SCM_ENVIRONMENT_LOCATION_IMMUTABLE)) |
5d3e2388 DH |
309 | scm_error_environment_immutable_binding (FUNC_NAME, env, sym); |
310 | else | |
311 | abort(); | |
312 | } | |
313 | #undef FUNC_NAME | |
314 | ||
315 | ||
316 | SCM_DEFINE (scm_environment_cell, "environment-cell", 3, 0, 0, | |
317 | (SCM env, SCM sym, SCM for_write), | |
0fb104ed MG |
318 | "Return the value cell which @var{env} binds to @var{sym}, or\n" |
319 | "@code{#f} if the binding does not live in a value cell.\n" | |
320 | "The argument @var{for-write} indicates whether the caller\n" | |
321 | "intends to modify the variable's value by mutating the value\n" | |
322 | "cell. If the variable is immutable, then\n" | |
323 | "@code{environment-cell} signals an\n" | |
324 | "@code{environment:immutable-location} error.\n" | |
325 | "If @var{sym} is unbound in @var{env}, signal an\n" | |
326 | "@code{environment:unbound} error.\n" | |
5d3e2388 | 327 | "If you use this function, you should consider using\n" |
0fb104ed MG |
328 | "@code{environment-observe}, to be notified when @var{sym} gets\n" |
329 | "re-bound to a new value cell, or becomes undefined.") | |
5d3e2388 DH |
330 | #define FUNC_NAME s_scm_environment_cell |
331 | { | |
332 | SCM location; | |
333 | ||
334 | SCM_ASSERT (SCM_ENVIRONMENT_P (env), env, SCM_ARG1, FUNC_NAME); | |
cc95e00a | 335 | SCM_ASSERT (scm_is_symbol (sym), sym, SCM_ARG2, FUNC_NAME); |
7888309b | 336 | SCM_ASSERT (scm_is_bool (for_write), for_write, SCM_ARG3, FUNC_NAME); |
5d3e2388 | 337 | |
7888309b | 338 | location = SCM_ENVIRONMENT_CELL (env, sym, scm_is_true (for_write)); |
5d3e2388 DH |
339 | if (!SCM_IMP (location)) |
340 | return location; | |
341 | else if (SCM_UNBNDP (location)) | |
342 | scm_error_environment_unbound (FUNC_NAME, env, sym); | |
bc36d050 | 343 | else if (scm_is_eq (location, SCM_ENVIRONMENT_LOCATION_IMMUTABLE)) |
5d3e2388 DH |
344 | scm_error_environment_immutable_location (FUNC_NAME, env, sym); |
345 | else /* no cell */ | |
346 | return location; | |
347 | } | |
348 | #undef FUNC_NAME | |
349 | ||
350 | ||
351 | /* This C function is identical to environment-cell, with the following | |
352 | * exceptions: If symbol is unbound in env, it returns the value | |
353 | * SCM_UNDEFINED, instead of signalling an error. If symbol is bound to an | |
354 | * immutable location but the cell is requested for write, the value | |
355 | * SCM_ENVIRONMENT_LOCATION_IMMUTABLE is returned. | |
356 | */ | |
357 | SCM | |
358 | scm_c_environment_cell(SCM env, SCM sym, int for_write) | |
359 | { | |
360 | SCM_ASSERT (SCM_ENVIRONMENT_P (env), env, SCM_ARG1, "scm_c_environment_cell"); | |
cc95e00a | 361 | SCM_ASSERT (scm_is_symbol (sym), sym, SCM_ARG2, "scm_c_environment_cell"); |
5d3e2388 DH |
362 | |
363 | return SCM_ENVIRONMENT_CELL (env, sym, for_write); | |
364 | } | |
365 | ||
366 | ||
367 | static void | |
368 | environment_default_observer (SCM env, SCM proc) | |
369 | { | |
9b26d381 | 370 | scm_call_1 (proc, env); |
5d3e2388 DH |
371 | } |
372 | ||
373 | ||
374 | SCM_DEFINE (scm_environment_observe, "environment-observe", 2, 0, 0, | |
375 | (SCM env, SCM proc), | |
0fb104ed MG |
376 | "Whenever @var{env}'s bindings change, apply @var{proc} to\n" |
377 | "@var{env}.\n" | |
5d3e2388 | 378 | "This function returns an object, token, which you can pass to\n" |
0fb104ed MG |
379 | "@code{environment-unobserve} to remove @var{proc} from the set\n" |
380 | "of procedures observing @var{env}. The type and value of\n" | |
381 | "token is unspecified.") | |
5d3e2388 DH |
382 | #define FUNC_NAME s_scm_environment_observe |
383 | { | |
384 | SCM_ASSERT (SCM_ENVIRONMENT_P (env), env, SCM_ARG1, FUNC_NAME); | |
385 | ||
386 | return SCM_ENVIRONMENT_OBSERVE (env, environment_default_observer, proc, 0); | |
387 | } | |
388 | #undef FUNC_NAME | |
389 | ||
390 | ||
391 | SCM_DEFINE (scm_environment_observe_weak, "environment-observe-weak", 2, 0, 0, | |
392 | (SCM env, SCM proc), | |
393 | "This function is the same as environment-observe, except that\n" | |
0fb104ed MG |
394 | "the reference @var{env} retains to @var{proc} is a weak\n" |
395 | "reference. This means that, if there are no other live,\n" | |
396 | "non-weak references to @var{proc}, it will be\n" | |
397 | "garbage-collected, and dropped from @var{env}'s\n" | |
5d3e2388 DH |
398 | "list of observing procedures.") |
399 | #define FUNC_NAME s_scm_environment_observe_weak | |
400 | { | |
401 | SCM_ASSERT (SCM_ENVIRONMENT_P (env), env, SCM_ARG1, FUNC_NAME); | |
402 | ||
403 | return SCM_ENVIRONMENT_OBSERVE (env, environment_default_observer, proc, 1); | |
404 | } | |
405 | #undef FUNC_NAME | |
406 | ||
407 | ||
408 | /* This is the C-level analog of the Scheme functions environment-observe and | |
409 | * environment-observe-weak. Whenever env's bindings change, call the | |
410 | * function proc, passing it env and data. If weak_p is non-zero, env will | |
411 | * retain only a weak reference to data, and if data is garbage collected, the | |
412 | * entire observation will be dropped. This function returns a token, with | |
413 | * the same meaning as those returned by environment-observe and | |
414 | * environment-observe-weak. | |
415 | */ | |
416 | SCM | |
417 | scm_c_environment_observe (SCM env, scm_environment_observer proc, SCM data, int weak_p) | |
418 | #define FUNC_NAME "scm_c_environment_observe" | |
419 | { | |
420 | SCM_ASSERT (SCM_ENVIRONMENT_P (env), env, SCM_ARG1, FUNC_NAME); | |
421 | ||
422 | return SCM_ENVIRONMENT_OBSERVE (env, proc, data, weak_p); | |
423 | } | |
424 | #undef FUNC_NAME | |
425 | ||
426 | ||
427 | SCM_DEFINE (scm_environment_unobserve, "environment-unobserve", 1, 0, 0, | |
428 | (SCM token), | |
429 | "Cancel the observation request which returned the value\n" | |
0fb104ed MG |
430 | "@var{token}. The return value is unspecified.\n" |
431 | "If a call @code{(environment-observe env proc)} returns\n" | |
432 | "@var{token}, then the call @code{(environment-unobserve token)}\n" | |
433 | "will cause @var{proc} to no longer be called when @var{env}'s\n" | |
434 | "bindings change.") | |
5d3e2388 DH |
435 | #define FUNC_NAME s_scm_environment_unobserve |
436 | { | |
437 | SCM env; | |
438 | ||
439 | SCM_ASSERT (SCM_OBSERVER_P (token), token, SCM_ARG1, FUNC_NAME); | |
440 | ||
441 | env = SCM_OBSERVER_ENVIRONMENT (token); | |
442 | SCM_ENVIRONMENT_UNOBSERVE (env, token); | |
443 | ||
444 | return SCM_UNSPECIFIED; | |
445 | } | |
446 | #undef FUNC_NAME | |
447 | ||
448 | ||
449 | static SCM | |
e841c3e0 | 450 | environment_mark (SCM env) |
5d3e2388 DH |
451 | { |
452 | return (*(SCM_ENVIRONMENT_FUNCS (env)->mark)) (env); | |
453 | } | |
454 | ||
455 | ||
1be6b49c | 456 | static size_t |
e841c3e0 | 457 | environment_free (SCM env) |
5d3e2388 | 458 | { |
4c9419ac MV |
459 | (*(SCM_ENVIRONMENT_FUNCS (env)->free)) (env); |
460 | return 0; | |
5d3e2388 DH |
461 | } |
462 | ||
463 | ||
464 | static int | |
e841c3e0 | 465 | environment_print (SCM env, SCM port, scm_print_state *pstate) |
5d3e2388 DH |
466 | { |
467 | return (*(SCM_ENVIRONMENT_FUNCS (env)->print)) (env, port, pstate); | |
468 | } | |
469 | ||
470 | \f | |
471 | ||
472 | /* observers */ | |
473 | ||
474 | static SCM | |
e841c3e0 | 475 | observer_mark (SCM observer) |
5d3e2388 DH |
476 | { |
477 | scm_gc_mark (SCM_OBSERVER_ENVIRONMENT (observer)); | |
478 | scm_gc_mark (SCM_OBSERVER_DATA (observer)); | |
479 | return SCM_BOOL_F; | |
480 | } | |
481 | ||
482 | ||
5d3e2388 | 483 | static int |
e81d98ec | 484 | observer_print (SCM type, SCM port, scm_print_state *pstate SCM_UNUSED) |
5d3e2388 | 485 | { |
b9bd8526 | 486 | SCM address = scm_from_size_t (SCM_UNPACK (type)); |
e11e83f3 | 487 | SCM base16 = scm_number_to_string (address, scm_from_int (16)); |
5d3e2388 DH |
488 | |
489 | scm_puts ("#<observer ", port); | |
18f9d343 | 490 | scm_display (base16, port); |
5d3e2388 DH |
491 | scm_puts (">", port); |
492 | ||
493 | return 1; | |
494 | } | |
495 | ||
496 | \f | |
497 | ||
498 | /* obarrays | |
499 | * | |
500 | * Obarrays form the basic lookup tables used to implement most of guile's | |
501 | * built-in environment types. An obarray is implemented as a hash table with | |
502 | * symbols as keys. The content of the data depends on the environment type. | |
503 | */ | |
504 | ||
505 | ||
506 | /* | |
a2d47b23 DH |
507 | * Enter symbol into obarray. The symbol must not already exist in obarray. |
508 | * The freshly generated (symbol . data) cell is returned. | |
5d3e2388 DH |
509 | */ |
510 | static SCM | |
511 | obarray_enter (SCM obarray, SCM symbol, SCM data) | |
512 | { | |
cc95e00a | 513 | size_t hash = scm_i_symbol_hash (symbol) % SCM_HASHTABLE_N_BUCKETS (obarray); |
5d3e2388 | 514 | SCM entry = scm_cons (symbol, data); |
4057a3e0 | 515 | SCM slot = scm_cons (entry, SCM_HASHTABLE_BUCKET (obarray, hash)); |
c35738c1 | 516 | SCM_SET_HASHTABLE_BUCKET (obarray, hash, slot); |
6fccb880 | 517 | SCM_HASHTABLE_INCREMENT (obarray); |
c35738c1 MD |
518 | if (SCM_HASHTABLE_N_ITEMS (obarray) > SCM_HASHTABLE_UPPER (obarray)) |
519 | scm_i_rehash (obarray, scm_i_hash_symbol, 0, "obarray_enter"); | |
5d3e2388 DH |
520 | |
521 | return entry; | |
522 | } | |
523 | ||
524 | ||
a2d47b23 DH |
525 | /* |
526 | * Enter symbol into obarray. An existing entry for symbol is replaced. If | |
527 | * an entry existed, the old (symbol . data) cell is returned, #f otherwise. | |
528 | */ | |
529 | static SCM | |
530 | obarray_replace (SCM obarray, SCM symbol, SCM data) | |
531 | { | |
cc95e00a | 532 | size_t hash = scm_i_symbol_hash (symbol) % SCM_HASHTABLE_N_BUCKETS (obarray); |
a2d47b23 DH |
533 | SCM new_entry = scm_cons (symbol, data); |
534 | SCM lsym; | |
535 | SCM slot; | |
536 | ||
4057a3e0 | 537 | for (lsym = SCM_HASHTABLE_BUCKET (obarray, hash); |
d2e53ed6 | 538 | !scm_is_null (lsym); |
c35738c1 | 539 | lsym = SCM_CDR (lsym)) |
a2d47b23 DH |
540 | { |
541 | SCM old_entry = SCM_CAR (lsym); | |
bc36d050 | 542 | if (scm_is_eq (SCM_CAR (old_entry), symbol)) |
a2d47b23 DH |
543 | { |
544 | SCM_SETCAR (lsym, new_entry); | |
545 | return old_entry; | |
546 | } | |
547 | } | |
548 | ||
4057a3e0 | 549 | slot = scm_cons (new_entry, SCM_HASHTABLE_BUCKET (obarray, hash)); |
c35738c1 | 550 | SCM_SET_HASHTABLE_BUCKET (obarray, hash, slot); |
6fccb880 | 551 | SCM_HASHTABLE_INCREMENT (obarray); |
c35738c1 MD |
552 | if (SCM_HASHTABLE_N_ITEMS (obarray) > SCM_HASHTABLE_UPPER (obarray)) |
553 | scm_i_rehash (obarray, scm_i_hash_symbol, 0, "obarray_replace"); | |
a2d47b23 DH |
554 | |
555 | return SCM_BOOL_F; | |
556 | } | |
557 | ||
558 | ||
5d3e2388 DH |
559 | /* |
560 | * Look up symbol in obarray | |
561 | */ | |
562 | static SCM | |
563 | obarray_retrieve (SCM obarray, SCM sym) | |
564 | { | |
cc95e00a | 565 | size_t hash = scm_i_symbol_hash (sym) % SCM_HASHTABLE_N_BUCKETS (obarray); |
5d3e2388 DH |
566 | SCM lsym; |
567 | ||
4057a3e0 | 568 | for (lsym = SCM_HASHTABLE_BUCKET (obarray, hash); |
d2e53ed6 | 569 | !scm_is_null (lsym); |
c35738c1 | 570 | lsym = SCM_CDR (lsym)) |
5d3e2388 DH |
571 | { |
572 | SCM entry = SCM_CAR (lsym); | |
bc36d050 | 573 | if (scm_is_eq (SCM_CAR (entry), sym)) |
5d3e2388 DH |
574 | return entry; |
575 | } | |
576 | ||
577 | return SCM_UNDEFINED; | |
578 | } | |
579 | ||
580 | ||
581 | /* | |
a2d47b23 DH |
582 | * Remove entry from obarray. If the symbol was found and removed, the old |
583 | * (symbol . data) cell is returned, #f otherwise. | |
5d3e2388 DH |
584 | */ |
585 | static SCM | |
586 | obarray_remove (SCM obarray, SCM sym) | |
587 | { | |
cc95e00a | 588 | size_t hash = scm_i_symbol_hash (sym) % SCM_HASHTABLE_N_BUCKETS (obarray); |
4057a3e0 | 589 | SCM table_entry = SCM_HASHTABLE_BUCKET (obarray, hash); |
35060ae9 | 590 | SCM handle = scm_sloppy_assq (sym, table_entry); |
34d19ef6 | 591 | |
d2e53ed6 | 592 | if (scm_is_pair (handle)) |
34d19ef6 | 593 | { |
35060ae9 | 594 | SCM new_table_entry = scm_delq1_x (handle, table_entry); |
c35738c1 MD |
595 | SCM_SET_HASHTABLE_BUCKET (obarray, hash, new_table_entry); |
596 | SCM_HASHTABLE_DECREMENT (obarray); | |
5d3e2388 | 597 | } |
35060ae9 DH |
598 | |
599 | return handle; | |
5d3e2388 DH |
600 | } |
601 | ||
602 | ||
603 | static void | |
604 | obarray_remove_all (SCM obarray) | |
605 | { | |
c35738c1 | 606 | size_t size = SCM_HASHTABLE_N_BUCKETS (obarray); |
1be6b49c | 607 | size_t i; |
5d3e2388 DH |
608 | |
609 | for (i = 0; i < size; i++) | |
610 | { | |
c35738c1 | 611 | SCM_SET_HASHTABLE_BUCKET (obarray, i, SCM_EOL); |
5d3e2388 | 612 | } |
c35738c1 | 613 | SCM_SET_HASHTABLE_N_ITEMS (obarray, 0); |
5d3e2388 DH |
614 | } |
615 | ||
616 | \f | |
617 | ||
618 | /* core environments base | |
619 | * | |
620 | * This struct and the corresponding functions form a base class for guile's | |
621 | * built-in environment types. | |
622 | */ | |
623 | ||
624 | ||
625 | struct core_environments_base { | |
626 | struct scm_environment_funcs *funcs; | |
627 | ||
628 | SCM observers; | |
629 | SCM weak_observers; | |
630 | }; | |
631 | ||
632 | ||
633 | #define CORE_ENVIRONMENTS_BASE(env) \ | |
634 | ((struct core_environments_base *) SCM_CELL_WORD_1 (env)) | |
635 | #define CORE_ENVIRONMENT_OBSERVERS(env) \ | |
636 | (CORE_ENVIRONMENTS_BASE (env)->observers) | |
637 | #define SCM_SET_CORE_ENVIRONMENT_OBSERVERS(env, v) \ | |
638 | (CORE_ENVIRONMENT_OBSERVERS (env) = (v)) | |
639 | #define CORE_ENVIRONMENT_WEAK_OBSERVER_VECTOR(env) \ | |
640 | (CORE_ENVIRONMENTS_BASE (env)->weak_observers) | |
641 | #define CORE_ENVIRONMENT_WEAK_OBSERVERS(env) \ | |
4057a3e0 | 642 | (scm_c_vector_ref (CORE_ENVIRONMENT_WEAK_OBSERVER_VECTOR (env), 0)) |
5d3e2388 | 643 | #define SCM_SET_CORE_ENVIRONMENT_WEAK_OBSERVERS(env, v) \ |
4057a3e0 | 644 | (scm_c_vector_set_x (CORE_ENVIRONMENT_WEAK_OBSERVER_VECTOR (env), 0, (v))) |
5d3e2388 DH |
645 | |
646 | \f | |
647 | ||
648 | static SCM | |
649 | core_environments_observe (SCM env, scm_environment_observer proc, SCM data, int weak_p) | |
650 | { | |
228a24ef DH |
651 | SCM observer = scm_double_cell (scm_tc16_observer, |
652 | SCM_UNPACK (env), | |
653 | SCM_UNPACK (data), | |
654 | (scm_t_bits) proc); | |
5d3e2388 DH |
655 | |
656 | if (!weak_p) | |
657 | { | |
658 | SCM observers = CORE_ENVIRONMENT_OBSERVERS (env); | |
659 | SCM new_observers = scm_cons (observer, observers); | |
660 | SCM_SET_CORE_ENVIRONMENT_OBSERVERS (env, new_observers); | |
661 | } | |
662 | else | |
663 | { | |
664 | SCM observers = CORE_ENVIRONMENT_WEAK_OBSERVERS (env); | |
665 | SCM new_observers = scm_acons (SCM_BOOL_F, observer, observers); | |
666 | SCM_SET_CORE_ENVIRONMENT_WEAK_OBSERVERS (env, new_observers); | |
667 | } | |
668 | ||
669 | return observer; | |
670 | } | |
671 | ||
672 | ||
673 | static void | |
674 | core_environments_unobserve (SCM env, SCM observer) | |
675 | { | |
676 | unsigned int handling_weaks; | |
677 | for (handling_weaks = 0; handling_weaks <= 1; ++handling_weaks) | |
678 | { | |
679 | SCM l = handling_weaks | |
680 | ? CORE_ENVIRONMENT_WEAK_OBSERVERS (env) | |
681 | : CORE_ENVIRONMENT_OBSERVERS (env); | |
682 | ||
d2e53ed6 | 683 | if (!scm_is_null (l)) |
5d3e2388 DH |
684 | { |
685 | SCM rest = SCM_CDR (l); | |
686 | SCM first = handling_weaks | |
687 | ? SCM_CDAR (l) | |
688 | : SCM_CAR (l); | |
689 | ||
bc36d050 | 690 | if (scm_is_eq (first, observer)) |
5d3e2388 DH |
691 | { |
692 | /* Remove the first observer */ | |
8ab3d8a0 KR |
693 | if (handling_weaks) |
694 | SCM_SET_CORE_ENVIRONMENT_WEAK_OBSERVERS (env, rest); | |
695 | else | |
696 | SCM_SET_CORE_ENVIRONMENT_OBSERVERS (env, rest); | |
5d3e2388 DH |
697 | return; |
698 | } | |
699 | ||
700 | do { | |
701 | SCM rest = SCM_CDR (l); | |
702 | ||
d2e53ed6 | 703 | if (!scm_is_null (rest)) |
5d3e2388 DH |
704 | { |
705 | SCM next = handling_weaks | |
706 | ? SCM_CDAR (l) | |
707 | : SCM_CAR (l); | |
708 | ||
bc36d050 | 709 | if (scm_is_eq (next, observer)) |
5d3e2388 DH |
710 | { |
711 | SCM_SETCDR (l, SCM_CDR (rest)); | |
712 | return; | |
713 | } | |
714 | } | |
715 | ||
716 | l = rest; | |
d2e53ed6 | 717 | } while (!scm_is_null (l)); |
5d3e2388 DH |
718 | } |
719 | } | |
720 | ||
721 | /* Dirk:FIXME:: What to do now, since the observer is not found? */ | |
722 | } | |
723 | ||
724 | ||
725 | static SCM | |
726 | core_environments_mark (SCM env) | |
727 | { | |
728 | scm_gc_mark (CORE_ENVIRONMENT_OBSERVERS (env)); | |
729 | return CORE_ENVIRONMENT_WEAK_OBSERVER_VECTOR (env); | |
730 | } | |
731 | ||
732 | ||
733 | static void | |
e81d98ec | 734 | core_environments_finalize (SCM env SCM_UNUSED) |
5d3e2388 DH |
735 | { |
736 | } | |
737 | ||
738 | ||
739 | static void | |
740 | core_environments_preinit (struct core_environments_base *body) | |
741 | { | |
742 | body->funcs = NULL; | |
743 | body->observers = SCM_BOOL_F; | |
744 | body->weak_observers = SCM_BOOL_F; | |
745 | } | |
746 | ||
747 | ||
748 | static void | |
749 | core_environments_init (struct core_environments_base *body, | |
750 | struct scm_environment_funcs *funcs) | |
751 | { | |
752 | body->funcs = funcs; | |
753 | body->observers = SCM_EOL; | |
e11e83f3 | 754 | body->weak_observers = scm_make_weak_value_alist_vector (scm_from_int (1)); |
5d3e2388 DH |
755 | } |
756 | ||
757 | ||
758 | /* Tell all observers to clear their caches. | |
759 | * | |
760 | * Environments have to be informed about changes in the following cases: | |
761 | * - The observed env has a new binding. This must be always reported. | |
762 | * - The observed env has dropped a binding. This must be always reported. | |
763 | * - A binding in the observed environment has changed. This must only be | |
764 | * reported, if there is a chance that the binding is being cached outside. | |
765 | * However, this potential optimization is not performed currently. | |
766 | * | |
767 | * Errors that occur while the observers are called are accumulated and | |
768 | * signalled as one single error message to the caller. | |
769 | */ | |
770 | ||
771 | struct update_data | |
772 | { | |
773 | SCM observer; | |
774 | SCM environment; | |
775 | }; | |
776 | ||
777 | ||
778 | static SCM | |
779 | update_catch_body (void *ptr) | |
780 | { | |
781 | struct update_data *data = (struct update_data *) ptr; | |
782 | SCM observer = data->observer; | |
783 | ||
784 | (*SCM_OBSERVER_PROC (observer)) | |
785 | (data->environment, SCM_OBSERVER_DATA (observer)); | |
786 | ||
787 | return SCM_UNDEFINED; | |
788 | } | |
789 | ||
790 | ||
791 | static SCM | |
792 | update_catch_handler (void *ptr, SCM tag, SCM args) | |
793 | { | |
794 | struct update_data *data = (struct update_data *) ptr; | |
795 | SCM observer = data->observer; | |
cc95e00a MV |
796 | SCM message = |
797 | scm_from_locale_string ("Observer `~A' signals `~A' error: ~S"); | |
5d3e2388 | 798 | |
1afff620 | 799 | return scm_cons (message, scm_list_3 (observer, tag, args)); |
5d3e2388 DH |
800 | } |
801 | ||
802 | ||
803 | static void | |
804 | core_environments_broadcast (SCM env) | |
805 | #define FUNC_NAME "core_environments_broadcast" | |
806 | { | |
807 | unsigned int handling_weaks; | |
808 | SCM errors = SCM_EOL; | |
809 | ||
810 | for (handling_weaks = 0; handling_weaks <= 1; ++handling_weaks) | |
811 | { | |
812 | SCM observers = handling_weaks | |
813 | ? CORE_ENVIRONMENT_WEAK_OBSERVERS (env) | |
814 | : CORE_ENVIRONMENT_OBSERVERS (env); | |
815 | ||
d2e53ed6 | 816 | for (; !scm_is_null (observers); observers = SCM_CDR (observers)) |
5d3e2388 DH |
817 | { |
818 | struct update_data data; | |
819 | SCM observer = handling_weaks | |
820 | ? SCM_CDAR (observers) | |
821 | : SCM_CAR (observers); | |
822 | SCM error; | |
823 | ||
824 | data.observer = observer; | |
825 | data.environment = env; | |
826 | ||
827 | error = scm_internal_catch (SCM_BOOL_T, | |
828 | update_catch_body, &data, | |
829 | update_catch_handler, &data); | |
830 | ||
831 | if (!SCM_UNBNDP (error)) | |
832 | errors = scm_cons (error, errors); | |
833 | } | |
834 | } | |
835 | ||
d2e53ed6 | 836 | if (!scm_is_null (errors)) |
5d3e2388 DH |
837 | { |
838 | /* Dirk:FIXME:: As soon as scm_misc_error is fixed to handle the name | |
839 | * parameter correctly it should not be necessary any more to also pass | |
840 | * namestr in order to get the desired information from the error | |
841 | * message. | |
842 | */ | |
843 | SCM ordered_errors = scm_reverse (errors); | |
844 | scm_misc_error | |
845 | (FUNC_NAME, | |
846 | "Observers of `~A' have signalled the following errors: ~S", | |
847 | scm_cons2 (env, ordered_errors, SCM_EOL)); | |
848 | } | |
849 | } | |
850 | #undef FUNC_NAME | |
851 | ||
852 | \f | |
853 | ||
854 | /* leaf environments | |
855 | * | |
856 | * A leaf environment is simply a mutable set of definitions. A leaf | |
857 | * environment supports no operations beyond the common set. | |
858 | * | |
859 | * Implementation: The obarray of the leaf environment holds (symbol . value) | |
860 | * pairs. No further information is necessary, since all bindings and | |
861 | * locations in a leaf environment are mutable. | |
862 | */ | |
863 | ||
864 | ||
865 | struct leaf_environment { | |
866 | struct core_environments_base base; | |
867 | ||
868 | SCM obarray; | |
869 | }; | |
870 | ||
871 | ||
872 | #define LEAF_ENVIRONMENT(env) \ | |
873 | ((struct leaf_environment *) SCM_CELL_WORD_1 (env)) | |
874 | ||
875 | \f | |
876 | ||
877 | static SCM | |
878 | leaf_environment_ref (SCM env, SCM sym) | |
879 | { | |
880 | SCM obarray = LEAF_ENVIRONMENT (env)->obarray; | |
881 | SCM binding = obarray_retrieve (obarray, sym); | |
882 | return SCM_UNBNDP (binding) ? binding : SCM_CDR (binding); | |
883 | } | |
884 | ||
885 | ||
886 | static SCM | |
887 | leaf_environment_fold (SCM env, scm_environment_folder proc, SCM data, SCM init) | |
888 | { | |
1be6b49c | 889 | size_t i; |
5d3e2388 DH |
890 | SCM result = init; |
891 | SCM obarray = LEAF_ENVIRONMENT (env)->obarray; | |
892 | ||
c35738c1 | 893 | for (i = 0; i < SCM_HASHTABLE_N_BUCKETS (obarray); i++) |
5d3e2388 DH |
894 | { |
895 | SCM l; | |
4057a3e0 | 896 | for (l = SCM_HASHTABLE_BUCKET (obarray, i); |
d2e53ed6 | 897 | !scm_is_null (l); |
c35738c1 | 898 | l = SCM_CDR (l)) |
5d3e2388 DH |
899 | { |
900 | SCM binding = SCM_CAR (l); | |
901 | SCM symbol = SCM_CAR (binding); | |
902 | SCM value = SCM_CDR (binding); | |
903 | result = (*proc) (data, symbol, value, result); | |
904 | } | |
905 | } | |
906 | return result; | |
907 | } | |
908 | ||
909 | ||
910 | static SCM | |
911 | leaf_environment_define (SCM env, SCM sym, SCM val) | |
912 | #define FUNC_NAME "leaf_environment_define" | |
913 | { | |
914 | SCM obarray = LEAF_ENVIRONMENT (env)->obarray; | |
5d3e2388 | 915 | |
a2d47b23 | 916 | obarray_replace (obarray, sym, val); |
5d3e2388 DH |
917 | core_environments_broadcast (env); |
918 | ||
919 | return SCM_ENVIRONMENT_SUCCESS; | |
920 | } | |
921 | #undef FUNC_NAME | |
922 | ||
923 | ||
924 | static SCM | |
925 | leaf_environment_undefine (SCM env, SCM sym) | |
926 | #define FUNC_NAME "leaf_environment_undefine" | |
927 | { | |
928 | SCM obarray = LEAF_ENVIRONMENT (env)->obarray; | |
a2d47b23 | 929 | SCM removed = obarray_remove (obarray, sym); |
5d3e2388 | 930 | |
7888309b | 931 | if (scm_is_true (removed)) |
a2d47b23 | 932 | core_environments_broadcast (env); |
5d3e2388 DH |
933 | |
934 | return SCM_ENVIRONMENT_SUCCESS; | |
935 | } | |
936 | #undef FUNC_NAME | |
937 | ||
938 | ||
939 | static SCM | |
940 | leaf_environment_set_x (SCM env, SCM sym, SCM val) | |
941 | #define FUNC_NAME "leaf_environment_set_x" | |
942 | { | |
943 | SCM obarray = LEAF_ENVIRONMENT (env)->obarray; | |
944 | SCM binding = obarray_retrieve (obarray, sym); | |
945 | ||
946 | if (!SCM_UNBNDP (binding)) | |
947 | { | |
948 | SCM_SETCDR (binding, val); | |
949 | return SCM_ENVIRONMENT_SUCCESS; | |
950 | } | |
951 | else | |
952 | { | |
953 | return SCM_UNDEFINED; | |
954 | } | |
955 | } | |
956 | #undef FUNC_NAME | |
957 | ||
958 | ||
959 | static SCM | |
e81d98ec | 960 | leaf_environment_cell (SCM env, SCM sym, int for_write SCM_UNUSED) |
5d3e2388 DH |
961 | { |
962 | SCM obarray = LEAF_ENVIRONMENT (env)->obarray; | |
963 | SCM binding = obarray_retrieve (obarray, sym); | |
964 | return binding; | |
965 | } | |
966 | ||
967 | ||
968 | static SCM | |
e841c3e0 | 969 | leaf_environment_mark (SCM env) |
5d3e2388 DH |
970 | { |
971 | scm_gc_mark (LEAF_ENVIRONMENT (env)->obarray); | |
972 | return core_environments_mark (env); | |
973 | } | |
974 | ||
975 | ||
4c9419ac | 976 | static void |
e841c3e0 | 977 | leaf_environment_free (SCM env) |
5d3e2388 DH |
978 | { |
979 | core_environments_finalize (env); | |
4c9419ac MV |
980 | scm_gc_free (LEAF_ENVIRONMENT (env), sizeof (struct leaf_environment), |
981 | "leaf environment"); | |
5d3e2388 DH |
982 | } |
983 | ||
984 | ||
985 | static int | |
e81d98ec | 986 | leaf_environment_print (SCM type, SCM port, scm_print_state *pstate SCM_UNUSED) |
5d3e2388 | 987 | { |
b9bd8526 | 988 | SCM address = scm_from_size_t (SCM_UNPACK (type)); |
e11e83f3 | 989 | SCM base16 = scm_number_to_string (address, scm_from_int (16)); |
5d3e2388 DH |
990 | |
991 | scm_puts ("#<leaf environment ", port); | |
18f9d343 | 992 | scm_display (base16, port); |
5d3e2388 DH |
993 | scm_puts (">", port); |
994 | ||
995 | return 1; | |
996 | } | |
997 | ||
998 | ||
999 | static struct scm_environment_funcs leaf_environment_funcs = { | |
1000 | leaf_environment_ref, | |
1001 | leaf_environment_fold, | |
1002 | leaf_environment_define, | |
1003 | leaf_environment_undefine, | |
1004 | leaf_environment_set_x, | |
1005 | leaf_environment_cell, | |
1006 | core_environments_observe, | |
1007 | core_environments_unobserve, | |
e841c3e0 KN |
1008 | leaf_environment_mark, |
1009 | leaf_environment_free, | |
1010 | leaf_environment_print | |
5d3e2388 DH |
1011 | }; |
1012 | ||
1013 | ||
1014 | void *scm_type_leaf_environment = &leaf_environment_funcs; | |
1015 | ||
1016 | ||
1017 | SCM_DEFINE (scm_make_leaf_environment, "make-leaf-environment", 0, 0, 0, | |
1018 | (), | |
1019 | "Create a new leaf environment, containing no bindings.\n" | |
1020 | "All bindings and locations created in the new environment\n" | |
1021 | "will be mutable.") | |
1022 | #define FUNC_NAME s_scm_make_leaf_environment | |
1023 | { | |
1be6b49c | 1024 | size_t size = sizeof (struct leaf_environment); |
4c9419ac | 1025 | struct leaf_environment *body = scm_gc_malloc (size, "leaf environment"); |
5d3e2388 DH |
1026 | SCM env; |
1027 | ||
1028 | core_environments_preinit (&body->base); | |
1029 | body->obarray = SCM_BOOL_F; | |
1030 | ||
1031 | env = scm_make_environment (body); | |
1032 | ||
1033 | core_environments_init (&body->base, &leaf_environment_funcs); | |
00ffa0e7 | 1034 | body->obarray = scm_c_make_hash_table (DEFAULT_OBARRAY_SIZE); |
5d3e2388 DH |
1035 | |
1036 | return env; | |
1037 | } | |
1038 | #undef FUNC_NAME | |
1039 | ||
1040 | ||
1041 | SCM_DEFINE (scm_leaf_environment_p, "leaf-environment?", 1, 0, 0, | |
1042 | (SCM object), | |
0fb104ed MG |
1043 | "Return @code{#t} if object is a leaf environment, or @code{#f}\n" |
1044 | "otherwise.") | |
5d3e2388 DH |
1045 | #define FUNC_NAME s_scm_leaf_environment_p |
1046 | { | |
7888309b | 1047 | return scm_from_bool (SCM_LEAF_ENVIRONMENT_P (object)); |
5d3e2388 DH |
1048 | } |
1049 | #undef FUNC_NAME | |
1050 | ||
1051 | \f | |
1052 | ||
1053 | /* eval environments | |
1054 | * | |
1055 | * A module's source code refers to definitions imported from other modules, | |
1056 | * and definitions made within itself. An eval environment combines two | |
1057 | * environments -- a local environment and an imported environment -- to | |
1058 | * produce a new environment in which both sorts of references can be | |
1059 | * resolved. | |
1060 | * | |
1061 | * Implementation: The obarray of the eval environment is used to cache | |
1062 | * entries from the local and imported environments such that in most of the | |
1063 | * cases only a single lookup is necessary. Since for neither the local nor | |
1064 | * the imported environment it is known, what kind of environment they form, | |
1065 | * the most general case is assumed. Therefore, entries in the obarray take | |
1066 | * one of the following forms: | |
1067 | * | |
1068 | * 1) (<symbol> location mutability . source-env), where mutability indicates | |
1069 | * one of the following states: IMMUTABLE if the location is known to be | |
1070 | * immutable, MUTABLE if the location is known to be mutable, UNKNOWN if | |
1071 | * the location has only been requested for non modifying accesses. | |
1072 | * | |
1073 | * 2) (symbol . source-env) if the symbol has a binding in the source-env, but | |
1074 | * if the source-env can't provide a cell for the binding. Thus, for every | |
1075 | * access, the source-env has to be contacted directly. | |
1076 | */ | |
1077 | ||
1078 | ||
1079 | struct eval_environment { | |
1080 | struct core_environments_base base; | |
1081 | ||
1082 | SCM obarray; | |
1083 | ||
1084 | SCM imported; | |
1085 | SCM imported_observer; | |
1086 | SCM local; | |
1087 | SCM local_observer; | |
1088 | }; | |
1089 | ||
1090 | ||
1091 | #define EVAL_ENVIRONMENT(env) \ | |
1092 | ((struct eval_environment *) SCM_CELL_WORD_1 (env)) | |
1093 | ||
93ccaef0 MV |
1094 | #define IMMUTABLE SCM_I_MAKINUM (0) |
1095 | #define MUTABLE SCM_I_MAKINUM (1) | |
1096 | #define UNKNOWN SCM_I_MAKINUM (2) | |
5d3e2388 DH |
1097 | |
1098 | #define CACHED_LOCATION(x) SCM_CAR (x) | |
1099 | #define CACHED_MUTABILITY(x) SCM_CADR (x) | |
1100 | #define SET_CACHED_MUTABILITY(x, v) SCM_SETCAR (SCM_CDR (x), (v)) | |
1101 | #define CACHED_SOURCE_ENVIRONMENT(x) SCM_CDDR (x) | |
1102 | ||
1103 | \f | |
1104 | ||
1105 | /* eval_environment_lookup will report one of the following distinct results: | |
1106 | * a) (<object> . value) if a cell could be obtained. | |
1107 | * b) <environment> if the environment has to be contacted directly. | |
1108 | * c) IMMUTABLE if an immutable cell was requested for write. | |
1109 | * d) SCM_UNDEFINED if there is no binding for the symbol. | |
1110 | */ | |
1111 | static SCM | |
1112 | eval_environment_lookup (SCM env, SCM sym, int for_write) | |
1113 | { | |
1114 | SCM obarray = EVAL_ENVIRONMENT (env)->obarray; | |
1115 | SCM binding = obarray_retrieve (obarray, sym); | |
1116 | ||
1117 | if (!SCM_UNBNDP (binding)) | |
1118 | { | |
1119 | /* The obarray holds an entry for the symbol. */ | |
1120 | ||
1121 | SCM entry = SCM_CDR (binding); | |
1122 | ||
d2e53ed6 | 1123 | if (scm_is_pair (entry)) |
5d3e2388 DH |
1124 | { |
1125 | /* The entry in the obarray is a cached location. */ | |
1126 | ||
1127 | SCM location = CACHED_LOCATION (entry); | |
1128 | SCM mutability; | |
1129 | ||
1130 | if (!for_write) | |
1131 | return location; | |
1132 | ||
1133 | mutability = CACHED_MUTABILITY (entry); | |
bc36d050 | 1134 | if (scm_is_eq (mutability, MUTABLE)) |
5d3e2388 DH |
1135 | return location; |
1136 | ||
bc36d050 | 1137 | if (scm_is_eq (mutability, UNKNOWN)) |
5d3e2388 DH |
1138 | { |
1139 | SCM source_env = CACHED_SOURCE_ENVIRONMENT (entry); | |
1140 | SCM location = SCM_ENVIRONMENT_CELL (source_env, sym, 1); | |
1141 | ||
d2e53ed6 | 1142 | if (scm_is_pair (location)) |
5d3e2388 DH |
1143 | { |
1144 | SET_CACHED_MUTABILITY (entry, MUTABLE); | |
1145 | return location; | |
1146 | } | |
1147 | else /* IMMUTABLE */ | |
1148 | { | |
1149 | SET_CACHED_MUTABILITY (entry, IMMUTABLE); | |
1150 | return IMMUTABLE; | |
1151 | } | |
1152 | } | |
1153 | ||
1154 | return IMMUTABLE; | |
1155 | } | |
1156 | else | |
1157 | { | |
1158 | /* The obarray entry is an environment */ | |
1159 | ||
1160 | return entry; | |
1161 | } | |
1162 | } | |
1163 | else | |
1164 | { | |
1165 | /* There is no entry for the symbol in the obarray. This can either | |
1166 | * mean that there has not been a request for the symbol yet, or that | |
1167 | * the symbol is really undefined. We are looking for the symbol in | |
1168 | * both the local and the imported environment. If we find a binding, a | |
1169 | * cached entry is created. | |
1170 | */ | |
1171 | ||
1172 | struct eval_environment *body = EVAL_ENVIRONMENT (env); | |
1173 | unsigned int handling_import; | |
1174 | ||
1175 | for (handling_import = 0; handling_import <= 1; ++handling_import) | |
1176 | { | |
1177 | SCM source_env = handling_import ? body->imported : body->local; | |
1178 | SCM location = SCM_ENVIRONMENT_CELL (source_env, sym, for_write); | |
1179 | ||
1180 | if (!SCM_UNBNDP (location)) | |
1181 | { | |
d2e53ed6 | 1182 | if (scm_is_pair (location)) |
5d3e2388 DH |
1183 | { |
1184 | SCM mutability = for_write ? MUTABLE : UNKNOWN; | |
1185 | SCM entry = scm_cons2 (location, mutability, source_env); | |
1186 | obarray_enter (obarray, sym, entry); | |
1187 | return location; | |
1188 | } | |
bc36d050 | 1189 | else if (scm_is_eq (location, SCM_ENVIRONMENT_LOCATION_NO_CELL)) |
5d3e2388 DH |
1190 | { |
1191 | obarray_enter (obarray, sym, source_env); | |
1192 | return source_env; | |
1193 | } | |
1194 | else | |
1195 | { | |
1196 | return IMMUTABLE; | |
1197 | } | |
1198 | } | |
1199 | } | |
1200 | ||
1201 | return SCM_UNDEFINED; | |
1202 | } | |
1203 | } | |
1204 | ||
1205 | ||
1206 | static SCM | |
1207 | eval_environment_ref (SCM env, SCM sym) | |
1208 | #define FUNC_NAME "eval_environment_ref" | |
1209 | { | |
1210 | SCM location = eval_environment_lookup (env, sym, 0); | |
1211 | ||
d2e53ed6 | 1212 | if (scm_is_pair (location)) |
5d3e2388 DH |
1213 | return SCM_CDR (location); |
1214 | else if (!SCM_UNBNDP (location)) | |
1215 | return SCM_ENVIRONMENT_REF (location, sym); | |
1216 | else | |
1217 | return SCM_UNDEFINED; | |
1218 | } | |
1219 | #undef FUNC_NAME | |
1220 | ||
1221 | ||
1222 | static SCM | |
1223 | eval_environment_folder (SCM extended_data, SCM symbol, SCM value, SCM tail) | |
1224 | { | |
1225 | SCM local = SCM_CAR (extended_data); | |
1226 | ||
1227 | if (!SCM_ENVIRONMENT_BOUND_P (local, symbol)) | |
1228 | { | |
1229 | SCM proc_as_nr = SCM_CADR (extended_data); | |
b9bd8526 | 1230 | unsigned long int proc_as_ul = scm_to_ulong (proc_as_nr); |
5d3e2388 DH |
1231 | scm_environment_folder proc = (scm_environment_folder) proc_as_ul; |
1232 | SCM data = SCM_CDDR (extended_data); | |
1233 | ||
1234 | return (*proc) (data, symbol, value, tail); | |
1235 | } | |
1236 | else | |
1237 | { | |
1238 | return tail; | |
1239 | } | |
1240 | } | |
1241 | ||
1242 | ||
1243 | static SCM | |
1244 | eval_environment_fold (SCM env, scm_environment_folder proc, SCM data, SCM init) | |
1245 | { | |
1246 | SCM local = EVAL_ENVIRONMENT (env)->local; | |
1247 | SCM imported = EVAL_ENVIRONMENT (env)->imported; | |
b9bd8526 | 1248 | SCM proc_as_nr = scm_from_ulong ((unsigned long) proc); |
5d3e2388 DH |
1249 | SCM extended_data = scm_cons2 (local, proc_as_nr, data); |
1250 | SCM tmp_result = scm_c_environment_fold (imported, eval_environment_folder, extended_data, init); | |
1251 | ||
1252 | return scm_c_environment_fold (local, proc, data, tmp_result); | |
1253 | } | |
1254 | ||
1255 | ||
1256 | static SCM | |
1257 | eval_environment_define (SCM env, SCM sym, SCM val) | |
1258 | #define FUNC_NAME "eval_environment_define" | |
1259 | { | |
1260 | SCM local = EVAL_ENVIRONMENT (env)->local; | |
1261 | return SCM_ENVIRONMENT_DEFINE (local, sym, val); | |
1262 | } | |
1263 | #undef FUNC_NAME | |
1264 | ||
1265 | ||
1266 | static SCM | |
1267 | eval_environment_undefine (SCM env, SCM sym) | |
1268 | #define FUNC_NAME "eval_environment_undefine" | |
1269 | { | |
1270 | SCM local = EVAL_ENVIRONMENT (env)->local; | |
1271 | return SCM_ENVIRONMENT_UNDEFINE (local, sym); | |
1272 | } | |
1273 | #undef FUNC_NAME | |
1274 | ||
1275 | ||
1276 | static SCM | |
1277 | eval_environment_set_x (SCM env, SCM sym, SCM val) | |
1278 | #define FUNC_NAME "eval_environment_set_x" | |
1279 | { | |
1280 | SCM location = eval_environment_lookup (env, sym, 1); | |
1281 | ||
d2e53ed6 | 1282 | if (scm_is_pair (location)) |
5d3e2388 DH |
1283 | { |
1284 | SCM_SETCDR (location, val); | |
1285 | return SCM_ENVIRONMENT_SUCCESS; | |
1286 | } | |
1287 | else if (SCM_ENVIRONMENT_P (location)) | |
1288 | { | |
1289 | return SCM_ENVIRONMENT_SET (location, sym, val); | |
1290 | } | |
bc36d050 | 1291 | else if (scm_is_eq (location, IMMUTABLE)) |
5d3e2388 DH |
1292 | { |
1293 | return SCM_ENVIRONMENT_LOCATION_IMMUTABLE; | |
1294 | } | |
1295 | else | |
1296 | { | |
1297 | return SCM_UNDEFINED; | |
1298 | } | |
1299 | } | |
1300 | #undef FUNC_NAME | |
1301 | ||
1302 | ||
1303 | static SCM | |
1304 | eval_environment_cell (SCM env, SCM sym, int for_write) | |
1305 | #define FUNC_NAME "eval_environment_cell" | |
1306 | { | |
1307 | SCM location = eval_environment_lookup (env, sym, for_write); | |
1308 | ||
d2e53ed6 | 1309 | if (scm_is_pair (location)) |
5d3e2388 DH |
1310 | return location; |
1311 | else if (SCM_ENVIRONMENT_P (location)) | |
1312 | return SCM_ENVIRONMENT_LOCATION_NO_CELL; | |
bc36d050 | 1313 | else if (scm_is_eq (location, IMMUTABLE)) |
5d3e2388 DH |
1314 | return SCM_ENVIRONMENT_LOCATION_IMMUTABLE; |
1315 | else | |
1316 | return SCM_UNDEFINED; | |
1317 | } | |
1318 | #undef FUNC_NAME | |
1319 | ||
1320 | ||
1321 | static SCM | |
e841c3e0 | 1322 | eval_environment_mark (SCM env) |
5d3e2388 DH |
1323 | { |
1324 | struct eval_environment *body = EVAL_ENVIRONMENT (env); | |
1325 | ||
1326 | scm_gc_mark (body->obarray); | |
1327 | scm_gc_mark (body->imported); | |
1328 | scm_gc_mark (body->imported_observer); | |
1329 | scm_gc_mark (body->local); | |
1330 | scm_gc_mark (body->local_observer); | |
1331 | ||
1332 | return core_environments_mark (env); | |
1333 | } | |
1334 | ||
1335 | ||
4c9419ac | 1336 | static void |
e841c3e0 | 1337 | eval_environment_free (SCM env) |
5d3e2388 DH |
1338 | { |
1339 | core_environments_finalize (env); | |
4c9419ac MV |
1340 | scm_gc_free (EVAL_ENVIRONMENT (env), sizeof (struct eval_environment), |
1341 | "eval environment"); | |
5d3e2388 DH |
1342 | } |
1343 | ||
1344 | ||
1345 | static int | |
e81d98ec | 1346 | eval_environment_print (SCM type, SCM port, scm_print_state *pstate SCM_UNUSED) |
5d3e2388 | 1347 | { |
b9bd8526 | 1348 | SCM address = scm_from_size_t (SCM_UNPACK (type)); |
e11e83f3 | 1349 | SCM base16 = scm_number_to_string (address, scm_from_int (16)); |
5d3e2388 DH |
1350 | |
1351 | scm_puts ("#<eval environment ", port); | |
18f9d343 | 1352 | scm_display (base16, port); |
5d3e2388 DH |
1353 | scm_puts (">", port); |
1354 | ||
1355 | return 1; | |
1356 | } | |
1357 | ||
1358 | ||
1359 | static struct scm_environment_funcs eval_environment_funcs = { | |
1360 | eval_environment_ref, | |
1361 | eval_environment_fold, | |
1362 | eval_environment_define, | |
1363 | eval_environment_undefine, | |
1364 | eval_environment_set_x, | |
1365 | eval_environment_cell, | |
1366 | core_environments_observe, | |
1367 | core_environments_unobserve, | |
e841c3e0 KN |
1368 | eval_environment_mark, |
1369 | eval_environment_free, | |
1370 | eval_environment_print | |
5d3e2388 DH |
1371 | }; |
1372 | ||
1373 | ||
1374 | void *scm_type_eval_environment = &eval_environment_funcs; | |
1375 | ||
1376 | ||
1377 | static void | |
e81d98ec | 1378 | eval_environment_observer (SCM caller SCM_UNUSED, SCM eval_env) |
5d3e2388 DH |
1379 | { |
1380 | SCM obarray = EVAL_ENVIRONMENT (eval_env)->obarray; | |
1381 | ||
1382 | obarray_remove_all (obarray); | |
1383 | core_environments_broadcast (eval_env); | |
1384 | } | |
1385 | ||
1386 | ||
1387 | SCM_DEFINE (scm_make_eval_environment, "make-eval-environment", 2, 0, 0, | |
1388 | (SCM local, SCM imported), | |
1389 | "Return a new environment object eval whose bindings are the\n" | |
0fb104ed MG |
1390 | "union of the bindings in the environments @var{local} and\n" |
1391 | "@var{imported}, with bindings from @var{local} taking\n" | |
1392 | "precedence. Definitions made in eval are placed in @var{local}.\n" | |
1393 | "Applying @code{environment-define} or\n" | |
1394 | "@code{environment-undefine} to eval has the same effect as\n" | |
1395 | "applying the procedure to @var{local}.\n" | |
1396 | "Note that eval incorporates @var{local} and @var{imported} by\n" | |
1397 | "reference:\n" | |
5d3e2388 | 1398 | "If, after creating eval, the program changes the bindings of\n" |
0fb104ed MG |
1399 | "@var{local} or @var{imported}, those changes will be visible\n" |
1400 | "in eval.\n" | |
5d3e2388 | 1401 | "Since most Scheme evaluation takes place in eval environments,\n" |
0fb104ed MG |
1402 | "they transparently cache the bindings received from @var{local}\n" |
1403 | "and @var{imported}. Thus, the first time the program looks up\n" | |
1404 | "a symbol in eval, eval may make calls to @var{local} or\n" | |
1405 | "@var{imported} to find their bindings, but subsequent\n" | |
1406 | "references to that symbol will be as fast as references to\n" | |
1407 | "bindings in finite environments.\n" | |
1408 | "In typical use, @var{local} will be a finite environment, and\n" | |
1409 | "@var{imported} will be an import environment") | |
5d3e2388 DH |
1410 | #define FUNC_NAME s_scm_make_eval_environment |
1411 | { | |
1412 | SCM env; | |
1413 | struct eval_environment *body; | |
1414 | ||
1415 | SCM_ASSERT (SCM_ENVIRONMENT_P (local), local, SCM_ARG1, FUNC_NAME); | |
1416 | SCM_ASSERT (SCM_ENVIRONMENT_P (imported), imported, SCM_ARG2, FUNC_NAME); | |
1417 | ||
4c9419ac | 1418 | body = scm_gc_malloc (sizeof (struct eval_environment), "eval environment"); |
5d3e2388 DH |
1419 | |
1420 | core_environments_preinit (&body->base); | |
1421 | body->obarray = SCM_BOOL_F; | |
1422 | body->imported = SCM_BOOL_F; | |
1423 | body->imported_observer = SCM_BOOL_F; | |
1424 | body->local = SCM_BOOL_F; | |
1425 | body->local_observer = SCM_BOOL_F; | |
1426 | ||
1427 | env = scm_make_environment (body); | |
1428 | ||
1429 | core_environments_init (&body->base, &eval_environment_funcs); | |
00ffa0e7 | 1430 | body->obarray = scm_c_make_hash_table (DEFAULT_OBARRAY_SIZE); |
5d3e2388 DH |
1431 | body->imported = imported; |
1432 | body->imported_observer | |
1433 | = SCM_ENVIRONMENT_OBSERVE (imported, eval_environment_observer, env, 1); | |
1434 | body->local = local; | |
1435 | body->local_observer | |
1436 | = SCM_ENVIRONMENT_OBSERVE (local, eval_environment_observer, env, 1); | |
1437 | ||
1438 | return env; | |
1439 | } | |
1440 | #undef FUNC_NAME | |
1441 | ||
1442 | ||
1443 | SCM_DEFINE (scm_eval_environment_p, "eval-environment?", 1, 0, 0, | |
1444 | (SCM object), | |
0fb104ed MG |
1445 | "Return @code{#t} if object is an eval environment, or @code{#f}\n" |
1446 | "otherwise.") | |
5d3e2388 DH |
1447 | #define FUNC_NAME s_scm_eval_environment_p |
1448 | { | |
7888309b | 1449 | return scm_from_bool (SCM_EVAL_ENVIRONMENT_P (object)); |
5d3e2388 DH |
1450 | } |
1451 | #undef FUNC_NAME | |
1452 | ||
1453 | ||
1454 | SCM_DEFINE (scm_eval_environment_local, "eval-environment-local", 1, 0, 0, | |
1455 | (SCM env), | |
0fb104ed | 1456 | "Return the local environment of eval environment @var{env}.") |
5d3e2388 DH |
1457 | #define FUNC_NAME s_scm_eval_environment_local |
1458 | { | |
1459 | SCM_ASSERT (SCM_EVAL_ENVIRONMENT_P (env), env, SCM_ARG1, FUNC_NAME); | |
1460 | ||
1461 | return EVAL_ENVIRONMENT (env)->local; | |
1462 | } | |
1463 | #undef FUNC_NAME | |
1464 | ||
1465 | ||
1466 | SCM_DEFINE (scm_eval_environment_set_local_x, "eval-environment-set-local!", 2, 0, 0, | |
1467 | (SCM env, SCM local), | |
0fb104ed | 1468 | "Change @var{env}'s local environment to @var{local}.") |
5d3e2388 DH |
1469 | #define FUNC_NAME s_scm_eval_environment_set_local_x |
1470 | { | |
1471 | struct eval_environment *body; | |
1472 | ||
1473 | SCM_ASSERT (SCM_EVAL_ENVIRONMENT_P (env), env, SCM_ARG1, FUNC_NAME); | |
1474 | SCM_ASSERT (SCM_ENVIRONMENT_P (local), local, SCM_ARG2, FUNC_NAME); | |
1475 | ||
1476 | body = EVAL_ENVIRONMENT (env); | |
1477 | ||
1478 | obarray_remove_all (body->obarray); | |
1479 | SCM_ENVIRONMENT_UNOBSERVE (body->local, body->local_observer); | |
1480 | ||
1481 | body->local = local; | |
1482 | body->local_observer | |
1483 | = SCM_ENVIRONMENT_OBSERVE (local, eval_environment_observer, env, 1); | |
1484 | ||
1485 | core_environments_broadcast (env); | |
1486 | ||
1487 | return SCM_UNSPECIFIED; | |
1488 | } | |
1489 | #undef FUNC_NAME | |
1490 | ||
1491 | ||
1492 | SCM_DEFINE (scm_eval_environment_imported, "eval-environment-imported", 1, 0, 0, | |
1493 | (SCM env), | |
0fb104ed | 1494 | "Return the imported environment of eval environment @var{env}.") |
5d3e2388 DH |
1495 | #define FUNC_NAME s_scm_eval_environment_imported |
1496 | { | |
1497 | SCM_ASSERT (SCM_EVAL_ENVIRONMENT_P (env), env, SCM_ARG1, FUNC_NAME); | |
1498 | ||
1499 | return EVAL_ENVIRONMENT (env)->imported; | |
1500 | } | |
1501 | #undef FUNC_NAME | |
1502 | ||
1503 | ||
1504 | SCM_DEFINE (scm_eval_environment_set_imported_x, "eval-environment-set-imported!", 2, 0, 0, | |
1505 | (SCM env, SCM imported), | |
0fb104ed | 1506 | "Change @var{env}'s imported environment to @var{imported}.") |
5d3e2388 DH |
1507 | #define FUNC_NAME s_scm_eval_environment_set_imported_x |
1508 | { | |
1509 | struct eval_environment *body; | |
1510 | ||
1511 | SCM_ASSERT (SCM_EVAL_ENVIRONMENT_P (env), env, SCM_ARG1, FUNC_NAME); | |
1512 | SCM_ASSERT (SCM_ENVIRONMENT_P (imported), imported, SCM_ARG2, FUNC_NAME); | |
1513 | ||
1514 | body = EVAL_ENVIRONMENT (env); | |
1515 | ||
1516 | obarray_remove_all (body->obarray); | |
1517 | SCM_ENVIRONMENT_UNOBSERVE (body->imported, body->imported_observer); | |
1518 | ||
1519 | body->imported = imported; | |
1520 | body->imported_observer | |
1521 | = SCM_ENVIRONMENT_OBSERVE (imported, eval_environment_observer, env, 1); | |
1522 | ||
1523 | core_environments_broadcast (env); | |
1524 | ||
1525 | return SCM_UNSPECIFIED; | |
1526 | } | |
1527 | #undef FUNC_NAME | |
1528 | ||
1529 | \f | |
1530 | ||
1531 | /* import environments | |
1532 | * | |
1533 | * An import environment combines the bindings of a set of argument | |
1534 | * environments, and checks for naming clashes. | |
1535 | * | |
1536 | * Implementation: The import environment does no caching at all. For every | |
1537 | * access, the list of imported environments is scanned. | |
1538 | */ | |
1539 | ||
1540 | ||
1541 | struct import_environment { | |
1542 | struct core_environments_base base; | |
1543 | ||
1544 | SCM imports; | |
1545 | SCM import_observers; | |
1546 | ||
1547 | SCM conflict_proc; | |
1548 | }; | |
1549 | ||
1550 | ||
1551 | #define IMPORT_ENVIRONMENT(env) \ | |
1552 | ((struct import_environment *) SCM_CELL_WORD_1 (env)) | |
1553 | ||
1554 | \f | |
1555 | ||
1556 | /* Lookup will report one of the following distinct results: | |
1557 | * a) <environment> if only environment binds the symbol. | |
1558 | * b) (env-1 env-2 ...) for conflicting bindings in env-1, ... | |
1559 | * c) SCM_UNDEFINED if there is no binding for the symbol. | |
1560 | */ | |
1561 | static SCM | |
1562 | import_environment_lookup (SCM env, SCM sym) | |
1563 | { | |
1564 | SCM imports = IMPORT_ENVIRONMENT (env)->imports; | |
1565 | SCM result = SCM_UNDEFINED; | |
1566 | SCM l; | |
1567 | ||
d2e53ed6 | 1568 | for (l = imports; !scm_is_null (l); l = SCM_CDR (l)) |
5d3e2388 DH |
1569 | { |
1570 | SCM imported = SCM_CAR (l); | |
1571 | ||
1572 | if (SCM_ENVIRONMENT_BOUND_P (imported, sym)) | |
1573 | { | |
1574 | if (SCM_UNBNDP (result)) | |
1575 | result = imported; | |
d2e53ed6 | 1576 | else if (scm_is_pair (result)) |
5d3e2388 DH |
1577 | result = scm_cons (imported, result); |
1578 | else | |
1579 | result = scm_cons2 (imported, result, SCM_EOL); | |
1580 | } | |
1581 | } | |
1582 | ||
d2e53ed6 | 1583 | if (scm_is_pair (result)) |
5d3e2388 DH |
1584 | return scm_reverse (result); |
1585 | else | |
1586 | return result; | |
1587 | } | |
1588 | ||
1589 | ||
1590 | static SCM | |
1591 | import_environment_conflict (SCM env, SCM sym, SCM imports) | |
1592 | { | |
1593 | SCM conflict_proc = IMPORT_ENVIRONMENT (env)->conflict_proc; | |
1594 | SCM args = scm_cons2 (env, sym, scm_cons (imports, SCM_EOL)); | |
1595 | ||
fdc28395 | 1596 | return scm_apply_0 (conflict_proc, args); |
5d3e2388 DH |
1597 | } |
1598 | ||
1599 | ||
1600 | static SCM | |
1601 | import_environment_ref (SCM env, SCM sym) | |
1602 | #define FUNC_NAME "import_environment_ref" | |
1603 | { | |
1604 | SCM owner = import_environment_lookup (env, sym); | |
1605 | ||
1606 | if (SCM_UNBNDP (owner)) | |
1607 | { | |
1608 | return SCM_UNDEFINED; | |
1609 | } | |
d2e53ed6 | 1610 | else if (scm_is_pair (owner)) |
5d3e2388 DH |
1611 | { |
1612 | SCM resolve = import_environment_conflict (env, sym, owner); | |
1613 | ||
1614 | if (SCM_ENVIRONMENT_P (resolve)) | |
1615 | return SCM_ENVIRONMENT_REF (resolve, sym); | |
1616 | else | |
1617 | return SCM_UNSPECIFIED; | |
1618 | } | |
1619 | else | |
1620 | { | |
1621 | return SCM_ENVIRONMENT_REF (owner, sym); | |
1622 | } | |
1623 | } | |
1624 | #undef FUNC_NAME | |
1625 | ||
1626 | ||
1627 | static SCM | |
1628 | import_environment_folder (SCM extended_data, SCM symbol, SCM value, SCM tail) | |
1629 | #define FUNC_NAME "import_environment_fold" | |
1630 | { | |
1631 | SCM import_env = SCM_CAR (extended_data); | |
1632 | SCM imported_env = SCM_CADR (extended_data); | |
1633 | SCM owner = import_environment_lookup (import_env, symbol); | |
1634 | SCM proc_as_nr = SCM_CADDR (extended_data); | |
b9bd8526 | 1635 | unsigned long int proc_as_ul = scm_to_ulong (proc_as_nr); |
5d3e2388 DH |
1636 | scm_environment_folder proc = (scm_environment_folder) proc_as_ul; |
1637 | SCM data = SCM_CDDDR (extended_data); | |
1638 | ||
d2e53ed6 | 1639 | if (scm_is_pair (owner) && scm_is_eq (SCM_CAR (owner), imported_env)) |
5d3e2388 DH |
1640 | owner = import_environment_conflict (import_env, symbol, owner); |
1641 | ||
1642 | if (SCM_ENVIRONMENT_P (owner)) | |
1643 | return (*proc) (data, symbol, value, tail); | |
1644 | else /* unresolved conflict */ | |
1645 | return (*proc) (data, symbol, SCM_UNSPECIFIED, tail); | |
1646 | } | |
1647 | #undef FUNC_NAME | |
1648 | ||
1649 | ||
1650 | static SCM | |
1651 | import_environment_fold (SCM env, scm_environment_folder proc, SCM data, SCM init) | |
1652 | { | |
b9bd8526 | 1653 | SCM proc_as_nr = scm_from_ulong ((unsigned long) proc); |
5d3e2388 DH |
1654 | SCM result = init; |
1655 | SCM l; | |
1656 | ||
d2e53ed6 | 1657 | for (l = IMPORT_ENVIRONMENT (env)->imports; !scm_is_null (l); l = SCM_CDR (l)) |
5d3e2388 DH |
1658 | { |
1659 | SCM imported_env = SCM_CAR (l); | |
1660 | SCM extended_data = scm_cons (env, scm_cons2 (imported_env, proc_as_nr, data)); | |
1661 | ||
1662 | result = scm_c_environment_fold (imported_env, import_environment_folder, extended_data, result); | |
1663 | } | |
1664 | ||
1665 | return result; | |
1666 | } | |
1667 | ||
1668 | ||
1669 | static SCM | |
e81d98ec DH |
1670 | import_environment_define (SCM env SCM_UNUSED, |
1671 | SCM sym SCM_UNUSED, | |
1672 | SCM val SCM_UNUSED) | |
5d3e2388 DH |
1673 | #define FUNC_NAME "import_environment_define" |
1674 | { | |
1675 | return SCM_ENVIRONMENT_BINDING_IMMUTABLE; | |
1676 | } | |
1677 | #undef FUNC_NAME | |
1678 | ||
1679 | ||
1680 | static SCM | |
e81d98ec DH |
1681 | import_environment_undefine (SCM env SCM_UNUSED, |
1682 | SCM sym SCM_UNUSED) | |
5d3e2388 DH |
1683 | #define FUNC_NAME "import_environment_undefine" |
1684 | { | |
1685 | return SCM_ENVIRONMENT_BINDING_IMMUTABLE; | |
1686 | } | |
1687 | #undef FUNC_NAME | |
1688 | ||
1689 | ||
1690 | static SCM | |
1691 | import_environment_set_x (SCM env, SCM sym, SCM val) | |
1692 | #define FUNC_NAME "import_environment_set_x" | |
1693 | { | |
1694 | SCM owner = import_environment_lookup (env, sym); | |
1695 | ||
1696 | if (SCM_UNBNDP (owner)) | |
1697 | { | |
1698 | return SCM_UNDEFINED; | |
1699 | } | |
d2e53ed6 | 1700 | else if (scm_is_pair (owner)) |
5d3e2388 DH |
1701 | { |
1702 | SCM resolve = import_environment_conflict (env, sym, owner); | |
1703 | ||
1704 | if (SCM_ENVIRONMENT_P (resolve)) | |
1705 | return SCM_ENVIRONMENT_SET (resolve, sym, val); | |
1706 | else | |
1707 | return SCM_ENVIRONMENT_LOCATION_IMMUTABLE; | |
1708 | } | |
1709 | else | |
1710 | { | |
1711 | return SCM_ENVIRONMENT_SET (owner, sym, val); | |
1712 | } | |
1713 | } | |
1714 | #undef FUNC_NAME | |
1715 | ||
1716 | ||
1717 | static SCM | |
1718 | import_environment_cell (SCM env, SCM sym, int for_write) | |
1719 | #define FUNC_NAME "import_environment_cell" | |
1720 | { | |
1721 | SCM owner = import_environment_lookup (env, sym); | |
1722 | ||
1723 | if (SCM_UNBNDP (owner)) | |
1724 | { | |
1725 | return SCM_UNDEFINED; | |
1726 | } | |
d2e53ed6 | 1727 | else if (scm_is_pair (owner)) |
5d3e2388 DH |
1728 | { |
1729 | SCM resolve = import_environment_conflict (env, sym, owner); | |
1730 | ||
1731 | if (SCM_ENVIRONMENT_P (resolve)) | |
1732 | return SCM_ENVIRONMENT_CELL (resolve, sym, for_write); | |
1733 | else | |
1734 | return SCM_ENVIRONMENT_LOCATION_NO_CELL; | |
1735 | } | |
1736 | else | |
1737 | { | |
1738 | return SCM_ENVIRONMENT_CELL (owner, sym, for_write); | |
1739 | } | |
1740 | } | |
1741 | #undef FUNC_NAME | |
1742 | ||
1743 | ||
1744 | static SCM | |
e841c3e0 | 1745 | import_environment_mark (SCM env) |
5d3e2388 DH |
1746 | { |
1747 | scm_gc_mark (IMPORT_ENVIRONMENT (env)->imports); | |
1748 | scm_gc_mark (IMPORT_ENVIRONMENT (env)->import_observers); | |
1749 | scm_gc_mark (IMPORT_ENVIRONMENT (env)->conflict_proc); | |
1750 | return core_environments_mark (env); | |
1751 | } | |
1752 | ||
1753 | ||
4c9419ac | 1754 | static void |
e841c3e0 | 1755 | import_environment_free (SCM env) |
5d3e2388 DH |
1756 | { |
1757 | core_environments_finalize (env); | |
4c9419ac MV |
1758 | scm_gc_free (IMPORT_ENVIRONMENT (env), sizeof (struct import_environment), |
1759 | "import environment"); | |
5d3e2388 DH |
1760 | } |
1761 | ||
1762 | ||
1763 | static int | |
e81d98ec DH |
1764 | import_environment_print (SCM type, SCM port, |
1765 | scm_print_state *pstate SCM_UNUSED) | |
5d3e2388 | 1766 | { |
b9bd8526 | 1767 | SCM address = scm_from_size_t (SCM_UNPACK (type)); |
e11e83f3 | 1768 | SCM base16 = scm_number_to_string (address, scm_from_int (16)); |
5d3e2388 DH |
1769 | |
1770 | scm_puts ("#<import environment ", port); | |
18f9d343 | 1771 | scm_display (base16, port); |
5d3e2388 DH |
1772 | scm_puts (">", port); |
1773 | ||
1774 | return 1; | |
1775 | } | |
1776 | ||
1777 | ||
1778 | static struct scm_environment_funcs import_environment_funcs = { | |
1779 | import_environment_ref, | |
1780 | import_environment_fold, | |
1781 | import_environment_define, | |
1782 | import_environment_undefine, | |
1783 | import_environment_set_x, | |
1784 | import_environment_cell, | |
1785 | core_environments_observe, | |
1786 | core_environments_unobserve, | |
e841c3e0 KN |
1787 | import_environment_mark, |
1788 | import_environment_free, | |
1789 | import_environment_print | |
5d3e2388 DH |
1790 | }; |
1791 | ||
1792 | ||
1793 | void *scm_type_import_environment = &import_environment_funcs; | |
1794 | ||
1795 | ||
1796 | static void | |
e81d98ec | 1797 | import_environment_observer (SCM caller SCM_UNUSED, SCM import_env) |
5d3e2388 DH |
1798 | { |
1799 | core_environments_broadcast (import_env); | |
1800 | } | |
1801 | ||
1802 | ||
1803 | SCM_DEFINE (scm_make_import_environment, "make-import-environment", 2, 0, 0, | |
1804 | (SCM imports, SCM conflict_proc), | |
0fb104ed MG |
1805 | "Return a new environment @var{imp} whose bindings are the union\n" |
1806 | "of the bindings from the environments in @var{imports};\n" | |
1807 | "@var{imports} must be a list of environments. That is,\n" | |
1808 | "@var{imp} binds a symbol to a location when some element of\n" | |
1809 | "@var{imports} does.\n" | |
1810 | "If two different elements of @var{imports} have a binding for\n" | |
1811 | "the same symbol, the @var{conflict-proc} is called with the\n" | |
1812 | "following parameters: the import environment, the symbol and\n" | |
1813 | "the list of the imported environments that bind the symbol.\n" | |
1814 | "If the @var{conflict-proc} returns an environment @var{env},\n" | |
1815 | "the conflict is considered as resolved and the binding from\n" | |
1816 | "@var{env} is used. If the @var{conflict-proc} returns some\n" | |
1817 | "non-environment object, the conflict is considered unresolved\n" | |
1818 | "and the symbol is treated as unspecified in the import\n" | |
1819 | "environment.\n" | |
1820 | "The checking for conflicts may be performed lazily, i. e. at\n" | |
5d3e2388 DH |
1821 | "the moment when a value or binding for a certain symbol is\n" |
1822 | "requested instead of the moment when the environment is\n" | |
1823 | "created or the bindings of the imports change.\n" | |
0fb104ed MG |
1824 | "All bindings in @var{imp} are immutable. If you apply\n" |
1825 | "@code{environment-define} or @code{environment-undefine} to\n" | |
1826 | "@var{imp}, Guile will signal an\n" | |
1827 | " @code{environment:immutable-binding} error. However,\n" | |
1828 | "notice that the set of bindings in @var{imp} may still change,\n" | |
1829 | "if one of its imported environments changes.") | |
5d3e2388 DH |
1830 | #define FUNC_NAME s_scm_make_import_environment |
1831 | { | |
1be6b49c | 1832 | size_t size = sizeof (struct import_environment); |
4c9419ac | 1833 | struct import_environment *body = scm_gc_malloc (size, "import environment"); |
5d3e2388 DH |
1834 | SCM env; |
1835 | ||
1836 | core_environments_preinit (&body->base); | |
1837 | body->imports = SCM_BOOL_F; | |
1838 | body->import_observers = SCM_BOOL_F; | |
1839 | body->conflict_proc = SCM_BOOL_F; | |
1840 | ||
1841 | env = scm_make_environment (body); | |
1842 | ||
1843 | core_environments_init (&body->base, &import_environment_funcs); | |
1844 | body->imports = SCM_EOL; | |
1845 | body->import_observers = SCM_EOL; | |
1846 | body->conflict_proc = conflict_proc; | |
1847 | ||
1848 | scm_import_environment_set_imports_x (env, imports); | |
1849 | ||
1850 | return env; | |
1851 | } | |
1852 | #undef FUNC_NAME | |
1853 | ||
1854 | ||
1855 | SCM_DEFINE (scm_import_environment_p, "import-environment?", 1, 0, 0, | |
1856 | (SCM object), | |
0fb104ed MG |
1857 | "Return @code{#t} if object is an import environment, or\n" |
1858 | "@code{#f} otherwise.") | |
5d3e2388 DH |
1859 | #define FUNC_NAME s_scm_import_environment_p |
1860 | { | |
7888309b | 1861 | return scm_from_bool (SCM_IMPORT_ENVIRONMENT_P (object)); |
5d3e2388 DH |
1862 | } |
1863 | #undef FUNC_NAME | |
1864 | ||
1865 | ||
1866 | SCM_DEFINE (scm_import_environment_imports, "import-environment-imports", 1, 0, 0, | |
1867 | (SCM env), | |
0fb104ed MG |
1868 | "Return the list of environments imported by the import\n" |
1869 | "environment @var{env}.") | |
5d3e2388 DH |
1870 | #define FUNC_NAME s_scm_import_environment_imports |
1871 | { | |
1872 | SCM_ASSERT (SCM_IMPORT_ENVIRONMENT_P (env), env, SCM_ARG1, FUNC_NAME); | |
1873 | ||
1874 | return IMPORT_ENVIRONMENT (env)->imports; | |
1875 | } | |
1876 | #undef FUNC_NAME | |
1877 | ||
1878 | ||
1879 | SCM_DEFINE (scm_import_environment_set_imports_x, "import-environment-set-imports!", 2, 0, 0, | |
1880 | (SCM env, SCM imports), | |
0fb104ed MG |
1881 | "Change @var{env}'s list of imported environments to\n" |
1882 | "@var{imports}, and check for conflicts.") | |
5d3e2388 DH |
1883 | #define FUNC_NAME s_scm_import_environment_set_imports_x |
1884 | { | |
1885 | struct import_environment *body = IMPORT_ENVIRONMENT (env); | |
1886 | SCM import_observers = SCM_EOL; | |
1887 | SCM l; | |
1888 | ||
1889 | SCM_ASSERT (SCM_IMPORT_ENVIRONMENT_P (env), env, SCM_ARG1, FUNC_NAME); | |
d2e53ed6 | 1890 | for (l = imports; scm_is_pair (l); l = SCM_CDR (l)) |
5d3e2388 DH |
1891 | { |
1892 | SCM obj = SCM_CAR (l); | |
dd85ce47 | 1893 | SCM_ASSERT (SCM_ENVIRONMENT_P (obj), imports, SCM_ARG2, FUNC_NAME); |
5d3e2388 | 1894 | } |
d2e53ed6 | 1895 | SCM_ASSERT (scm_is_null (l), imports, SCM_ARG2, FUNC_NAME); |
5d3e2388 | 1896 | |
d2e53ed6 | 1897 | for (l = body->import_observers; !scm_is_null (l); l = SCM_CDR (l)) |
5d3e2388 DH |
1898 | { |
1899 | SCM obs = SCM_CAR (l); | |
1900 | SCM_ENVIRONMENT_UNOBSERVE (env, obs); | |
1901 | } | |
1902 | ||
d2e53ed6 | 1903 | for (l = imports; !scm_is_null (l); l = SCM_CDR (l)) |
5d3e2388 DH |
1904 | { |
1905 | SCM imp = SCM_CAR (l); | |
1906 | SCM obs = SCM_ENVIRONMENT_OBSERVE (imp, import_environment_observer, env, 1); | |
1907 | import_observers = scm_cons (obs, import_observers); | |
1908 | } | |
1909 | ||
1910 | body->imports = imports; | |
1911 | body->import_observers = import_observers; | |
1912 | ||
1913 | return SCM_UNSPECIFIED; | |
1914 | } | |
1915 | #undef FUNC_NAME | |
1916 | ||
1917 | \f | |
1918 | ||
1919 | /* export environments | |
1920 | * | |
1921 | * An export environment restricts an environment to a specified set of | |
1922 | * bindings. | |
1923 | * | |
1924 | * Implementation: The export environment does no caching at all. For every | |
1925 | * access, the signature is scanned. The signature that is stored internally | |
1926 | * is an alist of pairs (symbol . (mutability)). | |
1927 | */ | |
1928 | ||
1929 | ||
1930 | struct export_environment { | |
1931 | struct core_environments_base base; | |
1932 | ||
1933 | SCM private; | |
1934 | SCM private_observer; | |
1935 | ||
1936 | SCM signature; | |
1937 | }; | |
1938 | ||
1939 | ||
1940 | #define EXPORT_ENVIRONMENT(env) \ | |
1941 | ((struct export_environment *) SCM_CELL_WORD_1 (env)) | |
1942 | ||
1943 | ||
1944 | SCM_SYMBOL (symbol_immutable_location, "immutable-location"); | |
1945 | SCM_SYMBOL (symbol_mutable_location, "mutable-location"); | |
1946 | ||
1947 | \f | |
1948 | ||
1949 | static SCM | |
1950 | export_environment_ref (SCM env, SCM sym) | |
1951 | #define FUNC_NAME "export_environment_ref" | |
1952 | { | |
1953 | struct export_environment *body = EXPORT_ENVIRONMENT (env); | |
1954 | SCM entry = scm_assq (sym, body->signature); | |
1955 | ||
7888309b | 1956 | if (scm_is_false (entry)) |
5d3e2388 DH |
1957 | return SCM_UNDEFINED; |
1958 | else | |
1959 | return SCM_ENVIRONMENT_REF (body->private, sym); | |
1960 | } | |
1961 | #undef FUNC_NAME | |
1962 | ||
1963 | ||
1964 | static SCM | |
1965 | export_environment_fold (SCM env, scm_environment_folder proc, SCM data, SCM init) | |
1966 | { | |
1967 | struct export_environment *body = EXPORT_ENVIRONMENT (env); | |
1968 | SCM result = init; | |
1969 | SCM l; | |
1970 | ||
d2e53ed6 | 1971 | for (l = body->signature; !scm_is_null (l); l = SCM_CDR (l)) |
5d3e2388 DH |
1972 | { |
1973 | SCM symbol = SCM_CAR (l); | |
1974 | SCM value = SCM_ENVIRONMENT_REF (body->private, symbol); | |
1975 | if (!SCM_UNBNDP (value)) | |
1976 | result = (*proc) (data, symbol, value, result); | |
1977 | } | |
1978 | return result; | |
1979 | } | |
1980 | ||
1981 | ||
1982 | static SCM | |
e81d98ec DH |
1983 | export_environment_define (SCM env SCM_UNUSED, |
1984 | SCM sym SCM_UNUSED, | |
1985 | SCM val SCM_UNUSED) | |
5d3e2388 DH |
1986 | #define FUNC_NAME "export_environment_define" |
1987 | { | |
1988 | return SCM_ENVIRONMENT_BINDING_IMMUTABLE; | |
1989 | } | |
1990 | #undef FUNC_NAME | |
1991 | ||
1992 | ||
1993 | static SCM | |
e81d98ec | 1994 | export_environment_undefine (SCM env SCM_UNUSED, SCM sym SCM_UNUSED) |
5d3e2388 DH |
1995 | #define FUNC_NAME "export_environment_undefine" |
1996 | { | |
1997 | return SCM_ENVIRONMENT_BINDING_IMMUTABLE; | |
1998 | } | |
1999 | #undef FUNC_NAME | |
2000 | ||
2001 | ||
2002 | static SCM | |
2003 | export_environment_set_x (SCM env, SCM sym, SCM val) | |
2004 | #define FUNC_NAME "export_environment_set_x" | |
2005 | { | |
2006 | struct export_environment *body = EXPORT_ENVIRONMENT (env); | |
2007 | SCM entry = scm_assq (sym, body->signature); | |
2008 | ||
7888309b | 2009 | if (scm_is_false (entry)) |
5d3e2388 DH |
2010 | { |
2011 | return SCM_UNDEFINED; | |
2012 | } | |
2013 | else | |
2014 | { | |
bc36d050 | 2015 | if (scm_is_eq (SCM_CADR (entry), symbol_mutable_location)) |
5d3e2388 DH |
2016 | return SCM_ENVIRONMENT_SET (body->private, sym, val); |
2017 | else | |
2018 | return SCM_ENVIRONMENT_LOCATION_IMMUTABLE; | |
2019 | } | |
2020 | } | |
2021 | #undef FUNC_NAME | |
2022 | ||
2023 | ||
2024 | static SCM | |
2025 | export_environment_cell (SCM env, SCM sym, int for_write) | |
2026 | #define FUNC_NAME "export_environment_cell" | |
2027 | { | |
2028 | struct export_environment *body = EXPORT_ENVIRONMENT (env); | |
2029 | SCM entry = scm_assq (sym, body->signature); | |
2030 | ||
7888309b | 2031 | if (scm_is_false (entry)) |
5d3e2388 DH |
2032 | { |
2033 | return SCM_UNDEFINED; | |
2034 | } | |
2035 | else | |
2036 | { | |
bc36d050 | 2037 | if (!for_write || scm_is_eq (SCM_CADR (entry), symbol_mutable_location)) |
5d3e2388 DH |
2038 | return SCM_ENVIRONMENT_CELL (body->private, sym, for_write); |
2039 | else | |
2040 | return SCM_ENVIRONMENT_LOCATION_IMMUTABLE; | |
2041 | } | |
2042 | } | |
2043 | #undef FUNC_NAME | |
2044 | ||
2045 | ||
2046 | static SCM | |
e841c3e0 | 2047 | export_environment_mark (SCM env) |
5d3e2388 DH |
2048 | { |
2049 | struct export_environment *body = EXPORT_ENVIRONMENT (env); | |
2050 | ||
2051 | scm_gc_mark (body->private); | |
2052 | scm_gc_mark (body->private_observer); | |
2053 | scm_gc_mark (body->signature); | |
2054 | ||
2055 | return core_environments_mark (env); | |
2056 | } | |
2057 | ||
2058 | ||
4c9419ac | 2059 | static void |
e841c3e0 | 2060 | export_environment_free (SCM env) |
5d3e2388 DH |
2061 | { |
2062 | core_environments_finalize (env); | |
4c9419ac MV |
2063 | scm_gc_free (EXPORT_ENVIRONMENT (env), sizeof (struct export_environment), |
2064 | "export environment"); | |
5d3e2388 DH |
2065 | } |
2066 | ||
2067 | ||
2068 | static int | |
e81d98ec DH |
2069 | export_environment_print (SCM type, SCM port, |
2070 | scm_print_state *pstate SCM_UNUSED) | |
5d3e2388 | 2071 | { |
b9bd8526 | 2072 | SCM address = scm_from_size_t (SCM_UNPACK (type)); |
e11e83f3 | 2073 | SCM base16 = scm_number_to_string (address, scm_from_int (16)); |
5d3e2388 DH |
2074 | |
2075 | scm_puts ("#<export environment ", port); | |
18f9d343 | 2076 | scm_display (base16, port); |
5d3e2388 DH |
2077 | scm_puts (">", port); |
2078 | ||
2079 | return 1; | |
2080 | } | |
2081 | ||
2082 | ||
2083 | static struct scm_environment_funcs export_environment_funcs = { | |
2084 | export_environment_ref, | |
2085 | export_environment_fold, | |
2086 | export_environment_define, | |
2087 | export_environment_undefine, | |
2088 | export_environment_set_x, | |
2089 | export_environment_cell, | |
2090 | core_environments_observe, | |
2091 | core_environments_unobserve, | |
e841c3e0 KN |
2092 | export_environment_mark, |
2093 | export_environment_free, | |
2094 | export_environment_print | |
5d3e2388 DH |
2095 | }; |
2096 | ||
2097 | ||
2098 | void *scm_type_export_environment = &export_environment_funcs; | |
2099 | ||
2100 | ||
2101 | static void | |
e81d98ec | 2102 | export_environment_observer (SCM caller SCM_UNUSED, SCM export_env) |
5d3e2388 DH |
2103 | { |
2104 | core_environments_broadcast (export_env); | |
2105 | } | |
2106 | ||
2107 | ||
2108 | SCM_DEFINE (scm_make_export_environment, "make-export-environment", 2, 0, 0, | |
2109 | (SCM private, SCM signature), | |
0fb104ed MG |
2110 | "Return a new environment @var{exp} containing only those\n" |
2111 | "bindings in private whose symbols are present in\n" | |
2112 | "@var{signature}. The @var{private} argument must be an\n" | |
2113 | "environment.\n\n" | |
2114 | "The environment @var{exp} binds symbol to location when\n" | |
2115 | "@var{env} does, and symbol is exported by @var{signature}.\n\n" | |
2116 | "@var{signature} is a list specifying which of the bindings in\n" | |
2117 | "@var{private} should be visible in @var{exp}. Each element of\n" | |
2118 | "@var{signature} should be a list of the form:\n" | |
5d3e2388 DH |
2119 | " (symbol attribute ...)\n" |
2120 | "where each attribute is one of the following:\n" | |
0fb104ed MG |
2121 | "@table @asis\n" |
2122 | "@item the symbol @code{mutable-location}\n" | |
2123 | " @var{exp} should treat the\n" | |
2124 | " location bound to symbol as mutable. That is, @var{exp}\n" | |
2125 | " will pass calls to @code{environment-set!} or\n" | |
2126 | " @code{environment-cell} directly through to private.\n" | |
2127 | "@item the symbol @code{immutable-location}\n" | |
2128 | " @var{exp} should treat\n" | |
2129 | " the location bound to symbol as immutable. If the program\n" | |
2130 | " applies @code{environment-set!} to @var{exp} and symbol, or\n" | |
2131 | " calls @code{environment-cell} to obtain a writable value\n" | |
2132 | " cell, @code{environment-set!} will signal an\n" | |
2133 | " @code{environment:immutable-location} error. Note that, even\n" | |
2134 | " if an export environment treats a location as immutable, the\n" | |
5d3e2388 DH |
2135 | " underlying environment may treat it as mutable, so its\n" |
2136 | " value may change.\n" | |
0fb104ed | 2137 | "@end table\n" |
5d3e2388 | 2138 | "It is an error for an element of signature to specify both\n" |
0fb104ed MG |
2139 | "@code{mutable-location} and @code{immutable-location}. If\n" |
2140 | "neither is specified, @code{immutable-location} is assumed.\n\n" | |
5d3e2388 | 2141 | "As a special case, if an element of signature is a lone\n" |
0fb104ed MG |
2142 | "symbol @var{sym}, it is equivalent to an element of the form\n" |
2143 | "@code{(sym)}.\n\n" | |
2144 | "All bindings in @var{exp} are immutable. If you apply\n" | |
2145 | "@code{environment-define} or @code{environment-undefine} to\n" | |
2146 | "@var{exp}, Guile will signal an\n" | |
2147 | "@code{environment:immutable-binding} error. However,\n" | |
2148 | "notice that the set of bindings in @var{exp} may still change,\n" | |
2149 | "if the bindings in private change.") | |
5d3e2388 DH |
2150 | #define FUNC_NAME s_scm_make_export_environment |
2151 | { | |
1be6b49c | 2152 | size_t size; |
5d3e2388 DH |
2153 | struct export_environment *body; |
2154 | SCM env; | |
2155 | ||
2156 | SCM_ASSERT (SCM_ENVIRONMENT_P (private), private, SCM_ARG1, FUNC_NAME); | |
2157 | ||
2158 | size = sizeof (struct export_environment); | |
4c9419ac | 2159 | body = scm_gc_malloc (size, "export environment"); |
5d3e2388 DH |
2160 | |
2161 | core_environments_preinit (&body->base); | |
2162 | body->private = SCM_BOOL_F; | |
2163 | body->private_observer = SCM_BOOL_F; | |
2164 | body->signature = SCM_BOOL_F; | |
2165 | ||
2166 | env = scm_make_environment (body); | |
2167 | ||
2168 | core_environments_init (&body->base, &export_environment_funcs); | |
2169 | body->private = private; | |
2170 | body->private_observer | |
2171 | = SCM_ENVIRONMENT_OBSERVE (private, export_environment_observer, env, 1); | |
2172 | body->signature = SCM_EOL; | |
2173 | ||
2174 | scm_export_environment_set_signature_x (env, signature); | |
2175 | ||
2176 | return env; | |
2177 | } | |
2178 | #undef FUNC_NAME | |
2179 | ||
2180 | ||
2181 | SCM_DEFINE (scm_export_environment_p, "export-environment?", 1, 0, 0, | |
2182 | (SCM object), | |
0fb104ed MG |
2183 | "Return @code{#t} if object is an export environment, or\n" |
2184 | "@code{#f} otherwise.") | |
5d3e2388 DH |
2185 | #define FUNC_NAME s_scm_export_environment_p |
2186 | { | |
7888309b | 2187 | return scm_from_bool (SCM_EXPORT_ENVIRONMENT_P (object)); |
5d3e2388 DH |
2188 | } |
2189 | #undef FUNC_NAME | |
2190 | ||
2191 | ||
2192 | SCM_DEFINE (scm_export_environment_private, "export-environment-private", 1, 0, 0, | |
2193 | (SCM env), | |
0fb104ed | 2194 | "Return the private environment of export environment @var{env}.") |
5d3e2388 DH |
2195 | #define FUNC_NAME s_scm_export_environment_private |
2196 | { | |
2197 | SCM_ASSERT (SCM_EXPORT_ENVIRONMENT_P (env), env, SCM_ARG1, FUNC_NAME); | |
2198 | ||
2199 | return EXPORT_ENVIRONMENT (env)->private; | |
2200 | } | |
2201 | #undef FUNC_NAME | |
2202 | ||
2203 | ||
2204 | SCM_DEFINE (scm_export_environment_set_private_x, "export-environment-set-private!", 2, 0, 0, | |
2205 | (SCM env, SCM private), | |
0fb104ed | 2206 | "Change the private environment of export environment @var{env}.") |
5d3e2388 DH |
2207 | #define FUNC_NAME s_scm_export_environment_set_private_x |
2208 | { | |
2209 | struct export_environment *body; | |
2210 | ||
2211 | SCM_ASSERT (SCM_EXPORT_ENVIRONMENT_P (env), env, SCM_ARG1, FUNC_NAME); | |
2212 | SCM_ASSERT (SCM_ENVIRONMENT_P (private), private, SCM_ARG2, FUNC_NAME); | |
2213 | ||
2214 | body = EXPORT_ENVIRONMENT (env); | |
2215 | SCM_ENVIRONMENT_UNOBSERVE (private, body->private_observer); | |
2216 | ||
2217 | body->private = private; | |
2218 | body->private_observer | |
2219 | = SCM_ENVIRONMENT_OBSERVE (private, export_environment_observer, env, 1); | |
2220 | ||
2221 | return SCM_UNSPECIFIED; | |
2222 | } | |
2223 | #undef FUNC_NAME | |
2224 | ||
2225 | ||
2226 | SCM_DEFINE (scm_export_environment_signature, "export-environment-signature", 1, 0, 0, | |
2227 | (SCM env), | |
0fb104ed | 2228 | "Return the signature of export environment @var{env}.") |
5d3e2388 DH |
2229 | #define FUNC_NAME s_scm_export_environment_signature |
2230 | { | |
2231 | SCM_ASSERT (SCM_EXPORT_ENVIRONMENT_P (env), env, SCM_ARG1, FUNC_NAME); | |
2232 | ||
2233 | return EXPORT_ENVIRONMENT (env)->signature; | |
2234 | } | |
2235 | #undef FUNC_NAME | |
2236 | ||
2237 | ||
2238 | static SCM | |
2239 | export_environment_parse_signature (SCM signature, const char* caller) | |
2240 | { | |
2241 | SCM result = SCM_EOL; | |
2242 | SCM l; | |
2243 | ||
d2e53ed6 | 2244 | for (l = signature; scm_is_pair (l); l = SCM_CDR (l)) |
5d3e2388 DH |
2245 | { |
2246 | SCM entry = SCM_CAR (l); | |
2247 | ||
cc95e00a | 2248 | if (scm_is_symbol (entry)) |
5d3e2388 DH |
2249 | { |
2250 | SCM new_entry = scm_cons2 (entry, symbol_immutable_location, SCM_EOL); | |
2251 | result = scm_cons (new_entry, result); | |
2252 | } | |
2253 | else | |
2254 | { | |
2255 | SCM sym; | |
2256 | SCM new_entry; | |
2257 | int immutable = 0; | |
2258 | int mutable = 0; | |
2259 | SCM mutability; | |
2260 | SCM l2; | |
2261 | ||
d2e53ed6 | 2262 | SCM_ASSERT (scm_is_pair (entry), entry, SCM_ARGn, caller); |
cc95e00a | 2263 | SCM_ASSERT (scm_is_symbol (SCM_CAR (entry)), entry, SCM_ARGn, caller); |
5d3e2388 DH |
2264 | |
2265 | sym = SCM_CAR (entry); | |
2266 | ||
d2e53ed6 | 2267 | for (l2 = SCM_CDR (entry); scm_is_pair (l2); l2 = SCM_CDR (l2)) |
5d3e2388 DH |
2268 | { |
2269 | SCM attribute = SCM_CAR (l2); | |
bc36d050 | 2270 | if (scm_is_eq (attribute, symbol_immutable_location)) |
5d3e2388 | 2271 | immutable = 1; |
bc36d050 | 2272 | else if (scm_is_eq (attribute, symbol_mutable_location)) |
5d3e2388 DH |
2273 | mutable = 1; |
2274 | else | |
2275 | SCM_ASSERT (0, entry, SCM_ARGn, caller); | |
2276 | } | |
d2e53ed6 | 2277 | SCM_ASSERT (scm_is_null (l2), entry, SCM_ARGn, caller); |
5d3e2388 DH |
2278 | SCM_ASSERT (!mutable || !immutable, entry, SCM_ARGn, caller); |
2279 | ||
2280 | if (!mutable && !immutable) | |
2281 | immutable = 1; | |
2282 | ||
2283 | mutability = mutable ? symbol_mutable_location : symbol_immutable_location; | |
2284 | new_entry = scm_cons2 (sym, mutability, SCM_EOL); | |
2285 | result = scm_cons (new_entry, result); | |
2286 | } | |
2287 | } | |
d2e53ed6 | 2288 | SCM_ASSERT (scm_is_null (l), signature, SCM_ARGn, caller); |
5d3e2388 DH |
2289 | |
2290 | /* Dirk:FIXME:: Now we know that signature is syntactically correct. There | |
2291 | * are, however, no checks for symbols entered twice with contradicting | |
2292 | * mutabilities. It would be nice, to implement this test, to be able to | |
2293 | * call the sort functions conveniently from C. | |
2294 | */ | |
2295 | ||
2296 | return scm_reverse (result); | |
2297 | } | |
2298 | ||
2299 | ||
2300 | SCM_DEFINE (scm_export_environment_set_signature_x, "export-environment-set-signature!", 2, 0, 0, | |
2301 | (SCM env, SCM signature), | |
0fb104ed | 2302 | "Change the signature of export environment @var{env}.") |
5d3e2388 DH |
2303 | #define FUNC_NAME s_scm_export_environment_set_signature_x |
2304 | { | |
2305 | SCM parsed_sig; | |
2306 | ||
2307 | SCM_ASSERT (SCM_EXPORT_ENVIRONMENT_P (env), env, SCM_ARG1, FUNC_NAME); | |
2308 | parsed_sig = export_environment_parse_signature (signature, FUNC_NAME); | |
2309 | ||
2310 | EXPORT_ENVIRONMENT (env)->signature = parsed_sig; | |
2311 | ||
2312 | return SCM_UNSPECIFIED; | |
2313 | } | |
2314 | #undef FUNC_NAME | |
2315 | ||
2316 | \f | |
2317 | ||
2318 | void | |
2319 | scm_environments_prehistory () | |
2320 | { | |
2321 | /* create environment smob */ | |
2322 | scm_tc16_environment = scm_make_smob_type ("environment", 0); | |
e841c3e0 KN |
2323 | scm_set_smob_mark (scm_tc16_environment, environment_mark); |
2324 | scm_set_smob_free (scm_tc16_environment, environment_free); | |
2325 | scm_set_smob_print (scm_tc16_environment, environment_print); | |
5d3e2388 DH |
2326 | |
2327 | /* create observer smob */ | |
2328 | scm_tc16_observer = scm_make_smob_type ("observer", 0); | |
e841c3e0 KN |
2329 | scm_set_smob_mark (scm_tc16_observer, observer_mark); |
2330 | scm_set_smob_print (scm_tc16_observer, observer_print); | |
de42a0ee DH |
2331 | |
2332 | /* create system environment */ | |
2333 | scm_system_environment = scm_make_leaf_environment (); | |
2334 | scm_permanent_object (scm_system_environment); | |
5d3e2388 DH |
2335 | } |
2336 | ||
2337 | ||
2338 | void | |
2339 | scm_init_environments () | |
2340 | { | |
480a873c | 2341 | #include "libguile/environments.x" |
5d3e2388 DH |
2342 | } |
2343 | ||
2344 | ||
2345 | /* | |
2346 | Local Variables: | |
2347 | c-file-style: "gnu" | |
2348 | End: | |
2349 | */ |