Commit | Line | Data |
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2b829bbb | 1 | /* Copyright (C) 1996,1997,1998,1999,2000,2001, 2003, 2004, 2006 Free Software Foundation, Inc. |
0f2d19dd | 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. | |
0f2d19dd | 7 | * |
73be1d9e MV |
8 | * This library is distributed in the hope that it will be useful, |
9 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
10 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
11 | * Lesser General Public License for more details. | |
0f2d19dd | 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 | */ |
1bbd0b84 | 17 | |
0f2d19dd | 18 | \f |
a6f7f57d RB |
19 | #if HAVE_CONFIG_H |
20 | # include <config.h> | |
21 | #endif | |
0f2d19dd | 22 | |
a0599745 | 23 | #include "libguile/_scm.h" |
4e047c3e | 24 | #include "libguile/async.h" |
a0599745 MD |
25 | #include "libguile/chars.h" |
26 | #include "libguile/eval.h" | |
27 | #include "libguile/alist.h" | |
28 | #include "libguile/weaks.h" | |
29 | #include "libguile/hashtab.h" | |
30 | #include "libguile/ports.h" | |
31 | #include "libguile/strings.h" | |
32 | ||
33 | #include "libguile/validate.h" | |
34 | #include "libguile/struct.h" | |
0f2d19dd | 35 | |
d15ad007 LC |
36 | #include "libguile/eq.h" |
37 | ||
95b88819 GH |
38 | #ifdef HAVE_STRING_H |
39 | #include <string.h> | |
40 | #endif | |
41 | ||
5e67dc27 LC |
42 | #include <gc/gc.h> |
43 | ||
0f2d19dd JB |
44 | \f |
45 | ||
46 | static SCM required_vtable_fields = SCM_BOOL_F; | |
98d5f601 | 47 | SCM scm_struct_table; |
0f2d19dd JB |
48 | |
49 | \f | |
a1ec6916 | 50 | SCM_DEFINE (scm_make_struct_layout, "make-struct-layout", 1, 0, 0, |
1bbd0b84 | 51 | (SCM fields), |
b380b885 | 52 | "Return a new structure layout object.\n\n" |
7c31152f | 53 | "@var{fields} must be a string made up of pairs of characters\n" |
b380b885 MD |
54 | "strung together. The first character of each pair describes a field\n" |
55 | "type, the second a field protection. Allowed types are 'p' for\n" | |
56 | "GC-protected Scheme data, 'u' for unprotected binary data, and 's' for\n" | |
04323af4 | 57 | "a field that points to the structure itself. Allowed protections\n" |
9401323e | 58 | "are 'w' for mutable fields, 'r' for read-only fields, and 'o' for opaque\n" |
b380b885 MD |
59 | "fields. The last field protection specification may be capitalized to\n" |
60 | "indicate that the field is a tail-array.") | |
1bbd0b84 | 61 | #define FUNC_NAME s_scm_make_struct_layout |
0f2d19dd JB |
62 | { |
63 | SCM new_sym; | |
d1ca2c64 | 64 | SCM_VALIDATE_STRING (1, fields); |
2ade72d7 | 65 | |
1bbd0b84 | 66 | { /* scope */ |
cc95e00a | 67 | const char * field_desc; |
1be6b49c | 68 | size_t len; |
0f2d19dd JB |
69 | int x; |
70 | ||
cc95e00a | 71 | len = scm_i_string_length (fields); |
2ade72d7 DH |
72 | if (len % 2 == 1) |
73 | SCM_MISC_ERROR ("odd length field specification: ~S", | |
1afff620 | 74 | scm_list_1 (fields)); |
2ade72d7 | 75 | |
cc95e00a | 76 | field_desc = scm_i_string_chars (fields); |
0f2d19dd JB |
77 | |
78 | for (x = 0; x < len; x += 2) | |
79 | { | |
80 | switch (field_desc[x]) | |
81 | { | |
82 | case 'u': | |
83 | case 'p': | |
84 | #if 0 | |
85 | case 'i': | |
86 | case 'd': | |
87 | #endif | |
88 | case 's': | |
89 | break; | |
90 | default: | |
2ade72d7 | 91 | SCM_MISC_ERROR ("unrecognized field type: ~S", |
1afff620 | 92 | scm_list_1 (SCM_MAKE_CHAR (field_desc[x]))); |
0f2d19dd JB |
93 | } |
94 | ||
95 | switch (field_desc[x + 1]) | |
96 | { | |
97 | case 'w': | |
2ade72d7 DH |
98 | if (field_desc[x] == 's') |
99 | SCM_MISC_ERROR ("self fields not writable", SCM_EOL); | |
0f2d19dd JB |
100 | case 'r': |
101 | case 'o': | |
102 | break; | |
2c36c351 MD |
103 | case 'R': |
104 | case 'W': | |
105 | case 'O': | |
2ade72d7 DH |
106 | if (field_desc[x] == 's') |
107 | SCM_MISC_ERROR ("self fields not allowed in tail array", | |
108 | SCM_EOL); | |
109 | if (x != len - 2) | |
110 | SCM_MISC_ERROR ("tail array field must be last field in layout", | |
111 | SCM_EOL); | |
2c36c351 | 112 | break; |
0f2d19dd | 113 | default: |
2ade72d7 | 114 | SCM_MISC_ERROR ("unrecognized ref specification: ~S", |
1afff620 | 115 | scm_list_1 (SCM_MAKE_CHAR (field_desc[x + 1]))); |
0f2d19dd JB |
116 | } |
117 | #if 0 | |
118 | if (field_desc[x] == 'd') | |
119 | { | |
2ade72d7 DH |
120 | if (field_desc[x + 2] != '-') |
121 | SCM_MISC_ERROR ("missing dash field at position ~A", | |
e11e83f3 | 122 | scm_list_1 (scm_from_int (x / 2))); |
0f2d19dd JB |
123 | x += 2; |
124 | goto recheck_ref; | |
125 | } | |
126 | #endif | |
127 | } | |
cc95e00a | 128 | new_sym = scm_string_to_symbol (fields); |
0f2d19dd | 129 | } |
8824ac88 MV |
130 | scm_remember_upto_here_1 (fields); |
131 | return new_sym; | |
0f2d19dd | 132 | } |
1bbd0b84 | 133 | #undef FUNC_NAME |
0f2d19dd JB |
134 | |
135 | \f | |
136 | ||
137 | ||
1cc91f1b | 138 | |
f7620510 | 139 | static void |
92c2555f | 140 | scm_struct_init (SCM handle, SCM layout, scm_t_bits * mem, int tail_elts, SCM inits) |
0f2d19dd | 141 | { |
cc95e00a MV |
142 | unsigned const char *fields_desc = |
143 | (unsigned const char *) scm_i_symbol_chars (layout) - 2; | |
35de7ebe | 144 | unsigned char prot = 0; |
cc95e00a | 145 | int n_fields = scm_i_symbol_length (layout) / 2; |
2c36c351 | 146 | int tailp = 0; |
d8c40b9f | 147 | |
0f2d19dd JB |
148 | while (n_fields) |
149 | { | |
2c36c351 MD |
150 | if (!tailp) |
151 | { | |
152 | fields_desc += 2; | |
153 | prot = fields_desc[1]; | |
154 | if (SCM_LAYOUT_TAILP (prot)) | |
155 | { | |
156 | tailp = 1; | |
157 | prot = prot == 'R' ? 'r' : prot == 'W' ? 'w' : 'o'; | |
d8c40b9f | 158 | *mem++ = tail_elts; |
2c36c351 MD |
159 | n_fields += tail_elts - 1; |
160 | if (n_fields == 0) | |
161 | break; | |
162 | } | |
163 | } | |
164 | ||
0f2d19dd JB |
165 | switch (*fields_desc) |
166 | { | |
167 | #if 0 | |
168 | case 'i': | |
2c36c351 | 169 | if ((prot != 'r' && prot != 'w') || inits == SCM_EOL) |
0f2d19dd JB |
170 | *mem = 0; |
171 | else | |
172 | { | |
b9bd8526 | 173 | *mem = scm_to_long (SCM_CAR (inits)); |
0f2d19dd JB |
174 | inits = SCM_CDR (inits); |
175 | } | |
176 | break; | |
177 | #endif | |
178 | ||
179 | case 'u': | |
d2e53ed6 | 180 | if ((prot != 'r' && prot != 'w') || scm_is_null (inits)) |
0f2d19dd JB |
181 | *mem = 0; |
182 | else | |
183 | { | |
b9bd8526 | 184 | *mem = scm_to_ulong (SCM_CAR (inits)); |
0f2d19dd JB |
185 | inits = SCM_CDR (inits); |
186 | } | |
187 | break; | |
188 | ||
189 | case 'p': | |
d2e53ed6 | 190 | if ((prot != 'r' && prot != 'w') || scm_is_null (inits)) |
d8c40b9f | 191 | *mem = SCM_UNPACK (SCM_BOOL_F); |
0f2d19dd JB |
192 | else |
193 | { | |
d8c40b9f | 194 | *mem = SCM_UNPACK (SCM_CAR (inits)); |
0f2d19dd JB |
195 | inits = SCM_CDR (inits); |
196 | } | |
197 | ||
198 | break; | |
199 | ||
200 | #if 0 | |
201 | case 'd': | |
2c36c351 | 202 | if ((prot != 'r' && prot != 'w') || inits == SCM_EOL) |
0f2d19dd JB |
203 | *((double *)mem) = 0.0; |
204 | else | |
205 | { | |
a5bfe84d | 206 | *mem = scm_num2dbl (SCM_CAR (inits), "scm_struct_init"); |
0f2d19dd JB |
207 | inits = SCM_CDR (inits); |
208 | } | |
209 | fields_desc += 2; | |
210 | break; | |
211 | #endif | |
212 | ||
213 | case 's': | |
d8c40b9f | 214 | *mem = SCM_UNPACK (handle); |
0f2d19dd JB |
215 | break; |
216 | } | |
217 | ||
0f2d19dd JB |
218 | n_fields--; |
219 | mem++; | |
220 | } | |
221 | } | |
222 | ||
223 | ||
a1ec6916 | 224 | SCM_DEFINE (scm_struct_p, "struct?", 1, 0, 0, |
1bbd0b84 | 225 | (SCM x), |
0233bfc1 | 226 | "Return @code{#t} iff @var{x} is a structure object, else\n" |
942e5b91 | 227 | "@code{#f}.") |
1bbd0b84 | 228 | #define FUNC_NAME s_scm_struct_p |
0f2d19dd | 229 | { |
7888309b | 230 | return scm_from_bool(SCM_STRUCTP (x)); |
0f2d19dd | 231 | } |
1bbd0b84 | 232 | #undef FUNC_NAME |
0f2d19dd | 233 | |
a1ec6916 | 234 | SCM_DEFINE (scm_struct_vtable_p, "struct-vtable?", 1, 0, 0, |
1bbd0b84 | 235 | (SCM x), |
0233bfc1 | 236 | "Return @code{#t} iff @var{x} is a vtable structure.") |
1bbd0b84 | 237 | #define FUNC_NAME s_scm_struct_vtable_p |
0f2d19dd JB |
238 | { |
239 | SCM layout; | |
92c2555f | 240 | scm_t_bits * mem; |
8824ac88 | 241 | int tmp; |
0f2d19dd JB |
242 | |
243 | if (!SCM_STRUCTP (x)) | |
244 | return SCM_BOOL_F; | |
245 | ||
246 | layout = SCM_STRUCT_LAYOUT (x); | |
247 | ||
cc95e00a MV |
248 | if (scm_i_symbol_length (layout) |
249 | < scm_i_string_length (required_vtable_fields)) | |
0f2d19dd JB |
250 | return SCM_BOOL_F; |
251 | ||
cc95e00a MV |
252 | tmp = strncmp (scm_i_symbol_chars (layout), |
253 | scm_i_string_chars (required_vtable_fields), | |
254 | scm_i_string_length (required_vtable_fields)); | |
8824ac88 MV |
255 | scm_remember_upto_here_1 (required_vtable_fields); |
256 | if (tmp) | |
0f2d19dd JB |
257 | return SCM_BOOL_F; |
258 | ||
259 | mem = SCM_STRUCT_DATA (x); | |
260 | ||
cc95e00a | 261 | return scm_from_bool (scm_is_symbol (SCM_PACK (mem[scm_vtable_index_layout]))); |
0f2d19dd | 262 | } |
1bbd0b84 | 263 | #undef FUNC_NAME |
0f2d19dd | 264 | |
14d1400f JB |
265 | |
266 | /* All struct data must be allocated at an address whose bottom three | |
267 | bits are zero. This is because the tag for a struct lives in the | |
268 | bottom three bits of the struct's car, and the upper bits point to | |
269 | the data of its vtable, which is a struct itself. Thus, if the | |
270 | address of that data doesn't end in three zeros, tagging it will | |
271 | destroy the pointer. | |
272 | ||
273 | This function allocates a block of memory, and returns a pointer at | |
274 | least scm_struct_n_extra_words words into the block. Furthermore, | |
275 | it guarantees that that pointer's least three significant bits are | |
276 | all zero. | |
277 | ||
278 | The argument n_words should be the number of words that should | |
279 | appear after the returned address. (That is, it shouldn't include | |
280 | scm_struct_n_extra_words.) | |
281 | ||
282 | This function initializes the following fields of the struct: | |
283 | ||
ad196599 | 284 | scm_struct_i_ptr --- the actual start of the block of memory; the |
14d1400f JB |
285 | address you should pass to 'free' to dispose of the block. |
286 | This field allows us to both guarantee that the returned | |
287 | address is divisible by eight, and allow the GC to free the | |
288 | block. | |
289 | ||
290 | scm_struct_i_n_words --- the number of words allocated to the | |
291 | block, including the extra fields. This is used by the GC. | |
292 | ||
14d1400f JB |
293 | Ugh. */ |
294 | ||
295 | ||
92c2555f | 296 | scm_t_bits * |
4c9419ac | 297 | scm_alloc_struct (int n_words, int n_extra, const char *what) |
14d1400f | 298 | { |
92c2555f | 299 | int size = sizeof (scm_t_bits) * (n_words + n_extra) + 7; |
4c9419ac | 300 | void * block = scm_gc_malloc (size, what); |
14d1400f JB |
301 | |
302 | /* Adjust the pointer to hide the extra words. */ | |
92c2555f | 303 | scm_t_bits * p = (scm_t_bits *) block + n_extra; |
14d1400f JB |
304 | |
305 | /* Adjust it even further so it's aligned on an eight-byte boundary. */ | |
92c2555f | 306 | p = (scm_t_bits *) (((scm_t_bits) p + 7) & ~7); |
14d1400f | 307 | |
ad196599 | 308 | /* Initialize a few fields as described above. */ |
92c2555f MV |
309 | p[scm_struct_i_free] = (scm_t_bits) scm_struct_free_standard; |
310 | p[scm_struct_i_ptr] = (scm_t_bits) block; | |
c8045e8d | 311 | p[scm_struct_i_n_words] = n_words; |
ad196599 | 312 | p[scm_struct_i_flags] = 0; |
14d1400f JB |
313 | |
314 | return p; | |
315 | } | |
316 | ||
5e67dc27 LC |
317 | \f |
318 | /* Finalization. */ | |
319 | ||
320 | ||
321 | /* Invoke the finalizer of the struct pointed to by PTR. */ | |
322 | static void | |
323 | struct_finalizer_trampoline (GC_PTR ptr, GC_PTR unused_data) | |
324 | { | |
325 | SCM obj = PTR2SCM (ptr); | |
326 | ||
327 | /* XXX - use less explicit code. */ | |
328 | scm_t_bits word0 = SCM_CELL_WORD_0 (obj) - scm_tc3_struct; | |
329 | scm_t_bits *vtable_data = (scm_t_bits *) word0; | |
330 | scm_t_bits *data = SCM_STRUCT_DATA (obj); | |
331 | scm_t_struct_free free_struct_data | |
332 | = ((scm_t_struct_free) vtable_data[scm_struct_i_free]); | |
333 | ||
334 | SCM_SET_CELL_TYPE (obj, scm_tc_free_cell); | |
335 | ||
336 | #if 0 | |
337 | /* A sanity check. However, this check can fail if the free function | |
338 | changed between the `make-struct' time and now. */ | |
339 | if (free_struct_data != (scm_t_struct_free)unused_data) | |
340 | abort (); | |
341 | #endif | |
342 | ||
343 | if (free_struct_data) | |
344 | free_struct_data (vtable_data, data); | |
345 | } | |
346 | ||
347 | ||
348 | ||
4c9419ac | 349 | void |
92c2555f MV |
350 | scm_struct_free_0 (scm_t_bits * vtable SCM_UNUSED, |
351 | scm_t_bits * data SCM_UNUSED) | |
ad196599 | 352 | { |
ad196599 MD |
353 | } |
354 | ||
4c9419ac | 355 | void |
92c2555f | 356 | scm_struct_free_light (scm_t_bits * vtable, scm_t_bits * data) |
ad196599 | 357 | { |
4c9419ac MV |
358 | size_t n = vtable [scm_struct_i_size] & ~SCM_STRUCTF_MASK; |
359 | scm_gc_free (data, n, "struct"); | |
ad196599 MD |
360 | } |
361 | ||
4c9419ac | 362 | void |
92c2555f | 363 | scm_struct_free_standard (scm_t_bits * vtable SCM_UNUSED, scm_t_bits * data) |
ad196599 | 364 | { |
c8045e8d | 365 | size_t n = (data[scm_struct_i_n_words] + scm_struct_n_extra_words) |
92c2555f | 366 | * sizeof (scm_t_bits) + 7; |
4c9419ac | 367 | scm_gc_free ((void *) data[scm_struct_i_ptr], n, "heavy struct"); |
ad196599 MD |
368 | } |
369 | ||
4c9419ac | 370 | void |
92c2555f | 371 | scm_struct_free_entity (scm_t_bits * vtable SCM_UNUSED, scm_t_bits * data) |
ad196599 | 372 | { |
c8045e8d | 373 | size_t n = (data[scm_struct_i_n_words] + scm_struct_entity_n_extra_words) |
92c2555f | 374 | * sizeof (scm_t_bits) + 7; |
4c9419ac | 375 | scm_gc_free ((void *) data[scm_struct_i_ptr], n, "entity struct"); |
ad196599 | 376 | } |
14d1400f | 377 | |
08c880a3 | 378 | |
5e67dc27 | 379 | \f |
a1ec6916 | 380 | SCM_DEFINE (scm_make_struct, "make-struct", 2, 0, 1, |
1bbd0b84 | 381 | (SCM vtable, SCM tail_array_size, SCM init), |
b380b885 | 382 | "Create a new structure.\n\n" |
1bee0e70 | 383 | "@var{type} must be a vtable structure (@pxref{Vtables}).\n\n" |
b380b885 MD |
384 | "@var{tail-elts} must be a non-negative integer. If the layout\n" |
385 | "specification indicated by @var{type} includes a tail-array,\n" | |
386 | "this is the number of elements allocated to that array.\n\n" | |
6386e25c | 387 | "The @var{init1}, @dots{} are optional arguments describing how\n" |
04323af4 MD |
388 | "successive fields of the structure should be initialized. Only fields\n" |
389 | "with protection 'r' or 'w' can be initialized, except for fields of\n" | |
390 | "type 's', which are automatically initialized to point to the new\n" | |
391 | "structure itself; fields with protection 'o' can not be initialized by\n" | |
392 | "Scheme programs.\n\n" | |
393 | "If fewer optional arguments than initializable fields are supplied,\n" | |
394 | "fields of type 'p' get default value #f while fields of type 'u' are\n" | |
395 | "initialized to 0.\n\n" | |
396 | "Structs are currently the basic representation for record-like data\n" | |
397 | "structures in Guile. The plan is to eventually replace them with a\n" | |
398 | "new representation which will at the same time be easier to use and\n" | |
399 | "more powerful.\n\n" | |
6386e25c | 400 | "For more information, see the documentation for @code{make-vtable-vtable}.") |
1bbd0b84 | 401 | #define FUNC_NAME s_scm_make_struct |
0f2d19dd JB |
402 | { |
403 | SCM layout; | |
a55c2b68 MV |
404 | size_t basic_size; |
405 | size_t tail_elts; | |
5e67dc27 | 406 | scm_t_bits *data, *c_vtable; |
0f2d19dd JB |
407 | SCM handle; |
408 | ||
34d19ef6 | 409 | SCM_VALIDATE_VTABLE (1, vtable); |
af45e3b0 | 410 | SCM_VALIDATE_REST_ARGUMENT (init); |
0f2d19dd | 411 | |
5e67dc27 LC |
412 | c_vtable = SCM_STRUCT_DATA (vtable); |
413 | ||
414 | layout = SCM_PACK (c_vtable [scm_vtable_index_layout]); | |
cc95e00a | 415 | basic_size = scm_i_symbol_length (layout) / 2; |
a55c2b68 | 416 | tail_elts = scm_to_size_t (tail_array_size); |
9de87eea | 417 | SCM_CRITICAL_SECTION_START; |
5e67dc27 | 418 | if (c_vtable[scm_struct_i_flags] & SCM_STRUCTF_ENTITY) |
a5bfe84d MD |
419 | { |
420 | data = scm_alloc_struct (basic_size + tail_elts, | |
98d5f601 | 421 | scm_struct_entity_n_extra_words, |
4c9419ac | 422 | "entity struct"); |
c8045e8d DH |
423 | data[scm_struct_i_procedure] = SCM_UNPACK (SCM_BOOL_F); |
424 | data[scm_struct_i_setter] = SCM_UNPACK (SCM_BOOL_F); | |
a5bfe84d MD |
425 | } |
426 | else | |
427 | data = scm_alloc_struct (basic_size + tail_elts, | |
428 | scm_struct_n_extra_words, | |
4c9419ac | 429 | "struct"); |
5e67dc27 | 430 | handle = scm_double_cell ((((scm_t_bits) c_vtable) |
228a24ef DH |
431 | + scm_tc3_struct), |
432 | (scm_t_bits) data, 0, 0); | |
f7620510 | 433 | scm_struct_init (handle, layout, data, tail_elts, init); |
5e67dc27 LC |
434 | |
435 | if (c_vtable[scm_struct_i_free]) | |
436 | { | |
437 | /* Register a finalizer for the newly created instance. */ | |
438 | GC_finalization_proc prev_finalizer; | |
439 | GC_PTR prev_finalizer_data; | |
440 | scm_t_struct_free free_struct = | |
441 | (scm_t_struct_free)c_vtable[scm_struct_i_free]; | |
442 | ||
443 | GC_REGISTER_FINALIZER_NO_ORDER (SCM2PTR (handle), | |
444 | struct_finalizer_trampoline, | |
445 | free_struct, | |
446 | &prev_finalizer, | |
447 | &prev_finalizer_data); | |
448 | } | |
449 | ||
9de87eea | 450 | SCM_CRITICAL_SECTION_END; |
0f2d19dd JB |
451 | return handle; |
452 | } | |
1bbd0b84 | 453 | #undef FUNC_NAME |
0f2d19dd JB |
454 | |
455 | ||
456 | ||
a1ec6916 | 457 | SCM_DEFINE (scm_make_vtable_vtable, "make-vtable-vtable", 2, 0, 1, |
04323af4 | 458 | (SCM user_fields, SCM tail_array_size, SCM init), |
b380b885 | 459 | "Return a new, self-describing vtable structure.\n\n" |
04323af4 MD |
460 | "@var{user-fields} is a string describing user defined fields of the\n" |
461 | "vtable beginning at index @code{vtable-offset-user}\n" | |
462 | "(see @code{make-struct-layout}).\n\n" | |
b380b885 MD |
463 | "@var{tail-size} specifies the size of the tail-array (if any) of\n" |
464 | "this vtable.\n\n" | |
6386e25c | 465 | "@var{init1}, @dots{} are the optional initializers for the fields of\n" |
04323af4 MD |
466 | "the vtable.\n\n" |
467 | "Vtables have one initializable system field---the struct printer.\n" | |
468 | "This field comes before the user fields in the initializers passed\n" | |
469 | "to @code{make-vtable-vtable} and @code{make-struct}, and thus works as\n" | |
470 | "a third optional argument to @code{make-vtable-vtable} and a fourth to\n" | |
471 | "@code{make-struct} when creating vtables:\n\n" | |
472 | "If the value is a procedure, it will be called instead of the standard\n" | |
473 | "printer whenever a struct described by this vtable is printed.\n" | |
474 | "The procedure will be called with arguments STRUCT and PORT.\n\n" | |
475 | "The structure of a struct is described by a vtable, so the vtable is\n" | |
476 | "in essence the type of the struct. The vtable is itself a struct with\n" | |
477 | "a vtable. This could go on forever if it weren't for the\n" | |
29b4f9fb | 478 | "vtable-vtables which are self-describing vtables, and thus terminate\n" |
04323af4 MD |
479 | "the chain.\n\n" |
480 | "There are several potential ways of using structs, but the standard\n" | |
481 | "one is to use three kinds of structs, together building up a type\n" | |
482 | "sub-system: one vtable-vtable working as the root and one or several\n" | |
483 | "\"types\", each with a set of \"instances\". (The vtable-vtable should be\n" | |
29b4f9fb | 484 | "compared to the class <class> which is the class of itself.)\n\n" |
1e6808ea | 485 | "@lisp\n" |
04323af4 MD |
486 | "(define ball-root (make-vtable-vtable \"pr\" 0))\n\n" |
487 | "(define (make-ball-type ball-color)\n" | |
488 | " (make-struct ball-root 0\n" | |
489 | " (make-struct-layout \"pw\")\n" | |
490 | " (lambda (ball port)\n" | |
491 | " (format port \"#<a ~A ball owned by ~A>\"\n" | |
492 | " (color ball)\n" | |
493 | " (owner ball)))\n" | |
494 | " ball-color))\n" | |
495 | "(define (color ball) (struct-ref (struct-vtable ball) vtable-offset-user))\n" | |
496 | "(define (owner ball) (struct-ref ball 0))\n\n" | |
497 | "(define red (make-ball-type 'red))\n" | |
498 | "(define green (make-ball-type 'green))\n\n" | |
499 | "(define (make-ball type owner) (make-struct type 0 owner))\n\n" | |
500 | "(define ball (make-ball green 'Nisse))\n" | |
501 | "ball @result{} #<a green ball owned by Nisse>\n" | |
9401323e | 502 | "@end lisp") |
1bbd0b84 | 503 | #define FUNC_NAME s_scm_make_vtable_vtable |
0f2d19dd JB |
504 | { |
505 | SCM fields; | |
506 | SCM layout; | |
a55c2b68 MV |
507 | size_t basic_size; |
508 | size_t tail_elts; | |
509 | scm_t_bits *data; | |
0f2d19dd JB |
510 | SCM handle; |
511 | ||
d1ca2c64 | 512 | SCM_VALIDATE_STRING (1, user_fields); |
af45e3b0 | 513 | SCM_VALIDATE_REST_ARGUMENT (init); |
0f2d19dd | 514 | |
1afff620 KN |
515 | fields = scm_string_append (scm_list_2 (required_vtable_fields, |
516 | user_fields)); | |
0f2d19dd | 517 | layout = scm_make_struct_layout (fields); |
cc95e00a | 518 | basic_size = scm_i_symbol_length (layout) / 2; |
a55c2b68 | 519 | tail_elts = scm_to_size_t (tail_array_size); |
9de87eea | 520 | SCM_CRITICAL_SECTION_START; |
a5bfe84d MD |
521 | data = scm_alloc_struct (basic_size + tail_elts, |
522 | scm_struct_n_extra_words, | |
4c9419ac | 523 | "struct"); |
228a24ef DH |
524 | handle = scm_double_cell ((scm_t_bits) data + scm_tc3_struct, |
525 | (scm_t_bits) data, 0, 0); | |
f7620510 DH |
526 | data [scm_vtable_index_layout] = SCM_UNPACK (layout); |
527 | scm_struct_init (handle, layout, data, tail_elts, scm_cons (layout, init)); | |
9de87eea | 528 | SCM_CRITICAL_SECTION_END; |
0f2d19dd JB |
529 | return handle; |
530 | } | |
1bbd0b84 | 531 | #undef FUNC_NAME |
0f2d19dd | 532 | |
d15ad007 LC |
533 | |
534 | /* Return true if S1 and S2 are equal structures, i.e., if their vtable and | |
535 | contents are the same. Field protections are honored. Thus, it is an | |
536 | error to test the equality of structures that contain opaque fields. */ | |
537 | SCM | |
538 | scm_i_struct_equalp (SCM s1, SCM s2) | |
539 | #define FUNC_NAME "scm_i_struct_equalp" | |
540 | { | |
541 | SCM vtable1, vtable2, layout; | |
542 | size_t struct_size, field_num; | |
543 | ||
544 | SCM_VALIDATE_STRUCT (1, s1); | |
545 | SCM_VALIDATE_STRUCT (2, s2); | |
546 | ||
547 | vtable1 = SCM_STRUCT_VTABLE (s1); | |
548 | vtable2 = SCM_STRUCT_VTABLE (s2); | |
549 | ||
550 | if (!scm_is_eq (vtable1, vtable2)) | |
551 | return SCM_BOOL_F; | |
552 | ||
553 | layout = SCM_STRUCT_LAYOUT (s1); | |
554 | struct_size = scm_i_symbol_length (layout) / 2; | |
555 | ||
556 | for (field_num = 0; field_num < struct_size; field_num++) | |
557 | { | |
558 | SCM s_field_num; | |
559 | SCM field1, field2; | |
560 | ||
561 | /* We have to use `scm_struct_ref ()' here so that fields are accessed | |
562 | consistently, notably wrt. field types and access rights. */ | |
563 | s_field_num = scm_from_size_t (field_num); | |
564 | field1 = scm_struct_ref (s1, s_field_num); | |
565 | field2 = scm_struct_ref (s2, s_field_num); | |
566 | ||
567 | if (scm_is_false (scm_equal_p (field1, field2))) | |
568 | return SCM_BOOL_F; | |
569 | } | |
570 | ||
571 | return SCM_BOOL_T; | |
572 | } | |
573 | #undef FUNC_NAME | |
574 | ||
575 | ||
0f2d19dd JB |
576 | \f |
577 | ||
578 | ||
a1ec6916 | 579 | SCM_DEFINE (scm_struct_ref, "struct-ref", 2, 0, 0, |
1bbd0b84 | 580 | (SCM handle, SCM pos), |
8f85c0c6 | 581 | "@deffnx {Scheme Procedure} struct-set! struct n value\n" |
b380b885 MD |
582 | "Access (or modify) the @var{n}th field of @var{struct}.\n\n" |
583 | "If the field is of type 'p', then it can be set to an arbitrary value.\n\n" | |
584 | "If the field is of type 'u', then it can only be set to a non-negative\n" | |
585 | "integer value small enough to fit in one machine word.") | |
1bbd0b84 | 586 | #define FUNC_NAME s_scm_struct_ref |
0f2d19dd | 587 | { |
5e840c2e | 588 | SCM answer = SCM_UNDEFINED; |
92c2555f | 589 | scm_t_bits * data; |
0f2d19dd | 590 | SCM layout; |
cc95e00a | 591 | size_t layout_len; |
a55c2b68 | 592 | size_t p; |
92c2555f | 593 | scm_t_bits n_fields; |
cc95e00a | 594 | const char *fields_desc; |
e51fe79c | 595 | char field_type = 0; |
0f2d19dd JB |
596 | |
597 | ||
34d19ef6 | 598 | SCM_VALIDATE_STRUCT (1, handle); |
0f2d19dd JB |
599 | |
600 | layout = SCM_STRUCT_LAYOUT (handle); | |
601 | data = SCM_STRUCT_DATA (handle); | |
a55c2b68 | 602 | p = scm_to_size_t (pos); |
0f2d19dd | 603 | |
cc95e00a MV |
604 | fields_desc = scm_i_symbol_chars (layout); |
605 | layout_len = scm_i_symbol_length (layout); | |
d8c40b9f | 606 | n_fields = data[scm_struct_i_n_words]; |
2c36c351 | 607 | |
34d19ef6 | 608 | SCM_ASSERT_RANGE(1, pos, p < n_fields); |
0f2d19dd | 609 | |
cc95e00a | 610 | if (p * 2 < layout_len) |
2c36c351 | 611 | { |
e51fe79c | 612 | char ref; |
2c36c351 MD |
613 | field_type = fields_desc[p * 2]; |
614 | ref = fields_desc[p * 2 + 1]; | |
615 | if ((ref != 'r') && (ref != 'w')) | |
616 | { | |
617 | if ((ref == 'R') || (ref == 'W')) | |
618 | field_type = 'u'; | |
619 | else | |
1afff620 | 620 | SCM_MISC_ERROR ("ref denied for field ~A", scm_list_1 (pos)); |
2c36c351 MD |
621 | } |
622 | } | |
cc95e00a MV |
623 | else if (fields_desc[layout_len - 1] != 'O') |
624 | field_type = fields_desc[layout_len - 2]; | |
2c36c351 | 625 | else |
1afff620 | 626 | SCM_MISC_ERROR ("ref denied for field ~A", scm_list_1 (pos)); |
2c36c351 | 627 | |
0f2d19dd JB |
628 | switch (field_type) |
629 | { | |
630 | case 'u': | |
b9bd8526 | 631 | answer = scm_from_ulong (data[p]); |
0f2d19dd JB |
632 | break; |
633 | ||
634 | #if 0 | |
635 | case 'i': | |
b9bd8526 | 636 | answer = scm_from_long (data[p]); |
0f2d19dd JB |
637 | break; |
638 | ||
639 | case 'd': | |
f8de44c1 | 640 | answer = scm_make_real (*((double *)&(data[p]))); |
0f2d19dd JB |
641 | break; |
642 | #endif | |
643 | ||
644 | case 's': | |
645 | case 'p': | |
d8c40b9f | 646 | answer = SCM_PACK (data[p]); |
0f2d19dd JB |
647 | break; |
648 | ||
649 | ||
650 | default: | |
2ade72d7 | 651 | SCM_MISC_ERROR ("unrecognized field type: ~S", |
1afff620 | 652 | scm_list_1 (SCM_MAKE_CHAR (field_type))); |
0f2d19dd JB |
653 | } |
654 | ||
655 | return answer; | |
656 | } | |
1bbd0b84 | 657 | #undef FUNC_NAME |
0f2d19dd JB |
658 | |
659 | ||
a1ec6916 | 660 | SCM_DEFINE (scm_struct_set_x, "struct-set!", 3, 0, 0, |
1bbd0b84 | 661 | (SCM handle, SCM pos, SCM val), |
e3239868 DH |
662 | "Set the slot of the structure @var{handle} with index @var{pos}\n" |
663 | "to @var{val}. Signal an error if the slot can not be written\n" | |
664 | "to.") | |
1bbd0b84 | 665 | #define FUNC_NAME s_scm_struct_set_x |
0f2d19dd | 666 | { |
92c2555f | 667 | scm_t_bits * data; |
0f2d19dd | 668 | SCM layout; |
cc95e00a | 669 | size_t layout_len; |
a55c2b68 | 670 | size_t p; |
0f2d19dd | 671 | int n_fields; |
cc95e00a | 672 | const char *fields_desc; |
e51fe79c | 673 | char field_type = 0; |
0f2d19dd | 674 | |
34d19ef6 | 675 | SCM_VALIDATE_STRUCT (1, handle); |
0f2d19dd JB |
676 | |
677 | layout = SCM_STRUCT_LAYOUT (handle); | |
678 | data = SCM_STRUCT_DATA (handle); | |
a55c2b68 | 679 | p = scm_to_size_t (pos); |
0f2d19dd | 680 | |
cc95e00a MV |
681 | fields_desc = scm_i_symbol_chars (layout); |
682 | layout_len = scm_i_symbol_length (layout); | |
d8c40b9f | 683 | n_fields = data[scm_struct_i_n_words]; |
0f2d19dd | 684 | |
34d19ef6 | 685 | SCM_ASSERT_RANGE (1, pos, p < n_fields); |
0f2d19dd | 686 | |
cc95e00a | 687 | if (p * 2 < layout_len) |
2c36c351 | 688 | { |
e51fe79c | 689 | char set_x; |
2c36c351 MD |
690 | field_type = fields_desc[p * 2]; |
691 | set_x = fields_desc [p * 2 + 1]; | |
692 | if (set_x != 'w') | |
1afff620 | 693 | SCM_MISC_ERROR ("set! denied for field ~A", scm_list_1 (pos)); |
2c36c351 | 694 | } |
cc95e00a MV |
695 | else if (fields_desc[layout_len - 1] == 'W') |
696 | field_type = fields_desc[layout_len - 2]; | |
2c36c351 | 697 | else |
1afff620 | 698 | SCM_MISC_ERROR ("set! denied for field ~A", scm_list_1 (pos)); |
2c36c351 | 699 | |
0f2d19dd JB |
700 | switch (field_type) |
701 | { | |
702 | case 'u': | |
d8c40b9f | 703 | data[p] = SCM_NUM2ULONG (3, val); |
0f2d19dd JB |
704 | break; |
705 | ||
706 | #if 0 | |
707 | case 'i': | |
e4b265d8 | 708 | data[p] = SCM_NUM2LONG (3, val); |
0f2d19dd JB |
709 | break; |
710 | ||
711 | case 'd': | |
712 | *((double *)&(data[p])) = scm_num2dbl (val, (char *)SCM_ARG3); | |
713 | break; | |
714 | #endif | |
715 | ||
716 | case 'p': | |
d8c40b9f | 717 | data[p] = SCM_UNPACK (val); |
0f2d19dd JB |
718 | break; |
719 | ||
720 | case 's': | |
2ade72d7 | 721 | SCM_MISC_ERROR ("self fields immutable", SCM_EOL); |
0f2d19dd JB |
722 | |
723 | default: | |
2ade72d7 | 724 | SCM_MISC_ERROR ("unrecognized field type: ~S", |
1afff620 | 725 | scm_list_1 (SCM_MAKE_CHAR (field_type))); |
0f2d19dd JB |
726 | } |
727 | ||
728 | return val; | |
729 | } | |
1bbd0b84 | 730 | #undef FUNC_NAME |
0f2d19dd JB |
731 | |
732 | ||
a1ec6916 | 733 | SCM_DEFINE (scm_struct_vtable, "struct-vtable", 1, 0, 0, |
1bbd0b84 | 734 | (SCM handle), |
b380b885 | 735 | "Return the vtable structure that describes the type of @var{struct}.") |
1bbd0b84 | 736 | #define FUNC_NAME s_scm_struct_vtable |
0f2d19dd | 737 | { |
34d19ef6 | 738 | SCM_VALIDATE_STRUCT (1, handle); |
0f2d19dd JB |
739 | return SCM_STRUCT_VTABLE (handle); |
740 | } | |
1bbd0b84 | 741 | #undef FUNC_NAME |
0f2d19dd JB |
742 | |
743 | ||
a1ec6916 | 744 | SCM_DEFINE (scm_struct_vtable_tag, "struct-vtable-tag", 1, 0, 0, |
1bbd0b84 | 745 | (SCM handle), |
e3239868 | 746 | "Return the vtable tag of the structure @var{handle}.") |
1bbd0b84 | 747 | #define FUNC_NAME s_scm_struct_vtable_tag |
0f2d19dd | 748 | { |
34d19ef6 | 749 | SCM_VALIDATE_VTABLE (1, handle); |
b9bd8526 | 750 | return scm_from_ulong (((unsigned long)SCM_STRUCT_DATA (handle)) >> 3); |
98d5f601 | 751 | } |
1bbd0b84 | 752 | #undef FUNC_NAME |
98d5f601 MD |
753 | |
754 | /* {Associating names and classes with vtables} | |
755 | * | |
756 | * The name of a vtable should probably be stored as a slot. This is | |
757 | * a backward compatible solution until agreement has been achieved on | |
758 | * how to associate names with vtables. | |
759 | */ | |
760 | ||
c014a02e ML |
761 | unsigned long |
762 | scm_struct_ihashq (SCM obj, unsigned long n) | |
98d5f601 | 763 | { |
ad196599 MD |
764 | /* The length of the hash table should be a relative prime it's not |
765 | necessary to shift down the address. */ | |
f1267706 | 766 | return SCM_UNPACK (obj) % n; |
98d5f601 MD |
767 | } |
768 | ||
769 | SCM | |
770 | scm_struct_create_handle (SCM obj) | |
771 | { | |
772 | SCM handle = scm_hash_fn_create_handle_x (scm_struct_table, | |
773 | obj, | |
774 | SCM_BOOL_F, | |
775 | scm_struct_ihashq, | |
776 | scm_sloppy_assq, | |
777 | 0); | |
7888309b | 778 | if (scm_is_false (SCM_CDR (handle))) |
98d5f601 MD |
779 | SCM_SETCDR (handle, scm_cons (SCM_BOOL_F, SCM_BOOL_F)); |
780 | return handle; | |
781 | } | |
782 | ||
a1ec6916 | 783 | SCM_DEFINE (scm_struct_vtable_name, "struct-vtable-name", 1, 0, 0, |
1bbd0b84 | 784 | (SCM vtable), |
e3239868 | 785 | "Return the name of the vtable @var{vtable}.") |
1bbd0b84 | 786 | #define FUNC_NAME s_scm_struct_vtable_name |
98d5f601 | 787 | { |
34d19ef6 | 788 | SCM_VALIDATE_VTABLE (1, vtable); |
98d5f601 MD |
789 | return SCM_STRUCT_TABLE_NAME (SCM_CDR (scm_struct_create_handle (vtable))); |
790 | } | |
1bbd0b84 | 791 | #undef FUNC_NAME |
98d5f601 | 792 | |
a1ec6916 | 793 | SCM_DEFINE (scm_set_struct_vtable_name_x, "set-struct-vtable-name!", 2, 0, 0, |
1bbd0b84 | 794 | (SCM vtable, SCM name), |
e3239868 | 795 | "Set the name of the vtable @var{vtable} to @var{name}.") |
1bbd0b84 | 796 | #define FUNC_NAME s_scm_set_struct_vtable_name_x |
98d5f601 | 797 | { |
34d19ef6 HWN |
798 | SCM_VALIDATE_VTABLE (1, vtable); |
799 | SCM_VALIDATE_SYMBOL (2, name); | |
98d5f601 MD |
800 | SCM_SET_STRUCT_TABLE_NAME (SCM_CDR (scm_struct_create_handle (vtable)), |
801 | name); | |
802 | return SCM_UNSPECIFIED; | |
0f2d19dd | 803 | } |
1bbd0b84 | 804 | #undef FUNC_NAME |
0f2d19dd JB |
805 | |
806 | ||
807 | \f | |
808 | ||
bafcafb2 | 809 | void |
1bbd0b84 | 810 | scm_print_struct (SCM exp, SCM port, scm_print_state *pstate) |
bafcafb2 | 811 | { |
7888309b | 812 | if (scm_is_true (scm_procedure_p (SCM_STRUCT_PRINTER (exp)))) |
4bfdf158 MD |
813 | scm_printer_apply (SCM_STRUCT_PRINTER (exp), exp, port, pstate); |
814 | else | |
bafcafb2 | 815 | { |
a1ae1799 MD |
816 | SCM vtable = SCM_STRUCT_VTABLE (exp); |
817 | SCM name = scm_struct_vtable_name (vtable); | |
818 | scm_puts ("#<", port); | |
7888309b | 819 | if (scm_is_true (name)) |
a1ae1799 MD |
820 | scm_display (name, port); |
821 | else | |
822 | scm_puts ("struct", port); | |
823 | scm_putc (' ', port); | |
0345e278 | 824 | scm_uintprint (SCM_UNPACK (vtable), 16, port); |
b7f3516f | 825 | scm_putc (':', port); |
0345e278 | 826 | scm_uintprint (SCM_UNPACK (exp), 16, port); |
b7f3516f | 827 | scm_putc ('>', port); |
bafcafb2 | 828 | } |
bafcafb2 | 829 | } |
1cc91f1b | 830 | |
08c880a3 MD |
831 | void |
832 | scm_struct_prehistory () | |
833 | { | |
5e67dc27 | 834 | /* Empty. */ |
08c880a3 MD |
835 | } |
836 | ||
0f2d19dd JB |
837 | void |
838 | scm_init_struct () | |
0f2d19dd | 839 | { |
98d5f601 | 840 | scm_struct_table |
e11e83f3 | 841 | = scm_permanent_object (scm_make_weak_key_hash_table (scm_from_int (31))); |
cc95e00a | 842 | required_vtable_fields = scm_from_locale_string ("prsrpw"); |
0f2d19dd | 843 | scm_permanent_object (required_vtable_fields); |
e11e83f3 MV |
844 | scm_c_define ("vtable-index-layout", scm_from_int (scm_vtable_index_layout)); |
845 | scm_c_define ("vtable-index-vtable", scm_from_int (scm_vtable_index_vtable)); | |
86d31dfe | 846 | scm_c_define ("vtable-index-printer", |
e11e83f3 MV |
847 | scm_from_int (scm_vtable_index_printer)); |
848 | scm_c_define ("vtable-offset-user", scm_from_int (scm_vtable_offset_user)); | |
a0599745 | 849 | #include "libguile/struct.x" |
0f2d19dd | 850 | } |
89e00824 ML |
851 | |
852 | /* | |
853 | Local Variables: | |
854 | c-file-style: "gnu" | |
855 | End: | |
856 | */ |