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2ade72d7 | 1 | /* Copyright (C) 1996,1997,1998,1999,2000,2001 Free Software Foundation, Inc. |
0f2d19dd JB |
2 | * |
3 | * This program is free software; you can redistribute it and/or modify | |
4 | * it under the terms of the GNU General Public License as published by | |
5 | * the Free Software Foundation; either version 2, or (at your option) | |
6 | * any later version. | |
7 | * | |
8 | * This program is distributed in the hope that it will be useful, | |
9 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
10 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
11 | * GNU General Public License for more details. | |
12 | * | |
13 | * You should have received a copy of the GNU General Public License | |
14 | * along with this software; see the file COPYING. If not, write to | |
82892bed JB |
15 | * the Free Software Foundation, Inc., 59 Temple Place, Suite 330, |
16 | * Boston, MA 02111-1307 USA | |
0f2d19dd JB |
17 | * |
18 | * As a special exception, the Free Software Foundation gives permission | |
19 | * for additional uses of the text contained in its release of GUILE. | |
20 | * | |
21 | * The exception is that, if you link the GUILE library with other files | |
22 | * to produce an executable, this does not by itself cause the | |
23 | * resulting executable to be covered by the GNU General Public License. | |
24 | * Your use of that executable is in no way restricted on account of | |
25 | * linking the GUILE library code into it. | |
26 | * | |
27 | * This exception does not however invalidate any other reasons why | |
28 | * the executable file might be covered by the GNU General Public License. | |
29 | * | |
30 | * This exception applies only to the code released by the | |
31 | * Free Software Foundation under the name GUILE. If you copy | |
32 | * code from other Free Software Foundation releases into a copy of | |
33 | * GUILE, as the General Public License permits, the exception does | |
34 | * not apply to the code that you add in this way. To avoid misleading | |
35 | * anyone as to the status of such modified files, you must delete | |
36 | * this exception notice from them. | |
37 | * | |
38 | * If you write modifications of your own for GUILE, it is your choice | |
39 | * whether to permit this exception to apply to your modifications. | |
82892bed | 40 | * If you do not wish that, delete this exception notice. */ |
1bbd0b84 GB |
41 | |
42 | /* Software engineering face-lift by Greg J. Badros, 11-Dec-1999, | |
43 | gjb@cs.washington.edu, http://www.cs.washington.edu/homes/gjb */ | |
44 | ||
0f2d19dd JB |
45 | \f |
46 | ||
a0599745 MD |
47 | #include "libguile/_scm.h" |
48 | #include "libguile/chars.h" | |
49 | #include "libguile/eval.h" | |
50 | #include "libguile/alist.h" | |
51 | #include "libguile/weaks.h" | |
52 | #include "libguile/hashtab.h" | |
53 | #include "libguile/ports.h" | |
54 | #include "libguile/strings.h" | |
55 | ||
56 | #include "libguile/validate.h" | |
57 | #include "libguile/struct.h" | |
0f2d19dd | 58 | |
95b88819 GH |
59 | #ifdef HAVE_STRING_H |
60 | #include <string.h> | |
61 | #endif | |
62 | ||
0f2d19dd JB |
63 | \f |
64 | ||
65 | static SCM required_vtable_fields = SCM_BOOL_F; | |
98d5f601 | 66 | SCM scm_struct_table; |
0f2d19dd JB |
67 | |
68 | \f | |
a1ec6916 | 69 | SCM_DEFINE (scm_make_struct_layout, "make-struct-layout", 1, 0, 0, |
1bbd0b84 | 70 | (SCM fields), |
b380b885 | 71 | "Return a new structure layout object.\n\n" |
7c31152f | 72 | "@var{fields} must be a string made up of pairs of characters\n" |
b380b885 MD |
73 | "strung together. The first character of each pair describes a field\n" |
74 | "type, the second a field protection. Allowed types are 'p' for\n" | |
75 | "GC-protected Scheme data, 'u' for unprotected binary data, and 's' for\n" | |
04323af4 | 76 | "a field that points to the structure itself. Allowed protections\n" |
b380b885 MD |
77 | "are 'w' for mutable fields, 'r' for read-only fields, and 'o' for opaque \n" |
78 | "fields. The last field protection specification may be capitalized to\n" | |
79 | "indicate that the field is a tail-array.") | |
1bbd0b84 | 80 | #define FUNC_NAME s_scm_make_struct_layout |
0f2d19dd JB |
81 | { |
82 | SCM new_sym; | |
d1ca2c64 | 83 | SCM_VALIDATE_STRING (1, fields); |
2ade72d7 | 84 | |
1bbd0b84 | 85 | { /* scope */ |
0f2d19dd | 86 | char * field_desc; |
1be6b49c | 87 | size_t len; |
0f2d19dd JB |
88 | int x; |
89 | ||
d1ca2c64 | 90 | len = SCM_STRING_LENGTH (fields); |
2ade72d7 DH |
91 | if (len % 2 == 1) |
92 | SCM_MISC_ERROR ("odd length field specification: ~S", | |
93 | SCM_LIST1 (fields)); | |
94 | ||
34f0f2b8 | 95 | field_desc = SCM_STRING_CHARS (fields); |
0f2d19dd JB |
96 | |
97 | for (x = 0; x < len; x += 2) | |
98 | { | |
99 | switch (field_desc[x]) | |
100 | { | |
101 | case 'u': | |
102 | case 'p': | |
103 | #if 0 | |
104 | case 'i': | |
105 | case 'd': | |
106 | #endif | |
107 | case 's': | |
108 | break; | |
109 | default: | |
2ade72d7 DH |
110 | SCM_MISC_ERROR ("unrecognized field type: ~S", |
111 | SCM_LIST1 (SCM_MAKE_CHAR (field_desc[x]))); | |
0f2d19dd JB |
112 | } |
113 | ||
114 | switch (field_desc[x + 1]) | |
115 | { | |
116 | case 'w': | |
2ade72d7 DH |
117 | if (field_desc[x] == 's') |
118 | SCM_MISC_ERROR ("self fields not writable", SCM_EOL); | |
0f2d19dd JB |
119 | case 'r': |
120 | case 'o': | |
121 | break; | |
2c36c351 MD |
122 | case 'R': |
123 | case 'W': | |
124 | case 'O': | |
2ade72d7 DH |
125 | if (field_desc[x] == 's') |
126 | SCM_MISC_ERROR ("self fields not allowed in tail array", | |
127 | SCM_EOL); | |
128 | if (x != len - 2) | |
129 | SCM_MISC_ERROR ("tail array field must be last field in layout", | |
130 | SCM_EOL); | |
2c36c351 | 131 | break; |
0f2d19dd | 132 | default: |
2ade72d7 DH |
133 | SCM_MISC_ERROR ("unrecognized ref specification: ~S", |
134 | SCM_LIST1 (SCM_MAKE_CHAR (field_desc[x + 1]))); | |
0f2d19dd JB |
135 | } |
136 | #if 0 | |
137 | if (field_desc[x] == 'd') | |
138 | { | |
2ade72d7 DH |
139 | if (field_desc[x + 2] != '-') |
140 | SCM_MISC_ERROR ("missing dash field at position ~A", | |
141 | SCM_LIST1 (SCM_MAKINUM (x / 2))); | |
0f2d19dd JB |
142 | x += 2; |
143 | goto recheck_ref; | |
144 | } | |
145 | #endif | |
146 | } | |
38ae064c | 147 | new_sym = scm_mem2symbol (field_desc, len); |
0f2d19dd JB |
148 | } |
149 | return scm_return_first (new_sym, fields); | |
150 | } | |
1bbd0b84 | 151 | #undef FUNC_NAME |
0f2d19dd JB |
152 | |
153 | \f | |
154 | ||
155 | ||
1cc91f1b | 156 | |
f7620510 DH |
157 | static void |
158 | scm_struct_init (SCM handle, SCM layout, scm_bits_t * mem, int tail_elts, SCM inits) | |
0f2d19dd | 159 | { |
a002f1a2 | 160 | unsigned char * fields_desc = (unsigned char *) SCM_SYMBOL_CHARS (layout) - 2; |
35de7ebe | 161 | unsigned char prot = 0; |
bfa974f0 | 162 | int n_fields = SCM_SYMBOL_LENGTH (layout) / 2; |
2c36c351 | 163 | int tailp = 0; |
d8c40b9f | 164 | |
0f2d19dd JB |
165 | while (n_fields) |
166 | { | |
2c36c351 MD |
167 | if (!tailp) |
168 | { | |
169 | fields_desc += 2; | |
170 | prot = fields_desc[1]; | |
171 | if (SCM_LAYOUT_TAILP (prot)) | |
172 | { | |
173 | tailp = 1; | |
174 | prot = prot == 'R' ? 'r' : prot == 'W' ? 'w' : 'o'; | |
d8c40b9f | 175 | *mem++ = tail_elts; |
2c36c351 MD |
176 | n_fields += tail_elts - 1; |
177 | if (n_fields == 0) | |
178 | break; | |
179 | } | |
180 | } | |
181 | ||
0f2d19dd JB |
182 | switch (*fields_desc) |
183 | { | |
184 | #if 0 | |
185 | case 'i': | |
2c36c351 | 186 | if ((prot != 'r' && prot != 'w') || inits == SCM_EOL) |
0f2d19dd JB |
187 | *mem = 0; |
188 | else | |
189 | { | |
a5bfe84d | 190 | *mem = scm_num2long (SCM_CAR (inits), SCM_ARGn, "scm_struct_init"); |
0f2d19dd JB |
191 | inits = SCM_CDR (inits); |
192 | } | |
193 | break; | |
194 | #endif | |
195 | ||
196 | case 'u': | |
54778cd3 | 197 | if ((prot != 'r' && prot != 'w') || SCM_NULLP (inits)) |
0f2d19dd JB |
198 | *mem = 0; |
199 | else | |
200 | { | |
d8c40b9f DH |
201 | *mem = scm_num2ulong (SCM_CAR (inits), |
202 | SCM_ARGn, | |
203 | "scm_struct_init"); | |
0f2d19dd JB |
204 | inits = SCM_CDR (inits); |
205 | } | |
206 | break; | |
207 | ||
208 | case 'p': | |
54778cd3 | 209 | if ((prot != 'r' && prot != 'w') || SCM_NULLP (inits)) |
d8c40b9f | 210 | *mem = SCM_UNPACK (SCM_BOOL_F); |
0f2d19dd JB |
211 | else |
212 | { | |
d8c40b9f | 213 | *mem = SCM_UNPACK (SCM_CAR (inits)); |
0f2d19dd JB |
214 | inits = SCM_CDR (inits); |
215 | } | |
216 | ||
217 | break; | |
218 | ||
219 | #if 0 | |
220 | case 'd': | |
2c36c351 | 221 | if ((prot != 'r' && prot != 'w') || inits == SCM_EOL) |
0f2d19dd JB |
222 | *((double *)mem) = 0.0; |
223 | else | |
224 | { | |
a5bfe84d | 225 | *mem = scm_num2dbl (SCM_CAR (inits), "scm_struct_init"); |
0f2d19dd JB |
226 | inits = SCM_CDR (inits); |
227 | } | |
228 | fields_desc += 2; | |
229 | break; | |
230 | #endif | |
231 | ||
232 | case 's': | |
d8c40b9f | 233 | *mem = SCM_UNPACK (handle); |
0f2d19dd JB |
234 | break; |
235 | } | |
236 | ||
0f2d19dd JB |
237 | n_fields--; |
238 | mem++; | |
239 | } | |
240 | } | |
241 | ||
242 | ||
a1ec6916 | 243 | SCM_DEFINE (scm_struct_p, "struct?", 1, 0, 0, |
1bbd0b84 | 244 | (SCM x), |
942e5b91 MG |
245 | "Return @code{#t} iff @var{obj} is a structure object, else\n" |
246 | "@code{#f}.") | |
1bbd0b84 | 247 | #define FUNC_NAME s_scm_struct_p |
0f2d19dd | 248 | { |
0c95b57d | 249 | return SCM_BOOL(SCM_STRUCTP (x)); |
0f2d19dd | 250 | } |
1bbd0b84 | 251 | #undef FUNC_NAME |
0f2d19dd | 252 | |
a1ec6916 | 253 | SCM_DEFINE (scm_struct_vtable_p, "struct-vtable?", 1, 0, 0, |
1bbd0b84 | 254 | (SCM x), |
942e5b91 | 255 | "Return @code{#t} iff obj is a vtable structure.") |
1bbd0b84 | 256 | #define FUNC_NAME s_scm_struct_vtable_p |
0f2d19dd JB |
257 | { |
258 | SCM layout; | |
d8c40b9f | 259 | scm_bits_t * mem; |
0f2d19dd JB |
260 | |
261 | if (!SCM_STRUCTP (x)) | |
262 | return SCM_BOOL_F; | |
263 | ||
264 | layout = SCM_STRUCT_LAYOUT (x); | |
265 | ||
bfa974f0 | 266 | if (SCM_SYMBOL_LENGTH (layout) < SCM_STRING_LENGTH (required_vtable_fields)) |
0f2d19dd JB |
267 | return SCM_BOOL_F; |
268 | ||
a002f1a2 | 269 | if (strncmp (SCM_SYMBOL_CHARS (layout), SCM_STRING_CHARS (required_vtable_fields), |
bfa974f0 | 270 | SCM_STRING_LENGTH (required_vtable_fields))) |
0f2d19dd JB |
271 | return SCM_BOOL_F; |
272 | ||
273 | mem = SCM_STRUCT_DATA (x); | |
274 | ||
275 | if (mem[1] != 0) | |
276 | return SCM_BOOL_F; | |
277 | ||
d8c40b9f | 278 | return SCM_BOOL (SCM_SYMBOLP (SCM_PACK (mem[0]))); |
0f2d19dd | 279 | } |
1bbd0b84 | 280 | #undef FUNC_NAME |
0f2d19dd | 281 | |
14d1400f JB |
282 | |
283 | /* All struct data must be allocated at an address whose bottom three | |
284 | bits are zero. This is because the tag for a struct lives in the | |
285 | bottom three bits of the struct's car, and the upper bits point to | |
286 | the data of its vtable, which is a struct itself. Thus, if the | |
287 | address of that data doesn't end in three zeros, tagging it will | |
288 | destroy the pointer. | |
289 | ||
290 | This function allocates a block of memory, and returns a pointer at | |
291 | least scm_struct_n_extra_words words into the block. Furthermore, | |
292 | it guarantees that that pointer's least three significant bits are | |
293 | all zero. | |
294 | ||
295 | The argument n_words should be the number of words that should | |
296 | appear after the returned address. (That is, it shouldn't include | |
297 | scm_struct_n_extra_words.) | |
298 | ||
299 | This function initializes the following fields of the struct: | |
300 | ||
ad196599 | 301 | scm_struct_i_ptr --- the actual start of the block of memory; the |
14d1400f JB |
302 | address you should pass to 'free' to dispose of the block. |
303 | This field allows us to both guarantee that the returned | |
304 | address is divisible by eight, and allow the GC to free the | |
305 | block. | |
306 | ||
307 | scm_struct_i_n_words --- the number of words allocated to the | |
308 | block, including the extra fields. This is used by the GC. | |
309 | ||
14d1400f JB |
310 | Ugh. */ |
311 | ||
312 | ||
c8045e8d | 313 | scm_bits_t * |
a5bfe84d | 314 | scm_alloc_struct (int n_words, int n_extra, char *who) |
14d1400f | 315 | { |
c8045e8d DH |
316 | int size = sizeof (scm_bits_t) * (n_words + n_extra) + 7; |
317 | void * block = scm_must_malloc (size, who); | |
14d1400f JB |
318 | |
319 | /* Adjust the pointer to hide the extra words. */ | |
c8045e8d | 320 | scm_bits_t * p = (scm_bits_t *) block + n_extra; |
14d1400f JB |
321 | |
322 | /* Adjust it even further so it's aligned on an eight-byte boundary. */ | |
c8045e8d | 323 | p = (scm_bits_t *) (((scm_bits_t) p + 7) & ~7); |
14d1400f | 324 | |
ad196599 | 325 | /* Initialize a few fields as described above. */ |
c8045e8d DH |
326 | p[scm_struct_i_free] = (scm_bits_t) scm_struct_free_standard; |
327 | p[scm_struct_i_ptr] = (scm_bits_t) block; | |
328 | p[scm_struct_i_n_words] = n_words; | |
ad196599 | 329 | p[scm_struct_i_flags] = 0; |
14d1400f JB |
330 | |
331 | return p; | |
332 | } | |
333 | ||
1be6b49c | 334 | size_t |
c8045e8d | 335 | scm_struct_free_0 (scm_bits_t * vtable, scm_bits_t * data) |
ad196599 MD |
336 | { |
337 | return 0; | |
338 | } | |
339 | ||
1be6b49c | 340 | size_t |
c8045e8d | 341 | scm_struct_free_light (scm_bits_t * vtable, scm_bits_t * data) |
ad196599 | 342 | { |
cfe66b72 | 343 | scm_must_free (data); |
c8045e8d | 344 | return vtable [scm_struct_i_size] & ~SCM_STRUCTF_MASK; |
ad196599 MD |
345 | } |
346 | ||
1be6b49c | 347 | size_t |
c8045e8d | 348 | scm_struct_free_standard (scm_bits_t * vtable, scm_bits_t * data) |
ad196599 | 349 | { |
c8045e8d DH |
350 | size_t n = (data[scm_struct_i_n_words] + scm_struct_n_extra_words) |
351 | * sizeof (scm_bits_t) + 7; | |
cfe66b72 | 352 | scm_must_free ((void *) data[scm_struct_i_ptr]); |
ad196599 MD |
353 | return n; |
354 | } | |
355 | ||
1be6b49c | 356 | size_t |
c8045e8d | 357 | scm_struct_free_entity (scm_bits_t * vtable, scm_bits_t * data) |
ad196599 | 358 | { |
c8045e8d DH |
359 | size_t n = (data[scm_struct_i_n_words] + scm_struct_entity_n_extra_words) |
360 | * sizeof (scm_bits_t) + 7; | |
cfe66b72 | 361 | scm_must_free ((void *) data[scm_struct_i_ptr]); |
ad196599 MD |
362 | return n; |
363 | } | |
14d1400f | 364 | |
08c880a3 MD |
365 | static void * |
366 | scm_struct_gc_init (void *dummy1, void *dummy2, void *dummy3) | |
367 | { | |
368 | scm_structs_to_free = SCM_EOL; | |
369 | return 0; | |
370 | } | |
371 | ||
372 | static void * | |
373 | scm_free_structs (void *dummy1, void *dummy2, void *dummy3) | |
374 | { | |
375 | SCM newchain = scm_structs_to_free; | |
376 | do | |
377 | { | |
378 | /* Mark vtables in GC chain. GC mark set means delay freeing. */ | |
379 | SCM chain = newchain; | |
1a551638 | 380 | while (!SCM_NULLP (chain)) |
08c880a3 MD |
381 | { |
382 | SCM vtable = SCM_STRUCT_VTABLE (chain); | |
383 | if (SCM_STRUCT_GC_CHAIN (vtable) != 0 && vtable != chain) | |
384 | SCM_SETGCMARK (vtable); | |
385 | chain = SCM_STRUCT_GC_CHAIN (chain); | |
386 | } | |
387 | /* Free unmarked structs. */ | |
388 | chain = newchain; | |
389 | newchain = SCM_EOL; | |
1a551638 | 390 | while (!SCM_NULLP (chain)) |
08c880a3 MD |
391 | { |
392 | SCM obj = chain; | |
393 | chain = SCM_STRUCT_GC_CHAIN (chain); | |
394 | if (SCM_GCMARKP (obj)) | |
395 | { | |
396 | SCM_CLRGCMARK (obj); | |
397 | SCM_SET_STRUCT_GC_CHAIN (obj, newchain); | |
398 | newchain = obj; | |
399 | } | |
400 | else | |
401 | { | |
402 | scm_bits_t word0 = SCM_CELL_WORD_0 (obj) - scm_tc3_cons_gloc; | |
403 | /* access as struct */ | |
404 | scm_bits_t * vtable_data = (scm_bits_t *) word0; | |
1a551638 | 405 | scm_bits_t * data = SCM_STRUCT_DATA (obj); |
08c880a3 MD |
406 | scm_struct_free_t free_struct_data |
407 | = ((scm_struct_free_t) vtable_data[scm_struct_i_free]); | |
408 | SCM_SET_CELL_TYPE (obj, scm_tc_free_cell); | |
409 | free_struct_data (vtable_data, data); | |
410 | } | |
411 | } | |
412 | } | |
1a551638 | 413 | while (!SCM_NULLP (newchain)); |
08c880a3 MD |
414 | return 0; |
415 | } | |
416 | ||
a1ec6916 | 417 | SCM_DEFINE (scm_make_struct, "make-struct", 2, 0, 1, |
1bbd0b84 | 418 | (SCM vtable, SCM tail_array_size, SCM init), |
b380b885 | 419 | "Create a new structure.\n\n" |
1bee0e70 | 420 | "@var{type} must be a vtable structure (@pxref{Vtables}).\n\n" |
b380b885 MD |
421 | "@var{tail-elts} must be a non-negative integer. If the layout\n" |
422 | "specification indicated by @var{type} includes a tail-array,\n" | |
423 | "this is the number of elements allocated to that array.\n\n" | |
6386e25c | 424 | "The @var{init1}, @dots{} are optional arguments describing how\n" |
04323af4 MD |
425 | "successive fields of the structure should be initialized. Only fields\n" |
426 | "with protection 'r' or 'w' can be initialized, except for fields of\n" | |
427 | "type 's', which are automatically initialized to point to the new\n" | |
428 | "structure itself; fields with protection 'o' can not be initialized by\n" | |
429 | "Scheme programs.\n\n" | |
430 | "If fewer optional arguments than initializable fields are supplied,\n" | |
431 | "fields of type 'p' get default value #f while fields of type 'u' are\n" | |
432 | "initialized to 0.\n\n" | |
433 | "Structs are currently the basic representation for record-like data\n" | |
434 | "structures in Guile. The plan is to eventually replace them with a\n" | |
435 | "new representation which will at the same time be easier to use and\n" | |
436 | "more powerful.\n\n" | |
6386e25c | 437 | "For more information, see the documentation for @code{make-vtable-vtable}.") |
1bbd0b84 | 438 | #define FUNC_NAME s_scm_make_struct |
0f2d19dd JB |
439 | { |
440 | SCM layout; | |
441 | int basic_size; | |
442 | int tail_elts; | |
c8045e8d | 443 | scm_bits_t * data; |
0f2d19dd JB |
444 | SCM handle; |
445 | ||
3b3b36dd GB |
446 | SCM_VALIDATE_VTABLE (1,vtable); |
447 | SCM_VALIDATE_INUM (2,tail_array_size); | |
af45e3b0 | 448 | SCM_VALIDATE_REST_ARGUMENT (init); |
0f2d19dd | 449 | |
d8c40b9f | 450 | layout = SCM_PACK (SCM_STRUCT_DATA (vtable) [scm_vtable_index_layout]); |
bfa974f0 | 451 | basic_size = SCM_SYMBOL_LENGTH (layout) / 2; |
0f2d19dd | 452 | tail_elts = SCM_INUM (tail_array_size); |
08c880a3 | 453 | SCM_NEWCELL2 (handle); |
0f2d19dd | 454 | SCM_DEFER_INTS; |
d8c40b9f | 455 | if (SCM_STRUCT_DATA (vtable)[scm_struct_i_flags] & SCM_STRUCTF_ENTITY) |
a5bfe84d MD |
456 | { |
457 | data = scm_alloc_struct (basic_size + tail_elts, | |
98d5f601 | 458 | scm_struct_entity_n_extra_words, |
a5bfe84d | 459 | "make-struct"); |
c8045e8d DH |
460 | data[scm_struct_i_procedure] = SCM_UNPACK (SCM_BOOL_F); |
461 | data[scm_struct_i_setter] = SCM_UNPACK (SCM_BOOL_F); | |
a5bfe84d MD |
462 | } |
463 | else | |
464 | data = scm_alloc_struct (basic_size + tail_elts, | |
465 | scm_struct_n_extra_words, | |
466 | "make-struct"); | |
54778cd3 | 467 | SCM_SET_CELL_WORD_1 (handle, data); |
08c880a3 | 468 | SCM_SET_STRUCT_GC_CHAIN (handle, 0); |
f7620510 | 469 | scm_struct_init (handle, layout, data, tail_elts, init); |
c8045e8d | 470 | SCM_SET_CELL_WORD_0 (handle, (scm_bits_t) SCM_STRUCT_DATA (vtable) + scm_tc3_cons_gloc); |
0f2d19dd JB |
471 | SCM_ALLOW_INTS; |
472 | return handle; | |
473 | } | |
1bbd0b84 | 474 | #undef FUNC_NAME |
0f2d19dd JB |
475 | |
476 | ||
477 | ||
a1ec6916 | 478 | SCM_DEFINE (scm_make_vtable_vtable, "make-vtable-vtable", 2, 0, 1, |
04323af4 | 479 | (SCM user_fields, SCM tail_array_size, SCM init), |
b380b885 | 480 | "Return a new, self-describing vtable structure.\n\n" |
04323af4 MD |
481 | "@var{user-fields} is a string describing user defined fields of the\n" |
482 | "vtable beginning at index @code{vtable-offset-user}\n" | |
483 | "(see @code{make-struct-layout}).\n\n" | |
b380b885 MD |
484 | "@var{tail-size} specifies the size of the tail-array (if any) of\n" |
485 | "this vtable.\n\n" | |
6386e25c | 486 | "@var{init1}, @dots{} are the optional initializers for the fields of\n" |
04323af4 MD |
487 | "the vtable.\n\n" |
488 | "Vtables have one initializable system field---the struct printer.\n" | |
489 | "This field comes before the user fields in the initializers passed\n" | |
490 | "to @code{make-vtable-vtable} and @code{make-struct}, and thus works as\n" | |
491 | "a third optional argument to @code{make-vtable-vtable} and a fourth to\n" | |
492 | "@code{make-struct} when creating vtables:\n\n" | |
493 | "If the value is a procedure, it will be called instead of the standard\n" | |
494 | "printer whenever a struct described by this vtable is printed.\n" | |
495 | "The procedure will be called with arguments STRUCT and PORT.\n\n" | |
496 | "The structure of a struct is described by a vtable, so the vtable is\n" | |
497 | "in essence the type of the struct. The vtable is itself a struct with\n" | |
498 | "a vtable. This could go on forever if it weren't for the\n" | |
29b4f9fb | 499 | "vtable-vtables which are self-describing vtables, and thus terminate\n" |
04323af4 MD |
500 | "the chain.\n\n" |
501 | "There are several potential ways of using structs, but the standard\n" | |
502 | "one is to use three kinds of structs, together building up a type\n" | |
503 | "sub-system: one vtable-vtable working as the root and one or several\n" | |
504 | "\"types\", each with a set of \"instances\". (The vtable-vtable should be\n" | |
29b4f9fb | 505 | "compared to the class <class> which is the class of itself.)\n\n" |
1e6808ea | 506 | "@lisp\n" |
04323af4 MD |
507 | "(define ball-root (make-vtable-vtable \"pr\" 0))\n\n" |
508 | "(define (make-ball-type ball-color)\n" | |
509 | " (make-struct ball-root 0\n" | |
510 | " (make-struct-layout \"pw\")\n" | |
511 | " (lambda (ball port)\n" | |
512 | " (format port \"#<a ~A ball owned by ~A>\"\n" | |
513 | " (color ball)\n" | |
514 | " (owner ball)))\n" | |
515 | " ball-color))\n" | |
516 | "(define (color ball) (struct-ref (struct-vtable ball) vtable-offset-user))\n" | |
517 | "(define (owner ball) (struct-ref ball 0))\n\n" | |
518 | "(define red (make-ball-type 'red))\n" | |
519 | "(define green (make-ball-type 'green))\n\n" | |
520 | "(define (make-ball type owner) (make-struct type 0 owner))\n\n" | |
521 | "(define ball (make-ball green 'Nisse))\n" | |
522 | "ball @result{} #<a green ball owned by Nisse>\n" | |
1e6808ea | 523 | "@end lisp\n") |
1bbd0b84 | 524 | #define FUNC_NAME s_scm_make_vtable_vtable |
0f2d19dd JB |
525 | { |
526 | SCM fields; | |
527 | SCM layout; | |
528 | int basic_size; | |
529 | int tail_elts; | |
c8045e8d | 530 | scm_bits_t * data; |
0f2d19dd JB |
531 | SCM handle; |
532 | ||
d1ca2c64 | 533 | SCM_VALIDATE_STRING (1, user_fields); |
04323af4 | 534 | SCM_VALIDATE_INUM (2, tail_array_size); |
af45e3b0 | 535 | SCM_VALIDATE_REST_ARGUMENT (init); |
0f2d19dd | 536 | |
e0c08f17 | 537 | fields = scm_string_append (SCM_LIST2 (required_vtable_fields, user_fields)); |
0f2d19dd | 538 | layout = scm_make_struct_layout (fields); |
bfa974f0 | 539 | basic_size = SCM_SYMBOL_LENGTH (layout) / 2; |
0f2d19dd | 540 | tail_elts = SCM_INUM (tail_array_size); |
08c880a3 | 541 | SCM_NEWCELL2 (handle); |
0f2d19dd | 542 | SCM_DEFER_INTS; |
a5bfe84d MD |
543 | data = scm_alloc_struct (basic_size + tail_elts, |
544 | scm_struct_n_extra_words, | |
545 | "make-vtable-vtable"); | |
54778cd3 | 546 | SCM_SET_CELL_WORD_1 (handle, data); |
08c880a3 | 547 | SCM_SET_STRUCT_GC_CHAIN (handle, 0); |
f7620510 DH |
548 | data [scm_vtable_index_layout] = SCM_UNPACK (layout); |
549 | scm_struct_init (handle, layout, data, tail_elts, scm_cons (layout, init)); | |
c8045e8d | 550 | SCM_SET_CELL_WORD_0 (handle, (scm_bits_t) data + scm_tc3_cons_gloc); |
0f2d19dd JB |
551 | SCM_ALLOW_INTS; |
552 | return handle; | |
553 | } | |
1bbd0b84 | 554 | #undef FUNC_NAME |
0f2d19dd JB |
555 | |
556 | \f | |
557 | ||
558 | ||
a1ec6916 | 559 | SCM_DEFINE (scm_struct_ref, "struct-ref", 2, 0, 0, |
1bbd0b84 | 560 | (SCM handle, SCM pos), |
b380b885 MD |
561 | "@deffnx primitive struct-set! struct n value\n" |
562 | "Access (or modify) the @var{n}th field of @var{struct}.\n\n" | |
563 | "If the field is of type 'p', then it can be set to an arbitrary value.\n\n" | |
564 | "If the field is of type 'u', then it can only be set to a non-negative\n" | |
565 | "integer value small enough to fit in one machine word.") | |
1bbd0b84 | 566 | #define FUNC_NAME s_scm_struct_ref |
0f2d19dd | 567 | { |
5e840c2e | 568 | SCM answer = SCM_UNDEFINED; |
d8c40b9f | 569 | scm_bits_t * data; |
0f2d19dd JB |
570 | SCM layout; |
571 | int p; | |
4d45e7b6 | 572 | scm_bits_t n_fields; |
e51fe79c DH |
573 | char * fields_desc; |
574 | char field_type = 0; | |
0f2d19dd JB |
575 | |
576 | ||
3b3b36dd GB |
577 | SCM_VALIDATE_STRUCT (1,handle); |
578 | SCM_VALIDATE_INUM (2,pos); | |
0f2d19dd JB |
579 | |
580 | layout = SCM_STRUCT_LAYOUT (handle); | |
581 | data = SCM_STRUCT_DATA (handle); | |
582 | p = SCM_INUM (pos); | |
583 | ||
e51fe79c | 584 | fields_desc = SCM_SYMBOL_CHARS (layout); |
d8c40b9f | 585 | n_fields = data[scm_struct_i_n_words]; |
2c36c351 | 586 | |
c751e5e3 | 587 | SCM_ASSERT_RANGE(1,pos, p < n_fields); |
0f2d19dd | 588 | |
bfa974f0 | 589 | if (p * 2 < SCM_SYMBOL_LENGTH (layout)) |
2c36c351 | 590 | { |
e51fe79c | 591 | char ref; |
2c36c351 MD |
592 | field_type = fields_desc[p * 2]; |
593 | ref = fields_desc[p * 2 + 1]; | |
594 | if ((ref != 'r') && (ref != 'w')) | |
595 | { | |
596 | if ((ref == 'R') || (ref == 'W')) | |
597 | field_type = 'u'; | |
598 | else | |
2ade72d7 | 599 | SCM_MISC_ERROR ("ref denied for field ~A", SCM_LIST1 (pos)); |
2c36c351 MD |
600 | } |
601 | } | |
bfa974f0 DH |
602 | else if (fields_desc[SCM_SYMBOL_LENGTH (layout) - 1] != 'O') |
603 | field_type = fields_desc[SCM_SYMBOL_LENGTH (layout) - 2]; | |
2c36c351 | 604 | else |
2ade72d7 | 605 | SCM_MISC_ERROR ("ref denied for field ~A", SCM_LIST1 (pos)); |
2c36c351 | 606 | |
0f2d19dd JB |
607 | switch (field_type) |
608 | { | |
609 | case 'u': | |
d8c40b9f | 610 | answer = scm_ulong2num (data[p]); |
0f2d19dd JB |
611 | break; |
612 | ||
613 | #if 0 | |
614 | case 'i': | |
615 | answer = scm_long2num (data[p]); | |
616 | break; | |
617 | ||
618 | case 'd': | |
f8de44c1 | 619 | answer = scm_make_real (*((double *)&(data[p]))); |
0f2d19dd JB |
620 | break; |
621 | #endif | |
622 | ||
623 | case 's': | |
624 | case 'p': | |
d8c40b9f | 625 | answer = SCM_PACK (data[p]); |
0f2d19dd JB |
626 | break; |
627 | ||
628 | ||
629 | default: | |
2ade72d7 DH |
630 | SCM_MISC_ERROR ("unrecognized field type: ~S", |
631 | SCM_LIST1 (SCM_MAKE_CHAR (field_type))); | |
0f2d19dd JB |
632 | } |
633 | ||
634 | return answer; | |
635 | } | |
1bbd0b84 | 636 | #undef FUNC_NAME |
0f2d19dd JB |
637 | |
638 | ||
a1ec6916 | 639 | SCM_DEFINE (scm_struct_set_x, "struct-set!", 3, 0, 0, |
1bbd0b84 | 640 | (SCM handle, SCM pos, SCM val), |
e3239868 DH |
641 | "Set the slot of the structure @var{handle} with index @var{pos}\n" |
642 | "to @var{val}. Signal an error if the slot can not be written\n" | |
643 | "to.") | |
1bbd0b84 | 644 | #define FUNC_NAME s_scm_struct_set_x |
0f2d19dd | 645 | { |
d8c40b9f | 646 | scm_bits_t * data; |
0f2d19dd JB |
647 | SCM layout; |
648 | int p; | |
649 | int n_fields; | |
e51fe79c DH |
650 | char * fields_desc; |
651 | char field_type = 0; | |
0f2d19dd | 652 | |
3b3b36dd GB |
653 | SCM_VALIDATE_STRUCT (1,handle); |
654 | SCM_VALIDATE_INUM (2,pos); | |
0f2d19dd JB |
655 | |
656 | layout = SCM_STRUCT_LAYOUT (handle); | |
657 | data = SCM_STRUCT_DATA (handle); | |
658 | p = SCM_INUM (pos); | |
659 | ||
e51fe79c | 660 | fields_desc = SCM_SYMBOL_CHARS (layout); |
d8c40b9f | 661 | n_fields = data[scm_struct_i_n_words]; |
0f2d19dd | 662 | |
c751e5e3 | 663 | SCM_ASSERT_RANGE (1,pos, p < n_fields); |
0f2d19dd | 664 | |
bfa974f0 | 665 | if (p * 2 < SCM_SYMBOL_LENGTH (layout)) |
2c36c351 | 666 | { |
e51fe79c | 667 | char set_x; |
2c36c351 MD |
668 | field_type = fields_desc[p * 2]; |
669 | set_x = fields_desc [p * 2 + 1]; | |
670 | if (set_x != 'w') | |
2ade72d7 | 671 | SCM_MISC_ERROR ("set! denied for field ~A", SCM_LIST1 (pos)); |
2c36c351 | 672 | } |
bfa974f0 DH |
673 | else if (fields_desc[SCM_SYMBOL_LENGTH (layout) - 1] == 'W') |
674 | field_type = fields_desc[SCM_SYMBOL_LENGTH (layout) - 2]; | |
2c36c351 | 675 | else |
2ade72d7 | 676 | SCM_MISC_ERROR ("set! denied for field ~A", SCM_LIST1 (pos)); |
2c36c351 | 677 | |
0f2d19dd JB |
678 | switch (field_type) |
679 | { | |
680 | case 'u': | |
d8c40b9f | 681 | data[p] = SCM_NUM2ULONG (3, val); |
0f2d19dd JB |
682 | break; |
683 | ||
684 | #if 0 | |
685 | case 'i': | |
e4b265d8 | 686 | data[p] = SCM_NUM2LONG (3, val); |
0f2d19dd JB |
687 | break; |
688 | ||
689 | case 'd': | |
690 | *((double *)&(data[p])) = scm_num2dbl (val, (char *)SCM_ARG3); | |
691 | break; | |
692 | #endif | |
693 | ||
694 | case 'p': | |
d8c40b9f | 695 | data[p] = SCM_UNPACK (val); |
0f2d19dd JB |
696 | break; |
697 | ||
698 | case 's': | |
2ade72d7 | 699 | SCM_MISC_ERROR ("self fields immutable", SCM_EOL); |
0f2d19dd JB |
700 | |
701 | default: | |
2ade72d7 DH |
702 | SCM_MISC_ERROR ("unrecognized field type: ~S", |
703 | SCM_LIST1 (SCM_MAKE_CHAR (field_type))); | |
0f2d19dd JB |
704 | } |
705 | ||
706 | return val; | |
707 | } | |
1bbd0b84 | 708 | #undef FUNC_NAME |
0f2d19dd JB |
709 | |
710 | ||
a1ec6916 | 711 | SCM_DEFINE (scm_struct_vtable, "struct-vtable", 1, 0, 0, |
1bbd0b84 | 712 | (SCM handle), |
b380b885 | 713 | "Return the vtable structure that describes the type of @var{struct}.") |
1bbd0b84 | 714 | #define FUNC_NAME s_scm_struct_vtable |
0f2d19dd | 715 | { |
3b3b36dd | 716 | SCM_VALIDATE_STRUCT (1,handle); |
0f2d19dd JB |
717 | return SCM_STRUCT_VTABLE (handle); |
718 | } | |
1bbd0b84 | 719 | #undef FUNC_NAME |
0f2d19dd JB |
720 | |
721 | ||
a1ec6916 | 722 | SCM_DEFINE (scm_struct_vtable_tag, "struct-vtable-tag", 1, 0, 0, |
1bbd0b84 | 723 | (SCM handle), |
e3239868 | 724 | "Return the vtable tag of the structure @var{handle}.") |
1bbd0b84 | 725 | #define FUNC_NAME s_scm_struct_vtable_tag |
0f2d19dd | 726 | { |
3b3b36dd | 727 | SCM_VALIDATE_VTABLE (1,handle); |
ad196599 | 728 | return scm_long2num ((long) SCM_STRUCT_DATA (handle) >> 3); |
98d5f601 | 729 | } |
1bbd0b84 | 730 | #undef FUNC_NAME |
98d5f601 MD |
731 | |
732 | /* {Associating names and classes with vtables} | |
733 | * | |
734 | * The name of a vtable should probably be stored as a slot. This is | |
735 | * a backward compatible solution until agreement has been achieved on | |
736 | * how to associate names with vtables. | |
737 | */ | |
738 | ||
c014a02e ML |
739 | unsigned long |
740 | scm_struct_ihashq (SCM obj, unsigned long n) | |
98d5f601 | 741 | { |
ad196599 MD |
742 | /* The length of the hash table should be a relative prime it's not |
743 | necessary to shift down the address. */ | |
f1267706 | 744 | return SCM_UNPACK (obj) % n; |
98d5f601 MD |
745 | } |
746 | ||
747 | SCM | |
748 | scm_struct_create_handle (SCM obj) | |
749 | { | |
750 | SCM handle = scm_hash_fn_create_handle_x (scm_struct_table, | |
751 | obj, | |
752 | SCM_BOOL_F, | |
753 | scm_struct_ihashq, | |
754 | scm_sloppy_assq, | |
755 | 0); | |
756 | if (SCM_FALSEP (SCM_CDR (handle))) | |
757 | SCM_SETCDR (handle, scm_cons (SCM_BOOL_F, SCM_BOOL_F)); | |
758 | return handle; | |
759 | } | |
760 | ||
a1ec6916 | 761 | SCM_DEFINE (scm_struct_vtable_name, "struct-vtable-name", 1, 0, 0, |
1bbd0b84 | 762 | (SCM vtable), |
e3239868 | 763 | "Return the name of the vtable @var{vtable}.") |
1bbd0b84 | 764 | #define FUNC_NAME s_scm_struct_vtable_name |
98d5f601 | 765 | { |
3b3b36dd | 766 | SCM_VALIDATE_VTABLE (1,vtable); |
98d5f601 MD |
767 | return SCM_STRUCT_TABLE_NAME (SCM_CDR (scm_struct_create_handle (vtable))); |
768 | } | |
1bbd0b84 | 769 | #undef FUNC_NAME |
98d5f601 | 770 | |
a1ec6916 | 771 | SCM_DEFINE (scm_set_struct_vtable_name_x, "set-struct-vtable-name!", 2, 0, 0, |
1bbd0b84 | 772 | (SCM vtable, SCM name), |
e3239868 | 773 | "Set the name of the vtable @var{vtable} to @var{name}.") |
1bbd0b84 | 774 | #define FUNC_NAME s_scm_set_struct_vtable_name_x |
98d5f601 | 775 | { |
3b3b36dd GB |
776 | SCM_VALIDATE_VTABLE (1,vtable); |
777 | SCM_VALIDATE_SYMBOL (2,name); | |
98d5f601 MD |
778 | SCM_SET_STRUCT_TABLE_NAME (SCM_CDR (scm_struct_create_handle (vtable)), |
779 | name); | |
780 | return SCM_UNSPECIFIED; | |
0f2d19dd | 781 | } |
1bbd0b84 | 782 | #undef FUNC_NAME |
0f2d19dd JB |
783 | |
784 | ||
785 | \f | |
786 | ||
bafcafb2 | 787 | void |
1bbd0b84 | 788 | scm_print_struct (SCM exp, SCM port, scm_print_state *pstate) |
bafcafb2 | 789 | { |
4bfdf158 MD |
790 | if (SCM_NFALSEP (scm_procedure_p (SCM_STRUCT_PRINTER (exp)))) |
791 | scm_printer_apply (SCM_STRUCT_PRINTER (exp), exp, port, pstate); | |
792 | else | |
bafcafb2 | 793 | { |
a1ae1799 MD |
794 | SCM vtable = SCM_STRUCT_VTABLE (exp); |
795 | SCM name = scm_struct_vtable_name (vtable); | |
796 | scm_puts ("#<", port); | |
797 | if (SCM_NFALSEP (name)) | |
798 | scm_display (name, port); | |
799 | else | |
800 | scm_puts ("struct", port); | |
801 | scm_putc (' ', port); | |
54778cd3 | 802 | scm_intprint (SCM_UNPACK (vtable), 16, port); |
b7f3516f | 803 | scm_putc (':', port); |
54778cd3 | 804 | scm_intprint (SCM_UNPACK (exp), 16, port); |
b7f3516f | 805 | scm_putc ('>', port); |
bafcafb2 | 806 | } |
bafcafb2 | 807 | } |
1cc91f1b | 808 | |
08c880a3 MD |
809 | void |
810 | scm_struct_prehistory () | |
811 | { | |
812 | scm_c_hook_add (&scm_before_mark_c_hook, scm_struct_gc_init, 0, 0); | |
813 | scm_c_hook_add (&scm_after_sweep_c_hook, scm_free_structs, 0, 0); | |
814 | } | |
815 | ||
0f2d19dd JB |
816 | void |
817 | scm_init_struct () | |
0f2d19dd | 818 | { |
98d5f601 MD |
819 | scm_struct_table |
820 | = scm_permanent_object (scm_make_weak_key_hash_table (SCM_MAKINUM (31))); | |
7c31152f | 821 | required_vtable_fields = scm_makfrom0str ("pruosrpw"); |
0f2d19dd | 822 | scm_permanent_object (required_vtable_fields); |
86d31dfe MV |
823 | scm_c_define ("vtable-index-layout", SCM_MAKINUM (scm_vtable_index_layout)); |
824 | scm_c_define ("vtable-index-vtable", SCM_MAKINUM (scm_vtable_index_vtable)); | |
825 | scm_c_define ("vtable-index-printer", | |
826 | SCM_MAKINUM (scm_vtable_index_printer)); | |
827 | scm_c_define ("vtable-offset-user", SCM_MAKINUM (scm_vtable_offset_user)); | |
8dc9439f | 828 | #ifndef SCM_MAGIC_SNARFER |
a0599745 | 829 | #include "libguile/struct.x" |
8dc9439f | 830 | #endif |
0f2d19dd | 831 | } |
89e00824 ML |
832 | |
833 | /* | |
834 | Local Variables: | |
835 | c-file-style: "gnu" | |
836 | End: | |
837 | */ |