Commit | Line | Data |
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8dee1541 | 1 | /* Copyright (C) 1996, 97, 98, 99, 2000 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 | ||
47 | #include <stdio.h> | |
a0599745 MD |
48 | #include "libguile/_scm.h" |
49 | #include "libguile/chars.h" | |
50 | #include "libguile/eval.h" | |
51 | #include "libguile/alist.h" | |
52 | #include "libguile/weaks.h" | |
53 | #include "libguile/hashtab.h" | |
54 | #include "libguile/ports.h" | |
55 | #include "libguile/strings.h" | |
56 | ||
57 | #include "libguile/validate.h" | |
58 | #include "libguile/struct.h" | |
0f2d19dd | 59 | |
95b88819 GH |
60 | #ifdef HAVE_STRING_H |
61 | #include <string.h> | |
62 | #endif | |
63 | ||
0f2d19dd JB |
64 | \f |
65 | ||
66 | static SCM required_vtable_fields = SCM_BOOL_F; | |
98d5f601 | 67 | SCM scm_struct_table; |
0f2d19dd JB |
68 | |
69 | \f | |
a1ec6916 | 70 | SCM_DEFINE (scm_make_struct_layout, "make-struct-layout", 1, 0, 0, |
1bbd0b84 | 71 | (SCM fields), |
b380b885 | 72 | "Return a new structure layout object.\n\n" |
7c31152f | 73 | "@var{fields} must be a string made up of pairs of characters\n" |
b380b885 MD |
74 | "strung together. The first character of each pair describes a field\n" |
75 | "type, the second a field protection. Allowed types are 'p' for\n" | |
76 | "GC-protected Scheme data, 'u' for unprotected binary data, and 's' for\n" | |
04323af4 | 77 | "a field that points to the structure itself. Allowed protections\n" |
b380b885 MD |
78 | "are 'w' for mutable fields, 'r' for read-only fields, and 'o' for opaque \n" |
79 | "fields. The last field protection specification may be capitalized to\n" | |
80 | "indicate that the field is a tail-array.") | |
1bbd0b84 | 81 | #define FUNC_NAME s_scm_make_struct_layout |
0f2d19dd JB |
82 | { |
83 | SCM new_sym; | |
d1ca2c64 | 84 | SCM_VALIDATE_STRING (1, fields); |
1bbd0b84 | 85 | { /* scope */ |
0f2d19dd JB |
86 | char * field_desc; |
87 | int len; | |
88 | int x; | |
89 | ||
d1ca2c64 | 90 | len = SCM_STRING_LENGTH (fields); |
34f0f2b8 | 91 | field_desc = SCM_STRING_CHARS (fields); |
1bbd0b84 | 92 | SCM_ASSERT (!(len & 1), fields, "odd length field specification", FUNC_NAME); |
0f2d19dd JB |
93 | |
94 | for (x = 0; x < len; x += 2) | |
95 | { | |
96 | switch (field_desc[x]) | |
97 | { | |
98 | case 'u': | |
99 | case 'p': | |
100 | #if 0 | |
101 | case 'i': | |
102 | case 'd': | |
103 | #endif | |
104 | case 's': | |
105 | break; | |
106 | default: | |
7866a09b | 107 | SCM_ASSERT (0, SCM_MAKE_CHAR (field_desc[x]) , "unrecognized field type", FUNC_NAME); |
0f2d19dd JB |
108 | } |
109 | ||
110 | switch (field_desc[x + 1]) | |
111 | { | |
112 | case 'w': | |
7866a09b | 113 | SCM_ASSERT (field_desc[x] != 's', SCM_MAKE_CHAR (field_desc[x + 1]), |
1bbd0b84 | 114 | "self fields not writable", FUNC_NAME); |
0f2d19dd JB |
115 | |
116 | case 'r': | |
117 | case 'o': | |
118 | break; | |
2c36c351 MD |
119 | case 'R': |
120 | case 'W': | |
121 | case 'O': | |
7866a09b | 122 | SCM_ASSERT (field_desc[x] != 's', SCM_MAKE_CHAR (field_desc[x + 1]), |
2c36c351 | 123 | "self fields not allowed in tail array", |
1bbd0b84 | 124 | FUNC_NAME); |
7866a09b | 125 | SCM_ASSERT (x == len - 2, SCM_MAKE_CHAR (field_desc[x + 1]), |
2c36c351 | 126 | "tail array field must be last field in layout", |
1bbd0b84 | 127 | FUNC_NAME); |
2c36c351 | 128 | break; |
0f2d19dd | 129 | default: |
7866a09b | 130 | SCM_ASSERT (0, SCM_MAKE_CHAR (field_desc[x]) , "unrecognized ref specification", FUNC_NAME); |
0f2d19dd JB |
131 | } |
132 | #if 0 | |
133 | if (field_desc[x] == 'd') | |
134 | { | |
1bbd0b84 | 135 | SCM_ASSERT (field_desc[x + 2] == '-', SCM_MAKINUM (x / 2), "missing dash field", FUNC_NAME); |
0f2d19dd JB |
136 | x += 2; |
137 | goto recheck_ref; | |
138 | } | |
139 | #endif | |
140 | } | |
141 | new_sym = SCM_CAR (scm_intern_obarray (field_desc, len, SCM_BOOL_F)); | |
142 | } | |
143 | return scm_return_first (new_sym, fields); | |
144 | } | |
1bbd0b84 | 145 | #undef FUNC_NAME |
0f2d19dd JB |
146 | |
147 | \f | |
148 | ||
149 | ||
1cc91f1b | 150 | |
f7620510 DH |
151 | static void |
152 | scm_struct_init (SCM handle, SCM layout, scm_bits_t * mem, int tail_elts, SCM inits) | |
0f2d19dd | 153 | { |
a002f1a2 | 154 | unsigned char * fields_desc = (unsigned char *) SCM_SYMBOL_CHARS (layout) - 2; |
35de7ebe | 155 | unsigned char prot = 0; |
bfa974f0 | 156 | int n_fields = SCM_SYMBOL_LENGTH (layout) / 2; |
2c36c351 | 157 | int tailp = 0; |
d8c40b9f | 158 | |
0f2d19dd JB |
159 | while (n_fields) |
160 | { | |
2c36c351 MD |
161 | if (!tailp) |
162 | { | |
163 | fields_desc += 2; | |
164 | prot = fields_desc[1]; | |
165 | if (SCM_LAYOUT_TAILP (prot)) | |
166 | { | |
167 | tailp = 1; | |
168 | prot = prot == 'R' ? 'r' : prot == 'W' ? 'w' : 'o'; | |
d8c40b9f | 169 | *mem++ = tail_elts; |
2c36c351 MD |
170 | n_fields += tail_elts - 1; |
171 | if (n_fields == 0) | |
172 | break; | |
173 | } | |
174 | } | |
175 | ||
0f2d19dd JB |
176 | switch (*fields_desc) |
177 | { | |
178 | #if 0 | |
179 | case 'i': | |
2c36c351 | 180 | if ((prot != 'r' && prot != 'w') || inits == SCM_EOL) |
0f2d19dd JB |
181 | *mem = 0; |
182 | else | |
183 | { | |
a5bfe84d | 184 | *mem = scm_num2long (SCM_CAR (inits), SCM_ARGn, "scm_struct_init"); |
0f2d19dd JB |
185 | inits = SCM_CDR (inits); |
186 | } | |
187 | break; | |
188 | #endif | |
189 | ||
190 | case 'u': | |
54778cd3 | 191 | if ((prot != 'r' && prot != 'w') || SCM_NULLP (inits)) |
0f2d19dd JB |
192 | *mem = 0; |
193 | else | |
194 | { | |
d8c40b9f DH |
195 | *mem = scm_num2ulong (SCM_CAR (inits), |
196 | SCM_ARGn, | |
197 | "scm_struct_init"); | |
0f2d19dd JB |
198 | inits = SCM_CDR (inits); |
199 | } | |
200 | break; | |
201 | ||
202 | case 'p': | |
54778cd3 | 203 | if ((prot != 'r' && prot != 'w') || SCM_NULLP (inits)) |
d8c40b9f | 204 | *mem = SCM_UNPACK (SCM_BOOL_F); |
0f2d19dd JB |
205 | else |
206 | { | |
d8c40b9f | 207 | *mem = SCM_UNPACK (SCM_CAR (inits)); |
0f2d19dd JB |
208 | inits = SCM_CDR (inits); |
209 | } | |
210 | ||
211 | break; | |
212 | ||
213 | #if 0 | |
214 | case 'd': | |
2c36c351 | 215 | if ((prot != 'r' && prot != 'w') || inits == SCM_EOL) |
0f2d19dd JB |
216 | *((double *)mem) = 0.0; |
217 | else | |
218 | { | |
a5bfe84d | 219 | *mem = scm_num2dbl (SCM_CAR (inits), "scm_struct_init"); |
0f2d19dd JB |
220 | inits = SCM_CDR (inits); |
221 | } | |
222 | fields_desc += 2; | |
223 | break; | |
224 | #endif | |
225 | ||
226 | case 's': | |
d8c40b9f | 227 | *mem = SCM_UNPACK (handle); |
0f2d19dd JB |
228 | break; |
229 | } | |
230 | ||
0f2d19dd JB |
231 | n_fields--; |
232 | mem++; | |
233 | } | |
234 | } | |
235 | ||
236 | ||
a1ec6916 | 237 | SCM_DEFINE (scm_struct_p, "struct?", 1, 0, 0, |
1bbd0b84 | 238 | (SCM x), |
b380b885 | 239 | "Return #t iff @var{obj} is a structure object, else #f.") |
1bbd0b84 | 240 | #define FUNC_NAME s_scm_struct_p |
0f2d19dd | 241 | { |
0c95b57d | 242 | return SCM_BOOL(SCM_STRUCTP (x)); |
0f2d19dd | 243 | } |
1bbd0b84 | 244 | #undef FUNC_NAME |
0f2d19dd | 245 | |
a1ec6916 | 246 | SCM_DEFINE (scm_struct_vtable_p, "struct-vtable?", 1, 0, 0, |
1bbd0b84 | 247 | (SCM x), |
b380b885 | 248 | "Return #t iff obj is a vtable structure.") |
1bbd0b84 | 249 | #define FUNC_NAME s_scm_struct_vtable_p |
0f2d19dd JB |
250 | { |
251 | SCM layout; | |
d8c40b9f | 252 | scm_bits_t * mem; |
0f2d19dd JB |
253 | |
254 | if (!SCM_STRUCTP (x)) | |
255 | return SCM_BOOL_F; | |
256 | ||
257 | layout = SCM_STRUCT_LAYOUT (x); | |
258 | ||
bfa974f0 | 259 | if (SCM_SYMBOL_LENGTH (layout) < SCM_STRING_LENGTH (required_vtable_fields)) |
0f2d19dd JB |
260 | return SCM_BOOL_F; |
261 | ||
a002f1a2 | 262 | if (strncmp (SCM_SYMBOL_CHARS (layout), SCM_STRING_CHARS (required_vtable_fields), |
bfa974f0 | 263 | SCM_STRING_LENGTH (required_vtable_fields))) |
0f2d19dd JB |
264 | return SCM_BOOL_F; |
265 | ||
266 | mem = SCM_STRUCT_DATA (x); | |
267 | ||
268 | if (mem[1] != 0) | |
269 | return SCM_BOOL_F; | |
270 | ||
d8c40b9f | 271 | return SCM_BOOL (SCM_SYMBOLP (SCM_PACK (mem[0]))); |
0f2d19dd | 272 | } |
1bbd0b84 | 273 | #undef FUNC_NAME |
0f2d19dd | 274 | |
14d1400f JB |
275 | |
276 | /* All struct data must be allocated at an address whose bottom three | |
277 | bits are zero. This is because the tag for a struct lives in the | |
278 | bottom three bits of the struct's car, and the upper bits point to | |
279 | the data of its vtable, which is a struct itself. Thus, if the | |
280 | address of that data doesn't end in three zeros, tagging it will | |
281 | destroy the pointer. | |
282 | ||
283 | This function allocates a block of memory, and returns a pointer at | |
284 | least scm_struct_n_extra_words words into the block. Furthermore, | |
285 | it guarantees that that pointer's least three significant bits are | |
286 | all zero. | |
287 | ||
288 | The argument n_words should be the number of words that should | |
289 | appear after the returned address. (That is, it shouldn't include | |
290 | scm_struct_n_extra_words.) | |
291 | ||
292 | This function initializes the following fields of the struct: | |
293 | ||
ad196599 | 294 | scm_struct_i_ptr --- the actual start of the block of memory; the |
14d1400f JB |
295 | address you should pass to 'free' to dispose of the block. |
296 | This field allows us to both guarantee that the returned | |
297 | address is divisible by eight, and allow the GC to free the | |
298 | block. | |
299 | ||
300 | scm_struct_i_n_words --- the number of words allocated to the | |
301 | block, including the extra fields. This is used by the GC. | |
302 | ||
14d1400f JB |
303 | Ugh. */ |
304 | ||
305 | ||
c8045e8d | 306 | scm_bits_t * |
a5bfe84d | 307 | scm_alloc_struct (int n_words, int n_extra, char *who) |
14d1400f | 308 | { |
c8045e8d DH |
309 | int size = sizeof (scm_bits_t) * (n_words + n_extra) + 7; |
310 | void * block = scm_must_malloc (size, who); | |
14d1400f JB |
311 | |
312 | /* Adjust the pointer to hide the extra words. */ | |
c8045e8d | 313 | scm_bits_t * p = (scm_bits_t *) block + n_extra; |
14d1400f JB |
314 | |
315 | /* Adjust it even further so it's aligned on an eight-byte boundary. */ | |
c8045e8d | 316 | p = (scm_bits_t *) (((scm_bits_t) p + 7) & ~7); |
14d1400f | 317 | |
ad196599 | 318 | /* Initialize a few fields as described above. */ |
c8045e8d DH |
319 | p[scm_struct_i_free] = (scm_bits_t) scm_struct_free_standard; |
320 | p[scm_struct_i_ptr] = (scm_bits_t) block; | |
321 | p[scm_struct_i_n_words] = n_words; | |
ad196599 | 322 | p[scm_struct_i_flags] = 0; |
14d1400f JB |
323 | |
324 | return p; | |
325 | } | |
326 | ||
97056309 | 327 | scm_sizet |
c8045e8d | 328 | scm_struct_free_0 (scm_bits_t * vtable, scm_bits_t * data) |
ad196599 MD |
329 | { |
330 | return 0; | |
331 | } | |
332 | ||
97056309 | 333 | scm_sizet |
c8045e8d | 334 | scm_struct_free_light (scm_bits_t * vtable, scm_bits_t * data) |
ad196599 | 335 | { |
cfe66b72 | 336 | scm_must_free (data); |
c8045e8d | 337 | return vtable [scm_struct_i_size] & ~SCM_STRUCTF_MASK; |
ad196599 MD |
338 | } |
339 | ||
97056309 | 340 | scm_sizet |
c8045e8d | 341 | scm_struct_free_standard (scm_bits_t * vtable, scm_bits_t * data) |
ad196599 | 342 | { |
c8045e8d DH |
343 | size_t n = (data[scm_struct_i_n_words] + scm_struct_n_extra_words) |
344 | * sizeof (scm_bits_t) + 7; | |
cfe66b72 | 345 | scm_must_free ((void *) data[scm_struct_i_ptr]); |
ad196599 MD |
346 | return n; |
347 | } | |
348 | ||
97056309 | 349 | scm_sizet |
c8045e8d | 350 | scm_struct_free_entity (scm_bits_t * vtable, scm_bits_t * data) |
ad196599 | 351 | { |
c8045e8d DH |
352 | size_t n = (data[scm_struct_i_n_words] + scm_struct_entity_n_extra_words) |
353 | * sizeof (scm_bits_t) + 7; | |
cfe66b72 | 354 | scm_must_free ((void *) data[scm_struct_i_ptr]); |
ad196599 MD |
355 | return n; |
356 | } | |
14d1400f | 357 | |
08c880a3 MD |
358 | static void * |
359 | scm_struct_gc_init (void *dummy1, void *dummy2, void *dummy3) | |
360 | { | |
361 | scm_structs_to_free = SCM_EOL; | |
362 | return 0; | |
363 | } | |
364 | ||
365 | static void * | |
366 | scm_free_structs (void *dummy1, void *dummy2, void *dummy3) | |
367 | { | |
368 | SCM newchain = scm_structs_to_free; | |
369 | do | |
370 | { | |
371 | /* Mark vtables in GC chain. GC mark set means delay freeing. */ | |
372 | SCM chain = newchain; | |
373 | while (SCM_NNULLP (chain)) | |
374 | { | |
375 | SCM vtable = SCM_STRUCT_VTABLE (chain); | |
376 | if (SCM_STRUCT_GC_CHAIN (vtable) != 0 && vtable != chain) | |
377 | SCM_SETGCMARK (vtable); | |
378 | chain = SCM_STRUCT_GC_CHAIN (chain); | |
379 | } | |
380 | /* Free unmarked structs. */ | |
381 | chain = newchain; | |
382 | newchain = SCM_EOL; | |
383 | while (SCM_NNULLP (chain)) | |
384 | { | |
385 | SCM obj = chain; | |
386 | chain = SCM_STRUCT_GC_CHAIN (chain); | |
387 | if (SCM_GCMARKP (obj)) | |
388 | { | |
389 | SCM_CLRGCMARK (obj); | |
390 | SCM_SET_STRUCT_GC_CHAIN (obj, newchain); | |
391 | newchain = obj; | |
392 | } | |
393 | else | |
394 | { | |
395 | scm_bits_t word0 = SCM_CELL_WORD_0 (obj) - scm_tc3_cons_gloc; | |
396 | /* access as struct */ | |
397 | scm_bits_t * vtable_data = (scm_bits_t *) word0; | |
398 | scm_bits_t * data = (scm_bits_t *) SCM_UNPACK (SCM_CDR (obj)); | |
399 | scm_struct_free_t free_struct_data | |
400 | = ((scm_struct_free_t) vtable_data[scm_struct_i_free]); | |
401 | SCM_SET_CELL_TYPE (obj, scm_tc_free_cell); | |
402 | free_struct_data (vtable_data, data); | |
403 | } | |
404 | } | |
405 | } | |
406 | while (SCM_NNULLP (newchain)); | |
407 | return 0; | |
408 | } | |
409 | ||
a1ec6916 | 410 | SCM_DEFINE (scm_make_struct, "make-struct", 2, 0, 1, |
1bbd0b84 | 411 | (SCM vtable, SCM tail_array_size, SCM init), |
b380b885 | 412 | "Create a new structure.\n\n" |
1bee0e70 | 413 | "@var{type} must be a vtable structure (@pxref{Vtables}).\n\n" |
b380b885 MD |
414 | "@var{tail-elts} must be a non-negative integer. If the layout\n" |
415 | "specification indicated by @var{type} includes a tail-array,\n" | |
416 | "this is the number of elements allocated to that array.\n\n" | |
6386e25c | 417 | "The @var{init1}, @dots{} are optional arguments describing how\n" |
04323af4 MD |
418 | "successive fields of the structure should be initialized. Only fields\n" |
419 | "with protection 'r' or 'w' can be initialized, except for fields of\n" | |
420 | "type 's', which are automatically initialized to point to the new\n" | |
421 | "structure itself; fields with protection 'o' can not be initialized by\n" | |
422 | "Scheme programs.\n\n" | |
423 | "If fewer optional arguments than initializable fields are supplied,\n" | |
424 | "fields of type 'p' get default value #f while fields of type 'u' are\n" | |
425 | "initialized to 0.\n\n" | |
426 | "Structs are currently the basic representation for record-like data\n" | |
427 | "structures in Guile. The plan is to eventually replace them with a\n" | |
428 | "new representation which will at the same time be easier to use and\n" | |
429 | "more powerful.\n\n" | |
6386e25c | 430 | "For more information, see the documentation for @code{make-vtable-vtable}.") |
1bbd0b84 | 431 | #define FUNC_NAME s_scm_make_struct |
0f2d19dd JB |
432 | { |
433 | SCM layout; | |
434 | int basic_size; | |
435 | int tail_elts; | |
c8045e8d | 436 | scm_bits_t * data; |
0f2d19dd JB |
437 | SCM handle; |
438 | ||
3b3b36dd GB |
439 | SCM_VALIDATE_VTABLE (1,vtable); |
440 | SCM_VALIDATE_INUM (2,tail_array_size); | |
af45e3b0 | 441 | SCM_VALIDATE_REST_ARGUMENT (init); |
0f2d19dd | 442 | |
d8c40b9f | 443 | layout = SCM_PACK (SCM_STRUCT_DATA (vtable) [scm_vtable_index_layout]); |
bfa974f0 | 444 | basic_size = SCM_SYMBOL_LENGTH (layout) / 2; |
0f2d19dd | 445 | tail_elts = SCM_INUM (tail_array_size); |
08c880a3 | 446 | SCM_NEWCELL2 (handle); |
0f2d19dd | 447 | SCM_DEFER_INTS; |
d8c40b9f | 448 | if (SCM_STRUCT_DATA (vtable)[scm_struct_i_flags] & SCM_STRUCTF_ENTITY) |
a5bfe84d MD |
449 | { |
450 | data = scm_alloc_struct (basic_size + tail_elts, | |
98d5f601 | 451 | scm_struct_entity_n_extra_words, |
a5bfe84d | 452 | "make-struct"); |
c8045e8d DH |
453 | data[scm_struct_i_procedure] = SCM_UNPACK (SCM_BOOL_F); |
454 | data[scm_struct_i_setter] = SCM_UNPACK (SCM_BOOL_F); | |
a5bfe84d MD |
455 | } |
456 | else | |
457 | data = scm_alloc_struct (basic_size + tail_elts, | |
458 | scm_struct_n_extra_words, | |
459 | "make-struct"); | |
54778cd3 | 460 | SCM_SET_CELL_WORD_1 (handle, data); |
08c880a3 | 461 | SCM_SET_STRUCT_GC_CHAIN (handle, 0); |
f7620510 | 462 | scm_struct_init (handle, layout, data, tail_elts, init); |
c8045e8d | 463 | SCM_SET_CELL_WORD_0 (handle, (scm_bits_t) SCM_STRUCT_DATA (vtable) + scm_tc3_cons_gloc); |
0f2d19dd JB |
464 | SCM_ALLOW_INTS; |
465 | return handle; | |
466 | } | |
1bbd0b84 | 467 | #undef FUNC_NAME |
0f2d19dd JB |
468 | |
469 | ||
470 | ||
a1ec6916 | 471 | SCM_DEFINE (scm_make_vtable_vtable, "make-vtable-vtable", 2, 0, 1, |
04323af4 | 472 | (SCM user_fields, SCM tail_array_size, SCM init), |
b380b885 | 473 | "Return a new, self-describing vtable structure.\n\n" |
04323af4 MD |
474 | "@var{user-fields} is a string describing user defined fields of the\n" |
475 | "vtable beginning at index @code{vtable-offset-user}\n" | |
476 | "(see @code{make-struct-layout}).\n\n" | |
b380b885 MD |
477 | "@var{tail-size} specifies the size of the tail-array (if any) of\n" |
478 | "this vtable.\n\n" | |
6386e25c | 479 | "@var{init1}, @dots{} are the optional initializers for the fields of\n" |
04323af4 MD |
480 | "the vtable.\n\n" |
481 | "Vtables have one initializable system field---the struct printer.\n" | |
482 | "This field comes before the user fields in the initializers passed\n" | |
483 | "to @code{make-vtable-vtable} and @code{make-struct}, and thus works as\n" | |
484 | "a third optional argument to @code{make-vtable-vtable} and a fourth to\n" | |
485 | "@code{make-struct} when creating vtables:\n\n" | |
486 | "If the value is a procedure, it will be called instead of the standard\n" | |
487 | "printer whenever a struct described by this vtable is printed.\n" | |
488 | "The procedure will be called with arguments STRUCT and PORT.\n\n" | |
489 | "The structure of a struct is described by a vtable, so the vtable is\n" | |
490 | "in essence the type of the struct. The vtable is itself a struct with\n" | |
491 | "a vtable. This could go on forever if it weren't for the\n" | |
29b4f9fb | 492 | "vtable-vtables which are self-describing vtables, and thus terminate\n" |
04323af4 MD |
493 | "the chain.\n\n" |
494 | "There are several potential ways of using structs, but the standard\n" | |
495 | "one is to use three kinds of structs, together building up a type\n" | |
496 | "sub-system: one vtable-vtable working as the root and one or several\n" | |
497 | "\"types\", each with a set of \"instances\". (The vtable-vtable should be\n" | |
29b4f9fb | 498 | "compared to the class <class> which is the class of itself.)\n\n" |
b380b885 | 499 | "@example\n" |
04323af4 MD |
500 | "(define ball-root (make-vtable-vtable \"pr\" 0))\n\n" |
501 | "(define (make-ball-type ball-color)\n" | |
502 | " (make-struct ball-root 0\n" | |
503 | " (make-struct-layout \"pw\")\n" | |
504 | " (lambda (ball port)\n" | |
505 | " (format port \"#<a ~A ball owned by ~A>\"\n" | |
506 | " (color ball)\n" | |
507 | " (owner ball)))\n" | |
508 | " ball-color))\n" | |
509 | "(define (color ball) (struct-ref (struct-vtable ball) vtable-offset-user))\n" | |
510 | "(define (owner ball) (struct-ref ball 0))\n\n" | |
511 | "(define red (make-ball-type 'red))\n" | |
512 | "(define green (make-ball-type 'green))\n\n" | |
513 | "(define (make-ball type owner) (make-struct type 0 owner))\n\n" | |
514 | "(define ball (make-ball green 'Nisse))\n" | |
515 | "ball @result{} #<a green ball owned by Nisse>\n" | |
b380b885 MD |
516 | "@end example\n" |
517 | "") | |
1bbd0b84 | 518 | #define FUNC_NAME s_scm_make_vtable_vtable |
0f2d19dd JB |
519 | { |
520 | SCM fields; | |
521 | SCM layout; | |
522 | int basic_size; | |
523 | int tail_elts; | |
c8045e8d | 524 | scm_bits_t * data; |
0f2d19dd JB |
525 | SCM handle; |
526 | ||
d1ca2c64 | 527 | SCM_VALIDATE_STRING (1, user_fields); |
04323af4 | 528 | SCM_VALIDATE_INUM (2, tail_array_size); |
af45e3b0 | 529 | SCM_VALIDATE_REST_ARGUMENT (init); |
0f2d19dd JB |
530 | |
531 | fields = scm_string_append (scm_listify (required_vtable_fields, | |
04323af4 | 532 | user_fields, |
0f2d19dd JB |
533 | SCM_UNDEFINED)); |
534 | layout = scm_make_struct_layout (fields); | |
bfa974f0 | 535 | basic_size = SCM_SYMBOL_LENGTH (layout) / 2; |
0f2d19dd | 536 | tail_elts = SCM_INUM (tail_array_size); |
08c880a3 | 537 | SCM_NEWCELL2 (handle); |
0f2d19dd | 538 | SCM_DEFER_INTS; |
a5bfe84d MD |
539 | data = scm_alloc_struct (basic_size + tail_elts, |
540 | scm_struct_n_extra_words, | |
541 | "make-vtable-vtable"); | |
54778cd3 | 542 | SCM_SET_CELL_WORD_1 (handle, data); |
08c880a3 | 543 | SCM_SET_STRUCT_GC_CHAIN (handle, 0); |
f7620510 DH |
544 | data [scm_vtable_index_layout] = SCM_UNPACK (layout); |
545 | scm_struct_init (handle, layout, data, tail_elts, scm_cons (layout, init)); | |
c8045e8d | 546 | SCM_SET_CELL_WORD_0 (handle, (scm_bits_t) data + scm_tc3_cons_gloc); |
0f2d19dd JB |
547 | SCM_ALLOW_INTS; |
548 | return handle; | |
549 | } | |
1bbd0b84 | 550 | #undef FUNC_NAME |
0f2d19dd JB |
551 | |
552 | \f | |
553 | ||
554 | ||
a1ec6916 | 555 | SCM_DEFINE (scm_struct_ref, "struct-ref", 2, 0, 0, |
1bbd0b84 | 556 | (SCM handle, SCM pos), |
b380b885 MD |
557 | "@deffnx primitive struct-set! struct n value\n" |
558 | "Access (or modify) the @var{n}th field of @var{struct}.\n\n" | |
559 | "If the field is of type 'p', then it can be set to an arbitrary value.\n\n" | |
560 | "If the field is of type 'u', then it can only be set to a non-negative\n" | |
561 | "integer value small enough to fit in one machine word.") | |
1bbd0b84 | 562 | #define FUNC_NAME s_scm_struct_ref |
0f2d19dd | 563 | { |
5e840c2e | 564 | SCM answer = SCM_UNDEFINED; |
d8c40b9f | 565 | scm_bits_t * data; |
0f2d19dd JB |
566 | SCM layout; |
567 | int p; | |
4d45e7b6 | 568 | scm_bits_t n_fields; |
0f2d19dd | 569 | unsigned char * fields_desc; |
f3667f52 | 570 | unsigned char field_type = 0; |
0f2d19dd JB |
571 | |
572 | ||
3b3b36dd GB |
573 | SCM_VALIDATE_STRUCT (1,handle); |
574 | SCM_VALIDATE_INUM (2,pos); | |
0f2d19dd JB |
575 | |
576 | layout = SCM_STRUCT_LAYOUT (handle); | |
577 | data = SCM_STRUCT_DATA (handle); | |
578 | p = SCM_INUM (pos); | |
579 | ||
a002f1a2 | 580 | fields_desc = SCM_SYMBOL_UCHARS (layout); |
d8c40b9f | 581 | n_fields = data[scm_struct_i_n_words]; |
2c36c351 | 582 | |
c751e5e3 | 583 | SCM_ASSERT_RANGE(1,pos, p < n_fields); |
0f2d19dd | 584 | |
bfa974f0 | 585 | if (p * 2 < SCM_SYMBOL_LENGTH (layout)) |
2c36c351 MD |
586 | { |
587 | unsigned char ref; | |
588 | field_type = fields_desc[p * 2]; | |
589 | ref = fields_desc[p * 2 + 1]; | |
590 | if ((ref != 'r') && (ref != 'w')) | |
591 | { | |
592 | if ((ref == 'R') || (ref == 'W')) | |
593 | field_type = 'u'; | |
594 | else | |
1bbd0b84 | 595 | SCM_ASSERT (0, pos, "ref denied", FUNC_NAME); |
2c36c351 MD |
596 | } |
597 | } | |
bfa974f0 DH |
598 | else if (fields_desc[SCM_SYMBOL_LENGTH (layout) - 1] != 'O') |
599 | field_type = fields_desc[SCM_SYMBOL_LENGTH (layout) - 2]; | |
2c36c351 MD |
600 | else |
601 | { | |
1bbd0b84 | 602 | SCM_ASSERT (0, pos, "ref denied", FUNC_NAME); |
35de7ebe | 603 | abort (); |
2c36c351 MD |
604 | } |
605 | ||
0f2d19dd JB |
606 | switch (field_type) |
607 | { | |
608 | case 'u': | |
d8c40b9f | 609 | answer = scm_ulong2num (data[p]); |
0f2d19dd JB |
610 | break; |
611 | ||
612 | #if 0 | |
613 | case 'i': | |
614 | answer = scm_long2num (data[p]); | |
615 | break; | |
616 | ||
617 | case 'd': | |
f8de44c1 | 618 | answer = scm_make_real (*((double *)&(data[p]))); |
0f2d19dd JB |
619 | break; |
620 | #endif | |
621 | ||
622 | case 's': | |
623 | case 'p': | |
d8c40b9f | 624 | answer = SCM_PACK (data[p]); |
0f2d19dd JB |
625 | break; |
626 | ||
627 | ||
628 | default: | |
7866a09b | 629 | SCM_ASSERT (0, SCM_MAKE_CHAR (field_type), "unrecognized field type", FUNC_NAME); |
0f2d19dd JB |
630 | break; |
631 | } | |
632 | ||
633 | return answer; | |
634 | } | |
1bbd0b84 | 635 | #undef FUNC_NAME |
0f2d19dd JB |
636 | |
637 | ||
a1ec6916 | 638 | SCM_DEFINE (scm_struct_set_x, "struct-set!", 3, 0, 0, |
1bbd0b84 | 639 | (SCM handle, SCM pos, SCM val), |
b380b885 | 640 | "") |
1bbd0b84 | 641 | #define FUNC_NAME s_scm_struct_set_x |
0f2d19dd | 642 | { |
d8c40b9f | 643 | scm_bits_t * data; |
0f2d19dd JB |
644 | SCM layout; |
645 | int p; | |
646 | int n_fields; | |
647 | unsigned char * fields_desc; | |
f3667f52 | 648 | unsigned char field_type = 0; |
0f2d19dd | 649 | |
3b3b36dd GB |
650 | SCM_VALIDATE_STRUCT (1,handle); |
651 | SCM_VALIDATE_INUM (2,pos); | |
0f2d19dd JB |
652 | |
653 | layout = SCM_STRUCT_LAYOUT (handle); | |
654 | data = SCM_STRUCT_DATA (handle); | |
655 | p = SCM_INUM (pos); | |
656 | ||
a002f1a2 | 657 | fields_desc = SCM_SYMBOL_UCHARS (layout); |
d8c40b9f | 658 | n_fields = data[scm_struct_i_n_words]; |
0f2d19dd | 659 | |
c751e5e3 | 660 | SCM_ASSERT_RANGE (1,pos, p < n_fields); |
0f2d19dd | 661 | |
bfa974f0 | 662 | if (p * 2 < SCM_SYMBOL_LENGTH (layout)) |
2c36c351 MD |
663 | { |
664 | unsigned char set_x; | |
665 | field_type = fields_desc[p * 2]; | |
666 | set_x = fields_desc [p * 2 + 1]; | |
667 | if (set_x != 'w') | |
1bbd0b84 | 668 | SCM_ASSERT (0, pos, "set_x denied", FUNC_NAME); |
2c36c351 | 669 | } |
bfa974f0 DH |
670 | else if (fields_desc[SCM_SYMBOL_LENGTH (layout) - 1] == 'W') |
671 | field_type = fields_desc[SCM_SYMBOL_LENGTH (layout) - 2]; | |
2c36c351 MD |
672 | else |
673 | { | |
1bbd0b84 | 674 | SCM_ASSERT (0, pos, "set_x denied", FUNC_NAME); |
35de7ebe | 675 | abort (); |
2c36c351 MD |
676 | } |
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': | |
1bbd0b84 | 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': | |
7866a09b | 699 | SCM_ASSERT (0, SCM_MAKE_CHAR (field_type), "self fields immutable", FUNC_NAME); |
0f2d19dd JB |
700 | break; |
701 | ||
702 | default: | |
7866a09b | 703 | SCM_ASSERT (0, SCM_MAKE_CHAR (field_type), "unrecognized field type", FUNC_NAME); |
0f2d19dd JB |
704 | break; |
705 | } | |
706 | ||
707 | return val; | |
708 | } | |
1bbd0b84 | 709 | #undef FUNC_NAME |
0f2d19dd JB |
710 | |
711 | ||
a1ec6916 | 712 | SCM_DEFINE (scm_struct_vtable, "struct-vtable", 1, 0, 0, |
1bbd0b84 | 713 | (SCM handle), |
b380b885 | 714 | "Return the vtable structure that describes the type of @var{struct}.") |
1bbd0b84 | 715 | #define FUNC_NAME s_scm_struct_vtable |
0f2d19dd | 716 | { |
3b3b36dd | 717 | SCM_VALIDATE_STRUCT (1,handle); |
0f2d19dd JB |
718 | return SCM_STRUCT_VTABLE (handle); |
719 | } | |
1bbd0b84 | 720 | #undef FUNC_NAME |
0f2d19dd JB |
721 | |
722 | ||
a1ec6916 | 723 | SCM_DEFINE (scm_struct_vtable_tag, "struct-vtable-tag", 1, 0, 0, |
1bbd0b84 | 724 | (SCM handle), |
b380b885 | 725 | "") |
1bbd0b84 | 726 | #define FUNC_NAME s_scm_struct_vtable_tag |
0f2d19dd | 727 | { |
3b3b36dd | 728 | SCM_VALIDATE_VTABLE (1,handle); |
ad196599 | 729 | return scm_long2num ((long) SCM_STRUCT_DATA (handle) >> 3); |
98d5f601 | 730 | } |
1bbd0b84 | 731 | #undef FUNC_NAME |
98d5f601 MD |
732 | |
733 | /* {Associating names and classes with vtables} | |
734 | * | |
735 | * The name of a vtable should probably be stored as a slot. This is | |
736 | * a backward compatible solution until agreement has been achieved on | |
737 | * how to associate names with vtables. | |
738 | */ | |
739 | ||
740 | unsigned int | |
741 | scm_struct_ihashq (SCM obj, unsigned int n) | |
742 | { | |
ad196599 MD |
743 | /* The length of the hash table should be a relative prime it's not |
744 | necessary to shift down the address. */ | |
f1267706 | 745 | return SCM_UNPACK (obj) % n; |
98d5f601 MD |
746 | } |
747 | ||
748 | SCM | |
749 | scm_struct_create_handle (SCM obj) | |
750 | { | |
751 | SCM handle = scm_hash_fn_create_handle_x (scm_struct_table, | |
752 | obj, | |
753 | SCM_BOOL_F, | |
754 | scm_struct_ihashq, | |
755 | scm_sloppy_assq, | |
756 | 0); | |
757 | if (SCM_FALSEP (SCM_CDR (handle))) | |
758 | SCM_SETCDR (handle, scm_cons (SCM_BOOL_F, SCM_BOOL_F)); | |
759 | return handle; | |
760 | } | |
761 | ||
a1ec6916 | 762 | SCM_DEFINE (scm_struct_vtable_name, "struct-vtable-name", 1, 0, 0, |
1bbd0b84 | 763 | (SCM vtable), |
b380b885 | 764 | "") |
1bbd0b84 | 765 | #define FUNC_NAME s_scm_struct_vtable_name |
98d5f601 | 766 | { |
3b3b36dd | 767 | SCM_VALIDATE_VTABLE (1,vtable); |
98d5f601 MD |
768 | return SCM_STRUCT_TABLE_NAME (SCM_CDR (scm_struct_create_handle (vtable))); |
769 | } | |
1bbd0b84 | 770 | #undef FUNC_NAME |
98d5f601 | 771 | |
a1ec6916 | 772 | SCM_DEFINE (scm_set_struct_vtable_name_x, "set-struct-vtable-name!", 2, 0, 0, |
1bbd0b84 | 773 | (SCM vtable, SCM name), |
b380b885 | 774 | "") |
1bbd0b84 | 775 | #define FUNC_NAME s_scm_set_struct_vtable_name_x |
98d5f601 | 776 | { |
3b3b36dd GB |
777 | SCM_VALIDATE_VTABLE (1,vtable); |
778 | SCM_VALIDATE_SYMBOL (2,name); | |
98d5f601 MD |
779 | SCM_SET_STRUCT_TABLE_NAME (SCM_CDR (scm_struct_create_handle (vtable)), |
780 | name); | |
781 | return SCM_UNSPECIFIED; | |
0f2d19dd | 782 | } |
1bbd0b84 | 783 | #undef FUNC_NAME |
0f2d19dd JB |
784 | |
785 | ||
786 | \f | |
787 | ||
bafcafb2 | 788 | void |
1bbd0b84 | 789 | scm_print_struct (SCM exp, SCM port, scm_print_state *pstate) |
bafcafb2 | 790 | { |
4bfdf158 MD |
791 | if (SCM_NFALSEP (scm_procedure_p (SCM_STRUCT_PRINTER (exp)))) |
792 | scm_printer_apply (SCM_STRUCT_PRINTER (exp), exp, port, pstate); | |
793 | else | |
bafcafb2 | 794 | { |
a1ae1799 MD |
795 | SCM vtable = SCM_STRUCT_VTABLE (exp); |
796 | SCM name = scm_struct_vtable_name (vtable); | |
797 | scm_puts ("#<", port); | |
798 | if (SCM_NFALSEP (name)) | |
799 | scm_display (name, port); | |
800 | else | |
801 | scm_puts ("struct", port); | |
802 | scm_putc (' ', port); | |
54778cd3 | 803 | scm_intprint (SCM_UNPACK (vtable), 16, port); |
b7f3516f | 804 | scm_putc (':', port); |
54778cd3 | 805 | scm_intprint (SCM_UNPACK (exp), 16, port); |
b7f3516f | 806 | scm_putc ('>', port); |
bafcafb2 | 807 | } |
bafcafb2 | 808 | } |
1cc91f1b | 809 | |
08c880a3 MD |
810 | void |
811 | scm_struct_prehistory () | |
812 | { | |
813 | scm_c_hook_add (&scm_before_mark_c_hook, scm_struct_gc_init, 0, 0); | |
814 | scm_c_hook_add (&scm_after_sweep_c_hook, scm_free_structs, 0, 0); | |
815 | } | |
816 | ||
0f2d19dd JB |
817 | void |
818 | scm_init_struct () | |
0f2d19dd | 819 | { |
98d5f601 MD |
820 | scm_struct_table |
821 | = scm_permanent_object (scm_make_weak_key_hash_table (SCM_MAKINUM (31))); | |
7c31152f | 822 | required_vtable_fields = scm_makfrom0str ("pruosrpw"); |
0f2d19dd | 823 | scm_permanent_object (required_vtable_fields); |
4bfdf158 MD |
824 | scm_sysintern ("vtable-index-layout", SCM_MAKINUM (scm_vtable_index_layout)); |
825 | scm_sysintern ("vtable-index-vtable", SCM_MAKINUM (scm_vtable_index_vtable)); | |
826 | scm_sysintern ("vtable-index-printer", SCM_MAKINUM (scm_vtable_index_printer)); | |
827 | scm_sysintern ("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 | */ |