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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 | 157 | static void |
92c2555f | 158 | scm_struct_init (SCM handle, SCM layout, scm_t_bits * 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; | |
92c2555f | 259 | scm_t_bits * 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 | ||
92c2555f | 313 | scm_t_bits * |
a5bfe84d | 314 | scm_alloc_struct (int n_words, int n_extra, char *who) |
14d1400f | 315 | { |
92c2555f | 316 | int size = sizeof (scm_t_bits) * (n_words + n_extra) + 7; |
c8045e8d | 317 | void * block = scm_must_malloc (size, who); |
14d1400f JB |
318 | |
319 | /* Adjust the pointer to hide the extra words. */ | |
92c2555f | 320 | scm_t_bits * p = (scm_t_bits *) block + n_extra; |
14d1400f JB |
321 | |
322 | /* Adjust it even further so it's aligned on an eight-byte boundary. */ | |
92c2555f | 323 | p = (scm_t_bits *) (((scm_t_bits) p + 7) & ~7); |
14d1400f | 324 | |
ad196599 | 325 | /* Initialize a few fields as described above. */ |
92c2555f MV |
326 | p[scm_struct_i_free] = (scm_t_bits) scm_struct_free_standard; |
327 | p[scm_struct_i_ptr] = (scm_t_bits) block; | |
c8045e8d | 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 |
92c2555f MV |
335 | scm_struct_free_0 (scm_t_bits * vtable SCM_UNUSED, |
336 | scm_t_bits * data SCM_UNUSED) | |
ad196599 MD |
337 | { |
338 | return 0; | |
339 | } | |
340 | ||
1be6b49c | 341 | size_t |
92c2555f | 342 | scm_struct_free_light (scm_t_bits * vtable, scm_t_bits * data) |
ad196599 | 343 | { |
cfe66b72 | 344 | scm_must_free (data); |
c8045e8d | 345 | return vtable [scm_struct_i_size] & ~SCM_STRUCTF_MASK; |
ad196599 MD |
346 | } |
347 | ||
1be6b49c | 348 | size_t |
92c2555f | 349 | scm_struct_free_standard (scm_t_bits * vtable SCM_UNUSED, scm_t_bits * data) |
ad196599 | 350 | { |
c8045e8d | 351 | size_t n = (data[scm_struct_i_n_words] + scm_struct_n_extra_words) |
92c2555f | 352 | * sizeof (scm_t_bits) + 7; |
cfe66b72 | 353 | scm_must_free ((void *) data[scm_struct_i_ptr]); |
ad196599 MD |
354 | return n; |
355 | } | |
356 | ||
1be6b49c | 357 | size_t |
92c2555f | 358 | scm_struct_free_entity (scm_t_bits * vtable SCM_UNUSED, scm_t_bits * data) |
ad196599 | 359 | { |
c8045e8d | 360 | size_t n = (data[scm_struct_i_n_words] + scm_struct_entity_n_extra_words) |
92c2555f | 361 | * sizeof (scm_t_bits) + 7; |
cfe66b72 | 362 | scm_must_free ((void *) data[scm_struct_i_ptr]); |
ad196599 MD |
363 | return n; |
364 | } | |
14d1400f | 365 | |
08c880a3 | 366 | static void * |
e81d98ec DH |
367 | scm_struct_gc_init (void *dummy1 SCM_UNUSED, |
368 | void *dummy2 SCM_UNUSED, | |
369 | void *dummy3 SCM_UNUSED) | |
08c880a3 MD |
370 | { |
371 | scm_structs_to_free = SCM_EOL; | |
372 | return 0; | |
373 | } | |
374 | ||
375 | static void * | |
e81d98ec DH |
376 | scm_free_structs (void *dummy1 SCM_UNUSED, |
377 | void *dummy2 SCM_UNUSED, | |
378 | void *dummy3 SCM_UNUSED) | |
08c880a3 MD |
379 | { |
380 | SCM newchain = scm_structs_to_free; | |
381 | do | |
382 | { | |
383 | /* Mark vtables in GC chain. GC mark set means delay freeing. */ | |
384 | SCM chain = newchain; | |
1a551638 | 385 | while (!SCM_NULLP (chain)) |
08c880a3 MD |
386 | { |
387 | SCM vtable = SCM_STRUCT_VTABLE (chain); | |
388 | if (SCM_STRUCT_GC_CHAIN (vtable) != 0 && vtable != chain) | |
389 | SCM_SETGCMARK (vtable); | |
390 | chain = SCM_STRUCT_GC_CHAIN (chain); | |
391 | } | |
392 | /* Free unmarked structs. */ | |
393 | chain = newchain; | |
394 | newchain = SCM_EOL; | |
1a551638 | 395 | while (!SCM_NULLP (chain)) |
08c880a3 MD |
396 | { |
397 | SCM obj = chain; | |
398 | chain = SCM_STRUCT_GC_CHAIN (chain); | |
399 | if (SCM_GCMARKP (obj)) | |
400 | { | |
401 | SCM_CLRGCMARK (obj); | |
402 | SCM_SET_STRUCT_GC_CHAIN (obj, newchain); | |
403 | newchain = obj; | |
404 | } | |
405 | else | |
406 | { | |
92c2555f | 407 | scm_t_bits word0 = SCM_CELL_WORD_0 (obj) - scm_tc3_cons_gloc; |
08c880a3 | 408 | /* access as struct */ |
92c2555f MV |
409 | scm_t_bits * vtable_data = (scm_t_bits *) word0; |
410 | scm_t_bits * data = SCM_STRUCT_DATA (obj); | |
411 | scm_t_struct_free free_struct_data | |
412 | = ((scm_t_struct_free) vtable_data[scm_struct_i_free]); | |
08c880a3 MD |
413 | SCM_SET_CELL_TYPE (obj, scm_tc_free_cell); |
414 | free_struct_data (vtable_data, data); | |
415 | } | |
416 | } | |
417 | } | |
1a551638 | 418 | while (!SCM_NULLP (newchain)); |
08c880a3 MD |
419 | return 0; |
420 | } | |
421 | ||
a1ec6916 | 422 | SCM_DEFINE (scm_make_struct, "make-struct", 2, 0, 1, |
1bbd0b84 | 423 | (SCM vtable, SCM tail_array_size, SCM init), |
b380b885 | 424 | "Create a new structure.\n\n" |
1bee0e70 | 425 | "@var{type} must be a vtable structure (@pxref{Vtables}).\n\n" |
b380b885 MD |
426 | "@var{tail-elts} must be a non-negative integer. If the layout\n" |
427 | "specification indicated by @var{type} includes a tail-array,\n" | |
428 | "this is the number of elements allocated to that array.\n\n" | |
6386e25c | 429 | "The @var{init1}, @dots{} are optional arguments describing how\n" |
04323af4 MD |
430 | "successive fields of the structure should be initialized. Only fields\n" |
431 | "with protection 'r' or 'w' can be initialized, except for fields of\n" | |
432 | "type 's', which are automatically initialized to point to the new\n" | |
433 | "structure itself; fields with protection 'o' can not be initialized by\n" | |
434 | "Scheme programs.\n\n" | |
435 | "If fewer optional arguments than initializable fields are supplied,\n" | |
436 | "fields of type 'p' get default value #f while fields of type 'u' are\n" | |
437 | "initialized to 0.\n\n" | |
438 | "Structs are currently the basic representation for record-like data\n" | |
439 | "structures in Guile. The plan is to eventually replace them with a\n" | |
440 | "new representation which will at the same time be easier to use and\n" | |
441 | "more powerful.\n\n" | |
6386e25c | 442 | "For more information, see the documentation for @code{make-vtable-vtable}.") |
1bbd0b84 | 443 | #define FUNC_NAME s_scm_make_struct |
0f2d19dd JB |
444 | { |
445 | SCM layout; | |
446 | int basic_size; | |
447 | int tail_elts; | |
92c2555f | 448 | scm_t_bits * data; |
0f2d19dd JB |
449 | SCM handle; |
450 | ||
3b3b36dd GB |
451 | SCM_VALIDATE_VTABLE (1,vtable); |
452 | SCM_VALIDATE_INUM (2,tail_array_size); | |
af45e3b0 | 453 | SCM_VALIDATE_REST_ARGUMENT (init); |
0f2d19dd | 454 | |
d8c40b9f | 455 | layout = SCM_PACK (SCM_STRUCT_DATA (vtable) [scm_vtable_index_layout]); |
bfa974f0 | 456 | basic_size = SCM_SYMBOL_LENGTH (layout) / 2; |
0f2d19dd | 457 | tail_elts = SCM_INUM (tail_array_size); |
08c880a3 | 458 | SCM_NEWCELL2 (handle); |
0f2d19dd | 459 | SCM_DEFER_INTS; |
d8c40b9f | 460 | if (SCM_STRUCT_DATA (vtable)[scm_struct_i_flags] & SCM_STRUCTF_ENTITY) |
a5bfe84d MD |
461 | { |
462 | data = scm_alloc_struct (basic_size + tail_elts, | |
98d5f601 | 463 | scm_struct_entity_n_extra_words, |
a5bfe84d | 464 | "make-struct"); |
c8045e8d DH |
465 | data[scm_struct_i_procedure] = SCM_UNPACK (SCM_BOOL_F); |
466 | data[scm_struct_i_setter] = SCM_UNPACK (SCM_BOOL_F); | |
a5bfe84d MD |
467 | } |
468 | else | |
469 | data = scm_alloc_struct (basic_size + tail_elts, | |
470 | scm_struct_n_extra_words, | |
471 | "make-struct"); | |
54778cd3 | 472 | SCM_SET_CELL_WORD_1 (handle, data); |
08c880a3 | 473 | SCM_SET_STRUCT_GC_CHAIN (handle, 0); |
f7620510 | 474 | scm_struct_init (handle, layout, data, tail_elts, init); |
92c2555f | 475 | SCM_SET_CELL_WORD_0 (handle, (scm_t_bits) SCM_STRUCT_DATA (vtable) + scm_tc3_cons_gloc); |
0f2d19dd JB |
476 | SCM_ALLOW_INTS; |
477 | return handle; | |
478 | } | |
1bbd0b84 | 479 | #undef FUNC_NAME |
0f2d19dd JB |
480 | |
481 | ||
482 | ||
a1ec6916 | 483 | SCM_DEFINE (scm_make_vtable_vtable, "make-vtable-vtable", 2, 0, 1, |
04323af4 | 484 | (SCM user_fields, SCM tail_array_size, SCM init), |
b380b885 | 485 | "Return a new, self-describing vtable structure.\n\n" |
04323af4 MD |
486 | "@var{user-fields} is a string describing user defined fields of the\n" |
487 | "vtable beginning at index @code{vtable-offset-user}\n" | |
488 | "(see @code{make-struct-layout}).\n\n" | |
b380b885 MD |
489 | "@var{tail-size} specifies the size of the tail-array (if any) of\n" |
490 | "this vtable.\n\n" | |
6386e25c | 491 | "@var{init1}, @dots{} are the optional initializers for the fields of\n" |
04323af4 MD |
492 | "the vtable.\n\n" |
493 | "Vtables have one initializable system field---the struct printer.\n" | |
494 | "This field comes before the user fields in the initializers passed\n" | |
495 | "to @code{make-vtable-vtable} and @code{make-struct}, and thus works as\n" | |
496 | "a third optional argument to @code{make-vtable-vtable} and a fourth to\n" | |
497 | "@code{make-struct} when creating vtables:\n\n" | |
498 | "If the value is a procedure, it will be called instead of the standard\n" | |
499 | "printer whenever a struct described by this vtable is printed.\n" | |
500 | "The procedure will be called with arguments STRUCT and PORT.\n\n" | |
501 | "The structure of a struct is described by a vtable, so the vtable is\n" | |
502 | "in essence the type of the struct. The vtable is itself a struct with\n" | |
503 | "a vtable. This could go on forever if it weren't for the\n" | |
29b4f9fb | 504 | "vtable-vtables which are self-describing vtables, and thus terminate\n" |
04323af4 MD |
505 | "the chain.\n\n" |
506 | "There are several potential ways of using structs, but the standard\n" | |
507 | "one is to use three kinds of structs, together building up a type\n" | |
508 | "sub-system: one vtable-vtable working as the root and one or several\n" | |
509 | "\"types\", each with a set of \"instances\". (The vtable-vtable should be\n" | |
29b4f9fb | 510 | "compared to the class <class> which is the class of itself.)\n\n" |
1e6808ea | 511 | "@lisp\n" |
04323af4 MD |
512 | "(define ball-root (make-vtable-vtable \"pr\" 0))\n\n" |
513 | "(define (make-ball-type ball-color)\n" | |
514 | " (make-struct ball-root 0\n" | |
515 | " (make-struct-layout \"pw\")\n" | |
516 | " (lambda (ball port)\n" | |
517 | " (format port \"#<a ~A ball owned by ~A>\"\n" | |
518 | " (color ball)\n" | |
519 | " (owner ball)))\n" | |
520 | " ball-color))\n" | |
521 | "(define (color ball) (struct-ref (struct-vtable ball) vtable-offset-user))\n" | |
522 | "(define (owner ball) (struct-ref ball 0))\n\n" | |
523 | "(define red (make-ball-type 'red))\n" | |
524 | "(define green (make-ball-type 'green))\n\n" | |
525 | "(define (make-ball type owner) (make-struct type 0 owner))\n\n" | |
526 | "(define ball (make-ball green 'Nisse))\n" | |
527 | "ball @result{} #<a green ball owned by Nisse>\n" | |
1e6808ea | 528 | "@end lisp\n") |
1bbd0b84 | 529 | #define FUNC_NAME s_scm_make_vtable_vtable |
0f2d19dd JB |
530 | { |
531 | SCM fields; | |
532 | SCM layout; | |
533 | int basic_size; | |
534 | int tail_elts; | |
92c2555f | 535 | scm_t_bits * data; |
0f2d19dd JB |
536 | SCM handle; |
537 | ||
d1ca2c64 | 538 | SCM_VALIDATE_STRING (1, user_fields); |
04323af4 | 539 | SCM_VALIDATE_INUM (2, tail_array_size); |
af45e3b0 | 540 | SCM_VALIDATE_REST_ARGUMENT (init); |
0f2d19dd | 541 | |
e0c08f17 | 542 | fields = scm_string_append (SCM_LIST2 (required_vtable_fields, user_fields)); |
0f2d19dd | 543 | layout = scm_make_struct_layout (fields); |
bfa974f0 | 544 | basic_size = SCM_SYMBOL_LENGTH (layout) / 2; |
0f2d19dd | 545 | tail_elts = SCM_INUM (tail_array_size); |
08c880a3 | 546 | SCM_NEWCELL2 (handle); |
0f2d19dd | 547 | SCM_DEFER_INTS; |
a5bfe84d MD |
548 | data = scm_alloc_struct (basic_size + tail_elts, |
549 | scm_struct_n_extra_words, | |
550 | "make-vtable-vtable"); | |
54778cd3 | 551 | SCM_SET_CELL_WORD_1 (handle, data); |
08c880a3 | 552 | SCM_SET_STRUCT_GC_CHAIN (handle, 0); |
f7620510 DH |
553 | data [scm_vtable_index_layout] = SCM_UNPACK (layout); |
554 | scm_struct_init (handle, layout, data, tail_elts, scm_cons (layout, init)); | |
92c2555f | 555 | SCM_SET_CELL_WORD_0 (handle, (scm_t_bits) data + scm_tc3_cons_gloc); |
0f2d19dd JB |
556 | SCM_ALLOW_INTS; |
557 | return handle; | |
558 | } | |
1bbd0b84 | 559 | #undef FUNC_NAME |
0f2d19dd JB |
560 | |
561 | \f | |
562 | ||
563 | ||
a1ec6916 | 564 | SCM_DEFINE (scm_struct_ref, "struct-ref", 2, 0, 0, |
1bbd0b84 | 565 | (SCM handle, SCM pos), |
b380b885 MD |
566 | "@deffnx primitive struct-set! struct n value\n" |
567 | "Access (or modify) the @var{n}th field of @var{struct}.\n\n" | |
568 | "If the field is of type 'p', then it can be set to an arbitrary value.\n\n" | |
569 | "If the field is of type 'u', then it can only be set to a non-negative\n" | |
570 | "integer value small enough to fit in one machine word.") | |
1bbd0b84 | 571 | #define FUNC_NAME s_scm_struct_ref |
0f2d19dd | 572 | { |
5e840c2e | 573 | SCM answer = SCM_UNDEFINED; |
92c2555f | 574 | scm_t_bits * data; |
0f2d19dd JB |
575 | SCM layout; |
576 | int p; | |
92c2555f | 577 | scm_t_bits n_fields; |
e51fe79c DH |
578 | char * fields_desc; |
579 | char field_type = 0; | |
0f2d19dd JB |
580 | |
581 | ||
3b3b36dd GB |
582 | SCM_VALIDATE_STRUCT (1,handle); |
583 | SCM_VALIDATE_INUM (2,pos); | |
0f2d19dd JB |
584 | |
585 | layout = SCM_STRUCT_LAYOUT (handle); | |
586 | data = SCM_STRUCT_DATA (handle); | |
587 | p = SCM_INUM (pos); | |
588 | ||
e51fe79c | 589 | fields_desc = SCM_SYMBOL_CHARS (layout); |
d8c40b9f | 590 | n_fields = data[scm_struct_i_n_words]; |
2c36c351 | 591 | |
c751e5e3 | 592 | SCM_ASSERT_RANGE(1,pos, p < n_fields); |
0f2d19dd | 593 | |
bfa974f0 | 594 | if (p * 2 < SCM_SYMBOL_LENGTH (layout)) |
2c36c351 | 595 | { |
e51fe79c | 596 | char ref; |
2c36c351 MD |
597 | field_type = fields_desc[p * 2]; |
598 | ref = fields_desc[p * 2 + 1]; | |
599 | if ((ref != 'r') && (ref != 'w')) | |
600 | { | |
601 | if ((ref == 'R') || (ref == 'W')) | |
602 | field_type = 'u'; | |
603 | else | |
2ade72d7 | 604 | SCM_MISC_ERROR ("ref denied for field ~A", SCM_LIST1 (pos)); |
2c36c351 MD |
605 | } |
606 | } | |
bfa974f0 DH |
607 | else if (fields_desc[SCM_SYMBOL_LENGTH (layout) - 1] != 'O') |
608 | field_type = fields_desc[SCM_SYMBOL_LENGTH (layout) - 2]; | |
2c36c351 | 609 | else |
2ade72d7 | 610 | SCM_MISC_ERROR ("ref denied for field ~A", SCM_LIST1 (pos)); |
2c36c351 | 611 | |
0f2d19dd JB |
612 | switch (field_type) |
613 | { | |
614 | case 'u': | |
d8c40b9f | 615 | answer = scm_ulong2num (data[p]); |
0f2d19dd JB |
616 | break; |
617 | ||
618 | #if 0 | |
619 | case 'i': | |
620 | answer = scm_long2num (data[p]); | |
621 | break; | |
622 | ||
623 | case 'd': | |
f8de44c1 | 624 | answer = scm_make_real (*((double *)&(data[p]))); |
0f2d19dd JB |
625 | break; |
626 | #endif | |
627 | ||
628 | case 's': | |
629 | case 'p': | |
d8c40b9f | 630 | answer = SCM_PACK (data[p]); |
0f2d19dd JB |
631 | break; |
632 | ||
633 | ||
634 | default: | |
2ade72d7 DH |
635 | SCM_MISC_ERROR ("unrecognized field type: ~S", |
636 | SCM_LIST1 (SCM_MAKE_CHAR (field_type))); | |
0f2d19dd JB |
637 | } |
638 | ||
639 | return answer; | |
640 | } | |
1bbd0b84 | 641 | #undef FUNC_NAME |
0f2d19dd JB |
642 | |
643 | ||
a1ec6916 | 644 | SCM_DEFINE (scm_struct_set_x, "struct-set!", 3, 0, 0, |
1bbd0b84 | 645 | (SCM handle, SCM pos, SCM val), |
e3239868 DH |
646 | "Set the slot of the structure @var{handle} with index @var{pos}\n" |
647 | "to @var{val}. Signal an error if the slot can not be written\n" | |
648 | "to.") | |
1bbd0b84 | 649 | #define FUNC_NAME s_scm_struct_set_x |
0f2d19dd | 650 | { |
92c2555f | 651 | scm_t_bits * data; |
0f2d19dd JB |
652 | SCM layout; |
653 | int p; | |
654 | int n_fields; | |
e51fe79c DH |
655 | char * fields_desc; |
656 | char field_type = 0; | |
0f2d19dd | 657 | |
3b3b36dd GB |
658 | SCM_VALIDATE_STRUCT (1,handle); |
659 | SCM_VALIDATE_INUM (2,pos); | |
0f2d19dd JB |
660 | |
661 | layout = SCM_STRUCT_LAYOUT (handle); | |
662 | data = SCM_STRUCT_DATA (handle); | |
663 | p = SCM_INUM (pos); | |
664 | ||
e51fe79c | 665 | fields_desc = SCM_SYMBOL_CHARS (layout); |
d8c40b9f | 666 | n_fields = data[scm_struct_i_n_words]; |
0f2d19dd | 667 | |
c751e5e3 | 668 | SCM_ASSERT_RANGE (1,pos, p < n_fields); |
0f2d19dd | 669 | |
bfa974f0 | 670 | if (p * 2 < SCM_SYMBOL_LENGTH (layout)) |
2c36c351 | 671 | { |
e51fe79c | 672 | char set_x; |
2c36c351 MD |
673 | field_type = fields_desc[p * 2]; |
674 | set_x = fields_desc [p * 2 + 1]; | |
675 | if (set_x != 'w') | |
2ade72d7 | 676 | SCM_MISC_ERROR ("set! denied for field ~A", SCM_LIST1 (pos)); |
2c36c351 | 677 | } |
bfa974f0 DH |
678 | else if (fields_desc[SCM_SYMBOL_LENGTH (layout) - 1] == 'W') |
679 | field_type = fields_desc[SCM_SYMBOL_LENGTH (layout) - 2]; | |
2c36c351 | 680 | else |
2ade72d7 | 681 | SCM_MISC_ERROR ("set! denied for field ~A", SCM_LIST1 (pos)); |
2c36c351 | 682 | |
0f2d19dd JB |
683 | switch (field_type) |
684 | { | |
685 | case 'u': | |
d8c40b9f | 686 | data[p] = SCM_NUM2ULONG (3, val); |
0f2d19dd JB |
687 | break; |
688 | ||
689 | #if 0 | |
690 | case 'i': | |
e4b265d8 | 691 | data[p] = SCM_NUM2LONG (3, val); |
0f2d19dd JB |
692 | break; |
693 | ||
694 | case 'd': | |
695 | *((double *)&(data[p])) = scm_num2dbl (val, (char *)SCM_ARG3); | |
696 | break; | |
697 | #endif | |
698 | ||
699 | case 'p': | |
d8c40b9f | 700 | data[p] = SCM_UNPACK (val); |
0f2d19dd JB |
701 | break; |
702 | ||
703 | case 's': | |
2ade72d7 | 704 | SCM_MISC_ERROR ("self fields immutable", SCM_EOL); |
0f2d19dd JB |
705 | |
706 | default: | |
2ade72d7 DH |
707 | SCM_MISC_ERROR ("unrecognized field type: ~S", |
708 | SCM_LIST1 (SCM_MAKE_CHAR (field_type))); | |
0f2d19dd JB |
709 | } |
710 | ||
711 | return val; | |
712 | } | |
1bbd0b84 | 713 | #undef FUNC_NAME |
0f2d19dd JB |
714 | |
715 | ||
a1ec6916 | 716 | SCM_DEFINE (scm_struct_vtable, "struct-vtable", 1, 0, 0, |
1bbd0b84 | 717 | (SCM handle), |
b380b885 | 718 | "Return the vtable structure that describes the type of @var{struct}.") |
1bbd0b84 | 719 | #define FUNC_NAME s_scm_struct_vtable |
0f2d19dd | 720 | { |
3b3b36dd | 721 | SCM_VALIDATE_STRUCT (1,handle); |
0f2d19dd JB |
722 | return SCM_STRUCT_VTABLE (handle); |
723 | } | |
1bbd0b84 | 724 | #undef FUNC_NAME |
0f2d19dd JB |
725 | |
726 | ||
a1ec6916 | 727 | SCM_DEFINE (scm_struct_vtable_tag, "struct-vtable-tag", 1, 0, 0, |
1bbd0b84 | 728 | (SCM handle), |
e3239868 | 729 | "Return the vtable tag of the structure @var{handle}.") |
1bbd0b84 | 730 | #define FUNC_NAME s_scm_struct_vtable_tag |
0f2d19dd | 731 | { |
3b3b36dd | 732 | SCM_VALIDATE_VTABLE (1,handle); |
ad196599 | 733 | return scm_long2num ((long) SCM_STRUCT_DATA (handle) >> 3); |
98d5f601 | 734 | } |
1bbd0b84 | 735 | #undef FUNC_NAME |
98d5f601 MD |
736 | |
737 | /* {Associating names and classes with vtables} | |
738 | * | |
739 | * The name of a vtable should probably be stored as a slot. This is | |
740 | * a backward compatible solution until agreement has been achieved on | |
741 | * how to associate names with vtables. | |
742 | */ | |
743 | ||
c014a02e ML |
744 | unsigned long |
745 | scm_struct_ihashq (SCM obj, unsigned long n) | |
98d5f601 | 746 | { |
ad196599 MD |
747 | /* The length of the hash table should be a relative prime it's not |
748 | necessary to shift down the address. */ | |
f1267706 | 749 | return SCM_UNPACK (obj) % n; |
98d5f601 MD |
750 | } |
751 | ||
752 | SCM | |
753 | scm_struct_create_handle (SCM obj) | |
754 | { | |
755 | SCM handle = scm_hash_fn_create_handle_x (scm_struct_table, | |
756 | obj, | |
757 | SCM_BOOL_F, | |
758 | scm_struct_ihashq, | |
759 | scm_sloppy_assq, | |
760 | 0); | |
761 | if (SCM_FALSEP (SCM_CDR (handle))) | |
762 | SCM_SETCDR (handle, scm_cons (SCM_BOOL_F, SCM_BOOL_F)); | |
763 | return handle; | |
764 | } | |
765 | ||
a1ec6916 | 766 | SCM_DEFINE (scm_struct_vtable_name, "struct-vtable-name", 1, 0, 0, |
1bbd0b84 | 767 | (SCM vtable), |
e3239868 | 768 | "Return the name of the vtable @var{vtable}.") |
1bbd0b84 | 769 | #define FUNC_NAME s_scm_struct_vtable_name |
98d5f601 | 770 | { |
3b3b36dd | 771 | SCM_VALIDATE_VTABLE (1,vtable); |
98d5f601 MD |
772 | return SCM_STRUCT_TABLE_NAME (SCM_CDR (scm_struct_create_handle (vtable))); |
773 | } | |
1bbd0b84 | 774 | #undef FUNC_NAME |
98d5f601 | 775 | |
a1ec6916 | 776 | SCM_DEFINE (scm_set_struct_vtable_name_x, "set-struct-vtable-name!", 2, 0, 0, |
1bbd0b84 | 777 | (SCM vtable, SCM name), |
e3239868 | 778 | "Set the name of the vtable @var{vtable} to @var{name}.") |
1bbd0b84 | 779 | #define FUNC_NAME s_scm_set_struct_vtable_name_x |
98d5f601 | 780 | { |
3b3b36dd GB |
781 | SCM_VALIDATE_VTABLE (1,vtable); |
782 | SCM_VALIDATE_SYMBOL (2,name); | |
98d5f601 MD |
783 | SCM_SET_STRUCT_TABLE_NAME (SCM_CDR (scm_struct_create_handle (vtable)), |
784 | name); | |
785 | return SCM_UNSPECIFIED; | |
0f2d19dd | 786 | } |
1bbd0b84 | 787 | #undef FUNC_NAME |
0f2d19dd JB |
788 | |
789 | ||
790 | \f | |
791 | ||
bafcafb2 | 792 | void |
1bbd0b84 | 793 | scm_print_struct (SCM exp, SCM port, scm_print_state *pstate) |
bafcafb2 | 794 | { |
4bfdf158 MD |
795 | if (SCM_NFALSEP (scm_procedure_p (SCM_STRUCT_PRINTER (exp)))) |
796 | scm_printer_apply (SCM_STRUCT_PRINTER (exp), exp, port, pstate); | |
797 | else | |
bafcafb2 | 798 | { |
a1ae1799 MD |
799 | SCM vtable = SCM_STRUCT_VTABLE (exp); |
800 | SCM name = scm_struct_vtable_name (vtable); | |
801 | scm_puts ("#<", port); | |
802 | if (SCM_NFALSEP (name)) | |
803 | scm_display (name, port); | |
804 | else | |
805 | scm_puts ("struct", port); | |
806 | scm_putc (' ', port); | |
54778cd3 | 807 | scm_intprint (SCM_UNPACK (vtable), 16, port); |
b7f3516f | 808 | scm_putc (':', port); |
54778cd3 | 809 | scm_intprint (SCM_UNPACK (exp), 16, port); |
b7f3516f | 810 | scm_putc ('>', port); |
bafcafb2 | 811 | } |
bafcafb2 | 812 | } |
1cc91f1b | 813 | |
08c880a3 MD |
814 | void |
815 | scm_struct_prehistory () | |
816 | { | |
817 | scm_c_hook_add (&scm_before_mark_c_hook, scm_struct_gc_init, 0, 0); | |
818 | scm_c_hook_add (&scm_after_sweep_c_hook, scm_free_structs, 0, 0); | |
819 | } | |
820 | ||
0f2d19dd JB |
821 | void |
822 | scm_init_struct () | |
0f2d19dd | 823 | { |
98d5f601 MD |
824 | scm_struct_table |
825 | = scm_permanent_object (scm_make_weak_key_hash_table (SCM_MAKINUM (31))); | |
7c31152f | 826 | required_vtable_fields = scm_makfrom0str ("pruosrpw"); |
0f2d19dd | 827 | scm_permanent_object (required_vtable_fields); |
86d31dfe MV |
828 | scm_c_define ("vtable-index-layout", SCM_MAKINUM (scm_vtable_index_layout)); |
829 | scm_c_define ("vtable-index-vtable", SCM_MAKINUM (scm_vtable_index_vtable)); | |
830 | scm_c_define ("vtable-index-printer", | |
831 | SCM_MAKINUM (scm_vtable_index_printer)); | |
832 | scm_c_define ("vtable-offset-user", SCM_MAKINUM (scm_vtable_offset_user)); | |
8dc9439f | 833 | #ifndef SCM_MAGIC_SNARFER |
a0599745 | 834 | #include "libguile/struct.x" |
8dc9439f | 835 | #endif |
0f2d19dd | 836 | } |
89e00824 ML |
837 | |
838 | /* | |
839 | Local Variables: | |
840 | c-file-style: "gnu" | |
841 | End: | |
842 | */ |