Commit | Line | Data |
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53af8255 | 1 | /* Copyright (C) 1996,1997,1998,1999,2000,2001, 2003 Free Software Foundation, Inc. |
0f2d19dd | 2 | * |
73be1d9e MV |
3 | * This library is free software; you can redistribute it and/or |
4 | * modify it under the terms of the GNU Lesser General Public | |
5 | * License as published by the Free Software Foundation; either | |
6 | * version 2.1 of the License, or (at your option) any later version. | |
0f2d19dd | 7 | * |
73be1d9e MV |
8 | * This library is distributed in the hope that it will be useful, |
9 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
10 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
11 | * Lesser General Public License for more details. | |
0f2d19dd | 12 | * |
73be1d9e MV |
13 | * You should have received a copy of the GNU Lesser General Public |
14 | * License along with this library; if not, write to the Free Software | |
15 | * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA | |
16 | */ | |
1bbd0b84 | 17 | |
0f2d19dd | 18 | \f |
a6f7f57d RB |
19 | #if HAVE_CONFIG_H |
20 | # include <config.h> | |
21 | #endif | |
0f2d19dd | 22 | |
a0599745 MD |
23 | #include "libguile/_scm.h" |
24 | #include "libguile/chars.h" | |
25 | #include "libguile/eval.h" | |
26 | #include "libguile/alist.h" | |
27 | #include "libguile/weaks.h" | |
28 | #include "libguile/hashtab.h" | |
29 | #include "libguile/ports.h" | |
30 | #include "libguile/strings.h" | |
31 | ||
32 | #include "libguile/validate.h" | |
33 | #include "libguile/struct.h" | |
0f2d19dd | 34 | |
95b88819 GH |
35 | #ifdef HAVE_STRING_H |
36 | #include <string.h> | |
37 | #endif | |
38 | ||
0f2d19dd JB |
39 | \f |
40 | ||
41 | static SCM required_vtable_fields = SCM_BOOL_F; | |
98d5f601 | 42 | SCM scm_struct_table; |
0f2d19dd JB |
43 | |
44 | \f | |
a1ec6916 | 45 | SCM_DEFINE (scm_make_struct_layout, "make-struct-layout", 1, 0, 0, |
1bbd0b84 | 46 | (SCM fields), |
b380b885 | 47 | "Return a new structure layout object.\n\n" |
7c31152f | 48 | "@var{fields} must be a string made up of pairs of characters\n" |
b380b885 MD |
49 | "strung together. The first character of each pair describes a field\n" |
50 | "type, the second a field protection. Allowed types are 'p' for\n" | |
51 | "GC-protected Scheme data, 'u' for unprotected binary data, and 's' for\n" | |
04323af4 | 52 | "a field that points to the structure itself. Allowed protections\n" |
9401323e | 53 | "are 'w' for mutable fields, 'r' for read-only fields, and 'o' for opaque\n" |
b380b885 MD |
54 | "fields. The last field protection specification may be capitalized to\n" |
55 | "indicate that the field is a tail-array.") | |
1bbd0b84 | 56 | #define FUNC_NAME s_scm_make_struct_layout |
0f2d19dd JB |
57 | { |
58 | SCM new_sym; | |
d1ca2c64 | 59 | SCM_VALIDATE_STRING (1, fields); |
2ade72d7 | 60 | |
1bbd0b84 | 61 | { /* scope */ |
0f2d19dd | 62 | char * field_desc; |
1be6b49c | 63 | size_t len; |
0f2d19dd JB |
64 | int x; |
65 | ||
d1ca2c64 | 66 | len = SCM_STRING_LENGTH (fields); |
2ade72d7 DH |
67 | if (len % 2 == 1) |
68 | SCM_MISC_ERROR ("odd length field specification: ~S", | |
1afff620 | 69 | scm_list_1 (fields)); |
2ade72d7 | 70 | |
34f0f2b8 | 71 | field_desc = SCM_STRING_CHARS (fields); |
0f2d19dd JB |
72 | |
73 | for (x = 0; x < len; x += 2) | |
74 | { | |
75 | switch (field_desc[x]) | |
76 | { | |
77 | case 'u': | |
78 | case 'p': | |
79 | #if 0 | |
80 | case 'i': | |
81 | case 'd': | |
82 | #endif | |
83 | case 's': | |
84 | break; | |
85 | default: | |
2ade72d7 | 86 | SCM_MISC_ERROR ("unrecognized field type: ~S", |
1afff620 | 87 | scm_list_1 (SCM_MAKE_CHAR (field_desc[x]))); |
0f2d19dd JB |
88 | } |
89 | ||
90 | switch (field_desc[x + 1]) | |
91 | { | |
92 | case 'w': | |
2ade72d7 DH |
93 | if (field_desc[x] == 's') |
94 | SCM_MISC_ERROR ("self fields not writable", SCM_EOL); | |
0f2d19dd JB |
95 | case 'r': |
96 | case 'o': | |
97 | break; | |
2c36c351 MD |
98 | case 'R': |
99 | case 'W': | |
100 | case 'O': | |
2ade72d7 DH |
101 | if (field_desc[x] == 's') |
102 | SCM_MISC_ERROR ("self fields not allowed in tail array", | |
103 | SCM_EOL); | |
104 | if (x != len - 2) | |
105 | SCM_MISC_ERROR ("tail array field must be last field in layout", | |
106 | SCM_EOL); | |
2c36c351 | 107 | break; |
0f2d19dd | 108 | default: |
2ade72d7 | 109 | SCM_MISC_ERROR ("unrecognized ref specification: ~S", |
1afff620 | 110 | scm_list_1 (SCM_MAKE_CHAR (field_desc[x + 1]))); |
0f2d19dd JB |
111 | } |
112 | #if 0 | |
113 | if (field_desc[x] == 'd') | |
114 | { | |
2ade72d7 DH |
115 | if (field_desc[x + 2] != '-') |
116 | SCM_MISC_ERROR ("missing dash field at position ~A", | |
93ccaef0 | 117 | scm_list_1 (SCM_I_MAKINUM (x / 2))); |
0f2d19dd JB |
118 | x += 2; |
119 | goto recheck_ref; | |
120 | } | |
121 | #endif | |
122 | } | |
38ae064c | 123 | new_sym = scm_mem2symbol (field_desc, len); |
0f2d19dd JB |
124 | } |
125 | return scm_return_first (new_sym, fields); | |
126 | } | |
1bbd0b84 | 127 | #undef FUNC_NAME |
0f2d19dd JB |
128 | |
129 | \f | |
130 | ||
131 | ||
1cc91f1b | 132 | |
f7620510 | 133 | static void |
92c2555f | 134 | scm_struct_init (SCM handle, SCM layout, scm_t_bits * mem, int tail_elts, SCM inits) |
0f2d19dd | 135 | { |
a002f1a2 | 136 | unsigned char * fields_desc = (unsigned char *) SCM_SYMBOL_CHARS (layout) - 2; |
35de7ebe | 137 | unsigned char prot = 0; |
bfa974f0 | 138 | int n_fields = SCM_SYMBOL_LENGTH (layout) / 2; |
2c36c351 | 139 | int tailp = 0; |
d8c40b9f | 140 | |
0f2d19dd JB |
141 | while (n_fields) |
142 | { | |
2c36c351 MD |
143 | if (!tailp) |
144 | { | |
145 | fields_desc += 2; | |
146 | prot = fields_desc[1]; | |
147 | if (SCM_LAYOUT_TAILP (prot)) | |
148 | { | |
149 | tailp = 1; | |
150 | prot = prot == 'R' ? 'r' : prot == 'W' ? 'w' : 'o'; | |
d8c40b9f | 151 | *mem++ = tail_elts; |
2c36c351 MD |
152 | n_fields += tail_elts - 1; |
153 | if (n_fields == 0) | |
154 | break; | |
155 | } | |
156 | } | |
157 | ||
0f2d19dd JB |
158 | switch (*fields_desc) |
159 | { | |
160 | #if 0 | |
161 | case 'i': | |
2c36c351 | 162 | if ((prot != 'r' && prot != 'w') || inits == SCM_EOL) |
0f2d19dd JB |
163 | *mem = 0; |
164 | else | |
165 | { | |
a5bfe84d | 166 | *mem = scm_num2long (SCM_CAR (inits), SCM_ARGn, "scm_struct_init"); |
0f2d19dd JB |
167 | inits = SCM_CDR (inits); |
168 | } | |
169 | break; | |
170 | #endif | |
171 | ||
172 | case 'u': | |
54778cd3 | 173 | if ((prot != 'r' && prot != 'w') || SCM_NULLP (inits)) |
0f2d19dd JB |
174 | *mem = 0; |
175 | else | |
176 | { | |
d8c40b9f DH |
177 | *mem = scm_num2ulong (SCM_CAR (inits), |
178 | SCM_ARGn, | |
179 | "scm_struct_init"); | |
0f2d19dd JB |
180 | inits = SCM_CDR (inits); |
181 | } | |
182 | break; | |
183 | ||
184 | case 'p': | |
54778cd3 | 185 | if ((prot != 'r' && prot != 'w') || SCM_NULLP (inits)) |
d8c40b9f | 186 | *mem = SCM_UNPACK (SCM_BOOL_F); |
0f2d19dd JB |
187 | else |
188 | { | |
d8c40b9f | 189 | *mem = SCM_UNPACK (SCM_CAR (inits)); |
0f2d19dd JB |
190 | inits = SCM_CDR (inits); |
191 | } | |
192 | ||
193 | break; | |
194 | ||
195 | #if 0 | |
196 | case 'd': | |
2c36c351 | 197 | if ((prot != 'r' && prot != 'w') || inits == SCM_EOL) |
0f2d19dd JB |
198 | *((double *)mem) = 0.0; |
199 | else | |
200 | { | |
a5bfe84d | 201 | *mem = scm_num2dbl (SCM_CAR (inits), "scm_struct_init"); |
0f2d19dd JB |
202 | inits = SCM_CDR (inits); |
203 | } | |
204 | fields_desc += 2; | |
205 | break; | |
206 | #endif | |
207 | ||
208 | case 's': | |
d8c40b9f | 209 | *mem = SCM_UNPACK (handle); |
0f2d19dd JB |
210 | break; |
211 | } | |
212 | ||
0f2d19dd JB |
213 | n_fields--; |
214 | mem++; | |
215 | } | |
216 | } | |
217 | ||
218 | ||
a1ec6916 | 219 | SCM_DEFINE (scm_struct_p, "struct?", 1, 0, 0, |
1bbd0b84 | 220 | (SCM x), |
0233bfc1 | 221 | "Return @code{#t} iff @var{x} is a structure object, else\n" |
942e5b91 | 222 | "@code{#f}.") |
1bbd0b84 | 223 | #define FUNC_NAME s_scm_struct_p |
0f2d19dd | 224 | { |
7888309b | 225 | return scm_from_bool(SCM_STRUCTP (x)); |
0f2d19dd | 226 | } |
1bbd0b84 | 227 | #undef FUNC_NAME |
0f2d19dd | 228 | |
a1ec6916 | 229 | SCM_DEFINE (scm_struct_vtable_p, "struct-vtable?", 1, 0, 0, |
1bbd0b84 | 230 | (SCM x), |
0233bfc1 | 231 | "Return @code{#t} iff @var{x} is a vtable structure.") |
1bbd0b84 | 232 | #define FUNC_NAME s_scm_struct_vtable_p |
0f2d19dd JB |
233 | { |
234 | SCM layout; | |
92c2555f | 235 | scm_t_bits * mem; |
0f2d19dd JB |
236 | |
237 | if (!SCM_STRUCTP (x)) | |
238 | return SCM_BOOL_F; | |
239 | ||
240 | layout = SCM_STRUCT_LAYOUT (x); | |
241 | ||
bfa974f0 | 242 | if (SCM_SYMBOL_LENGTH (layout) < SCM_STRING_LENGTH (required_vtable_fields)) |
0f2d19dd JB |
243 | return SCM_BOOL_F; |
244 | ||
a002f1a2 | 245 | if (strncmp (SCM_SYMBOL_CHARS (layout), SCM_STRING_CHARS (required_vtable_fields), |
bfa974f0 | 246 | SCM_STRING_LENGTH (required_vtable_fields))) |
0f2d19dd JB |
247 | return SCM_BOOL_F; |
248 | ||
249 | mem = SCM_STRUCT_DATA (x); | |
250 | ||
7888309b | 251 | return scm_from_bool (SCM_SYMBOLP (SCM_PACK (mem[scm_vtable_index_layout]))); |
0f2d19dd | 252 | } |
1bbd0b84 | 253 | #undef FUNC_NAME |
0f2d19dd | 254 | |
14d1400f JB |
255 | |
256 | /* All struct data must be allocated at an address whose bottom three | |
257 | bits are zero. This is because the tag for a struct lives in the | |
258 | bottom three bits of the struct's car, and the upper bits point to | |
259 | the data of its vtable, which is a struct itself. Thus, if the | |
260 | address of that data doesn't end in three zeros, tagging it will | |
261 | destroy the pointer. | |
262 | ||
263 | This function allocates a block of memory, and returns a pointer at | |
264 | least scm_struct_n_extra_words words into the block. Furthermore, | |
265 | it guarantees that that pointer's least three significant bits are | |
266 | all zero. | |
267 | ||
268 | The argument n_words should be the number of words that should | |
269 | appear after the returned address. (That is, it shouldn't include | |
270 | scm_struct_n_extra_words.) | |
271 | ||
272 | This function initializes the following fields of the struct: | |
273 | ||
ad196599 | 274 | scm_struct_i_ptr --- the actual start of the block of memory; the |
14d1400f JB |
275 | address you should pass to 'free' to dispose of the block. |
276 | This field allows us to both guarantee that the returned | |
277 | address is divisible by eight, and allow the GC to free the | |
278 | block. | |
279 | ||
280 | scm_struct_i_n_words --- the number of words allocated to the | |
281 | block, including the extra fields. This is used by the GC. | |
282 | ||
14d1400f JB |
283 | Ugh. */ |
284 | ||
285 | ||
92c2555f | 286 | scm_t_bits * |
4c9419ac | 287 | scm_alloc_struct (int n_words, int n_extra, const char *what) |
14d1400f | 288 | { |
92c2555f | 289 | int size = sizeof (scm_t_bits) * (n_words + n_extra) + 7; |
4c9419ac | 290 | void * block = scm_gc_malloc (size, what); |
14d1400f JB |
291 | |
292 | /* Adjust the pointer to hide the extra words. */ | |
92c2555f | 293 | scm_t_bits * p = (scm_t_bits *) block + n_extra; |
14d1400f JB |
294 | |
295 | /* Adjust it even further so it's aligned on an eight-byte boundary. */ | |
92c2555f | 296 | p = (scm_t_bits *) (((scm_t_bits) p + 7) & ~7); |
14d1400f | 297 | |
ad196599 | 298 | /* Initialize a few fields as described above. */ |
92c2555f MV |
299 | p[scm_struct_i_free] = (scm_t_bits) scm_struct_free_standard; |
300 | p[scm_struct_i_ptr] = (scm_t_bits) block; | |
c8045e8d | 301 | p[scm_struct_i_n_words] = n_words; |
ad196599 | 302 | p[scm_struct_i_flags] = 0; |
14d1400f JB |
303 | |
304 | return p; | |
305 | } | |
306 | ||
4c9419ac | 307 | void |
92c2555f MV |
308 | scm_struct_free_0 (scm_t_bits * vtable SCM_UNUSED, |
309 | scm_t_bits * data SCM_UNUSED) | |
ad196599 | 310 | { |
ad196599 MD |
311 | } |
312 | ||
4c9419ac | 313 | void |
92c2555f | 314 | scm_struct_free_light (scm_t_bits * vtable, scm_t_bits * data) |
ad196599 | 315 | { |
4c9419ac MV |
316 | size_t n = vtable [scm_struct_i_size] & ~SCM_STRUCTF_MASK; |
317 | scm_gc_free (data, n, "struct"); | |
ad196599 MD |
318 | } |
319 | ||
4c9419ac | 320 | void |
92c2555f | 321 | scm_struct_free_standard (scm_t_bits * vtable SCM_UNUSED, scm_t_bits * data) |
ad196599 | 322 | { |
c8045e8d | 323 | size_t n = (data[scm_struct_i_n_words] + scm_struct_n_extra_words) |
92c2555f | 324 | * sizeof (scm_t_bits) + 7; |
4c9419ac | 325 | scm_gc_free ((void *) data[scm_struct_i_ptr], n, "heavy struct"); |
ad196599 MD |
326 | } |
327 | ||
4c9419ac | 328 | void |
92c2555f | 329 | scm_struct_free_entity (scm_t_bits * vtable SCM_UNUSED, scm_t_bits * data) |
ad196599 | 330 | { |
c8045e8d | 331 | size_t n = (data[scm_struct_i_n_words] + scm_struct_entity_n_extra_words) |
92c2555f | 332 | * sizeof (scm_t_bits) + 7; |
4c9419ac | 333 | scm_gc_free ((void *) data[scm_struct_i_ptr], n, "entity struct"); |
ad196599 | 334 | } |
14d1400f | 335 | |
b4a1358c MD |
336 | static void * |
337 | scm_struct_gc_init (void *dummy1 SCM_UNUSED, | |
338 | void *dummy2 SCM_UNUSED, | |
339 | void *dummy3 SCM_UNUSED) | |
340 | { | |
341 | scm_i_structs_to_free = SCM_EOL; | |
342 | return 0; | |
343 | } | |
344 | ||
08c880a3 | 345 | static void * |
e81d98ec DH |
346 | scm_free_structs (void *dummy1 SCM_UNUSED, |
347 | void *dummy2 SCM_UNUSED, | |
348 | void *dummy3 SCM_UNUSED) | |
08c880a3 | 349 | { |
ffd72400 | 350 | SCM newchain = scm_i_structs_to_free; |
08c880a3 MD |
351 | do |
352 | { | |
353 | /* Mark vtables in GC chain. GC mark set means delay freeing. */ | |
354 | SCM chain = newchain; | |
1a551638 | 355 | while (!SCM_NULLP (chain)) |
08c880a3 MD |
356 | { |
357 | SCM vtable = SCM_STRUCT_VTABLE (chain); | |
358 | if (SCM_STRUCT_GC_CHAIN (vtable) != 0 && vtable != chain) | |
c8a1bdc4 | 359 | SCM_SET_GC_MARK (vtable); |
08c880a3 MD |
360 | chain = SCM_STRUCT_GC_CHAIN (chain); |
361 | } | |
362 | /* Free unmarked structs. */ | |
363 | chain = newchain; | |
364 | newchain = SCM_EOL; | |
1a551638 | 365 | while (!SCM_NULLP (chain)) |
08c880a3 MD |
366 | { |
367 | SCM obj = chain; | |
368 | chain = SCM_STRUCT_GC_CHAIN (chain); | |
c8a1bdc4 | 369 | if (SCM_GC_MARK_P (obj)) |
08c880a3 | 370 | { |
c8a1bdc4 | 371 | SCM_CLEAR_GC_MARK (obj); |
08c880a3 MD |
372 | SCM_SET_STRUCT_GC_CHAIN (obj, newchain); |
373 | newchain = obj; | |
374 | } | |
375 | else | |
376 | { | |
904a077d MV |
377 | /* XXX - use less explicit code. */ |
378 | scm_t_bits word0 = SCM_CELL_WORD_0 (obj) - scm_tc3_struct; | |
92c2555f MV |
379 | scm_t_bits * vtable_data = (scm_t_bits *) word0; |
380 | scm_t_bits * data = SCM_STRUCT_DATA (obj); | |
381 | scm_t_struct_free free_struct_data | |
382 | = ((scm_t_struct_free) vtable_data[scm_struct_i_free]); | |
08c880a3 MD |
383 | SCM_SET_CELL_TYPE (obj, scm_tc_free_cell); |
384 | free_struct_data (vtable_data, data); | |
385 | } | |
386 | } | |
387 | } | |
1a551638 | 388 | while (!SCM_NULLP (newchain)); |
08c880a3 MD |
389 | return 0; |
390 | } | |
391 | ||
a1ec6916 | 392 | SCM_DEFINE (scm_make_struct, "make-struct", 2, 0, 1, |
1bbd0b84 | 393 | (SCM vtable, SCM tail_array_size, SCM init), |
b380b885 | 394 | "Create a new structure.\n\n" |
1bee0e70 | 395 | "@var{type} must be a vtable structure (@pxref{Vtables}).\n\n" |
b380b885 MD |
396 | "@var{tail-elts} must be a non-negative integer. If the layout\n" |
397 | "specification indicated by @var{type} includes a tail-array,\n" | |
398 | "this is the number of elements allocated to that array.\n\n" | |
6386e25c | 399 | "The @var{init1}, @dots{} are optional arguments describing how\n" |
04323af4 MD |
400 | "successive fields of the structure should be initialized. Only fields\n" |
401 | "with protection 'r' or 'w' can be initialized, except for fields of\n" | |
402 | "type 's', which are automatically initialized to point to the new\n" | |
403 | "structure itself; fields with protection 'o' can not be initialized by\n" | |
404 | "Scheme programs.\n\n" | |
405 | "If fewer optional arguments than initializable fields are supplied,\n" | |
406 | "fields of type 'p' get default value #f while fields of type 'u' are\n" | |
407 | "initialized to 0.\n\n" | |
408 | "Structs are currently the basic representation for record-like data\n" | |
409 | "structures in Guile. The plan is to eventually replace them with a\n" | |
410 | "new representation which will at the same time be easier to use and\n" | |
411 | "more powerful.\n\n" | |
6386e25c | 412 | "For more information, see the documentation for @code{make-vtable-vtable}.") |
1bbd0b84 | 413 | #define FUNC_NAME s_scm_make_struct |
0f2d19dd JB |
414 | { |
415 | SCM layout; | |
a55c2b68 MV |
416 | size_t basic_size; |
417 | size_t tail_elts; | |
92c2555f | 418 | scm_t_bits * data; |
0f2d19dd JB |
419 | SCM handle; |
420 | ||
34d19ef6 | 421 | SCM_VALIDATE_VTABLE (1, vtable); |
af45e3b0 | 422 | SCM_VALIDATE_REST_ARGUMENT (init); |
0f2d19dd | 423 | |
d8c40b9f | 424 | layout = SCM_PACK (SCM_STRUCT_DATA (vtable) [scm_vtable_index_layout]); |
bfa974f0 | 425 | basic_size = SCM_SYMBOL_LENGTH (layout) / 2; |
a55c2b68 | 426 | tail_elts = scm_to_size_t (tail_array_size); |
0f2d19dd | 427 | SCM_DEFER_INTS; |
d8c40b9f | 428 | if (SCM_STRUCT_DATA (vtable)[scm_struct_i_flags] & SCM_STRUCTF_ENTITY) |
a5bfe84d MD |
429 | { |
430 | data = scm_alloc_struct (basic_size + tail_elts, | |
98d5f601 | 431 | scm_struct_entity_n_extra_words, |
4c9419ac | 432 | "entity struct"); |
c8045e8d DH |
433 | data[scm_struct_i_procedure] = SCM_UNPACK (SCM_BOOL_F); |
434 | data[scm_struct_i_setter] = SCM_UNPACK (SCM_BOOL_F); | |
a5bfe84d MD |
435 | } |
436 | else | |
437 | data = scm_alloc_struct (basic_size + tail_elts, | |
438 | scm_struct_n_extra_words, | |
4c9419ac | 439 | "struct"); |
228a24ef DH |
440 | handle = scm_double_cell ((((scm_t_bits) SCM_STRUCT_DATA (vtable)) |
441 | + scm_tc3_struct), | |
442 | (scm_t_bits) data, 0, 0); | |
f7620510 | 443 | scm_struct_init (handle, layout, data, tail_elts, init); |
0f2d19dd JB |
444 | SCM_ALLOW_INTS; |
445 | return handle; | |
446 | } | |
1bbd0b84 | 447 | #undef FUNC_NAME |
0f2d19dd JB |
448 | |
449 | ||
450 | ||
a1ec6916 | 451 | SCM_DEFINE (scm_make_vtable_vtable, "make-vtable-vtable", 2, 0, 1, |
04323af4 | 452 | (SCM user_fields, SCM tail_array_size, SCM init), |
b380b885 | 453 | "Return a new, self-describing vtable structure.\n\n" |
04323af4 MD |
454 | "@var{user-fields} is a string describing user defined fields of the\n" |
455 | "vtable beginning at index @code{vtable-offset-user}\n" | |
456 | "(see @code{make-struct-layout}).\n\n" | |
b380b885 MD |
457 | "@var{tail-size} specifies the size of the tail-array (if any) of\n" |
458 | "this vtable.\n\n" | |
6386e25c | 459 | "@var{init1}, @dots{} are the optional initializers for the fields of\n" |
04323af4 MD |
460 | "the vtable.\n\n" |
461 | "Vtables have one initializable system field---the struct printer.\n" | |
462 | "This field comes before the user fields in the initializers passed\n" | |
463 | "to @code{make-vtable-vtable} and @code{make-struct}, and thus works as\n" | |
464 | "a third optional argument to @code{make-vtable-vtable} and a fourth to\n" | |
465 | "@code{make-struct} when creating vtables:\n\n" | |
466 | "If the value is a procedure, it will be called instead of the standard\n" | |
467 | "printer whenever a struct described by this vtable is printed.\n" | |
468 | "The procedure will be called with arguments STRUCT and PORT.\n\n" | |
469 | "The structure of a struct is described by a vtable, so the vtable is\n" | |
470 | "in essence the type of the struct. The vtable is itself a struct with\n" | |
471 | "a vtable. This could go on forever if it weren't for the\n" | |
29b4f9fb | 472 | "vtable-vtables which are self-describing vtables, and thus terminate\n" |
04323af4 MD |
473 | "the chain.\n\n" |
474 | "There are several potential ways of using structs, but the standard\n" | |
475 | "one is to use three kinds of structs, together building up a type\n" | |
476 | "sub-system: one vtable-vtable working as the root and one or several\n" | |
477 | "\"types\", each with a set of \"instances\". (The vtable-vtable should be\n" | |
29b4f9fb | 478 | "compared to the class <class> which is the class of itself.)\n\n" |
1e6808ea | 479 | "@lisp\n" |
04323af4 MD |
480 | "(define ball-root (make-vtable-vtable \"pr\" 0))\n\n" |
481 | "(define (make-ball-type ball-color)\n" | |
482 | " (make-struct ball-root 0\n" | |
483 | " (make-struct-layout \"pw\")\n" | |
484 | " (lambda (ball port)\n" | |
485 | " (format port \"#<a ~A ball owned by ~A>\"\n" | |
486 | " (color ball)\n" | |
487 | " (owner ball)))\n" | |
488 | " ball-color))\n" | |
489 | "(define (color ball) (struct-ref (struct-vtable ball) vtable-offset-user))\n" | |
490 | "(define (owner ball) (struct-ref ball 0))\n\n" | |
491 | "(define red (make-ball-type 'red))\n" | |
492 | "(define green (make-ball-type 'green))\n\n" | |
493 | "(define (make-ball type owner) (make-struct type 0 owner))\n\n" | |
494 | "(define ball (make-ball green 'Nisse))\n" | |
495 | "ball @result{} #<a green ball owned by Nisse>\n" | |
9401323e | 496 | "@end lisp") |
1bbd0b84 | 497 | #define FUNC_NAME s_scm_make_vtable_vtable |
0f2d19dd JB |
498 | { |
499 | SCM fields; | |
500 | SCM layout; | |
a55c2b68 MV |
501 | size_t basic_size; |
502 | size_t tail_elts; | |
503 | scm_t_bits *data; | |
0f2d19dd JB |
504 | SCM handle; |
505 | ||
d1ca2c64 | 506 | SCM_VALIDATE_STRING (1, user_fields); |
af45e3b0 | 507 | SCM_VALIDATE_REST_ARGUMENT (init); |
0f2d19dd | 508 | |
1afff620 KN |
509 | fields = scm_string_append (scm_list_2 (required_vtable_fields, |
510 | user_fields)); | |
0f2d19dd | 511 | layout = scm_make_struct_layout (fields); |
bfa974f0 | 512 | basic_size = SCM_SYMBOL_LENGTH (layout) / 2; |
a55c2b68 | 513 | tail_elts = scm_to_size_t (tail_array_size); |
0f2d19dd | 514 | SCM_DEFER_INTS; |
a5bfe84d MD |
515 | data = scm_alloc_struct (basic_size + tail_elts, |
516 | scm_struct_n_extra_words, | |
4c9419ac | 517 | "struct"); |
228a24ef DH |
518 | handle = scm_double_cell ((scm_t_bits) data + scm_tc3_struct, |
519 | (scm_t_bits) data, 0, 0); | |
f7620510 DH |
520 | data [scm_vtable_index_layout] = SCM_UNPACK (layout); |
521 | scm_struct_init (handle, layout, data, tail_elts, scm_cons (layout, init)); | |
0f2d19dd JB |
522 | SCM_ALLOW_INTS; |
523 | return handle; | |
524 | } | |
1bbd0b84 | 525 | #undef FUNC_NAME |
0f2d19dd JB |
526 | |
527 | \f | |
528 | ||
529 | ||
a1ec6916 | 530 | SCM_DEFINE (scm_struct_ref, "struct-ref", 2, 0, 0, |
1bbd0b84 | 531 | (SCM handle, SCM pos), |
8f85c0c6 | 532 | "@deffnx {Scheme Procedure} struct-set! struct n value\n" |
b380b885 MD |
533 | "Access (or modify) the @var{n}th field of @var{struct}.\n\n" |
534 | "If the field is of type 'p', then it can be set to an arbitrary value.\n\n" | |
535 | "If the field is of type 'u', then it can only be set to a non-negative\n" | |
536 | "integer value small enough to fit in one machine word.") | |
1bbd0b84 | 537 | #define FUNC_NAME s_scm_struct_ref |
0f2d19dd | 538 | { |
5e840c2e | 539 | SCM answer = SCM_UNDEFINED; |
92c2555f | 540 | scm_t_bits * data; |
0f2d19dd | 541 | SCM layout; |
a55c2b68 | 542 | size_t p; |
92c2555f | 543 | scm_t_bits n_fields; |
e51fe79c DH |
544 | char * fields_desc; |
545 | char field_type = 0; | |
0f2d19dd JB |
546 | |
547 | ||
34d19ef6 | 548 | SCM_VALIDATE_STRUCT (1, handle); |
0f2d19dd JB |
549 | |
550 | layout = SCM_STRUCT_LAYOUT (handle); | |
551 | data = SCM_STRUCT_DATA (handle); | |
a55c2b68 | 552 | p = scm_to_size_t (pos); |
0f2d19dd | 553 | |
e51fe79c | 554 | fields_desc = SCM_SYMBOL_CHARS (layout); |
d8c40b9f | 555 | n_fields = data[scm_struct_i_n_words]; |
2c36c351 | 556 | |
34d19ef6 | 557 | SCM_ASSERT_RANGE(1, pos, p < n_fields); |
0f2d19dd | 558 | |
bfa974f0 | 559 | if (p * 2 < SCM_SYMBOL_LENGTH (layout)) |
2c36c351 | 560 | { |
e51fe79c | 561 | char ref; |
2c36c351 MD |
562 | field_type = fields_desc[p * 2]; |
563 | ref = fields_desc[p * 2 + 1]; | |
564 | if ((ref != 'r') && (ref != 'w')) | |
565 | { | |
566 | if ((ref == 'R') || (ref == 'W')) | |
567 | field_type = 'u'; | |
568 | else | |
1afff620 | 569 | SCM_MISC_ERROR ("ref denied for field ~A", scm_list_1 (pos)); |
2c36c351 MD |
570 | } |
571 | } | |
bfa974f0 DH |
572 | else if (fields_desc[SCM_SYMBOL_LENGTH (layout) - 1] != 'O') |
573 | field_type = fields_desc[SCM_SYMBOL_LENGTH (layout) - 2]; | |
2c36c351 | 574 | else |
1afff620 | 575 | SCM_MISC_ERROR ("ref denied for field ~A", scm_list_1 (pos)); |
2c36c351 | 576 | |
0f2d19dd JB |
577 | switch (field_type) |
578 | { | |
579 | case 'u': | |
d8c40b9f | 580 | answer = scm_ulong2num (data[p]); |
0f2d19dd JB |
581 | break; |
582 | ||
583 | #if 0 | |
584 | case 'i': | |
585 | answer = scm_long2num (data[p]); | |
586 | break; | |
587 | ||
588 | case 'd': | |
f8de44c1 | 589 | answer = scm_make_real (*((double *)&(data[p]))); |
0f2d19dd JB |
590 | break; |
591 | #endif | |
592 | ||
593 | case 's': | |
594 | case 'p': | |
d8c40b9f | 595 | answer = SCM_PACK (data[p]); |
0f2d19dd JB |
596 | break; |
597 | ||
598 | ||
599 | default: | |
2ade72d7 | 600 | SCM_MISC_ERROR ("unrecognized field type: ~S", |
1afff620 | 601 | scm_list_1 (SCM_MAKE_CHAR (field_type))); |
0f2d19dd JB |
602 | } |
603 | ||
604 | return answer; | |
605 | } | |
1bbd0b84 | 606 | #undef FUNC_NAME |
0f2d19dd JB |
607 | |
608 | ||
a1ec6916 | 609 | SCM_DEFINE (scm_struct_set_x, "struct-set!", 3, 0, 0, |
1bbd0b84 | 610 | (SCM handle, SCM pos, SCM val), |
e3239868 DH |
611 | "Set the slot of the structure @var{handle} with index @var{pos}\n" |
612 | "to @var{val}. Signal an error if the slot can not be written\n" | |
613 | "to.") | |
1bbd0b84 | 614 | #define FUNC_NAME s_scm_struct_set_x |
0f2d19dd | 615 | { |
92c2555f | 616 | scm_t_bits * data; |
0f2d19dd | 617 | SCM layout; |
a55c2b68 | 618 | size_t p; |
0f2d19dd | 619 | int n_fields; |
e51fe79c DH |
620 | char * fields_desc; |
621 | char field_type = 0; | |
0f2d19dd | 622 | |
34d19ef6 | 623 | SCM_VALIDATE_STRUCT (1, handle); |
0f2d19dd JB |
624 | |
625 | layout = SCM_STRUCT_LAYOUT (handle); | |
626 | data = SCM_STRUCT_DATA (handle); | |
a55c2b68 | 627 | p = scm_to_size_t (pos); |
0f2d19dd | 628 | |
e51fe79c | 629 | fields_desc = SCM_SYMBOL_CHARS (layout); |
d8c40b9f | 630 | n_fields = data[scm_struct_i_n_words]; |
0f2d19dd | 631 | |
34d19ef6 | 632 | SCM_ASSERT_RANGE (1, pos, p < n_fields); |
0f2d19dd | 633 | |
bfa974f0 | 634 | if (p * 2 < SCM_SYMBOL_LENGTH (layout)) |
2c36c351 | 635 | { |
e51fe79c | 636 | char set_x; |
2c36c351 MD |
637 | field_type = fields_desc[p * 2]; |
638 | set_x = fields_desc [p * 2 + 1]; | |
639 | if (set_x != 'w') | |
1afff620 | 640 | SCM_MISC_ERROR ("set! denied for field ~A", scm_list_1 (pos)); |
2c36c351 | 641 | } |
bfa974f0 DH |
642 | else if (fields_desc[SCM_SYMBOL_LENGTH (layout) - 1] == 'W') |
643 | field_type = fields_desc[SCM_SYMBOL_LENGTH (layout) - 2]; | |
2c36c351 | 644 | else |
1afff620 | 645 | SCM_MISC_ERROR ("set! denied for field ~A", scm_list_1 (pos)); |
2c36c351 | 646 | |
0f2d19dd JB |
647 | switch (field_type) |
648 | { | |
649 | case 'u': | |
d8c40b9f | 650 | data[p] = SCM_NUM2ULONG (3, val); |
0f2d19dd JB |
651 | break; |
652 | ||
653 | #if 0 | |
654 | case 'i': | |
e4b265d8 | 655 | data[p] = SCM_NUM2LONG (3, val); |
0f2d19dd JB |
656 | break; |
657 | ||
658 | case 'd': | |
659 | *((double *)&(data[p])) = scm_num2dbl (val, (char *)SCM_ARG3); | |
660 | break; | |
661 | #endif | |
662 | ||
663 | case 'p': | |
d8c40b9f | 664 | data[p] = SCM_UNPACK (val); |
0f2d19dd JB |
665 | break; |
666 | ||
667 | case 's': | |
2ade72d7 | 668 | SCM_MISC_ERROR ("self fields immutable", SCM_EOL); |
0f2d19dd JB |
669 | |
670 | default: | |
2ade72d7 | 671 | SCM_MISC_ERROR ("unrecognized field type: ~S", |
1afff620 | 672 | scm_list_1 (SCM_MAKE_CHAR (field_type))); |
0f2d19dd JB |
673 | } |
674 | ||
675 | return val; | |
676 | } | |
1bbd0b84 | 677 | #undef FUNC_NAME |
0f2d19dd JB |
678 | |
679 | ||
a1ec6916 | 680 | SCM_DEFINE (scm_struct_vtable, "struct-vtable", 1, 0, 0, |
1bbd0b84 | 681 | (SCM handle), |
b380b885 | 682 | "Return the vtable structure that describes the type of @var{struct}.") |
1bbd0b84 | 683 | #define FUNC_NAME s_scm_struct_vtable |
0f2d19dd | 684 | { |
34d19ef6 | 685 | SCM_VALIDATE_STRUCT (1, handle); |
0f2d19dd JB |
686 | return SCM_STRUCT_VTABLE (handle); |
687 | } | |
1bbd0b84 | 688 | #undef FUNC_NAME |
0f2d19dd JB |
689 | |
690 | ||
a1ec6916 | 691 | SCM_DEFINE (scm_struct_vtable_tag, "struct-vtable-tag", 1, 0, 0, |
1bbd0b84 | 692 | (SCM handle), |
e3239868 | 693 | "Return the vtable tag of the structure @var{handle}.") |
1bbd0b84 | 694 | #define FUNC_NAME s_scm_struct_vtable_tag |
0f2d19dd | 695 | { |
34d19ef6 | 696 | SCM_VALIDATE_VTABLE (1, handle); |
ad196599 | 697 | return scm_long2num ((long) SCM_STRUCT_DATA (handle) >> 3); |
98d5f601 | 698 | } |
1bbd0b84 | 699 | #undef FUNC_NAME |
98d5f601 MD |
700 | |
701 | /* {Associating names and classes with vtables} | |
702 | * | |
703 | * The name of a vtable should probably be stored as a slot. This is | |
704 | * a backward compatible solution until agreement has been achieved on | |
705 | * how to associate names with vtables. | |
706 | */ | |
707 | ||
c014a02e ML |
708 | unsigned long |
709 | scm_struct_ihashq (SCM obj, unsigned long n) | |
98d5f601 | 710 | { |
ad196599 MD |
711 | /* The length of the hash table should be a relative prime it's not |
712 | necessary to shift down the address. */ | |
f1267706 | 713 | return SCM_UNPACK (obj) % n; |
98d5f601 MD |
714 | } |
715 | ||
716 | SCM | |
717 | scm_struct_create_handle (SCM obj) | |
718 | { | |
719 | SCM handle = scm_hash_fn_create_handle_x (scm_struct_table, | |
720 | obj, | |
721 | SCM_BOOL_F, | |
722 | scm_struct_ihashq, | |
723 | scm_sloppy_assq, | |
724 | 0); | |
7888309b | 725 | if (scm_is_false (SCM_CDR (handle))) |
98d5f601 MD |
726 | SCM_SETCDR (handle, scm_cons (SCM_BOOL_F, SCM_BOOL_F)); |
727 | return handle; | |
728 | } | |
729 | ||
a1ec6916 | 730 | SCM_DEFINE (scm_struct_vtable_name, "struct-vtable-name", 1, 0, 0, |
1bbd0b84 | 731 | (SCM vtable), |
e3239868 | 732 | "Return the name of the vtable @var{vtable}.") |
1bbd0b84 | 733 | #define FUNC_NAME s_scm_struct_vtable_name |
98d5f601 | 734 | { |
34d19ef6 | 735 | SCM_VALIDATE_VTABLE (1, vtable); |
98d5f601 MD |
736 | return SCM_STRUCT_TABLE_NAME (SCM_CDR (scm_struct_create_handle (vtable))); |
737 | } | |
1bbd0b84 | 738 | #undef FUNC_NAME |
98d5f601 | 739 | |
a1ec6916 | 740 | SCM_DEFINE (scm_set_struct_vtable_name_x, "set-struct-vtable-name!", 2, 0, 0, |
1bbd0b84 | 741 | (SCM vtable, SCM name), |
e3239868 | 742 | "Set the name of the vtable @var{vtable} to @var{name}.") |
1bbd0b84 | 743 | #define FUNC_NAME s_scm_set_struct_vtable_name_x |
98d5f601 | 744 | { |
34d19ef6 HWN |
745 | SCM_VALIDATE_VTABLE (1, vtable); |
746 | SCM_VALIDATE_SYMBOL (2, name); | |
98d5f601 MD |
747 | SCM_SET_STRUCT_TABLE_NAME (SCM_CDR (scm_struct_create_handle (vtable)), |
748 | name); | |
749 | return SCM_UNSPECIFIED; | |
0f2d19dd | 750 | } |
1bbd0b84 | 751 | #undef FUNC_NAME |
0f2d19dd JB |
752 | |
753 | ||
754 | \f | |
755 | ||
bafcafb2 | 756 | void |
1bbd0b84 | 757 | scm_print_struct (SCM exp, SCM port, scm_print_state *pstate) |
bafcafb2 | 758 | { |
7888309b | 759 | if (scm_is_true (scm_procedure_p (SCM_STRUCT_PRINTER (exp)))) |
4bfdf158 MD |
760 | scm_printer_apply (SCM_STRUCT_PRINTER (exp), exp, port, pstate); |
761 | else | |
bafcafb2 | 762 | { |
a1ae1799 MD |
763 | SCM vtable = SCM_STRUCT_VTABLE (exp); |
764 | SCM name = scm_struct_vtable_name (vtable); | |
765 | scm_puts ("#<", port); | |
7888309b | 766 | if (scm_is_true (name)) |
a1ae1799 MD |
767 | scm_display (name, port); |
768 | else | |
769 | scm_puts ("struct", port); | |
770 | scm_putc (' ', port); | |
54778cd3 | 771 | scm_intprint (SCM_UNPACK (vtable), 16, port); |
b7f3516f | 772 | scm_putc (':', port); |
54778cd3 | 773 | scm_intprint (SCM_UNPACK (exp), 16, port); |
b7f3516f | 774 | scm_putc ('>', port); |
bafcafb2 | 775 | } |
bafcafb2 | 776 | } |
1cc91f1b | 777 | |
08c880a3 MD |
778 | void |
779 | scm_struct_prehistory () | |
780 | { | |
ea5c9285 | 781 | scm_i_structs_to_free = SCM_EOL; |
b4a1358c | 782 | scm_c_hook_add (&scm_before_sweep_c_hook, scm_struct_gc_init, 0, 0); |
53af8255 MD |
783 | /* With the new lazy sweep GC, the point at which the entire heap is |
784 | swept is just before the mark phase. */ | |
785 | scm_c_hook_add (&scm_before_mark_c_hook, scm_free_structs, 0, 0); | |
08c880a3 MD |
786 | } |
787 | ||
0f2d19dd JB |
788 | void |
789 | scm_init_struct () | |
0f2d19dd | 790 | { |
98d5f601 | 791 | scm_struct_table |
93ccaef0 | 792 | = scm_permanent_object (scm_make_weak_key_hash_table (SCM_I_MAKINUM (31))); |
6902384e | 793 | required_vtable_fields = scm_makfrom0str ("prsrpw"); |
0f2d19dd | 794 | scm_permanent_object (required_vtable_fields); |
93ccaef0 MV |
795 | scm_c_define ("vtable-index-layout", SCM_I_MAKINUM (scm_vtable_index_layout)); |
796 | scm_c_define ("vtable-index-vtable", SCM_I_MAKINUM (scm_vtable_index_vtable)); | |
86d31dfe | 797 | scm_c_define ("vtable-index-printer", |
93ccaef0 MV |
798 | SCM_I_MAKINUM (scm_vtable_index_printer)); |
799 | scm_c_define ("vtable-offset-user", SCM_I_MAKINUM (scm_vtable_offset_user)); | |
a0599745 | 800 | #include "libguile/struct.x" |
0f2d19dd | 801 | } |
89e00824 ML |
802 | |
803 | /* | |
804 | Local Variables: | |
805 | c-file-style: "gnu" | |
806 | End: | |
807 | */ |