| 1 | /* Copyright (C) 1995, 1996, 1999, 2000 Free Software Foundation, Inc. |
| 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 |
| 15 | * the Free Software Foundation, Inc., 59 Temple Place, Suite 330, |
| 16 | * Boston, MA 02111-1307 USA |
| 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. |
| 40 | * If you do not wish that, delete this exception notice. */ |
| 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 | |
| 45 | \f |
| 46 | |
| 47 | /* This file and objects.h contains those minimal pieces of the Guile |
| 48 | * Object Oriented Programming System which need to be included in |
| 49 | * libguile. See the comments in objects.h. |
| 50 | */ |
| 51 | |
| 52 | #include "libguile/_scm.h" |
| 53 | |
| 54 | #include "libguile/struct.h" |
| 55 | #include "libguile/procprop.h" |
| 56 | #include "libguile/chars.h" |
| 57 | #include "libguile/keywords.h" |
| 58 | #include "libguile/smob.h" |
| 59 | #include "libguile/eval.h" |
| 60 | #include "libguile/alist.h" |
| 61 | #include "libguile/ports.h" |
| 62 | #include "libguile/strings.h" |
| 63 | #include "libguile/vectors.h" |
| 64 | |
| 65 | #include "libguile/validate.h" |
| 66 | #include "libguile/objects.h" |
| 67 | \f |
| 68 | |
| 69 | SCM scm_metaclass_standard; |
| 70 | SCM scm_metaclass_operator; |
| 71 | |
| 72 | /* These variables are filled in by the object system when loaded. */ |
| 73 | SCM scm_class_boolean, scm_class_char, scm_class_pair; |
| 74 | SCM scm_class_procedure, scm_class_string, scm_class_symbol; |
| 75 | SCM scm_class_procedure_with_setter, scm_class_primitive_generic; |
| 76 | SCM scm_class_vector, scm_class_null; |
| 77 | SCM scm_class_integer, scm_class_real, scm_class_complex; |
| 78 | SCM scm_class_unknown; |
| 79 | |
| 80 | SCM *scm_port_class = 0; |
| 81 | SCM *scm_smob_class = 0; |
| 82 | |
| 83 | SCM scm_no_applicable_method; |
| 84 | |
| 85 | /* This function is used for efficient type dispatch. */ |
| 86 | SCM_DEFINE (scm_class_of, "class-of", 1, 0, 0, |
| 87 | (SCM x), |
| 88 | "") |
| 89 | #define FUNC_NAME s_scm_class_of |
| 90 | { |
| 91 | switch (SCM_ITAG3 (x)) |
| 92 | { |
| 93 | case scm_tc3_int_1: |
| 94 | case scm_tc3_int_2: |
| 95 | return scm_class_integer; |
| 96 | |
| 97 | case scm_tc3_imm24: |
| 98 | if (SCM_CHARP (x)) |
| 99 | return scm_class_char; |
| 100 | else |
| 101 | { |
| 102 | switch (SCM_ISYMNUM (x)) |
| 103 | { |
| 104 | case SCM_ISYMNUM (SCM_BOOL_F): |
| 105 | case SCM_ISYMNUM (SCM_BOOL_T): |
| 106 | return scm_class_boolean; |
| 107 | case SCM_ISYMNUM (SCM_EOL): |
| 108 | return scm_class_null; |
| 109 | default: |
| 110 | return scm_class_unknown; |
| 111 | } |
| 112 | } |
| 113 | |
| 114 | case scm_tc3_cons: |
| 115 | switch (SCM_TYP7 (x)) |
| 116 | { |
| 117 | case scm_tcs_cons_nimcar: |
| 118 | return scm_class_pair; |
| 119 | case scm_tcs_closures: |
| 120 | return scm_class_procedure; |
| 121 | case scm_tc7_symbol: |
| 122 | return scm_class_symbol; |
| 123 | case scm_tc7_vector: |
| 124 | case scm_tc7_wvect: |
| 125 | #ifdef HAVE_ARRAYS |
| 126 | case scm_tc7_bvect: |
| 127 | case scm_tc7_byvect: |
| 128 | case scm_tc7_svect: |
| 129 | case scm_tc7_ivect: |
| 130 | case scm_tc7_uvect: |
| 131 | case scm_tc7_fvect: |
| 132 | case scm_tc7_dvect: |
| 133 | case scm_tc7_cvect: |
| 134 | #endif |
| 135 | return scm_class_vector; |
| 136 | case scm_tc7_string: |
| 137 | case scm_tc7_substring: |
| 138 | return scm_class_string; |
| 139 | case scm_tc7_asubr: |
| 140 | case scm_tc7_subr_0: |
| 141 | case scm_tc7_subr_1: |
| 142 | case scm_tc7_cxr: |
| 143 | case scm_tc7_subr_3: |
| 144 | case scm_tc7_subr_2: |
| 145 | case scm_tc7_rpsubr: |
| 146 | case scm_tc7_subr_1o: |
| 147 | case scm_tc7_subr_2o: |
| 148 | case scm_tc7_lsubr_2: |
| 149 | case scm_tc7_lsubr: |
| 150 | if (SCM_SUBR_GENERIC (x) && *SCM_SUBR_GENERIC (x)) |
| 151 | return scm_class_primitive_generic; |
| 152 | else |
| 153 | return scm_class_procedure; |
| 154 | case scm_tc7_cclo: |
| 155 | return scm_class_procedure; |
| 156 | case scm_tc7_pws: |
| 157 | return scm_class_procedure_with_setter; |
| 158 | |
| 159 | case scm_tc7_smob: |
| 160 | { |
| 161 | long type = SCM_TYP16 (x); |
| 162 | if (type != scm_tc16_port_with_ps) |
| 163 | return scm_smob_class[SCM_TC2SMOBNUM (type)]; |
| 164 | x = SCM_PORT_WITH_PS_PORT (x); |
| 165 | /* fall through to ports */ |
| 166 | } |
| 167 | case scm_tc7_port: |
| 168 | return scm_port_class[(SCM_WRTNG & SCM_CELL_WORD_0 (x) |
| 169 | ? (SCM_RDNG & SCM_CELL_WORD_0 (x) |
| 170 | ? SCM_INOUT_PCLASS_INDEX | SCM_PTOBNUM (x) |
| 171 | : SCM_OUT_PCLASS_INDEX | SCM_PTOBNUM (x)) |
| 172 | : SCM_IN_PCLASS_INDEX | SCM_PTOBNUM (x))]; |
| 173 | case scm_tcs_cons_gloc: |
| 174 | /* must be a struct */ |
| 175 | if (SCM_OBJ_CLASS_FLAGS (x) & SCM_CLASSF_GOOPS_VALID) |
| 176 | return SCM_CLASS_OF (x); |
| 177 | else if (SCM_OBJ_CLASS_FLAGS (x) & SCM_CLASSF_GOOPS) |
| 178 | { |
| 179 | /* Goops object */ |
| 180 | if (! SCM_FALSEP (SCM_OBJ_CLASS_REDEF (x))) |
| 181 | scm_change_object_class (x, |
| 182 | SCM_CLASS_OF (x), /* old */ |
| 183 | SCM_OBJ_CLASS_REDEF (x)); /* new */ |
| 184 | return SCM_CLASS_OF (x); |
| 185 | } |
| 186 | else |
| 187 | { |
| 188 | /* ordinary struct */ |
| 189 | SCM handle = scm_struct_create_handle (SCM_STRUCT_VTABLE (x)); |
| 190 | if (SCM_NFALSEP (SCM_STRUCT_TABLE_CLASS (SCM_CDR (handle)))) |
| 191 | return SCM_STRUCT_TABLE_CLASS (SCM_CDR (handle)); |
| 192 | else |
| 193 | { |
| 194 | SCM name = SCM_STRUCT_TABLE_NAME (SCM_CDR (handle)); |
| 195 | SCM class = scm_make_extended_class (SCM_NFALSEP (name) |
| 196 | ? SCM_SYMBOL_CHARS (name) |
| 197 | : 0); |
| 198 | SCM_SET_STRUCT_TABLE_CLASS (SCM_CDR (handle), class); |
| 199 | return class; |
| 200 | } |
| 201 | } |
| 202 | default: |
| 203 | if (SCM_CONSP (x)) |
| 204 | return scm_class_pair; |
| 205 | else |
| 206 | return scm_class_unknown; |
| 207 | } |
| 208 | |
| 209 | case scm_tc3_cons_gloc: |
| 210 | case scm_tc3_tc7_1: |
| 211 | case scm_tc3_tc7_2: |
| 212 | case scm_tc3_closure: |
| 213 | /* Never reached */ |
| 214 | break; |
| 215 | } |
| 216 | return scm_class_unknown; |
| 217 | } |
| 218 | #undef FUNC_NAME |
| 219 | |
| 220 | /* (SCM_IM_DISPATCH ARGS N-SPECIALIZED |
| 221 | * #((TYPE1 ... ENV FORMALS FORM ...) ...) |
| 222 | * GF) |
| 223 | * |
| 224 | * (SCM_IM_HASH_DISPATCH ARGS N-SPECIALIZED HASHSET MASK |
| 225 | * #((TYPE1 ... ENV FORMALS FORM ...) ...) |
| 226 | * GF) |
| 227 | * |
| 228 | * ARGS is either a list of expressions, in which case they |
| 229 | * are interpreted as the arguments of an application, or |
| 230 | * a non-pair, which is interpreted as a single expression |
| 231 | * yielding all arguments. |
| 232 | * |
| 233 | * SCM_IM_DISPATCH expressions in generic functions always |
| 234 | * have ARGS = the symbol `args' or the iloc #@0-0. |
| 235 | * |
| 236 | * Need FORMALS in order to support varying arity. This |
| 237 | * also avoids the need for renaming of bindings. |
| 238 | * |
| 239 | * We should probably not complicate this mechanism by |
| 240 | * introducing "optimizations" for getters and setters or |
| 241 | * primitive methods. Getters and setter will normally be |
| 242 | * compiled into @slot-[ref|set!] or a procedure call. |
| 243 | * They rely on the dispatch performed before executing |
| 244 | * the code which contains them. |
| 245 | * |
| 246 | * We might want to use a more efficient representation of |
| 247 | * this form in the future, perhaps after we have introduced |
| 248 | * low-level support for syntax-case macros. |
| 249 | */ |
| 250 | |
| 251 | SCM |
| 252 | scm_mcache_lookup_cmethod (SCM cache, SCM args) |
| 253 | { |
| 254 | int i, n, end, mask; |
| 255 | SCM ls, methods, z = SCM_CDDR (cache); |
| 256 | n = SCM_INUM (SCM_CAR (z)); /* maximum number of specializers */ |
| 257 | methods = SCM_CADR (z); |
| 258 | |
| 259 | if (SCM_NIMP (methods)) |
| 260 | { |
| 261 | /* Prepare for linear search */ |
| 262 | mask = -1; |
| 263 | i = 0; |
| 264 | end = SCM_VECTOR_LENGTH (methods); |
| 265 | } |
| 266 | else |
| 267 | { |
| 268 | /* Compute a hash value */ |
| 269 | int hashset = SCM_INUM (methods); |
| 270 | int j = n; |
| 271 | mask = SCM_INUM (SCM_CAR (z = SCM_CDDR (z))); |
| 272 | methods = SCM_CADR (z); |
| 273 | i = 0; |
| 274 | ls = args; |
| 275 | if (SCM_NIMP (ls)) |
| 276 | do |
| 277 | { |
| 278 | i += SCM_STRUCT_DATA (scm_class_of (SCM_CAR (ls))) |
| 279 | [scm_si_hashsets + hashset]; |
| 280 | ls = SCM_CDR (ls); |
| 281 | } |
| 282 | while (j-- && SCM_NIMP (ls)); |
| 283 | i &= mask; |
| 284 | end = i; |
| 285 | } |
| 286 | |
| 287 | /* Search for match */ |
| 288 | do |
| 289 | { |
| 290 | int j = n; |
| 291 | z = SCM_VELTS (methods)[i]; |
| 292 | ls = args; /* list of arguments */ |
| 293 | if (SCM_NIMP (ls)) |
| 294 | do |
| 295 | { |
| 296 | /* More arguments than specifiers => CLASS != ENV */ |
| 297 | if (! SCM_EQ_P (scm_class_of (SCM_CAR (ls)), SCM_CAR (z))) |
| 298 | goto next_method; |
| 299 | ls = SCM_CDR (ls); |
| 300 | z = SCM_CDR (z); |
| 301 | } |
| 302 | while (j-- && SCM_NIMP (ls)); |
| 303 | /* Fewer arguments than specifiers => CAR != ENV */ |
| 304 | if (!(SCM_IMP (SCM_CAR (z)) || SCM_CONSP (SCM_CAR (z)))) |
| 305 | goto next_method; |
| 306 | return z; |
| 307 | next_method: |
| 308 | i = (i + 1) & mask; |
| 309 | } while (i != end); |
| 310 | return SCM_BOOL_F; |
| 311 | } |
| 312 | |
| 313 | SCM |
| 314 | scm_mcache_compute_cmethod (SCM cache, SCM args) |
| 315 | { |
| 316 | SCM cmethod = scm_mcache_lookup_cmethod (cache, args); |
| 317 | if (SCM_IMP (cmethod)) |
| 318 | /* No match - memoize */ |
| 319 | return scm_memoize_method (cache, args); |
| 320 | return cmethod; |
| 321 | } |
| 322 | |
| 323 | SCM |
| 324 | scm_apply_generic (SCM gf, SCM args) |
| 325 | { |
| 326 | SCM cmethod = scm_mcache_compute_cmethod (SCM_ENTITY_PROCEDURE (gf), args); |
| 327 | return scm_eval_body (SCM_CDR (SCM_CMETHOD_CODE (cmethod)), |
| 328 | SCM_EXTEND_ENV (SCM_CAR (SCM_CMETHOD_CODE (cmethod)), |
| 329 | args, |
| 330 | SCM_CMETHOD_ENV (cmethod))); |
| 331 | } |
| 332 | |
| 333 | SCM |
| 334 | scm_call_generic_0 (SCM gf) |
| 335 | { |
| 336 | return scm_apply_generic (gf, SCM_EOL); |
| 337 | } |
| 338 | |
| 339 | SCM |
| 340 | scm_call_generic_1 (SCM gf, SCM a1) |
| 341 | { |
| 342 | return scm_apply_generic (gf, SCM_LIST1 (a1)); |
| 343 | } |
| 344 | |
| 345 | SCM |
| 346 | scm_call_generic_2 (SCM gf, SCM a1, SCM a2) |
| 347 | { |
| 348 | return scm_apply_generic (gf, SCM_LIST2 (a1, a2)); |
| 349 | } |
| 350 | |
| 351 | SCM |
| 352 | scm_call_generic_3 (SCM gf, SCM a1, SCM a2, SCM a3) |
| 353 | { |
| 354 | return scm_apply_generic (gf, SCM_LIST3 (a1, a2, a3)); |
| 355 | } |
| 356 | |
| 357 | SCM_DEFINE (scm_entity_p, "entity?", 1, 0, 0, |
| 358 | (SCM obj), |
| 359 | "") |
| 360 | #define FUNC_NAME s_scm_entity_p |
| 361 | { |
| 362 | return SCM_BOOL(SCM_STRUCTP (obj) && SCM_I_ENTITYP (obj)); |
| 363 | } |
| 364 | #undef FUNC_NAME |
| 365 | |
| 366 | SCM_DEFINE (scm_operator_p, "operator?", 1, 0, 0, |
| 367 | (SCM obj), |
| 368 | "") |
| 369 | #define FUNC_NAME s_scm_operator_p |
| 370 | { |
| 371 | return SCM_BOOL(SCM_STRUCTP (obj) |
| 372 | && SCM_I_OPERATORP (obj) |
| 373 | && !SCM_I_ENTITYP (obj)); |
| 374 | } |
| 375 | #undef FUNC_NAME |
| 376 | |
| 377 | SCM_DEFINE (scm_set_object_procedure_x, "set-object-procedure!", 2, 0, 0, |
| 378 | (SCM obj, SCM proc), |
| 379 | "") |
| 380 | #define FUNC_NAME s_scm_set_object_procedure_x |
| 381 | { |
| 382 | SCM_ASSERT (SCM_STRUCTP (obj) |
| 383 | && ((SCM_CLASS_FLAGS (obj) & SCM_CLASSF_OPERATOR) |
| 384 | || (SCM_I_ENTITYP (obj) |
| 385 | && !(SCM_OBJ_CLASS_FLAGS (obj) |
| 386 | & SCM_CLASSF_PURE_GENERIC))), |
| 387 | obj, |
| 388 | SCM_ARG1, |
| 389 | FUNC_NAME); |
| 390 | SCM_VALIDATE_PROC (2,proc); |
| 391 | if (SCM_I_ENTITYP (obj)) |
| 392 | SCM_SET_ENTITY_PROCEDURE (obj, proc); |
| 393 | else |
| 394 | SCM_OPERATOR_CLASS (obj)->procedure = proc; |
| 395 | return SCM_UNSPECIFIED; |
| 396 | } |
| 397 | #undef FUNC_NAME |
| 398 | |
| 399 | #ifdef GUILE_DEBUG |
| 400 | SCM_DEFINE (scm_object_procedure, "object-procedure", 1, 0, 0, |
| 401 | (SCM obj), |
| 402 | "") |
| 403 | #define FUNC_NAME s_scm_object_procedure |
| 404 | { |
| 405 | SCM_ASSERT (SCM_STRUCTP (obj) |
| 406 | && ((SCM_CLASS_FLAGS (obj) & SCM_CLASSF_OPERATOR) |
| 407 | || SCM_I_ENTITYP (obj)), |
| 408 | obj, SCM_ARG1, FUNC_NAME); |
| 409 | return (SCM_I_ENTITYP (obj) |
| 410 | ? SCM_ENTITY_PROCEDURE (obj) |
| 411 | : SCM_OPERATOR_CLASS (obj)->procedure); |
| 412 | } |
| 413 | #undef FUNC_NAME |
| 414 | #endif /* GUILE_DEBUG */ |
| 415 | |
| 416 | /* The following procedures are not a part of Goops but a minimal |
| 417 | * object system built upon structs. They are here for those who |
| 418 | * want to implement their own object system. |
| 419 | */ |
| 420 | |
| 421 | SCM |
| 422 | scm_i_make_class_object (SCM meta, |
| 423 | SCM layout_string, |
| 424 | unsigned long flags) |
| 425 | { |
| 426 | SCM c; |
| 427 | SCM layout = scm_make_struct_layout (layout_string); |
| 428 | c = scm_make_struct (meta, |
| 429 | SCM_INUM0, |
| 430 | SCM_LIST4 (layout, SCM_BOOL_F, SCM_EOL, SCM_EOL)); |
| 431 | SCM_SET_CLASS_FLAGS (c, flags); |
| 432 | return c; |
| 433 | } |
| 434 | |
| 435 | SCM_DEFINE (scm_make_class_object, "make-class-object", 2, 0, 0, |
| 436 | (SCM metaclass, SCM layout), |
| 437 | "") |
| 438 | #define FUNC_NAME s_scm_make_class_object |
| 439 | { |
| 440 | unsigned long flags = 0; |
| 441 | SCM_VALIDATE_STRUCT (1,metaclass); |
| 442 | SCM_VALIDATE_STRING (2,layout); |
| 443 | if (SCM_EQ_P (metaclass, scm_metaclass_operator)) |
| 444 | flags = SCM_CLASSF_OPERATOR; |
| 445 | return scm_i_make_class_object (metaclass, layout, flags); |
| 446 | } |
| 447 | #undef FUNC_NAME |
| 448 | |
| 449 | SCM_DEFINE (scm_make_subclass_object, "make-subclass-object", 2, 0, 0, |
| 450 | (SCM class, SCM layout), |
| 451 | "") |
| 452 | #define FUNC_NAME s_scm_make_subclass_object |
| 453 | { |
| 454 | SCM pl; |
| 455 | SCM_VALIDATE_STRUCT (1,class); |
| 456 | SCM_VALIDATE_STRING (2,layout); |
| 457 | pl = SCM_PACK (SCM_STRUCT_DATA (class) [scm_vtable_index_layout]); |
| 458 | /* Convert symbol->string */ |
| 459 | pl = scm_makfromstr (SCM_SYMBOL_CHARS (pl), SCM_SYMBOL_LENGTH (pl), 0); |
| 460 | return scm_i_make_class_object (SCM_STRUCT_VTABLE (class), |
| 461 | scm_string_append (SCM_LIST2 (pl, layout)), |
| 462 | SCM_CLASS_FLAGS (class)); |
| 463 | } |
| 464 | #undef FUNC_NAME |
| 465 | |
| 466 | void |
| 467 | scm_init_objects () |
| 468 | { |
| 469 | SCM ms = scm_makfrom0str (SCM_METACLASS_STANDARD_LAYOUT); |
| 470 | SCM mt = scm_make_vtable_vtable (ms, SCM_INUM0, |
| 471 | SCM_LIST3 (SCM_BOOL_F, SCM_EOL, SCM_EOL)); |
| 472 | |
| 473 | SCM os = scm_makfrom0str (SCM_METACLASS_OPERATOR_LAYOUT); |
| 474 | SCM ot = scm_make_vtable_vtable (os, SCM_INUM0, |
| 475 | SCM_LIST3 (SCM_BOOL_F, SCM_EOL, SCM_EOL)); |
| 476 | |
| 477 | SCM es = scm_makfrom0str (SCM_ENTITY_LAYOUT); |
| 478 | SCM el = scm_make_struct_layout (es); |
| 479 | SCM et = scm_make_struct (mt, SCM_INUM0, |
| 480 | SCM_LIST4 (el, SCM_BOOL_F, SCM_EOL, SCM_EOL)); |
| 481 | |
| 482 | scm_sysintern ("<class>", mt); |
| 483 | scm_metaclass_standard = mt; |
| 484 | scm_sysintern ("<operator-class>", ot); |
| 485 | scm_metaclass_operator = ot; |
| 486 | SCM_SET_CLASS_FLAGS (et, SCM_CLASSF_OPERATOR | SCM_CLASSF_ENTITY); |
| 487 | SCM_SET_CLASS_DESTRUCTOR (et, scm_struct_free_entity); |
| 488 | scm_sysintern ("<entity>", et); |
| 489 | |
| 490 | #ifndef SCM_MAGIC_SNARFER |
| 491 | #include "libguile/objects.x" |
| 492 | #endif |
| 493 | } |
| 494 | |
| 495 | /* |
| 496 | Local Variables: |
| 497 | c-file-style: "gnu" |
| 498 | End: |
| 499 | */ |