1 /* Copyright (C) 1995,1996,1999,2000,2001, 2003, 2004, 2006, 2008 Free Software Foundation, Inc.
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.
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.
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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
21 /* This file and objects.h contains those minimal pieces of the Guile
22 * Object Oriented Programming System which need to be included in
23 * libguile. See the comments in objects.h.
30 #include "libguile/_scm.h"
32 #include "libguile/struct.h"
33 #include "libguile/procprop.h"
34 #include "libguile/chars.h"
35 #include "libguile/keywords.h"
36 #include "libguile/smob.h"
37 #include "libguile/eval.h"
38 #include "libguile/alist.h"
39 #include "libguile/ports.h"
40 #include "libguile/strings.h"
41 #include "libguile/vectors.h"
43 #include "libguile/validate.h"
44 #include "libguile/objects.h"
45 #include "libguile/goops.h"
49 SCM scm_metaclass_standard;
50 SCM scm_metaclass_operator;
52 /* The cache argument for scm_mcache_lookup_cmethod has one of two possible
56 * (SCM_IM_DISPATCH ARGS N-SPECIALIZED
57 * #((TYPE1 ... ENV FORMALS FORM ...) ...)
61 * (SCM_IM_HASH_DISPATCH ARGS N-SPECIALIZED HASHSET MASK
62 * #((TYPE1 ... ENV FORMALS FORM ...) ...)
65 * ARGS is either a list of expressions, in which case they
66 * are interpreted as the arguments of an application, or
67 * a non-pair, which is interpreted as a single expression
68 * yielding all arguments.
70 * SCM_IM_DISPATCH expressions in generic functions always
71 * have ARGS = the symbol `args' or the iloc #@0-0.
73 * Need FORMALS in order to support varying arity. This
74 * also avoids the need for renaming of bindings.
76 * We should probably not complicate this mechanism by
77 * introducing "optimizations" for getters and setters or
78 * primitive methods. Getters and setter will normally be
79 * compiled into @slot-[ref|set!] or a procedure call.
80 * They rely on the dispatch performed before executing
81 * the code which contains them.
83 * We might want to use a more efficient representation of
84 * this form in the future, perhaps after we have introduced
85 * low-level support for syntax-case macros.
89 scm_mcache_lookup_cmethod (SCM cache, SCM args)
91 unsigned long i, mask, n, end;
92 SCM ls, methods, z = SCM_CDDR (cache);
93 n = scm_to_ulong (SCM_CAR (z)); /* maximum number of specializers */
94 methods = SCM_CADR (z);
96 if (scm_is_simple_vector (methods))
98 /* cache format #1: prepare for linear search */
101 end = SCM_SIMPLE_VECTOR_LENGTH (methods);
105 /* cache format #2: compute a hash value */
106 unsigned long hashset = scm_to_ulong (methods);
109 mask = scm_to_ulong (SCM_CAR (z));
110 methods = SCM_CADR (z);
113 if (!scm_is_null (ls))
116 i += SCM_STRUCT_DATA (scm_class_of (SCM_CAR (ls)))
117 [scm_si_hashsets + hashset];
120 while (j-- && !scm_is_null (ls));
125 /* Search for match */
129 z = SCM_SIMPLE_VECTOR_REF (methods, i);
130 ls = args; /* list of arguments */
131 if (!scm_is_null (ls))
134 /* More arguments than specifiers => CLASS != ENV */
135 if (! scm_is_eq (scm_class_of (SCM_CAR (ls)), SCM_CAR (z)))
140 while (j-- && !scm_is_null (ls));
141 /* Fewer arguments than specifiers => CAR != ENV */
142 if (scm_is_null (SCM_CAR (z)) || scm_is_pair (SCM_CAR (z)))
151 scm_mcache_compute_cmethod (SCM cache, SCM args)
153 SCM cmethod = scm_mcache_lookup_cmethod (cache, args);
154 if (scm_is_false (cmethod))
155 /* No match - memoize */
156 return scm_memoize_method (cache, args);
161 scm_apply_generic (SCM gf, SCM args)
163 SCM cmethod = scm_mcache_compute_cmethod (SCM_ENTITY_PROCEDURE (gf), args);
164 return scm_eval_body (SCM_CDR (SCM_CMETHOD_CODE (cmethod)),
165 SCM_EXTEND_ENV (SCM_CAR (SCM_CMETHOD_CODE (cmethod)),
167 SCM_CMETHOD_ENV (cmethod)));
171 scm_call_generic_0 (SCM gf)
173 return scm_apply_generic (gf, SCM_EOL);
177 scm_call_generic_1 (SCM gf, SCM a1)
179 return scm_apply_generic (gf, scm_list_1 (a1));
183 scm_call_generic_2 (SCM gf, SCM a1, SCM a2)
185 return scm_apply_generic (gf, scm_list_2 (a1, a2));
189 scm_call_generic_3 (SCM gf, SCM a1, SCM a2, SCM a3)
191 return scm_apply_generic (gf, scm_list_3 (a1, a2, a3));
194 SCM_DEFINE (scm_entity_p, "entity?", 1, 0, 0,
196 "Return @code{#t} if @var{obj} is an entity.")
197 #define FUNC_NAME s_scm_entity_p
199 return scm_from_bool(SCM_STRUCTP (obj) && SCM_I_ENTITYP (obj));
203 SCM_DEFINE (scm_operator_p, "operator?", 1, 0, 0,
205 "Return @code{#t} if @var{obj} is an operator.")
206 #define FUNC_NAME s_scm_operator_p
208 return scm_from_bool(SCM_STRUCTP (obj)
209 && SCM_I_OPERATORP (obj)
210 && !SCM_I_ENTITYP (obj));
214 /* XXX - What code requires the object procedure to be only of certain
217 SCM_DEFINE (scm_valid_object_procedure_p, "valid-object-procedure?", 1, 0, 0,
219 "Return @code{#t} iff @var{proc} is a procedure that can be used "
220 "with @code{set-object-procedure}. It is always valid to use "
221 "a closure constructed by @code{lambda}.")
222 #define FUNC_NAME s_scm_valid_object_procedure_p
226 switch (SCM_TYP7 (proc))
230 case scm_tcs_closures:
234 case scm_tc7_lsubr_2:
240 SCM_DEFINE (scm_set_object_procedure_x, "set-object-procedure!", 2, 0, 0,
242 "Set the object procedure of @var{obj} to @var{proc}.\n"
243 "@var{obj} must be either an entity or an operator.")
244 #define FUNC_NAME s_scm_set_object_procedure_x
246 SCM_ASSERT (SCM_STRUCTP (obj)
247 && ((SCM_CLASS_FLAGS (obj) & SCM_CLASSF_OPERATOR)
248 || (SCM_I_ENTITYP (obj)
249 && !(SCM_OBJ_CLASS_FLAGS (obj)
250 & SCM_CLASSF_PURE_GENERIC))),
254 SCM_ASSERT (scm_valid_object_procedure_p (proc), proc, SCM_ARG2, FUNC_NAME);
255 if (SCM_I_ENTITYP (obj))
256 SCM_SET_ENTITY_PROCEDURE (obj, proc);
258 SCM_OPERATOR_CLASS (obj)->procedure = proc;
259 return SCM_UNSPECIFIED;
264 SCM_DEFINE (scm_object_procedure, "object-procedure", 1, 0, 0,
266 "Return the object procedure of @var{obj}. @var{obj} must be\n"
267 "an entity or an operator.")
268 #define FUNC_NAME s_scm_object_procedure
270 SCM_ASSERT (SCM_STRUCTP (obj)
271 && ((SCM_CLASS_FLAGS (obj) & SCM_CLASSF_OPERATOR)
272 || SCM_I_ENTITYP (obj)),
273 obj, SCM_ARG1, FUNC_NAME);
274 return (SCM_I_ENTITYP (obj)
275 ? SCM_ENTITY_PROCEDURE (obj)
276 : SCM_OPERATOR_CLASS (obj)->procedure);
279 #endif /* GUILE_DEBUG */
281 /* The following procedures are not a part of Goops but a minimal
282 * object system built upon structs. They are here for those who
283 * want to implement their own object system.
287 scm_i_make_class_object (SCM meta,
292 SCM layout = scm_make_struct_layout (layout_string);
293 c = scm_make_struct (meta,
295 scm_list_4 (layout, SCM_BOOL_F, SCM_EOL, SCM_EOL));
296 SCM_SET_CLASS_FLAGS (c, flags);
300 SCM_DEFINE (scm_make_class_object, "make-class-object", 2, 0, 0,
301 (SCM metaclass, SCM layout),
302 "Create a new class object of class @var{metaclass}, with the\n"
303 "slot layout specified by @var{layout}.")
304 #define FUNC_NAME s_scm_make_class_object
306 unsigned long flags = 0;
307 SCM_VALIDATE_STRUCT (1, metaclass);
308 SCM_VALIDATE_STRING (2, layout);
309 if (scm_is_eq (metaclass, scm_metaclass_operator))
310 flags = SCM_CLASSF_OPERATOR;
311 return scm_i_make_class_object (metaclass, layout, flags);
315 SCM_DEFINE (scm_make_subclass_object, "make-subclass-object", 2, 0, 0,
316 (SCM class, SCM layout),
317 "Create a subclass object of @var{class}, with the slot layout\n"
318 "specified by @var{layout}.")
319 #define FUNC_NAME s_scm_make_subclass_object
322 SCM_VALIDATE_STRUCT (1, class);
323 SCM_VALIDATE_STRING (2, layout);
324 pl = SCM_PACK (SCM_STRUCT_DATA (class) [scm_vtable_index_layout]);
325 pl = scm_symbol_to_string (pl);
326 return scm_i_make_class_object (SCM_STRUCT_VTABLE (class),
327 scm_string_append (scm_list_2 (pl, layout)),
328 SCM_CLASS_FLAGS (class));
335 SCM ms = scm_from_locale_string (SCM_METACLASS_STANDARD_LAYOUT);
336 SCM mt = scm_make_vtable_vtable (ms, SCM_INUM0,
337 scm_list_3 (SCM_BOOL_F, SCM_EOL, SCM_EOL));
339 SCM os = scm_from_locale_string (SCM_METACLASS_OPERATOR_LAYOUT);
340 SCM ot = scm_make_vtable_vtable (os, SCM_INUM0,
341 scm_list_3 (SCM_BOOL_F, SCM_EOL, SCM_EOL));
343 SCM es = scm_from_locale_string (SCM_ENTITY_LAYOUT);
344 SCM el = scm_make_struct_layout (es);
345 SCM et = scm_make_struct (mt, SCM_INUM0,
346 scm_list_4 (el, SCM_BOOL_F, SCM_EOL, SCM_EOL));
348 scm_c_define ("<class>", mt);
349 scm_metaclass_standard = mt;
350 scm_c_define ("<operator-class>", ot);
351 scm_metaclass_operator = ot;
352 SCM_SET_CLASS_FLAGS (et, SCM_CLASSF_OPERATOR | SCM_CLASSF_ENTITY);
353 SCM_SET_CLASS_DESTRUCTOR (et, scm_struct_free_entity);
354 scm_c_define ("<entity>", et);
356 #include "libguile/objects.x"