/* Copyright (C) 1995,1996,1999,2000,2001, 2003, 2004, 2006, 2008 Free Software Foundation, Inc. * * This library is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public * License as published by the Free Software Foundation; either * version 2.1 of the License, or (at your option) any later version. * * This library is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with this library; if not, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA */ /* This file and objects.h contains those minimal pieces of the Guile * Object Oriented Programming System which need to be included in * libguile. See the comments in objects.h. */ #ifdef HAVE_CONFIG_H # include #endif #include "libguile/_scm.h" #include "libguile/struct.h" #include "libguile/procprop.h" #include "libguile/chars.h" #include "libguile/keywords.h" #include "libguile/smob.h" #include "libguile/eval.h" #include "libguile/alist.h" #include "libguile/ports.h" #include "libguile/strings.h" #include "libguile/vectors.h" #include "libguile/validate.h" #include "libguile/objects.h" #include "libguile/goops.h" SCM scm_metaclass_standard; SCM scm_metaclass_operator; /* The cache argument for scm_mcache_lookup_cmethod has one of two possible * formats: * * Format #1: * (SCM_IM_DISPATCH ARGS N-SPECIALIZED * #((TYPE1 ... ENV FORMALS FORM ...) ...) * GF) * * Format #2: * (SCM_IM_HASH_DISPATCH ARGS N-SPECIALIZED HASHSET MASK * #((TYPE1 ... ENV FORMALS FORM ...) ...) * GF) * * ARGS is either a list of expressions, in which case they * are interpreted as the arguments of an application, or * a non-pair, which is interpreted as a single expression * yielding all arguments. * * SCM_IM_DISPATCH expressions in generic functions always * have ARGS = the symbol `args' or the iloc #@0-0. * * Need FORMALS in order to support varying arity. This * also avoids the need for renaming of bindings. * * We should probably not complicate this mechanism by * introducing "optimizations" for getters and setters or * primitive methods. Getters and setter will normally be * compiled into @slot-[ref|set!] or a procedure call. * They rely on the dispatch performed before executing * the code which contains them. * * We might want to use a more efficient representation of * this form in the future, perhaps after we have introduced * low-level support for syntax-case macros. */ SCM scm_mcache_lookup_cmethod (SCM cache, SCM args) { unsigned long i, mask, n, end; SCM ls, methods, z = SCM_CDDR (cache); n = scm_to_ulong (SCM_CAR (z)); /* maximum number of specializers */ methods = SCM_CADR (z); if (scm_is_simple_vector (methods)) { /* cache format #1: prepare for linear search */ mask = -1; i = 0; end = SCM_SIMPLE_VECTOR_LENGTH (methods); } else { /* cache format #2: compute a hash value */ unsigned long hashset = scm_to_ulong (methods); long j = n; z = SCM_CDDR (z); mask = scm_to_ulong (SCM_CAR (z)); methods = SCM_CADR (z); i = 0; ls = args; if (!scm_is_null (ls)) do { i += SCM_STRUCT_DATA (scm_class_of (SCM_CAR (ls))) [scm_si_hashsets + hashset]; ls = SCM_CDR (ls); } while (j-- && !scm_is_null (ls)); i &= mask; end = i; } /* Search for match */ do { long j = n; z = SCM_SIMPLE_VECTOR_REF (methods, i); ls = args; /* list of arguments */ if (!scm_is_null (ls)) do { /* More arguments than specifiers => CLASS != ENV */ if (! scm_is_eq (scm_class_of (SCM_CAR (ls)), SCM_CAR (z))) goto next_method; ls = SCM_CDR (ls); z = SCM_CDR (z); } while (j-- && !scm_is_null (ls)); /* Fewer arguments than specifiers => CAR != ENV */ if (scm_is_null (SCM_CAR (z)) || scm_is_pair (SCM_CAR (z))) return z; next_method: i = (i + 1) & mask; } while (i != end); return SCM_BOOL_F; } SCM scm_mcache_compute_cmethod (SCM cache, SCM args) { SCM cmethod = scm_mcache_lookup_cmethod (cache, args); if (scm_is_false (cmethod)) /* No match - memoize */ return scm_memoize_method (cache, args); return cmethod; } SCM scm_apply_generic (SCM gf, SCM args) { SCM cmethod = scm_mcache_compute_cmethod (SCM_ENTITY_PROCEDURE (gf), args); return scm_eval_body (SCM_CDR (SCM_CMETHOD_CODE (cmethod)), SCM_EXTEND_ENV (SCM_CAR (SCM_CMETHOD_CODE (cmethod)), args, SCM_CMETHOD_ENV (cmethod))); } SCM scm_call_generic_0 (SCM gf) { return scm_apply_generic (gf, SCM_EOL); } SCM scm_call_generic_1 (SCM gf, SCM a1) { return scm_apply_generic (gf, scm_list_1 (a1)); } SCM scm_call_generic_2 (SCM gf, SCM a1, SCM a2) { return scm_apply_generic (gf, scm_list_2 (a1, a2)); } SCM scm_call_generic_3 (SCM gf, SCM a1, SCM a2, SCM a3) { return scm_apply_generic (gf, scm_list_3 (a1, a2, a3)); } SCM_DEFINE (scm_entity_p, "entity?", 1, 0, 0, (SCM obj), "Return @code{#t} if @var{obj} is an entity.") #define FUNC_NAME s_scm_entity_p { return scm_from_bool(SCM_STRUCTP (obj) && SCM_I_ENTITYP (obj)); } #undef FUNC_NAME SCM_DEFINE (scm_operator_p, "operator?", 1, 0, 0, (SCM obj), "Return @code{#t} if @var{obj} is an operator.") #define FUNC_NAME s_scm_operator_p { return scm_from_bool(SCM_STRUCTP (obj) && SCM_I_OPERATORP (obj) && !SCM_I_ENTITYP (obj)); } #undef FUNC_NAME /* XXX - What code requires the object procedure to be only of certain types? */ SCM_DEFINE (scm_valid_object_procedure_p, "valid-object-procedure?", 1, 0, 0, (SCM proc), "Return @code{#t} iff @var{proc} is a procedure that can be used " "with @code{set-object-procedure}. It is always valid to use " "a closure constructed by @code{lambda}.") #define FUNC_NAME s_scm_valid_object_procedure_p { if (SCM_IMP (proc)) return SCM_BOOL_F; switch (SCM_TYP7 (proc)) { default: return SCM_BOOL_F; case scm_tcs_closures: case scm_tc7_subr_1: case scm_tc7_subr_2: case scm_tc7_subr_3: case scm_tc7_lsubr_2: return SCM_BOOL_T; } } #undef FUNC_NAME SCM_DEFINE (scm_set_object_procedure_x, "set-object-procedure!", 2, 0, 0, (SCM obj, SCM proc), "Set the object procedure of @var{obj} to @var{proc}.\n" "@var{obj} must be either an entity or an operator.") #define FUNC_NAME s_scm_set_object_procedure_x { SCM_ASSERT (SCM_STRUCTP (obj) && ((SCM_CLASS_FLAGS (obj) & SCM_CLASSF_OPERATOR) || (SCM_I_ENTITYP (obj) && !(SCM_OBJ_CLASS_FLAGS (obj) & SCM_CLASSF_PURE_GENERIC))), obj, SCM_ARG1, FUNC_NAME); SCM_ASSERT (scm_valid_object_procedure_p (proc), proc, SCM_ARG2, FUNC_NAME); if (SCM_I_ENTITYP (obj)) SCM_SET_ENTITY_PROCEDURE (obj, proc); else SCM_OPERATOR_CLASS (obj)->procedure = proc; return SCM_UNSPECIFIED; } #undef FUNC_NAME #ifdef GUILE_DEBUG SCM_DEFINE (scm_object_procedure, "object-procedure", 1, 0, 0, (SCM obj), "Return the object procedure of @var{obj}. @var{obj} must be\n" "an entity or an operator.") #define FUNC_NAME s_scm_object_procedure { SCM_ASSERT (SCM_STRUCTP (obj) && ((SCM_CLASS_FLAGS (obj) & SCM_CLASSF_OPERATOR) || SCM_I_ENTITYP (obj)), obj, SCM_ARG1, FUNC_NAME); return (SCM_I_ENTITYP (obj) ? SCM_ENTITY_PROCEDURE (obj) : SCM_OPERATOR_CLASS (obj)->procedure); } #undef FUNC_NAME #endif /* GUILE_DEBUG */ /* The following procedures are not a part of Goops but a minimal * object system built upon structs. They are here for those who * want to implement their own object system. */ SCM scm_i_make_class_object (SCM meta, SCM layout_string, unsigned long flags) { SCM c; SCM layout = scm_make_struct_layout (layout_string); c = scm_make_struct (meta, SCM_INUM0, scm_list_4 (layout, SCM_BOOL_F, SCM_EOL, SCM_EOL)); SCM_SET_CLASS_FLAGS (c, flags); return c; } SCM_DEFINE (scm_make_class_object, "make-class-object", 2, 0, 0, (SCM metaclass, SCM layout), "Create a new class object of class @var{metaclass}, with the\n" "slot layout specified by @var{layout}.") #define FUNC_NAME s_scm_make_class_object { unsigned long flags = 0; SCM_VALIDATE_STRUCT (1, metaclass); SCM_VALIDATE_STRING (2, layout); if (scm_is_eq (metaclass, scm_metaclass_operator)) flags = SCM_CLASSF_OPERATOR; return scm_i_make_class_object (metaclass, layout, flags); } #undef FUNC_NAME SCM_DEFINE (scm_make_subclass_object, "make-subclass-object", 2, 0, 0, (SCM class, SCM layout), "Create a subclass object of @var{class}, with the slot layout\n" "specified by @var{layout}.") #define FUNC_NAME s_scm_make_subclass_object { SCM pl; SCM_VALIDATE_STRUCT (1, class); SCM_VALIDATE_STRING (2, layout); pl = SCM_PACK (SCM_STRUCT_DATA (class) [scm_vtable_index_layout]); pl = scm_symbol_to_string (pl); return scm_i_make_class_object (SCM_STRUCT_VTABLE (class), scm_string_append (scm_list_2 (pl, layout)), SCM_CLASS_FLAGS (class)); } #undef FUNC_NAME void scm_init_objects () { SCM ms = scm_from_locale_string (SCM_METACLASS_STANDARD_LAYOUT); SCM mt = scm_make_vtable_vtable (ms, SCM_INUM0, scm_list_3 (SCM_BOOL_F, SCM_EOL, SCM_EOL)); SCM os = scm_from_locale_string (SCM_METACLASS_OPERATOR_LAYOUT); SCM ot = scm_make_vtable_vtable (os, SCM_INUM0, scm_list_3 (SCM_BOOL_F, SCM_EOL, SCM_EOL)); SCM es = scm_from_locale_string (SCM_ENTITY_LAYOUT); SCM el = scm_make_struct_layout (es); SCM et = scm_make_struct (mt, SCM_INUM0, scm_list_4 (el, SCM_BOOL_F, SCM_EOL, SCM_EOL)); scm_c_define ("", mt); scm_metaclass_standard = mt; scm_c_define ("", ot); scm_metaclass_operator = ot; SCM_SET_CLASS_FLAGS (et, SCM_CLASSF_OPERATOR | SCM_CLASSF_ENTITY); SCM_SET_CLASS_DESTRUCTOR (et, scm_struct_free_entity); scm_c_define ("", et); #include "libguile/objects.x" } /* Local Variables: c-file-style: "gnu" End: */