/* classes: h_files */ #ifndef SCM_OBJECTS_H #define SCM_OBJECTS_H /* Copyright (C) 1996,1999,2000,2001, 2003, 2006 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.c contains those minimal pieces of the Guile * Object Oriented Programming System which need to be included in * libguile. * * {Objects and structs} * * Objects are currently based upon structs. Although the struct * implementation will change thoroughly in the future, objects will * still be based upon structs. */ #include "libguile/__scm.h" #include "libguile/struct.h" /* {Class flags} * * These are used for efficient identification of instances of a * certain class or its subclasses when traversal of the inheritance * graph would be too costly. */ #define SCM_CLASS_FLAGS(class) (SCM_STRUCT_DATA (class) [scm_struct_i_flags]) #define SCM_OBJ_CLASS_FLAGS(obj) (SCM_STRUCT_VTABLE_DATA (obj) [scm_struct_i_flags]) #define SCM_SET_CLASS_FLAGS(c, f) (SCM_CLASS_FLAGS (c) |= (f)) #define SCM_CLEAR_CLASS_FLAGS(c, f) (SCM_CLASS_FLAGS (c) &= ~(f)) #define SCM_CLASSF_MASK SCM_STRUCTF_MASK #define SCM_CLASSF_ENTITY SCM_STRUCTF_ENTITY /* Operator classes need to be identified in the evaluator. (Entities also have SCM_CLASSF_OPERATOR set in their vtable.) */ #define SCM_CLASSF_OPERATOR (1L << 29) #define SCM_I_OPERATORP(obj)\ ((SCM_OBJ_CLASS_FLAGS (obj) & SCM_CLASSF_OPERATOR) != 0) #define SCM_OPERATOR_CLASS(obj)\ ((struct scm_metaclass_operator *) SCM_STRUCT_DATA (obj)) #define SCM_OBJ_OPERATOR_CLASS(obj)\ ((struct scm_metaclass_operator *) SCM_STRUCT_VTABLE_DATA (obj)) #define SCM_OPERATOR_PROCEDURE(obj) (SCM_OBJ_OPERATOR_CLASS (obj)->procedure) #define SCM_OPERATOR_SETTER(obj) (SCM_OBJ_OPERATOR_CLASS (obj)->setter) #define SCM_I_ENTITYP(obj)\ ((SCM_OBJ_CLASS_FLAGS (obj) & SCM_CLASSF_ENTITY) != 0) #define SCM_ENTITY_PROCEDURE(obj) \ (SCM_PACK (SCM_STRUCT_DATA (obj) [scm_struct_i_procedure])) #define SCM_SET_ENTITY_PROCEDURE(obj, v) \ (SCM_STRUCT_DATA (obj) [scm_struct_i_procedure] = SCM_UNPACK (v)) #define SCM_ENTITY_SETTER(obj) (SCM_PACK (SCM_STRUCT_DATA (obj)[scm_struct_i_setter])) #define SCM_SET_ENTITY_SETTER(obj, v) \ (SCM_STRUCT_DATA (obj) [scm_struct_i_setter] = SCM_UNPACK (v)) #define SCM_SET_CLASS_DESTRUCTOR(c, d) SCM_SET_VTABLE_DESTRUCTOR (c, d) #define SCM_SET_CLASS_INSTANCE_SIZE(c, s) \ (SCM_STRUCT_DATA (c)[scm_struct_i_size] \ = (SCM_STRUCT_DATA (c) [scm_struct_i_size] & SCM_STRUCTF_MASK) | s) /* {Operator classes} * * Instances of operator classes can work as operators, i. e., they * can be applied to arguments just as if they were ordinary * procedures. * * For instances of operator classes, the procedures to be applied are * stored in four dedicated slots in the associated class object. * Which one is selected depends on the number of arguments in the * application. * * If zero arguments are passed, the first will be selected. * If one argument is passed, the second will be selected. * If two arguments are passed, the third will be selected. * If three or more arguments are passed, the fourth will be selected. * * This is complicated and may seem gratuitous but has to do with the * architecture of the evaluator. Using only one procedure would * result in a great deal less efficient application, loss of * tail-recursion and would be difficult to reconcile with the * debugging evaluator. * * Also, using this "forked" application in low-level code has the * advantage of speeding up some code. An example is method dispatch * for generic operators applied to few arguments. On the user level, * the "forked" application will be hidden by mechanisms in the GOOPS * package. * * Operator classes have the metaclass . * * An example of an operator class is the class . */ #define SCM_METACLASS_STANDARD_LAYOUT "" struct scm_metaclass_standard { SCM layout; SCM vcell; SCM vtable; SCM print; }; #define SCM_METACLASS_OPERATOR_LAYOUT "popo" struct scm_metaclass_operator { SCM layout; SCM vcell; SCM vtable; SCM print; SCM procedure; SCM setter; }; /* {Entity classes} * * For instances of entity classes (entities), the procedures to be * applied are stored in the instance itself rather than in the class * object as is the case for instances of operator classes (see above). * * An example of an entity class is the class of generic methods. */ #define SCM_ENTITY_LAYOUT "" /* {Interface to Goops} * * The evaluator contains a multi-method dispatch mechanism. * This interface is used by that mechanism and during creation of * smob and struct classes. */ /* Internal representation of Goops objects. */ #define SCM_CLASSF_PURE_GENERIC (0x010 << 20) #define SCM_CLASSF_GOOPS_VALID (0x080 << 20) #define SCM_CLASSF_GOOPS (0x100 << 20) #define scm_si_redefined 5 #define scm_si_hashsets 6 #define SCM_CLASS_OF(x) SCM_STRUCT_VTABLE (x) #define SCM_OBJ_CLASS_REDEF(x) (SCM_PACK (SCM_STRUCT_VTABLE_DATA (x) [scm_si_redefined])) typedef struct scm_effective_slot_definition { SCM name; long location; SCM init_value; SCM (*get) (SCM obj, SCM slotdef); SCM (*set) (SCM obj, SCM slotdef, SCM value); } scm_effective_slot_definition; #define SCM_ESLOTDEF(x) ((scm_effective_slot_definition *) SCM_CDR (x)) #define SCM_CMETHOD_CODE(cmethod) SCM_CDR (cmethod) #define SCM_CMETHOD_FORMALS(cmethod) SCM_CAR (SCM_CMETHOD_CODE (cmethod)) #define SCM_CMETHOD_BODY(cmethod) SCM_CDR (SCM_CMETHOD_CODE (cmethod)) #define SCM_CMETHOD_ENV(cmethod) SCM_CAR (cmethod) /* Port classes */ #define SCM_IN_PCLASS_INDEX 0x000 #define SCM_OUT_PCLASS_INDEX 0x100 #define SCM_INOUT_PCLASS_INDEX 0x200 /* Plugin proxy classes for basic types. */ SCM_API SCM scm_metaclass_standard; SCM_API SCM scm_metaclass_operator; /* Goops functions. */ SCM_API SCM scm_make_extended_class (char const *type_name, int applicablep); SCM_API void scm_i_inherit_applicable (SCM c); SCM_API void scm_make_port_classes (long ptobnum, char *type_name); SCM_API void scm_change_object_class (SCM, SCM, SCM); SCM_API SCM scm_memoize_method (SCM x, SCM args); SCM_API SCM scm_mcache_lookup_cmethod (SCM cache, SCM args); SCM_API SCM scm_mcache_compute_cmethod (SCM cache, SCM args); /* The following are declared in __scm.h SCM_API SCM scm_call_generic_0 (SCM gf); SCM_API SCM scm_call_generic_1 (SCM gf, SCM a1); SCM_API SCM scm_call_generic_2 (SCM gf, SCM a1, SCM a2); SCM_API SCM scm_apply_generic (SCM gf, SCM args); */ SCM_API SCM scm_call_generic_3 (SCM gf, SCM a1, SCM a2, SCM a3); SCM_API SCM scm_entity_p (SCM obj); SCM_API SCM scm_operator_p (SCM obj); SCM_API SCM scm_valid_object_procedure_p (SCM proc); SCM_API SCM scm_set_object_procedure_x (SCM obj, SCM proc); #ifdef GUILE_DEBUG SCM_API SCM scm_object_procedure (SCM obj); #endif SCM_API SCM scm_make_class_object (SCM metaclass, SCM layout); SCM_API SCM scm_make_subclass_object (SCM c, SCM layout); SCM_API SCM scm_i_make_class_object (SCM metaclass, SCM layout_string, unsigned long flags); SCM_API void scm_init_objects (void); #endif /* SCM_OBJECTS_H */ /* Local Variables: c-file-style: "gnu" End: */