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/*
*
* s t k l o s . c -- STklos support
*
* Copyright © 1993-1999 Erick Gallesio - I3S-CNRS/ESSI <eg@unice.fr>
*
*
* Permission to use, copy, modify, distribute,and license this
* software and its documentation for any purpose is hereby granted,
* provided that existing copyright notices are retained in all
* copies and that this notice is included verbatim in any
* distributions. No written agreement, license, or royalty fee is
* required for any of the authorized uses.
* This software is provided ``AS IS'' without express or implied
* warranty.
*
* Author: Erick Gallesio [eg@unice.fr]
* Creation date: 9-Feb-1994 15:56
* Last file update: 3-Sep-1999 20:58 (eg)
*/
#ifdef USE_STKLOS
#include "stk.h"
#include "stklos.h"
#include "extend.h"
#include "module.h"
#define CLASSP(x) (INSTANCEP(x) && SUBCLASSP(CLASS_OF(x), Class))
#define GENERICP(x) (INSTANCEP(x) && SUBCLASSP(CLASS_OF(x), Generic))
#define METHODP(x) (INSTANCEP(x) && SUBCLASSP(CLASS_OF(x), Method))
#define NCLASSP(x) (!CLASSP(x))
#define NGENERICP(x) (!GENERICP(x))
#define NMETHODP(x) (!METHODP(x))
#define SPEC_OF(x) THE_SLOT_OF(x, S_specializers)
#define DEFVAR(v,val) {STk_define_public_var(STklos,(v),(val)); \
STk_export_symbol(v, STklos);}
#define GETVAR(v) (*(STk_varlookup((v), MOD_ENV(STklos),FALSE)))
#define CALL_GF1(name,a) (Apply1(GETVAR(Intern(name)), a))
#define CALL_GF2(name,a,b) (Apply2(GETVAR(Intern(name)), a, b))
#define CALL_GF3(name,a,b,c) (Apply(GETVAR(Intern(name)), LIST3(a, b, c)))
#define CALL_GF4(name,a,b,c,d) (Apply(GETVAR(Intern(name)), LIST4(a, b, c, d)))
#define CLASS_REDEF(c) THE_SLOT_OF(c, S_redefined)
#define TEST_CHANGE_CLASS(obj, classe) \
{ \
classe = CLASS_OF(obj); \
if (CLASS_REDEF(classe) != Ntruth) \
CALL_GF3("change-object-class", obj, classe, CLASS_REDEF(classe)); \
}
#define NXT_MTHD_METHODS CAR
#define NXT_MTHD_ARGS CDR
static char initialized = 0;
static SCM STklos;
static SCM Top, Object, Class, Generic, Method, Simple_method, Accessor,
Procedure_class, Entity_class;
static SCM Boolean, Char, Pair, Procedure, String, Symbol, Vector, Number,
Liste, Null, Real, Integer, Keyword, UnknownClass;
#ifdef USE_TK
static SCM Widget;
#endif
static void set_slot_value_if_unbound(SCM classe, SCM obj, SCM slot_name, SCM form);
/*****************************************************************************/
static SCM make_instance(SCM classe, long size, int type)
{
register SCM z;
register long i;
NEWCELL(z, STk_tc_instance);
INST(z) = must_malloc(sizeof(Instance) + (size-1)*sizeof(SCM));
CLASS_OF(z) = classe;
INST_TYPE(z) = type;
ACCESSORS_OF(z) = classe? THE_SLOT_OF(classe, S_getters_n_setters) : NIL;
NUMBER_OF_SLOTS(z) = size;
/* Set all the slots to unbound */
for (i = 0; i < size; i++)
THE_SLOT_OF(z, i) = UNBOUND;
return z;
}
void STk_free_instance(SCM o)
{
free(INST(o));
}
SCM STk_STklos_value(SCM symbol)
{
return GETVAR(symbol);
}
/******************************************************************************
*
* Compute-cpl
*
* This version doesn't handle multiple-inheritance. It serves only for
* booting classes and will be overaloaded in Scheme
*
******************************************************************************/
static SCM compute_cpl(SCM supers, SCM res)
{
return NULLP(supers)? Reverse(res)
: compute_cpl(THE_SLOT_OF(CAR(supers), S_direct_supers),
Cons(CAR(supers), res));
}
/******************************************************************************
*
* compute-slots
*
******************************************************************************/
static SCM remove_duplicate_slots(SCM l, SCM res, SCM slots_already_seen)
{
SCM tmp;
if (NULLP(l)) return res;
tmp = CONSP(CAR(l)) ? CAR(CAR(l)) : CAR(l);
if (NSYMBOLP(tmp)) Err("%compute-slots: bad slot name", tmp);
if (STk_memq(tmp, slots_already_seen) == Ntruth) {
res = Cons(CAR(l), res);
slots_already_seen = Cons(tmp, slots_already_seen);
}
return remove_duplicate_slots(CDR(l), res, slots_already_seen);
}
static SCM build_slots_list(SCM dslots, SCM cpl)
{
register SCM res = dslots;
for (cpl = CDR(cpl); NNULLP(cpl); cpl = CDR(cpl))
res = STk_append2(THE_SLOT_OF(CAR(cpl), S_direct_slots), res);
/* res contains a list of slots. Remove slots which appears more than once */
return remove_duplicate_slots(Reverse(res), NIL, NIL);
}
static PRIMITIVE compute_slots(SCM classe)
{
if (NCLASSP(classe)) Err("%compute-slots: bad class", classe);
return build_slots_list(THE_SLOT_OF(classe, S_direct_slots),
THE_SLOT_OF(classe, S_cpl));
}
/******************************************************************************
*
* compute-getters-n-setters
*
* This version doesn't handle slot options. It serves only for booting
* classes and will be overaloaded in Scheme.
*
******************************************************************************/
static SCM compute_getters_n_setters(SCM slots)
{
SCM res = NIL;
long i = 0;
for ( ; NNULLP(slots); slots = CDR(slots))
res = Cons(Cons(CAR(slots),
Cons(Ntruth,
STk_makeinteger(i++))),
res);
return res;
}
/******************************************************************************
*
* initialize-object
*
******************************************************************************/
static PRIMITIVE initialize_object(SCM obj, SCM initargs)
{
static char k_init_keyword[] = ":init-keyword";
SCM tmp, get_n_set, slots;
SCM init_keyword = STk_makekey(k_init_keyword);
SCM classe = CLASS_OF(obj);
ENTER_PRIMITIVE("%initialize-object");
if (NINSTANCEP(obj)) Serror("bad object", obj);
if (NCONSP(initargs) && NNULLP(initargs)) Serror("bad init list", initargs);
get_n_set = THE_SLOT_OF(classe, S_getters_n_setters);
slots = THE_SLOT_OF(classe, S_slots);
/* See for each slot how it must be initialized */
for ( ; NNULLP(slots); get_n_set=CDR(get_n_set), slots=CDR(slots)) {
SCM slot_name = CAR(slots);
SCM slot_value = NULL;
if (CONSP(slot_name)) {
/* This slot admits (perhaps) to be initialized at creation time */
tmp = STk_get_keyword(init_keyword,CDR(slot_name), NULL);
slot_name = CAR(slot_name);
if (tmp) {
/* an initarg was provided for this slot */
if (NKEYWORDP(tmp)) Serror("initarg must be a keyword. It was", tmp);
slot_value = STk_get_keyword(tmp, initargs, NULL);
}
}
if (slot_value)
/* set slot to provided value */
STk_slot_set(obj, slot_name, slot_value);
else {
/* set slot to its :initform if it exists */
tmp = CAR(CDR(CAR(get_n_set)));
if (tmp != Ntruth)
set_slot_value_if_unbound(classe, obj, slot_name, tmp);
}
}
return obj;
}
/******************************************************************************/
SCM STk_basic_make_class(SCM classe, SCM name, SCM dsupers, SCM dslots)
{
SCM z, cpl, slots, g_n_s;
/* Allocate one instance */
z = make_instance(classe, NUMBER_OF_CLASS_SLOTS, TYPE_INSTANCE);
/* Initialize its slots */
cpl = compute_cpl(dsupers, LIST1(z));
slots = build_slots_list(dslots, cpl);
g_n_s = compute_getters_n_setters(slots);
THE_SLOT_OF(z, S_name) = name;
THE_SLOT_OF(z, S_direct_supers) = dsupers;
THE_SLOT_OF(z, S_direct_slots) = dslots;
THE_SLOT_OF(z, S_direct_subclasses) = NIL;
THE_SLOT_OF(z, S_direct_methods) = NIL;
THE_SLOT_OF(z, S_cpl) = cpl;
THE_SLOT_OF(z, S_slots) = slots;
THE_SLOT_OF(z, S_nfields) = STk_makeinteger(STk_llength(slots));
THE_SLOT_OF(z, S_getters_n_setters) = g_n_s;
THE_SLOT_OF(z, S_redefined) = Ntruth;
THE_SLOT_OF(z, S_environment) = MOD_ENV(STklos);
/* Don't forget to set the accessors list of the object */
ACCESSORS_OF(z) = THE_SLOT_OF(classe, S_getters_n_setters);
/* Add this class in the direct-subclasses slot of dsupers */
{
SCM tmp;
for (tmp = dsupers; NNULLP(tmp); tmp = CDR(tmp)) {
THE_SLOT_OF(CAR(tmp), S_direct_subclasses) =
Cons(z,
THE_SLOT_OF(CAR(tmp), S_direct_subclasses));
}
}
return z;
}
/******************************************************************************/
static void create_Top_Object_Class(void)
{
SCM tmp, slots_of_class = Cons(Intern("name"),
Cons(Intern("direct-supers"),
Cons(Intern("direct-slots"),
Cons(Intern("direct-subclasses"),
Cons(Intern("direct-methods"),
Cons(Intern("cpl"),
Cons(Intern("slots"),
Cons(Intern("nfields"),
Cons(Intern("getters-n-setters"),
Cons(Intern("redefined"),
Cons(Intern("environment"),
NIL)))))))))));
/* protect Top, Object and Class against garbage collection */
STk_gc_protect(&Top); STk_gc_protect(&Object); STk_gc_protect(&Class);
/**** <Class> ****/
tmp = Intern("<class>");
Class = make_instance(NULL, NUMBER_OF_CLASS_SLOTS, TYPE_INSTANCE);
CLASS_OF(Class) = Class;
ACCESSORS_OF(Class) = compute_getters_n_setters(slots_of_class);
THE_SLOT_OF(Class, S_name) = tmp;
THE_SLOT_OF(Class, S_direct_supers) = NIL; /* will be changed */
THE_SLOT_OF(Class, S_direct_slots) = slots_of_class;
THE_SLOT_OF(Class, S_direct_subclasses)= NIL;
THE_SLOT_OF(Class, S_direct_methods) = NIL;
THE_SLOT_OF(Class, S_cpl) = NIL; /* will be changed */
THE_SLOT_OF(Class, S_slots) = slots_of_class;
THE_SLOT_OF(Class, S_nfields) = STk_makeinteger(NUMBER_OF_CLASS_SLOTS);
THE_SLOT_OF(Class, S_getters_n_setters)= ACCESSORS_OF(Class);
THE_SLOT_OF(Class, S_redefined) = Ntruth;
THE_SLOT_OF(Class, S_environment) = MOD_ENV(STklos);
DEFVAR(tmp, Class);
/**** <Top> ****/
tmp = Intern("<top>");
Top = STk_basic_make_class(Class, tmp, NIL, NIL);
DEFVAR(tmp, Top);
/**** <Object> ****/
tmp = Intern("<object>");
Object = STk_basic_make_class(Class, tmp, LIST1(Top), NIL);
DEFVAR(tmp, Object);
/* <top> <object> and <class> were partially initialized. Correct them here */
THE_SLOT_OF(Object, S_direct_subclasses) = LIST1(Class);
THE_SLOT_OF(Class, S_direct_supers) = LIST1(Object);
THE_SLOT_OF(Class, S_cpl) = LIST3(Class, Object, Top);
}
/******************************************************************************/
static PRIMITIVE instancep(SCM obj)
{
return INSTANCEP(obj)? Truth: Ntruth;
}
static SCM class_of(SCM obj)
{
if (INSTANCEP(obj)) {
SCM classe;
TEST_CHANGE_CLASS(obj, classe);
return CLASS_OF(obj);
}
switch (TYPE(obj)) {
case tc_boolean: return Boolean;
case tc_char: return Char;
case tc_cons: return Pair;
case tc_nil: return Null;
case tc_string: return String;
case tc_symbol: return Symbol;
case tc_vector: return Vector;
case tc_flonum: return Real;
case tc_integer:
case tc_bignum: return Integer;
case tc_keyword: return Keyword;
#ifdef USE_TK
case tc_tkcommand: return Widget;
#endif
default: if (EXTENDEDP(obj))
return STk_extended_class_of(obj);
else
return (STk_procedurep(obj) == Truth)?
Procedure: UnknownClass;
}
}
/******************************************************************************
*
* Meta object accessors
*
******************************************************************************/
static PRIMITIVE class_name(SCM obj)
{
if (NCLASSP(obj)) Err("class-name: bad class", obj);
return STk_slot_ref(obj, Intern("name"));
}
static PRIMITIVE class_direct_supers(SCM obj)
{
if (NCLASSP(obj)) Err("class-direct-supers: bad class", obj);
return STk_slot_ref(obj, Intern("direct-supers"));
}
static PRIMITIVE class_direct_slots(SCM obj)
{
if (NCLASSP(obj)) Err("class-direct-slots: bad class", obj);
return STk_slot_ref(obj, Intern("direct-slots"));
}
static PRIMITIVE class_direct_subs(SCM obj)
{
if (NCLASSP(obj)) Err("class-direct-subclasses: bad class", obj);
return STk_slot_ref(obj, Intern("direct-subclasses"));
}
static PRIMITIVE class_direct_methods(SCM obj)
{
if (NCLASSP(obj)) Err("class-direct-methods: bad class", obj);
return STk_slot_ref(obj, Intern("direct-methods"));
}
static PRIMITIVE class_cpl(SCM obj)
{
if (NCLASSP(obj)) Err("class-precedence-list: bad class", obj);
return STk_slot_ref(obj, Intern("cpl"));
}
static PRIMITIVE class_slots(SCM obj)
{
if (NCLASSP(obj)) Err("class-slots: bad class", obj);
return STk_slot_ref(obj, Intern("slots"));
}
static PRIMITIVE class_environment(SCM obj)
{
if (NCLASSP(obj)) Err("class-environment: bad class", obj);
return STk_slot_ref(obj, Intern("environment"));
}
static PRIMITIVE gf_name(SCM obj)
{
if (NGENERICP(obj)) Err("generic-function-name: bad function", obj);
return STk_slot_ref(obj, Intern("name"));
}
static PRIMITIVE gf_methods(SCM obj)
{
if (NGENERICP(obj)) Err("generic-function-methods: bad function", obj);
return STk_slot_ref(obj, Intern("methods"));
}
static PRIMITIVE method_gf(SCM obj)
{
if (NMETHODP(obj)) Err("method-generic-function: bad method", obj);
return STk_slot_ref(obj, Intern("generic-function"));
}
static PRIMITIVE method_specializers(SCM obj)
{
if (NMETHODP(obj)) Err("method-specializers: bad method", obj);
return STk_slot_ref(obj, Intern("specializers"));
}
static PRIMITIVE method_procedure(SCM obj)
{
if (NMETHODP(obj)) Err("method-procedure: bad method", obj);
return STk_slot_ref(obj, Intern("procedure"));
}
/******************************************************************************
*
* S l o t a c c e s s
*
******************************************************************************/
static PRIMITIVE fast_slot_ref(SCM obj, SCM index)
{
register long i = STk_integer_value(index);
ENTER_PRIMITIVE("%fast-slot-ref");
if (NINSTANCEP(obj)) Serror("bad object", obj);
if (i < 0 || i >= NUMBER_OF_SLOTS(obj)) Serror("bad index", index);
return THE_SLOT_OF(obj, i);
}
static PRIMITIVE fast_slot_set(SCM obj, SCM index, SCM value)
{
register long i = STk_integer_value(index);
ENTER_PRIMITIVE("%fast-slot-set!");
if (NINSTANCEP(obj)) Serror("bad object", obj);
if (i < 0 || i >= NUMBER_OF_SLOTS(obj)) Serror("bad index", index);
THE_SLOT_OF(obj, i) = value;
return UNDEFINED;
}
/** Utilities **/
static SCM get_slot_value(SCM classe, SCM obj, SCM slot_name)
{
register SCM l;
for (l=ACCESSORS_OF(obj); NNULLP(l); l=CDR(l)) {
if (EQ(CAR(CAR(l)), slot_name)) {
l = CDR(CDR(CAR(l)));
/* Two cases here:
* - l is an integer (the offset of this slot in the slots vector)
* - otherwise (car l) is the getter function to apply
*/
if (INTEGERP(l))
return THE_SLOT_OF(obj, INTEGER(l));
else { /* We must evaluate (apply (car l) (list obj))
* where (car l) is known to be a closure of arity 1 */
register SCM code, env;
code = CAR(l);
env = add_frame(CLOSPARAMS(code), LIST1(obj), CLOSENV(code));
/* Evaluate the closure body */
for(code=CLOSBODY(code); NNULLP(code); code=CDR(code))
l = EVALCAR(code);
return l;
}
}
}
return CALL_GF3("slot-missing", classe, obj, slot_name);
}
static SCM set_slot_value(SCM classe, SCM obj, SCM slot_name, SCM value)
{
register SCM l;
for (l=ACCESSORS_OF(obj); NNULLP(l); l=CDR(l)) {
if (EQ(CAR(CAR(l)), slot_name)) {
l = CDR(CDR(CAR(l)));
/* Two cases here:
* - l is an integer (the offset of this slot in the slots vector)
* - otherwise (cadr l) is the setter function to apply
*/
if (INTEGERP(l))
THE_SLOT_OF(obj, INTEGER(l)) = value;
else { /* We must evaluate (apply (cadr l) (list obj value))
* where (cadr l) is known to be a closure of arity 2 */
register SCM code, env;
code = CAR(CDR(l));
env = add_frame(CLOSPARAMS(code), LIST2(obj, value), CLOSENV(code));
/* Evaluate the closure body */
for(code=CLOSBODY(code); NNULLP(code); code=CDR(code))
EVALCAR(code);
}
return UNDEFINED;
}
}
return CALL_GF4("slot-missing", classe, obj, slot_name, value);
}
static void set_slot_value_if_unbound(SCM classe, SCM obj, SCM slot_name, SCM form)
{
SCM old_val = get_slot_value(classe, obj, slot_name);
if (old_val == UNBOUND)
set_slot_value(classe, obj, slot_name, Apply0(form));
}
static SCM test_slot_existence(SCM classe, SCM obj, SCM slot_name)
{
register SCM l;
for (l=ACCESSORS_OF(obj); NNULLP(l); l=CDR(l))
if (EQ(CAR(CAR(l)), slot_name)) return Truth;
return Ntruth;
}
/* ======================================== */
static PRIMITIVE slot_ref_using_class(SCM classe, SCM obj, SCM slot_name)
{
SCM res;
ENTER_PRIMITIVE("slot-ref-using-class");
if (NCLASSP(classe)) Serror("bad class", classe);
if (NINSTANCEP(obj)) Serror("bad object", obj);
res = get_slot_value(classe, obj, slot_name);
if (res == UNBOUND)
return CALL_GF3("slot-unbound", classe, obj, slot_name);
return res;
}
static PRIMITIVE slot_set_using_class(SCM l, int len)
{
ENTER_PRIMITIVE("slot-set-using-class!");
if (len != 4) Serror("bad number of parameters", NIL);
{
SCM classe = CAR(l);
SCM obj = CAR(CDR(l));
if (NCLASSP(classe)) Serror("bad class", classe);
if (NINSTANCEP(obj)) Serror("bad object", obj);
return set_slot_value(classe, obj, CAR(CDR(CDR(l))), CAR(CDR(CDR(CDR(l)))));
}
}
static PRIMITIVE slot_boundp_using_class(SCM classe, SCM obj, SCM slot_name)
{
ENTER_PRIMITIVE("slot-bound-using-class?");
if (NCLASSP(classe)) Serror("bad class", classe);
if (NSYMBOLP(slot_name)) Serror("bad slot name",slot_name);
if (NINSTANCEP(obj)) Serror("bad object", obj);
return (get_slot_value(classe, obj, slot_name) == UNBOUND) ? Ntruth : Truth;
}
static PRIMITIVE slot_exists_using_class(SCM classe, SCM obj, SCM slot_name)
{
ENTER_PRIMITIVE("slot-exists-using-class?");
if (NCLASSP(classe)) Serror("bad class", classe);
if (NSYMBOLP(slot_name)) Serror("bad slot name",slot_name);
if (NINSTANCEP(obj)) Serror("bad object", obj);
return test_slot_existence(classe, obj, slot_name);
}
/* ======================================== */
PRIMITIVE STk_slot_ref(SCM obj, SCM slot_name)
{
SCM res, classe;
if (NINSTANCEP(obj)) Err("slot-ref: bad object", obj);
TEST_CHANGE_CLASS(obj, classe);
res = get_slot_value(classe, obj, slot_name);
if (res == UNBOUND)
return CALL_GF3("slot-unbound", classe, obj, slot_name);
return res;
}
PRIMITIVE STk_slot_set(SCM obj, SCM slot_name, SCM value)
{
SCM classe;
if (NINSTANCEP(obj)) Err("slot-set!: bad object", obj);
TEST_CHANGE_CLASS(obj, classe);
return set_slot_value(classe, obj, slot_name, value);
}
static PRIMITIVE slot_boundp(SCM obj, SCM slot_name)
{
SCM classe;
if (NINSTANCEP(obj)) Err("slot-bound?: bad object", obj);
TEST_CHANGE_CLASS(obj, classe);
return (get_slot_value(classe, obj, slot_name) == UNBOUND) ? Ntruth : Truth;
}
static PRIMITIVE slot_existsp(SCM obj, SCM slot_name)
{
SCM classe;
ENTER_PRIMITIVE("slot-exists?");
if (NSYMBOLP(slot_name)) Serror("bad slot name", slot_name);
if (NINSTANCEP(obj)) Serror("bad object", obj);
TEST_CHANGE_CLASS(obj, classe);
return test_slot_existence(classe, obj, slot_name);
}
/******************************************************************************
*
* %allocate-instance (the low level instance allocation primitive)
*
******************************************************************************/
PRIMITIVE STk_allocate_instance(SCM classe)
{
int type;
if (NCLASSP(classe)) Err("%allocate-instance: bad class", classe);
if (EQ(classe, Generic)) type= TYPE_GENERIC;
else
if (EQ(classe, Accessor)) type = TYPE_ACCESSOR;
else
if (EQ(classe, Simple_method)) type = TYPE_SIMPLE_METHOD;
else type = TYPE_INSTANCE;
return make_instance(classe,
STk_integer_value(THE_SLOT_OF(classe, S_nfields)),
type);
}
/******************************************************************************
*
* %modify-instance (used by change-class to modify in place)
*
******************************************************************************/
static PRIMITIVE modify_instance(SCM old, SCM new)
{
struct obj tmp;
if (NINSTANCEP(old) || NINSTANCEP(new))
Err("%modify-instance: both parameters must be instances", NIL);
/* Exchange the data contained in old and new. We exchange rather than
* scratch the old value with new to be correct with GC
*/
tmp = *old;
*old = *new;
*new = tmp;
return UNDEFINED;
}
static PRIMITIVE stklos_version(void)
{
return STk_makestring(STKLOS_VERSION);
}
/******************************************************************************
*
* GGGG FFFFF
* G F
* G GG FFF
* G G F
* GGG E N E R I C F U N C T I O N S
*
* This implementation provides
* - generic functions (with class specializers)
* - multi-methods
* - next-method
* - a hard-coded MOP for standard gf, which can be overloaded for non-std gf
*
******************************************************************************/
SCM STk_make_next_method(SCM methods, SCM args, SCM gf)
{
register SCM z, l;
/* if gf is NIL, args already contains the GF in front of args.
* This saves the cost of a a cons. This situation is very frequent since
* most of the time next-method is called without parameter and we just have
* to propagate the previous args.
*/
l = (NULLP(gf))? args : Cons(gf, args);
NEWCELL(z, tc_next_method);
CAR(z) = methods;
CDR(z) = l;
return z;
}
SCM STk_apply_next_method(SCM next, SCM provided_args)
{
SCM methods = NXT_MTHD_METHODS(next);
SCM args, tmp;
if (NULLP(provided_args)) {
tmp = NXT_MTHD_ARGS(next);
args = CDR(tmp);
}
else {
tmp = Cons(CAR(NXT_MTHD_ARGS(next)), provided_args);
args = provided_args;
}
if (NULLP(methods)) {
SCM gf = CAR(NXT_MTHD_ARGS(next));
return CALL_GF2("no-next-method", gf, args);
}
else {
SCM m = CAR(methods);
SCM new_next = STk_make_next_method(CDR(methods),tmp, NIL);
/* m is the function to call with args. */
return Apply(THE_SLOT_OF(m, S_procedure), Cons(new_next, args));
}
}
static PRIMITIVE next_method_exists(SCM next)
{
if (NTYPEP(next, tc_next_method))
Err("next-method-exists: bad next method'", next);
return NULLP(NXT_MTHD_METHODS(next))? Ntruth : Truth;
}
int STk_methodp(SCM obj)
{
return METHODP(obj);
}
/******************************************************************************
*
* Protocol for calling a generic fumction
* This protocol is roughly equivalent to (parameter are a little bit different
* for efficiency reasons):
*
* + apply-generic (gf args)
* + compute-applicable-methods (gf args ...)
* + sort-applicable-methods (methods args)
* + apply-methods (gf methods args)
*
* apply-methods calls make-next-method to build the "continuation" of a a
* method. Applying a next-method will call apply-next-method which in
* turn will call apply again to call effectively the following method.
*
******************************************************************************/
static int applicablep(SCM actual, SCM formal)
{
register SCM ptr;
/* We test that (memq formal (slot-ref actual 'cpl))
* However, we don't call memq here since we already know that
* the list is well formed
*/
for (ptr=THE_SLOT_OF(actual, S_cpl); NNULLP(ptr); ptr = CDR(ptr)) {
if (CONSP(ptr)) {
if (EQ(CAR(ptr), formal)) return TRUE;
}
else
Err("Internal error in applicable: bad list", actual);
}
return FALSE;
}
static int more_specificp(SCM m1, SCM m2, SCM *targs)
{
register SCM s1, s2;
register int i;
/*
* Note:
* m1 and m2 can have != length (i.e. one can be one element longer than the
* other when we have a dotted parameter list). For instance, with the call
* (M 1)
* with
* (define-method M (a . l) ....)
* (define-method M (a) ....)
*
* we consider that the second method is more specific.
*
* BTW, targs is an array of types. We don't need it's size since
* we already know that m1 and m2 are applicable (no risk to go past
* the end of this array).
*
*/
for (i=0,s1=SPEC_OF(m1),s2=SPEC_OF(m2); ; i++,s1=CDR(s1),s2=CDR(s2)) {
if (NULLP(s1)) return 1;
if (NULLP(s2)) return 0;
if (CAR(s1) != CAR(s2)) {
register SCM l, cs1 = CAR(s1), cs2 = CAR(s2);
for (l = THE_SLOT_OF(targs[i], S_cpl); ; l = CDR(l)) {
if (EQ(cs1, CAR(l))) return 1;
if (EQ(cs2, CAR(l))) return 0;
}
return 0;/* should not occur! */
}
}
return 0; /* should not occur! */
}
#define BUFFSIZE 32 /* big enough for most uses */
static SCM sort_applicable_methods(SCM method_list, int size, SCM *targs)
{
int i, j, incr;
SCM *v, vector;
SCM buffer[BUFFSIZE];
SCM save = method_list;
/* For reasonably sized method_lists we can try to avoid all the
* consing and reorder the list in place...
* This idea is due to David McClain <Dave_McClain@msn.com>
*/
if (size <= BUFFSIZE) {
for(i=0; i < size; i++) {
buffer[i] = CAR(method_list);
method_list = CDR(method_list);
}
vector = NIL; /* for GCC */
v = buffer;
}
else {
/* Too many elements in method_list to keep everything locally */
vector = STk_vector(save, size);
v = VECT(vector);
}
/* Use a simple shell sort since it is generally faster than qsort on
* small vectors (which is probably mostly the case when we have to
* sort a list of applicable methods).
*/
for (incr = size / 2; incr; incr /= 2) {
for (i = incr; i < size; i++) {
for (j = i-incr ;j >= 0; j -= incr) {
if (more_specificp(v[j], v[j+incr], targs)) break;
else {
SCM tmp = v[j+incr];
v[j+incr] = v[j];
v[j] = tmp;
}
}
}
}
if (size <= BUFFSIZE) {
/* We did it in locally, so restore the original list (reordered) in-place */
for(i=0, method_list=save; i < size; i++, v++) {
CAR(method_list) = *v;
method_list = CDR(method_list);
}
return save;
}
/* If we are here, that's that we did it the hard way... */
return STk_vector2list(vector);
}
SCM STk_compute_applicable_methods(SCM gf, SCM args, int len, int find_method)
{
register int i;
int count = 0;
SCM l, fl, applicable = NIL;
SCM save = args;
SCM buffer[BUFFSIZE], *types, *p;
SCM tmp;
/* Build the list of arguments types */
if (len >= BUFFSIZE) {
tmp = STk_makevect(len, NULL);
types = p = VECT(tmp);
}
else
types = p = buffer;
for ( ; NNULLP(args); args = CDR(args))
*p++ = class_of(CAR(args));
/* Build a list of all applicable methods */
for (l = THE_SLOT_OF(gf, S_methods); NNULLP(l); l = CDR(l)) {
for (i=0, fl=SPEC_OF(CAR(l)); ; i++, fl=CDR(fl)) {
if (INSTANCEP(fl) || /* We have a dotted argument list */
(i >= len && NULLP(fl))) { /* both list exhausted */
applicable = Cons(CAR(l), applicable);
count += 1;
break;
}
if (i >= len || NULLP(fl) || !applicablep(types[i], CAR(fl))) break;
}
}
if (count == 0) {
if (find_method) return Ntruth;
CALL_GF2("no-applicable-method", gf, save);
/* if we are here, it's because no-applicable-method hasn't signaled an error */
return NIL;
}
return (count == 1) ? applicable :
sort_applicable_methods(applicable, count, types);
}
static SCM apply_methods(SCM gf, SCM methods, SCM args)
{
SCM m, next;
if (NULLP(methods)) {
/*
* methods can be NIL if we have a no-applicable-method handler which
* doesn't signal an error (or dont ends with a call to next-method)
* In this case return an undefined value
*/
return UNDEFINED;
}
m = CAR(methods);
next = FASTMETHODP(m) ? UNBOUND : STk_make_next_method(CDR(methods), args, gf);
/* Next-method is set to UNBOUND for simple_method and accessors */
return Apply(THE_SLOT_OF(m, S_procedure), Cons(next, args));
}
SCM STk_apply_generic(SCM gf, SCM args)
{
if (NGENERICP(gf)) Err("apply: bad generic function", gf);
if (NULLP(THE_SLOT_OF(gf, S_methods))) CALL_GF2("no-method", gf, args);
return
apply_methods(gf,
STk_compute_applicable_methods(gf,args,STk_llength(args),FALSE),
args);
}
SCM STk_apply_user_generic(SCM gf, SCM args)
{
if (NGENERICP(gf)) Err("apply: bad generic function", gf);
return CALL_GF2("apply-generic", gf, args);
}
/******************************************************************************
*
* A simple make (which will be redefined later in Scheme)
* This version handles only creation of gf, methods and classes (no instances)
*
* Since this code will disappear when Stklos will be fully booted,
* no precaution is taken to be efficient.
*
******************************************************************************/
static char k_name[] = ":name"; /* Use vars since makekey patches */
static char k_specializers[] = ":specializers"; /* its argument. This avoids the */
static char k_procedure[] = ":procedure"; /* -fwritable_string */
static char k_dsupers[] = ":dsupers";
static char k_slots[] = ":slots";
static char k_gf[] = ":generic-function";
static PRIMITIVE lmake(SCM args, int len)
{
SCM classe, z;
if (len == 0) Err("make: parameter list is null", NIL);
classe = CAR(args); args = CDR(args);
if (classe == Generic) {
z = make_instance(classe,
STk_llength(THE_SLOT_OF(classe, S_slots)),
TYPE_GENERIC);
THE_SLOT_OF(z, S_name) = STk_get_keyword(STk_makekey(k_name), args,
Intern("???"));
THE_SLOT_OF(z, S_methods) = NIL;
}
else {
z = make_instance(classe,
STk_llength(THE_SLOT_OF(classe, S_slots)), TYPE_INSTANCE);
if (classe == Method || classe == Simple_method || classe == Accessor) {
THE_SLOT_OF(z, S_generic_function) =
STk_get_keyword(STk_makekey(k_gf), args, Ntruth);
THE_SLOT_OF(z, S_specializers) =
STk_get_keyword(STk_makekey(k_specializers), args, NIL);
THE_SLOT_OF(z, S_procedure) =
STk_get_keyword(STk_makekey(k_procedure), args, NIL);
}
else {
/* In all the others case, make a new class .... No instance here */
THE_SLOT_OF(z, S_name) =
STk_get_keyword(STk_makekey(k_name), args, Intern("???"));
THE_SLOT_OF(z, S_direct_supers) =
STk_get_keyword(STk_makekey(k_dsupers), args, NIL);
THE_SLOT_OF(z, S_direct_slots) =
STk_get_keyword(STk_makekey(k_slots), args, NIL);
}
}
return z;
}
static PRIMITIVE find_method(SCM l, int len)
{
SCM gf;
ENTER_PRIMITIVE("find-method");
if (len == 0) Serror("no parameter list", NIL);
gf = CAR(l); l = CDR(l);
if (NGENERICP(gf)) Serror("bad generic function", gf);
if (NULLP(THE_SLOT_OF(gf, S_methods))) Serror("no methods for generic", gf);
return STk_compute_applicable_methods(gf, l, len-1, TRUE);
}
static PRIMITIVE user_more_specificp(SCM m1, SCM m2, SCM targs)
{
SCM l, v;
int i, len;
ENTER_PRIMITIVE("%method-more-specific?");
if (NMETHODP(m1)) Serror("bad method", m1);
if (NMETHODP(m2)) Serror("bad method", m2);
if ((len=STk_llength(targs)) < 0) Serror("bad argument", targs);
/* Verify that all the arguments of targs are classes and place them in a vector*/
v = STk_makevect(len, NIL);
for (i=0, l=targs; NNULLP(l); i++, l=CDR(l)) {
if (NCLASSP(CAR(l))) Serror("bad argument", targs);
VECT(v)[i] = CAR(l);
}
return more_specificp(m1, m2, VECT(v)) ? Truth: Ntruth;
}
/******************************************************************************
*
* Initializations
*
******************************************************************************/
static void select_STklos_module(void)
{
STk_selected_module = STklos = STk_make_module(Intern("stklos"));
}
static void make_stdcls(SCM *var, char *name, SCM meta, SCM super, SCM slots)
{
SCM tmp = Intern(name);
*var = STk_basic_make_class(meta, tmp, LIST1(super), slots);
STk_gc_protect(var);
DEFVAR(tmp, *var);
}
static void make_standard_classes(void)
{
SCM tmp1 = LIST3(Intern("generic-function"),
Intern("specializers"),
Intern("procedure"));
SCM tmp2 = LIST2(Intern("name"),
Intern("methods"));
/* Generic functions classes */
make_stdcls(&Procedure_class, "<procedure-class>", Class, Class, NIL);
make_stdcls(&Entity_class, "<entity-class>", Class, Procedure_class, NIL);
make_stdcls(&Method, "<method>", Class, Object, tmp1);
make_stdcls(&Simple_method, "<simple-method>", Class, Method, NIL);
make_stdcls(&Accessor, "<accessor-method>", Class, Simple_method, NIL);
make_stdcls(&Generic, "<generic>", Entity_class, Object, tmp2);
/* Primitive types classes */
make_stdcls(&Boolean, "<boolean>", Class, Top, NIL);
make_stdcls(&Char, "<char>", Class, Top, NIL);
make_stdcls(&Liste, "<list>", Class, Top, NIL);
make_stdcls(&Pair, "<pair>", Class, Liste, NIL);
make_stdcls(&Null, "<null>", Class, Liste, NIL);
make_stdcls(&String, "<string>", Class, Top, NIL);
make_stdcls(&Symbol, "<symbol>", Class, Top, NIL);
make_stdcls(&Vector, "<vector>", Class, Top, NIL);
make_stdcls(&Number, "<number>", Class, Top, NIL);
make_stdcls(&Real, "<real>", Class, Number, NIL);
make_stdcls(&Integer, "<integer>", Class, Real, NIL);
make_stdcls(&Keyword, "<keyword>", Class, Top, NIL);
make_stdcls(&UnknownClass, "<unknown>", Class, Top, NIL);
make_stdcls(&Procedure, "<procedure>", Procedure_class, Top, NIL);
#ifdef USE_TK
make_stdcls(&Widget, "<widget>", Procedure_class, Procedure, NIL);
#endif
}
/**
*
* Definition of Extended type classes
*
**/
SCM STk_make_extended_class(char *name)
{
/*
* This function is called when a new extended type is defined and returns
* a new class for it. Furthermore, it defines a global variable for this class.
* If STklos is not initialized, it returns NIL.
* Extended types defined before initialization of STklos will be done
* when STklos is inited by "define_extended_type_classes"
*/
if (initialized) {
SCM tmp1, tmp2;
char buffer[200];
sprintf(buffer, "<%s>", name);
tmp1 = Intern(buffer);
tmp2 = STk_basic_make_class(Class, tmp1, LIST1(Top), NIL);
DEFVAR(tmp1, tmp2);
return tmp2;
}
return NIL;
}
static void define_extended_type_classes(void)
{
/*
* This function is called when STklos is initialized. It performs
* the definition of classes for extended types defined before STklos
* loading
*/
int i;
initialized = TRUE;
for (i = tc_start_extd; ; i++) {
char *name = STk_get_extended_name(i);
if (!name) return;
STk_register_extended_class(STk_make_extended_class(name), i);
}
}
static void add_primitive(char *name, int type, void *fct_ptr)
{
STk_add_new_primitive(name, type, fct_ptr);
STk_export_symbol(Intern(name), STklos);
}
/*===========================================================================*/
PRIMITIVE STk_init_STklos(void)
{
SCM curmod = STk_selected_module;
Top = Object = Class = Generic = Method = Simple_method = Accessor = NIL;
select_STklos_module();
create_Top_Object_Class();
make_standard_classes();
/* Define new primitives and export them */
add_primitive("stklos-version", tc_subr_0, stklos_version);
add_primitive("instance?", tc_subr_1, instancep);
add_primitive("slot-ref-using-class", tc_subr_3, slot_ref_using_class);
add_primitive("slot-set-using-class!", tc_lsubr, slot_set_using_class);
add_primitive("slot-bound-using-class?", tc_subr_3, slot_boundp_using_class);
add_primitive("slot-exists-using-class?", tc_subr_3, slot_exists_using_class);
add_primitive("slot-ref", tc_subr_2, STk_slot_ref);
add_primitive("slot-set!", tc_subr_3, STk_slot_set);
add_primitive("slot-bound?", tc_subr_2, slot_boundp);
add_primitive("class-of", tc_subr_1, class_of);
add_primitive("class-name", tc_subr_1, class_name);
add_primitive("class-direct-supers", tc_subr_1, class_direct_supers);
add_primitive("class-direct-subclasses", tc_subr_1, class_direct_subs);
add_primitive("class-direct-methods", tc_subr_1, class_direct_methods);
add_primitive("class-direct-slots", tc_subr_1, class_direct_slots);
add_primitive("class-precedence-list", tc_subr_1, class_cpl);
add_primitive("class-slots", tc_subr_1, class_slots);
add_primitive("class-environment", tc_subr_1, class_environment);
add_primitive("generic-function-name", tc_subr_1, gf_name);
add_primitive("generic-function-methods", tc_subr_1, gf_methods);
add_primitive("method-generic-function", tc_subr_1, method_gf);
add_primitive("method-specializers", tc_subr_1, method_specializers);
add_primitive("method-procedure", tc_subr_1, method_procedure);
add_primitive("slot-exists?", tc_subr_2, slot_existsp);
add_primitive("make", tc_lsubr, lmake);
add_primitive("find-method", tc_lsubr, find_method);
/* Unexported primitives */
STk_add_new_primitive("%allocate-instance", tc_subr_1, STk_allocate_instance);
STk_add_new_primitive("%initialize-object", tc_subr_2, initialize_object);
STk_add_new_primitive("%compute-slots", tc_subr_1, compute_slots);
STk_add_new_primitive("%modify-instance", tc_subr_2, modify_instance);
STk_add_new_primitive("%method-more-specific?", tc_subr_3, user_more_specificp);
STk_add_new_primitive("%fast-slot-ref", tc_subr_2, fast_slot_ref);
STk_add_new_primitive("%fast-slot-set!", tc_subr_3, fast_slot_set);
STk_add_new_primitive("%next-method-exists?", tc_subr_1, next_method_exists);
/* Define classes for already defined extended type */
define_extended_type_classes();
/* Reset the default module we have to the one we have when starting inits */
STk_selected_module = curmod;
return UNDEFINED;
}
#else
/* Don't produce an empty object file since some compiler (loader?) don't
* manage them correctly
*/
static char not_used = '?';
#endif
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