111 lines
2.5 KiB
C
111 lines
2.5 KiB
C
/**
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* See Copyright Notice in picrin.h
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*/
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#include "picrin.h"
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#include "picrin/pair.h"
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#include "picrin/proc.h"
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#include "picrin/dict.h"
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static pic_value
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var_lookup(pic_state *pic, pic_value var)
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{
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pic_value val, env;
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struct pic_dict *binding;
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val = pic_ref(pic, pic->PICRIN_BASE, "current-dynamic-environment");
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if (pic_eq_p(val, var)) {
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return pic_false_value();
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}
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env = pic_apply0(pic, pic_proc_ptr(val));
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while (! pic_nil_p(env)) {
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pic_assert_type(pic, pic_car(pic, env), dict);
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binding = pic_dict_ptr(pic_car(pic, env));
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if (pic_dict_has(pic, binding, var)) {
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return pic_dict_ref(pic, binding, var);
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}
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env = pic_cdr(pic, env);
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}
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return pic_false_value();
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}
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static pic_value
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var_call(pic_state *pic)
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{
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struct pic_proc *self = pic_get_proc(pic);
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pic_value val, tmp, box, conv;
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size_t n;
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n = pic_get_args(pic, "|oo", &val, &tmp);
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box = var_lookup(pic, pic_obj_value(self));
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if (! pic_test(box)) {
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box = pic_attr_ref(pic, pic_obj_value(self), "@@box");
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}
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switch (n) {
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case 0:
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return pic_car(pic, box);
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case 1:
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conv = pic_attr_ref(pic, pic_obj_value(self), "@@converter");
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if (pic_test(conv)) {
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pic_assert_type(pic, conv, proc);
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val = pic_apply1(pic, pic_proc_ptr(conv), val);
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}
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pic_set_car(pic, box, val);
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return pic_none_value();
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case 2:
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assert(pic_false_p(tmp));
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conv = pic_attr_ref(pic, pic_obj_value(self), "@@converter");
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if (pic_test(conv)) {
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pic_assert_type(pic, conv, proc);
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return pic_apply1(pic, pic_proc_ptr(conv), val);
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} else {
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return val;
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}
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}
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UNREACHABLE();
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}
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struct pic_proc *
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pic_make_var(pic_state *pic, pic_value init, struct pic_proc *conv)
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{
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struct pic_proc *var;
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var = pic_make_proc(pic, var_call, "<var-call>");
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pic_attr_set(pic, pic_obj_value(var), "@@box", pic_list1(pic, init));
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pic_attr_set(pic, pic_obj_value(var), "@@converter", conv ? pic_obj_value(conv) : pic_false_value());
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return var;
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}
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static pic_value
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pic_var_make_parameter(pic_state *pic)
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{
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struct pic_proc *conv = NULL;
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pic_value init;
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pic_get_args(pic, "o|l", &init, &conv);
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return pic_obj_value(pic_make_var(pic, init, conv));
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}
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void
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pic_init_var(pic_state *pic)
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{
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pic_define_noexport(pic, "current-dynamic-environment", pic_false_value());
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pic_defun(pic, "make-parameter", pic_var_make_parameter);
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pic_set(pic, pic->PICRIN_BASE, "current-dynamic-environment", pic_obj_value(pic_make_var(pic, pic_nil_value(), NULL)));
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}
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