92 lines
2.0 KiB
C
92 lines
2.0 KiB
C
/**
|
|
* See Copyright Notice in picrin.h
|
|
*/
|
|
|
|
#include "picrin.h"
|
|
#include "object.h"
|
|
#include "state.h"
|
|
|
|
/* implementated by deep binding */
|
|
|
|
static pic_value
|
|
var_call(pic_state *pic)
|
|
{
|
|
pic_value self, val;
|
|
int n;
|
|
|
|
n = pic_get_args(pic, "&|o", &self, &val);
|
|
|
|
if (n == 0) {
|
|
pic_value env, it;
|
|
|
|
pic_for_each(env, pic->dyn_env, it) {
|
|
if (pic_weak_has(pic, env, self)) {
|
|
return pic_weak_ref(pic, env, self);
|
|
}
|
|
}
|
|
PIC_UNREACHABLE(); /* logic flaw */
|
|
} else {
|
|
pic_value conv;
|
|
|
|
conv = pic_closure_ref(pic, 0);
|
|
if (! pic_false_p(pic, conv)) {
|
|
val = pic_call(pic, conv, 1, val);
|
|
}
|
|
pic_weak_set(pic, pic_car(pic, pic->dyn_env), self, val);
|
|
return pic_undef_value(pic);
|
|
}
|
|
}
|
|
|
|
pic_value
|
|
pic_make_var(pic_state *pic, pic_value init, pic_value conv)
|
|
{
|
|
pic_value var, env = pic->dyn_env;
|
|
|
|
var = pic_lambda(pic, var_call, 1, conv);
|
|
while (1) {
|
|
if (pic_nil_p(pic, pic_cdr(pic, env))) { /* top dyn env */
|
|
if (! pic_false_p(pic, conv)) {
|
|
init = pic_call(pic, conv, 1, init);
|
|
}
|
|
pic_weak_set(pic, pic_car(pic, env), var, init);
|
|
break;
|
|
}
|
|
env = pic_cdr(pic, env);
|
|
}
|
|
return var;
|
|
}
|
|
|
|
static pic_value
|
|
pic_var_make_parameter(pic_state *pic)
|
|
{
|
|
pic_value init, conv = pic_false_value(pic);
|
|
|
|
pic_get_args(pic, "o|l", &init, &conv);
|
|
|
|
return pic_make_var(pic, init, conv);
|
|
}
|
|
|
|
static pic_value
|
|
pic_var_with_dynamic_environment(pic_state *pic)
|
|
{
|
|
pic_value alist, thunk, env, it, elt, val;
|
|
|
|
pic_get_args(pic, "ol", &alist, &thunk);
|
|
|
|
env = pic_make_weak(pic);
|
|
pic_for_each(elt, alist, it) {
|
|
pic_weak_set(pic, env, pic_car(pic, elt), pic_cdr(pic, elt));
|
|
}
|
|
pic->dyn_env = pic_cons(pic, env, pic->dyn_env);
|
|
val = pic_call(pic, thunk, 0);
|
|
pic->dyn_env = pic_cdr(pic, pic->dyn_env);
|
|
return val;
|
|
}
|
|
|
|
void
|
|
pic_init_var(pic_state *pic)
|
|
{
|
|
pic_defun(pic, "make-parameter", pic_var_make_parameter);
|
|
pic_defun(pic, "with-dynamic-environment", pic_var_with_dynamic_environment);
|
|
}
|