112 lines
2.3 KiB
C
112 lines
2.3 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/private/object.h"
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KHASH_DEFINE(weak, struct object *, pic_value, kh_ptr_hash_func, kh_ptr_hash_equal)
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pic_value
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pic_make_weak(pic_state *pic)
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{
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struct weak *weak;
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weak = (struct weak *)pic_obj_alloc(pic, sizeof(struct weak), PIC_TYPE_WEAK);
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weak->prev = NULL;
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kh_init(weak, &weak->hash);
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return pic_obj_value(weak);
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}
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pic_value
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pic_weak_ref(pic_state *pic, pic_value weak, pic_value key)
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{
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khash_t(weak) *h = &pic_weak_ptr(pic, weak)->hash;
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int it;
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it = kh_get(weak, h, pic_obj_ptr(key));
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if (it == kh_end(h)) {
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pic_errorf(pic, "element not found for a key: ~s", key);
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}
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return kh_val(h, it);
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}
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void
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pic_weak_set(pic_state *pic, pic_value weak, pic_value key, pic_value val)
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{
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khash_t(weak) *h = &pic_weak_ptr(pic, weak)->hash;
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int ret;
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int it;
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it = kh_put(weak, h, pic_obj_ptr(key), &ret);
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kh_val(h, it) = val;
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}
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bool
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pic_weak_has(pic_state *pic, pic_value weak, pic_value key)
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{
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khash_t(weak) *h = &pic_weak_ptr(pic, weak)->hash;
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return kh_get(weak, h, pic_obj_ptr(key)) != kh_end(h);
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}
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void
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pic_weak_del(pic_state *pic, pic_value weak, pic_value key)
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{
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khash_t(weak) *h = &pic_weak_ptr(pic, weak)->hash;
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int it;
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it = kh_get(weak, h, pic_obj_ptr(key));
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if (it == kh_end(h)) {
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pic_errorf(pic, "no slot named ~s found in ephemeron", key);
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}
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kh_del(weak, h, it);
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}
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static pic_value
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weak_call(pic_state *pic)
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{
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pic_value key, val, weak;
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int n;
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n = pic_get_args(pic, "o|o", &key, &val);
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if (! pic_obj_p(pic, key)) {
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pic_errorf(pic, "attempted to set a non-object key '~s' in an ephemeron", key);
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}
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weak = pic_closure_ref(pic, 0);
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if (n == 1) {
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if (! pic_weak_has(pic, weak, key)) {
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return pic_false_value(pic);
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}
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return pic_cons(pic, key, pic_weak_ref(pic, weak, key));
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} else {
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if (pic_undef_p(pic, val)) {
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if (pic_weak_has(pic, weak, key)) {
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pic_weak_del(pic, weak, key);
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}
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} else {
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pic_weak_set(pic, weak, key, val);
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}
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return pic_undef_value(pic);
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}
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}
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static pic_value
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pic_weak_make_ephemeron(pic_state *pic)
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{
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pic_get_args(pic, "");
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return pic_lambda(pic, weak_call, 1, pic_make_weak(pic));
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}
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void
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pic_init_weak(pic_state *pic)
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{
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pic_defun(pic, "make-ephemeron", pic_weak_make_ephemeron);
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}
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