/* tree inserter
* inserts element into the tree
* if replace set to true - substitues previous element with
* the same key value. Otherwise - appends new element.
*
* returns 0 in case of success, non-zero value otherwise.
* */
int _node_insert(Tree* t, Node** r, void* element, int replace) {
Node* n = *r;
if ( ! n ) {
n = *r = (Node*)malloc(sizeof(Node));
if (! n ) return -2;
n->data = t->cl(element);
n->left = NULL;
n->right = NULL;
return 0;
}
/* node exists */
if ( t->lf(element, n->data) ) {
return _node_insert(t, &n->left, element, replace);
} else if ( t->lf(n->data, element) || !replace ) {
return _node_insert(t, &n->right, element, replace);
} else {
t->dt(n->data);
n->data = t->cl(element);
return 0;
}
}
/*
nfa state map:
rule a?
|------------------ε-------------------|
| ∨
<start> --ε--> <s1> --a--> <s2> --ε--> <end>
*/
static size_t _gen_op_rpq(struct reg_pattern* pattern, struct reg_ast_node* root, size_t start_state_pos){
size_t s1_pos = _node_new(pattern);
_node_insert(pattern, start_state_pos, NULL, s1_pos);
size_t s2_pos = _gen_op(pattern, root->childs[0], s1_pos);
size_t end_pos = _node_new(pattern);
_node_insert(pattern, start_state_pos, NULL, end_pos);
_node_insert(pattern, s2_pos, NULL, end_pos);
return end_pos;
}
/*
nfa state map:
rule: ab
--ε-->
<start> --a--> <s1> --ε--> <s2> --b--> <end>
*/
static size_t _gen_op_and(struct reg_pattern* pattern, struct reg_ast_node* root, size_t start_state_pos){
assert(root->op == op_and);
size_t s1_pos = _gen_op(pattern, root->childs[0], start_state_pos);
size_t s2_pos = _node_new(pattern);
_node_insert(pattern, s1_pos, NULL, s2_pos);
size_t end = _gen_op(pattern, root->childs[1], s2_pos);
return end;
}
/*
nfa state map:
rule: [a-b]
<start> --[a-b]--> <end>
*/
static size_t _gen_op_range(struct reg_pattern* pattern, struct reg_ast_node* root, size_t start_state_pos){
assert(root->op == op_range);
struct reg_range* range = &(root->value.range);
size_t end_pos = _node_new(pattern);
int is_insert = 0;
is_insert = _node_insert(pattern, start_state_pos, range, end_pos);
assert(is_insert);
return end_pos;
}
int tree_insert(Tree* t, void* element, int replace) {
return _node_insert(t, &t->root, element, replace);
}
