bool filter_fold(sfilter * sf, stoken_t * sout)
{
stoken_t *last = &sf->fold_last;
stoken_t *current = &sf->fold_current;
//printf("state = %d\n", sf->fold_state);
if (sf->fold_state == 4 && !st_is_empty(last)) {
//printf("LINE = %d\n", __LINE__);
st_copy(sout, last);
//printf("%d emit = %c, %s\n", __LINE__, sout->type, sout->val);
sf->fold_state = 2;
st_clear(last);
return true;
}
while (filter_syntax(sf, current)) {
//printf("state = %d\n", sf->fold_state);
//printf("current = %c, %s\n", current->type, current->val);
if (sf->fold_state == 0) {
if (current->type == '(') {
continue;
}
if (st_is_unary_op(current)) {
continue;
}
sf->fold_state = 1;
}
if (st_is_empty(last)) {
//printf("LINE = %d\n", __LINE__);
if (current->type == '1') {
//printf("LINE = %d\n", __LINE__);
sf->fold_state = 2;
st_copy(last, current);
}
//printf("LINE = %d\n", __LINE__);
st_copy(sout, current);
//printf("emit = %c, %s\n", sout->type, sout->val);
return true;
} else if (last->type == '1' && st_is_arith_op(current)) {
//printf("LINE = %d\n", __LINE__);
st_copy(last, current);
//sf->fold_state = 1;
} else if (last->type == 'o' && current->type == '1') {
//printf("LINE = %d\n", __LINE__);
//continue;
st_copy(last, current);
} else {
//printf("LINE = %d\n", __LINE__);
if (sf->fold_state == 2) {
if (last->type != '1') {
st_copy(sout, last);
st_copy(last, current);
// printf("%d emit = %c, %s\n", __LINE__, sout->type, sout->val);
sf->fold_state = 4;
} else {
st_copy(sout, current);
st_clear(last);
}
return true;
} else {
//printf("LINE = %d\n", __LINE__);
if (last->type == 'o') {
//printf("STATE = %d, LINE = %d\n", sf->fold_state, __LINE__);
st_copy(sout, last);
st_copy(last, current);
sf->fold_state = 4;
} else {
//printf("LINE = %d\n", __LINE__);
sf->fold_state = 2;
st_copy(sout, current);
st_clear(last);
}
//printf("emit = %c, %s\n", sout->type, sout->val);
return true;
}
}
}
if (!st_is_empty(last)) {
if (st_is_arith_op(last)) {
//printf("\nstate = %d, emit = %c, %s\n", sf->fold_state, last->type, last->val);
st_copy(sout, last);
st_clear(last);
return true;
} else {
st_clear(last);
}
}
return false;
}
static uint _rt_test(struct _rt_stack* sp)
{
return ((sp->type != STACK_NULL) || (sp->type == STACK_NUM && sp->num != 0) ||
((sp->type == STACK_PTR || sp->type == STACK_RO_PTR) && (st_is_empty(&sp->single_ptr) == 0)));
}
