void sooty::lexing::detail::fold_impl(std::set<base_lexer_ptr> visited_nodes, const base_lexer_ptr& lhs, const base_lexer_ptr& rhs)
{
if (!lhs || !rhs)
return;
if (visited_nodes.find(lhs) != visited_nodes.end())
return;
visited_nodes.insert(lhs);
if (lhs->type == base_lexer::lexer_type::marker) {
fold_impl(visited_nodes, lhs->on_success, rhs);
}
else if (rhs->type == base_lexer::lexer_type::marker) {
base_lexer_ptr saved_lhs = clone_tree(lhs);
*lhs = *rhs;
fold_impl(visited_nodes, lhs->on_success, saved_lhs);
}
// if lhs is partially equivalent to rhs, then we need to try rhs
// if it fails, but try the one /after/ rhs if it succeeds
else if ( partially_equivalent(lhs, rhs) )
{
if (lhs->on_failure)
append_failure(lhs->on_failure, rhs);
else
lhs->on_failure = rhs;
if (lhs->on_success)
fold_impl(visited_nodes, lhs->on_success, rhs->on_success);
else
lhs->on_success = rhs->on_success;
}
// rhs is partially equivalent to lhs, which means that we have to
// test rhs first, *then* lhs.
else if ( partially_equivalent(rhs, lhs) )
{
base_lexer_ptr lhs_copy = clone_tree(lhs);
*lhs = *rhs;
visited_nodes.erase(lhs);
fold_impl(visited_nodes, lhs, lhs_copy);
}
else if ( equivalent(lhs, rhs) )
{
if (lhs->on_success)
fold_impl(visited_nodes, lhs->on_success, rhs->on_success);
else {
lhs->on_success = rhs->on_success;
if (lhs->on_failure) {
append_failure(lhs->on_success, lhs->on_failure);
lhs->on_failure = base_lexer_ptr();
}
}
}
else {
if (lhs->on_failure)
fold_impl(visited_nodes, lhs->on_failure, rhs);
else
lhs->on_failure = rhs;
}
}
parse_node_t *clone_tree( parse_node_t *tokens ){
parse_node_t *ret = NULL;
if ( tokens ){
ret = malloc( sizeof( *tokens ));
*ret = *tokens;
ret->down = clone_tree( ret->down );
ret->next = clone_tree( ret->next );
if ( ret->data )
ret->data = strdup( ret->data );
}
return ret;
}
lexer operator [](semantic_action action) const {
static char _ = 0;
detail::base_lexer_ptr marker(new detail::base_lexer(detail::base_lexer::lexer_type::marker, _, _));
detail::base_lexer_ptr actor(new detail::base_lexer(detail::base_lexer::lexer_type::actor, _, _));
actor->action = action;
++_;
append_success(marker, clone_tree(this->base_lexer));
append_success(marker, actor);
return lexer(marker);
}
lexer operator * () const {
detail::base_lexer_ptr new_lhs = clone_tree(this->base_lexer);
detail::zero_or_more(new_lhs);
return lexer(new_lhs);
}
