tree-sitter/src/compiler/build_tables/item_set_closure.cpp
2014-01-12 09:13:53 -08:00

32 lines
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1.1 KiB
C++

#include "item_set_closure.h"
#include "./next_symbols.h"
#include "grammar.h"
#include "item.h"
#include <vector>
using std::vector;
namespace tree_sitter {
namespace build_tables {
static bool vector_contains(vector<Item> items, build_tables::Item item) {
return (std::find(items.begin(), items.end(), item) != items.end());
}
static void add_item(vector<Item> &vector, const Item &item, const Grammar &grammar) {
if (!vector_contains(vector, item)) {
vector.push_back(item);
for (rules::Symbol rule : next_non_terminals(item, grammar)) {
Item next_item = Item::at_beginning_of_rule(rule.name, grammar);
add_item(vector, next_item, grammar);
}
}
}
ItemSet item_set_closure(const ItemSet &item_set, const Grammar &grammar) {
vector<Item> items;
for (Item item : item_set)
add_item(items, item, grammar);
return ItemSet(items);
}
}
}