tree-sitter/src/compiler/build_tables/item_set_closure.cpp
2014-02-12 08:21:59 -08:00

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1.2 KiB
C++

#include "item_set_closure.h"
#include "./follow_sets.h"
#include "grammar.h"
#include "item.h"
namespace tree_sitter {
namespace build_tables {
static bool contains(ParseItemSet items, ParseItem item) {
return (std::find(items.begin(), items.end(), item) != items.end());
}
static void add_item(ParseItemSet &item_set, const ParseItem &item, const Grammar &grammar) {
if (!contains(item_set, item)) {
item_set.insert(item);
for (auto pair : follow_sets(item, grammar)) {
auto non_terminal = pair.first;
auto terminals = pair.second;
for (rules::Symbol terminal : terminals) {
auto next_item = ParseItem(non_terminal, grammar.rule(non_terminal), {}, terminal);
add_item(item_set, next_item, grammar);
}
}
}
}
const ParseItemSet item_set_closure(const ParseItemSet &item_set, const Grammar &grammar) {
ParseItemSet result;
for (ParseItem item : item_set)
add_item(result, item, grammar);
return result;
}
}
}