tree-sitter/src/compiler/rules/metadata.cc

#include "compiler/rules/metadata.h"
#include <string>
#include <map>
#include "compiler/rules/visitor.h"

namespace tree_sitter  {
    using std::hash;
    using std::make_shared;
    using std::map;

    namespace rules {
        Metadata::Metadata(rule_ptr rule, map<MetadataKey, int> values) : rule(rule), value(values) {}

        bool Metadata::operator==(const Rule &rule) const {
            auto other = dynamic_cast<const Metadata *>(&rule);
            return other && other->value == value && other->rule->operator==(*this->rule);
        }

        size_t Metadata::hash_code() const {
            size_t result = hash<size_t>()(value.size());
            for (auto &pair : value) {
                result ^= hash<int>()(pair.first);
                result ^= hash<int>()(pair.second);
            }
            return result;
        }

        rule_ptr Metadata::copy() const {
            return make_shared<Metadata>(rule->copy(), value);
        }

        int Metadata::value_for(MetadataKey key) const {
            auto pair = value.find(key);
            return (pair != value.end()) ?
                pair->second :
                0;
        }

        std::string Metadata::to_string() const {
            return "#<metadata " + rule->to_string() + ">";
        }

        void Metadata::accept(Visitor *visitor) const {
            visitor->visit(this);
        }
    }
}