/*
 * Copyright 2013 (c) MuleSoft, Inc.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND,
 * either express or implied. See the License for the specific
 * language governing permissions and limitations under the License.
 */
package org.xbib.raml.yagi.framework.grammar;

import java.util.HashSet;
import java.util.Set;
import java.util.function.Function;
import org.xbib.raml.yagi.framework.grammar.rule.Rule;

public class RuleTraverser {

    private final Set<Rule> visitedRules = new HashSet<>();

    public <T extends Rule> T traverse(T rule, Function<Rule, Boolean> callable) {
        visitedRules.add(rule);
        final Boolean apply = callable.apply(rule);
        if (apply != null && apply) {
            for (Rule child : rule.getChildren()) {
                if (!visitedRules.contains(child)) {
                    traverse(child, callable);
                }
            }
        }

        return rule;
    }

}
