/*
* Copyright (C) 2009 Mathias Doenitz
*
* 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.parboiled.matchers;
import org.jetbrains.annotations.NotNull;
import org.parboiled.MatcherContext;
import org.parboiled.Rule;
import org.parboiled.errors.GrammarException;
import org.parboiled.matchervisitors.MatcherVisitor;
/**
* A {@link Matcher} that repeatedly tries its submatcher against the input. Always succeeds.
*/
public class ZeroOrMoreMatcher extends AbstractMatcher {
public final Matcher subMatcher;
public ZeroOrMoreMatcher(@NotNull Rule subRule) {
super(subRule);
this.subMatcher = getChildren().get(0);
}
public boolean match(@NotNull MatcherContext context) {
int lastIndex = context.getCurrentIndex();
while (subMatcher.getSubContext(context).runMatcher()) {
int currentLocation = context.getCurrentIndex();
if (currentLocation == lastIndex) {
throw new GrammarException("The inner rule of ZeroOrMore rule '%s' must not allow empty matches",
context.getPath());
}
lastIndex = currentLocation;
}
context.createNode();
return true;
}
public <R> R accept(@NotNull MatcherVisitor<R> visitor) {
return visitor.visit(this);
}
}