001/*
002 * Sonar, open source software quality management tool.
003 * Copyright (C) 2008-2012 SonarSource
004 * mailto:contact AT sonarsource DOT com
005 *
006 * Sonar is free software; you can redistribute it and/or
007 * modify it under the terms of the GNU Lesser General Public
008 * License as published by the Free Software Foundation; either
009 * version 3 of the License, or (at your option) any later version.
010 *
011 * Sonar is distributed in the hope that it will be useful,
012 * but WITHOUT ANY WARRANTY; without even the implied warranty of
013 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
014 * Lesser General Public License for more details.
015 *
016 * You should have received a copy of the GNU Lesser General Public
017 * License along with Sonar; if not, write to the Free Software
018 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02
019 */
020package org.sonar.duplications.statement;
021
022import java.util.ArrayList;
023import java.util.List;
024
025import org.sonar.duplications.statement.matcher.TokenMatcher;
026import org.sonar.duplications.token.Token;
027import org.sonar.duplications.token.TokenQueue;
028
029public final class StatementChannel {
030
031  private final TokenMatcher[] tokenMatchers;
032  private final boolean blackHole;
033
034  public static StatementChannel create(TokenMatcher... tokenMatchers) {
035    return new StatementChannel(false, tokenMatchers);
036  }
037
038  public static StatementChannel createBlackHole(TokenMatcher... tokenMatchers) {
039    return new StatementChannel(true, tokenMatchers);
040  }
041
042  private StatementChannel(boolean blackHole, TokenMatcher... tokenMatchers) {
043    if (tokenMatchers == null || tokenMatchers.length == 0) {
044      throw new IllegalArgumentException();
045    }
046    this.blackHole = blackHole;
047    this.tokenMatchers = tokenMatchers;
048  }
049
050  public boolean consume(TokenQueue tokenQueue, List<Statement> output) {
051    List<Token> matchedTokenList = new ArrayList<Token>();
052    for (TokenMatcher tokenMatcher : tokenMatchers) {
053      if (!tokenMatcher.matchToken(tokenQueue, matchedTokenList)) {
054        tokenQueue.pushForward(matchedTokenList);
055        return false;
056      }
057    }
058
059    // all matchers were successful, so now build the statement
060    // matchedTokenList.size() check is for case with ForgiveLastTokenMatcher
061    if (!blackHole && !matchedTokenList.isEmpty()) {
062      output.add(new Statement(matchedTokenList));
063    }
064    return true;
065  }
066
067}