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     */
020    package org.sonar.duplications.statement;
021    
022    import java.util.ArrayList;
023    import java.util.List;
024    
025    import org.sonar.duplications.statement.matcher.TokenMatcher;
026    import org.sonar.duplications.token.Token;
027    import org.sonar.duplications.token.TokenQueue;
028    
029    public 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    }