Tools/Java/Source/Cpptasks/net/sf/antcontrib/cpptasks/parser/LetterState.java

   1 /*
   2  *
   3  * Copyright 2002-2004 The Ant-Contrib project
   4  *
   5  *  Licensed under the Apache License, Version 2.0 (the "License");
   6  *  you may not use this file except in compliance with the License.
   7  *  You may obtain a copy of the License at
   8  *
   9  *      http://www.apache.org/licenses/LICENSE-2.0
  10  *
  11  *  Unless required by applicable law or agreed to in writing, software
  12  *  distributed under the License is distributed on an "AS IS" BASIS,
  13  *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  14  *  See the License for the specific language governing permissions and
  15  *  limitations under the License.
  16  */
  17 package net.sf.antcontrib.cpptasks.parser;
  18
  19 /**
  20  * This parser state checks consumed characters against a specific character.
  21  *
  22  * @author Curt Arnold
  23  */
  24 public final class LetterState
  25     extends AbstractParserState {
  26   /**
  27    * Next state if a match is found.
  28    */
  29   private final AbstractParserState nextState;
  30
  31   /**
  32    * Next state if not match is found.
  33    */
  34   private final AbstractParserState noMatchState;
  35
  36   /**
  37    * Character to match.
  38    */
  39   private final char thisLetter;
  40
  41   /**
  42    * Constructor.
  43    *
  44    * @param parser
  45    *            parser
  46    * @param matchLetter
  47    *            letter to match
  48    * @param nextStateArg
  49    *            next state if a match on the letter
  50    * @param noMatchStateArg
  51    *            state if no match on letter
  52    */
  53   public LetterState(final AbstractParser parser,
  54                      final char matchLetter,
  55                      final AbstractParserState nextStateArg,
  56                      final AbstractParserState noMatchStateArg) {
  57     super(parser);
  58     this.thisLetter = matchLetter;
  59     this.nextState = nextStateArg;
  60     this.noMatchState = noMatchStateArg;
  61   }
  62
  63   /**
  64    * Consumes a character and returns the next state for the parser.
  65    *
  66    * @param ch
  67    *            next character
  68    * @return the configured nextState if ch is the expected character or the
  69    *         configure noMatchState otherwise.
  70    */
  71   public AbstractParserState consume(final char ch) {
  72     if (ch == thisLetter) {
  73       return nextState;
  74     }
  75     if (ch == '\n') {
  76       getParser().getNewLineState();
  77     }
  78     return noMatchState;
  79   }
  80 }