Tools/Java/Source/Cpptasks/net/sf/antcontrib/cpptasks/parser/WhitespaceOrLetterState.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 or
  21  * whitespace.
  22  *
  23  * @author Curt Arnold
  24  */
  25 public final class WhitespaceOrLetterState
  26     extends AbstractParserState {
  27   /**
  28    * Next state if the character is found.
  29    */
  30   private final AbstractParserState nextState;
  31
  32   /**
  33    * Character to match.
  34    */
  35   private final char thisLetter;
  36
  37   /**
  38    * Constructor.
  39    *
  40    * @param parser
  41    *            parser
  42    * @param matchLetter
  43    *            letter to match
  44    * @param nextStateArg
  45    *            next state if a match on the letter
  46    */
  47   public WhitespaceOrLetterState(final AbstractParser parser,
  48                                  final char matchLetter,
  49                                  final AbstractParserState nextStateArg) {
  50     super(parser);
  51     this.thisLetter = matchLetter;
  52     this.nextState = nextStateArg;
  53   }
  54
  55   /**
  56    * Consumes a character and returns the next state for the parser.
  57    *
  58    * @param ch
  59    *            next character @returns the configured nextState if ch is the
  60    *            expected character or the configure noMatchState otherwise.
  61    * @return next state
  62    */
  63   public AbstractParserState consume(final char ch) {
  64     if (ch == thisLetter) {
  65       return nextState;
  66     }
  67     if (ch == ' ' || ch == '\t') {
  68       return this;
  69     }
  70     if (ch == '\n') {
  71       getParser().getNewLineState();
  72     }
  73     return null;
  74   }
  75 }