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 org.codehaus.mojo.natives.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 /**
28 * Next state if a match is found.
29 */
30 private final AbstractParserState nextState;
31
32 /**
33 * Next state if not match is found.
34 */
35 private final AbstractParserState noMatchState;
36
37 /**
38 * Character to match.
39 */
40 private final char thisLetter;
41
42 /**
43 * Constructor.
44 *
45 * @param parser parser
46 * @param matchLetter letter to match
47 * @param nextStateArg next state if a match on the letter
48 * @param noMatchStateArg state if no match on letter
49 */
50 public LetterState( final AbstractParser parser, final char matchLetter, final AbstractParserState nextStateArg,
51 final AbstractParserState noMatchStateArg )
52 {
53 super( parser );
54 this.thisLetter = matchLetter;
55 this.nextState = nextStateArg;
56 this.noMatchState = noMatchStateArg;
57 }
58
59 /**
60 * Consumes a character and returns the next state for the parser.
61 *
62 * @param ch next character
63 * @return the configured nextState if ch is the expected character or the configure noMatchState otherwise.
64 */
65 public AbstractParserState consume( final char ch )
66 {
67 if ( ch == thisLetter )
68 {
69 return nextState;
70 }
71 if ( ch == '\n' )
72 {
73 getParser().getNewLineState();
74 }
75 return noMatchState;
76 }
77 }