01: /*
02: Copyright (c) 2003, Dennis M. Sosnoski
03: All rights reserved.
04:
05: Redistribution and use in source and binary forms, with or without modification,
06: are permitted provided that the following conditions are met:
07:
08: * Redistributions of source code must retain the above copyright notice, this
09: list of conditions and the following disclaimer.
10: * Redistributions in binary form must reproduce the above copyright notice,
11: this list of conditions and the following disclaimer in the documentation
12: and/or other materials provided with the distribution.
13: * Neither the name of JargP nor the names of its contributors may be used
14: to endorse or promote products derived from this software without specific
15: prior written permission.
16:
17: THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
18: ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
19: WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
20: DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
21: ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
22: (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
23: LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
24: ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25: (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
26: SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27: */
28:
29: package org.jargp;
30:
31: /**
32: * Character tracker for processing text. This is effectively a specialized
33: * iterator for processing characters in a string one at a time.
34: *
35: * @author Dennis M. Sosnoski
36: * @version 1.0
37: */
38:
39: public class CharTracker {
40: /** String supplying character data. */
41: private final String m_source;
42:
43: /** Current position within string. */
44: private int m_position;
45:
46: /**
47: * Constructor
48: *
49: * @param source string supplying character data
50: * @param offset initial character position within source string
51: */
52:
53: public CharTracker(String source, int offset) {
54: m_source = source;
55: m_position = offset;
56: }
57:
58: /**
59: * Get next character from string, advancing past that character.
60: *
61: * @return next character from string
62: * @exception ArrayIndexOutOfBoundsException if past end of text
63: */
64:
65: public char next() {
66: if (m_position < m_source.length()) {
67: return m_source.charAt(m_position++);
68: } else {
69: throw new ArrayIndexOutOfBoundsException(m_position);
70: }
71: }
72:
73: /**
74: * Peek next character from string. Gets the next character without
75: * advancing the current character position.
76: *
77: * @return next character from string
78: * @exception ArrayIndexOutOfBoundsException if past end of text
79: */
80:
81: public char peek() {
82: if (m_position < m_source.length()) {
83: return m_source.charAt(m_position);
84: } else {
85: throw new ArrayIndexOutOfBoundsException(m_position);
86: }
87: }
88:
89: /**
90: * Check if another character is available.
91: *
92: * @return <code>true</code> if a character is available,
93: * <code>false</code> if at end
94: */
95:
96: public boolean hasNext() {
97: return m_position < m_source.length();
98: }
99: }
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