LineMap.java revision 3193:3b3bea483542 
1/*
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3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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5 * This code is free software; you can redistribute it and/or modify it
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7 * published by the Free Software Foundation.  Oracle designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Oracle in the LICENSE file that accompanied this code.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
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19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
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24 */
25
26package com.sun.source.tree;
27
28/**
29 * Provides methods to convert between character positions and line numbers
30 * for a compilation unit.
31 *
32 * @since 1.6
33 */
34public interface LineMap {
35    /**
36     * Finds the start position of a line.
37     *
38     * @param line line number (beginning at 1)
39     * @return     position of first character in line
40     * @throws  IndexOutOfBoundsException
41     *           if {@code lineNumber < 1}
42     *           if {@code lineNumber > no. of lines}
43     */
44    long getStartPosition(long line);
45
46    /**
47     * Finds the position corresponding to a (line,column).
48     *
49     * @param   line    line number (beginning at 1)
50     * @param   column  tab-expanded column number (beginning 1)
51     *
52     * @return  position of character
53     * @throws  IndexOutOfBoundsException
54     *           if {@code line < 1}
55     *           if {@code line > no. of lines}
56     */
57    long getPosition(long line, long column);
58
59    /**
60     * Finds the line containing a position; a line termination
61     * character is on the line it terminates.
62     *
63     * @param   pos  character offset of the position
64     * @return the line number of pos (first line is 1)
65     */
66    long getLineNumber(long pos);
67
68    /**
69     * Finds the column for a character position.
70     * Tab characters preceding the position on the same line
71     * will be expanded when calculating the column number.
72     *
73     * @param  pos   character offset of the position
74     * @return       the tab-expanded column number of pos (first column is 1)
75     */
76    long getColumnNumber(long pos);
77
78}
79