SourcePositions.java revision 3193:3b3bea483542 
1/*
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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.
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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).
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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.util;
27
28import com.sun.source.tree.*;
29
30/**
31 * Provides methods to obtain the position of a Tree within a CompilationUnit.
32 * A position is defined as a simple character offset from the start of a
33 * CompilationUnit where the first character is at offset 0.
34 *
35 * @author Peter von der Ahé
36 * @since 1.6
37 */
38public interface SourcePositions {
39
40    /**
41     * Returns the starting position of tree within file.  If tree is not found within
42     * file, or if the starting position is not available,
43     * return {@link javax.tools.Diagnostic#NOPOS}.
44     * The returned position must be at the start of the yield of this tree, that
45     * is for any sub-tree of this tree, the following must hold:
46     *
47     * <p>
48     * {@code tree.getStartPosition() <= subtree.getStartPosition()} or <br>
49     * {@code tree.getStartPosition() == NOPOS} or <br>
50     * {@code subtree.getStartPosition() == NOPOS}
51     * </p>
52     *
53     * @param file CompilationUnit in which to find tree.
54     * @param tree tree for which a position is sought.
55     * @return the start position of tree.
56     */
57     long getStartPosition(CompilationUnitTree file, Tree tree);
58
59    /**
60     * Returns the ending position of tree within file.  If tree is not found within
61     * file, or if the ending position is not available,
62     * return {@link javax.tools.Diagnostic#NOPOS}.
63     * The returned position must be at the end of the yield of this tree,
64     * that is for any sub-tree of this tree, the following must hold:
65     *
66     * <p>
67     * {@code tree.getEndPosition() >= subtree.getEndPosition()} or <br>
68     * {@code tree.getEndPosition() == NOPOS} or <br>
69     * {@code subtree.getEndPosition() == NOPOS}
70     * </p>
71     *
72     * In addition, the following must hold:
73     *
74     * <p>
75     * {@code tree.getStartPosition() <= tree.getEndPosition()}  or <br>
76     * {@code tree.getStartPosition() == NOPOS} or <br>
77     * {@code tree.getEndPosition() == NOPOS}
78     * </p>
79     *
80     * @param file CompilationUnit in which to find tree.
81     * @param tree tree for which a position is sought.
82     * @return the end position of tree.
83     */
84     long getEndPosition(CompilationUnitTree file, Tree tree);
85
86}
87