--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/langtools/src/share/classes/com/sun/source/tree/LineMap.java	Sat Dec 01 00:00:00 2007 +0000
@@ -0,0 +1,78 @@
+/*
+ * Copyright 2006 Sun Microsystems, Inc.  All Rights Reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.  Sun designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Sun in the LICENSE file that accompanied this code.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
+ * CA 95054 USA or visit www.sun.com if you need additional information or
+ * have any questions.
+ */
+
+package com.sun.source.tree;
+
+/**
+ * Provides methods to convert between character positions and line numbers
+ * for a compilation unit.
+ *
+ * @since 1.6
+ */
+public interface LineMap {
+    /**
+     * Find the start position of a line.
+     *
+     * @param line line number (beginning at 1)
+     * @return     position of first character in line
+     * @throws  IndexOutOfBoundsException
+     *           if <tt>lineNumber < 1</tt>
+     *           if <tt>lineNumber > no. of lines</tt>
+     */
+    long getStartPosition(long line);
+
+    /**
+     * Find the position corresponding to a (line,column).
+     *
+     * @param   line    line number (beginning at 1)
+     * @param   column  tab-expanded column number (beginning 1)
+     *
+     * @return  position of character
+     * @throws  IndexOutOfBoundsException
+     *           if {@code line < 1}
+     *           if {@code line > no. of lines}
+     */
+    long getPosition(long line, long column);
+
+    /**
+     * Find the line containing a position; a line termination
+     * character is on the line it terminates.
+     *
+     * @param   pos  character offset of the position
+     * @return the line number of pos (first line is 1)
+     */
+    long getLineNumber(long pos);
+
+    /**
+     * Find the column for a character position.
+     * Tab characters preceding the position on the same line
+     * will be expanded when calculating the column number.
+     *
+     * @param  pos   character offset of the position
+     * @return       the tab-expanded column number of pos (first column is 1)
+     */
+    long getColumnNumber(long pos);
+
+}