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diff --git a/bundles/org.eclipse.compare/compare/org/eclipse/compare/contentmergeviewer/ITokenComparator.java b/bundles/org.eclipse.compare/compare/org/eclipse/compare/contentmergeviewer/ITokenComparator.java
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+++ b/bundles/org.eclipse.compare/compare/org/eclipse/compare/contentmergeviewer/ITokenComparator.java
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+/*
+ * Licensed Materials - Property of IBM,
+ * WebSphere Studio Workbench
+ * (c) Copyright IBM Corp 2000, 2001
+ */
+package org.eclipse.compare.contentmergeviewer;
+
+import org.eclipse.compare.rangedifferencer.IRangeComparator;
+
+
+/**
+ * For performing a so-called "token compare" on a line of text.
+ * This interface extends the <code>IRangeComparator</code> interface
+ * so that it can be used by the <code>TextMergeViewer</code>.
+ * <p>
+ * <code>TextMergeViewer</code> activates the token compare when navigating into
+ * a range of differing lines. At first the lines are selected as a block.
+ * When navigating into this block the token compare shows for every line 
+ * the differing token by selecting them.
+ * <p>
+ * <code>TextMergeViewer</code>'s default token comparator works on characters separated
+ * by whitespace. If a different strategy is needed (for example, to use Java tokens in
+ * a Java-aware merge viewer), clients may create their own token
+ * comparators by implementing this interface (and overriding the
+ * <code>TextMergeViewer.createTokenComparator</code> factory method).
+ * </p>
+ *
+ * @see TextMergeViewer
+ */
+public interface ITokenComparator extends IRangeComparator {
+
+	/**
+	 * Returns the start character position of the token with the given index.
+	 * If the index is out of range (but not negative) the character position
+	 * behind the last character (the length of the input string) is returned.
+	 *
+	 * @param index index of the token for which to return the start position
+	 * @return the start position of the token with the given index
+	 * @throws java.lang.IndexOutOfBoundsException if index is negative
+	 */
+	int getTokenStart(int index);
+
+	/**
+	 * Returns the character length of the token with the given index.
+	 * If the index is out of range (but not negative) the value 0 is returned.
+	 *
+	 * @param index index of the token for which to return the start position
+	 * @return the character length of the token with the given index
+	 * @throws java.lang.IndexOutOfBoundsException if index is negative
+	 */
+	int getTokenLength(int index);
+}