--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/fschmidt/util/diff/Difference.java	Sun Oct 05 17:24:15 2025 -0600
@@ -0,0 +1,160 @@
+/*
+Copyright (c) 2008  Franklin Schmidt <fschmidt@gmail.com>
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in
+all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+THE SOFTWARE.
+*/
+
+package fschmidt.util.diff;
+
+/*
+taken from http://www.incava.org/projects/java-diff/
+*/
+
+/**
+ * Represents a difference, as used in <code>Diff</code>. A difference consists
+ * of two pairs of starting and ending points, each pair representing either the
+ * "from" or the "to" collection passed to <code>Diff</code>. If an ending point
+ * is -1, then the difference was either a deletion or an addition. For example,
+ * if <code>getDeletedEnd()</code> returns -1, then the difference represents an
+ * addition.
+ */
+public class Difference
+{
+	public static final int NONE = -1;
+	
+	/**
+	 * The point at which the deletion starts.
+	 */
+	private int delStart = NONE;
+
+	/**
+	 * The point at which the deletion ends.
+	 */
+	private int delEnd = NONE;
+
+	/**
+	 * The point at which the addition starts.
+	 */
+	private int addStart = NONE;
+
+	/**
+	 * The point at which the addition ends.
+	 */
+	private int addEnd = NONE;
+
+	/**
+	 * Creates the difference for the given start and end points for the
+	 * deletion and addition.
+	 */
+	public Difference(int delStart, int delEnd, int addStart, int addEnd)
+	{
+		this.delStart = delStart;
+		this.delEnd   = delEnd;
+		this.addStart = addStart;
+		this.addEnd   = addEnd;
+	}
+
+	/**
+	 * The point at which the deletion starts, if any. A value equal to
+	 * <code>NONE</code> means this is an addition.
+	 */
+	public int getDeletedStart()
+	{
+		return delStart;
+	}
+
+	/**
+	 * The point at which the deletion ends, if any. A value equal to
+	 * <code>NONE</code> means this is an addition.
+	 */
+	public int getDeletedEnd()
+	{
+		return delEnd;
+	}
+
+	/**
+	 * The point at which the addition starts, if any. A value equal to
+	 * <code>NONE</code> means this must be an addition.
+	 */
+	public int getAddedStart()
+	{
+		return addStart;
+	}
+
+	/**
+	 * The point at which the addition ends, if any. A value equal to
+	 * <code>NONE</code> means this must be an addition.
+	 */
+	public int getAddedEnd()
+	{
+		return addEnd;
+	}
+
+	/**
+	 * Sets the point as deleted. The start and end points will be modified to
+	 * include the given line.
+	 */
+	public void setDeleted(int line)
+	{
+		delStart = Math.min(line, delStart);
+		delEnd   = Math.max(line, delEnd);
+	}
+
+	/**
+	 * Sets the point as added. The start and end points will be modified to
+	 * include the given line.
+	 */
+	public void setAdded(int line)
+	{
+		addStart = Math.min(line, addStart);
+		addEnd   = Math.max(line, addEnd);
+	}
+
+	/**
+	 * Compares this object to the other for equality. Both objects must be of
+	 * type Difference, with the same starting and ending points.
+	 */
+	public boolean equals(Object obj)
+	{
+		if (obj instanceof Difference) {
+			Difference other = (Difference)obj;
+
+			return (delStart == other.delStart && 
+					delEnd   == other.delEnd && 
+					addStart == other.addStart && 
+					addEnd   == other.addEnd);
+		}
+		else {
+			return false;
+		}
+	}
+
+	/**
+	 * Returns a string representation of this difference.
+	 */
+	public String toString()
+	{
+		StringBuffer buf = new StringBuffer();
+		buf.append("del: [" + delStart + ", " + delEnd + "]");
+		buf.append(" ");
+		buf.append("add: [" + addStart + ", " + addEnd + "]");
+		return buf.toString();
+	}
+
+}