--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/fschmidt/util/java/ArrayUtils.java	Sun Oct 05 17:24:15 2025 -0600
@@ -0,0 +1,52 @@
+/*
+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.java;
+
+
+public final class ArrayUtils {
+	private ArrayUtils() {}  // never
+
+	public static void swap( Object[] a, int i, int j ) {
+		Object t = a[i];
+		a[i] = a[j];
+		a[j] = t;
+	}
+
+	public static void reverse( Object[] a ) {
+		for( int i=0, j=a.length-1; i<j; i++, j-- ) {
+			swap(a,i,j);
+		}
+	}
+
+	public static String unique(String[] a) {
+		return (String)unique((Object[])a);
+	}
+
+	public static Object unique(Object[] a) {
+		if( a==null )
+			return null;
+		if( a.length > 1 )
+			throw new IllegalArgumentException("array not unique");
+		return a.length==0 ? null : a[0];
+	}
+}