Added Copyable interface

Author: cicirello

lib/jpt2.jar

@@ -30,18 +30,18 @@
 import java.math.BigInteger;
 
 import org.cicirello.math.rand.RandomIndexer;
+import org.cicirello.util.Copyable;
 
 /**
  * Representation of a permutation of the integers from 0 to N-1, inclusive.
  * This class provides the functionality to generate random permutations, and to
  * manipulate permutations in a variety of ways.
  * 
  * @author <a href=https://www.cicirello.org/ target=_top>Vincent A. Cicirello</a>, <a href=https://www.cicirello.org/ target=_top>https://www.cicirello.org/</a> 
- * @version 7.26.2019
+ * @version 9.23.2019
  * @since 1.0
  */
-public final class Permutation implements Serializable, Iterable<Permutation>
-{
+public final class Permutation implements Serializable, Iterable<Permutation>, Copyable {
 
 	private static final long serialVersionUID = 1L;
 
@@ -207,6 +207,11 @@ public Permutation(Permutation p, int length) {
 		}
 	}
 
+	@Override
+	public Permutation copy() {
+		return new Permutation(this);
+	}
+	
 
 	/**
 	* Generates a unique integer representing the permutation.  Maps the permutations of the integers, 0..(N-1), to 

src/org/cicirello/permutations/Permutation.java

@@ -0,0 +1,41 @@
+/*
+ * Copyright 2019 Vincent A. Cicirello, <https://www.cicirello.org/>.
+ *
+ * This file is part of JavaPermutationTools (https://jpt.cicirello.org/).
+ *
+ * JavaPermutationTools is free software: you can 
+ * redistribute it and/or modify it under the terms of the GNU 
+ * General Public License as published by the Free Software 
+ * Foundation, either version 3 of the License, or (at your 
+ * option) any later version.
+ *
+ * JavaPermutationTools 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 for more 
+ * details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with JavaPermutationTools.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+ 
+package org.cicirello.util;
+
+/**
+ * A simple interface for objects that can be copied.
+ *
+ * @since 2.0
+ *
+ * @author <a href=https://www.cicirello.org/ target=_top>Vincent A. Cicirello</a>, 
+ * <a href=https://www.cicirello.org/ target=_top>https://www.cicirello.org/</a>
+ * @version 9.23.2019
+ */
+public interface Copyable {
+	
+	/**
+	 * Creates an identical copy of this object.
+	 * @return an identical copy of this object.
+	 */
+	Copyable copy();
+}

src/org/cicirello/util/Copyable.java

@@ -0,0 +1,28 @@
+/*
+ * Copyright 2019 Vincent A. Cicirello, <https://www.cicirello.org/>.
+ *
+ * This file is part of JavaPermutationTools (https://jpt.cicirello.org/).
+ *
+ * JavaPermutationTools is free software: you can 
+ * redistribute it and/or modify it under the terms of the GNU 
+ * General Public License as published by the Free Software 
+ * Foundation, either version 3 of the License, or (at your 
+ * option) any later version.
+ *
+ * JavaPermutationTools 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 for more 
+ * details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with JavaPermutationTools.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+ 
+ /**
+ * This package includes classes and interfaces that serve some useful utility purpose. 
+ * @version 9.23.2019
+ * @since 2.0
+ */
+package org.cicirello.util;

src/org/cicirello/util/package-info.java

@@ -240,6 +240,18 @@ public void testPermutationCopyConstructor() {
 		}
 	}
 
+	@Test
+	public void testPermutationCopyMethod() {
+		for (int n = 1; n <= 10; n++) {
+			for (int i = 0; i < 10; i++) {
+				Permutation p = new Permutation(n);
+				Permutation copy = p.copy();
+				assertEquals("copy should create an identical copy", p, copy);
+				assertTrue("copy should be a new object", p != copy);
+			}
+		}
+	}
+	
 	@Test
 	public void testPermutationConstructorCopyPartial() {
 		for (int n = 1; n <= 10; n++) {