view src/tests/gov/nasa/jpf/util/PermutationGeneratorTest.java @ 4:d0a0ff1c0e10

added some infrastructure to pull-generate permutations (total, random and pair-wise so far). The generators produce index arrays, i.e. permutations of [0..N-1], which can be used to permute processing order of any indexable data structure, for instance in CGs. This also includes a bare-bones PermutationCG that takes the desired PermutationGenerator as input. Due to the N! nature of the beast, beware of TotalPermutations in such CGs, even if most permutations are handled by state matching.
author Peter Mehlitz <pcmehlitz@gmail.com>
date Thu, 05 Feb 2015 18:53:33 -0800
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children 3a19eedcc13d
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/*
 * Copyright (C) 2015, United States Government, as represented by the
 * Administrator of the National Aeronautics and Space Administration.
 * All rights reserved.
 *
 * The Java Pathfinder core (jpf-core) platform is licensed under the
 * Apache License, Version 2.0 (the "License"); you may not use this file except
 * in compliance with the License. You may obtain a copy of the License at
 * 
 *        http://www.apache.org/licenses/LICENSE-2.0. 
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and 
 * limitations under the License.
 */
package gov.nasa.jpf.util;

import gov.nasa.jpf.util.test.TestJPF;
import org.junit.Test;

/**
 * regression test for PermutationGenerator
 */
public class PermutationGeneratorTest extends TestJPF {
  
  @Test
  public void testTotalPermutation(){
    PermutationGenerator pg = new TotalPermutationGenerator(4);
    long nPerm = pg.getNumberOfPermutations();
    assertTrue( nPerm == 24);
    
    while (pg.hasNext()){
      int[] perms = pg.next();
      assertTrue(perms != null);
      pg.printOn(System.out);
    }
  }
  
  @Test
  public void testPairPermutation(){
    PermutationGenerator pg = new PairPermutationGenerator(4);
    long nPerm = pg.getNumberOfPermutations();
    assertTrue( nPerm == 7);
    
    while (pg.hasNext()){
      int[] perms = pg.next();
      assertTrue(perms != null);
      pg.printOn(System.out);
    }
  }

  @Test
  public void testRandomPermutation(){
    int nPermutations = 14;
    PermutationGenerator pg = new RandomPermutationGenerator(4, nPermutations, 42);
    long nPerm = pg.getNumberOfPermutations();
    assertTrue( nPerm == nPermutations);
    
    while (pg.hasNext()){
      int[] perms = pg.next();
      assertTrue(perms != null);
      pg.printOn(System.out);
    }    
  }
}