NodeWalkTest.java

/*
 * Copyright 2015 S. Webber
 *
 * 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 org.oakgp.node.walk;

import static org.junit.Assert.assertEquals;
import static org.junit.Assert.assertSame;
import static org.oakgp.TestUtils.assertNodeEquals;
import static org.oakgp.TestUtils.createVariable;
import static org.oakgp.TestUtils.integerConstant;
import static org.oakgp.TestUtils.readNode;
import static org.oakgp.function.math.IntegerUtils.INTEGER_UTILS;
import static org.oakgp.node.NodeType.isConstant;
import static org.oakgp.node.NodeType.isFunction;
import static org.oakgp.node.NodeType.isVariable;

import java.util.function.Function;
import java.util.function.Predicate;

import org.junit.Test;
import org.oakgp.node.ConstantNode;
import org.oakgp.node.FunctionNode;
import org.oakgp.node.Node;
import org.oakgp.node.VariableNode;

public class NodeWalkTest {
   @Test
   public void testReplaceAt_VariableNode() {
      final VariableNode v = createVariable(0);
      final ConstantNode c = integerConstant(Integer.MAX_VALUE);
      assertSame(v, NodeWalk.replaceAt(v, 0, t -> t));
      assertSame(c, NodeWalk.replaceAt(v, 0, t -> c));
   }

   @Test
   public void testReplaceAll_VariableNode() {
      final VariableNode v = createVariable(0);
      final ConstantNode c = integerConstant(Integer.MAX_VALUE);
      Function<Node, Node> replacement = n -> c;
      assertSame(c, NodeWalk.replaceAll(v, n -> n == v, replacement));
      assertSame(v, NodeWalk.replaceAll(v, n -> n == c, replacement));
   }

   @Test
   public void testGet_VariableNode() {
      final VariableNode v = createVariable(0);
      assertSame(v, NodeWalk.getAt(v, 0));
   }

   @Test
   public void testReplaceAt_ConstantNode() {
      ConstantNode n1 = integerConstant(9);
      ConstantNode n2 = integerConstant(5);
      assertEquals(n1, NodeWalk.replaceAt(n1, 0, t -> t));
      assertEquals(n2, NodeWalk.replaceAt(n1, 0, t -> n2));
   }

   @Test
   public void testReplaceAll_ConstantNode() {
      ConstantNode n1 = integerConstant(9);
      ConstantNode n2 = integerConstant(5);
      Function<Node, Node> replacement = n -> n2;
      assertSame(n2, NodeWalk.replaceAll(n1, n -> n == n1, replacement));
      assertSame(n1, NodeWalk.replaceAll(n1, n -> n == n2, replacement));
   }

   @Test
   public void testGet_ConstantNode() {
      ConstantNode c = integerConstant(9);
      assertSame(c, NodeWalk.getAt(c, 0));
   }

   @Test
   public void testReplaceAt_FunctionNode() {
      FunctionNode n = createFunctionNode();
      java.util.function.Function<Node, Node> replacement = t -> integerConstant(9);

      assertEquals("(+ (* 9 v1) (+ v2 1))", NodeWalk.replaceAt(n, 0, replacement).toString());
      assertEquals("(+ (* v0 9) (+ v2 1))", NodeWalk.replaceAt(n, 1, replacement).toString());
      assertEquals("(+ 9 (+ v2 1))", NodeWalk.replaceAt(n, 2, replacement).toString());
      assertEquals("(+ (* v0 v1) (+ 9 1))", NodeWalk.replaceAt(n, 3, replacement).toString());
      assertEquals("(+ (* v0 v1) (+ v2 9))", NodeWalk.replaceAt(n, 4, replacement).toString());
      assertEquals("(+ (* v0 v1) 9)", NodeWalk.replaceAt(n, 5, replacement).toString());
      assertEquals("9", NodeWalk.replaceAt(n, 6, replacement).toString());
   }

   @Test
   public void testReplaceAll_FunctionNode() {
      Node input = readNode("(- (- (* -1 v3) 0) (- 13 v1))");
      ConstantNode integerConstant = integerConstant(42);
      java.util.function.Function<Node, Node> replacement = n -> integerConstant;

      assertSame(input, NodeWalk.replaceAll(input, n -> false, replacement));
      assertSame(integerConstant, NodeWalk.replaceAll(input, n -> true, replacement));

      assertNodeEquals("(- (- (* -1 42) 0) (- 13 42))", NodeWalk.replaceAll(input, n -> isVariable(n), replacement));
      assertNodeEquals("(- (- (* 42 v3) 42) (- 42 v1))", NodeWalk.replaceAll(input, n -> isConstant(n), replacement));

      Predicate<Node> criteria = n -> isFunction(n) && ((FunctionNode) n).getFunction() == INTEGER_UTILS.getSubtract();
      assertNodeEquals("(+ (+ (* -1 v3) 0) (+ 13 v1))",
            NodeWalk.replaceAll(input, criteria, n -> new FunctionNode(INTEGER_UTILS.getAdd(), ((FunctionNode) n).getArguments())));
   }

   @Test
   public void testGetAt_FunctionNode() {
      FunctionNode n = createFunctionNode();

      assertEquals("v0", NodeWalk.getAt(n, 0).toString());
      assertEquals("v1", NodeWalk.getAt(n, 1).toString());
      assertEquals("(* v0 v1)", NodeWalk.getAt(n, 2).toString());
      assertEquals("v2", NodeWalk.getAt(n, 3).toString());
      assertEquals("1", NodeWalk.getAt(n, 4).toString());
      assertEquals("(+ v2 1)", NodeWalk.getAt(n, 5).toString());
      assertEquals("(+ (* v0 v1) (+ v2 1))", NodeWalk.getAt(n, 6).toString());
   }

   /** Returns representation of: {@code (x*y)+z+1} */
   private FunctionNode createFunctionNode() {
      return new FunctionNode(INTEGER_UTILS.getAdd(), new FunctionNode(INTEGER_UTILS.getMultiply(), createVariable(0), createVariable(1)), new FunctionNode(
            INTEGER_UTILS.getAdd(), createVariable(2), integerConstant(1)));
   }
}