Node.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;

import org.oakgp.Assignments;
import org.oakgp.Type;

/** A node represents a single point of a tree structure. */
public interface Node {
   /**
    * Returns the result of evaluating this {@code Node} using the values of the specified {@code Assignments}.
    *
    * @param assignments
    *           represents the values to assign to any variables used in the evaluation of this {@code Node}
    * @return the result of evaluating this {@code Node} using the values of the specified {@code Assignments}
    */
   <T> T evaluate(Assignments assignments);

   /** Returns the total number of nodes represented by this {@code Node} - including any child-nodes. */
   int getNodeCount();

   /**
    * Returns the height of this {@code Node}.
    * <p>
    * The height of a node is the number of edges on the longest downward path between that node and a leaf.
    */
   int getHeight();

   /**
    * Returns the {@code Type} of this {@code Node}.
    * <p>
    * This indicates the type of the value returned when {@code #evaluate(Assignments)} is called on this {@code Node}.
    */
   Type getType();

   /**
    * Returns the {@code NodeType} of this {@code Node}.
    * <p>
    * This can be used to determine if the node is a function, constant or variable node.
    */
   NodeType getNodeType();
}