001// Copyright 2004, 2005 The Apache Software Foundation
002//
003// Licensed under the Apache License, Version 2.0 (the "License");
004// you may not use this file except in compliance with the License.
005// You may obtain a copy of the License at
006//
007//     http://www.apache.org/licenses/LICENSE-2.0
008//
009// Unless required by applicable law or agreed to in writing, software
010// distributed under the License is distributed on an "AS IS" BASIS,
011// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
012// See the License for the specific language governing permissions and
013// limitations under the License.
014
015package org.apache.hivemind.conditional;
016
017/**
018 * An AST node in the tree parsed from the conditional expression. Nodes form a binary tree, each
019 * node may have a left and a right sub-node.
020 * 
021 * @author Howard M. Lewis Ship
022 * @since 1.1
023 */
024public interface Node
025{
026    public Node getLeft();
027
028    public Node getRight();
029
030    /**
031     * Evaluates the nodes using the context to provide access to runtime information.
032     */
033    public boolean evaluate(EvaluationContext context);
034}