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. 014 015 package 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 */ 024 public 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 }