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 * Provides context when evaluating an AST of {@link org.apache.hivemind.conditional.Node}s.
019 * Effectively, a wrapper around certain runtime operations.
020 * 
021 * @author Howard M. Lewis Ship
022 * @since 1.1
023 */
024public interface EvaluationContext
025{
026    /**
027     * Returns true if the given system property is set.
028     */
029
030    public boolean isPropertySet(String propertyName);
031    
032    /**
033     * Returns true if the class, specified by FQCN, exists.
034     * 
035     */
036    
037    public boolean doesClassExist(String className);
038}