- /*
- * Copyright 2002,2004 The Apache Software Foundation.
- *
- * 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.apache.commons.jexl;
-
-
- /**
- * <p>
- * Represents a single JEXL expression. This simple interface
- * provides access to the underlying expression through getExpression(),
- * and it provides hooks to add a pre- and post- expression resolver.
- * </p>
- *
- * <p>
- * An expression is different than a script - it is simply a reference of
- * an expression.
- * </p>
- *
- * @author <a href="mailto:geirm@apache.org">Geir Magnusson Jr.</a>
- * @version $Id: Expression.java,v 1.7 2004/08/23 13:53:34 dion Exp $
- */
- public interface Expression
- {
- /**
- * Evaluates the expression with the variables contained in the
- * supplied {@link JexlContext}.
- *
- * @param context A JexlContext containing variables.
- * @return The result of this evaluation
- */
- Object evaluate(JexlContext context) throws Exception;
-
- /**
- * Returns the JEXL expression this Expression was created with.
- *
- * @return The JEXL expression to be evaluated
- */
- String getExpression();
-
- /**
- * allows addition of a resolver to allow custom interdiction of
- * expression evaluation
- *
- * @param resolver resolver to be called before Jexl expression evaluated
- */
- void addPreResolver(JexlExprResolver resolver);
-
- /**
- * allows addition of a resolver to allow custom interdiction of
- * expression evaluation
- *
- * @param resolver resolver to be called if Jexl expression evaluated to null
- */
- void addPostResolver(JexlExprResolver resolver);
- }