expression.java

大名鼎鼎的java动态脚本语言。已经通过了sun的认证

/*
 $Id: Expression.java,v 1.6 2005/11/13 16:42:09 blackdrag Exp $

 Copyright 2003 (C) James Strachan and Bob Mcwhirter. All Rights Reserved.

 Redistribution and use of this software and associated documentation
 ("Software"), with or without modification, are permitted provided
 that the following conditions are met:

 1. Redistributions of source code must retain copyright
    statements and notices.  Redistributions must also contain a
    copy of this document.

 2. Redistributions in binary form must reproduce the
    above copyright notice, this list of conditions and the
    following disclaimer in the documentation and/or other
    materials provided with the distribution.

 3. The name "groovy" must not be used to endorse or promote
    products derived from this Software without prior written
    permission of The Codehaus.  For written permission,
    please contact [e-mail].

 4. Products derived from this Software may not be called "groovy"
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    permission of The Codehaus. "groovy" is a registered
    trademark of The Codehaus.

 5. Due credit should be given to The Codehaus -
    http://groovy.codehaus.org/

 THIS SOFTWARE IS PROVIDED BY THE CODEHAUS AND CONTRIBUTORS
 ``AS IS'' AND ANY EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT
 NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
 FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL
 THE CODEHAUS OR ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
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 HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
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 ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
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 */
package org.codehaus.groovy.ast.expr;

import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;

import org.codehaus.groovy.ast.ASTNode;
import org.codehaus.groovy.ast.ClassHelper;
import org.codehaus.groovy.ast.ClassNode;

/**
 * Represents a base class for expressions which evaluate as an object
 * 
 * @author <a href="mailto:[e-mail]">James Strachan</a>
 * @version $Revision: 1.6 $
 */
public abstract class Expression extends ASTNode {

    private ClassNode type=ClassHelper.DYNAMIC_TYPE;
    
    /**
     * Return a copy of the expression calling the transformer on any nested expressions 
     * @param transformer
     * @return
     */
    public abstract Expression transformExpression(ExpressionTransformer transformer);

    /**
     * Transforms the list of expressions
     * @return a new list of transformed expressions
     */
    protected List transformExpressions(List expressions, ExpressionTransformer transformer) {
        List list = new ArrayList(expressions.size());
        for (Iterator iter = expressions.iterator(); iter.hasNext(); ) {
            list.add(transformer.transform((Expression) iter.next()));
        }
        return list;
    }
    
    public ClassNode getType() {
        return type;
    }
    
    public void setType(ClassNode t) {
        type=t;
    }
}