groovy-core/src/main/org/codehaus/groovy/ast/expr/EmptyExpression.java

/*
 * Copyright 2003-2007 the original author or authors.
 *
 * 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.codehaus.groovy.ast.expr;

import org.codehaus.groovy.ast.GroovyCodeVisitor;

/**
 * This class is a place holder for an empty expression. 
 * Empty expression are used in closures lists like (;). During
 * class Generation this expression should be either ignored or
 * reaplce with a null value.
 *   
 * @author Jochen Theodorou
 * @see org.codehaus.groovy.ast.stmt.EmptyStatement
 */
public class EmptyExpression extends Expression {
    public static final EmptyExpression INSTANCE = new EmptyExpression();

    public Expression transformExpression(ExpressionTransformer transformer) {
        return this;
    }

    public void visit(GroovyCodeVisitor visitor) {
        return;
    }
}