001: /*
002: $Id: ConstantExpression.java 3264 2005-12-14 16:51:43Z blackdrag $
003:
004: Copyright 2003 (C) James Strachan and Bob Mcwhirter. All Rights Reserved.
005:
006: Redistribution and use of this software and associated documentation
007: ("Software"), with or without modification, are permitted provided
008: that the following conditions are met:
009:
010: 1. Redistributions of source code must retain copyright
011: statements and notices. Redistributions must also contain a
012: copy of this document.
013:
014: 2. Redistributions in binary form must reproduce the
015: above copyright notice, this list of conditions and the
016: following disclaimer in the documentation and/or other
017: materials provided with the distribution.
018:
019: 3. The name "groovy" must not be used to endorse or promote
020: products derived from this Software without prior written
021: permission of The Codehaus. For written permission,
022: please contact info@codehaus.org.
023:
024: 4. Products derived from this Software may not be called "groovy"
025: nor may "groovy" appear in their names without prior written
026: permission of The Codehaus. "groovy" is a registered
027: trademark of The Codehaus.
028:
029: 5. Due credit should be given to The Codehaus -
030: http://groovy.codehaus.org/
031:
032: THIS SOFTWARE IS PROVIDED BY THE CODEHAUS AND CONTRIBUTORS
033: ``AS IS'' AND ANY EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT
034: NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
035: FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
036: THE CODEHAUS OR ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
037: INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
038: (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
039: SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
040: HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
041: STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
042: ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
043: OF THE POSSIBILITY OF SUCH DAMAGE.
044:
045: */
046: package org.codehaus.groovy.ast.expr;
047:
048: import org.codehaus.groovy.ast.ClassHelper;
049: import org.codehaus.groovy.ast.GroovyCodeVisitor;
050:
051: /**
052: * Represents a constant expression such as null, true, false
053: *
054: * @author <a href="mailto:james@coredevelopers.net">James Strachan</a>
055: * @version $Revision: 3264 $
056: */
057: public class ConstantExpression extends Expression {
058: public static final ConstantExpression VOID = new ConstantExpression(
059: Void.class);
060: public static final ConstantExpression NULL = new ConstantExpression(
061: null);
062: public static final ConstantExpression TRUE = new ConstantExpression(
063: Boolean.TRUE);
064: public static final ConstantExpression FALSE = new ConstantExpression(
065: Boolean.FALSE);
066: public static final ConstantExpression EMPTY_STRING = new ConstantExpression(
067: "");
068: //public static final Expression EMPTY_ARRAY = new PropertyExpression(new ClassExpression(ArgumentListExpression.class.getName()), "EMPTY_ARRAY");
069: public static final ConstantExpression EMTPY_EXPRESSION = new ConstantExpression(
070: null);
071:
072: private Object value;
073:
074: public ConstantExpression(Object value) {
075: this .value = value;
076: if (this .value != null)
077: setType(ClassHelper.make(value.getClass()));
078: }
079:
080: public String toString() {
081: return super .toString() + "[value=" + value + "]";
082: }
083:
084: public void visit(GroovyCodeVisitor visitor) {
085: visitor.visitConstantExpression(this );
086: }
087:
088: public Expression transformExpression(
089: ExpressionTransformer transformer) {
090: return this ;
091: }
092:
093: /**
094: * @return the value of this constant expression
095: */
096: public Object getValue() {
097: return value;
098: }
099:
100: public String getText() {
101: return (value == null) ? "null" : value.toString();
102: }
103: }
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