001    /*
002     $Id: GStringExpression.java,v 1.12 2005/05/20 16:28:49 phk Exp $
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 groovy.lang.GString;
049    
050    import java.util.ArrayList;
051    import java.util.Iterator;
052    import java.util.List;
053    
054    import org.codehaus.groovy.ast.GroovyCodeVisitor;
055    import org.codehaus.groovy.classgen.AsmClassGenerator;
056    
057    /**
058     * Represents a String expression which contains embedded values inside
059     * it such as "hello there ${user} how are you" which is expanded lazily
060     * 
061     * @author <a href="mailto:james@coredevelopers.net">James Strachan</a>
062     * @version $Revision: 1.12 $
063     */
064    public class GStringExpression extends Expression {
065    
066        private String verbatimText;
067        private List strings = new ArrayList();
068        private List values = new ArrayList();
069    
070        public GStringExpression(String verbatimText) {
071            this.verbatimText = verbatimText;
072            super.setTypeClass(GString.class);
073        }
074    
075        public GStringExpression(String verbatimText, List strings, List values) {
076            this.verbatimText = verbatimText;
077            this.strings = strings;
078            this.values = values;
079            super.setTypeClass(GString.class);
080        }
081    
082        public void visit(GroovyCodeVisitor visitor) {
083            visitor.visitGStringExpression(this);
084        }
085    
086        public Expression transformExpression(ExpressionTransformer transformer) {
087            return new GStringExpression(
088                verbatimText,
089                transformExpressions(strings, transformer),
090                transformExpressions(values, transformer));
091        }
092    
093        protected void resolveType(AsmClassGenerator resolver) {
094            //
095        }
096    
097        public String toString() {
098            return super.toString() + "[strings: " + strings + " values: " + values + "]";
099        }
100    
101        public String getText() {
102            return verbatimText;
103        }
104    
105        public List getStrings() {
106            return strings;
107        }
108    
109        public List getValues() {
110            return values;
111        }
112    
113        public void addString(ConstantExpression text) {
114            if (text == null) {
115                throw new NullPointerException("Cannot add a null text expression");
116            }
117            strings.add(text);
118        }
119    
120        public void addValue(Expression value) {
121            // If the first thing is an value, then we need a dummy empty string in front of it so that when we
122            // toString it they come out in the correct order.
123            if (strings.size() == 0)
124                strings.add(ConstantExpression.EMPTY_STRING);
125            values.add(value);
126        }
127    
128        public Expression getValue(int idx) {
129            return (Expression) values.get(idx);
130        }
131    
132        public boolean isConstantString() {
133            return values.isEmpty();
134        }
135    
136        public Expression asConstantString() {
137            StringBuffer buffer = new StringBuffer();
138            for (Iterator iter = strings.iterator(); iter.hasNext();) {
139                ConstantExpression expression = (ConstantExpression) iter.next();
140                Object value = expression.getValue();
141                if (value != null) {
142                    buffer.append(value);
143                }
144            }
145            return new ConstantExpression(buffer.toString());
146        }
147    }