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1   /*
2    $Id: GStringExpression.java,v 1.14 2005/11/13 16:42:09 blackdrag Exp $
3   
4    Copyright 2003 (C) James Strachan and Bob Mcwhirter. All Rights Reserved.
5   
6    Redistribution and use of this software and associated documentation
7    ("Software"), with or without modification, are permitted provided
8    that the following conditions are met:
9   
10   1. Redistributions of source code must retain copyright
11      statements and notices.  Redistributions must also contain a
12      copy of this document.
13  
14   2. Redistributions in binary form must reproduce the
15      above copyright notice, this list of conditions and the
16      following disclaimer in the documentation and/or other
17      materials provided with the distribution.
18  
19   3. The name "groovy" must not be used to endorse or promote
20      products derived from this Software without prior written
21      permission of The Codehaus.  For written permission,
22      please contact info@codehaus.org.
23  
24   4. Products derived from this Software may not be called "groovy"
25      nor may "groovy" appear in their names without prior written
26      permission of The Codehaus. "groovy" is a registered
27      trademark of The Codehaus.
28  
29   5. Due credit should be given to The Codehaus -
30      http://groovy.codehaus.org/
31  
32   THIS SOFTWARE IS PROVIDED BY THE CODEHAUS AND CONTRIBUTORS
33   ``AS IS'' AND ANY EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT
34   NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
35   FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL
36   THE CODEHAUS OR ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
37   INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
38   (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
39   SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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41   STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
42   ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
43   OF THE POSSIBILITY OF SUCH DAMAGE.
44  
45   */
46  package org.codehaus.groovy.ast.expr;
47  
48  import java.util.ArrayList;
49  import java.util.Iterator;
50  import java.util.List;
51  
52  import org.codehaus.groovy.ast.ClassHelper;
53  import org.codehaus.groovy.ast.GroovyCodeVisitor;
54  
55  /***
56   * Represents a String expression which contains embedded values inside
57   * it such as "hello there ${user} how are you" which is expanded lazily
58   * 
59   * @author <a href="mailto:james@coredevelopers.net">James Strachan</a>
60   * @version $Revision: 1.14 $
61   */
62  public class GStringExpression extends Expression {
63  
64      private String verbatimText;
65      private List strings = new ArrayList();
66      private List values = new ArrayList();
67      
68      public GStringExpression(String verbatimText) {
69          this.verbatimText = verbatimText;
70          super.setType(ClassHelper.GSTRING_TYPE);
71      }
72  
73      public GStringExpression(String verbatimText, List strings, List values) {
74          this.verbatimText = verbatimText;
75          this.strings = strings;
76          this.values = values;
77          super.setType(ClassHelper.GSTRING_TYPE);
78      }
79  
80      public void visit(GroovyCodeVisitor visitor) {
81          visitor.visitGStringExpression(this);
82      }
83  
84      public Expression transformExpression(ExpressionTransformer transformer) {
85          return new GStringExpression(
86              verbatimText,
87              transformExpressions(strings, transformer),
88              transformExpressions(values, transformer));
89      }
90  
91      public String toString() {
92          return super.toString() + "[strings: " + strings + " values: " + values + "]";
93      }
94  
95      public String getText() {
96          return verbatimText;
97      }
98  
99      public List getStrings() {
100         return strings;
101     }
102 
103     public List getValues() {
104         return values;
105     }
106 
107     public void addString(ConstantExpression text) {
108         if (text == null) {
109             throw new NullPointerException("Cannot add a null text expression");
110         }
111         strings.add(text);
112     }
113 
114     public void addValue(Expression value) {
115         // If the first thing is an value, then we need a dummy empty string in front of it so that when we
116         // toString it they come out in the correct order.
117         if (strings.size() == 0)
118             strings.add(ConstantExpression.EMPTY_STRING);
119         values.add(value);
120     }
121 
122     public Expression getValue(int idx) {
123         return (Expression) values.get(idx);
124     }
125 
126     public boolean isConstantString() {
127         return values.isEmpty();
128     }
129 
130     public Expression asConstantString() {
131         StringBuffer buffer = new StringBuffer();
132         for (Iterator iter = strings.iterator(); iter.hasNext();) {
133             ConstantExpression expression = (ConstantExpression) iter.next();
134             Object value = expression.getValue();
135             if (value != null) {
136                 buffer.append(value);
137             }
138         }
139         return new ConstantExpression(buffer.toString());
140     }
141 }