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Java > Open Source Codes > org > jboss > aspects > dbc > condition > parser > BeanshellGenerator


1 /*
2   * JBoss, Home of Professional Open Source
3   * Copyright 2005, JBoss Inc., and individual contributors as indicated
4   * by the @authors tag. See the copyright.txt in the distribution for a
5   * full listing of individual contributors.
6   *
7   * This is free software; you can redistribute it and/or modify it
8   * under the terms of the GNU Lesser General Public License as
9   * published by the Free Software Foundation; either version 2.1 of
10   * the License, or (at your option) any later version.
11   *
12   * This software is distributed in the hope that it will be useful,
13   * but WITHOUT ANY WARRANTY; without even the implied warranty of
14   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15   * Lesser General Public License for more details.
16   *
17   * You should have received a copy of the GNU Lesser General Public
18   * License along with this software; if not, write to the Free
19   * Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
20   * 02110-1301 USA, or see the FSF site: http://www.fsf.org.
21   */
22 package org.jboss.aspects.dbc.condition.parser;
23
24 /**
25  *
26  * @author <a HREF="mailto:kabir.khan@jboss.org">Kabir Khan</a>
27  * @version $Revision: 37406 $
28  */
29 public class BeanshellGenerator implements ExpressionVisitor
30 {
31    Expression expr;
32    StringBuffer JavaDoc code;
33    int indent;
34    //int level;
35
36    public BeanshellGenerator(Expression expr)
37    {
38       this.expr = expr;
39    }
40    
41    public String JavaDoc createBeanshellCode()
42    {
43       code = new StringBuffer JavaDoc();
44       //code.append("boolean " + RET_NAME + " = false;\n");
45 expr.accept(this);
46       return code.toString();
47    }
48    
49    public void visit(Expression expr)
50    {
51       expr.accept(this);
52    }
53
54    public void visit(BooleanExpression expr)
55    {
56       if (expr.isTopLevel())
57       {
58          code.append("return (" + expr.getExpression() + ");\n");
59       }
60       else
61       {
62          code.append(expr.getExpression());
63       }
64    }
65
66    public void visit(ForAllExpression expr)
67    {
68       createLoopCode(expr, false);
69    }
70
71    public void visit(ExistsExpression expr)
72    {
73       createLoopCode(expr, true);
74    }
75
76    public void visit(ImpliesExpression expr)
77    {
78       indent();
79       code.append("if (");
80       expr.getLhs().accept(this);
81       code.append("){\n");
82       indent++;
83       indent();
84       code.append("if(!(");
85       expr.getRhs().accept(this);
86       code.append(")){\n");
87       indent++;
88       indent();
89       code.append("return false;\n");
90       indent--;
91       indent();
92       code.append("}\n");
93       
94       indent--;
95       indent();
96       code.append("}\n");
97       
98       if (expr.isTopLevel())
99       {
100          code.append("return true;\n");
101       }
102    }
103    
104    public void visit(JavaExpression expr)
105    {
106       code.append(expr.getJava());
107       code.append("\nreturn true;\n");
108    }
109    
110    private void indent()
111    {
112       for (int i = 0 ; i < indent * 2 ; i++)
113       {
114          code.append(" ");
115       }
116    }
117
118    private void createLoopCode(LoopExpression expr, boolean breakType)
119    {
120       String JavaDoc declaration = expr.getDeclaration();
121       String JavaDoc collection = expr.getCollection();
122       Expression body = expr.getBody();
123       
124       indent();
125       code.append("for (" + declaration + " : " + collection + "){\n");
126       indent++;
127
128       if (body instanceof BooleanExpression)
129       {
130          indent();
131          code.append("if (");
132          
133          if (!breakType)
134          {
135             code.append("!");
136          }
137
138          code.append("(");
139         body.accept(this);
140          code.append(")){\n");
141
142          indent++;
143          indent();
144          code.append("return "+ breakType + ";\n");
145          
146          indent--;
147          indent();
148          code.append("}\n");
149       }
150       else if (body instanceof ImpliesExpression)
151       {
152          body.accept(this);
153       }
154       else
155       {
156         body.accept(this);
157       }
158       indent--;
159       indent();
160       code.append("}\n");
161       if (expr.isTopLevel())
162       {
163          indent();
164          code.append("return "+ !breakType + ";\n");
165       }
166    }
167 }
168
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