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1   /***
2    * Redistribution and use of this software and associated documentation
3    * ("Software"), with or without modification, are permitted provided
4    * that the following conditions are met:
5    *
6    * 1. Redistributions of source code must retain copyright
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8    *    copy of this document.
9    *
10   * 2. Redistributions in binary form must reproduce the
11   *    above copyright notice, this list of conditions and the
12   *    following disclaimer in the documentation and/or other
13   *    materials provided with the distribution.
14   *
15   * 3. The name "Exolab" must not be used to endorse or promote
16   *    products derived from this Software without prior written
17   *    permission of Exoffice Technologies.  For written permission,
18   *    please contact info@exolab.org.
19   *
20   * 4. Products derived from this Software may not be called "Exolab"
21   *    nor may "Exolab" appear in their names without prior written
22   *    permission of Exoffice Technologies. Exolab is a registered
23   *    trademark of Exoffice Technologies.
24   *
25   * 5. Due credit should be given to the Exolab Project
26   *    (http://www.exolab.org/).
27   *
28   * THIS SOFTWARE IS PROVIDED BY EXOFFICE TECHNOLOGIES AND CONTRIBUTORS
29   * ``AS IS'' AND ANY EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT
30   * NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
31   * FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL
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38   * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
39   * OF THE POSSIBILITY OF SUCH DAMAGE.
40   *
41   * Copyright 2000-2001,2003 (C) Exoffice Technologies Inc. All Rights Reserved.
42   */
43  
44  package org.exolab.jms.selector;
45  
46  import java.util.HashSet;
47  
48  
49  /***
50   * This interface specifies the methods needed to create all of the
51   * expressions supported by the message selector. It exists solely to
52   * decouple the expression evaluation classes from the parser.
53   *
54   * @version     $Revision: 1.1 $ $Date: 2004/11/26 01:50:44 $
55   * @author      <a href="mailto:tma@netspace.net.au">Tim Anderson</a>
56   * @see         Expression
57   * @see         org.exolab.jms.selector.parser.SelectorTokenTypes
58   * @see         org.exolab.jms.selector.parser.SelectorTreeParser
59   */
60  public interface ExpressionFactory {
61  
62      /***
63       * Create a binary operator expression
64       *
65       * @param operator the operator token type from SelectorTokenTypes
66       * @param left the left-hand side of the binary expression
67       * @param right the right-hand side of the binary expression
68       * @return a new binary expression
69       * @throws SelectorException if the operator is not a valid binary operator
70       */
71      Expression binaryOperator(int operator, Expression left, Expression right)
72          throws SelectorException;
73  
74      /***
75       * Create an unary operator expression
76       *
77       * @param operator the operator token type from SelectorTokenTypes
78       * @param operand the expression to apply the operator to
79       * @return a new unary expression
80       * @throws SelectorException if the operator is not a valid unary operator
81       */
82      Expression unaryOperator(int operator, Expression operand)
83          throws SelectorException;
84  
85      /***
86       * Create an identifier expression
87       *
88       * @param name the name of the identifier
89       * @return a new identifier expression
90       * @throws SelectorException is name is not a valid identifier
91       */
92      Expression identifier(String name) throws SelectorException;
93  
94      /***
95       * Create an 'is null' expression
96       *
97       * @param identifier the identifer expression to apply the 'is null' test
98       * @return an 'is null' expression
99       * @throws SelectorException for any error
100      */
101     Expression isNull(Expression identifier) throws SelectorException;
102 
103     /***
104      * Create a 'like' expression
105      *
106      * @param identifier the identifer to apply the 'like' test to
107      * @param pattern the search pattern
108      * @param escape the escape character. This may be null
109      * @return a new 'like' expression
110      * @throws SelectorException if the pattern or escape is invalid
111      */
112     Expression like(Expression identifier, String pattern, String escape)
113         throws SelectorException;
114 
115     /***
116      * Create a 'between' expression that returns the result of:<br/>
117      * <code>num1 >= num2 and num1 <= num3</code>
118      * when evaluated
119      *
120      * @param num1 an arithmethic expression
121      * @param num2 an arithmethic expression
122      * @param num3 an arithmethic expression
123      * @return a new 'between' expression
124      * @throws SelectorException for any error
125      */
126     Expression between(Expression num1, Expression num2, Expression num3)
127         throws SelectorException;
128 
129     /***
130      * Create an 'in' expression
131      *
132      * @param identifier string identifer to apply the 'in' test to
133      * @param set the set of string values to compare against
134      * @return a new 'in' expression
135      * @throws SelectorException for any error
136      */
137     Expression in(Expression identifier, HashSet set) throws SelectorException;
138 
139     /***
140      * Create a literal expression
141      *
142      * @param type the operator token type from SelectorTokenTypes
143      * @param text the literal text
144      * @return a new literal expression
145      * @throws SelectorException if type is not a valid literal type
146      */
147     Expression literal(int type, String text) throws SelectorException;
148 
149 } //-- ExpressionFactory