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Java > Open Source Codes > net > sf > jga > fn > adaptor > AndUnary


1 // ============================================================================
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// $Id: AndUnary.java,v 1.8 2006/01/08 00:52:25 davidahall Exp $
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// Copyright (c) 2002-2005 David A. Hall
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// ============================================================================
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// The contents of this file are subject to the Common Development and
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// Distribution License (CDDL), Version 1.0 (the License); you may not use this
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// file except in compliance with the License. You should have received a copy
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// of the the License along with this file: if not, a copy of the License is
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// available from Sun Microsystems, Inc.
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//
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// http://www.sun.com/cddl/cddl.html
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//
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// From time to time, the license steward (initially Sun Microsystems, Inc.) may
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// publish revised and/or new versions of the License. You may not use,
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// distribute, or otherwise make this file available under subsequent versions
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// of the License.
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//
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// Alternatively, the contents of this file may be used under the terms of the
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// GNU Lesser General Public License Version 2.1 or later (the "LGPL"), in which
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// case the provisions of the LGPL are applicable instead of those above. If you
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// wish to allow use of your version of this file only under the terms of the
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// LGPL, and not to allow others to use your version of this file under the
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// terms of the CDDL, indicate your decision by deleting the provisions above
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// and replace them with the notice and other provisions required by the LGPL.
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// If you do not delete the provisions above, a recipient may use your version
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// of this file under the terms of either the CDDL or the LGPL.
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//
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// This library is distributed in the hope that it will be useful,
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// but WITHOUT ANY WARRANTY; without even the implied warranty of
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// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
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// ============================================================================
32

33 package net.sf.jga.fn.adaptor;
34
35 import net.sf.jga.fn.UnaryFunctor;
36 import net.sf.jga.fn.UnaryPredicate;
37
38 /**
39  * Unary that performs a shortcircuit and operation using a given pair of
40  * Boolean UnaryFunctors. When the first functor returns true, the second
41  * is not evaluated.
42  **/

43
44 public class AndUnary<T> extends UnaryPredicate<T> {
45
46     static final long serialVersionUID = -4087333621367458086L;
47     
48     // The two unarys that are tested
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private UnaryFunctor<T,Boolean JavaDoc> _first;
50     private UnaryFunctor<T,Boolean JavaDoc> _second;
51     
52     /**
53      * Builds a AndUnary functor, given the two functors that may be executed.
54      * @throws IllegalArgumentException if any of the functors is missing
55      */

56     public AndUnary(UnaryFunctor<T,Boolean JavaDoc> first, UnaryFunctor<T,Boolean JavaDoc> second) {
57         if (first == null || second == null) {
58             throw new IllegalArgumentException JavaDoc("Two functors are required");
59         }
60         
61         _first = first;
62         _second = second;
63     }
64
65
66     public UnaryFunctor<T,Boolean JavaDoc> getFirstFunctor() { return _first; }
67
68     public UnaryFunctor<T,Boolean JavaDoc> getSecondFunctor() { return _second; }
69     
70     
71     public Boolean JavaDoc fn(T arg) {
72         return _first.fn(arg) && _second.fn(arg);
73     }
74
75     /**
76      * Calls the Visitor's <code>visit(AndUnary)</code> method, if it
77      * implements the nested Visitor interface.
78      */

79     public void accept(net.sf.jga.fn.Visitor v) {
80         if (v instanceof AndUnary.Visitor)
81             ((AndUnary.Visitor)v).visit(this);
82         else
83             v.visit(this);
84     }
85
86     // Object overrides
87

88     public String JavaDoc toString() {
89         return _first +" && " +_second;
90     }
91     
92     // AcyclicVisitor
93

94     /**
95      * Interface for classes that may interpret an <b>AndUnaryFunctor</b> predicate.
96      */

97     public interface Visitor extends net.sf.jga.fn.Visitor {
98         public void visit(AndUnary host);
99     }
100 }
101
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