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Java > Open Source Codes > net > sf > jga > fn > arithmetic > Arithmetic


1 // ============================================================================
2 // $Id: Arithmetic.java,v 1.7 2005/08/02 23:45:05 davidahall Exp $
3 // Copyright (c) 2003-2005 David A. Hall
4 // ============================================================================
5 // The contents of this file are subject to the Common Development and
6 // Distribution License (CDDL), Version 1.0 (the License); you may not use this
7 // file except in compliance with the License. You should have received a copy
8 // of the the License along with this file: if not, a copy of the License is
9 // available from Sun Microsystems, Inc.
10 //
11 // http://www.sun.com/cddl/cddl.html
12 //
13 // From time to time, the license steward (initially Sun Microsystems, Inc.) may
14 // publish revised and/or new versions of the License. You may not use,
15 // distribute, or otherwise make this file available under subsequent versions
16 // of the License.
17 //
18 // Alternatively, the contents of this file may be used under the terms of the
19 // GNU Lesser General Public License Version 2.1 or later (the "LGPL"), in which
20 // case the provisions of the LGPL are applicable instead of those above. If you
21 // wish to allow use of your version of this file only under the terms of the
22 // LGPL, and not to allow others to use your version of this file under the
23 // terms of the CDDL, indicate your decision by deleting the provisions above
24 // and replace them with the notice and other provisions required by the LGPL.
25 // If you do not delete the provisions above, a recipient may use your version
26 // of this file under the terms of either the CDDL or the LGPL.
27 //
28 // This library is distributed in the hope that it will be useful,
29 // but WITHOUT ANY WARRANTY; without even the implied warranty of
30 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
31 // ============================================================================
32
33 package net.sf.jga.fn.arithmetic;
34
35 import java.io.Serializable JavaDoc;
36
37 /**
38  * Defines arithmetic operations for classes derived from Number.
39  * <p>
40  * An implementation of Arithmetic for classes (such as BigDecimal and
41  * BigInteger) that provide the appropriate operations can simply map these
42  * methods to the methods provided by the Number. For the reference types,
43  * the implementation will need to dereference the arguments, perform the
44  * specified operation on the resulting primitives, and box up the result in
45  * a new reference type.
46  * <p>
47  * This interface may be used with user-defined Number implementations. For
48  * Example, assuming that a <code>Fraction</code> class has been defined,
49  * support for Fraction Arithmetic could be provided by<br>
50  * <pre>
51  * public class FractionMath implements Arithmetic&lt;Fraction&gt; {
52  * public Fraction plus (Fraction x, Fraction y) {
53  * // implementation omitted
54  * }
55  * ...
56  * }
57  * </pre>
58  * <p>
59  * To use Fractions with the various arithmetic Functors, it is necessary to
60  * register the Arithmetic implementation with the ArithmeticFactory.<br>
61  * <pre>
62  * ArithmeticFactory.register(Fraction.class, new FractionMath());
63  * </pre>
64  * <p>
65  * Copyright &copy; 2003-2005 David A. Hall
66  *
67  * @author <a HREF="mailto:davidahall@users.sourceforge.net">David A. Hall</a>
68  */
69
70 public interface Arithmetic<T extends Number JavaDoc> extends Serializable JavaDoc {
71     /**
72      * Returns the given value in the appropriate type
73      * @throws IllegalArgumentException if the value cannot be converted
74      */
75
76     public T valueOf(Number JavaDoc value) throws IllegalArgumentException JavaDoc;
77     
78     /**
79      * Returns the value 0 of the appropriate type
80      */
81
82     public T zero();
83
84     /**
85      * Returns the value 1 of the appropriate type
86      */
87
88     public T one();
89
90     /**
91     * For numeric arguments x and y, returns x + y
92     * @return the sum of the two arguments
93     */
94
95     public T plus (T x, T y);
96
97    /**
98     * For numeric arguments x and y, returns x - y
99     * @return the difference of the two arguments
100     */
101      
102     public T minus (T x, T y);
103      
104    /**
105     * For numeric arguments x and y, returns x * y
106     * @return the product of the two arguments
107     */
108
109     public T multiplies (T x, T y);
110
111     /**
112      * For numeric arguments x and y, returns x / y
113      * @return the quotient of the two arguments
114      */
115
116     public T divides (T x, T y);
117
118     /**
119      * for numeric argument x, returns -x
120      * @return the negative of its argument
121      */
122
123     public T negate (T x);
124 }
125
126
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