Coverage Report

Coverage Report - org.apache.commons.functor.core.composite.TransposedFunction

Classes in this File

Line Coverage

Branch Coverage

Complexity

TransposedFunction

92%

13/14

70%

14/20

2.143

 /*
  * Licensed to the Apache Software Foundation (ASF) under one or more
  * contributor license agreements.  See the NOTICE file distributed with
  * this work for additional information regarding copyright ownership.
  * The ASF licenses this file to You under the Apache License, Version 2.0
  * (the "License"); you may not use this file except in compliance with
  * the License.  You may obtain a copy of the License at
  *
  *      http://www.apache.org/licenses/LICENSE-2.0
  *
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS,
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
 package org.apache.commons.functor.core.composite;
 
 import java.io.Serializable;
 
 import org.apache.commons.functor.BinaryFunction;
 
 /**
  * Transposes (swaps) the arguments to some other
  * {@link BinaryFunction function}.
  * For example, given a function <i>f</i>
  * and the ordered pair of arguments <i>a</i>,
  * <i>b</i>.
  * {@link #evaluate evaluates} to
  * <code>f.evaluate(b,a)</code>.
  * <p>
  * Note that although this class implements
  * {@link Serializable}, a given instance will
  * only be truly <code>Serializable</code> if the
  * underlying functor is.  Attempts to serialize
  * an instance whose delegate is not
  * <code>Serializable</code> will result in an exception.
  * </p>
  * @version $Revision: 1171154 $ $Date: 2011-09-15 17:58:38 +0200 (Thu, 15 Sep 2011) $
  * @author Rodney Waldhoff
  */
 public class TransposedFunction<L, R, T> implements BinaryFunction<L, R, T>, Serializable {
     /**
      * serialVersionUID declaration.
      */
     private static final long serialVersionUID = -5824252875453493940L;
     // attributes
     // ------------------------------------------------------------------------
     private final BinaryFunction<? super R, ? super L, ? extends T> function;
 
     // constructor
     // ------------------------------------------------------------------------
     /**
      * Create a new TransposedFunction.
      * @param function BinaryFunction to transpose.
      */
     public TransposedFunction(BinaryFunction<? super R, ? super L, ? extends T> function) {
         if (function == null) {
             throw new IllegalArgumentException("BinaryFunction argument was null");
         }
         this.function = function;
     }
 
     // functor interface
     // ------------------------------------------------------------------------
     /**
      * {@inheritDoc}
      */
     public final T evaluate(L left, R right) {
         return function.evaluate(right, left);
     }
 
     /**
      * {@inheritDoc}
      */
     public final boolean equals(Object that) {
         return that == this || (that instanceof TransposedFunction<?, ?, ?>
                                     && equals((TransposedFunction<?, ?, ?>) that));
     }
 
     /**
      * Learn whether another TransposedFunction is equal to this.
      * @param that TransposedFunction to test
      * @return boolean
      */
     public final boolean equals(TransposedFunction<?, ?, ?> that) {
         return null != that && (null == function ? null == that.function : function.equals(that.function));
     }
 
     /**
      * {@inheritDoc}
      */
     public int hashCode() {
         int hash = "TransposedFunction".hashCode();
         if (null != function) {
             hash ^= function.hashCode();
         }
         return hash;
     }
 
     /**
      * {@inheritDoc}
      */
     public String toString() {
         return "TransposedFunction<" + function + ">";
     }
 
     // static
     // ------------------------------------------------------------------------
     /**
      * Transpose a BinaryFunction.
      * @param f BinaryFunction to transpose
      * @return TransposedFunction
      */
     public static <L, R, T> TransposedFunction<R, L, T> transpose(BinaryFunction<? super L, ? super R, ? extends T> f) {
         return null == f ? null : new TransposedFunction<R, L, T>(f);
     }
 
 }

1		/*
2		* Licensed to the Apache Software Foundation (ASF) under one or more
3		* contributor license agreements. See the NOTICE file distributed with
4		* this work for additional information regarding copyright ownership.
5		* The ASF licenses this file to You under the Apache License, Version 2.0
6		* (the "License"); you may not use this file except in compliance with
7		* the License. You may obtain a copy of the License at
8		*
9		* http://www.apache.org/licenses/LICENSE-2.0
10		*
11		* Unless required by applicable law or agreed to in writing, software
12		* distributed under the License is distributed on an "AS IS" BASIS,
13		* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14		* See the License for the specific language governing permissions and
15		* limitations under the License.
16		*/
17		package org.apache.commons.functor.core.composite;
18
19		import java.io.Serializable;
20
21		import org.apache.commons.functor.BinaryFunction;
22
23		/**
24		* Transposes (swaps) the arguments to some other
25		* {@link BinaryFunction function}.
26		* For example, given a function <i>f</i>
27		* and the ordered pair of arguments <i>a</i>,
28		* <i>b</i>.
29		* {@link #evaluate evaluates} to
30		* <code>f.evaluate(b,a)</code>.
31		* <p>
32		* Note that although this class implements
33		* {@link Serializable}, a given instance will
34		* only be truly <code>Serializable</code> if the
35		* underlying functor is. Attempts to serialize
36		* an instance whose delegate is not
37		* <code>Serializable</code> will result in an exception.
38		* </p>
39		* @version $Revision: 1171154 $ $Date: 2011-09-15 17:58:38 +0200 (Thu, 15 Sep 2011) $
40		* @author Rodney Waldhoff
41		*/
42		public class TransposedFunction<L, R, T> implements BinaryFunction<L, R, T>, Serializable {
43		/**
44		* serialVersionUID declaration.
45		*/
46		private static final long serialVersionUID = -5824252875453493940L;
47		// attributes
48		// ------------------------------------------------------------------------
49		private final BinaryFunction<? super R, ? super L, ? extends T> function;
50
51		// constructor
52		// ------------------------------------------------------------------------
53		/**
54		* Create a new TransposedFunction.
55		* @param function BinaryFunction to transpose.
56		*/
57	18	public TransposedFunction(BinaryFunction<? super R, ? super L, ? extends T> function) {
58	18	if (function == null) {
59	0	throw new IllegalArgumentException("BinaryFunction argument was null");
60		}
61	18	this.function = function;
62	18	}
63
64		// functor interface
65		// ------------------------------------------------------------------------
66		/**
67		* {@inheritDoc}
68		*/
69		public final T evaluate(L left, R right) {
70	4	return function.evaluate(right, left);
71		}
72
73		/**
74		* {@inheritDoc}
75		*/
76		public final boolean equals(Object that) {
77	22	return that == this \|\| (that instanceof TransposedFunction<?, ?, ?>
78		&& equals((TransposedFunction<?, ?, ?>) that));
79		}
80
81		/**
82		* Learn whether another TransposedFunction is equal to this.
83		* @param that TransposedFunction to test
84		* @return boolean
85		*/
86		public final boolean equals(TransposedFunction<?, ?, ?> that) {
87	14	return null != that && (null == function ? null == that.function : function.equals(that.function));
88		}
89
90		/**
91		* {@inheritDoc}
92		*/
93		public int hashCode() {
94	24	int hash = "TransposedFunction".hashCode();
95	24	if (null != function) {
96	24	hash ^= function.hashCode();
97		}
98	24	return hash;
99		}
100
101		/**
102		* {@inheritDoc}
103		*/
104		public String toString() {
105	16	return "TransposedFunction<" + function + ">";
106		}
107
108		// static
109		// ------------------------------------------------------------------------
110		/**
111		* Transpose a BinaryFunction.
112		* @param f BinaryFunction to transpose
113		* @return TransposedFunction
114		*/
115		public static <L, R, T> TransposedFunction<R, L, T> transpose(BinaryFunction<? super L, ? super R, ? extends T> f) {
116	4	return null == f ? null : new TransposedFunction<R, L, T>(f);
117		}
118
119		}