1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
|
/* *******************************************************************
* Copyright (c) 1999-2001 Xerox Corporation,
* 2002 Palo Alto Research Center, Incorporated (PARC).
* All rights reserved.
* This program and the accompanying materials are made available
* under the terms of the Common Public License v1.0
* which accompanies this distribution and is available at
* http://www.eclipse.org/legal/cpl-v10.html
*
* Contributors:
* Xerox/PARC initial implementation
* ******************************************************************/
package org.aspectj.testing.compare;
import java.util.Iterator;
import java.util.Collection;
import java.util.List;
/** Minor methods for short-circuiting comparisons */
public class CompareUtil {
/**
* Callers may abort equality checks with false
* if this passes its misc short-circuit semantics.
* A false result does not mean the arguments
* are equal, but a true result does mean they are not equal.
* <pre>if (notSame(foo,bar,true)) then return false;</pre>
* @param lhs the Object on the left-hand-side to compare
* @param rhs the Object on the right-hand-side to compare
* @param considerType if true, then also return true if the
* right-hand-side cannot be assigned to the left-hand-side
* @return true if lhs and rhs are not the same per considerType.
*/
public static boolean notSame(Object lhs, Object rhs, boolean considerType) {
if (null == lhs) {
return (!(null == rhs));
} else if (null == rhs) {
return true;
} else if (lhs== rhs) {
return false; // known to be same
} else if (considerType) {
Class lhClass = lhs.getClass();
Class rhClass = rhs.getClass();
if (!lhClass.isAssignableFrom(rhClass)) {
return true;
}
}
return false; // unknown whether equal or not
}
/**
* Return null/equal comparison:
* <li>null considered to be lesser</li>
* <li>reference or Object.equals() considered to be 0</li>
* <li>return Integer.MAX_VALUE for all other cases</li>
* <table>
* <tr><td>result</td><td>input</td></tr>
* <tr><td>-1</td><td>null < rhs</td></tr>
* <tr><td>1</td><td>lhs > null</td></tr>
* <tr><td>0</td><td>null == null</td></tr>
* <tr><td>0</td><td>lhs == rhs</td></tr>
* <tr><td>0</td><td>lhs.equals(rhs)</td></tr>
* <tr><td>Integer.MAX_VALUE</td><td>{all other cases}</td></tr>
* </table>
* @see Comparator
* @return Integer.MAX_VALUE if uncertain, value otherwise
*/
public static int compare(Object lhs, Object rhs) {
if (null == lhs) {
return (null == rhs ? 0 : -1);
} else if (null == rhs) {
return 1;
} else if (lhs == rhs) {
return 0; // known to be same
} else {
return Integer.MAX_VALUE;
}
}
/**
* Return boolean comparison where true > false.
* (Comparable not defined for Boolean)
* @see Comparator
*/
public static int compare(boolean lhs, boolean rhs) {
return (lhs == rhs ? 0 : (lhs ? 1 : -1));
}
/**
* Return String comparison based on {@link compare(Object,Object)}
* and {@link String.compareTo(String)}.
* @see Comparator
*/
public static int compare(String lhs, String rhs) {
int result = compare((Object) lhs, (Object) rhs);
if (Integer.MAX_VALUE == result) {
result = lhs.compareTo(rhs);
}
return result;
}
/**
* Compare two Collections by reference to a standard List.
* The first Collection to not contain a standard element
* when the other does loses. Order is ignored.
* The left-hand-side acts as the standard if the standard is null.
* @param lhs the List from the left-hand-side
* @param rhs the Collection from the right-hand-side
* @param standard the List to act as the standard (if null, use lhs)
* @param return -1 if lhs is null and rhs is not, 1 if reverse;
* 0 if both have all elements in standard,
* 1 if lhs has a standard element rhs does not, -1 if reverse
* (testing in standard order)
*/
public static int compare(List lhs, Collection rhs, List standard) {
int result = compare(lhs, rhs);
if (result == Integer.MAX_VALUE) {
if (null == standard) {
result = compare(lhs, rhs, lhs); // use lhs as standard
} else {
boolean leftHasThem = lhs.containsAll(standard);
boolean rightHasThem = rhs.containsAll(standard);
if (leftHasThem != rightHasThem) {
result = (leftHasThem ? 1 : -1);
} else if (leftHasThem) {
result = 0; // they both have them
} else { // first to not have an element loses
Iterator standardIterator = standard.iterator();
while (standardIterator.hasNext()) {
Object standardObject = standardIterator.next();
boolean leftHasIt = lhs.contains(standardObject);
boolean rightHasIt = rhs.contains(standardObject);
if (leftHasIt != rightHasIt) {
result = (leftHasIt ? 1 : -1);
break;
}
}
}
}
}
return result;
}
} // class Util
|
