29 lines
780 B
Java
29 lines
780 B
Java
|
//: net/mindview/util/Sets.java
|
||
|
|
package net.mindview.util;
|
||
|
|
import java.util.*;
|
||
|
|
|
||
|
|
public class Sets {
|
||
|
|
public static <T> Set<T> union(Set<T> a, Set<T> b) {
|
||
|
|
Set<T> result = new HashSet<T>(a);
|
||
|
|
result.addAll(b);
|
||
|
|
return result;
|
||
|
|
}
|
||
|
|
public static <T>
|
||
|
|
Set<T> intersection(Set<T> a, Set<T> b) {
|
||
|
|
Set<T> result = new HashSet<T>(a);
|
||
|
|
result.retainAll(b);
|
||
|
|
return result;
|
||
|
|
}
|
||
|
|
// Subtract subset from superset:
|
||
|
|
public static <T> Set<T>
|
||
|
|
difference(Set<T> superset, Set<T> subset) {
|
||
|
|
Set<T> result = new HashSet<T>(superset);
|
||
|
|
result.removeAll(subset);
|
||
|
|
return result;
|
||
|
|
}
|
||
|
|
// Reflexive--everything not in the intersection:
|
||
|
|
public static <T> Set<T> complement(Set<T> a, Set<T> b) {
|
||
|
|
return difference(union(a, b), intersection(a, b));
|
||
|
|
}
|
||
|
|
} ///:~
|