1.1 --- a/CollectionUtils.m	Tue Apr 15 18:02:40 2008 -0700
     1.2 +++ b/CollectionUtils.m	Fri May 02 12:49:43 2008 -0700
     1.3 @@ -161,7 +161,9 @@
     1.4  
     1.5  
     1.6  
     1.7 +
     1.8  @implementation NSSet (MYUtils)
     1.9 +
    1.10  + (NSSet*) my_unionOfSet: (NSSet*)set1 andSet: (NSSet*)set2
    1.11  {
    1.12      if( set1 == set2 || set2.count==0 )
    1.13 @@ -175,6 +177,19 @@
    1.14      }
    1.15  }
    1.16  
    1.17 ++ (NSSet*) my_intersectionOfSet: (NSSet*)set1 andSet: (NSSet*)set2
    1.18 +{
    1.19 +    if( set1 == set2 || set1.count==0 )
    1.20 +        return set1;
    1.21 +    else if( set2.count==0 )
    1.22 +        return set2;
    1.23 +    else {
    1.24 +        NSMutableSet *result = [set1 mutableCopy];
    1.25 +        [result intersectSet: set2];
    1.26 +        return [result autorelease];
    1.27 +    }
    1.28 +}
    1.29 +
    1.30  + (NSSet*) my_differenceOfSet: (NSSet*)set1 andSet: (NSSet*)set2
    1.31  {
    1.32      if( set1.count==0 || set2.count==0 )
    1.33 @@ -187,6 +202,7 @@
    1.34          return [result autorelease];
    1.35      }
    1.36  }
    1.37 +
    1.38  @end
    1.39  
    1.40