NSSetCategory - CocoaDev

People have expressed their desire for greater functionality from NSSet. Anyone who wants to write a few of the methods (or improve existing methods) should feel more than welcome.

At least one person has said they want:

*- (NSSet *)intersectionWithSet:(NSSet *)aSet; *- (NSSet *)setByAddingSet:(NSSet *)aSet; *- (NSSet *)setByRemovingSet:(NSSet *)aSet; *- (NSSet *)setByAddingObject:(id)anObject; *- (NSSet *)setByRemovingObject:(id)anObject;

NSSet category CocoaDevUsersAdditions:

NSSet+CocoaDevUsersAdditions.h

#import <Foundation/Foundation.h>

@interface NSSet (CocoaDevUsersAdditions)

(NSSet *)setByUnioningSet:(NSSet *)aSet;
(NSSet *)setByMinusingSet:(NSSet *)aSet;
(NSSet *)setByIntersectingSet:(NSSet *)aSet;
(NSSet *)setByComplementingIntersectionWithSet:(NSSet *)aSet;
(NSSet *)setByAddingObject:(id)anObject;
(NSSet *)setByAddingObjectsFromArray:(NSArray *)anArray;
(NSSet *)setByRemovingObject:(id)anObject;

// NOTE: results set contains instance of NSNull if result of performing selector with some object is nil

(NSSet *)resultsOfMakeObjectsPerformSelector:(SEL)aSelector;
(NSSet *)resultsOfMakeObjectsPerformSelector:(SEL)aSelector withObject:(id)anObject;

@end

NSSet+CocoaDevUsersAdditions.m

#import “NSSet+CocoaDevUsersAdditions.h”

@implementation NSSet (CocoaDevUsersAdditions)

(NSSet *)setByUnioningSet:(NSSet *)aSet { id ret = self mutableCopy] autorelease]; [ret unionSet:aSet]; return ret; }
(NSSet *)setByMinusingSet:(NSSet *)aSet { id ret = [[self mutableCopy] autorelease]; [ret minusSet:aSet]; return ret; }
(NSSet *)setByIntersectingSet:(NSSet *)aSet { id ret = [[self mutableCopy] autorelease]; [ret intersectSet:aSet]; return ret; }
(NSSet *)setByComplementingIntersectionWithSet:(NSSet *)aSet { id ret = [[self mutableCopy] autorelease]; [ret unionSet:aSet]; [ret minusSet:[self setByIntersectingSet:aSet; return ret; }
(NSSet *)setByAddingObject:(id)anObject { id ret = self mutableCopy] autorelease]; [ret addObject:anObject]; return ret; }
(NSSet *)setByAddingObjectsFromArray:(NSArray *)anArray { id ret = [[self mutableCopy] autorelease]; [ret addObjectsFromArray:anArray]; return ret; }
(NSSet *)setByRemovingObject:(id)anObject { id ret = [[self mutableCopy] autorelease]; [ret removeObject:anObject]; return ret; }
(NSSet *)resultsOfMakeObjectsPerformSelector:(SEL)aSelector { NSMutableSet *result = [NSMutableSet set]; NSEnumerator *objectEnumerator; id obj; id objResult;

if (aSelector == NULL) { [NSException raise:NSInvalidArgumentException format:@”aSelector cannot be NULL.”]; }

objectEnumerator = [self objectEnumerator]; while (obj = [objectEnumerator nextObject]) { objResult = [obj performSelector:aSelector]; if (objResult == nil) objResult = [NSNull null]; [result addObject:objResult]; }

return result; }
(NSSet *)resultsOfMakeObjectsPerformSelector:(SEL)aSelector withObject:(id)anObject { NSMutableSet *result = [NSMutableSet set]; NSEnumerator *objectEnumerator; id obj; id objResult;

if (aSelector == NULL) { [NSException raise:NSInvalidArgumentException format:@”aSelector cannot be NULL.”]; }

objectEnumerator = [self objectEnumerator]; while (obj = [objectEnumerator nextObject]) { objResult = [obj performSelector:aSelector withObject:anObject]; if (objResult == nil) objResult = [NSNull null]; [result addObject:objResult]; }

return result; } @end

[[Category:CocoaDevUsersAdditions