NSArray map method like Ruby's Array#map method

NSArray+FRBMethods.h

@interface NSArray (FRBMethods)
- (NSArray *)map:(id (^)(id item))block;
@end

NSArray+FRBMethods.m

@implementation NSArray (FRBMethods)

- (NSArray *)map:(id (^)(id item))block
{
  id current;
  NSMutableArray * collection = [NSMutableArray array];
  NSEnumerator * e = [self objectEnumerator];
  
  while (current = [e nextObject]) 
  {
    id result = block(current);
    [collection addObject:result];
  }
  
  return (NSArray *)collection;
}

@end