Kata 9/23 Block Methods

typedef NSInteger (^ib_enum_bool_t)(id);
typedef id (^ib_enum_id_t)(id);

- (void)deleteIf:(ib_enum_bool_t)blk {
    for (NSInteger i = (self.count - 1); i >= 0; --i) {
        if (blk([self objectAtIndex:i])) {
            [self removeObjectAtIndex:i];
        }
    }
}

- (NSArray *)map:(ib_enum_id_t)blk {
    NSMutableArray *mappedArray = [NSMutableArray array];

    for (NSInteger i = (self.count - 1); i >= 0; --i) {
        [mappedArray unshiftObject:blk([self objectAtIndex:i])];
    }

    return mappedArray;
}