How to create block factories in Objective-C

Block Factory Pattern

    BOOL(^(^comparator)(NSString *, NSString *, BOOL))(NSString *, NSDictionary *) = ^BOOL(^(NSString *prefixString, NSString *typeString, BOOL hasNumberedSuffix))(NSString *, NSDictionary *) {
        return ^BOOL(NSString *str, NSDictionary *dict) {
            
            NSString *regexString = [NSString stringWithFormat:@"%@_([0-9]{2})_%@", prefixString, typeString];
            NSError *err = nil;
            NSRegularExpression *regex = [NSRegularExpression regularExpressionWithPattern:regexString options:nil error:&err];
            if ([[regex matchesInString:str options:0 range:NSMakeRange(0, [str length])] count] > 0) {
                return YES;
            } else {
                return NO;
            }
        };
    };