NSString SyntacticSugar Category

NSString+SyntacticSugar.m

#define NUMARGS(...)  (sizeof((id[]){__VA_ARGS__})/sizeof(id))
#define $(...) ([NSString concatenateObjectsWithObjectCount:NUMARGS(__VA_ARGS__) objectList:__VA_ARGS__])

#import <Foundation/Foundation.h>

@interface NSString (SyntacticSugar)

+ (instancetype)concatenateObjectsWithObjectCount:(NSInteger)count objectList:(id)firstObject, ...;

@end


@implementation NSString (SyntacticSugar)

+ (instancetype)concatenateObjectsWithObjectCount:(NSInteger)count objectList:(id)firstObject, ...{
    
    NSMutableArray *arguments = [NSMutableArray array];
    id object;
    // pointer to variable argument list
    va_list argumentList;
    
    // set argumentList to point to firstObject
    va_start(argumentList, firstObject);
    object = firstObject;
    
    while (true) {
        // Only add object if its non-nil or not NSNull
        if (object && object != [NSNull null]) {
            [arguments addObject:object];
        } else {
            count--;
        }
        // break once we've processed all valid objects in argumentList
        if (arguments.count >= count) {
            break;
        }
        // get the next argument on the list
        object = va_arg(argumentList, id);
    }
    // release memory
    va_end(argumentList);
    
    return [arguments componentsJoinedByString:@""];
    
}


@end