Generic Currying in Objective-c

gistfile1.m

//The magic method
-(id (^)(id,...)) getSelector:(SEL) aSelector forTarget:(id) target withFirstArguments:(id) firstArguments, ... {
    
    NSMutableArray* firstArgumentsArray = [NSMutableArray array];
    va_list first_args;
    va_start(first_args, firstArguments);
    do
    {
        [firstArgumentsArray addObject:firstArguments];
    }
    while( (firstArguments = va_arg(first_args,id)) );
    
    va_end(first_args);
    
    id (^blockName)(id,...) = ^id(id values,...) {
        
        SEL theSelector;
        NSMethodSignature *aSignature;
        NSInvocation *anInvocation;
        
        
        theSelector = aSelector;
        aSignature = [self methodSignatureForSelector:theSelector];
        
        anInvocation = [NSInvocation invocationWithMethodSignature:aSignature];
        [anInvocation setSelector:theSelector];
        [anInvocation setTarget:self];
        int index = 2;

        for (id firstArgumentId in firstArgumentsArray) {
            id coiso = firstArgumentId;
            [anInvocation setArgument:&coiso atIndex:index++];
        }
        
        va_list args;
        va_start(args, values);
        id value = values;
        do
        {
            [anInvocation setArgument:&value atIndex:index++];
        }
        while( (value = va_arg(args,id)));
        
        va_end(args);
        
        [anInvocation invoke];
        id tempResult;
        [anInvocation getReturnValue:&tempResult];
        id result = tempResult;
        return result;
    };
    
    return blockName;
    
}

//Example methods
-(id) sumA:(NSNumber*) a WithB:(NSNumber*) b {
    return [NSNumber numberWithInt:([a intValue] + [b intValue])];
}

-(id) sumA:(NSNumber*) a WithB:(NSNumber*) b withC:(NSNumber*) c{
    return [NSNumber numberWithInt:([a intValue] + [b intValue] + [c intValue])];
}



//Usage
id (^blockName)(id,...) = [self getSelector:@selector(sumA:WithB:) forTarget:self withFirstArguments:@2,nil];
NSLog(@"%@",blockName(@3,nil)); //Output: 5
    
blockName = [self getSelector:@selector(sumA:WithB:withC:) forTarget:self withFirstArguments:@2,nil];
NSLog(@"%@",blockName(@3,@4,nil)); //Output: 9
    
blockName = [self getSelector:@selector(sumA:WithB:withC:) forTarget:self withFirstArguments:@2,@5,nil];
NSLog(@"%@",blockName(@1,nil)); //Output: 8