Autocomplete and refactoring compatible keyPaths: https://holtwick.de/blog/keypath-refatoring

KeyPathHelper.m

// (C)opyright 2018-06-20 Dirk Holtwick, holtwick.it. All rights reserved.

#import <Foundation/Foundation.h>

#define keyPath(k) YES ? @#k : (k ? @"": nil)
#define keyPathFromObject(o, k) YES ? @#k : ((o ?: o.k) ? @"" : nil)

@interface Sample : NSObject
@property id greeting;
@end

@implementation Sample
@end

@interface Demo : NSObject
@property Sample *sample;
@end

@implementation Demo

- (instancetype)init {
    self = [super init];
    if (self) {
        self.sample = [[Sample alloc] init];
        self.sample.greeting = @"Hello World";

        id akp = keyPath(self.sample.greeting);
        id a = [self valueForKeyPath:akp];
        NSLog(@"Result: %@ = %@", akp, a);

        id bkp = keyPathFromObject(self.sample, greeting);
        id b = [self.sample valueForKeyPath:bkp];
        NSLog(@"Result: %@ = %@", bkp, a);

        NSAssert([a isEqualToString:b], @"Same");
    }
    return self;
}

@end

int main(int argc, const char * argv[]) {
    @autoreleasepool {
        [[Demo alloc] init];
    }
    return 0;
}