Access a nested element using NSIndexPath

Question

Is there an API to use NSIndexPathfor navigating / accessing a nested array design in the iOS SDK? I looked through the docs for NSIndexPathand NSArray?

For instance:

NSArray *nested = @[
    @[
        @[@1, @2], @[@10, @20]
    ],
    @[
        @[@11, @22], @[@110, @220]
    ],
    @[
        @[@111, @222], @[@1110, @2220]
    ]
];

If I wanted to simulate the access path to @ 222, I could compile:

NSIndexPath *path = [[[NSIndexPatch indexPathWithIndex: 2] indexPathByAddingIndex: 0] indexPathByAddingIndex: 1];

So, do I need to write my own recursive accessor?

id probe = nested;
for (NSInteger position = 0; position < path.length; position++) {
    probe = probe[path indexAtPosition: position];
}

I would be struck by the fact that Apple went so far as to actually simulate the design, but then did not provide an API to combine the two. I would expect a method on NSArrayor NSIndexPaththat would do something like:

id value = [nested objectAtIndexPath: path];

Or maybe there is a more idiomatic twist that I miss?

---

UPDATE:

I decided to follow the advice of @CrimsonChris and compiled the following:

NSArray + NestedAccess.h

#import <Foundation/Foundation.h>
@interface NSObject (NestedAccess)
- (id) objectAtPath: (NSIndexPath*) path;
@end

NSArray + NestedAccess.c

#import "NSArray+NestedAccess.h"
@implementation NSArray (NestedAccess)
- (id) objectAtPath: (NSIndexPath*) path {
    id probe = self;
    for (NSInteger position = 0; position < path.length; position++) {
        probe = ((NSArray*)probe)[path indexAtPosition: position];
    }
    return probe;
}
@end

Answer 1

, NSIndexPath! NSIndexPath " " NSArrays. .

Answer 2

:

NSLog (@"nested 222: %@", nested[2][0][1]);

NSLog:

222: 222

, , , :

@222, :

NSIndexPath, , . .