get/set values from dictionary with a path

dictionary path

//: Playground - noun: a place where people can play

import UIKit

extension Array {
    private var x:Element? { return self.first }
    private var xs: [Element] { return [Element](self.dropFirst()) }
    var parts: (Element?, [Element]) {
        return (self.x, self.xs)
    }
}

extension Dictionary {
    subscript(path: [Key]) -> Any? {
        get {
            let (x, xs) = path.parts
            switch (x, xs) {
            case (let .Some(key), _) where xs.count == 0:
                return self[key]
                
            case (let .Some(key), _) where xs.count > 0:
                if let sub = self[key] as? Dictionary<Key, AnyObject> {
                    return sub[xs]
                }
            default:
                break
            }
            return nil
        }
        set {
            let (x, xs) = path.parts
            switch (x, xs) {
            case (let .Some(key), _) where xs.count == 0:
                self[key] = newValue as? Value
                
            case (let .Some(key), _) where xs.count > 0:
                var sub = self[key] as? Dictionary<Key, AnyObject>
                if sub == nil {
                    sub = Dictionary<Key,AnyObject>()
                }
                sub![xs] = newValue
                self[key] = sub as? Value
            default:
                break
            }
        }
    }
}

var dictionary: [String: AnyObject] = [
    "a":
    [
        "b":
        [
            "c": "result"
        ]
    ]
]

let path = "a/b/c".componentsSeparatedByString("/")

print("\ndictionary: \(dictionary) \npath: \(path) \nvalue: \(dictionary[path])")
dictionary[path] = "another result"
print()
print("\ndictionary: \(dictionary) \npath: \(path) \nvalue: \(dictionary[path])")

print()
print(dictionary[[]])
dictionary[[]] = "q"
print(dictionary[[]])

let path2 = "z/y/x".componentsSeparatedByString("/")
print("\ndictionary: \(dictionary) \npath: \(path2) \nvalue: \(dictionary[path2])")
dictionary[path2] = "another result"
print()
print("\ndictionary: \(dictionary) \npath: \(path2) \nvalue: \(dictionary[path2])")