SortedDictionary used to sort contents before JSON serialization

SortedDictionary.swift

// We have a parent just to pass face control in JSONSerialization
@objc class SortedDictionary: NSDictionary {
    let _values: NSMutableArray = []
    let _keys: NSMutableOrderedSet = []

    override var count: Int {
        return _keys.count
    }

    override func keyEnumerator() -> NSEnumerator {
        return _keys.objectEnumerator()
    }

    override func object(forKey aKey: Any) -> Any? {
        let index = _keys.index(of: aKey)
        if index != NSNotFound {
            return _values[index]
        }
        return nil
    }

    private func setObject(_ anObject: Any, forKey aKey: String) {
        let index = _keys.index(of: aKey)
        if index != NSNotFound {
            _values[index] = convertObject(anObject)
        } else {
            _keys.add(aKey)
            _values.add(convertObject(anObject))
        }
    }

    private func convertObject(_ object: Any) -> Any {
        if let dict = object as? [String: Any] {
            return SortedDictionary(dict)
        } else if let array = object as? [Any] {
            return array.map {
                convertObject($0)
            }
        } else {
            return object
        }
    }

    @objc convenience init(_ dictionary: [String: Any]) {
        self.init()
        dictionary.sorted {
            $0.0.compare($1.0, options: [.caseInsensitive, .forcedOrdering]) == .orderedAscending
        }
        .forEach {
            self.setObject($0.value, forKey: $0.key)
        }
    }
}

@molind I found a sorting bug: "a" and "A" will be randomized, so the output will not be stable. It can be fixed by specifying [.forcedOrdering, .caseInsensitive]

@molind I found a sorting bug: "a" and "A" will be randomized, so the output will not be stable. It can be fixed by specifying [.forcedOrdering, .caseInsensitive]

Thanks for mentioning this. I'll update gist right now.