For type classifying JSON

JsonType.swift

/// Utilities for (eventually) dealing with 

/// To be able to map a dictionary we extend it (from thoughtbot/Argo project)

// pure merge for Dictionaries
func + <T, U>(var lhs: [T: U], rhs: [T: U]) -> [T: U] {
    for (key, val) in rhs {
        lhs[key] = val  /// Potential loss: Same key will lose existing lhs value.
    }
    
    return lhs
}

extension Dictionary {
    func map<T>(f: Value -> T) -> [Key: T] {
        return self.reduce([:]) { $0 + [$1.0: f($1.1)] }
    }
}

/// Move these to own file
public enum JsonValue {
    case Object([Swift.String : JsonValue])
    case Array([JsonValue])
    case String(Swift.String)
    case Number(NSNumber)
    case Null
}


public extension JsonValue {
    static func parse(json: AnyObject) -> JsonValue {
        switch json {
        case let value as [AnyObject]: return .Array(value.map(parse))
            
        case let value as [Swift.String : AnyObject]: return .Object(value.map(parse))
            
        case let value as Swift.String: return .String(value)
            
        case let value as NSNumber: return .Number(value)
        default: return .Null
        }
    }
}