Using a switch case to unwrap optionals when parsing JSON data (Swift 1.2)

gistfile1.as

import Foundation

func parse( data: NSData ) {
    var error: NSError? = nil
    switch NSJSONSerialization.JSONObjectWithData( data, options: nil, error: &error ) {
    case .Some(let dictionary as NSDictionary):
        println( "JSON contained dictionary: \(dictionary)" )
    case .Some(let array as NSArray):
        println( "JSON Contained array: \(array)" )
    default:
        println( "Could not parse: \(error)" )
    }
}

parse( "{\"hello\" : \"world\"}".dataUsingEncoding( NSUTF8StringEncoding, allowLossyConversion: true)! )

parse( "[\"hello\", \"world\"]".dataUsingEncoding( NSUTF8StringEncoding, allowLossyConversion: true)! )

parse( "not json".dataUsingEncoding( NSUTF8StringEncoding, allowLossyConversion: true)! )