Working version of Dictionary#map in Swift

dictionary-map.swift

//
// cf. http://nomothetis.svbtle.com/smashing-swift
//
extension Dictionary {
    func map<R>(transform:(ValueType)->R)->Dictionary<KeyType, R> {
        var result:Dictionary<KeyType, R> = [:]
        for (k, v) in self {
            result[k] = transform(v)
        }
        return result
    }
}