I ported Haskell's [Aeson](http://hackage.haskell.org/package/aeson-0.10.0.0/docs/Data-...) library to [Swift](https://github.com/PKAuth/SwiftAeson). You might find it helpful with verbosity and better type checking. Note that there is some hackery to satisfy Swift's type checker (and its type inference usually doesn't help too much).