scalaz
Union types using Curry-Howard isomorphism
http://en.wikipedia.org/wiki/Curry-Howard_correspondence
http://www.chuusai.com/2011/06/09/scala-union-types-curry-howard/
Union types using Curry-Howard isomorphism
http://en.wikipedia.org/wiki/Curry-Howard_correspondence
http://www.chuusai.com/2011/06/09/scala-union-types-curry-howard/