[Haskell-cafe] Type-directed functions with data kinds

Andres Löh andres.loeh at gmail.com
Thu Oct 25 18:03:07 CEST 2012


Hi Iavor.

> If you don't want to use the class system, you could write `repeat` with a
> type like this:
>
>     repeat :: Proxy n -> a -> Vector n a
>
> (`Proxy` is the singleton family 'data Proxy n = Proxy`).

How is the polymorphism becoming any less parametric by using this
particular Proxy type?

Cheers,
  Andres



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