[Haskell-cafe] Haskell is a declarative language? Let's see how easy it is to declare types of things.

[Andres Löh]

Hi Johannes.

I know this isn't really an answer, but ...

> 1. for explicit declaration of type variables, as in
>
> reverse :: forall (a :: *) . [a] -> [a]
>
> I have to switch on RankNTypes and/or KindSignatures (ghc suggests).

... you can do this with "ExplicitForall" rather than "RankNTypes",
which indeed does not enable rank-n types, but only allows you to use
the "forall" syntax.

Cheers,
  Andres

-- 
Andres Löh, Haskell Consultant
Well-Typed LLP, http://www.well-typed.com