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

Andres Löh andres at well-typed.com
Wed Apr 3 18:06:32 CEST 2013

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.


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

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