Re: Fwd: Generalize `E{0,1,2,3,6,9,12}` from `Data.Fixed`

On Mon, 17 Sep 2018, andrew.lelechenko@gmail.com wrote:

Instead of having

``` data E0

instance HasResolution E0 where     resolution _ = 1 ```

and repeating it as many times as there are `E` datatypes, I propose to add the following type:

``` {-# LANGUAGE DataKinds      #-} {-# LANGUAGE KindSignatures #-}

import GHC.TypeLits (Nat, KnownNat, natVal)

data E (n :: Nat) ```

I'd prefer a Haskell 98 solution and simply use type level Peano numbers and define E0, E3 etc. as type synonyms. If this is not sufficiently compatible we could setup a new module.