[GHC] #10776: DataKinds promotion of String -> Symbol and Natural -> Nat

GHC ghc-devs at haskell.org
Sun Aug 16 15:43:37 UTC 2015


#10776: DataKinds promotion of String -> Symbol and Natural -> Nat
-------------------------------------+-------------------------------------
        Reporter:  htebalaka         |                   Owner:
            Type:  feature request   |                  Status:  new
        Priority:  normal            |               Milestone:
       Component:  Compiler (Type    |                 Version:  7.10.2
  checker)                           |
      Resolution:                    |                Keywords:  DataKinds
Operating System:  Unknown/Multiple  |            Architecture:
                                     |  Unknown/Multiple
 Type of failure:  None/Unknown      |               Test Case:
      Blocked By:                    |                Blocking:
 Related Tickets:                    |  Differential Revisions:
-------------------------------------+-------------------------------------
Description changed by htebalaka:

Old description:

> Exactly what it says on the tin. It would be nice if the following would
> compile:
>
> {{{#!hs
> {-# LANGUAGE DataKinds, KindSignatures, GADTs #-}
>
> import GHC.TypeLits
> import GHC.Natural
>
> data X = X String Natural
>
> data Y :: X -> * where
>     Y :: Y (X "hello" 4)
> }}}
>
> I kind of assume there's already a ticket for this, but couldn't find
> one, so figured I'd open one in case.

New description:

 Exactly what it says on the tin. It would be nice if the following would
 compile:

 {{{#!hs
 {-# LANGUAGE DataKinds, KindSignatures, GADTs #-}

 import GHC.TypeLits
 import GHC.Natural

 data X = X String Natural

 data Y :: X -> * where
     Y :: Y ('X "hello" 4)
 }}}

 I kind of assume there's already a ticket for this, but couldn't find one,
 so figured I'd open one in case.

--

--
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/10776#comment:1>
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