Runtime representation confusingly displayed
- 3.20170605:
> :set -XRankNTypes -XTypeInType
> import GHC.Exts (TYPE, RuntimeRep(LiftedRep))
> type Pair (a::TYPE rep) (b::TYPE rep') rep'' = forall (r::TYPE rep''). (a -> b -> r) -> r
> :kind Pair
Pair :: * -> * -> *
> :kind Pair Int
Pair Int :: * -> *
> :kind Pair Int Float
Pair Int Float :: *
> :kind Pair Int Float LiftedRep
Pair Int Float LiftedRep :: *
It still behaves oddly with -fprint-explicit-runtime-reps
enabled
> :set -fprint-explicit-runtime-reps
> :kind Pair
Pair :: * -> * -> forall (rep'' :: RuntimeRep) -> *
> :kind Pair Int
Pair Int :: * -> forall (rep'' :: RuntimeRep) -> *
> :kind Pair Int Float
Pair Int Float :: *
> :kind Pair Int Float LiftedRep
Pair Int Float LiftedRep :: *
I would have also expected to see Pair
's kind displayed something like this
forall {rep :: RuntimeRep} {rep' :: RuntimeRep}. TYPE rep -> TYPE rep' -> forall (rep'' :: RuntimeRep) -> *
which is how the kind of the corresponding newtype
gets displayed
> newtype Pair2 (a::TYPE rep) (b::TYPE rep') rep'' = P2 (forall (r::TYPE rep''). (a -> b -> r) -> r)
> :kind Pair2
Pair2 :: forall {rep :: RuntimeRep} {rep' :: RuntimeRep}.
TYPE rep -> TYPE rep' -> forall (rep'' :: RuntimeRep) -> *
Trac metadata
Trac field | Value |
---|---|
Version | 8.0.1 |
Type | Bug |
TypeOfFailure | OtherFailure |
Priority | normal |
Resolution | Unresolved |
Component | Compiler |
Test case | |
Differential revisions | |
BlockedBy | |
Related | |
Blocking | |
CC | |
Operating system | |
Architecture |