List rules for `Coercible` instances
:info
on Data.Coerce.Coercible doesn't display any instances, it's a special class so it should be special-cased
ghci> :i Coercible
type role Coercible representational representational
class a ~R# b => Coercible (a :: k) (b :: k)
-- Defined in ‘GHC.Types’
The base case would be easy to display:
instance Coercible a a -- Generated on the fly
but it's trickier to describe the … instance succinctly:
instance Coercible b b' => Coercible (D a b c) (D a b' c')
same for newtypes.
Maybe it's better to list concrete examples
coerce @(Reader _ _)
:: Reader a b -> (a -> Identity b)
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 |