Type family and GADT error
This bug was posted to glasgow-haskell-users@haskell.org by Roberto Zunino, archived at http://www.haskell.org/pipermail/glasgow-haskell-users/2007-September/013149.html I am copying the post with the bug into trac:
Here's unsafeCoerce:
type family Const a type instance Const a = ()
data T a where T :: a -> T (Const a)
coerce :: forall a b . a -> b coerce x = case T x :: T (Const b) of T y -> y
And this indeed "works"... Here's the result with the latest RC:
- TypeFam> coerce () 2
<interactive>: internal error: stg_ap_v_ret
(GHC version 6.9.20070918 for x86_64_unknown_linux)
Please report this as a GHC bug: http://www.haskell.org/ghc/reportabug
Aborted
Regards, Zun.
Trac metadata
Trac field | Value |
---|---|
Version | 6.9 |
Type | Bug |
TypeOfFailure | OtherFailure |
Priority | high |
Resolution | Unresolved |
Component | Compiler (Type checker) |
Test case | |
Differential revisions | |
BlockedBy | |
Related | |
Blocking | |
CC | |
Operating system | Unknown |
Architecture | Unknown |