EmptyDataDecls and type context
the following code fails to parse correctly or typecheck under 6.12.1
{-# LANGUAGE EmptyDataDecls #-}
data Show a => Foo a
error:
No context is allowed on a GADT-style data declaration
(You can put a context on each contructor, though.)
it works with 6.10.
this is the reason of HList failure on 6.12.
Trac metadata
Trac field | Value |
---|---|
Version | 6.12.1 |
Type | Bug |
TypeOfFailure | OtherFailure |
Priority | normal |
Resolution | Unresolved |
Component | Compiler |
Test case | |
Differential revisions | |
BlockedBy | |
Related | |
Blocking | |
CC | |
Operating system | |
Architecture |