Unlifted class method rejected
If I say
class C a where
meth :: Array# a
I get
• Expecting a lifted type, but ‘Array# a’ is unlifted
• In the type signature: meth :: Array# a
In the class declaration for ‘C’
This definition looks OK to me. I don't see why we can't have an unlifted member of a class.
(As @oerjan points out in ticket:12708#comment:128807, we can't have a levity-polymorphic class member, but this is solidly levity-monomorphic.)
I'm happy to lift this restriction in ongoing work in this area, but I wanted to double-check before doing so.
For the record, the same error occurs even when the class has more than one member, so it's not the no-unlifted-newtypes restriction.
Trac metadata
Trac field | Value |
---|---|
Version | 8.1 |
Type | Bug |
TypeOfFailure | OtherFailure |
Priority | normal |
Resolution | Unresolved |
Component | Compiler |
Test case | |
Differential revisions | |
BlockedBy | |
Related | |
Blocking | |
CC | |
Operating system | |
Architecture |