Coercible solver incomplete with recursive newtypes
The following module fails to compile due to infinite recursion:
import Data.Coerce
newtype Bar a = Bar (Either a (Bar a))
newtype Age = MkAge Int
x :: Bar Age
x = coerce (Bar (Left (5 :: Int)))
It tries to coerce Bar Int
to Bar Age
. This is clearly doable, via tyconapp decomposition. But we don't find it. Before worrying too much about it, though, we'll wait for a real example.
Do speak up if this problem is ruining your day!
Trac metadata
Trac field | Value |
---|---|
Version | 7.10.1-rc3 |
Type | Bug |
TypeOfFailure | OtherFailure |
Priority | low |
Resolution | Unresolved |
Component | Compiler |
Test case | |
Differential revisions | |
BlockedBy | |
Related | |
Blocking | |
CC | |
Operating system | |
Architecture |