Add a test case for tricky type synonyms involving visible dependent kinds
This code does not typecheck on GHC 8.6.1:
{-# LANGUAGE DataKinds #-}
{-# LANGUAGE PolyKinds #-}
module Bug where
import Data.Kind
data A :: Type -> Type
data B a :: A a -> Type
type C a = B aHowever, it //does// typecheck on GHC HEAD, after commit 5e45ad10 (Finish fix for #14880 (closed).). This is very cool, although it does alarm me that there is no test case which checks for this at the moment. Let's add one to ensure that this stays fixed.
Trac metadata
| Trac field | Value |
|---|---|
| Version | 8.7 |
| Type | Bug |
| TypeOfFailure | OtherFailure |
| Priority | normal |
| Resolution | Unresolved |
| Component | Compiler (Type checker) |
| Test case | |
| Differential revisions | |
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| Related | |
| Blocking | |
| CC | |
| Operating system | |
| Architecture |