Empty case does not detect kinds
{-# language TypeInType, EmptyCase #-}
module Silly where
import Data.Kind
f :: Type -> Int
f x = case x of
GHC warns
Pattern match(es) are non-exhaustive
In a case alternative: Patterns not matched: _ :: *
In fact, Type
is only a type because of TypeInType
. It has no actual values, so the empty case is exhaustive.
To be honest, I kind of wish GHC would give me a warning for doing something so silly as to even give a function an argument of type Type
, but I imagine that might be hard.
Trac metadata
Trac field | Value |
---|---|
Version | 8.2.1 |
Type | Bug |
TypeOfFailure | OtherFailure |
Priority | low |
Resolution | Unresolved |
Component | Compiler (Type checker) |
Test case | |
Differential revisions | |
BlockedBy | |
Related | |
Blocking | |
CC | |
Operating system | |
Architecture |