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Getting a Typeable instance for (':)

I'm trying to get a Typeable instance for (':)

I am using DataKinds and [*].

I have TypeOperators, StandaloneDeriving and PolyKinds enabled

I cannot get an instance like

I tried

deriving instance Typeable (':)

and

deriving instance Typeable ':

and

deriving instance Typeable ((':))

but they all get parsing errors.

I know that if I write

data List a = Cons a (List a) | Empty

deriving instance Typeable (Cons)

I get the expected result, but I don't want to rewrite my existing code to use my own list type.

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1 answer


It seems to work

 deriving instance Typeable '(:)


Presumably '

intended to mean a "full type constructor", including if it's stripped? Seems a little odd to me. This is consistent with tuples, however where you write

'(a, b)
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