GHCi does not support some TH elements, while those elemenst are working in hs files

Hello. Below is a code, which works when using runhaskell, but does not work in GHCi.

In GHCi we get following error: runQ [d| instance ( y ~ (t->t) ) => Member Vector y where member v = test |] <interactive>:19:6:

Exotic predicate type not (yet) handled by Template Haskell

y ~ (t -> t)

code:

{-# LANGUAGE TypeFamilies #-} {-# LANGUAGE FlexibleContexts #-} {-# LANGUAGE UndecidableInstances #-} {-# LANGUAGE FlexibleInstances #-} {-# LANGUAGE MultiParamTypeClasses #-} {-# LANGUAGE TemplateHaskell #-} module Main where

import Language.Haskell.TH

class a ~ b => HEq a b

test :: a -> a test x = x

data Vector class Member a b where member :: a -> b

main :: IO () main = print =<< runQ [d| instance y ~ (t->t) => Member Vector y where member v = test |]

Trac metadata

Trac field	Value
Version	7.7
Type	Bug
TypeOfFailure	OtherFailure
Priority	normal
Resolution	Unresolved
Component	GHCi
Test case
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CC	hvr
Operating system
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