id	summary	reporter	owner	description	type	status	priority	milestone	component	version	resolution	keywords	cc	os	architecture	failure	difficulty	testcase	blockedby	blocking	related
1772	GHC doesn't like 'inline' type function applications	jpbernardy	chak	"{{{
{-# LANGUAGE TypeFamilies #-}

import Prelude hiding (foldl, foldr, foldl1, foldr1, mapM_, sequence_,
		elem, notElem, concat, concatMap, and, or, any, all,
		sum, product, maximum, minimum)
import Data.Monoid

type family Element t

class Foldable t where
        foldMap :: Monoid m => (Element t -> m) -> t -> m

	foldr :: (Element t -> b -> b) -> b -> t -> b
	-- foldr :: Element t ~ a => (a -> b -> b) -> b -> t -> b
	foldr f z t = appEndo (foldMap (Endo . f) t) z
}}}
GHC chokes on the above module. If the signature of foldr is replaced by the commented one, GHC is happy. It seems to me that the two expressions should be equivalent."	bug	closed	normal	6.10 branch	Compiler (Type checker)	6.9	fixed			Unknown/Multiple	Unknown/Multiple		Unknown