id	summary	reporter	owner	description	type	status	priority	milestone	component	version	resolution	keywords	cc
220	Parse error when TypeFamilies and ConstraintKinds collide	NeilMitchell	nibro	"An HLint user reported: http://code.google.com/p/ndmitchell/issues/detail?id=543

{{{
» cat ParseError.hs                                                                                                                                     {-# LANGUAGE TypeFamilies #-}
{-# LANGUAGE ConstraintKinds #-}
class Foo a where type Bar a
type Bazable a b = (Bar a ~ Maybe b)
baz :: Bazable a b => a -> a
baz = id
}}}

Gives: Parse error in type: Bar a ~ Maybe b

The failure only occurs when I have a `~` constraint in a constraint kind. ~ constraints normally work, and constraint kinds normally work, but together HSE explodes."	bug report	new	major		parser				NeilMitchell