id,summary,reporter,owner,description,type,status,priority,milestone,component,version,resolution,keywords,cc,os,architecture,failure,difficulty,testcase,blockedby,blocking,related
5853,Out-of-memory crash when using RULES and type families,porges,simonpj,"GHC(i) 7.4.1 crashes with an OOM error on the following code:

{{{
{-# LANGUAGE NoImplicitPrelude, TypeFamilies #-}

import Prelude (undefined,Bool(..),Show(..),(.))

type family Elem f :: *
type family Subst f b :: *

class (Subst fa (Elem fa) ~ fa) => F fa where
	(<$>) :: (Elem fa ~ a, Elem fb ~ b,
	          Subst fa b ~ fb, Subst fb a ~ fa) =>
			 (a -> b) -> (fa -> fb)

{-# RULES
""map/map"" forall f g xs. f <$> (g <$> xs) = (f.g) <$> xs
	#-}
}}}",bug,closed,high,7.4.2,Compiler,7.4.1,fixed,,dimitris@…,Windows,x86_64 (amd64),Compile-time crash,Unknown,typecheck/should_fail/T5853,,,