Re: Making rule application less fragile

Note also that you are attaching your rule to 'fmap', however, since your rule only applies to the 'Parser' monad (if I am reading it properly) then 'fmap' will have been replaced by the 'fmap' in the Functor Parser instance. So you would probably be better off doing something like instance Functor Parser where fmap = parserFmap {-# RULES forall x . parserFmap S.pack ( ... Also, you have to be careful attaching rules to functions you don't define, as you don't know how it will interact with other rules, inline pragmas or whatnot that might already be attached to that function. John -- John Meacham - ⑆repetae.net⑆john⑈