On Sep 8, 2010, at 8:19 AM, Kevin Jardine wrote: > Hi Tony, > > I stared at that specific section for at least half an hour earlier > today but could not figure out how it applied in my specific case. The > only examples I have see are for deriving Num. Do you have any more > detail on how I could use that extension? > > Kevin > > On Sep 8, 2:05 pm, Tony Morris <[email protected]> wrote: >> I think you might want -XGeneralizedNewtypeDeriving >> >> http://haskell.org/ghc/docs/6.12.2/html/users_guide/deriving.html#id6... >> >> On 08/09/10 22:01, Kevin Jardine wrote: >>
I'm not sure if it's what he originally had in mind, but if your Obj class has a ToObj instance (which would be reasonable), then that extension allows your other classes to derive it: > newtype Foo = Foo Obj deriving ToObj -- James_______________________________________________ Haskell-Cafe mailing list [email protected] http://www.haskell.org/mailman/listinfo/haskell-cafe
