On Tue, May 19, 2009 at 6:22 PM, Denis Bueno <[email protected]> wrote: > On Tue, May 19, 2009 at 16:07, Jason Dusek <[email protected]> wrote: >> The former page also has a curious discussion of standalone >> deriving with a `for` keyword: >> >> >> http://www.haskell.org/ghc/dist/current/docs/users_guide/type-extensions.html#stand-alone-deriving > > Without this extension, adding an Eq implementation to a data type for > which you do not have source requires an explicit class declaration, > even if there is no reason the original data type author couldn't have > written "deriving Eq". Standalone deriving allows you to get the > convenience of deriving classes everywhere, not just on datatypes for > which you can obtain, and use, the source. > > Denis > _______________________________________________
I think what he's referring to is that StandaloneDeriving actually has the syntax deriving instance Eq Foo not deriving Eq for foo Alex _______________________________________________ Glasgow-haskell-users mailing list [email protected] http://www.haskell.org/mailman/listinfo/glasgow-haskell-users
