16 Jan
2012
16 Jan
'12
10:22 a.m.
2012/1/16 Simon Hengel
voidM :: Monad m => m a -> m () voidM m = m >> return ()
Is voidM meant to be used with instance of Monad that are no monads, and hence have no Functor instance (like HtmlM[1])?
You could easily implement a Functor instance for this type, since it would mirror the instance for `Const a` [2], i.e. only change the type parameter, and otherwise be the identity function. Erik [1] http://hackage.haskell.org/packages/archive/blaze-html/0.4.3.1/doc/html/Text... [2] http://hackage.haskell.org/packages/archive/base/latest/doc/html/Control-App...