On 3/31/10 12:44, Heinrich Apfelmus wrote:
go Next (Single x t1) = liftM (Single x) (rewrite f t1) go Next (Fork t1 t2 ) = liftM2 Fork (rewrite f t1) (rewrite f t2)In particular, liftM and liftM2 make it apparent that we're just wrapping the result in a constructor.
A small remark: I prefer using applicative notation for this:
go Next (Single x t1) = Single x <$> rewrite f t1 go Next (Fork t1 t2 ) = Fork <$> rewrite f t1 <*> rewrite f t2
Martijn. _______________________________________________ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
