[Haskell-cafe] How efficient is read?

[Tom Hawkins]

>
> The tarball was missing its Rules.hs; as it happens, GHC has a module
> named Rules.hs as well, hence the confusing error. I've uploaded a
> fresh one that should work.

Thanks.  This builds and installs fine.

But I think there is something wrong with the generated parser.  It
doesn't look for (..) groupings.  For example:

data Something = Something Int (Maybe String)
  deriving Show {-! derive : Parse !-}

There is nothing in the generated parser to look for parens around the
Maybe in case it is a (Just string).

Am I missing something?