hugs / ghc difference over '(..)' imports

[Duncan Coutts]

There is a difference between hugs and ghc in how they treat imports with the 
'(..)' notation. Here's my example:

module CTree(
	--other stuff
	Const(..)
   ) where

import ATree (Const)

--const has constructors CInt, CChar, CStr

under hugs this module exports CInt, CChar, CStr
but under ghc it does not. Under ghc it only exports the constructors if I 
import 'Const' like this:

import ATree (Const(..))

I don't know which is the right behaviour w.r.t. the H98 standard, but it 
tripped me up.

Duncan