GHC 5.02, import Prelude hiding ...

Malcolm Wallace Malcolm.Wallace@cs.york.ac.uk
Sat, 13 Oct 2001 21:44:19 +0100


> In the current Report draft, the idea is that a hiding clause hides
> both qualified and unqualified names
> 
> 	import Foo hiding( f )
> hides Foo.f as well as unqualified f.
> 
> I think we all agreed that is a good change.  But we (ahem, I) forgot
> to propagate that change to the sections about the Prelude.

That's odd, because in my paper copy of the Report, I had already
(many months ago) scored out the following sentence in section 5.6.1:

  "The Prelude module is always available as a qualified import:
   an implicit `import qualified Prelude' is part of every module
   and names prefixed by `Prelude.' can always be used to refer to
   entities in the Prelude."

So I think you must have declared this as a definite change at some
point in the past, although I agree that the errata list as of today
does not seem to specify its removal.  Maybe a CVS conflict that got
resolved the wrong way or something?

> The fact that this makes the Report behave like GHC is purely
> coincidental :-)

And the fact that I have now (last week actually) fixed nhc98 to match
ghc's behaviour, based on my already-amended paper copy of the Report,
is just confirmation that this is the correct course of action.  :-)

Regards,
    Malcolm