Hello, It seems to me that there are 2 or 3 independend extensions proposed here: 1. The one has nothing to do with qualified names, and allows explicit enumerations in module-style exports,e.g. module M (module A(f,g)) where ... I think the semantics of this should be the same as for "module A", except with an additional filtering that we only export those entities whose original unqualified name matched "f" and "g". Related to this, it might be nice to also allow "hiding" declarations as well. Then we can write things like: module M (moudle M hiding (f)) where... 2. Another proposal is to allow "as" clauses for "module"-style exports, e.g. module M (module A as P) where ... This gives an exporting module some control over how qualified names in the importing module are constructed, e.g. if "f" and "g" were exported from "M": import M as T -- introduces the names "f","g", "T.P.f", "T.P.g" import qualified M as T -- introduces the names "T.P.f", "T.P.g" import M(f) -- introduces "f", and "T.P.f" 3. Then we can also allow for "qualified" module-style exports which is what Sim on wrote, e.g. module M(qualified module A as P) where ... This has a different semantics in non-qualified imports, and the way explicit exports work: import M as T -- introduces "P.f", "P.g", "T.P.f", "T.P.g" import qualified M as T -- introduces "T.P.f", "T.P.g" import M(f) -- error, M does not export "f" import M(P.f) -- introduces "P.f" and "T.P.f" What do people think should happen in the following situation? module N (module M) where import M Should the qualified names paired with the entities be lost or kept? Losing the qualified names in this situation seems to be easier to implement, but perhaps this is not what a programmer expects? -Iavor On Tue, 8 Mar 2005 16:02:38 -0000, Simon Marlow wrote:

On 08 March 2005 15:39, Malcolm Wallace wrote:

...

"Simon Marlow" writes:

...

...

module R( qualified module Q( f,g ) ) where f = ...; g = ...

If we're going to allow (... items ...) at all, then I suggest instead that the last example be written:

module R( qualified module R(f,g) as Q ) where f = ...; g = ...

I initially understood the first form to mean something different, although admittedly the original example does not actually illustrate it:

module R( f,g, qualified module Q( f,g ) ) where import qualified Q (f,g,h) f = ...; g = ...

That is, the subordinate items mentioned in conjunction with the qualified export are a subset of those imported from Q, not those defined in R. Within the subordinate clause of the export list, they do not need further qualification since they belong unambiguously to Q.

Yes, I think we're all on the same page here. That's my understanding of the meaning of 'qualified module Q(f,g)' too, and I think it's what Simon intended.

Cheers, Simon _______________________________________________ Libraries mailing list Libraries@haskell.org http://www.haskell.org/mailman/listinfo/libraries