modules: import hiding, and usage patterns

[Claus Reinke]

Just saw this wiki update (*)

    http://wiki.ecmascript.org/doku.php?id=harmony:modules&do=diff&1328732818

and this sentence:

    If there is a conflict between the names from two distinct imports,
    and exactly one of the imports uses the ''*'' form, then the other
    import takes precedence.

I have two issues with this:

- implicit override instead of ambiguity warning/error
    (add an explicit import, and change semantics of implicit
    imports elsewhere in the current module, without a type
    system to catch the change)

- no way to filter items from the "*" form
    (can't resolve ambiguities explicitly)

I would prefer a way to resolve such ambiguities explicitly
by selectively hiding imports (import * hiding {x,y} from M),
with warnings/errors for unresolved ambiguities.

If there is going to be an implicit "import *" from a standard
prelude, it would also be good to have a way to turn the
implicit import into an explicit import (with selective hiding).

Great to see updates to the modules proposal - could you
please have a look at the module usage patterns outlined in

    supporting ES upgrading with a programming pattern repo?
    https://mail.mozilla.org/pipermail/es-discuss/2011-November/018240.html

It would be nice to see how these patterns will be handled
by ES6 modules (I hope the answer isn't always "use loaders",
but JS coders seem to have grown used to dynamic module
usage patterns which don't seem covered by the static aspects
of ES6 modules).

Finally, about the wiki: the list of old page revisions for each
proposal links to page revisions, not to diffs - am I missing
something, or could the wiki be configured to add diff links
(to previous revision)? Also, the RSS feed still has escaped
URLs, so the links do not lead to the intended page (*).

Claus

(*) the wiki RSS feed url escape problems still persist:
    https://mail.mozilla.org/pipermail/es-discuss/2011-April/013927.html