Yehuda Katz wrote:
> I would be open to making it take a block, but I'm not aware of any 
> use-case where that would be helpful, so I left it out at the beginning 
> to reduce the need for extra ceremony.
...
> Again, I'm open to doing it a different way. I chose this initially 
> because it makes it easier to implement at parse-time (which is required 
> for performance) and because I can't think of any use-case where more 
> granular application of namespaces would actually be useful, but I'd be 
> fine with "use" taking a block if it moved the proposal forward.

I suppose there's another argument in favor of an explicit bounding of 
the "use" area: where do you *start*? If this is parse time, having it 
start at the first "use" call seems a little odd; you'd almost want it 
to be a whole-file pragma. But starting it at the beginning of the file 
seems just as odd, since a use anywhere in the body changes all method 
dispatches.

- Charlie