[Python-3000] [Python-Dev] Python 3000 Status Update (Long!)

[Greg Ewing]

Nick Coghlan wrote:
> There is no function call per loop even when using a 
> generator expression - a generator function is implicit defined, and 
> then called once to instantiate the generator.

You're right -- I must have been half-thinking of
map() at the time. Resuming the generator ought to
be faster than a function call. But still a bit
slower than in-line code, perhaps.

> I believe the point of adding set 
> literal and comprehension syntax is to make it possible to easily speed 
> up membership tests for items in known groups

Yes, but set(generator) would do that just as well
as {generator} if it weren't any slower.

So the reasons for keeping the comprehension notations
are (a) slightly more convenient syntax and (b) maybe
a bit faster.

--
Greg