At 21:08 02.05.2004 -0700, Guido van Rossum wrote:
Armin Rigo <arigo@tunes.org>:
Early binding is closer to the idea that turning a listcomp into a genexprs should just work if you only iterate once on the result.
Greg Ewing:
I'm not sure that's an idea we should be promulgating in the first place. The original motivation for generator expressions was things like
total = sum(x**2 for x in stuff)
where not only will the sequence be used just once, but it will be used *immediately* before doing anything else.
yes, but the question is how much easy is to grasp what "used *immediately*" means for a genexp, or IOW how much education is needed. this looks innocent enough: l = list_of_my_strings() for pfx in discard_prefixes: l = ( x for x in l if not x.startswith(pfx) ) # this is not using l *immediately* use_strings(l)
Those are the use cases we need to advertise this as targeting, I think, not "any listcomp that's only used once".
Right -- thanks for saying it so clearly! Early binding seems to be trying to solve a problem with a use for genexprs that's questionable at best.