On Mon, Apr 23, 2018 at 4:54 PM, Greg Ewing <[email protected]> wrote: > Tim Peters wrote: > >> if (diff := x - x_base) and (g := gcd(diff, n)) > 1: >> return g > > > My problem with this is -- how do you read such code out loud?
It could be-- "if diff, which we let equal x - x_base, and g, which ..." or "if diff, which we set equal to x - x_base, and g, which ...." or "if diff, which we define to be x - x_base, and g, which ...." or "if diff, which we define as x - x_base, and g, which ....." etc. --Chris > > From my Pascal days I'm used to reading ":=" as "becomes". So > this says: > > "If diff becomes x - base and g becomes gcd(diff, n) is > greater than or equal to 1 then return g." > > But "diff becomes x - base" is not what we're testing! That > makes it sound like the result of x - base may or may not > get assigned to diff, which is not what's happening at all. > > The "as" variant makes more sense when you read it as an > English sentence: > > if ((x - x_base) as diff) and ... > > "If x - x_base (and by the way, I'm going to call that > diff so I can refer to it later) is not zero ..." > > -- > Greg > > _______________________________________________ > Python-Dev mailing list > [email protected] > https://mail.python.org/mailman/listinfo/python-dev > Unsubscribe: > https://mail.python.org/mailman/options/python-dev/chris.jerdonek%40gmail.com _______________________________________________ Python-Dev mailing list [email protected] https://mail.python.org/mailman/listinfo/python-dev Unsubscribe: https://mail.python.org/mailman/options/python-dev/archive%40mail-archive.com