On Sat, 13 Jun 2009, John Yeung wrote: > On Jun 13, 5:22 pm, "Rhodri James" <rho...@wildebst.demon.co.uk> > > wrote: > > Such an understanding would be clearly wrong in the context > > in which we were talking (and denotational semantics is a > > branch of category theory, which is not specific to computer > > science if you don't mind). If None is nothing, then it can't > > be a string, int, float or anything else, because they're all > > something. > > I appreciate your explanation, and your politeness. > > And I accept your answer, as well as Steven's and Paul's for that > matter. I still think it is understandable (and people may choose to > understand in a condescending way, if they wish) that someone might > not get the difference between what you are saying and the statement > that all elements of the empty set are floats. I mean, what's in the > empty set? Nothing. But you've said that floats are something. How > is it that nothing is something? [...]
Also accepting that Python's implementation of None and all() are well-defined and practical, I would add that philosophically these matters of emptiness and nothingness are far from concluded. Bertrand Russell, for one, would have disputed the behaviour of all([]), although he may have appreciated its usefulness. Regards, John
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