On Sat, Jul 18, 2020 at 3:29 AM <emmanuel.coir...@caissedesdepots.fr> wrote:
> > adept at ignoring them, we will again have difficulties when debugging > > as we won't easily see them. > > Besides which, the problem is solved: > > > > namespace.var is a lookup > > var is a store > > These rules can't be deduced from a few examples, or from experience from > other languages. You have to explicitly learn them. Since newcomers won't > propably learn them first (if at all), they won't understand how it works, > and they will propably introduce bugs hard to debug. They'll think it's a > kind of "swith case" new construct, and will use it that way, completly > ignoring the "capturing" property that shows in some cases and not in > others. > > match entree[-1]: > case Sides.SPAM: > # newcomers will understand that entree[-1] == Sides.SPAM and > write the code they need > > SPAM = "spam" > match entree[-1]: > case SPAM: > # newcomers will understand that entree[-1] == "spam" and > write the code they need > # ignoring that now, in the following code, SPAM == anything > but "spam" > # introducing a bug anywhere in the following code where SPAM > is expected to hold the > # initial value > If a constant's actually constant, as in SPAM: Final = "spam" then it'll throw an error. Likewise, the first time it does something totally unexpected like insert something into what they thought held a match pattern, it'll break their initial assumptions and hopefully get them to read the documentation, to form a more accurate mental model. <http://python.org/psf/codeofconduct/>As long as > namespace.var is a lookup > var is a store is big, bold, and front & center in the docs, I think everyone will catch on very quickly and wrap their vars in a class, even if they never use it for more than a glorified switch-case. Designing an entire feature around what someone who's never encountered it before thinks it might do doesn't seem useful, since anyone could bring any number of assumptions. -Em
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