Spec: Version and platform checking underspecified

Currently, the "Version and platform checking" section of the typing spec is very barebones. It basically says:

Type checkers are expected to understand simple version and platform checks. [...] Don’t expect a checker to understand obfuscations like "".join(reversed(sys.platform)) == "xunil".

Of course, there's a world of difference between these two forms.

The type stubs document goes into a bit more of detail, and reflects the currently implemented functionality quite well, as far as I know. It would be a good starting point.

Maybe it would also make sense to support platform checks using startswith(), as that is officially recommended in the Python docs, and is required to properly support some Unix variants, like FreeBSD, that include the version number in the platform string. See also python/typeshed#11876.

Inizia confrontando la sezione “Version and platform checking” della specifica di typing con il documento collegato sugli stub dei tipi, che riflette il comportamento attuale. Esamina la documentazione di Python e la issue di typeshed collegate nel report, quindi definisci i controlli supportati e decidi se startswith() debba appartenere alla specifica. Il lavoro è completato quando la specifica descrive con precisione il comportamento previsto per il controllo della versione e della piattaforma.