On Thu, Sep 22, 2016 at 11:42 AM, Steven D'Aprano <st...@pearwood.info>
> > This makes it necessary to use string representation for names
> > that are not yet bound, which affects almost every class definition.
> Almost every class? Really? I find that implausible. Still, I can see it
> affecting *many* class definitions, so let's not quibble.
I would say this affects a "rare class here and there." Almost all typing
will be with things defined in the `typing` module (or built-ins). I guess
once in a while we'll see e.g. `Sequence[CustomThing]`, but it will be
uncommon for that typing involving `CutomThing` to be within CustomThing
itself (well, unless you use much more recursion than Python encourages).
> -1 on complicating the simple Python model that expressions are
> evaluated when they are reached.
I think there is a decent argument for a more general concept of macros, or
symbols, or simpler delayed evaluation than lambda for Python in general.
I see places where this would be very nice for Pandas, for example, and for
Dask (I work with the developers of both of those projects).
In such a hypothetical future world we might come to allow, e.g.
`Sequence[#CustomThing]` where some general lazy facility or indirection is
indicated by the '#' (just a placeholder for this comment, not a
proposal). But if that comes about, it should be available everywhere, not
only in annotations.
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