Readability changes:
* Tweak framing to also acknowledge that variadic generics have been wanted for other things too (though as far as I've been able to tell there isn't a consistent enough pattern to the other use cases to justify including them in the PEP)
* Move the Array example much earlier (both because reading a detailed example is going to be a faster way of getting the gist for people in a hurry, and because we want to make it clear to numerical computing folks from the start that we can also specify a datatype here). (We still have a more detailed Array example later; I'm leaving that there for the time being pending some discussion with Pradeep, but eventually I guess it'll be removed and absorbed into this earlier example)
* Make it clear that other types can appear in `Union` alongside `TypeVarTuple` instances.
Semantic changes:
* Disallow a `Union` of more than one type variable tuple (I thought this would be easier than concatenation of more than one type variable tuple, but Pradeep points out it could still get hairy for type checkers, so disallow it for now to be on the safe safe)
Also some *more* type fixes...
Semantic changes:
* Unparameterised variadics are compatible with parameterised variadics in both direction
* Allow suffixing
Readability changes:
* De-emphasise unparameterised `Array` behaving like `Array[Any, ...]` to avoid the suggestion that `Array[Any, ...]` might be supported
* Explicitly forbid `Array[Any, ...]` and similar
* Clarify that only `*args` can be annotated as `*Ts`; other arguments must use `Tuple[*Ts]`
* Remove 'Final Notes' section (I was hoping we'd have more edge cases to add to this, but in the end there haven't been any, and the only example we do have is obscure enough that I think we can just remove it)
Also some minor typo fixes.
There was confusion around what to do with SERVER_PORT if HTTP_HOST is
sent. Now it's clear these two variables are only used if HTTP_HOST is
not present.
* PEP 646: Simplify based on typing-sig discussions
Feature removals:
* Remove `Map` (to be added in a separate PEP)
* Remove support for all forms of concatenation other than simply prefixing of a single `TypeVarTuple` (fancier forms of concatenation to also be added in a separate PEP)
Semantic changes:
* Try switching `Ts` back to mean the 'unpacked' version (such that `Ts = int, str; Tuple[Ts] = Tuple[int, str]`) to see whether everything still works. (Might revert this, pending future discussion in typing-sig.)
* PEP 646: Clarify that prefixing is not allowed in Callable
* Update PEP 646 based on discussions in typing-sig
Semantic changes:
* Switch back to `Ts` meaning types packed in a `Tuple`
* Disallow unpacked usages of `Ts`
* Unparameterised `Tensor` behaves like `Tensor[Any, ...]`
Clarifications:
* `TypeVarTuple`s are invariant
* `TypeVarTuple`s can not be bound to unknown-length types (e.g. `Tuple[int, ...]`
* `TypeVarTuple`s can not be bound to unions of types
* Empty `*args` behaves like `Tuple[()]`
* `TypeVarTuple`s can not appear in slices
Readability changes:
* Reorder some sections for better flow
* Update PEP 646 with Eric's suggestions and other tweaks
Semantic changes:
* Revert to `*args: *Ts` for new behaviour, and `*args: Tuple[*Ts]` for old behaviour
Fixes:
* Unpacking in Aliases/Ideal Array Type sections
* Various typo/grammar fixes
Other:
* State explicitly that TypeVarTuples can be used in callback protocols
Irit Katriel
Sean Lockwood
Jacob Walls
David Foster
Naren Santhanam
Thomas Kluyver
Ken Jin
Dennis Sweeney
Brett Cannon
Florian Bruhin
Yury Selivanov
Matthew Rahtz
Inada Naoki
Eric Traut
Mark Shannon
Łukasz Langa
Ned Deily
Evan Carroll
Matej Dujava
JimJJewett
Brandt Bucher
Petr Viktorin
Mario Corchero
Gus Monod
Hugo van Kemenade