> @Hatfield-Dodds, if we changed typing.Callable to return ((int, int), str) but collections.abc.Callable continued to return ([int, int], str), would that suffice for your purposes?

For performance reasons I'd prefer that the return value be hashable for both, but we've already shipped the workarounds [0,1,2] for 3.9.0 and will maintain that until 3.9 reaches EOL in any case.

Whether we return (int, int, str) or ((int, int), str) doesn't make much difference to me, the latter will require a trivial patch to [2] so please do whatever makes most sense upstream.


> Also, maybe we should make builtins.callable generic as well?

I like this idea :-)


[0] https://hypothesis.readthedocs.io/en/latest/changes.html#v5-39-0
[1] https://github.com/HypothesisWorks/hypothesis/pull/2653/files#diff-c56f048e926cce76dc6cd811924136f5c97e0f68f59625869b4ab01f1dbe10e0L1473-R1480
[2] https://github.com/HypothesisWorks/hypothesis/pull/2653/files#diff-f6a209c019f3f6af11a027a0035e3fc736935d9920fd85da726f9abf4c325d6bR562-R567