Experimental Syntax

What it does

Checks for experimental syntax that is not part of the Python typing specification.

Why is this bad?

Experimental syntax is specific to ty. It may be rejected by other type checkers and may never be standardized, or be subject to breaking changes.

Examples

[environment]
python-version = "3.14"

class A: ...


class B: ...


def f(value: A & B) -> None: ...  # error: [experimental-syntax]
def g(value: ~A) -> None: ...  # error: [experimental-syntax]