python
Semaphore's value argument
Currently we assume that the semaphore's value must be an integer: https://github.com/python/typeshed/blob/1af9de664f41b51bd3b71dac349564c5c25df810/stdlib/asyncio/locks.pyi#L88-L93
Generally this is correct, but I had a use case where I wanted to disable the semaphore without restructuring my code, so I used float("inf") as the value to ensure that it never unlocks. This works perfectly fine, because the only operations that value needs to support are:
- Adding 1
- Subtracting 1
- Comparing to 0
The infinity float value does all of these fine. So I therefore wonder if we should make this type be int | Literal[math.inf]? I agree that general floats are not a good idea because they will get below 0 without triggering the wait.
I therefore wonder if we should make this type be int | Literal[math.inf]?
Unfortunately the type system does not allow this; float is not an allowed literal type. Cross-linking python/typing#1160.
I'm honestly wary to allow arbitrary floats here as using them could lead to bugs due to floating point math. I would suggest to use a big int instead, e.g. 2**64-1.
