How is phantom-types different from beartype?

[majidaldo]

how is this functionally different from beartype? in beartype you can check Annotated[basetype, <predicates>].

[antonagestam]

@majidaldo Hi 👋

Generally speaking beartype is a runtime type-checker and phantom-types is a category of types.

I did not know beartype supports Annotated[basetype, <predicates>], but I suspect the main difference to that would be that phantom types have full compatibility with static type checkers, that's really the main selling point of phantom types: to "store" results from runtime type checks in the static type system.

[antonagestam]

@majidaldo Also, I forgot to mention, phantom-types are compatible with beartype (and other runtime type checkers), as mentioned here: https://github.com/antonagestam/phantom-types#runtime-type-checking