Enhancement: Infer TypeVar as its bound/constraint

[DanCardin]

Summary

Given this line https://github.com/litestar-org/type-lens/blob/main/type_lens/type_view.py#L227 I think that could/should be rephrased as if isinstance(self.annotation, typ): return TypeView(Union[bytes, str]).is_subtype_of(typ). And that seems interesting.

Because it does feel like T = TypeVar(int, float); TypeVar(T).is_subtype_of(int) should return True, or that T = TypeVar(bound=Union[int, float]); TypeVar(T).is_union should return True.

Following from that, it feels like either TypeView should either transparently be doing something equivalent to the following:

        if isinstance(annotation, TypeVar):
            bound = self.annotation.__bound__
            if bound:
                return TypeView(bound)

            constraints = self.annotation.__constraints__
            return TypeView(Union[*constraints])

or it should have a method like resolve_type_var which does this recursively (because e.g. list[T]) or something...

I suppose the contravariant/covariant kwargs for constraints are a meaningful consideration potentially...but i dunno...

Basic Example

No response

Drawbacks and Impact

No response

Unresolved questions

No response

[DanCardin]

I think perhaps a .concretize() method makes the most sense as an API/method.

And then the clause in is_subtype_of could be

if self.is_type_var:
    return self.concretize().is_subtype_of(typ)

(which would still return False if it was just TypeVar('T') with no constraints/bounds