Add Cls and PropName so fields can be specialized by derived types

[dnwpark]

Replace type(typing.Self) with the class that is evaluating the annotation.

For example:

class NodeA:
    child: type(Self) | None

class NodeB(NodeA):
    pass

would be equivalent to:

class NodeA:
    child: NodeA | None

class NodeB(NodeA):
    child: NodeB | None

[vercel]

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Project	Deployment	Actions	Updated (UTC)
python-typemap	Ready	Preview, Comment	Feb 2, 2026 6:22pm

[msullivan]

Why not just Self? And do we need this?

[dnwpark]

@msullivan I've added an rough implementation for PropName and qblike_3 example to show why I want both of these.

Given a table User, I want to be able to join the table on itself, so I create a UserAlias class. This alias's attributes need to have their FieldTable values different from the base User type. Otherwise, the select will combine them and only select from User.

This is based on an example from the sql alchemy docs: https://docs.sqlalchemy.org/en/20/tutorial/data_select.html#tutorial-using-aliases

[vercel]

Additional Suggestion:

GetMember operator doesn't set current_cls context, causing Cls type references to remain unresolved when accessing member types