El sáb, 16 abr 2022 a las 12:51, John Hagen (<johnthagen@gmail.com>) escribió:

The original (superseded) PEP 622 proposed adding a @sealed decorator so that users could define algebraic data types (ADTs) that static type checkers could verify are `match`ed exhaustively:

- https://peps.python.org/pep-0622/#sealed-classes-as-algebraic-data-types

There is a somewhat fairly-upvoted question about ADTs in Python, indicating interest in this area:

- https://stackoverflow.com/questions/16258553

@sealed would be very valuable towards making ADT usage within Python more type-safe. Is there any historical discussion about why @sealed was dropped from the final pattern matching PEP?

I don't recall exactly, but my sense was that the original proposal was too big and complicated, so it was slimmed down into PEP 634. A number of non-essential features were dropped.

What would be the next steps needed to push this forward? Would writing a new PEP be the next step?

Yes, this would need to be a new PEP. I'd probably be willing to sponsor such a PEP.

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