Hello, In the context of pattern matching, not accepting a match subject that does not match any of the case clauses is probably going to be frequent if not the most frequent. Thus, when PEP 634, 635, 636 are -- hopefully -- accepted, and experience with the feature is gained, this idea might be worth reconsidering, allowing the rewrite of something like
https://github.com/gvanrossum/patma/blob/master/examples/over.py#L57-L68 ``` match args: case [Point2d(x, y)]: return Point3d(x, y, 0) case [p := Point3d()]: return p case [x := int(), y := int()]: return Point3d(x, y, 0) case [x := int(), y := int(), z := int()]: return Point3d(x, y, z) case _: raise TypeError("Huh?") ``` into ``` match args: case [Point2d(x, y)]: ... case ...: ... case ...: ... case ...: ... case _: impossible ``` where `impossible` raises AssertionError. Best regards, Jean Abou-Samra _______________________________________________ Python-Dev mailing list -- [email protected] To unsubscribe send an email to [email protected] https://mail.python.org/mailman3/lists/python-dev.python.org/ Message archived at https://mail.python.org/archives/list/[email protected]/message/3D6TDUJ4V3Q6DF3UCSBUF7ETGYAG46AJ/ Code of Conduct: http://python.org/psf/codeofconduct/