On Dec 31, 2019, at 21:35, Guido van Rossum <gu...@python.org> wrote: > > There were match proposals in the past — have you looked those up? Maybe they > solve your problem without that syntax — or maybe they would benefit from it.
Most of the existing proposals require a lot more syntax—a new form using two or three new keywords or symbols, and often a new dunder protocol as well. What I was trying to do this weekend was come up with something that reads as similarly as possible, with smaller changes to the language. The key is that before the walrus operator, it was hard to imagine how you could leverage if/elif chains (essentially the same way Python covers 90% of what C switch can do without needing a new structure) and tuple unpacking. Now it seems much more feasible. (Also, dataclass is close enough to a “case class”—and provides a model for building them manually—that the proposal no longer requires a new opt-in mechanism for simulating ADTs before it can even get off the ground.) _______________________________________________ Python-ideas mailing list -- python-ideas@python.org To unsubscribe send an email to python-ideas-le...@python.org https://mail.python.org/mailman3/lists/python-ideas.python.org/ Message archived at https://mail.python.org/archives/list/python-ideas@python.org/message/BZLEKPARSTANN46VMA6PHFZGNDRDT3ZJ/ Code of Conduct: http://python.org/psf/codeofconduct/
