Hello, On 2020年12月27日 14:10:59 +0100 Dave Halter <[email protected]> wrote:
> I'm late, but I still wanted to add that I share some of the criticism > that Mark has brought up. > > I'm in love with Rust's pattern matching, so I feel like I'm not > against pattern matching generally. However I feel like while the PEP > is well written, there are some things that it does not tackle: > > - Sum Types aka Tagged Unions are what makes pattern matching > necessary. I think we should rather have a discussion about inclusion > of Sum Types. Python had sum types (well, superset of them) since ~forever (just like any other object-oriented language). Your typical Haskell sum datatype: data Tree a = Leaf a | Branch (Tree a) (Tree a) directly translates to: class Tree: pass class Leaf(Tree): def __init__(self, val): ... class Branch(Tree): def __init__(self, l, r): ... "Leaf" and "Branch" are the tags you're looking for. Recent dataclasses cut on the amount of boilerplate required. -- Best regards, Paul mailto:[email protected] _______________________________________________ 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/YNFTRO3FAJ3CIIC4NQOVOMYPR2QPALIY/ Code of Conduct: http://python.org/psf/codeofconduct/