[Python-ideas] Yet Another Switch-Case Syntax Proposal

[Haoyi Li]

Fun fact: we've had pattern matching on 2.7 using MacroPy for a year now

https://github.com/lihaoyi/macropy#pattern-matching

@caseclass Nil():
    pass
@caseclass Cons(x, xs):
    pass
def reduce(op, my_list):
    with switch(my_list):
        if Cons(x, Nil()):
            return x
        elif Cons(x, xs):
            return op(x, reduce(op, xs))




On Tue, Apr 22, 2014 at 4:29 PM, Andrew Barnert <
abarnert at yahoo.com.dmarc.invalid> wrote:

> On Apr 22, 2014, at 15:20, Oleg Broytman <phd at phdru.name> wrote:
>
> > On Tue, Apr 22, 2014 at 03:06:55PM -0700, Devin Jeanpierre <
> jeanpierreda at gmail.com> wrote:
> >> Why is it that every time someone brings up switch/case, they're being
> >> inspired by C and Java instead of ML or Haskell?
> >
> >   How many people know imperative, procedural and OO languages? And how
> > many know functional or logic-based languages?
>
> I think most people know multi-paradigm languages. C++ has similar
> features, even if many of them are restricted to it's compile-time template
> engine. Most JavaScript programs are all about passing anonymous functions
> to higher-order functions as callbacks, of abstractions on top of that like
> futures. And so on.
>
> Anyway, people don't have a problem learning map, any, comprehensions,
> unpacking, or other functional-derived features in Python even if they come
> from C; in fact, those features are often why they don't want to go back to
> C. The issue is always finding the right balance, borrowing features that
> fit into the language well and make code easier to read but not trying to
> encourage recursive folds over loops or rebuild I/O around monads or pure
> but nondeterministic functions.
> _______________________________________________
> Python-ideas mailing list
> Python-ideas at python.org
> https://mail.python.org/mailman/listinfo/python-ideas
> Code of Conduct: http://python.org/psf/codeofconduct/
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mail.python.org/pipermail/python-ideas/attachments/20140422/7cfda4e4/attachment.html>