RetroSearch Browse

Wed Oct 21 21:50:30 EDT 2015 · https://mail.python.org/pipermail/python-dev/2015-October/142005.html

Well the whole point is not to have to figure out how to implement that
right now.

On Wed, Oct 21, 2015 at 6:45 PM, Random832 <random832 at fastmail.com> wrote:

> Guido van Rossum <guido at python.org> writes:
> > The proposal is to allow this to be written as follows in
> > implementation (non-stub) modules:
> >
> > class Foo(Generic[T]):
> > @overload
> > def __getitem__(self, i: int) -> T: ...
> > @overload
> > def __getitem__(self, s: slice) -> Foo[T]: ...
> > def __getitem__(self, x):
> > <actual implementation goes here>
> >
> > The actual implementation must be last, so at run time it will
> > override the definition.
>
> How about this to allow overloads to have actual implementations?
>
> @overloaded
> def __getitem__(self, x):
>     <default implementation, if none of the overloads matched>
>
> @overloaded returns a function which will check the types against the
> overloads (or anyway any overloads that have actual implementations),
> call them returning the result if applicable, otherwise call the
> original function.
>
> Some magic with help() would improve usability, too - it could print all
> the overloads and their docstrings.  Maybe even @overload('__getitem__')
> def __get_int(self, i: int), to make it so order doesn't matter.
>
> That just leaves the question of how's this all gonna work with
> subclasses.
>
> _______________________________________________
> Python-Dev mailing list
> Python-Dev at python.org
> https://mail.python.org/mailman/listinfo/python-dev
> Unsubscribe:
> https://mail.python.org/mailman/options/python-dev/guido%40python.org
>

-- 
--Guido van Rossum (python.org/~guido)
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mail.python.org/pipermail/python-dev/attachments/20151021/4a1bdd6c/attachment.html>

Home - News ( United States | United Kingdom | Italy | Germany ) - Football scores

Showing content from https://mail.python.org/pipermail/python-dev/2015-October/142005.html below:

[Python-Dev] PEP 484 -- proposal to allow @overload in non-stub files