[Python-Dev] PEP 443 - Single-dispatch generic functions (original) (raw)

Ethan Furman ethan at stoneleaf.us
Thu May 23 22:19:20 CEST 2013

On 05/23/2013 01:10 PM, Łukasz Langa wrote:

On 23 maj 2013, at 20:59, PJ Eby <pje at telecommunity.com> wrote:

As to the ability to do multiple types registration, you could support it only in type annotations, e.g.:

@func.register def doit(foo: [int, float]): ... Initially I thought so, too. But it seems other people might think this means "a sequence with the first element being an integer, and the second a float". The BDFL seems to have yet a different idea: http://mail.python.org/pipermail/python-ideas/2012-December/018129.html This is clearly material for a separate PEP, wink wink, nudge nudge. To the point though. Based on this, and the fact PEP 8 currently disallows annotations within the standard library, I came to the conclusion that currently we should not include the annotation-driven form. I generally lean towards returning the undecorated function, so that if you say: @func.register def doint(foo: int): ... Me too. The PEP has been updated to specify that explicitly.

So with this decision made, are there any open issues left? Or can we invite Guido back to the discussion? ;)

-- Ethan

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