Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > comp.lang.python > #90285

Re: functions, optional parameters

Path csiph.com!usenet.pasdenom.info!news.redatomik.org!newsfeed.xs4all.nl!newsfeed1a.news.xs4all.nl!xs4all!newsgate.cistron.nl!newsgate.news.xs4all.nl!post.news.xs4all.nl!not-for-mail
Return-Path <davea@davea.name>
X-Original-To python-list@python.org
Delivered-To python-list@mail.python.org
X-Spam-Status OK 0.019
X-Spam-Evidence '*H*': 0.96; '*S*': 0.00; 'true,': 0.05; 'compiler': 0.07; 'debug': 0.07; 'none,': 0.07; 'tries': 0.07; 'differently.': 0.09; 'immutable': 0.09; 'suggest': 0.14; 'binding,': 0.16; 'complicated,': 0.16; 'literals,': 0.16; 'mutable': 0.16; 'optional': 0.16; 'subject:parameters': 0.16; 'wrote:': 0.18; 'header:User-Agent:1': 0.23; 'looks': 0.24; 'sort': 0.25; 'references': 0.26; 'header:In-Reply-To:1': 0.27; 'point': 0.28; 'chris': 0.29; "doesn't": 0.30; "d'aprano": 0.31; 'int,': 0.31; 'steven': 0.31; 'cases': 0.33; 'guess': 0.33; 'could': 0.34; "can't": 0.35; 'common': 0.35; 'except': 0.35; 'something': 0.35; 'late': 0.35; 'but': 0.35; 'false': 0.36; 'wrong': 0.37; 'to:addr :python-list': 0.38; 'list,': 0.38; 'pm,': 0.38; 'to:addr:python.org': 0.39; 'expression': 0.60; 'name': 0.63; 'such': 0.63; 'different': 0.65; 'charset:windows-1252': 0.65; 'side': 0.67; 'received:74.208': 0.68; 'default': 0.69; 'evaluate': 0.72; 'obvious': 0.74; '2015': 0.84; 'optimized,': 0.84; 'absolutely': 0.87
Date Sun, 10 May 2015 07:25:58 -0400
From Dave Angel <davea@davea.name>
User-Agent Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.6.0
MIME-Version 1.0
To python-list@python.org
Subject Re: functions, optional parameters
References <72lu1cxvmg.ln2@news.c0t0d0s0.de> <554cd511$0$12979$c3e8da3$5496439d@news.astraweb.com> <ui2v1cx5co.ln2@news.c0t0d0s0.de> <554ec664$0$13001$c3e8da3$5496439d@news.astraweb.com> <CAPTjJmq+XKq4SER-Hy-3RK=jAv-rHqNEw9ugJym_yH-d2GwFvQ@mail.gmail.com>
In-Reply-To <CAPTjJmq+XKq4SER-Hy-3RK=jAv-rHqNEw9ugJym_yH-d2GwFvQ@mail.gmail.com>
Content-Type text/plain; charset=windows-1252; format=flowed
Content-Transfer-Encoding 7bit
X-Provags-ID V03:K0:OTNmExApjhE9FLLhAe1UU1g0zNE/KumVez/vRdp6cU6Hod2DhTQ Ma8K1UrMx4Y0WCIbtxgI49k/ludB90oytcWOugcsdXQZ0UBGY8lFjLHVv+1TF9k+QYeXE4c YssbuvQIU0YpxTLXwdfgMSvwadA3RcpcuX4aUsSM1EIodkN6VX5mMd6RwR0Hv9dRBUeoFhj 6fhRrtp7XETlmjvm59AMw==
X-UI-Out-Filterresults notjunk:1;
X-BeenThere python-list@python.org
X-Mailman-Version 2.1.20+
Precedence list
List-Id General discussion list for the Python programming language <python-list.python.org>
List-Unsubscribe <https://mail.python.org/mailman/options/python-list>, <mailto:python-list-request@python.org?subject=unsubscribe>
List-Archive <http://mail.python.org/pipermail/python-list/>
List-Post <mailto:python-list@python.org>
List-Help <mailto:python-list-request@python.org?subject=help>
List-Subscribe <https://mail.python.org/mailman/listinfo/python-list>, <mailto:python-list-request@python.org?subject=subscribe>
Newsgroups comp.lang.python
Message-ID <mailman.307.1431257173.12865.python-list@python.org> (permalink)
Lines 27
NNTP-Posting-Host 2001:888:2000:d::a6
X-Trace 1431257173 news.xs4all.nl 2847 [2001:888:2000:d::a6]:33938
X-Complaints-To abuse@xs4all.nl
Xref csiph.com comp.lang.python:90285

Show key headers only | View raw

On 05/09/2015 11:33 PM, Chris Angelico wrote:
> On Sun, May 10, 2015 at 12:45 PM, Steven D'Aprano
> <steve+comp.lang.python@pearwood.info> wrote:
>> This is the point where some people try to suggest some sort of complicated,
>> fragile, DWIM heuristic where the compiler tries to guess whether the user
>> actually wants the default to use early or late binding, based on what the
>> expression looks like. "0 is an immutable int, use early binding; [] is a
>> mutable list, use late binding." sort of thing. Such a thing might work
>> well for the obvious cases, but it would be a bugger to debug and
>> work-around for the non-obvious cases when it guesses wrong -- and it will.
>
> What you could have is "late-binding semantics, optional early binding
> as an optimization but only in cases where the result is
> indistinguishable". That would allow common cases (int/bool/str/None
> literals) to be optimized, since there's absolutely no way for them to
> evaluate differently.
>

Except for literals, True, False and None, I can't see any way to 
optimize such a thing.  Just because the name on the right side 
references an immutable object at compile time, it doesn't follow that 
it'll still be the same object later.

Unless late binding means something very different than I understood.

-- 
DaveA

Back to comp.lang.python | Previous | Next — Previous in thread | Next in thread | Find similar | Unroll thread

Thread

functions, optional parameters Michael Welle <mwe012008@gmx.net> - 2015-05-08 13:59 +0200
  Re: functions, optional parameters Rustom Mody <rustompmody@gmail.com> - 2015-05-08 05:09 -0700
    Re: functions, optional parameters Michael Welle <mwe012008@gmx.net> - 2015-05-08 14:36 +0200
  Re: functions, optional parameters Chris Angelico <rosuav@gmail.com> - 2015-05-08 22:39 +1000
    Re: functions, optional parameters Michael Welle <mwe012008@gmx.net> - 2015-05-08 14:57 +0200
  Re: functions, optional parameters Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2015-05-09 01:24 +1000
    Re: functions, optional parameters Chris Angelico <rosuav@gmail.com> - 2015-05-09 02:02 +1000
      Re: functions, optional parameters Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2015-05-09 03:36 +1000
        Re: functions, optional parameters Chris Angelico <rosuav@gmail.com> - 2015-05-09 03:49 +1000
          Re: functions, optional parameters Mel Wilson <mwilson@the-wire.com> - 2015-05-08 18:49 +0000
          Re: functions, optional parameters Gregory Ewing <greg.ewing@canterbury.ac.nz> - 2015-05-09 13:41 +1200
            Re: functions, optional parameters Chris Angelico <rosuav@gmail.com> - 2015-05-09 12:05 +1000
              Re: functions, optional parameters Gregory Ewing <greg.ewing@canterbury.ac.nz> - 2015-05-09 19:27 +1200
          Re: functions, optional parameters Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2015-05-09 12:52 +1000
    Re: functions, optional parameters Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2015-05-09 03:26 +1000
    Re: functions, optional parameters Michael Welle <mwe012008@gmx.net> - 2015-05-08 17:50 +0200
      Re: functions, optional parameters Ian Kelly <ian.g.kelly@gmail.com> - 2015-05-09 10:57 -0600
      Re: functions, optional parameters Chris Angelico <rosuav@gmail.com> - 2015-05-10 13:33 +1000
        Re: functions, optional parameters Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2015-05-10 15:20 +1000
          Re: functions, optional parameters Chris Angelico <rosuav@gmail.com> - 2015-05-10 18:59 +1000
      Re: functions, optional parameters Rustom Mody <rustompmody@gmail.com> - 2015-05-09 20:35 -0700
        Re: functions, optional parameters Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2015-05-10 15:25 +1000
      Re: functions, optional parameters Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2015-05-10 12:45 +1000
        Re: functions, optional parameters Dave Angel <davea@davea.name> - 2015-05-10 07:25 -0400
        Re: functions, optional parameters Chris Angelico <rosuav@gmail.com> - 2015-05-11 00:39 +1000
        Re: functions, optional parameters Michael Welle <mwe012008@gmx.net> - 2015-05-11 07:58 +0200
    Re: functions, optional parameters Ian Kelly <ian.g.kelly@gmail.com> - 2015-05-08 09:48 -0600

csiph-web