Re: Encapsulation in Python

From	Mark Lawrence <breamoreboy@yahoo.co.uk>
Newsgroups	comp.lang.python
Subject	Re: Encapsulation in Python
Date	2016-03-15 04:41 +0000
Message-ID	<mailman.153.1458016938.12893.python-list@python.org> (permalink)
References	(12 earlier) <nc7ef9$sgf$1@dont-email.me> <mailman.137.1457997645.12893.python-list@python.org> <nc7it9$ejq$1@dont-email.me> <mailman.140.1458001784.12893.python-list@python.org> <nc7n8k$qru$1@dont-email.me>

Show all headers | View raw

On 15/03/2016 01:10, BartC wrote:
> On 15/03/2016 00:28, Mark Lawrence wrote:
>> On 14/03/2016 23:56, BartC wrote:
>
>>> Anything so terrible about that that Python needs to keep well clear of
>>> or that you think its users should be deprived of?
>>
>> Yes, it is not even valid Python.  Switch has been rejected via at least
>> one PEP and from what I see it adds nothing to the language, so let's
>> deprive it from people who clearly don't need it in the first place.
>
> Every time you need to test X against more than one other value, then
> you have a potential use for switch.
>
> But yes you can do without switch if you have too. Same for many features.
>
>> I am only rude to people such as yourself who refuse to provide code, in
>> fact anything, to support your case.  Your "benchmark" for the switch
>> was yet another laughable farce, which only tested the function calls,
>> building tuples, running loops, there was nothing to test with respect
>> to the actual switch which was meant to be tested.  So just in case you
>> missed it above, where is the profile for this test?
>
> I've shown the task. I'm sure you can also do some tests and show us
> some results.
>
>>> I agree with you. But once you've got the language right, then there's
>>> no harm looking at performance. A switch statement like the above can be
>>> executed in a single byte-code.
>>>
>>
>> Really?  Then please show us all just how it can be done via a patch to
>> the cPython code on the bug tracker.
>
> The one-byte-code switch works when all case expressions are known at
> compile-time. It makes use of a jump-table within the byte-code.
>
> The total sequence will be more than one byte-code, typically:
>
> LOAD_FAST                The index
> SWITCH                   Jump to the right label
> ....
> L5:                      One of multiple labels
>   ...                     Deal with the code in this branch
> JUMP_ABSOLUTE            Break out of the switch
>
> ...                      Provision is needed for the jump-table
>
> But only one is needed for testing and dispatch. Now I've sketched it
> out, perhaps you can fill in the details for yourself... (I'm not
> getting involved in CPython development.)
>
>

I have no interest at this level.  If I were I might as well have stuck 
with C in the first place.  I do find it rather strange that something 
so simple wasn't approved when the PEP(s) were discussed as it looks so 
easy to implement.

-- 
My fellow Pythonistas, ask not what our language can do for you, ask
what you can do for our language.

Mark Lawrence

Thread

Re: Encapsulation in Python Ian Kelly <ian.g.kelly@gmail.com> - 2016-03-10 08:27 -0700
  Re: Encapsulation in Python Rick Johnson <rantingrickjohnson@gmail.com> - 2016-03-10 16:45 -0800
    Re: Encapsulation in Python Ian Kelly <ian.g.kelly@gmail.com> - 2016-03-11 08:47 -0700
      Re: Encapsulation in Python Rick Johnson <rantingrickjohnson@gmail.com> - 2016-03-11 18:39 -0800
        Re: Encapsulation in Python Ian Kelly <ian.g.kelly@gmail.com> - 2016-03-12 09:44 -0700
          Re: Encapsulation in Python Rick Johnson <rantingrickjohnson@gmail.com> - 2016-03-12 19:11 -0800
          Re: Encapsulation in Python Steven D'Aprano <steve@pearwood.info> - 2016-03-13 21:11 +1100
            Re: Encapsulation in Python Rick Johnson <rantingrickjohnson@gmail.com> - 2016-03-14 10:32 -0700
              Re: Encapsulation in Python Ian Kelly <ian.g.kelly@gmail.com> - 2016-03-14 15:09 -0600
              Re: Encapsulation in Python Mark Lawrence <breamoreboy@yahoo.co.uk> - 2016-03-14 21:23 +0000
                Re: Encapsulation in Python BartC <bc@freeuk.com> - 2016-03-14 22:07 +0000
                Re: Encapsulation in Python Mark Lawrence <breamoreboy@yahoo.co.uk> - 2016-03-14 22:20 +0000
                Re: Encapsulation in Python BartC <bc@freeuk.com> - 2016-03-14 22:40 +0000
                Re: Encapsulation in Python Mark Lawrence <breamoreboy@yahoo.co.uk> - 2016-03-14 23:19 +0000
                Re: Encapsulation in Python BartC <bc@freeuk.com> - 2016-03-14 23:56 +0000
                Re: Encapsulation in Python Chris Angelico <rosuav@gmail.com> - 2016-03-15 11:12 +1100
                Re: Encapsulation in Python BartC <bc@freeuk.com> - 2016-03-15 00:54 +0000
                Re: Encapsulation in Python Chris Angelico <rosuav@gmail.com> - 2016-03-15 11:58 +1100
                Re: Encapsulation in Python BartC <bc@freeuk.com> - 2016-03-15 01:22 +0000
                Re: Encapsulation in Python Chris Angelico <rosuav@gmail.com> - 2016-03-15 13:02 +1100
                Re: Encapsulation in Python Mark Lawrence <breamoreboy@yahoo.co.uk> - 2016-03-15 00:28 +0000
                Re: Encapsulation in Python BartC <bc@freeuk.com> - 2016-03-15 01:10 +0000
                Re: Encapsulation in Python Chris Angelico <rosuav@gmail.com> - 2016-03-15 12:23 +1100
                Re: Encapsulation in Python Mark Lawrence <breamoreboy@yahoo.co.uk> - 2016-03-15 04:41 +0000
                Re: Encapsulation in Python rurpy@yahoo.com - 2016-03-14 17:17 -0700
                Re: Encapsulation in Python Chris Angelico <rosuav@gmail.com> - 2016-03-15 11:25 +1100
                Re: Encapsulation in Python Steven D'Aprano <steve@pearwood.info> - 2016-03-15 13:06 +1100
                Re: Encapsulation in Python Chris Angelico <rosuav@gmail.com> - 2016-03-15 13:14 +1100
                Re: Encapsulation in Python Steven D'Aprano <steve@pearwood.info> - 2016-03-15 13:40 +1100
                Re: Encapsulation in Python Rick Johnson <rantingrickjohnson@gmail.com> - 2016-03-14 21:08 -0700
                Re: Encapsulation in Python Mark Lawrence <breamoreboy@yahoo.co.uk> - 2016-03-15 00:47 +0000
                Re: Encapsulation in Python Steven D'Aprano <steve@pearwood.info> - 2016-03-15 13:46 +1100
                Re: Encapsulation in Python Chris Angelico <rosuav@gmail.com> - 2016-03-15 11:56 +1100
                Re: Encapsulation in Python Mark Lawrence <breamoreboy@yahoo.co.uk> - 2016-03-15 04:36 +0000
                Re: Encapsulation in Python Steven D'Aprano <steve@pearwood.info> - 2016-03-15 13:01 +1100
                Re: Encapsulation in Python Mark Lawrence <breamoreboy@yahoo.co.uk> - 2016-03-15 04:45 +0000
                Re: Encapsulation in Python Christian Gollwitzer <auriocus@gmx.de> - 2016-03-15 22:02 +0100
                Re: Encapsulation in Python BartC <bc@freeuk.com> - 2016-03-16 00:39 +0000
                Re: Encapsulation in Python BartC <bc@freeuk.com> - 2016-03-16 22:58 +0000
        Re: Encapsulation in Python sohcahtoa82@gmail.com - 2016-03-14 11:11 -0700
          Re: Encapsulation in Python Rick Johnson <rantingrickjohnson@gmail.com> - 2016-03-14 23:09 -0700
      Re: Encapsulation in Python Rick Johnson <rantingrickjohnson@gmail.com> - 2016-03-11 18:56 -0800
    Re: Encapsulation in Python Gregory Ewing <greg.ewing@canterbury.ac.nz> - 2016-03-12 13:52 +1300
      Re: Encapsulation in Python Rick Johnson <rantingrickjohnson@gmail.com> - 2016-03-12 08:49 -0800
        Re: Encapsulation in Python Chris Angelico <rosuav@gmail.com> - 2016-03-13 08:10 +1100
          Re: Encapsulation in Python Rick Johnson <rantingrickjohnson@gmail.com> - 2016-03-12 19:36 -0800
            Re: Encapsulation in Python Chris Angelico <rosuav@gmail.com> - 2016-03-13 15:05 +1100
        Re: Encapsulation in Python Gregory Ewing <greg.ewing@canterbury.ac.nz> - 2016-03-14 12:35 +1300
          Re: Encapsulation in Python Rick Johnson <rantingrickjohnson@gmail.com> - 2016-03-14 15:55 -0700

csiph-web