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Groups > comp.lang.python > #99606

Re: Late-binding of function defaults (was Re: What is a function parameter =[] for?)

From Chris Angelico <rosuav@gmail.com>
Newsgroups comp.lang.python
Subject Re: Late-binding of function defaults (was Re: What is a function parameter =[] for?)
Date 2015-11-27 10:07 +1100
Message-ID <mailman.156.1448579571.20593.python-list@python.org> (permalink)
References (14 earlier) <n35mps$dv8$1@dont-email.me> <b70213fa-2b4a-475b-a444-eaaf43c2a69e@googlegroups.com> <n36v80$1nt$1@dont-email.me> <mailman.140.1448547231.20593.python-list@python.org> <n380t1$b69$1@dont-email.me>

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On Fri, Nov 27, 2015 at 9:27 AM, BartC <bc@freeuk.com> wrote:
> On 26/11/2015 13:15, Chris Angelico wrote:
>>
>> On Thu, Nov 26, 2015 at 11:53 PM, BartC <bc@freeuk.com> wrote:
>
>
>>> http://pastebin.com/JrVTher6
>
>
>> #14 and #15: Are you assuming that a character is a byte and that
>> diacritical-free English is the only language in the world?
>
>
> I don't think that need be the assumption. Any UTF8 string that fits within
> 8 bytes could also be represented by an integer value.

Okay, so you're making UTF-8 your visible string representation.
That's better than assuming character==byte, but it still has the case
insensitivity problem.

>> Case
>> insensitivity is a *pain* when you try to be language-agnostic; for
>> instance, the case-folding rules of English state that U+0069 LATIN
>> SMALL LETTER I and U+0049 LATIN CAPITAL LETTER I are identical, but
>> Turkish would upper-case the first to U+0130 LATIN CAPITAL LETTER I
>> WITH DOT ABOVE and lower-case the second to U+0131 LATIN SMALL LETTER
>> DOTLESS I. German has U+00DF LATIN SMALL LETTER SHARP S (also called
>> eszett), which traditionally upper-cases to "SS", which lower-cases to
>> "ss".
>
>
> I use Windows which is also case insensitive with regard to filenames and
> such. How does it solve those problems? How about web-site names, email
> addresses and Google searches?

Windows: I'm not sure, and frankly, I don't trust it. A quick test
showed a couple of failures:

C:\Users\Rosuav\Desktop>dir /b TE*
teßting
C:\Users\Rosuav\Desktop>dir /b TESST*
File Not Found

C:\Users\Rosuav\Desktop>dir /b ParıldıYOR*
Parıldıyor Parts & Pieces
C:\Users\Rosuav\Desktop>dir /b PARILDIYOR*
File Not Found

It might be case insensitive only for ASCII.

(Note: This test was done on Windows 7, because that's the VM I had
handy. Things might be different on newer Windowses, but I can't
check.

Web site names: Presumably you mean DNS. It started out as an
ASCII-only protocol, and grew a number of gross hacks to support
"internationalized domain names". I'm not sure where the case
insensitivity is applied; but it doesn't matter too much, because
conflicts can be resolved at registration. Also, you'll generally see
IDNs in country-specific TLDs, so there'll be only one language (or a
small family of languages) used, reducing the likelihood of
collisions.

Google searches are (deliberately) a LOT more sloppy than just case
sensitivity. You can search for something without diacriticals and get
back results with diacriticals; you can transpose letters, omit
letters, have extra letters, and it'll generally figure out what you
want. This is absolutely awesome for a search engine, but equally
horrifying for name lookups in a program.

None of these is something I'd recommend following.

> Within a program source code (where you have mainly technical users), you
> can just impose some restrictions on keywords and identifiers otherwise
> there are plenty of problems even without case switching, if you want to
> allow Unicode here.

I would strongly support ASCII-only *language keywords*. You don't
have many of them (compared to the number of identifiers in a
program), and everyone has to type them. But for identifiers, Python 3
defines character validity based on Unicode categories, and performs
NFKC normalization on all names. That's pretty straight-forward. No
case sensitivity hassles, no messy non-transitive equalities, it's
easy.

ChrisA

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Re: Late-binding of function defaults (was Re: What is a function parameter =[] for?) Laura Creighton <lac@openend.se> - 2015-11-19 21:18 +0100
  Re: Late-binding of function defaults (was Re: What is a function parameter =[] for?) Marko Rauhamaa <marko@pacujo.net> - 2015-11-19 22:57 +0200
    Re: Late-binding of function defaults (was Re: What is a function parameter =[] for?) Laura Creighton <lac@openend.se> - 2015-11-19 23:41 +0100
      Re: Late-binding of function defaults (was Re: What is a function parameter =[] for?) BartC <bc@freeuk.com> - 2015-11-20 14:00 +0000
    Re: Late-binding of function defaults (was Re: What is a function parameter =[] for?) Steven D'Aprano <steve@pearwood.info> - 2015-11-20 11:33 +1100
      Re: Late-binding of function defaults (was Re: What is a function parameter =[] for?) Antoon Pardon <antoon.pardon@rece.vub.ac.be> - 2015-11-25 09:14 +0100
        Re: Late-binding of function defaults (was Re: What is a function parameter =[] for?) Steven D'Aprano <steve@pearwood.info> - 2015-11-25 21:52 +1100
          Re: Late-binding of function defaults (was Re: What is a function parameter =[] for?) Antoon Pardon <antoon.pardon@rece.vub.ac.be> - 2015-11-25 13:25 +0100
          Re: Late-binding of function defaults (was Re: What is a function parameter =[] for?) BartC <bc@freeuk.com> - 2015-11-25 13:20 +0000
            Re: Late-binding of function defaults (was Re: What is a function parameter =[] for?) Ned Batchelder <ned@nedbatchelder.com> - 2015-11-25 07:13 -0800
              Re: Late-binding of function defaults (was Re: What is a function parameter =[] for?) Laura Creighton <lac@openend.se> - 2015-11-25 16:59 +0100
                Multiplication [was Re: Late-binding of function defaults] Steven D'Aprano <steve@pearwood.info> - 2015-11-26 05:09 +1100
                Re: Multiplication [was Re: Late-binding of function defaults] Laura Creighton <lac@openend.se> - 2015-11-25 19:45 +0100
                Re: Multiplication [was Re: Late-binding of function defaults] Marko Rauhamaa <marko@pacujo.net> - 2015-11-25 23:04 +0200
              Re: Late-binding of function defaults (was Re: What is a function parameter =[] for?) Arie van Wingerden <xapwing@gmail.com> - 2015-11-25 17:12 +0100
              Re: Late-binding of function defaults (was Re: What is a function parameter =[] for?) Chris Angelico <rosuav@gmail.com> - 2015-11-26 03:29 +1100
              Re: Late-binding of function defaults (was Re: What is a function parameter =[] for?) BartC <bc@freeuk.com> - 2015-11-25 17:18 +0000
                Re: Late-binding of function defaults (was Re: What is a function parameter =[] for?) Ian Kelly <ian.g.kelly@gmail.com> - 2015-11-25 11:03 -0700
                Re: Late-binding of function defaults (was Re: What is a function parameter =[] for?) BartC <bc@freeuk.com> - 2015-11-25 18:48 +0000
                Re: Late-binding of function defaults (was Re: What is a function parameter =[] for?) Mark Lawrence <breamoreboy@yahoo.co.uk> - 2015-11-25 20:50 +0000
                Re: Late-binding of function defaults (was Re: What is a function parameter =[] for?) BartC <bc@freeuk.com> - 2015-11-25 21:56 +0000
                Re: Late-binding of function defaults (was Re: What is a function parameter =[] for?) Marko Rauhamaa <marko@pacujo.net> - 2015-11-26 00:16 +0200
                Re: Late-binding of function defaults (was Re: What is a function parameter =[] for?) BartC <bc@freeuk.com> - 2015-11-25 22:41 +0000
                Re: Late-binding of function defaults (was Re: What is a function parameter =[] for?) Steven D'Aprano <steve@pearwood.info> - 2015-11-26 11:31 +1100
                Re: Late-binding of function defaults (was Re: What is a function parameter =[] for?) BartC <bc@freeuk.com> - 2015-11-26 01:23 +0000
                Re: Late-binding of function defaults (was Re: What is a function parameter =[] for?) Ned Batchelder <ned@nedbatchelder.com> - 2015-11-25 17:52 -0800
                Re: Late-binding of function defaults (was Re: What is a function parameter =[] for?) Ben Finney <ben+python@benfinney.id.au> - 2015-11-26 16:08 +1100
                Re: Late-binding of function defaults (was Re: What is a function parameter =[] for?) Mark Lawrence <breamoreboy@yahoo.co.uk> - 2015-11-26 06:39 +0000
                Re: Late-binding of function defaults (was Re: What is a function parameter =[] for?) Antoon Pardon <antoon.pardon@rece.vub.ac.be> - 2015-11-26 09:31 +0100
                Re: Late-binding of function defaults (was Re: What is a function parameter =[] for?) BartC <bc@freeuk.com> - 2015-11-26 12:53 +0000
                Re: Late-binding of function defaults (was Re: What is a function parameter =[] for?) Chris Angelico <rosuav@gmail.com> - 2015-11-27 00:15 +1100
                Re: Late-binding of function defaults (was Re: What is a function parameter =[] for?) BartC <bc@freeuk.com> - 2015-11-26 14:40 +0000
                Re: Late-binding of function defaults (was Re: What is a function parameter =[] for?) MRAB <python@mrabarnett.plus.com> - 2015-11-26 16:14 +0000
                Re: Late-binding of function defaults (was Re: What is a function parameter =[] for?) BartC <bc@freeuk.com> - 2015-11-26 22:27 +0000
                Re: Late-binding of function defaults (was Re: What is a function parameter =[] for?) Chris Angelico <rosuav@gmail.com> - 2015-11-27 10:07 +1100
                Re: Late-binding of function defaults (was Re: What is a function parameter =[] for?) Random832 <random832@fastmail.com> - 2015-11-26 19:15 -0500
                Re: Late-binding of function defaults (was Re: What is a function parameter =[] for?) Chris Angelico <rosuav@gmail.com> - 2015-11-27 11:48 +1100
                Re: Late-binding of function defaults (was Re: What is a function parameter =[] for?) MRAB <python@mrabarnett.plus.com> - 2015-11-27 01:15 +0000
                Re: Late-binding of function defaults (was Re: What is a function parameter =[] for?) MRAB <python@mrabarnett.plus.com> - 2015-11-26 16:16 +0000
                Re: Late-binding of function defaults (was Re: What is a function   parameter =[] for?) Gregory Ewing <greg.ewing@canterbury.ac.nz> - 2015-11-27 10:48 +1300
                Re: Late-binding of function defaults (was Re: What is a function parameter =[] for?) Steven D'Aprano <steve@pearwood.info> - 2015-11-27 12:46 +1100
                Re: Late-binding of function defaults (was Re: What is a function parameter =[] for?) BartC <bc@freeuk.com> - 2015-11-27 02:01 +0000
                Re: Late-binding of function defaults (was Re: What is a function parameter =[] for?) Marko Rauhamaa <marko@pacujo.net> - 2015-11-26 08:41 +0200
                Re: Late-binding of function defaults (was Re: What is a function parameter =[] for?) Steven D'Aprano <steve@pearwood.info> - 2015-11-27 12:09 +1100
                Re: Late-binding of function defaults (was Re: What is a function parameter =[] for?) BartC <bc@freeuk.com> - 2015-11-27 10:31 +0000
                Re: Late-binding of function defaults (was Re: What is a function parameter =[] for?) Marko Rauhamaa <marko@pacujo.net> - 2015-11-27 13:30 +0200
              Re: Late-binding of function defaults (was Re: What is a function parameter =[] for?) Ben Finney <ben+python@benfinney.id.au> - 2015-11-26 06:57 +1100
                Re: Late-binding of function defaults (was Re: What is a function parameter =[] for?) Marko Rauhamaa <marko@pacujo.net> - 2015-11-25 23:00 +0200
            Re: Late-binding of function defaults (was Re: What is a function parameter =[] for?) Emile van Sebille <emile@fenx.com> - 2015-11-25 10:56 -0800
            Re: Late-binding of function defaults (was Re: What is a function parameter =[] for?) Steven D'Aprano <steve@pearwood.info> - 2015-11-26 13:01 +1100
          Re: Late-binding of function defaults (was Re: What is a function parameter =[] for?) Chris Angelico <rosuav@gmail.com> - 2015-11-26 00:24 +1100
          Re: Late-binding of function defaults (was Re: What is a function parameter =[] for?) Antoon Pardon <antoon.pardon@rece.vub.ac.be> - 2015-11-25 15:17 +0100
          Re: Late-binding of function defaults (was Re: What is a function parameter =[] for?) Emile van Sebille <emile@fenx.com> - 2015-11-25 10:51 -0800
      Re: Late-binding of function defaults (was Re: What is a function parameter =[] for?) Chris Angelico <rosuav@gmail.com> - 2015-11-25 19:32 +1100
        Re: Late-binding of function defaults (was Re: What is a function parameter =[] for?) Marko Rauhamaa <marko@pacujo.net> - 2015-11-25 10:43 +0200
          Re: Late-binding of function defaults (was Re: What is a function parameter =[] for?) Steven D'Aprano <steve@pearwood.info> - 2015-11-25 21:58 +1100
        Re: Late-binding of function defaults (was Re: What is a function parameter =[] for?) BartC <bc@freeuk.com> - 2015-11-25 12:35 +0000
          Re: Late-binding of function defaults (was Re: What is a function parameter =[] for?) Marko Rauhamaa <marko@pacujo.net> - 2015-11-25 15:06 +0200
            Re: Late-binding of function defaults (was Re: What is a function parameter =[] for?) BartC <bc@freeuk.com> - 2015-11-25 13:37 +0000
              Re: Late-binding of function defaults (was Re: What is a function parameter =[] for?) Marko Rauhamaa <marko@pacujo.net> - 2015-11-25 15:53 +0200
                Re: Late-binding of function defaults (was Re: What is a function parameter =[] for?) BartC <bc@freeuk.com> - 2015-11-25 14:34 +0000
                Re: Late-binding of function defaults (was Re: What is a function parameter =[] for?) Dennis Lee Bieber <wlfraed@ix.netcom.com> - 2015-11-25 13:32 -0500
                Re: Late-binding of function defaults (was Re: What is a function parameter =[] for?) Steven D'Aprano <steve@pearwood.info> - 2015-11-26 11:53 +1100
                Re: Late-binding of function defaults (was Re: What is a function parameter =[] for?) Marko Rauhamaa <marko@pacujo.net> - 2015-11-26 08:52 +0200
                Re: Late-binding of function defaults (was Re: What is a function parameter =[] for?) Chris Angelico <rosuav@gmail.com> - 2015-11-26 18:14 +1100
                Re: Late-binding of function defaults (was Re: What is a function parameter =[] for?) Marko Rauhamaa <marko@pacujo.net> - 2015-11-26 10:27 +0200
                Re: Late-binding of function defaults (was Re: What is a function parameter =[] for?) Chris Angelico <rosuav@gmail.com> - 2015-11-26 19:34 +1100
                Re: Late-binding of function defaults (was Re: What is a function parameter =[] for?) Marko Rauhamaa <marko@pacujo.net> - 2015-11-26 12:54 +0200
                Re: Late-binding of function defaults (was Re: What is a function parameter =[] for?) Chris Angelico <rosuav@gmail.com> - 2015-11-26 22:04 +1100
                Re: Late-binding of function defaults (was Re: What is a function parameter =[] for?) Marko Rauhamaa <marko@pacujo.net> - 2015-11-26 13:23 +0200
                Re: Late-binding of function defaults (was Re: What is a function parameter =[] for?) Chris Angelico <rosuav@gmail.com> - 2015-11-26 22:35 +1100
                Re: Late-binding of function defaults (was Re: What is a function parameter =[] for?) Marko Rauhamaa <marko@pacujo.net> - 2015-11-26 14:03 +0200
                Re: Late-binding of function defaults (was Re: What is a function parameter =[] for?) Steven D'Aprano <steve@pearwood.info> - 2015-11-27 12:43 +1100
                Re: Late-binding of function defaults (was Re: What is a function parameter =[] for?) Antoon Pardon <antoon.pardon@rece.vub.ac.be> - 2015-11-26 09:45 +0100
                Re: Late-binding of function defaults (was Re: What is a function parameter =[] for?) Gregory Ewing <greg.ewing@canterbury.ac.nz> - 2015-11-27 10:20 +1300
                Re: Late-binding of function defaults (was Re: What is a function parameter =[] for?) Marko Rauhamaa <marko@pacujo.net> - 2015-11-26 23:36 +0200
                Re: Late-binding of function defaults (was Re: What is a function parameter =[] for?) Steven D'Aprano <steve@pearwood.info> - 2015-11-27 12:23 +1100
                Re: Late-binding of function defaults (was Re: What is a function parameter =[] for?) Mark Lawrence <breamoreboy@yahoo.co.uk> - 2015-11-26 11:17 +0000
            Re: Late-binding of function defaults (was Re: What is a function parameter =[] for?) Chris Angelico <rosuav@gmail.com> - 2015-11-26 00:44 +1100
            Re: Late-binding of function defaults (was Re: What is a function parameter =[] for?) Ben Finney <ben+python@benfinney.id.au> - 2015-11-26 06:55 +1100
            Re: Late-binding of function defaults (was Re: What is a function parameter =[] for?) Random832 <random832@fastmail.com> - 2015-11-26 00:52 +0000
            Re: Late-binding of function defaults (was Re: What is a function parameter =[] for?) Ian Kelly <ian.g.kelly@gmail.com> - 2015-11-25 20:01 -0700
            Semantics of collection types (was: Late-binding of function defaults (was Re: What is a function parameter =[] for?)) Ben Finney <ben+python@benfinney.id.au> - 2015-11-26 16:04 +1100
          Re: Late-binding of function defaults (was Re: What is a function parameter =[] for?) Chris Angelico <rosuav@gmail.com> - 2015-11-26 00:35 +1100
        Re: Late-binding of function defaults (was Re: What is a function parameter =[] for?) Larry Hudson <orgnut@yahoo.com> - 2015-11-25 22:44 -0800
      Re: Late-binding of function defaults (was Re: What is a function parameter =[] for?) Antoon Pardon <antoon.pardon@rece.vub.ac.be> - 2015-11-25 10:13 +0100

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