Re: FSR and unicode compliance - was Re: RE Module Performance

Date	2013-07-28 21:55 +0200
From	Antoon Pardon <antoon.pardon@rece.vub.ac.be>
Subject	Re: FSR and unicode compliance - was Re: RE Module Performance
References	(11 earlier) <8203e802-9dc5-44c5-9547-6e1947ee224b@googlegroups.com> <mailman.5160.1374890711.3114.python-list@python.org> <f4bb2528-930e-4c0a-820e-66f00ac2b5b6@googlegroups.com> <mailman.5191.1375026785.3114.python-list@python.org> <c5eed93b-bfa1-44fe-9a8f-67a7d9380b20@googlegroups.com>
Newsgroups	comp.lang.python
Message-ID	<mailman.5204.1375041352.3114.python-list@python.org> (permalink)

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Op 28-07-13 21:23, wxjmfauth@gmail.com schreef:
> Le dimanche 28 juillet 2013 17:52:47 UTC+2, Michael Torrie a écrit :
>> On 07/27/2013 12:21 PM, wxjmfauth@gmail.com wrote:
>>
>>> Good point. FSR, nice tool for those who wish to teach
>>
>>> Unicode. It is not every day, one has such an opportunity.
>>
>>
>>
>> I had a long e-mail composed, but decided to chop it down, but still too
>>
>> long.  so I ditched a lot of the context, which jmf also seems to do.
>>
>> Apologies.
>>
>>
>>
>> 1. FSR *is* UTF-32 so it is as unicode compliant as UTF-32, since UTF-32
>>
>> is an official encoding.  FSR only differs from UTF-32 in that the
>>
>> padding zeros are stripped off such that it is stored in the most
>>
>> compact form that can handle all the characters in string, which is
>>
>> always known at string creation time.  Now you can argue many things,
>>
>> but to say FSR is not unicode compliant is quite a stretch!  What
>>
>> unicode entities or characters cannot be stored in strings using FSR?
>>
>> What sequences of bytes in FSR result in invalid Unicode entities?
>>
>>
>>
>> 2. strings in Python *never change*.  They are immutable.  The +
>>
>> operator always copies strings character by character into a new string
>>
>> object, even if Python had used UTF-8 internally.  If you're doing a lot
>>
>> of string concatenations, perhaps you're using the wrong data type.  A
>>
>> byte buffer might be better for you, where you can stuff utf-8 sequences
>>
>> into it to your heart's content.
>>
>>
>>
>> 3. UTF-8 and UTF-16 encodings, being variable width encodings, mean that
>>
>> slicing a string would be very very slow, and that's unacceptable for
>>
>> the use cases of python strings.  I'm assuming you understand big O
>>
>> notation, as you talk of experience in many languages over the years.
>>
>> FSR and UTF-32 both are O(1) for slicing and lookups.  UTF-8, 16 and any
>>
>> variable-width encoding are always O(n).  A lot slower!
>>
>>
>>
>> 4. Unicode is, well, unicode.  You seem to hop all over the place from
>>
>> talking about code points to bytes to bits, using them all
>>
>> interchangeably.  And now you seem to be claiming that a particular byte
>>
>> encoding standard is by definition unicode (UTF-8).  Or at least that's
>>
>> how it sounds.  And also claim FSR is not compliant with unicode
>>
>> standards, which appears to me to be completely false.
>>
>>
>>
>> Is my understanding of these things wrong?
>
> ------
>
> Compare these (a BDFL exemple, where I'using a non-ascii char)
>
> Py 3.2 (narrow build)
>
>>>> timeit.timeit("a = 'hundred'; 'x' in a")
> 0.09897159682121348
>>>> timeit.timeit("a = 'hundre€'; 'x' in a")
> 0.09079501961732461
>>>> sys.getsizeof('d')
> 32
>>>> sys.getsizeof('€')
> 32
>>>> sys.getsizeof('dd')
> 34
>>>> sys.getsizeof('d€')
> 34
>
>
> Py3.3
>
>>>> timeit.timeit("a = 'hundred'; 'x' in a")
> 0.12183182740848858
>>>> timeit.timeit("a = 'hundre€'; 'x' in a")
> 0.2365732969632326
>>>> sys.getsizeof('d')
> 26
>>>> sys.getsizeof('€')
> 40
>>>> sys.getsizeof('dd')
> 27
>>>> sys.getsizeof('d€')
> 42
>
> Tell me which one seems to be more "unicode compliant"?

Cant tell, you give no relevant information on which one can decide
this question.

> The goal of Unicode is to handle every char "equaly".

Not to this kind of detail, which is looking at irrelevant
implementation details.

> Now, the problem: memory. Do not forget that à la "FSR"
> mechanism for a non-ascii user is *irrelevant*. As
> soon as one uses one single non-ascii, your ascii feature
> is lost. (That why we have all these dedicated coding
> schemes, utfs included).

So? Why should that trouble me? As far as I understand
whether I have an ascii string or not is totally irrelevant
to the application programmer. Within the application I
just process strings and let the programming environment
keep track of these details in a transparant way unless
you start looking at things like getsizeof, which gives
you implementation details that are mostly irrelevant
in deciding whether the behaviour is compliant or not.

>>>> sys.getsizeof('abc' * 1000 + 'z')
> 3026
>>>> sys.getsizeof('abc' * 1000 + '\U00010010')
> 12044
>
> A bit secret. The larger a repertoire of characters
> is, the more bits you needs.
> Secret #2. You can not escape from this.

And totally unimportant for deciding complyance.

-- 
Antoon Pardon

Thread

RE Module Performance Devyn Collier Johnson <devyncjohnson@gmail.com> - 2013-07-11 19:44 -0400
  Re: RE Module Performance wxjmfauth@gmail.com - 2013-07-12 02:23 -0700
    Re: RE Module Performance Chris Angelico <rosuav@gmail.com> - 2013-07-12 19:27 +1000
    Re: RE Module Performance Joshua Landau <joshua@landau.ws> - 2013-07-12 10:39 +0100
    Re: RE Module Performance Chris Angelico <rosuav@gmail.com> - 2013-07-12 19:40 +1000
    Re: RE Module Performance Devyn Collier Johnson <devyncjohnson@gmail.com> - 2013-07-12 06:45 -0400
    Re: RE Module Performance Joshua Landau <joshua@landau.ws> - 2013-07-12 16:59 +0100
    Re: RE Module Performance Peter Otten <__peter__@web.de> - 2013-07-12 18:15 +0200
    Re: RE Module Performance Chris Angelico <rosuav@gmail.com> - 2013-07-13 02:21 +1000
    Re: RE Module Performance Devyn Collier Johnson <devyncjohnson@gmail.com> - 2013-07-12 13:58 -0400
      Re: RE Module Performance Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2013-07-13 05:37 +0000
        Re: RE Module Performance 88888 Dihedral <dihedral88888@gmail.com> - 2013-07-14 11:17 -0700
          Re: RE Module Performance Devyn Collier Johnson <devyncjohnson@gmail.com> - 2013-07-15 06:06 -0400
            Re: RE Module Performance Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2013-07-15 12:36 +0000
              Dihedral Devyn Collier Johnson <devyncjohnson@gmail.com> - 2013-07-15 08:52 -0400
              Re: Dihedral Joel Goldstick <joel.goldstick@gmail.com> - 2013-07-15 09:03 -0400
              Re: Dihedral Wayne Werner <wayne@waynewerner.com> - 2013-07-15 17:43 -0500
              Re: Dihedral Fábio Santos <fabiosantosart@gmail.com> - 2013-07-15 23:54 +0100
              Re: Dihedral Chris Angelico <rosuav@gmail.com> - 2013-07-16 08:59 +1000
              Re: Dihedral Tim Delaney <timothy.c.delaney@gmail.com> - 2013-07-16 16:06 +1000
              Re: Dihedral Stefan Behnel <stefan_ml@behnel.de> - 2013-07-24 20:08 +0200
              Re: Dihedral Chris Angelico <rosuav@gmail.com> - 2013-07-25 04:23 +1000
              Re: Dihedral Dennis Lee Bieber <wlfraed@ix.netcom.com> - 2013-07-24 20:15 -0400
    Re: RE Module Performance Tim Delaney <timothy.c.delaney@gmail.com> - 2013-07-13 08:16 +1000
    Re: RE Module Performance Michael Torrie <torriem@gmail.com> - 2013-07-12 17:13 -0600
      Re: RE Module Performance wxjmfauth@gmail.com - 2013-07-24 06:40 -0700
        Re: RE Module Performance Chris Angelico <rosuav@gmail.com> - 2013-07-24 23:48 +1000
        Re: RE Module Performance David Hutto <dwightdhutto@gmail.com> - 2013-07-24 10:17 -0400
        Re: RE Module Performance David Hutto <dwightdhutto@gmail.com> - 2013-07-24 10:19 -0400
        Re: RE Module Performance Chris Angelico <rosuav@gmail.com> - 2013-07-25 00:34 +1000
          Re: RE Module Performance Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2013-07-25 07:02 +0000
            Re: RE Module Performance Chris Angelico <rosuav@gmail.com> - 2013-07-25 17:39 +1000
        Re: RE Module Performance Michael Torrie <torriem@gmail.com> - 2013-07-24 08:47 -0600
          Re: RE Module Performance wxjmfauth@gmail.com - 2013-07-25 02:27 -0700
            Re: RE Module Performance Chris Angelico <rosuav@gmail.com> - 2013-07-25 20:14 +1000
              Re: RE Module Performance wxjmfauth@gmail.com - 2013-07-25 12:07 -0700
                Re: RE Module Performance Chris Angelico <rosuav@gmail.com> - 2013-07-26 05:18 +1000
                RE: RE Module Performance "Prasad, Ramit" <ramit.prasad@jpmorgan.com> - 2013-07-25 19:30 +0000
                Re: RE Module Performance Michael Torrie <torriem@gmail.com> - 2013-07-25 21:06 -0600
        Re: RE Module Performance Michael Torrie <torriem@gmail.com> - 2013-07-24 09:00 -0600
          Re: RE Module Performance Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2013-07-25 05:56 +0000
        Re: RE Module Performance Chris Angelico <rosuav@gmail.com> - 2013-07-25 00:56 +1000
        Re: RE Module Performance Terry Reedy <tjreedy@udel.edu> - 2013-07-24 13:52 -0400
        Re: RE Module Performance Chris Angelico <rosuav@gmail.com> - 2013-07-25 04:15 +1000
          Re: RE Module Performance Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2013-07-25 07:15 +0000
            Re: RE Module Performance Chris Angelico <rosuav@gmail.com> - 2013-07-25 17:58 +1000
              Re: RE Module Performance Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2013-07-25 09:22 +0000
                Re: RE Module Performance Chris Angelico <rosuav@gmail.com> - 2013-07-25 20:07 +1000
        Re: RE Module Performance Terry Reedy <tjreedy@udel.edu> - 2013-07-24 18:09 -0400
        Re: RE Module Performance Chris Angelico <rosuav@gmail.com> - 2013-07-25 08:19 +1000
        Re: RE Module Performance Michael Torrie <torriem@gmail.com> - 2013-07-24 16:59 -0600
        Re: RE Module Performance Chris Angelico <rosuav@gmail.com> - 2013-07-25 09:24 +1000
        Re: RE Module Performance Serhiy Storchaka <storchaka@gmail.com> - 2013-07-25 08:49 +0300
        Re: RE Module Performance Chris Angelico <rosuav@gmail.com> - 2013-07-25 15:58 +1000
        Re: RE Module Performance Jeremy Sanders <jeremy@jeremysanders.net> - 2013-07-25 14:36 +0100
          Re: RE Module Performance Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2013-07-25 15:26 +0000
            Re: RE Module Performance Chris Angelico <rosuav@gmail.com> - 2013-07-26 01:36 +1000
              Re: RE Module Performance Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2013-07-25 17:18 +0000
                Re: RE Module Performance Chris Angelico <rosuav@gmail.com> - 2013-07-26 03:27 +1000
                Re: RE Module Performance Ian Kelly <ian.g.kelly@gmail.com> - 2013-07-25 15:45 -0500
                Re: RE Module Performance Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2013-07-26 02:48 +0000
                Re: RE Module Performance Ian Kelly <ian.g.kelly@gmail.com> - 2013-07-25 21:20 -0600
                Re: RE Module Performance wxjmfauth@gmail.com - 2013-07-26 06:36 -0700
                Re: RE Module Performance wxjmfauth@gmail.com - 2013-07-26 08:46 -0700
                Re: RE Module Performance Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2013-07-27 06:28 +0000
                Re: RE Module Performance Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2013-07-27 03:37 +0000
                Re: RE Module Performance Ian Kelly <ian.g.kelly@gmail.com> - 2013-07-26 22:12 -0600
                Re: RE Module Performance Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2013-07-27 05:04 +0000
                Re: RE Module Performance Dennis Lee Bieber <wlfraed@ix.netcom.com> - 2013-07-27 12:13 -0400
                Re: RE Module Performance wxjmfauth@gmail.com - 2013-07-26 06:19 -0700
                Re: RE Module Performance Michael Torrie <torriem@gmail.com> - 2013-07-25 21:09 -0600
                Re: RE Module Performance wxjmfauth@gmail.com - 2013-07-26 06:21 -0700
                Re: RE Module Performance Michael Torrie <torriem@gmail.com> - 2013-07-26 20:05 -0600
                Re: RE Module Performance wxjmfauth@gmail.com - 2013-07-27 11:21 -0700
                Re: RE Module Performance Ian Kelly <ian.g.kelly@gmail.com> - 2013-07-27 21:53 -0600
                Re: RE Module Performance wxjmfauth@gmail.com - 2013-07-28 11:13 -0700
                Re: RE Module Performance MRAB <python@mrabarnett.plus.com> - 2013-07-28 20:04 +0100
                Re: RE Module Performance wxjmfauth@gmail.com - 2013-07-28 12:30 -0700
                Re: RE Module Performance Lele Gaifax <lele@metapensiero.it> - 2013-07-28 22:45 +0200
                Re: RE Module Performance Antoon Pardon <antoon.pardon@rece.vub.ac.be> - 2013-07-28 22:01 +0200
                Re: RE Module Performance wxjmfauth@gmail.com - 2013-07-30 07:01 -0700
                Re: RE Module Performance Antoon Pardon <antoon.pardon@rece.vub.ac.be> - 2013-07-30 16:38 +0200
                Re: RE Module Performance Chris Angelico <rosuav@gmail.com> - 2013-07-30 15:45 +0100
                Re: RE Module Performance MRAB <python@mrabarnett.plus.com> - 2013-07-30 17:13 +0100
                Re: RE Module Performance Antoon Pardon <antoon.pardon@rece.vub.ac.be> - 2013-07-30 18:39 +0200
                Re: RE Module Performance MRAB <python@mrabarnett.plus.com> - 2013-07-30 18:14 +0100
                Re: RE Module Performance Neil Hodgson <nhodgson@iinet.net.au> - 2013-07-31 13:09 +1000
                Re: RE Module Performance Tim Delaney <timothy.c.delaney@gmail.com> - 2013-07-31 03:27 +1000
                Re: RE Module Performance Joshua Landau <joshua@landau.ws> - 2013-07-30 18:40 +0100
                Re: RE Module Performance Antoon Pardon <antoon.pardon@rece.vub.ac.be> - 2013-07-30 20:19 +0200
                Re: RE Module Performance wxjmfauth@gmail.com - 2013-07-30 12:09 -0700
                Re: RE Module Performance Chris Angelico <rosuav@gmail.com> - 2013-07-30 21:04 +0100
                Re: RE Module Performance Michael Torrie <torriem@gmail.com> - 2013-07-30 21:54 -0600
                Re: RE Module Performance Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2013-07-31 05:45 +0000
                Re: RE Module Performance Chris Angelico <rosuav@gmail.com> - 2013-07-31 08:17 +0100
                Re: RE Module Performance wxjmfauth@gmail.com - 2013-07-31 13:15 -0700
                Re: RE Module Performance Chris Angelico <rosuav@gmail.com> - 2013-07-31 21:41 +0100
                Re: RE Module Performance Antoon Pardon <antoon.pardon@rece.vub.ac.be> - 2013-07-31 10:11 +0200
                Re: RE Module Performance wxjmfauth@gmail.com - 2013-07-31 01:32 -0700
                Re: RE Module Performance Antoon Pardon <antoon.pardon@rece.vub.ac.be> - 2013-07-31 10:59 +0200
                Re: RE Module Performance Michael Torrie <torriem@gmail.com> - 2013-07-31 08:44 -0600
                Re: RE Module Performance Terry Reedy <tjreedy@udel.edu> - 2013-07-30 17:05 -0400
                Re: RE Module Performance Michael Torrie <torriem@gmail.com> - 2013-07-30 21:30 -0600
                Re: RE Module Performance Antoon Pardon <antoon.pardon@rece.vub.ac.be> - 2013-07-31 09:23 +0200
                Re: RE Module Performance Michael Torrie <torriem@gmail.com> - 2013-07-31 08:27 -0600
                Re: RE Module Performance Antoon Pardon <antoon.pardon@rece.vub.ac.be> - 2013-07-28 10:45 +0200
                FSR and unicode compliance - was Re: RE Module Performance Michael Torrie <torriem@gmail.com> - 2013-07-28 09:52 -0600
                Re: FSR and unicode compliance - was Re: RE Module Performance wxjmfauth@gmail.com - 2013-07-28 12:23 -0700
                Re: FSR and unicode compliance - was Re: RE Module Performance MRAB <python@mrabarnett.plus.com> - 2013-07-28 20:44 +0100
                Re: FSR and unicode compliance - was Re: RE Module Performance Antoon Pardon <antoon.pardon@rece.vub.ac.be> - 2013-07-28 21:55 +0200
                Re: FSR and unicode compliance - was Re: RE Module Performance Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2013-07-28 20:52 +0000
                Re: FSR and unicode compliance - was Re: RE Module Performance wxjmfauth@gmail.com - 2013-07-29 04:43 -0700
                Re: FSR and unicode compliance - was Re: RE Module Performance Chris Angelico <rosuav@gmail.com> - 2013-07-29 12:57 +0100
                Re: FSR and unicode compliance - was Re: RE Module Performance wxjmfauth@gmail.com - 2013-07-29 05:56 -0700
                Re: FSR and unicode compliance - was Re: RE Module Performance wxjmfauth@gmail.com - 2013-07-29 07:20 -0700
                Re: FSR and unicode compliance - was Re: RE Module Performance Chris Angelico <rosuav@gmail.com> - 2013-07-29 15:49 +0100
                Re: FSR and unicode compliance - was Re: RE Module Performance wxjmfauth@gmail.com - 2013-07-29 09:31 -0700
                Re: FSR and unicode compliance - was Re: RE Module Performance Heiko Wundram <modelnine@modelnine.org> - 2013-07-29 14:06 +0200
                Re: FSR and unicode compliance - was Re: RE Module Performance Devyn Collier Johnson <devyncjohnson@gmail.com> - 2013-07-29 08:43 -0400
                Re: FSR and unicode compliance - was Re: RE Module Performance Chris Angelico <rosuav@gmail.com> - 2013-07-28 18:03 +0100
                Re: FSR and unicode compliance - was Re: RE Module Performance Terry Reedy <tjreedy@udel.edu> - 2013-07-28 13:36 -0400
                Re: FSR and unicode compliance - was Re: RE Module Performance wxjmfauth@gmail.com - 2013-07-29 06:36 -0700
                Re: FSR and unicode compliance - was Re: RE Module Performance Chris Angelico <rosuav@gmail.com> - 2013-07-28 19:03 +0100
                Re: RE Module Performance Joshua Landau <joshua@landau.ws> - 2013-07-28 19:19 +0100
                Re: RE Module Performance Chris Angelico <rosuav@gmail.com> - 2013-07-28 19:29 +0100
                Re: RE Module Performance Terry Reedy <tjreedy@udel.edu> - 2013-07-28 15:06 -0400
                Re: RE Module Performance Joshua Landau <joshua@landau.ws> - 2013-07-28 23:14 +0100
                Re: RE Module Performance Antoon Pardon <antoon.pardon@rece.vub.ac.be> - 2013-07-28 20:51 +0200
                Re: RE Module Performance Chris Angelico <rosuav@gmail.com> - 2013-07-29 00:07 +0100
                Re: RE Module Performance Antoon Pardon <antoon.pardon@rece.vub.ac.be> - 2013-07-26 22:38 +0200
        Re: RE Module Performance Devyn Collier Johnson <devyncjohnson@gmail.com> - 2013-07-25 09:44 -0400
        Re: RE Module Performance Ian Kelly <ian.g.kelly@gmail.com> - 2013-07-25 15:53 -0500
    Re: RE Module Performance MRAB <python@mrabarnett.plus.com> - 2013-07-13 00:16 +0100
    Re: RE Module Performance Tim Delaney <timothy.c.delaney@gmail.com> - 2013-07-14 05:34 +1000
    Re: RE Module Performance Devyn Collier Johnson <devyncjohnson@gmail.com> - 2013-07-16 06:30 -0400
      Re: RE Module Performance 88888 Dihedral <dihedral88888@gmail.com> - 2013-07-18 13:17 -0700

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