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Re: Micro Python -- a lean and efficient implementation of Python 3

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On 04/06/2014 12:01, Tim Chase wrote:
> On 2014-06-04 00:58, Paul Rubin wrote:
>> Steven D'Aprano <steve@pearwood.info> writes:
>>>> Maybe there's a use-case for a microcontroller that works in
>>>> ISO-8859-5 natively, thus using only eight bits per character,
>>> That won't even make the Russians happy, since in Russia there
>>> are multiple incompatible legacy encodings.
>>
>> I've never understood why not use UTF-8 for everything.
>
> If you use UTF-8 for everything, then you end up in a world where
> string-indexing (see ChrisA's other side thread on this topic) is no
> longer an O(1) operation, but an O(N) operation.  Some of us slice
> strings for a living. ;-)  I understand that using UTF-32 would allow
> us to maintain O(1) indexing at the cost of every string occupying 4
> bytes per character.  The FSR (again, as I understand it) allows
> strings that fit in one-byte-per-character to use that, scaling up to
> use wider characters internally as they're actually needed/used.
>
........
I believe that we should distinguish between glyph/character indexing and string 
indexing. Even in unicode it may be hard to decide where a visual glyph starts 
and ends. I assume most people would like to assign one glyph to one unicode, 
but that's not always possible with composed glyphs.

 >>> for a in (u'\xc5',u'A\u030a'):
... 	for o in (u'\xf6',u'o\u0308'):
... 		u=a+u'ngstr'+o+u'm'
... 		print("%s %s" % (repr(u),u))
...
u'\xc5ngstr\xf6m' Ångström
u'\xc5ngstro\u0308m' Ångström
u'A\u030angstr\xf6m' Ångström
u'A\u030angstro\u0308m' Ångström
 >>> u'\xc5ngstr\xf6m'==u'\xc5ngstro\u0308m'
False

so even unicode doesn't always allow for O(1) glyph indexing. I know this is 
artificial, but this is the same situation as utf8 faces just the frequency of 
occurrence is different. A very large amount of computing is still western 
centric so searching a byte string for latin characters is still efficient; 
searching for an n with a tilde on top might not be so easy.
-- 
Robin Becker

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Re: Micro Python -- a lean and efficient implementation of Python 3 Paul Sokolovsky <pmiscml@gmail.com> - 2014-06-04 00:41 +0300
  Re: Micro Python -- a lean and efficient implementation of Python 3 Rustom Mody <rustompmody@gmail.com> - 2014-06-03 20:37 -0700
    Re: Micro Python -- a lean and efficient implementation of Python 3 Chris Angelico <rosuav@gmail.com> - 2014-06-04 13:52 +1000
      Re: Micro Python -- a lean and efficient implementation of Python 3 Rustom Mody <rustompmody@gmail.com> - 2014-06-03 21:40 -0700
        Re: Micro Python -- a lean and efficient implementation of Python 3 Ian Kelly <ian.g.kelly@gmail.com> - 2014-06-03 23:02 -0600
        Re: Micro Python -- a lean and efficient implementation of Python 3 Chris Angelico <rosuav@gmail.com> - 2014-06-04 17:16 +1000
          Re: Micro Python -- a lean and efficient implementation of Python 3 Steven D'Aprano <steve@pearwood.info> - 2014-06-04 07:42 +0000
            Re: Micro Python -- a lean and efficient implementation of Python 3 Paul Rubin <no.email@nospam.invalid> - 2014-06-04 00:58 -0700
              Re: Micro Python -- a lean and efficient implementation of Python 3 Robin Becker <robin@reportlab.com> - 2014-06-04 11:06 +0100
              Re: Micro Python -- a lean and efficient implementation of Python 3 Tim Chase <python.list@tim.thechases.com> - 2014-06-04 06:01 -0500
                Re: Micro Python -- a lean and efficient implementation of Python 3 Marko Rauhamaa <marko@pacujo.net> - 2014-06-04 14:57 +0300
                Re: Micro Python -- a lean and efficient implementation of Python 3 Tim Chase <python.list@tim.thechases.com> - 2014-06-04 07:25 -0500
                Re: Micro Python -- a lean and efficient implementation of Python 3 Paul Rubin <no.email@nospam.invalid> - 2014-06-04 11:25 -0700
              Re: Micro Python -- a lean and efficient implementation of Python 3 Robin Becker <robin@reportlab.com> - 2014-06-04 12:53 +0100
                Re: Micro Python -- a lean and efficient implementation of Python 3 Marko Rauhamaa <marko@pacujo.net> - 2014-06-04 15:17 +0300
                Re: Micro Python -- a lean and efficient implementation of Python 3 Robin Becker <robin@reportlab.com> - 2014-06-04 13:31 +0100
                Re: Micro Python -- a lean and efficient implementation of Python 3 Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2014-06-04 13:51 +0000
                Re: Micro Python -- a lean and efficient implementation of Python 3 wxjmfauth@gmail.com - 2014-06-10 00:32 -0700
                Re: Micro Python -- a lean and efficient implementation of Python 3 wxjmfauth@gmail.com - 2014-06-10 02:13 -0700
              Re: Micro Python -- a lean and efficient implementation of Python 3 Tim Chase <python.list@tim.thechases.com> - 2014-06-04 07:21 -0500
              Re: Micro Python -- a lean and efficient implementation of Python 3 Travis Griggs <travisgriggs@gmail.com> - 2014-06-06 09:59 -0700
                Re: Micro Python -- a lean and efficient implementation of Python 3 Roy Smith <roy@panix.com> - 2014-06-06 13:29 -0400
              Re: Micro Python -- a lean and efficient implementation of Python 3 Tim Chase <python.list@tim.thechases.com> - 2014-06-06 21:20 -0500
                Re: Micro Python -- a lean and efficient implementation of Python 3 wxjmfauth@gmail.com - 2014-06-10 12:27 -0700
        Re: Micro Python -- a lean and efficient implementation of Python 3 Chris Angelico <rosuav@gmail.com> - 2014-06-04 17:20 +1000
        Re: Micro Python -- a lean and efficient implementation of Python 3 Wolfgang Maier <wolfgang.maier@biologie.uni-freiburg.de> - 2014-06-04 10:00 +0200
      Re: Micro Python -- a lean and efficient implementation of Python 3 Roy Smith <roy@panix.com> - 2014-06-04 14:42 -0400
        Re: Micro Python -- a lean and efficient implementation of Python 3 Rustom Mody <rustompmody@gmail.com> - 2014-06-04 19:06 -0700
          Re: Micro Python -- a lean and efficient implementation of Python 3 Roy Smith <roy@panix.com> - 2014-06-05 09:59 -0400
            Re: Micro Python -- a lean and efficient implementation of Python 3 Chris Angelico <rosuav@gmail.com> - 2014-06-06 01:33 +1000
    Re: Micro Python -- a lean and efficient implementation of Python 3 Steven D'Aprano <steve@pearwood.info> - 2014-06-04 05:20 +0000
      Re: Micro Python -- a lean and efficient implementation of Python 3 Rustom Mody <rustompmody@gmail.com> - 2014-06-03 22:36 -0700
      Re: Micro Python -- a lean and efficient implementation of Python 3 Ian Kelly <ian.g.kelly@gmail.com> - 2014-06-03 23:55 -0600
      Re: Micro Python -- a lean and efficient implementation of Python 3 Terry Reedy <tjreedy@udel.edu> - 2014-06-04 03:00 -0400
      Re: Micro Python -- a lean and efficient implementation of Python 3 Chris Angelico <rosuav@gmail.com> - 2014-06-04 17:10 +1000

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