Re: Everything is an object in python - object class and type class

References	<14976c1b-a620-426f-b529-41a3c04e9c1a@googlegroups.com> <7f287dcf-8d52-4ab8-9768-88d1f75da269@googlegroups.com> <3t5bx.755107$dj1.564752@fx03.am4>
From	Ian Kelly <ian.g.kelly@gmail.com>
Date	2015-06-02 09:09 -0600
Subject	Re: Everything is an object in python - object class and type class
Newsgroups	comp.lang.python
Message-ID	<mailman.65.1433257833.13271.python-list@python.org> (permalink)

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On Mon, Jun 1, 2015 at 4:59 PM, BartC <bc@freeuk.com> wrote:
> I'm developing a new language along the lines of Python, perhaps a brief
> description of how things are done there might help. Or just give a
> different perspective.
>
> Objects in this language are tagged: there's a code attached to each
> indicating what kind of data is stored. These codes are integers, or
> enumerations, for example:
>
>  Int =    1
>  String = 2
>  List =   3
>  Class =  4
>
> And the following are examples of object instances with their tags:
>
> a is (Int,    42)
> b is (String, "ABCXYZ")
> c is (List,   [10,20,30,40])
> d is (Class,  2 or <String>)
>
> The last one might be tricky to grasp: it's really just a number, but one
> that represents a class or type (or tag). If printed, it could display
> <String> rather than just 2. (And when used to do something with the class,
> the 2 might be an index into a set of tables.)
>
> d is not /the/ class itself, but just a reference to it (this is pseudo-code
> not Python):
>
> print (b)                 =>  ABCXYZ
> print (typeof(b))         =>  String <2>
>
> print (d)                 =>  String <2>
> print (typeof(d))         =>  Class  <4>
> print (typeof(typeof(d))) =>  Class  <4>
>
> In my own language, the connection between class and type is hazy (I've only
> just added classes so it needs to be hazy until I understand them more).
>
> 'Type' includes everything, including all the built-in types such as the
> tags above, but also user-defined classes. In fact classes are the mechanism
> used to define new types. But with both designated by an integer within the
> same band (eg. built-int types 1 to 20, user-defined classes 21 and up), it
> is easier not to have a strong distinction ... at the moment.
>
> I haven't a root class yet that is the base of all the others. I don't think
> it's necessary internally to make things work. But it might be a useful
> concept in the language. Calling it 'object' however might give rise to
> confusion as 'object' is informally used to refer to instances. (I've never
> used OO but have picked up some of the jargon!)
>
> (This is almost certainly not how Python does things. Although the Python
> language doesn't go into details as to its implementation provided the
> behaviour is correct.)

It sounds quite similar to me. In CPython at least, every object has a
direct pointer to its type rather than an array index (which is
essentially just an offset from a pointer).

Thread

Everything is an object in python - object class and type class Eddilbert Macharia <edd.cowan@gmail.com> - 2015-05-31 07:34 -0700
  Re: Everything is an object in python - object class and type class Marco Buttu <marco.buttu@gmail.com> - 2015-05-31 17:13 +0200
  Re: Everything is an object in python - object class and type class Terry Reedy <tjreedy@udel.edu> - 2015-05-31 11:37 -0400
  Re: Everything is an object in python - object class and type class Steven D'Aprano <steve@pearwood.info> - 2015-06-01 04:00 +1000
    Re: Everything is an object in python - object class and type class "Dr. Bigcock" <dreamingforward@gmail.com> - 2015-06-01 10:35 -0700
  Re: Everything is an object in python - object class and type class Eddilbert Macharia <edd.cowan@gmail.com> - 2015-05-31 17:29 -0700
    Re: Everything is an object in python - object class and type class Steven D'Aprano <steve@pearwood.info> - 2015-06-01 14:09 +1000
  Re: Everything is an object in python - object class and type class Eddilbert Macharia <edd.cowan@gmail.com> - 2015-05-31 20:09 -0700
    Re: Everything is an object in python - object class and type class Steven D'Aprano <steve@pearwood.info> - 2015-06-01 14:24 +1000
  Re: Everything is an object in python - object class and type class Eddilbert Macharia <edd.cowan@gmail.com> - 2015-06-01 05:03 -0700
    Re: Everything is an object in python - object class and type class BartC <bc@freeuk.com> - 2015-06-01 23:59 +0100
      Re: Everything is an object in python - object class and type class BartC <bc@freeuk.com> - 2015-06-02 11:45 +0100
        Re: Everything is an object in python - object class and type class Rustom Mody <rustompmody@gmail.com> - 2015-06-02 04:16 -0700
      Re: Everything is an object in python - object class and type class Ian Kelly <ian.g.kelly@gmail.com> - 2015-06-02 09:09 -0600
    Re: Everything is an object in python - object class and type class TheDoctor <dreamingforward@gmail.com> - 2015-06-01 17:24 -0700
      Re: Everything is an object in python - object class and type class Chris Angelico <rosuav@gmail.com> - 2015-06-02 10:32 +1000
        Re: Everything is an object in python - object class and type class TheDoctor <dreamingforward@gmail.com> - 2015-06-01 18:02 -0700
          Re: Everything is an object in python - object class and type class Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2015-06-02 16:30 +1000
        Re: Everything is an object in python - object class and type class TheDoctor <dreamingforward@gmail.com> - 2015-06-01 18:15 -0700
          Re: Everything is an object in python - object class and type class Chris Angelico <rosuav@gmail.com> - 2015-06-02 11:30 +1000
          Re: Everything is an object in python - object class and type class random832@fastmail.us - 2015-06-02 00:13 -0400
          Re: Everything is an object in python - object class and type class Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2015-06-02 16:23 +1000
      Re: Everything is an object in python - object class and type class Rustom Mody <rustompmody@gmail.com> - 2015-06-01 20:15 -0700
        Re: Everything is an object in python - object class and type class Mark Lawrence <breamoreboy@yahoo.co.uk> - 2015-06-02 04:46 +0100
        Re: Everything is an object in python - object class and type class TheDoctor <dreamingforward@gmail.com> - 2015-06-01 21:47 -0700
          Re: Everything is an object in python - object class and type class Rustom Mody <rustompmody@gmail.com> - 2015-06-01 22:01 -0700
            Religion [was Re: Everything is an object in python - object class and type class] Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2015-06-02 16:04 +1000
              Re: Religion [was Re: Everything is an object in python - object class and type class] Rustom Mody <rustompmody@gmail.com> - 2015-06-01 23:17 -0700
              Re: Religion [was Re: Everything is an object in python - object class and type class] Mark Lawrence <breamoreboy@yahoo.co.uk> - 2015-06-02 07:20 +0100
      Re: Everything is an object in python - object class and type class random832@fastmail.us - 2015-06-02 00:08 -0400
        Re: Everything is an object in python - object class and type class TheDoctor <dreamingforward@gmail.com> - 2015-06-01 21:54 -0700
      Re: Everything is an object in python - object class and type class Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2015-06-02 17:12 +1000
        Re: Everything is an object in python - object class and type class Rustom Mody <rustompmody@gmail.com> - 2015-06-02 00:44 -0700
          Re: Everything is an object in python - object class and type class Chris Angelico <rosuav@gmail.com> - 2015-06-02 18:37 +1000
            Re: Everything is an object in python - object class and type class Rustom Mody <rustompmody@gmail.com> - 2015-06-02 02:18 -0700
            Re: Everything is an object in python - object class and type class Marko Rauhamaa <marko@pacujo.net> - 2015-06-02 12:23 +0300
  Re: Everything is an object in python - object class and type class vern.muhr@gmail.com - 2015-06-01 14:12 -0700
  Re: Everything is an object in python - object class and type class Eddilbert Macharia <edd.cowan@gmail.com> - 2015-06-02 03:36 -0700
    Re: Everything is an object in python - object class and type class Mark Lawrence <breamoreboy@yahoo.co.uk> - 2015-06-02 12:11 +0100
    Re: Everything is an object in python - object class and type class Steven D'Aprano <steve@pearwood.info> - 2015-06-02 21:27 +1000
      Re: Everything is an object in python - object class and type class Rustom Mody <rustompmody@gmail.com> - 2015-06-02 04:40 -0700
        Re: Everything is an object in python - object class and type class Steven D'Aprano <steve@pearwood.info> - 2015-06-03 01:08 +1000
          Re: Everything is an object in python - object class and type class Rustom Mody <rustompmody@gmail.com> - 2015-06-02 09:14 -0700
      Re: Everything is an object in python - object class and type class BartC <bc@freeuk.com> - 2015-06-02 13:49 +0100
        Re: Everything is an object in python - object class and type class Marko Rauhamaa <marko@pacujo.net> - 2015-06-02 16:13 +0300
        Re: Everything is an object in python - object class and type class Steven D'Aprano <steve@pearwood.info> - 2015-06-03 03:00 +1000
          Re: Everything is an object in python - object class and type class BartC <bc@freeuk.com> - 2015-06-02 18:59 +0100
            Re: Everything is an object in python - object class and type class random832@fastmail.us - 2015-06-02 14:07 -0400
            Re: Everything is an object in python - object class and type class Ned Batchelder <ned@nedbatchelder.com> - 2015-06-02 11:10 -0700
              Re: Everything is an object in python - object class and type class Ian Kelly <ian.g.kelly@gmail.com> - 2015-06-02 13:36 -0600
            Re: Everything is an object in python - object class and type class Jon Ribbens <jon+usenet@unequivocal.co.uk> - 2015-06-02 18:10 +0000
            Re: Everything is an object in python - object class and type class "Dr. Bigcock" <dreamingforward@gmail.com> - 2015-06-02 11:22 -0700
              Re: Everything is an object in python - object class and type class Jon Ribbens <jon+usenet@unequivocal.co.uk> - 2015-06-02 18:47 +0000
                Re: Everything is an object in python - object class and type class "Dr. Bigcock" <dreamingforward@gmail.com> - 2015-06-02 12:00 -0700
                Re: Everything is an object in python - object class and type class Jon Ribbens <jon+usenet@unequivocal.co.uk> - 2015-06-02 19:31 +0000
                Re: Everything is an object in python - object class and type class Ian Kelly <ian.g.kelly@gmail.com> - 2015-06-02 13:50 -0600
                Re: Everything is an object in python - object class and type class Grant Edwards <invalid@invalid.invalid> - 2015-06-02 21:19 +0000
                Re: Everything is an object in python - object class and type class Marko Rauhamaa <marko@pacujo.net> - 2015-06-03 01:33 +0300
                Re: Everything is an object in python - object class and type class "Dr. Bigcock" <dreamingforward@gmail.com> - 2015-06-02 15:49 -0700
                Re: Everything is an object in python - object class and type class Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2015-06-03 18:13 +1000
                Re: Everything is an object in python - object class and type class "Dr. Bigcock" <dreamingforward@gmail.com> - 2015-06-03 21:38 -0700
                Re: Everything is an object in python - object class and type class Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2015-06-03 18:24 +1000
                Re: Everything is an object in python - object class and type class Marko Rauhamaa <marko@pacujo.net> - 2015-06-03 11:57 +0300
                Re: Everything is an object in python - object class and type class Ian Kelly <ian.g.kelly@gmail.com> - 2015-06-03 07:57 -0600
                Re: Everything is an object in python - object class and type class "Dr. Bigcock" <dreamingforward@gmail.com> - 2015-06-03 21:42 -0700
                Re: Everything is an object in python - object class and type class "Dr. Bigcock" <dreamingforward@gmail.com> - 2015-06-02 12:58 -0700
                Re: Everything is an object in python - object class and type class Mark Lawrence <breamoreboy@yahoo.co.uk> - 2015-06-02 22:47 +0100
                Re: Everything is an object in python - object class and type class Ian Kelly <ian.g.kelly@gmail.com> - 2015-06-02 18:49 -0600
                Re: Everything is an object in python - object class and type class Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2015-06-03 18:32 +1000
                Re: Everything is an object in python - object class and type class Ian Kelly <ian.g.kelly@gmail.com> - 2015-06-02 13:37 -0600
            Re: Everything is an object in python - object class and type class Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2015-06-03 18:08 +1000
          Re: Everything is an object in python - object class and type class "Dr. Bigcock" <dreamingforward@gmail.com> - 2015-06-02 11:00 -0700
      Re: Everything is an object in python - object class and type class Eddilbert Macharia <edd.cowan@gmail.com> - 2015-06-02 21:16 -0700
        Re: Everything is an object in python - object class and type class Mark Lawrence <breamoreboy@yahoo.co.uk> - 2015-06-03 06:23 +0100
        Re: Everything is an object in python - object class and type class BartC <bc@freeuk.com> - 2015-06-03 11:20 +0100
          Re: Everything is an object in python - object class and type class Chris Angelico <rosuav@gmail.com> - 2015-06-03 20:38 +1000
            Re: Everything is an object in python - object class and type class BartC <bc@freeuk.com> - 2015-06-03 12:08 +0100
              Re: Everything is an object in python - object class and type class Marko Rauhamaa <marko@pacujo.net> - 2015-06-03 15:08 +0300
                Re: Everything is an object in python - object class and type class BartC <bc@freeuk.com> - 2015-06-03 17:00 +0100
                Re: Everything is an object in python - object class and type class Mark Lawrence <breamoreboy@yahoo.co.uk> - 2015-06-03 17:29 +0100
                Re: Everything is an object in python - object class and type class BartC <bc@freeuk.com> - 2015-06-03 19:59 +0100
                Re: Everything is an object in python - object class and type class Mark Lawrence <breamoreboy@yahoo.co.uk> - 2015-06-03 21:58 +0100
                Re: Everything is an object in python - object class and type class BartC <bc@freeuk.com> - 2015-06-03 22:33 +0100
                Re: Everything is an object in python - object class and type class Mark Lawrence <breamoreboy@yahoo.co.uk> - 2015-06-03 22:49 +0100
                Re: Everything is an object in python - object class and type class BartC <bc@freeuk.com> - 2015-06-04 00:04 +0100
                Re: Everything is an object in python - object class and type class Laura Creighton <lac@openend.se> - 2015-06-04 12:06 +0200
                Re: Everything is an object in python - object class and type class BartC <bc@freeuk.com> - 2015-06-04 13:01 +0100
                Re: Everything is an object in python - object class and type class Laura Creighton <lac@openend.se> - 2015-06-04 15:39 +0200
                Re: Everything is an object in python - object class and type class "Dr. Bigcock" <dreamingforward@gmail.com> - 2015-06-03 21:50 -0700
                Re: Everything is an object in python - object class and type class Eddilbert Macharia <edd.cowan@gmail.com> - 2015-06-03 22:43 -0700
                Re: Everything is an object in python - object class and type class Michael Torrie <torriem@gmail.com> - 2015-06-03 10:36 -0600
                Re: Everything is an object in python - object class and type class BartC <bc@freeuk.com> - 2015-06-03 18:26 +0100
                Re: Everything is an object in python - object class and type class Steven D'Aprano <steve@pearwood.info> - 2015-06-05 00:11 +1000
                Re: Everything is an object in python - object class and type class Terry Reedy <tjreedy@udel.edu> - 2015-06-03 13:17 -0400
              Re: Everything is an object in python - object class and type class Chris Angelico <rosuav@gmail.com> - 2015-06-03 22:19 +1000
              Re: Everything is an object in python - object class and type class Marco Buttu <marco.buttu@gmail.com> - 2015-06-03 14:10 +0200
          Re: Everything is an object in python - object class and type class BartC <bc@freeuk.com> - 2015-06-03 12:13 +0100
          Re: Everything is an object in python - object class and type class Terry Reedy <tjreedy@udel.edu> - 2015-06-03 13:05 -0400
    Re: Everything is an object in python - object class and type class Terry Reedy <tjreedy@udel.edu> - 2015-06-02 12:23 -0400
  Re: Everything is an object in python - object class and type class Eddilbert Macharia <edd.cowan@gmail.com> - 2015-06-03 06:17 -0700

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