Re: "C++20 Coroutines" by Martin Bond

From	HorseyWorsey@the_stables.com
Newsgroups	comp.lang.c++
Subject	Re: "C++20 Coroutines" by Martin Bond
Date	2021-09-22 09:26 +0000
Organization	Aioe.org NNTP Server
Message-ID	<siesre$171$1@gioia.aioe.org> (permalink)
References	<siauhc$mg6$1@dont-email.me> <sic9jh$bo0$1@gioia.aioe.org> <sicu8j$qg5$1@gioia.aioe.org> <sieejh$1am$1@gioia.aioe.org>

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On Wed, 22 Sep 2021 05:22:59 -0000 (UTC)
Juha Nieminen <nospam@thanks.invalid> wrote:
>You *can* achieve the same effect as coroutines without them, but it
>requires you to manually create the data containers where all the
>necessary variables are stored so that execution can continue from
>the point where it left, and you have to manually create jump statements

Isn't that the point of class methods and variables? Ie: Black boxing state.

>to wherever there are these yield points. (The more yield points there
>are in your "coroutine", the more conditional gotos are required.)

Having multiple yield points sounds like asking for sphagetti code. And thats
before you have to consider recursion in the co-routine and the effect of
threading on it (I have no idea what effects they are but I suspect its messy).

>One practical example of where a coroutine is useful is a library that
>decompresses compressed data from a file into a buffer of fixed size.
>Whenever the buffer gets full, execution is returned to the caller
>for it to consume the contents of the buffer, after which the
>execution is returned to the decompressor, which continues from
>where it left off. However, since the buffer can typically get full at
>several points in the decompressor code, even in the middle of eg.
>expanding a block of data, the decompressor needs to somehow store
>its exact state in order to know how to continue with the decompression
>once execution is resumed. There may be several different places in
>the decompression code where stuff is written to the buffer, and at
>any moment the buffer may get full. Coroutines can make this whole
>thing a lot simpler, as at any point you can just add a yield, with
>essentially no extra work to store the state of the decompressor.

Hmm, not convinced thats any simpler than using object or global state.

Thread

"C++20 Coroutines" by Martin Bond Lynn McGuire <lynnmcguire5@gmail.com> - 2021-09-20 16:30 -0500
  Re: "C++20 Coroutines" by Martin Bond Bo Persson <bo@bo-persson.se> - 2021-09-21 09:28 +0200
  Re: "C++20 Coroutines" by Martin Bond Bonita Montero <Bonita.Montero@gmail.com> - 2021-09-21 11:45 +0200
    Re: "C++20 Coroutines" by Martin Bond HorseyWorsey@the_stables.com - 2021-09-21 15:37 +0000
      Re: "C++20 Coroutines" by Martin Bond Bonita Montero <Bonita.Montero@gmail.com> - 2021-09-21 17:40 +0200
      Re: "C++20 Coroutines" by Martin Bond Juha Nieminen <nospam@thanks.invalid> - 2021-09-22 05:22 +0000
        Re: "C++20 Coroutines" by Martin Bond HorseyWorsey@the_stables.com - 2021-09-22 09:26 +0000
          Re: "C++20 Coroutines" by Martin Bond Bonita Montero <Bonita.Montero@gmail.com> - 2021-09-22 16:40 +0200
            Re: "C++20 Coroutines" by Martin Bond HorseyWorsey@the_stables.com - 2021-09-22 15:01 +0000
              Re: "C++20 Coroutines" by Martin Bond Bonita Montero <Bonita.Montero@gmail.com> - 2021-09-23 05:38 +0200
                Re: "C++20 Coroutines" by Martin Bond Branimir Maksimovic <branimir.maksimovic@gmail.com> - 2021-09-23 09:05 +0000
                Re: "C++20 Coroutines" by Martin Bond Bonita Montero <Bonita.Montero@gmail.com> - 2021-09-24 18:15 +0200
                Re: "C++20 Coroutines" by Martin Bond Branimir Maksimovic <branimir.maksimovic@gmail.com> - 2021-09-25 00:57 +0000
                Re: "C++20 Coroutines" by Martin Bond HorseyWorsey@the_stables.com - 2021-09-23 09:11 +0000
                Re: "C++20 Coroutines" by Martin Bond Bonita Montero <Bonita.Montero@gmail.com> - 2021-09-24 18:17 +0200
                Re: "C++20 Coroutines" by Martin Bond HorseyWorsey@the_stables.com - 2021-09-25 09:19 +0000
                Re: "C++20 Coroutines" by Martin Bond Bonita Montero <Bonita.Montero@gmail.com> - 2021-09-25 12:00 +0200
                Re: "C++20 Coroutines" by Martin Bond HorseyWorsey@the_stables.com - 2021-09-25 10:09 +0000
                Re: "C++20 Coroutines" by Martin Bond Bonita Montero <Bonita.Montero@gmail.com> - 2021-09-25 12:18 +0200
                Re: "C++20 Coroutines" by Martin Bond HorseyWorsey@the_stables.com - 2021-09-25 10:39 +0000
                Re: "C++20 Coroutines" by Martin Bond Bonita Montero <Bonita.Montero@gmail.com> - 2021-09-25 12:42 +0200
                Re: "C++20 Coroutines" by Martin Bond HorseyWorsey@the_stables.com - 2021-09-25 10:44 +0000
                Re: "C++20 Coroutines" by Martin Bond Bonita Montero <Bonita.Montero@gmail.com> - 2021-09-25 13:14 +0200
                Re: "C++20 Coroutines" by Martin Bond Branimir Maksimovic <branimir.maksimovic@gmail.com> - 2021-09-25 12:44 +0000
                Re: "C++20 Coroutines" by Martin Bond Bonita Montero <Bonita.Montero@gmail.com> - 2021-09-25 15:58 +0200
                Re: "C++20 Coroutines" by Martin Bond Branimir Maksimovic <branimir.maksimovic@gmail.com> - 2021-09-25 13:59 +0000
                Re: "C++20 Coroutines" by Martin Bond Bonita Montero <Bonita.Montero@gmail.com> - 2021-09-25 16:23 +0200
                Re: "C++20 Coroutines" by Martin Bond Bonita Montero <Bonita.Montero@gmail.com> - 2021-09-28 07:24 +0200
                Re: "C++20 Coroutines" by Martin Bond HorseyWorsey@the_stables.com - 2021-09-25 15:28 +0000
                Re: "C++20 Coroutines" by Martin Bond HorseyWorsey@the_stables.com - 2021-09-25 15:04 +0000
                Re: "C++20 Coroutines" by Martin Bond Bonita Montero <Bonita.Montero@gmail.com> - 2021-09-25 18:44 +0200
                Re: "C++20 Coroutines" by Martin Bond HorseyWorsey@the_stables.com - 2021-09-26 14:15 +0000
                Re: "C++20 Coroutines" by Martin Bond Branimir Maksimovic <branimir.maksimovic@gmail.com> - 2021-09-25 12:32 +0000
          Re: "C++20 Coroutines" by Martin Bond Juha Nieminen <nospam@thanks.invalid> - 2021-09-23 07:42 +0000
            Re: "C++20 Coroutines" by Martin Bond HorseyWorsey@the_stables.com - 2021-09-23 09:14 +0000
              Re: "C++20 Coroutines" by Martin Bond Juha Nieminen <nospam@thanks.invalid> - 2021-09-24 04:42 +0000
            Re: "C++20 Coroutines" by Martin Bond Bonita Montero <Bonita.Montero@gmail.com> - 2021-09-24 18:19 +0200
              Re: "C++20 Coroutines" by Martin Bond Ben Bacarisse <ben.usenet@bsb.me.uk> - 2021-09-24 21:07 +0100
                Re: "C++20 Coroutines" by Martin Bond Tim Rentsch <tr.17687@z991.linuxsc.com> - 2021-10-06 13:19 -0700
              Re: "C++20 Coroutines" by Martin Bond Branimir Maksimovic <branimir.maksimovic@gmail.com> - 2021-09-25 00:58 +0000
                Re: "C++20 Coroutines" by Martin Bond Juha Nieminen <nospam@thanks.invalid> - 2021-09-27 05:39 +0000
                Re: "C++20 Coroutines" by Martin Bond Branimir Maksimovic <branimir.maksimovic@gmail.com> - 2021-09-29 02:30 +0000
              Re: "C++20 Coroutines" by Martin Bond HorseyWorsey@the_stables.com - 2021-09-25 09:20 +0000
        Re: "C++20 Coroutines" by Martin Bond "Alf P. Steinbach" <alf.p.steinbach@gmail.com> - 2021-09-22 11:31 +0200
      Re: "C++20 Coroutines" by Martin Bond Sam <sam@email-scan.com> - 2021-09-22 18:43 -0400
        Re: "C++20 Coroutines" by Martin Bond Juha Nieminen <nospam@thanks.invalid> - 2021-09-23 07:45 +0000
          Re: "C++20 Coroutines" by Martin Bond "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2021-09-23 01:53 -0700
          Re: "C++20 Coroutines" by Martin Bond Sam <sam@email-scan.com> - 2021-09-24 19:21 -0400
            Re: "C++20 Coroutines" by Martin Bond HorseyWorsey@the_stables.com - 2021-09-25 09:28 +0000
              Re: "C++20 Coroutines" by Martin Bond Branimir Maksimovic <branimir.maksimovic@gmail.com> - 2021-09-25 12:38 +0000
            Re: "C++20 Coroutines" by Martin Bond Juha Nieminen <nospam@thanks.invalid> - 2021-09-27 05:42 +0000
  Re: "C++20 Coroutines" by Martin Bond "Alf P. Steinbach" <alf.p.steinbach@gmail.com> - 2021-09-25 15:14 +0200
    Re: "C++20 Coroutines" by Martin Bond Manfred <noname@add.invalid> - 2021-09-25 23:07 +0200
      Re: "C++20 Coroutines" by Martin Bond "Alf P. Steinbach" <alf.p.steinbach@gmail.com> - 2021-09-26 01:50 +0200
        Re: "C++20 Coroutines" by Martin Bond Manfred <noname@add.invalid> - 2021-09-26 19:12 +0200

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