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Re: Implementing a two-way Turing Machine tape as an improvement to std::deque

From Ben <ben.usenet@bsb.me.uk>
Newsgroups comp.theory
Subject Re: Implementing a two-way Turing Machine tape as an improvement to std::deque
Date 2022-05-13 20:04 +0100
Organization A noiseless patient Spider
Message-ID <87czghxni1.fsf@bsb.me.uk> (permalink)
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olcott <NoOne@NoWhere.com> writes:

> On 5/13/2022 11:35 AM, Ben wrote:
>> olcott <NoOne@NoWhere.com> writes:
>> 
>>> On 5/13/2022 6:01 AM, Ben wrote:
>>>> olcott <NoOne@NoWhere.com> writes:

>>>>> What about memory allocation?
>>>>
>>>> What about it?  std::string does it.
>>>
>>> It is probably much slower than my system now that I added reserve.

Odd that you are prepared to guess.

>>> I do like the idea of simplicity, it is my primary design goal.
>>
>> Using a std::string for the tape is very simple.
>
> How does it compare for speed on your test code when you use
> Tape_Type::reserve()?

Using reserve makes no difference to the speed of either one in the only
test case I have that takes long enough to measure.  This is what I'd
expect.  The test case does 47,176,870 transitions and the tape ends up
being only 12,289 symbols long.  The memory allocation will be a tiny
fraction of the cost.  It's not measurable.

Of course that's just one test case.  What TMs are you using to test?

-- 
Ben.
"le génie humain a des limites, quand la bêtise humaine n’en a pas"
Alexandre Dumas (fils)

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Thread

Implementing a two-way Turing Machine tape as an improvement to std::deque olcott <NoOne@NoWhere.com> - 2022-05-12 17:51 -0500
  Re: Implementing a two-way Turing Machine tape as an improvement to std::deque Mr Flibble <flibble@reddwarf.jmc> - 2022-05-12 23:56 +0100
    Re: Implementing a two-way Turing Machine tape as an improvement to std::deque olcott <NoOne@NoWhere.com> - 2022-05-12 18:09 -0500
      Re: Implementing a two-way Turing Machine tape as an improvement to std::deque Mr Flibble <flibble@reddwarf.jmc> - 2022-05-13 00:22 +0100
        Re: Implementing a two-way Turing Machine tape as an improvement to std::deque olcott <NoOne@NoWhere.com> - 2022-05-12 18:38 -0500
          Re: Implementing a two-way Turing Machine tape as an improvement to std::deque Mr Flibble <flibble@reddwarf.jmc> - 2022-05-13 00:40 +0100
            Re: Implementing a two-way Turing Machine tape as an improvement to std::deque olcott <NoOne@NoWhere.com> - 2022-05-12 18:49 -0500
              Re: Implementing a two-way Turing Machine tape as an improvement to std::deque Mr Flibble <flibble@reddwarf.jmc> - 2022-05-13 00:53 +0100
                Re: Implementing a two-way Turing Machine tape as an improvement to std::deque olcott <NoOne@NoWhere.com> - 2022-05-12 19:12 -0500
                Re: Implementing a two-way Turing Machine tape as an improvement to std::deque Mr Flibble <flibble@reddwarf.jmc> - 2022-05-13 01:58 +0100
                Re: Implementing a two-way Turing Machine tape as an improvement to std::deque olcott <NoOne@NoWhere.com> - 2022-05-12 20:34 -0500
                Re: Implementing a two-way Turing Machine tape as an improvement to std::deque Mr Flibble <flibble@reddwarf.jmc> - 2022-05-13 08:02 +0100
                Re: Implementing a two-way Turing Machine tape as an improvement to std::deque tth <tth@none.invalid> - 2022-05-13 09:10 +0200
                Re: Implementing a two-way Turing Machine tape as an improvement to std::deque olcott <NoOne@NoWhere.com> - 2022-05-13 10:58 -0500
                Re: Implementing a two-way Turing Machine tape as an improvement to std::deque Mr Flibble <flibble@reddwarf.jmc> - 2022-05-13 17:02 +0100
                Re: Implementing a two-way Turing Machine tape as an improvement to std::deque "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2022-05-13 12:44 -0700
  Re: Implementing a two-way Turing Machine tape as an improvement to std::deque Richard Damon <Richard@Damon-Family.org> - 2022-05-12 19:23 -0400
    Re: Implementing a two-way Turing Machine tape as an improvement to std::deque olcott <NoOne@NoWhere.com> - 2022-05-12 18:32 -0500
  Re: Implementing a two-way Turing Machine tape as an improvement to std::deque Ben <ben.usenet@bsb.me.uk> - 2022-05-13 01:06 +0100
    Re: Implementing a two-way Turing Machine tape as an improvement to std::deque olcott <NoOne@NoWhere.com> - 2022-05-12 19:55 -0500
      Re: Implementing a two-way Turing Machine tape as an improvement to std::deque Mr Flibble <flibble@reddwarf.jmc> - 2022-05-13 02:01 +0100
        Re: Implementing a two-way Turing Machine tape as an improvement to std::deque olcott <NoOne@NoWhere.com> - 2022-05-12 20:36 -0500
          Re: Implementing a two-way Turing Machine tape as an improvement to std::deque Mr Flibble <flibble@reddwarf.jmc> - 2022-05-13 08:04 +0100
            Re: Implementing a two-way Turing Machine tape as an improvement to std::deque olcott <NoOne@NoWhere.com> - 2022-05-13 11:00 -0500
              Re: Implementing a two-way Turing Machine tape as an improvement to std::deque Mr Flibble <flibble@reddwarf.jmc> - 2022-05-13 17:04 +0100
                Re: Implementing a two-way Turing Machine tape as an improvement to std::deque olcott <NoOne@NoWhere.com> - 2022-05-13 12:05 -0500
      Re: Implementing a two-way Turing Machine tape as an improvement to std::deque Ben <ben.usenet@bsb.me.uk> - 2022-05-13 02:38 +0100
        Re: Implementing a two-way Turing Machine tape as an improvement to std::deque olcott <NoOne@NoWhere.com> - 2022-05-12 21:37 -0500
          Re: Implementing a two-way Turing Machine tape as an improvement to std::deque Python <python@example.invalid> - 2022-05-13 04:39 +0200
          Re: Implementing a two-way Turing Machine tape as an improvement to std::deque Ben <ben.usenet@bsb.me.uk> - 2022-05-13 12:01 +0100
            Re: Implementing a two-way Turing Machine tape as an improvement to std::deque olcott <NoOne@NoWhere.com> - 2022-05-13 10:41 -0500
              Re: Implementing a two-way Turing Machine tape as an improvement to std::deque Richard Damon <Richard@Damon-Family.org> - 2022-05-13 11:56 -0400
              Re: Implementing a two-way Turing Machine tape as an improvement to std::deque Ben <ben.usenet@bsb.me.uk> - 2022-05-13 17:35 +0100
                Re: Implementing a two-way Turing Machine tape as an improvement to std::deque olcott <NoOne@NoWhere.com> - 2022-05-13 12:12 -0500
                Re: Implementing a two-way Turing Machine tape as an improvement to std::deque Ben <ben.usenet@bsb.me.uk> - 2022-05-13 20:04 +0100
                Re: Implementing a two-way Turing Machine tape as an improvement to std::deque olcott <NoOne@NoWhere.com> - 2022-05-13 14:19 -0500

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