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Re: Add nested-function support in a language the based on a stack-machine

From	Martin Ward <martin@gkc.org.uk>
Newsgroups	comp.compilers
Subject	Re: Add nested-function support in a language the based on a stack-machine
Date	2018-03-23 10:44 +0000
Organization	Compilers Central
Message-ID	<18-03-090@comp.compilers> (permalink)
References	<6effed5e-6c90-f5f4-0c80-a03c61fd2127@gkc.org.uk> <18-03-042@comp.compilers> <18-03-047@comp.compilers> <18-03-075@comp.compilers> <18-03-077@comp.compilers>

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On 19/03/18 19:50, Gene Wirchenko wrote:
>> Faster machines and larger memories mean that it becomes more
>> important to use the best algorithms.
>
> How does that follow?

It follows because data expands to fill the memory available.

> One could argue exactly the opposite as there are resources to
> waste.
>
> [Depends on the algorithms.  If they're linear, things are fine, not
> so fine if they're O(N^2) or O(2^N) -John]

My first computer had 8K of RAM and a 1MHz clock speed.
If I wanted to sort 1,000 values I could use bubble sort, O(N^2),
or quicksort, O(N log N).

So, bubble sort would need of the order of 1,000,000 instructions
and take about 1 second: this might well be acceptable for an operation
you only need to do a few times an hour. Quicksort would need
of the order of 10,000 instructions and take 0.01 seconds.

My current laptop (not the latest model) has 8Gb of RAM:
literally, over a million times as much RAM, and a 1.7 GHz clock.
Even accounting for more powerful instructions, the clock is
only of the order 10,000 times faster, while the memory is 1,000,000
times larger. Now 1,000,000,000 values will fit in RAM.
Sorting these with bubble sort will need of the order 10^18 instructions
which takes 100,000,000 seconds (over 1,000 years) while quicksort
needs 300,000,000,000 instructions and takes only a few seconds.

For a linear algorithm, say a linear search, my first computer
takes 0.001 seconds to process the data, while my new laptop
takes 0.1 seconds. So if I need to execute this linear algorithm
more than 10 times a second, my old computer will be fine
but my new laptop would struggle. I would need to look hard
for a sub-linear algorithm.

Conclusion: even for linear algorithms things may not be fine
and more powerful sub-linear algorithms may be needed.

--
			Martin

Dr Martin Ward | Email: martin@gkc.org.uk | http://www.gkc.org.uk
G.K.Chesterton site: http://www.gkc.org.uk/gkc | Erdos number: 4
[Give or take the detail that bubble sort is never the right algorithm
since insertion sort is shorter and faster, I agree. -John]

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Re: Add nested-function support in a language the based on a stack-machine Martin Ward <martin@gkc.org.uk> - 2018-03-12 16:17 +0000
  Re: Add nested-function support in a language the based on a stack-machine Kaz Kylheku <157-073-9834@kylheku.com> - 2018-03-13 03:02 +0000
    Re: Add nested-function support in a language the based on a stack-machine Martin Ward <martin@gkc.org.uk> - 2018-03-19 11:04 +0000
      Re: Add nested-function support in a language the based on a stack-machine Gene Wirchenko <genew@telus.net> - 2018-03-19 12:50 -0700
        Re: Add nested-function support in a language the based on a stack-machine Kaz Kylheku <157-073-9834@kylheku.com> - 2018-03-20 16:16 +0000
        Re: Add nested-function support in a language the based on a stack-machine Martin Ward <martin@gkc.org.uk> - 2018-03-23 10:44 +0000
          Re: algorithm performance, was Add nested-function support in a language the based on a stack-machine Andy Walker <anw@cuboid.co.uk> - 2018-03-23 18:47 +0000
            Re: algorithm performance, was Add nested-function support in a language the based on a stack-machine anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2018-03-24 14:06 +0000
              Re: algorithm performance, was Add nested-function support in a language the based on a stack-machine rpw3@rpw3.org (Rob Warnock) - 2018-03-25 07:02 +0000
                Re: algorithm performance "Robin Vowels" <robin51@dodo.com.au> - 2018-03-27 01:22 +1100
          Re: sorting performance, Add nested-function support in a language the based on a stack-machine w.clodius@icloud.com (William Clodius) - 2018-03-24 23:25 -0600
      Re: Add nested-function support in a language the based on a stack-machine anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2018-03-20 09:06 +0000
        Re: Add nested-function support in a language the based on a stack-machine Bill Findlay <findlaybill@blueyonder.co.uk> - 2018-03-20 12:49 +0000
        Re: language design after Algol 60, was Add nested-function support Martin Ward <martin@gkc.org.uk> - 2018-03-27 14:46 +0100
          Re: language design after Algol 60, was Add nested-function support anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2018-03-30 14:20 +0000
          Re: language design after Algol 60, was Add nested-function support Martin Ward <martin@gkc.org.uk> - 2018-04-06 16:09 +0100
            Re: language design after Algol 60, was Add nested-function support "Derek M. Jones" <derek@_NOSPAM_knosof.co.uk> - 2018-04-08 14:21 +0100
              Re: language design after Algol 60, was Add nested-function support George Neuner <gneuner2@comcast.net> - 2018-04-09 16:51 -0400
                Re: language design after Algol 60, was Add nested-function support anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2018-04-10 05:48 +0000
                Re: language design after Algol 60, was Add nested-function support George Neuner <gneuner2@comcast.net> - 2018-04-10 14:32 -0400
                Re: language design after Algol 60, was Add nested-function support Hans-Peter Diettrich <DrDiettrich1@netscape.net> - 2018-04-12 01:09 +0200
                Re: language design after Algol 60, was Add nested-function support bartc <bc@freeuk.com> - 2018-04-12 11:51 +0100
                Re: language design after Algol 60, was Add nested-function support bartc <bc@freeuk.com> - 2018-04-12 19:40 +0100
                Re: language design after Algol 60, was Add nested-function support Martin Ward <martin@gkc.org.uk> - 2018-04-13 14:10 +0100
                Re: language design after Algol 60 "Robin Vowels" <robin51@dodo.com.au> - 2018-04-14 14:11 +1000
                RE: language design after Algol 60 "Costello, Roger L." <costello@mitre.org> - 2018-04-16 12:56 +0000
                Re: language design after Algol 60 "Robin Vowels" <robin51@dodo.com.au> - 2018-04-17 19:08 +1000
                Re: Language design after Algol 60 "Robin Vowels" <robin51@dodo.com.au> - 2018-04-18 14:58 +1000
                Re: language design after Algol 60 Gene Wirchenko <genew@telus.net> - 2018-04-18 16:12 -0700
                Re: language design after Algol 60 Martin Ward <martin@gkc.org.uk> - 2018-05-01 10:42 +0100
                Re: language design after Algol 60 "Robin Vowels" <robin51@dodo.com.au> - 2018-04-14 14:19 +1000
                Re: language design after Algol 60 bartc <bc@freeuk.com> - 2018-04-14 20:43 +0100
                Re: language design after Algol 60 Andy Walker <anw@cuboid.co.uk> - 2018-04-15 00:04 +0100
                Re: language design after Algol 60, was Add nested-function support rpw3@rpw3.org (Rob Warnock) - 2018-04-12 14:05 +0000
                Re: language design after Algol 60, was Add nested-function support George Neuner <gneuner2@comcast.net> - 2018-04-12 20:51 -0400
                Re: OOP language design after Algol 60, was Add nested-function support Kaz Kylheku <157-073-9834@kylheku.com> - 2018-04-13 03:22 +0000
                Re: OOP language design after Algol 60, was Add nested-function support Hans-Peter Diettrich <DrDiettrich1@netscape.net> - 2018-04-13 10:22 +0200
                Re: OOP language design after Algol 60, was Add nested-function support George Neuner <gneuner2@comcast.net> - 2018-04-14 13:40 -0400
                Re: OOP language design after Algol 60, was Add nested-function support Hans-Peter Diettrich <DrDiettrich1@netscape.net> - 2018-04-15 00:12 +0200
                Re: OOP language design after Algol 60, was Add nested-function support Hans-Peter Diettrich <DrDiettrich1@netscape.net> - 2018-04-15 00:23 +0200
                Re: language design after Algol 60, was Add nested-function support "Derek M. Jones" <derek@_NOSPAM_knosof.co.uk> - 2018-04-10 13:15 +0100
                Re: language design after Algol 60, was Add nested-function support Hans-Peter Diettrich <DrDiettrich1@netscape.net> - 2018-04-11 13:27 +0200
                Re: language design after Algol 60, was Add nested-function support "Derek M. Jones" <derek@_NOSPAM_knosof.co.uk> - 2018-04-11 20:06 +0100
                Re: language design after Algol 60, was Add nested-function support Kaz Kylheku <157-073-9834@kylheku.com> - 2018-04-10 18:32 +0000
                Re: language design after Algol 60, was Add nested-function support George Neuner <gneuner2@comcast.net> - 2018-04-12 20:57 -0400
                Re: OOP language design after Algol 60, was Add nested-function support Kaz Kylheku <157-073-9834@kylheku.com> - 2018-04-13 03:28 +0000
            Re: language design after Algol 60, was Add nested-function support albert@cherry.spenarnc.xs4all.nl (Albert van der Horst) - 2018-05-05 13:50 +0200
      Re: Add nested-function support in a language the based on a stack-machine mac <acolvin@efunct.com> - 2018-03-20 15:27 +0000
  Re: Add nested-function support in a language the based on a stack-machine w.clodius@icloud.com (William Clodius) - 2018-03-12 21:09 -0600
    Re: Add nested-function support in a language the based on a stack-machine Kartik Agaram <ak@akkartik.com> - 2018-03-13 13:27 -0700
      Re: Add nested-function support in a language the based on a stack-machine Kaz Kylheku <157-073-9834@kylheku.com> - 2018-03-14 00:07 +0000
        Re: Add nested-function support in a language the based on a stack-machine Kartik Agaram <ak@akkartik.com> - 2018-03-13 22:31 -0700
          Re: Add nested-function support in a language the based on a stack-machine Kaz Kylheku <157-073-9834@kylheku.com> - 2018-03-14 14:49 +0000
    Re: Add nested-function support in a language the based on a stack-machine Kaz Kylheku <157-073-9834@kylheku.com> - 2018-03-13 20:51 +0000
    Re: Add nested-function support in a language the based on a stack-machine Andy Walker <anw@cuboid.co.uk> - 2018-03-14 00:27 +0000
      Re: Add nested-function support in a language the based on a stack-machine Andy Walker <anw@cuboid.co.uk> - 2018-03-14 16:37 +0000
  Re: Add nested-function support in a language the based on a stack-machine anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2018-03-14 15:16 +0000

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