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* [COFF] Tail-recursion was Re: [TUHS] Lorinda Cherry
       [not found]                   ` <20220222103948.1B0482206F@orac.inputplus.co.uk>
@ 2022-02-23  0:48                     ` Will Senn
  2022-02-23  0:53                       ` silas poulson
  2022-02-23  1:45                       ` Charles H. Sauer (he/him)
  0 siblings, 2 replies; 3+ messages in thread
From: Will Senn @ 2022-02-23  0:48 UTC (permalink / raw)
  To: COFF

My all time favorite presentation on tail-recursion:

https://www.youtube.com/watch?v=-PX0BV9hGZY


On 2/22/22 4:39 AM, Ralph Corderoy wrote:
> Hi Otto,
>
>> MacOS uses the GNU implementation which has a long standing issue with
>> deep recursion.  It even cannot handle the tail recursive calls used
>> here and will run out of its stack.
> When learning dc and seeing it relied on tail calls, the first thing
> I did was check it did tail-call elimination, and it did.  That was
> GNU dc.
>
> Trying just now, I see no growth in memory usage despite heavy CPU load
> shown by TIME increasing.
>
>      $ dc
>      !ps u `pidof dc`
>      USER       PID %CPU %MEM    VSZ   RSS TTY      STAT START   TIME COMMAND
>      ralph    11489  0.0  0.0   2332  1484 pts/1    S+   10:33   0:00 dc
>      [lmx]smlmx
>      ^C
>      Interrupt!
>      !ps u `pidof dc`
>      USER       PID %CPU %MEM    VSZ   RSS TTY      STAT START   TIME COMMAND
>      ralph    11489 75.5  0.0   2332  1488 pts/1    S+   10:33   0:46 dc
>
> The memory used remained at that level during the macro execution too,
> watched from outside.
>
> Do you have more detail on what GNU dc can't handle?  dc without
> tail-call elimination is a bit crippled.
>

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^ permalink raw reply	[flat|nested] 3+ messages in thread

* Re: [COFF] Tail-recursion was Re: [TUHS] Lorinda Cherry
  2022-02-23  0:48                     ` [COFF] Tail-recursion was Re: [TUHS] Lorinda Cherry Will Senn
@ 2022-02-23  0:53                       ` silas poulson
  2022-02-23  1:45                       ` Charles H. Sauer (he/him)
  1 sibling, 0 replies; 3+ messages in thread
From: silas poulson @ 2022-02-23  0:53 UTC (permalink / raw)
  To: Will Senn; +Cc: COFF

Yes! That’s such as fun presentation!

For those who want the fast version, skip to 6:00 mark.

Silas

> On 23 Feb 2022, at 00:48, Will Senn <will.senn@gmail.com> wrote:
> 
> My all time favorite presentation on tail-recursion:
> 
> https://www.youtube.com/watch?v=-PX0BV9hGZY
> 
> 
> On 2/22/22 4:39 AM, Ralph Corderoy wrote:
>> Hi Otto,
>> 
>>> MacOS uses the GNU implementation which has a long standing issue with
>>> deep recursion.  It even cannot handle the tail recursive calls used
>>> here and will run out of its stack.
>> When learning dc and seeing it relied on tail calls, the first thing
>> I did was check it did tail-call elimination, and it did.  That was
>> GNU dc.
>> 
>> Trying just now, I see no growth in memory usage despite heavy CPU load
>> shown by TIME increasing.
>> 
>>     $ dc
>>     !ps u `pidof dc`
>>     USER       PID %CPU %MEM    VSZ   RSS TTY      STAT START   TIME COMMAND
>>     ralph    11489  0.0  0.0   2332  1484 pts/1    S+   10:33   0:00 dc
>>     [lmx]smlmx
>>     ^C
>>     Interrupt!
>>     !ps u `pidof dc`
>>     USER       PID %CPU %MEM    VSZ   RSS TTY      STAT START   TIME COMMAND
>>     ralph    11489 75.5  0.0   2332  1488 pts/1    S+   10:33   0:46 dc
>> 
>> The memory used remained at that level during the macro execution too,
>> watched from outside.
>> 
>> Do you have more detail on what GNU dc can't handle?  dc without
>> tail-call elimination is a bit crippled.
>> 
> 
> _______________________________________________
> COFF mailing list
> COFF@minnie.tuhs.org
> https://minnie.tuhs.org/cgi-bin/mailman/listinfo/coff

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^ permalink raw reply	[flat|nested] 3+ messages in thread

* Re: [COFF] Tail-recursion was Re: [TUHS] Lorinda Cherry
  2022-02-23  0:48                     ` [COFF] Tail-recursion was Re: [TUHS] Lorinda Cherry Will Senn
  2022-02-23  0:53                       ` silas poulson
@ 2022-02-23  1:45                       ` Charles H. Sauer (he/him)
  1 sibling, 0 replies; 3+ messages in thread
From: Charles H. Sauer (he/him) @ 2022-02-23  1:45 UTC (permalink / raw)
  To: coff

An opportunity for Auto-Tune??

On 2/22/2022 6:48 PM, Will Senn wrote:
> My all time favorite presentation on tail-recursion:
> 
> https://www.youtube.com/watch?v=-PX0BV9hGZY

-- 
voice: +1.512.784.7526       e-mail: sauer@technologists.com
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^ permalink raw reply	[flat|nested] 3+ messages in thread

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2022-02-23  0:48                     ` [COFF] Tail-recursion was Re: [TUHS] Lorinda Cherry Will Senn
2022-02-23  0:53                       ` silas poulson
2022-02-23  1:45                       ` Charles H. Sauer (he/him)

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