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Re: anything faster than say [+] lines?

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From:
Andy Bach
Date:
September 26, 2019 15:47
Subject:
Re: anything faster than say [+] lines?
Message ID:
SN6PR09MB3790BB5A0E29660C6FE7E037C0860@SN6PR09MB3790.namprd09.prod.outlook.com
>  Still, it's just "works for me":

seq 1000000 | time perl6 -ne 'my $y += $_; END { print $y; }'

I think that's still the wrong one - your missing the "Int"
$ seq 1000000 | perl6 -ne 'my Int $y += $_; END { print $y; }'
500000500000

though that works here, admittedly, my p6 is sort old
This is Rakudo version 2018.03 built on MoarVM version 2018.03
implementing Perl 6.c.

I'm a little puzzled, I'd've thought the loop around the 'my Int $y' would redeclare a local $y each time.  Instead it behaves like:
$ time perl6 -e 'my Int $y = 0;for ( 1 .. 1000000) { $y += $_} ;  say $y; '

(which is signficantly faster ;-)
500000500000
real 0m1.229s
user 0m1.254s
sys 0m0.040s

)
________________________________
From: Joseph Brenner <doomvox@gmail.com>
Sent: Wednesday, September 25, 2019 11:13 PM
To: William Michels <wjm1@caa.columbia.edu>
Cc: Marc Chantreux <eiro@phear.org>; Vittore Scolari <vittore.scolari@gmail.com>; Elizabeth Mattijsen <liz@dijkmat.nl>; perl6 <perl6-users@perl.org>
Subject: Re: anything faster than say [+] lines?

Oh, wait.  I tried the wrong one-liner.  Still, it's just "works for me":

seq 1000000 | time perl6 -ne 'my $y += $_; END { print $y; }'
50000050000029.29user 0.06system 0:28.41elapsed 103%CPU
(0avgtext+0avgdata 76196maxresident)k
63328inputs+0outputs (32major+15588minor)pagefaults 0swaps



On 9/25/19, Joseph Brenner <doomvox@gmail.com> wrote:
> I just gave that one-liner a try, but I didn't see that error:
>
>> seq 1000000 | time perl6 -e 'say [+] lines'
> 500000500000
> 28.70user 0.07system 0:28.29elapsed 101%CPU (0avgtext+0avgdata
> 74188maxresident)k
> 63424inputs+0outputs (32major+15409minor)pagefaults 0swaps
>
>
> perl6 --version
> This is Rakudo Star version 2019.03.1 built on MoarVM version 2019.03
> implementing Perl 6.d.
>
> uname -a
> Linux fandango 4.9.0-8-686 #1 SMP Debian 4.9.144-3 (2019-02-02) i686
> GNU/Linux
>
>
>
> On 9/24/19, William Michels via perl6-users <perl6-users@perl.org> wrote:
>> I'm seeing a strange error. I started trying out Marc's original code,
>> then tried to adapt some Perl5-type solutions from SO to see how they
>> performed when re-written as Perl6. One thing I wanted to explicitly
>> test was how restricting to an "Int" type affected performance.
>>
>> However, I found a surprising result: a sequence of one-million Ints
>> throws an error, but a sequence of 999,999 Ints does not:
>>
>>> mbook:~ homedir$ seq 1000000 | time perl6 -e 'say [+] lines'
>>> 500000500000
>>>         4.81 real         4.86 user         0.20 sys
>>> mbook:~ homedir$ seq 1000000 | time perl6 -ne 'my $y += $_; END { print
>>> $y; }'
>>> 500000500000        4.88 real         5.06 user         0.19 sys
>>> mbook:~ homedir$ seq 1000000 | time perl6 -ne 'my Int $y += $_; END {
>>> print $y; }'
>>> Type check failed in assignment to $y; expected Int but got Num
>>> (500000500000e0)
>>>   in block <unit> at -e line 1
>>> 499999500000        4.77 real         4.97 user         0.19 sys
>>> mbook:~ homedir$ seq 999999 | time perl6 -ne 'my Int $y += $_; END {
>>> print
>>> $y; }'
>>> 499999500000        4.86 real         5.05 user         0.19 sys
>>> mbook:~ homedir$ perl6 -v
>>> This is Rakudo version 2019.07.1 built on MoarVM version 2019.07.1
>>> implementing Perl 6.d.
>>> mbook:~ homedir$
>>
>> Any comments or explanation appreciated,
>>
>> Best Regards, Bill.
>>
>>
>>
>>
>> On Tue, Sep 24, 2019 at 1:59 AM Marc Chantreux <eiro@phear.org> wrote:
>>>
>>> hello,
>>>
>>> > > > > nice ... but when x is ~ 75440 (not always), there is a problem
>>> > > > What is x here?
>>> > > sorry. x is the arg of seq (number of lines).
>>> > That never happens on my laptop
>>>
>>> well.. so it's a problem with my station. nevermind :)
>>>
>>> thanks again for helping
>>> marc
>>
>

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