I've tested with a file with 1M numbers between 1..100.
The quick answer would be: use `say lines.sum`. But since `[+]` is already
internally optimized to `.sum`, that doesn't make much sense.
If you know that you will only see integer numbers, you can make it a bit
faster by explicitly coercing to `Int` before summing:
say lines.map(*.Int).sum
This takes it down from 2.9 seconds to 2.5 seconds for me.
A quicker way I found is to bypass the overhead of finding lines, by slurping
the whole file in one go, then splitting on newline and then summing:
say slurp.split("\n").sum
This brings it down from 2.9 to about 2 seconds.
Without resorting to NQP, I think that is what the current state of affairs is.
> On 23 Sep 2019, at 19:57, Marc Chantreux <[email protected]> wrote:
>
> hello,
>
> question: in raku, is there a faster solution than
>
> say [+] lines
>
> long story;
>
> here is a thread i would like to reply to
>
> https://stackoverflow.com/questions/450799/shell-command-to-sum-integers-one-per-line
>
> because:
>
> * the perl5 answer is fast compared to the other dynamic langages
> * the shortest solution is very interesting: even if you have an average
> level in dc (i think i have one), this is not that easy to read the
> answer (commented in the post)
>
> dc -f infile -e '[+z1<r]srz1<rp'
>
> obvioulsy: raku would be my prefered answer with:
>
> seq 100000000 | perl6 -e 'say [+] lines'
>
> but ...
>
> seq 100000000 | time perl6 -e 'say [+] lines'
> 5000000050000000
> perl6 -e 'say [+] lines' 1591,80s user 3,04s system 122% cpu 21:36,63 total
>
> seq 100000000 | time /usr/bin/perl6 -e 'say [+] lines'
> 5000000050000000
> /usr/bin/perl6 -e 'say [+] lines' 2171,01s user 4,64s system 129% cpu
> 28:04,73 total
>
> when
>
> perl6 -v
> This is Rakudo version 2019.03.1 built on MoarVM version 2019.03
> implementing Perl 6.d.
> /usr/bin/perl6 -v
> This is Rakudo version 2018.12 built on MoarVM version 2018.12
> implementing Perl 6.d.
>
> regards
> marc
