The SF Perl Raku Study Group, 08/07 at 1pm PDT

[Joseph Brenner]

Walt Whitman, "Democratic Vistas" (1871):

 "... ahead, though dimly yet, we see, in vistas,
 a copious, sane, gigantic offspring."

The Raku Study Group

August 7, 2022  1pm in California, 9pm in the UK

Zoom meeting link:
  https://us02web.zoom.us/j/83144051426?pwd=UTVhclVPeVJlM0k0M3FNN1JqNXg0Zz09

Passcode: 4RakuRoll

RSVPs are useful, though not needed:
  https://www.meetup.com/san-francisco-perl/events/287625950/

Re: something between run and qx() ?

[Marc Chantreux]

Hi Liz!

> sub prefix:<`>(*@a) { (run @a, :out).out.lines }

Thanks for this example, I now can write things like

.say for grep / '.txt' $ /, `
for ` { .say if / '.txt' $ / }

which made me remember I wrote something similar (but not working) for
the FOSDEM talk:

sub prefix:<`>(|c) is tighter(:<.>) { (run :out, c).out.lines }

the `is tighter` thing was because I hoped I could write something like

`.grep( / '.txt' $ / ).say

Is is something to do to fix it ?

Thanks everything you do on Raku!

regards
-- 
Marc Chantreux
Pôle de Calcul et Services Avancés à la Recherche (CESAR)
http://annuaire.unistra.fr/p/20200

Re: something between run and qx() ?

[Elizabeth Mattijsen]

> On 4 Aug 2022, at 14:38, Marc Chantreux  wrote:
> It would be nice to define a backtrick operator (like in rc) so we
> could write
> 
>   my @installed-files =
>   grep *.IO.f,
>   map *.trim,
>   `< dpkg-query -f ${db-fsys:Files} -W gnuplot* >;
> 
> insead of
> 
>   my @installed-files =
>   grep *.IO.f,
>   map *.trim,
>   ( run :out, < dpkg-query -f ${db-fsys:Files} -W gnuplot* > ).out.lines;

sub prefix:<`>(*@a) { (run @a, :out).out.lines }

dd ` ;
("Changes", "LICENSE", "META6.json", "README.md", "bin", "dist.ini", "lib", 
"releases", "resources", "run-tests", "t").Seq


Liz

Re: something between run and qx() ?

[Marc Chantreux]

hello Liz and thanks for helping,

> I believe you could use App::Rak for that: 
> $ zef install App::Rak

I'll test rak at some point but in this case, I can just write

dpkg-query -f \${db-fsys:Files} -W gnuplot\* |
raku -pe '.=trim; .say if .trim.IO.f'

I asked the question about qx() and run because because I still have
the "removing bash with raku" in mind and this is typically the kind
of things where both tools comes with flaws.

It would be nice to define a backtrick operator (like in rc) so we
could write

my @installed-files =
grep *.IO.f,
map *.trim,
`< dpkg-query -f ${db-fsys:Files} -W gnuplot* >;

insead of

my @installed-files =
grep *.IO.f,
map *.trim,
( run :out, < dpkg-query -f ${db-fsys:Files} -W gnuplot* > ).out.lines;

regards,

-- 
Marc Chantreux
Pôle de Calcul et Services Avancés à la Recherche (CESAR)
http://annuaire.unistra.fr/p/20200

Re: something between run and qx() ?

[Marc Chantreux]

Hi Brian and thanks for your reply.

> There is the 'x' adverb for Q -- I think qx is equivalent to Q:x

exactly. that's why Q:x doesn't help as it still run sh -c to execute
the command.

regards,
-- 
Marc Chantreux
Pôle de Calcul et Services Avancés à la Recherche (CESAR)
http://annuaire.unistra.fr/p/20200

Re: something between run and qx() ?

[Brian Duggan]

On Thursday, August  4, Marc Chantreux wrote: 
> I read the Proc documentation and tried to see if there was another
> command or an adverb to the qx construction (something like :r for run).
 
There is the 'x' adverb for Q -- I think qx is equivalent to Q:x

https://docs.raku.org/syntax/Q

Brian

Re: something between run and qx() ?

[Elizabeth Mattijsen]

> On 4 Aug 2022, at 10:35, Marc Chantreux  wrote:
> 
> hello people,
> 
> I found myself choosing between
> 
> raku -e '
>   (run :out, <
>   dpkg-query -f ${db-fsys:Files} -W gnuplot*
>   > ).out>>.lines>>.trim>>.grep(*.IO.f)>>.say'
> 
> and
> 
> raku -e '
>   qx<
>   dpkg-query -f \${db-fsys:Files} -W gnuplot\*
>   >.lines.trim>>.grep(*.IO.f)>>.say'
> 
> I really love the qx syntax but
> 
> * it runs an extra useless sh processus
> * I need to quote the shell symbols
> 
> I read the Proc documentation and tried to see if there was another
> command or an adverb to the qx construction (something like :r for run).
> 
> What I really would like to write is:
> 
> raku -e ' qx:r< dpkg-query -f ${db-fsys:Files} -W gnuplot* 
> >.lines>>.grep(*.IO.f)>>.say '

I believe you could use App::Rak for that:


$ zef install App::Rak
$ dpkg-query -f ${db-fsys:Files} -W gnuplot* | rak '*.trim.IO.f' 
--/show-line-number


Liz