raku -e'.say for lines() ==> grep(/^WARN/) ==> sort' sample.log
is not very satisfying because for the "for" which breaks the flow.
OTOH this
raku -e'lines().grep(/^WARN/).sort».say' sample.log
doesn't use the feed operator and this
raku -e'lines() ==> grep(/^WARN/) ==> sort() ==> say()' sample.log
outputs a list on one line, not each line on its own. This one works, but
it feels awkward:
raku -e'lines() ==> grep(/^WARN/) ==> sort() ==> reduce({$^a ~ "\n" ~ $^b})
==> say()' sample.log
On Fri, May 8, 2020 at 5:49 PM yary <not....@gmail.com> wrote:
> All good ideas so far, in the "more than one way to do it" spirit, can use
> "state" instead of "my", since state only initializes 1st time it's hit.
>
> raku -ne 'state @i;@i.push($_) if .starts-with(q[WARN]); END .say for
> @i.sort' sample.log
>
> Or adapting Brad's answer with the feed operator for fun
>
> raku -e 'for lines() ==> grep /^WARN/ ==> sort() {.say}' sample.log
>
> Now, I didn't want to use 'map' in there, because of a habit of only using
> 'map' when I want the return values. When looping for side-effects only,
> like saying each value in a list, I want to use 'for'. UnFORtunately though
> I cannot find anything as clean looking as
>
> raku -e 'lines() ==> grep /^WARN/ ==> sort() ==> map *.say' sample.log
>
> reading entirely L-to-R which does NOT use map... ideas?
>
> -y
>
>
> On Fri, May 8, 2020 at 10:10 AM William Michels via perl6-users <
> perl6-us...@perl.org> wrote:
> >
> > On Fri, May 8, 2020 at 5:16 AM WFB <wolfgang.banas...@gmail.com> wrote:
> > >
> > > Hi,
> > >
> > > I am trying to write an one-liner to go through all lines in a logfile
> and look for an certain key word, store the line and sort them before
> printing them out.
> > >
> > > My approach was:
> > > raku -ne "BEGIN {my @i }; @i.push($_); if $_ ~~ /^WARN/; END {
> @i.sort.say }"
> > > That does not work because @i does not exist in the if clause. I tried
> our @i as well with no luck.
> > >
> > > How can I store data that can be accessed in the END phaser? Or is
> there another way to archive it? TIMTOWTDI^^
> > >
> > > One hint I found was the variable $ and @ respectively. But those
> variables are created for each line new...
> > >
> > >
> > > I did not found a help or examples for -npe except raku -h. Is there
> more helpful stuff somewhere in doc.raku.org? If so I could'nt find it.
> > >
> > > Thanks,
> > > Wolfgang
> >
> > Hi Wolfgang,
> >
> > This is a first attempt at doing what you want: I'm sure it can be
> > shortened. Since one of your requirements is doing a sort on filtered
> > values stored in an array, I abandoned use of the "-ne" one-liner
> > flag, using "-e" and "for lines()" instead. I also used grep instead
> > of smart-matching:
> >
> > perl6 -e 'my @i; for lines() {if .grep(/^WARN/) -> ($s)
> > {@i.push($s)};}; .say for @i.sort;'
> >
> > Note: the "-> ($s)" section where I store grepped matches comes from a
> > Jonathan Worthington answer found here (thanks Jonathan!):
> >
> >
> stackoverflow.com/questions/58982745/raku-one-line-expression-to-capture-group-from-string
> >
> > I certainly would be interested to learn if there's a phaser solution
> > to this problem (and I also have a sneaking suspicion that Supply
> > might be useful here... ).
> >
> > HTH, Bill.
>
--
Fernando Santagata
