Re: What is Perl way to simultaneously assign to three separate arrays?

> what is the "Perl way" to simultaneously push $1, $2, and $3 to the three arrays @ids, @urls, and @titles?

None, any golfing here would be awkward for just 3 arrays and too hard to maintain.

Truth is - like you already realized - that it doesn't make sense to have three different arrays.

This

    my ($url, $id, $title) = ($_ =~ m|<h6 class="project-title"><a hre
+f="(/proje
+cts/(\d+)/.+?\?ref=discovery)" target="">(.+?)</a></h6>|o );
    push @project, [$url, $id, $title];
[download]

already does the trick.

( IMHO even better $project{$id} = [$url,$title] )

Please note that I didn't try to replace ($url, $id, $title) with @matches cause you'd loose self-documenting names.

But if you really want to condense it further try

    push @project, [ m|<h6 class="project-title"> ... yadda ... </h6>|
+o ];
[download]

HTH!

Cheers Rolf

PS: Je suis Charlie!

PS: As a side note, better dump references

dump \@urls, \@ids, \@titles;
[download]

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Re^2: What is Perl way to simultaneously assign to three separate arrays? by CoVAX (Beadle) on Feb 15, 2015 at 04:41 UTC
Thank you for your comments, esp. named captures and proper use of dump. When I run the code, the array ends up having nine separate scalar elements instead of three references to anonymous arrays containing three scalar elements each Here's what I'm currently getting: `[ "/projects/2138137193/iblab?ref=discovery", 2138137193, "iBlab", "/projects/2060538158/nz-hosting?ref=discovery", 2060538158, "NZ Hosting", "/projects/1956727289/how-to-build-a-spaceship?ref=discovery", 1956727289, "How To Build A Spaceship", ]` [download] Here's what I want: `[ [ "/projects/2138137193/iblab?ref=discovery", 2138137193, "iBlab" ], [ "/projects/2060538158/nz-hosting?ref=discovery", 2060538158, "NZ Hosting" ], [ "/projects/1956727289/how-to-build-a-spaceship?ref=discovery", 1956727289, "How To Build A Spaceship" ] ]` [download] How is this possible given the constraint that the entire HTML content is a scalar (obtained via LWP)? (I realize I can "post-process" the @projects array but I'd like to know if everything can be done in a single assignment without any munging afterward.) #! perl -w use strict; use Data::Dump qw(dump); my $html = '<h6 class="project-title"><a href="/projects +/2138137193/iblab?ref=discovery" target="">iBlab</a></h6><h6 class="p +roject-title"><a href="/projects/2060538158/nz-hosting?ref=discovery" + target="">NZ Hosting</a></h6><h6 class="project-title"><a href="/pro +jects/1956727289/how-to-build-a-spaceship?ref=discovery" target="">Ho +w To Build A Spaceship</a></h6>'; my @projects = $html =~ m\|<h6 class="project-title"><a href="(/project +s/(\d+)/.+?\?ref=discovery)" target="">(.+?)</a></h6>\|g; dump \@projects; [download] Searched for donut and crumpit. Found donate and stumbit instead.	[reply] [d/l] [select]
Re^3: What is Perl way to simultaneously assign to three separate arrays? by LanX (Saint) on Feb 15, 2015 at 10:42 UTC
> I'd like to know if everything can be done in a single assignment without any munging afterward.) No, you are using /g in list context which swallows the whole file now and returns a flat list. You need an external loop to process the 3 groups update With a post `while` you can have the loop in the same line `push @res, [ $1,$2,$3 ] while m/.../g` In the OP you were originally looping with $_ , that's confusing. you should rather be concerned about maintainability than shortness. Cheers Rolf PS: Je suis Charlie!	[reply] [d/l]
Re^4: What is Perl way to simultaneously assign to three separate arrays? by CoVAX (Beadle) on Feb 15, 2015 at 20:40 UTC
you should rather be concerned about maintainability than shortness. Agreed. Still, I am fascinated by idiomatic Perl and its myriad other ways of doing something (the Schwartzian Transform comes to mind). Searched for donut and crumpit. Found donate and stumbit instead.	[reply]
Re^3: What is Perl way to simultaneously assign to three separate arrays? by CoVAX (Beadle) on Feb 15, 2015 at 08:42 UTC
Here's what I came up with to "post-process" the array to get what I wanted: #! /usr/bin/perl -w use strict; use Data::Dump qw(dump); my @src = ( "/projects/2138137193/iblab?ref=discovery", 2138137193, "iBlab", "/projects/2060538158/nz-hosting?ref=discovery", 2060538158, "NZ Hosting", "/projects/1956727289/how-to-build-a-spaceship?ref=discovery", 1956727289, "How To Build A Spaceship" ); my @dst = (); my $by = 3; my $len = @src / $by; die "Not an integral multiple\n" unless ( 0 == @src % $by ); for (my $i = 0; $i < $len; $i++) { push @dst, [ splice @src, 0, 3 ]; } dump \@dst; [download] The output: `[ [ "/projects/2138137193/iblab?ref=discovery", 2138137193, "iBlab", ], [ "/projects/2060538158/nz-hosting?ref=discovery", 2060538158, "NZ Hosting", ], [ "/projects/1956727289/how-to-build-a-spaceship?ref=discovery", 1956727289, "How To Build A Spaceship", ], ]` [download] I don't know why but lately I've been in a mood to "do it in one statement" or "do it in place". So I have to ask: "Can this be done in-place with just one array?" Searched for donut and crumpit. Found donate and stumbit instead.	[reply] [d/l] [select]

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