Beefy Boxes and Bandwidth Generously Provided by pair Networks
Do you know where your variables are?
 
PerlMonks  

pairwise() doesn't seem to work...

by 7stud (Deacon)
on Oct 06, 2010 at 09:06 UTC ( #863738=perlquestion: print w/ replies, xml ) Need Help??
7stud has asked for the wisdom of the Perl Monks concerning the following question:

Dear Monks,

This is what I get when I try to use pairwise() in List::MoreUtils,

use strict; use warnings; use 5.010; use List::MoreUtils; my @arr1 = (1, 2, 3); my @arr2 = (10, 20, 30); my %hash = pairwise { ($a, $b) } @arr1, @arr2; use Data::Dumper; say Dumper(\%hash); --output:-- Name "main::b" used only once: possible typo at 1perl.pl line 10. Name "main::a" used only once: possible typo at 1perl.pl line 10. Can't call method "pairwise" on an undefined value at 1perl.pl line 10 +.

Comment on pairwise() doesn't seem to work...
Download Code
Re: pairwise() doesn't seem to work...
by Corion (Pope) on Oct 06, 2010 at 09:19 UTC

    You need to import pairwise from List::MoreUtils. It seems that Perl interprets pairwise { ($a, $b) } as indirect object notation otherwise:

    use List::MoreUtils qw( pairwise );
Re: pairwise() doesn't seem to work...
by eyepopslikeamosquito (Canon) on Oct 06, 2010 at 09:20 UTC

    You need to explicitly import pairwise like so:

    use List::MoreUtils qw(pairwise);

      Thanks.
Re: pairwise() doesn't seem to work...
by AnomalousMonk (Abbot) on Oct 06, 2010 at 10:02 UTC

    And get rid of the  Name "main::whatever" used only once ... warnings with a  use vars qw($a $b); (or similar) statement.

    >perl -wMstrict -le "use 5.010; use List::MoreUtils qw(pairwise); my @arr1 = (1, 2, 3); my @arr2 = (10, 20, 30); use vars qw($a $b); my %hash = pairwise { ($a, $b) } @arr1, @arr2; use Data::Dumper; say Dumper(\%hash); " $VAR1 = { '1' => 10, '3' => 30, '2' => 20 };

Log In?
Username:
Password:

What's my password?
Create A New User
Node Status?
node history
Node Type: perlquestion [id://863738]
Approved by marto
help
Chatterbox?
and the web crawler heard nothing...

How do I use this? | Other CB clients
Other Users?
Others studying the Monastery: (12)
As of 2015-03-04 12:19 GMT
Sections?
Information?
Find Nodes?
Leftovers?
    Voting Booth?

    When putting a smiley right before a closing parenthesis, do you:









    Results (110 votes), past polls