I have this code: 
use strict;

my @list = qw/ box cow dog apple ant/;

# A "normal" use of sort
my @sorted = sort {$a cmp $b} @list;
print join (',', @sorted), "\n";

#return the sort sub and count in a list
sub mcc {
    my $count = 0;
    return (sub {$count++; $_->[0] cmp $_->[1] }, $count);
}

# see below
my @f = mcc();

# why can't I say something like mcc()[0] ???
print sort {$f[0]} @list;

[download]
It looks to me as though the anon sub returns the result of cmp and only the result of cmp, but perl says Sort subroutine didn't return a numeric value at sort1.pl line 19.

What am I missing? Also, how can I avoid using @f?

--traveler

In reply to Closures and sort by traveler

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post, it's "PerlMonks-approved HTML":


  • Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
  • Titles consisting of a single word are discouraged, and in most cases are disallowed outright.
  • Read Where should I post X? if you're not absolutely sure you're posting in the right place.
  • Please read these before you post! —
  • Posts may use any of the Perl Monks Approved HTML tags:
    a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)
            For:     Use:
    & &amp;
    < &lt;
    > &gt;
    [ &#91;
    ] &#93;
  • Link using PerlMonks shortcuts! What shortcuts can I use for linking?
  • See Writeup Formatting Tips and other pages linked from there for more info.