in reply to Re: Accessing $a and $b of 'sort' across package boundaries
in thread Accessing $a and $b of 'sort' across package boundaries

Is that usage of sort any better/worse/different than something like this? 
foreach ( sort gs::long_strings_first($a,$b), @$raw_hash_keys_ar ) {
    #do_stuff;
}

package gs;
sub long_strings_first {
 my ($first, $second) = @_;
 ...
}

[download]

Replies are listed 'Best First'.
Re^3: Accessing $a and $b of 'sort' across package boundaries
by ikegami (Patriarch) on Jun 06, 2005 at 19:34 UTC

    Yes, I think there's a substantial difference in performance. Feel free to Benchmark.

    Also, doing my ($first, $second) = @_; instead of referencing $_[0] and $_[1] directly adds to the cost. It doesn't give anything in return either, since the names are no more descriptive than $_[0] and $_[1].

[reply]
[d/l]
[select]
      ah. That makes sense -- i figured it was something like that. So is there any difference in these two, assuming the long_strings_first is how you defined it (using $_[0] and $_1 directly)? 
      sort gs::long_strings_first @$raw_hash_keys_ar;
sort gs::long_strings_first($a,$b) @$raw_hash_keys_ar;

      [download]
      (first one seems better in appearence, but just curious if any techincal sort-magic difference)
[reply]
[d/l]

        Actually,
        sort gs::long_strings_first($a,$b) @$raw_hash_keys_ar;
        won't run. You mean
        sort { gs::long_strings_first($a,$b) } @$raw_hash_keys_ar;

        Like I said, I think there's a substantial difference in performance. Let's put it to the test:

        Read more... (849 Bytes)
        sub implicit
{ my @array = sort   gs::long_strings_first                   @data; }
sub explicit
{ my @array = sort { gs::long_strings_first($a,$b)          } @data; }
sub explicit_np
{ my @array = sort { gs::long_strings_first_no_proto($a,$b) } @data; }

__END__

              Rate explicit_np    explicit    implicit
explicit_np  606/s          --         -1%        -49%
explicit     610/s          1%          --        -49%
implicit    1187/s         96%         95%          --

        [download]
[reply]
[d/l]
[select]

In Section Seekers of Perl Wisdom