Re: Accessing $a and $b of 'sort' across package boundaries

Use the alternate usage of sort:

foreach ( sort gs::long_strings_first @$raw_hash_keys_ar ) {
    #do_stuff;
}

package gs;
sub long_strings_first($$) {
    return 0 unless defined $_[0];
    return 0 unless defined $_[1];

    length $_[1] <=> length $_[0]
                 ||
        lc $_[1] cmp lc $_[0]
}
[download]

Why did you check if $b is undefined and not $a? If there can be undefined values in the list to be sorted, both $a and $b could be undefined. I added the extra check.

Comment on Re: Accessing $a and $b of 'sort' across package boundaries Select or Download Code

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Re^2: Accessing $a and $b of 'sort' across package boundaries by davidrw (Prior) on Jun 06, 2005 at 19:26 UTC
Is that usage of sort any better/worse/different than something like this? `foreach ( sort gs::long_strings_first($a,$b), @$raw_hash_keys_ar ) { #do_stuff; } package gs; sub long_strings_first { my ($first, $second) = @_; ... }` [download]	[reply] [d/l]
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]
Re^4: Accessing $a and $b of 'sort' across package boundaries by davidrw (Prior) on Jun 06, 2005 at 19:49 UTC
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]
Re^5: Accessing $a and $b of 'sort' across package boundaries by ikegami (Patriarch) on Jun 06, 2005 at 20:54 UTC
Re^2: Accessing $a and $b of 'sort' across package boundaries by ff (Hermit) on Jun 06, 2005 at 19:28 UTC
Actually that `return 0 unless defined` bit was a ghastly way of checking whether there was even something to sort. Thanks for your interpretation and improvement of my lines. :-) (And thank you for the illustration of this other way of using `sort` that I didn't know/think about before. I've needed this for a while....)	[reply] [d/l] [select]