in reply to complex sort

You understand sort well, so there's not much efficiency to be gained, I think.
However, I would have used some complex data structure for readability. This also removes the need for temporary variables. (but adds an array)
my @data =
        sort {
                $a->[7] cmp $b->[7] ||
                $b->[6] <=> $a->[6] ||  # '' == 0
                $a->[0] <=> $b->[0] ||
                $a->[1] <=> $b->[1] ||
                $a->[2] <=> $b->[2] ||
                $a->[4] cmp $b->[4] ||
                $a->[3] cmp $b->[3]
        } map {
                [ /^(\d+)(\D+)(\d+)(\D*)R(\d+)(B?)(\d*)\.(\w+)$/ ]
        } <DATA>;
print "$_->[0]$_->[1]$_->[2]$_->[3]R$_->[4]$_->[5]$_->[6].$_->[7]\n" f
+or @data;

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I've made some mistake in there, but I leave it up to you to find and fix it. For some reason, my version puts 113B28R2.ras two places too high (top==0) in the array.

I think my version is more readable, and threrefore more reliable and maintainable (if the bug is fixed, that is ;))

2;0 juerd@ouranos:~$ perl -e'undef christmas'
Segmentation fault
2;139 juerd@ouranos:~$

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Re: Re: complex sort
by jynx (Priest) on Dec 25, 2001 at 04:51 UTC

    a couple points,

    The bug is that you sort the second type position numerically instead of lexicographically. However, i don't like the way you leave the elements in @data as array references when you're through sorting. You should have finished up the Schwartz Transform so that the original data was still there, just reorganized. If we make those corrections we come up with:

    my @data =
        map { join '', @$_[0..3],'R',@$_[4..6],'.',$_->[7], "\n" }
        sort { $a->[7] cmp $b->[7] ||
               $b->[6] <=> $a->[6] ||
               $a->[0] <=> $b->[0] ||
               $a->[1] cmp $b->[1] ||
               $a->[2] <=> $b->[2] ||
               $a->[4] <=> $b->[4] || # update: changed (see 1)
               $a->[3] cmp $b->[3] }
        map { [ /^(\d+)(\D+)(\d+)(\D*)R(\d+)(B?)(\d*)\.(\w+)$/ ] }
        <DATA>;

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    jynx

    update: Unfortunately, before i even got to post this, Ovid posted a better solution that makes sure all the values are defined before being sorted as well.

    1: this was changed due to Ovid's note...

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