Re^3: beginner - ordering tuples

do you mind if I simplify it to a one liner?

use strict;
use warnings;
 
my @datas;
 
# for (<DATA>){
#   push @datas, [ m/<(\d+),(\d+)>/ ];
# }
 
@datas = sort { $a->[0] <=> $b->[0] || $a->[1] <=> $b->[1] } 
              map { [ m/<(\d+),(\d+)>/ ] } <DATA>;
 
use Data::Dumper;
print Dumper \@datas;
 
__DATA__
<7,22>
<12,20>
<7,15>
<1,5>
<7,10>
[download]

please see sort about how the ~~boolean~~ three states condition decides about the ordering.

the perlop || is - like in C - short circuiting, that is the RHS is only evaluated (and returned) when the LHS is false (i.e 0 if <=> compares equal values).

If your tuples have more than 2 elements you should ask for a generic solution.

Cheers Rolf

Comment on Re^3: beginner - ordering tuples Select or Download Code

Replies are listed 'Best First'.
Re^4: beginner - ordering tuples by 7stud (Deacon) on Nov 13, 2010 at 22:19 UTC
In your elegant solution, you need to switch around your second conditional to: `$b->[1] <=> $a[1]`	[reply] [d/l]
Re^5: beginner - ordering tuples by LanX (Saint) on Nov 14, 2010 at 02:22 UTC
Right, I missed that the second position should be descending. You forgot a dereferencing: `$b->[1] <=> $a->[1]` Cheers Rolf	[reply] [d/l]