Re: Custom Sort An AoA

[kcott]

G'day Limbic~Region,

This is a general solution which appears to tick all the boxes:

@list = sort { @$a <=> @$b || do {
    my $cmp;
    ($cmp = $a->[-$_] cmp $b->[-$_]) ? last : next for 1 .. @$a;
    $cmp;
} } @list;

Here's my test:

<Reveal this spoiler or all in this thread>

Update: I wrote that this was "a general solution"; however, having reviewed some of your comments in this thread, I see what I've provided wasn't what you meant.

I've converted the code I originally posted, into what I suspect is closer to what you want; but, if it's not, please provide more details about what you're looking for.

#!/usr/bin/env perl

use strict;
use warnings;

use Scalar::Util qw{looks_like_number};

my @master_alpha_list = (
    ['blah', 'asdf', 'foo', 'bar'],
    ['two'],
    ['zzz', 'def', 'ghi'],
    ['one'],
    ['mmm', 'def', 'ghi'],
    ['qqq', 'xyz', 'aaa']
);

my @master_num_list = (
    [ 0, 1, 2, 3 ],
    [ 2 ],
    [ 9, 3, 6 ],
    [ 1 ],
    [ 5, 3, 6 ],
    [ 7, 8, 1 ],
);

my @alpha_asc = sort { @$a <=> @$b || gen_sort() } @master_alpha_list;
my @alpha_dsc = sort { @$a <=> @$b || gen_sort(1) } @master_alpha_list
+;
my @num_asc = sort { @$a <=> @$b || gen_sort() } @master_num_list;
my @num_dsc = sort { @$a <=> @$b || gen_sort(1) } @master_num_list;

use Data::Dump;
dd $_ for (\@alpha_asc, \@alpha_dsc, \@num_asc, \@num_dsc);

sub gen_sort {
    my ($desc) = @_;

    my $compare = looks_like_number($a->[0]) ? \&cmp_num : \&cmp_alpha
+;
    my ($x, $y) = $desc ? ($b, $a) : ($a, $b);
    my $cmp;
    ($cmp = $compare->($x->[-$_], $y->[-$_])) ? last : next for 1 .. @
+$a;

    return $cmp;
}

sub cmp_alpha { $_[0] cmp $_[1] }
sub cmp_num { $_[0] <=> $_[1] }

Output:

[
  ["one"],
  ["two"],
  ["qqq", "xyz", "aaa"],
  ["mmm", "def", "ghi"],
  ["zzz", "def", "ghi"],
  ["blah", "asdf", "foo", "bar"],
]
[
  ["two"],
  ["one"],
  ["zzz", "def", "ghi"],
  ["mmm", "def", "ghi"],
  ["qqq", "xyz", "aaa"],
  ["blah", "asdf", "foo", "bar"],
]
[[1], [2], [7, 8, 1], [5, 3, 6], [9, 3, 6], [0 .. 3]]
[[2], [1], [9, 3, 6], [5, 3, 6], [7, 8, 1], [0 .. 3]]