G'day monks!

I have two arrays of array refs. Each of these has a "date" column, but the columnar position is not the same for both arrays.

There is another field that identifies which array is currently being looked at, and hence can indicate the position of the date column.

What sorting strategy can I use to interleave the two arrays, sorting by the applicable date ?

#! perl
use strict;
use warnings;
use JSON;

my $json = JSON->new();

my $ary1 = [
  [ 1,1,1,1,1,'2018-03-01', 'src1', 1,1,1,1 ],
  [ 1,1,1,1,1,'2018-02-15', 'src1', 1,1,1,1 ],
  [ 1,1,1,1,1,'2018-04-11', 'src1', 1,1,1,1 ],
  [ 1,1,1,1,1,'2018-03-11', 'src1', 1,1,1,1 ],
];

my $ary2 = [
  [ 2,2,2,2,'2018-03-02', 2, 'src2', 2,2,2,2 ],
  [ 2,2,2,2,'2018-01-25', 2, 'src2', 2,2,2,2 ],
  [ 2,2,2,2,'2018-04-22', 2, 'src2', 2,2,2,2 ],
  [ 2,2,2,2,'2018-03-22', 2, 'src2', 2,2,2,2 ],
];


sub by_dates {
  # What should this sort routine look like so
  # that both arrays are interleaved, sorting
  # by the applicable date column?
}

my @combined = (@$ary1, @$ary2);
my @sorted   = sort by_dates @combined;

print $json->encode(\@sorted);
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