#! 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);