If you are happy to amend your delta to fit its structure then Struct::Diff offers a solution.

use strict;
use Test::More tests => 2;
use Storable qw(dclone);
use Struct::Diff qw/diff patch/;

my $orig =
  { a =>
    { b =>
      [ 'c', 'd' ],
      e =>
      [
       [ 'f' ]
      ]
    }
  };

my $new = dclone($orig);

my $delta = {
    D => {
        a => {
            D => {
                e => {
                    D => [
                        {   D => [
                                {   O => 'f',
                                    N => 'g'
                                }
                            ]
                        }
                    ]
                }
            }
        }
    }
};

patch ( $new, $delta );

my $augmented =
  { a =>
    { b =>
      [ 'c', 'd' ],
      e =>
      [
       [ 'g' ]
      ]
    }
  };

is_deeply( $new, $augmented, "augment" );

my $diff = diff( $orig, $new, noU => 1 );
is_deeply( $diff, $delta, "reduce" );

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In reply to Re: Augmenting and reducing data structures by hippo
in thread Augmenting and reducing data structures by sciurius

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