Catmandu::Iterator

  package My::MockIterator;
  use Moo;
  
  with 'Catmandu::Iterable';
  sub generator {
    sub {
        # Generator some random data
        +{ random => rand };
    }
  } 
  package main;
 
  my $it = My::MockIterator->new;
  my first = $it->first;
  $it->each(sub {
  my $item = shift;
  print $item->{random} , "\n";
  });
  my $it2 = $it->map(sub { shift->{random} * 2 });

If you provide a generator, then the class will generator all methods from Catmandu::Iterable.

Catmandu::Iterable