#pseudo code 
# error handling omitted!

sub parser_factory {
   my $file_path = shift;
   my %options = @_;
   fh = open_file($file_path)

   my $iterator = sub {
   # closure ; flag end of data/closing file omitted
   while( header = read(fh)) {
      length = get_length(header)
      body = read(fh,length)
      type = get_type(header)
      class =get_record_class(header) # return class name
      return class->new(body);
   
    }
   }
   return $iterator
}