yes, an object for your chunk-o-data. but if your stream-o-data isn't likely to change i would say no object for the parser.

just have your object's creation method take a whole chunk-o-data.

package ChunkOData;

sub from {
  my ($class, $chunk) = @_;
  $chunk =~ s/\n\t//g;  # continuation lines are easy
  # parse $chunk like you already know how
  # shove it into a hash
  return bless \%self, $class;
}

# write some accessors

# write some common useful junk


package main;

local $/ = '';
while (my $chunk_text = <>) {
 my $chunk = ChunkOData->from $chunk_text;
 next unless $chunk->type eq 'UR';
 $chunk->owner('me');
 if ($chunk->is_a_certain_type) {
   $chunk->do_some_standard_thing;
   $chunk->do_something_else($with_my_info);
   subroutines_are_good($chunk);
 }
 $chunk->print;
}
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if your stream-o-data is blank-line seperated (or other $/ -able format) this is a simple way to get started.

you might also use one of the Order-keeping Hash modules from the CPAN in an object for your key field. then you could do something like:

my $key = $chunk->key;
next unless $key{OU} eq 'VALUE1';
my $otherkey = $chunk->key_as_string;  # X=foo/Y=bar/..
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