Hello, BrowserUK.

I see. Example XML is just 613KB.

Copying Twig object is terribly slow. I guess Data::Dumper or dclone of storable will not do any good, because it is just huge.

    for ( $someData->children_copy( 'managedObject') ){
        handle_managedObject($t, $_);
    }
[download]

Without copy, it is very fast.

    for ( $someData->children( 'managedObject') ){
        handle_managedObject($t, $_);
    }
[download]

So, I vaguely imagined rewriting managedObject sub using regex, for example ...

my ($t, $element)=@_;

# create rewrite rules using Twig 
my %rewrite_rules =(
    q/name="name"/ => "some value",
);


#replace with regex
my $buffer=$element->sprint; #get plain text of element
for (keys %rewrite_rules){
    $buffer =~ s/ $_  (.*?)  >  .*?  (?=<)
                /${_} ${1} $rewrite_rules{$_}/sx;
}

#just print out without changing $element
print $fh $buffer;

I will do like this, if I were.

Regards and thanks for your response.