sub foo {
  my ($t, $elt)= @_;
  # apply translations to the name, and text of all descendant nodes
  if( my $name = $elt->att('NAME') ) {
    $elt->set_att( 'NAME', apply_translations($name) );
  }
  my @descendants = $elt->descendants( 'BAR' );
  foreach my $descendant (@descendants) {
    if( my $text = $descendant->text ) {
      $descendant->set_text( apply_translations( $text ) );
    }
  }
}

sub apply_translations {
  my $text = shift;
  foreach (@translations) {
    $text =~ s/$_->{match}/$_->{replacement}/g;
  }
  return $text;
}