$this->{ template } =~ s/$re/$this->replacement( $callback, $key, $1, $2 )/eg;

##</code><code>##

sub replacement {
  my $this = shift;
  my ( $cb, $key, $first, $second ) = @_;
  return
    $cb->( $key, $this->mask_block_params( $first, $second ) );
}

##</code><code>##