/edit?items=[(\w+)];location=(\w+);flags={(\d+)};... 
  { 
    if ( $arg->{location} eq 'US' ) {
      for my $item ( @{$arg->{items}} ) {
        if ( $arg->{flags}{54} ) {
          $r->print "item: $item qualifies for discount 54 processing<br>\n";
        }
      }
    }
    
    # other optional args that we may / may not have
    if ( defined $arg->{style} ) {
      $r->print("you have style! $arg->{style}<br>\n"
    }
    
  }; 

#  args are placed in hashref $arg
#  [] indicates that the named arg should be an array.
#  {} indicates that the named arg should be a hash.
#     for a URL of flags=54&amp;flags=23&amp;flags=red
#      might yeild
#        $arg->{flags} = {
#          54 => 54,
#          23 => 23,
#          red => 'red',
#        };
#      so that programmers can use keys values as they are comfy?
#  optional args (ie the ...) are available in $arg

##</code><code>##

:DESPATCH

  /edit?node=(\w+);... { 
      print "You're trying to edit '$node'"; 
    }; 

:PARAM

  node  {
    my ( $node ) = @_;
    my $db = My::Database->new(...);
    return $node if $db->selectValue( sql => "select count(*) from nodes where node=?", param => [$node] );
    print "invalid node: $node";
    return undef;
  }


##</code><code>##

/edit?name=(\w+);city=(\w+);... { 
    print "Edit '$name' in '$city'"; 
  }; 

/edit?name=(\w+);job=(.*);... { 
    print "Edit '$name' who does '$job'"; 
  };