package OuterPkg;

use strict;
use warnings;
use Carp qw/cluck/;


sub foo {
   my $sub =(caller(0))[3];
   $"=",";
   return "Calling $sub(@_)";
}



use Import2Package 'DTD' => 'myDSL';


package myDSL {
   print
     TABLE {
        TR {
           TD {1}, TD{foo()},
        }
     }
}

#  TABLE(); # not visible in outer Package

##</code><code>##

exec "perl OuterPkg.pl" unless caller();

use strict;
use warnings;
use Carp qw/cluck/;



package Import2Package;

sub delegate_subs {
   my ( $pkg, $super )=@_;
   use vars '$AUTOLOAD';

   no strict 'refs';
   *{${pkg}."::AUTOLOAD"} =
     sub  {
        my $delegate = $AUTOLOAD;       
        $delegate =~ s/.*:://;          # strip packagename
        goto &{"${super}::${delegate}"};
     }
  }

sub install_vocab {
   my ( $pkg, $super ) = @_;

   my @vocab = qw/TABLE TR TD/;

   my $level = 0;
   no strict 'refs';
   for my $CMD (@vocab) {
      *{"${pkg}::$CMD"} = sub (&) {
         $level++;
         my @inside = $_[0]->();
         $level--;
         my $indent = "\n" . "\t" x $level;
         my $tag =lc($CMD);
         return join "",map {"<$tag>$_</$tag>"}  @inside;
      }
   }
   *{"${pkg}::render"} = sub { print @_ };
   
}



sub import {
   my ($self, $dtd, $pkg) =@_;
   my $super = (caller())[0];

   delegate_subs $pkg => $super;
   install_vocab $pkg, $super;

}


1;

##</code><code>##

<table><tr><td>1</td></tr><tr><td>Calling OuterPkg::foo()</td></tr></table>