From what I saw nesting and conditional commenting seem to be of special interest... which can be done with this solution:

if ($habibi) {
  print $habibi;
  <<'' if (0); #forget the following
  print " talks often much cr*p";<P>

  $h++
}
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Warning about whitespaces in "empty" lines ending a heredoc seem to be a good application for code filters. (...finally)

"empty" lines ending a heredoc have trailing spaces at the end, by definition. perlcritic catches that :).

--
 David Serrano
 (Please treat my english text just like Perl code, i.e. feel free to notify me of any syntax, grammar, style and/or spelling error. Thank you!).

> "empty" lines ending a heredoc have trailing spaces at the end, by definition.

I'm not sure I understand what you mean with "by definition"...(?)

you're suggesting to use perlcritic?

I think a feature/syntax/pragma allowing trailing whitespace in Here-Docs would have many advantages.

(Talking about the "right tool", emacs visualizes trailing whitespaces by default. ;)

Cheers Rolf