Re: RFC 263 (v1) Add null() keyword and fundamental data type

[Nathan Wiger]

Graham Barr wrote:
>
> If you want an operator to act differently on some piece of data then a pragma
> is the way to do it.

I was thinking about this on the way to work. As much as I don't like
conflating undef and null, I dislike even more the idea of the 200 pages
in Learning Perl that will have to now be devoted to why these two:

   $name = undef;
   $name = null;

Are not the same thing.

If everyone's in agreement, what I'll do is redraft the RFC to say Perl
6 should include a "use tristate" pragma which obeys blocks:

   $a = undef;
   $b = 1;
   $c = $a + $b;    # 1
   {
      use tristate;
      $d = $a + $b; # undef
   }
   $e = $c + $d;    # 1


Thoughts?

-Nate