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

[Russ Allbery]

Tom Christiansen <[EMAIL PROTECTED]> writes:

>>    $a = null;
>>    $b = ($a == 42);
>>    print defined($b)? "defined" : "not defined";

>> would print "not defined", maybe?

> In a sane world of real (non-oo-sneaky) perl, the "==" operator returns 
> only 1 or "".  Both are defined.

But if you say:

  use tristate;

then $a == 42 returns undef if $a is undef.  Most Perl programs may not
want these semantics, but they're often useful, and for more things than
just databases.  Think error propagation.

-- 
Russ Allbery ([EMAIL PROTECTED])             <http://www.eyrie.org/~eagle/>