assign-if-uninitialized [Was: Generalizing ?? !!]

[Larry Wall]

On Tue, Jun 19, 2007 at 11:50:35AM -0400, Charles Bailey wrote:
: Yep.  For that matter, if I had to pick one change in this area that'd
: have maximum impact, I'd say a good assign-if-uninitialized idiom
: would be way ahead of an if-then-else idiom.

Depending on how you mean "uninitialized", that would be either:

    $x //= 42;          # init if undefined

or

    state $x = 42;      # init first time through

Both of which are getting borrowed back into Perl 5, as it happens.

Larry