?:?:?:

• Most folks know about the ?: operator

          *{$p . '::' . $n} = (ref $v ? $v : \$v);

• It's a compact version of an if-else block

• What if you want a compact version of an if-elsif-else block?

        sub sign {
          my $x = shift;
          if ($x < 0) { return -1 }
          elsif ($x == 0) { return 0 }
          else { return +1 }
        }

• No problem:

        sub sign {
             $_[0] <  0 ? -1 :
             $_[0] == 0 ?  0 :
                           1 ;
        }

• Everything is as it should be

• The precedence is fine, the short-circuiting is fine

• The folks who designed the ?: operator are very smart

• So chain together as many as you want

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Copyright © 2003 M. J. Dominus