Re: Sub args: choose one of two?

[Patrick R. Michaud]

On Thu, Jul 02, 2015 at 03:21:11PM -0500, Tom Browder wrote:
> Okay, a second look shows me that's not quite as bad as I first though.


Another possibility is to let MAIN unpack the args for you, but then check 
the exclusivity directly instead of using multisubs to do it:

   sub MAIN(:$need, :$hope) {
       unless $need.defined xor $hope.defined {
           say "Usage: Exactly one of --need or --hope required";
           exit 1;
       }
       # rest of MAIN goes here
   }


Or use a one() junction, which reads quite nicely:

   sub MAIN(:$need, :$hope) {
       unless one( $need.defined, $hope.defined ) {
           say "Usage: Exactly one of --need or --hope required";
           exit 1;
       }
       # rest of MAIN goes here
   }


Pm