for ( 0 .. $#{ $hash{$set}{data} } ) {
    $hash{$set}{min} = $hash{$set}{min} < $hash{$set}{data}[$_]
                     ? $hash{$set}{min} 
                     : $hash{$set}{data}[$_];
}
[download]

I personally find the above solution easier to read. However, since this is in a loop, and regular ? : evaluates the data twice, your proposed operator could be considerably faster in some cases. Naturally, the premature optimization alarms are ringing here, so I'm going to stop typing now (:

----
I wanted to explore how Perl's closures can be manipulated, and ended up creating an object system by accident.
-- Schemer

Note: All code is untested, unless otherwise stated