Mark J. Reed wrote:
All of which is just by way of agreeing with Jon: formal logic is not
the primary motivator behind Perl's design. So while it should be
considered, it's not a knockout punch to say "but logic doesn't work
that way."
I think another thing to consider is a survey of the various other common
languages and see what semantics they have with an expression like this pseudocode:
true xor true xor true
I would like to know in what languages the above expression is false ... or
true.
I suggest that to aid learnability, Perl 6 has the same semantics for 'xor' as
other languages with that operator, unless there is a good explicit reason to do
differently; that is, don't do differently just for the heck of it.
I submit that Perl 5 appears to result in true, as tested with:
perl -e "print (5 xor 2 xor 3)"
... which returns 1, indicating also that Perl 5 xor doesn't short-circuit.
Regardless of the above, I think Perl 6 should have both operators, testing
exactly 1 or an odd number.
-- Darren Duncan
