On Sun, 27 Oct 2002, Damian Conway wrote: : Luke Palmer wrote: : : > You know, \ and friends as xor is appealing to me. : : Hmmmm. I quite like that too. :-)
Except what about unary xor, i.e. 1's complement? Besides, Windows programmers would continually be writing $a / $b and wonder why they don't get one($a,$b); : > Also, a question about superpositions: Is : > : > $x = 1 | 2 | 3 : > : > equivalent to : > : > $x = 1 | 2 : > $x |= 3 : : No. The precedence is wrong. How so? : > or : > : > $x = (1 | 2) | 3 : : Yes. It's not clear that that shouldn't do the Right thing just like $a < $b < $c : [Large amounts of how-to-think-of-it snipped...] : So the effect is the same either way. So why not just make it the same? Otherwise you can't really use |= to add to a set like you wanted. All you can do is make a new set that holds the old set plus the new member, which isn't the same thing, since in set theory a set is a thing distinct from its members. : The only time you'd notice any difference between $x1 and $x2 is if you : asked for their eigenstates, in which case $x1 would give you : three states (C<1>, C<2>, and C<3>) and $x2 would give you two states : (C<any(1,2)> and C<3>). I think we should make people people write any(any(1,2),3) if that's the weird thing they want. I think | and & should automatically reduce as long as you're combining similars. Or at least |= should have the notion of appending to an existing any, just as ~= appends to an existing string. The length of your "how to think of it" is indicative that mere mortals will choose not to think of it at all... Larry