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
