On 2/7/06, Robin Houston <[EMAIL PROTECTED]> wrote:
> Any undef undefined match if !defined $a
> Any Regex pattern match match if $a =~ /$b/
> Code() Code() results are equal match if $a->() eq $b->()
> Any Code() simple closure truth match if $b->() (ignoring $a)
> Num numish[!] numeric equality match if $a == $b
> Any Str string equality match if $a eq $b
> Any Num numeric equality match if $a == $b
>
> which retains commutativity in all cases. Of course it's
> different in Perl 6, because the "dotted entries" like
> .[number] and .method need to behave non-commutatively.
> But is it really necessary for coderefs?
My interpretation (which may be totally off, as I don't have any
confirmation that anybody else is thinking the same way I am) is that
the synopsis is wrong, and commutivity of ~~ is a happy coincidence
wherever it exists. The way I've been thinking about ~~ is just as
the following object-oriented sugar:
role Pattern {
method match(Any $x) {...}
}
sub infix:<~~> (Any $x, Pattern $y) {
$y.match($x);
}
And then the interpretation of ~~ is determined by its right-hand side.
Luke
