HaloO,
I wrote:
I wonder if that couldn't simply be
method attr is rw
{
return self.blahh;
}
Or am I missing something?
Hmm, I forget something along the lines of
method attr ($rhs)
{
if $rhs > 10 { return self.blahh }
else { return self.blubb }
}
which might be with my concept of equality of object as instance of
a class and of a method invocation as "instance of a method class"
written as
method attr is rw
{
yield $rhs; # coroutine like return
# we resume here after assignment
if $rhs > 10 { self.blahh = $rhs}
else { self.blubb = $rhs}
}
The yield there will return the current invocation of the method
as assignment proxy. The assignment operator needs to be overloaded
for this type something like this
multi sub infix:<=>(AssignmentProxy $lhs, $rhs)
{
$lhs.resume($rhs);
}
With this in place an AssignmentProxy might actually work as rvalue,
too. Thus one can drop the 'is rw' from attr and all the magic is in
the yield declarator/statement.
class Obj
{
has $.foo = 'foo';
has $.blubb = 'blubb';
has $.blahh = 'blahh';
method attr
{
yield $rhs = self.foo;
if $rhs > 10 { self.blahh = $rhs}
else { self.blubb = $rhs}
}
}
my $x = Obj.new;
say $x.attr; # prints 'foo'
$x.attr = 42;
say $x.blahh; # prints 42
So the return type of a yield might actually be ResumeProxy:
sub foo ($x, $y)
{
my $count = 0;
while $count < $y - $x { yield ++count; }
yield -1 while True;
}
say foo(7,23).resume.resume; # prints 3
my $f = foo(10,15);
say $f; # prints 1
$f.resume while $f != -1;
say $f; # prints -1
Regards, TSa.
--
"The unavoidable price of reliability is simplicity" -- C.A.R. Hoare
"Simplicity does not precede complexity, but follows it." -- A.J. Perlis
1 + 2 + 3 + 4 + ... = -1/12 -- Srinivasa Ramanujan
