> On 25 Sep 2015, at 12:05, 宋文泰 (via RT) <[email protected]> wrote:
>
> # New Ticket Created by 宋文泰
> # Please include the string: [perl #126176]
> # in the subject line of all future correspondence about this issue.
> # <URL: https://rt.perl.org/Ticket/Display.html?id=126176 >
>
>
> ``` perl6 code
> my $lastval = 4;
> sub lastval () is rw { return $lastval }
> dd $lastval;
> lastval() = 5;
> dd $lastval;
> ```
>
> Int $lastval = 4
> Cannot assign to a readonly variable or a value
> in block at t3.p6:7
>
> This is perl6 version 2015.09-115-g4653d98 built on MoarVM version
> 2015.09-36-g51dcbe4
Unfortunately, “is rw” doesn’t (yet anyway) make a left value subroutine work.
You need it to return a Proxy object as well:
my $lastval;
sub lastval() is rw {
Proxy.new(
FETCH => { $lastval }, # as a RHS, like $a =
lastval;
STORE => -> $, $value { $lastval = $value }, # as a LHS, like lastval()
= $a
)
}
lastval() = 42;
say $lastval;
At one point Perl 6 may develop syntactic sugar for this, but for now this is
the way to do this.
Ticket can be closed as NotABug
Liz
