# New Ticket Created by Moritz Lenz
# Please include the string: [perl #130183]
# in the subject line of all future correspondence about this issue.
# <URL: https://rt.perl.org/Ticket/Display.html?id=130183 >
In this small example, I get an exception where I don't expect one:
role LL[::T] {
has T $.item;
has LL[T] $.next;
method visit(&c) {
c($.item);
$.next.visit(&c) if $.next;
}
}
my $t = LL[Int].new(
item => 5,
next => LL[Int].new( item => 4 ),
);
say $t.perl;
$t.visit(&say);
Output:
LL[Int].new(item => 5, next => LL[Int].new(item => 4, next => LL[T]))
5
No such method 'visit' for invocant of type 'Int'
in method visit at role-param-bug.p6 line 6
in block <unit> at role-param-bug.p6 line 15
It calls method visit on an Int, but $.next is a LL[Int], as the .perl
output confirms.
When I add a 'dd $.next' before the dying recursion call, it reports
$.next as Int 4. Which the type constraint shouldn't even allow as value
for $.next.
Other observations:
* changing the name of the attribute doesn't make a difference
* changing $.next.visit(&c) to $!next.visit(&c) makes the error go away.
Cheers,
Moritz
--
Moritz Lenz
https://deploybook.com/ -- https://perlgeek.de/ -- https://perl6.org/
