RosettaCodeData/Task/Add-a-variable-to-a-class-instance-at-runtime/Raku/add-a-variable-to-a-class-instance-at-runtime-1.raku
2023-07-01 13:44:08 -04:00

22 lines
793 B
Raku

class Bar { } # an empty class
my $object = Bar.new; # new instance
role a_role { # role to add a variable: foo,
has $.foo is rw = 2; # with an initial value of 2
}
$object does a_role; # compose in the role
say $object.foo; # prints: 2
$object.foo = 5; # change the variable
say $object.foo; # prints: 5
my $ohno = Bar.new; # new Bar object
#say $ohno.foo; # runtime error, base Bar class doesn't have the variable foo
my $this = $object.new; # instantiate a new Bar derived from $object
say $this.foo; # prints: 2 - original role value
my $that = $object.clone; # instantiate a new Bar derived from $object copying any variables
say $that.foo; # 5 - value from the cloned object