相关疑难解决方法(0)

我试图回答这个问题,并认为我可以使用元对象协议向类添加属性.这是一个最小的例子,我尝试在构造后test向类中添加一个属性Configuration:

use v6;

class Configuration {
}

my $config = Configuration.new;
my $attr = Attribute.new(
    :name('$.test'), # Trying to add a "test" attribute
    :type(Str),
    :has_accessor(1), 
    :package(Configuration)
);
$config.^add_attribute( $attr );
$config.^compose();
say "Current attributes: ", join ', ', $config.^attributes();
$attr.set_value( $config, "Hello" ); # <-- This fails with no such attribute '$.test'
say $config.test;

当我运行这个时,我得到:

Current attributes: $.test
P6opaque: no such attribute '$.test' on type Configuration in a Configuration when trying to bind a …