perl - 使用 "override"或只是简单地在 perl 中重新定义子例程

Question

有这个示例代码 - 2 个扩展了 Some 的包打包并重新定义 func方法。

use 5.014;
use warnings;

package Some {
    use Moose;
    use warnings;
    sub func { say 'func from Some'; }
}

package Over {
    use Moose;
    use warnings;
    extends 'Some';
    override 'func' => sub { say 'func from Over'; };
}

package Plain {
    use Moose;
    use warnings;
    extends 'Some';
    sub func { say 'func from Plain'; };
}

#main
for my $package ( qw(Some Over Plain) ) {
    my $instance = $package->new();
    $instance->func;
}

运行代码给出:

func from Some
func from Over
func from Plain

例如 func方法在两种情况下都被重新定义，没有任何警告或类似的。

问题:

这两种方式之间有什么有意义的区别吗？

我什么时候应该使用 override当平原重新定义？

这是在某些文档中讨论过的吗？

Answer 1

documentation完美地回答了这个问题。

override ($name, &sub)

An override method is a way of explicitly saying "I am overriding this method from my superclass". You can call super within this method, and it will work as expected. The same thing can be accomplished with a normal method call and the SUPER:: pseudo-package; it is really your choice.