MooseX :: AttributeHelpers和MooseX :: FollowPBP是否正确交互？

Question

以下代码定义了两个类(DeckA和DeckB),它们的区别仅在于它们是否使用MooseX :: AttributeHelpers附带的功能.Moose生成的吸气剂DeckB不是我的预期.这是一个错误还是我误解了MooseX :: AttributeHelpers和MooseX :: FollowPBP应该如何互动？

我现在的解决方法是避免is在这种情况下使用参数,而是声明a reader并writer根据需要.

use strict;
use warnings;

my %moose_args = (
    isa     => 'ArrayRef[Str]',
    is      => 'ro',
    default => sub {[]},
);

my %moose_attr_helper_args = (
    metaclass => 'Collection::Array',
    provides => {
        elements => 'get_all_cards',
    },
);

package DeckA;
use Moose;
use MooseX::FollowPBP;
use MooseX::AttributeHelpers;
has 'cards' => (%moose_args);

package DeckB;
use Moose;
use MooseX::FollowPBP;
use MooseX::AttributeHelpers;
has 'cards' => (%moose_args, %moose_attr_helper_args);

package main;
for my $class (qw(DeckA DeckB)){
    my $deck = $class->new;
    print "\n$class\n";
    for my $method ( qw(cards get_cards get_all_cards) ){
        print "$method: ", $deck->can($method) ? 'yes' : 'no', "\n";
    }
}

输出:

DeckA
cards: no
get_cards: yes
get_all_cards: no

DeckB
cards: yes          # Not what I expected.
get_cards: no       # Not what I expected.
get_all_cards: yes

Answer 1

当您使用MX :: AH的元类选项时,它们不起作用.

然而,最新的Moose已经集成了对原生助手的支持,并略微调整了API.此版本使用traits(应用于属性的角色),它应该可以正常使用MX :: FollowPBP.