你如何在 Moose 中创建子类型？

Question

我刚开始使用Moose 。

我正在创建一个简单的通知 object 并想检查输入是否属于“电子邮件”类型。 （暂时忽略简单的正则表达式匹配）。

从文档中我认为它应该类似于以下代码：

# --- contents of message.pl --- #
package Message;
use Moose;

subtype 'Email' => as 'Str' => where { /.*@.*/ } ;

has 'subject' => ( isa => 'Str', is => 'rw',);
has 'to'      => ( isa => 'Email', is => 'rw',);

no Moose; 1;
#############################
package main;

my $msg = Message->new( 
    subject => 'Hello, World!', 
    to => 'coolkids@example.com' 
);  
print $msg->{to} . "\n";

但我收到以下错误：

String found where operator expected at message.pl line 5, near "subtype 'Email'"
    (Do you need to predeclare subtype?)
String found where operator expected at message.pl line 5, near "as 'Str'"
    (Do you need to predeclare as?)
syntax error at message.pl line 5, near "subtype 'Email'"
BEGIN not safe after errors--compilation aborted at message.pl line 10.

任何人都知道如何在 Moose 中创建自定义 Email 子类型？

Moose 版本：0.72 perl 版本：5.10.0，平台：linux-ubuntu 8.10

Answer 1

我也是 Moose 的新手，但我认为对于subtype ，您需要添加

use Moose::Util::TypeConstraints;

Answer 2

这是我之前从食谱中偷来的一个：

package MyPackage;
use Moose;
use Email::Valid;
use Moose::Util::TypeConstraints;

subtype 'Email'
   => as 'Str'
   => where { Email::Valid->address($_) }
   => message { "$_ is not a valid email address" };

has 'email'        => (is =>'ro' , isa => 'Email', required => 1 );