MooseX::Types 和强制错误

Question

随着this answer 的继续，哇，我正在与我自己的 Moose“类型库”战斗 - 所以尝试使用“MooseX::Types”。

基于上述MooseX::Types 文档和对上述答案的“hoobs”评论，我将自己的“类型”定义为下一个：

package MyTypes;
use 5.016;
use Moose;
use MooseX::Types -declare => [qw( Dir File )];    
use MooseX::Types::Moose qw( Str );

use Path::Class::Dir;
use Path::Class::File;

class_type Dir, { class => 'Path::Class::Dir' };
coerce Dir, from Str, via { Path::Class::Dir->new($_) };

class_type File, { class => 'Path::Class::File' };
coerce File, from Str, via { Path::Class::File->new($_) };

1;

并在我的包中使用它

package MyDir;
use Moose;
use warnings;
use MyTypes qw(Dir);    #to get the Dir type and its coercion

has 'path' => (
    is => 'ro',
    isa => Dir,      # Dir is defined in the package MyTypes
    required => 1,
);
1;

并尝试使用下一个短脚本

use 5.016;
use warnings;
use MyDir;
my $d = MyDir->new(path => "/tmp");

错误：

Attribute (path) does not pass the type constraint because: Validation failed for 'MyTypes::Dir' with value /tmp (not isa Path::Class::Dir) at /Users/me/perl5/perlbrew/perls/perl-5.16.3/lib/site_perl/5.16.3/darwin-2level/Moose/Meta/Attribute.pm line 1279.
    Moose::Meta::Attribute::verify_against_type_constraint(Moose::Meta::Attribute=HASH(0x7f9e9b1c2618), "/tmp", "instance", MyDir=HASH(0x7f9e9b826bb8)) called at /Users/me/perl5/perlbrew/perls/perl-5.16.3/lib/site_perl/5.16.3/darwin-2level/Moose/Meta/Attribute.pm line 1266
    Moose::Meta::Attribute::_coerce_and_verify(Moose::Meta::Attribute=HASH(0x7f9e9b1c2618), "/tmp", MyDir=HASH(0x7f9e9b826bb8)) called at /Users/me/perl5/perlbrew/perls/perl-5.16.3/lib/site_perl/5.16.3/darwin-2level/Moose/Meta/Attribute.pm line 536
    Moose::Meta::Attribute::initialize_instance_slot(Moose::Meta::Attribute=HASH(0x7f9e9b1c2618), Moose::Meta::Instance=HASH(0x7f9e9b1c3588), MyDir=HASH(0x7f9e9b826bb8), HASH(0x7f9e9b826a98)) called at /Users/me/perl5/perlbrew/perls/perl-5.16.3/lib/site_perl/5.16.3/darwin-2level/Class/MOP/Class.pm line 525
    Class::MOP::Class::_construct_instance(Moose::Meta::Class=HASH(0x7f9e9b9e6990), HASH(0x7f9e9b826a98)) called at /Users/me/perl5/perlbrew/perls/perl-5.16.3/lib/site_perl/5.16.3/darwin-2level/Class/MOP/Class.pm line 498
    Class::MOP::Class::new_object(Moose::Meta::Class=HASH(0x7f9e9b9e6990), HASH(0x7f9e9b826a98)) called at /Users/me/perl5/perlbrew/perls/perl-5.16.3/lib/site_perl/5.16.3/darwin-2level/Moose/Meta/Class.pm line 284
    Moose::Meta::Class::new_object(Moose::Meta::Class=HASH(0x7f9e9b9e6990), HASH(0x7f9e9b826a98)) called at /Users/me/perl5/perlbrew/perls/perl-5.16.3/lib/site_perl/5.16.3/darwin-2level/Moose/Object.pm line 28
    Moose::Object::new("MyDir", "path", "/tmp") called at t.pl line 5

所以，不接受 'Str' 也不做强制。

以上几行有什么问题？我很确定这是一个非常小的错误，因为我遵循了 MooseX::Types 文档（至少我希望如此） - 但无法找到错误。

我开始对 Moose 真的绝望了，请帮助...

Ps：我的目标是在一个地方（包）定义我自己的所有“类型”，并在需要它们的任何地方使用它，只需一次“使用...”。

Answer 1

您需要告诉 Moose 可以在该属性上使用强制转换。为此，您可以在属性定义中添加 coerce：

has 'path' => (
    is => 'ro',
    isa => Dir,      # Dir is defined in the package MyTypes
    required => 1,
    coerce => 1,
    );