perl – Moose深度强制 – 用户定义类型的ArrayRef

发布时间：2020-12-15 21:45:09 所属栏目：大数据来源：网络整理

导读：我在以下子类型和强制链中缺少什么？我希望能够强制验证类型的arrayref或死于以下输入：强制字符串有效字符串具有混合强制和有效字符串的Arrayref 假设所有类型都是完全命名空间,并且未声明的函数validate和coerce_str validate(返回bool)并强制并分别从

我在以下子类型和强制链中缺少什么？我希望能够强制验证类型的arrayref或死于以下输入：

>强制字符串
>有效字符串
>具有混合强制和有效字符串的Arrayref

假设所有类型都是完全命名空间,并且未声明的函数validate和coerce_str validate(返回bool)并强制并分别从输入中返回有效字符串.

subtype 'CustomType'
  => as 'Str'
    => where { validate($_) }
  ;

coerce 'CustomType'
  => from 'Str'
    => via { if (my $coerced = coerce_str($_)) {
               return $coerced;
             } 
             return $_;
           }
  ;

subtype 'ArrayRefofCustomTypes'
  => as 'ArrayRef[CustomType]'
  ;

coerce 'ArrayRefofCustomTypes'
  => from 'CustomType'
    => via { [ $_ ] }
  ;

has 'values' => ( is => 'ro',required => 1,isa => 'ArrayRefofCustomTypes',coerce => 1,);

我知道CustomType有效;因为我可以定义一个属性,并使用强制字符串或已经有效的字符串初始化对象.我不确定该怎么做的是显式地处理从构造函数中传递到传递的arrayref并单独验证所有包含的字符串.我已经阅读了关于深度强制(http://search.cpan.org/dist/Moose/lib/Moose/Manual/Types.pod#Deep_coercion)的文档几次,我只是不太明白,我希望有人可以指出我正确的方向.谢谢！

在这里,我将其简化为更简洁的概述,但是：

{ 
  package My::Class;

  use strict;
  use warnings;

  use Moose;
  use Moose::Util::TypeConstraints;

  subtype 'CustomType'
    => as 'Str'
      => where { validate($_) }
    ;

  coerce 'CustomType'
    => from 'Str'
      => via { if (my $coerced = coerce_str($_)) {
                 return $coerced;
               } 
               return $_;
             }
    ;

  subtype 'ArrayRefofCustomTypes'
    => as 'ArrayRef[CustomType]'
    ;

  coerce 'ArrayRefofCustomTypes'
    => from 'CustomType'
      => via { [ $_ ] }
    ;

  has 'values' => ( is => 'ro',);

  sub validate {
    my $val = shift;
    if ($val =~ /^w+$/) {
      return 1;
    }
    return ();
  }

  sub coerce_str {
    my $val = shift;
    $val =~ s/W/_/g;
    return $val;
  }
}

{
  package main;

  use strict;
  use warnings;
  use Test::More qw/no_plan/;

  new_ok( 'My::Class' => [ values => [ 'valid' ] ]); #ok
  new_ok( 'My::Class' => [ values => [ qw/valid valid still_valid/ ] ]); #ok
  new_ok( 'My::Class' => [ values => 'valid' ]); # ok
  new_ok( 'My::Class' => [ values => [ 'invalid; needs some coercion - ^&%&^' ] ]); #not ok
  new_ok( 'My::Class' => [ values => 'invalid; needs some coercion - ^&%&^' ]); # not ok
  cmp_ok( My::Class::coerce_str('invalid; needs some coercion - ^&%&^'),'eq','invalid__needs_some_coercion________','properly coerces strings'); #ok

}

按原样运行给出了以下内容.问题不是验证,而是我没有明确定义我的强制,我不确定我缺少什么：

ok 1 - The object isa My::Class
ok 2 - The object isa My::Class
ok 3 - The object isa My::Class    
not ok 4 - new() died
#   Failed test 'new() died'
#   at testcoercion.pl line 63.
#     Error was:  Attribute (values) does not pass the type constraint because: Validation failed for 'ArrayRefofCustomTypes' with value [ "invalid; needs some coercion - ^&%&^" ] at C:/strawberry/perl/site/lib/Moose/Meta/Attribute.pm line 1131

<< cut >>

not ok 5 - new() died
#   Failed test 'new() died'
#   at testcoercion.pl line 64.
#     Error was:  Attribute (values) does not pass the type constraint because: Validation failed for 'ArrayRefofCustomTypes' with value "invalid; needs some coercion - ^&%&^" at C:/strawberry/perl/site/lib/Moose/Meta/Attribute.pm line 1131

<< cut >>

ok 6 - properly coerces strings
1..6
# Looks like you failed 2 tests of 6.

解决方法

你使用的一切都应该工作正常.例如,考虑这个测试：

my $customtype = Moose::Util::TypeConstraints::find_type_constraint('CustomType');
print "'a' validates as customtype? ",($customtype->check('a') ? 'yes' : 'no'),"n";

my $arraytype = Moose::Util::TypeConstraints::find_type_constraint('ArrayRefofCustomTypes');
print "[ 'a' ] validates as array? ",($arraytype->check([ 'a' ]) ? 'yes' : 'no'),"n";

{
    package Class;
    use Moose;
    has 'values' => ( is => 'ro',);
}

my $obj = Class->new(values => 'a');
print $obj->dump(2);

这打印：

'a' validates as customtype? yes
[ 'a' ] validates as array? yes
$VAR1 = bless( {
                 'values' => [
                               'a'
                             ]
               },'Class' );

结论：如果遇到问题,可以使用其他代码.你能粘贴一些不能按预期工作的代码吗？

（编辑：李大同）

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