Moose＆isa ArrayRef

Question

我正在尝试使用Moose :: Meta :: Attribute :: Native :: Trait :: Array，但它看起来像ArrayRef helper不适用于我。贝娄是我的代码返回

Can't call method "add_item" on unblessed reference at bug.pl line 42.

我用驼鹿2.0007和Perl v5.10.1。 Moose :: Autobox已安装。 我会很感激任何建议。

#!/usr/bin/perl 

use strict; 

package CycleSplit; 
use Moose; 
has 'name'=>(isa=>'Str', is=>'rw'); 
has 'start'=>(isa=>'Num', is=>'rw'); 
has 'length'=>(isa=>'Num', is=>'rw'); 
1; 

package Cycle; 
use Moose; 
my @empty=(); 
has 'name' => (isa => 'Str', is => 'rw'); 
has 'splits' => (
    traits => ['Array'], 
    isa=>'ArrayRef[CycleSplit]', 
    is => 'rw', 
    default=>sub { [] }, 
    handles=>{ 
     add_item=>'push', 
    }, 
); 


no Moose; 
1; 

package Main; 

sub Main { 
    my $cyc=Cycle->new(); 
    $cyc->name("Days of week"); 

    for my $i (1..7) { 
     my $spl=CycleSplit->new(); 
     $spl->name("Day $i"); 
     $spl->start($i/7-(1/7)); 
     $spl->length(1/7); 
     $cyc->splits->add_item($spl); 
    } 

    my $text=''; 
    foreach my $spl ($cyc->splits) { 
     $text.=$spl->name." "; 
    } 

    print $text; 
} 

Main; 

Answer 1

handles将方法添加到类本身而不是属性。另一个问题是splits属性仍然是arrayref，因此您需要在几秒钟内解除引用foreach。更正后的代码如下：

sub Main { 
    my $cyc=Cycle->new(); 
    $cyc->name("Days of week"); 

    for my $i (1..7) { 
     my $spl=CycleSplit->new(); 
     $spl->name("Day $i"); 
     $spl->start($i/7-(1/7)); 
     $spl->length(1/7); 
     $cyc->add_item($spl);    # removed splits 
    } 

    my $text=''; 
    foreach my $spl (@{ $cyc->splits }) { # added array dereference 
     $text.=$spl->name." "; 
    } 

    print $text; 
}