MooseX::Declare and Moose subtypes

[Anonymous Monk]

Dear Perl Monks,

I am trying to use the new MooseX::Declare syntax, in conjunction with Moose subtypes. Here is my code:

use strict;
use v5.10;

use MooseX::Declare;
use Moose::Util::TypeConstraints;

subtype 'PositiveInt'
    => as 'Int'
    => where { $_ > 0 }
    => message { "Number '$_' is not positive" };
    

class BankAccount {
    use MooseX::StrictConstructor;
    
    has balance => ( isa => 'Int', is => 'rw', default => 0 );
    
    method deposit ( PositiveInt :$amount ) {
        $self->balance( $self->balance + $amount );
    }
}


my $a = BankAccount->new( balance => 100 );

$a->deposit( amount => 50 );

say $a->balance;

This code gives the following error when executed:

'PositiveInt' could not be parsed to a type constraint - maybe you nee
+d to pre-declare the type with class_type at /home/moose/perl5/lib/pe
+rl5/MooseX/Declare/Syntax/MethodDeclaration.pm line 40

I haven't been able to find a class_type() method in the MooseX::Declare documentation. Could someone enlighten me about what should be done ?

Thank you in advance

[merlyn]

Your problem is compile-time vs run-time. The subtype isn't being created until runtime, but it needs to be present at compiletime when you get to the method header. Solution: use BEGIN or put it in a separate file and "use" the file.

[Anonymous Monk]

This works ! This is awesome !

Thanks !!!