Bug #81816 for Moo: Default not set, and dies in BUILD(), when used with Moo::Role

Sat Dec 08 18:38:33 2012 RSAVAGE [...] cpan.org - Ticket created

Subject:

Default not set, and dies in BUILD(), when used with Moo::Role

See attached. Unpack and run: perl -Ilib scripts/test.pl Output (3 lines): ron@zigzag:~/perl.modules/Local-MooDemo1$ perl -Ilib scripts/test.pl Use of uninitialized value in say at lib/Local/MooDemo1.pm line 24. Initial value of config: ron@zigzag:~/perl.modules/Local-MooDemo1$ Comment out line 7: use Moo::Role; and the scripts runs ok.

Subject:

Local-MooDemo1-1.00.tar.gz

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Sat Dec 08 19:29:49 2012 perl [...] toby.ink - Correspondence added

I'm not especially surprised this doesn't work. Moo and Moo::Role aren't really intended to be imported into the same package. Of course raising a compile-time error would be nice.

Sat Dec 08 19:29:51 2012 The RT System itself - Status changed from 'new' to 'open'

Sat Dec 08 19:31:10 2012 perl [...] toby.ink - Correspondence added

Here's a smaller test case... use strict; use warnings; use Test::More tests => 1; { package Local::Test; use Moo; use Moo::Role; has attr => ( is => 'ro', default => sub { 1 }, required=>0, ); sub BUILD { my $self = shift; $self->attr + 1; } } new_ok 'Local::Test';

Sat Dec 08 20:13:50 2012 ron [...] savage.net.au - Correspondence added

Subject:	Re: [rt.cpan.org #81816] Default not set, and dies in BUILD(), when used with Moo::Role
Date:	Sun, 09 Dec 2012 12:08:18 +1100
To:	bug-Moo [...] rt.cpan.org
From:	Ron Savage <ron [...] savage.net.au>

Hi Toby On 09/12/12 11:29, Toby Inkster via RT wrote: Show quoted text

> <URL: https://rt.cpan.org/Ticket/Display.html?id=81816> > > I'm not especially surprised this doesn't work. Moo and Moo::Role aren't > really intended to be imported into the same package.

What then is the solution/alternative to wanting to use Moo/Other to create the class and Moo::Role/Other to make it a role? Show quoted text

> Of course raising a compile-time error would be nice.

Documenting the problem would be nice too..... -- Ron Savage http://savage.net.au/ Ph: 0421 920 622

Sat Dec 08 20:31:34 2012 perl [...] toby.ink - Correspondence added

Show quoted text

> What then is the solution/alternative to wanting to use Moo/Other to > create the class and Moo::Role/Other to make it a role?

Ultimately it's the same solution as when you want to create a combination paring knife and childs' toy. Stop wanting that. That said, there is a hack to make it work. Define your package (let's assume it's called "Foo") as a Moo::Role, then at the *end* of the package add: our @ISA = do { package Foo::_; use Moo; with 'Foo'; __PACKAGE__ }; I'll leave figuring out why that works as an exercise for the reader. :-)

Sat Dec 08 21:26:58 2012 ron [...] savage.net.au - Correspondence added

Subject:	Re: [rt.cpan.org #81816] Default not set, and dies in BUILD(), when used with Moo::Role
Date:	Sun, 09 Dec 2012 13:21:23 +1100
To:	bug-Moo [...] rt.cpan.org
From:	Ron Savage <ron [...] savage.net.au>

Hi Toby On 09/12/12 12:31, Toby Inkster via RT wrote: Show quoted text

> <URL: https://rt.cpan.org/Ticket/Display.html?id=81816> >

>> What then is the solution/alternative to wanting to use Moo/Other to >> create the class and Moo::Role/Other to make it a role?

> > Ultimately it's the same solution as when you want to create a > combination paring knife and childs' toy. Stop wanting that.

He, he, he. Show quoted text

> That said, there is a hack to make it work. Define your package (let's > assume it's called "Foo") as a Moo::Role, then at the *end* of the > package add: > > our @ISA = do { package Foo::_; use Moo; with 'Foo'; __PACKAGE__ }; > > I'll leave figuring out why that works as an exercise for the reader. :-)

Reversal of roles? My hack will be to drop Moo::Role, and use 'extends'. Thanx. I'd better start re-writing my article. Mega-pain. -- Ron Savage http://savage.net.au/ Ph: 0421 920 622

Sun Dec 09 07:42:42 2012 perl [...] toby.ink - Correspondence added

This branch on git provides an exception when somebody tries to create a package that is both a Moo class and a Moo role: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?p=gitmo/ Moo.git;a=shortlog;h=refs/heads/moo-chimera-warning-rt81727

Sun Dec 09 19:18:12 2012 ron [...] savage.net.au - Correspondence added

Subject:	Re: [rt.cpan.org #81816] Default not set, and dies in BUILD(), when used with Moo::Role
Date:	Mon, 10 Dec 2012 11:12:36 +1100
To:	bug-Moo [...] rt.cpan.org
From:	Ron Savage <ron [...] savage.net.au>

Hi Toby On 09/12/12 23:42, Toby Inkster via RT wrote: Show quoted text

> <URL: https://rt.cpan.org/Ticket/Display.html?id=81816> > > This branch on git provides an exception when somebody tries to create a > package that is both a Moo class and a Moo role: > > http://git.shadowcat.co.uk/gitweb/gitweb.cgi?p=gitmo/ > Moo.git;a=shortlog;h=refs/heads/moo-chimera-warning-rt81727

Great idea. $many x $thanx; -- Ron Savage http://savage.net.au/ Ph: 0421 920 622

Sat Dec 15 16:35:21 2012 rt-cpan [...] trout.me.uk - Correspondence added

On Sun Dec 09 19:18:12 2012, ron@savage.net.au wrote: Show quoted text

> Hi Toby > > > On 09/12/12 23:42, Toby Inkster via RT wrote:

> > <URL: https://rt.cpan.org/Ticket/Display.html?id=81816> > > > > This branch on git provides an exception when somebody tries to create a > > package that is both a Moo class and a Moo role: > > > > http://git.shadowcat.co.uk/gitweb/gitweb.cgi?p=gitmo/ > > Moo.git;a=shortlog;h=refs/heads/moo-chimera-warning-rt81727

> > Great idea. $many x $thanx;

Released in 1.0.7 Cheers gentlemen.

Sat Dec 15 16:35:23 2012 rt-cpan [...] trout.me.uk - Status changed from 'open' to 'resolved'