Indeed it works now, I think the problem I had was that I was defining the List before the Thing in the list.
Ive also upgraded today so that may have helped too. Thanks Tom Howe Morgan Stanley | Technology 25 Cabot Square | Canary Wharf | Floor 03 London, E14 4QA Phone: +44 20 7425-9380 tom.h...@morganstanley.com > -----Original Message----- > From: John Napiorkowski [mailto:jjn1...@yahoo.com] > Sent: 15 January 2009 14:43 > To: Howe, Tom (IT); moose@perl.org > Subject: RE: Possible to use coerce and auto_deref? > > > > > --- On Thu, 1/15/09, Howe, Tom (IT) > <tom.h...@morganstanley.com> wrote: > > > From: Howe, Tom (IT) <tom.h...@morganstanley.com> > > Subject: RE: Possible to use coerce and auto_deref? > > To: jjn1...@yahoo.com > > Date: Thursday, January 15, 2009, 9:29 AM unfortunately auto_deref > > wont work on a custom type, it needs to be ArrayRef[..] > > Hmm, I would think this should work, given that the source > code checks 'is_a_type_of' not that actual type name. If > that doesn't work for you, I would write a test case to prove > it and submit it. > > --john > > > > > I'm using Types to manage them which is handy but does cause some > > cyclical issues. > > > > I seem to have got around it for now - It seems that it makes a big > > difference where you put your 'use's. > > > > > > > > > > > > > > > -----Original Message----- > > > From: John Napiorkowski [mailto:jjn1...@yahoo.com] > > > Sent: 15 January 2009 14:22 > > > To: Howe, Tom (IT) > > > Subject: Re: Possible to use coerce and auto_deref? > > > > > > > > > > > > > > > --- On Wed, 1/14/09, Howe, Tom (IT) > > > <tom.h...@morganstanley.com> wrote: > > > > > > > From: Howe, Tom (IT) > > <tom.h...@morganstanley.com> > > > > Subject: Possible to use coerce and auto_deref? > > > > To: "Sartak" <sar...@gmail.com> > > > > Cc: ch...@prather.org, "Yuval Kogman" > > <nothingm...@woobling.org>, > > > > "Stevan Little" > > <stevan.lit...@iinteractive.com>, moose@perl.org > > > > Date: Wednesday, January 14, 2009, 1:06 PM I have > > something > > > like this: > > > > > > > > subtype 'Thing' > > > > => as 'Object' > > > > => where { $_->isa('ThingClass') > > }; > > > > > > > > coerce 'Thing' > > > > => from 'Str' > > > > => via { ThingClass->new ( xyz=> $_ ) > > }; > > > > > > > > > > > > has 'things' => ( > > > > is=>'rw', > > > > isa=>'ArrayRef[Thing]', > > > > lazy=>1, > > > > coerce=>1, > > > > auto_deref=>1, > > > > default => sub { [] }, > > > > }; > > > > > > Try, > > > > > > subtype 'Thing' > > > => as 'Object' > > > => where { $_->isa('ThingClass') }; > > > > > > coerce 'Thing' > > > => from 'Str' > > > => via { ThingClass->new ( xyz=> $_ ) }; > > > > > > subtype 'ThingList', > > > as 'ArrayRef[Thing]' > > > > > > coerce 'ThingList', > > > from 'ArrayRef[Str]', > > > via { > > > [ThingClass->new(xyz=>$_) for @$_]; > > > }; > > > > > > Right now 'deep' coercions, that is coercions > > that coerce > > > elements inside parameterized and structured types, > > are not > > > automatically applied. There's been lengthy > > discussion about > > > this and although at first blush seems useful you > > quickly get > > > into crazy edge cases. > > > > > > So for now if you want them, you'll need to do the > > extra > > > lifting. Consider something like MooseX::Types or at > > least > > > put your types and coercions into a separate library, > > that > > > will help you organize and reuse. > > > > > > John > > > > > > > > > > > > > > > But if I pass in a list of strings to convert to > > Things, I get the > > > > error: > > > > > > > > "Cannot coerce without a type coercion" > > > > > > > > I've managed to get around it by defining a > > type 'ArrayRef[Thing]' > > > > > > > > Eg > > > > Subtype 'ArrayRef[Thing]' > > > > => as 'ArrayRef' > > > > => where { > > > > foreach (@{$_} .... > > > > }; > > > > > > > > Coerce 'ArrayRef[Thing]' > > > > => from 'ArrayRef' > > > > > > > > But this means > > > > A) I'm essentially reimplementing ArrayRef > > each time. > > > > B) It always coerces! > > > > > > > > It should ideally check before it coerces... > > > > > > > > Anything I can do to improve on this? > > > > > > > > > > > > > > > > > > > > > > > > Also, I'd like to be able to declare > > something like > > > > > > > > has 'foo' => ( is=>'rw', > > > > delegate=> sub { Foo->instance }, handles > > =>[qw/x y z/] ) > > > > > > > > Where, if no value is passed in to foo() on > > construction, > > > the accessor > > > > created for foo() will always trigger the > > delegate sub but will not > > > > store anything in the object in the way default > > does. > > > > > > > > > > > > I tried this .. > > > > > > > > has 'foo' => ( is=>'rw', > > > > isa=>'Object', handles=> [qw/meth1 > > meth2 meth3/]); > > > > > > > > around 'foo' => sub { > > > > my ($next,$self,@args) = @_; > > > > if (@args) { > > > > return $self->$next(@args); > > > > } else { > > > > return $self->$next() || > > Foo->instance(); > > > > } > > > > }; > > > > > > > > But got error: > > > > > > > > Cannot delegate meth1 to meth1 because the value > > of foo is not > > > > defined... > > > > > > > > > > > > Is there some way to do this? > > > > > > > > Thanks > > > > > > > > Tom > > > > > > > > > > > > > > > > > -----Original Message----- > > > > > From: Sartak [mailto:sar...@gmail.com] > > > > > Sent: 07 January 2009 12:39 > > > > > To: Howe, Tom (IT) > > > > > Cc: ch...@prather.org; Yuval Kogman; Stevan > > Little; > > > > moose@perl.org > > > > > Subject: Re: Possible to disable/rename > > meta() method > > > > > > > > > > On Wed, Jan 7, 2009 at 4:49 AM, Howe, Tom > > (IT) > > > > > <tom.h...@morganstanley.com> wrote: > > > > > > Would be nice to be able to optionally > > rename or > > > > prefix it. > > > > > > > > > > > > I don't think a object meta class > > should add > > > > methods to the > > > > > main interface unless the object > > specifically needs to > > > > expose them. > > > > > > > > > > > > So by default there could be a > > _moose_meta() > > > > method and an > > > > > easy way to create a meta() -> > > _moose_meta() > > > > handler if > > > > > required (per class). This could be a global > > option if > > > > want > > > > > to retain compatibility with existing > > modules that > > > > require it. > > > > > > > > > > Yes, we all agree that it would be useful to > > give > > > > users the > > > > > ability to rename or not install a meta. The > > problem > > > > is that > > > > > in quite a few places in Class::MOP, Moose, > > and all of MooseX, we > > > > > call $pkg->meta with the expectation > > > > that it'll be > > > > > there and return the metaclass. > > > > > > > > > > It's just a small design problem, one we > > can fix > > > > with enough > > > > > grunt work. :) > > > > > > > > > > > > > > > > > Thanks > > > > > > > > > > Shawn > > > > > > > > > > > Ps. How do I subscribe to the mail > > list? > > > > > > > > > > Send mail to moose-subscr...@perl.org. > > > > > > > > > > > -------------------------------------------------------- > > > > > > > > NOTICE: If received in error, please destroy and > > notify > > > sender. Sender > > > > does not intend to waive confidentiality or > > privilege. Use of this > > > > email is prohibited when received in error. > > > > > > > > > > > > > > -------------------------------------------------------- > > > > NOTICE: If received in error, please destroy and notify > sender. Sender > > does not intend to waive confidentiality or privilege. Use of this > > email is prohibited when received in error. > > > > -------------------------------------------------------- NOTICE: If received in error, please destroy and notify sender. Sender does not intend to waive confidentiality or privilege. Use of this email is prohibited when received in error.
