Re: attr initializers (Class::MOP and Moose)

Ricardo,

As mentioned in #moose, I very much like this idea. I do have a few  
questions ...

On Feb 6, 2008, at 12:18 PM, Ricardo SIGNES wrote:
> The initializer may be a coderef or a method name (referring to a  
> method on the
> instance.)  It's called like this:
>
>   $instance->$initializer($value, $name, $callback);

What is $name for again?

> The callback, when called, will set the instance slot to the passed- 
> in value.
> It makes it easy to have your initializer do the "hard" work  
> without having to
> worry about going through the several chains of methods needed to  
> set a slot
> value.  The example in the tests should look something like this:
>
>   package Example;
>   use Moose;
>
>   has foo => (
>     is => 'rw',
>     initializer => sub {
>       my ($self, $value, $name, $callback) = @_;
>       $callback->($value * 2);
>     }
>   );

I wonder if callback could be optional? And if it is not called, then  
it will just use the return value of the initializer sub?

> I think, but have not tested, that this will also work:
>
>   package Example;
>   use Moose;
>
>   has foo => (
>     is => 'rw',
>     setter      => 'set_foo',
>     initializer => 'set_foo',
>   );

What exactly would that be useful for? I am not sure I understand  
without seeing an example set_foo.

- Stevan