Beefy Boxes and Bandwidth Generously Provided by pair Networks
Your skill will accomplish
what the force of many cannot
 
PerlMonks  

comment on

( [id://3333]=superdoc: print w/replies, xml ) Need Help??

It's difficult to get roles and attributes to play nice. Attributes basically have two parts to the implementation:

  1. They need to be initialized in the constructor; and

  2. You need to provide accessors for them.

The accessors are easy. But your role framework doesn't have any control over the constructor; the constructor gets built by the class framework!

That's why if you look at Perl implementations of roles, you'll see them fall into two neat categories:

  • Moose::Role, Mouse::Role, Moo::Role, and p5-mop roles all allow you to define attributes in roles.

    These role implementations are all part of larger frameworks that include a class builder.

  • Role::Tiny and Role::Tiny do not allow you to define attributes in roles.

    These role implementations are stand-alone.

So basically, if you want to write a role implementation that supports attributes, you'll need to write a class implementation to support it.

I'm not saying you shouldn't do it. It's a good learning experience.

use Moops; class Cow :rw { has name => (default => 'Ermintrude') }; say Cow->new->name

In reply to Re^3: Object::InsideOut and Roles/Mixins by tobyink
in thread Object::InsideOut and Roles/Mixins by Yary

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post; it's "PerlMonks-approved HTML":



  • Are you posting in the right place? Check out Where do I post X? to know for sure.
  • Posts may use any of the Perl Monks Approved HTML tags. Currently these include the following:
    <code> <a> <b> <big> <blockquote> <br /> <dd> <dl> <dt> <em> <font> <h1> <h2> <h3> <h4> <h5> <h6> <hr /> <i> <li> <nbsp> <ol> <p> <small> <strike> <strong> <sub> <sup> <table> <td> <th> <tr> <tt> <u> <ul>
  • Snippets of code should be wrapped in <code> tags not <pre> tags. In fact, <pre> tags should generally be avoided. If they must be used, extreme care should be taken to ensure that their contents do not have long lines (<70 chars), in order to prevent horizontal scrolling (and possible janitor intervention).
  • Want more info? How to link or How to display code and escape characters are good places to start.
Log In?
Username:
Password:

What's my password?
Create A New User
Domain Nodelet?
Chatterbox?
and the web crawler heard nothing...

How do I use this?Last hourOther CB clients
Other Users?
Others chilling in the Monastery: (5)
As of 2024-03-29 13:33 GMT
Sections?
Information?
Find Nodes?
Leftovers?
    Voting Booth?

    No recent polls found