I actually always use accesors when dealing with attributes to allow for subclasses to override how they wish to deal with an attribute.

But that brings us back the the whole public/private/protected/friend issue of encapsulation of data in Perl objects (or lack thereof). If what Perl Mouse describes as a class's "own data" is private data specific to the implementation, then it's perfectly acceptable not to use an accessor -- though that may limit the ability of a subclass. (Not all classes need to be subclassable.) If subclassing is desireable, then it may make sense to implement "protected" accessor/mutators that can only be called by subclasses -- at least for data which pertain to general properties of the object which would be relevant to subclasses.

One benefit of inside-out objects for OO purists is that such subclassability must be made explicit. By default (under the most commonly-seen implementations, anyway), all properties are lexicals and thus private and can be used directly. Accessors/mutator need only be written when it makes sense for the interface, whether that is fully public or only for subclasses.

Any inside-out object generating module that automatically defaults to creating accessors/mutators for all properties defeats this benefit of inside-out objects towards encouraging "good" design. <cough>Class::Std</cough> (whoops -- misread the docs)

-xdg

Code written by xdg and posted on PerlMonks is public domain. It is provided as is with no warranties, express or implied, of any kind. Posted code may not have been tested. Use of posted code is at your own risk.

In reply to Re^4: Perl OO and accessors by xdg
in thread Perl OO and accessors by dragonchild

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


  • Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
  • Titles consisting of a single word are discouraged, and in most cases are disallowed outright.
  • Read Where should I post X? if you're not absolutely sure you're posting in the right place.
  • Please read these before you post! —
  • Posts may use any of the Perl Monks Approved HTML tags:
    a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)
            For:     Use:
    & &amp;
    < &lt;
    > &gt;
    [ &#91;
    ] &#93;
  • Link using PerlMonks shortcuts! What shortcuts can I use for linking?
  • See Writeup Formatting Tips and other pages linked from there for more info.