Roles are the Perl way to ensure a class adheres to a certain design. In Linux you can OPEN a socket or a file or a device driver or whatever else. They are treated the same because they conform to a certain interface. You might want plug in different sorting algorithms without knowing the details of how they work. A role is just one language's implementation of a concept with the goals of reusing code, minimizing dependency, and designing with flexibility in mind. Sub classes and abstract classes have greater dependency because changing a parent class changes every child class. Often times you'll want to change behavior of a child object, but.. oh wait all that code is in the parent.

HackaMol - OO Perl for molecular hacking PDF explaining design

Add Dry-Run testing to classes

http://blogs.perl.org/users/ovid/2010/01/roles-without-moose.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! —

• How do I compose an effective node title?
• How do I post a question effectively?
• Markup in the Monastery

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:
	&		&
	<		&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.