Beefy Boxes and Bandwidth Generously Provided by pair Networks
We don't bite newbies here... much

comment on

( #3333=superdoc: print w/replies, xml ) Need Help??

On Saturday, June 23rd, Damian Conway had a little free-for-all workshop that he gave at College of DuPage in Wheaton, IL. Although the whole day was fascinating, the most useful part for me was his discussion of ``Ten criteria for knowing when to use object-oriented design''. Apparently, Damian was once a member of Spinal Tap, because his list goes to eleven.

Damian said that this list, in expanded form, is going to be part of the standard Perl distribution soon.

  1. Design is large, or is likely to become large
  2. When data is aggregated into obvious structures, especially if there's a lot of data in each aggregate
    For instance, an IP address is not a good candidate: There's only 4 bytes of information related to an IP address. An immigrant going through customs has a lot of data related to him, such as name, country of origin, luggage carried, destination, etc.
  3. When types of data form a natural hierarchy that lets us use inheritance.
    Inheritance is one of the most powerful feature of OO, and the ability to use it is a flag.
  4. When operations on data varies on data type
    GIFs and JPGs might have their cropping done differently, even though they're both graphics.
  5. When it's likely you'll have to add data types later
    OO gives you the room to expand in the future.
  6. When interactions between data is best shown by operators
    Some relations are best shown by using operators, which can be overloaded.
  7. When implementation of components is likely to change, especially in the same program
  8. When the system design is already object-oriented
  9. When huge numbers of clients use your code
    If your code will be distributed to others who will use it, a standard interface will make maintenence and safety easier.
  10. When you have a piece of data on which many different operations are applied
    Graphics images, for instance, might be blurred, cropped, rotated, and adjusted.
  11. When the kinds of operations have standard names (check, process, etc)
    Objects allow you to have a DB::check, ISBN::check, Shape::check, etc without having conflicts between the types of check.

In reply to Damian Conway's ten rules for when to use OO by petdance

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, 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, 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.
  • Log In?

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

    How do I use this? | Other CB clients
    Other Users?
    Others surveying the Monastery: (4)
    As of 2021-03-01 07:55 GMT
    Find Nodes?
      Voting Booth?

      No recent polls found