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Re: How is this "pattern" called?

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On 5/18/2012 2:13 PM, Gene Wirchenko wrote:

>
>       I have tended to avoid using OOP patterns except for what I came
> up with myself.  I did try reading one of the OOP patterns books, but
> ugh!
> ...
>       If you *really* need that, fine, but I do not.


To me, this is the key part here.  If you actually get the Gang of Four 
book on patterns and read it -- and I mean read ALL of it, starting with 
the front inside cover -- it says in the *introduction* not to use the 
patterns exactly as presented, but to modify them to your particular 
requirements.  Patterns are there for you to get ideas from, but they 
are not laws that must be followed with out deviation.  You're still 
required to think when using any given pattern.

In addition, with each pattern (that I've read, at least), the GOF 
include a list of pro's and con's, and sometimes the cons are quite 
surprising.  For example the Visitor pattern doesn't work well when the 
nodes/tree to traverse under goes lots of changes.  The reason is that 
the Visitor pattern isolates the implementation for each node, and it 
can be a pain to go back into each implementation and add code for each 
new type of node.  They recommend not using the Visitor pattern at all 
in this circumstance.  Just use polymorphism and add the visitor API to 
each node directly.

*That* is the biggest advantage to patterns and their study, imo.  NOT 
"rah rah yay patterns" but telling you when using a pattern might leave 
you up a creek with no paddle.  It allows you to eliminate a broad swath 
of design space quickly and points you in a better direction.

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Re: How is this "pattern" called? Jim Janney <jjanney@shell.xmission.com> - 2012-05-18 10:03 -0600
  Re: How is this "pattern" called? Gene Wirchenko <genew@ocis.net> - 2012-05-18 10:50 -0700
    Re: How is this "pattern" called? markspace <-@.> - 2012-05-18 12:20 -0700
      Re: How is this "pattern" called? Gene Wirchenko <genew@ocis.net> - 2012-05-18 14:13 -0700
        Re: How is this "pattern" called? Patricia Shanahan <pats@acm.org> - 2012-05-18 14:35 -0700
          Re: How is this "pattern" called? Gene Wirchenko <genew@ocis.net> - 2012-05-18 15:29 -0700
            Re: How is this "pattern" called? Arne Vajhøj <arne@vajhoej.dk> - 2012-05-19 22:38 -0400
              Re: How is this "pattern" called? Lew <noone@lewscanon.com> - 2012-05-20 11:34 -0700
                Re: How is this "pattern" called? Arne Vajhøj <arne@vajhoej.dk> - 2012-05-20 14:59 -0400
                Re: How is this "pattern" called? Patricia Shanahan <pats@acm.org> - 2012-05-20 12:03 -0700
                Re: How is this "pattern" called? markspace <-@.> - 2012-05-20 13:19 -0700
                Re: How is this "pattern" called? Wanja Gayk <brixomatic@yahoo.com> - 2012-05-30 14:32 +0200
                Re: How is this "pattern" called? Lew <noone@lewscanon.com> - 2012-06-02 09:25 -0700
              Re: How is this "pattern" called? Gene Wirchenko <genew@ocis.net> - 2012-05-20 20:40 -0700
                Re: How is this "pattern" called? Wanja Gayk <brixomatic@yahoo.com> - 2012-05-30 14:33 +0200
          Re: How is this "pattern" called? Wanja Gayk <brixomatic@yahoo.com> - 2012-05-30 14:32 +0200
        Re: How is this "pattern" called? markspace <-@.> - 2012-05-18 15:28 -0700
        Re: How is this "pattern" called? Arne Vajhøj <arne@vajhoej.dk> - 2012-05-19 22:37 -0400
          Re: How is this "pattern" called? Gene Wirchenko <genew@ocis.net> - 2012-05-20 20:43 -0700
            Re: How is this "pattern" called? Lew <noone@lewscanon.com> - 2012-05-21 00:09 -0700
              Re: How is this "pattern" called? Gene Wirchenko <genew@ocis.net> - 2012-05-21 10:04 -0700
            Re: How is this "pattern" called? Wanja Gayk <brixomatic@yahoo.com> - 2012-05-30 23:58 +0200
    Re: How is this "pattern" called? Arne Vajhøj <arne@vajhoej.dk> - 2012-05-19 22:33 -0400
      Re: How is this "pattern" called? Gene Wirchenko <genew@ocis.net> - 2012-05-20 20:44 -0700
        Re: How is this "pattern" called? Lew <noone@lewscanon.com> - 2012-05-21 00:11 -0700

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