From phf at cs.jhu.edu  Thu Sep 15 02:00:14 2005
From: phf at cs.jhu.edu (=?ISO-8859-1?Q?Peter_Fr=F6hlich?=)
Date: Thu, 15 Sep 2005 02:00:14 -0400
Subject: [Patterns] Hello?
Message-ID: <62afbf0ce1fefd55bc288377600ebed3@cs.jhu.edu>

Hi all,

Well, actually I don't know about "all," is anyone here? :-) Even if 
not, thanks for showing up for the first meeting, which already started 
to get "intense" in the most unexpected ways (and only in good ways of 
course :-).

As I said, next week I'd like to briefly catch any remaining issues 
from chapter 1 regarding the basic OO principles, but then focus on 
chapter 2 which is their big motivating case study. This means that 
they'll explain *lots* of patterns on a fairly high level and 
illustrate their utility in the specific example system.

In terms of our discussion, I'd suggest focussing on the big picture, 
not on too many individual patterns (we have the rest of the semester 
for that). So I'd like to consider the overall benefits and problems 
anyone can see with using these patterns, whether any of these benefits 
are more accidental to the chosen system, and maybe some of the 
implications of patterns for the overall architecture of the system.

Feel free to disagree of course, it's not just "my" study group, it's 
"yours" as well. :-) If anything else comes up before the next meeting 
(maybe while you're reading the chapters) feel free to email the list 
and start chatting.

Cheers,
Peter
--
Peter H. Froehlich <><><><><><> http://www.cs.jhu.edu/~phf/
OpenPGP: ABC2 9BCC 1445 86E9 4D59  F532 A8B2 BFAE 342B E9D9


From phf at cs.jhu.edu  Mon Sep 26 01:54:07 2005
From: phf at cs.jhu.edu (=?ISO-8859-1?Q?Peter_Fr=F6hlich?=)
Date: Mon, 26 Sep 2005 01:54:07 -0400
Subject: [Patterns] From Promit on Monostate
Message-ID: <930fce7fee54ad01b8e3352d92832b4b@cs.jhu.edu>

FYI...

> From: Promit Roy <promit at jhu.edu>
> Date: September 23, 2005 02:09:11 EDT
> To: patterns at cs.jhu.edu
> Subject: Monostates
>
> So, I looked up a few articles describing the monostate pattern.
>
> http://www.objectmentor.com/resources/articles/ 
> SingletonAndMonostate.pdf --  this is a particularly nice doc on both  
> singletons and monostates.
>
> Short blurb:
> To recap, the singleton pattern structurally enforces the fact that  
> you can never have more than one instance of a class at a time, and it  
> is obvious to the developers that they are dealing with a singleton.  
> On the other hand, the monostate pattern enforces the behavior of a  
> singleton without the structure of a singleton, e.g., the singleton  
> behavior is encapsulated from the developers.
>
> So why choose one over the other?
>
> "If you plan on deriving classes from the singleton and you want those  
> classes to be singletons, your better choice is monostate. That's  
> because all classes derived from a monostate are monostates. Classes  
> derived singleton classes are not singletons by default. You would  
> have to add the static method and attribute to each derived class."
>
> Some other articles:
> http://www.devx.com/getHelpOn/10MinuteSolution/16361
> http://www.informit.com/guides/content.asp?g=cplusplus&seqNum=147&rl=1
>
> Promit
--
Peter H. Froehlich <><><><><><> http://www.cs.jhu.edu/~phf/
OpenPGP: ABC2 9BCC 1445 86E9 4D59  F532 A8B2 BFAE 342B E9D9


From phf at cs.jhu.edu  Mon Sep 26 02:05:38 2005
From: phf at cs.jhu.edu (=?ISO-8859-1?Q?Peter_Fr=F6hlich?=)
Date: Mon, 26 Sep 2005 02:05:38 -0400
Subject: [Patterns] Reminder: Patterns for next Meetings...
Message-ID: <eeed8c86b266653d74e844a9268b2c8a@cs.jhu.edu>

Hi all,

Sorry that I have not updated the website yet, I will... :-) Here's 
just a short reminder on what we've set as our schedule:

   Week 3: Singleton, Monostate, and Pools (only Singleton is from the 
book)
   Week 4: Observer and Mediator (both from the book)
   Week 5: Composite and Visitor (both from the book)

I hope I remember this correctly? Let me know if not... :-) I hope that 
the links Promit sent on Monostate are good for preparing that topic. 
As for pools, here's a summary that's decent:

   http://www.developer.com/java/other/article.php/626171

Here are two more Java-specific articles:

   http://www.javaworld.com/javaworld/jw-06-1998/jw-06-object-pool.html
   http://www.javaworld.com/javaworld/javatips/jw-javatip78.html

There are some connections between pools and factories, as well as 
between pools and flyweights. I guess we'll get to some of those in the 
conversation. :-)

Cheers,
Peter
--
Peter H. Froehlich <><><><><><> http://www.cs.jhu.edu/~phf/
OpenPGP: ABC2 9BCC 1445 86E9 4D59  F532 A8B2 BFAE 342B E9D9