On Wed, 28 Jul 2004 20:08:28 +0200 Han-Wen Nienhuys <[EMAIL PROTECTED]> wrote:
> [EMAIL PROTECTED] writes:
> >
> > See: "Design Patterns" by Erich Gamma, Richard Helm, Ralph Johnson
> and
> > John Vlissides ("gang of four"), Addison-Wesley, 1995. ISBN
> 0-201-63361-2.
> >
> > A must-have book for software designers! (Actually, this book
> motivated a
> > whole bunch of other books by various authors over the last couple of
>
> > years, some of which you may also find to be interesting.)
>
> I am a skeptic of the whole concept of "pattern." Until someone can
> give a proper formalization of the concept, I will just solve the
> problem at hand with whatever technique I feel is appropriate.
>
> In other words, if you can explain me why what "An observer pattern"
> is, and why it would solve the engraver broadcast/acknowledge better,
> I will consider using it. (No, I don't feel inclined to read the book).
>
> --
>
> Han-Wen Nienhuys | [EMAIL PROTECTED] |
> http://www.xs4all.nl/~hanwen
They are simple:
- Chain of Responsibility means just 'put the output of a function as the input
of the next function', and
- Observer Pattern means that you have several 'observators' which keep track on
their state. When a certain state is present on an observer, the observer
notifies another observer, and the another one then fetches the changed state
and reacts according to the changed state.
Design patterns are nice in the sense that they are the 'building blocks' of an
UML diagram and manage to describe data flow to some extent (as a 2D diagram).
Another family are the very commonly used resign pattern, which are to be avoided ;)
http://www.dcc.unicamp.br/~oliva/fun/prog/resign-patterns
--
Heikki Junes
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