[Newbies] Design best practice : put state-independent methods onclass side?

David Mitchell david.mitchell at gmail.com
Tue Mar 25 20:47:32 UTC 2008

(forgot to copy the list)

Classes are certainly well known, but not the only way to get a well
 known object.

 My pragmatic issue with using class side methods for Singletons is
 that it is a bunch of work to refactor the class side behavior to
 instance side later. Look at the original PWS server for a squeak
 specific example.

 My design issue is that classes are for making instances (technically
 for defining behavior of instances). Making them the building block of
 the program means that I'm giving them extra responsibility. I like to
 keep the responsibility list as small as possible.

 (Someone walked off with my Design Patterns Smalltalk Companion, which
 wrote about these issues better than I can.)

 On Tue, Mar 25, 2008 at 2:51 PM, Ramon Leon <ramon.leon at allresnet.com> wrote:
 > > I'm guessing you like that the class methods can be invoked
 >  > easily from the class name. What you want is a well known object.
 >  Like a class?
 >  > I wouldn't use a class object just to create a well known
 >  > object. I'd probably start with a Singleton and work from there.
 >  Like a class?  Classes are singletons, what do you have against using them
 >  as such?
 >  Ramon Leon
 >  http://onsmalltalk.com

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