From: Tobias Weber <towb@...>
Date: 2008-05-24T20:09:51+09:00
Subject: How to model something

Hi,
my programm needs to store persons. They have a weight and a gender. You 
are only allowed to ask males for their weight, females will throw 
dishes/exceptions. There *is* a method to change someones gender.

I could have 'if gender' in every accessor or use the state pattern. But 
that has no state, so I'm confused. I would have to access the variable 
in the wrapper class.

The programm can also shoot people into space, in which case the 
implementation of weight changes but the same restrictions apply.
The proxy pattern will help here, probably by having weight first call 
delegate.weight, and if that isn't NoMethodException multiplying with 
gravity.

Any advice or implementations of similar problems I could look at?

(and in reality people are TV series with 6 genders and 5 other 
attributes, and space is just but a remote place to store things)

-- 
  Tobias Weber