Fwd: Design with Visitor

[This message was incorrectly sent to the bounces address. I'm
forwarding it to the list on behalf of Mathieu.  -Bob]


Subject: Design with Visitor
From: "Mathieu SUEN" <mathk.sue@xxxxxxxxx>
Date: Wed, 24 May 2006 23:14:58 +0200
To: beginners-bounces@xxxxxxxxxxxxxxxxxxxxxxxxxx

Hi squeakers,

I have to build  a lite code for home work.
The objective is to gave to user a possibility to store his sport
performance.

So I have design a Class Performance(with PerformanceCollection) and I
wanted to let things like TimeLaps, Date, Distance, and so on.
for a later implementation (if we wanted to add others).

So I provide a Measure abstract  class.

Hence I add a dictionary in my Performance with the class for key and
the instance for value:

for example:

Performance>>addMeasure: aMeasure
          dictionaryOfMesure at: aMeasure class put: aMeasure

Now I have to bring them in a Seaside UI so I guess that Visitor Pattern
( ;-) ) can help me but my complex structure mess my brain.
So I ask you if you think that can be possible(and how) or other pattern
can be more suitable for this problem.

Thank you for your attention (: