Re: A working document

On Fri, 21 Dec 2001, Anthony Mallet wrote:

[...]
> | 3) Are codels pure code? (no data structures). That would imply =
> | disjunction between code and data which is contrary to object oriented =
> | paradigm, which has its benefits.
>
> Yes, definitely. Codels are made of code, and perform tasks on data that
> come from elsewhere.
>
> The purpose of modules is to give a specification of their interface in
> terms of functionality, so that the decision procedures can do symbolic
> reasonning. Besides this, you are free to put what you need into the
> codels. For instance, I see no problem in sharing the same class between
> several modules, and thus use a pure object oriented approach _within_
> codels, to manipulate the structure that are exchanged between the
> modules.

Mmmm, I really don't like this too much: you have no encapsulation of
the data in this way, and that will lead to
uncontrolled/undeterministic behaviour sooner or later. I mean: a
codel can not rely on having a consistent view on the data, if this
data is ``somewhere else''...

[...]
> | 5) The question wether communication should be handled within codels or =
> | outside I would answer in favour of - inside. After all we want to hide =
> | from the user all the unnecessary details - he/she should concentrate on =
> | the task not on the communication details. Maybe special communication =
> | codels would do the trick (an intermediate solution).
>
> I completely agree with you on the fact that communication should not be
> left to the user (user = module programmer). This is exactly why I think
> that communication should _not_ be defined within codels: codels are the
> only part the programmer will write. The communication should be handled
> by the module internal engine (which is roughly the same for all modules,
> and thus it is generic and written only once).
> Are you ok with this?

This seems to correspond to what I had in mind: the ``dummy user''
doesn't have to take care about communication, but the ``advanced
user/application builder'' does. Both use different codels, I guess.

Herman