Re: multiple inheritance

Lebesque,

Thanks for your patience with the length of my response. Loved the
proposed approach which (for brevity) I'll call the PI (Pseudo
Inheritance) design technique. I recoded and experimented with this
approach this weekend.

Comparing 'PI' to 'MI' (after coding) my executive summary (short form)
of the differences as follows.

----------

1. Top level specification of state space in multiple inheritance

A. The PI design technique is a wrapper for functionality around
pre-existing state space.

B. MI allows (obviously) state and functional (static and dynamic) inheritance

C. The PI technique offered (by Lebesque) is a 'functional inheritance'
(dynamic component) high cost approach.

D. The approach fails if the inherited state space (static component) is
intrinsic to the target functionality.

2. Therefore - (e.g. Child_cls is Parent_cls and "kind of is" House_cls).

A. Dynamically true
B. Statically false

C. Which is a formal agreement of your phrase '(e.g. A is C and "kind of is"
B)'.

D. The 'kind of' is a logical marker for the PI non-inheritance of
functional state space.

----------

Since I use MI for 'top level specifications' (as above) my use of PI
would be as a 'functional wrapper'. As a 'functional wrapper' on
pre-existing state space its a good approach if all you needed was a small
wrapping functionality around a pre-existing state space.

I have a follow up to this (post) if it is of interest. It has your code
redone to prove the 2.A, 2.B assertions above. The proff also shows the
severe limitations of C# as a strategic migration tool to factor out common
code. It brings out in code the 'kind of' (see above) inheritance
architecture flaw in C#.

To restate: The re-write of your code shows the 'statically false' assertion
in your 'e.g' given in executive summary above. Sort of explains the above
executive summary in code.

Thanks for your thoughtful and insightful input. I haven't used this
approach but to overcome C# limitations (MI in IMHO ) this approach is
pretty handy :-)

Shawnk

PS. Let me know if you want me to post the rewritten proof of your code.

PPS. High cost based on quantitative/qualitative metrics (1) character
count, (2) visual complexity of pass through code and (3) logical complexity
of pass through code.
.

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