Re: Does Ada really need MULTIPLE inheritance?

[eichmann@h.cs.wvu.wvnet.edu (David A Eichmann,316K)]

From article <8910161521.AA27039@ajpo.sei.cmu.edu>, by NCOHEN@IBM.COM ("Norman H. Cohen"):
...
> Since nobody at either workshop was a strenuous advocate of multiple
> inheritance, I would like to see the argument for multiple inheritance

OK, let's say I'm creating refinements of a general concept of vehicle,
which contains two attributes, means of propulsion(motor, air, etc.) and
operating medium(land, air, water).  I can make an initial refinement
of air vehicles (adding appropriate attributes), land vehicles, and water
vehicles - refining by medium; or I can refine to motor vehicles, air
(powered) vehicles, etc - refining by propulsion.  With single inheritance,
I must choose one over the other.  With multiple inheritance, there is
no need.  A motorized air vehicle is an instance of both air vehicle AND
an instance of motorized vehicle.  My initial design choice is not coloring
subsequent interpretations and perspectives on the objects in question.


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David Eichmann
Dept. of Statistics and Computer Science
West Virginia University                  Phone: (304) 293-3607
Morgantown, WV  26506                     Email: eichmann@a.cs.wvu.wvnet.edu