Re: Usage of Interfaces with Ada 95

[Matthew Heaney <matthewjheaney@earthlink.net>]

Michael Erdmann <Michael.Erdmann@snafu.de> writes:

> This is not the point! The point is, that i like to setup a 
> repository of concepts, which is specialized when it is used.
> For example, the iterator (or enumerator) is a very general
> concept which requieres basicaly the following methods
> 
>     First          - Return the first element
>     Next           - Fetch the next element
>     HasMoreElement - Check if there is more
> 
> 
> By introducing a set of concepts i like to standarize the coding.

Again, your use of the term "concept" is unfortunate, because that
already has a specific meaning, which is that it is something *not* in
code.

Code may reify a concept, but a concept by itself it not code.  If you
want to standardize the coding, then do so!  But that is completely
orthogonal to the idea of a concept.

For example, all the containers and iterators in the Charles library
reify your iterator concept above.  So what's the problem?  That library
does exactly what you want, which is to iterate over the elements in a
container.

Charles, the STL, and the Ada predefined I/O packages are all designed
using static polymorphism.  You seem to want to use dynamic
polymorphism.  Why?  If static polymorophism does the job, what are you
complaining about?