[Dune] Usage of Barton-Nackman in DUNE expecially for documentation purposes

[Peter Bastian]

Hello All,

Markus Blatt wrote:
> Hi,
> 
> .....

Yes, I agree that BN adds a lot of complexity, especially for 
implementors (and in case of communicate the user is an implementor). I 
myself faltered often between using it or not for many of the reasons 
you mentioned.

> 
> So let us come to one point where Barton-Nackman is IMHO useful:
> 
> It is very easy to provide default implementations of methods (which
> might not be optimized for the specific case, but still ok). Thus
> releasing the User or Developer from the burden of constantly
> reinventing the wheel for each special case and still give him the
> possiblity to rewrite some methods to gain more efficiency for his
> special implementation.
> 

For me the main reason for using then BN is *that there is a base class 
at all*, i.e.
you can tell the *implementor*: "Look, here is the base class (interface 
with documentation of the methods, *without* implementation of the 
methods) and you have to write just such a class". If you do not use BN 
then you have to teach the implementor by example by showing him a 
special implementation. And then he has to extract the interface from 
the implementation which might become complex.

Just my opinion.

-- Peter
------------------------------------------------------------------
Peter Bastian, IWR,Uni Heidelberg, INF 348,R 020, 69120 Heidelberg
email: Peter.Bastian at iwr.uni-heidelberg.de   Tel: +49 6221 54 4984
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