[saga-rg] multiple inheritance...

[Thilo Kielmann]

Hi all,

using multiple interfaces (as in Java) exactly avoids code
inheritance. Classes just have to provide the sum of their interfaces;
where the implementation comes from (either cut-and-paste or
single/multiple inheritance) is a completely different story...

So, put the use of multiple interfaces into the spec and do not make
inheritance mandatory.


My 2 cents,


Thilo

On Fri, Sep 02, 2005 at 05:29:12PM +0200, Andre Merzky wrote:
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> Date: Fri, 2 Sep 2005 17:29:12 +0200
> From: Andre Merzky <andre at merzky.net>
> To: Simple API for Grid Applications WG <saga-rg at ggf.org>
> Subject: [saga-rg] multiple inheritance...
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> 
> Hi all, 
> 
> as we started to define the strawman in a OO way, we decided
> to use only simple OO features, and in particular no
> polumorphosm and multiple inheritance.  The strawman right
> now respects that.
> 
> However, as we now ponder over additional interfaces, such
> as permissions, we get into trouble: the file class would
> for example implement both the attribute and the permission
> interface, and hence would be inheriting multiple bases.
> 
> In terms of implementation this can be avoided I think,
> although not beautifully.  Hence the question, if that
> limitation is neccessary/wanted/needed on specification
> level.
> 
> Plymorphism on the other hand can _not_ easily be avoided on
> implementation level once it is written down in the spec,
> and hence should not enter it.
> 
> So, my opinion is to allow multiple interfaces on classes in
> the spec, bat take care that an implementation can be done
> w/o the need for multiple inheritance.
> 
> Any other opinions? :-)
> 
> If not, I would adjust the respective part in the intro.
> 
> Cheers, Andre.
> 
> 
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-- 
Thilo Kielmann                                 http://www.cs.vu.nl/~kielmann/