Multiple inheritance (Was: OOP)_(re)

Wed, 28 May 1997 12:00:18 +0100

>According to Pierre Phaneuf:
>>
>> I strongly advises *agains't* multiple inheritance. It is the OOP
'goto'
>> equivalent. Everything MI can do, you can do without MI if you design


>  * are there existing Pascal standards (ANSI Object Pascal, Delphi)
>    requiring it?  (I *really* don't know.)


Hi,

I, also, am against MI as it, along with quite a lot of features of C/C++,
make it quite a dangerous language for writing reliable programs.... Having
said that I think that Interface support along the lines of Delphi 3.0/
Java IS a good idea..Unfortunately it would take quite a bit to implement I
guess and (if done the Delphi way) would "tie" you to an ActiveX/OLE way of
doing things as everything in Delphi 3.0 is based on the IUnknown interface
with it's associated AddRef, QueryInterface and Release methods.....

Just my 2p's worth,
Dave


 ----
Peter Gerwinski 
To: gpc@hut.fi
28 May 1997 11:17
Multiple inheritance (Was: OOP)

>According to Pierre Phaneuf:
>>
>> I strongly advises *agains't* multiple inheritance. It is the OOP
'goto'
>> equivalent. Everything MI can do, you can do without MI if you design
>> well. C++ is the bloated monster we know today in part because of that
>> pseudo-feature. Neither Modula-3 or Oberon has multiple inheritance and
>> both have been used in programming operating systems and huges
projects.
>
>I don't vote for or against multiple inheritance, but
>
>  * are there existing Pascal standards (ANSI Object Pascal, Delphi)
>    requiring it?  (I *really* don't know.)
>
>  * There are few places in my planned object hierarchy (I am *also*
>    working on a completely new library;) where MI could be useful:
>    There are several independent branches of recursive objects, say
>    `VisibleObj' and `DataObj', which all have a `Child ( i: Integer )'
>    method returning the `i'th child.  It would be nice to implement
>    some stuff, say a `ForEach' method, in a common ancestor.  Without
>    MI, this common ancestor must be a *very* "low" object, `BaseObj'
>    itself, the parent of all objects.  I am not sure if it is wise to
>    make *every* object in the hierarchy potentially recursive.
>
>  * Whether we want to use it or not, I would like to think about how
>    to implement it due to academical curiousity.
>
> (* And: C++ has it, and we must demonstrate that GPC is not inferior.
;*)
>
>Greetings,
>
>    Peter
>
>  Dipl.-Phys. Peter Gerwinski, Essen, Germany, free physicist and
programmer
>peter.gerwinski@uni-essen.de - http://home.pages.de/~peter.gerwinski/
[970201]
> maintainer GNU Pascal [970510] - http://home.pages.de/~gnu-pascal/
[970125]
> 

Peter Gerwinski (peter@agnes.dida.physik.uni-essen.de)