Re: OOP Language for OS Development

[JKop <NULL@NULL.NULL>]

Steven Wurster posted:

> Calum <calum.bulk@ntlworld.com> wrote in message
> news:<c6ap5j$1nh$1@newsg1.svr.pol.co.uk>... 
>> 
>> I am in no doubt that Eiffel is cleaner safer language, however 
that's
>> not quite the same as power.
>> 
>> So what can you express in Eiffel that cannot be expressed in C++? 
>> [Actually, resolving name-clashes in multiple inheritance is one, 
>> contracts is another.]  But are these fundamentally difficult in 
C++,
>> or  just a little uglier? 
> 
> Contracting is fundamentally difficult in C++, because adhering to 
the
> inheritance rules of contracting is not easily accomplished.  Doing 
so
> requires a lot of preprocessor directives/macros, and makes the 
code
> extremely ugly.
> 
> Resolving name clashes in C++ *can* be difficult if there are a lot 
of
> them, and you need to make sweeping changes.  Automated search and
> replace can help, of course, but may not do everything you need. 
> Otherwise, it's just flat out ugly in C++.
> 
> Eiffel supports selective exporting, covariant argument 
redefinition,
> constrained genericity, and has polymorphism by default without any
> added performance penalty.  C++ supports none of these.  Eiffel 
also
> fully supports the Open Closed Principle, while C++ does not (due 
to
> requirement of virtual keyword and private access limitations).  
None
> of these issues really affect the choice about whether one can 
develop
> an OS with them or not.
> 
> 
>> Are parameterized types in Eiffel as flexible as those in C++?
> 
> Not really.  Eiffel supports constrained genericity, but it does 
not
> support expression templates like C++ does.  Of course, expression
> templates are really a side-effect in C++, as they were not part of
> the original intention.  They are great for performance and 
expressive
> power, but they are damn ugly.  :-)
> 
> Steve


Why the hell would you want automatic polymorphism? There's times 
when I want functions NOT to be polymorphic!

-JKop