Re: Mixing OO and DB

S Perryman <q_at_q.com> wrote in news:fpjf5b$rul$1_at_aioe.org:

> Yagotta B. Kidding wrote:
>

>> Invasion of the OOP clones,  not less.  Are these dudes, like,  for
>> real,  still fighting over the Circle/Ellipse 'problem',  Liskov's
>> 'principle' ?  Wow !  

The problem with the LSP so much beloved by the OOP crowd, apparently because the principle gives an aura of theoretical respectability to the otherwise misguided and dull OOP enterprise, is that in general it is undecidable. In practical terms, it means that the type system is unable to check whether the LSP in a given piece of code is honored or violated rendering it pretty much a theoretical curiosity, therefore. In general, behavioural subtype checking is undecidable which means that those OOP program out there work only by accident !

For a more detailed treatment of the subtyping problem, you may want to visit Oleg Kiselyov's site :

http://okmij.org/ftp/Computation/Subtyping/

> Hence my correction to a particular claim that has been made.
>
>
> Regards,
> Steven Perryman
>
Received on Thu Feb 21 2008 - 16:24:56 CET