Stream interfaces

[Topmind]

> tgagne at ix.netcom.com (Thomas Gagne) wrote (abridged):
> > Your correct.  People are confusing inheritence and usefulness.  I 
> > don't have enough spare cycles to worry about a class'
> > inheritence unless I've discovered missing functionality.  Since
> > I haven't, I haven't.
> 
> Well, I have. In the streams hierarchy, too. Albeit not that vendor and 
> in a beta product so I probably shouldn't say too much about it, but the 
> hierarchy was very similar. The problem was analogous to methods added to 
> WriteStream not magically appearing in ExternalWriteStream.
> 
> The vendor's fix was to cut&paste methods from one class to the other. 
> But this is just sticking plaster. The class hierarchy is deeply wrong, 
> violates "once and only once" all over the place and needs refactoring. 
> It's not about missing functionality so much as how we can add new kinds 
> of stream without more error-prone cut&paste.
> 
> Whether this can be fixed without breaking existing clients, or fixed at 
> all without multiple inheritance, I don't know because I've not tried it. 
> I hope it can be and the problem is not with Smalltalk generally but just 
> this particular bit of library design. But for whatever reason, this bit 
> of library design is not ideal.
> 


Where did the deep hierarchy kind of library design trend start? 
Can anybody pinpoint an event or "leader" who appears to 
have started that trend/fad?

And, why did the other vendors follow?

"Technical sociology" would make a fascnating topic or
study area IMO.

>   Dave Harris, Nottingham, UK 

-tmind-