Re: Do people who use Ada also use ocaml or F#?

["Yannick Duchêne (Hibou57)" <yannick_duchene@yahoo.fr>]

Le Sun, 31 Oct 2010 03:31:01 +0100, Jeffrey Carter  
<spam.jrcarter.not@spam.not.acm.org> a écrit:
> Not at all. I've been using Ada since 1984, and am reckoned to have a  
> passable understanding of it. I am reasonably familiar with the  
> programming-by-extension features (see my use of a type extension to  
> avoid access types in a recent discussion of S expressions), but I have  
> made several errors when dealing with code that uses these features in  
> their more normal, obfuscatory manner. Normally I would think it's just  
> a failing on my part, but the many problems others have had help me  
> think that maybe it's not.
May be there was too much derivation levels ? Two levels should be  
sufficient in most of case I feel.

> HOOD is a design method, and has nothing to do with programming by  
> extension, which is an implementation technique that has nothing to do  
> with object orientedness.
As much as I understand it (I could not access any reference, as there are  
near to none at all on the web), HOOD do have to deal with object, and is  
not an implementation technique, but a analysis and design method. Pretty  
sure HOOD is to be considered object-oriented (will have to ask for a PDF  
book about HOOD later, I am thinking about it since some time).

> and (unfortunately) seen far too much S/W that uses programming by  
> extension that is not object oriented.
May be confusion between re-use and extension ? I know the most loud OOD  
voices expose classification and re-use in the mean time, so that it  
present derivation as both a way of classification and re-use. But  
classification/extensions and re-use are different things. You indeed  
re-use something when you extend, but to re-use is not to extend; and the  
primary topic with extension, is only extension, not re-use, which (the  
latter) only appears as a side-effect.

Indeed, if you extend to re-use, you break object boundaries and  
identifications. If you extend to extend, you are more likely to preserve  
objects identifications.

(as far as i can understand)

-- 
Si les chats miaulent et font autant de vocalises bizarres, c’est pas pour  
les chiens.