Another day in the ordeal of cartesianProduct

[bearophile]

Andrei Alexandrescu:

> For those who wouldn't know how to search the Net, these indeed 
> are quite appropriate.

People are often a bit lazy in clicking on links present in 
newsgroup messages, and they are even more lazy in searching 
things. So I've seen numerous times that if you give them links 
they will be more willing to read. This is especially true about 
topics they know nothing about, because they have a higher 
"cognitive impedance".

Google gives many results about this topic, but not all of them 
are good. That link from mozilla is a little video that doesn't 
tell a lot. The papers from Wadler were the ones Haskell 
typeclases come from, they are harder, but they are more 
fundamental. But starting from those papers is hard, so better to 
start from some examples and simpler explanations.

In the Haskell wiki there are more practical texts on this topic, 
and comparisons:
http://www.haskell.org/tutorial/classes.html
http://www.haskell.org/haskellwiki/OOP_vs_type_classes

Plus an online free chapter of what maybe is the best book about 
Haskell:
http://book.realworldhaskell.org/read/using-typeclasses.html


> It's a matter of what priorities the language has and what 
> other features are available overlapping with the projected 
> usefulness.

I agree. On the other hand the main point of this thread is that 
someone perceives as not good enough or not sufficient the 
current features of D. Even if their perception is wrong (and you 
are an expert on this field, so we trust your words), I think the 
topic is worth discussing.

Bye,
bearophile