[Haskell-cafe] Teaching haskell at the 42 french school

[Artyom]

 > what do you think of allowing ONLY pointfree? It may end-up by having 
different answers and promote beautiful and concise code

This would be very sadistic, yes – to people who would have to read code 
written by 42's graduates! I urge you to avoid it.

 > Red black trees are fun, aren't they?

They are also on a rather different level of difficulty from rewriting 
Data.List and friends (which is what beginners often do on their first 
day of learning). So, I don't understand what your intended level 
actually is. If it's “can understand red-black trees and write them 
without blindly copying code”, you could skip rewriting Data.List and go 
straight to:

* monad transformers
* lenses
* the Cont monad
* free monads

On the other hand, if rewriting Data.List is necessary, then take a look 
at Richard Bird's book Thinking Functionally With Haskell – it would be 
a perfect fit for you.