[Haskell-cafe] Re: Grokking monads by not overlooking concatMap

Achim Schneider wrote:

-- That's the one I've been looking for. Remember that -- return e = [e] f'''' = concatMap (\x -> concatMap (\y -> concatMap (\_ -> [(x,y)]) (if x*y == 8 then [()] else [])) [2..8]) [1..4]

Morale: Premature term elimination is the root of all misunderstanding.

Haskell wins the wickedness of design contest by using [()] and [] as truth values.

Maybe you wanted to say: "... by using [()] as True value and [] as False value" ... which does not seem that wicked (at least to me). Peter.