Re: [Haskell-cafe] Short circuiting and the Maybe monad

2008/5/13 Abhay Parvate :

Yes, I had always desired that the operator >>= should have been right associative for this short cut even when written without the 'do' notation.

You pretty much always want "a >>= b >>= c" to parse as "(a >>= b) >>= c" and not "a >>= (b >>= c)". In the latter case, the two uses of (>>=) aren't in the same monad. You can get desired effect with the Kleisli composition operator (>=>), which is in recent versions of Control.Monad. Unfortunately, it has the same precedence as (>>=), so you can't use them together without parentheses. Using it, "a >>= b >>= c" can be rewritten "a >>= (b >=> c)" which is short for "a >>= \x -> b x >>= c". -- Dave Menendez http://www.eyrie.org/~zednenem/