Using the Applicative methods to optimise "do" desugaring is still
possible, it's just not that easy to have that weaken the generated
constraint from Monad to Applicative since only degenerate programs
like this one won't use a Monad method:
Is this still true, once Monad is a subclass of Applicative which defines return?
I'd still somewhat prefer if return get's merged with the preceding statement so sometimes only a Functor constraint is generated but I think, I should adjust your desugaring then..
Sebastian