Re: [Haskell-cafe] Smarter do notation

On 5 September 2011 08:35, Max Bolingbroke wrote:

(If you do want to support the type checker only generating requests for an Applicative constraint you could just insist that user code writes "pure" instead of "return", in which case this would be quite easy to implement)

I take back this parenthetical remark. Using pure instead of return only solves the most boring 1/2 of the problem :-) 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: do computation1 computation2 computation3 Max