(a) Non-determism is an effect, e.g. simple list is non-determinism monad, for small discrete distributions! (b) Yes. We can write effectful code "implicitly" - You might look into *Automatically Escaping Monads* - https://www.youtube.com/watch?v=wG8AErq6Bbo, slides: http://benl.ouroborus.net/talks/2016-HIW-Escape.pdf - http://disciple.ouroborus.net/ or https://github.com/DDCSF/ddc Interstingly, while searching for the paper, I stumbled upon Oleg Kiselyov's (not me) paper from *Effects Without Monads: Non-determinism*, which is a different approach. Maybe that's what you are looking after http://okmij.org/ftp/tagless-final/nondet-paper.pdf - Oleg On 11.01.2018 21:41, Benjamin Redelings wrote:
Hi Oleg,
I like monads, really I do. I am just not asking a question about how I can (or should) use monads.
I guess we can split my question into two branches: (a) why are monads a perfect solution to my problem? (b) can we extend the HM type system to support non-determinism directly?
What I am actually interested in is (b), so I don't want to get sidetracked with (a) if it means ignoring (b). I will think if I can respond to (a) without completely getting side-tracked and ignoring (b). Does that make sense?
take care,
-BenRI
P.S. Thanks for the links!