[jhanschoo]

Can you elaborate what you mean by that? Support of sum and product types are used everywhere in typed functional languages and I don't know of any way they are exploited specifically in IO in a way that does not generalize to other domains.

[jimsimmons]

Whoops looks like I confused algebraic datatypes and algebraic effects. Actually this confusion / realization because of your comment just clicked something for me, so thanks!!