By: Tom Sydney Kerckhove <syd@cs-syd.eu>
Export less of the federation, and fold it more plainly Three of its exports were used by nothing at all: not the library, not the tests, not the end-to-end driver. A published surface is a promise, so it should only hold what somebody asked for. Collecting the issuers was a foldr over an Either that had to carry a failure past every remaining element by hand. foldM does that.