Should predicate-like kw args end with questionmark

[sbelak]

(foo {:fluffy? true} xs)

vs.

(foo {:fluffy true} xs)

clojure.core seems to adhere to the later (see spec/map-of, core.server/start-server), but a lot of libraries (random example https://github.com/ztellman/aleph/blob/f540bb101299448cd3f867f9b0172f5c12acd535/src/aleph/http.clj#L20) use the former.

[maxcountryman]

Aleph also uses boolean-containing vars formatted in this way.

(when fluffy? :aww)

I personally find this much easier to read.

[bbatsov]

I'll close this ticket in favour of #182, that generated a bigger conversation on the subject.