Is cmp supposed to be used with sort/sorted?

[stutonk]

cmp and functions like it that return either -1, 0, or 1 when comparing two items -- are they meant to be used with sort/sorted? If not, is there a standard lib function or functions with which they're intended to be used?

[sogaiu]

cmp and functions like it that return either -1, 0, or 1 when comparing two items -- are they meant to be used with sort/sorted

I don't think so.

IIUC, sort and sorted are meant to be used with things that return truthy / falsy values and all of -1, 0, and 1 are truthy.

Here are some examples for sort:

(do
  (def arr @[2 0 1])
  (sort arr >)
  arr)
# =>
@[2 1 0]

(do
  (def arr @[[:fun 0] [:swim 2] [:play -1]])
  (sort arr (fn [[_ x] [_ y]]
              (< x y)))
  arr)
# =>
'@[(:play -1) (:fun 0) (:swim 2)]

---

cmp seems to be used as part of the internal macro do-compare (which is in turn used by compare and compare-reduce -- the latter which is then used by compare=, ..., compare>= which are in turn used by the predicates zero?, ..., odd?)...all of that stuff is listed under "Polymorphic comparisons"...phew! (^^;

Possibly of interest might be this document.