(.module: lux
  (lux/control [order]))

## [Signatures]
(sig: #export (Enum e)
  {#.doc "Enumerable types, with a notion of moving forward and backwards through a type's instances."}
  (: (order.Order e) order)
  (: (-> e e) succ)
  (: (-> e e) pred))

## [Functions]
(def: (range' <= succ from to)
  (All [a] (-> (-> a a Bool) (-> a a) a a (List a)))
  (if (<= to from)
    (#.Cons from (range' <= succ (succ from) to))
    #.Nil))

(def: #export (range (^open) from to)
  {#.doc "An inclusive [from, to] range of values."}
  (All [a] (-> (Enum a) a a (List a)))
  (range' <= succ from to))