;; Trivial but convenient functions.

;; Integer predecessor (number -> number)
(def! inc (fn* [a] (+ a 1)))

;; Integer predecessor (number -> number)
(def! dec (fn* (a) (- a 1)))

;; Integer nullity test (number -> boolean)
(def! zero? (fn* (n) (= 0 n)))

;; Returns the unchanged argument.
(def! identity (fn* (x) x))

;; Generate a hopefully unique symbol. See section "Plugging the Leaks"
;; of http://www.gigamonkeys.com/book/macros-defining-your-own.html
(def! gensym
  (let* [counter (atom 0)]
    (fn* []
      (symbol (str "G__" (swap! counter inc))))))