Carp/test/short_circuiting.carp

(load "Test.carp")
(use Test)

(def g 0) ;; Global variable used to detect if too many forms are evaluated.

(defn inc-true []
  (do (update! g inc)
      true))

(defn inc-false []
  (do (update! g inc)
      false))

(defn short-circuit-and []
  (do (set! g 0)
      (ignore (and (inc-false) (inc-true))) ;; Only the first form should be evaluated.
      g))

(defn short-circuit-or []
  (do (set! g 0)
      (ignore (or (inc-true) (inc-false))) ;; Only the first form should be evaluated.
      g))

(defn eval-both-expr-in-and []
  (do (set! g 0)
      (ignore (and (inc-true) (inc-true))) ;; Both forms evaluate.
      g))

(defn eval-both-expr-in-or []
  (do (set! g 0)
      (ignore (or (inc-false) (inc-false))) ;; Both forms evaluate.
      g))

(defn vararg-and []
  (do (set! g 0)
      (ignore (and* (inc-true) (inc-true) (inc-false) (inc-true) (inc-true))) ;; 3 expressions will evaluate.
      g))

(defn vararg-or []
  (do (set! g 0)
      (ignore (or* (inc-false) (inc-false) (inc-true) (inc-false) (inc-false))) ;; 3 expressions will evaluate.
      g))

(deftest test
  (assert-equal test
                1
                (short-circuit-and)
                "'and' short circuits")
  (assert-equal test
                1
                (short-circuit-or)
                "'or' short circuits")
  (assert-equal test
                2
                (eval-both-expr-in-and)
                "'and' can evaluate second expr")
  (assert-equal test
                2
                (eval-both-expr-in-or)
                "'or' can evaluate second expr")
  (assert-equal test
                3
                (vararg-and)
                "'and*' works")
  (assert-equal test
                3
                (vararg-or)
                "'or*' works")
  )