55 lines
1.2 KiB
Hy
55 lines
1.2 KiB
Hy
;; Copyright 2019 the authors.
|
|
;; This file is part of Hy, which is free software licensed under the Expat
|
|
;; license. See the LICENSE.
|
|
|
|
(require [hy.contrib.loop [loop]])
|
|
(import sys)
|
|
|
|
(defn tco-sum [x y]
|
|
(loop [[x x] [y y]]
|
|
(cond
|
|
[(> y 0) (recur (inc x) (dec y))]
|
|
[(< y 0) (recur (dec x) (inc y))]
|
|
[True x])))
|
|
|
|
(defn non-tco-sum [x y]
|
|
(cond
|
|
[(> y 0) (inc (non-tco-sum x (dec y)))]
|
|
[(< y 0) (dec (non-tco-sum x (inc y)))]
|
|
[True x]))
|
|
|
|
(defn test-loop []
|
|
;; non-tco-sum should fail
|
|
(try
|
|
(setv n (non-tco-sum 100 10000))
|
|
(except [e RuntimeError]
|
|
(assert True))
|
|
(else
|
|
(assert False)))
|
|
|
|
;; tco-sum should not fail
|
|
(try
|
|
(setv n (tco-sum 100 10000))
|
|
(except [e RuntimeError]
|
|
(assert False))
|
|
(else
|
|
(assert (= n 10100)))))
|
|
|
|
(defn test-recur-in-wrong-loc []
|
|
(defn bad-recur [n]
|
|
(loop [[i n]]
|
|
(if (= i 0)
|
|
0
|
|
(inc (recur (dec i))))))
|
|
|
|
(try
|
|
(bad-recur 3)
|
|
(except [e TypeError]
|
|
(assert True))
|
|
(else
|
|
(assert False))))
|
|
|
|
(defn test-recur-string []
|
|
"test that `loop` doesn't touch a string named `recur`"
|
|
(assert (= (loop [] (+ "recur" "1")) "recur1")))
|