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comparison src/clojure/contrib/test_contrib/test_monads.clj @ 10:ef7dbbd6452c

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added clojure source goodness
author Robert McIntyre <rlm@mit.edu>
date Sat, 21 Aug 2010 06:25:44 -0400
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9:35cf337adfcf 10:ef7dbbd6452c
1 ;; Test routines for monads.clj
2
3 ;; by Konrad Hinsen
4 ;; last updated March 28, 2009
5
6 ;; Copyright (c) Konrad Hinsen, 2008. All rights reserved. The use
7 ;; and distribution terms for this software are covered by the Eclipse
8 ;; Public License 1.0 (http://opensource.org/licenses/eclipse-1.0.php)
9 ;; which can be found in the file epl-v10.html at the root of this
10 ;; distribution. By using this software in any fashion, you are
11 ;; agreeing to be bound by the terms of this license. You must not
12 ;; remove this notice, or any other, from this software.
13
14 (ns clojure.contrib.test-monads
15 (:use [clojure.test :only (deftest is are run-tests)]
16 [clojure.contrib.monads
17 :only (with-monad domonad m-lift m-seq m-chain
18 sequence-m maybe-m state-m maybe-t sequence-t)]))
19
20 (deftest sequence-monad
21 (with-monad sequence-m
22 (are [a b] (= a b)
23 (domonad [x (range 3) y (range 2)] (+ x y))
24 '(0 1 1 2 2 3)
25 (domonad [x (range 5) y (range (+ 1 x)) :when (= (+ x y) 2)] (list x y))
26 '((1 1) (2 0))
27 ((m-lift 2 #(list %1 %2)) (range 3) (range 2))
28 '((0 0) (0 1) (1 0) (1 1) (2 0) (2 1))
29 (m-seq (replicate 3 (range 2)))
30 '((0 0 0) (0 0 1) (0 1 0) (0 1 1) (1 0 0) (1 0 1) (1 1 0) (1 1 1))
31 ((m-chain (replicate 3 range)) 5)
32 '(0 0 0 1 0 0 1 0 1 2)
33 (m-plus (range 3) (range 2))
34 '(0 1 2 0 1))))
35
36 (deftest maybe-monad
37 (with-monad maybe-m
38 (let [m+ (m-lift 2 +)
39 mdiv (fn [x y] (domonad [a x b y :when (not (zero? b))] (/ a b)))]
40 (are [a b] (= a b)
41 (m+ (m-result 1) (m-result 3))
42 (m-result 4)
43 (mdiv (m-result 1) (m-result 3))
44 (m-result (/ 1 3))
45 (m+ 1 (mdiv (m-result 1) (m-result 0)))
46 m-zero
47 (m-plus m-zero (m-result 1) m-zero (m-result 2))
48 (m-result 1)))))
49
50 (deftest seq-maybe-monad
51 (with-monad (maybe-t sequence-m)
52 (letfn [(pairs [xs] ((m-lift 2 #(list %1 %2)) xs xs))]
53 (are [a b] (= a b)
54 ((m-lift 1 inc) (for [n (range 10)] (when (odd? n) n)))
55 '(nil 2 nil 4 nil 6 nil 8 nil 10)
56 (pairs (for [n (range 5)] (when (odd? n) n)))
57 '(nil nil (1 1) nil (1 3) nil nil nil (3 1) nil (3 3) nil nil)))))
58
59 (deftest state-maybe-monad
60 (with-monad (maybe-t state-m)
61 (is (= (for [[a b c d] (list [1 2 3 4] [nil 2 3 4] [ 1 nil 3 4]
62 [nil nil 3 4] [1 2 nil nil])]
63 (let [f (domonad
64 [x (m-plus (m-result a) (m-result b))
65 y (m-plus (m-result c) (m-result d))]
66 (+ x y))]
67 (f :state)))
68 (list [4 :state] [5 :state] [4 :state] [nil :state] [nil :state])))))
69
70 (deftest state-seq-monad
71 (with-monad (sequence-t state-m)
72 (is (= (let [[a b c d] [1 2 10 20]
73 f (domonad
74 [x (m-plus (m-result a) (m-result b))
75 y (m-plus (m-result c) (m-result d))]
76 (+ x y))]
77 (f :state)))
78 (list [(list 11 21 12 22) :state]))))