summary refs log tree commit diff
path: root/tests/monads.scm
blob: b51e705f01e5e0530e38d0238fc9140eb76aaede (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
;;; GNU Guix --- Functional package management for GNU
;;; Copyright © 2013, 2014 Ludovic Courtès <ludo@gnu.org>
;;;
;;; This file is part of GNU Guix.
;;;
;;; GNU Guix is free software; you can redistribute it and/or modify it
;;; under the terms of the GNU General Public License as published by
;;; the Free Software Foundation; either version 3 of the License, or (at
;;; your option) any later version.
;;;
;;; GNU Guix is distributed in the hope that it will be useful, but
;;; WITHOUT ANY WARRANTY; without even the implied warranty of
;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
;;; GNU General Public License for more details.
;;;
;;; You should have received a copy of the GNU General Public License
;;; along with GNU Guix.  If not, see <http://www.gnu.org/licenses/>.

(define-module (test-monads)
  #:use-module (guix store)
  #:use-module (guix monads)
  #:use-module (guix derivations)
  #:use-module ((guix packages)
                #:select (package-derivation %current-system))
  #:use-module (gnu packages)
  #:use-module (gnu packages bootstrap)
  #:use-module (ice-9 match)
  #:use-module (rnrs io ports)
  #:use-module (srfi srfi-1)
  #:use-module (srfi srfi-26)
  #:use-module (srfi srfi-64))

;; Test the (guix store) module.

(define %store
  (open-connection))

;; Make sure we build everything by ourselves.
(set-build-options %store #:use-substitutes? #f)

(define %monads
  (list %identity-monad %store-monad))

(define %monad-run
  (list identity
        (cut run-with-store %store <>)))


(test-begin "monads")

(test-assert "monad?"
  (and (every monad? %monads)
       (every (compose procedure? monad-bind) %monads)
       (every (compose procedure? monad-return) %monads)))

;; The 3 "monad laws": <http://www.haskell.org/haskellwiki/Monad_laws>.

(test-assert "left identity"
  (every (lambda (monad run)
           (let ((number (random 777)))
             (with-monad monad
               (define (f x)
                 (return (* (1+ number) 2)))

               (= (run (>>= (return number) f))
                  (run (f number))))))
         %monads
         %monad-run))

(test-assert "right identity"
  (every (lambda (monad run)
           (with-monad monad
             (let ((number (return (random 777))))
               (= (run (>>= number return))
                  (run number)))))
         %monads
         %monad-run))

(test-assert "associativity"
  (every (lambda (monad run)
           (with-monad monad
             (define (f x)
               (return (+ 1 x)))
             (define (g x)
               (return (* 2 x)))

             (let ((number (return (random 777))))
               (= (run (>>= (>>= number f) g))
                  (run (>>= number (lambda (x) (>>= (f x) g))))))))
         %monads
         %monad-run))

(test-assert "lift"
  (every (lambda (monad run)
           (let ((f (lift1 1+ monad)))
             (with-monad monad
               (let ((number (random 777)))
                 (= (run (>>= (return number) f))
                    (1+ number))))))
         %monads
         %monad-run))

(test-assert "mlet* + text-file + package-file"
  (run-with-store %store
    (mlet* %store-monad ((guile (package-file %bootstrap-guile "bin/guile"))
                         (file  (text-file "monadic" guile)))
      (return (equal? (call-with-input-file file get-string-all)
                      guile)))
    #:guile-for-build (package-derivation %store %bootstrap-guile)))

(test-assert "mlet* + derivation-expression"
  (run-with-store %store
    (mlet* %store-monad ((guile  (package-file %bootstrap-guile "bin/guile"))
                         (gdrv   (package->derivation %bootstrap-guile))
                         (exp -> `(let ((out (assoc-ref %outputs "out")))
                                    (mkdir out)
                                    (symlink ,guile
                                             (string-append out "/guile-rocks"))))
                         (drv    (derivation-expression "rocks" exp
                                                        #:inputs
                                                        `(("g" ,gdrv))))
                         (out -> (derivation->output-path drv))
                         (built? (built-derivations (list drv))))
      (return (and built?
                   (equal? guile
                           (readlink (string-append out "/guile-rocks"))))))
    #:guile-for-build (package-derivation %store %bootstrap-guile)))

(test-assert "text-file*"
  (let ((references (store-lift references)))
    (run-with-store %store
      (mlet* %store-monad
          ((drv  (package->derivation %bootstrap-guile))
           (guile -> (derivation->output-path drv))
           (file (text-file "bar" "This is bar."))
           (text (text-file* "foo"
                             %bootstrap-guile "/bin/guile "
                             `(,%bootstrap-guile "out") "/bin/guile "
                             drv "/bin/guile "
                             file))
           (done (built-derivations (list text)))
           (out -> (derivation->output-path text))
           (refs (references out)))
        ;; Make sure we get the right references and the right content.
        (return (and (lset= string=? refs (list guile file))
                     (equal? (call-with-input-file out get-string-all)
                             (string-append guile "/bin/guile "
                                            guile "/bin/guile "
                                            guile "/bin/guile "
                                            file)))))
      #:guile-for-build (package-derivation %store %bootstrap-guile))))

(test-assert "mapm"
  (every (lambda (monad run)
           (with-monad monad
             (equal? (run (mapm monad (lift1 1+ monad) (map return (iota 10))))
                     (map 1+ (iota 10)))))
         %monads
         %monad-run))

(test-assert "sequence"
  (every (lambda (monad run)
           (let* ((input (iota 100))
                  (order '()))
             (define (frob i)
               ;; The side effect here is used to keep track of the order in
               ;; which monadic values are bound.
               (set! order (cons i order))
               i)

             (and (equal? input
                          (run (sequence monad
                                         (map (lift1 frob monad) input))))

                  ;; Make sure this is from left to right.
                  (equal? order (reverse input)))))
         %monads
         %monad-run))

(test-assert "listm"
  (every (lambda (monad run)
           (run (with-monad monad
                  (let ((lst (listm monad
                                    (return 1) (return 2) (return 3))))
                    (mlet monad ((lst lst))
                      (return (equal? '(1 2 3) lst)))))))
         %monads
         %monad-run))

(test-assert "anym"
  (every (lambda (monad run)
           (eq? (run (with-monad monad
                       (let ((lst (list (return 1) (return 2) (return 3))))
                         (anym monad
                               (lambda (x)
                                 (and (odd? x) 'odd!))
                               lst))))
                'odd!))
         %monads
         %monad-run))

(test-end "monads")


(exit (= (test-runner-fail-count (test-runner-current)) 0))