| 1 | ;;; GNU Guix --- Functional package management for GNU |
| 2 | ;;; Copyright © 2013, 2014, 2015, 2016 Ludovic Courtès <ludo@gnu.org> |
| 3 | ;;; |
| 4 | ;;; This file is part of GNU Guix. |
| 5 | ;;; |
| 6 | ;;; GNU Guix is free software; you can redistribute it and/or modify it |
| 7 | ;;; under the terms of the GNU General Public License as published by |
| 8 | ;;; the Free Software Foundation; either version 3 of the License, or (at |
| 9 | ;;; your option) any later version. |
| 10 | ;;; |
| 11 | ;;; GNU Guix is distributed in the hope that it will be useful, but |
| 12 | ;;; WITHOUT ANY WARRANTY; without even the implied warranty of |
| 13 | ;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 14 | ;;; GNU General Public License for more details. |
| 15 | ;;; |
| 16 | ;;; You should have received a copy of the GNU General Public License |
| 17 | ;;; along with GNU Guix. If not, see <http://www.gnu.org/licenses/>. |
| 18 | |
| 19 | (define-module (test-monads) |
| 20 | #:use-module (guix tests) |
| 21 | #:use-module (guix store) |
| 22 | #:use-module (guix monads) |
| 23 | #:use-module (guix grafts) |
| 24 | #:use-module (guix derivations) |
| 25 | #:use-module (guix packages) |
| 26 | #:use-module (gnu packages) |
| 27 | #:use-module (gnu packages bootstrap) |
| 28 | #:use-module ((gnu packages base) #:select (coreutils)) |
| 29 | #:use-module (ice-9 match) |
| 30 | #:use-module (rnrs io ports) |
| 31 | #:use-module (srfi srfi-1) |
| 32 | #:use-module (srfi srfi-26) |
| 33 | #:use-module (srfi srfi-64)) |
| 34 | |
| 35 | ;; Test the (guix monads) module. |
| 36 | |
| 37 | (define %store |
| 38 | (open-connection-for-tests)) |
| 39 | |
| 40 | ;; Globally disable grafts because they can trigger early builds. |
| 41 | (%graft? #f) |
| 42 | |
| 43 | (define %monads |
| 44 | (list %identity-monad %store-monad %state-monad)) |
| 45 | |
| 46 | (define %monad-run |
| 47 | (list identity |
| 48 | (cut run-with-store %store <>) |
| 49 | (cut run-with-state <> '()))) |
| 50 | |
| 51 | (define-syntax-rule (values->list exp) |
| 52 | (call-with-values (lambda () exp) |
| 53 | list)) |
| 54 | |
| 55 | \f |
| 56 | (test-begin "monads") |
| 57 | |
| 58 | (test-assert "monad?" |
| 59 | (and (every monad? %monads) |
| 60 | (every (compose procedure? monad-bind) %monads) |
| 61 | (every (compose procedure? monad-return) %monads))) |
| 62 | |
| 63 | ;; The 3 "monad laws": <http://www.haskell.org/haskellwiki/Monad_laws>. |
| 64 | |
| 65 | (test-assert "left identity" |
| 66 | (every (lambda (monad run) |
| 67 | (let ((number (random 777))) |
| 68 | (with-monad monad |
| 69 | (define (f x) |
| 70 | (return (* (1+ number) 2))) |
| 71 | |
| 72 | (= (run (>>= (return number) f)) |
| 73 | (run (f number)))))) |
| 74 | %monads |
| 75 | %monad-run)) |
| 76 | |
| 77 | (test-assert "right identity" |
| 78 | (every (lambda (monad run) |
| 79 | (with-monad monad |
| 80 | (let ((number (return (random 777)))) |
| 81 | (= (run (>>= number return)) |
| 82 | (run number))))) |
| 83 | %monads |
| 84 | %monad-run)) |
| 85 | |
| 86 | (test-assert "associativity" |
| 87 | (every (lambda (monad run) |
| 88 | (with-monad monad |
| 89 | (define (f x) |
| 90 | (return (+ 1 x))) |
| 91 | (define (g x) |
| 92 | (return (* 2 x))) |
| 93 | |
| 94 | (let ((number (return (random 777)))) |
| 95 | (= (run (>>= (>>= number f) g)) |
| 96 | (run (>>= number (lambda (x) (>>= (f x) g)))))))) |
| 97 | %monads |
| 98 | %monad-run)) |
| 99 | |
| 100 | (test-assert "lift" |
| 101 | (every (lambda (monad run) |
| 102 | (let ((f (lift1 1+ monad)) |
| 103 | (g (apply lift1 1+ (list monad)))) |
| 104 | (with-monad monad |
| 105 | (let ((number (random 777))) |
| 106 | (= (run (>>= (return number) f)) |
| 107 | (run (>>= (return number) g)) |
| 108 | (1+ number)))))) |
| 109 | %monads |
| 110 | %monad-run)) |
| 111 | |
| 112 | (test-assert ">>= with more than two arguments" |
| 113 | (every (lambda (monad run) |
| 114 | (let ((1+ (lift1 1+ monad)) |
| 115 | (2* (lift1 (cut * 2 <>) monad))) |
| 116 | (with-monad monad |
| 117 | (let ((number (random 777))) |
| 118 | (= (run (>>= (return number) |
| 119 | 1+ 1+ 1+ |
| 120 | 2* 2* 2*)) |
| 121 | (* 8 (+ number 3))))))) |
| 122 | %monads |
| 123 | %monad-run)) |
| 124 | |
| 125 | (test-assert "mbegin" |
| 126 | (every (lambda (monad run) |
| 127 | (with-monad monad |
| 128 | (let* ((been-there? #f) |
| 129 | (number (mbegin monad |
| 130 | (return 1) |
| 131 | (begin |
| 132 | (set! been-there? #t) |
| 133 | (return 2)) |
| 134 | (return 3)))) |
| 135 | (and (= (run number) 3) |
| 136 | been-there?)))) |
| 137 | %monads |
| 138 | %monad-run)) |
| 139 | |
| 140 | (test-assert "mlet* + text-file + package-file" |
| 141 | (run-with-store %store |
| 142 | (mlet* %store-monad ((guile (package-file %bootstrap-guile "bin/guile")) |
| 143 | (file (text-file "monadic" guile))) |
| 144 | (return (equal? (call-with-input-file file get-string-all) |
| 145 | guile))) |
| 146 | #:guile-for-build (package-derivation %store %bootstrap-guile))) |
| 147 | |
| 148 | (test-assert "package-file, default system" |
| 149 | ;; The default system should be the one at '>>=' time, not the one at |
| 150 | ;; invocation time. See <http://bugs.gnu.org/18002>. |
| 151 | (run-with-store %store |
| 152 | (mlet* %store-monad |
| 153 | ((system -> (%current-system)) |
| 154 | (file (parameterize ((%current-system "foobar64-linux")) |
| 155 | (package-file coreutils "bin/ls"))) |
| 156 | (cu (package->derivation coreutils))) |
| 157 | (return (string=? file |
| 158 | (string-append (derivation->output-path cu) |
| 159 | "/bin/ls")))) |
| 160 | #:guile-for-build (package-derivation %store %bootstrap-guile))) |
| 161 | |
| 162 | (test-assert "package-file + package->cross-derivation" |
| 163 | (run-with-store %store |
| 164 | (mlet* %store-monad ((target -> "mips64el-linux-gnu") |
| 165 | (file (package-file coreutils "bin/ls" |
| 166 | #:target target)) |
| 167 | (xcu (package->cross-derivation coreutils target))) |
| 168 | (let ((output (derivation->output-path xcu))) |
| 169 | (return (string=? file (string-append output "/bin/ls"))))) |
| 170 | #:guile-for-build (package-derivation %store %bootstrap-guile))) |
| 171 | |
| 172 | (test-assert "interned-file" |
| 173 | (run-with-store %store |
| 174 | (mlet* %store-monad ((file -> (search-path %load-path "guix.scm")) |
| 175 | (a (interned-file file)) |
| 176 | (b (interned-file file "b"))) |
| 177 | (return (equal? (call-with-input-file file get-string-all) |
| 178 | (call-with-input-file a get-string-all) |
| 179 | (call-with-input-file b get-string-all)))) |
| 180 | #:guile-for-build (package-derivation %store %bootstrap-guile))) |
| 181 | |
| 182 | (test-assert "mapm" |
| 183 | (every (lambda (monad run) |
| 184 | (with-monad monad |
| 185 | (equal? (run (mapm monad (lift1 1+ monad) (iota 10))) |
| 186 | (map 1+ (iota 10))))) |
| 187 | %monads |
| 188 | %monad-run)) |
| 189 | |
| 190 | (test-assert "sequence" |
| 191 | (every (lambda (monad run) |
| 192 | (let* ((input (iota 100)) |
| 193 | (order '())) |
| 194 | (define (frob i) |
| 195 | (mlet monad ((foo (return 'foo))) |
| 196 | ;; The side effect here is used to keep track of the order in |
| 197 | ;; which monadic values are bound. Perform the side effect |
| 198 | ;; within a '>>=' so that it is performed when the return |
| 199 | ;; value is actually bound. |
| 200 | (set! order (cons i order)) |
| 201 | (return i))) |
| 202 | |
| 203 | (and (equal? input |
| 204 | (run (sequence monad (map frob input)))) |
| 205 | |
| 206 | ;; Make sure this is from left to right. |
| 207 | (equal? order (reverse input))))) |
| 208 | %monads |
| 209 | %monad-run)) |
| 210 | |
| 211 | (test-assert "listm" |
| 212 | (every (lambda (monad run) |
| 213 | (run (with-monad monad |
| 214 | (let ((lst (listm monad |
| 215 | (return 1) (return 2) (return 3)))) |
| 216 | (mlet monad ((lst lst)) |
| 217 | (return (equal? '(1 2 3) lst))))))) |
| 218 | %monads |
| 219 | %monad-run)) |
| 220 | |
| 221 | (test-assert "anym" |
| 222 | (every (lambda (monad run) |
| 223 | (eq? (run (with-monad monad |
| 224 | (anym monad |
| 225 | (lift1 (lambda (x) |
| 226 | (and (odd? x) 'odd!)) |
| 227 | monad) |
| 228 | (append (make-list 1000 0) |
| 229 | (list 1 2))))) |
| 230 | 'odd!)) |
| 231 | %monads |
| 232 | %monad-run)) |
| 233 | |
| 234 | (test-equal "set-current-state" |
| 235 | (list '(a a d) 'd) |
| 236 | (values->list |
| 237 | (run-with-state |
| 238 | (mlet* %state-monad ((init (current-state)) |
| 239 | (init2 (set-current-state 'b))) |
| 240 | (mbegin %state-monad |
| 241 | (set-current-state 'c) |
| 242 | (set-current-state 'd) |
| 243 | (mlet %state-monad ((last (current-state))) |
| 244 | (return (list init init2 last))))) |
| 245 | 'a))) |
| 246 | |
| 247 | (test-equal "state-push etc." |
| 248 | (list '((z . 2) (p . (1)) (a . (1))) '(2 1)) |
| 249 | (values->list |
| 250 | (run-with-state |
| 251 | (mbegin %state-monad |
| 252 | (state-push 1) ;(1) |
| 253 | (state-push 2) ;(2 1) |
| 254 | (mlet* %state-monad ((z (state-pop)) ;(1) |
| 255 | (p (current-state)) |
| 256 | (a (state-push z))) ;(2 1) |
| 257 | (return `((z . ,z) (p . ,p) (a . ,a))))) |
| 258 | '()))) |
| 259 | |
| 260 | (test-end "monads") |