[MLton-commit] r5041

[Vesa Karvonen]

Initial commit of a lib of misc utils to be refactored.
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A   mltonlib/trunk/com/ssh/misc-util/unstable/promise-test.sml

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Added: mltonlib/trunk/com/ssh/misc-util/unstable/promise-test.sml
===================================================================
--- mltonlib/trunk/com/ssh/misc-util/unstable/promise-test.sml	2007-01-12 12:29:56 UTC (rev 5040)
+++ mltonlib/trunk/com/ssh/misc-util/unstable/promise-test.sml	2007-01-12 12:30:10 UTC (rev 5041)
@@ -0,0 +1,179 @@
+(* Copyright (C) 2007 SSH Communications Security, Helsinki, Finland
+ *
+ * This code is released under the MLton license, a BSD-style license.
+ * See the LICENSE file or http://mlton.org/License for details.
+ *)
+
+(*
+ * Copyright (c) 2006 SSH Communications Security, Helsinki, Finland
+ *               All rights reserved.
+ *
+ * Unit tests for the {Promise} module.
+ *)
+
+val () = let
+   open Type UnitTest
+
+   val fix = Tie.fix
+
+   local
+      open Promise
+   in
+      val D = delay
+      val E = eager
+      val F = force
+      val L = lazy
+      val Y = Y
+   end
+
+   (* lazy stream *)
+   datatype 'a stream' = NIL | CONS of 'a * 'a stream
+   withtype 'a stream = 'a stream' Promise.t
+
+   local
+      fun strip s = case F s of NIL => raise Empty | CONS x => x
+   in
+      fun hd s = #1 (strip s)
+      fun tl s = #2 (strip s)
+   end
+
+   fun cons x = E (CONS x)
+
+   fun streamDrop (s, i) =
+       L (fn () =>
+             if 0 = i then
+                s
+             else
+                streamDrop (tl s, i - 1))
+
+   fun streamSub (s, i) = hd (streamDrop (s, i))
+
+   (* helpers *)
+   fun inc x = (x += 1 ; !x)
+in
+   unitTests
+      (title "Promise.fix")
+
+      (testRaises
+          Fix.Fix
+          (fn () =>
+              fix Y (fn invalid =>
+                        (F invalid ; E ()))))
+
+      (testEq
+          int
+          (fn () => let
+                 fun streamZipWith fxy (xs, ys) =
+                     D (fn () =>
+                           CONS (fxy (hd xs, hd ys),
+                                 streamZipWith fxy (tl xs, tl ys)))
+
+                 val fibs =
+                     fix Y (fn fibs =>
+                               0 </cons/> 1 </cons/>
+                                 (streamZipWith
+                                     op +
+                                     (L (fn () => tl fibs), fibs)))
+              in
+                 {expect = 8,
+                  actual = streamSub (fibs, 6)}
+              end))
+
+      (title "Promise - memoization")
+
+      (testEq
+          (list int)
+          (fn () => let
+                 val count = ref 0
+                 val s = D (fn () => inc count)
+              in
+                 {expect = [1, 1, 1],
+                  actual = [F s, F s, !count]}
+              end))
+
+      (testEq
+          (list int)
+          (fn () => let
+                 val count = ref 0
+                 val s = D (fn () => inc count)
+              in
+                 {expect = [2, 1],
+                  actual = [F s + F s, !count]}
+              end))
+
+      (testEq
+          (list int)
+          (fn () => let
+                 val count = ref 0
+                 val r = D (fn () => inc count)
+                 val s = L (Thunk.mk r)
+                 val t = L (Thunk.mk s)
+              in
+                 {expect = [1, 1, 1],
+                  actual = [F t, F r, !count]}
+              end))
+
+      (testEq
+          (list int)
+          (fn () => let
+                 val count = ref 0
+                 fun ones () = D (fn () => CONS (inc count, ones ()))
+                 val s = ones ()
+              in
+                 {expect = [5, 5, 5],
+                  actual = [streamSub (s, 4), streamSub (s, 4), !count]}
+              end))
+
+      (title "Promise - reentrancy")
+
+      (testEq
+          (list int)
+          (fn () => let
+                 val count = ref 0
+                 val x = ref 5
+                 val p = fix Y (fn p =>
+                                   D (fn () =>
+                                         if inc count > !x then
+                                            !count
+                                         else
+                                            F p))
+              in
+                 {expect = [6, 6],
+                  actual = [F p, (x := 10 ; F p)]}
+              end))
+
+      (testEq
+          int
+          (fn () => let
+                 val first = ref true
+                 val f = fix Y (fn f =>
+                                   D (fn () =>
+                                         if !first then
+                                            (first := false ; F f)
+                                         else
+                                            2))
+              in
+                 {expect = 2,
+                  actual = F f}
+              end))
+
+      (testEq
+          (list int)
+          (fn () => let
+                 val count = ref 5
+                 val p = fix Y (fn p =>
+                                   D (fn () =>
+                                         if !count <= 0 then
+                                            !count
+                                         else
+                                            (count -= 1
+                                           ; ignore (F p)
+                                           ; count += 2
+                                           ; !count)))
+              in
+                 {expect = [5, 0, 10],
+                  actual = [!count, F p, !count]}
+              end))
+
+      $
+end


Property changes on: mltonlib/trunk/com/ssh/misc-util/unstable/promise-test.sml
___________________________________________________________________
Name: svn:eol-style
   + native