[MLton-commit] r5035

[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/misc.sml

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Added: mltonlib/trunk/com/ssh/misc-util/unstable/misc.sml
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--- mltonlib/trunk/com/ssh/misc-util/unstable/misc.sml	2007-01-12 12:28:23 UTC (rev 5034)
+++ mltonlib/trunk/com/ssh/misc-util/unstable/misc.sml	2007-01-12 12:28:35 UTC (rev 5035)
@@ -0,0 +1,44 @@
+(* 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.
+ *)
+
+(*
+ * Some miscellaneous utilities.
+ *)
+
+structure Misc :> sig
+   val ranqd1 : Word32.t UnOp.t
+   (**
+    * This implements the quick-and-dirty linear congruential pseudo
+    * random number generator described on page 284 of the book Numerical
+    * Recipes in C.  Perhaps the most important feature of this generator
+    * is that it cycles through all 32-bit words.  This is useful if you
+    * want to generate unique 32-bit identifiers.
+    *
+    * Warning: If you need a high-quality pseudo random number generator
+    * for simulation purposes, then this isn't for you.
+    *)
+
+   val psdes : Word32.t Sq.t UnOp.t
+   (**
+    * This implements the "Pseudo-DES" algorithm described in section 7.5
+    * of the book Numerical Recipes in C.
+    *)
+end = struct
+   fun ranqd1 s : Word32.t = s * 0w1664525 + 0w1013904223
+
+   val psdes =
+       flip (foldl (fn ((c1, c2), (lw, rw)) => let
+                       open Word32
+                       val a = rw xorb c1
+                       val al = a andb 0wxFFFF
+                       val ah = a >> 0w16
+                       val b = al*al + notb (ah*ah)
+                    in (rw,
+                        lw xorb (al*ah + (c2 xorb (b >> 0w16 orb b << 0w16))))
+                    end))
+            [(0wxBAA96887, 0wx4B0F3B58), (0wx1E17D32C, 0wxE874F0C3),
+             (0wx03BCDC3C, 0wx6955C5A6), (0wx0F33D1B2, 0wx55A7CA46)]
+end


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