[MLton-commit] r4822

[Vesa K. <ve...@ml...>]

Added conversions to/from big/little endian byte vectors.
----------------------------------------------------------------------

U   mltonlib/trunk/com/ssh/extended-basis/unstable/detail/mk-word-ext.fun
U   mltonlib/trunk/com/ssh/extended-basis/unstable/public/word.sig

----------------------------------------------------------------------

Modified: mltonlib/trunk/com/ssh/extended-basis/unstable/detail/mk-word-ext.fun
===================================================================
--- mltonlib/trunk/com/ssh/extended-basis/unstable/detail/mk-word-ext.fun	2006-11-14 12:59:50 UTC (rev 4821)
+++ mltonlib/trunk/com/ssh/extended-basis/unstable/detail/mk-word-ext.fun	2006-11-14 17:08:09 UTC (rev 4822)
@@ -11,8 +11,33 @@
    open W
    type t = word
    val bounds as (minWord, maxWord) = (fromInt 0, fromInt~1)
+   val numBytes = Int.quot (Int.+ (wordSize, 7), 8)
+   local
+      fun mk fold bs =
+          if numBytes <> Word8Vector.length bs then
+             raise Subscript
+          else
+             fold (fn (b, w) =>
+                      W.orb (W.<< (w, 0w8), W.fromLarge (Word8.toLarge b)))
+                  (W.fromInt 0)
+                  bs
+   in
+      val fromBigBytes = mk Word8Vector.foldl
+      val fromLittleBytes = mk Word8Vector.foldr
+   end
    val fromWord = fromLarge o Word.toLarge
    val fromWordX = fromLarge o Word.toLargeX
+   local
+      fun mk idx w =
+          Word8Vector.tabulate
+             (numBytes,
+              fn i =>
+                 Word8.fromLarge
+                    (W.toLarge (W.>> (w, Word.* (0w8, Word.fromInt (idx i))))))
+   in
+      val toBigBytes = mk (fn i => Int.- (Int.- (numBytes, 1), i))
+      val toLittleBytes = mk (fn i => i)
+   end
    val toWord = Word.fromLarge o toLarge
    val toWordX = Word.fromLarge o toLargeX
    val embString = (toString, fromString)

Modified: mltonlib/trunk/com/ssh/extended-basis/unstable/public/word.sig
===================================================================
--- mltonlib/trunk/com/ssh/extended-basis/unstable/public/word.sig	2006-11-14 12:59:50 UTC (rev 4821)
+++ mltonlib/trunk/com/ssh/extended-basis/unstable/public/word.sig	2006-11-14 17:08:09 UTC (rev 4822)
@@ -17,6 +17,12 @@
 
    (** == Bounds == *)
 
+   val numBytes : int
+   (**
+    * The number of bytes (8-bit words) it takes to store a {word}.  This
+    * is always equal to {(wordSize + 7) quot 8}.
+    *)
+
    val maxWord : word
    (**
     * The maximal representable {word}.  This is always equal to {fromInt
@@ -36,6 +42,22 @@
 
    (** == Conversions == *)
 
+   val fromBigBytes : Word8Vector.vector -> word
+   (**
+    * Converts a vector of bytes in big-endian order to a word.  Raises
+    * {Subscript} if the length of the given vector is not equal to
+    * {numBytes}.  Extra bits, if any, in the most significant byte are
+    * ignored.
+    *)
+
+   val fromLittleBytes : Word8Vector.vector -> word
+   (**
+    * Converts a vector of bytes in little-endian order to a word.  Raises
+    * {Subscript} if the length of the given vector is not equal to
+    * {numBytes}.  Extra bits, if any, in the most significant byte are
+    * ignored.
+    *)
+
    val fromWord : Word.word -> word
    (**
     * Converts the given word {w : Word.word} to the value {w(mod
@@ -53,6 +75,20 @@
     * significant bit of {w}.
     *)
 
+   val toBigBytes : word -> Word8Vector.vector
+   (**
+    * Converts the given word to a vector of bytes in big-endian order.
+    * Extra bits, if any, in the most significant byte will be set to
+    * zeroes.
+    *)
+
+   val toLittleBytes : word -> Word8Vector.vector
+   (**
+    * Converts the given word to a vector of bytes in little-endian order.
+    * Extra bits, if any, in the most significant byte will be set to
+    * zeroes.
+    *)
+
    val toWord : word -> Word.word
    (**
     * Converts the given word {w : word} to the value {w(mod