Changeset 83 for Deliverables/D4.1/Byte.ml

Timestamp:

Sep 16, 2010, 3:31:33 PM (11 years ago)

Author:

mulligan

Message:

Lots of work done on tidying up code.

File:

• Deliverables/D4.1/Byte.ml (modified) (5 diffs)

Deliverables/D4.1/Byte.ml

@@ -4 +4 @@
 (*              operations on them.                                          *)
 (* CREATED:     10/09/2010, Dominic Mulligan                                 *)
-(* BUGS:                                                                     *)
+(* BUGS:        `from_int' not yet implemented.                              *)
 (*^*^*^*^*^*^*^*^*^*^*^*^*^*^*^*^*^*^*^*^*^*^*^*^*^*^*^*^*^*^*^*^*^*^*^*^*^*^*)
 
@@ -20 +20 @@
   val from_nibbles: nibble -> nibble -> byte
   val from_nibble: nibble -> byte
-(*
-  val from_int: int -> byte
-*)
+  (* val from_int: int -> byte *)
+
   val to_bit: byte -> bit option
   val to_nibble: byte -> nibble option
@@ -48 +47 @@
   val zip_bit: (bit -> bit -> bit) -> byte -> byte -> byte
   val to_string: byte -> string
+
+  val zero: byte
+  val half_add: byte -> byte -> (byte * bit)
+  val full_add: (byte * bit) -> byte -> (byte * bit)
 end
 
@@ -74 +77 @@
                               (Bit.from_bool false) (Bit.from_bool false) in
       (n1, n2)
+  (* let from_int = assert false                                 DPM: finish! *)
 
   let get_nibble_at index (n1, n2) =
@@ -197 +201 @@
       (new_n1, new_n2)
   let to_string = iter_nibble Nibble.to_string
+
+  let zero = (Nibble.zero, Nibble.zero)
+  let half_add (l1, l2) (r1, r2) =
+    let (a2, c2) = Nibble.half_add l2 r2 in
+    let (a1, c1) = Nibble.full_add (l1, c2) r2 in
+      ((a1, a2), c1)
+  let full_add ((l1, l2), c) (r1, r2) =
+    let (a2, c2) = Nibble.full_add (l2, c) r2 in
+    let (a1, c1) = Nibble.full_add (l1, c2) r2 in
+      ((a1, a2), c1)
 end;;