--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/scala/comp1.scala	Thu Feb 21 16:07:40 2013 +0000
@@ -0,0 +1,73 @@
+package object comp1 {
+
+import lib._
+import turing._
+import abacus._
+
+// TMs used in the translation
+
+val TMInc = TM(List((WOc, 1), (R, 2), (WOc, 3), (R, 2), (WOc, 3), (R, 4), 
+                    (L, 7), (WBk, 5), (R, 6), (WBk, 5), (WOc, 3), (R, 6),
+                    (L, 8), (L, 7), (R, 9), (L, 7), (R, 10), (WBk, 9)))
+
+val TMDec = TM(List((WOc, 1), (R, 2), (L, 14), (R, 3), (L, 4), (R, 3),
+                    (R, 5), (WBk, 4), (R, 6), (WBk, 5), (L, 7), (L, 8),
+                    (L, 11), (WBk, 7), (WOc, 8), (R, 9), (L, 10), (R, 9),
+                    (R, 5), (WBk, 10), (L, 12), (L, 11), (R, 13), (L, 11),
+                    (R, 17), (WBk, 13), (L, 15), (L, 14), (R, 16), (L, 14),
+                    (R, 0), (WBk, 16)))
+
+val TMGoto = TM(List((Nop, 1), (Nop, 1)))
+
+def TMFindnth(n: Int) : TM = n match {
+  case 0 => TM(Nil)
+  case n => TMFindnth(n - 1) ++ TM(List((WOc, 2 * n - 1), (R, 2 * n), (R, 2 * n + 1), (R, 2 * n)))
+}
+
+def TMMopup(n: Int) = {
+  def TMMopup1(n: Int) : TM = n match {
+    case 0 => TM(Nil)
+    case n => TMMopup1(n - 1) ++ TM(List((R, 2 * n + 1), (WBk, 2 * n), (R, 2 * n - 1), (WOc, 2 * n)))
+  }
+
+  val TMMopup2 = TM(List((R, 2), (R, 1), (L, 5), (WBk, 3), (R, 4), (WBk, 3),
+                         (R, 2), (WBk, 3), (L, 5), (L, 6), (R, 0), (L, 6)))
+
+  TMMopup1(n) ++ TMMopup2.shift(2 * n)
+}
+
+
+
+// Abacus to TM translation
+def layout(p: AProg) = p.map(_ match {
+  case Inc(n) => 2 * n + 9 
+  case Dec(n, _) => 2 * n + 16 
+  case Goto(n) => 1
+})
+
+def start(p: AProg, n: Int) = layout(p).take(n).sum + 1
+
+def compile_Inc(s: Int, n: Int) = 
+  TMFindnth(n).shift(s - 1) ++ TMInc.shift(2 * n).shift(s - 1)
+
+def compile_Dec(s: Int, n: Int, e: Int) = 
+  TMFindnth(n).shift(s - 1) ++ TMDec.shift(2 * n).shift(s - 1).adjust(e)
+
+def compile_Goto(s: Int) = TMGoto.shift(s - 1)
+
+def compile(p: AProg, s: Int, i: AInst) = i match {
+  case Inc(n) => compile_Inc(s, n)
+  case Dec(n, e) => compile_Dec(s, n, start(p, e))
+  case Goto(e) => compile_Goto(start(p, e))
+}
+
+// component TMs for each instruction
+def TMs(p: AProg) = {
+  val ss = (0 until p.length).map (start(p,_))
+  (ss zip p).map{case (n, i) => compile(p, n, i)}
+}
+
+def toTM(p: AProg) = TMs(p).reduceLeft(_ ++ _)
+    
+}
+