Fix Logical Primitive translation

compiler/src/l3/CL3ToCPSTranslator.scala

@@ -56,19 +56,17 @@ object CL3ToCPSTranslator extends (S.Tree => C.Tree) {
       transformArgs(primArgs)(Seq())
     }
 
+    // Builds a CPS If out of its arguments
     def transformTestPrim( p: L3TestPrimitive,
                                 primArgs: Seq[S.Tree],
                                 thenC: C.Name,
                                 elseC: C.Name): C.Tree = {
-
-      val start: C.Tree = C.If(p, Seq(), thenC, elseC)
-      primArgs.foldLeft(start) {
-        case (C.If(_, s, _, _), e) =>
-          transform(e)(v => {
-            C.If(p, s :+ v, thenC, elseC)
-          })
-        case _ => throw new Exception("unreachable code")
+      def transformArgs(args: Seq[S.Tree])(atoms: Seq[C.Atom]): C.Tree = args match {
+        case Nil => C.If(p, atoms, thenC, elseC)
+        case x::xs =>
+          transform(x)(v => transformArgs(xs)(atoms :+ v))
       }
+      transformArgs(primArgs)(Seq())
     }
 
     tree match {
@@ -126,8 +124,7 @@ object CL3ToCPSTranslator extends (S.Tree => C.Tree) {
                               S.Lit(BooleanLit(false))(tree.pos)
                               )(tree.pos)
           transform(newPrim)(ctx)
-        case p : L3ValuePrimitive =>
-          transformValPrim(p, args)
+        case p : L3ValuePrimitive => transformValPrim(p, args)
         }
       case S.Halt(arg) => transform(arg)(a => C.Halt(a))
     }