refactor traversal interface. Make distinction between traverseNode a…

…nd traverseScope

src/codegen/ParamCodegen.scala

@@ -11,8 +11,7 @@ abstract class ParamCodegen(implicit compiler:Spade) extends Pass with BFSTopolo
     val allNodes = new BFSTopologicalTraversal with GraphSchedular {
       type N = Parameter
       val forward = false
-      override def traverseNode(n:N, prev:T) = traverse(List(n), prev)
-    }.schedule(compiler.designParam).toSet.toList
+    }.scheduleNode(compiler.designParam).toSet.toList
     traverse(scheduleDepFree(allNodes), ())
   }
 

src/codegen/SpadeCodegen.scala

@@ -3,12 +3,4 @@ package codegen
 
 import prism.traversal._
 
-abstract class SpadeCodegen(implicit compiler:Spade) extends SpadeTraversal with ChildFirstTraversal with Codegen {
-  override def runPass = {
-    traverseNode(compiler.top)
-  }
-
-  override def quote(n:Any):String = {
-    super[SpadeTraversal].quote(n)
-  }
-}
+abstract class SpadeCodegen(implicit compiler:Spade) extends SpadeTraversal with ChildFirstTraversal with Codegen

src/codegen/dot/SpadeIRDotCodegen.scala

@@ -27,10 +27,4 @@ class SpadeIRDotCodegen[M<:SpadeNode:ClassTag:TypeTag](val fileName:String)(impl
     }
   }
 
-  override def runPass = {
-    compiler.top.collectDown[M]().headOption.foreach { node =>
-      traverseNode(node)
-    }
-  }
-
 }

src/pass/SpadeTraversal.scala

@@ -5,4 +5,6 @@ import spade._
 
 import prism.traversal._
 
-trait SpadeTraversal extends SpadePass with SpadeWorld with prism.traversal.Traversal
+trait SpadeTraversal extends SpadePass with SpadeWorld with prism.traversal.Traversal { self:HierarchicalTraversal =>
+  def top = compiler.top
+}