2 files changed, 36 insertions, 29 deletions
diff --git a/src/dotty/tools/dotc/core/pickling/Edge.scala b/src/dotty/tools/dotc/core/pickling/Edge.scala
index 543f85831..dbdc7fe65 100644
--- a/src/dotty/tools/dotc/core/pickling/Edge.scala
+++ b/src/dotty/tools/dotc/core/pickling/Edge.scala
@@ -1,16 +1,45 @@
 package dotty.tools.dotc
-package core.pickling
+package core
+package pickling
 
 import util.Positions._
-import ast.tpd._
+import ast.tpd.{Tree, MemberDef}
 import core.Contexts._
 
 abstract class Edge {
+  
   def offset(pos: Position): Int
   def seq(op1: () => Unit, op2: () => Unit): Unit
+  
+  private val noOp = () => ()
+  
+  def traverseAll(root: Tree)(op: Tree => Unit)(implicit ctx: Context) = {
+    
+    def elemsTraversal(xs: TraversableOnce[Any]): () => Unit = 
+      (noOp /: xs) ((op, x) => () => seq(op, elemTraversal(x)))
+
+    def elemTraversal(x: Any): () => Unit = () => x match {        
+      case x: Tree @ unchecked =>
+        op(x)
+        
+        val annotTraversal = x match {
+          case x: MemberDef => elemsTraversal(x.symbol.annotations)
+          case _ => noOp
+        }
+        val childrenTraversal = elemsTraversal(x.productIterator)
+        seq(annotTraversal, childrenTraversal)
+      case xs: List[_] =>
+        elemsTraversal(xs)()
+      case _ =>
+        ()
+    }
+ 
+    elemTraversal(root)()
+  }
 }
 
 object Edge {
+
   object left extends Edge {
     def offset(pos: Position): Int = pos.start
     def seq(op1: () => Unit, op2: () => Unit) = { op1(); op2() }
diff --git a/src/dotty/tools/dotc/core/pickling/PositionPickler.scala b/src/dotty/tools/dotc/core/pickling/PositionPickler.scala
index 0cf519b23..84ab35462 100644
--- a/src/dotty/tools/dotc/core/pickling/PositionPickler.scala
+++ b/src/dotty/tools/dotc/core/pickling/PositionPickler.scala
@@ -14,35 +14,13 @@ class PositionPickler(pickler: TastyPickler, addrOfTree: Tree => Option[Addr]) {
   val buf = new PositionBuffer
   pickler.newSection("Positions", buf)
   import buf._
-  
-  val noOp = () => ()
-  
-  def traverseAll(root: Tree, recorder: PositionRecorder)(implicit ctx: Context) = {
-    import recorder.edge.{seq, offset}
     
-    def elemsTraversal(xs: TraversableOnce[Any]): () => Unit = 
-      (noOp /: xs) ((op, x) => () => seq(op, elemTraversal(x)))
-
-    def elemTraversal(x: Any): () => Unit = () => x match {        
-      case x: Tree @ unchecked =>
-        if (x.pos.exists)
-          for (addr <- addrOfTree(x))
-            recorder.record(addr, offset(x.pos))
-        
-        val annotTraversal = x match {
-          case x: MemberDef => elemsTraversal(x.symbol.annotations)
-          case _ => noOp
-        }
-        val childrenTraversal = elemsTraversal(x.productIterator)
-        seq(annotTraversal, childrenTraversal)
-      case xs: List[_] =>
-        elemsTraversal(xs)()
-      case _ =>
-        ()
+  def traverseAll(root: Tree, recorder: PositionRecorder)(implicit ctx: Context) = 
+    recorder.edge.traverseAll(root) { tree =>
+      if (tree.pos.exists)
+        for (addr <- addrOfTree(tree))
+          recorder.record(addr, recorder.edge.offset(tree.pos))
     }
- 
-    elemTraversal(root)()
-  }
   
   def picklePositions(root: Tree)(implicit ctx: Context) = {
     traverseAll(root, startPos)