First version of position pickler.

1 files changed, 51 insertions, 0 deletions

diff --git a/src/dotty/tools/dotc/core/pickling/PositionPickler.scala b/src/dotty/tools/dotc/core/pickling/PositionPickler.scala
new file mode 100644
index 000000000..0cf519b23
--- /dev/null
+++ b/src/dotty/tools/dotc/core/pickling/PositionPickler.scala
@@ -0,0 +1,51 @@
+package dotty.tools
+package dotc
+package core
+package pickling
+
+import ast.tpd._
+import PickleFormat._
+import core._
+import Contexts._, Symbols._, Types._, Names._, Constants._, Decorators._, Annotations._
+import collection.mutable
+import TastyBuffer._
+
+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 _ =>
+        ()
+    }
+ 
+    elemTraversal(root)()
+  }
+  
+  def picklePositions(root: Tree)(implicit ctx: Context) = {
+    traverseAll(root, startPos)
+    traverseAll(root, endPos)
+  }
+}
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