Partial cleanup and generalization of tree prin...

Partial cleanup and generalization of tree printing. You can now print
a tree in direct case class form with `showRaw(tree)`. Should make
NodePrinters redundant.

4 files changed, 63 insertions, 4 deletions

diff --git a/src/library/scala/reflect/api/Symbols.scala b/src/library/scala/reflect/api/Symbols.scala
index 3c4408aacd..31bcdebe7e 100755
--- a/src/library/scala/reflect/api/Symbols.scala
+++ b/src/library/scala/reflect/api/Symbols.scala
@@ -36,6 +36,9 @@ trait Symbols { self: Universe =>
      */
     def fullName: String
 
+    /** An id number which is unique for all symbols in this universe */
+    def id: Int
+
     /**
      * Set when symbol has a modifier of the form private[X], NoSymbol otherwise.
      *
diff --git a/src/library/scala/reflect/api/TreePrinters.scala b/src/library/scala/reflect/api/TreePrinters.scala
new file mode 100644
index 0000000000..15fba0e418
--- /dev/null
+++ b/src/library/scala/reflect/api/TreePrinters.scala
@@ -0,0 +1,59 @@
+package scala.reflect
+package api
+
+import java.io.{ PrintWriter, StringWriter }
+
+trait TreePrinters { self: Universe =>
+
+  trait TreePrinter {
+    def print(args: Any*)
+    protected var typesPrinted = false
+    protected var uniqueIds = false
+    def withTypesPrinted: this.type = { typesPrinted = true; this }
+    def withUniqueIds: this.type = { uniqueIds = true; this }
+  }
+
+  def show(tree: Tree, mkPrinter: PrintWriter => TreePrinter = newTreePrinter): String = {
+    val buffer = new StringWriter()
+    val writer = new PrintWriter(buffer)
+    val printer = mkPrinter(writer)
+    printer.print(tree)
+    writer.flush()
+    buffer.toString
+  }
+
+  def showRaw(tree: Tree): String = show(tree, new RawTreePrinter(_))
+
+  /** Hook to define what `show(tree)` means.
+   */
+  def newTreePrinter(out: PrintWriter): TreePrinter
+
+  class RawTreePrinter(out: PrintWriter) extends TreePrinter {
+    def print(args: Any*): Unit = args foreach {
+      case EmptyTree =>
+        print("EmptyTree")
+      case tree @ TypeTree() =>
+        print("TypeTree()")
+        if (tree.tpe != null)
+          print(".setType(", tree.tpe, ")")
+        else if (tree.original != null)
+          print(".setOriginal(", tree.original, ")")
+      case tree: Tree =>
+        print(tree.productPrefix+"(")
+        val it = tree.productIterator
+        while (it.hasNext) {
+          it.next() match {
+            case name: Name if uniqueIds && tree.hasSymbol && tree.symbol != NoSymbol =>
+              print(tree.symbol.name, "#", tree.symbol.id)
+            case arg =>
+              print(arg)
+          }
+          print(if (it.hasNext) ", " else ")")
+        }
+        if (typesPrinted)
+          print(".setType(", tree.tpe, ")")
+      case arg =>
+        out.print(arg)
+    }
+  }
+}
diff --git a/src/library/scala/reflect/api/Trees.scala b/src/library/scala/reflect/api/Trees.scala
index 64793fb303..478c47a210 100644
--- a/src/library/scala/reflect/api/Trees.scala
+++ b/src/library/scala/reflect/api/Trees.scala
@@ -16,10 +16,6 @@ trait Trees /*extends reflect.generic.Trees*/ { self: Universe =>
 
   type Modifiers <: AbsModifiers
 
-  /** Hook to define what toString means on a tree
-   */
-  def show(tree: Tree): String
-
   abstract class AbsModifiers {
     def hasModifier(mod: Modifier.Value): Boolean
     def allModifiers: Set[Modifier.Value]
diff --git a/src/library/scala/reflect/api/Universe.scala b/src/library/scala/reflect/api/Universe.scala
index ad145b12ac..03acbdda2c 100755
--- a/src/library/scala/reflect/api/Universe.scala
+++ b/src/library/scala/reflect/api/Universe.scala
@@ -8,6 +8,7 @@ abstract class Universe extends Symbols
                            with Names
                            with Trees
                            with Positions
+                           with TreePrinters
                            with AnnotationInfos
                            with StandardDefinitions {
   type Position