scala version of test reg traverser

1 files changed, 45 insertions, 0 deletions

diff --git a/sources/scalac/transformer/matching/TestRegTraverser.scala b/sources/scalac/transformer/matching/TestRegTraverser.scala
new file mode 100644
index 0000000000..9db9dac492
--- /dev/null
+++ b/sources/scalac/transformer/matching/TestRegTraverser.scala
@@ -0,0 +1,45 @@
+/*     ____ ____  ____ ____  ______                                     *\
+**    / __// __ \/ __// __ \/ ____/    SOcos COmpiles Scala             **
+**  __\_ \/ /_/ / /__/ /_/ /\_ \       (c) 2002, LAMP/EPFL              **
+** /_____/\____/\___/\____/____/                                        **
+**                                                                      **
+** $Id$
+\*                                                                      */
+
+package scalac.transformer.matching;
+
+import scalac.ast._;
+import scalac.util._;
+import scalac.symtab._;
+
+import java.util.{Set,HashSet};
+
+object TestRegTraverser extends Traverser {
+
+  var result:boolean = false;
+  var variables:Set = null:Set;
+
+  override def traverse( tree:Tree ):Unit = {
+
+    tree.match {
+      case Tree$Alternative(_) =>
+	result = true;
+      case Tree$Bind(_, pat) =>
+	variables.add(tree.symbol());
+	traverse(pat);
+      case Tree$Ident( name ) =>
+        result = ((name != Names.WILDCARD)
+		  && variables.contains(tree.symbol()))
+      case Tree$CaseDef(pat, _, _) =>
+	traverse(pat);
+      case _ =>
+	super.traverse( tree );
+    }
+  }
+
+  def apply(t:Tree):boolean = {
+    variables = new HashSet();
+    traverse(t);
+    result
+  }
+}