diff --git "a/Scala-\346\235\245\351\200\222\345\275\222\344\270\200\344\270\213\345\220\247" "b/Scala-\346\235\245\351\200\222\345\275\222\344\270\200\344\270\213\345\220\247"
new file mode 100644
index 0000000000000000000000000000000000000000..45395303dbddb9aef00b7db06b8c882c5e9f4334
--- /dev/null
+++ "b/Scala-\346\235\245\351\200\222\345\275\222\344\270\200\344\270\213\345\220\247"
@@ -0,0 +1,10 @@
+sealed class Node(subnodes: Traversable[Node]) extends Traversable[Node] {
+  def foreach[U](f: Node => U) {
+    f(this)
+    subnodes foreach f
+  }
+}
+
+case class Atom(id: String) extends Node(Nil)
+
+case class Molecule(atoms: List[Node]) extends Node(atoms)