Initial data commit

Task/Stack/Io/stack.io

@@ -0,0 +1,21 @@
+Node := Object clone do(
+    next := nil
+    obj := nil
+)
+
+Stack := Object clone do(
+    node := nil
+
+    pop := method(
+        obj := node obj
+        node = node next
+        obj
+    )
+
+    push := method(obj,
+        nn := Node clone
+        nn obj = obj
+        nn next = self node
+        self node = nn
+    )
+)