more work on continuation support

classpath/avian/Continuations.java

@@ -0,0 +1,27 @@
+/* Copyright (c) 2009, Avian Contributors
+
+   Permission to use, copy, modify, and/or distribute this software
+   for any purpose with or without fee is hereby granted, provided
+   that the above copyright notice and this permission notice appear
+   in all copies.
+
+   There is NO WARRANTY for this software.  See license.txt for
+   details. */
+
+package avian;
+
+import java.util.concurrent.Callable;
+
+public abstract class Continuations {
+  public static native <T> T callWithCurrentContinuation
+    (CallbackReceiver<T> receiver) throws Exception;
+
+  public static native <T> T dynamicWind(Runnable before,
+                                         Callable<T> thunk,
+                                         Runnable after) throws Exception;
+
+  private static class Continuation<T> implements Callback<T> {
+    public native void handleResult(T result);
+    public native void handleException(Throwable exception);
+  }
+}