8139266: add JSAdapter example with fallthrough

Reviewed-by: attila, hannesw

nashorn/samples/jsadapter-fallthrough.js

@@ -0,0 +1,57 @@
+/*
+ * Copyright (c) 2015, Oracle and/or its affiliates. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ *   - Redistributions of source code must retain the above copyright
+ *     notice, this list of conditions and the following disclaimer.
+ *
+ *   - Redistributions in binary form must reproduce the above copyright
+ *     notice, this list of conditions and the following disclaimer in the
+ *     documentation and/or other materials provided with the distribution.
+ *
+ *   - Neither the name of Oracle nor the names of its
+ *     contributors may be used to endorse or promote products derived
+ *     from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
+ * IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
+ * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT OWNER OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+ * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
+ * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+ * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+// Demonstrate how to provide a default fall-through solution for adapted Java
+// objects, forwarding all calls that are not adapted.
+
+var Date = Java.type('java.time.LocalDate')
+
+function wrapDate(d) {
+    return new JSAdapter() {
+        __call__: function() {
+            // adapted (extra) methods
+            if (arguments[0] === 'yesterday') {
+                return d.minusDays(1)
+            }
+            // fall-through: forward all other, non-adapted method calls
+            var args = [d].concat(Array.prototype.slice.call(arguments, 1)) 
+            return Function.call.apply(d[arguments[0]], args)
+        }
+    }
+}
+
+var now = wrapDate(Date.now())
+
+print(now)
+print(now.yesterday()) // adapted
+print(now.lengthOfMonth()) // fall through to original method
+print(now.atTime(23, 42)) // arguments are passed through
+