--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/jdk/src/share/classes/java/lang/invoke/FilterOneArgument.java	Wed Mar 23 23:02:31 2011 -0700
@@ -0,0 +1,80 @@
+/*
+ * Copyright (c) 2008, 2011, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.  Oracle designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Oracle in the LICENSE file that accompanied this code.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+package java.lang.invoke;
+
+import static java.lang.invoke.MethodHandleStatics.*;
+import static java.lang.invoke.MethodHandles.Lookup.IMPL_LOOKUP;
+
+/**
+ * Unary function composition, useful for many small plumbing jobs.
+ * The invoke method takes a single reference argument, and returns a reference
+ * Internally, it first calls the {@code filter} method on the argument,
+ * Making up the difference between the raw method type and the
+ * final method type is the responsibility of a JVM-level adapter.
+ * @author jrose
+ */
+class FilterOneArgument extends BoundMethodHandle {
+    protected final MethodHandle filter;  // Object -> Object
+    protected final MethodHandle target;  // Object -> Object
+
+    @Override
+    public String toString() {
+        return target.toString();
+    }
+
+    protected Object invoke(Object argument) throws Throwable {
+        Object filteredArgument = filter.invokeExact(argument);
+        return target.invokeExact(filteredArgument);
+    }
+
+    private static final MethodHandle INVOKE;
+    static {
+        try {
+            INVOKE =
+                IMPL_LOOKUP.findVirtual(FilterOneArgument.class, "invoke",
+                                        MethodType.genericMethodType(1));
+        } catch (ReflectiveOperationException ex) {
+            throw uncaughtException(ex);
+        }
+    }
+
+    protected FilterOneArgument(MethodHandle filter, MethodHandle target) {
+        super(INVOKE);
+        this.filter = filter;
+        this.target = target;
+    }
+
+    public static MethodHandle make(MethodHandle filter, MethodHandle target) {
+        if (filter == null)  return target;
+        if (target == null)  return filter;
+        return new FilterOneArgument(filter, target);
+    }
+
+//    MethodHandle make(MethodHandle filter1, MethodHandle filter2, MethodHandle target) {
+//        MethodHandle filter = make(filter1, filter2);
+//        return make(filter, target);
+//    }
+}