--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/jdk/src/share/classes/java/util/stream/StreamShape.java	Tue Apr 16 22:50:48 2013 -0400
@@ -0,0 +1,70 @@
+/*
+ * Copyright (c) 2012, 2013, 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.util.stream;
+
+/**
+ * An enum describing the known shape specializations for stream abstractions.
+ * Each will correspond to a specific subinterface of {@link BaseStream}
+ * (e.g., {@code REFERENCE} corresponds to {@code Stream}, {@code INT_VALUE}
+ * corresponds to {@code IntStream}).  Each may also correspond to
+ * specializations of value-handling abstractions such as {@code Spliterator},
+ * {@code Consumer}, etc.
+ *
+ * @apiNote
+ * This enum is used by implementations to determine compatibility between
+ * streams and operations (i.e., if the output shape of a stream is compatible
+ * with the input shape of the next operation).
+ *
+ * <p>Some APIs require you to specify both a generic type and a stream shape
+ * for input or output elements, such as {@link TerminalOp} which has both
+ * generic type parameters for its input types, and a getter for the
+ * input shape.  When representing primitive streams in this way, the
+ * generic type parameter should correspond to the wrapper type for that
+ * primitive type.
+ *
+ * @since 1.8
+ */
+enum StreamShape {
+    /**
+     * The shape specialization corresponding to {@code Stream} and elements
+     * that are object references.
+     */
+    REFERENCE,
+    /**
+     * The shape specialization corresponding to {@code IntStream} and elements
+     * that are {@code int} values.
+     */
+    INT_VALUE,
+    /**
+     * The shape specialization corresponding to {@code LongStream} and elements
+     * that are {@code long} values.
+     */
+    LONG_VALUE,
+    /**
+     * The shape specialization corresponding to {@code DoubleStream} and
+     * elements that are {@code double} values.
+     */
+    DOUBLE_VALUE
+}