7115046: Add AST node for lambda expressions

Add tree nodes for representing lambda expressions and update relevant visitors interfaces

Reviewed-by: jjg

langtools/src/share/classes/com/sun/source/tree/LambdaExpressionTree.java

@@ -0,0 +1,56 @@
+/*
+ * Copyright (c) 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 com.sun.source.tree;
+
+import java.util.List;
+
+/**
+ * A tree node for a lambda expression.
+ *
+ * For example:
+ * <pre>
+ *   ()->{}
+ *   (List<String> ls)->ls.size()
+ *   (x,y)-> { return x + y; }
+ * </pre>
+ */
+public interface LambdaExpressionTree extends ExpressionTree {
+
+    /**
+     * Lambda expressions come in two forms: (i) expression lambdas, whose body
+     * is an expression, and (ii) statement lambdas, whose body is a block
+     */
+    public enum BodyKind {
+        /** enum constant for expression lambdas */
+        EXPRESSION,
+        /** enum constant for statement lambdas */
+        STATEMENT;
+    }
+
+    List<? extends VariableTree> getParameters();
+    Tree getBody();
+    BodyKind getBodyKind();
+}