1 /*
   2  * Copyright (c) 2011, 2014, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.  Oracle designates this
   8  * particular file as subject to the "Classpath" exception as provided
   9  * by Oracle in the LICENSE file that accompanied this code.
  10  *
  11  * This code is distributed in the hope that it will be useful, but WITHOUT
  12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  14  * version 2 for more details (a copy is included in the LICENSE file that
  15  * accompanied this code).
  16  *
  17  * You should have received a copy of the GNU General Public License version
  18  * 2 along with this work; if not, write to the Free Software Foundation,
  19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  20  *
  21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  22  * or visit www.oracle.com if you need additional information or have any
  23  * questions.
  24  */
  25 
  26 package com.sun.source.tree;
  27 
  28 import java.util.List;
  29 
  30 /**
  31  * A tree node for a lambda expression.
  32  *
  33  * For example:
  34  * <pre>{@code
  35  *   ()->{}
  36  *   (List<String> ls)->ls.size()
  37  *   (x,y)-> { return x + y; }
  38  * }</pre>
  39  */
  40 @jdk.Exported
  41 public interface LambdaExpressionTree extends ExpressionTree {
  42 
  43     /**
  44      * Lambda expressions come in two forms:
  45      * <ul compact>
  46      * <li> expression lambdas, whose body is an expression, and
  47      * <li> statement lambdas, whose body is a block
  48      * </ul>
  49      */
  50     @jdk.Exported
  51     public enum BodyKind {
  52         /** enum constant for expression lambdas */
  53         EXPRESSION,
  54         /** enum constant for statement lambdas */
  55         STATEMENT
  56     }
  57 
  58     /**
  59      * Returns the parameters of this lambda expression.
  60      * @return the parameters
  61      */
  62     List<? extends VariableTree> getParameters();
  63 
  64     /**
  65      * Returns the body of the lambda expression.
  66      * @return the body
  67      */
  68     Tree getBody();
  69 
  70     /**
  71      * Returns the kind of the body of the lambda expression.
  72      * @return the kind of the body
  73      */
  74     BodyKind getBodyKind();
  75 }