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1   /*
2    * Copyright (c) 2010, 2013, 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 jdk.nashorn.internal.ir;
27  
28  import java.util.List;
29  import jdk.nashorn.internal.ir.visitor.NodeVisitor;
30  
31  /**
32   * Represents a block used as a statement.
33   */
34  public class BlockStatement extends Statement {
35      /** Block to execute. */
36      private final Block block;
37  
38      /**
39       * Constructor
40       *
41       * @param lineNumber line number
42       * @param block the block to execute
43       */
44      public BlockStatement(final int lineNumber, final Block block) {
45          super(lineNumber, block.getToken(), block.getFinish());
46          this.block = block;
47      }
48  
49      private BlockStatement(final BlockStatement blockStatement, final Block block) {
50          super(blockStatement);
51          this.block = block;
52      }
53  
54      /**
55       * Use this method to create a block statement meant to replace a single statement.
56       * @param stmt the statement to replace
57       * @param newStmts the statements for the new block statement
58       * @return a block statement with the new statements. It will have the line number, token, and finish of the
59       * original statement.
60       */
61      public static Statement createReplacement(final Statement stmt, final List<Statement> newStmts) {
62          return createReplacement(stmt, stmt.getFinish(), newStmts);
63      }
64  
65      /**
66       * Use this method to create a block statement meant to replace a single statement.
67       * @param stmt the statement to replace
68       * @param finish the new finish for the block
69       * @param newStmts the statements for the new block statement
70       * @return a block statement with the new statements. It will have the line number, and token of the
71       * original statement.
72       */
73      public static Statement createReplacement(final Statement stmt, int finish, final List<Statement> newStmts) {
74          return new BlockStatement(stmt.getLineNumber(), new Block(stmt.getToken(), finish, newStmts));
75      }
76  
77      @Override
78      public boolean isTerminal() {
79          return block.isTerminal();
80      }
81  
82      @Override
83      public Node accept(final NodeVisitor<? extends LexicalContext> visitor) {
84          if (visitor.enterBlockStatement(this)) {
85              return visitor.leaveBlockStatement(setBlock((Block)block.accept(visitor)));
86          }
87  
88          return this;
89      }
90  
91      @Override
92      public void toString(final StringBuilder sb) {
93          block.toString(sb);
94      }
95  
96      /**
97       * Return the block to be executed
98       * @return the block
99       */
100     public Block getBlock() {
101         return block;
102     }
103 
104     /**
105      * Reset the block to be executed
106      * @param block the block
107      * @return new or same execute node
108      */
109     public BlockStatement setBlock(final Block block) {
110         if (this.block == block) {
111             return this;
112         }
113         return new BlockStatement(this, block);
114     }
115 }