1 /*
2  * Copyright (c) 2012-2017 The ANTLR Project. All rights reserved.
3  * Use of this file is governed by the BSD 3-clause license that
4  * can be found in the LICENSE.txt file in the project root.
5  */
6 
7 package org.antlr.v4.runtime.atn;
8 
9 import org.antlr.v4.runtime.Lexer;
10 import org.antlr.v4.runtime.misc.MurmurHash;
11 
12 /**
13  * Implements the {@code type} lexer action by calling {@link Lexer#setType}
14  * with the assigned type.
15  *
16  * @author Sam Harwell
17  * @since 4.2
18  */
19 public class LexerTypeAction implements LexerAction {
20 	private final int type;
21 
22 	/**
23 	 * Constructs a new {@code type} action with the specified token type value.
24 	 * @param type The type to assign to the token using {@link Lexer#setType}.
25 	 */
LexerTypeAction(int type)26 	public LexerTypeAction(int type) {
27 		this.type = type;
28 	}
29 
30 	/**
31 	 * Gets the type to assign to a token created by the lexer.
32 	 * @return The type to assign to a token created by the lexer.
33 	 */
getType()34 	public int getType() {
35 		return type;
36 	}
37 
38 	/**
39 	 * {@inheritDoc}
40 	 * @return This method returns {@link LexerActionType#TYPE}.
41 	 */
42 	@Override
getActionType()43 	public LexerActionType getActionType() {
44 		return LexerActionType.TYPE;
45 	}
46 
47 	/**
48 	 * {@inheritDoc}
49 	 * @return This method returns {@code false}.
50 	 */
51 	@Override
isPositionDependent()52 	public boolean isPositionDependent() {
53 		return false;
54 	}
55 
56 	/**
57 	 * {@inheritDoc}
58 	 *
59 	 * <p>This action is implemented by calling {@link Lexer#setType} with the
60 	 * value provided by {@link #getType}.</p>
61 	 */
62 	@Override
execute(Lexer lexer)63 	public void execute(Lexer lexer) {
64 		lexer.setType(type);
65 	}
66 
67 	@Override
hashCode()68 	public int hashCode() {
69 		int hash = MurmurHash.initialize();
70 		hash = MurmurHash.update(hash, getActionType().ordinal());
71 		hash = MurmurHash.update(hash, type);
72 		return MurmurHash.finish(hash, 2);
73 	}
74 
75 	@Override
equals(Object obj)76 	public boolean equals(Object obj) {
77 		if (obj == this) {
78 			return true;
79 		}
80 		else if (!(obj instanceof LexerTypeAction)) {
81 			return false;
82 		}
83 
84 		return type == ((LexerTypeAction)obj).type;
85 	}
86 
87 	@Override
toString()88 	public String toString() {
89 		return String.format("type(%d)", type);
90 	}
91 }
92