Mon, 17 Dec 2012 07:47:05 -0800
8004832: Add new doclint package
Reviewed-by: mcimadamore
1 /*
2 * Copyright (c) 1999, 2012, 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 */
26 package com.sun.tools.javac.parser;
28 import java.nio.*;
29 import java.util.List;
30 import java.util.ArrayList;
32 import com.sun.tools.javac.util.Position.LineMap;
33 import com.sun.tools.javac.parser.JavaTokenizer.*;
35 import static com.sun.tools.javac.parser.Tokens.*;
37 /** The lexical analyzer maps an input stream consisting of
38 * ASCII characters and Unicode escapes into a token sequence.
39 *
40 * <p><b>This is NOT part of any supported API.
41 * If you write code that depends on this, you do so at your own risk.
42 * This code and its internal interfaces are subject to change or
43 * deletion without notice.</b>
44 */
45 public class Scanner implements Lexer {
47 private Tokens tokens;
49 /** The token, set by nextToken().
50 */
51 private Token token;
53 /** The previous token, set by nextToken().
54 */
55 private Token prevToken;
57 /** Buffer of saved tokens (used during lookahead)
58 */
59 private List<Token> savedTokens = new ArrayList<Token>();
61 private JavaTokenizer tokenizer;
62 /**
63 * Create a scanner from the input array. This method might
64 * modify the array. To avoid copying the input array, ensure
65 * that {@code inputLength < input.length} or
66 * {@code input[input.length -1]} is a white space character.
67 *
68 * @param fac the factory which created this Scanner
69 * @param buf the input, might be modified
70 * Must be positive and less than or equal to input.length.
71 */
72 protected Scanner(ScannerFactory fac, CharBuffer buf) {
73 this(fac, new JavaTokenizer(fac, buf));
74 }
76 protected Scanner(ScannerFactory fac, char[] buf, int inputLength) {
77 this(fac, new JavaTokenizer(fac, buf, inputLength));
78 }
80 protected Scanner(ScannerFactory fac, JavaTokenizer tokenizer) {
81 this.tokenizer = tokenizer;
82 tokens = fac.tokens;
83 token = prevToken = DUMMY;
84 }
86 public Token token() {
87 return token(0);
88 }
90 public Token token(int lookahead) {
91 if (lookahead == 0) {
92 return token;
93 } else {
94 ensureLookahead(lookahead);
95 return savedTokens.get(lookahead - 1);
96 }
97 }
98 //where
99 private void ensureLookahead(int lookahead) {
100 for (int i = savedTokens.size() ; i < lookahead ; i ++) {
101 savedTokens.add(tokenizer.readToken());
102 }
103 }
105 public Token prevToken() {
106 return prevToken;
107 }
109 public void nextToken() {
110 prevToken = token;
111 if (!savedTokens.isEmpty()) {
112 token = savedTokens.remove(0);
113 } else {
114 token = tokenizer.readToken();
115 }
116 }
118 public Token split() {
119 Token[] splitTokens = token.split(tokens);
120 prevToken = splitTokens[0];
121 token = splitTokens[1];
122 return token;
123 }
125 public LineMap getLineMap() {
126 return tokenizer.getLineMap();
127 }
129 public int errPos() {
130 return tokenizer.errPos();
131 }
133 public void errPos(int pos) {
134 tokenizer.errPos(pos);
135 }
136 }