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src/share/classes/com/sun/tools/javac/parser/Scanner.java@959103a6100f (annotated)

src/share/classes/com/sun/tools/javac/parser/Scanner.java

Wed, 27 Apr 2016 01:34:52 +0800

author

aoqi

date

Wed, 27 Apr 2016 01:34:52 +0800

changeset 0

959103a6100f

child 2525

2eb010b6cb22

permissions

-rw-r--r--

Initial load
http://hg.openjdk.java.net/jdk8u/jdk8u/langtools/
changeset: 2573:53ca196be1ae
tag: jdk8u25-b17

aoqi@0	1	/*
aoqi@0	2	* Copyright (c) 1999, 2013, Oracle and/or its affiliates. All rights reserved.
aoqi@0	3	* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
aoqi@0	4	*
aoqi@0	5	* This code is free software; you can redistribute it and/or modify it
aoqi@0	6	* under the terms of the GNU General Public License version 2 only, as
aoqi@0	7	* published by the Free Software Foundation. Oracle designates this
aoqi@0	8	* particular file as subject to the "Classpath" exception as provided
aoqi@0	9	* by Oracle in the LICENSE file that accompanied this code.
aoqi@0	10	*
aoqi@0	11	* This code is distributed in the hope that it will be useful, but WITHOUT
aoqi@0	12	* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
aoqi@0	13	* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
aoqi@0	14	* version 2 for more details (a copy is included in the LICENSE file that
aoqi@0	15	* accompanied this code).
aoqi@0	16	*
aoqi@0	17	* You should have received a copy of the GNU General Public License version
aoqi@0	18	* 2 along with this work; if not, write to the Free Software Foundation,
aoqi@0	19	* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
aoqi@0	20	*
aoqi@0	21	* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
aoqi@0	22	* or visit www.oracle.com if you need additional information or have any
aoqi@0	23	* questions.
aoqi@0	24	*/
aoqi@0	25
aoqi@0	26	package com.sun.tools.javac.parser;
aoqi@0	27
aoqi@0	28	import java.nio.*;
aoqi@0	29	import java.util.List;
aoqi@0	30	import java.util.ArrayList;
aoqi@0	31
aoqi@0	32	import com.sun.tools.javac.util.Position.LineMap;
aoqi@0	33	import com.sun.tools.javac.parser.JavaTokenizer.*;
aoqi@0	34
aoqi@0	35	import static com.sun.tools.javac.parser.Tokens.*;
aoqi@0	36
aoqi@0	37	/** The lexical analyzer maps an input stream consisting of
aoqi@0	38	* ASCII characters and Unicode escapes into a token sequence.
aoqi@0	39	*
aoqi@0	40	* <p><b>This is NOT part of any supported API.
aoqi@0	41	* If you write code that depends on this, you do so at your own risk.
aoqi@0	42	* This code and its internal interfaces are subject to change or
aoqi@0	43	* deletion without notice.</b>
aoqi@0	44	*/
aoqi@0	45	public class Scanner implements Lexer {
aoqi@0	46
aoqi@0	47	private Tokens tokens;
aoqi@0	48
aoqi@0	49	/** The token, set by nextToken().
aoqi@0	50	*/
aoqi@0	51	private Token token;
aoqi@0	52
aoqi@0	53	/** The previous token, set by nextToken().
aoqi@0	54	*/
aoqi@0	55	private Token prevToken;
aoqi@0	56
aoqi@0	57	/** Buffer of saved tokens (used during lookahead)
aoqi@0	58	*/
aoqi@0	59	private List<Token> savedTokens = new ArrayList<Token>();
aoqi@0	60
aoqi@0	61	private JavaTokenizer tokenizer;
aoqi@0	62
aoqi@0	63	/**
aoqi@0	64	* Create a scanner from the input array. This method might
aoqi@0	65	* modify the array. To avoid copying the input array, ensure
aoqi@0	66	* that {@code inputLength < input.length} or
aoqi@0	67	* {@code input[input.length -1]} is a white space character.
aoqi@0	68	*
aoqi@0	69	* @param fac the factory which created this Scanner
aoqi@0	70	* @param buf the input, might be modified
aoqi@0	71	* Must be positive and less than or equal to input.length.
aoqi@0	72	*/
aoqi@0	73	protected Scanner(ScannerFactory fac, CharBuffer buf) {
aoqi@0	74	this(fac, new JavaTokenizer(fac, buf));
aoqi@0	75	}
aoqi@0	76
aoqi@0	77	protected Scanner(ScannerFactory fac, char[] buf, int inputLength) {
aoqi@0	78	this(fac, new JavaTokenizer(fac, buf, inputLength));
aoqi@0	79	}
aoqi@0	80
aoqi@0	81	protected Scanner(ScannerFactory fac, JavaTokenizer tokenizer) {
aoqi@0	82	this.tokenizer = tokenizer;
aoqi@0	83	tokens = fac.tokens;
aoqi@0	84	token = prevToken = DUMMY;
aoqi@0	85	}
aoqi@0	86
aoqi@0	87	public Token token() {
aoqi@0	88	return token(0);
aoqi@0	89	}
aoqi@0	90
aoqi@0	91	public Token token(int lookahead) {
aoqi@0	92	if (lookahead == 0) {
aoqi@0	93	return token;
aoqi@0	94	} else {
aoqi@0	95	ensureLookahead(lookahead);
aoqi@0	96	return savedTokens.get(lookahead - 1);
aoqi@0	97	}
aoqi@0	98	}
aoqi@0	99	//where
aoqi@0	100	private void ensureLookahead(int lookahead) {
aoqi@0	101	for (int i = savedTokens.size() ; i < lookahead ; i ++) {
aoqi@0	102	savedTokens.add(tokenizer.readToken());
aoqi@0	103	}
aoqi@0	104	}
aoqi@0	105
aoqi@0	106	public Token prevToken() {
aoqi@0	107	return prevToken;
aoqi@0	108	}
aoqi@0	109
aoqi@0	110	public void nextToken() {
aoqi@0	111	prevToken = token;
aoqi@0	112	if (!savedTokens.isEmpty()) {
aoqi@0	113	token = savedTokens.remove(0);
aoqi@0	114	} else {
aoqi@0	115	token = tokenizer.readToken();
aoqi@0	116	}
aoqi@0	117	}
aoqi@0	118
aoqi@0	119	public Token split() {
aoqi@0	120	Token[] splitTokens = token.split(tokens);
aoqi@0	121	prevToken = splitTokens[0];
aoqi@0	122	token = splitTokens[1];
aoqi@0	123	return token;
aoqi@0	124	}
aoqi@0	125
aoqi@0	126	public LineMap getLineMap() {
aoqi@0	127	return tokenizer.getLineMap();
aoqi@0	128	}
aoqi@0	129
aoqi@0	130	public int errPos() {
aoqi@0	131	return tokenizer.errPos();
aoqi@0	132	}
aoqi@0	133
aoqi@0	134	public void errPos(int pos) {
aoqi@0	135	tokenizer.errPos(pos);
aoqi@0	136	}
aoqi@0	137	}