1ed67a71e4
* java/io/StreamTokenizer.java (TT_NONE): Now private. (nextToken): Handle backslashed newline. From Oskar Liljeblad. For PR java.io/301. From-SVN: r35511
652 lines
19 KiB
Java
652 lines
19 KiB
Java
/* Copyright (C) 1998, 1999, 2000 Free Software Foundation
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This file is part of libgcj.
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This software is copyrighted work licensed under the terms of the
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Libgcj License. Please consult the file "LIBGCJ_LICENSE" for
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details. */
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package java.io;
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/**
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* This class parses streams of characters into tokens. There are a
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* million-zillion flags that can be set to control the parsing, as
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* described under the various method headings.
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*
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* @author Warren Levy <warrenl@cygnus.com>
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* @date October 25, 1998.
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*/
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/* Written using "Java Class Libraries", 2nd edition, ISBN 0-201-31002-3
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* "The Java Language Specification", ISBN 0-201-63451-1
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* plus online API docs for JDK 1.2 beta from http://www.javasoft.com.
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* Status: Believed complete and correct.
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*/
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public class StreamTokenizer
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{
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/** A constant indicating that the end of the stream has been read. */
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public static final int TT_EOF = -1;
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/** A constant indicating that the end of the line has been read. */
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public static final int TT_EOL = '\n';
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/** A constant indicating that a number token has been read. */
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public static final int TT_NUMBER = -2;
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/** A constant indicating that a word token has been read. */
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public static final int TT_WORD = -3;
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/** A constant indicating that no tokens have been read yet. */
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private static final int TT_NONE = -4;
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/**
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* Contains the type of the token read resulting from a call to nextToken
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* The rules are as follows:
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* <ul>
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* <li>For a token consisting of a single ordinary character, this is the
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* value of that character.
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* <li>For a quoted string, this is the value of the quote character
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* <li>For a word, this is TT_WORD
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* <li>For a number, this is TT_NUMBER
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* <li>For the end of the line, this is TT_EOL
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* <li>For the end of the stream, this is TT_EOF
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* </ul>
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*/
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public int ttype = TT_NONE;
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/** The String associated with word and string tokens. */
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public String sval;
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/** The numeric value associated with number tokens. */
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public double nval;
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/* Indicates whether end-of-line is recognized as a token. */
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private boolean eolSignificant = false;
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/* Indicates whether word tokens are automatically made lower case. */
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private boolean lowerCase = false;
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/* Indicates whether C++ style comments are recognized and skipped. */
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private boolean slashSlash = false;
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/* Indicates whether C style comments are recognized and skipped. */
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private boolean slashStar = false;
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/* Attribute tables of each byte from 0x00 to 0xFF. */
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private boolean[] whitespace = new boolean[256];
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private boolean[] alphabetic = new boolean[256];
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private boolean[] numeric = new boolean[256];
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private boolean[] quote = new boolean[256];
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private boolean[] comment = new boolean[256];
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/* The Reader associated with this class. */
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private PushbackReader in;
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/* Indicates if a token has been pushed back. */
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private boolean pushedBack = false;
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/* Contains the current line number of the reader. */
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private int lineNumber = 1;
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/**
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* This method reads bytes from an <code>InputStream</code> and tokenizes
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* them. For details on how this method operates by default, see
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* <code>StreamTokenizer(Reader)</code>.
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*
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* @param in The <code>InputStream</code> to read from
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*
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* @deprecated Since JDK 1.1.
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*/
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public StreamTokenizer(InputStream is)
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{
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this(new InputStreamReader(is));
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}
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/**
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* This method initializes a new <code>StreamTokenizer</code> to read
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* characters from a <code>Reader</code> and parse them. The char values
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* have their hight bits masked so that the value is treated a character
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* in the range of 0x0000 to 0x00FF.
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* <p>
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* This constructor sets up the parsing table to parse the stream in the
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* following manner:
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* <ul>
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* <li>The values 'A' through 'Z', 'a' through 'z' and 0xA0 through 0xFF
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* are initialized as alphabetic
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* <li>The values 0x00 through 0x20 are initialized as whitespace
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* <li>The values '\'' and '"' are initialized as quote characters
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* <li>'/' is a comment character
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* <li>Numbers will be parsed
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* <li>EOL is not treated as significant
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* <li>C and C++ (//) comments are not recognized
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* </ul>
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*
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* @param in The <code>Reader</code> to read chars from
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*/
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public StreamTokenizer(Reader r)
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{
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in = new PushbackReader(r);
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whitespaceChars(0x00, 0x20);
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wordChars('A', 'Z');
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wordChars('a', 'z');
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wordChars(0xA0, 0xFF);
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commentChar('/');
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quoteChar('\'');
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quoteChar('"');
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parseNumbers();
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}
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/**
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* This method sets the comment attribute on the specified character.
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*
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* @param c The character to set the comment attribute for, passed as an int
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*/
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public void commentChar(int ch)
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{
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if (ch >= 0 && ch <= 255)
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comment[ch] = true;
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}
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/**
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* This method sets a flag that indicates whether or not the end of line
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* sequence terminates and is a token. The defaults to <code>false</code>
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*
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* @param flag <code>true</code> if EOF is significant, <code>false</code>
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* otherwise
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*/
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public void eolIsSignificant(boolean flag)
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{
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eolSignificant = flag;
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}
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/**
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* This method returns the current line number. Note that if the
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* <code>pushBack()</code> method is called, it has no effect on the
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* line number returned by this method.
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*
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* @return The current line number
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*/
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public int lineno()
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{
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return lineNumber;
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}
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/**
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* This method sets a flag that indicates whether or not alphabetic
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* tokens that are returned should be converted to lower case.
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*
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* @param flag <code>true</code> to convert to lower case,
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* <code>false</code> otherwise
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*/
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public void lowerCaseMode(boolean flag)
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{
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lowerCase = flag;
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}
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private boolean isWhitespace(int ch)
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{
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return (ch >= 0 && ch <= 255 && whitespace[ch]);
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}
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private boolean isAlphabetic(int ch)
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{
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return ((ch > 255) || (ch >= 0 && alphabetic[ch]));
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}
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private boolean isNumeric(int ch)
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{
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return (ch >= 0 && ch <= 255 && numeric[ch]);
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}
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private boolean isQuote(int ch)
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{
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return (ch >= 0 && ch <= 255 && quote[ch]);
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}
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private boolean isComment(int ch)
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{
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return (ch >= 0 && ch <= 255 && comment[ch]);
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}
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/**
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* This method reads the next token from the stream. It sets the
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* <code>ttype</code> variable to the appropriate token type and
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* returns it. It also can set <code>sval</code> or <code>nval</code>
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* as described below. The parsing strategy is as follows:
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* <ul>
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* <li>Skip any whitespace characters.
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* <li>If a numeric character is encountered, attempt to parse a numeric
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* value. Leading '-' characters indicate a numeric only if followed by
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* another non-'-' numeric. The value of the numeric token is terminated
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* by either the first non-numeric encountered, or the second occurrence of
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* '-' or '.'. The token type returned is TT_NUMBER and <code>nval</code>
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* is set to the value parsed.
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* <li>If an alphabetic character is parsed, all subsequent characters
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* are read until the first non-alphabetic or non-numeric character is
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* encountered. The token type returned is TT_WORD and the value parsed
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* is stored in <code>sval</code>. If lower case mode is set, the token
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* stored in <code>sval</code> is converted to lower case. The end of line
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* sequence terminates a word only if EOL signficance has been turned on.
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* The start of a comment also terminates a word. Any character with a
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* non-alphabetic and non-numeric attribute (such as white space, a quote,
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* or a commet) are treated as non-alphabetic and terminate the word.
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* <li>If a comment charcters is parsed, then all remaining characters on
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* the current line are skipped and another token is parsed. Any EOL or
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* EOF's encountered are not discarded, but rather terminate the comment.
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* <li>If a quote character is parsed, then all characters up to the
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* second occurrence of the same quote character are parsed into a
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* <code>String</code>. This <code>String</code> is stored as
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* <code>sval</code>, but is not converted to lower case, even if lower case
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* mode is enabled. The token type returned is the value of the quote
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* character encountered. Any escape sequences
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* (\b (backspace), \t (HTAB), \n (linefeed), \f (form feed), \r
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* (carriage return), \" (double quote), \' (single quote), \\
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* (backslash), \XXX (octal esacpe)) are converted to the appropriate
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* char values. Invalid esacape sequences are left in untranslated.
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* Unicode characters like ('\ u0000') are not recognized.
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* <li>If the C++ comment sequence "//" is encountered, and the parser
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* is configured to handle that sequence, then the remainder of the line
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* is skipped and another token is read exactly as if a character with
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* the comment attribute was encountered.
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* <li>If the C comment sequence "/*" is encountered, and the parser
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* is configured to handle that sequence, then all characters up to and
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* including the comment terminator sequence are discarded and another
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* token is parsed.
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* <li>If all cases above are not met, then the character is an ordinary
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* character that is parsed as a token by itself. The char encountered
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* is returned as the token type.
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* </ul>
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*
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* @return The token type
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* @exception IOException If an I/O error occurs
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*/
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public int nextToken() throws IOException
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{
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if (pushedBack)
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{
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pushedBack = false;
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if (ttype != TT_NONE)
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return ttype;
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}
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sval = null;
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int ch;
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// Skip whitespace. Deal with EOL along the way.
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while (isWhitespace(ch = in.read()))
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if (ch == '\n' || ch == '\r')
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{
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lineNumber++;
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// Throw away \n if in combination with \r.
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if (ch == '\r' && (ch = in.read()) != '\n')
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{
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if (ch != TT_EOF)
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in.unread(ch);
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}
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if (eolSignificant)
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return (ttype = TT_EOL);
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}
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if (ch == TT_EOF)
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ttype = TT_EOF;
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else if (isNumeric(ch))
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{
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if (ch == '-')
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{
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// Read ahead to see if this is an ordinary '-' rather than numeric.
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ch = in.read();
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if (ch != TT_EOF)
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in.unread(ch);
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if (isNumeric(ch) && ch != '-')
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ch = '-';
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else
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return (ttype = '-');
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}
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StringBuffer tokbuf = new StringBuffer();
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tokbuf.append((char) ch);
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int decCount = 0;
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while (isNumeric(ch = in.read()) && ch != '-')
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if (ch == '.' && decCount++ > 0)
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break;
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else
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tokbuf.append((char) ch);
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if (ch != TT_EOF)
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in.unread(ch);
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ttype = TT_NUMBER;
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nval = Double.valueOf(tokbuf.toString()).doubleValue();
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}
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else if (isAlphabetic(ch))
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{
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StringBuffer tokbuf = new StringBuffer();
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tokbuf.append((char) ch);
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while (isAlphabetic(ch = in.read()) || isNumeric(ch))
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tokbuf.append((char) ch);
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if (ch != TT_EOF)
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in.unread(ch);
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ttype = TT_WORD;
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sval = tokbuf.toString();
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if (lowerCase)
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sval.toLowerCase();
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}
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else if (isComment(ch))
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{
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while ((ch = in.read()) != '\n' && ch != '\r' && ch != TT_EOF)
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;
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if (ch != TT_EOF)
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in.unread(ch);
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return nextToken(); // Recursive, but not too deep in normal cases.
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}
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else if (isQuote(ch))
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{
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ttype = ch;
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StringBuffer tokbuf = new StringBuffer();
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while ((ch = in.read()) != ttype && ch != '\n' && ch != '\r' &&
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ch != TT_EOF)
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{
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if (ch == '\\')
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switch (ch = in.read())
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{
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case 'a': ch = 0x7;
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break;
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case 'b': ch = '\b';
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break;
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case 'f': ch = 0xC;
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break;
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case 'n': ch = '\n';
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break;
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case 'r': ch = '\r';
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break;
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case 't': ch = '\t';
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break;
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case 'v': ch = 0xB;
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break;
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case '\n': ch = '\n';
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break;
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case '\r': ch = '\r';
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break;
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case '\"':
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case '\'':
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case '\\':
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break;
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default:
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int ch1, nextch;
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if ((nextch = ch1 = ch) >= '0' && ch <= '7')
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{
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ch -= '0';
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if ((nextch = in.read()) >= '0' && nextch <= '7')
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{
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ch = ch * 8 + nextch - '0';
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if ((nextch = in.read()) >= '0' && nextch <= '7' &&
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ch1 >= '0' && ch1 <= '3')
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{
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ch = ch * 8 + nextch - '0';
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nextch = in.read();
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}
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}
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}
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if (nextch != TT_EOF)
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in.unread(nextch);
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}
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tokbuf.append((char) ch);
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}
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// Throw away matching quote char.
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if (ch != ttype && ch != TT_EOF)
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in.unread(ch);
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sval = tokbuf.toString();
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}
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else
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{
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if (ch == '/')
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if ((ch = in.read()) == '/' && slashSlash)
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{
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while ((ch = in.read()) != '\n' && ch != '\r' && ch != TT_EOF)
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;
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if (ch != TT_EOF)
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in.unread(ch);
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return nextToken(); // Recursive, but not too deep in normal cases
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}
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else if (ch == '*' && slashStar)
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{
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while (true)
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{
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ch = in.read();
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if (ch == '*')
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{
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if ((ch = in.read()) == '/')
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break;
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else if (ch != TT_EOF)
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in.unread(ch);
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}
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else if (ch == '\n' || ch == '\r')
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{
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lineNumber++;
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if (ch == '\r' && (ch = in.read()) != '\n')
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{
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if (ch != TT_EOF)
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in.unread(ch);
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}
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}
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else if (ch == TT_EOF)
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{
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break;
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}
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}
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return nextToken(); // Recursive, but not too deep in normal cases
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}
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else
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{
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if (ch != TT_EOF)
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in.unread(ch);
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ch = '/';
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}
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ttype = ch;
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}
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return ttype;
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}
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private void resetChar(int ch)
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{
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whitespace[ch] = alphabetic[ch] = numeric[ch] = quote[ch] = comment[ch] =
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false;
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}
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/**
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* This method makes the specified character an ordinary character. This
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* means that none of the attributes (whitespace, alphabetic, numeric,
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* quote, or comment) will be set on this character. This character will
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* parse as its own token.
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*
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* @param c The charcter to make ordinary, passed as an int
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*/
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public void ordinaryChar(int ch)
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{
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if (ch >= 0 && ch <= 255)
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resetChar(ch);
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}
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/**
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* This method makes all the characters in the specified range, range
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* terminators included, ordinary. This means the none of the attributes
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* (whitespace, alphabetic, numeric, quote, or comment) will be set on
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* any of the characters in the range. This makes each character in this
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* range parse as its own token.
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*
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* @param low The low end of the range of values to set the whitespace
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* attribute for
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* @param high The high end of the range of values to set the whitespace
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* attribute for
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*/
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public void ordinaryChars(int low, int hi)
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{
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if (low < 0)
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low = 0;
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if (hi > 255)
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hi = 255;
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for (int i = low; i <= hi; i++)
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resetChar(i);
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}
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/**
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* This method sets the numeric attribute on the characters '0' - '9' and
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* the characters '.' and '-'.
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*/
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public void parseNumbers()
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{
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for (int i = 0; i <= 9; i++)
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numeric['0' + i] = true;
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numeric['.'] = true;
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numeric['-'] = true;
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}
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/**
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* This method returns the current line number. Note that if the
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* <code>pushBack()</code> method is called, it has no effect on the
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* line number returned by this method.
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*
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* @return The current line number
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*/
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public void pushBack()
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{
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// pushBack may cause the lineno method to return an incorrect value
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// if lineno is called before the next call to nextToken.
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pushedBack = true;
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}
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/**
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* This method sets the quote attribute on the specified character.
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*
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* @param c The character to set the quote attribute for, passed as an int.
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*/
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public void quoteChar(int ch)
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{
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if (ch >= 0 && ch <= 255)
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quote[ch] = true;
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}
|
|
|
|
/**
|
|
* This method removes all attributes (whitespace, alphabetic, numeric,
|
|
* quote, and comment) from all characters. It is equivalent to calling
|
|
* <code>ordinaryChars(0x00, 0xFF)</code>.
|
|
*
|
|
* @see ordinaryChars
|
|
*/
|
|
public void resetSyntax()
|
|
{
|
|
ordinaryChars(0x00, 0xFF);
|
|
}
|
|
|
|
/**
|
|
* This method sets a flag that indicates whether or not "C++" language style
|
|
* comments ("//" comments through EOL ) are handled by the parser.
|
|
* If this is <code>true</code> commented out sequences are skipped and
|
|
* ignored by the parser. This defaults to <code>false</code>.
|
|
*
|
|
* @param flag <code>true</code> to recognized and handle "C++" style
|
|
* comments, <code>false</code> otherwise
|
|
*/
|
|
public void slashSlashComments(boolean flag)
|
|
{
|
|
slashSlash = flag;
|
|
}
|
|
|
|
/**
|
|
* This method sets a flag that indicates whether or not "C" language style
|
|
* comments (with nesting not allowed) are handled by the parser.
|
|
* If this is <code>true</code> commented out sequences are skipped and
|
|
* ignored by the parser. This defaults to <code>false</code>.
|
|
*
|
|
* @param flag <code>true</code> to recognized and handle "C" style comments,
|
|
* <code>false</code> otherwise
|
|
*/
|
|
public void slashStarComments(boolean flag)
|
|
{
|
|
slashStar = flag;
|
|
}
|
|
|
|
/**
|
|
* This method returns the current token value as a <code>String</code> in
|
|
* the form "Token[x], line n", where 'n' is the current line numbers and
|
|
* 'x' is determined as follows.
|
|
* <p>
|
|
* <ul>
|
|
* <li>If no token has been read, then 'x' is "NOTHING" and 'n' is 0
|
|
* <li>If <code>ttype</code> is TT_EOF, then 'x' is "EOF"
|
|
* <li>If <code>ttype</code> is TT_EOL, then 'x' is "EOL"
|
|
* <li>If <code>ttype</code> is TT_WORD, then 'x' is <code>sval</code>
|
|
* <li>If <code>ttype</code> is TT_NUMBER, then 'x' is "n=strnval" where
|
|
* 'strnval' is <code>String.valueOf(nval)</code>.
|
|
* <li>If <code>ttype</code> is a quote character, then 'x' is
|
|
* <code>sval</code>
|
|
* <li>For all other cases, 'x' is <code>ttype</code>
|
|
* </ul>
|
|
*/
|
|
public String toString()
|
|
{
|
|
String tempstr;
|
|
if (ttype == TT_EOF)
|
|
tempstr = "EOF";
|
|
else if (ttype == TT_EOL)
|
|
tempstr = "EOL";
|
|
else if (ttype == TT_WORD)
|
|
tempstr = sval;
|
|
else if (ttype == TT_NUMBER)
|
|
tempstr = "n=" + nval;
|
|
else if (ttype == TT_NONE)
|
|
tempstr = "NOTHING";
|
|
else // must be an ordinary char.
|
|
tempstr = "\'" + (char) ttype + "\'";
|
|
|
|
return "Token[" + tempstr + "], line " + lineno();
|
|
}
|
|
|
|
/**
|
|
* This method sets the whitespace attribute for all charcters in the
|
|
* specified range, range terminators included.
|
|
*
|
|
* @param low The low end of the range of values to set the whitespace
|
|
* attribute for
|
|
* @param high The high end of the range of values to set the whitespace
|
|
* attribute for
|
|
*/
|
|
public void whitespaceChars(int low, int hi)
|
|
{
|
|
if (low < 0)
|
|
low = 0;
|
|
if (hi > 255)
|
|
hi = 255;
|
|
for (int i = low; i <= hi; i++)
|
|
whitespace[i] = true;
|
|
}
|
|
|
|
/**
|
|
* This method sets the alphabetic attribute for all charcters in the
|
|
* specified range, range terminators included.
|
|
*
|
|
* @param low The low end of the range of values to set the alphabetic
|
|
* attribute for
|
|
* @param high The high end of the range of values to set the alphabetic
|
|
* attribute for
|
|
*/
|
|
public void wordChars(int low, int hi)
|
|
{
|
|
if (low < 0)
|
|
low = 0;
|
|
if (hi > 255)
|
|
hi = 255;
|
|
for (int i = low; i <= hi; i++)
|
|
alphabetic[i] = true;
|
|
}
|
|
}
|