1 /* StreamTokenizer.java -- parses streams of characters into tokens
2 Copyright (C) 1998, 1999, 2000, 2001, 2002, 2003 Free Software Foundation
4 This file is part of GNU Classpath.
6 GNU Classpath is free software; you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation; either version 2, or (at your option)
11 GNU Classpath is distributed in the hope that it will be useful, but
12 WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 General Public License for more details.
16 You should have received a copy of the GNU General Public License
17 along with GNU Classpath; see the file COPYING. If not, write to the
18 Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
21 Linking this library statically or dynamically with other modules is
22 making a combined work based on this library. Thus, the terms and
23 conditions of the GNU General Public License cover the whole
26 As a special exception, the copyright holders of this library give you
27 permission to link this library with independent modules to produce an
28 executable, regardless of the license terms of these independent
29 modules, and to copy and distribute the resulting executable under
30 terms of your choice, provided that you also meet, for each linked
31 independent module, the terms and conditions of the license of that
32 module. An independent module is a module which is not derived from
33 or based on this library. If you modify this library, you may extend
34 this exception to your version of the library, but you are not
35 obligated to do so. If you do not wish to do so, delete this
36 exception statement from your version. */
41 * This class parses streams of characters into tokens. There are a
42 * million-zillion flags that can be set to control the parsing, as
43 * described under the various method headings.
45 * @author Warren Levy <warrenl@cygnus.com>
46 * @date October 25, 1998.
48 /* Written using "Java Class Libraries", 2nd edition, ISBN 0-201-31002-3
49 * "The Java Language Specification", ISBN 0-201-63451-1
50 * plus online API docs for JDK 1.2 beta from http://www.javasoft.com.
51 * Status: Believed complete and correct.
54 public class StreamTokenizer
56 /** A constant indicating that the end of the stream has been read. */
57 public static final int TT_EOF
= -1;
59 /** A constant indicating that the end of the line has been read. */
60 public static final int TT_EOL
= '\n';
62 /** A constant indicating that a number token has been read. */
63 public static final int TT_NUMBER
= -2;
65 /** A constant indicating that a word token has been read. */
66 public static final int TT_WORD
= -3;
68 /** A constant indicating that no tokens have been read yet. */
69 private static final int TT_NONE
= -4;
72 * Contains the type of the token read resulting from a call to nextToken
73 * The rules are as follows:
75 * <li>For a token consisting of a single ordinary character, this is the
76 * value of that character.
77 * <li>For a quoted string, this is the value of the quote character
78 * <li>For a word, this is TT_WORD
79 * <li>For a number, this is TT_NUMBER
80 * <li>For the end of the line, this is TT_EOL
81 * <li>For the end of the stream, this is TT_EOF
84 public int ttype
= TT_NONE
;
86 /** The String associated with word and string tokens. */
89 /** The numeric value associated with number tokens. */
92 /* Indicates whether end-of-line is recognized as a token. */
93 private boolean eolSignificant
= false;
95 /* Indicates whether word tokens are automatically made lower case. */
96 private boolean lowerCase
= false;
98 /* Indicates whether C++ style comments are recognized and skipped. */
99 private boolean slashSlash
= false;
101 /* Indicates whether C style comments are recognized and skipped. */
102 private boolean slashStar
= false;
104 /* Attribute tables of each byte from 0x00 to 0xFF. */
105 private boolean[] whitespace
= new boolean[256];
106 private boolean[] alphabetic
= new boolean[256];
107 private boolean[] numeric
= new boolean[256];
108 private boolean[] quote
= new boolean[256];
109 private boolean[] comment
= new boolean[256];
111 /* The Reader associated with this class. */
112 private PushbackReader in
;
114 /* Indicates if a token has been pushed back. */
115 private boolean pushedBack
= false;
117 /* Contains the current line number of the reader. */
118 private int lineNumber
= 1;
121 * This method reads bytes from an <code>InputStream</code> and tokenizes
122 * them. For details on how this method operates by default, see
123 * <code>StreamTokenizer(Reader)</code>.
125 * @param in The <code>InputStream</code> to read from
127 * @deprecated Since JDK 1.1.
129 public StreamTokenizer(InputStream is
)
131 this(new InputStreamReader(is
));
135 * This method initializes a new <code>StreamTokenizer</code> to read
136 * characters from a <code>Reader</code> and parse them. The char values
137 * have their hight bits masked so that the value is treated a character
138 * in the range of 0x0000 to 0x00FF.
140 * This constructor sets up the parsing table to parse the stream in the
143 * <li>The values 'A' through 'Z', 'a' through 'z' and 0xA0 through 0xFF
144 * are initialized as alphabetic
145 * <li>The values 0x00 through 0x20 are initialized as whitespace
146 * <li>The values '\'' and '"' are initialized as quote characters
147 * <li>'/' is a comment character
148 * <li>Numbers will be parsed
149 * <li>EOL is not treated as significant
150 * <li>C and C++ (//) comments are not recognized
153 * @param in The <code>Reader</code> to read chars from
155 public StreamTokenizer(Reader r
)
157 in
= new PushbackReader(r
);
159 whitespaceChars(0x00, 0x20);
162 wordChars(0xA0, 0xFF);
170 * This method sets the comment attribute on the specified
171 * character. Other attributes for the character are cleared.
173 * @param c The character to set the comment attribute for, passed as an int
175 public void commentChar(int ch
)
177 if (ch
>= 0 && ch
<= 255)
180 whitespace
[ch
] = false;
181 alphabetic
[ch
] = false;
188 * This method sets a flag that indicates whether or not the end of line
189 * sequence terminates and is a token. The defaults to <code>false</code>
191 * @param flag <code>true</code> if EOF is significant, <code>false</code>
194 public void eolIsSignificant(boolean flag
)
196 eolSignificant
= flag
;
200 * This method returns the current line number. Note that if the
201 * <code>pushBack()</code> method is called, it has no effect on the
202 * line number returned by this method.
204 * @return The current line number
212 * This method sets a flag that indicates whether or not alphabetic
213 * tokens that are returned should be converted to lower case.
215 * @param flag <code>true</code> to convert to lower case,
216 * <code>false</code> otherwise
218 public void lowerCaseMode(boolean flag
)
223 private boolean isWhitespace(int ch
)
225 return (ch
>= 0 && ch
<= 255 && whitespace
[ch
]);
228 private boolean isAlphabetic(int ch
)
230 return ((ch
> 255) || (ch
>= 0 && alphabetic
[ch
]));
233 private boolean isNumeric(int ch
)
235 return (ch
>= 0 && ch
<= 255 && numeric
[ch
]);
238 private boolean isQuote(int ch
)
240 return (ch
>= 0 && ch
<= 255 && quote
[ch
]);
243 private boolean isComment(int ch
)
245 return (ch
>= 0 && ch
<= 255 && comment
[ch
]);
249 * This method reads the next token from the stream. It sets the
250 * <code>ttype</code> variable to the appropriate token type and
251 * returns it. It also can set <code>sval</code> or <code>nval</code>
252 * as described below. The parsing strategy is as follows:
254 * <li>Skip any whitespace characters.
255 * <li>If a numeric character is encountered, attempt to parse a numeric
256 * value. Leading '-' characters indicate a numeric only if followed by
257 * another non-'-' numeric. The value of the numeric token is terminated
258 * by either the first non-numeric encountered, or the second occurrence of
259 * '-' or '.'. The token type returned is TT_NUMBER and <code>nval</code>
260 * is set to the value parsed.
261 * <li>If an alphabetic character is parsed, all subsequent characters
262 * are read until the first non-alphabetic or non-numeric character is
263 * encountered. The token type returned is TT_WORD and the value parsed
264 * is stored in <code>sval</code>. If lower case mode is set, the token
265 * stored in <code>sval</code> is converted to lower case. The end of line
266 * sequence terminates a word only if EOL signficance has been turned on.
267 * The start of a comment also terminates a word. Any character with a
268 * non-alphabetic and non-numeric attribute (such as white space, a quote,
269 * or a commet) are treated as non-alphabetic and terminate the word.
270 * <li>If a comment character is parsed, then all remaining characters on
271 * the current line are skipped and another token is parsed. Any EOL or
272 * EOF's encountered are not discarded, but rather terminate the comment.
273 * <li>If a quote character is parsed, then all characters up to the
274 * second occurrence of the same quote character are parsed into a
275 * <code>String</code>. This <code>String</code> is stored as
276 * <code>sval</code>, but is not converted to lower case, even if lower case
277 * mode is enabled. The token type returned is the value of the quote
278 * character encountered. Any escape sequences
279 * (\b (backspace), \t (HTAB), \n (linefeed), \f (form feed), \r
280 * (carriage return), \" (double quote), \' (single quote), \\
281 * (backslash), \XXX (octal esacpe)) are converted to the appropriate
282 * char values. Invalid esacape sequences are left in untranslated.
283 * Unicode characters like ('\ u0000') are not recognized.
284 * <li>If the C++ comment sequence "//" is encountered, and the parser
285 * is configured to handle that sequence, then the remainder of the line
286 * is skipped and another token is read exactly as if a character with
287 * the comment attribute was encountered.
288 * <li>If the C comment sequence "/*" is encountered, and the parser
289 * is configured to handle that sequence, then all characters up to and
290 * including the comment terminator sequence are discarded and another
292 * <li>If all cases above are not met, then the character is an ordinary
293 * character that is parsed as a token by itself. The char encountered
294 * is returned as the token type.
297 * @return The token type
298 * @exception IOException If an I/O error occurs
300 public int nextToken() throws IOException
305 if (ttype
!= TT_NONE
)
312 // Skip whitespace. Deal with EOL along the way.
313 while (isWhitespace(ch
= in
.read()))
314 if (ch
== '\n' || ch
== '\r')
318 // Throw away \n if in combination with \r.
319 if (ch
== '\r' && (ch
= in
.read()) != '\n')
325 return (ttype
= TT_EOL
);
329 if ((ch
= in
.read()) == '/' && slashSlash
)
331 while ((ch
= in
.read()) != '\n' && ch
!= '\r' && ch
!= TT_EOF
)
335 return nextToken(); // Recursive, but not too deep in normal cases
337 else if (ch
== '*' && slashStar
)
344 if ((ch
= in
.read()) == '/')
346 else if (ch
!= TT_EOF
)
349 else if (ch
== '\n' || ch
== '\r')
352 if (ch
== '\r' && (ch
= in
.read()) != '\n')
358 else if (ch
== TT_EOF
)
363 return nextToken(); // Recursive, but not too deep in normal cases
374 else if (isNumeric(ch
))
376 boolean isNegative
= false;
379 // Read ahead to see if this is an ordinary '-' rather than numeric.
381 if (isNumeric(ch
) && ch
!= '-')
389 return (ttype
= '-');
393 StringBuffer tokbuf
= new StringBuffer();
394 tokbuf
.append((char) ch
);
397 while (isNumeric(ch
= in
.read()) && ch
!= '-')
398 if (ch
== '.' && decCount
++ > 0)
401 tokbuf
.append((char) ch
);
408 nval
= Double
.valueOf(tokbuf
.toString()).doubleValue();
410 catch (NumberFormatException _
)
417 else if (isAlphabetic(ch
))
419 StringBuffer tokbuf
= new StringBuffer();
420 tokbuf
.append((char) ch
);
421 while (isAlphabetic(ch
= in
.read()) || isNumeric(ch
))
422 tokbuf
.append((char) ch
);
426 sval
= tokbuf
.toString();
428 sval
= sval
.toLowerCase();
430 else if (isComment(ch
))
432 while ((ch
= in
.read()) != '\n' && ch
!= '\r' && ch
!= TT_EOF
)
436 return nextToken(); // Recursive, but not too deep in normal cases.
438 else if (isQuote(ch
))
441 StringBuffer tokbuf
= new StringBuffer();
442 while ((ch
= in
.read()) != ttype
&& ch
!= '\n' && ch
!= '\r' &&
446 switch (ch
= in
.read())
462 case '\n': ch
= '\n';
464 case '\r': ch
= '\r';
472 if ((nextch
= ch1
= ch
) >= '0' && ch
<= '7')
475 if ((nextch
= in
.read()) >= '0' && nextch
<= '7')
477 ch
= ch
* 8 + nextch
- '0';
478 if ((nextch
= in
.read()) >= '0' && nextch
<= '7' &&
479 ch1
>= '0' && ch1
<= '3')
481 ch
= ch
* 8 + nextch
- '0';
487 if (nextch
!= TT_EOF
)
491 tokbuf
.append((char) ch
);
494 // Throw away matching quote char.
495 if (ch
!= ttype
&& ch
!= TT_EOF
)
498 sval
= tokbuf
.toString();
508 private void resetChar(int ch
)
510 whitespace
[ch
] = alphabetic
[ch
] = numeric
[ch
] = quote
[ch
] = comment
[ch
] =
515 * This method makes the specified character an ordinary character. This
516 * means that none of the attributes (whitespace, alphabetic, numeric,
517 * quote, or comment) will be set on this character. This character will
518 * parse as its own token.
520 * @param c The character to make ordinary, passed as an int
522 public void ordinaryChar(int ch
)
524 if (ch
>= 0 && ch
<= 255)
529 * This method makes all the characters in the specified range, range
530 * terminators included, ordinary. This means the none of the attributes
531 * (whitespace, alphabetic, numeric, quote, or comment) will be set on
532 * any of the characters in the range. This makes each character in this
533 * range parse as its own token.
535 * @param low The low end of the range of values to set the whitespace
537 * @param high The high end of the range of values to set the whitespace
540 public void ordinaryChars(int low
, int hi
)
546 for (int i
= low
; i
<= hi
; i
++)
551 * This method sets the numeric attribute on the characters '0' - '9' and
552 * the characters '.' and '-'.
554 public void parseNumbers()
556 for (int i
= 0; i
<= 9; i
++)
557 numeric
['0' + i
] = true;
564 * Puts the current token back into the StreamTokenizer so
565 * <code>nextToken</code> will return the same value on the next call.
566 * May cause the lineno method to return an incorrect value
567 * if lineno is called before the next call to nextToken.
569 public void pushBack()
575 * This method sets the quote attribute on the specified character.
576 * Other attributes for the character are cleared.
578 * @param c The character to set the quote attribute for, passed as an int.
580 public void quoteChar(int ch
)
582 if (ch
>= 0 && ch
<= 255)
586 whitespace
[ch
] = false;
587 alphabetic
[ch
] = false;
593 * This method removes all attributes (whitespace, alphabetic, numeric,
594 * quote, and comment) from all characters. It is equivalent to calling
595 * <code>ordinaryChars(0x00, 0xFF)</code>.
597 * @see #ordinaryChars(int, int)
599 public void resetSyntax()
601 ordinaryChars(0x00, 0xFF);
605 * This method sets a flag that indicates whether or not "C++" language style
606 * comments ("//" comments through EOL ) are handled by the parser.
607 * If this is <code>true</code> commented out sequences are skipped and
608 * ignored by the parser. This defaults to <code>false</code>.
610 * @param flag <code>true</code> to recognized and handle "C++" style
611 * comments, <code>false</code> otherwise
613 public void slashSlashComments(boolean flag
)
619 * This method sets a flag that indicates whether or not "C" language style
620 * comments (with nesting not allowed) are handled by the parser.
621 * If this is <code>true</code> commented out sequences are skipped and
622 * ignored by the parser. This defaults to <code>false</code>.
624 * @param flag <code>true</code> to recognized and handle "C" style comments,
625 * <code>false</code> otherwise
627 public void slashStarComments(boolean flag
)
633 * This method returns the current token value as a <code>String</code> in
634 * the form "Token[x], line n", where 'n' is the current line numbers and
635 * 'x' is determined as follows.
638 * <li>If no token has been read, then 'x' is "NOTHING" and 'n' is 0
639 * <li>If <code>ttype</code> is TT_EOF, then 'x' is "EOF"
640 * <li>If <code>ttype</code> is TT_EOL, then 'x' is "EOL"
641 * <li>If <code>ttype</code> is TT_WORD, then 'x' is <code>sval</code>
642 * <li>If <code>ttype</code> is TT_NUMBER, then 'x' is "n=strnval" where
643 * 'strnval' is <code>String.valueOf(nval)</code>.
644 * <li>If <code>ttype</code> is a quote character, then 'x' is
646 * <li>For all other cases, 'x' is <code>ttype</code>
649 public String
toString()
654 else if (ttype
== TT_EOL
)
656 else if (ttype
== TT_WORD
)
658 else if (ttype
== TT_NUMBER
)
659 tempstr
= "n=" + nval
;
660 else if (ttype
== TT_NONE
)
662 else // must be an ordinary char.
663 tempstr
= "\'" + (char) ttype
+ "\'";
665 return "Token[" + tempstr
+ "], line " + lineno();
669 * This method sets the whitespace attribute for all characters in the
670 * specified range, range terminators included.
672 * @param low The low end of the range of values to set the whitespace
674 * @param high The high end of the range of values to set the whitespace
677 public void whitespaceChars(int low
, int hi
)
683 for (int i
= low
; i
<= hi
; i
++)
686 whitespace
[i
] = true;
691 * This method sets the alphabetic attribute for all characters in the
692 * specified range, range terminators included.
694 * @param low The low end of the range of values to set the alphabetic
696 * @param high The high end of the range of values to set the alphabetic
699 public void wordChars(int low
, int hi
)
705 for (int i
= low
; i
<= hi
; i
++)
706 alphabetic
[i
] = true;