1 /*
2 * Copyright 1999-2008 Sun Microsystems, Inc. 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. Sun designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Sun 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
22 * CA 95054 USA or visit www.sun.com if you need additional information or
23 * have any questions.
24 */
25
26 package java.util.regex;
27
28 import java.security.AccessController;
29 import java.security.PrivilegedAction;
30 import java.text.CharacterIterator;
31 import java.text.Normalizer;
32 import java.util.Map;
33 import java.util.ArrayList;
34 import java.util.HashMap;
35 import java.util.Arrays;
36
37
38 /**
39 * A compiled representation of a regular expression.
40 *
41 * <p> A regular expression, specified as a string, must first be compiled into
42 * an instance of this class. The resulting pattern can then be used to create
43 * a {@link Matcher} object that can match arbitrary {@link
44 * java.lang.CharSequence </code>character sequences<code>} against the regular
45 * expression. All of the state involved in performing a match resides in the
46 * matcher, so many matchers can share the same pattern.
47 *
48 * <p> A typical invocation sequence is thus
49 *
50 * <blockquote><pre>
51 * Pattern p = Pattern.{@link #compile compile}("a*b");
52 * Matcher m = p.{@link #matcher matcher}("aaaaab");
53 * boolean b = m.{@link Matcher#matches matches}();</pre></blockquote>
54 *
55 * <p> A {@link #matches matches} method is defined by this class as a
56 * convenience for when a regular expression is used just once. This method
57 * compiles an expression and matches an input sequence against it in a single
58 * invocation. The statement
59 *
60 * <blockquote><pre>
61 * boolean b = Pattern.matches("a*b", "aaaaab");</pre></blockquote>
62 *
63 * is equivalent to the three statements above, though for repeated matches it
64 * is less efficient since it does not allow the compiled pattern to be reused.
65 *
66 * <p> Instances of this class are immutable and are safe for use by multiple
67 * concurrent threads. Instances of the {@link Matcher} class are not safe for
68 * such use.
69 *
70 *
71 * <a name="sum">
72 * <h4> Summary of regular-expression constructs </h4>
73 *
74 * <table border="0" cellpadding="1" cellspacing="0"
75 * summary="Regular expression constructs, and what they match">
76 *
77 * <tr align="left">
78 * <th bgcolor="#CCCCFF" align="left" id="construct">Construct</th>
79 * <th bgcolor="#CCCCFF" align="left" id="matches">Matches</th>
80 * </tr>
81 *
82 * <tr><th> </th></tr>
83 * <tr align="left"><th colspan="2" id="characters">Characters</th></tr>
84 *
85 * <tr><td valign="top" headers="construct characters"><i>x</i></td>
86 * <td headers="matches">The character <i>x</i></td></tr>
87 * <tr><td valign="top" headers="construct characters"><tt>\\</tt></td>
88 * <td headers="matches">The backslash character</td></tr>
89 * <tr><td valign="top" headers="construct characters"><tt>\0</tt><i>n</i></td>
90 * <td headers="matches">The character with octal value <tt>0</tt><i>n</i>
91 * (0 <tt><=</tt> <i>n</i> <tt><=</tt> 7)</td></tr>
92 * <tr><td valign="top" headers="construct characters"><tt>\0</tt><i>nn</i></td>
93 * <td headers="matches">The character with octal value <tt>0</tt><i>nn</i>
94 * (0 <tt><=</tt> <i>n</i> <tt><=</tt> 7)</td></tr>
95 * <tr><td valign="top" headers="construct characters"><tt>\0</tt><i>mnn</i></td>
96 * <td headers="matches">The character with octal value <tt>0</tt><i>mnn</i>
97 * (0 <tt><=</tt> <i>m</i> <tt><=</tt> 3,
98 * 0 <tt><=</tt> <i>n</i> <tt><=</tt> 7)</td></tr>
99 * <tr><td valign="top" headers="construct characters"><tt>\x</tt><i>hh</i></td>
100 * <td headers="matches">The character with hexadecimal value <tt>0x</tt><i>hh</i></td></tr>
101 * <tr><td valign="top" headers="construct characters"><tt>\u</tt><i>hhhh</i></td>
102 * <td headers="matches">The character with hexadecimal value <tt>0x</tt><i>hhhh</i></td></tr>
103 * <tr><td valign="top" headers="matches"><tt>\t</tt></td>
104 * <td headers="matches">The tab character (<tt>'\u0009'</tt>)</td></tr>
105 * <tr><td valign="top" headers="construct characters"><tt>\n</tt></td>
106 * <td headers="matches">The newline (line feed) character (<tt>'\u000A'</tt>)</td></tr>
107 * <tr><td valign="top" headers="construct characters"><tt>\r</tt></td>
108 * <td headers="matches">The carriage-return character (<tt>'\u000D'</tt>)</td></tr>
109 * <tr><td valign="top" headers="construct characters"><tt>\f</tt></td>
110 * <td headers="matches">The form-feed character (<tt>'\u000C'</tt>)</td></tr>
111 * <tr><td valign="top" headers="construct characters"><tt>\a</tt></td>
112 * <td headers="matches">The alert (bell) character (<tt>'\u0007'</tt>)</td></tr>
113 * <tr><td valign="top" headers="construct characters"><tt>\e</tt></td>
114 * <td headers="matches">The escape character (<tt>'\u001B'</tt>)</td></tr>
115 * <tr><td valign="top" headers="construct characters"><tt>\c</tt><i>x</i></td>
116 * <td headers="matches">The control character corresponding to <i>x</i></td></tr>
117 *
118 * <tr><th> </th></tr>
119 * <tr align="left"><th colspan="2" id="classes">Character classes</th></tr>
120 *
121 * <tr><td valign="top" headers="construct classes"><tt>[abc]</tt></td>
122 * <td headers="matches"><tt>a</tt>, <tt>b</tt>, or <tt>c</tt> (simple class)</td></tr>
123 * <tr><td valign="top" headers="construct classes"><tt>[^abc]</tt></td>
124 * <td headers="matches">Any character except <tt>a</tt>, <tt>b</tt>, or <tt>c</tt> (negation)</td></tr>
125 * <tr><td valign="top" headers="construct classes"><tt>[a-zA-Z]</tt></td>
126 * <td headers="matches"><tt>a</tt> through <tt>z</tt>
127 * or <tt>A</tt> through <tt>Z</tt>, inclusive (range)</td></tr>
128 * <tr><td valign="top" headers="construct classes"><tt>[a-d[m-p]]</tt></td>
129 * <td headers="matches"><tt>a</tt> through <tt>d</tt>,
130 * or <tt>m</tt> through <tt>p</tt>: <tt>[a-dm-p]</tt> (union)</td></tr>
131 * <tr><td valign="top" headers="construct classes"><tt>[a-z&&[def]]</tt></td>
132 * <td headers="matches"><tt>d</tt>, <tt>e</tt>, or <tt>f</tt> (intersection)</tr>
133 * <tr><td valign="top" headers="construct classes"><tt>[a-z&&[^bc]]</tt></td>
134 * <td headers="matches"><tt>a</tt> through <tt>z</tt>,
135 * except for <tt>b</tt> and <tt>c</tt>: <tt>[ad-z]</tt> (subtraction)</td></tr>
136 * <tr><td valign="top" headers="construct classes"><tt>[a-z&&[^m-p]]</tt></td>
137 * <td headers="matches"><tt>a</tt> through <tt>z</tt>,
138 * and not <tt>m</tt> through <tt>p</tt>: <tt>[a-lq-z]</tt>(subtraction)</td></tr>
139 * <tr><th> </th></tr>
140 *
141 * <tr align="left"><th colspan="2" id="predef">Predefined character classes</th></tr>
142 *
143 * <tr><td valign="top" headers="construct predef"><tt>.</tt></td>
144 * <td headers="matches">Any character (may or may not match <a href="#lt">line terminators</a>)</td></tr>
145 * <tr><td valign="top" headers="construct predef"><tt>\d</tt></td>
146 * <td headers="matches">A digit: <tt>[0-9]</tt></td></tr>
147 * <tr><td valign="top" headers="construct predef"><tt>\D</tt></td>
148 * <td headers="matches">A non-digit: <tt>[^0-9]</tt></td></tr>
149 * <tr><td valign="top" headers="construct predef"><tt>\s</tt></td>
150 * <td headers="matches">A whitespace character: <tt>[ \t\n\x0B\f\r]</tt></td></tr>
151 * <tr><td valign="top" headers="construct predef"><tt>\S</tt></td>
152 * <td headers="matches">A non-whitespace character: <tt>[^\s]</tt></td></tr>
153 * <tr><td valign="top" headers="construct predef"><tt>\w</tt></td>
154 * <td headers="matches">A word character: <tt>[a-zA-Z_0-9]</tt></td></tr>
155 * <tr><td valign="top" headers="construct predef"><tt>\W</tt></td>
156 * <td headers="matches">A non-word character: <tt>[^\w]</tt></td></tr>
157 *
158 * <tr><th> </th></tr>
159 * <tr align="left"><th colspan="2" id="posix">POSIX character classes</b> (US-ASCII only)<b></th></tr>
160 *
161 * <tr><td valign="top" headers="construct posix"><tt>\p{Lower}</tt></td>
162 * <td headers="matches">A lower-case alphabetic character: <tt>[a-z]</tt></td></tr>
163 * <tr><td valign="top" headers="construct posix"><tt>\p{Upper}</tt></td>
164 * <td headers="matches">An upper-case alphabetic character:<tt>[A-Z]</tt></td></tr>
165 * <tr><td valign="top" headers="construct posix"><tt>\p{ASCII}</tt></td>
166 * <td headers="matches">All ASCII:<tt>[\x00-\x7F]</tt></td></tr>
167 * <tr><td valign="top" headers="construct posix"><tt>\p{Alpha}</tt></td>
168 * <td headers="matches">An alphabetic character:<tt>[\p{Lower}\p{Upper}]</tt></td></tr>
169 * <tr><td valign="top" headers="construct posix"><tt>\p{Digit}</tt></td>
170 * <td headers="matches">A decimal digit: <tt>[0-9]</tt></td></tr>
171 * <tr><td valign="top" headers="construct posix"><tt>\p{Alnum}</tt></td>
172 * <td headers="matches">An alphanumeric character:<tt>[\p{Alpha}\p{Digit}]</tt></td></tr>
173 * <tr><td valign="top" headers="construct posix"><tt>\p{Punct}</tt></td>
174 * <td headers="matches">Punctuation: One of <tt>!"#$%&'()*+,-./:;<=>?@[\]^_`{|}~</tt></td></tr>
175 * <!-- <tt>[\!"#\$%&'\(\)\*\+,\-\./:;\<=\>\?@\[\\\]\^_`\{\|\}~]</tt>
176 * <tt>[\X21-\X2F\X31-\X40\X5B-\X60\X7B-\X7E]</tt> -->
177 * <tr><td valign="top" headers="construct posix"><tt>\p{Graph}</tt></td>
178 * <td headers="matches">A visible character: <tt>[\p{Alnum}\p{Punct}]</tt></td></tr>
179 * <tr><td valign="top" headers="construct posix"><tt>\p{Print}</tt></td>
180 * <td headers="matches">A printable character: <tt>[\p{Graph}\x20]</tt></td></tr>
181 * <tr><td valign="top" headers="construct posix"><tt>\p{Blank}</tt></td>
182 * <td headers="matches">A space or a tab: <tt>[ \t]</tt></td></tr>
183 * <tr><td valign="top" headers="construct posix"><tt>\p{Cntrl}</tt></td>
184 * <td headers="matches">A control character: <tt>[\x00-\x1F\x7F]</tt></td></tr>
185 * <tr><td valign="top" headers="construct posix"><tt>\p{XDigit}</tt></td>
186 * <td headers="matches">A hexadecimal digit: <tt>[0-9a-fA-F]</tt></td></tr>
187 * <tr><td valign="top" headers="construct posix"><tt>\p{Space}</tt></td>
188 * <td headers="matches">A whitespace character: <tt>[ \t\n\x0B\f\r]</tt></td></tr>
189 *
190 * <tr><th> </th></tr>
191 * <tr align="left"><th colspan="2">java.lang.Character classes (simple <a href="#jcc">java character type</a>)</th></tr>
192 *
193 * <tr><td valign="top"><tt>\p{javaLowerCase}</tt></td>
194 * <td>Equivalent to java.lang.Character.isLowerCase()</td></tr>
195 * <tr><td valign="top"><tt>\p{javaUpperCase}</tt></td>
196 * <td>Equivalent to java.lang.Character.isUpperCase()</td></tr>
197 * <tr><td valign="top"><tt>\p{javaWhitespace}</tt></td>
198 * <td>Equivalent to java.lang.Character.isWhitespace()</td></tr>
199 * <tr><td valign="top"><tt>\p{javaMirrored}</tt></td>
200 * <td>Equivalent to java.lang.Character.isMirrored()</td></tr>
201 *
202 * <tr><th> </th></tr>
203 * <tr align="left"><th colspan="2" id="unicode">Classes for Unicode blocks and categories</th></tr>
204 *
205 * <tr><td valign="top" headers="construct unicode"><tt>\p{InGreek}</tt></td>
206 * <td headers="matches">A character in the Greek block (simple <a href="#ubc">block</a>)</td></tr>
207 * <tr><td valign="top" headers="construct unicode"><tt>\p{Lu}</tt></td>
208 * <td headers="matches">An uppercase letter (simple <a href="#ubc">category</a>)</td></tr>
209 * <tr><td valign="top" headers="construct unicode"><tt>\p{Sc}</tt></td>
210 * <td headers="matches">A currency symbol</td></tr>
211 * <tr><td valign="top" headers="construct unicode"><tt>\P{InGreek}</tt></td>
212 * <td headers="matches">Any character except one in the Greek block (negation)</td></tr>
213 * <tr><td valign="top" headers="construct unicode"><tt>[\p{L}&&[^\p{Lu}]] </tt></td>
214 * <td headers="matches">Any letter except an uppercase letter (subtraction)</td></tr>
215 *
216 * <tr><th> </th></tr>
217 * <tr align="left"><th colspan="2" id="bounds">Boundary matchers</th></tr>
218 *
219 * <tr><td valign="top" headers="construct bounds"><tt>^</tt></td>
220 * <td headers="matches">The beginning of a line</td></tr>
221 * <tr><td valign="top" headers="construct bounds"><tt>$</tt></td>
222 * <td headers="matches">The end of a line</td></tr>
223 * <tr><td valign="top" headers="construct bounds"><tt>\b</tt></td>
224 * <td headers="matches">A word boundary</td></tr>
225 * <tr><td valign="top" headers="construct bounds"><tt>\B</tt></td>
226 * <td headers="matches">A non-word boundary</td></tr>
227 * <tr><td valign="top" headers="construct bounds"><tt>\A</tt></td>
228 * <td headers="matches">The beginning of the input</td></tr>
229 * <tr><td valign="top" headers="construct bounds"><tt>\G</tt></td>
230 * <td headers="matches">The end of the previous match</td></tr>
231 * <tr><td valign="top" headers="construct bounds"><tt>\Z</tt></td>
232 * <td headers="matches">The end of the input but for the final
233 * <a href="#lt">terminator</a>, if any</td></tr>
234 * <tr><td valign="top" headers="construct bounds"><tt>\z</tt></td>
235 * <td headers="matches">The end of the input</td></tr>
236 *
237 * <tr><th> </th></tr>
238 * <tr align="left"><th colspan="2" id="greedy">Greedy quantifiers</th></tr>
239 *
240 * <tr><td valign="top" headers="construct greedy"><i>X</i><tt>?</tt></td>
241 * <td headers="matches"><i>X</i>, once or not at all</td></tr>
242 * <tr><td valign="top" headers="construct greedy"><i>X</i><tt>*</tt></td>
243 * <td headers="matches"><i>X</i>, zero or more times</td></tr>
244 * <tr><td valign="top" headers="construct greedy"><i>X</i><tt>+</tt></td>
245 * <td headers="matches"><i>X</i>, one or more times</td></tr>
246 * <tr><td valign="top" headers="construct greedy"><i>X</i><tt>{</tt><i>n</i><tt>}</tt></td>
247 * <td headers="matches"><i>X</i>, exactly <i>n</i> times</td></tr>
248 * <tr><td valign="top" headers="construct greedy"><i>X</i><tt>{</tt><i>n</i><tt>,}</tt></td>
249 * <td headers="matches"><i>X</i>, at least <i>n</i> times</td></tr>
250 * <tr><td valign="top" headers="construct greedy"><i>X</i><tt>{</tt><i>n</i><tt>,</tt><i>m</i><tt>}</tt></td>
251 * <td headers="matches"><i>X</i>, at least <i>n</i> but not more than <i>m</i> times</td></tr>
252 *
253 * <tr><th> </th></tr>
254 * <tr align="left"><th colspan="2" id="reluc">Reluctant quantifiers</th></tr>
255 *
256 * <tr><td valign="top" headers="construct reluc"><i>X</i><tt>??</tt></td>
257 * <td headers="matches"><i>X</i>, once or not at all</td></tr>
258 * <tr><td valign="top" headers="construct reluc"><i>X</i><tt>*?</tt></td>
259 * <td headers="matches"><i>X</i>, zero or more times</td></tr>
260 * <tr><td valign="top" headers="construct reluc"><i>X</i><tt>+?</tt></td>
261 * <td headers="matches"><i>X</i>, one or more times</td></tr>
262 * <tr><td valign="top" headers="construct reluc"><i>X</i><tt>{</tt><i>n</i><tt>}?</tt></td>
263 * <td headers="matches"><i>X</i>, exactly <i>n</i> times</td></tr>
264 * <tr><td valign="top" headers="construct reluc"><i>X</i><tt>{</tt><i>n</i><tt>,}?</tt></td>
265 * <td headers="matches"><i>X</i>, at least <i>n</i> times</td></tr>
266 * <tr><td valign="top" headers="construct reluc"><i>X</i><tt>{</tt><i>n</i><tt>,</tt><i>m</i><tt>}?</tt></td>
267 * <td headers="matches"><i>X</i>, at least <i>n</i> but not more than <i>m</i> times</td></tr>
268 *
269 * <tr><th> </th></tr>
270 * <tr align="left"><th colspan="2" id="poss">Possessive quantifiers</th></tr>
271 *
272 * <tr><td valign="top" headers="construct poss"><i>X</i><tt>?+</tt></td>
273 * <td headers="matches"><i>X</i>, once or not at all</td></tr>
274 * <tr><td valign="top" headers="construct poss"><i>X</i><tt>*+</tt></td>
275 * <td headers="matches"><i>X</i>, zero or more times</td></tr>
276 * <tr><td valign="top" headers="construct poss"><i>X</i><tt>++</tt></td>
277 * <td headers="matches"><i>X</i>, one or more times</td></tr>
278 * <tr><td valign="top" headers="construct poss"><i>X</i><tt>{</tt><i>n</i><tt>}+</tt></td>
279 * <td headers="matches"><i>X</i>, exactly <i>n</i> times</td></tr>
280 * <tr><td valign="top" headers="construct poss"><i>X</i><tt>{</tt><i>n</i><tt>,}+</tt></td>
281 * <td headers="matches"><i>X</i>, at least <i>n</i> times</td></tr>
282 * <tr><td valign="top" headers="construct poss"><i>X</i><tt>{</tt><i>n</i><tt>,</tt><i>m</i><tt>}+</tt></td>
283 * <td headers="matches"><i>X</i>, at least <i>n</i> but not more than <i>m</i> times</td></tr>
284 *
285 * <tr><th> </th></tr>
286 * <tr align="left"><th colspan="2" id="logical">Logical operators</th></tr>
287 *
288 * <tr><td valign="top" headers="construct logical"><i>XY</i></td>
289 * <td headers="matches"><i>X</i> followed by <i>Y</i></td></tr>
290 * <tr><td valign="top" headers="construct logical"><i>X</i><tt>|</tt><i>Y</i></td>
291 * <td headers="matches">Either <i>X</i> or <i>Y</i></td></tr>
292 * <tr><td valign="top" headers="construct logical"><tt>(</tt><i>X</i><tt>)</tt></td>
293 * <td headers="matches">X, as a <a href="#cg">capturing group</a></td></tr>
294 *
295 * <tr><th> </th></tr>
296 * <tr align="left"><th colspan="2" id="backref">Back references</th></tr>
297 *
298 * <tr><td valign="bottom" headers="construct backref"><tt>\</tt><i>n</i></td>
299 * <td valign="bottom" headers="matches">Whatever the <i>n</i><sup>th</sup>
300 * <a href="#cg">capturing group</a> matched</td></tr>
301 *
302 * <tr><td valign="bottom" headers="construct backref"><tt>\</tt><i>k</i><<i>name</i>></td>
303 * <td valign="bottom" headers="matches">Whatever the
304 * <a href="#groupname">named-capturing group</a> "name" matched</td></tr>
305 *
306 * <tr><th> </th></tr>
307 * <tr align="left"><th colspan="2" id="quot">Quotation</th></tr>
308 *
309 * <tr><td valign="top" headers="construct quot"><tt>\</tt></td>
310 * <td headers="matches">Nothing, but quotes the following character</td></tr>
311 * <tr><td valign="top" headers="construct quot"><tt>\Q</tt></td>
312 * <td headers="matches">Nothing, but quotes all characters until <tt>\E</tt></td></tr>
313 * <tr><td valign="top" headers="construct quot"><tt>\E</tt></td>
314 * <td headers="matches">Nothing, but ends quoting started by <tt>\Q</tt></td></tr>
315 * <!-- Metachars: !$()*+.<>?[\]^{|} -->
316 *
317 * <tr><th> </th></tr>
318 * <tr align="left"><th colspan="2" id="special">Special constructs (named-capturing and non-capturing)</th></tr>
319 *
320 * <tr><td valign="top" headers="construct special"><tt>(?<<a href="#groupname">name</a>></tt><i>X</i><tt>)</tt></td>
321 * <td headers="matches"><i>X</i>, as a named-capturing group</td></tr>
322 * <tr><td valign="top" headers="construct special"><tt>(?:</tt><i>X</i><tt>)</tt></td>
323 * <td headers="matches"><i>X</i>, as a non-capturing group</td></tr>
324 * <tr><td valign="top" headers="construct special"><tt>(?idmsux-idmsux) </tt></td>
325 * <td headers="matches">Nothing, but turns match flags <a href="#CASE_INSENSITIVE">i</a>
326 * <a href="#UNIX_LINES">d</a> <a href="#MULTILINE">m</a> <a href="#DOTALL">s</a>
327 * <a href="#UNICODE_CASE">u</a> <a href="#COMMENTS">x</a> on - off</td></tr>
328 * <tr><td valign="top" headers="construct special"><tt>(?idmsux-idmsux:</tt><i>X</i><tt>)</tt> </td>
329 * <td headers="matches"><i>X</i>, as a <a href="#cg">non-capturing group</a> with the
330 * given flags <a href="#CASE_INSENSITIVE">i</a> <a href="#UNIX_LINES">d</a>
331 * <a href="#MULTILINE">m</a> <a href="#DOTALL">s</a> <a href="#UNICODE_CASE">u</a >
332 * <a href="#COMMENTS">x</a> on - off</td></tr>
333 * <tr><td valign="top" headers="construct special"><tt>(?=</tt><i>X</i><tt>)</tt></td>
334 * <td headers="matches"><i>X</i>, via zero-width positive lookahead</td></tr>
335 * <tr><td valign="top" headers="construct special"><tt>(?!</tt><i>X</i><tt>)</tt></td>
336 * <td headers="matches"><i>X</i>, via zero-width negative lookahead</td></tr>
337 * <tr><td valign="top" headers="construct special"><tt>(?<=</tt><i>X</i><tt>)</tt></td>
338 * <td headers="matches"><i>X</i>, via zero-width positive lookbehind</td></tr>
339 * <tr><td valign="top" headers="construct special"><tt>(?<!</tt><i>X</i><tt>)</tt></td>
340 * <td headers="matches"><i>X</i>, via zero-width negative lookbehind</td></tr>
341 * <tr><td valign="top" headers="construct special"><tt>(?></tt><i>X</i><tt>)</tt></td>
342 * <td headers="matches"><i>X</i>, as an independent, non-capturing group</td></tr>
343 *
344 * </table>
345 *
346 * <hr>
347 *
348 *
349 * <a name="bs">
350 * <h4> Backslashes, escapes, and quoting </h4>
351 *
352 * <p> The backslash character (<tt>'\'</tt>) serves to introduce escaped
353 * constructs, as defined in the table above, as well as to quote characters
354 * that otherwise would be interpreted as unescaped constructs. Thus the
355 * expression <tt>\\</tt> matches a single backslash and <tt>\{</tt> matches a
356 * left brace.
357 *
358 * <p> It is an error to use a backslash prior to any alphabetic character that
359 * does not denote an escaped construct; these are reserved for future
360 * extensions to the regular-expression language. A backslash may be used
361 * prior to a non-alphabetic character regardless of whether that character is
362 * part of an unescaped construct.
363 *
364 * <p> Backslashes within string literals in Java source code are interpreted
365 * as required by the <a
366 * href="http://java.sun.com/docs/books/jls">Java Language
367 * Specification</a> as either <a
368 * href="http://java.sun.com/docs/books/jls/third_edition/html/lexical.html#100850">Unicode
369 * escapes</a> or other <a
370 * href="http://java.sun.com/docs/books/jls/third_edition/html/lexical.html#101089">character
371 * escapes</a>. It is therefore necessary to double backslashes in string
372 * literals that represent regular expressions to protect them from
373 * interpretation by the Java bytecode compiler. The string literal
374 * <tt>"\b"</tt>, for example, matches a single backspace character when
375 * interpreted as a regular expression, while <tt>"\\b"</tt> matches a
376 * word boundary. The string literal <tt>"\(hello\)"</tt> is illegal
377 * and leads to a compile-time error; in order to match the string
378 * <tt>(hello)</tt> the string literal <tt>"\\(hello\\)"</tt>
379 * must be used.
380 *
381 * <a name="cc">
382 * <h4> Character Classes </h4>
383 *
384 * <p> Character classes may appear within other character classes, and
385 * may be composed by the union operator (implicit) and the intersection
386 * operator (<tt>&&</tt>).
387 * The union operator denotes a class that contains every character that is
388 * in at least one of its operand classes. The intersection operator
389 * denotes a class that contains every character that is in both of its
390 * operand classes.
391 *
392 * <p> The precedence of character-class operators is as follows, from
393 * highest to lowest:
394 *
395 * <blockquote><table border="0" cellpadding="1" cellspacing="0"
396 * summary="Precedence of character class operators.">
397 * <tr><th>1 </th>
398 * <td>Literal escape </td>
399 * <td><tt>\x</tt></td></tr>
400 * <tr><th>2 </th>
401 * <td>Grouping</td>
402 * <td><tt>[...]</tt></td></tr>
403 * <tr><th>3 </th>
404 * <td>Range</td>
405 * <td><tt>a-z</tt></td></tr>
406 * <tr><th>4 </th>
407 * <td>Union</td>
408 * <td><tt>[a-e][i-u]</tt></td></tr>
409 * <tr><th>5 </th>
410 * <td>Intersection</td>
411 * <td><tt>[a-z&&[aeiou]]</tt></td></tr>
412 * </table></blockquote>
413 *
414 * <p> Note that a different set of metacharacters are in effect inside
415 * a character class than outside a character class. For instance, the
416 * regular expression <tt>.</tt> loses its special meaning inside a
417 * character class, while the expression <tt>-</tt> becomes a range
418 * forming metacharacter.
419 *
420 * <a name="lt">
421 * <h4> Line terminators </h4>
422 *
423 * <p> A <i>line terminator</i> is a one- or two-character sequence that marks
424 * the end of a line of the input character sequence. The following are
425 * recognized as line terminators:
426 *
427 * <ul>
428 *
429 * <li> A newline (line feed) character (<tt>'\n'</tt>),
430 *
431 * <li> A carriage-return character followed immediately by a newline
432 * character (<tt>"\r\n"</tt>),
433 *
434 * <li> A standalone carriage-return character (<tt>'\r'</tt>),
435 *
436 * <li> A next-line character (<tt>'\u0085'</tt>),
437 *
438 * <li> A line-separator character (<tt>'\u2028'</tt>), or
439 *
440 * <li> A paragraph-separator character (<tt>'\u2029</tt>).
441 *
442 * </ul>
443 * <p>If {@link #UNIX_LINES} mode is activated, then the only line terminators
444 * recognized are newline characters.
445 *
446 * <p> The regular expression <tt>.</tt> matches any character except a line
447 * terminator unless the {@link #DOTALL} flag is specified.
448 *
449 * <p> By default, the regular expressions <tt>^</tt> and <tt>$</tt> ignore
450 * line terminators and only match at the beginning and the end, respectively,
451 * of the entire input sequence. If {@link #MULTILINE} mode is activated then
452 * <tt>^</tt> matches at the beginning of input and after any line terminator
453 * except at the end of input. When in {@link #MULTILINE} mode <tt>$</tt>
454 * matches just before a line terminator or the end of the input sequence.
455 *
456 * <a name="cg">
457 * <h4> Groups and capturing </h4>
458 *
459 * <a name="gnumber">
460 * <h5> Group number </h5>
461 * <p> Capturing groups are numbered by counting their opening parentheses from
462 * left to right. In the expression <tt>((A)(B(C)))</tt>, for example, there
463 * are four such groups: </p>
464 *
465 * <blockquote><table cellpadding=1 cellspacing=0 summary="Capturing group numberings">
466 * <tr><th>1 </th>
467 * <td><tt>((A)(B(C)))</tt></td></tr>
468 * <tr><th>2 </th>
469 * <td><tt>(A)</tt></td></tr>
470 * <tr><th>3 </th>
471 * <td><tt>(B(C))</tt></td></tr>
472 * <tr><th>4 </th>
473 * <td><tt>(C)</tt></td></tr>
474 * </table></blockquote>
475 *
476 * <p> Group zero always stands for the entire expression.
477 *
478 * <p> Capturing groups are so named because, during a match, each subsequence
479 * of the input sequence that matches such a group is saved. The captured
480 * subsequence may be used later in the expression, via a back reference, and
481 * may also be retrieved from the matcher once the match operation is complete.
482 *
483 * <a name="groupname">
484 * <h5> Group name </h5>
485 * <p>A capturing group can also be assigned a "name", a <tt>named-capturing group</tt>,
486 * and then be back-referenced later by the "name". Group names are composed of
487 * the following characters:
488 *
489 * <ul>
490 * <li> The uppercase letters <tt>'A'</tt> through <tt>'Z'</tt>
491 * (<tt>'\u0041'</tt> through <tt>'\u005a'</tt>),
492 * <li> The lowercase letters <tt>'a'</tt> through <tt>'z'</tt>
493 * (<tt>'\u0061'</tt> through <tt>'\u007a'</tt>),
494 * <li> The digits <tt>'0'</tt> through <tt>'9'</tt>
495 * (<tt>'\u0030'</tt> through <tt>'\u0039'</tt>),
496 * </ul>
497 *
498 * <p> A <tt>named-capturing group</tt> is still numbered as described in
499 * <a href="#gnumber">Group number</a>.
500 *
501 * <p> The captured input associated with a group is always the subsequence
502 * that the group most recently matched. If a group is evaluated a second time
503 * because of quantification then its previously-captured value, if any, will
504 * be retained if the second evaluation fails. Matching the string
505 * <tt>"aba"</tt> against the expression <tt>(a(b)?)+</tt>, for example, leaves
506 * group two set to <tt>"b"</tt>. All captured input is discarded at the
507 * beginning of each match.
508 *
509 * <p> Groups beginning with <tt>(?</tt> are either pure, <i>non-capturing</i> groups
510 * that do not capture text and do not count towards the group total, or
511 * <i>named-capturing</i> group.
512 *
513 * <h4> Unicode support </h4>
514 *
515 * <p> This class is in conformance with Level 1 of <a
516 * href="http://www.unicode.org/reports/tr18/"><i>Unicode Technical
517 * Standard #18: Unicode Regular Expression Guidelines</i></a>, plus RL2.1
518 * Canonical Equivalents.
519 *
520 * <p> Unicode escape sequences such as <tt>\u2014</tt> in Java source code
521 * are processed as described in <a
522 * href="http://java.sun.com/docs/books/jls/third_edition/html/lexical.html#100850">\u00A73.3</a>
523 * of the Java Language Specification. Such escape sequences are also
524 * implemented directly by the regular-expression parser so that Unicode
525 * escapes can be used in expressions that are read from files or from the
526 * keyboard. Thus the strings <tt>"\u2014"</tt> and <tt>"\\u2014"</tt>,
527 * while not equal, compile into the same pattern, which matches the character
528 * with hexadecimal value <tt>0x2014</tt>.
529 *
530 * <a name="ubc"> <p>Unicode blocks and categories are written with the
531 * <tt>\p</tt> and <tt>\P</tt> constructs as in
532 * Perl. <tt>\p{</tt><i>prop</i><tt>}</tt> matches if the input has the
533 * property <i>prop</i>, while <tt>\P{</tt><i>prop</i><tt>}</tt> does not match if
534 * the input has that property. Blocks are specified with the prefix
535 * <tt>In</tt>, as in <tt>InMongolian</tt>. Categories may be specified with
536 * the optional prefix <tt>Is</tt>: Both <tt>\p{L}</tt> and <tt>\p{IsL}</tt>
537 * denote the category of Unicode letters. Blocks and categories can be used
538 * both inside and outside of a character class.
539 *
540 * <p> The supported categories are those of
541 * <a href="http://www.unicode.org/unicode/standard/standard.html">
542 * <i>The Unicode Standard</i></a> in the version specified by the
543 * {@link java.lang.Character Character} class. The category names are those
544 * defined in the Standard, both normative and informative.
545 * The block names supported by <code>Pattern</code> are the valid block names
546 * accepted and defined by
547 * {@link java.lang.Character.UnicodeBlock#forName(String) UnicodeBlock.forName}.
548 *
549 * <a name="jcc"> <p>Categories that behave like the java.lang.Character
550 * boolean is<i>methodname</i> methods (except for the deprecated ones) are
551 * available through the same <tt>\p{</tt><i>prop</i><tt>}</tt> syntax where
552 * the specified property has the name <tt>java<i>methodname</i></tt>.
553 *
554 * <h4> Comparison to Perl 5 </h4>
555 *
556 * <p>The <code>Pattern</code> engine performs traditional NFA-based matching
557 * with ordered alternation as occurs in Perl 5.
558 *
559 * <p> Perl constructs not supported by this class: </p>
560 *
561 * <ul>
562 *
563 * <li><p> The conditional constructs <tt>(?{</tt><i>X</i><tt>})</tt> and
564 * <tt>(?(</tt><i>condition</i><tt>)</tt><i>X</i><tt>|</tt><i>Y</i><tt>)</tt>,
565 * </p></li>
566 *
567 * <li><p> The embedded code constructs <tt>(?{</tt><i>code</i><tt>})</tt>
568 * and <tt>(??{</tt><i>code</i><tt>})</tt>,</p></li>
569 *
570 * <li><p> The embedded comment syntax <tt>(?#comment)</tt>, and </p></li>
571 *
572 * <li><p> The preprocessing operations <tt>\l</tt> <tt>\u</tt>,
573 * <tt>\L</tt>, and <tt>\U</tt>. </p></li>
574 *
575 * </ul>
576 *
577 * <p> Constructs supported by this class but not by Perl: </p>
578 *
579 * <ul>
580 *
581 * <li><p> Possessive quantifiers, which greedily match as much as they can
582 * and do not back off, even when doing so would allow the overall match to
583 * succeed. </p></li>
584 *
585 * <li><p> Character-class union and intersection as described
586 * <a href="#cc">above</a>.</p></li>
587 *
588 * </ul>
589 *
590 * <p> Notable differences from Perl: </p>
591 *
592 * <ul>
593 *
594 * <li><p> In Perl, <tt>\1</tt> through <tt>\9</tt> are always interpreted
595 * as back references; a backslash-escaped number greater than <tt>9</tt> is
596 * treated as a back reference if at least that many subexpressions exist,
597 * otherwise it is interpreted, if possible, as an octal escape. In this
598 * class octal escapes must always begin with a zero. In this class,
599 * <tt>\1</tt> through <tt>\9</tt> are always interpreted as back
600 * references, and a larger number is accepted as a back reference if at
601 * least that many subexpressions exist at that point in the regular
602 * expression, otherwise the parser will drop digits until the number is
603 * smaller or equal to the existing number of groups or it is one digit.
604 * </p></li>
605 *
606 * <li><p> Perl uses the <tt>g</tt> flag to request a match that resumes
607 * where the last match left off. This functionality is provided implicitly
608 * by the {@link Matcher} class: Repeated invocations of the {@link
609 * Matcher#find find} method will resume where the last match left off,
610 * unless the matcher is reset. </p></li>
611 *
612 * <li><p> In Perl, embedded flags at the top level of an expression affect
613 * the whole expression. In this class, embedded flags always take effect
614 * at the point at which they appear, whether they are at the top level or
615 * within a group; in the latter case, flags are restored at the end of the
616 * group just as in Perl. </p></li>
617 *
618 * <li><p> Perl is forgiving about malformed matching constructs, as in the
619 * expression <tt>*a</tt>, as well as dangling brackets, as in the
620 * expression <tt>abc]</tt>, and treats them as literals. This
621 * class also accepts dangling brackets but is strict about dangling
622 * metacharacters like +, ? and *, and will throw a
623 * {@link PatternSyntaxException} if it encounters them. </p></li>
624 *
625 * </ul>
626 *
627 *
628 * <p> For a more precise description of the behavior of regular expression
629 * constructs, please see <a href="http://www.oreilly.com/catalog/regex3/">
630 * <i>Mastering Regular Expressions, 3nd Edition</i>, Jeffrey E. F. Friedl,
631 * O'Reilly and Associates, 2006.</a>
632 * </p>
633 *
634 * @see java.lang.String#split(String, int)
635 * @see java.lang.String#split(String)
636 *
637 * @author Mike McCloskey
638 * @author Mark Reinhold
639 * @author JSR-51 Expert Group
640 * @since 1.4
641 * @spec JSR-51
642 */
643
644 public final class Pattern
645 implements java.io.Serializable
646 {
647
648 /**
649 * Regular expression modifier values. Instead of being passed as
650 * arguments, they can also be passed as inline modifiers.
651 * For example, the following statements have the same effect.
652 * <pre>
653 * RegExp r1 = RegExp.compile("abc", Pattern.I|Pattern.M);
654 * RegExp r2 = RegExp.compile("(?im)abc", 0);
655 * </pre>
656 *
657 * The flags are duplicated so that the familiar Perl match flag
658 * names are available.
659 */
660
661 /**
662 * Enables Unix lines mode.
663 *
664 * <p> In this mode, only the <tt>'\n'</tt> line terminator is recognized
665 * in the behavior of <tt>.</tt>, <tt>^</tt>, and <tt>$</tt>.
666 *
667 * <p> Unix lines mode can also be enabled via the embedded flag
668 * expression <tt>(?d)</tt>.
669 */
670 public static final int UNIX_LINES = 0x01;
671
672 /**
673 * Enables case-insensitive matching.
674 *
675 * <p> By default, case-insensitive matching assumes that only characters
676 * in the US-ASCII charset are being matched. Unicode-aware
677 * case-insensitive matching can be enabled by specifying the {@link
678 * #UNICODE_CASE} flag in conjunction with this flag.
679 *
680 * <p> Case-insensitive matching can also be enabled via the embedded flag
681 * expression <tt>(?i)</tt>.
682 *
683 * <p> Specifying this flag may impose a slight performance penalty. </p>
684 */
685 public static final int CASE_INSENSITIVE = 0x02;
686
687 /**
688 * Permits whitespace and comments in pattern.
689 *
690 * <p> In this mode, whitespace is ignored, and embedded comments starting
691 * with <tt>#</tt> are ignored until the end of a line.
692 *
693 * <p> Comments mode can also be enabled via the embedded flag
694 * expression <tt>(?x)</tt>.
695 */
696 public static final int COMMENTS = 0x04;
697
698 /**
699 * Enables multiline mode.
700 *
701 * <p> In multiline mode the expressions <tt>^</tt> and <tt>$</tt> match
702 * just after or just before, respectively, a line terminator or the end of
703 * the input sequence. By default these expressions only match at the
704 * beginning and the end of the entire input sequence.
705 *
706 * <p> Multiline mode can also be enabled via the embedded flag
707 * expression <tt>(?m)</tt>. </p>
708 */
709 public static final int MULTILINE = 0x08;
710
711 /**
712 * Enables literal parsing of the pattern.
713 *
714 * <p> When this flag is specified then the input string that specifies
715 * the pattern is treated as a sequence of literal characters.
716 * Metacharacters or escape sequences in the input sequence will be
717 * given no special meaning.
718 *
719 * <p>The flags CASE_INSENSITIVE and UNICODE_CASE retain their impact on
720 * matching when used in conjunction with this flag. The other flags
721 * become superfluous.
722 *
723 * <p> There is no embedded flag character for enabling literal parsing.
724 * @since 1.5
725 */
726 public static final int LITERAL = 0x10;
727
728 /**
729 * Enables dotall mode.
730 *
731 * <p> In dotall mode, the expression <tt>.</tt> matches any character,
732 * including a line terminator. By default this expression does not match
733 * line terminators.
734 *
735 * <p> Dotall mode can also be enabled via the embedded flag
736 * expression <tt>(?s)</tt>. (The <tt>s</tt> is a mnemonic for
737 * "single-line" mode, which is what this is called in Perl.) </p>
738 */
739 public static final int DOTALL = 0x20;
740
741 /**
742 * Enables Unicode-aware case folding.
743 *
744 * <p> When this flag is specified then case-insensitive matching, when
745 * enabled by the {@link #CASE_INSENSITIVE} flag, is done in a manner
746 * consistent with the Unicode Standard. By default, case-insensitive
747 * matching assumes that only characters in the US-ASCII charset are being
748 * matched.
749 *
750 * <p> Unicode-aware case folding can also be enabled via the embedded flag
751 * expression <tt>(?u)</tt>.
752 *
753 * <p> Specifying this flag may impose a performance penalty. </p>
754 */
755 public static final int UNICODE_CASE = 0x40;
756
757 /**
758 * Enables canonical equivalence.
759 *
760 * <p> When this flag is specified then two characters will be considered
761 * to match if, and only if, their full canonical decompositions match.
762 * The expression <tt>"a\u030A"</tt>, for example, will match the
763 * string <tt>"\u00E5"</tt> when this flag is specified. By default,
764 * matching does not take canonical equivalence into account.
765 *
766 * <p> There is no embedded flag character for enabling canonical
767 * equivalence.
768 *
769 * <p> Specifying this flag may impose a performance penalty. </p>
770 */
771 public static final int CANON_EQ = 0x80;
772
773 /* Pattern has only two serialized components: The pattern string
774 * and the flags, which are all that is needed to recompile the pattern
775 * when it is deserialized.
776 */
777
778 /** use serialVersionUID from Merlin b59 for interoperability */
779 private static final long serialVersionUID = 5073258162644648461L;
780
781 /**
782 * The original regular-expression pattern string.
783 *
784 * @serial
785 */
786 private String pattern;
787
788 /**
789 * The original pattern flags.
790 *
791 * @serial
792 */
793 private int flags;
794
795 /**
796 * Boolean indicating this Pattern is compiled; this is necessary in order
797 * to lazily compile deserialized Patterns.
798 */
799 private transient volatile boolean compiled = false;
800
801 /**
802 * The normalized pattern string.
803 */
804 private transient String normalizedPattern;
805
806 /**
807 * The starting point of state machine for the find operation. This allows
808 * a match to start anywhere in the input.
809 */
810 transient Node root;
811
812 /**
813 * The root of object tree for a match operation. The pattern is matched
814 * at the beginning. This may include a find that uses BnM or a First
815 * node.
816 */
817 transient Node matchRoot;
818
819 /**
820 * Temporary storage used by parsing pattern slice.
821 */
822 transient int[] buffer;
823
824 /**
825 * Map the "name" of the "named capturing group" to its group id
826 * node.
827 */
828 transient volatile Map<String, Integer> namedGroups;
829
830 /**
831 * Temporary storage used while parsing group references.
832 */
833 transient GroupHead[] groupNodes;
834
835 /**
836 * Temporary null terminated code point array used by pattern compiling.
837 */
838 private transient int[] temp;
839
840 /**
841 * The number of capturing groups in this Pattern. Used by matchers to
842 * allocate storage needed to perform a match.
843 */
844 transient int capturingGroupCount;
845
846 /**
847 * The local variable count used by parsing tree. Used by matchers to
848 * allocate storage needed to perform a match.
849 */
850 transient int localCount;
851
852 /**
853 * Index into the pattern string that keeps track of how much has been
854 * parsed.
855 */
856 private transient int cursor;
857
858 /**
859 * Holds the length of the pattern string.
860 */
861 private transient int patternLength;
862
863 /**
864 * Compiles the given regular expression into a pattern. </p>
865 *
866 * @param regex
867 * The expression to be compiled
868 *
869 * @throws PatternSyntaxException
870 * If the expression's syntax is invalid
871 */
872 public static Pattern compile(String regex) {
873 return new Pattern(regex, 0);
874 }
875
876 /**
877 * Compiles the given regular expression into a pattern with the given
878 * flags. </p>
879 *
880 * @param regex
881 * The expression to be compiled
882 *
883 * @param flags
884 * Match flags, a bit mask that may include
885 * {@link #CASE_INSENSITIVE}, {@link #MULTILINE}, {@link #DOTALL},
886 * {@link #UNICODE_CASE}, {@link #CANON_EQ}, {@link #UNIX_LINES},
887 * {@link #LITERAL} and {@link #COMMENTS}
888 *
889 * @throws IllegalArgumentException
890 * If bit values other than those corresponding to the defined
891 * match flags are set in <tt>flags</tt>
892 *
893 * @throws PatternSyntaxException
894 * If the expression's syntax is invalid
895 */
896 public static Pattern compile(String regex, int flags) {
897 return new Pattern(regex, flags);
898 }
899
900 /**
901 * Returns the regular expression from which this pattern was compiled.
902 * </p>
903 *
904 * @return The source of this pattern
905 */
906 public String pattern() {
907 return pattern;
908 }
909
910 /**
911 * <p>Returns the string representation of this pattern. This
912 * is the regular expression from which this pattern was
913 * compiled.</p>
914 *
915 * @return The string representation of this pattern
916 * @since 1.5
917 */
918 public String toString() {
919 return pattern;
920 }
921
922 /**
923 * Creates a matcher that will match the given input against this pattern.
924 * </p>
925 *
926 * @param input
927 * The character sequence to be matched
928 *
929 * @return A new matcher for this pattern
930 */
931 public Matcher matcher(CharSequence input) {
932 if (!compiled) {
933 synchronized(this) {
934 if (!compiled)
935 compile();
936 }
937 }
938 Matcher m = new Matcher(this, input);
939 return m;
940 }
941
942 /**
943 * Returns this pattern's match flags. </p>
944 *
945 * @return The match flags specified when this pattern was compiled
946 */
947 public int flags() {
948 return flags;
949 }
950
951 /**
952 * Compiles the given regular expression and attempts to match the given
953 * input against it.
954 *
955 * <p> An invocation of this convenience method of the form
956 *
957 * <blockquote><pre>
958 * Pattern.matches(regex, input);</pre></blockquote>
959 *
960 * behaves in exactly the same way as the expression
961 *
962 * <blockquote><pre>
963 * Pattern.compile(regex).matcher(input).matches()</pre></blockquote>
964 *
965 * <p> If a pattern is to be used multiple times, compiling it once and reusing
966 * it will be more efficient than invoking this method each time. </p>
967 *
968 * @param regex
969 * The expression to be compiled
970 *
971 * @param input
972 * The character sequence to be matched
973 *
974 * @throws PatternSyntaxException
975 * If the expression's syntax is invalid
976 */
977 public static boolean matches(String regex, CharSequence input) {
978 Pattern p = Pattern.compile(regex);
979 Matcher m = p.matcher(input);
980 return m.matches();
981 }
982
983 /**
984 * Splits the given input sequence around matches of this pattern.
985 *
986 * <p> The array returned by this method contains each substring of the
987 * input sequence that is terminated by another subsequence that matches
988 * this pattern or is terminated by the end of the input sequence. The
989 * substrings in the array are in the order in which they occur in the
990 * input. If this pattern does not match any subsequence of the input then
991 * the resulting array has just one element, namely the input sequence in
992 * string form.
993 *
994 * <p> The <tt>limit</tt> parameter controls the number of times the
995 * pattern is applied and therefore affects the length of the resulting
996 * array. If the limit <i>n</i> is greater than zero then the pattern
997 * will be applied at most <i>n</i> - 1 times, the array's
998 * length will be no greater than <i>n</i>, and the array's last entry
999 * will contain all input beyond the last matched delimiter. If <i>n</i>
1000 * is non-positive then the pattern will be applied as many times as
1001 * possible and the array can have any length. If <i>n</i> is zero then
1002 * the pattern will be applied as many times as possible, the array can
1003 * have any length, and trailing empty strings will be discarded.
1004 *
1005 * <p> The input <tt>"boo:and:foo"</tt>, for example, yields the following
1006 * results with these parameters:
1007 *
1008 * <blockquote><table cellpadding=1 cellspacing=0
1009 * summary="Split examples showing regex, limit, and result">
1010 * <tr><th><P align="left"><i>Regex </i></th>
1011 * <th><P align="left"><i>Limit </i></th>
1012 * <th><P align="left"><i>Result </i></th></tr>
1013 * <tr><td align=center>:</td>
1014 * <td align=center>2</td>
1015 * <td><tt>{ "boo", "and:foo" }</tt></td></tr>
1016 * <tr><td align=center>:</td>
1017 * <td align=center>5</td>
1018 * <td><tt>{ "boo", "and", "foo" }</tt></td></tr>
1019 * <tr><td align=center>:</td>
1020 * <td align=center>-2</td>
1021 * <td><tt>{ "boo", "and", "foo" }</tt></td></tr>
1022 * <tr><td align=center>o</td>
1023 * <td align=center>5</td>
1024 * <td><tt>{ "b", "", ":and:f", "", "" }</tt></td></tr>
1025 * <tr><td align=center>o</td>
1026 * <td align=center>-2</td>
1027 * <td><tt>{ "b", "", ":and:f", "", "" }</tt></td></tr>
1028 * <tr><td align=center>o</td>
1029 * <td align=center>0</td>
1030 * <td><tt>{ "b", "", ":and:f" }</tt></td></tr>
1031 * </table></blockquote>
1032 *
1033 *
1034 * @param input
1035 * The character sequence to be split
1036 *
1037 * @param limit
1038 * The result threshold, as described above
1039 *
1040 * @return The array of strings computed by splitting the input
1041 * around matches of this pattern
1042 */
1043 public String[] split(CharSequence input, int limit) {
1044 int index = 0;
1045 boolean matchLimited = limit > 0;
1046 ArrayList<String> matchList = new ArrayList<String>();
1047 Matcher m = matcher(input);
1048
1049 // Add segments before each match found
1050 while(m.find()) {
1051 if (!matchLimited || matchList.size() < limit - 1) {
1052 String match = input.subSequence(index, m.start()).toString();
1053 matchList.add(match);
1054 index = m.end();
1055 } else if (matchList.size() == limit - 1) { // last one
1056 String match = input.subSequence(index,
1057 input.length()).toString();
1058 matchList.add(match);
1059 index = m.end();
1060 }
1061 }
1062
1063 // If no match was found, return this
1064 if (index == 0)
1065 return new String[] {input.toString()};
1066
1067 // Add remaining segment
1068 if (!matchLimited || matchList.size() < limit)
1069 matchList.add(input.subSequence(index, input.length()).toString());
1070
1071 // Construct result
1072 int resultSize = matchList.size();
1073 if (limit == 0)
1074 while (resultSize > 0 && matchList.get(resultSize-1).equals(""))
1075 resultSize--;
1076 String[] result = new String[resultSize];
1077 return matchList.subList(0, resultSize).toArray(result);
1078 }
1079
1080 /**
1081 * Splits the given input sequence around matches of this pattern.
1082 *
1083 * <p> This method works as if by invoking the two-argument {@link
1084 * #split(java.lang.CharSequence, int) split} method with the given input
1085 * sequence and a limit argument of zero. Trailing empty strings are
1086 * therefore not included in the resulting array. </p>
1087 *
1088 * <p> The input <tt>"boo:and:foo"</tt>, for example, yields the following
1089 * results with these expressions:
1090 *
1091 * <blockquote><table cellpadding=1 cellspacing=0
1092 * summary="Split examples showing regex and result">
1093 * <tr><th><P align="left"><i>Regex </i></th>
1094 * <th><P align="left"><i>Result</i></th></tr>
1095 * <tr><td align=center>:</td>
1096 * <td><tt>{ "boo", "and", "foo" }</tt></td></tr>
1097 * <tr><td align=center>o</td>
1098 * <td><tt>{ "b", "", ":and:f" }</tt></td></tr>
1099 * </table></blockquote>
1100 *
1101 *
1102 * @param input
1103 * The character sequence to be split
1104 *
1105 * @return The array of strings computed by splitting the input
1106 * around matches of this pattern
1107 */
1108 public String[] split(CharSequence input) {
1109 return split(input, 0);
1110 }
1111
1112 /**
1113 * Returns a literal pattern <code>String</code> for the specified
1114 * <code>String</code>.
1115 *
1116 * <p>This method produces a <code>String</code> that can be used to
1117 * create a <code>Pattern</code> that would match the string
1118 * <code>s</code> as if it were a literal pattern.</p> Metacharacters
1119 * or escape sequences in the input sequence will be given no special
1120 * meaning.
1121 *
1122 * @param s The string to be literalized
1123 * @return A literal string replacement
1124 * @since 1.5
1125 */
1126 public static String quote(String s) {
1127 int slashEIndex = s.indexOf("\\E");
1128 if (slashEIndex == -1)
1129 return "\\Q" + s + "\\E";
1130
1131 StringBuilder sb = new StringBuilder(s.length() * 2);
1132 sb.append("\\Q");
1133 slashEIndex = 0;
1134 int current = 0;
1135 while ((slashEIndex = s.indexOf("\\E", current)) != -1) {
1136 sb.append(s.substring(current, slashEIndex));
1137 current = slashEIndex + 2;
1138 sb.append("\\E\\\\E\\Q");
1139 }
1140 sb.append(s.substring(current, s.length()));
1141 sb.append("\\E");
1142 return sb.toString();
1143 }
1144
1145 /**
1146 * Recompile the Pattern instance from a stream. The original pattern
1147 * string is read in and the object tree is recompiled from it.
1148 */
1149 private void readObject(java.io.ObjectInputStream s)
1150 throws java.io.IOException, ClassNotFoundException {
1151
1152 // Read in all fields
1153 s.defaultReadObject();
1154
1155 // Initialize counts
1156 capturingGroupCount = 1;
1157 localCount = 0;
1158
1159 // if length > 0, the Pattern is lazily compiled
1160 compiled = false;
1161 if (pattern.length() == 0) {
1162 root = new Start(lastAccept);
1163 matchRoot = lastAccept;
1164 compiled = true;
1165 }
1166 }
1167
1168 /**
1169 * This private constructor is used to create all Patterns. The pattern
1170 * string and match flags are all that is needed to completely describe
1171 * a Pattern. An empty pattern string results in an object tree with
1172 * only a Start node and a LastNode node.
1173 */
1174 private Pattern(String p, int f) {
1175 pattern = p;
1176 flags = f;
1177
1178 // Reset group index count
1179 capturingGroupCount = 1;
1180 localCount = 0;
1181
1182 if (pattern.length() > 0) {
1183 compile();
1184 } else {
1185 root = new Start(lastAccept);
1186 matchRoot = lastAccept;
1187 }
1188 }
1189
1190 /**
1191 * The pattern is converted to normalizedD form and then a pure group
1192 * is constructed to match canonical equivalences of the characters.
1193 */
1194 private void normalize() {
1195 boolean inCharClass = false;
1196 int lastCodePoint = -1;
1197
1198 // Convert pattern into normalizedD form
1199 normalizedPattern = Normalizer.normalize(pattern, Normalizer.Form.NFD);
1200 patternLength = normalizedPattern.length();
1201
1202 // Modify pattern to match canonical equivalences
1203 StringBuilder newPattern = new StringBuilder(patternLength);
1204 for(int i=0; i<patternLength; ) {
1205 int c = normalizedPattern.codePointAt(i);
1206 StringBuilder sequenceBuffer;
1207 if ((Character.getType(c) == Character.NON_SPACING_MARK)
1208 && (lastCodePoint != -1)) {
1209 sequenceBuffer = new StringBuilder();
1210 sequenceBuffer.appendCodePoint(lastCodePoint);
1211 sequenceBuffer.appendCodePoint(c);
1212 while(Character.getType(c) == Character.NON_SPACING_MARK) {
1213 i += Character.charCount(c);
1214 if (i >= patternLength)
1215 break;
1216 c = normalizedPattern.codePointAt(i);
1217 sequenceBuffer.appendCodePoint(c);
1218 }
1219 String ea = produceEquivalentAlternation(
1220 sequenceBuffer.toString());
1221 newPattern.setLength(newPattern.length()-Character.charCount(lastCodePoint));
1222 newPattern.append("(?:").append(ea).append(")");
1223 } else if (c == '[' && lastCodePoint != '\\') {
1224 i = normalizeCharClass(newPattern, i);
1225 } else {
1226 newPattern.appendCodePoint(c);
1227 }
1228 lastCodePoint = c;
1229 i += Character.charCount(c);
1230 }
1231 normalizedPattern = newPattern.toString();
1232 }
1233
1234 /**
1235 * Complete the character class being parsed and add a set
1236 * of alternations to it that will match the canonical equivalences
1237 * of the characters within the class.
1238 */
1239 private int normalizeCharClass(StringBuilder newPattern, int i) {
1240 StringBuilder charClass = new StringBuilder();
1241 StringBuilder eq = null;
1242 int lastCodePoint = -1;
1243 String result;
1244
1245 i++;
1246 charClass.append("[");
1247 while(true) {
1248 int c = normalizedPattern.codePointAt(i);
1249 StringBuilder sequenceBuffer;
1250
1251 if (c == ']' && lastCodePoint != '\\') {
1252 charClass.append((char)c);
1253 break;
1254 } else if (Character.getType(c) == Character.NON_SPACING_MARK) {
1255 sequenceBuffer = new StringBuilder();
1256 sequenceBuffer.appendCodePoint(lastCodePoint);
1257 while(Character.getType(c) == Character.NON_SPACING_MARK) {
1258 sequenceBuffer.appendCodePoint(c);
1259 i += Character.charCount(c);
1260 if (i >= normalizedPattern.length())
1261 break;
1262 c = normalizedPattern.codePointAt(i);
1263 }
1264 String ea = produceEquivalentAlternation(
1265 sequenceBuffer.toString());
1266
1267 charClass.setLength(charClass.length()-Character.charCount(lastCodePoint));
1268 if (eq == null)
1269 eq = new StringBuilder();
1270 eq.append('|');
1271 eq.append(ea);
1272 } else {
1273 charClass.appendCodePoint(c);
1274 i++;
1275 }
1276 if (i == normalizedPattern.length())
1277 throw error("Unclosed character class");
1278 lastCodePoint = c;
1279 }
1280
1281 if (eq != null) {
1282 result = "(?:"+charClass.toString()+eq.toString()+")";
1283 } else {
1284 result = charClass.toString();
1285 }
1286
1287 newPattern.append(result);
1288 return i;
1289 }
1290
1291 /**
1292 * Given a specific sequence composed of a regular character and
1293 * combining marks that follow it, produce the alternation that will
1294 * match all canonical equivalences of that sequence.
1295 */
1296 private String produceEquivalentAlternation(String source) {
1297 int len = countChars(source, 0, 1);
1298 if (source.length() == len)
1299 // source has one character.
1300 return source;
1301
1302 String base = source.substring(0,len);
1303 String combiningMarks = source.substring(len);
1304
1305 String[] perms = producePermutations(combiningMarks);
1306 StringBuilder result = new StringBuilder(source);
1307
1308 // Add combined permutations
1309 for(int x=0; x<perms.length; x++) {
1310 String next = base + perms[x];
1311 if (x>0)
1312 result.append("|"+next);
1313 next = composeOneStep(next);
1314 if (next != null)
1315 result.append("|"+produceEquivalentAlternation(next));
1316 }
1317 return result.toString();
1318 }
1319
1320 /**
1321 * Returns an array of strings that have all the possible
1322 * permutations of the characters in the input string.
1323 * This is used to get a list of all possible orderings
1324 * of a set of combining marks. Note that some of the permutations
1325 * are invalid because of combining class collisions, and these
1326 * possibilities must be removed because they are not canonically
1327 * equivalent.
1328 */
1329 private String[] producePermutations(String input) {
1330 if (input.length() == countChars(input, 0, 1))
1331 return new String[] {input};
1332
1333 if (input.length() == countChars(input, 0, 2)) {
1334 int c0 = Character.codePointAt(input, 0);
1335 int c1 = Character.codePointAt(input, Character.charCount(c0));
1336 if (getClass(c1) == getClass(c0)) {
1337 return new String[] {input};
1338 }
1339 String[] result = new String[2];
1340 result[0] = input;
1341 StringBuilder sb = new StringBuilder(2);
1342 sb.appendCodePoint(c1);
1343 sb.appendCodePoint(c0);
1344 result[1] = sb.toString();
1345 return result;
1346 }
1347
1348 int length = 1;
1349 int nCodePoints = countCodePoints(input);
1350 for(int x=1; x<nCodePoints; x++)
1351 length = length * (x+1);
1352
1353 String[] temp = new String[length];
1354
1355 int combClass[] = new int[nCodePoints];
1356 for(int x=0, i=0; x<nCodePoints; x++) {
1357 int c = Character.codePointAt(input, i);
1358 combClass[x] = getClass(c);
1359 i += Character.charCount(c);
1360 }
1361
1362 // For each char, take it out and add the permutations
1363 // of the remaining chars
1364 int index = 0;
1365 int len;
1366 // offset maintains the index in code units.
1367 loop: for(int x=0, offset=0; x<nCodePoints; x++, offset+=len) {
1368 len = countChars(input, offset, 1);
1369 boolean skip = false;
1370 for(int y=x-1; y>=0; y--) {
1371 if (combClass[y] == combClass[x]) {
1372 continue loop;
1373 }
1374 }
1375 StringBuilder sb = new StringBuilder(input);
1376 String otherChars = sb.delete(offset, offset+len).toString();
1377 String[] subResult = producePermutations(otherChars);
1378
1379 String prefix = input.substring(offset, offset+len);
1380 for(int y=0; y<subResult.length; y++)
1381 temp[index++] = prefix + subResult[y];
1382 }
1383 String[] result = new String[index];
1384 for (int x=0; x<index; x++)
1385 result[x] = temp[x];
1386 return result;
1387 }
1388
1389 private int getClass(int c) {
1390 return sun.text.Normalizer.getCombiningClass(c);
1391 }
1392
1393 /**
1394 * Attempts to compose input by combining the first character
1395 * with the first combining mark following it. Returns a String
1396 * that is the composition of the leading character with its first
1397 * combining mark followed by the remaining combining marks. Returns
1398 * null if the first two characters cannot be further composed.
1399 */
1400 private String composeOneStep(String input) {
1401 int len = countChars(input, 0, 2);
1402 String firstTwoCharacters = input.substring(0, len);
1403 String result = Normalizer.normalize(firstTwoCharacters, Normalizer.Form.NFC);
1404
1405 if (result.equals(firstTwoCharacters))
1406 return null;
1407 else {
1408 String remainder = input.substring(len);
1409 return result + remainder;
1410 }
1411 }
1412
1413 /**
1414 * Preprocess any \Q...\E sequences in `temp', meta-quoting them.
1415 * See the description of `quotemeta' in perlfunc(1).
1416 */
1417 private void RemoveQEQuoting() {
1418 final int pLen = patternLength;
1419 int i = 0;
1420 while (i < pLen-1) {
1421 if (temp[i] != '\\')
1422 i += 1;
1423 else if (temp[i + 1] != 'Q')
1424 i += 2;
1425 else
1426 break;
1427 }
1428 if (i >= pLen - 1) // No \Q sequence found
1429 return;
1430 int j = i;
1431 i += 2;
1432 int[] newtemp = new int[j + 2*(pLen-i) + 2];
1433 System.arraycopy(temp, 0, newtemp, 0, j);
1434
1435 boolean inQuote = true;
1436 while (i < pLen) {
1437 int c = temp[i++];
1438 if (! ASCII.isAscii(c) || ASCII.isAlnum(c)) {
1439 newtemp[j++] = c;
1440 } else if (c != '\\') {
1441 if (inQuote) newtemp[j++] = '\\';
1442 newtemp[j++] = c;
1443 } else if (inQuote) {
1444 if (temp[i] == 'E') {
1445 i++;
1446 inQuote = false;
1447 } else {
1448 newtemp[j++] = '\\';
1449 newtemp[j++] = '\\';
1450 }
1451 } else {
1452 if (temp[i] == 'Q') {
1453 i++;
1454 inQuote = true;
1455 } else {
1456 newtemp[j++] = c;
1457 if (i != pLen)
1458 newtemp[j++] = temp[i++];
1459 }
1460 }
1461 }
1462
1463 patternLength = j;
1464 temp = Arrays.copyOf(newtemp, j + 2); // double zero termination
1465 }
1466
1467 /**
1468 * Copies regular expression to an int array and invokes the parsing
1469 * of the expression which will create the object tree.
1470 */
1471 private void compile() {
1472 // Handle canonical equivalences
1473 if (has(CANON_EQ) && !has(LITERAL)) {
1474 normalize();
1475 } else {
1476 normalizedPattern = pattern;
1477 }
1478 patternLength = normalizedPattern.length();
1479
1480 // Copy pattern to int array for convenience
1481 // Use double zero to terminate pattern
1482 temp = new int[patternLength + 2];
1483
1484 boolean hasSupplementary = false;
1485 int c, count = 0;
1486 // Convert all chars into code points
1487 for (int x = 0; x < patternLength; x += Character.charCount(c)) {
1488 c = normalizedPattern.codePointAt(x);
1489 if (isSupplementary(c)) {
1490 hasSupplementary = true;
1491 }
1492 temp[count++] = c;
1493 }
1494
1495 patternLength = count; // patternLength now in code points
1496
1497 if (! has(LITERAL))
1498 RemoveQEQuoting();
1499
1500 // Allocate all temporary objects here.
1501 buffer = new int[32];
1502 groupNodes = new GroupHead[10];
1503 namedGroups = null;
1504
1505 if (has(LITERAL)) {
1506 // Literal pattern handling
1507 matchRoot = newSlice(temp, patternLength, hasSupplementary);
1508 matchRoot.next = lastAccept;
1509 } else {
1510 // Start recursive descent parsing
1511 matchRoot = expr(lastAccept);
1512 // Check extra pattern characters
1513 if (patternLength != cursor) {
1514 if (peek() == ')') {
1515 throw error("Unmatched closing ')'");
1516 } else {
1517 throw error("Unexpected internal error");
1518 }
1519 }
1520 }
1521
1522 // Peephole optimization
1523 if (matchRoot instanceof Slice) {
1524 root = BnM.optimize(matchRoot);
1525 if (root == matchRoot) {
1526 root = hasSupplementary ? new StartS(matchRoot) : new Start(matchRoot);
1527 }
1528 } else if (matchRoot instanceof Begin || matchRoot instanceof First) {
1529 root = matchRoot;
1530 } else {
1531 root = hasSupplementary ? new StartS(matchRoot) : new Start(matchRoot);
1532 }
1533
1534 // Release temporary storage
1535 temp = null;
1536 buffer = null;
1537 groupNodes = null;
1538 patternLength = 0;
1539 compiled = true;
1540 }
1541
1542 Map<String, Integer> namedGroups() {
1543 if (namedGroups == null)
1544 namedGroups = new HashMap<String, Integer>(2);
1545 return namedGroups;
1546 }
1547
1548 /**
1549 * Used to print out a subtree of the Pattern to help with debugging.
1550 */
1551 private static void printObjectTree(Node node) {
1552 while(node != null) {
1553 if (node instanceof Prolog) {
1554 System.out.println(node);
1555 printObjectTree(((Prolog)node).loop);
1556 System.out.println("**** end contents prolog loop");
1557 } else if (node instanceof Loop) {
1558 System.out.println(node);
1559 printObjectTree(((Loop)node).body);
1560 System.out.println("**** end contents Loop body");
1561 } else if (node instanceof Curly) {
1562 System.out.println(node);
1563 printObjectTree(((Curly)node).atom);
1564 System.out.println("**** end contents Curly body");
1565 } else if (node instanceof GroupCurly) {
1566 System.out.println(node);
1567 printObjectTree(((GroupCurly)node).atom);
1568 System.out.println("**** end contents GroupCurly body");
1569 } else if (node instanceof GroupTail) {
1570 System.out.println(node);
1571 System.out.println("Tail next is "+node.next);
1572 return;
1573 } else {
1574 System.out.println(node);
1575 }
1576 node = node.next;
1577 if (node != null)
1578 System.out.println("->next:");
1579 if (node == Pattern.accept) {
1580 System.out.println("Accept Node");
1581 node = null;
1582 }
1583 }
1584 }
1585
1586 /**
1587 * Used to accumulate information about a subtree of the object graph
1588 * so that optimizations can be applied to the subtree.
1589 */
1590 static final class TreeInfo {
1591 int minLength;
1592 int maxLength;
1593 boolean maxValid;
1594 boolean deterministic;
1595
1596 TreeInfo() {
1597 reset();
1598 }
1599 void reset() {
1600 minLength = 0;
1601 maxLength = 0;
1602 maxValid = true;
1603 deterministic = true;
1604 }
1605 }
1606
1607 /*
1608 * The following private methods are mainly used to improve the
1609 * readability of the code. In order to let the Java compiler easily
1610 * inline them, we should not put many assertions or error checks in them.
1611 */
1612
1613 /**
1614 * Indicates whether a particular flag is set or not.
1615 */
1616 private boolean has(int f) {
1617 return (flags & f) != 0;
1618 }
1619
1620 /**
1621 * Match next character, signal error if failed.
1622 */
1623 private void accept(int ch, String s) {
1624 int testChar = temp[cursor++];
1625 if (has(COMMENTS))
1626 testChar = parsePastWhitespace(testChar);
1627 if (ch != testChar) {
1628 throw error(s);
1629 }
1630 }
1631
1632 /**
1633 * Mark the end of pattern with a specific character.
1634 */
1635 private void mark(int c) {
1636 temp[patternLength] = c;
1637 }
1638
1639 /**
1640 * Peek the next character, and do not advance the cursor.
1641 */
1642 private int peek() {
1643 int ch = temp[cursor];
1644 if (has(COMMENTS))
1645 ch = peekPastWhitespace(ch);
1646 return ch;
1647 }
1648
1649 /**
1650 * Read the next character, and advance the cursor by one.
1651 */
1652 private int read() {
1653 int ch = temp[cursor++];
1654 if (has(COMMENTS))
1655 ch = parsePastWhitespace(ch);
1656 return ch;
1657 }
1658
1659 /**
1660 * Read the next character, and advance the cursor by one,
1661 * ignoring the COMMENTS setting
1662 */
1663 private int readEscaped() {
1664 int ch = temp[cursor++];
1665 return ch;
1666 }
1667
1668 /**
1669 * Advance the cursor by one, and peek the next character.
1670 */
1671 private int next() {
1672 int ch = temp[++cursor];
1673 if (has(COMMENTS))
1674 ch = peekPastWhitespace(ch);
1675 return ch;
1676 }
1677
1678 /**
1679 * Advance the cursor by one, and peek the next character,
1680 * ignoring the COMMENTS setting
1681 */
1682 private int nextEscaped() {
1683 int ch = temp[++cursor];
1684 return ch;
1685 }
1686
1687 /**
1688 * If in xmode peek past whitespace and comments.
1689 */
1690 private int peekPastWhitespace(int ch) {
1691 while (ASCII.isSpace(ch) || ch == '#') {
1692 while (ASCII.isSpace(ch))
1693 ch = temp[++cursor];
1694 if (ch == '#') {
1695 ch = peekPastLine();
1696 }
1697 }
1698 return ch;
1699 }
1700
1701 /**
1702 * If in xmode parse past whitespace and comments.
1703 */
1704 private int parsePastWhitespace(int ch) {
1705 while (ASCII.isSpace(ch) || ch == '#') {
1706 while (ASCII.isSpace(ch))
1707 ch = temp[cursor++];
1708 if (ch == '#')
1709 ch = parsePastLine();
1710 }
1711 return ch;
1712 }
1713
1714 /**
1715 * xmode parse past comment to end of line.
1716 */
1717 private int parsePastLine() {
1718 int ch = temp[cursor++];
1719 while (ch != 0 && !isLineSeparator(ch))
1720 ch = temp[cursor++];
1721 return ch;
1722 }
1723
1724 /**
1725 * xmode peek past comment to end of line.
1726 */
1727 private int peekPastLine() {
1728 int ch = temp[++cursor];
1729 while (ch != 0 && !isLineSeparator(ch))
1730 ch = temp[++cursor];
1731 return ch;
1732 }
1733
1734 /**
1735 * Determines if character is a line separator in the current mode
1736 */
1737 private boolean isLineSeparator(int ch) {
1738 if (has(UNIX_LINES)) {
1739 return ch == '\n';
1740 } else {
1741 return (ch == '\n' ||
1742 ch == '\r' ||
1743 (ch|1) == '\u2029' ||
1744 ch == '\u0085');
1745 }
1746 }
1747
1748 /**
1749 * Read the character after the next one, and advance the cursor by two.
1750 */
1751 private int skip() {
1752 int i = cursor;
1753 int ch = temp[i+1];
1754 cursor = i + 2;
1755 return ch;
1756 }
1757
1758 /**
1759 * Unread one next character, and retreat cursor by one.
1760 */
1761 private void unread() {
1762 cursor--;
1763 }
1764
1765 /**
1766 * Internal method used for handling all syntax errors. The pattern is
1767 * displayed with a pointer to aid in locating the syntax error.
1768 */
1769 private PatternSyntaxException error(String s) {
1770 return new PatternSyntaxException(s, normalizedPattern, cursor - 1);
1771 }
1772
1773 /**
1774 * Determines if there is any supplementary character or unpaired
1775 * surrogate in the specified range.
1776 */
1777 private boolean findSupplementary(int start, int end) {
1778 for (int i = start; i < end; i++) {
1779 if (isSupplementary(temp[i]))
1780 return true;
1781 }
1782 return false;
1783 }
1784
1785 /**
1786 * Determines if the specified code point is a supplementary
1787 * character or unpaired surrogate.
1788 */
1789 private static final boolean isSupplementary(int ch) {
1790 return ch >= Character.MIN_SUPPLEMENTARY_CODE_POINT || isSurrogate(ch);
1791 }
1792
1793 /**
1794 * The following methods handle the main parsing. They are sorted
1795 * according to their precedence order, the lowest one first.
1796 */
1797
1798 /**
1799 * The expression is parsed with branch nodes added for alternations.
1800 * This may be called recursively to parse sub expressions that may
1801 * contain alternations.
1802 */
1803 private Node expr(Node end) {
1804 Node prev = null;
1805 Node firstTail = null;
1806 Node branchConn = null;
1807
1808 for (;;) {
1809 Node node = sequence(end);
1810 Node nodeTail = root; //double return
1811 if (prev == null) {
1812 prev = node;
1813 firstTail = nodeTail;
1814 } else {
1815 // Branch
1816 if (branchConn == null) {
1817 branchConn = new BranchConn();
1818 branchConn.next = end;
1819 }
1820 if (node == end) {
1821 // if the node returned from sequence() is "end"
1822 // we have an empty expr, set a null atom into
1823 // the branch to indicate to go "next" directly.
1824 node = null;
1825 } else {
1826 // the "tail.next" of each atom goes to branchConn
1827 nodeTail.next = branchConn;
1828 }
1829 if (prev instanceof Branch) {
1830 ((Branch)prev).add(node);
1831 } else {
1832 if (prev == end) {
1833 prev = null;
1834 } else {
1835 // replace the "end" with "branchConn" at its tail.next
1836 // when put the "prev" into the branch as the first atom.
1837 firstTail.next = branchConn;
1838 }
1839 prev = new Branch(prev, node, branchConn);
1840 }
1841 }
1842 if (peek() != '|') {
1843 return prev;
1844 }
1845 next();
1846 }
1847 }
1848
1849 /**
1850 * Parsing of sequences between alternations.
1851 */
1852 private Node sequence(Node end) {
1853 Node head = null;
1854 Node tail = null;
1855 Node node = null;
1856 LOOP:
1857 for (;;) {
1858 int ch = peek();
1859 switch (ch) {
1860 case '(':
1861 // Because group handles its own closure,
1862 // we need to treat it differently
1863 node = group0();
1864 // Check for comment or flag group
1865 if (node == null)
1866 continue;
1867 if (head == null)
1868 head = node;
1869 else
1870 tail.next = node;
1871 // Double return: Tail was returned in root
1872 tail = root;
1873 continue;
1874 case '[':
1875 node = clazz(true);
1876 break;
1877 case '\\':
1878 ch = nextEscaped();
1879 if (ch == 'p' || ch == 'P') {
1880 boolean oneLetter = true;
1881 boolean comp = (ch == 'P');
1882 ch = next(); // Consume { if present
1883 if (ch != '{') {
1884 unread();
1885 } else {
1886 oneLetter = false;
1887 }
1888 node = family(oneLetter).maybeComplement(comp);
1889 } else {
1890 unread();
1891 node = atom();
1892 }
1893 break;
1894 case '^':
1895 next();
1896 if (has(MULTILINE)) {
1897 if (has(UNIX_LINES))
1898 node = new UnixCaret();
1899 else
1900 node = new Caret();
1901 } else {
1902 node = new Begin();
1903 }
1904 break;
1905 case '$':
1906 next();
1907 if (has(UNIX_LINES))
1908 node = new UnixDollar(has(MULTILINE));
1909 else
1910 node = new Dollar(has(MULTILINE));
1911 break;
1912 case '.':
1913 next();
1914 if (has(DOTALL)) {
1915 node = new All();
1916 } else {
1917 if (has(UNIX_LINES))
1918 node = new UnixDot();
1919 else {
1920 node = new Dot();
1921 }
1922 }
1923 break;
1924 case '|':
1925 case ')':
1926 break LOOP;
1927 case ']': // Now interpreting dangling ] and } as literals
1928 case '}':
1929 node = atom();
1930 break;
1931 case '?':
1932 case '*':
1933 case '+':
1934 next();
1935 throw error("Dangling meta character '" + ((char)ch) + "'");
1936 case 0:
1937 if (cursor >= patternLength) {
1938 break LOOP;
1939 }
1940 // Fall through
1941 default:
1942 node = atom();
1943 break;
1944 }
1945
1946 node = closure(node);
1947
1948 if (head == null) {
1949 head = tail = node;
1950 } else {
1951 tail.next = node;
1952 tail = node;
1953 }
1954 }
1955 if (head == null) {
1956 return end;
1957 }
1958 tail.next = end;
1959 root = tail; //double return
1960 return head;
1961 }
1962
1963 /**
1964 * Parse and add a new Single or Slice.
1965 */
1966 private Node atom() {
1967 int first = 0;
1968 int prev = -1;
1969 boolean hasSupplementary = false;
1970 int ch = peek();
1971 for (;;) {
1972 switch (ch) {
1973 case '*':
1974 case '+':
1975 case '?':
1976 case '{':
1977 if (first > 1) {
1978 cursor = prev; // Unwind one character
1979 first--;
1980 }
1981 break;
1982 case '$':
1983 case '.':
1984 case '^':
1985 case '(':
1986 case '[':
1987 case '|':
1988 case ')':
1989 break;
1990 case '\\':
1991 ch = nextEscaped();
1992 if (ch == 'p' || ch == 'P') { // Property
1993 if (first > 0) { // Slice is waiting; handle it first
1994 unread();
1995 break;
1996 } else { // No slice; just return the family node
1997 boolean comp = (ch == 'P');
1998 boolean oneLetter = true;
1999 ch = next(); // Consume { if present
2000 if (ch != '{')
2001 unread();
2002 else
2003 oneLetter = false;
2004 return family(oneLetter).maybeComplement(comp);
2005 }
2006 }
2007 unread();
2008 prev = cursor;
2009 ch = escape(false, first == 0);
2010 if (ch >= 0) {
2011 append(ch, first);
2012 first++;
2013 if (isSupplementary(ch)) {
2014 hasSupplementary = true;
2015 }
2016 ch = peek();
2017 continue;
2018 } else if (first == 0) {
2019 return root;
2020 }
2021 // Unwind meta escape sequence
2022 cursor = prev;
2023 break;
2024 case 0:
2025 if (cursor >= patternLength) {
2026 break;
2027 }
2028 // Fall through
2029 default:
2030 prev = cursor;
2031 append(ch, first);
2032 first++;
2033 if (isSupplementary(ch)) {
2034 hasSupplementary = true;
2035 }
2036 ch = next();
2037 continue;
2038 }
2039 break;
2040 }
2041 if (first == 1) {
2042 return newSingle(buffer[0]);
2043 } else {
2044 return newSlice(buffer, first, hasSupplementary);
2045 }
2046 }
2047
2048 private void append(int ch, int len) {
2049 if (len >= buffer.length) {
2050 int[] tmp = new int[len+len];
2051 System.arraycopy(buffer, 0, tmp, 0, len);
2052 buffer = tmp;
2053 }
2054 buffer[len] = ch;
2055 }
2056
2057 /**
2058 * Parses a backref greedily, taking as many numbers as it
2059 * can. The first digit is always treated as a backref, but
2060 * multi digit numbers are only treated as a backref if at
2061 * least that many backrefs exist at this point in the regex.
2062 */
2063 private Node ref(int refNum) {
2064 boolean done = false;
2065 while(!done) {
2066 int ch = peek();
2067 switch(ch) {
2068 case '0':
2069 case '1':
2070 case '2':
2071 case '3':
2072 case '4':
2073 case '5':
2074 case '6':
2075 case '7':
2076 case '8':
2077 case '9':
2078 int newRefNum = (refNum * 10) + (ch - '0');
2079 // Add another number if it doesn't make a group
2080 // that doesn't exist
2081 if (capturingGroupCount - 1 < newRefNum) {
2082 done = true;
2083 break;
2084 }
2085 refNum = newRefNum;
2086 read();
2087 break;
2088 default:
2089 done = true;
2090 break;
2091 }
2092 }
2093 if (has(CASE_INSENSITIVE))
2094 return new CIBackRef(refNum, has(UNICODE_CASE));
2095 else
2096 return new BackRef(refNum);
2097 }
2098
2099 /**
2100 * Parses an escape sequence to determine the actual value that needs
2101 * to be matched.
2102 * If -1 is returned and create was true a new object was added to the tree
2103 * to handle the escape sequence.
2104 * If the returned value is greater than zero, it is the value that
2105 * matches the escape sequence.
2106 */
2107 private int escape(boolean inclass, boolean create) {
2108 int ch = skip();
2109 switch (ch) {
2110 case '0':
2111 return o();
2112 case '1':
2113 case '2':
2114 case '3':
2115 case '4':
2116 case '5':
2117 case '6':
2118 case '7':
2119 case '8':
2120 case '9':
2121 if (inclass) break;
2122 if (create) {
2123 root = ref((ch - '0'));
2124 }
2125 return -1;
2126 case 'A':
2127 if (inclass) break;
2128 if (create) root = new Begin();
2129 return -1;
2130 case 'B':
2131 if (inclass) break;
2132 if (create) root = new Bound(Bound.NONE);
2133 return -1;
2134 case 'C':
2135 break;
2136 case 'D':
2137 if (create) root = new Ctype(ASCII.DIGIT).complement();
2138 return -1;
2139 case 'E':
2140 case 'F':
2141 break;
2142 case 'G':
2143 if (inclass) break;
2144 if (create) root = new LastMatch();
2145 return -1;
2146 case 'H':
2147 case 'I':
2148 case 'J':
2149 case 'K':
2150 case 'L':
2151 case 'M':
2152 case 'N':
2153 case 'O':
2154 case 'P':
2155 case 'Q':
2156 case 'R':
2157 break;
2158 case 'S':
2159 if (create) root = new Ctype(ASCII.SPACE).complement();
2160 return -1;
2161 case 'T':
2162 case 'U':
2163 case 'V':
2164 break;
2165 case 'W':
2166 if (create) root = new Ctype(ASCII.WORD).complement();
2167 return -1;
2168 case 'X':
2169 case 'Y':
2170 break;
2171 case 'Z':
2172 if (inclass) break;
2173 if (create) {
2174 if (has(UNIX_LINES))
2175 root = new UnixDollar(false);
2176 else
2177 root = new Dollar(false);
2178 }
2179 return -1;
2180 case 'a':
2181 return '\007';
2182 case 'b':
2183 if (inclass) break;
2184 if (create) root = new Bound(Bound.BOTH);
2185 return -1;
2186 case 'c':
2187 return c();
2188 case 'd':
2189 if (create) root = new Ctype(ASCII.DIGIT);
2190 return -1;
2191 case 'e':
2192 return '\033';
2193 case 'f':
2194 return '\f';
2195 case 'g':
2196 case 'h':
2197 case 'i':
2198 case 'j':
2199 break;
2200 case 'k':
2201 if (inclass)
2202 break;
2203 if (read() != '<')
2204 throw error("\\k is not followed by '<' for named capturing group");
2205 String name = groupname(read());
2206 if (!namedGroups().containsKey(name))
2207 throw error("(named capturing group <"+ name+"> does not exit");
2208 if (create) {
2209 if (has(CASE_INSENSITIVE))
2210 root = new CIBackRef(namedGroups().get(name), has(UNICODE_CASE));
2211 else
2212 root = new BackRef(namedGroups().get(name));
2213 }
2214 return -1;
2215 case 'l':
2216 case 'm':
2217 break;
2218 case 'n':
2219 return '\n';
2220 case 'o':
2221 case 'p':
2222 case 'q':
2223 break;
2224 case 'r':
2225 return '\r';
2226 case 's':
2227 if (create) root = new Ctype(ASCII.SPACE);
2228 return -1;
2229 case 't':
2230 return '\t';
2231 case 'u':
2232 return u();
2233 case 'v':
2234 return '\013';
2235 case 'w':
2236 if (create) root = new Ctype(ASCII.WORD);
2237 return -1;
2238 case 'x':
2239 return x();
2240 case 'y':
2241 break;
2242 case 'z':
2243 if (inclass) break;
2244 if (create) root = new End();
2245 return -1;
2246 default:
2247 return ch;
2248 }
2249 throw error("Illegal/unsupported escape sequence");
2250 }
2251
2252 /**
2253 * Parse a character class, and return the node that matches it.
2254 *
2255 * Consumes a ] on the way out if consume is true. Usually consume
2256 * is true except for the case of [abc&&def] where def is a separate
2257 * right hand node with "understood" brackets.
2258 */
2259 private CharProperty clazz(boolean consume) {
2260 CharProperty prev = null;
2261 CharProperty node = null;
2262 BitClass bits = new BitClass();
2263 boolean include = true;
2264 boolean firstInClass = true;
2265 int ch = next();
2266 for (;;) {
2267 switch (ch) {
2268 case '^':
2269 // Negates if first char in a class, otherwise literal
2270 if (firstInClass) {
2271 if (temp[cursor-1] != '[')
2272 break;
2273 ch = next();
2274 include = !include;
2275 continue;
2276 } else {
2277 // ^ not first in class, treat as literal
2278 break;
2279 }
2280 case '[':
2281 firstInClass = false;
2282 node = clazz(true);
2283 if (prev == null)
2284 prev = node;
2285 else
2286 prev = union(prev, node);
2287 ch = peek();
2288 continue;
2289 case '&':
2290 firstInClass = false;
2291 ch = next();
2292 if (ch == '&') {
2293 ch = next();
2294 CharProperty rightNode = null;
2295 while (ch != ']' && ch != '&') {
2296 if (ch == '[') {
2297 if (rightNode == null)
2298 rightNode = clazz(true);
2299 else
2300 rightNode = union(rightNode, clazz(true));
2301 } else { // abc&&def
2302 unread();
2303 rightNode = clazz(false);
2304 }
2305 ch = peek();
2306 }
2307 if (rightNode != null)
2308 node = rightNode;
2309 if (prev == null) {
2310 if (rightNode == null)
2311 throw error("Bad class syntax");
2312 else
2313 prev = rightNode;
2314 } else {
2315 prev = intersection(prev, node);
2316 }
2317 } else {
2318 // treat as a literal &
2319 unread();
2320 break;
2321 }
2322 continue;
2323 case 0:
2324 firstInClass = false;
2325 if (cursor >= patternLength)
2326 throw error("Unclosed character class");
2327 break;
2328 case ']':
2329 firstInClass = false;
2330 if (prev != null) {
2331 if (consume)
2332 next();
2333 return prev;
2334 }
2335 break;
2336 default:
2337 firstInClass = false;
2338 break;
2339 }
2340 node = range(bits);
2341 if (include) {
2342 if (prev == null) {
2343 prev = node;
2344 } else {
2345 if (prev != node)
2346 prev = union(prev, node);
2347 }
2348 } else {
2349 if (prev == null) {
2350 prev = node.complement();
2351 } else {
2352 if (prev != node)
2353 prev = setDifference(prev, node);
2354 }
2355 }
2356 ch = peek();
2357 }
2358 }
2359
2360 private CharProperty bitsOrSingle(BitClass bits, int ch) {
2361 /* Bits can only handle codepoints in [u+0000-u+00ff] range.
2362 Use "single" node instead of bits when dealing with unicode
2363 case folding for codepoints listed below.
2364 (1)Uppercase out of range: u+00ff, u+00b5
2365 toUpperCase(u+00ff) -> u+0178
2366 toUpperCase(u+00b5) -> u+039c
2367 (2)LatinSmallLetterLongS u+17f
2368 toUpperCase(u+017f) -> u+0053
2369 (3)LatinSmallLetterDotlessI u+131
2370 toUpperCase(u+0131) -> u+0049
2371 (4)LatinCapitalLetterIWithDotAbove u+0130
2372 toLowerCase(u+0130) -> u+0069
2373 (5)KelvinSign u+212a
2374 toLowerCase(u+212a) ==> u+006B
2375 (6)AngstromSign u+212b
2376 toLowerCase(u+212b) ==> u+00e5
2377 */
2378 int d;
2379 if (ch < 256 &&
2380 !(has(CASE_INSENSITIVE) && has(UNICODE_CASE) &&
2381 (ch == 0xff || ch == 0xb5 ||
2382 ch == 0x49 || ch == 0x69 || //I and i
2383 ch == 0x53 || ch == 0x73 || //S and s
2384 ch == 0x4b || ch == 0x6b || //K and k
2385 ch == 0xc5 || ch == 0xe5))) //A+ring
2386 return bits.add(ch, flags());
2387 return newSingle(ch);
2388 }
2389
2390 /**
2391 * Parse a single character or a character range in a character class
2392 * and return its representative node.
2393 */
2394 private CharProperty range(BitClass bits) {
2395 int ch = peek();
2396 if (ch == '\\') {
2397 ch = nextEscaped();
2398 if (ch == 'p' || ch == 'P') { // A property
2399 boolean comp = (ch == 'P');
2400 boolean oneLetter = true;
2401 // Consume { if present
2402 ch = next();
2403 if (ch != '{')
2404 unread();
2405 else
2406 oneLetter = false;
2407 return family(oneLetter).maybeComplement(comp);
2408 } else { // ordinary escape
2409 unread();
2410 ch = escape(true, true);
2411 if (ch == -1)
2412 return (CharProperty) root;
2413 }
2414 } else {
2415 ch = single();
2416 }
2417 if (ch >= 0) {
2418 if (peek() == '-') {
2419 int endRange = temp[cursor+1];
2420 if (endRange == '[') {
2421 return bitsOrSingle(bits, ch);
2422 }
2423 if (endRange != ']') {
2424 next();
2425 int m = single();
2426 if (m < ch)
2427 throw error("Illegal character range");
2428 if (has(CASE_INSENSITIVE))
2429 return caseInsensitiveRangeFor(ch, m);
2430 else
2431 return rangeFor(ch, m);
2432 }
2433 }
2434 return bitsOrSingle(bits, ch);
2435 }
2436 throw error("Unexpected character '"+((char)ch)+"'");
2437 }
2438
2439 private int single() {
2440 int ch = peek();
2441 switch (ch) {
2442 case '\\':
2443 return escape(true, false);
2444 default:
2445 next();
2446 return ch;
2447 }
2448 }
2449
2450 /**
2451 * Parses a Unicode character family and returns its representative node.
2452 */
2453 private CharProperty family(boolean singleLetter) {
2454 next();
2455 String name;
2456
2457 if (singleLetter) {
2458 int c = temp[cursor];
2459 if (!Character.isSupplementaryCodePoint(c)) {
2460 name = String.valueOf((char)c);
2461 } else {
2462 name = new String(temp, cursor, 1);
2463 }
2464 read();
2465 } else {
2466 int i = cursor;
2467 mark('}');
2468 while(read() != '}') {
2469 }
2470 mark('\000');
2471 int j = cursor;
2472 if (j > patternLength)
2473 throw error("Unclosed character family");
2474 if (i + 1 >= j)
2475 throw error("Empty character family");
2476 name = new String(temp, i, j-i-1);
2477 }
2478
2479 if (name.startsWith("In")) {
2480 return unicodeBlockPropertyFor(name.substring(2));
2481 } else {
2482 if (name.startsWith("Is"))
2483 name = name.substring(2);
2484 return charPropertyNodeFor(name);
2485 }
2486 }
2487
2488 /**
2489 * Returns a CharProperty matching all characters in a UnicodeBlock.
2490 */
2491 private CharProperty unicodeBlockPropertyFor(String name) {
2492 final Character.UnicodeBlock block;
2493 try {
2494 block = Character.UnicodeBlock.forName(name);
2495 } catch (IllegalArgumentException iae) {
2496 throw error("Unknown character block name {" + name + "}");
2497 }
2498 return new CharProperty() {
2499 boolean isSatisfiedBy(int ch) {
2500 return block == Character.UnicodeBlock.of(ch);}};
2501 }
2502
2503 /**
2504 * Returns a CharProperty matching all characters in a named property.
2505 */
2506 private CharProperty charPropertyNodeFor(String name) {
2507 CharProperty p = CharPropertyNames.charPropertyFor(name);
2508 if (p == null)
2509 throw error("Unknown character property name {" + name + "}");
2510 return p;
2511 }
2512
2513 /**
2514 * Parses and returns the name of a "named capturing group", the trailing
2515 * ">" is consumed after parsing.
2516 */
2517 private String groupname(int ch) {
2518 StringBuilder sb = new StringBuilder();
2519 sb.append(Character.toChars(ch));
2520 while (ASCII.isLower(ch=read()) || ASCII.isUpper(ch) ||
2521 ASCII.isDigit(ch)) {
2522 sb.append(Character.toChars(ch));
2523 }
2524 if (sb.length() == 0)
2525 throw error("named capturing group has 0 length name");
2526 if (ch != '>')
2527 throw error("named capturing group is missing trailing '>'");
2528 return sb.toString();
2529 }
2530
2531 /**
2532 * Parses a group and returns the head node of a set of nodes that process
2533 * the group. Sometimes a double return system is used where the tail is
2534 * returned in root.
2535 */
2536 private Node group0() {
2537 boolean capturingGroup = false;
2538 Node head = null;
2539 Node tail = null;
2540 int save = flags;
2541 root = null;
2542 int ch = next();
2543 if (ch == '?') {
2544 ch = skip();
2545 switch (ch) {
2546 case ':': // (?:xxx) pure group
2547 head = createGroup(true);
2548 tail = root;
2549 head.next = expr(tail);
2550 break;
2551 case '=': // (?=xxx) and (?!xxx) lookahead
2552 case '!':
2553 head = createGroup(true);
2554 tail = root;
2555 head.next = expr(tail);
2556 if (ch == '=') {
2557 head = tail = new Pos(head);
2558 } else {
2559 head = tail = new Neg(head);
2560 }
2561 break;
2562 case '>': // (?>xxx) independent group
2563 head = createGroup(true);
2564 tail = root;
2565 head.next = expr(tail);
2566 head = tail = new Ques(head, INDEPENDENT);
2567 break;
2568 case '<': // (?<xxx) look behind
2569 ch = read();
2570 if (Character.isLetter(ch)) { // named captured group
2571 String name = groupname(ch);
2572 if (namedGroups().containsKey(name))
2573 throw error("Named capturing group <" + name
2574 + "> is already defined");
2575 capturingGroup = true;
2576 head = createGroup(false);
2577 tail = root;
2578 namedGroups().put(name, capturingGroupCount-1);
2579 head.next = expr(tail);
2580 break;
2581 }
2582 int start = cursor;
2583 head = createGroup(true);
2584 tail = root;
2585 head.next = expr(tail);
2586 tail.next = lookbehindEnd;
2587 TreeInfo info = new TreeInfo();
2588 head.study(info);
2589 if (info.maxValid == false) {
2590 throw error("Look-behind group does not have "
2591 + "an obvious maximum length");
2592 }
2593 boolean hasSupplementary = findSupplementary(start, patternLength);
2594 if (ch == '=') {
2595 head = tail = (hasSupplementary ?
2596 new BehindS(head, info.maxLength,
2597 info.minLength) :
2598 new Behind(head, info.maxLength,
2599 info.minLength));
2600 } else if (ch == '!') {
2601 head = tail = (hasSupplementary ?
2602 new NotBehindS(head, info.maxLength,
2603 info.minLength) :
2604 new NotBehind(head, info.maxLength,
2605 info.minLength));
2606 } else {
2607 throw error("Unknown look-behind group");
2608 }
2609 break;
2610 case '$':
2611 case '@':
2612 throw error("Unknown group type");
2613 default: // (?xxx:) inlined match flags
2614 unread();
2615 addFlag();
2616 ch = read();
2617 if (ch == ')') {
2618 return null; // Inline modifier only
2619 }
2620 if (ch != ':') {
2621 throw error("Unknown inline modifier");
2622 }
2623 head = createGroup(true);
2624 tail = root;
2625 head.next = expr(tail);
2626 break;
2627 }
2628 } else { // (xxx) a regular group
2629 capturingGroup = true;
2630 head = createGroup(false);
2631 tail = root;
2632 head.next = expr(tail);
2633 }
2634
2635 accept(')', "Unclosed group");
2636 flags = save;
2637
2638 // Check for quantifiers
2639 Node node = closure(head);
2640 if (node == head) { // No closure
2641 root = tail;
2642 return node; // Dual return
2643 }
2644 if (head == tail) { // Zero length assertion
2645 root = node;
2646 return node; // Dual return
2647 }
2648
2649 if (node instanceof Ques) {
2650 Ques ques = (Ques) node;
2651 if (ques.type == POSSESSIVE) {
2652 root = node;
2653 return node;
2654 }
2655 tail.next = new BranchConn();
2656 tail = tail.next;
2657 if (ques.type == GREEDY) {
2658 head = new Branch(head, null, tail);
2659 } else { // Reluctant quantifier
2660 head = new Branch(null, head, tail);
2661 }
2662 root = tail;
2663 return head;
2664 } else if (node instanceof Curly) {
2665 Curly curly = (Curly) node;
2666 if (curly.type == POSSESSIVE) {
2667 root = node;
2668 return node;
2669 }
2670 // Discover if the group is deterministic
2671 TreeInfo info = new TreeInfo();
2672 if (head.study(info)) { // Deterministic
2673 GroupTail temp = (GroupTail) tail;
2674 head = root = new GroupCurly(head.next, curly.cmin,
2675 curly.cmax, curly.type,
2676 ((GroupTail)tail).localIndex,
2677 ((GroupTail)tail).groupIndex,
2678 capturingGroup);
2679 return head;
2680 } else { // Non-deterministic
2681 int temp = ((GroupHead) head).localIndex;
2682 Loop loop;
2683 if (curly.type == GREEDY)
2684 loop = new Loop(this.localCount, temp);
2685 else // Reluctant Curly
2686 loop = new LazyLoop(this.localCount, temp);
2687 Prolog prolog = new Prolog(loop);
2688 this.localCount += 1;
2689 loop.cmin = curly.cmin;
2690 loop.cmax = curly.cmax;
2691 loop.body = head;
2692 tail.next = loop;
2693 root = loop;
2694 return prolog; // Dual return
2695 }
2696 }
2697 throw error("Internal logic error");
2698 }
2699
2700 /**
2701 * Create group head and tail nodes using double return. If the group is
2702 * created with anonymous true then it is a pure group and should not
2703 * affect group counting.
2704 */
2705 private Node createGroup(boolean anonymous) {
2706 int localIndex = localCount++;
2707 int groupIndex = 0;
2708 if (!anonymous)
2709 groupIndex = capturingGroupCount++;
2710 GroupHead head = new GroupHead(localIndex);
2711 root = new GroupTail(localIndex, groupIndex);
2712 if (!anonymous && groupIndex < 10)
2713 groupNodes[groupIndex] = head;
2714 return head;
2715 }
2716
2717 /**
2718 * Parses inlined match flags and set them appropriately.
2719 */
2720 private void addFlag() {
2721 int ch = peek();
2722 for (;;) {
2723 switch (ch) {
2724 case 'i':
2725 flags |= CASE_INSENSITIVE;
2726 break;
2727 case 'm':
2728 flags |= MULTILINE;
2729 break;
2730 case 's':
2731 flags |= DOTALL;
2732 break;
2733 case 'd':
2734 flags |= UNIX_LINES;
2735 break;
2736 case 'u':
2737 flags |= UNICODE_CASE;
2738 break;
2739 case 'c':
2740 flags |= CANON_EQ;
2741 break;
2742 case 'x':
2743 flags |= COMMENTS;
2744 break;
2745 case '-': // subFlag then fall through
2746 ch = next();
2747 subFlag();
2748 default:
2749 return;
2750 }
2751 ch = next();
2752 }
2753 }
2754
2755 /**
2756 * Parses the second part of inlined match flags and turns off
2757 * flags appropriately.
2758 */
2759 private void subFlag() {
2760 int ch = peek();
2761 for (;;) {
2762 switch (ch) {
2763 case 'i':
2764 flags &= ~CASE_INSENSITIVE;
2765 break;
2766 case 'm':
2767 flags &= ~MULTILINE;
2768 break;
2769 case 's':
2770 flags &= ~DOTALL;
2771 break;
2772 case 'd':
2773 flags &= ~UNIX_LINES;
2774 break;
2775 case 'u':
2776 flags &= ~UNICODE_CASE;
2777 break;
2778 case 'c':
2779 flags &= ~CANON_EQ;
2780 break;
2781 case 'x':
2782 flags &= ~COMMENTS;
2783 break;
2784 default:
2785 return;
2786 }
2787 ch = next();
2788 }
2789 }
2790
2791 static final int MAX_REPS = 0x7FFFFFFF;
2792
2793 static final int GREEDY = 0;
2794
2795 static final int LAZY = 1;
2796
2797 static final int POSSESSIVE = 2;
2798
2799 static final int INDEPENDENT = 3;
2800
2801 /**
2802 * Processes repetition. If the next character peeked is a quantifier
2803 * then new nodes must be appended to handle the repetition.
2804 * Prev could be a single or a group, so it could be a chain of nodes.
2805 */
2806 private Node closure(Node prev) {
2807 Node atom;
2808 int ch = peek();
2809 switch (ch) {
2810 case '?':
2811 ch = next();
2812 if (ch == '?') {
2813 next();
2814 return new Ques(prev, LAZY);
2815 } else if (ch == '+') {
2816 next();
2817 return new Ques(prev, POSSESSIVE);
2818 }
2819 return new Ques(prev, GREEDY);
2820 case '*':
2821 ch = next();
2822 if (ch == '?') {
2823 next();
2824 return new Curly(prev, 0, MAX_REPS, LAZY);
2825 } else if (ch == '+') {
2826 next();
2827 return new Curly(prev, 0, MAX_REPS, POSSESSIVE);
2828 }
2829 return new Curly(prev, 0, MAX_REPS, GREEDY);
2830 case '+':
2831 ch = next();
2832 if (ch == '?') {
2833 next();
2834 return new Curly(prev, 1, MAX_REPS, LAZY);
2835 } else if (ch == '+') {
2836 next();
2837 return new Curly(prev, 1, MAX_REPS, POSSESSIVE);
2838 }
2839 return new Curly(prev, 1, MAX_REPS, GREEDY);
2840 case '{':
2841 ch = temp[cursor+1];
2842 if (ASCII.isDigit(ch)) {
2843 skip();
2844 int cmin = 0;
2845 do {
2846 cmin = cmin * 10 + (ch - '0');
2847 } while (ASCII.isDigit(ch = read()));
2848 int cmax = cmin;
2849 if (ch == ',') {
2850 ch = read();
2851 cmax = MAX_REPS;
2852 if (ch != '}') {
2853 cmax = 0;
2854 while (ASCII.isDigit(ch)) {
2855 cmax = cmax * 10 + (ch - '0');
2856 ch = read();
2857 }
2858 }
2859 }
2860 if (ch != '}')
2861 throw error("Unclosed counted closure");
2862 if (((cmin) | (cmax) | (cmax - cmin)) < 0)
2863 throw error("Illegal repetition range");
2864 Curly curly;
2865 ch = peek();
2866 if (ch == '?') {
2867 next();
2868 curly = new Curly(prev, cmin, cmax, LAZY);
2869 } else if (ch == '+') {
2870 next();
2871 curly = new Curly(prev, cmin, cmax, POSSESSIVE);
2872 } else {
2873 curly = new Curly(prev, cmin, cmax, GREEDY);
2874 }
2875 return curly;
2876 } else {
2877 throw error("Illegal repetition");
2878 }
2879 default:
2880 return prev;
2881 }
2882 }
2883
2884 /**
2885 * Utility method for parsing control escape sequences.
2886 */
2887 private int c() {
2888 if (cursor < patternLength) {
2889 return read() ^ 64;
2890 }
2891 throw error("Illegal control escape sequence");
2892 }
2893
2894 /**
2895 * Utility method for parsing octal escape sequences.
2896 */
2897 private int o() {
2898 int n = read();
2899 if (((n-'0')|('7'-n)) >= 0) {
2900 int m = read();
2901 if (((m-'0')|('7'-m)) >= 0) {
2902 int o = read();
2903 if ((((o-'0')|('7'-o)) >= 0) && (((n-'0')|('3'-n)) >= 0)) {
2904 return (n - '0') * 64 + (m - '0') * 8 + (o - '0');
2905 }
2906 unread();
2907 return (n - '0') * 8 + (m - '0');
2908 }
2909 unread();
2910 return (n - '0');
2911 }
2912 throw error("Illegal octal escape sequence");
2913 }
2914
2915 /**
2916 * Utility method for parsing hexadecimal escape sequences.
2917 */
2918 private int x() {
2919 int n = read();
2920 if (ASCII.isHexDigit(n)) {
2921 int m = read();
2922 if (ASCII.isHexDigit(m)) {
2923 return ASCII.toDigit(n) * 16 + ASCII.toDigit(m);
2924 }
2925 }
2926 throw error("Illegal hexadecimal escape sequence");
2927 }
2928
2929 /**
2930 * Utility method for parsing unicode escape sequences.
2931 */
2932 private int cursor() {
2933 return cursor;
2934 }
2935
2936 private void setcursor(int pos) {
2937 cursor = pos;
2938 }
2939
2940 private int uxxxx() {
2941 int n = 0;
2942 for (int i = 0; i < 4; i++) {
2943 int ch = read();
2944 if (!ASCII.isHexDigit(ch)) {
2945 throw error("Illegal Unicode escape sequence");
2946 }
2947 n = n * 16 + ASCII.toDigit(ch);
2948 }
2949 return n;
2950 }
2951
2952 private int u() {
2953 int n = uxxxx();
2954 if (Character.isHighSurrogate((char)n)) {
2955 int cur = cursor();
2956 if (read() == '\\' && read() == 'u') {
2957 int n2 = uxxxx();
2958 if (Character.isLowSurrogate((char)n2))
2959 return Character.toCodePoint((char)n, (char)n2);
2960 }
2961 setcursor(cur);
2962 }
2963 return n;
2964 }
2965
2966 //
2967 // Utility methods for code point support
2968 //
2969
2970 /**
2971 * Tests a surrogate value.
2972 */
2973 private static final boolean isSurrogate(int c) {
2974 return c >= Character.MIN_HIGH_SURROGATE && c <= Character.MAX_LOW_SURROGATE;
2975 }
2976
2977 private static final int countChars(CharSequence seq, int index,
2978 int lengthInCodePoints) {
2979 // optimization
2980 if (lengthInCodePoints == 1 && !Character.isHighSurrogate(seq.charAt(index))) {
2981 assert (index >= 0 && index < seq.length());
2982 return 1;
2983 }
2984 int length = seq.length();
2985 int x = index;
2986 if (lengthInCodePoints >= 0) {
2987 assert (index >= 0 && index < length);
2988 for (int i = 0; x < length && i < lengthInCodePoints; i++) {
2989 if (Character.isHighSurrogate(seq.charAt(x++))) {
2990 if (x < length && Character.isLowSurrogate(seq.charAt(x))) {
2991 x++;
2992 }
2993 }
2994 }
2995 return x - index;
2996 }
2997
2998 assert (index >= 0 && index <= length);
2999 if (index == 0) {
3000 return 0;
3001 }
3002 int len = -lengthInCodePoints;
3003 for (int i = 0; x > 0 && i < len; i++) {
3004 if (Character.isLowSurrogate(seq.charAt(--x))) {
3005 if (x > 0 && Character.isHighSurrogate(seq.charAt(x-1))) {
3006 x--;
3007 }
3008 }
3009 }
3010 return index - x;
3011 }
3012
3013 private static final int countCodePoints(CharSequence seq) {
3014 int length = seq.length();
3015 int n = 0;
3016 for (int i = 0; i < length; ) {
3017 n++;
3018 if (Character.isHighSurrogate(seq.charAt(i++))) {
3019 if (i < length && Character.isLowSurrogate(seq.charAt(i))) {
3020 i++;
3021 }
3022 }
3023 }
3024 return n;
3025 }
3026
3027 /**
3028 * Creates a bit vector for matching Latin-1 values. A normal BitClass
3029 * never matches values above Latin-1, and a complemented BitClass always
3030 * matches values above Latin-1.
3031 */
3032 private static final class BitClass extends BmpCharProperty {
3033 final boolean[] bits;
3034 BitClass() { bits = new boolean[256]; }
3035 private BitClass(boolean[] bits) { this.bits = bits; }
3036 BitClass add(int c, int flags) {
3037 assert c >= 0 && c <= 255;
3038 if ((flags & CASE_INSENSITIVE) != 0) {
3039 if (ASCII.isAscii(c)) {
3040 bits[ASCII.toUpper(c)] = true;
3041 bits[ASCII.toLower(c)] = true;
3042 } else if ((flags & UNICODE_CASE) != 0) {
3043 bits[Character.toLowerCase(c)] = true;
3044 bits[Character.toUpperCase(c)] = true;
3045 }
3046 }
3047 bits[c] = true;
3048 return this;
3049 }
3050 boolean isSatisfiedBy(int ch) {
3051 return ch < 256 && bits[ch];
3052 }
3053 }
3054
3055 /**
3056 * Returns a suitably optimized, single character matcher.
3057 */
3058 private CharProperty newSingle(final int ch) {
3059 if (has(CASE_INSENSITIVE)) {
3060 int lower, upper;
3061 if (has(UNICODE_CASE)) {
3062 upper = Character.toUpperCase(ch);
3063 lower = Character.toLowerCase(upper);
3064 if (upper != lower)
3065 return new SingleU(lower);
3066 } else if (ASCII.isAscii(ch)) {
3067 lower = ASCII.toLower(ch);
3068 upper = ASCII.toUpper(ch);
3069 if (lower != upper)
3070 return new SingleI(lower, upper);
3071 }
3072 }
3073 if (isSupplementary(ch))
3074 return new SingleS(ch); // Match a given Unicode character
3075 return new Single(ch); // Match a given BMP character
3076 }
3077
3078 /**
3079 * Utility method for creating a string slice matcher.
3080 */
3081 private Node newSlice(int[] buf, int count, boolean hasSupplementary) {
3082 int[] tmp = new int[count];
3083 if (has(CASE_INSENSITIVE)) {
3084 if (has(UNICODE_CASE)) {
3085 for (int i = 0; i < count; i++) {
3086 tmp[i] = Character.toLowerCase(
3087 Character.toUpperCase(buf[i]));
3088 }
3089 return hasSupplementary? new SliceUS(tmp) : new SliceU(tmp);
3090 }
3091 for (int i = 0; i < count; i++) {
3092 tmp[i] = ASCII.toLower(buf[i]);
3093 }
3094 return hasSupplementary? new SliceIS(tmp) : new SliceI(tmp);
3095 }
3096 for (int i = 0; i < count; i++) {
3097 tmp[i] = buf[i];
3098 }
3099 return hasSupplementary ? new SliceS(tmp) : new Slice(tmp);
3100 }
3101
3102 /**
3103 * The following classes are the building components of the object
3104 * tree that represents a compiled regular expression. The object tree
3105 * is made of individual elements that handle constructs in the Pattern.
3106 * Each type of object knows how to match its equivalent construct with
3107 * the match() method.
3108 */
3109
3110 /**
3111 * Base class for all node classes. Subclasses should override the match()
3112 * method as appropriate. This class is an accepting node, so its match()
3113 * always returns true.
3114 */
3115 static class Node extends Object {
3116 Node next;
3117 Node() {
3118 next = Pattern.accept;
3119 }
3120 /**
3121 * This method implements the classic accept node.
3122 */
3123 boolean match(Matcher matcher, int i, CharSequence seq) {
3124 matcher.last = i;
3125 matcher.groups[0] = matcher.first;
3126 matcher.groups[1] = matcher.last;
3127 return true;
3128 }
3129 /**
3130 * This method is good for all zero length assertions.
3131 */
3132 boolean study(TreeInfo info) {
3133 if (next != null) {
3134 return next.study(info);
3135 } else {
3136 return info.deterministic;
3137 }
3138 }
3139 }
3140
3141 static class LastNode extends Node {
3142 /**
3143 * This method implements the classic accept node with
3144 * the addition of a check to see if the match occurred
3145 * using all of the input.
3146 */
3147 boolean match(Matcher matcher, int i, CharSequence seq) {
3148 if (matcher.acceptMode == Matcher.ENDANCHOR && i != matcher.to)
3149 return false;
3150 matcher.last = i;
3151 matcher.groups[0] = matcher.first;
3152 matcher.groups[1] = matcher.last;
3153 return true;
3154 }
3155 }
3156
3157 /**
3158 * Used for REs that can start anywhere within the input string.
3159 * This basically tries to match repeatedly at each spot in the
3160 * input string, moving forward after each try. An anchored search
3161 * or a BnM will bypass this node completely.
3162 */
3163 static class Start extends Node {
3164 int minLength;
3165 Start(Node node) {
3166 this.next = node;
3167 TreeInfo info = new TreeInfo();
3168 next.study(info);
3169 minLength = info.minLength;
3170 }
3171 boolean match(Matcher matcher, int i, CharSequence seq) {
3172 if (i > matcher.to - minLength) {
3173 matcher.hitEnd = true;
3174 return false;
3175 }
3176 boolean ret = false;
3177 int guard = matcher.to - minLength;
3178 for (; i <= guard; i++) {
3179 if (ret = next.match(matcher, i, seq))
3180 break;
3181 if (i == guard)
3182 matcher.hitEnd = true;
3183 }
3184 if (ret) {
3185 matcher.first = i;
3186 matcher.groups[0] = matcher.first;
3187 matcher.groups[1] = matcher.last;
3188 }
3189 return ret;
3190 }
3191 boolean study(TreeInfo info) {
3192 next.study(info);
3193 info.maxValid = false;
3194 info.deterministic = false;
3195 return false;
3196 }
3197 }
3198
3199 /*
3200 * StartS supports supplementary characters, including unpaired surrogates.
3201 */
3202 static final class StartS extends Start {
3203 StartS(Node node) {
3204 super(node);
3205 }
3206 boolean match(Matcher matcher, int i, CharSequence seq) {
3207 if (i > matcher.to - minLength) {
3208 matcher.hitEnd = true;
3209 return false;
3210 }
3211 boolean ret = false;
3212 int guard = matcher.to - minLength;
3213 while (i <= guard) {
3214 if ((ret = next.match(matcher, i, seq)) || i == guard)
3215 break;
3216 // Optimization to move to the next character. This is
3217 // faster than countChars(seq, i, 1).
3218 if (Character.isHighSurrogate(seq.charAt(i++))) {
3219 if (i < seq.length() && Character.isLowSurrogate(seq.charAt(i))) {
3220 i++;
3221 }
3222 }
3223 if (i == guard)
3224 matcher.hitEnd = true;
3225 }
3226 if (ret) {
3227 matcher.first = i;
3228 matcher.groups[0] = matcher.first;
3229 matcher.groups[1] = matcher.last;
3230 }
3231 return ret;
3232 }
3233 }
3234
3235 /**
3236 * Node to anchor at the beginning of input. This object implements the
3237 * match for a \A sequence, and the caret anchor will use this if not in
3238 * multiline mode.
3239 */
3240 static final class Begin extends Node {
3241 boolean match(Matcher matcher, int i, CharSequence seq) {
3242 int fromIndex = (matcher.anchoringBounds) ?
3243 matcher.from : 0;
3244 if (i == fromIndex && next.match(matcher, i, seq)) {
3245 matcher.first = i;
3246 matcher.groups[0] = i;
3247 matcher.groups[1] = matcher.last;
3248 return true;
3249 } else {
3250 return false;
3251 }
3252 }
3253 }
3254
3255 /**
3256 * Node to anchor at the end of input. This is the absolute end, so this
3257 * should not match at the last newline before the end as $ will.
3258 */
3259 static final class End extends Node {
3260 boolean match(Matcher matcher, int i, CharSequence seq) {
3261 int endIndex = (matcher.anchoringBounds) ?
3262 matcher.to : matcher.getTextLength();
3263 if (i == endIndex) {
3264 matcher.hitEnd = true;
3265 return next.match(matcher, i, seq);
3266 }
3267 return false;
3268 }
3269 }
3270
3271 /**
3272 * Node to anchor at the beginning of a line. This is essentially the
3273 * object to match for the multiline ^.
3274 */
3275 static final class Caret extends Node {
3276 boolean match(Matcher matcher, int i, CharSequence seq) {
3277 int startIndex = matcher.from;
3278 int endIndex = matcher.to;
3279 if (!matcher.anchoringBounds) {
3280 startIndex = 0;
3281 endIndex = matcher.getTextLength();
3282 }
3283 // Perl does not match ^ at end of input even after newline
3284 if (i == endIndex) {
3285 matcher.hitEnd = true;
3286 return false;
3287 }
3288 if (i > startIndex) {
3289 char ch = seq.charAt(i-1);
3290 if (ch != '\n' && ch != '\r'
3291 && (ch|1) != '\u2029'
3292 && ch != '\u0085' ) {
3293 return false;
3294 }
3295 // Should treat /r/n as one newline
3296 if (ch == '\r' && seq.charAt(i) == '\n')
3297 return false;
3298 }
3299 return next.match(matcher, i, seq);
3300 }
3301 }
3302
3303 /**
3304 * Node to anchor at the beginning of a line when in unixdot mode.
3305 */
3306 static final class UnixCaret extends Node {
3307 boolean match(Matcher matcher, int i, CharSequence seq) {
3308 int startIndex = matcher.from;
3309 int endIndex = matcher.to;
3310 if (!matcher.anchoringBounds) {
3311 startIndex = 0;
3312 endIndex = matcher.getTextLength();
3313 }
3314 // Perl does not match ^ at end of input even after newline
3315 if (i == endIndex) {
3316 matcher.hitEnd = true;
3317 return false;
3318 }
3319 if (i > startIndex) {
3320 char ch = seq.charAt(i-1);
3321 if (ch != '\n') {
3322 return false;
3323 }
3324 }
3325 return next.match(matcher, i, seq);
3326 }
3327 }
3328
3329 /**
3330 * Node to match the location where the last match ended.
3331 * This is used for the \G construct.
3332 */
3333 static final class LastMatch extends Node {
3334 boolean match(Matcher matcher, int i, CharSequence seq) {
3335 if (i != matcher.oldLast)
3336 return false;
3337 return next.match(matcher, i, seq);
3338 }
3339 }
3340
3341 /**
3342 * Node to anchor at the end of a line or the end of input based on the
3343 * multiline mode.
3344 *
3345 * When not in multiline mode, the $ can only match at the very end
3346 * of the input, unless the input ends in a line terminator in which
3347 * it matches right before the last line terminator.
3348 *
3349 * Note that \r\n is considered an atomic line terminator.
3350 *
3351 * Like ^ the $ operator matches at a position, it does not match the
3352 * line terminators themselves.
3353 */
3354 static final class Dollar extends Node {
3355 boolean multiline;
3356 Dollar(boolean mul) {
3357 multiline = mul;
3358 }
3359 boolean match(Matcher matcher, int i, CharSequence seq) {
3360 int endIndex = (matcher.anchoringBounds) ?
3361 matcher.to : matcher.getTextLength();
3362 if (!multiline) {
3363 if (i < endIndex - 2)
3364 return false;
3365 if (i == endIndex - 2) {
3366 char ch = seq.charAt(i);
3367 if (ch != '\r')
3368 return false;
3369 ch = seq.charAt(i + 1);
3370 if (ch != '\n')
3371 return false;
3372 }
3373 }
3374 // Matches before any line terminator; also matches at the
3375 // end of input
3376 // Before line terminator:
3377 // If multiline, we match here no matter what
3378 // If not multiline, fall through so that the end
3379 // is marked as hit; this must be a /r/n or a /n
3380 // at the very end so the end was hit; more input
3381 // could make this not match here
3382 if (i < endIndex) {
3383 char ch = seq.charAt(i);
3384 if (ch == '\n') {
3385 // No match between \r\n
3386 if (i > 0 && seq.charAt(i-1) == '\r')
3387 return false;
3388 if (multiline)
3389 return next.match(matcher, i, seq);
3390 } else if (ch == '\r' || ch == '\u0085' ||
3391 (ch|1) == '\u2029') {
3392 if (multiline)
3393 return next.match(matcher, i, seq);
3394 } else { // No line terminator, no match
3395 return false;
3396 }
3397 }
3398 // Matched at current end so hit end
3399 matcher.hitEnd = true;
3400 // If a $ matches because of end of input, then more input
3401 // could cause it to fail!
3402 matcher.requireEnd = true;
3403 return next.match(matcher, i, seq);
3404 }
3405 boolean study(TreeInfo info) {
3406 next.study(info);
3407 return info.deterministic;
3408 }
3409 }
3410
3411 /**
3412 * Node to anchor at the end of a line or the end of input based on the
3413 * multiline mode when in unix lines mode.
3414 */
3415 static final class UnixDollar extends Node {
3416 boolean multiline;
3417 UnixDollar(boolean mul) {
3418 multiline = mul;
3419 }
3420 boolean match(Matcher matcher, int i, CharSequence seq) {
3421 int endIndex = (matcher.anchoringBounds) ?
3422 matcher.to : matcher.getTextLength();
3423 if (i < endIndex) {
3424 char ch = seq.charAt(i);
3425 if (ch == '\n') {
3426 // If not multiline, then only possible to
3427 // match at very end or one before end
3428 if (multiline == false && i != endIndex - 1)
3429 return false;
3430 // If multiline return next.match without setting
3431 // matcher.hitEnd
3432 if (multiline)
3433 return next.match(matcher, i, seq);
3434 } else {
3435 return false;
3436 }
3437 }
3438 // Matching because at the end or 1 before the end;
3439 // more input could change this so set hitEnd
3440 matcher.hitEnd = true;
3441 // If a $ matches because of end of input, then more input
3442 // could cause it to fail!
3443 matcher.requireEnd = true;
3444 return next.match(matcher, i, seq);
3445 }
3446 boolean study(TreeInfo info) {
3447 next.study(info);
3448 return info.deterministic;
3449 }
3450 }
3451
3452 /**
3453 * Abstract node class to match one character satisfying some
3454 * boolean property.
3455 */
3456 private static abstract class CharProperty extends Node {
3457 abstract boolean isSatisfiedBy(int ch);
3458 CharProperty complement() {
3459 return new CharProperty() {
3460 boolean isSatisfiedBy(int ch) {
3461 return ! CharProperty.this.isSatisfiedBy(ch);}};
3462 }
3463 CharProperty maybeComplement(boolean complement) {
3464 return complement ? complement() : this;
3465 }
3466 boolean match(Matcher matcher, int i, CharSequence seq) {
3467 if (i < matcher.to) {
3468 int ch = Character.codePointAt(seq, i);
3469 return isSatisfiedBy(ch)
3470 && next.match(matcher, i+Character.charCount(ch), seq);
3471 } else {
3472 matcher.hitEnd = true;
3473 return false;
3474 }
3475 }
3476 boolean study(TreeInfo info) {
3477 info.minLength++;
3478 info.maxLength++;
3479 return next.study(info);
3480 }
3481 }
3482
3483 /**
3484 * Optimized version of CharProperty that works only for
3485 * properties never satisfied by Supplementary characters.
3486 */
3487 private static abstract class BmpCharProperty extends CharProperty {
3488 boolean match(Matcher matcher, int i, CharSequence seq) {
3489 if (i < matcher.to) {
3490 return isSatisfiedBy(seq.charAt(i))
3491 && next.match(matcher, i+1, seq);
3492 } else {
3493 matcher.hitEnd = true;
3494 return false;
3495 }
3496 }
3497 }
3498
3499 /**
3500 * Node class that matches a Supplementary Unicode character
3501 */
3502 static final class SingleS extends CharProperty {
3503 final int c;
3504 SingleS(int c) { this.c = c; }
3505 boolean isSatisfiedBy(int ch) {
3506 return ch == c;
3507 }
3508 }
3509
3510 /**
3511 * Optimization -- matches a given BMP character
3512 */
3513 static final class Single extends BmpCharProperty {
3514 final int c;
3515 Single(int c) { this.c = c; }
3516 boolean isSatisfiedBy(int ch) {
3517 return ch == c;
3518 }
3519 }
3520
3521 /**
3522 * Case insensitive matches a given BMP character
3523 */
3524 static final class SingleI extends BmpCharProperty {
3525 final int lower;
3526 final int upper;
3527 SingleI(int lower, int upper) {
3528 this.lower = lower;
3529 this.upper = upper;
3530 }
3531 boolean isSatisfiedBy(int ch) {
3532 return ch == lower || ch == upper;
3533 }
3534 }
3535
3536 /**
3537 * Unicode case insensitive matches a given Unicode character
3538 */
3539 static final class SingleU extends CharProperty {
3540 final int lower;
3541 SingleU(int lower) {
3542 this.lower = lower;
3543 }
3544 boolean isSatisfiedBy(int ch) {
3545 return lower == ch ||
3546 lower == Character.toLowerCase(Character.toUpperCase(ch));
3547 }
3548 }
3549
3550 /**
3551 * Node class that matches a Unicode category.
3552 */
3553 static final class Category extends CharProperty {
3554 final int typeMask;
3555 Category(int typeMask) { this.typeMask = typeMask; }
3556 boolean isSatisfiedBy(int ch) {
3557 return (typeMask & (1 << Character.getType(ch))) != 0;
3558 }
3559 }
3560
3561 /**
3562 * Node class that matches a POSIX type.
3563 */
3564 static final class Ctype extends BmpCharProperty {
3565 final int ctype;
3566 Ctype(int ctype) { this.ctype = ctype; }
3567 boolean isSatisfiedBy(int ch) {
3568 return ch < 128 && ASCII.isType(ch, ctype);
3569 }
3570 }
3571
3572 /**
3573 * Base class for all Slice nodes
3574 */
3575 static class SliceNode extends Node {
3576 int[] buffer;
3577 SliceNode(int[] buf) {
3578 buffer = buf;
3579 }
3580 boolean study(TreeInfo info) {
3581 info.minLength += buffer.length;
3582 info.maxLength += buffer.length;
3583 return next.study(info);
3584 }
3585 }
3586
3587 /**
3588 * Node class for a case sensitive/BMP-only sequence of literal
3589 * characters.
3590 */
3591 static final class Slice extends SliceNode {
3592 Slice(int[] buf) {
3593 super(buf);
3594 }
3595 boolean match(Matcher matcher, int i, CharSequence seq) {
3596 int[] buf = buffer;
3597 int len = buf.length;
3598 for (int j=0; j<len; j++) {
3599 if ((i+j) >= matcher.to) {
3600 matcher.hitEnd = true;
3601 return false;
3602 }
3603 if (buf[j] != seq.charAt(i+j))
3604 return false;
3605 }
3606 return next.match(matcher, i+len, seq);
3607 }
3608 }
3609
3610 /**
3611 * Node class for a case_insensitive/BMP-only sequence of literal
3612 * characters.
3613 */
3614 static class SliceI extends SliceNode {
3615 SliceI(int[] buf) {
3616 super(buf);
3617 }
3618 boolean match(Matcher matcher, int i, CharSequence seq) {
3619 int[] buf = buffer;
3620 int len = buf.length;
3621 for (int j=0; j<len; j++) {
3622 if ((i+j) >= matcher.to) {
3623 matcher.hitEnd = true;
3624 return false;
3625 }
3626 int c = seq.charAt(i+j);
3627 if (buf[j] != c &&
3628 buf[j] != ASCII.toLower(c))
3629 return false;
3630 }
3631 return next.match(matcher, i+len, seq);
3632 }
3633 }
3634
3635 /**
3636 * Node class for a unicode_case_insensitive/BMP-only sequence of
3637 * literal characters. Uses unicode case folding.
3638 */
3639 static final class SliceU extends SliceNode {
3640 SliceU(int[] buf) {
3641 super(buf);
3642 }
3643 boolean match(Matcher matcher, int i, CharSequence seq) {
3644 int[] buf = buffer;
3645 int len = buf.length;
3646 for (int j=0; j<len; j++) {
3647 if ((i+j) >= matcher.to) {
3648 matcher.hitEnd = true;
3649 return false;
3650 }
3651 int c = seq.charAt(i+j);
3652 if (buf[j] != c &&
3653 buf[j] != Character.toLowerCase(Character.toUpperCase(c)))
3654 return false;
3655 }
3656 return next.match(matcher, i+len, seq);
3657 }
3658 }
3659
3660 /**
3661 * Node class for a case sensitive sequence of literal characters
3662 * including supplementary characters.
3663 */
3664 static final class SliceS extends SliceNode {
3665 SliceS(int[] buf) {
3666 super(buf);
3667 }
3668 boolean match(Matcher matcher, int i, CharSequence seq) {
3669 int[] buf = buffer;
3670 int x = i;
3671 for (int j = 0; j < buf.length; j++) {
3672 if (x >= matcher.to) {
3673 matcher.hitEnd = true;
3674 return false;
3675 }
3676 int c = Character.codePointAt(seq, x);
3677 if (buf[j] != c)
3678 return false;
3679 x += Character.charCount(c);
3680 if (x > matcher.to) {
3681 matcher.hitEnd = true;
3682 return false;
3683 }
3684 }
3685 return next.match(matcher, x, seq);
3686 }
3687 }
3688
3689 /**
3690 * Node class for a case insensitive sequence of literal characters
3691 * including supplementary characters.
3692 */
3693 static class SliceIS extends SliceNode {
3694 SliceIS(int[] buf) {
3695 super(buf);
3696 }
3697 int toLower(int c) {
3698 return ASCII.toLower(c);
3699 }
3700 boolean match(Matcher matcher, int i, CharSequence seq) {
3701 int[] buf = buffer;
3702 int x = i;
3703 for (int j = 0; j < buf.length; j++) {
3704 if (x >= matcher.to) {
3705 matcher.hitEnd = true;
3706 return false;
3707 }
3708 int c = Character.codePointAt(seq, x);
3709 if (buf[j] != c && buf[j] != toLower(c))
3710 return false;
3711 x += Character.charCount(c);
3712 if (x > matcher.to) {
3713 matcher.hitEnd = true;
3714 return false;
3715 }
3716 }
3717 return next.match(matcher, x, seq);
3718 }
3719 }
3720
3721 /**
3722 * Node class for a case insensitive sequence of literal characters.
3723 * Uses unicode case folding.
3724 */
3725 static final class SliceUS extends SliceIS {
3726 SliceUS(int[] buf) {
3727 super(buf);
3728 }
3729 int toLower(int c) {
3730 return Character.toLowerCase(Character.toUpperCase(c));
3731 }
3732 }
3733
3734 private static boolean inRange(int lower, int ch, int upper) {
3735 return lower <= ch && ch <= upper;
3736 }
3737
3738 /**
3739 * Returns node for matching characters within an explicit value range.
3740 */
3741 private static CharProperty rangeFor(final int lower,
3742 final int upper) {
3743 return new CharProperty() {
3744 boolean isSatisfiedBy(int ch) {
3745 return inRange(lower, ch, upper);}};
3746 }
3747
3748 /**
3749 * Returns node for matching characters within an explicit value
3750 * range in a case insensitive manner.
3751 */
3752 private CharProperty caseInsensitiveRangeFor(final int lower,
3753 final int upper) {
3754 if (has(UNICODE_CASE))
3755 return new CharProperty() {
3756 boolean isSatisfiedBy(int ch) {
3757 if (inRange(lower, ch, upper))
3758 return true;
3759 int up = Character.toUpperCase(ch);
3760 return inRange(lower, up, upper) ||
3761 inRange(lower, Character.toLowerCase(up), upper);}};
3762 return new CharProperty() {
3763 boolean isSatisfiedBy(int ch) {
3764 return inRange(lower, ch, upper) ||
3765 ASCII.isAscii(ch) &&
3766 (inRange(lower, ASCII.toUpper(ch), upper) ||
3767 inRange(lower, ASCII.toLower(ch), upper));
3768 }};
3769 }
3770
3771 /**
3772 * Implements the Unicode category ALL and the dot metacharacter when
3773 * in dotall mode.
3774 */
3775 static final class All extends CharProperty {
3776 boolean isSatisfiedBy(int ch) {
3777 return true;
3778 }
3779 }
3780
3781 /**
3782 * Node class for the dot metacharacter when dotall is not enabled.
3783 */
3784 static final class Dot extends CharProperty {
3785 boolean isSatisfiedBy(int ch) {
3786 return (ch != '\n' && ch != '\r'
3787 && (ch|1) != '\u2029'
3788 && ch != '\u0085');
3789 }
3790 }
3791
3792 /**
3793 * Node class for the dot metacharacter when dotall is not enabled
3794 * but UNIX_LINES is enabled.
3795 */
3796 static final class UnixDot extends CharProperty {
3797 boolean isSatisfiedBy(int ch) {
3798 return ch != '\n';
3799 }
3800 }
3801
3802 /**
3803 * The 0 or 1 quantifier. This one class implements all three types.
3804 */
3805 static final class Ques extends Node {
3806 Node atom;
3807 int type;
3808 Ques(Node node, int type) {
3809 this.atom = node;
3810 this.type = type;
3811 }
3812 boolean match(Matcher matcher, int i, CharSequence seq) {
3813 switch (type) {
3814 case GREEDY:
3815 return (atom.match(matcher, i, seq) && next.match(matcher, matcher.last, seq))
3816 || next.match(matcher, i, seq);
3817 case LAZY:
3818 return next.match(matcher, i, seq)
3819 || (atom.match(matcher, i, seq) && next.match(matcher, matcher.last, seq));
3820 case POSSESSIVE:
3821 if (atom.match(matcher, i, seq)) i = matcher.last;
3822 return next.match(matcher, i, seq);
3823 default:
3824 return atom.match(matcher, i, seq) && next.match(matcher, matcher.last, seq);
3825 }
3826 }
3827 boolean study(TreeInfo info) {
3828 if (type != INDEPENDENT) {
3829 int minL = info.minLength;
3830 atom.study(info);
3831 info.minLength = minL;
3832 info.deterministic = false;
3833 return next.study(info);
3834 } else {
3835 atom.study(info);
3836 return next.study(info);
3837 }
3838 }
3839 }
3840
3841 /**
3842 * Handles the curly-brace style repetition with a specified minimum and
3843 * maximum occurrences. The * quantifier is handled as a special case.
3844 * This class handles the three types.
3845 */
3846 static final class Curly extends Node {
3847 Node atom;
3848 int type;
3849 int cmin;
3850 int cmax;
3851
3852 Curly(Node node, int cmin, int cmax, int type) {
3853 this.atom = node;
3854 this.type = type;
3855 this.cmin = cmin;
3856 this.cmax = cmax;
3857 }
3858 boolean match(Matcher matcher, int i, CharSequence seq) {
3859 int j;
3860 for (j = 0; j < cmin; j++) {
3861 if (atom.match(matcher, i, seq)) {
3862 i = matcher.last;
3863 continue;
3864 }
3865 return false;
3866 }
3867 if (type == GREEDY)
3868 return match0(matcher, i, j, seq);
3869 else if (type == LAZY)
3870 return match1(matcher, i, j, seq);
3871 else
3872 return match2(matcher, i, j, seq);
3873 }
3874 // Greedy match.
3875 // i is the index to start matching at
3876 // j is the number of atoms that have matched
3877 boolean match0(Matcher matcher, int i, int j, CharSequence seq) {
3878 if (j >= cmax) {
3879 // We have matched the maximum... continue with the rest of
3880 // the regular expression
3881 return next.match(matcher, i, seq);
3882 }
3883 int backLimit = j;
3884 while (atom.match(matcher, i, seq)) {
3885 // k is the length of this match
3886 int k = matcher.last - i;
3887 if (k == 0) // Zero length match
3888 break;
3889 // Move up index and number matched
3890 i = matcher.last;
3891 j++;
3892 // We are greedy so match as many as we can
3893 while (j < cmax) {
3894 if (!atom.match(matcher, i, seq))
3895 break;
3896 if (i + k != matcher.last) {
3897 if (match0(matcher, matcher.last, j+1, seq))
3898 return true;
3899 break;
3900 }
3901 i += k;
3902 j++;
3903 }
3904 // Handle backing off if match fails
3905 while (j >= backLimit) {
3906 if (next.match(matcher, i, seq))
3907 return true;
3908 i -= k;
3909 j--;
3910 }
3911 return false;
3912 }
3913 return next.match(matcher, i, seq);
3914 }
3915 // Reluctant match. At this point, the minimum has been satisfied.
3916 // i is the index to start matching at
3917 // j is the number of atoms that have matched
3918 boolean match1(Matcher matcher, int i, int j, CharSequence seq) {
3919 for (;;) {
3920 // Try finishing match without consuming any more
3921 if (next.match(matcher, i, seq))
3922 return true;
3923 // At the maximum, no match found
3924 if (j >= cmax)
3925 return false;
3926 // Okay, must try one more atom
3927 if (!atom.match(matcher, i, seq))
3928 return false;
3929 // If we haven't moved forward then must break out
3930 if (i == matcher.last)
3931 return false;
3932 // Move up index and number matched
3933 i = matcher.last;
3934 j++;
3935 }
3936 }
3937 boolean match2(Matcher matcher, int i, int j, CharSequence seq) {
3938 for (; j < cmax; j++) {
3939 if (!atom.match(matcher, i, seq))
3940 break;
3941 if (i == matcher.last)
3942 break;
3943 i = matcher.last;
3944 }
3945 return next.match(matcher, i, seq);
3946 }
3947 boolean study(TreeInfo info) {
3948 // Save original info
3949 int minL = info.minLength;
3950 int maxL = info.maxLength;
3951 boolean maxV = info.maxValid;
3952 boolean detm = info.deterministic;
3953 info.reset();
3954
3955 atom.study(info);
3956
3957 int temp = info.minLength * cmin + minL;
3958 if (temp < minL) {
3959 temp = 0xFFFFFFF; // arbitrary large number
3960 }
3961 info.minLength = temp;
3962
3963 if (maxV & info.maxValid) {
3964 temp = info.maxLength * cmax + maxL;
3965 info.maxLength = temp;
3966 if (temp < maxL) {
3967 info.maxValid = false;
3968 }
3969 } else {
3970 info.maxValid = false;
3971 }
3972
3973 if (info.deterministic && cmin == cmax)
3974 info.deterministic = detm;
3975 else
3976 info.deterministic = false;
3977
3978 return next.study(info);
3979 }
3980 }
3981
3982 /**
3983 * Handles the curly-brace style repetition with a specified minimum and
3984 * maximum occurrences in deterministic cases. This is an iterative
3985 * optimization over the Prolog and Loop system which would handle this
3986 * in a recursive way. The * quantifier is handled as a special case.
3987 * If capture is true then this class saves group settings and ensures
3988 * that groups are unset when backing off of a group match.
3989 */
3990 static final class GroupCurly extends Node {
3991 Node atom;
3992 int type;
3993 int cmin;
3994 int cmax;
3995 int localIndex;
3996 int groupIndex;
3997 boolean capture;
3998
3999 GroupCurly(Node node, int cmin, int cmax, int type, int local,
4000 int group, boolean capture) {
4001 this.atom = node;
4002 this.type = type;
4003 this.cmin = cmin;
4004 this.cmax = cmax;
4005 this.localIndex = local;
4006 this.groupIndex = group;
4007 this.capture = capture;
4008 }
4009 boolean match(Matcher matcher, int i, CharSequence seq) {
4010 int[] groups = matcher.groups;
4011 int[] locals = matcher.locals;
4012 int save0 = locals[localIndex];
4013 int save1 = 0;
4014 int save2 = 0;
4015
4016 if (capture) {
4017 save1 = groups[groupIndex];
4018 save2 = groups[groupIndex+1];
4019 }
4020
4021 // Notify GroupTail there is no need to setup group info
4022 // because it will be set here
4023 locals[localIndex] = -1;
4024
4025 boolean ret = true;
4026 for (int j = 0; j < cmin; j++) {
4027 if (atom.match(matcher, i, seq)) {
4028 if (capture) {
4029 groups[groupIndex] = i;
4030 groups[groupIndex+1] = matcher.last;
4031 }
4032 i = matcher.last;
4033 } else {
4034 ret = false;
4035 break;
4036 }
4037 }
4038 if (ret) {
4039 if (type == GREEDY) {
4040 ret = match0(matcher, i, cmin, seq);
4041 } else if (type == LAZY) {
4042 ret = match1(matcher, i, cmin, seq);
4043 } else {
4044 ret = match2(matcher, i, cmin, seq);
4045 }
4046 }
4047 if (!ret) {
4048 locals[localIndex] = save0;
4049 if (capture) {
4050 groups[groupIndex] = save1;
4051 groups[groupIndex+1] = save2;
4052 }
4053 }
4054 return ret;
4055 }
4056 // Aggressive group match
4057 boolean match0(Matcher matcher, int i, int j, CharSequence seq) {
4058 int[] groups = matcher.groups;
4059 int save0 = 0;
4060 int save1 = 0;
4061 if (capture) {
4062 save0 = groups[groupIndex];
4063 save1 = groups[groupIndex+1];
4064 }
4065 for (;;) {
4066 if (j >= cmax)
4067 break;
4068 if (!atom.match(matcher, i, seq))
4069 break;
4070 int k = matcher.last - i;
4071 if (k <= 0) {
4072 if (capture) {
4073 groups[groupIndex] = i;
4074 groups[groupIndex+1] = i + k;
4075 }
4076 i = i + k;
4077 break;
4078 }
4079 for (;;) {
4080 if (capture) {
4081 groups[groupIndex] = i;
4082 groups[groupIndex+1] = i + k;
4083 }
4084 i = i + k;
4085 if (++j >= cmax)
4086 break;
4087 if (!atom.match(matcher, i, seq))
4088 break;
4089 if (i + k != matcher.last) {
4090 if (match0(matcher, i, j, seq))
4091 return true;
4092 break;
4093 }
4094 }
4095 while (j > cmin) {
4096 if (next.match(matcher, i, seq)) {
4097 if (capture) {
4098 groups[groupIndex+1] = i;
4099 groups[groupIndex] = i - k;
4100 }
4101 i = i - k;
4102 return true;
4103 }
4104 // backing off
4105 if (capture) {
4106 groups[groupIndex+1] = i;
4107 groups[groupIndex] = i - k;
4108 }
4109 i = i - k;
4110 j--;
4111 }
4112 break;
4113 }
4114 if (capture) {
4115 groups[groupIndex] = save0;
4116 groups[groupIndex+1] = save1;
4117 }
4118 return next.match(matcher, i, seq);
4119 }
4120 // Reluctant matching
4121 boolean match1(Matcher matcher, int i, int j, CharSequence seq) {
4122 for (;;) {
4123 if (next.match(matcher, i, seq))
4124 return true;
4125 if (j >= cmax)
4126 return false;
4127 if (!atom.match(matcher, i, seq))
4128 return false;
4129 if (i == matcher.last)
4130 return false;
4131 if (capture) {
4132 matcher.groups[groupIndex] = i;
4133 matcher.groups[groupIndex+1] = matcher.last;
4134 }
4135 i = matcher.last;
4136 j++;
4137 }
4138 }
4139 // Possessive matching
4140 boolean match2(Matcher matcher, int i, int j, CharSequence seq) {
4141 for (; j < cmax; j++) {
4142 if (!atom.match(matcher, i, seq)) {
4143 break;
4144 }
4145 if (capture) {
4146 matcher.groups[groupIndex] = i;
4147 matcher.groups[groupIndex+1] = matcher.last;
4148 }
4149 if (i == matcher.last) {
4150 break;
4151 }
4152 i = matcher.last;
4153 }
4154 return next.match(matcher, i, seq);
4155 }
4156 boolean study(TreeInfo info) {
4157 // Save original info
4158 int minL = info.minLength;
4159 int maxL = info.maxLength;
4160 boolean maxV = info.maxValid;
4161 boolean detm = info.deterministic;
4162 info.reset();
4163
4164 atom.study(info);
4165
4166 int temp = info.minLength * cmin + minL;
4167 if (temp < minL) {
4168 temp = 0xFFFFFFF; // Arbitrary large number
4169 }
4170 info.minLength = temp;
4171
4172 if (maxV & info.maxValid) {
4173 temp = info.maxLength * cmax + maxL;
4174 info.maxLength = temp;
4175 if (temp < maxL) {
4176 info.maxValid = false;
4177 }
4178 } else {
4179 info.maxValid = false;
4180 }
4181
4182 if (info.deterministic && cmin == cmax) {
4183 info.deterministic = detm;
4184 } else {
4185 info.deterministic = false;
4186 }
4187
4188 return next.study(info);
4189 }
4190 }
4191
4192 /**
4193 * A Guard node at the end of each atom node in a Branch. It
4194 * serves the purpose of chaining the "match" operation to
4195 * "next" but not the "study", so we can collect the TreeInfo
4196 * of each atom node without including the TreeInfo of the
4197 * "next".
4198 */
4199 static final class BranchConn extends Node {
4200 BranchConn() {};
4201 boolean match(Matcher matcher, int i, CharSequence seq) {
4202 return next.match(matcher, i, seq);
4203 }
4204 boolean study(TreeInfo info) {
4205 return info.deterministic;
4206 }
4207 }
4208
4209 /**
4210 * Handles the branching of alternations. Note this is also used for
4211 * the ? quantifier to branch between the case where it matches once
4212 * and where it does not occur.
4213 */
4214 static final class Branch extends Node {
4215 Node[] atoms = new Node[2];
4216 int size = 2;
4217 Node conn;
4218 Branch(Node first, Node second, Node branchConn) {
4219 conn = branchConn;
4220 atoms[0] = first;
4221 atoms[1] = second;
4222 }
4223
4224 void add(Node node) {
4225 if (size >= atoms.length) {
4226 Node[] tmp = new Node[atoms.length*2];
4227 System.arraycopy(atoms, 0, tmp, 0, atoms.length);
4228 atoms = tmp;
4229 }
4230 atoms[size++] = node;
4231 }
4232
4233 boolean match(Matcher matcher, int i, CharSequence seq) {
4234 for (int n = 0; n < size; n++) {
4235 if (atoms[n] == null) {
4236 if (conn.next.match(matcher, i, seq))
4237 return true;
4238 } else if (atoms[n].match(matcher, i, seq)) {
4239 return true;
4240 }
4241 }
4242 return false;
4243 }
4244
4245 boolean study(TreeInfo info) {
4246 int minL = info.minLength;
4247 int maxL = info.maxLength;
4248 boolean maxV = info.maxValid;
4249
4250 int minL2 = Integer.MAX_VALUE; //arbitrary large enough num
4251 int maxL2 = -1;
4252 for (int n = 0; n < size; n++) {
4253 info.reset();
4254 if (atoms[n] != null)
4255 atoms[n].study(info);
4256 minL2 = Math.min(minL2, info.minLength);
4257 maxL2 = Math.max(maxL2, info.maxLength);
4258 maxV = (maxV & info.maxValid);
4259 }
4260
4261 minL += minL2;
4262 maxL += maxL2;
4263
4264 info.reset();
4265 conn.next.study(info);
4266
4267 info.minLength += minL;
4268 info.maxLength += maxL;
4269 info.maxValid &= maxV;
4270 info.deterministic = false;
4271 return false;
4272 }
4273 }
4274
4275 /**
4276 * The GroupHead saves the location where the group begins in the locals
4277 * and restores them when the match is done.
4278 *
4279 * The matchRef is used when a reference to this group is accessed later
4280 * in the expression. The locals will have a negative value in them to
4281 * indicate that we do not want to unset the group if the reference
4282 * doesn't match.
4283 */
4284 static final class GroupHead extends Node {
4285 int localIndex;
4286 GroupHead(int localCount) {
4287 localIndex = localCount;
4288 }
4289 boolean match(Matcher matcher, int i, CharSequence seq) {
4290 int save = matcher.locals[localIndex];
4291 matcher.locals[localIndex] = i;
4292 boolean ret = next.match(matcher, i, seq);
4293 matcher.locals[localIndex] = save;
4294 return ret;
4295 }
4296 boolean matchRef(Matcher matcher, int i, CharSequence seq) {
4297 int save = matcher.locals[localIndex];
4298 matcher.locals[localIndex] = ~i; // HACK
4299 boolean ret = next.match(matcher, i, seq);
4300 matcher.locals[localIndex] = save;
4301 return ret;
4302 }
4303 }
4304
4305 /**
4306 * Recursive reference to a group in the regular expression. It calls
4307 * matchRef because if the reference fails to match we would not unset
4308 * the group.
4309 */
4310 static final class GroupRef extends Node {
4311 GroupHead head;
4312 GroupRef(GroupHead head) {
4313 this.head = head;
4314 }
4315 boolean match(Matcher matcher, int i, CharSequence seq) {
4316 return head.matchRef(matcher, i, seq)
4317 && next.match(matcher, matcher.last, seq);
4318 }
4319 boolean study(TreeInfo info) {
4320 info.maxValid = false;
4321 info.deterministic = false;
4322 return next.study(info);
4323 }
4324 }
4325
4326 /**
4327 * The GroupTail handles the setting of group beginning and ending
4328 * locations when groups are successfully matched. It must also be able to
4329 * unset groups that have to be backed off of.
4330 *
4331 * The GroupTail node is also used when a previous group is referenced,
4332 * and in that case no group information needs to be set.
4333 */
4334 static final class GroupTail extends Node {
4335 int localIndex;
4336 int groupIndex;
4337 GroupTail(int localCount, int groupCount) {
4338 localIndex = localCount;
4339 groupIndex = groupCount + groupCount;
4340 }
4341 boolean match(Matcher matcher, int i, CharSequence seq) {
4342 int tmp = matcher.locals[localIndex];
4343 if (tmp >= 0) { // This is the normal group case.
4344 // Save the group so we can unset it if it
4345 // backs off of a match.
4346 int groupStart = matcher.groups[groupIndex];
4347 int groupEnd = matcher.groups[groupIndex+1];
4348
4349 matcher.groups[groupIndex] = tmp;
4350 matcher.groups[groupIndex+1] = i;
4351 if (next.match(matcher, i, seq)) {
4352 return true;
4353 }
4354 matcher.groups[groupIndex] = groupStart;
4355 matcher.groups[groupIndex+1] = groupEnd;
4356 return false;
4357 } else {
4358 // This is a group reference case. We don't need to save any
4359 // group info because it isn't really a group.
4360 matcher.last = i;
4361 return true;
4362 }
4363 }
4364 }
4365
4366 /**
4367 * This sets up a loop to handle a recursive quantifier structure.
4368 */
4369 static final class Prolog extends Node {
4370 Loop loop;
4371 Prolog(Loop loop) {
4372 this.loop = loop;
4373 }
4374 boolean match(Matcher matcher, int i, CharSequence seq) {
4375 return loop.matchInit(matcher, i, seq);
4376 }
4377 boolean study(TreeInfo info) {
4378 return loop.study(info);
4379 }
4380 }
4381
4382 /**
4383 * Handles the repetition count for a greedy Curly. The matchInit
4384 * is called from the Prolog to save the index of where the group
4385 * beginning is stored. A zero length group check occurs in the
4386 * normal match but is skipped in the matchInit.
4387 */
4388 static class Loop extends Node {
4389 Node body;
4390 int countIndex; // local count index in matcher locals
4391 int beginIndex; // group beginning index
4392 int cmin, cmax;
4393 Loop(int countIndex, int beginIndex) {
4394 this.countIndex = countIndex;
4395 this.beginIndex = beginIndex;
4396 }
4397 boolean match(Matcher matcher, int i, CharSequence seq) {
4398 // Avoid infinite loop in zero-length case.
4399 if (i > matcher.locals[beginIndex]) {
4400 int count = matcher.locals[countIndex];
4401
4402 // This block is for before we reach the minimum
4403 // iterations required for the loop to match
4404 if (count < cmin) {
4405 matcher.locals[countIndex] = count + 1;
4406 boolean b = body.match(matcher, i, seq);
4407 // If match failed we must backtrack, so
4408 // the loop count should NOT be incremented
4409 if (!b)
4410 matcher.locals[countIndex] = count;
4411 // Return success or failure since we are under
4412 // minimum
4413 return b;
4414 }
4415 // This block is for after we have the minimum
4416 // iterations required for the loop to match
4417 if (count < cmax) {
4418 matcher.locals[countIndex] = count + 1;
4419 boolean b = body.match(matcher, i, seq);
4420 // If match failed we must backtrack, so
4421 // the loop count should NOT be incremented
4422 if (!b)
4423 matcher.locals[countIndex] = count;
4424 else
4425 return true;
4426 }
4427 }
4428 return next.match(matcher, i, seq);
4429 }
4430 boolean matchInit(Matcher matcher, int i, CharSequence seq) {
4431 int save = matcher.locals[countIndex];
4432 boolean ret = false;
4433 if (0 < cmin) {
4434 matcher.locals[countIndex] = 1;
4435 ret = body.match(matcher, i, seq);
4436 } else if (0 < cmax) {
4437 matcher.locals[countIndex] = 1;
4438 ret = body.match(matcher, i, seq);
4439 if (ret == false)
4440 ret = next.match(matcher, i, seq);
4441 } else {
4442 ret = next.match(matcher, i, seq);
4443 }
4444 matcher.locals[countIndex] = save;
4445 return ret;
4446 }
4447 boolean study(TreeInfo info) {
4448 info.maxValid = false;
4449 info.deterministic = false;
4450 return false;
4451 }
4452 }
4453
4454 /**
4455 * Handles the repetition count for a reluctant Curly. The matchInit
4456 * is called from the Prolog to save the index of where the group
4457 * beginning is stored. A zero length group check occurs in the
4458 * normal match but is skipped in the matchInit.
4459 */
4460 static final class LazyLoop extends Loop {
4461 LazyLoop(int countIndex, int beginIndex) {
4462 super(countIndex, beginIndex);
4463 }
4464 boolean match(Matcher matcher, int i, CharSequence seq) {
4465 // Check for zero length group
4466 if (i > matcher.locals[beginIndex]) {
4467 int count = matcher.locals[countIndex];
4468 if (count < cmin) {
4469 matcher.locals[countIndex] = count + 1;
4470 boolean result = body.match(matcher, i, seq);
4471 // If match failed we must backtrack, so
4472 // the loop count should NOT be incremented
4473 if (!result)
4474 matcher.locals[countIndex] = count;
4475 return result;
4476 }
4477 if (next.match(matcher, i, seq))
4478 return true;
4479 if (count < cmax) {
4480 matcher.locals[countIndex] = count + 1;
4481 boolean result = body.match(matcher, i, seq);
4482 // If match failed we must backtrack, so
4483 // the loop count should NOT be incremented
4484 if (!result)
4485 matcher.locals[countIndex] = count;
4486 return result;
4487 }
4488 return false;
4489 }
4490 return next.match(matcher, i, seq);
4491 }
4492 boolean matchInit(Matcher matcher, int i, CharSequence seq) {
4493 int save = matcher.locals[countIndex];
4494 boolean ret = false;
4495 if (0 < cmin) {
4496 matcher.locals[countIndex] = 1;
4497 ret = body.match(matcher, i, seq);
4498 } else if (next.match(matcher, i, seq)) {
4499 ret = true;
4500 } else if (0 < cmax) {
4501 matcher.locals[countIndex] = 1;
4502 ret = body.match(matcher, i, seq);
4503 }
4504 matcher.locals[countIndex] = save;
4505 return ret;
4506 }
4507 boolean study(TreeInfo info) {
4508 info.maxValid = false;
4509 info.deterministic = false;
4510 return false;
4511 }
4512 }
4513
4514 /**
4515 * Refers to a group in the regular expression. Attempts to match
4516 * whatever the group referred to last matched.
4517 */
4518 static class BackRef extends Node {
4519 int groupIndex;
4520 BackRef(int groupCount) {
4521 super();
4522 groupIndex = groupCount + groupCount;
4523 }
4524 boolean match(Matcher matcher, int i, CharSequence seq) {
4525 int j = matcher.groups[groupIndex];
4526 int k = matcher.groups[groupIndex+1];
4527
4528 int groupSize = k - j;
4529
4530 // If the referenced group didn't match, neither can this
4531 if (j < 0)
4532 return false;
4533
4534 // If there isn't enough input left no match
4535 if (i + groupSize > matcher.to) {
4536 matcher.hitEnd = true;
4537 return false;
4538 }
4539
4540 // Check each new char to make sure it matches what the group
4541 // referenced matched last time around
4542 for (int index=0; index<groupSize; index++)
4543 if (seq.charAt(i+index) != seq.charAt(j+index))
4544 return false;
4545
4546 return next.match(matcher, i+groupSize, seq);
4547 }
4548 boolean study(TreeInfo info) {
4549 info.maxValid = false;
4550 return next.study(info);
4551 }
4552 }
4553
4554 static class CIBackRef extends Node {
4555 int groupIndex;
4556 boolean doUnicodeCase;
4557 CIBackRef(int groupCount, boolean doUnicodeCase) {
4558 super();
4559 groupIndex = groupCount + groupCount;
4560 this.doUnicodeCase = doUnicodeCase;
4561 }
4562 boolean match(Matcher matcher, int i, CharSequence seq) {
4563 int j = matcher.groups[groupIndex];
4564 int k = matcher.groups[groupIndex+1];
4565
4566 int groupSize = k - j;
4567
4568 // If the referenced group didn't match, neither can this
4569 if (j < 0)
4570 return false;
4571
4572 // If there isn't enough input left no match
4573 if (i + groupSize > matcher.to) {
4574 matcher.hitEnd = true;
4575 return false;
4576 }
4577
4578 // Check each new char to make sure it matches what the group
4579 // referenced matched last time around
4580 int x = i;
4581 for (int index=0; index<groupSize; index++) {
4582 int c1 = Character.codePointAt(seq, x);
4583 int c2 = Character.codePointAt(seq, j);
4584 if (c1 != c2) {
4585 if (doUnicodeCase) {
4586 int cc1 = Character.toUpperCase(c1);
4587 int cc2 = Character.toUpperCase(c2);
4588 if (cc1 != cc2 &&
4589 Character.toLowerCase(cc1) !=
4590 Character.toLowerCase(cc2))
4591 return false;
4592 } else {
4593 if (ASCII.toLower(c1) != ASCII.toLower(c2))
4594 return false;
4595 }
4596 }
4597 x += Character.charCount(c1);
4598 j += Character.charCount(c2);
4599 }
4600
4601 return next.match(matcher, i+groupSize, seq);
4602 }
4603 boolean study(TreeInfo info) {
4604 info.maxValid = false;
4605 return next.study(info);
4606 }
4607 }
4608
4609 /**
4610 * Searches until the next instance of its atom. This is useful for
4611 * finding the atom efficiently without passing an instance of it
4612 * (greedy problem) and without a lot of wasted search time (reluctant
4613 * problem).
4614 */
4615 static final class First extends Node {
4616 Node atom;
4617 First(Node node) {
4618 this.atom = BnM.optimize(node);
4619 }
4620 boolean match(Matcher matcher, int i, CharSequence seq) {
4621 if (atom instanceof BnM) {
4622 return atom.match(matcher, i, seq)
4623 && next.match(matcher, matcher.last, seq);
4624 }
4625 for (;;) {
4626 if (i > matcher.to) {
4627 matcher.hitEnd = true;
4628 return false;
4629 }
4630 if (atom.match(matcher, i, seq)) {
4631 return next.match(matcher, matcher.last, seq);
4632 }
4633 i += countChars(seq, i, 1);
4634 matcher.first++;
4635 }
4636 }
4637 boolean study(TreeInfo info) {
4638 atom.study(info);
4639 info.maxValid = false;
4640 info.deterministic = false;
4641 return next.study(info);
4642 }
4643 }
4644
4645 static final class Conditional extends Node {
4646 Node cond, yes, not;
4647 Conditional(Node cond, Node yes, Node not) {
4648 this.cond = cond;
4649 this.yes = yes;
4650 this.not = not;
4651 }
4652 boolean match(Matcher matcher, int i, CharSequence seq) {
4653 if (cond.match(matcher, i, seq)) {
4654 return yes.match(matcher, i, seq);
4655 } else {
4656 return not.match(matcher, i, seq);
4657 }
4658 }
4659 boolean study(TreeInfo info) {
4660 int minL = info.minLength;
4661 int maxL = info.maxLength;
4662 boolean maxV = info.maxValid;
4663 info.reset();
4664 yes.study(info);
4665
4666 int minL2 = info.minLength;
4667 int maxL2 = info.maxLength;
4668 boolean maxV2 = info.maxValid;
4669 info.reset();
4670 not.study(info);
4671
4672 info.minLength = minL + Math.min(minL2, info.minLength);
4673 info.maxLength = maxL + Math.max(maxL2, info.maxLength);
4674 info.maxValid = (maxV & maxV2 & info.maxValid);
4675 info.deterministic = false;
4676 return next.study(info);
4677 }
4678 }
4679
4680 /**
4681 * Zero width positive lookahead.
4682 */
4683 static final class Pos extends Node {
4684 Node cond;
4685 Pos(Node cond) {
4686 this.cond = cond;
4687 }
4688 boolean match(Matcher matcher, int i, CharSequence seq) {
4689 int savedTo = matcher.to;
4690 boolean conditionMatched = false;
4691
4692 // Relax transparent region boundaries for lookahead
4693 if (matcher.transparentBounds)
4694 matcher.to = matcher.getTextLength();
4695 try {
4696 conditionMatched = cond.match(matcher, i, seq);
4697 } finally {
4698 // Reinstate region boundaries
4699 matcher.to = savedTo;
4700 }
4701 return conditionMatched && next.match(matcher, i, seq);
4702 }
4703 }
4704
4705 /**
4706 * Zero width negative lookahead.
4707 */
4708 static final class Neg extends Node {
4709 Node cond;
4710 Neg(Node cond) {
4711 this.cond = cond;
4712 }
4713 boolean match(Matcher matcher, int i, CharSequence seq) {
4714 int savedTo = matcher.to;
4715 boolean conditionMatched = false;
4716
4717 // Relax transparent region boundaries for lookahead
4718 if (matcher.transparentBounds)
4719 matcher.to = matcher.getTextLength();
4720 try {
4721 if (i < matcher.to) {
4722 conditionMatched = !cond.match(matcher, i, seq);
4723 } else {
4724 // If a negative lookahead succeeds then more input
4725 // could cause it to fail!
4726 matcher.requireEnd = true;
4727 conditionMatched = !cond.match(matcher, i, seq);
4728 }
4729 } finally {
4730 // Reinstate region boundaries
4731 matcher.to = savedTo;
4732 }
4733 return conditionMatched && next.match(matcher, i, seq);
4734 }
4735 }
4736
4737 /**
4738 * For use with lookbehinds; matches the position where the lookbehind
4739 * was encountered.
4740 */
4741 static Node lookbehindEnd = new Node() {
4742 boolean match(Matcher matcher, int i, CharSequence seq) {
4743 return i == matcher.lookbehindTo;
4744 }
4745 };
4746
4747 /**
4748 * Zero width positive lookbehind.
4749 */
4750 static class Behind extends Node {
4751 Node cond;
4752 int rmax, rmin;
4753 Behind(Node cond, int rmax, int rmin) {
4754 this.cond = cond;
4755 this.rmax = rmax;
4756 this.rmin = rmin;
4757 }
4758
4759 boolean match(Matcher matcher, int i, CharSequence seq) {
4760 int savedFrom = matcher.from;
4761 boolean conditionMatched = false;
4762 int startIndex = (!matcher.transparentBounds) ?
4763 matcher.from : 0;
4764 int from = Math.max(i - rmax, startIndex);
4765 // Set end boundary
4766 int savedLBT = matcher.lookbehindTo;
4767 matcher.lookbehindTo = i;
4768 // Relax transparent region boundaries for lookbehind
4769 if (matcher.transparentBounds)
4770 matcher.from = 0;
4771 for (int j = i - rmin; !conditionMatched && j >= from; j--) {
4772 conditionMatched = cond.match(matcher, j, seq);
4773 }
4774 matcher.from = savedFrom;
4775 matcher.lookbehindTo = savedLBT;
4776 return conditionMatched && next.match(matcher, i, seq);
4777 }
4778 }
4779
4780 /**
4781 * Zero width positive lookbehind, including supplementary
4782 * characters or unpaired surrogates.
4783 */
4784 static final class BehindS extends Behind {
4785 BehindS(Node cond, int rmax, int rmin) {
4786 super(cond, rmax, rmin);
4787 }
4788 boolean match(Matcher matcher, int i, CharSequence seq) {
4789 int rmaxChars = countChars(seq, i, -rmax);
4790 int rminChars = countChars(seq, i, -rmin);
4791 int savedFrom = matcher.from;
4792 int startIndex = (!matcher.transparentBounds) ?
4793 matcher.from : 0;
4794 boolean conditionMatched = false;
4795 int from = Math.max(i - rmaxChars, startIndex);
4796 // Set end boundary
4797 int savedLBT = matcher.lookbehindTo;
4798 matcher.lookbehindTo = i;
4799 // Relax transparent region boundaries for lookbehind
4800 if (matcher.transparentBounds)
4801 matcher.from = 0;
4802
4803 for (int j = i - rminChars;
4804 !conditionMatched && j >= from;
4805 j -= j>from ? countChars(seq, j, -1) : 1) {
4806 conditionMatched = cond.match(matcher, j, seq);
4807 }
4808 matcher.from = savedFrom;
4809 matcher.lookbehindTo = savedLBT;
4810 return conditionMatched && next.match(matcher, i, seq);
4811 }
4812 }
4813
4814 /**
4815 * Zero width negative lookbehind.
4816 */
4817 static class NotBehind extends Node {
4818 Node cond;
4819 int rmax, rmin;
4820 NotBehind(Node cond, int rmax, int rmin) {
4821 this.cond = cond;
4822 this.rmax = rmax;
4823 this.rmin = rmin;
4824 }
4825
4826 boolean match(Matcher matcher, int i, CharSequence seq) {
4827 int savedLBT = matcher.lookbehindTo;
4828 int savedFrom = matcher.from;
4829 boolean conditionMatched = false;
4830 int startIndex = (!matcher.transparentBounds) ?
4831 matcher.from : 0;
4832 int from = Math.max(i - rmax, startIndex);
4833 matcher.lookbehindTo = i;
4834 // Relax transparent region boundaries for lookbehind
4835 if (matcher.transparentBounds)
4836 matcher.from = 0;
4837 for (int j = i - rmin; !conditionMatched && j >= from; j--) {
4838 conditionMatched = cond.match(matcher, j, seq);
4839 }
4840 // Reinstate region boundaries
4841 matcher.from = savedFrom;
4842 matcher.lookbehindTo = savedLBT;
4843 return !conditionMatched && next.match(matcher, i, seq);
4844 }
4845 }
4846
4847 /**
4848 * Zero width negative lookbehind, including supplementary
4849 * characters or unpaired surrogates.
4850 */
4851 static final class NotBehindS extends NotBehind {
4852 NotBehindS(Node cond, int rmax, int rmin) {
4853 super(cond, rmax, rmin);
4854 }
4855 boolean match(Matcher matcher, int i, CharSequence seq) {
4856 int rmaxChars = countChars(seq, i, -rmax);
4857 int rminChars = countChars(seq, i, -rmin);
4858 int savedFrom = matcher.from;
4859 int savedLBT = matcher.lookbehindTo;
4860 boolean conditionMatched = false;
4861 int startIndex = (!matcher.transparentBounds) ?
4862 matcher.from : 0;
4863 int from = Math.max(i - rmaxChars, startIndex);
4864 matcher.lookbehindTo = i;
4865 // Relax transparent region boundaries for lookbehind
4866 if (matcher.transparentBounds)
4867 matcher.from = 0;
4868 for (int j = i - rminChars;
4869 !conditionMatched && j >= from;
4870 j -= j>from ? countChars(seq, j, -1) : 1) {
4871 conditionMatched = cond.match(matcher, j, seq);
4872 }
4873 //Reinstate region boundaries
4874 matcher.from = savedFrom;
4875 matcher.lookbehindTo = savedLBT;
4876 return !conditionMatched && next.match(matcher, i, seq);
4877 }
4878 }
4879
4880 /**
4881 * Returns the set union of two CharProperty nodes.
4882 */
4883 private static CharProperty union(final CharProperty lhs,
4884 final CharProperty rhs) {
4885 return new CharProperty() {
4886 boolean isSatisfiedBy(int ch) {
4887 return lhs.isSatisfiedBy(ch) || rhs.isSatisfiedBy(ch);}};
4888 }
4889
4890 /**
4891 * Returns the set intersection of two CharProperty nodes.
4892 */
4893 private static CharProperty intersection(final CharProperty lhs,
4894 final CharProperty rhs) {
4895 return new CharProperty() {
4896 boolean isSatisfiedBy(int ch) {
4897 return lhs.isSatisfiedBy(ch) && rhs.isSatisfiedBy(ch);}};
4898 }
4899
4900 /**
4901 * Returns the set difference of two CharProperty nodes.
4902 */
4903 private static CharProperty setDifference(final CharProperty lhs,
4904 final CharProperty rhs) {
4905 return new CharProperty() {
4906 boolean isSatisfiedBy(int ch) {
4907 return ! rhs.isSatisfiedBy(ch) && lhs.isSatisfiedBy(ch);}};
4908 }
4909
4910 /**
4911 * Handles word boundaries. Includes a field to allow this one class to
4912 * deal with the different types of word boundaries we can match. The word
4913 * characters include underscores, letters, and digits. Non spacing marks
4914 * can are also part of a word if they have a base character, otherwise
4915 * they are ignored for purposes of finding word boundaries.
4916 */
4917 static final class Bound extends Node {
4918 static int LEFT = 0x1;
4919 static int RIGHT= 0x2;
4920 static int BOTH = 0x3;
4921 static int NONE = 0x4;
4922 int type;
4923 Bound(int n) {
4924 type = n;
4925 }
4926 int check(Matcher matcher, int i, CharSequence seq) {
4927 int ch;
4928 boolean left = false;
4929 int startIndex = matcher.from;
4930 int endIndex = matcher.to;
4931 if (matcher.transparentBounds) {
4932 startIndex = 0;
4933 endIndex = matcher.getTextLength();
4934 }
4935 if (i > startIndex) {
4936 ch = Character.codePointBefore(seq, i);
4937 left = (ch == '_' || Character.isLetterOrDigit(ch) ||
4938 ((Character.getType(ch) == Character.NON_SPACING_MARK)
4939 && hasBaseCharacter(matcher, i-1, seq)));
4940 }
4941 boolean right = false;
4942 if (i < endIndex) {
4943 ch = Character.codePointAt(seq, i);
4944 right = (ch == '_' || Character.isLetterOrDigit(ch) ||
4945 ((Character.getType(ch) == Character.NON_SPACING_MARK)
4946 && hasBaseCharacter(matcher, i, seq)));
4947 } else {
4948 // Tried to access char past the end
4949 matcher.hitEnd = true;
4950 // The addition of another char could wreck a boundary
4951 matcher.requireEnd = true;
4952 }
4953 return ((left ^ right) ? (right ? LEFT : RIGHT) : NONE);
4954 }
4955 boolean match(Matcher matcher, int i, CharSequence seq) {
4956 return (check(matcher, i, seq) & type) > 0
4957 && next.match(matcher, i, seq);
4958 }
4959 }
4960
4961 /**
4962 * Non spacing marks only count as word characters in bounds calculations
4963 * if they have a base character.
4964 */
4965 private static boolean hasBaseCharacter(Matcher matcher, int i,
4966 CharSequence seq)
4967 {
4968 int start = (!matcher.transparentBounds) ?
4969 matcher.from : 0;
4970 for (int x=i; x >= start; x--) {
4971 int ch = Character.codePointAt(seq, x);
4972 if (Character.isLetterOrDigit(ch))
4973 return true;
4974 if (Character.getType(ch) == Character.NON_SPACING_MARK)
4975 continue;
4976 return false;
4977 }
4978 return false;
4979 }
4980
4981 /**
4982 * Attempts to match a slice in the input using the Boyer-Moore string
4983 * matching algorithm. The algorithm is based on the idea that the
4984 * pattern can be shifted farther ahead in the search text if it is
4985 * matched right to left.
4986 * <p>
4987 * The pattern is compared to the input one character at a time, from
4988 * the rightmost character in the pattern to the left. If the characters
4989 * all match the pattern has been found. If a character does not match,
4990 * the pattern is shifted right a distance that is the maximum of two
4991 * functions, the bad character shift and the good suffix shift. This
4992 * shift moves the attempted match position through the input more
4993 * quickly than a naive one position at a time check.
4994 * <p>
4995 * The bad character shift is based on the character from the text that
4996 * did not match. If the character does not appear in the pattern, the
4997 * pattern can be shifted completely beyond the bad character. If the
4998 * character does occur in the pattern, the pattern can be shifted to
4999 * line the pattern up with the next occurrence of that character.
5000 * <p>
5001 * The good suffix shift is based on the idea that some subset on the right
5002 * side of the pattern has matched. When a bad character is found, the
5003 * pattern can be shifted right by the pattern length if the subset does
5004 * not occur again in pattern, or by the amount of distance to the
5005 * next occurrence of the subset in the pattern.
5006 *
5007 * Boyer-Moore search methods adapted from code by Amy Yu.
5008 */
5009 static class BnM extends Node {
5010 int[] buffer;
5011 int[] lastOcc;
5012 int[] optoSft;
5013
5014 /**
5015 * Pre calculates arrays needed to generate the bad character
5016 * shift and the good suffix shift. Only the last seven bits
5017 * are used to see if chars match; This keeps the tables small
5018 * and covers the heavily used ASCII range, but occasionally
5019 * results in an aliased match for the bad character shift.
5020 */
5021 static Node optimize(Node node) {
5022 if (!(node instanceof Slice)) {
5023 return node;
5024 }
5025
5026 int[] src = ((Slice) node).buffer;
5027 int patternLength = src.length;
5028 // The BM algorithm requires a bit of overhead;
5029 // If the pattern is short don't use it, since
5030 // a shift larger than the pattern length cannot
5031 // be used anyway.
5032 if (patternLength < 4) {
5033 return node;
5034 }
5035 int i, j, k;
5036 int[] lastOcc = new int[128];
5037 int[] optoSft = new int[patternLength];
5038 // Precalculate part of the bad character shift
5039 // It is a table for where in the pattern each
5040 // lower 7-bit value occurs
5041 for (i = 0; i < patternLength; i++) {
5042 lastOcc[src[i]&0x7F] = i + 1;
5043 }
5044 // Precalculate the good suffix shift
5045 // i is the shift amount being considered
5046 NEXT: for (i = patternLength; i > 0; i--) {
5047 // j is the beginning index of suffix being considered
5048 for (j = patternLength - 1; j >= i; j--) {
5049 // Testing for good suffix
5050 if (src[j] == src[j-i]) {
5051 // src[j..len] is a good suffix
5052 optoSft[j-1] = i;
5053 } else {
5054 // No match. The array has already been
5055 // filled up with correct values before.
5056 continue NEXT;
5057 }
5058 }
5059 // This fills up the remaining of optoSft
5060 // any suffix can not have larger shift amount
5061 // then its sub-suffix. Why???
5062 while (j > 0) {
5063 optoSft[--j] = i;
5064 }
5065 }
5066 // Set the guard value because of unicode compression
5067 optoSft[patternLength-1] = 1;
5068 if (node instanceof SliceS)
5069 return new BnMS(src, lastOcc, optoSft, node.next);
5070 return new BnM(src, lastOcc, optoSft, node.next);
5071 }
5072 BnM(int[] src, int[] lastOcc, int[] optoSft, Node next) {
5073 this.buffer = src;
5074 this.lastOcc = lastOcc;
5075 this.optoSft = optoSft;
5076 this.next = next;
5077 }
5078 boolean match(Matcher matcher, int i, CharSequence seq) {
5079 int[] src = buffer;
5080 int patternLength = src.length;
5081 int last = matcher.to - patternLength;
5082
5083 // Loop over all possible match positions in text
5084 NEXT: while (i <= last) {
5085 // Loop over pattern from right to left
5086 for (int j = patternLength - 1; j >= 0; j--) {
5087 int ch = seq.charAt(i+j);
5088 if (ch != src[j]) {
5089 // Shift search to the right by the maximum of the
5090 // bad character shift and the good suffix shift
5091 i += Math.max(j + 1 - lastOcc[ch&0x7F], optoSft[j]);
5092 continue NEXT;
5093 }
5094 }
5095 // Entire pattern matched starting at i
5096 matcher.first = i;
5097 boolean ret = next.match(matcher, i + patternLength, seq);
5098 if (ret) {
5099 matcher.first = i;
5100 matcher.groups[0] = matcher.first;
5101 matcher.groups[1] = matcher.last;
5102 return true;
5103 }
5104 i++;
5105 }
5106 // BnM is only used as the leading node in the unanchored case,
5107 // and it replaced its Start() which always searches to the end
5108 // if it doesn't find what it's looking for, so hitEnd is true.
5109 matcher.hitEnd = true;
5110 return false;
5111 }
5112 boolean study(TreeInfo info) {
5113 info.minLength += buffer.length;
5114 info.maxValid = false;
5115 return next.study(info);
5116 }
5117 }
5118
5119 /**
5120 * Supplementary support version of BnM(). Unpaired surrogates are
5121 * also handled by this class.
5122 */
5123 static final class BnMS extends BnM {
5124 int lengthInChars;
5125
5126 BnMS(int[] src, int[] lastOcc, int[] optoSft, Node next) {
5127 super(src, lastOcc, optoSft, next);
5128 for (int x = 0; x < buffer.length; x++) {
5129 lengthInChars += Character.charCount(buffer[x]);
5130 }
5131 }
5132 boolean match(Matcher matcher, int i, CharSequence seq) {
5133 int[] src = buffer;
5134 int patternLength = src.length;
5135 int last = matcher.to - lengthInChars;
5136
5137 // Loop over all possible match positions in text
5138 NEXT: while (i <= last) {
5139 // Loop over pattern from right to left
5140 int ch;
5141 for (int j = countChars(seq, i, patternLength), x = patternLength - 1;
5142 j > 0; j -= Character.charCount(ch), x--) {
5143 ch = Character.codePointBefore(seq, i+j);
5144 if (ch != src[x]) {
5145 // Shift search to the right by the maximum of the
5146 // bad character shift and the good suffix shift
5147 int n = Math.max(x + 1 - lastOcc[ch&0x7F], optoSft[x]);
5148 i += countChars(seq, i, n);
5149 continue NEXT;
5150 }
5151 }
5152 // Entire pattern matched starting at i
5153 matcher.first = i;
5154 boolean ret = next.match(matcher, i + lengthInChars, seq);
5155 if (ret) {
5156 matcher.first = i;
5157 matcher.groups[0] = matcher.first;
5158 matcher.groups[1] = matcher.last;
5159 return true;
5160 }
5161 i += countChars(seq, i, 1);
5162 }
5163 matcher.hitEnd = true;
5164 return false;
5165 }
5166 }
5167
5168 ///////////////////////////////////////////////////////////////////////////////
5169 ///////////////////////////////////////////////////////////////////////////////
5170
5171 /**
5172 * This must be the very first initializer.
5173 */
5174 static Node accept = new Node();
5175
5176 static Node lastAccept = new LastNode();
5177
5178 private static class CharPropertyNames {
5179
5180 static CharProperty charPropertyFor(String name) {
5181 CharPropertyFactory m = map.get(name);
5182 return m == null ? null : m.make();
5183 }
5184
5185 private static abstract class CharPropertyFactory {
5186 abstract CharProperty make();
5187 }
5188
5189 private static void defCategory(String name,
5190 final int typeMask) {
5191 map.put(name, new CharPropertyFactory() {
5192 CharProperty make() { return new Category(typeMask);}});
5193 }
5194
5195 private static void defRange(String name,
5196 final int lower, final int upper) {
5197 map.put(name, new CharPropertyFactory() {
5198 CharProperty make() { return rangeFor(lower, upper);}});
5199 }
5200
5201 private static void defCtype(String name,
5202 final int ctype) {
5203 map.put(name, new CharPropertyFactory() {
5204 CharProperty make() { return new Ctype(ctype);}});
5205 }
5206
5207 private static abstract class CloneableProperty
5208 extends CharProperty implements Cloneable
5209 {
5210 public CloneableProperty clone() {
5211 try {
5212 return (CloneableProperty) super.clone();
5213 } catch (CloneNotSupportedException e) {
5214 throw new AssertionError(e);
5215 }
5216 }
5217 }
5218
5219 private static void defClone(String name,
5220 final CloneableProperty p) {
5221 map.put(name, new CharPropertyFactory() {
5222 CharProperty make() { return p.clone();}});
5223 }
5224
5225 private static final HashMap<String, CharPropertyFactory> map
5226 = new HashMap<String, CharPropertyFactory>();
5227
5228 static {
5229 // Unicode character property aliases, defined in
5230 // http://www.unicode.org/Public/UNIDATA/PropertyValueAliases.txt
5231 defCategory("Cn", 1<<Character.UNASSIGNED);
5232 defCategory("Lu", 1<<Character.UPPERCASE_LETTER);
5233 defCategory("Ll", 1<<Character.LOWERCASE_LETTER);
5234 defCategory("Lt", 1<<Character.TITLECASE_LETTER);
5235 defCategory("Lm", 1<<Character.MODIFIER_LETTER);
5236 defCategory("Lo", 1<<Character.OTHER_LETTER);
5237 defCategory("Mn", 1<<Character.NON_SPACING_MARK);
5238 defCategory("Me", 1<<Character.ENCLOSING_MARK);
5239 defCategory("Mc", 1<<Character.COMBINING_SPACING_MARK);
5240 defCategory("Nd", 1<<Character.DECIMAL_DIGIT_NUMBER);
5241 defCategory("Nl", 1<<Character.LETTER_NUMBER);
5242 defCategory("No", 1<<Character.OTHER_NUMBER);
5243 defCategory("Zs", 1<<Character.SPACE_SEPARATOR);
5244 defCategory("Zl", 1<<Character.LINE_SEPARATOR);
5245 defCategory("Zp", 1<<Character.PARAGRAPH_SEPARATOR);
5246 defCategory("Cc", 1<<Character.CONTROL);
5247 defCategory("Cf", 1<<Character.FORMAT);
5248 defCategory("Co", 1<<Character.PRIVATE_USE);
5249 defCategory("Cs", 1<<Character.SURROGATE);
5250 defCategory("Pd", 1<<Character.DASH_PUNCTUATION);
5251 defCategory("Ps", 1<<Character.START_PUNCTUATION);
5252 defCategory("Pe", 1<<Character.END_PUNCTUATION);
5253 defCategory("Pc", 1<<Character.CONNECTOR_PUNCTUATION);
5254 defCategory("Po", 1<<Character.OTHER_PUNCTUATION);
5255 defCategory("Sm", 1<<Character.MATH_SYMBOL);
5256 defCategory("Sc", 1<<Character.CURRENCY_SYMBOL);
5257 defCategory("Sk", 1<<Character.MODIFIER_SYMBOL);
5258 defCategory("So", 1<<Character.OTHER_SYMBOL);
5259 defCategory("Pi", 1<<Character.INITIAL_QUOTE_PUNCTUATION);
5260 defCategory("Pf", 1<<Character.FINAL_QUOTE_PUNCTUATION);
5261 defCategory("L", ((1<<Character.UPPERCASE_LETTER) |
5262 (1<<Character.LOWERCASE_LETTER) |
5263 (1<<Character.TITLECASE_LETTER) |
5264 (1<<Character.MODIFIER_LETTER) |
5265 (1<<Character.OTHER_LETTER)));
5266 defCategory("M", ((1<<Character.NON_SPACING_MARK) |
5267 (1<<Character.ENCLOSING_MARK) |
5268 (1<<Character.COMBINING_SPACING_MARK)));
5269 defCategory("N", ((1<<Character.DECIMAL_DIGIT_NUMBER) |
5270 (1<<Character.LETTER_NUMBER) |
5271 (1<<Character.OTHER_NUMBER)));
5272 defCategory("Z", ((1<<Character.SPACE_SEPARATOR) |
5273 (1<<Character.LINE_SEPARATOR) |
5274 (1<<Character.PARAGRAPH_SEPARATOR)));
5275 defCategory("C", ((1<<Character.CONTROL) |
5276 (1<<Character.FORMAT) |
5277 (1<<Character.PRIVATE_USE) |
5278 (1<<Character.SURROGATE))); // Other
5279 defCategory("P", ((1<<Character.DASH_PUNCTUATION) |
5280 (1<<Character.START_PUNCTUATION) |
5281 (1<<Character.END_PUNCTUATION) |
5282 (1<<Character.CONNECTOR_PUNCTUATION) |
5283 (1<<Character.OTHER_PUNCTUATION) |
5284 (1<<Character.INITIAL_QUOTE_PUNCTUATION) |
5285 (1<<Character.FINAL_QUOTE_PUNCTUATION)));
5286 defCategory("S", ((1<<Character.MATH_SYMBOL) |
5287 (1<<Character.CURRENCY_SYMBOL) |
5288 (1<<Character.MODIFIER_SYMBOL) |
5289 (1<<Character.OTHER_SYMBOL)));
5290 defCategory("LC", ((1<<Character.UPPERCASE_LETTER) |
5291 (1<<Character.LOWERCASE_LETTER) |
5292 (1<<Character.TITLECASE_LETTER)));
5293 defCategory("LD", ((1<<Character.UPPERCASE_LETTER) |
5294 (1<<Character.LOWERCASE_LETTER) |
5295 (1<<Character.TITLECASE_LETTER) |
5296 (1<<Character.MODIFIER_LETTER) |
5297 (1<<Character.OTHER_LETTER) |
5298 (1<<Character.DECIMAL_DIGIT_NUMBER)));
5299 defRange("L1", 0x00, 0xFF); // Latin-1
5300 map.put("all", new CharPropertyFactory() {
5301 CharProperty make() { return new All(); }});
5302
5303 // Posix regular expression character classes, defined in
5304 // http://www.unix.org/onlinepubs/009695399/basedefs/xbd_chap09.html
5305 defRange("ASCII", 0x00, 0x7F); // ASCII
5306 defCtype("Alnum", ASCII.ALNUM); // Alphanumeric characters
5307 defCtype("Alpha", ASCII.ALPHA); // Alphabetic characters
5308 defCtype("Blank", ASCII.BLANK); // Space and tab characters
5309 defCtype("Cntrl", ASCII.CNTRL); // Control characters
5310 defRange("Digit", '0', '9'); // Numeric characters
5311 defCtype("Graph", ASCII.GRAPH); // printable and visible
5312 defRange("Lower", 'a', 'z'); // Lower-case alphabetic
5313 defRange("Print", 0x20, 0x7E); // Printable characters
5314 defCtype("Punct", ASCII.PUNCT); // Punctuation characters
5315 defCtype("Space", ASCII.SPACE); // Space characters
5316 defRange("Upper", 'A', 'Z'); // Upper-case alphabetic
5317 defCtype("XDigit",ASCII.XDIGIT); // hexadecimal digits
5318
5319 // Java character properties, defined by methods in Character.java
5320 defClone("javaLowerCase", new CloneableProperty() {
5321 boolean isSatisfiedBy(int ch) {
5322 return Character.isLowerCase(ch);}});
5323 defClone("javaUpperCase", new CloneableProperty() {
5324 boolean isSatisfiedBy(int ch) {
5325 return Character.isUpperCase(ch);}});
5326 defClone("javaTitleCase", new CloneableProperty() {
5327 boolean isSatisfiedBy(int ch) {
5328 return Character.isTitleCase(ch);}});
5329 defClone("javaDigit", new CloneableProperty() {
5330 boolean isSatisfiedBy(int ch) {
5331 return Character.isDigit(ch);}});
5332 defClone("javaDefined", new CloneableProperty() {
5333 boolean isSatisfiedBy(int ch) {
5334 return Character.isDefined(ch);}});
5335 defClone("javaLetter", new CloneableProperty() {
5336 boolean isSatisfiedBy(int ch) {
5337 return Character.isLetter(ch);}});
5338 defClone("javaLetterOrDigit", new CloneableProperty() {
5339 boolean isSatisfiedBy(int ch) {
5340 return Character.isLetterOrDigit(ch);}});
5341 defClone("javaJavaIdentifierStart", new CloneableProperty() {
5342 boolean isSatisfiedBy(int ch) {
5343 return Character.isJavaIdentifierStart(ch);}});
5344 defClone("javaJavaIdentifierPart", new CloneableProperty() {
5345 boolean isSatisfiedBy(int ch) {
5346 return Character.isJavaIdentifierPart(ch);}});
5347 defClone("javaUnicodeIdentifierStart", new CloneableProperty() {
5348 boolean isSatisfiedBy(int ch) {
5349 return Character.isUnicodeIdentifierStart(ch);}});
5350 defClone("javaUnicodeIdentifierPart", new CloneableProperty() {
5351 boolean isSatisfiedBy(int ch) {
5352 return Character.isUnicodeIdentifierPart(ch);}});
5353 defClone("javaIdentifierIgnorable", new CloneableProperty() {
5354 boolean isSatisfiedBy(int ch) {
5355 return Character.isIdentifierIgnorable(ch);}});
5356 defClone("javaSpaceChar", new CloneableProperty() {
5357 boolean isSatisfiedBy(int ch) {
5358 return Character.isSpaceChar(ch);}});
5359 defClone("javaWhitespace", new CloneableProperty() {
5360 boolean isSatisfiedBy(int ch) {
5361 return Character.isWhitespace(ch);}});
5362 defClone("javaISOControl", new CloneableProperty() {
5363 boolean isSatisfiedBy(int ch) {
5364 return Character.isISOControl(ch);}});
5365 defClone("javaMirrored", new CloneableProperty() {
5366 boolean isSatisfiedBy(int ch) {
5367 return Character.isMirrored(ch);}});
5368 }
5369 }
5370 }