1 /*
2 * Copyright (c) 1999, 2013, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation. Oracle designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Oracle in the LICENSE file that accompanied this code.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 */
25
26 package java.util.regex;
27
28 import java.text.Normalizer;
29 import java.util.Locale;
30 import java.util.Iterator;
31 import java.util.Map;
32 import java.util.ArrayList;
33 import java.util.HashMap;
34 import java.util.Arrays;
35 import java.util.NoSuchElementException;
36 import java.util.Spliterator;
37 import java.util.Spliterators;
38 import java.util.function.Predicate;
39 import java.util.stream.Stream;
40 import java.util.stream.StreamSupport;
41
42
43 /**
44 * A compiled representation of a regular expression.
45 *
46 * <p> A regular expression, specified as a string, must first be compiled into
47 * an instance of this class. The resulting pattern can then be used to create
48 * a {@link Matcher} object that can match arbitrary {@link
49 * java.lang.CharSequence </code>character sequences<code>} against the regular
50 * expression. All of the state involved in performing a match resides in the
51 * matcher, so many matchers can share the same pattern.
52 *
53 * <p> A typical invocation sequence is thus
54 *
55 * <blockquote><pre>
56 * Pattern p = Pattern.{@link #compile compile}("a*b");
57 * Matcher m = p.{@link #matcher matcher}("aaaaab");
58 * boolean b = m.{@link Matcher#matches matches}();</pre></blockquote>
59 *
60 * <p> A {@link #matches matches} method is defined by this class as a
61 * convenience for when a regular expression is used just once. This method
62 * compiles an expression and matches an input sequence against it in a single
63 * invocation. The statement
64 *
65 * <blockquote><pre>
66 * boolean b = Pattern.matches("a*b", "aaaaab");</pre></blockquote>
67 *
68 * is equivalent to the three statements above, though for repeated matches it
69 * is less efficient since it does not allow the compiled pattern to be reused.
70 *
71 * <p> Instances of this class are immutable and are safe for use by multiple
72 * concurrent threads. Instances of the {@link Matcher} class are not safe for
73 * such use.
74 *
75 *
76 * <a name="sum">
77 * <h4> Summary of regular-expression constructs </h4>
78 *
79 * <table border="0" cellpadding="1" cellspacing="0"
80 * summary="Regular expression constructs, and what they match">
81 *
82 * <tr align="left">
83 * <th bgcolor="#CCCCFF" align="left" id="construct">Construct</th>
84 * <th bgcolor="#CCCCFF" align="left" id="matches">Matches</th>
85 * </tr>
86 *
87 * <tr><th> </th></tr>
88 * <tr align="left"><th colspan="2" id="characters">Characters</th></tr>
89 *
90 * <tr><td valign="top" headers="construct characters"><i>x</i></td>
91 * <td headers="matches">The character <i>x</i></td></tr>
92 * <tr><td valign="top" headers="construct characters"><tt>\\</tt></td>
93 * <td headers="matches">The backslash character</td></tr>
94 * <tr><td valign="top" headers="construct characters"><tt>\0</tt><i>n</i></td>
95 * <td headers="matches">The character with octal value <tt>0</tt><i>n</i>
96 * (0 <tt><=</tt> <i>n</i> <tt><=</tt> 7)</td></tr>
97 * <tr><td valign="top" headers="construct characters"><tt>\0</tt><i>nn</i></td>
98 * <td headers="matches">The character with octal value <tt>0</tt><i>nn</i>
99 * (0 <tt><=</tt> <i>n</i> <tt><=</tt> 7)</td></tr>
100 * <tr><td valign="top" headers="construct characters"><tt>\0</tt><i>mnn</i></td>
101 * <td headers="matches">The character with octal value <tt>0</tt><i>mnn</i>
102 * (0 <tt><=</tt> <i>m</i> <tt><=</tt> 3,
103 * 0 <tt><=</tt> <i>n</i> <tt><=</tt> 7)</td></tr>
104 * <tr><td valign="top" headers="construct characters"><tt>\x</tt><i>hh</i></td>
105 * <td headers="matches">The character with hexadecimal value <tt>0x</tt><i>hh</i></td></tr>
106 * <tr><td valign="top" headers="construct characters"><tt>\u</tt><i>hhhh</i></td>
107 * <td headers="matches">The character with hexadecimal value <tt>0x</tt><i>hhhh</i></td></tr>
108 * <tr><td valign="top" headers="construct characters"><tt>\x</tt><i>{h...h}</i></td>
109 * <td headers="matches">The character with hexadecimal value <tt>0x</tt><i>h...h</i>
110 * ({@link java.lang.Character#MIN_CODE_POINT Character.MIN_CODE_POINT}
111 * <= <tt>0x</tt><i>h...h</i> <= 
112 * {@link java.lang.Character#MAX_CODE_POINT Character.MAX_CODE_POINT})</td></tr>
113 * <tr><td valign="top" headers="matches"><tt>\t</tt></td>
114 * <td headers="matches">The tab character (<tt>'\u0009'</tt>)</td></tr>
115 * <tr><td valign="top" headers="construct characters"><tt>\n</tt></td>
116 * <td headers="matches">The newline (line feed) character (<tt>'\u000A'</tt>)</td></tr>
117 * <tr><td valign="top" headers="construct characters"><tt>\r</tt></td>
118 * <td headers="matches">The carriage-return character (<tt>'\u000D'</tt>)</td></tr>
119 * <tr><td valign="top" headers="construct characters"><tt>\f</tt></td>
120 * <td headers="matches">The form-feed character (<tt>'\u000C'</tt>)</td></tr>
121 * <tr><td valign="top" headers="construct characters"><tt>\a</tt></td>
122 * <td headers="matches">The alert (bell) character (<tt>'\u0007'</tt>)</td></tr>
123 * <tr><td valign="top" headers="construct characters"><tt>\e</tt></td>
124 * <td headers="matches">The escape character (<tt>'\u001B'</tt>)</td></tr>
125 * <tr><td valign="top" headers="construct characters"><tt>\c</tt><i>x</i></td>
126 * <td headers="matches">The control character corresponding to <i>x</i></td></tr>
127 *
128 * <tr><th> </th></tr>
129 * <tr align="left"><th colspan="2" id="classes">Character classes</th></tr>
130 *
131 * <tr><td valign="top" headers="construct classes"><tt>[abc]</tt></td>
132 * <td headers="matches"><tt>a</tt>, <tt>b</tt>, or <tt>c</tt> (simple class)</td></tr>
133 * <tr><td valign="top" headers="construct classes"><tt>[^abc]</tt></td>
134 * <td headers="matches">Any character except <tt>a</tt>, <tt>b</tt>, or <tt>c</tt> (negation)</td></tr>
135 * <tr><td valign="top" headers="construct classes"><tt>[a-zA-Z]</tt></td>
136 * <td headers="matches"><tt>a</tt> through <tt>z</tt>
137 * or <tt>A</tt> through <tt>Z</tt>, inclusive (range)</td></tr>
138 * <tr><td valign="top" headers="construct classes"><tt>[a-d[m-p]]</tt></td>
139 * <td headers="matches"><tt>a</tt> through <tt>d</tt>,
140 * or <tt>m</tt> through <tt>p</tt>: <tt>[a-dm-p]</tt> (union)</td></tr>
141 * <tr><td valign="top" headers="construct classes"><tt>[a-z&&[def]]</tt></td>
142 * <td headers="matches"><tt>d</tt>, <tt>e</tt>, or <tt>f</tt> (intersection)</tr>
143 * <tr><td valign="top" headers="construct classes"><tt>[a-z&&[^bc]]</tt></td>
144 * <td headers="matches"><tt>a</tt> through <tt>z</tt>,
145 * except for <tt>b</tt> and <tt>c</tt>: <tt>[ad-z]</tt> (subtraction)</td></tr>
146 * <tr><td valign="top" headers="construct classes"><tt>[a-z&&[^m-p]]</tt></td>
147 * <td headers="matches"><tt>a</tt> through <tt>z</tt>,
148 * and not <tt>m</tt> through <tt>p</tt>: <tt>[a-lq-z]</tt>(subtraction)</td></tr>
149 * <tr><th> </th></tr>
150 *
151 * <tr align="left"><th colspan="2" id="predef">Predefined character classes</th></tr>
152 *
153 * <tr><td valign="top" headers="construct predef"><tt>.</tt></td>
154 * <td headers="matches">Any character (may or may not match <a href="#lt">line terminators</a>)</td></tr>
155 * <tr><td valign="top" headers="construct predef"><tt>\d</tt></td>
156 * <td headers="matches">A digit: <tt>[0-9]</tt></td></tr>
157 * <tr><td valign="top" headers="construct predef"><tt>\D</tt></td>
158 * <td headers="matches">A non-digit: <tt>[^0-9]</tt></td></tr>
159 * <tr><td valign="top" headers="construct predef"><tt>\h</tt></td>
160 * <td headers="matches">A horizontal whitespace character:
161 * <tt>[ \t\xA0\u1680\u180e\u2000-\u200a\u202f\u205f\u3000]</tt></td></tr>
162 * <tr><td valign="top" headers="construct predef"><tt>\H</tt></td>
163 * <td headers="matches">A non-horizontal whitespace character: <tt>[^\h]</tt></td></tr>
164 * <tr><td valign="top" headers="construct predef"><tt>\s</tt></td>
165 * <td headers="matches">A whitespace character: <tt>[ \t\n\x0B\f\r]</tt></td></tr>
166 * <tr><td valign="top" headers="construct predef"><tt>\S</tt></td>
167 * <td headers="matches">A non-whitespace character: <tt>[^\s]</tt></td></tr>
168 * <tr><td valign="top" headers="construct predef"><tt>\v</tt></td>
169 * <td headers="matches">A vertical whitespace character: <tt>[\n\x0B\f\r\x85\u2028\u2029]</tt>
170 * </td></tr>
171 * <tr><td valign="top" headers="construct predef"><tt>\V</tt></td>
172 * <td headers="matches">A non-vertical whitespace character: <tt>[^\v]</tt></td></tr>
173 * <tr><td valign="top" headers="construct predef"><tt>\w</tt></td>
174 * <td headers="matches">A word character: <tt>[a-zA-Z_0-9]</tt></td></tr>
175 * <tr><td valign="top" headers="construct predef"><tt>\W</tt></td>
176 * <td headers="matches">A non-word character: <tt>[^\w]</tt></td></tr>
177 * <tr><th> </th></tr>
178 * <tr align="left"><th colspan="2" id="posix">POSIX character classes</b> (US-ASCII only)<b></th></tr>
179 *
180 * <tr><td valign="top" headers="construct posix"><tt>\p{Lower}</tt></td>
181 * <td headers="matches">A lower-case alphabetic character: <tt>[a-z]</tt></td></tr>
182 * <tr><td valign="top" headers="construct posix"><tt>\p{Upper}</tt></td>
183 * <td headers="matches">An upper-case alphabetic character:<tt>[A-Z]</tt></td></tr>
184 * <tr><td valign="top" headers="construct posix"><tt>\p{ASCII}</tt></td>
185 * <td headers="matches">All ASCII:<tt>[\x00-\x7F]</tt></td></tr>
186 * <tr><td valign="top" headers="construct posix"><tt>\p{Alpha}</tt></td>
187 * <td headers="matches">An alphabetic character:<tt>[\p{Lower}\p{Upper}]</tt></td></tr>
188 * <tr><td valign="top" headers="construct posix"><tt>\p{Digit}</tt></td>
189 * <td headers="matches">A decimal digit: <tt>[0-9]</tt></td></tr>
190 * <tr><td valign="top" headers="construct posix"><tt>\p{Alnum}</tt></td>
191 * <td headers="matches">An alphanumeric character:<tt>[\p{Alpha}\p{Digit}]</tt></td></tr>
192 * <tr><td valign="top" headers="construct posix"><tt>\p{Punct}</tt></td>
193 * <td headers="matches">Punctuation: One of <tt>!"#$%&'()*+,-./:;<=>?@[\]^_`{|}~</tt></td></tr>
194 * <!-- <tt>[\!"#\$%&'\(\)\*\+,\-\./:;\<=\>\?@\[\\\]\^_`\{\|\}~]</tt>
195 * <tt>[\X21-\X2F\X31-\X40\X5B-\X60\X7B-\X7E]</tt> -->
196 * <tr><td valign="top" headers="construct posix"><tt>\p{Graph}</tt></td>
197 * <td headers="matches">A visible character: <tt>[\p{Alnum}\p{Punct}]</tt></td></tr>
198 * <tr><td valign="top" headers="construct posix"><tt>\p{Print}</tt></td>
199 * <td headers="matches">A printable character: <tt>[\p{Graph}\x20]</tt></td></tr>
200 * <tr><td valign="top" headers="construct posix"><tt>\p{Blank}</tt></td>
201 * <td headers="matches">A space or a tab: <tt>[ \t]</tt></td></tr>
202 * <tr><td valign="top" headers="construct posix"><tt>\p{Cntrl}</tt></td>
203 * <td headers="matches">A control character: <tt>[\x00-\x1F\x7F]</tt></td></tr>
204 * <tr><td valign="top" headers="construct posix"><tt>\p{XDigit}</tt></td>
205 * <td headers="matches">A hexadecimal digit: <tt>[0-9a-fA-F]</tt></td></tr>
206 * <tr><td valign="top" headers="construct posix"><tt>\p{Space}</tt></td>
207 * <td headers="matches">A whitespace character: <tt>[ \t\n\x0B\f\r]</tt></td></tr>
208 *
209 * <tr><th> </th></tr>
210 * <tr align="left"><th colspan="2">java.lang.Character classes (simple <a href="#jcc">java character type</a>)</th></tr>
211 *
212 * <tr><td valign="top"><tt>\p{javaLowerCase}</tt></td>
213 * <td>Equivalent to java.lang.Character.isLowerCase()</td></tr>
214 * <tr><td valign="top"><tt>\p{javaUpperCase}</tt></td>
215 * <td>Equivalent to java.lang.Character.isUpperCase()</td></tr>
216 * <tr><td valign="top"><tt>\p{javaWhitespace}</tt></td>
217 * <td>Equivalent to java.lang.Character.isWhitespace()</td></tr>
218 * <tr><td valign="top"><tt>\p{javaMirrored}</tt></td>
219 * <td>Equivalent to java.lang.Character.isMirrored()</td></tr>
220 *
221 * <tr><th> </th></tr>
222 * <tr align="left"><th colspan="2" id="unicode">Classes for Unicode scripts, blocks, categories and binary properties</th></tr>
223 * * <tr><td valign="top" headers="construct unicode"><tt>\p{IsLatin}</tt></td>
224 * <td headers="matches">A Latin script character (<a href="#usc">script</a>)</td></tr>
225 * <tr><td valign="top" headers="construct unicode"><tt>\p{InGreek}</tt></td>
226 * <td headers="matches">A character in the Greek block (<a href="#ubc">block</a>)</td></tr>
227 * <tr><td valign="top" headers="construct unicode"><tt>\p{Lu}</tt></td>
228 * <td headers="matches">An uppercase letter (<a href="#ucc">category</a>)</td></tr>
229 * <tr><td valign="top" headers="construct unicode"><tt>\p{IsAlphabetic}</tt></td>
230 * <td headers="matches">An alphabetic character (<a href="#ubpc">binary property</a>)</td></tr>
231 * <tr><td valign="top" headers="construct unicode"><tt>\p{Sc}</tt></td>
232 * <td headers="matches">A currency symbol</td></tr>
233 * <tr><td valign="top" headers="construct unicode"><tt>\P{InGreek}</tt></td>
234 * <td headers="matches">Any character except one in the Greek block (negation)</td></tr>
235 * <tr><td valign="top" headers="construct unicode"><tt>[\p{L}&&[^\p{Lu}]] </tt></td>
236 * <td headers="matches">Any letter except an uppercase letter (subtraction)</td></tr>
237 *
238 * <tr><th> </th></tr>
239 * <tr align="left"><th colspan="2" id="bounds">Boundary matchers</th></tr>
240 *
241 * <tr><td valign="top" headers="construct bounds"><tt>^</tt></td>
242 * <td headers="matches">The beginning of a line</td></tr>
243 * <tr><td valign="top" headers="construct bounds"><tt>$</tt></td>
244 * <td headers="matches">The end of a line</td></tr>
245 * <tr><td valign="top" headers="construct bounds"><tt>\b</tt></td>
246 * <td headers="matches">A word boundary</td></tr>
247 * <tr><td valign="top" headers="construct bounds"><tt>\B</tt></td>
248 * <td headers="matches">A non-word boundary</td></tr>
249 * <tr><td valign="top" headers="construct bounds"><tt>\A</tt></td>
250 * <td headers="matches">The beginning of the input</td></tr>
251 * <tr><td valign="top" headers="construct bounds"><tt>\G</tt></td>
252 * <td headers="matches">The end of the previous match</td></tr>
253 * <tr><td valign="top" headers="construct bounds"><tt>\Z</tt></td>
254 * <td headers="matches">The end of the input but for the final
255 * <a href="#lt">terminator</a>, if any</td></tr>
256 * <tr><td valign="top" headers="construct bounds"><tt>\z</tt></td>
257 * <td headers="matches">The end of the input</td></tr>
258 *
259 * <tr><th> </th></tr>
260 * <tr align="left"><th colspan="2" id="lineending">Linebreak matcher</th></tr>
261 * <tr><td valign="top" headers="construct lineending"><tt>\R</tt></td>
262 * <td headers="matches">Any Unicode linebreak sequence, is equivalent to
263 * <tt>\u000D\u000A|[\u000A\u000B\u000C\u000D\u0085\u2028\u2029]
264 * </tt></td></tr>
265 *
266 * <tr><th> </th></tr>
267 * <tr align="left"><th colspan="2" id="greedy">Greedy quantifiers</th></tr>
268 *
269 * <tr><td valign="top" headers="construct greedy"><i>X</i><tt>?</tt></td>
270 * <td headers="matches"><i>X</i>, once or not at all</td></tr>
271 * <tr><td valign="top" headers="construct greedy"><i>X</i><tt>*</tt></td>
272 * <td headers="matches"><i>X</i>, zero or more times</td></tr>
273 * <tr><td valign="top" headers="construct greedy"><i>X</i><tt>+</tt></td>
274 * <td headers="matches"><i>X</i>, one or more times</td></tr>
275 * <tr><td valign="top" headers="construct greedy"><i>X</i><tt>{</tt><i>n</i><tt>}</tt></td>
276 * <td headers="matches"><i>X</i>, exactly <i>n</i> times</td></tr>
277 * <tr><td valign="top" headers="construct greedy"><i>X</i><tt>{</tt><i>n</i><tt>,}</tt></td>
278 * <td headers="matches"><i>X</i>, at least <i>n</i> times</td></tr>
279 * <tr><td valign="top" headers="construct greedy"><i>X</i><tt>{</tt><i>n</i><tt>,</tt><i>m</i><tt>}</tt></td>
280 * <td headers="matches"><i>X</i>, at least <i>n</i> but not more than <i>m</i> times</td></tr>
281 *
282 * <tr><th> </th></tr>
283 * <tr align="left"><th colspan="2" id="reluc">Reluctant quantifiers</th></tr>
284 *
285 * <tr><td valign="top" headers="construct reluc"><i>X</i><tt>??</tt></td>
286 * <td headers="matches"><i>X</i>, once or not at all</td></tr>
287 * <tr><td valign="top" headers="construct reluc"><i>X</i><tt>*?</tt></td>
288 * <td headers="matches"><i>X</i>, zero or more times</td></tr>
289 * <tr><td valign="top" headers="construct reluc"><i>X</i><tt>+?</tt></td>
290 * <td headers="matches"><i>X</i>, one or more times</td></tr>
291 * <tr><td valign="top" headers="construct reluc"><i>X</i><tt>{</tt><i>n</i><tt>}?</tt></td>
292 * <td headers="matches"><i>X</i>, exactly <i>n</i> times</td></tr>
293 * <tr><td valign="top" headers="construct reluc"><i>X</i><tt>{</tt><i>n</i><tt>,}?</tt></td>
294 * <td headers="matches"><i>X</i>, at least <i>n</i> times</td></tr>
295 * <tr><td valign="top" headers="construct reluc"><i>X</i><tt>{</tt><i>n</i><tt>,</tt><i>m</i><tt>}?</tt></td>
296 * <td headers="matches"><i>X</i>, at least <i>n</i> but not more than <i>m</i> times</td></tr>
297 *
298 * <tr><th> </th></tr>
299 * <tr align="left"><th colspan="2" id="poss">Possessive quantifiers</th></tr>
300 *
301 * <tr><td valign="top" headers="construct poss"><i>X</i><tt>?+</tt></td>
302 * <td headers="matches"><i>X</i>, once or not at all</td></tr>
303 * <tr><td valign="top" headers="construct poss"><i>X</i><tt>*+</tt></td>
304 * <td headers="matches"><i>X</i>, zero or more times</td></tr>
305 * <tr><td valign="top" headers="construct poss"><i>X</i><tt>++</tt></td>
306 * <td headers="matches"><i>X</i>, one or more times</td></tr>
307 * <tr><td valign="top" headers="construct poss"><i>X</i><tt>{</tt><i>n</i><tt>}+</tt></td>
308 * <td headers="matches"><i>X</i>, exactly <i>n</i> times</td></tr>
309 * <tr><td valign="top" headers="construct poss"><i>X</i><tt>{</tt><i>n</i><tt>,}+</tt></td>
310 * <td headers="matches"><i>X</i>, at least <i>n</i> times</td></tr>
311 * <tr><td valign="top" headers="construct poss"><i>X</i><tt>{</tt><i>n</i><tt>,</tt><i>m</i><tt>}+</tt></td>
312 * <td headers="matches"><i>X</i>, at least <i>n</i> but not more than <i>m</i> times</td></tr>
313 *
314 * <tr><th> </th></tr>
315 * <tr align="left"><th colspan="2" id="logical">Logical operators</th></tr>
316 *
317 * <tr><td valign="top" headers="construct logical"><i>XY</i></td>
318 * <td headers="matches"><i>X</i> followed by <i>Y</i></td></tr>
319 * <tr><td valign="top" headers="construct logical"><i>X</i><tt>|</tt><i>Y</i></td>
320 * <td headers="matches">Either <i>X</i> or <i>Y</i></td></tr>
321 * <tr><td valign="top" headers="construct logical"><tt>(</tt><i>X</i><tt>)</tt></td>
322 * <td headers="matches">X, as a <a href="#cg">capturing group</a></td></tr>
323 *
324 * <tr><th> </th></tr>
325 * <tr align="left"><th colspan="2" id="backref">Back references</th></tr>
326 *
327 * <tr><td valign="bottom" headers="construct backref"><tt>\</tt><i>n</i></td>
328 * <td valign="bottom" headers="matches">Whatever the <i>n</i><sup>th</sup>
329 * <a href="#cg">capturing group</a> matched</td></tr>
330 *
331 * <tr><td valign="bottom" headers="construct backref"><tt>\</tt><i>k</i><<i>name</i>></td>
332 * <td valign="bottom" headers="matches">Whatever the
333 * <a href="#groupname">named-capturing group</a> "name" matched</td></tr>
334 *
335 * <tr><th> </th></tr>
336 * <tr align="left"><th colspan="2" id="quot">Quotation</th></tr>
337 *
338 * <tr><td valign="top" headers="construct quot"><tt>\</tt></td>
339 * <td headers="matches">Nothing, but quotes the following character</td></tr>
340 * <tr><td valign="top" headers="construct quot"><tt>\Q</tt></td>
341 * <td headers="matches">Nothing, but quotes all characters until <tt>\E</tt></td></tr>
342 * <tr><td valign="top" headers="construct quot"><tt>\E</tt></td>
343 * <td headers="matches">Nothing, but ends quoting started by <tt>\Q</tt></td></tr>
344 * <!-- Metachars: !$()*+.<>?[\]^{|} -->
345 *
346 * <tr><th> </th></tr>
347 * <tr align="left"><th colspan="2" id="special">Special constructs (named-capturing and non-capturing)</th></tr>
348 *
349 * <tr><td valign="top" headers="construct special"><tt>(?<<a href="#groupname">name</a>></tt><i>X</i><tt>)</tt></td>
350 * <td headers="matches"><i>X</i>, as a named-capturing group</td></tr>
351 * <tr><td valign="top" headers="construct special"><tt>(?:</tt><i>X</i><tt>)</tt></td>
352 * <td headers="matches"><i>X</i>, as a non-capturing group</td></tr>
353 * <tr><td valign="top" headers="construct special"><tt>(?idmsuxU-idmsuxU) </tt></td>
354 * <td headers="matches">Nothing, but turns match flags <a href="#CASE_INSENSITIVE">i</a>
355 * <a href="#UNIX_LINES">d</a> <a href="#MULTILINE">m</a> <a href="#DOTALL">s</a>
356 * <a href="#UNICODE_CASE">u</a> <a href="#COMMENTS">x</a> <a href="#UNICODE_CHARACTER_CLASS">U</a>
357 * on - off</td></tr>
358 * <tr><td valign="top" headers="construct special"><tt>(?idmsux-idmsux:</tt><i>X</i><tt>)</tt> </td>
359 * <td headers="matches"><i>X</i>, as a <a href="#cg">non-capturing group</a> with the
360 * given flags <a href="#CASE_INSENSITIVE">i</a> <a href="#UNIX_LINES">d</a>
361 * <a href="#MULTILINE">m</a> <a href="#DOTALL">s</a> <a href="#UNICODE_CASE">u</a >
362 * <a href="#COMMENTS">x</a> on - off</td></tr>
363 * <tr><td valign="top" headers="construct special"><tt>(?=</tt><i>X</i><tt>)</tt></td>
364 * <td headers="matches"><i>X</i>, via zero-width positive lookahead</td></tr>
365 * <tr><td valign="top" headers="construct special"><tt>(?!</tt><i>X</i><tt>)</tt></td>
366 * <td headers="matches"><i>X</i>, via zero-width negative lookahead</td></tr>
367 * <tr><td valign="top" headers="construct special"><tt>(?<=</tt><i>X</i><tt>)</tt></td>
368 * <td headers="matches"><i>X</i>, via zero-width positive lookbehind</td></tr>
369 * <tr><td valign="top" headers="construct special"><tt>(?<!</tt><i>X</i><tt>)</tt></td>
370 * <td headers="matches"><i>X</i>, via zero-width negative lookbehind</td></tr>
371 * <tr><td valign="top" headers="construct special"><tt>(?></tt><i>X</i><tt>)</tt></td>
372 * <td headers="matches"><i>X</i>, as an independent, non-capturing group</td></tr>
373 *
374 * </table>
375 *
376 * <hr>
377 *
378 *
379 * <a name="bs">
380 * <h4> Backslashes, escapes, and quoting </h4>
381 *
382 * <p> The backslash character (<tt>'\'</tt>) serves to introduce escaped
383 * constructs, as defined in the table above, as well as to quote characters
384 * that otherwise would be interpreted as unescaped constructs. Thus the
385 * expression <tt>\\</tt> matches a single backslash and <tt>\{</tt> matches a
386 * left brace.
387 *
388 * <p> It is an error to use a backslash prior to any alphabetic character that
389 * does not denote an escaped construct; these are reserved for future
390 * extensions to the regular-expression language. A backslash may be used
391 * prior to a non-alphabetic character regardless of whether that character is
392 * part of an unescaped construct.
393 *
394 * <p> Backslashes within string literals in Java source code are interpreted
395 * as required by
396 * <cite>The Java™ Language Specification</cite>
397 * as either Unicode escapes (section 3.3) or other character escapes (section 3.10.6)
398 * It is therefore necessary to double backslashes in string
399 * literals that represent regular expressions to protect them from
400 * interpretation by the Java bytecode compiler. The string literal
401 * <tt>"\b"</tt>, for example, matches a single backspace character when
402 * interpreted as a regular expression, while <tt>"\\b"</tt> matches a
403 * word boundary. The string literal <tt>"\(hello\)"</tt> is illegal
404 * and leads to a compile-time error; in order to match the string
405 * <tt>(hello)</tt> the string literal <tt>"\\(hello\\)"</tt>
406 * must be used.
407 *
408 * <a name="cc">
409 * <h4> Character Classes </h4>
410 *
411 * <p> Character classes may appear within other character classes, and
412 * may be composed by the union operator (implicit) and the intersection
413 * operator (<tt>&&</tt>).
414 * The union operator denotes a class that contains every character that is
415 * in at least one of its operand classes. The intersection operator
416 * denotes a class that contains every character that is in both of its
417 * operand classes.
418 *
419 * <p> The precedence of character-class operators is as follows, from
420 * highest to lowest:
421 *
422 * <blockquote><table border="0" cellpadding="1" cellspacing="0"
423 * summary="Precedence of character class operators.">
424 * <tr><th>1 </th>
425 * <td>Literal escape </td>
426 * <td><tt>\x</tt></td></tr>
427 * <tr><th>2 </th>
428 * <td>Grouping</td>
429 * <td><tt>[...]</tt></td></tr>
430 * <tr><th>3 </th>
431 * <td>Range</td>
432 * <td><tt>a-z</tt></td></tr>
433 * <tr><th>4 </th>
434 * <td>Union</td>
435 * <td><tt>[a-e][i-u]</tt></td></tr>
436 * <tr><th>5 </th>
437 * <td>Intersection</td>
438 * <td><tt>[a-z&&[aeiou]]</tt></td></tr>
439 * </table></blockquote>
440 *
441 * <p> Note that a different set of metacharacters are in effect inside
442 * a character class than outside a character class. For instance, the
443 * regular expression <tt>.</tt> loses its special meaning inside a
444 * character class, while the expression <tt>-</tt> becomes a range
445 * forming metacharacter.
446 *
447 * <a name="lt">
448 * <h4> Line terminators </h4>
449 *
450 * <p> A <i>line terminator</i> is a one- or two-character sequence that marks
451 * the end of a line of the input character sequence. The following are
452 * recognized as line terminators:
453 *
454 * <ul>
455 *
456 * <li> A newline (line feed) character (<tt>'\n'</tt>),
457 *
458 * <li> A carriage-return character followed immediately by a newline
459 * character (<tt>"\r\n"</tt>),
460 *
461 * <li> A standalone carriage-return character (<tt>'\r'</tt>),
462 *
463 * <li> A next-line character (<tt>'\u0085'</tt>),
464 *
465 * <li> A line-separator character (<tt>'\u2028'</tt>), or
466 *
467 * <li> A paragraph-separator character (<tt>'\u2029</tt>).
468 *
469 * </ul>
470 * <p>If {@link #UNIX_LINES} mode is activated, then the only line terminators
471 * recognized are newline characters.
472 *
473 * <p> The regular expression <tt>.</tt> matches any character except a line
474 * terminator unless the {@link #DOTALL} flag is specified.
475 *
476 * <p> By default, the regular expressions <tt>^</tt> and <tt>$</tt> ignore
477 * line terminators and only match at the beginning and the end, respectively,
478 * of the entire input sequence. If {@link #MULTILINE} mode is activated then
479 * <tt>^</tt> matches at the beginning of input and after any line terminator
480 * except at the end of input. When in {@link #MULTILINE} mode <tt>$</tt>
481 * matches just before a line terminator or the end of the input sequence.
482 *
483 * <a name="cg">
484 * <h4> Groups and capturing </h4>
485 *
486 * <a name="gnumber">
487 * <h5> Group number </h5>
488 * <p> Capturing groups are numbered by counting their opening parentheses from
489 * left to right. In the expression <tt>((A)(B(C)))</tt>, for example, there
490 * are four such groups: </p>
491 *
492 * <blockquote><table cellpadding=1 cellspacing=0 summary="Capturing group numberings">
493 * <tr><th>1 </th>
494 * <td><tt>((A)(B(C)))</tt></td></tr>
495 * <tr><th>2 </th>
496 * <td><tt>(A)</tt></td></tr>
497 * <tr><th>3 </th>
498 * <td><tt>(B(C))</tt></td></tr>
499 * <tr><th>4 </th>
500 * <td><tt>(C)</tt></td></tr>
501 * </table></blockquote>
502 *
503 * <p> Group zero always stands for the entire expression.
504 *
505 * <p> Capturing groups are so named because, during a match, each subsequence
506 * of the input sequence that matches such a group is saved. The captured
507 * subsequence may be used later in the expression, via a back reference, and
508 * may also be retrieved from the matcher once the match operation is complete.
509 *
510 * <a name="groupname">
511 * <h5> Group name </h5>
512 * <p>A capturing group can also be assigned a "name", a <tt>named-capturing group</tt>,
513 * and then be back-referenced later by the "name". Group names are composed of
514 * the following characters. The first character must be a <tt>letter</tt>.
515 *
516 * <ul>
517 * <li> The uppercase letters <tt>'A'</tt> through <tt>'Z'</tt>
518 * (<tt>'\u0041'</tt> through <tt>'\u005a'</tt>),
519 * <li> The lowercase letters <tt>'a'</tt> through <tt>'z'</tt>
520 * (<tt>'\u0061'</tt> through <tt>'\u007a'</tt>),
521 * <li> The digits <tt>'0'</tt> through <tt>'9'</tt>
522 * (<tt>'\u0030'</tt> through <tt>'\u0039'</tt>),
523 * </ul>
524 *
525 * <p> A <tt>named-capturing group</tt> is still numbered as described in
526 * <a href="#gnumber">Group number</a>.
527 *
528 * <p> The captured input associated with a group is always the subsequence
529 * that the group most recently matched. If a group is evaluated a second time
530 * because of quantification then its previously-captured value, if any, will
531 * be retained if the second evaluation fails. Matching the string
532 * <tt>"aba"</tt> against the expression <tt>(a(b)?)+</tt>, for example, leaves
533 * group two set to <tt>"b"</tt>. All captured input is discarded at the
534 * beginning of each match.
535 *
536 * <p> Groups beginning with <tt>(?</tt> are either pure, <i>non-capturing</i> groups
537 * that do not capture text and do not count towards the group total, or
538 * <i>named-capturing</i> group.
539 *
540 * <h4> Unicode support </h4>
541 *
542 * <p> This class is in conformance with Level 1 of <a
543 * href="http://www.unicode.org/reports/tr18/"><i>Unicode Technical
544 * Standard #18: Unicode Regular Expression</i></a>, plus RL2.1
545 * Canonical Equivalents.
546 * <p>
547 * <b>Unicode escape sequences</b> such as <tt>\u2014</tt> in Java source code
548 * are processed as described in section 3.3 of
549 * <cite>The Java™ Language Specification</cite>.
550 * Such escape sequences are also implemented directly by the regular-expression
551 * parser so that Unicode escapes can be used in expressions that are read from
552 * files or from the keyboard. Thus the strings <tt>"\u2014"</tt> and
553 * <tt>"\\u2014"</tt>, while not equal, compile into the same pattern, which
554 * matches the character with hexadecimal value <tt>0x2014</tt>.
555 * <p>
556 * A Unicode character can also be represented in a regular-expression by
557 * using its <b>Hex notation</b>(hexadecimal code point value) directly as described in construct
558 * <tt>\x{...}</tt>, for example a supplementary character U+2011F
559 * can be specified as <tt>\x{2011F}</tt>, instead of two consecutive
560 * Unicode escape sequences of the surrogate pair
561 * <tt>\uD840</tt><tt>\uDD1F</tt>.
562 * <p>
563 * Unicode scripts, blocks, categories and binary properties are written with
564 * the <tt>\p</tt> and <tt>\P</tt> constructs as in Perl.
565 * <tt>\p{</tt><i>prop</i><tt>}</tt> matches if
566 * the input has the property <i>prop</i>, while <tt>\P{</tt><i>prop</i><tt>}</tt>
567 * does not match if the input has that property.
568 * <p>
569 * Scripts, blocks, categories and binary properties can be used both inside
570 * and outside of a character class.
571 * <a name="usc">
572 * <p>
573 * <b>Scripts</b> are specified either with the prefix {@code Is}, as in
574 * {@code IsHiragana}, or by using the {@code script} keyword (or its short
575 * form {@code sc})as in {@code script=Hiragana} or {@code sc=Hiragana}.
576 * <p>
577 * The script names supported by <code>Pattern</code> are the valid script names
578 * accepted and defined by
579 * {@link java.lang.Character.UnicodeScript#forName(String) UnicodeScript.forName}.
580 * <a name="ubc">
581 * <p>
582 * <b>Blocks</b> are specified with the prefix {@code In}, as in
583 * {@code InMongolian}, or by using the keyword {@code block} (or its short
584 * form {@code blk}) as in {@code block=Mongolian} or {@code blk=Mongolian}.
585 * <p>
586 * The block names supported by <code>Pattern</code> are the valid block names
587 * accepted and defined by
588 * {@link java.lang.Character.UnicodeBlock#forName(String) UnicodeBlock.forName}.
589 * <p>
590 * <a name="ucc">
591 * <b>Categories</b> may be specified with the optional prefix {@code Is}:
592 * Both {@code \p{L}} and {@code \p{IsL}} denote the category of Unicode
593 * letters. Same as scripts and blocks, categories can also be specified
594 * by using the keyword {@code general_category} (or its short form
595 * {@code gc}) as in {@code general_category=Lu} or {@code gc=Lu}.
596 * <p>
597 * The supported categories are those of
598 * <a href="http://www.unicode.org/unicode/standard/standard.html">
599 * <i>The Unicode Standard</i></a> in the version specified by the
600 * {@link java.lang.Character Character} class. The category names are those
601 * defined in the Standard, both normative and informative.
602 * <p>
603 * <a name="ubpc">
604 * <b>Binary properties</b> are specified with the prefix {@code Is}, as in
605 * {@code IsAlphabetic}. The supported binary properties by <code>Pattern</code>
606 * are
607 * <ul>
608 * <li> Alphabetic
609 * <li> Ideographic
610 * <li> Letter
611 * <li> Lowercase
612 * <li> Uppercase
613 * <li> Titlecase
614 * <li> Punctuation
615 * <Li> Control
616 * <li> White_Space
617 * <li> Digit
618 * <li> Hex_Digit
619 * <li> Join_Control
620 * <li> Noncharacter_Code_Point
621 * <li> Assigned
622 * </ul>
623 * <p>
624 * The following <b>Predefined Character classes</b> and <b>POSIX character classes</b>
625 * are in conformance with the recommendation of <i>Annex C: Compatibility Properties</i>
626 * of <a href="http://www.unicode.org/reports/tr18/"><i>Unicode Regular Expression
627 * </i></a>, when {@link #UNICODE_CHARACTER_CLASS} flag is specified.
628 * <p>
629 * <table border="0" cellpadding="1" cellspacing="0"
630 * summary="predefined and posix character classes in Unicode mode">
631 * <tr align="left">
632 * <th bgcolor="#CCCCFF" align="left" id="classes">Classes</th>
633 * <th bgcolor="#CCCCFF" align="left" id="matches">Matches</th>
634 *</tr>
635 * <tr><td><tt>\p{Lower}</tt></td>
636 * <td>A lowercase character:<tt>\p{IsLowercase}</tt></td></tr>
637 * <tr><td><tt>\p{Upper}</tt></td>
638 * <td>An uppercase character:<tt>\p{IsUppercase}</tt></td></tr>
639 * <tr><td><tt>\p{ASCII}</tt></td>
640 * <td>All ASCII:<tt>[\x00-\x7F]</tt></td></tr>
641 * <tr><td><tt>\p{Alpha}</tt></td>
642 * <td>An alphabetic character:<tt>\p{IsAlphabetic}</tt></td></tr>
643 * <tr><td><tt>\p{Digit}</tt></td>
644 * <td>A decimal digit character:<tt>p{IsDigit}</tt></td></tr>
645 * <tr><td><tt>\p{Alnum}</tt></td>
646 * <td>An alphanumeric character:<tt>[\p{IsAlphabetic}\p{IsDigit}]</tt></td></tr>
647 * <tr><td><tt>\p{Punct}</tt></td>
648 * <td>A punctuation character:<tt>p{IsPunctuation}</tt></td></tr>
649 * <tr><td><tt>\p{Graph}</tt></td>
650 * <td>A visible character: <tt>[^\p{IsWhite_Space}\p{gc=Cc}\p{gc=Cs}\p{gc=Cn}]</tt></td></tr>
651 * <tr><td><tt>\p{Print}</tt></td>
652 * <td>A printable character: <tt>[\p{Graph}\p{Blank}&&[^\p{Cntrl}]]</tt></td></tr>
653 * <tr><td><tt>\p{Blank}</tt></td>
654 * <td>A space or a tab: <tt>[\p{IsWhite_Space}&&[^\p{gc=Zl}\p{gc=Zp}\x0a\x0b\x0c\x0d\x85]]</tt></td></tr>
655 * <tr><td><tt>\p{Cntrl}</tt></td>
656 * <td>A control character: <tt>\p{gc=Cc}</tt></td></tr>
657 * <tr><td><tt>\p{XDigit}</tt></td>
658 * <td>A hexadecimal digit: <tt>[\p{gc=Nd}\p{IsHex_Digit}]</tt></td></tr>
659 * <tr><td><tt>\p{Space}</tt></td>
660 * <td>A whitespace character:<tt>\p{IsWhite_Space}</tt></td></tr>
661 * <tr><td><tt>\d</tt></td>
662 * <td>A digit: <tt>\p{IsDigit}</tt></td></tr>
663 * <tr><td><tt>\D</tt></td>
664 * <td>A non-digit: <tt>[^\d]</tt></td></tr>
665 * <tr><td><tt>\s</tt></td>
666 * <td>A whitespace character: <tt>\p{IsWhite_Space}</tt></td></tr>
667 * <tr><td><tt>\S</tt></td>
668 * <td>A non-whitespace character: <tt>[^\s]</tt></td></tr>
669 * <tr><td><tt>\w</tt></td>
670 * <td>A word character: <tt>[\p{Alpha}\p{gc=Mn}\p{gc=Me}\p{gc=Mc}\p{Digit}\p{gc=Pc}\p{IsJoin_Control}]</tt></td></tr>
671 * <tr><td><tt>\W</tt></td>
672 * <td>A non-word character: <tt>[^\w]</tt></td></tr>
673 * </table>
674 * <p>
675 * <a name="jcc">
676 * Categories that behave like the java.lang.Character
677 * boolean is<i>methodname</i> methods (except for the deprecated ones) are
678 * available through the same <tt>\p{</tt><i>prop</i><tt>}</tt> syntax where
679 * the specified property has the name <tt>java<i>methodname</i></tt>.
680 *
681 * <h4> Comparison to Perl 5 </h4>
682 *
683 * <p>The <code>Pattern</code> engine performs traditional NFA-based matching
684 * with ordered alternation as occurs in Perl 5.
685 *
686 * <p> Perl constructs not supported by this class: </p>
687 *
688 * <ul>
689 * <li><p> Predefined character classes (Unicode character)
690 * <p><tt>\X </tt>Match Unicode
691 * <a href="http://www.unicode.org/reports/tr18/#Default_Grapheme_Clusters">
692 * <i>extended grapheme cluster</i></a>
693 * </p></li>
694 *
695 * <li><p> The backreference constructs, <tt>\g{</tt><i>n</i><tt>}</tt> for
696 * the <i>n</i><sup>th</sup><a href="#cg">capturing group</a> and
697 * <tt>\g{</tt><i>name</i><tt>}</tt> for
698 * <a href="#groupname">named-capturing group</a>.
699 * </p></li>
700 *
701 * <li><p> The named character construct, <tt>\N{</tt><i>name</i><tt>}</tt>
702 * for a Unicode character by its name.
703 * </p></li>
704 *
705 * <li><p> The conditional constructs
706 * <tt>(?(</tt><i>condition</i><tt>)</tt><i>X</i><tt>)</tt> and
707 * <tt>(?(</tt><i>condition</i><tt>)</tt><i>X</i><tt>|</tt><i>Y</i><tt>)</tt>,
708 * </p></li>
709 *
710 * <li><p> The embedded code constructs <tt>(?{</tt><i>code</i><tt>})</tt>
711 * and <tt>(??{</tt><i>code</i><tt>})</tt>,</p></li>
712 *
713 * <li><p> The embedded comment syntax <tt>(?#comment)</tt>, and </p></li>
714 *
715 * <li><p> The preprocessing operations <tt>\l</tt> <tt>\u</tt>,
716 * <tt>\L</tt>, and <tt>\U</tt>. </p></li>
717 *
718 * </ul>
719 *
720 * <p> Constructs supported by this class but not by Perl: </p>
721 *
722 * <ul>
723 *
724 * <li><p> Character-class union and intersection as described
725 * <a href="#cc">above</a>.</p></li>
726 *
727 * </ul>
728 *
729 * <p> Notable differences from Perl: </p>
730 *
731 * <ul>
732 *
733 * <li><p> In Perl, <tt>\1</tt> through <tt>\9</tt> are always interpreted
734 * as back references; a backslash-escaped number greater than <tt>9</tt> is
735 * treated as a back reference if at least that many subexpressions exist,
736 * otherwise it is interpreted, if possible, as an octal escape. In this
737 * class octal escapes must always begin with a zero. In this class,
738 * <tt>\1</tt> through <tt>\9</tt> are always interpreted as back
739 * references, and a larger number is accepted as a back reference if at
740 * least that many subexpressions exist at that point in the regular
741 * expression, otherwise the parser will drop digits until the number is
742 * smaller or equal to the existing number of groups or it is one digit.
743 * </p></li>
744 *
745 * <li><p> Perl uses the <tt>g</tt> flag to request a match that resumes
746 * where the last match left off. This functionality is provided implicitly
747 * by the {@link Matcher} class: Repeated invocations of the {@link
748 * Matcher#find find} method will resume where the last match left off,
749 * unless the matcher is reset. </p></li>
750 *
751 * <li><p> In Perl, embedded flags at the top level of an expression affect
752 * the whole expression. In this class, embedded flags always take effect
753 * at the point at which they appear, whether they are at the top level or
754 * within a group; in the latter case, flags are restored at the end of the
755 * group just as in Perl. </p></li>
756 *
757 * </ul>
758 *
759 *
760 * <p> For a more precise description of the behavior of regular expression
761 * constructs, please see <a href="http://www.oreilly.com/catalog/regex3/">
762 * <i>Mastering Regular Expressions, 3nd Edition</i>, Jeffrey E. F. Friedl,
763 * O'Reilly and Associates, 2006.</a>
764 * </p>
765 *
766 * @see java.lang.String#split(String, int)
767 * @see java.lang.String#split(String)
768 *
769 * @author Mike McCloskey
770 * @author Mark Reinhold
771 * @author JSR-51 Expert Group
772 * @since 1.4
773 * @spec JSR-51
774 */
775
776 public final class Pattern
777 implements java.io.Serializable
778 {
779
780 /**
781 * Regular expression modifier values. Instead of being passed as
782 * arguments, they can also be passed as inline modifiers.
783 * For example, the following statements have the same effect.
784 * <pre>
785 * RegExp r1 = RegExp.compile("abc", Pattern.I|Pattern.M);
786 * RegExp r2 = RegExp.compile("(?im)abc", 0);
787 * </pre>
788 *
789 * The flags are duplicated so that the familiar Perl match flag
790 * names are available.
791 */
792
793 /**
794 * Enables Unix lines mode.
795 *
796 * <p> In this mode, only the <tt>'\n'</tt> line terminator is recognized
797 * in the behavior of <tt>.</tt>, <tt>^</tt>, and <tt>$</tt>.
798 *
799 * <p> Unix lines mode can also be enabled via the embedded flag
800 * expression <tt>(?d)</tt>.
801 */
802 public static final int UNIX_LINES = 0x01;
803
804 /**
805 * Enables case-insensitive matching.
806 *
807 * <p> By default, case-insensitive matching assumes that only characters
808 * in the US-ASCII charset are being matched. Unicode-aware
809 * case-insensitive matching can be enabled by specifying the {@link
810 * #UNICODE_CASE} flag in conjunction with this flag.
811 *
812 * <p> Case-insensitive matching can also be enabled via the embedded flag
813 * expression <tt>(?i)</tt>.
814 *
815 * <p> Specifying this flag may impose a slight performance penalty. </p>
816 */
817 public static final int CASE_INSENSITIVE = 0x02;
818
819 /**
820 * Permits whitespace and comments in pattern.
821 *
822 * <p> In this mode, whitespace is ignored, and embedded comments starting
823 * with <tt>#</tt> are ignored until the end of a line.
824 *
825 * <p> Comments mode can also be enabled via the embedded flag
826 * expression <tt>(?x)</tt>.
827 */
828 public static final int COMMENTS = 0x04;
829
830 /**
831 * Enables multiline mode.
832 *
833 * <p> In multiline mode the expressions <tt>^</tt> and <tt>$</tt> match
834 * just after or just before, respectively, a line terminator or the end of
835 * the input sequence. By default these expressions only match at the
836 * beginning and the end of the entire input sequence.
837 *
838 * <p> Multiline mode can also be enabled via the embedded flag
839 * expression <tt>(?m)</tt>. </p>
840 */
841 public static final int MULTILINE = 0x08;
842
843 /**
844 * Enables literal parsing of the pattern.
845 *
846 * <p> When this flag is specified then the input string that specifies
847 * the pattern is treated as a sequence of literal characters.
848 * Metacharacters or escape sequences in the input sequence will be
849 * given no special meaning.
850 *
851 * <p>The flags CASE_INSENSITIVE and UNICODE_CASE retain their impact on
852 * matching when used in conjunction with this flag. The other flags
853 * become superfluous.
854 *
855 * <p> There is no embedded flag character for enabling literal parsing.
856 * @since 1.5
857 */
858 public static final int LITERAL = 0x10;
859
860 /**
861 * Enables dotall mode.
862 *
863 * <p> In dotall mode, the expression <tt>.</tt> matches any character,
864 * including a line terminator. By default this expression does not match
865 * line terminators.
866 *
867 * <p> Dotall mode can also be enabled via the embedded flag
868 * expression <tt>(?s)</tt>. (The <tt>s</tt> is a mnemonic for
869 * "single-line" mode, which is what this is called in Perl.) </p>
870 */
871 public static final int DOTALL = 0x20;
872
873 /**
874 * Enables Unicode-aware case folding.
875 *
876 * <p> When this flag is specified then case-insensitive matching, when
877 * enabled by the {@link #CASE_INSENSITIVE} flag, is done in a manner
878 * consistent with the Unicode Standard. By default, case-insensitive
879 * matching assumes that only characters in the US-ASCII charset are being
880 * matched.
881 *
882 * <p> Unicode-aware case folding can also be enabled via the embedded flag
883 * expression <tt>(?u)</tt>.
884 *
885 * <p> Specifying this flag may impose a performance penalty. </p>
886 */
887 public static final int UNICODE_CASE = 0x40;
888
889 /**
890 * Enables canonical equivalence.
891 *
892 * <p> When this flag is specified then two characters will be considered
893 * to match if, and only if, their full canonical decompositions match.
894 * The expression <tt>"a\u030A"</tt>, for example, will match the
895 * string <tt>"\u00E5"</tt> when this flag is specified. By default,
896 * matching does not take canonical equivalence into account.
897 *
898 * <p> There is no embedded flag character for enabling canonical
899 * equivalence.
900 *
901 * <p> Specifying this flag may impose a performance penalty. </p>
902 */
903 public static final int CANON_EQ = 0x80;
904
905 /**
906 * Enables the Unicode version of <i>Predefined character classes</i> and
907 * <i>POSIX character classes</i>.
908 *
909 * <p> When this flag is specified then the (US-ASCII only)
910 * <i>Predefined character classes</i> and <i>POSIX character classes</i>
911 * are in conformance with
912 * <a href="http://www.unicode.org/reports/tr18/"><i>Unicode Technical
913 * Standard #18: Unicode Regular Expression</i></a>
914 * <i>Annex C: Compatibility Properties</i>.
915 * <p>
916 * The UNICODE_CHARACTER_CLASS mode can also be enabled via the embedded
917 * flag expression <tt>(?U)</tt>.
918 * <p>
919 * The flag implies UNICODE_CASE, that is, it enables Unicode-aware case
920 * folding.
921 * <p>
922 * Specifying this flag may impose a performance penalty. </p>
923 * @since 1.7
924 */
925 public static final int UNICODE_CHARACTER_CLASS = 0x100;
926
927 /* Pattern has only two serialized components: The pattern string
928 * and the flags, which are all that is needed to recompile the pattern
929 * when it is deserialized.
930 */
931
932 /** use serialVersionUID from Merlin b59 for interoperability */
933 private static final long serialVersionUID = 5073258162644648461L;
934
935 /**
936 * The original regular-expression pattern string.
937 *
938 * @serial
939 */
940 private String pattern;
941
942 /**
943 * The original pattern flags.
944 *
945 * @serial
946 */
947 private int flags;
948
949 /**
950 * Boolean indicating this Pattern is compiled; this is necessary in order
951 * to lazily compile deserialized Patterns.
952 */
953 private transient volatile boolean compiled = false;
954
955 /**
956 * The normalized pattern string.
957 */
958 private transient String normalizedPattern;
959
960 /**
961 * The starting point of state machine for the find operation. This allows
962 * a match to start anywhere in the input.
963 */
964 transient Node root;
965
966 /**
967 * The root of object tree for a match operation. The pattern is matched
968 * at the beginning. This may include a find that uses BnM or a First
969 * node.
970 */
971 transient Node matchRoot;
972
973 /**
974 * Temporary storage used by parsing pattern slice.
975 */
976 transient int[] buffer;
977
978 /**
979 * Map the "name" of the "named capturing group" to its group id
980 * node.
981 */
982 transient volatile Map<String, Integer> namedGroups;
983
984 /**
985 * Temporary storage used while parsing group references.
986 */
987 transient GroupHead[] groupNodes;
988
989 /**
990 * Temporary null terminated code point array used by pattern compiling.
991 */
992 private transient int[] temp;
993
994 /**
995 * The number of capturing groups in this Pattern. Used by matchers to
996 * allocate storage needed to perform a match.
997 */
998 transient int capturingGroupCount;
999
1000 /**
1001 * The local variable count used by parsing tree. Used by matchers to
1002 * allocate storage needed to perform a match.
1003 */
1004 transient int localCount;
1005
1006 /**
1007 * Index into the pattern string that keeps track of how much has been
1008 * parsed.
1009 */
1010 private transient int cursor;
1011
1012 /**
1013 * Holds the length of the pattern string.
1014 */
1015 private transient int patternLength;
1016
1017 /**
1018 * If the Start node might possibly match supplementary characters.
1019 * It is set to true during compiling if
1020 * (1) There is supplementary char in pattern, or
1021 * (2) There is complement node of Category or Block
1022 */
1023 private transient boolean hasSupplementary;
1024
1025 /**
1026 * Compiles the given regular expression into a pattern. </p>
1027 *
1028 * @param regex
1029 * The expression to be compiled
1030 *
1031 * @throws PatternSyntaxException
1032 * If the expression's syntax is invalid
1033 */
1034 public static Pattern compile(String regex) {
1035 return new Pattern(regex, 0);
1036 }
1037
1038 /**
1039 * Compiles the given regular expression into a pattern with the given
1040 * flags. </p>
1041 *
1042 * @param regex
1043 * The expression to be compiled
1044 *
1045 * @param flags
1046 * Match flags, a bit mask that may include
1047 * {@link #CASE_INSENSITIVE}, {@link #MULTILINE}, {@link #DOTALL},
1048 * {@link #UNICODE_CASE}, {@link #CANON_EQ}, {@link #UNIX_LINES},
1049 * {@link #LITERAL}, {@link #UNICODE_CHARACTER_CLASS}
1050 * and {@link #COMMENTS}
1051 *
1052 * @throws IllegalArgumentException
1053 * If bit values other than those corresponding to the defined
1054 * match flags are set in <tt>flags</tt>
1055 *
1056 * @throws PatternSyntaxException
1057 * If the expression's syntax is invalid
1058 */
1059 public static Pattern compile(String regex, int flags) {
1060 return new Pattern(regex, flags);
1061 }
1062
1063 /**
1064 * Returns the regular expression from which this pattern was compiled.
1065 * </p>
1066 *
1067 * @return The source of this pattern
1068 */
1069 public String pattern() {
1070 return pattern;
1071 }
1072
1073 /**
1074 * <p>Returns the string representation of this pattern. This
1075 * is the regular expression from which this pattern was
1076 * compiled.</p>
1077 *
1078 * @return The string representation of this pattern
1079 * @since 1.5
1080 */
1081 public String toString() {
1082 return pattern;
1083 }
1084
1085 /**
1086 * Creates a matcher that will match the given input against this pattern.
1087 * </p>
1088 *
1089 * @param input
1090 * The character sequence to be matched
1091 *
1092 * @return A new matcher for this pattern
1093 */
1094 public Matcher matcher(CharSequence input) {
1095 if (!compiled) {
1096 synchronized(this) {
1097 if (!compiled)
1098 compile();
1099 }
1100 }
1101 Matcher m = new Matcher(this, input);
1102 return m;
1103 }
1104
1105 /**
1106 * Returns this pattern's match flags. </p>
1107 *
1108 * @return The match flags specified when this pattern was compiled
1109 */
1110 public int flags() {
1111 return flags;
1112 }
1113
1114 /**
1115 * Compiles the given regular expression and attempts to match the given
1116 * input against it.
1117 *
1118 * <p> An invocation of this convenience method of the form
1119 *
1120 * <blockquote><pre>
1121 * Pattern.matches(regex, input);</pre></blockquote>
1122 *
1123 * behaves in exactly the same way as the expression
1124 *
1125 * <blockquote><pre>
1126 * Pattern.compile(regex).matcher(input).matches()</pre></blockquote>
1127 *
1128 * <p> If a pattern is to be used multiple times, compiling it once and reusing
1129 * it will be more efficient than invoking this method each time. </p>
1130 *
1131 * @param regex
1132 * The expression to be compiled
1133 *
1134 * @param input
1135 * The character sequence to be matched
1136 *
1137 * @throws PatternSyntaxException
1138 * If the expression's syntax is invalid
1139 */
1140 public static boolean matches(String regex, CharSequence input) {
1141 Pattern p = Pattern.compile(regex);
1142 Matcher m = p.matcher(input);
1143 return m.matches();
1144 }
1145
1146 /**
1147 * Splits the given input sequence around matches of this pattern.
1148 *
1149 * <p> The array returned by this method contains each substring of the
1150 * input sequence that is terminated by another subsequence that matches
1151 * this pattern or is terminated by the end of the input sequence. The
1152 * substrings in the array are in the order in which they occur in the
1153 * input. If this pattern does not match any subsequence of the input then
1154 * the resulting array has just one element, namely the input sequence in
1155 * string form.
1156 *
1157 * <p> The <tt>limit</tt> parameter controls the number of times the
1158 * pattern is applied and therefore affects the length of the resulting
1159 * array. If the limit <i>n</i> is greater than zero then the pattern
1160 * will be applied at most <i>n</i> - 1 times, the array's
1161 * length will be no greater than <i>n</i>, and the array's last entry
1162 * will contain all input beyond the last matched delimiter. If <i>n</i>
1163 * is non-positive then the pattern will be applied as many times as
1164 * possible and the array can have any length. If <i>n</i> is zero then
1165 * the pattern will be applied as many times as possible, the array can
1166 * have any length, and trailing empty strings will be discarded.
1167 *
1168 * <p> The input <tt>"boo:and:foo"</tt>, for example, yields the following
1169 * results with these parameters:
1170 *
1171 * <blockquote><table cellpadding=1 cellspacing=0
1172 * summary="Split examples showing regex, limit, and result">
1173 * <tr><th><P align="left"><i>Regex </i></th>
1174 * <th><P align="left"><i>Limit </i></th>
1175 * <th><P align="left"><i>Result </i></th></tr>
1176 * <tr><td align=center>:</td>
1177 * <td align=center>2</td>
1178 * <td><tt>{ "boo", "and:foo" }</tt></td></tr>
1179 * <tr><td align=center>:</td>
1180 * <td align=center>5</td>
1181 * <td><tt>{ "boo", "and", "foo" }</tt></td></tr>
1182 * <tr><td align=center>:</td>
1183 * <td align=center>-2</td>
1184 * <td><tt>{ "boo", "and", "foo" }</tt></td></tr>
1185 * <tr><td align=center>o</td>
1186 * <td align=center>5</td>
1187 * <td><tt>{ "b", "", ":and:f", "", "" }</tt></td></tr>
1188 * <tr><td align=center>o</td>
1189 * <td align=center>-2</td>
1190 * <td><tt>{ "b", "", ":and:f", "", "" }</tt></td></tr>
1191 * <tr><td align=center>o</td>
1192 * <td align=center>0</td>
1193 * <td><tt>{ "b", "", ":and:f" }</tt></td></tr>
1194 * </table></blockquote>
1195 *
1196 *
1197 * @param input
1198 * The character sequence to be split
1199 *
1200 * @param limit
1201 * The result threshold, as described above
1202 *
1203 * @return The array of strings computed by splitting the input
1204 * around matches of this pattern
1205 */
1206 public String[] split(CharSequence input, int limit) {
1207 int index = 0;
1208 boolean matchLimited = limit > 0;
1209 ArrayList<String> matchList = new ArrayList<>();
1210 Matcher m = matcher(input);
1211
1212 // Add segments before each match found
1213 while(m.find()) {
1214 if (!matchLimited || matchList.size() < limit - 1) {
1215 String match = input.subSequence(index, m.start()).toString();
1216 matchList.add(match);
1217 index = m.end();
1218 } else if (matchList.size() == limit - 1) { // last one
1219 String match = input.subSequence(index,
1220 input.length()).toString();
1221 matchList.add(match);
1222 index = m.end();
1223 }
1224 }
1225
1226 // If no match was found, return this
1227 if (index == 0)
1228 return new String[] {input.toString()};
1229
1230 // Add remaining segment
1231 if (!matchLimited || matchList.size() < limit)
1232 matchList.add(input.subSequence(index, input.length()).toString());
1233
1234 // Construct result
1235 int resultSize = matchList.size();
1236 if (limit == 0)
1237 while (resultSize > 0 && matchList.get(resultSize-1).equals(""))
1238 resultSize--;
1239 String[] result = new String[resultSize];
1240 return matchList.subList(0, resultSize).toArray(result);
1241 }
1242
1243 /**
1244 * Splits the given input sequence around matches of this pattern.
1245 *
1246 * <p> This method works as if by invoking the two-argument {@link
1247 * #split(java.lang.CharSequence, int) split} method with the given input
1248 * sequence and a limit argument of zero. Trailing empty strings are
1249 * therefore not included in the resulting array. </p>
1250 *
1251 * <p> The input <tt>"boo:and:foo"</tt>, for example, yields the following
1252 * results with these expressions:
1253 *
1254 * <blockquote><table cellpadding=1 cellspacing=0
1255 * summary="Split examples showing regex and result">
1256 * <tr><th><P align="left"><i>Regex </i></th>
1257 * <th><P align="left"><i>Result</i></th></tr>
1258 * <tr><td align=center>:</td>
1259 * <td><tt>{ "boo", "and", "foo" }</tt></td></tr>
1260 * <tr><td align=center>o</td>
1261 * <td><tt>{ "b", "", ":and:f" }</tt></td></tr>
1262 * </table></blockquote>
1263 *
1264 *
1265 * @param input
1266 * The character sequence to be split
1267 *
1268 * @return The array of strings computed by splitting the input
1269 * around matches of this pattern
1270 */
1271 public String[] split(CharSequence input) {
1272 return split(input, 0);
1273 }
1274
1275 /**
1276 * Returns a literal pattern <code>String</code> for the specified
1277 * <code>String</code>.
1278 *
1279 * <p>This method produces a <code>String</code> that can be used to
1280 * create a <code>Pattern</code> that would match the string
1281 * <code>s</code> as if it were a literal pattern.</p> Metacharacters
1282 * or escape sequences in the input sequence will be given no special
1283 * meaning.
1284 *
1285 * @param s The string to be literalized
1286 * @return A literal string replacement
1287 * @since 1.5
1288 */
1289 public static String quote(String s) {
1290 int slashEIndex = s.indexOf("\\E");
1291 if (slashEIndex == -1)
1292 return "\\Q" + s + "\\E";
1293
1294 StringBuilder sb = new StringBuilder(s.length() * 2);
1295 sb.append("\\Q");
1296 slashEIndex = 0;
1297 int current = 0;
1298 while ((slashEIndex = s.indexOf("\\E", current)) != -1) {
1299 sb.append(s.substring(current, slashEIndex));
1300 current = slashEIndex + 2;
1301 sb.append("\\E\\\\E\\Q");
1302 }
1303 sb.append(s.substring(current, s.length()));
1304 sb.append("\\E");
1305 return sb.toString();
1306 }
1307
1308 /**
1309 * Recompile the Pattern instance from a stream. The original pattern
1310 * string is read in and the object tree is recompiled from it.
1311 */
1312 private void readObject(java.io.ObjectInputStream s)
1313 throws java.io.IOException, ClassNotFoundException {
1314
1315 // Read in all fields
1316 s.defaultReadObject();
1317
1318 // Initialize counts
1319 capturingGroupCount = 1;
1320 localCount = 0;
1321
1322 // if length > 0, the Pattern is lazily compiled
1323 compiled = false;
1324 if (pattern.length() == 0) {
1325 root = new Start(lastAccept);
1326 matchRoot = lastAccept;
1327 compiled = true;
1328 }
1329 }
1330
1331 /**
1332 * This private constructor is used to create all Patterns. The pattern
1333 * string and match flags are all that is needed to completely describe
1334 * a Pattern. An empty pattern string results in an object tree with
1335 * only a Start node and a LastNode node.
1336 */
1337 private Pattern(String p, int f) {
1338 pattern = p;
1339 flags = f;
1340
1341 // to use UNICODE_CASE if UNICODE_CHARACTER_CLASS present
1342 if ((flags & UNICODE_CHARACTER_CLASS) != 0)
1343 flags |= UNICODE_CASE;
1344
1345 // Reset group index count
1346 capturingGroupCount = 1;
1347 localCount = 0;
1348
1349 if (pattern.length() > 0) {
1350 compile();
1351 } else {
1352 root = new Start(lastAccept);
1353 matchRoot = lastAccept;
1354 }
1355 }
1356
1357 /**
1358 * The pattern is converted to normalizedD form and then a pure group
1359 * is constructed to match canonical equivalences of the characters.
1360 */
1361 private void normalize() {
1362 boolean inCharClass = false;
1363 int lastCodePoint = -1;
1364
1365 // Convert pattern into normalizedD form
1366 normalizedPattern = Normalizer.normalize(pattern, Normalizer.Form.NFD);
1367 patternLength = normalizedPattern.length();
1368
1369 // Modify pattern to match canonical equivalences
1370 StringBuilder newPattern = new StringBuilder(patternLength);
1371 for(int i=0; i<patternLength; ) {
1372 int c = normalizedPattern.codePointAt(i);
1373 StringBuilder sequenceBuffer;
1374 if ((Character.getType(c) == Character.NON_SPACING_MARK)
1375 && (lastCodePoint != -1)) {
1376 sequenceBuffer = new StringBuilder();
1377 sequenceBuffer.appendCodePoint(lastCodePoint);
1378 sequenceBuffer.appendCodePoint(c);
1379 while(Character.getType(c) == Character.NON_SPACING_MARK) {
1380 i += Character.charCount(c);
1381 if (i >= patternLength)
1382 break;
1383 c = normalizedPattern.codePointAt(i);
1384 sequenceBuffer.appendCodePoint(c);
1385 }
1386 String ea = produceEquivalentAlternation(
1387 sequenceBuffer.toString());
1388 newPattern.setLength(newPattern.length()-Character.charCount(lastCodePoint));
1389 newPattern.append("(?:").append(ea).append(")");
1390 } else if (c == '[' && lastCodePoint != '\\') {
1391 i = normalizeCharClass(newPattern, i);
1392 } else {
1393 newPattern.appendCodePoint(c);
1394 }
1395 lastCodePoint = c;
1396 i += Character.charCount(c);
1397 }
1398 normalizedPattern = newPattern.toString();
1399 }
1400
1401 /**
1402 * Complete the character class being parsed and add a set
1403 * of alternations to it that will match the canonical equivalences
1404 * of the characters within the class.
1405 */
1406 private int normalizeCharClass(StringBuilder newPattern, int i) {
1407 StringBuilder charClass = new StringBuilder();
1408 StringBuilder eq = null;
1409 int lastCodePoint = -1;
1410 String result;
1411
1412 i++;
1413 charClass.append("[");
1414 while(true) {
1415 int c = normalizedPattern.codePointAt(i);
1416 StringBuilder sequenceBuffer;
1417
1418 if (c == ']' && lastCodePoint != '\\') {
1419 charClass.append((char)c);
1420 break;
1421 } else if (Character.getType(c) == Character.NON_SPACING_MARK) {
1422 sequenceBuffer = new StringBuilder();
1423 sequenceBuffer.appendCodePoint(lastCodePoint);
1424 while(Character.getType(c) == Character.NON_SPACING_MARK) {
1425 sequenceBuffer.appendCodePoint(c);
1426 i += Character.charCount(c);
1427 if (i >= normalizedPattern.length())
1428 break;
1429 c = normalizedPattern.codePointAt(i);
1430 }
1431 String ea = produceEquivalentAlternation(
1432 sequenceBuffer.toString());
1433
1434 charClass.setLength(charClass.length()-Character.charCount(lastCodePoint));
1435 if (eq == null)
1436 eq = new StringBuilder();
1437 eq.append('|');
1438 eq.append(ea);
1439 } else {
1440 charClass.appendCodePoint(c);
1441 i++;
1442 }
1443 if (i == normalizedPattern.length())
1444 throw error("Unclosed character class");
1445 lastCodePoint = c;
1446 }
1447
1448 if (eq != null) {
1449 result = "(?:"+charClass.toString()+eq.toString()+")";
1450 } else {
1451 result = charClass.toString();
1452 }
1453
1454 newPattern.append(result);
1455 return i;
1456 }
1457
1458 /**
1459 * Given a specific sequence composed of a regular character and
1460 * combining marks that follow it, produce the alternation that will
1461 * match all canonical equivalences of that sequence.
1462 */
1463 private String produceEquivalentAlternation(String source) {
1464 int len = countChars(source, 0, 1);
1465 if (source.length() == len)
1466 // source has one character.
1467 return source;
1468
1469 String base = source.substring(0,len);
1470 String combiningMarks = source.substring(len);
1471
1472 String[] perms = producePermutations(combiningMarks);
1473 StringBuilder result = new StringBuilder(source);
1474
1475 // Add combined permutations
1476 for(int x=0; x<perms.length; x++) {
1477 String next = base + perms[x];
1478 if (x>0)
1479 result.append("|"+next);
1480 next = composeOneStep(next);
1481 if (next != null)
1482 result.append("|"+produceEquivalentAlternation(next));
1483 }
1484 return result.toString();
1485 }
1486
1487 /**
1488 * Returns an array of strings that have all the possible
1489 * permutations of the characters in the input string.
1490 * This is used to get a list of all possible orderings
1491 * of a set of combining marks. Note that some of the permutations
1492 * are invalid because of combining class collisions, and these
1493 * possibilities must be removed because they are not canonically
1494 * equivalent.
1495 */
1496 private String[] producePermutations(String input) {
1497 if (input.length() == countChars(input, 0, 1))
1498 return new String[] {input};
1499
1500 if (input.length() == countChars(input, 0, 2)) {
1501 int c0 = Character.codePointAt(input, 0);
1502 int c1 = Character.codePointAt(input, Character.charCount(c0));
1503 if (getClass(c1) == getClass(c0)) {
1504 return new String[] {input};
1505 }
1506 String[] result = new String[2];
1507 result[0] = input;
1508 StringBuilder sb = new StringBuilder(2);
1509 sb.appendCodePoint(c1);
1510 sb.appendCodePoint(c0);
1511 result[1] = sb.toString();
1512 return result;
1513 }
1514
1515 int length = 1;
1516 int nCodePoints = countCodePoints(input);
1517 for(int x=1; x<nCodePoints; x++)
1518 length = length * (x+1);
1519
1520 String[] temp = new String[length];
1521
1522 int combClass[] = new int[nCodePoints];
1523 for(int x=0, i=0; x<nCodePoints; x++) {
1524 int c = Character.codePointAt(input, i);
1525 combClass[x] = getClass(c);
1526 i += Character.charCount(c);
1527 }
1528
1529 // For each char, take it out and add the permutations
1530 // of the remaining chars
1531 int index = 0;
1532 int len;
1533 // offset maintains the index in code units.
1534 loop: for(int x=0, offset=0; x<nCodePoints; x++, offset+=len) {
1535 len = countChars(input, offset, 1);
1536 boolean skip = false;
1537 for(int y=x-1; y>=0; y--) {
1538 if (combClass[y] == combClass[x]) {
1539 continue loop;
1540 }
1541 }
1542 StringBuilder sb = new StringBuilder(input);
1543 String otherChars = sb.delete(offset, offset+len).toString();
1544 String[] subResult = producePermutations(otherChars);
1545
1546 String prefix = input.substring(offset, offset+len);
1547 for(int y=0; y<subResult.length; y++)
1548 temp[index++] = prefix + subResult[y];
1549 }
1550 String[] result = new String[index];
1551 for (int x=0; x<index; x++)
1552 result[x] = temp[x];
1553 return result;
1554 }
1555
1556 private int getClass(int c) {
1557 return sun.text.Normalizer.getCombiningClass(c);
1558 }
1559
1560 /**
1561 * Attempts to compose input by combining the first character
1562 * with the first combining mark following it. Returns a String
1563 * that is the composition of the leading character with its first
1564 * combining mark followed by the remaining combining marks. Returns
1565 * null if the first two characters cannot be further composed.
1566 */
1567 private String composeOneStep(String input) {
1568 int len = countChars(input, 0, 2);
1569 String firstTwoCharacters = input.substring(0, len);
1570 String result = Normalizer.normalize(firstTwoCharacters, Normalizer.Form.NFC);
1571
1572 if (result.equals(firstTwoCharacters))
1573 return null;
1574 else {
1575 String remainder = input.substring(len);
1576 return result + remainder;
1577 }
1578 }
1579
1580 /**
1581 * Preprocess any \Q...\E sequences in `temp', meta-quoting them.
1582 * See the description of `quotemeta' in perlfunc(1).
1583 */
1584 private void RemoveQEQuoting() {
1585 final int pLen = patternLength;
1586 int i = 0;
1587 while (i < pLen-1) {
1588 if (temp[i] != '\\')
1589 i += 1;
1590 else if (temp[i + 1] != 'Q')
1591 i += 2;
1592 else
1593 break;
1594 }
1595 if (i >= pLen - 1) // No \Q sequence found
1596 return;
1597 int j = i;
1598 i += 2;
1599 int[] newtemp = new int[j + 3*(pLen-i) + 2];
1600 System.arraycopy(temp, 0, newtemp, 0, j);
1601
1602 boolean inQuote = true;
1603 boolean beginQuote = true;
1604 while (i < pLen) {
1605 int c = temp[i++];
1606 if (!ASCII.isAscii(c) || ASCII.isAlpha(c)) {
1607 newtemp[j++] = c;
1608 } else if (ASCII.isDigit(c)) {
1609 if (beginQuote) {
1610 /*
1611 * A unicode escape \[0xu] could be before this quote,
1612 * and we don't want this numeric char to processed as
1613 * part of the escape.
1614 */
1615 newtemp[j++] = '\\';
1616 newtemp[j++] = 'x';
1617 newtemp[j++] = '3';
1618 }
1619 newtemp[j++] = c;
1620 } else if (c != '\\') {
1621 if (inQuote) newtemp[j++] = '\\';
1622 newtemp[j++] = c;
1623 } else if (inQuote) {
1624 if (temp[i] == 'E') {
1625 i++;
1626 inQuote = false;
1627 } else {
1628 newtemp[j++] = '\\';
1629 newtemp[j++] = '\\';
1630 }
1631 } else {
1632 if (temp[i] == 'Q') {
1633 i++;
1634 inQuote = true;
1635 beginQuote = true;
1636 continue;
1637 } else {
1638 newtemp[j++] = c;
1639 if (i != pLen)
1640 newtemp[j++] = temp[i++];
1641 }
1642 }
1643
1644 beginQuote = false;
1645 }
1646
1647 patternLength = j;
1648 temp = Arrays.copyOf(newtemp, j + 2); // double zero termination
1649 }
1650
1651 /**
1652 * Copies regular expression to an int array and invokes the parsing
1653 * of the expression which will create the object tree.
1654 */
1655 private void compile() {
1656 // Handle canonical equivalences
1657 if (has(CANON_EQ) && !has(LITERAL)) {
1658 normalize();
1659 } else {
1660 normalizedPattern = pattern;
1661 }
1662 patternLength = normalizedPattern.length();
1663
1664 // Copy pattern to int array for convenience
1665 // Use double zero to terminate pattern
1666 temp = new int[patternLength + 2];
1667
1668 hasSupplementary = false;
1669 int c, count = 0;
1670 // Convert all chars into code points
1671 for (int x = 0; x < patternLength; x += Character.charCount(c)) {
1672 c = normalizedPattern.codePointAt(x);
1673 if (isSupplementary(c)) {
1674 hasSupplementary = true;
1675 }
1676 temp[count++] = c;
1677 }
1678
1679 patternLength = count; // patternLength now in code points
1680
1681 if (! has(LITERAL))
1682 RemoveQEQuoting();
1683
1684 // Allocate all temporary objects here.
1685 buffer = new int[32];
1686 groupNodes = new GroupHead[10];
1687 namedGroups = null;
1688
1689 if (has(LITERAL)) {
1690 // Literal pattern handling
1691 matchRoot = newSlice(temp, patternLength, hasSupplementary);
1692 matchRoot.next = lastAccept;
1693 } else {
1694 // Start recursive descent parsing
1695 matchRoot = expr(lastAccept);
1696 // Check extra pattern characters
1697 if (patternLength != cursor) {
1698 if (peek() == ')') {
1699 throw error("Unmatched closing ')'");
1700 } else {
1701 throw error("Unexpected internal error");
1702 }
1703 }
1704 }
1705
1706 // Peephole optimization
1707 if (matchRoot instanceof Slice) {
1708 root = BnM.optimize(matchRoot);
1709 if (root == matchRoot) {
1710 root = hasSupplementary ? new StartS(matchRoot) : new Start(matchRoot);
1711 }
1712 } else if (matchRoot instanceof Begin || matchRoot instanceof First) {
1713 root = matchRoot;
1714 } else {
1715 root = hasSupplementary ? new StartS(matchRoot) : new Start(matchRoot);
1716 }
1717
1718 // Release temporary storage
1719 temp = null;
1720 buffer = null;
1721 groupNodes = null;
1722 patternLength = 0;
1723 compiled = true;
1724 }
1725
1726 Map<String, Integer> namedGroups() {
1727 if (namedGroups == null)
1728 namedGroups = new HashMap<>(2);
1729 return namedGroups;
1730 }
1731
1732 /**
1733 * Used to print out a subtree of the Pattern to help with debugging.
1734 */
1735 private static void printObjectTree(Node node) {
1736 while(node != null) {
1737 if (node instanceof Prolog) {
1738 System.out.println(node);
1739 printObjectTree(((Prolog)node).loop);
1740 System.out.println("**** end contents prolog loop");
1741 } else if (node instanceof Loop) {
1742 System.out.println(node);
1743 printObjectTree(((Loop)node).body);
1744 System.out.println("**** end contents Loop body");
1745 } else if (node instanceof Curly) {
1746 System.out.println(node);
1747 printObjectTree(((Curly)node).atom);
1748 System.out.println("**** end contents Curly body");
1749 } else if (node instanceof GroupCurly) {
1750 System.out.println(node);
1751 printObjectTree(((GroupCurly)node).atom);
1752 System.out.println("**** end contents GroupCurly body");
1753 } else if (node instanceof GroupTail) {
1754 System.out.println(node);
1755 System.out.println("Tail next is "+node.next);
1756 return;
1757 } else {
1758 System.out.println(node);
1759 }
1760 node = node.next;
1761 if (node != null)
1762 System.out.println("->next:");
1763 if (node == Pattern.accept) {
1764 System.out.println("Accept Node");
1765 node = null;
1766 }
1767 }
1768 }
1769
1770 /**
1771 * Used to accumulate information about a subtree of the object graph
1772 * so that optimizations can be applied to the subtree.
1773 */
1774 static final class TreeInfo {
1775 int minLength;
1776 int maxLength;
1777 boolean maxValid;
1778 boolean deterministic;
1779
1780 TreeInfo() {
1781 reset();
1782 }
1783 void reset() {
1784 minLength = 0;
1785 maxLength = 0;
1786 maxValid = true;
1787 deterministic = true;
1788 }
1789 }
1790
1791 /*
1792 * The following private methods are mainly used to improve the
1793 * readability of the code. In order to let the Java compiler easily
1794 * inline them, we should not put many assertions or error checks in them.
1795 */
1796
1797 /**
1798 * Indicates whether a particular flag is set or not.
1799 */
1800 private boolean has(int f) {
1801 return (flags & f) != 0;
1802 }
1803
1804 /**
1805 * Match next character, signal error if failed.
1806 */
1807 private void accept(int ch, String s) {
1808 int testChar = temp[cursor++];
1809 if (has(COMMENTS))
1810 testChar = parsePastWhitespace(testChar);
1811 if (ch != testChar) {
1812 throw error(s);
1813 }
1814 }
1815
1816 /**
1817 * Mark the end of pattern with a specific character.
1818 */
1819 private void mark(int c) {
1820 temp[patternLength] = c;
1821 }
1822
1823 /**
1824 * Peek the next character, and do not advance the cursor.
1825 */
1826 private int peek() {
1827 int ch = temp[cursor];
1828 if (has(COMMENTS))
1829 ch = peekPastWhitespace(ch);
1830 return ch;
1831 }
1832
1833 /**
1834 * Read the next character, and advance the cursor by one.
1835 */
1836 private int read() {
1837 int ch = temp[cursor++];
1838 if (has(COMMENTS))
1839 ch = parsePastWhitespace(ch);
1840 return ch;
1841 }
1842
1843 /**
1844 * Read the next character, and advance the cursor by one,
1845 * ignoring the COMMENTS setting
1846 */
1847 private int readEscaped() {
1848 int ch = temp[cursor++];
1849 return ch;
1850 }
1851
1852 /**
1853 * Advance the cursor by one, and peek the next character.
1854 */
1855 private int next() {
1856 int ch = temp[++cursor];
1857 if (has(COMMENTS))
1858 ch = peekPastWhitespace(ch);
1859 return ch;
1860 }
1861
1862 /**
1863 * Advance the cursor by one, and peek the next character,
1864 * ignoring the COMMENTS setting
1865 */
1866 private int nextEscaped() {
1867 int ch = temp[++cursor];
1868 return ch;
1869 }
1870
1871 /**
1872 * If in xmode peek past whitespace and comments.
1873 */
1874 private int peekPastWhitespace(int ch) {
1875 while (ASCII.isSpace(ch) || ch == '#') {
1876 while (ASCII.isSpace(ch))
1877 ch = temp[++cursor];
1878 if (ch == '#') {
1879 ch = peekPastLine();
1880 }
1881 }
1882 return ch;
1883 }
1884
1885 /**
1886 * If in xmode parse past whitespace and comments.
1887 */
1888 private int parsePastWhitespace(int ch) {
1889 while (ASCII.isSpace(ch) || ch == '#') {
1890 while (ASCII.isSpace(ch))
1891 ch = temp[cursor++];
1892 if (ch == '#')
1893 ch = parsePastLine();
1894 }
1895 return ch;
1896 }
1897
1898 /**
1899 * xmode parse past comment to end of line.
1900 */
1901 private int parsePastLine() {
1902 int ch = temp[cursor++];
1903 while (ch != 0 && !isLineSeparator(ch))
1904 ch = temp[cursor++];
1905 return ch;
1906 }
1907
1908 /**
1909 * xmode peek past comment to end of line.
1910 */
1911 private int peekPastLine() {
1912 int ch = temp[++cursor];
1913 while (ch != 0 && !isLineSeparator(ch))
1914 ch = temp[++cursor];
1915 return ch;
1916 }
1917
1918 /**
1919 * Determines if character is a line separator in the current mode
1920 */
1921 private boolean isLineSeparator(int ch) {
1922 if (has(UNIX_LINES)) {
1923 return ch == '\n';
1924 } else {
1925 return (ch == '\n' ||
1926 ch == '\r' ||
1927 (ch|1) == '\u2029' ||
1928 ch == '\u0085');
1929 }
1930 }
1931
1932 /**
1933 * Read the character after the next one, and advance the cursor by two.
1934 */
1935 private int skip() {
1936 int i = cursor;
1937 int ch = temp[i+1];
1938 cursor = i + 2;
1939 return ch;
1940 }
1941
1942 /**
1943 * Unread one next character, and retreat cursor by one.
1944 */
1945 private void unread() {
1946 cursor--;
1947 }
1948
1949 /**
1950 * Internal method used for handling all syntax errors. The pattern is
1951 * displayed with a pointer to aid in locating the syntax error.
1952 */
1953 private PatternSyntaxException error(String s) {
1954 return new PatternSyntaxException(s, normalizedPattern, cursor - 1);
1955 }
1956
1957 /**
1958 * Determines if there is any supplementary character or unpaired
1959 * surrogate in the specified range.
1960 */
1961 private boolean findSupplementary(int start, int end) {
1962 for (int i = start; i < end; i++) {
1963 if (isSupplementary(temp[i]))
1964 return true;
1965 }
1966 return false;
1967 }
1968
1969 /**
1970 * Determines if the specified code point is a supplementary
1971 * character or unpaired surrogate.
1972 */
1973 private static final boolean isSupplementary(int ch) {
1974 return ch >= Character.MIN_SUPPLEMENTARY_CODE_POINT ||
1975 Character.isSurrogate((char)ch);
1976 }
1977
1978 /**
1979 * The following methods handle the main parsing. They are sorted
1980 * according to their precedence order, the lowest one first.
1981 */
1982
1983 /**
1984 * The expression is parsed with branch nodes added for alternations.
1985 * This may be called recursively to parse sub expressions that may
1986 * contain alternations.
1987 */
1988 private Node expr(Node end) {
1989 Node prev = null;
1990 Node firstTail = null;
1991 Branch branch = null;
1992 Node branchConn = null;
1993
1994 for (;;) {
1995 Node node = sequence(end);
1996 Node nodeTail = root; //double return
1997 if (prev == null) {
1998 prev = node;
1999 firstTail = nodeTail;
2000 } else {
2001 // Branch
2002 if (branchConn == null) {
2003 branchConn = new BranchConn();
2004 branchConn.next = end;
2005 }
2006 if (node == end) {
2007 // if the node returned from sequence() is "end"
2008 // we have an empty expr, set a null atom into
2009 // the branch to indicate to go "next" directly.
2010 node = null;
2011 } else {
2012 // the "tail.next" of each atom goes to branchConn
2013 nodeTail.next = branchConn;
2014 }
2015 if (prev == branch) {
2016 branch.add(node);
2017 } else {
2018 if (prev == end) {
2019 prev = null;
2020 } else {
2021 // replace the "end" with "branchConn" at its tail.next
2022 // when put the "prev" into the branch as the first atom.
2023 firstTail.next = branchConn;
2024 }
2025 prev = branch = new Branch(prev, node, branchConn);
2026 }
2027 }
2028 if (peek() != '|') {
2029 return prev;
2030 }
2031 next();
2032 }
2033 }
2034
2035 @SuppressWarnings("fallthrough")
2036 /**
2037 * Parsing of sequences between alternations.
2038 */
2039 private Node sequence(Node end) {
2040 Node head = null;
2041 Node tail = null;
2042 Node node = null;
2043 LOOP:
2044 for (;;) {
2045 int ch = peek();
2046 switch (ch) {
2047 case '(':
2048 // Because group handles its own closure,
2049 // we need to treat it differently
2050 node = group0();
2051 // Check for comment or flag group
2052 if (node == null)
2053 continue;
2054 if (head == null)
2055 head = node;
2056 else
2057 tail.next = node;
2058 // Double return: Tail was returned in root
2059 tail = root;
2060 continue;
2061 case '[':
2062 node = clazz(true);
2063 break;
2064 case '\\':
2065 ch = nextEscaped();
2066 if (ch == 'p' || ch == 'P') {
2067 boolean oneLetter = true;
2068 boolean comp = (ch == 'P');
2069 ch = next(); // Consume { if present
2070 if (ch != '{') {
2071 unread();
2072 } else {
2073 oneLetter = false;
2074 }
2075 node = family(oneLetter, comp);
2076 } else {
2077 unread();
2078 node = atom();
2079 }
2080 break;
2081 case '^':
2082 next();
2083 if (has(MULTILINE)) {
2084 if (has(UNIX_LINES))
2085 node = new UnixCaret();
2086 else
2087 node = new Caret();
2088 } else {
2089 node = new Begin();
2090 }
2091 break;
2092 case '$':
2093 next();
2094 if (has(UNIX_LINES))
2095 node = new UnixDollar(has(MULTILINE));
2096 else
2097 node = new Dollar(has(MULTILINE));
2098 break;
2099 case '.':
2100 next();
2101 if (has(DOTALL)) {
2102 node = new All();
2103 } else {
2104 if (has(UNIX_LINES))
2105 node = new UnixDot();
2106 else {
2107 node = new Dot();
2108 }
2109 }
2110 break;
2111 case '|':
2112 case ')':
2113 break LOOP;
2114 case ']': // Now interpreting dangling ] and } as literals
2115 case '}':
2116 node = atom();
2117 break;
2118 case '?':
2119 case '*':
2120 case '+':
2121 next();
2122 throw error("Dangling meta character '" + ((char)ch) + "'");
2123 case 0:
2124 if (cursor >= patternLength) {
2125 break LOOP;
2126 }
2127 // Fall through
2128 default:
2129 node = atom();
2130 break;
2131 }
2132
2133 node = closure(node);
2134
2135 if (head == null) {
2136 head = tail = node;
2137 } else {
2138 tail.next = node;
2139 tail = node;
2140 }
2141 }
2142 if (head == null) {
2143 return end;
2144 }
2145 tail.next = end;
2146 root = tail; //double return
2147 return head;
2148 }
2149
2150 @SuppressWarnings("fallthrough")
2151 /**
2152 * Parse and add a new Single or Slice.
2153 */
2154 private Node atom() {
2155 int first = 0;
2156 int prev = -1;
2157 boolean hasSupplementary = false;
2158 int ch = peek();
2159 for (;;) {
2160 switch (ch) {
2161 case '*':
2162 case '+':
2163 case '?':
2164 case '{':
2165 if (first > 1) {
2166 cursor = prev; // Unwind one character
2167 first--;
2168 }
2169 break;
2170 case '$':
2171 case '.':
2172 case '^':
2173 case '(':
2174 case '[':
2175 case '|':
2176 case ')':
2177 break;
2178 case '\\':
2179 ch = nextEscaped();
2180 if (ch == 'p' || ch == 'P') { // Property
2181 if (first > 0) { // Slice is waiting; handle it first
2182 unread();
2183 break;
2184 } else { // No slice; just return the family node
2185 boolean comp = (ch == 'P');
2186 boolean oneLetter = true;
2187 ch = next(); // Consume { if present
2188 if (ch != '{')
2189 unread();
2190 else
2191 oneLetter = false;
2192 return family(oneLetter, comp);
2193 }
2194 }
2195 unread();
2196 prev = cursor;
2197 ch = escape(false, first == 0, false);
2198 if (ch >= 0) {
2199 append(ch, first);
2200 first++;
2201 if (isSupplementary(ch)) {
2202 hasSupplementary = true;
2203 }
2204 ch = peek();
2205 continue;
2206 } else if (first == 0) {
2207 return root;
2208 }
2209 // Unwind meta escape sequence
2210 cursor = prev;
2211 break;
2212 case 0:
2213 if (cursor >= patternLength) {
2214 break;
2215 }
2216 // Fall through
2217 default:
2218 prev = cursor;
2219 append(ch, first);
2220 first++;
2221 if (isSupplementary(ch)) {
2222 hasSupplementary = true;
2223 }
2224 ch = next();
2225 continue;
2226 }
2227 break;
2228 }
2229 if (first == 1) {
2230 return newSingle(buffer[0]);
2231 } else {
2232 return newSlice(buffer, first, hasSupplementary);
2233 }
2234 }
2235
2236 private void append(int ch, int len) {
2237 if (len >= buffer.length) {
2238 int[] tmp = new int[len+len];
2239 System.arraycopy(buffer, 0, tmp, 0, len);
2240 buffer = tmp;
2241 }
2242 buffer[len] = ch;
2243 }
2244
2245 /**
2246 * Parses a backref greedily, taking as many numbers as it
2247 * can. The first digit is always treated as a backref, but
2248 * multi digit numbers are only treated as a backref if at
2249 * least that many backrefs exist at this point in the regex.
2250 */
2251 private Node ref(int refNum) {
2252 boolean done = false;
2253 while(!done) {
2254 int ch = peek();
2255 switch(ch) {
2256 case '0':
2257 case '1':
2258 case '2':
2259 case '3':
2260 case '4':
2261 case '5':
2262 case '6':
2263 case '7':
2264 case '8':
2265 case '9':
2266 int newRefNum = (refNum * 10) + (ch - '0');
2267 // Add another number if it doesn't make a group
2268 // that doesn't exist
2269 if (capturingGroupCount - 1 < newRefNum) {
2270 done = true;
2271 break;
2272 }
2273 refNum = newRefNum;
2274 read();
2275 break;
2276 default:
2277 done = true;
2278 break;
2279 }
2280 }
2281 if (has(CASE_INSENSITIVE))
2282 return new CIBackRef(refNum, has(UNICODE_CASE));
2283 else
2284 return new BackRef(refNum);
2285 }
2286
2287 /**
2288 * Parses an escape sequence to determine the actual value that needs
2289 * to be matched.
2290 * If -1 is returned and create was true a new object was added to the tree
2291 * to handle the escape sequence.
2292 * If the returned value is greater than zero, it is the value that
2293 * matches the escape sequence.
2294 */
2295 private int escape(boolean inclass, boolean create, boolean isrange) {
2296 int ch = skip();
2297 switch (ch) {
2298 case '0':
2299 return o();
2300 case '1':
2301 case '2':
2302 case '3':
2303 case '4':
2304 case '5':
2305 case '6':
2306 case '7':
2307 case '8':
2308 case '9':
2309 if (inclass) break;
2310 if (create) {
2311 root = ref((ch - '0'));
2312 }
2313 return -1;
2314 case 'A':
2315 if (inclass) break;
2316 if (create) root = new Begin();
2317 return -1;
2318 case 'B':
2319 if (inclass) break;
2320 if (create) root = new Bound(Bound.NONE, has(UNICODE_CHARACTER_CLASS));
2321 return -1;
2322 case 'C':
2323 break;
2324 case 'D':
2325 if (create) root = has(UNICODE_CHARACTER_CLASS)
2326 ? new Utype(UnicodeProp.DIGIT).complement()
2327 : new Ctype(ASCII.DIGIT).complement();
2328 return -1;
2329 case 'E':
2330 case 'F':
2331 break;
2332 case 'G':
2333 if (inclass) break;
2334 if (create) root = new LastMatch();
2335 return -1;
2336 case 'H':
2337 if (create) root = new HorizWS().complement();
2338 return -1;
2339 case 'I':
2340 case 'J':
2341 case 'K':
2342 case 'L':
2343 case 'M':
2344 case 'N':
2345 case 'O':
2346 case 'P':
2347 case 'Q':
2348 break;
2349 case 'R':
2350 if (inclass) break;
2351 if (create) root = new LineEnding();
2352 return -1;
2353 case 'S':
2354 if (create) root = has(UNICODE_CHARACTER_CLASS)
2355 ? new Utype(UnicodeProp.WHITE_SPACE).complement()
2356 : new Ctype(ASCII.SPACE).complement();
2357 return -1;
2358 case 'T':
2359 case 'U':
2360 break;
2361 case 'V':
2362 if (create) root = new VertWS().complement();
2363 return -1;
2364 case 'W':
2365 if (create) root = has(UNICODE_CHARACTER_CLASS)
2366 ? new Utype(UnicodeProp.WORD).complement()
2367 : new Ctype(ASCII.WORD).complement();
2368 return -1;
2369 case 'X':
2370 case 'Y':
2371 break;
2372 case 'Z':
2373 if (inclass) break;
2374 if (create) {
2375 if (has(UNIX_LINES))
2376 root = new UnixDollar(false);
2377 else
2378 root = new Dollar(false);
2379 }
2380 return -1;
2381 case 'a':
2382 return '\007';
2383 case 'b':
2384 if (inclass) break;
2385 if (create) root = new Bound(Bound.BOTH, has(UNICODE_CHARACTER_CLASS));
2386 return -1;
2387 case 'c':
2388 return c();
2389 case 'd':
2390 if (create) root = has(UNICODE_CHARACTER_CLASS)
2391 ? new Utype(UnicodeProp.DIGIT)
2392 : new Ctype(ASCII.DIGIT);
2393 return -1;
2394 case 'e':
2395 return '\033';
2396 case 'f':
2397 return '\f';
2398 case 'g':
2399 break;
2400 case 'h':
2401 if (create) root = new HorizWS();
2402 return -1;
2403 case 'i':
2404 case 'j':
2405 break;
2406 case 'k':
2407 if (inclass)
2408 break;
2409 if (read() != '<')
2410 throw error("\\k is not followed by '<' for named capturing group");
2411 String name = groupname(read());
2412 if (!namedGroups().containsKey(name))
2413 throw error("(named capturing group <"+ name+"> does not exit");
2414 if (create) {
2415 if (has(CASE_INSENSITIVE))
2416 root = new CIBackRef(namedGroups().get(name), has(UNICODE_CASE));
2417 else
2418 root = new BackRef(namedGroups().get(name));
2419 }
2420 return -1;
2421 case 'l':
2422 case 'm':
2423 break;
2424 case 'n':
2425 return '\n';
2426 case 'o':
2427 case 'p':
2428 case 'q':
2429 break;
2430 case 'r':
2431 return '\r';
2432 case 's':
2433 if (create) root = has(UNICODE_CHARACTER_CLASS)
2434 ? new Utype(UnicodeProp.WHITE_SPACE)
2435 : new Ctype(ASCII.SPACE);
2436 return -1;
2437 case 't':
2438 return '\t';
2439 case 'u':
2440 return u();
2441 case 'v':
2442 // '\v' was implemented as VT/0x0B in releases < 1.8 (though
2443 // undocumented). In JDK8 '\v' is specified as a predefined
2444 // character class for all vertical whitespace characters.
2445 // So [-1, root=VertWS node] pair is returned (instead of a
2446 // single 0x0B). This breaks the range if '\v' is used as
2447 // the start or end value, such as [\v-...] or [...-\v], in
2448 // which a single definite value (0x0B) is expected. For
2449 // compatiblity concern '\013'/0x0B is returned if isrange.
2450 if (isrange)
2451 return '\013';
2452 if (create) root = new VertWS();
2453 return -1;
2454 case 'w':
2455 if (create) root = has(UNICODE_CHARACTER_CLASS)
2456 ? new Utype(UnicodeProp.WORD)
2457 : new Ctype(ASCII.WORD);
2458 return -1;
2459 case 'x':
2460 return x();
2461 case 'y':
2462 break;
2463 case 'z':
2464 if (inclass) break;
2465 if (create) root = new End();
2466 return -1;
2467 default:
2468 return ch;
2469 }
2470 throw error("Illegal/unsupported escape sequence");
2471 }
2472
2473 /**
2474 * Parse a character class, and return the node that matches it.
2475 *
2476 * Consumes a ] on the way out if consume is true. Usually consume
2477 * is true except for the case of [abc&&def] where def is a separate
2478 * right hand node with "understood" brackets.
2479 */
2480 private CharProperty clazz(boolean consume) {
2481 CharProperty prev = null;
2482 CharProperty node = null;
2483 BitClass bits = new BitClass();
2484 boolean include = true;
2485 boolean firstInClass = true;
2486 int ch = next();
2487 for (;;) {
2488 switch (ch) {
2489 case '^':
2490 // Negates if first char in a class, otherwise literal
2491 if (firstInClass) {
2492 if (temp[cursor-1] != '[')
2493 break;
2494 ch = next();
2495 include = !include;
2496 continue;
2497 } else {
2498 // ^ not first in class, treat as literal
2499 break;
2500 }
2501 case '[':
2502 firstInClass = false;
2503 node = clazz(true);
2504 if (prev == null)
2505 prev = node;
2506 else
2507 prev = union(prev, node);
2508 ch = peek();
2509 continue;
2510 case '&':
2511 firstInClass = false;
2512 ch = next();
2513 if (ch == '&') {
2514 ch = next();
2515 CharProperty rightNode = null;
2516 while (ch != ']' && ch != '&') {
2517 if (ch == '[') {
2518 if (rightNode == null)
2519 rightNode = clazz(true);
2520 else
2521 rightNode = union(rightNode, clazz(true));
2522 } else { // abc&&def
2523 unread();
2524 rightNode = clazz(false);
2525 }
2526 ch = peek();
2527 }
2528 if (rightNode != null)
2529 node = rightNode;
2530 if (prev == null) {
2531 if (rightNode == null)
2532 throw error("Bad class syntax");
2533 else
2534 prev = rightNode;
2535 } else {
2536 prev = intersection(prev, node);
2537 }
2538 } else {
2539 // treat as a literal &
2540 unread();
2541 break;
2542 }
2543 continue;
2544 case 0:
2545 firstInClass = false;
2546 if (cursor >= patternLength)
2547 throw error("Unclosed character class");
2548 break;
2549 case ']':
2550 firstInClass = false;
2551 if (prev != null) {
2552 if (consume)
2553 next();
2554 return prev;
2555 }
2556 break;
2557 default:
2558 firstInClass = false;
2559 break;
2560 }
2561 node = range(bits);
2562 if (include) {
2563 if (prev == null) {
2564 prev = node;
2565 } else {
2566 if (prev != node)
2567 prev = union(prev, node);
2568 }
2569 } else {
2570 if (prev == null) {
2571 prev = node.complement();
2572 } else {
2573 if (prev != node)
2574 prev = setDifference(prev, node);
2575 }
2576 }
2577 ch = peek();
2578 }
2579 }
2580
2581 private CharProperty bitsOrSingle(BitClass bits, int ch) {
2582 /* Bits can only handle codepoints in [u+0000-u+00ff] range.
2583 Use "single" node instead of bits when dealing with unicode
2584 case folding for codepoints listed below.
2585 (1)Uppercase out of range: u+00ff, u+00b5
2586 toUpperCase(u+00ff) -> u+0178
2587 toUpperCase(u+00b5) -> u+039c
2588 (2)LatinSmallLetterLongS u+17f
2589 toUpperCase(u+017f) -> u+0053
2590 (3)LatinSmallLetterDotlessI u+131
2591 toUpperCase(u+0131) -> u+0049
2592 (4)LatinCapitalLetterIWithDotAbove u+0130
2593 toLowerCase(u+0130) -> u+0069
2594 (5)KelvinSign u+212a
2595 toLowerCase(u+212a) ==> u+006B
2596 (6)AngstromSign u+212b
2597 toLowerCase(u+212b) ==> u+00e5
2598 */
2599 int d;
2600 if (ch < 256 &&
2601 !(has(CASE_INSENSITIVE) && has(UNICODE_CASE) &&
2602 (ch == 0xff || ch == 0xb5 ||
2603 ch == 0x49 || ch == 0x69 || //I and i
2604 ch == 0x53 || ch == 0x73 || //S and s
2605 ch == 0x4b || ch == 0x6b || //K and k
2606 ch == 0xc5 || ch == 0xe5))) //A+ring
2607 return bits.add(ch, flags());
2608 return newSingle(ch);
2609 }
2610
2611 /**
2612 * Parse a single character or a character range in a character class
2613 * and return its representative node.
2614 */
2615 private CharProperty range(BitClass bits) {
2616 int ch = peek();
2617 if (ch == '\\') {
2618 ch = nextEscaped();
2619 if (ch == 'p' || ch == 'P') { // A property
2620 boolean comp = (ch == 'P');
2621 boolean oneLetter = true;
2622 // Consume { if present
2623 ch = next();
2624 if (ch != '{')
2625 unread();
2626 else
2627 oneLetter = false;
2628 return family(oneLetter, comp);
2629 } else { // ordinary escape
2630 boolean isrange = temp[cursor+1] == '-';
2631 unread();
2632 ch = escape(true, true, isrange);
2633 if (ch == -1)
2634 return (CharProperty) root;
2635 }
2636 } else {
2637 next();
2638 }
2639 if (ch >= 0) {
2640 if (peek() == '-') {
2641 int endRange = temp[cursor+1];
2642 if (endRange == '[') {
2643 return bitsOrSingle(bits, ch);
2644 }
2645 if (endRange != ']') {
2646 next();
2647 int m = peek();
2648 if (m == '\\') {
2649 m = escape(true, false, true);
2650 } else {
2651 next();
2652 }
2653 if (m < ch) {
2654 throw error("Illegal character range");
2655 }
2656 if (has(CASE_INSENSITIVE))
2657 return caseInsensitiveRangeFor(ch, m);
2658 else
2659 return rangeFor(ch, m);
2660 }
2661 }
2662 return bitsOrSingle(bits, ch);
2663 }
2664 throw error("Unexpected character '"+((char)ch)+"'");
2665 }
2666
2667 /**
2668 * Parses a Unicode character family and returns its representative node.
2669 */
2670 private CharProperty family(boolean singleLetter,
2671 boolean maybeComplement)
2672 {
2673 next();
2674 String name;
2675 CharProperty node = null;
2676
2677 if (singleLetter) {
2678 int c = temp[cursor];
2679 if (!Character.isSupplementaryCodePoint(c)) {
2680 name = String.valueOf((char)c);
2681 } else {
2682 name = new String(temp, cursor, 1);
2683 }
2684 read();
2685 } else {
2686 int i = cursor;
2687 mark('}');
2688 while(read() != '}') {
2689 }
2690 mark('\000');
2691 int j = cursor;
2692 if (j > patternLength)
2693 throw error("Unclosed character family");
2694 if (i + 1 >= j)
2695 throw error("Empty character family");
2696 name = new String(temp, i, j-i-1);
2697 }
2698
2699 int i = name.indexOf('=');
2700 if (i != -1) {
2701 // property construct \p{name=value}
2702 String value = name.substring(i + 1);
2703 name = name.substring(0, i).toLowerCase(Locale.ENGLISH);
2704 if ("sc".equals(name) || "script".equals(name)) {
2705 node = unicodeScriptPropertyFor(value);
2706 } else if ("blk".equals(name) || "block".equals(name)) {
2707 node = unicodeBlockPropertyFor(value);
2708 } else if ("gc".equals(name) || "general_category".equals(name)) {
2709 node = charPropertyNodeFor(value);
2710 } else {
2711 throw error("Unknown Unicode property {name=<" + name + ">, "
2712 + "value=<" + value + ">}");
2713 }
2714 } else {
2715 if (name.startsWith("In")) {
2716 // \p{inBlockName}
2717 node = unicodeBlockPropertyFor(name.substring(2));
2718 } else if (name.startsWith("Is")) {
2719 // \p{isGeneralCategory} and \p{isScriptName}
2720 name = name.substring(2);
2721 UnicodeProp uprop = UnicodeProp.forName(name);
2722 if (uprop != null)
2723 node = new Utype(uprop);
2724 if (node == null)
2725 node = CharPropertyNames.charPropertyFor(name);
2726 if (node == null)
2727 node = unicodeScriptPropertyFor(name);
2728 } else {
2729 if (has(UNICODE_CHARACTER_CLASS)) {
2730 UnicodeProp uprop = UnicodeProp.forPOSIXName(name);
2731 if (uprop != null)
2732 node = new Utype(uprop);
2733 }
2734 if (node == null)
2735 node = charPropertyNodeFor(name);
2736 }
2737 }
2738 if (maybeComplement) {
2739 if (node instanceof Category || node instanceof Block)
2740 hasSupplementary = true;
2741 node = node.complement();
2742 }
2743 return node;
2744 }
2745
2746
2747 /**
2748 * Returns a CharProperty matching all characters belong to
2749 * a UnicodeScript.
2750 */
2751 private CharProperty unicodeScriptPropertyFor(String name) {
2752 final Character.UnicodeScript script;
2753 try {
2754 script = Character.UnicodeScript.forName(name);
2755 } catch (IllegalArgumentException iae) {
2756 throw error("Unknown character script name {" + name + "}");
2757 }
2758 return new Script(script);
2759 }
2760
2761 /**
2762 * Returns a CharProperty matching all characters in a UnicodeBlock.
2763 */
2764 private CharProperty unicodeBlockPropertyFor(String name) {
2765 final Character.UnicodeBlock block;
2766 try {
2767 block = Character.UnicodeBlock.forName(name);
2768 } catch (IllegalArgumentException iae) {
2769 throw error("Unknown character block name {" + name + "}");
2770 }
2771 return new Block(block);
2772 }
2773
2774 /**
2775 * Returns a CharProperty matching all characters in a named property.
2776 */
2777 private CharProperty charPropertyNodeFor(String name) {
2778 CharProperty p = CharPropertyNames.charPropertyFor(name);
2779 if (p == null)
2780 throw error("Unknown character property name {" + name + "}");
2781 return p;
2782 }
2783
2784 /**
2785 * Parses and returns the name of a "named capturing group", the trailing
2786 * ">" is consumed after parsing.
2787 */
2788 private String groupname(int ch) {
2789 StringBuilder sb = new StringBuilder();
2790 sb.append(Character.toChars(ch));
2791 while (ASCII.isLower(ch=read()) || ASCII.isUpper(ch) ||
2792 ASCII.isDigit(ch)) {
2793 sb.append(Character.toChars(ch));
2794 }
2795 if (sb.length() == 0)
2796 throw error("named capturing group has 0 length name");
2797 if (ch != '>')
2798 throw error("named capturing group is missing trailing '>'");
2799 return sb.toString();
2800 }
2801
2802 /**
2803 * Parses a group and returns the head node of a set of nodes that process
2804 * the group. Sometimes a double return system is used where the tail is
2805 * returned in root.
2806 */
2807 private Node group0() {
2808 boolean capturingGroup = false;
2809 Node head = null;
2810 Node tail = null;
2811 int save = flags;
2812 root = null;
2813 int ch = next();
2814 if (ch == '?') {
2815 ch = skip();
2816 switch (ch) {
2817 case ':': // (?:xxx) pure group
2818 head = createGroup(true);
2819 tail = root;
2820 head.next = expr(tail);
2821 break;
2822 case '=': // (?=xxx) and (?!xxx) lookahead
2823 case '!':
2824 head = createGroup(true);
2825 tail = root;
2826 head.next = expr(tail);
2827 if (ch == '=') {
2828 head = tail = new Pos(head);
2829 } else {
2830 head = tail = new Neg(head);
2831 }
2832 break;
2833 case '>': // (?>xxx) independent group
2834 head = createGroup(true);
2835 tail = root;
2836 head.next = expr(tail);
2837 head = tail = new Ques(head, INDEPENDENT);
2838 break;
2839 case '<': // (?<xxx) look behind
2840 ch = read();
2841 if (ASCII.isLower(ch) || ASCII.isUpper(ch)) {
2842 // named captured group
2843 String name = groupname(ch);
2844 if (namedGroups().containsKey(name))
2845 throw error("Named capturing group <" + name
2846 + "> is already defined");
2847 capturingGroup = true;
2848 head = createGroup(false);
2849 tail = root;
2850 namedGroups().put(name, capturingGroupCount-1);
2851 head.next = expr(tail);
2852 break;
2853 }
2854 int start = cursor;
2855 head = createGroup(true);
2856 tail = root;
2857 head.next = expr(tail);
2858 tail.next = lookbehindEnd;
2859 TreeInfo info = new TreeInfo();
2860 head.study(info);
2861 if (info.maxValid == false) {
2862 throw error("Look-behind group does not have "
2863 + "an obvious maximum length");
2864 }
2865 boolean hasSupplementary = findSupplementary(start, patternLength);
2866 if (ch == '=') {
2867 head = tail = (hasSupplementary ?
2868 new BehindS(head, info.maxLength,
2869 info.minLength) :
2870 new Behind(head, info.maxLength,
2871 info.minLength));
2872 } else if (ch == '!') {
2873 head = tail = (hasSupplementary ?
2874 new NotBehindS(head, info.maxLength,
2875 info.minLength) :
2876 new NotBehind(head, info.maxLength,
2877 info.minLength));
2878 } else {
2879 throw error("Unknown look-behind group");
2880 }
2881 break;
2882 case '$':
2883 case '@':
2884 throw error("Unknown group type");
2885 default: // (?xxx:) inlined match flags
2886 unread();
2887 addFlag();
2888 ch = read();
2889 if (ch == ')') {
2890 return null; // Inline modifier only
2891 }
2892 if (ch != ':') {
2893 throw error("Unknown inline modifier");
2894 }
2895 head = createGroup(true);
2896 tail = root;
2897 head.next = expr(tail);
2898 break;
2899 }
2900 } else { // (xxx) a regular group
2901 capturingGroup = true;
2902 head = createGroup(false);
2903 tail = root;
2904 head.next = expr(tail);
2905 }
2906
2907 accept(')', "Unclosed group");
2908 flags = save;
2909
2910 // Check for quantifiers
2911 Node node = closure(head);
2912 if (node == head) { // No closure
2913 root = tail;
2914 return node; // Dual return
2915 }
2916 if (head == tail) { // Zero length assertion
2917 root = node;
2918 return node; // Dual return
2919 }
2920
2921 if (node instanceof Ques) {
2922 Ques ques = (Ques) node;
2923 if (ques.type == POSSESSIVE) {
2924 root = node;
2925 return node;
2926 }
2927 tail.next = new BranchConn();
2928 tail = tail.next;
2929 if (ques.type == GREEDY) {
2930 head = new Branch(head, null, tail);
2931 } else { // Reluctant quantifier
2932 head = new Branch(null, head, tail);
2933 }
2934 root = tail;
2935 return head;
2936 } else if (node instanceof Curly) {
2937 Curly curly = (Curly) node;
2938 if (curly.type == POSSESSIVE) {
2939 root = node;
2940 return node;
2941 }
2942 // Discover if the group is deterministic
2943 TreeInfo info = new TreeInfo();
2944 if (head.study(info)) { // Deterministic
2945 GroupTail temp = (GroupTail) tail;
2946 head = root = new GroupCurly(head.next, curly.cmin,
2947 curly.cmax, curly.type,
2948 ((GroupTail)tail).localIndex,
2949 ((GroupTail)tail).groupIndex,
2950 capturingGroup);
2951 return head;
2952 } else { // Non-deterministic
2953 int temp = ((GroupHead) head).localIndex;
2954 Loop loop;
2955 if (curly.type == GREEDY)
2956 loop = new Loop(this.localCount, temp);
2957 else // Reluctant Curly
2958 loop = new LazyLoop(this.localCount, temp);
2959 Prolog prolog = new Prolog(loop);
2960 this.localCount += 1;
2961 loop.cmin = curly.cmin;
2962 loop.cmax = curly.cmax;
2963 loop.body = head;
2964 tail.next = loop;
2965 root = loop;
2966 return prolog; // Dual return
2967 }
2968 }
2969 throw error("Internal logic error");
2970 }
2971
2972 /**
2973 * Create group head and tail nodes using double return. If the group is
2974 * created with anonymous true then it is a pure group and should not
2975 * affect group counting.
2976 */
2977 private Node createGroup(boolean anonymous) {
2978 int localIndex = localCount++;
2979 int groupIndex = 0;
2980 if (!anonymous)
2981 groupIndex = capturingGroupCount++;
2982 GroupHead head = new GroupHead(localIndex);
2983 root = new GroupTail(localIndex, groupIndex);
2984 if (!anonymous && groupIndex < 10)
2985 groupNodes[groupIndex] = head;
2986 return head;
2987 }
2988
2989 @SuppressWarnings("fallthrough")
2990 /**
2991 * Parses inlined match flags and set them appropriately.
2992 */
2993 private void addFlag() {
2994 int ch = peek();
2995 for (;;) {
2996 switch (ch) {
2997 case 'i':
2998 flags |= CASE_INSENSITIVE;
2999 break;
3000 case 'm':
3001 flags |= MULTILINE;
3002 break;
3003 case 's':
3004 flags |= DOTALL;
3005 break;
3006 case 'd':
3007 flags |= UNIX_LINES;
3008 break;
3009 case 'u':
3010 flags |= UNICODE_CASE;
3011 break;
3012 case 'c':
3013 flags |= CANON_EQ;
3014 break;
3015 case 'x':
3016 flags |= COMMENTS;
3017 break;
3018 case 'U':
3019 flags |= (UNICODE_CHARACTER_CLASS | UNICODE_CASE);
3020 break;
3021 case '-': // subFlag then fall through
3022 ch = next();
3023 subFlag();
3024 default:
3025 return;
3026 }
3027 ch = next();
3028 }
3029 }
3030
3031 @SuppressWarnings("fallthrough")
3032 /**
3033 * Parses the second part of inlined match flags and turns off
3034 * flags appropriately.
3035 */
3036 private void subFlag() {
3037 int ch = peek();
3038 for (;;) {
3039 switch (ch) {
3040 case 'i':
3041 flags &= ~CASE_INSENSITIVE;
3042 break;
3043 case 'm':
3044 flags &= ~MULTILINE;
3045 break;
3046 case 's':
3047 flags &= ~DOTALL;
3048 break;
3049 case 'd':
3050 flags &= ~UNIX_LINES;
3051 break;
3052 case 'u':
3053 flags &= ~UNICODE_CASE;
3054 break;
3055 case 'c':
3056 flags &= ~CANON_EQ;
3057 break;
3058 case 'x':
3059 flags &= ~COMMENTS;
3060 break;
3061 case 'U':
3062 flags &= ~(UNICODE_CHARACTER_CLASS | UNICODE_CASE);
3063 default:
3064 return;
3065 }
3066 ch = next();
3067 }
3068 }
3069
3070 static final int MAX_REPS = 0x7FFFFFFF;
3071
3072 static final int GREEDY = 0;
3073
3074 static final int LAZY = 1;
3075
3076 static final int POSSESSIVE = 2;
3077
3078 static final int INDEPENDENT = 3;
3079
3080 /**
3081 * Processes repetition. If the next character peeked is a quantifier
3082 * then new nodes must be appended to handle the repetition.
3083 * Prev could be a single or a group, so it could be a chain of nodes.
3084 */
3085 private Node closure(Node prev) {
3086 Node atom;
3087 int ch = peek();
3088 switch (ch) {
3089 case '?':
3090 ch = next();
3091 if (ch == '?') {
3092 next();
3093 return new Ques(prev, LAZY);
3094 } else if (ch == '+') {
3095 next();
3096 return new Ques(prev, POSSESSIVE);
3097 }
3098 return new Ques(prev, GREEDY);
3099 case '*':
3100 ch = next();
3101 if (ch == '?') {
3102 next();
3103 return new Curly(prev, 0, MAX_REPS, LAZY);
3104 } else if (ch == '+') {
3105 next();
3106 return new Curly(prev, 0, MAX_REPS, POSSESSIVE);
3107 }
3108 return new Curly(prev, 0, MAX_REPS, GREEDY);
3109 case '+':
3110 ch = next();
3111 if (ch == '?') {
3112 next();
3113 return new Curly(prev, 1, MAX_REPS, LAZY);
3114 } else if (ch == '+') {
3115 next();
3116 return new Curly(prev, 1, MAX_REPS, POSSESSIVE);
3117 }
3118 return new Curly(prev, 1, MAX_REPS, GREEDY);
3119 case '{':
3120 ch = temp[cursor+1];
3121 if (ASCII.isDigit(ch)) {
3122 skip();
3123 int cmin = 0;
3124 do {
3125 cmin = cmin * 10 + (ch - '0');
3126 } while (ASCII.isDigit(ch = read()));
3127 int cmax = cmin;
3128 if (ch == ',') {
3129 ch = read();
3130 cmax = MAX_REPS;
3131 if (ch != '}') {
3132 cmax = 0;
3133 while (ASCII.isDigit(ch)) {
3134 cmax = cmax * 10 + (ch - '0');
3135 ch = read();
3136 }
3137 }
3138 }
3139 if (ch != '}')
3140 throw error("Unclosed counted closure");
3141 if (((cmin) | (cmax) | (cmax - cmin)) < 0)
3142 throw error("Illegal repetition range");
3143 Curly curly;
3144 ch = peek();
3145 if (ch == '?') {
3146 next();
3147 curly = new Curly(prev, cmin, cmax, LAZY);
3148 } else if (ch == '+') {
3149 next();
3150 curly = new Curly(prev, cmin, cmax, POSSESSIVE);
3151 } else {
3152 curly = new Curly(prev, cmin, cmax, GREEDY);
3153 }
3154 return curly;
3155 } else {
3156 throw error("Illegal repetition");
3157 }
3158 default:
3159 return prev;
3160 }
3161 }
3162
3163 /**
3164 * Utility method for parsing control escape sequences.
3165 */
3166 private int c() {
3167 if (cursor < patternLength) {
3168 return read() ^ 64;
3169 }
3170 throw error("Illegal control escape sequence");
3171 }
3172
3173 /**
3174 * Utility method for parsing octal escape sequences.
3175 */
3176 private int o() {
3177 int n = read();
3178 if (((n-'0')|('7'-n)) >= 0) {
3179 int m = read();
3180 if (((m-'0')|('7'-m)) >= 0) {
3181 int o = read();
3182 if ((((o-'0')|('7'-o)) >= 0) && (((n-'0')|('3'-n)) >= 0)) {
3183 return (n - '0') * 64 + (m - '0') * 8 + (o - '0');
3184 }
3185 unread();
3186 return (n - '0') * 8 + (m - '0');
3187 }
3188 unread();
3189 return (n - '0');
3190 }
3191 throw error("Illegal octal escape sequence");
3192 }
3193
3194 /**
3195 * Utility method for parsing hexadecimal escape sequences.
3196 */
3197 private int x() {
3198 int n = read();
3199 if (ASCII.isHexDigit(n)) {
3200 int m = read();
3201 if (ASCII.isHexDigit(m)) {
3202 return ASCII.toDigit(n) * 16 + ASCII.toDigit(m);
3203 }
3204 } else if (n == '{' && ASCII.isHexDigit(peek())) {
3205 int ch = 0;
3206 while (ASCII.isHexDigit(n = read())) {
3207 ch = (ch << 4) + ASCII.toDigit(n);
3208 if (ch > Character.MAX_CODE_POINT)
3209 throw error("Hexadecimal codepoint is too big");
3210 }
3211 if (n != '}')
3212 throw error("Unclosed hexadecimal escape sequence");
3213 return ch;
3214 }
3215 throw error("Illegal hexadecimal escape sequence");
3216 }
3217
3218 /**
3219 * Utility method for parsing unicode escape sequences.
3220 */
3221 private int cursor() {
3222 return cursor;
3223 }
3224
3225 private void setcursor(int pos) {
3226 cursor = pos;
3227 }
3228
3229 private int uxxxx() {
3230 int n = 0;
3231 for (int i = 0; i < 4; i++) {
3232 int ch = read();
3233 if (!ASCII.isHexDigit(ch)) {
3234 throw error("Illegal Unicode escape sequence");
3235 }
3236 n = n * 16 + ASCII.toDigit(ch);
3237 }
3238 return n;
3239 }
3240
3241 private int u() {
3242 int n = uxxxx();
3243 if (Character.isHighSurrogate((char)n)) {
3244 int cur = cursor();
3245 if (read() == '\\' && read() == 'u') {
3246 int n2 = uxxxx();
3247 if (Character.isLowSurrogate((char)n2))
3248 return Character.toCodePoint((char)n, (char)n2);
3249 }
3250 setcursor(cur);
3251 }
3252 return n;
3253 }
3254
3255 //
3256 // Utility methods for code point support
3257 //
3258
3259 private static final int countChars(CharSequence seq, int index,
3260 int lengthInCodePoints) {
3261 // optimization
3262 if (lengthInCodePoints == 1 && !Character.isHighSurrogate(seq.charAt(index))) {
3263 assert (index >= 0 && index < seq.length());
3264 return 1;
3265 }
3266 int length = seq.length();
3267 int x = index;
3268 if (lengthInCodePoints >= 0) {
3269 assert (index >= 0 && index < length);
3270 for (int i = 0; x < length && i < lengthInCodePoints; i++) {
3271 if (Character.isHighSurrogate(seq.charAt(x++))) {
3272 if (x < length && Character.isLowSurrogate(seq.charAt(x))) {
3273 x++;
3274 }
3275 }
3276 }
3277 return x - index;
3278 }
3279
3280 assert (index >= 0 && index <= length);
3281 if (index == 0) {
3282 return 0;
3283 }
3284 int len = -lengthInCodePoints;
3285 for (int i = 0; x > 0 && i < len; i++) {
3286 if (Character.isLowSurrogate(seq.charAt(--x))) {
3287 if (x > 0 && Character.isHighSurrogate(seq.charAt(x-1))) {
3288 x--;
3289 }
3290 }
3291 }
3292 return index - x;
3293 }
3294
3295 private static final int countCodePoints(CharSequence seq) {
3296 int length = seq.length();
3297 int n = 0;
3298 for (int i = 0; i < length; ) {
3299 n++;
3300 if (Character.isHighSurrogate(seq.charAt(i++))) {
3301 if (i < length && Character.isLowSurrogate(seq.charAt(i))) {
3302 i++;
3303 }
3304 }
3305 }
3306 return n;
3307 }
3308
3309 /**
3310 * Creates a bit vector for matching Latin-1 values. A normal BitClass
3311 * never matches values above Latin-1, and a complemented BitClass always
3312 * matches values above Latin-1.
3313 */
3314 private static final class BitClass extends BmpCharProperty {
3315 final boolean[] bits;
3316 BitClass() { bits = new boolean[256]; }
3317 private BitClass(boolean[] bits) { this.bits = bits; }
3318 BitClass add(int c, int flags) {
3319 assert c >= 0 && c <= 255;
3320 if ((flags & CASE_INSENSITIVE) != 0) {
3321 if (ASCII.isAscii(c)) {
3322 bits[ASCII.toUpper(c)] = true;
3323 bits[ASCII.toLower(c)] = true;
3324 } else if ((flags & UNICODE_CASE) != 0) {
3325 bits[Character.toLowerCase(c)] = true;
3326 bits[Character.toUpperCase(c)] = true;
3327 }
3328 }
3329 bits[c] = true;
3330 return this;
3331 }
3332 boolean isSatisfiedBy(int ch) {
3333 return ch < 256 && bits[ch];
3334 }
3335 }
3336
3337 /**
3338 * Returns a suitably optimized, single character matcher.
3339 */
3340 private CharProperty newSingle(final int ch) {
3341 if (has(CASE_INSENSITIVE)) {
3342 int lower, upper;
3343 if (has(UNICODE_CASE)) {
3344 upper = Character.toUpperCase(ch);
3345 lower = Character.toLowerCase(upper);
3346 if (upper != lower)
3347 return new SingleU(lower);
3348 } else if (ASCII.isAscii(ch)) {
3349 lower = ASCII.toLower(ch);
3350 upper = ASCII.toUpper(ch);
3351 if (lower != upper)
3352 return new SingleI(lower, upper);
3353 }
3354 }
3355 if (isSupplementary(ch))
3356 return new SingleS(ch); // Match a given Unicode character
3357 return new Single(ch); // Match a given BMP character
3358 }
3359
3360 /**
3361 * Utility method for creating a string slice matcher.
3362 */
3363 private Node newSlice(int[] buf, int count, boolean hasSupplementary) {
3364 int[] tmp = new int[count];
3365 if (has(CASE_INSENSITIVE)) {
3366 if (has(UNICODE_CASE)) {
3367 for (int i = 0; i < count; i++) {
3368 tmp[i] = Character.toLowerCase(
3369 Character.toUpperCase(buf[i]));
3370 }
3371 return hasSupplementary? new SliceUS(tmp) : new SliceU(tmp);
3372 }
3373 for (int i = 0; i < count; i++) {
3374 tmp[i] = ASCII.toLower(buf[i]);
3375 }
3376 return hasSupplementary? new SliceIS(tmp) : new SliceI(tmp);
3377 }
3378 for (int i = 0; i < count; i++) {
3379 tmp[i] = buf[i];
3380 }
3381 return hasSupplementary ? new SliceS(tmp) : new Slice(tmp);
3382 }
3383
3384 /**
3385 * The following classes are the building components of the object
3386 * tree that represents a compiled regular expression. The object tree
3387 * is made of individual elements that handle constructs in the Pattern.
3388 * Each type of object knows how to match its equivalent construct with
3389 * the match() method.
3390 */
3391
3392 /**
3393 * Base class for all node classes. Subclasses should override the match()
3394 * method as appropriate. This class is an accepting node, so its match()
3395 * always returns true.
3396 */
3397 static class Node extends Object {
3398 Node next;
3399 Node() {
3400 next = Pattern.accept;
3401 }
3402 /**
3403 * This method implements the classic accept node.
3404 */
3405 boolean match(Matcher matcher, int i, CharSequence seq) {
3406 matcher.last = i;
3407 matcher.groups[0] = matcher.first;
3408 matcher.groups[1] = matcher.last;
3409 return true;
3410 }
3411 /**
3412 * This method is good for all zero length assertions.
3413 */
3414 boolean study(TreeInfo info) {
3415 if (next != null) {
3416 return next.study(info);
3417 } else {
3418 return info.deterministic;
3419 }
3420 }
3421 }
3422
3423 static class LastNode extends Node {
3424 /**
3425 * This method implements the classic accept node with
3426 * the addition of a check to see if the match occurred
3427 * using all of the input.
3428 */
3429 boolean match(Matcher matcher, int i, CharSequence seq) {
3430 if (matcher.acceptMode == Matcher.ENDANCHOR && i != matcher.to)
3431 return false;
3432 matcher.last = i;
3433 matcher.groups[0] = matcher.first;
3434 matcher.groups[1] = matcher.last;
3435 return true;
3436 }
3437 }
3438
3439 /**
3440 * Used for REs that can start anywhere within the input string.
3441 * This basically tries to match repeatedly at each spot in the
3442 * input string, moving forward after each try. An anchored search
3443 * or a BnM will bypass this node completely.
3444 */
3445 static class Start extends Node {
3446 int minLength;
3447 Start(Node node) {
3448 this.next = node;
3449 TreeInfo info = new TreeInfo();
3450 next.study(info);
3451 minLength = info.minLength;
3452 }
3453 boolean match(Matcher matcher, int i, CharSequence seq) {
3454 if (i > matcher.to - minLength) {
3455 matcher.hitEnd = true;
3456 return false;
3457 }
3458 int guard = matcher.to - minLength;
3459 for (; i <= guard; i++) {
3460 if (next.match(matcher, i, seq)) {
3461 matcher.first = i;
3462 matcher.groups[0] = matcher.first;
3463 matcher.groups[1] = matcher.last;
3464 return true;
3465 }
3466 }
3467 matcher.hitEnd = true;
3468 return false;
3469 }
3470 boolean study(TreeInfo info) {
3471 next.study(info);
3472 info.maxValid = false;
3473 info.deterministic = false;
3474 return false;
3475 }
3476 }
3477
3478 /*
3479 * StartS supports supplementary characters, including unpaired surrogates.
3480 */
3481 static final class StartS extends Start {
3482 StartS(Node node) {
3483 super(node);
3484 }
3485 boolean match(Matcher matcher, int i, CharSequence seq) {
3486 if (i > matcher.to - minLength) {
3487 matcher.hitEnd = true;
3488 return false;
3489 }
3490 int guard = matcher.to - minLength;
3491 while (i <= guard) {
3492 //if ((ret = next.match(matcher, i, seq)) || i == guard)
3493 if (next.match(matcher, i, seq)) {
3494 matcher.first = i;
3495 matcher.groups[0] = matcher.first;
3496 matcher.groups[1] = matcher.last;
3497 return true;
3498 }
3499 if (i == guard)
3500 break;
3501 // Optimization to move to the next character. This is
3502 // faster than countChars(seq, i, 1).
3503 if (Character.isHighSurrogate(seq.charAt(i++))) {
3504 if (i < seq.length() &&
3505 Character.isLowSurrogate(seq.charAt(i))) {
3506 i++;
3507 }
3508 }
3509 }
3510 matcher.hitEnd = true;
3511 return false;
3512 }
3513 }
3514
3515 /**
3516 * Node to anchor at the beginning of input. This object implements the
3517 * match for a \A sequence, and the caret anchor will use this if not in
3518 * multiline mode.
3519 */
3520 static final class Begin extends Node {
3521 boolean match(Matcher matcher, int i, CharSequence seq) {
3522 int fromIndex = (matcher.anchoringBounds) ?
3523 matcher.from : 0;
3524 if (i == fromIndex && next.match(matcher, i, seq)) {
3525 matcher.first = i;
3526 matcher.groups[0] = i;
3527 matcher.groups[1] = matcher.last;
3528 return true;
3529 } else {
3530 return false;
3531 }
3532 }
3533 }
3534
3535 /**
3536 * Node to anchor at the end of input. This is the absolute end, so this
3537 * should not match at the last newline before the end as $ will.
3538 */
3539 static final class End extends Node {
3540 boolean match(Matcher matcher, int i, CharSequence seq) {
3541 int endIndex = (matcher.anchoringBounds) ?
3542 matcher.to : matcher.getTextLength();
3543 if (i == endIndex) {
3544 matcher.hitEnd = true;
3545 return next.match(matcher, i, seq);
3546 }
3547 return false;
3548 }
3549 }
3550
3551 /**
3552 * Node to anchor at the beginning of a line. This is essentially the
3553 * object to match for the multiline ^.
3554 */
3555 static final class Caret extends Node {
3556 boolean match(Matcher matcher, int i, CharSequence seq) {
3557 int startIndex = matcher.from;
3558 int endIndex = matcher.to;
3559 if (!matcher.anchoringBounds) {
3560 startIndex = 0;
3561 endIndex = matcher.getTextLength();
3562 }
3563 // Perl does not match ^ at end of input even after newline
3564 if (i == endIndex) {
3565 matcher.hitEnd = true;
3566 return false;
3567 }
3568 if (i > startIndex) {
3569 char ch = seq.charAt(i-1);
3570 if (ch != '\n' && ch != '\r'
3571 && (ch|1) != '\u2029'
3572 && ch != '\u0085' ) {
3573 return false;
3574 }
3575 // Should treat /r/n as one newline
3576 if (ch == '\r' && seq.charAt(i) == '\n')
3577 return false;
3578 }
3579 return next.match(matcher, i, seq);
3580 }
3581 }
3582
3583 /**
3584 * Node to anchor at the beginning of a line when in unixdot mode.
3585 */
3586 static final class UnixCaret extends Node {
3587 boolean match(Matcher matcher, int i, CharSequence seq) {
3588 int startIndex = matcher.from;
3589 int endIndex = matcher.to;
3590 if (!matcher.anchoringBounds) {
3591 startIndex = 0;
3592 endIndex = matcher.getTextLength();
3593 }
3594 // Perl does not match ^ at end of input even after newline
3595 if (i == endIndex) {
3596 matcher.hitEnd = true;
3597 return false;
3598 }
3599 if (i > startIndex) {
3600 char ch = seq.charAt(i-1);
3601 if (ch != '\n') {
3602 return false;
3603 }
3604 }
3605 return next.match(matcher, i, seq);
3606 }
3607 }
3608
3609 /**
3610 * Node to match the location where the last match ended.
3611 * This is used for the \G construct.
3612 */
3613 static final class LastMatch extends Node {
3614 boolean match(Matcher matcher, int i, CharSequence seq) {
3615 if (i != matcher.oldLast)
3616 return false;
3617 return next.match(matcher, i, seq);
3618 }
3619 }
3620
3621 /**
3622 * Node to anchor at the end of a line or the end of input based on the
3623 * multiline mode.
3624 *
3625 * When not in multiline mode, the $ can only match at the very end
3626 * of the input, unless the input ends in a line terminator in which
3627 * it matches right before the last line terminator.
3628 *
3629 * Note that \r\n is considered an atomic line terminator.
3630 *
3631 * Like ^ the $ operator matches at a position, it does not match the
3632 * line terminators themselves.
3633 */
3634 static final class Dollar extends Node {
3635 boolean multiline;
3636 Dollar(boolean mul) {
3637 multiline = mul;
3638 }
3639 boolean match(Matcher matcher, int i, CharSequence seq) {
3640 int endIndex = (matcher.anchoringBounds) ?
3641 matcher.to : matcher.getTextLength();
3642 if (!multiline) {
3643 if (i < endIndex - 2)
3644 return false;
3645 if (i == endIndex - 2) {
3646 char ch = seq.charAt(i);
3647 if (ch != '\r')
3648 return false;
3649 ch = seq.charAt(i + 1);
3650 if (ch != '\n')
3651 return false;
3652 }
3653 }
3654 // Matches before any line terminator; also matches at the
3655 // end of input
3656 // Before line terminator:
3657 // If multiline, we match here no matter what
3658 // If not multiline, fall through so that the end
3659 // is marked as hit; this must be a /r/n or a /n
3660 // at the very end so the end was hit; more input
3661 // could make this not match here
3662 if (i < endIndex) {
3663 char ch = seq.charAt(i);
3664 if (ch == '\n') {
3665 // No match between \r\n
3666 if (i > 0 && seq.charAt(i-1) == '\r')
3667 return false;
3668 if (multiline)
3669 return next.match(matcher, i, seq);
3670 } else if (ch == '\r' || ch == '\u0085' ||
3671 (ch|1) == '\u2029') {
3672 if (multiline)
3673 return next.match(matcher, i, seq);
3674 } else { // No line terminator, no match
3675 return false;
3676 }
3677 }
3678 // Matched at current end so hit end
3679 matcher.hitEnd = true;
3680 // If a $ matches because of end of input, then more input
3681 // could cause it to fail!
3682 matcher.requireEnd = true;
3683 return next.match(matcher, i, seq);
3684 }
3685 boolean study(TreeInfo info) {
3686 next.study(info);
3687 return info.deterministic;
3688 }
3689 }
3690
3691 /**
3692 * Node to anchor at the end of a line or the end of input based on the
3693 * multiline mode when in unix lines mode.
3694 */
3695 static final class UnixDollar extends Node {
3696 boolean multiline;
3697 UnixDollar(boolean mul) {
3698 multiline = mul;
3699 }
3700 boolean match(Matcher matcher, int i, CharSequence seq) {
3701 int endIndex = (matcher.anchoringBounds) ?
3702 matcher.to : matcher.getTextLength();
3703 if (i < endIndex) {
3704 char ch = seq.charAt(i);
3705 if (ch == '\n') {
3706 // If not multiline, then only possible to
3707 // match at very end or one before end
3708 if (multiline == false && i != endIndex - 1)
3709 return false;
3710 // If multiline return next.match without setting
3711 // matcher.hitEnd
3712 if (multiline)
3713 return next.match(matcher, i, seq);
3714 } else {
3715 return false;
3716 }
3717 }
3718 // Matching because at the end or 1 before the end;
3719 // more input could change this so set hitEnd
3720 matcher.hitEnd = true;
3721 // If a $ matches because of end of input, then more input
3722 // could cause it to fail!
3723 matcher.requireEnd = true;
3724 return next.match(matcher, i, seq);
3725 }
3726 boolean study(TreeInfo info) {
3727 next.study(info);
3728 return info.deterministic;
3729 }
3730 }
3731
3732 /**
3733 * Node class that matches a Unicode line ending '\R'
3734 */
3735 static final class LineEnding extends Node {
3736 boolean match(Matcher matcher, int i, CharSequence seq) {
3737 // (u+000Du+000A|[u+000Au+000Bu+000Cu+000Du+0085u+2028u+2029])
3738 if (i < matcher.to) {
3739 int ch = seq.charAt(i);
3740 if (ch == 0x0A || ch == 0x0B || ch == 0x0C ||
3741 ch == 0x85 || ch == 0x2028 || ch == 0x2029)
3742 return next.match(matcher, i + 1, seq);
3743 if (ch == 0x0D) {
3744 i++;
3745 if (i < matcher.to && seq.charAt(i) == 0x0A)
3746 i++;
3747 return next.match(matcher, i, seq);
3748 }
3749 } else {
3750 matcher.hitEnd = true;
3751 }
3752 return false;
3753 }
3754 boolean study(TreeInfo info) {
3755 info.minLength++;
3756 info.maxLength += 2;
3757 return next.study(info);
3758 }
3759 }
3760
3761 /**
3762 * Abstract node class to match one character satisfying some
3763 * boolean property.
3764 */
3765 private static abstract class CharProperty extends Node {
3766 abstract boolean isSatisfiedBy(int ch);
3767 CharProperty complement() {
3768 return new CharProperty() {
3769 boolean isSatisfiedBy(int ch) {
3770 return ! CharProperty.this.isSatisfiedBy(ch);}};
3771 }
3772 boolean match(Matcher matcher, int i, CharSequence seq) {
3773 if (i < matcher.to) {
3774 int ch = Character.codePointAt(seq, i);
3775 return isSatisfiedBy(ch)
3776 && next.match(matcher, i+Character.charCount(ch), seq);
3777 } else {
3778 matcher.hitEnd = true;
3779 return false;
3780 }
3781 }
3782 boolean study(TreeInfo info) {
3783 info.minLength++;
3784 info.maxLength++;
3785 return next.study(info);
3786 }
3787 }
3788
3789 /**
3790 * Optimized version of CharProperty that works only for
3791 * properties never satisfied by Supplementary characters.
3792 */
3793 private static abstract class BmpCharProperty extends CharProperty {
3794 boolean match(Matcher matcher, int i, CharSequence seq) {
3795 if (i < matcher.to) {
3796 return isSatisfiedBy(seq.charAt(i))
3797 && next.match(matcher, i+1, seq);
3798 } else {
3799 matcher.hitEnd = true;
3800 return false;
3801 }
3802 }
3803 }
3804
3805 /**
3806 * Node class that matches a Supplementary Unicode character
3807 */
3808 static final class SingleS extends CharProperty {
3809 final int c;
3810 SingleS(int c) { this.c = c; }
3811 boolean isSatisfiedBy(int ch) {
3812 return ch == c;
3813 }
3814 }
3815
3816 /**
3817 * Optimization -- matches a given BMP character
3818 */
3819 static final class Single extends BmpCharProperty {
3820 final int c;
3821 Single(int c) { this.c = c; }
3822 boolean isSatisfiedBy(int ch) {
3823 return ch == c;
3824 }
3825 }
3826
3827 /**
3828 * Case insensitive matches a given BMP character
3829 */
3830 static final class SingleI extends BmpCharProperty {
3831 final int lower;
3832 final int upper;
3833 SingleI(int lower, int upper) {
3834 this.lower = lower;
3835 this.upper = upper;
3836 }
3837 boolean isSatisfiedBy(int ch) {
3838 return ch == lower || ch == upper;
3839 }
3840 }
3841
3842 /**
3843 * Unicode case insensitive matches a given Unicode character
3844 */
3845 static final class SingleU extends CharProperty {
3846 final int lower;
3847 SingleU(int lower) {
3848 this.lower = lower;
3849 }
3850 boolean isSatisfiedBy(int ch) {
3851 return lower == ch ||
3852 lower == Character.toLowerCase(Character.toUpperCase(ch));
3853 }
3854 }
3855
3856 /**
3857 * Node class that matches a Unicode block.
3858 */
3859 static final class Block extends CharProperty {
3860 final Character.UnicodeBlock block;
3861 Block(Character.UnicodeBlock block) {
3862 this.block = block;
3863 }
3864 boolean isSatisfiedBy(int ch) {
3865 return block == Character.UnicodeBlock.of(ch);
3866 }
3867 }
3868
3869 /**
3870 * Node class that matches a Unicode script
3871 */
3872 static final class Script extends CharProperty {
3873 final Character.UnicodeScript script;
3874 Script(Character.UnicodeScript script) {
3875 this.script = script;
3876 }
3877 boolean isSatisfiedBy(int ch) {
3878 return script == Character.UnicodeScript.of(ch);
3879 }
3880 }
3881
3882 /**
3883 * Node class that matches a Unicode category.
3884 */
3885 static final class Category extends CharProperty {
3886 final int typeMask;
3887 Category(int typeMask) { this.typeMask = typeMask; }
3888 boolean isSatisfiedBy(int ch) {
3889 return (typeMask & (1 << Character.getType(ch))) != 0;
3890 }
3891 }
3892
3893 /**
3894 * Node class that matches a Unicode "type"
3895 */
3896 static final class Utype extends CharProperty {
3897 final UnicodeProp uprop;
3898 Utype(UnicodeProp uprop) { this.uprop = uprop; }
3899 boolean isSatisfiedBy(int ch) {
3900 return uprop.is(ch);
3901 }
3902 }
3903
3904 /**
3905 * Node class that matches a POSIX type.
3906 */
3907 static final class Ctype extends BmpCharProperty {
3908 final int ctype;
3909 Ctype(int ctype) { this.ctype = ctype; }
3910 boolean isSatisfiedBy(int ch) {
3911 return ch < 128 && ASCII.isType(ch, ctype);
3912 }
3913 }
3914
3915 /**
3916 * Node class that matches a Perl vertical whitespace
3917 */
3918 static final class VertWS extends BmpCharProperty {
3919 boolean isSatisfiedBy(int cp) {
3920 return (cp >= 0x0A && cp <= 0x0D) ||
3921 cp == 0x85 || cp == 0x2028 || cp == 0x2029;
3922 }
3923 }
3924
3925 /**
3926 * Node class that matches a Perl horizontal whitespace
3927 */
3928 static final class HorizWS extends BmpCharProperty {
3929 boolean isSatisfiedBy(int cp) {
3930 return cp == 0x09 || cp == 0x20 || cp == 0xa0 ||
3931 cp == 0x1680 || cp == 0x180e ||
3932 cp >= 0x2000 && cp <= 0x200a ||
3933 cp == 0x202f || cp == 0x205f || cp == 0x3000;
3934 }
3935 }
3936
3937 /**
3938 * Base class for all Slice nodes
3939 */
3940 static class SliceNode extends Node {
3941 int[] buffer;
3942 SliceNode(int[] buf) {
3943 buffer = buf;
3944 }
3945 boolean study(TreeInfo info) {
3946 info.minLength += buffer.length;
3947 info.maxLength += buffer.length;
3948 return next.study(info);
3949 }
3950 }
3951
3952 /**
3953 * Node class for a case sensitive/BMP-only sequence of literal
3954 * characters.
3955 */
3956 static final class Slice extends SliceNode {
3957 Slice(int[] buf) {
3958 super(buf);
3959 }
3960 boolean match(Matcher matcher, int i, CharSequence seq) {
3961 int[] buf = buffer;
3962 int len = buf.length;
3963 for (int j=0; j<len; j++) {
3964 if ((i+j) >= matcher.to) {
3965 matcher.hitEnd = true;
3966 return false;
3967 }
3968 if (buf[j] != seq.charAt(i+j))
3969 return false;
3970 }
3971 return next.match(matcher, i+len, seq);
3972 }
3973 }
3974
3975 /**
3976 * Node class for a case_insensitive/BMP-only sequence of literal
3977 * characters.
3978 */
3979 static class SliceI extends SliceNode {
3980 SliceI(int[] buf) {
3981 super(buf);
3982 }
3983 boolean match(Matcher matcher, int i, CharSequence seq) {
3984 int[] buf = buffer;
3985 int len = buf.length;
3986 for (int j=0; j<len; j++) {
3987 if ((i+j) >= matcher.to) {
3988 matcher.hitEnd = true;
3989 return false;
3990 }
3991 int c = seq.charAt(i+j);
3992 if (buf[j] != c &&
3993 buf[j] != ASCII.toLower(c))
3994 return false;
3995 }
3996 return next.match(matcher, i+len, seq);
3997 }
3998 }
3999
4000 /**
4001 * Node class for a unicode_case_insensitive/BMP-only sequence of
4002 * literal characters. Uses unicode case folding.
4003 */
4004 static final class SliceU extends SliceNode {
4005 SliceU(int[] buf) {
4006 super(buf);
4007 }
4008 boolean match(Matcher matcher, int i, CharSequence seq) {
4009 int[] buf = buffer;
4010 int len = buf.length;
4011 for (int j=0; j<len; j++) {
4012 if ((i+j) >= matcher.to) {
4013 matcher.hitEnd = true;
4014 return false;
4015 }
4016 int c = seq.charAt(i+j);
4017 if (buf[j] != c &&
4018 buf[j] != Character.toLowerCase(Character.toUpperCase(c)))
4019 return false;
4020 }
4021 return next.match(matcher, i+len, seq);
4022 }
4023 }
4024
4025 /**
4026 * Node class for a case sensitive sequence of literal characters
4027 * including supplementary characters.
4028 */
4029 static final class SliceS extends SliceNode {
4030 SliceS(int[] buf) {
4031 super(buf);
4032 }
4033 boolean match(Matcher matcher, int i, CharSequence seq) {
4034 int[] buf = buffer;
4035 int x = i;
4036 for (int j = 0; j < buf.length; j++) {
4037 if (x >= matcher.to) {
4038 matcher.hitEnd = true;
4039 return false;
4040 }
4041 int c = Character.codePointAt(seq, x);
4042 if (buf[j] != c)
4043 return false;
4044 x += Character.charCount(c);
4045 if (x > matcher.to) {
4046 matcher.hitEnd = true;
4047 return false;
4048 }
4049 }
4050 return next.match(matcher, x, seq);
4051 }
4052 }
4053
4054 /**
4055 * Node class for a case insensitive sequence of literal characters
4056 * including supplementary characters.
4057 */
4058 static class SliceIS extends SliceNode {
4059 SliceIS(int[] buf) {
4060 super(buf);
4061 }
4062 int toLower(int c) {
4063 return ASCII.toLower(c);
4064 }
4065 boolean match(Matcher matcher, int i, CharSequence seq) {
4066 int[] buf = buffer;
4067 int x = i;
4068 for (int j = 0; j < buf.length; j++) {
4069 if (x >= matcher.to) {
4070 matcher.hitEnd = true;
4071 return false;
4072 }
4073 int c = Character.codePointAt(seq, x);
4074 if (buf[j] != c && buf[j] != toLower(c))
4075 return false;
4076 x += Character.charCount(c);
4077 if (x > matcher.to) {
4078 matcher.hitEnd = true;
4079 return false;
4080 }
4081 }
4082 return next.match(matcher, x, seq);
4083 }
4084 }
4085
4086 /**
4087 * Node class for a case insensitive sequence of literal characters.
4088 * Uses unicode case folding.
4089 */
4090 static final class SliceUS extends SliceIS {
4091 SliceUS(int[] buf) {
4092 super(buf);
4093 }
4094 int toLower(int c) {
4095 return Character.toLowerCase(Character.toUpperCase(c));
4096 }
4097 }
4098
4099 private static boolean inRange(int lower, int ch, int upper) {
4100 return lower <= ch && ch <= upper;
4101 }
4102
4103 /**
4104 * Returns node for matching characters within an explicit value range.
4105 */
4106 private static CharProperty rangeFor(final int lower,
4107 final int upper) {
4108 return new CharProperty() {
4109 boolean isSatisfiedBy(int ch) {
4110 return inRange(lower, ch, upper);}};
4111 }
4112
4113 /**
4114 * Returns node for matching characters within an explicit value
4115 * range in a case insensitive manner.
4116 */
4117 private CharProperty caseInsensitiveRangeFor(final int lower,
4118 final int upper) {
4119 if (has(UNICODE_CASE))
4120 return new CharProperty() {
4121 boolean isSatisfiedBy(int ch) {
4122 if (inRange(lower, ch, upper))
4123 return true;
4124 int up = Character.toUpperCase(ch);
4125 return inRange(lower, up, upper) ||
4126 inRange(lower, Character.toLowerCase(up), upper);}};
4127 return new CharProperty() {
4128 boolean isSatisfiedBy(int ch) {
4129 return inRange(lower, ch, upper) ||
4130 ASCII.isAscii(ch) &&
4131 (inRange(lower, ASCII.toUpper(ch), upper) ||
4132 inRange(lower, ASCII.toLower(ch), upper));
4133 }};
4134 }
4135
4136 /**
4137 * Implements the Unicode category ALL and the dot metacharacter when
4138 * in dotall mode.
4139 */
4140 static final class All extends CharProperty {
4141 boolean isSatisfiedBy(int ch) {
4142 return true;
4143 }
4144 }
4145
4146 /**
4147 * Node class for the dot metacharacter when dotall is not enabled.
4148 */
4149 static final class Dot extends CharProperty {
4150 boolean isSatisfiedBy(int ch) {
4151 return (ch != '\n' && ch != '\r'
4152 && (ch|1) != '\u2029'
4153 && ch != '\u0085');
4154 }
4155 }
4156
4157 /**
4158 * Node class for the dot metacharacter when dotall is not enabled
4159 * but UNIX_LINES is enabled.
4160 */
4161 static final class UnixDot extends CharProperty {
4162 boolean isSatisfiedBy(int ch) {
4163 return ch != '\n';
4164 }
4165 }
4166
4167 /**
4168 * The 0 or 1 quantifier. This one class implements all three types.
4169 */
4170 static final class Ques extends Node {
4171 Node atom;
4172 int type;
4173 Ques(Node node, int type) {
4174 this.atom = node;
4175 this.type = type;
4176 }
4177 boolean match(Matcher matcher, int i, CharSequence seq) {
4178 switch (type) {
4179 case GREEDY:
4180 return (atom.match(matcher, i, seq) && next.match(matcher, matcher.last, seq))
4181 || next.match(matcher, i, seq);
4182 case LAZY:
4183 return next.match(matcher, i, seq)
4184 || (atom.match(matcher, i, seq) && next.match(matcher, matcher.last, seq));
4185 case POSSESSIVE:
4186 if (atom.match(matcher, i, seq)) i = matcher.last;
4187 return next.match(matcher, i, seq);
4188 default:
4189 return atom.match(matcher, i, seq) && next.match(matcher, matcher.last, seq);
4190 }
4191 }
4192 boolean study(TreeInfo info) {
4193 if (type != INDEPENDENT) {
4194 int minL = info.minLength;
4195 atom.study(info);
4196 info.minLength = minL;
4197 info.deterministic = false;
4198 return next.study(info);
4199 } else {
4200 atom.study(info);
4201 return next.study(info);
4202 }
4203 }
4204 }
4205
4206 /**
4207 * Handles the curly-brace style repetition with a specified minimum and
4208 * maximum occurrences. The * quantifier is handled as a special case.
4209 * This class handles the three types.
4210 */
4211 static final class Curly extends Node {
4212 Node atom;
4213 int type;
4214 int cmin;
4215 int cmax;
4216
4217 Curly(Node node, int cmin, int cmax, int type) {
4218 this.atom = node;
4219 this.type = type;
4220 this.cmin = cmin;
4221 this.cmax = cmax;
4222 }
4223 boolean match(Matcher matcher, int i, CharSequence seq) {
4224 int j;
4225 for (j = 0; j < cmin; j++) {
4226 if (atom.match(matcher, i, seq)) {
4227 i = matcher.last;
4228 continue;
4229 }
4230 return false;
4231 }
4232 if (type == GREEDY)
4233 return match0(matcher, i, j, seq);
4234 else if (type == LAZY)
4235 return match1(matcher, i, j, seq);
4236 else
4237 return match2(matcher, i, j, seq);
4238 }
4239 // Greedy match.
4240 // i is the index to start matching at
4241 // j is the number of atoms that have matched
4242 boolean match0(Matcher matcher, int i, int j, CharSequence seq) {
4243 if (j >= cmax) {
4244 // We have matched the maximum... continue with the rest of
4245 // the regular expression
4246 return next.match(matcher, i, seq);
4247 }
4248 int backLimit = j;
4249 while (atom.match(matcher, i, seq)) {
4250 // k is the length of this match
4251 int k = matcher.last - i;
4252 if (k == 0) // Zero length match
4253 break;
4254 // Move up index and number matched
4255 i = matcher.last;
4256 j++;
4257 // We are greedy so match as many as we can
4258 while (j < cmax) {
4259 if (!atom.match(matcher, i, seq))
4260 break;
4261 if (i + k != matcher.last) {
4262 if (match0(matcher, matcher.last, j+1, seq))
4263 return true;
4264 break;
4265 }
4266 i += k;
4267 j++;
4268 }
4269 // Handle backing off if match fails
4270 while (j >= backLimit) {
4271 if (next.match(matcher, i, seq))
4272 return true;
4273 i -= k;
4274 j--;
4275 }
4276 return false;
4277 }
4278 return next.match(matcher, i, seq);
4279 }
4280 // Reluctant match. At this point, the minimum has been satisfied.
4281 // i is the index to start matching at
4282 // j is the number of atoms that have matched
4283 boolean match1(Matcher matcher, int i, int j, CharSequence seq) {
4284 for (;;) {
4285 // Try finishing match without consuming any more
4286 if (next.match(matcher, i, seq))
4287 return true;
4288 // At the maximum, no match found
4289 if (j >= cmax)
4290 return false;
4291 // Okay, must try one more atom
4292 if (!atom.match(matcher, i, seq))
4293 return false;
4294 // If we haven't moved forward then must break out
4295 if (i == matcher.last)
4296 return false;
4297 // Move up index and number matched
4298 i = matcher.last;
4299 j++;
4300 }
4301 }
4302 boolean match2(Matcher matcher, int i, int j, CharSequence seq) {
4303 for (; j < cmax; j++) {
4304 if (!atom.match(matcher, i, seq))
4305 break;
4306 if (i == matcher.last)
4307 break;
4308 i = matcher.last;
4309 }
4310 return next.match(matcher, i, seq);
4311 }
4312 boolean study(TreeInfo info) {
4313 // Save original info
4314 int minL = info.minLength;
4315 int maxL = info.maxLength;
4316 boolean maxV = info.maxValid;
4317 boolean detm = info.deterministic;
4318 info.reset();
4319
4320 atom.study(info);
4321
4322 int temp = info.minLength * cmin + minL;
4323 if (temp < minL) {
4324 temp = 0xFFFFFFF; // arbitrary large number
4325 }
4326 info.minLength = temp;
4327
4328 if (maxV & info.maxValid) {
4329 temp = info.maxLength * cmax + maxL;
4330 info.maxLength = temp;
4331 if (temp < maxL) {
4332 info.maxValid = false;
4333 }
4334 } else {
4335 info.maxValid = false;
4336 }
4337
4338 if (info.deterministic && cmin == cmax)
4339 info.deterministic = detm;
4340 else
4341 info.deterministic = false;
4342 return next.study(info);
4343 }
4344 }
4345
4346 /**
4347 * Handles the curly-brace style repetition with a specified minimum and
4348 * maximum occurrences in deterministic cases. This is an iterative
4349 * optimization over the Prolog and Loop system which would handle this
4350 * in a recursive way. The * quantifier is handled as a special case.
4351 * If capture is true then this class saves group settings and ensures
4352 * that groups are unset when backing off of a group match.
4353 */
4354 static final class GroupCurly extends Node {
4355 Node atom;
4356 int type;
4357 int cmin;
4358 int cmax;
4359 int localIndex;
4360 int groupIndex;
4361 boolean capture;
4362
4363 GroupCurly(Node node, int cmin, int cmax, int type, int local,
4364 int group, boolean capture) {
4365 this.atom = node;
4366 this.type = type;
4367 this.cmin = cmin;
4368 this.cmax = cmax;
4369 this.localIndex = local;
4370 this.groupIndex = group;
4371 this.capture = capture;
4372 }
4373 boolean match(Matcher matcher, int i, CharSequence seq) {
4374 int[] groups = matcher.groups;
4375 int[] locals = matcher.locals;
4376 int save0 = locals[localIndex];
4377 int save1 = 0;
4378 int save2 = 0;
4379
4380 if (capture) {
4381 save1 = groups[groupIndex];
4382 save2 = groups[groupIndex+1];
4383 }
4384
4385 // Notify GroupTail there is no need to setup group info
4386 // because it will be set here
4387 locals[localIndex] = -1;
4388
4389 boolean ret = true;
4390 for (int j = 0; j < cmin; j++) {
4391 if (atom.match(matcher, i, seq)) {
4392 if (capture) {
4393 groups[groupIndex] = i;
4394 groups[groupIndex+1] = matcher.last;
4395 }
4396 i = matcher.last;
4397 } else {
4398 ret = false;
4399 break;
4400 }
4401 }
4402 if (ret) {
4403 if (type == GREEDY) {
4404 ret = match0(matcher, i, cmin, seq);
4405 } else if (type == LAZY) {
4406 ret = match1(matcher, i, cmin, seq);
4407 } else {
4408 ret = match2(matcher, i, cmin, seq);
4409 }
4410 }
4411 if (!ret) {
4412 locals[localIndex] = save0;
4413 if (capture) {
4414 groups[groupIndex] = save1;
4415 groups[groupIndex+1] = save2;
4416 }
4417 }
4418 return ret;
4419 }
4420 // Aggressive group match
4421 boolean match0(Matcher matcher, int i, int j, CharSequence seq) {
4422 // don't back off passing the starting "j"
4423 int min = j;
4424 int[] groups = matcher.groups;
4425 int save0 = 0;
4426 int save1 = 0;
4427 if (capture) {
4428 save0 = groups[groupIndex];
4429 save1 = groups[groupIndex+1];
4430 }
4431 for (;;) {
4432 if (j >= cmax)
4433 break;
4434 if (!atom.match(matcher, i, seq))
4435 break;
4436 int k = matcher.last - i;
4437 if (k <= 0) {
4438 if (capture) {
4439 groups[groupIndex] = i;
4440 groups[groupIndex+1] = i + k;
4441 }
4442 i = i + k;
4443 break;
4444 }
4445 for (;;) {
4446 if (capture) {
4447 groups[groupIndex] = i;
4448 groups[groupIndex+1] = i + k;
4449 }
4450 i = i + k;
4451 if (++j >= cmax)
4452 break;
4453 if (!atom.match(matcher, i, seq))
4454 break;
4455 if (i + k != matcher.last) {
4456 if (match0(matcher, i, j, seq))
4457 return true;
4458 break;
4459 }
4460 }
4461 while (j > min) {
4462 if (next.match(matcher, i, seq)) {
4463 if (capture) {
4464 groups[groupIndex+1] = i;
4465 groups[groupIndex] = i - k;
4466 }
4467 i = i - k;
4468 return true;
4469 }
4470 // backing off
4471 if (capture) {
4472 groups[groupIndex+1] = i;
4473 groups[groupIndex] = i - k;
4474 }
4475 i = i - k;
4476 j--;
4477 }
4478 break;
4479 }
4480 if (capture) {
4481 groups[groupIndex] = save0;
4482 groups[groupIndex+1] = save1;
4483 }
4484 return next.match(matcher, i, seq);
4485 }
4486 // Reluctant matching
4487 boolean match1(Matcher matcher, int i, int j, CharSequence seq) {
4488 for (;;) {
4489 if (next.match(matcher, i, seq))
4490 return true;
4491 if (j >= cmax)
4492 return false;
4493 if (!atom.match(matcher, i, seq))
4494 return false;
4495 if (i == matcher.last)
4496 return false;
4497 if (capture) {
4498 matcher.groups[groupIndex] = i;
4499 matcher.groups[groupIndex+1] = matcher.last;
4500 }
4501 i = matcher.last;
4502 j++;
4503 }
4504 }
4505 // Possessive matching
4506 boolean match2(Matcher matcher, int i, int j, CharSequence seq) {
4507 for (; j < cmax; j++) {
4508 if (!atom.match(matcher, i, seq)) {
4509 break;
4510 }
4511 if (capture) {
4512 matcher.groups[groupIndex] = i;
4513 matcher.groups[groupIndex+1] = matcher.last;
4514 }
4515 if (i == matcher.last) {
4516 break;
4517 }
4518 i = matcher.last;
4519 }
4520 return next.match(matcher, i, seq);
4521 }
4522 boolean study(TreeInfo info) {
4523 // Save original info
4524 int minL = info.minLength;
4525 int maxL = info.maxLength;
4526 boolean maxV = info.maxValid;
4527 boolean detm = info.deterministic;
4528 info.reset();
4529
4530 atom.study(info);
4531
4532 int temp = info.minLength * cmin + minL;
4533 if (temp < minL) {
4534 temp = 0xFFFFFFF; // Arbitrary large number
4535 }
4536 info.minLength = temp;
4537
4538 if (maxV & info.maxValid) {
4539 temp = info.maxLength * cmax + maxL;
4540 info.maxLength = temp;
4541 if (temp < maxL) {
4542 info.maxValid = false;
4543 }
4544 } else {
4545 info.maxValid = false;
4546 }
4547
4548 if (info.deterministic && cmin == cmax) {
4549 info.deterministic = detm;
4550 } else {
4551 info.deterministic = false;
4552 }
4553 return next.study(info);
4554 }
4555 }
4556
4557 /**
4558 * A Guard node at the end of each atom node in a Branch. It
4559 * serves the purpose of chaining the "match" operation to
4560 * "next" but not the "study", so we can collect the TreeInfo
4561 * of each atom node without including the TreeInfo of the
4562 * "next".
4563 */
4564 static final class BranchConn extends Node {
4565 BranchConn() {};
4566 boolean match(Matcher matcher, int i, CharSequence seq) {
4567 return next.match(matcher, i, seq);
4568 }
4569 boolean study(TreeInfo info) {
4570 return info.deterministic;
4571 }
4572 }
4573
4574 /**
4575 * Handles the branching of alternations. Note this is also used for
4576 * the ? quantifier to branch between the case where it matches once
4577 * and where it does not occur.
4578 */
4579 static final class Branch extends Node {
4580 Node[] atoms = new Node[2];
4581 int size = 2;
4582 Node conn;
4583 Branch(Node first, Node second, Node branchConn) {
4584 conn = branchConn;
4585 atoms[0] = first;
4586 atoms[1] = second;
4587 }
4588
4589 void add(Node node) {
4590 if (size >= atoms.length) {
4591 Node[] tmp = new Node[atoms.length*2];
4592 System.arraycopy(atoms, 0, tmp, 0, atoms.length);
4593 atoms = tmp;
4594 }
4595 atoms[size++] = node;
4596 }
4597
4598 boolean match(Matcher matcher, int i, CharSequence seq) {
4599 for (int n = 0; n < size; n++) {
4600 if (atoms[n] == null) {
4601 if (conn.next.match(matcher, i, seq))
4602 return true;
4603 } else if (atoms[n].match(matcher, i, seq)) {
4604 return true;
4605 }
4606 }
4607 return false;
4608 }
4609
4610 boolean study(TreeInfo info) {
4611 int minL = info.minLength;
4612 int maxL = info.maxLength;
4613 boolean maxV = info.maxValid;
4614
4615 int minL2 = Integer.MAX_VALUE; //arbitrary large enough num
4616 int maxL2 = -1;
4617 for (int n = 0; n < size; n++) {
4618 info.reset();
4619 if (atoms[n] != null)
4620 atoms[n].study(info);
4621 minL2 = Math.min(minL2, info.minLength);
4622 maxL2 = Math.max(maxL2, info.maxLength);
4623 maxV = (maxV & info.maxValid);
4624 }
4625
4626 minL += minL2;
4627 maxL += maxL2;
4628
4629 info.reset();
4630 conn.next.study(info);
4631
4632 info.minLength += minL;
4633 info.maxLength += maxL;
4634 info.maxValid &= maxV;
4635 info.deterministic = false;
4636 return false;
4637 }
4638 }
4639
4640 /**
4641 * The GroupHead saves the location where the group begins in the locals
4642 * and restores them when the match is done.
4643 *
4644 * The matchRef is used when a reference to this group is accessed later
4645 * in the expression. The locals will have a negative value in them to
4646 * indicate that we do not want to unset the group if the reference
4647 * doesn't match.
4648 */
4649 static final class GroupHead extends Node {
4650 int localIndex;
4651 GroupHead(int localCount) {
4652 localIndex = localCount;
4653 }
4654 boolean match(Matcher matcher, int i, CharSequence seq) {
4655 int save = matcher.locals[localIndex];
4656 matcher.locals[localIndex] = i;
4657 boolean ret = next.match(matcher, i, seq);
4658 matcher.locals[localIndex] = save;
4659 return ret;
4660 }
4661 boolean matchRef(Matcher matcher, int i, CharSequence seq) {
4662 int save = matcher.locals[localIndex];
4663 matcher.locals[localIndex] = ~i; // HACK
4664 boolean ret = next.match(matcher, i, seq);
4665 matcher.locals[localIndex] = save;
4666 return ret;
4667 }
4668 }
4669
4670 /**
4671 * Recursive reference to a group in the regular expression. It calls
4672 * matchRef because if the reference fails to match we would not unset
4673 * the group.
4674 */
4675 static final class GroupRef extends Node {
4676 GroupHead head;
4677 GroupRef(GroupHead head) {
4678 this.head = head;
4679 }
4680 boolean match(Matcher matcher, int i, CharSequence seq) {
4681 return head.matchRef(matcher, i, seq)
4682 && next.match(matcher, matcher.last, seq);
4683 }
4684 boolean study(TreeInfo info) {
4685 info.maxValid = false;
4686 info.deterministic = false;
4687 return next.study(info);
4688 }
4689 }
4690
4691 /**
4692 * The GroupTail handles the setting of group beginning and ending
4693 * locations when groups are successfully matched. It must also be able to
4694 * unset groups that have to be backed off of.
4695 *
4696 * The GroupTail node is also used when a previous group is referenced,
4697 * and in that case no group information needs to be set.
4698 */
4699 static final class GroupTail extends Node {
4700 int localIndex;
4701 int groupIndex;
4702 GroupTail(int localCount, int groupCount) {
4703 localIndex = localCount;
4704 groupIndex = groupCount + groupCount;
4705 }
4706 boolean match(Matcher matcher, int i, CharSequence seq) {
4707 int tmp = matcher.locals[localIndex];
4708 if (tmp >= 0) { // This is the normal group case.
4709 // Save the group so we can unset it if it
4710 // backs off of a match.
4711 int groupStart = matcher.groups[groupIndex];
4712 int groupEnd = matcher.groups[groupIndex+1];
4713
4714 matcher.groups[groupIndex] = tmp;
4715 matcher.groups[groupIndex+1] = i;
4716 if (next.match(matcher, i, seq)) {
4717 return true;
4718 }
4719 matcher.groups[groupIndex] = groupStart;
4720 matcher.groups[groupIndex+1] = groupEnd;
4721 return false;
4722 } else {
4723 // This is a group reference case. We don't need to save any
4724 // group info because it isn't really a group.
4725 matcher.last = i;
4726 return true;
4727 }
4728 }
4729 }
4730
4731 /**
4732 * This sets up a loop to handle a recursive quantifier structure.
4733 */
4734 static final class Prolog extends Node {
4735 Loop loop;
4736 Prolog(Loop loop) {
4737 this.loop = loop;
4738 }
4739 boolean match(Matcher matcher, int i, CharSequence seq) {
4740 return loop.matchInit(matcher, i, seq);
4741 }
4742 boolean study(TreeInfo info) {
4743 return loop.study(info);
4744 }
4745 }
4746
4747 /**
4748 * Handles the repetition count for a greedy Curly. The matchInit
4749 * is called from the Prolog to save the index of where the group
4750 * beginning is stored. A zero length group check occurs in the
4751 * normal match but is skipped in the matchInit.
4752 */
4753 static class Loop extends Node {
4754 Node body;
4755 int countIndex; // local count index in matcher locals
4756 int beginIndex; // group beginning index
4757 int cmin, cmax;
4758 Loop(int countIndex, int beginIndex) {
4759 this.countIndex = countIndex;
4760 this.beginIndex = beginIndex;
4761 }
4762 boolean match(Matcher matcher, int i, CharSequence seq) {
4763 // Avoid infinite loop in zero-length case.
4764 if (i > matcher.locals[beginIndex]) {
4765 int count = matcher.locals[countIndex];
4766
4767 // This block is for before we reach the minimum
4768 // iterations required for the loop to match
4769 if (count < cmin) {
4770 matcher.locals[countIndex] = count + 1;
4771 boolean b = body.match(matcher, i, seq);
4772 // If match failed we must backtrack, so
4773 // the loop count should NOT be incremented
4774 if (!b)
4775 matcher.locals[countIndex] = count;
4776 // Return success or failure since we are under
4777 // minimum
4778 return b;
4779 }
4780 // This block is for after we have the minimum
4781 // iterations required for the loop to match
4782 if (count < cmax) {
4783 matcher.locals[countIndex] = count + 1;
4784 boolean b = body.match(matcher, i, seq);
4785 // If match failed we must backtrack, so
4786 // the loop count should NOT be incremented
4787 if (!b)
4788 matcher.locals[countIndex] = count;
4789 else
4790 return true;
4791 }
4792 }
4793 return next.match(matcher, i, seq);
4794 }
4795 boolean matchInit(Matcher matcher, int i, CharSequence seq) {
4796 int save = matcher.locals[countIndex];
4797 boolean ret = false;
4798 if (0 < cmin) {
4799 matcher.locals[countIndex] = 1;
4800 ret = body.match(matcher, i, seq);
4801 } else if (0 < cmax) {
4802 matcher.locals[countIndex] = 1;
4803 ret = body.match(matcher, i, seq);
4804 if (ret == false)
4805 ret = next.match(matcher, i, seq);
4806 } else {
4807 ret = next.match(matcher, i, seq);
4808 }
4809 matcher.locals[countIndex] = save;
4810 return ret;
4811 }
4812 boolean study(TreeInfo info) {
4813 info.maxValid = false;
4814 info.deterministic = false;
4815 return false;
4816 }
4817 }
4818
4819 /**
4820 * Handles the repetition count for a reluctant Curly. The matchInit
4821 * is called from the Prolog to save the index of where the group
4822 * beginning is stored. A zero length group check occurs in the
4823 * normal match but is skipped in the matchInit.
4824 */
4825 static final class LazyLoop extends Loop {
4826 LazyLoop(int countIndex, int beginIndex) {
4827 super(countIndex, beginIndex);
4828 }
4829 boolean match(Matcher matcher, int i, CharSequence seq) {
4830 // Check for zero length group
4831 if (i > matcher.locals[beginIndex]) {
4832 int count = matcher.locals[countIndex];
4833 if (count < cmin) {
4834 matcher.locals[countIndex] = count + 1;
4835 boolean result = body.match(matcher, i, seq);
4836 // If match failed we must backtrack, so
4837 // the loop count should NOT be incremented
4838 if (!result)
4839 matcher.locals[countIndex] = count;
4840 return result;
4841 }
4842 if (next.match(matcher, i, seq))
4843 return true;
4844 if (count < cmax) {
4845 matcher.locals[countIndex] = count + 1;
4846 boolean result = body.match(matcher, i, seq);
4847 // If match failed we must backtrack, so
4848 // the loop count should NOT be incremented
4849 if (!result)
4850 matcher.locals[countIndex] = count;
4851 return result;
4852 }
4853 return false;
4854 }
4855 return next.match(matcher, i, seq);
4856 }
4857 boolean matchInit(Matcher matcher, int i, CharSequence seq) {
4858 int save = matcher.locals[countIndex];
4859 boolean ret = false;
4860 if (0 < cmin) {
4861 matcher.locals[countIndex] = 1;
4862 ret = body.match(matcher, i, seq);
4863 } else if (next.match(matcher, i, seq)) {
4864 ret = true;
4865 } else if (0 < cmax) {
4866 matcher.locals[countIndex] = 1;
4867 ret = body.match(matcher, i, seq);
4868 }
4869 matcher.locals[countIndex] = save;
4870 return ret;
4871 }
4872 boolean study(TreeInfo info) {
4873 info.maxValid = false;
4874 info.deterministic = false;
4875 return false;
4876 }
4877 }
4878
4879 /**
4880 * Refers to a group in the regular expression. Attempts to match
4881 * whatever the group referred to last matched.
4882 */
4883 static class BackRef extends Node {
4884 int groupIndex;
4885 BackRef(int groupCount) {
4886 super();
4887 groupIndex = groupCount + groupCount;
4888 }
4889 boolean match(Matcher matcher, int i, CharSequence seq) {
4890 int j = matcher.groups[groupIndex];
4891 int k = matcher.groups[groupIndex+1];
4892
4893 int groupSize = k - j;
4894
4895 // If the referenced group didn't match, neither can this
4896 if (j < 0)
4897 return false;
4898
4899 // If there isn't enough input left no match
4900 if (i + groupSize > matcher.to) {
4901 matcher.hitEnd = true;
4902 return false;
4903 }
4904
4905 // Check each new char to make sure it matches what the group
4906 // referenced matched last time around
4907 for (int index=0; index<groupSize; index++)
4908 if (seq.charAt(i+index) != seq.charAt(j+index))
4909 return false;
4910
4911 return next.match(matcher, i+groupSize, seq);
4912 }
4913 boolean study(TreeInfo info) {
4914 info.maxValid = false;
4915 return next.study(info);
4916 }
4917 }
4918
4919 static class CIBackRef extends Node {
4920 int groupIndex;
4921 boolean doUnicodeCase;
4922 CIBackRef(int groupCount, boolean doUnicodeCase) {
4923 super();
4924 groupIndex = groupCount + groupCount;
4925 this.doUnicodeCase = doUnicodeCase;
4926 }
4927 boolean match(Matcher matcher, int i, CharSequence seq) {
4928 int j = matcher.groups[groupIndex];
4929 int k = matcher.groups[groupIndex+1];
4930
4931 int groupSize = k - j;
4932
4933 // If the referenced group didn't match, neither can this
4934 if (j < 0)
4935 return false;
4936
4937 // If there isn't enough input left no match
4938 if (i + groupSize > matcher.to) {
4939 matcher.hitEnd = true;
4940 return false;
4941 }
4942
4943 // Check each new char to make sure it matches what the group
4944 // referenced matched last time around
4945 int x = i;
4946 for (int index=0; index<groupSize; index++) {
4947 int c1 = Character.codePointAt(seq, x);
4948 int c2 = Character.codePointAt(seq, j);
4949 if (c1 != c2) {
4950 if (doUnicodeCase) {
4951 int cc1 = Character.toUpperCase(c1);
4952 int cc2 = Character.toUpperCase(c2);
4953 if (cc1 != cc2 &&
4954 Character.toLowerCase(cc1) !=
4955 Character.toLowerCase(cc2))
4956 return false;
4957 } else {
4958 if (ASCII.toLower(c1) != ASCII.toLower(c2))
4959 return false;
4960 }
4961 }
4962 x += Character.charCount(c1);
4963 j += Character.charCount(c2);
4964 }
4965
4966 return next.match(matcher, i+groupSize, seq);
4967 }
4968 boolean study(TreeInfo info) {
4969 info.maxValid = false;
4970 return next.study(info);
4971 }
4972 }
4973
4974 /**
4975 * Searches until the next instance of its atom. This is useful for
4976 * finding the atom efficiently without passing an instance of it
4977 * (greedy problem) and without a lot of wasted search time (reluctant
4978 * problem).
4979 */
4980 static final class First extends Node {
4981 Node atom;
4982 First(Node node) {
4983 this.atom = BnM.optimize(node);
4984 }
4985 boolean match(Matcher matcher, int i, CharSequence seq) {
4986 if (atom instanceof BnM) {
4987 return atom.match(matcher, i, seq)
4988 && next.match(matcher, matcher.last, seq);
4989 }
4990 for (;;) {
4991 if (i > matcher.to) {
4992 matcher.hitEnd = true;
4993 return false;
4994 }
4995 if (atom.match(matcher, i, seq)) {
4996 return next.match(matcher, matcher.last, seq);
4997 }
4998 i += countChars(seq, i, 1);
4999 matcher.first++;
5000 }
5001 }
5002 boolean study(TreeInfo info) {
5003 atom.study(info);
5004 info.maxValid = false;
5005 info.deterministic = false;
5006 return next.study(info);
5007 }
5008 }
5009
5010 static final class Conditional extends Node {
5011 Node cond, yes, not;
5012 Conditional(Node cond, Node yes, Node not) {
5013 this.cond = cond;
5014 this.yes = yes;
5015 this.not = not;
5016 }
5017 boolean match(Matcher matcher, int i, CharSequence seq) {
5018 if (cond.match(matcher, i, seq)) {
5019 return yes.match(matcher, i, seq);
5020 } else {
5021 return not.match(matcher, i, seq);
5022 }
5023 }
5024 boolean study(TreeInfo info) {
5025 int minL = info.minLength;
5026 int maxL = info.maxLength;
5027 boolean maxV = info.maxValid;
5028 info.reset();
5029 yes.study(info);
5030
5031 int minL2 = info.minLength;
5032 int maxL2 = info.maxLength;
5033 boolean maxV2 = info.maxValid;
5034 info.reset();
5035 not.study(info);
5036
5037 info.minLength = minL + Math.min(minL2, info.minLength);
5038 info.maxLength = maxL + Math.max(maxL2, info.maxLength);
5039 info.maxValid = (maxV & maxV2 & info.maxValid);
5040 info.deterministic = false;
5041 return next.study(info);
5042 }
5043 }
5044
5045 /**
5046 * Zero width positive lookahead.
5047 */
5048 static final class Pos extends Node {
5049 Node cond;
5050 Pos(Node cond) {
5051 this.cond = cond;
5052 }
5053 boolean match(Matcher matcher, int i, CharSequence seq) {
5054 int savedTo = matcher.to;
5055 boolean conditionMatched = false;
5056
5057 // Relax transparent region boundaries for lookahead
5058 if (matcher.transparentBounds)
5059 matcher.to = matcher.getTextLength();
5060 try {
5061 conditionMatched = cond.match(matcher, i, seq);
5062 } finally {
5063 // Reinstate region boundaries
5064 matcher.to = savedTo;
5065 }
5066 return conditionMatched && next.match(matcher, i, seq);
5067 }
5068 }
5069
5070 /**
5071 * Zero width negative lookahead.
5072 */
5073 static final class Neg extends Node {
5074 Node cond;
5075 Neg(Node cond) {
5076 this.cond = cond;
5077 }
5078 boolean match(Matcher matcher, int i, CharSequence seq) {
5079 int savedTo = matcher.to;
5080 boolean conditionMatched = false;
5081
5082 // Relax transparent region boundaries for lookahead
5083 if (matcher.transparentBounds)
5084 matcher.to = matcher.getTextLength();
5085 try {
5086 if (i < matcher.to) {
5087 conditionMatched = !cond.match(matcher, i, seq);
5088 } else {
5089 // If a negative lookahead succeeds then more input
5090 // could cause it to fail!
5091 matcher.requireEnd = true;
5092 conditionMatched = !cond.match(matcher, i, seq);
5093 }
5094 } finally {
5095 // Reinstate region boundaries
5096 matcher.to = savedTo;
5097 }
5098 return conditionMatched && next.match(matcher, i, seq);
5099 }
5100 }
5101
5102 /**
5103 * For use with lookbehinds; matches the position where the lookbehind
5104 * was encountered.
5105 */
5106 static Node lookbehindEnd = new Node() {
5107 boolean match(Matcher matcher, int i, CharSequence seq) {
5108 return i == matcher.lookbehindTo;
5109 }
5110 };
5111
5112 /**
5113 * Zero width positive lookbehind.
5114 */
5115 static class Behind extends Node {
5116 Node cond;
5117 int rmax, rmin;
5118 Behind(Node cond, int rmax, int rmin) {
5119 this.cond = cond;
5120 this.rmax = rmax;
5121 this.rmin = rmin;
5122 }
5123
5124 boolean match(Matcher matcher, int i, CharSequence seq) {
5125 int savedFrom = matcher.from;
5126 boolean conditionMatched = false;
5127 int startIndex = (!matcher.transparentBounds) ?
5128 matcher.from : 0;
5129 int from = Math.max(i - rmax, startIndex);
5130 // Set end boundary
5131 int savedLBT = matcher.lookbehindTo;
5132 matcher.lookbehindTo = i;
5133 // Relax transparent region boundaries for lookbehind
5134 if (matcher.transparentBounds)
5135 matcher.from = 0;
5136 for (int j = i - rmin; !conditionMatched && j >= from; j--) {
5137 conditionMatched = cond.match(matcher, j, seq);
5138 }
5139 matcher.from = savedFrom;
5140 matcher.lookbehindTo = savedLBT;
5141 return conditionMatched && next.match(matcher, i, seq);
5142 }
5143 }
5144
5145 /**
5146 * Zero width positive lookbehind, including supplementary
5147 * characters or unpaired surrogates.
5148 */
5149 static final class BehindS extends Behind {
5150 BehindS(Node cond, int rmax, int rmin) {
5151 super(cond, rmax, rmin);
5152 }
5153 boolean match(Matcher matcher, int i, CharSequence seq) {
5154 int rmaxChars = countChars(seq, i, -rmax);
5155 int rminChars = countChars(seq, i, -rmin);
5156 int savedFrom = matcher.from;
5157 int startIndex = (!matcher.transparentBounds) ?
5158 matcher.from : 0;
5159 boolean conditionMatched = false;
5160 int from = Math.max(i - rmaxChars, startIndex);
5161 // Set end boundary
5162 int savedLBT = matcher.lookbehindTo;
5163 matcher.lookbehindTo = i;
5164 // Relax transparent region boundaries for lookbehind
5165 if (matcher.transparentBounds)
5166 matcher.from = 0;
5167
5168 for (int j = i - rminChars;
5169 !conditionMatched && j >= from;
5170 j -= j>from ? countChars(seq, j, -1) : 1) {
5171 conditionMatched = cond.match(matcher, j, seq);
5172 }
5173 matcher.from = savedFrom;
5174 matcher.lookbehindTo = savedLBT;
5175 return conditionMatched && next.match(matcher, i, seq);
5176 }
5177 }
5178
5179 /**
5180 * Zero width negative lookbehind.
5181 */
5182 static class NotBehind extends Node {
5183 Node cond;
5184 int rmax, rmin;
5185 NotBehind(Node cond, int rmax, int rmin) {
5186 this.cond = cond;
5187 this.rmax = rmax;
5188 this.rmin = rmin;
5189 }
5190
5191 boolean match(Matcher matcher, int i, CharSequence seq) {
5192 int savedLBT = matcher.lookbehindTo;
5193 int savedFrom = matcher.from;
5194 boolean conditionMatched = false;
5195 int startIndex = (!matcher.transparentBounds) ?
5196 matcher.from : 0;
5197 int from = Math.max(i - rmax, startIndex);
5198 matcher.lookbehindTo = i;
5199 // Relax transparent region boundaries for lookbehind
5200 if (matcher.transparentBounds)
5201 matcher.from = 0;
5202 for (int j = i - rmin; !conditionMatched && j >= from; j--) {
5203 conditionMatched = cond.match(matcher, j, seq);
5204 }
5205 // Reinstate region boundaries
5206 matcher.from = savedFrom;
5207 matcher.lookbehindTo = savedLBT;
5208 return !conditionMatched && next.match(matcher, i, seq);
5209 }
5210 }
5211
5212 /**
5213 * Zero width negative lookbehind, including supplementary
5214 * characters or unpaired surrogates.
5215 */
5216 static final class NotBehindS extends NotBehind {
5217 NotBehindS(Node cond, int rmax, int rmin) {
5218 super(cond, rmax, rmin);
5219 }
5220 boolean match(Matcher matcher, int i, CharSequence seq) {
5221 int rmaxChars = countChars(seq, i, -rmax);
5222 int rminChars = countChars(seq, i, -rmin);
5223 int savedFrom = matcher.from;
5224 int savedLBT = matcher.lookbehindTo;
5225 boolean conditionMatched = false;
5226 int startIndex = (!matcher.transparentBounds) ?
5227 matcher.from : 0;
5228 int from = Math.max(i - rmaxChars, startIndex);
5229 matcher.lookbehindTo = i;
5230 // Relax transparent region boundaries for lookbehind
5231 if (matcher.transparentBounds)
5232 matcher.from = 0;
5233 for (int j = i - rminChars;
5234 !conditionMatched && j >= from;
5235 j -= j>from ? countChars(seq, j, -1) : 1) {
5236 conditionMatched = cond.match(matcher, j, seq);
5237 }
5238 //Reinstate region boundaries
5239 matcher.from = savedFrom;
5240 matcher.lookbehindTo = savedLBT;
5241 return !conditionMatched && next.match(matcher, i, seq);
5242 }
5243 }
5244
5245 /**
5246 * Returns the set union of two CharProperty nodes.
5247 */
5248 private static CharProperty union(final CharProperty lhs,
5249 final CharProperty rhs) {
5250 return new CharProperty() {
5251 boolean isSatisfiedBy(int ch) {
5252 return lhs.isSatisfiedBy(ch) || rhs.isSatisfiedBy(ch);}};
5253 }
5254
5255 /**
5256 * Returns the set intersection of two CharProperty nodes.
5257 */
5258 private static CharProperty intersection(final CharProperty lhs,
5259 final CharProperty rhs) {
5260 return new CharProperty() {
5261 boolean isSatisfiedBy(int ch) {
5262 return lhs.isSatisfiedBy(ch) && rhs.isSatisfiedBy(ch);}};
5263 }
5264
5265 /**
5266 * Returns the set difference of two CharProperty nodes.
5267 */
5268 private static CharProperty setDifference(final CharProperty lhs,
5269 final CharProperty rhs) {
5270 return new CharProperty() {
5271 boolean isSatisfiedBy(int ch) {
5272 return ! rhs.isSatisfiedBy(ch) && lhs.isSatisfiedBy(ch);}};
5273 }
5274
5275 /**
5276 * Handles word boundaries. Includes a field to allow this one class to
5277 * deal with the different types of word boundaries we can match. The word
5278 * characters include underscores, letters, and digits. Non spacing marks
5279 * can are also part of a word if they have a base character, otherwise
5280 * they are ignored for purposes of finding word boundaries.
5281 */
5282 static final class Bound extends Node {
5283 static int LEFT = 0x1;
5284 static int RIGHT= 0x2;
5285 static int BOTH = 0x3;
5286 static int NONE = 0x4;
5287 int type;
5288 boolean useUWORD;
5289 Bound(int n, boolean useUWORD) {
5290 type = n;
5291 this.useUWORD = useUWORD;
5292 }
5293
5294 boolean isWord(int ch) {
5295 return useUWORD ? UnicodeProp.WORD.is(ch)
5296 : (ch == '_' || Character.isLetterOrDigit(ch));
5297 }
5298
5299 int check(Matcher matcher, int i, CharSequence seq) {
5300 int ch;
5301 boolean left = false;
5302 int startIndex = matcher.from;
5303 int endIndex = matcher.to;
5304 if (matcher.transparentBounds) {
5305 startIndex = 0;
5306 endIndex = matcher.getTextLength();
5307 }
5308 if (i > startIndex) {
5309 ch = Character.codePointBefore(seq, i);
5310 left = (isWord(ch) ||
5311 ((Character.getType(ch) == Character.NON_SPACING_MARK)
5312 && hasBaseCharacter(matcher, i-1, seq)));
5313 }
5314 boolean right = false;
5315 if (i < endIndex) {
5316 ch = Character.codePointAt(seq, i);
5317 right = (isWord(ch) ||
5318 ((Character.getType(ch) == Character.NON_SPACING_MARK)
5319 && hasBaseCharacter(matcher, i, seq)));
5320 } else {
5321 // Tried to access char past the end
5322 matcher.hitEnd = true;
5323 // The addition of another char could wreck a boundary
5324 matcher.requireEnd = true;
5325 }
5326 return ((left ^ right) ? (right ? LEFT : RIGHT) : NONE);
5327 }
5328 boolean match(Matcher matcher, int i, CharSequence seq) {
5329 return (check(matcher, i, seq) & type) > 0
5330 && next.match(matcher, i, seq);
5331 }
5332 }
5333
5334 /**
5335 * Non spacing marks only count as word characters in bounds calculations
5336 * if they have a base character.
5337 */
5338 private static boolean hasBaseCharacter(Matcher matcher, int i,
5339 CharSequence seq)
5340 {
5341 int start = (!matcher.transparentBounds) ?
5342 matcher.from : 0;
5343 for (int x=i; x >= start; x--) {
5344 int ch = Character.codePointAt(seq, x);
5345 if (Character.isLetterOrDigit(ch))
5346 return true;
5347 if (Character.getType(ch) == Character.NON_SPACING_MARK)
5348 continue;
5349 return false;
5350 }
5351 return false;
5352 }
5353
5354 /**
5355 * Attempts to match a slice in the input using the Boyer-Moore string
5356 * matching algorithm. The algorithm is based on the idea that the
5357 * pattern can be shifted farther ahead in the search text if it is
5358 * matched right to left.
5359 * <p>
5360 * The pattern is compared to the input one character at a time, from
5361 * the rightmost character in the pattern to the left. If the characters
5362 * all match the pattern has been found. If a character does not match,
5363 * the pattern is shifted right a distance that is the maximum of two
5364 * functions, the bad character shift and the good suffix shift. This
5365 * shift moves the attempted match position through the input more
5366 * quickly than a naive one position at a time check.
5367 * <p>
5368 * The bad character shift is based on the character from the text that
5369 * did not match. If the character does not appear in the pattern, the
5370 * pattern can be shifted completely beyond the bad character. If the
5371 * character does occur in the pattern, the pattern can be shifted to
5372 * line the pattern up with the next occurrence of that character.
5373 * <p>
5374 * The good suffix shift is based on the idea that some subset on the right
5375 * side of the pattern has matched. When a bad character is found, the
5376 * pattern can be shifted right by the pattern length if the subset does
5377 * not occur again in pattern, or by the amount of distance to the
5378 * next occurrence of the subset in the pattern.
5379 *
5380 * Boyer-Moore search methods adapted from code by Amy Yu.
5381 */
5382 static class BnM extends Node {
5383 int[] buffer;
5384 int[] lastOcc;
5385 int[] optoSft;
5386
5387 /**
5388 * Pre calculates arrays needed to generate the bad character
5389 * shift and the good suffix shift. Only the last seven bits
5390 * are used to see if chars match; This keeps the tables small
5391 * and covers the heavily used ASCII range, but occasionally
5392 * results in an aliased match for the bad character shift.
5393 */
5394 static Node optimize(Node node) {
5395 if (!(node instanceof Slice)) {
5396 return node;
5397 }
5398
5399 int[] src = ((Slice) node).buffer;
5400 int patternLength = src.length;
5401 // The BM algorithm requires a bit of overhead;
5402 // If the pattern is short don't use it, since
5403 // a shift larger than the pattern length cannot
5404 // be used anyway.
5405 if (patternLength < 4) {
5406 return node;
5407 }
5408 int i, j, k;
5409 int[] lastOcc = new int[128];
5410 int[] optoSft = new int[patternLength];
5411 // Precalculate part of the bad character shift
5412 // It is a table for where in the pattern each
5413 // lower 7-bit value occurs
5414 for (i = 0; i < patternLength; i++) {
5415 lastOcc[src[i]&0x7F] = i + 1;
5416 }
5417 // Precalculate the good suffix shift
5418 // i is the shift amount being considered
5419 NEXT: for (i = patternLength; i > 0; i--) {
5420 // j is the beginning index of suffix being considered
5421 for (j = patternLength - 1; j >= i; j--) {
5422 // Testing for good suffix
5423 if (src[j] == src[j-i]) {
5424 // src[j..len] is a good suffix
5425 optoSft[j-1] = i;
5426 } else {
5427 // No match. The array has already been
5428 // filled up with correct values before.
5429 continue NEXT;
5430 }
5431 }
5432 // This fills up the remaining of optoSft
5433 // any suffix can not have larger shift amount
5434 // then its sub-suffix. Why???
5435 while (j > 0) {
5436 optoSft[--j] = i;
5437 }
5438 }
5439 // Set the guard value because of unicode compression
5440 optoSft[patternLength-1] = 1;
5441 if (node instanceof SliceS)
5442 return new BnMS(src, lastOcc, optoSft, node.next);
5443 return new BnM(src, lastOcc, optoSft, node.next);
5444 }
5445 BnM(int[] src, int[] lastOcc, int[] optoSft, Node next) {
5446 this.buffer = src;
5447 this.lastOcc = lastOcc;
5448 this.optoSft = optoSft;
5449 this.next = next;
5450 }
5451 boolean match(Matcher matcher, int i, CharSequence seq) {
5452 int[] src = buffer;
5453 int patternLength = src.length;
5454 int last = matcher.to - patternLength;
5455
5456 // Loop over all possible match positions in text
5457 NEXT: while (i <= last) {
5458 // Loop over pattern from right to left
5459 for (int j = patternLength - 1; j >= 0; j--) {
5460 int ch = seq.charAt(i+j);
5461 if (ch != src[j]) {
5462 // Shift search to the right by the maximum of the
5463 // bad character shift and the good suffix shift
5464 i += Math.max(j + 1 - lastOcc[ch&0x7F], optoSft[j]);
5465 continue NEXT;
5466 }
5467 }
5468 // Entire pattern matched starting at i
5469 matcher.first = i;
5470 boolean ret = next.match(matcher, i + patternLength, seq);
5471 if (ret) {
5472 matcher.first = i;
5473 matcher.groups[0] = matcher.first;
5474 matcher.groups[1] = matcher.last;
5475 return true;
5476 }
5477 i++;
5478 }
5479 // BnM is only used as the leading node in the unanchored case,
5480 // and it replaced its Start() which always searches to the end
5481 // if it doesn't find what it's looking for, so hitEnd is true.
5482 matcher.hitEnd = true;
5483 return false;
5484 }
5485 boolean study(TreeInfo info) {
5486 info.minLength += buffer.length;
5487 info.maxValid = false;
5488 return next.study(info);
5489 }
5490 }
5491
5492 /**
5493 * Supplementary support version of BnM(). Unpaired surrogates are
5494 * also handled by this class.
5495 */
5496 static final class BnMS extends BnM {
5497 int lengthInChars;
5498
5499 BnMS(int[] src, int[] lastOcc, int[] optoSft, Node next) {
5500 super(src, lastOcc, optoSft, next);
5501 for (int x = 0; x < buffer.length; x++) {
5502 lengthInChars += Character.charCount(buffer[x]);
5503 }
5504 }
5505 boolean match(Matcher matcher, int i, CharSequence seq) {
5506 int[] src = buffer;
5507 int patternLength = src.length;
5508 int last = matcher.to - lengthInChars;
5509
5510 // Loop over all possible match positions in text
5511 NEXT: while (i <= last) {
5512 // Loop over pattern from right to left
5513 int ch;
5514 for (int j = countChars(seq, i, patternLength), x = patternLength - 1;
5515 j > 0; j -= Character.charCount(ch), x--) {
5516 ch = Character.codePointBefore(seq, i+j);
5517 if (ch != src[x]) {
5518 // Shift search to the right by the maximum of the
5519 // bad character shift and the good suffix shift
5520 int n = Math.max(x + 1 - lastOcc[ch&0x7F], optoSft[x]);
5521 i += countChars(seq, i, n);
5522 continue NEXT;
5523 }
5524 }
5525 // Entire pattern matched starting at i
5526 matcher.first = i;
5527 boolean ret = next.match(matcher, i + lengthInChars, seq);
5528 if (ret) {
5529 matcher.first = i;
5530 matcher.groups[0] = matcher.first;
5531 matcher.groups[1] = matcher.last;
5532 return true;
5533 }
5534 i += countChars(seq, i, 1);
5535 }
5536 matcher.hitEnd = true;
5537 return false;
5538 }
5539 }
5540
5541 ///////////////////////////////////////////////////////////////////////////////
5542 ///////////////////////////////////////////////////////////////////////////////
5543
5544 /**
5545 * This must be the very first initializer.
5546 */
5547 static Node accept = new Node();
5548
5549 static Node lastAccept = new LastNode();
5550
5551 private static class CharPropertyNames {
5552
5553 static CharProperty charPropertyFor(String name) {
5554 CharPropertyFactory m = map.get(name);
5555 return m == null ? null : m.make();
5556 }
5557
5558 private static abstract class CharPropertyFactory {
5559 abstract CharProperty make();
5560 }
5561
5562 private static void defCategory(String name,
5563 final int typeMask) {
5564 map.put(name, new CharPropertyFactory() {
5565 CharProperty make() { return new Category(typeMask);}});
5566 }
5567
5568 private static void defRange(String name,
5569 final int lower, final int upper) {
5570 map.put(name, new CharPropertyFactory() {
5571 CharProperty make() { return rangeFor(lower, upper);}});
5572 }
5573
5574 private static void defCtype(String name,
5575 final int ctype) {
5576 map.put(name, new CharPropertyFactory() {
5577 CharProperty make() { return new Ctype(ctype);}});
5578 }
5579
5580 private static abstract class CloneableProperty
5581 extends CharProperty implements Cloneable
5582 {
5583 public CloneableProperty clone() {
5584 try {
5585 return (CloneableProperty) super.clone();
5586 } catch (CloneNotSupportedException e) {
5587 throw new AssertionError(e);
5588 }
5589 }
5590 }
5591
5592 private static void defClone(String name,
5593 final CloneableProperty p) {
5594 map.put(name, new CharPropertyFactory() {
5595 CharProperty make() { return p.clone();}});
5596 }
5597
5598 private static final HashMap<String, CharPropertyFactory> map
5599 = new HashMap<>();
5600
5601 static {
5602 // Unicode character property aliases, defined in
5603 // http://www.unicode.org/Public/UNIDATA/PropertyValueAliases.txt
5604 defCategory("Cn", 1<<Character.UNASSIGNED);
5605 defCategory("Lu", 1<<Character.UPPERCASE_LETTER);
5606 defCategory("Ll", 1<<Character.LOWERCASE_LETTER);
5607 defCategory("Lt", 1<<Character.TITLECASE_LETTER);
5608 defCategory("Lm", 1<<Character.MODIFIER_LETTER);
5609 defCategory("Lo", 1<<Character.OTHER_LETTER);
5610 defCategory("Mn", 1<<Character.NON_SPACING_MARK);
5611 defCategory("Me", 1<<Character.ENCLOSING_MARK);
5612 defCategory("Mc", 1<<Character.COMBINING_SPACING_MARK);
5613 defCategory("Nd", 1<<Character.DECIMAL_DIGIT_NUMBER);
5614 defCategory("Nl", 1<<Character.LETTER_NUMBER);
5615 defCategory("No", 1<<Character.OTHER_NUMBER);
5616 defCategory("Zs", 1<<Character.SPACE_SEPARATOR);
5617 defCategory("Zl", 1<<Character.LINE_SEPARATOR);
5618 defCategory("Zp", 1<<Character.PARAGRAPH_SEPARATOR);
5619 defCategory("Cc", 1<<Character.CONTROL);
5620 defCategory("Cf", 1<<Character.FORMAT);
5621 defCategory("Co", 1<<Character.PRIVATE_USE);
5622 defCategory("Cs", 1<<Character.SURROGATE);
5623 defCategory("Pd", 1<<Character.DASH_PUNCTUATION);
5624 defCategory("Ps", 1<<Character.START_PUNCTUATION);
5625 defCategory("Pe", 1<<Character.END_PUNCTUATION);
5626 defCategory("Pc", 1<<Character.CONNECTOR_PUNCTUATION);
5627 defCategory("Po", 1<<Character.OTHER_PUNCTUATION);
5628 defCategory("Sm", 1<<Character.MATH_SYMBOL);
5629 defCategory("Sc", 1<<Character.CURRENCY_SYMBOL);
5630 defCategory("Sk", 1<<Character.MODIFIER_SYMBOL);
5631 defCategory("So", 1<<Character.OTHER_SYMBOL);
5632 defCategory("Pi", 1<<Character.INITIAL_QUOTE_PUNCTUATION);
5633 defCategory("Pf", 1<<Character.FINAL_QUOTE_PUNCTUATION);
5634 defCategory("L", ((1<<Character.UPPERCASE_LETTER) |
5635 (1<<Character.LOWERCASE_LETTER) |
5636 (1<<Character.TITLECASE_LETTER) |
5637 (1<<Character.MODIFIER_LETTER) |
5638 (1<<Character.OTHER_LETTER)));
5639 defCategory("M", ((1<<Character.NON_SPACING_MARK) |
5640 (1<<Character.ENCLOSING_MARK) |
5641 (1<<Character.COMBINING_SPACING_MARK)));
5642 defCategory("N", ((1<<Character.DECIMAL_DIGIT_NUMBER) |
5643 (1<<Character.LETTER_NUMBER) |
5644 (1<<Character.OTHER_NUMBER)));
5645 defCategory("Z", ((1<<Character.SPACE_SEPARATOR) |
5646 (1<<Character.LINE_SEPARATOR) |
5647 (1<<Character.PARAGRAPH_SEPARATOR)));
5648 defCategory("C", ((1<<Character.CONTROL) |
5649 (1<<Character.FORMAT) |
5650 (1<<Character.PRIVATE_USE) |
5651 (1<<Character.SURROGATE))); // Other
5652 defCategory("P", ((1<<Character.DASH_PUNCTUATION) |
5653 (1<<Character.START_PUNCTUATION) |
5654 (1<<Character.END_PUNCTUATION) |
5655 (1<<Character.CONNECTOR_PUNCTUATION) |
5656 (1<<Character.OTHER_PUNCTUATION) |
5657 (1<<Character.INITIAL_QUOTE_PUNCTUATION) |
5658 (1<<Character.FINAL_QUOTE_PUNCTUATION)));
5659 defCategory("S", ((1<<Character.MATH_SYMBOL) |
5660 (1<<Character.CURRENCY_SYMBOL) |
5661 (1<<Character.MODIFIER_SYMBOL) |
5662 (1<<Character.OTHER_SYMBOL)));
5663 defCategory("LC", ((1<<Character.UPPERCASE_LETTER) |
5664 (1<<Character.LOWERCASE_LETTER) |
5665 (1<<Character.TITLECASE_LETTER)));
5666 defCategory("LD", ((1<<Character.UPPERCASE_LETTER) |
5667 (1<<Character.LOWERCASE_LETTER) |
5668 (1<<Character.TITLECASE_LETTER) |
5669 (1<<Character.MODIFIER_LETTER) |
5670 (1<<Character.OTHER_LETTER) |
5671 (1<<Character.DECIMAL_DIGIT_NUMBER)));
5672 defRange("L1", 0x00, 0xFF); // Latin-1
5673 map.put("all", new CharPropertyFactory() {
5674 CharProperty make() { return new All(); }});
5675
5676 // Posix regular expression character classes, defined in
5677 // http://www.unix.org/onlinepubs/009695399/basedefs/xbd_chap09.html
5678 defRange("ASCII", 0x00, 0x7F); // ASCII
5679 defCtype("Alnum", ASCII.ALNUM); // Alphanumeric characters
5680 defCtype("Alpha", ASCII.ALPHA); // Alphabetic characters
5681 defCtype("Blank", ASCII.BLANK); // Space and tab characters
5682 defCtype("Cntrl", ASCII.CNTRL); // Control characters
5683 defRange("Digit", '0', '9'); // Numeric characters
5684 defCtype("Graph", ASCII.GRAPH); // printable and visible
5685 defRange("Lower", 'a', 'z'); // Lower-case alphabetic
5686 defRange("Print", 0x20, 0x7E); // Printable characters
5687 defCtype("Punct", ASCII.PUNCT); // Punctuation characters
5688 defCtype("Space", ASCII.SPACE); // Space characters
5689 defRange("Upper", 'A', 'Z'); // Upper-case alphabetic
5690 defCtype("XDigit",ASCII.XDIGIT); // hexadecimal digits
5691
5692 // Java character properties, defined by methods in Character.java
5693 defClone("javaLowerCase", new CloneableProperty() {
5694 boolean isSatisfiedBy(int ch) {
5695 return Character.isLowerCase(ch);}});
5696 defClone("javaUpperCase", new CloneableProperty() {
5697 boolean isSatisfiedBy(int ch) {
5698 return Character.isUpperCase(ch);}});
5699 defClone("javaAlphabetic", new CloneableProperty() {
5700 boolean isSatisfiedBy(int ch) {
5701 return Character.isAlphabetic(ch);}});
5702 defClone("javaIdeographic", new CloneableProperty() {
5703 boolean isSatisfiedBy(int ch) {
5704 return Character.isIdeographic(ch);}});
5705 defClone("javaTitleCase", new CloneableProperty() {
5706 boolean isSatisfiedBy(int ch) {
5707 return Character.isTitleCase(ch);}});
5708 defClone("javaDigit", new CloneableProperty() {
5709 boolean isSatisfiedBy(int ch) {
5710 return Character.isDigit(ch);}});
5711 defClone("javaDefined", new CloneableProperty() {
5712 boolean isSatisfiedBy(int ch) {
5713 return Character.isDefined(ch);}});
5714 defClone("javaLetter", new CloneableProperty() {
5715 boolean isSatisfiedBy(int ch) {
5716 return Character.isLetter(ch);}});
5717 defClone("javaLetterOrDigit", new CloneableProperty() {
5718 boolean isSatisfiedBy(int ch) {
5719 return Character.isLetterOrDigit(ch);}});
5720 defClone("javaJavaIdentifierStart", new CloneableProperty() {
5721 boolean isSatisfiedBy(int ch) {
5722 return Character.isJavaIdentifierStart(ch);}});
5723 defClone("javaJavaIdentifierPart", new CloneableProperty() {
5724 boolean isSatisfiedBy(int ch) {
5725 return Character.isJavaIdentifierPart(ch);}});
5726 defClone("javaUnicodeIdentifierStart", new CloneableProperty() {
5727 boolean isSatisfiedBy(int ch) {
5728 return Character.isUnicodeIdentifierStart(ch);}});
5729 defClone("javaUnicodeIdentifierPart", new CloneableProperty() {
5730 boolean isSatisfiedBy(int ch) {
5731 return Character.isUnicodeIdentifierPart(ch);}});
5732 defClone("javaIdentifierIgnorable", new CloneableProperty() {
5733 boolean isSatisfiedBy(int ch) {
5734 return Character.isIdentifierIgnorable(ch);}});
5735 defClone("javaSpaceChar", new CloneableProperty() {
5736 boolean isSatisfiedBy(int ch) {
5737 return Character.isSpaceChar(ch);}});
5738 defClone("javaWhitespace", new CloneableProperty() {
5739 boolean isSatisfiedBy(int ch) {
5740 return Character.isWhitespace(ch);}});
5741 defClone("javaISOControl", new CloneableProperty() {
5742 boolean isSatisfiedBy(int ch) {
5743 return Character.isISOControl(ch);}});
5744 defClone("javaMirrored", new CloneableProperty() {
5745 boolean isSatisfiedBy(int ch) {
5746 return Character.isMirrored(ch);}});
5747 }
5748 }
5749
5750 /**
5751 * Creates a predicate which can be used to match a string.
5752 *
5753 * @return The predicate which can be used for matching on a string
5754 * @since 1.8
5755 */
5756 public Predicate<String> asPredicate() {
5757 return s -> matcher(s).find();
5758 }
5759
5760 /**
5761 * Creates a stream from the given input sequence around matches of this
5762 * pattern.
5763 *
5764 * <p> The stream returned by this method contains each substring of the
5765 * input sequence that is terminated by another subsequence that matches
5766 * this pattern or is terminated by the end of the input sequence. The
5767 * substrings in the stream are in the order in which they occur in the
5768 * input.
5769 *
5770 * <p> If this pattern does not match any subsequence of the input then
5771 * the resulting stream has just one element, namely the input sequence in
5772 * string form.
5773 *
5774 * <p> If the input sequence is mutable, it must remain constant during the
5775 * execution of the terminal stream operation. Otherwise, the result of the
5776 * terminal stream operation is undefined.
5777 *
5778 * @param input
5779 * The character sequence to be split
5780 *
5781 * @return The stream of strings computed by splitting the input
5782 * around matches of this pattern
5783 * @see #split(CharSequence)
5784 * @since 1.8
5785 */
5786 public Stream<String> splitAsStream(final CharSequence input) {
5787 class MatcherIterator implements Iterator<String> {
5788 private final Matcher matcher;
5789 // The start position of the next sub-sequence of input
5790 // when current == input.length there are no more elements
5791 private int current;
5792 // null if the next element, if any, needs to obtained
5793 private String nextElement;
5794
5795 MatcherIterator() {
5796 this.matcher = matcher(input);
5797 }
5798
5799 public String next() {
5800 if (!hasNext())
5801 throw new NoSuchElementException();
5802
5803 String n = nextElement;
5804 nextElement = null;
5805 return n;
5806 }
5807
5808 public boolean hasNext() {
5809 if (nextElement != null)
5810 return true;
5811
5812 if (current == input.length())
5813 return false;
5814
5815 if (matcher.find()) {
5816 nextElement = input.subSequence(current, matcher.start()).toString();
5817 current = matcher.end();
5818 } else {
5819 nextElement = input.subSequence(current, input.length()).toString();
5820 current = input.length();
5821 }
5822 return true;
5823 }
5824 }
5825 return StreamSupport.stream(Spliterators.spliteratorUnknownSize(
5826 new MatcherIterator(), Spliterator.ORDERED | Spliterator.NONNULL));
5827 }
5828 }