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 {@linkplain
49 * java.lang.CharSequence character sequences} 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 * <h3><a name="sum">Summary of regular-expression constructs</a></h3>
77 *
78 * <table border="0" cellpadding="1" cellspacing="0"
79 * summary="Regular expression constructs, and what they match">
80 *
81 * <tr align="left">
82 * <th align="left" id="construct">Construct</th>
83 * <th align="left" id="matches">Matches</th>
84 * </tr>
85 *
86 * <tr><th> </th></tr>
87 * <tr align="left"><th colspan="2" id="characters">Characters</th></tr>
88 *
89 * <tr><td valign="top" headers="construct characters"><i>x</i></td>
90 * <td headers="matches">The character <i>x</i></td></tr>
91 * <tr><td valign="top" headers="construct characters"><tt>\\</tt></td>
92 * <td headers="matches">The backslash character</td></tr>
93 * <tr><td valign="top" headers="construct characters"><tt>\0</tt><i>n</i></td>
94 * <td headers="matches">The character with octal value <tt>0</tt><i>n</i>
95 * (0 <tt><=</tt> <i>n</i> <tt><=</tt> 7)</td></tr>
96 * <tr><td valign="top" headers="construct characters"><tt>\0</tt><i>nn</i></td>
97 * <td headers="matches">The character with octal value <tt>0</tt><i>nn</i>
98 * (0 <tt><=</tt> <i>n</i> <tt><=</tt> 7)</td></tr>
99 * <tr><td valign="top" headers="construct characters"><tt>\0</tt><i>mnn</i></td>
100 * <td headers="matches">The character with octal value <tt>0</tt><i>mnn</i>
101 * (0 <tt><=</tt> <i>m</i> <tt><=</tt> 3,
102 * 0 <tt><=</tt> <i>n</i> <tt><=</tt> 7)</td></tr>
103 * <tr><td valign="top" headers="construct characters"><tt>\x</tt><i>hh</i></td>
104 * <td headers="matches">The character with hexadecimal value <tt>0x</tt><i>hh</i></td></tr>
105 * <tr><td valign="top" headers="construct characters"><tt>\u</tt><i>hhhh</i></td>
106 * <td headers="matches">The character with hexadecimal value <tt>0x</tt><i>hhhh</i></td></tr>
107 * <tr><td valign="top" headers="construct characters"><tt>\x</tt><i>{h...h}</i></td>
108 * <td headers="matches">The character with hexadecimal value <tt>0x</tt><i>h...h</i>
109 * ({@link java.lang.Character#MIN_CODE_POINT Character.MIN_CODE_POINT}
110 * <= <tt>0x</tt><i>h...h</i> <=
111 * {@link java.lang.Character#MAX_CODE_POINT Character.MAX_CODE_POINT})</td></tr>
112 * <tr><td valign="top" headers="matches"><tt>\t</tt></td>
113 * <td headers="matches">The tab character (<tt>'\u0009'</tt>)</td></tr>
114 * <tr><td valign="top" headers="construct characters"><tt>\n</tt></td>
115 * <td headers="matches">The newline (line feed) character (<tt>'\u000A'</tt>)</td></tr>
116 * <tr><td valign="top" headers="construct characters"><tt>\r</tt></td>
117 * <td headers="matches">The carriage-return character (<tt>'\u000D'</tt>)</td></tr>
118 * <tr><td valign="top" headers="construct characters"><tt>\f</tt></td>
119 * <td headers="matches">The form-feed character (<tt>'\u000C'</tt>)</td></tr>
120 * <tr><td valign="top" headers="construct characters"><tt>\a</tt></td>
121 * <td headers="matches">The alert (bell) character (<tt>'\u0007'</tt>)</td></tr>
122 * <tr><td valign="top" headers="construct characters"><tt>\e</tt></td>
123 * <td headers="matches">The escape character (<tt>'\u001B'</tt>)</td></tr>
124 * <tr><td valign="top" headers="construct characters"><tt>\c</tt><i>x</i></td>
125 * <td headers="matches">The control character corresponding to <i>x</i></td></tr>
126 *
127 * <tr><th> </th></tr>
128 * <tr align="left"><th colspan="2" id="classes">Character classes</th></tr>
129 *
130 * <tr><td valign="top" headers="construct classes">{@code [abc]}</td>
131 * <td headers="matches">{@code a}, {@code b}, or {@code c} (simple class)</td></tr>
132 * <tr><td valign="top" headers="construct classes">{@code [^abc]}</td>
133 * <td headers="matches">Any character except {@code a}, {@code b}, or {@code c} (negation)</td></tr>
134 * <tr><td valign="top" headers="construct classes">{@code [a-zA-Z]}</td>
135 * <td headers="matches">{@code a} through {@code z}
136 * or {@code A} through {@code Z}, inclusive (range)</td></tr>
137 * <tr><td valign="top" headers="construct classes">{@code [a-d[m-p]]}</td>
138 * <td headers="matches">{@code a} through {@code d},
139 * or {@code m} through {@code p}: {@code [a-dm-p]} (union)</td></tr>
140 * <tr><td valign="top" headers="construct classes">{@code [a-z&&[def]]}</td>
141 * <td headers="matches">{@code d}, {@code e}, or {@code f} (intersection)</tr>
142 * <tr><td valign="top" headers="construct classes">{@code [a-z&&[^bc]]}</td>
143 * <td headers="matches">{@code a} through {@code z},
144 * except for {@code b} and {@code c}: {@code [ad-z]} (subtraction)</td></tr>
145 * <tr><td valign="top" headers="construct classes">{@code [a-z&&[^m-p]]}</td>
146 * <td headers="matches">{@code a} through {@code z},
147 * and not {@code m} through {@code p}: {@code [a-lq-z]}(subtraction)</td></tr>
148 * <tr><th> </th></tr>
149 *
150 * <tr align="left"><th colspan="2" id="predef">Predefined character classes</th></tr>
151 *
152 * <tr><td valign="top" headers="construct predef"><tt>.</tt></td>
153 * <td headers="matches">Any character (may or may not match <a href="#lt">line terminators</a>)</td></tr>
154 * <tr><td valign="top" headers="construct predef"><tt>\d</tt></td>
155 * <td headers="matches">A digit: <tt>[0-9]</tt></td></tr>
156 * <tr><td valign="top" headers="construct predef"><tt>\D</tt></td>
157 * <td headers="matches">A non-digit: <tt>[^0-9]</tt></td></tr>
158 * <tr><td valign="top" headers="construct predef"><tt>\h</tt></td>
159 * <td headers="matches">A horizontal whitespace character:
160 * <tt>[ \t\xA0\u1680\u180e\u2000-\u200a\u202f\u205f\u3000]</tt></td></tr>
161 * <tr><td valign="top" headers="construct predef"><tt>\H</tt></td>
162 * <td headers="matches">A non-horizontal whitespace character: <tt>[^\h]</tt></td></tr>
163 * <tr><td valign="top" headers="construct predef"><tt>\s</tt></td>
164 * <td headers="matches">A whitespace character: <tt>[ \t\n\x0B\f\r]</tt></td></tr>
165 * <tr><td valign="top" headers="construct predef"><tt>\S</tt></td>
166 * <td headers="matches">A non-whitespace character: <tt>[^\s]</tt></td></tr>
167 * <tr><td valign="top" headers="construct predef"><tt>\v</tt></td>
168 * <td headers="matches">A vertical whitespace character: <tt>[\n\x0B\f\r\x85\u2028\u2029]</tt>
169 * </td></tr>
170 * <tr><td valign="top" headers="construct predef"><tt>\V</tt></td>
171 * <td headers="matches">A non-vertical whitespace character: <tt>[^\v]</tt></td></tr>
172 * <tr><td valign="top" headers="construct predef"><tt>\w</tt></td>
173 * <td headers="matches">A word character: <tt>[a-zA-Z_0-9]</tt></td></tr>
174 * <tr><td valign="top" headers="construct predef"><tt>\W</tt></td>
175 * <td headers="matches">A non-word character: <tt>[^\w]</tt></td></tr>
176 * <tr><th> </th></tr>
177 * <tr align="left"><th colspan="2" id="posix"><b>POSIX character classes (US-ASCII only)</b></th></tr>
178 *
179 * <tr><td valign="top" headers="construct posix">{@code \p{Lower}}</td>
180 * <td headers="matches">A lower-case alphabetic character: {@code [a-z]}</td></tr>
181 * <tr><td valign="top" headers="construct posix">{@code \p{Upper}}</td>
182 * <td headers="matches">An upper-case alphabetic character:{@code [A-Z]}</td></tr>
183 * <tr><td valign="top" headers="construct posix">{@code \p{ASCII}}</td>
184 * <td headers="matches">All ASCII:{@code [\x00-\x7F]}</td></tr>
185 * <tr><td valign="top" headers="construct posix">{@code \p{Alpha}}</td>
186 * <td headers="matches">An alphabetic character:{@code [\p{Lower}\p{Upper}]}</td></tr>
187 * <tr><td valign="top" headers="construct posix">{@code \p{Digit}}</td>
188 * <td headers="matches">A decimal digit: {@code [0-9]}</td></tr>
189 * <tr><td valign="top" headers="construct posix">{@code \p{Alnum}}</td>
190 * <td headers="matches">An alphanumeric character:{@code [\p{Alpha}\p{Digit}]}</td></tr>
191 * <tr><td valign="top" headers="construct posix">{@code \p{Punct}}</td>
192 * <td headers="matches">Punctuation: One of {@code !"#$%&'()*+,-./:;<=>?@[\]^_`{|}~}</td></tr>
193 * <!-- {@code [\!"#\$%&'\(\)\*\+,\-\./:;\<=\>\?@\[\\\]\^_`\{\|\}~]}
194 * {@code [\X21-\X2F\X31-\X40\X5B-\X60\X7B-\X7E]} -->
195 * <tr><td valign="top" headers="construct posix">{@code \p{Graph}}</td>
196 * <td headers="matches">A visible character: {@code [\p{Alnum}\p{Punct}]}</td></tr>
197 * <tr><td valign="top" headers="construct posix">{@code \p{Print}}</td>
198 * <td headers="matches">A printable character: {@code [\p{Graph}\x20]}</td></tr>
199 * <tr><td valign="top" headers="construct posix">{@code \p{Blank}}</td>
200 * <td headers="matches">A space or a tab: {@code [ \t]}</td></tr>
201 * <tr><td valign="top" headers="construct posix">{@code \p{Cntrl}}</td>
202 * <td headers="matches">A control character: {@code [\x00-\x1F\x7F]}</td></tr>
203 * <tr><td valign="top" headers="construct posix">{@code \p{XDigit}}</td>
204 * <td headers="matches">A hexadecimal digit: {@code [0-9a-fA-F]}</td></tr>
205 * <tr><td valign="top" headers="construct posix">{@code \p{Space}}</td>
206 * <td headers="matches">A whitespace character: {@code [ \t\n\x0B\f\r]}</td></tr>
207 *
208 * <tr><th> </th></tr>
209 * <tr align="left"><th colspan="2">java.lang.Character classes (simple <a href="#jcc">java character type</a>)</th></tr>
210 *
211 * <tr><td valign="top"><tt>\p{javaLowerCase}</tt></td>
212 * <td>Equivalent to java.lang.Character.isLowerCase()</td></tr>
213 * <tr><td valign="top"><tt>\p{javaUpperCase}</tt></td>
214 * <td>Equivalent to java.lang.Character.isUpperCase()</td></tr>
215 * <tr><td valign="top"><tt>\p{javaWhitespace}</tt></td>
216 * <td>Equivalent to java.lang.Character.isWhitespace()</td></tr>
217 * <tr><td valign="top"><tt>\p{javaMirrored}</tt></td>
218 * <td>Equivalent to java.lang.Character.isMirrored()</td></tr>
219 *
220 * <tr><th> </th></tr>
221 * <tr align="left"><th colspan="2" id="unicode">Classes for Unicode scripts, blocks, categories and binary properties</th></tr>
222 * <tr><td valign="top" headers="construct unicode">{@code \p{IsLatin}}</td>
223 * <td headers="matches">A Latin script character (<a href="#usc">script</a>)</td></tr>
224 * <tr><td valign="top" headers="construct unicode">{@code \p{InGreek}}</td>
225 * <td headers="matches">A character in the Greek block (<a href="#ubc">block</a>)</td></tr>
226 * <tr><td valign="top" headers="construct unicode">{@code \p{Lu}}</td>
227 * <td headers="matches">An uppercase letter (<a href="#ucc">category</a>)</td></tr>
228 * <tr><td valign="top" headers="construct unicode">{@code \p{IsAlphabetic}}</td>
229 * <td headers="matches">An alphabetic character (<a href="#ubpc">binary property</a>)</td></tr>
230 * <tr><td valign="top" headers="construct unicode">{@code \p{Sc}}</td>
231 * <td headers="matches">A currency symbol</td></tr>
232 * <tr><td valign="top" headers="construct unicode">{@code \P{InGreek}}</td>
233 * <td headers="matches">Any character except one in the Greek block (negation)</td></tr>
234 * <tr><td valign="top" headers="construct unicode">{@code [\p{L}&&[^\p{Lu}]]}</td>
235 * <td headers="matches">Any letter except an uppercase letter (subtraction)</td></tr>
236 *
237 * <tr><th> </th></tr>
238 * <tr align="left"><th colspan="2" id="bounds">Boundary matchers</th></tr>
239 *
240 * <tr><td valign="top" headers="construct bounds"><tt>^</tt></td>
241 * <td headers="matches">The beginning of a line</td></tr>
242 * <tr><td valign="top" headers="construct bounds"><tt>$</tt></td>
243 * <td headers="matches">The end of a line</td></tr>
244 * <tr><td valign="top" headers="construct bounds"><tt>\b</tt></td>
245 * <td headers="matches">A word boundary</td></tr>
246 * <tr><td valign="top" headers="construct bounds"><tt>\B</tt></td>
247 * <td headers="matches">A non-word boundary</td></tr>
248 * <tr><td valign="top" headers="construct bounds"><tt>\A</tt></td>
249 * <td headers="matches">The beginning of the input</td></tr>
250 * <tr><td valign="top" headers="construct bounds"><tt>\G</tt></td>
251 * <td headers="matches">The end of the previous match</td></tr>
252 * <tr><td valign="top" headers="construct bounds"><tt>\Z</tt></td>
253 * <td headers="matches">The end of the input but for the final
254 * <a href="#lt">terminator</a>, if any</td></tr>
255 * <tr><td valign="top" headers="construct bounds"><tt>\z</tt></td>
256 * <td headers="matches">The end of the input</td></tr>
257 *
258 * <tr><th> </th></tr>
259 * <tr align="left"><th colspan="2" id="lineending">Linebreak matcher</th></tr>
260 * <tr><td valign="top" headers="construct lineending"><tt>\R</tt></td>
261 * <td headers="matches">Any Unicode linebreak sequence, is equivalent to
262 * <tt>\u000D\u000A|[\u000A\u000B\u000C\u000D\u0085\u2028\u2029]
263 * </tt></td></tr>
264 *
265 * <tr><th> </th></tr>
266 * <tr align="left"><th colspan="2" id="greedy">Greedy quantifiers</th></tr>
267 *
268 * <tr><td valign="top" headers="construct greedy"><i>X</i><tt>?</tt></td>
269 * <td headers="matches"><i>X</i>, once or not at all</td></tr>
270 * <tr><td valign="top" headers="construct greedy"><i>X</i><tt>*</tt></td>
271 * <td headers="matches"><i>X</i>, zero or more times</td></tr>
272 * <tr><td valign="top" headers="construct greedy"><i>X</i><tt>+</tt></td>
273 * <td headers="matches"><i>X</i>, one or more times</td></tr>
274 * <tr><td valign="top" headers="construct greedy"><i>X</i><tt>{</tt><i>n</i><tt>}</tt></td>
275 * <td headers="matches"><i>X</i>, exactly <i>n</i> times</td></tr>
276 * <tr><td valign="top" headers="construct greedy"><i>X</i><tt>{</tt><i>n</i><tt>,}</tt></td>
277 * <td headers="matches"><i>X</i>, at least <i>n</i> times</td></tr>
278 * <tr><td valign="top" headers="construct greedy"><i>X</i><tt>{</tt><i>n</i><tt>,</tt><i>m</i><tt>}</tt></td>
279 * <td headers="matches"><i>X</i>, at least <i>n</i> but not more than <i>m</i> times</td></tr>
280 *
281 * <tr><th> </th></tr>
282 * <tr align="left"><th colspan="2" id="reluc">Reluctant quantifiers</th></tr>
283 *
284 * <tr><td valign="top" headers="construct reluc"><i>X</i><tt>??</tt></td>
285 * <td headers="matches"><i>X</i>, once or not at all</td></tr>
286 * <tr><td valign="top" headers="construct reluc"><i>X</i><tt>*?</tt></td>
287 * <td headers="matches"><i>X</i>, zero or more times</td></tr>
288 * <tr><td valign="top" headers="construct reluc"><i>X</i><tt>+?</tt></td>
289 * <td headers="matches"><i>X</i>, one or more times</td></tr>
290 * <tr><td valign="top" headers="construct reluc"><i>X</i><tt>{</tt><i>n</i><tt>}?</tt></td>
291 * <td headers="matches"><i>X</i>, exactly <i>n</i> times</td></tr>
292 * <tr><td valign="top" headers="construct reluc"><i>X</i><tt>{</tt><i>n</i><tt>,}?</tt></td>
293 * <td headers="matches"><i>X</i>, at least <i>n</i> times</td></tr>
294 * <tr><td valign="top" headers="construct reluc"><i>X</i><tt>{</tt><i>n</i><tt>,</tt><i>m</i><tt>}?</tt></td>
295 * <td headers="matches"><i>X</i>, at least <i>n</i> but not more than <i>m</i> times</td></tr>
296 *
297 * <tr><th> </th></tr>
298 * <tr align="left"><th colspan="2" id="poss">Possessive quantifiers</th></tr>
299 *
300 * <tr><td valign="top" headers="construct poss"><i>X</i><tt>?+</tt></td>
301 * <td headers="matches"><i>X</i>, once or not at all</td></tr>
302 * <tr><td valign="top" headers="construct poss"><i>X</i><tt>*+</tt></td>
303 * <td headers="matches"><i>X</i>, zero or more times</td></tr>
304 * <tr><td valign="top" headers="construct poss"><i>X</i><tt>++</tt></td>
305 * <td headers="matches"><i>X</i>, one or more times</td></tr>
306 * <tr><td valign="top" headers="construct poss"><i>X</i><tt>{</tt><i>n</i><tt>}+</tt></td>
307 * <td headers="matches"><i>X</i>, exactly <i>n</i> times</td></tr>
308 * <tr><td valign="top" headers="construct poss"><i>X</i><tt>{</tt><i>n</i><tt>,}+</tt></td>
309 * <td headers="matches"><i>X</i>, at least <i>n</i> times</td></tr>
310 * <tr><td valign="top" headers="construct poss"><i>X</i><tt>{</tt><i>n</i><tt>,</tt><i>m</i><tt>}+</tt></td>
311 * <td headers="matches"><i>X</i>, at least <i>n</i> but not more than <i>m</i> times</td></tr>
312 *
313 * <tr><th> </th></tr>
314 * <tr align="left"><th colspan="2" id="logical">Logical operators</th></tr>
315 *
316 * <tr><td valign="top" headers="construct logical"><i>XY</i></td>
317 * <td headers="matches"><i>X</i> followed by <i>Y</i></td></tr>
318 * <tr><td valign="top" headers="construct logical"><i>X</i><tt>|</tt><i>Y</i></td>
319 * <td headers="matches">Either <i>X</i> or <i>Y</i></td></tr>
320 * <tr><td valign="top" headers="construct logical"><tt>(</tt><i>X</i><tt>)</tt></td>
321 * <td headers="matches">X, as a <a href="#cg">capturing group</a></td></tr>
322 *
323 * <tr><th> </th></tr>
324 * <tr align="left"><th colspan="2" id="backref">Back references</th></tr>
325 *
326 * <tr><td valign="bottom" headers="construct backref"><tt>\</tt><i>n</i></td>
327 * <td valign="bottom" headers="matches">Whatever the <i>n</i><sup>th</sup>
328 * <a href="#cg">capturing group</a> matched</td></tr>
329 *
330 * <tr><td valign="bottom" headers="construct backref"><tt>\</tt><i>k</i><<i>name</i>></td>
331 * <td valign="bottom" headers="matches">Whatever the
332 * <a href="#groupname">named-capturing group</a> "name" matched</td></tr>
333 *
334 * <tr><th> </th></tr>
335 * <tr align="left"><th colspan="2" id="quot">Quotation</th></tr>
336 *
337 * <tr><td valign="top" headers="construct quot"><tt>\</tt></td>
338 * <td headers="matches">Nothing, but quotes the following character</td></tr>
339 * <tr><td valign="top" headers="construct quot"><tt>\Q</tt></td>
340 * <td headers="matches">Nothing, but quotes all characters until <tt>\E</tt></td></tr>
341 * <tr><td valign="top" headers="construct quot"><tt>\E</tt></td>
342 * <td headers="matches">Nothing, but ends quoting started by <tt>\Q</tt></td></tr>
343 * <!-- Metachars: !$()*+.<>?[\]^{|} -->
344 *
345 * <tr><th> </th></tr>
346 * <tr align="left"><th colspan="2" id="special">Special constructs (named-capturing and non-capturing)</th></tr>
347 *
348 * <tr><td valign="top" headers="construct special"><tt>(?<<a href="#groupname">name</a>></tt><i>X</i><tt>)</tt></td>
349 * <td headers="matches"><i>X</i>, as a named-capturing group</td></tr>
350 * <tr><td valign="top" headers="construct special"><tt>(?:</tt><i>X</i><tt>)</tt></td>
351 * <td headers="matches"><i>X</i>, as a non-capturing group</td></tr>
352 * <tr><td valign="top" headers="construct special"><tt>(?idmsuxU-idmsuxU) </tt></td>
353 * <td headers="matches">Nothing, but turns match flags <a href="#CASE_INSENSITIVE">i</a>
354 * <a href="#UNIX_LINES">d</a> <a href="#MULTILINE">m</a> <a href="#DOTALL">s</a>
355 * <a href="#UNICODE_CASE">u</a> <a href="#COMMENTS">x</a> <a href="#UNICODE_CHARACTER_CLASS">U</a>
356 * on - off</td></tr>
357 * <tr><td valign="top" headers="construct special"><tt>(?idmsux-idmsux:</tt><i>X</i><tt>)</tt> </td>
358 * <td headers="matches"><i>X</i>, as a <a href="#cg">non-capturing group</a> with the
359 * given flags <a href="#CASE_INSENSITIVE">i</a> <a href="#UNIX_LINES">d</a>
360 * <a href="#MULTILINE">m</a> <a href="#DOTALL">s</a> <a href="#UNICODE_CASE">u</a >
361 * <a href="#COMMENTS">x</a> on - off</td></tr>
362 * <tr><td valign="top" headers="construct special"><tt>(?=</tt><i>X</i><tt>)</tt></td>
363 * <td headers="matches"><i>X</i>, via zero-width positive lookahead</td></tr>
364 * <tr><td valign="top" headers="construct special"><tt>(?!</tt><i>X</i><tt>)</tt></td>
365 * <td headers="matches"><i>X</i>, via zero-width negative lookahead</td></tr>
366 * <tr><td valign="top" headers="construct special"><tt>(?<=</tt><i>X</i><tt>)</tt></td>
367 * <td headers="matches"><i>X</i>, via zero-width positive lookbehind</td></tr>
368 * <tr><td valign="top" headers="construct special"><tt>(?<!</tt><i>X</i><tt>)</tt></td>
369 * <td headers="matches"><i>X</i>, via zero-width negative lookbehind</td></tr>
370 * <tr><td valign="top" headers="construct special"><tt>(?></tt><i>X</i><tt>)</tt></td>
371 * <td headers="matches"><i>X</i>, as an independent, non-capturing group</td></tr>
372 *
373 * </table>
374 *
375 * <hr>
376 *
377 *
378 * <h3><a name="bs">Backslashes, escapes, and quoting</a></h3>
379 *
380 * <p> The backslash character (<tt>'\'</tt>) serves to introduce escaped
381 * constructs, as defined in the table above, as well as to quote characters
382 * that otherwise would be interpreted as unescaped constructs. Thus the
383 * expression <tt>\\</tt> matches a single backslash and <tt>\{</tt> matches a
384 * left brace.
385 *
386 * <p> It is an error to use a backslash prior to any alphabetic character that
387 * does not denote an escaped construct; these are reserved for future
388 * extensions to the regular-expression language. A backslash may be used
389 * prior to a non-alphabetic character regardless of whether that character is
390 * part of an unescaped construct.
391 *
392 * <p> Backslashes within string literals in Java source code are interpreted
393 * as required by
394 * <cite>The Java™ Language Specification</cite>
395 * as either Unicode escapes (section 3.3) or other character escapes (section 3.10.6)
396 * It is therefore necessary to double backslashes in string
397 * literals that represent regular expressions to protect them from
398 * interpretation by the Java bytecode compiler. The string literal
399 * <tt>"\b"</tt>, for example, matches a single backspace character when
400 * interpreted as a regular expression, while <tt>"\\b"</tt> matches a
401 * word boundary. The string literal <tt>"\(hello\)"</tt> is illegal
402 * and leads to a compile-time error; in order to match the string
403 * <tt>(hello)</tt> the string literal <tt>"\\(hello\\)"</tt>
404 * must be used.
405 *
406 * <h3><a name="cc">Character Classes</a></h3>
407 *
408 * <p> Character classes may appear within other character classes, and
409 * may be composed by the union operator (implicit) and the intersection
410 * operator (<tt>&&</tt>).
411 * The union operator denotes a class that contains every character that is
412 * in at least one of its operand classes. The intersection operator
413 * denotes a class that contains every character that is in both of its
414 * operand classes.
415 *
416 * <p> The precedence of character-class operators is as follows, from
417 * highest to lowest:
418 *
419 * <blockquote><table border="0" cellpadding="1" cellspacing="0"
420 * summary="Precedence of character class operators.">
421 * <tr><th>1 </th>
422 * <td>Literal escape </td>
423 * <td><tt>\x</tt></td></tr>
424 * <tr><th>2 </th>
425 * <td>Grouping</td>
426 * <td><tt>[...]</tt></td></tr>
427 * <tr><th>3 </th>
428 * <td>Range</td>
429 * <td><tt>a-z</tt></td></tr>
430 * <tr><th>4 </th>
431 * <td>Union</td>
432 * <td><tt>[a-e][i-u]</tt></td></tr>
433 * <tr><th>5 </th>
434 * <td>Intersection</td>
435 * <td>{@code [a-z&&[aeiou]]}</td></tr>
436 * </table></blockquote>
437 *
438 * <p> Note that a different set of metacharacters are in effect inside
439 * a character class than outside a character class. For instance, the
440 * regular expression <tt>.</tt> loses its special meaning inside a
441 * character class, while the expression <tt>-</tt> becomes a range
442 * forming metacharacter.
443 *
444 * <h3><a name="lt">Line terminators</a></h3>
445 *
446 * <p> A <i>line terminator</i> is a one- or two-character sequence that marks
447 * the end of a line of the input character sequence. The following are
448 * recognized as line terminators:
449 *
450 * <ul>
451 *
452 * <li> A newline (line feed) character (<tt>'\n'</tt>),
453 *
454 * <li> A carriage-return character followed immediately by a newline
455 * character (<tt>"\r\n"</tt>),
456 *
457 * <li> A standalone carriage-return character (<tt>'\r'</tt>),
458 *
459 * <li> A next-line character (<tt>'\u0085'</tt>),
460 *
461 * <li> A line-separator character (<tt>'\u2028'</tt>), or
462 *
463 * <li> A paragraph-separator character (<tt>'\u2029</tt>).
464 *
465 * </ul>
466 * <p>If {@link #UNIX_LINES} mode is activated, then the only line terminators
467 * recognized are newline characters.
468 *
469 * <p> The regular expression <tt>.</tt> matches any character except a line
470 * terminator unless the {@link #DOTALL} flag is specified.
471 *
472 * <p> By default, the regular expressions <tt>^</tt> and <tt>$</tt> ignore
473 * line terminators and only match at the beginning and the end, respectively,
474 * of the entire input sequence. If {@link #MULTILINE} mode is activated then
475 * <tt>^</tt> matches at the beginning of input and after any line terminator
476 * except at the end of input. When in {@link #MULTILINE} mode <tt>$</tt>
477 * matches just before a line terminator or the end of the input sequence.
478 *
479 * <h3><a name="cg">Groups and capturing</a></h3>
480 *
481 * <h4><a name="gnumber">Group number</a></h4>
482 * <p> Capturing groups are numbered by counting their opening parentheses from
483 * left to right. In the expression <tt>((A)(B(C)))</tt>, for example, there
484 * are four such groups: </p>
485 *
486 * <blockquote><table cellpadding=1 cellspacing=0 summary="Capturing group numberings">
487 * <tr><th>1 </th>
488 * <td><tt>((A)(B(C)))</tt></td></tr>
489 * <tr><th>2 </th>
490 * <td><tt>(A)</tt></td></tr>
491 * <tr><th>3 </th>
492 * <td><tt>(B(C))</tt></td></tr>
493 * <tr><th>4 </th>
494 * <td><tt>(C)</tt></td></tr>
495 * </table></blockquote>
496 *
497 * <p> Group zero always stands for the entire expression.
498 *
499 * <p> Capturing groups are so named because, during a match, each subsequence
500 * of the input sequence that matches such a group is saved. The captured
501 * subsequence may be used later in the expression, via a back reference, and
502 * may also be retrieved from the matcher once the match operation is complete.
503 *
504 * <h4><a name="groupname">Group name</a></h4>
505 * <p>A capturing group can also be assigned a "name", a <tt>named-capturing group</tt>,
506 * and then be back-referenced later by the "name". Group names are composed of
507 * the following characters. The first character must be a <tt>letter</tt>.
508 *
509 * <ul>
510 * <li> The uppercase letters <tt>'A'</tt> through <tt>'Z'</tt>
511 * (<tt>'\u0041'</tt> through <tt>'\u005a'</tt>),
512 * <li> The lowercase letters <tt>'a'</tt> through <tt>'z'</tt>
513 * (<tt>'\u0061'</tt> through <tt>'\u007a'</tt>),
514 * <li> The digits <tt>'0'</tt> through <tt>'9'</tt>
515 * (<tt>'\u0030'</tt> through <tt>'\u0039'</tt>),
516 * </ul>
517 *
518 * <p> A <tt>named-capturing group</tt> is still numbered as described in
519 * <a href="#gnumber">Group number</a>.
520 *
521 * <p> The captured input associated with a group is always the subsequence
522 * that the group most recently matched. If a group is evaluated a second time
523 * because of quantification then its previously-captured value, if any, will
524 * be retained if the second evaluation fails. Matching the string
525 * <tt>"aba"</tt> against the expression <tt>(a(b)?)+</tt>, for example, leaves
526 * group two set to <tt>"b"</tt>. All captured input is discarded at the
527 * beginning of each match.
528 *
529 * <p> Groups beginning with <tt>(?</tt> are either pure, <i>non-capturing</i> groups
530 * that do not capture text and do not count towards the group total, or
531 * <i>named-capturing</i> group.
532 *
533 * <h3> Unicode support </h3>
534 *
535 * <p> This class is in conformance with Level 1 of <a
536 * href="http://www.unicode.org/reports/tr18/"><i>Unicode Technical
537 * Standard #18: Unicode Regular Expression</i></a>, plus RL2.1
538 * Canonical Equivalents.
539 * <p>
540 * <b>Unicode escape sequences</b> such as <tt>\u2014</tt> in Java source code
541 * are processed as described in section 3.3 of
542 * <cite>The Java™ Language Specification</cite>.
543 * Such escape sequences are also implemented directly by the regular-expression
544 * parser so that Unicode escapes can be used in expressions that are read from
545 * files or from the keyboard. Thus the strings <tt>"\u2014"</tt> and
546 * <tt>"\\u2014"</tt>, while not equal, compile into the same pattern, which
547 * matches the character with hexadecimal value <tt>0x2014</tt>.
548 * <p>
549 * A Unicode character can also be represented in a regular-expression by
550 * using its <b>Hex notation</b>(hexadecimal code point value) directly as described in construct
551 * <tt>\x{...}</tt>, for example a supplementary character U+2011F
552 * can be specified as <tt>\x{2011F}</tt>, instead of two consecutive
553 * Unicode escape sequences of the surrogate pair
554 * <tt>\uD840</tt><tt>\uDD1F</tt>.
555 * <p>
556 * Unicode scripts, blocks, categories and binary properties are written with
557 * the <tt>\p</tt> and <tt>\P</tt> constructs as in Perl.
558 * <tt>\p{</tt><i>prop</i><tt>}</tt> matches if
559 * the input has the property <i>prop</i>, while <tt>\P{</tt><i>prop</i><tt>}</tt>
560 * does not match if the input has that property.
561 * <p>
562 * Scripts, blocks, categories and binary properties can be used both inside
563 * and outside of a character class.
564 *
565 * <p>
566 * <b><a name="usc">Scripts</a></b> are specified either with the prefix {@code Is}, as in
567 * {@code IsHiragana}, or by using the {@code script} keyword (or its short
568 * form {@code sc})as in {@code script=Hiragana} or {@code sc=Hiragana}.
569 * <p>
570 * The script names supported by <code>Pattern</code> are the valid script names
571 * accepted and defined by
572 * {@link java.lang.Character.UnicodeScript#forName(String) UnicodeScript.forName}.
573 *
574 * <p>
575 * <b><a name="ubc">Blocks</a></b> are specified with the prefix {@code In}, as in
576 * {@code InMongolian}, or by using the keyword {@code block} (or its short
577 * form {@code blk}) as in {@code block=Mongolian} or {@code blk=Mongolian}.
578 * <p>
579 * The block names supported by <code>Pattern</code> are the valid block names
580 * accepted and defined by
581 * {@link java.lang.Character.UnicodeBlock#forName(String) UnicodeBlock.forName}.
582 * <p>
583 *
584 * <b><a name="ucc">Categories</a></b> may be specified with the optional prefix {@code Is}:
585 * Both {@code \p{L}} and {@code \p{IsL}} denote the category of Unicode
586 * letters. Same as scripts and blocks, categories can also be specified
587 * by using the keyword {@code general_category} (or its short form
588 * {@code gc}) as in {@code general_category=Lu} or {@code gc=Lu}.
589 * <p>
590 * The supported categories are those of
591 * <a href="http://www.unicode.org/unicode/standard/standard.html">
592 * <i>The Unicode Standard</i></a> in the version specified by the
593 * {@link java.lang.Character Character} class. The category names are those
594 * defined in the Standard, both normative and informative.
595 * <p>
596 *
597 * <b><a name="ubpc">Binary properties</a></b> are specified with the prefix {@code Is}, as in
598 * {@code IsAlphabetic}. The supported binary properties by <code>Pattern</code>
599 * are
600 * <ul>
601 * <li> Alphabetic
602 * <li> Ideographic
603 * <li> Letter
604 * <li> Lowercase
605 * <li> Uppercase
606 * <li> Titlecase
607 * <li> Punctuation
608 * <Li> Control
609 * <li> White_Space
610 * <li> Digit
611 * <li> Hex_Digit
612 * <li> Join_Control
613 * <li> Noncharacter_Code_Point
614 * <li> Assigned
615 * </ul>
616 * <p>
617 * The following <b>Predefined Character classes</b> and <b>POSIX character classes</b>
618 * are in conformance with the recommendation of <i>Annex C: Compatibility Properties</i>
619 * of <a href="http://www.unicode.org/reports/tr18/"><i>Unicode Regular Expression
620 * </i></a>, when {@link #UNICODE_CHARACTER_CLASS} flag is specified.
621 *
622 * <table border="0" cellpadding="1" cellspacing="0"
623 * summary="predefined and posix character classes in Unicode mode">
624 * <tr align="left">
625 * <th align="left" id="predef_classes">Classes</th>
626 * <th align="left" id="predef_matches">Matches</th>
627 *</tr>
628 * <tr><td><tt>\p{Lower}</tt></td>
629 * <td>A lowercase character:<tt>\p{IsLowercase}</tt></td></tr>
630 * <tr><td><tt>\p{Upper}</tt></td>
631 * <td>An uppercase character:<tt>\p{IsUppercase}</tt></td></tr>
632 * <tr><td><tt>\p{ASCII}</tt></td>
633 * <td>All ASCII:<tt>[\x00-\x7F]</tt></td></tr>
634 * <tr><td><tt>\p{Alpha}</tt></td>
635 * <td>An alphabetic character:<tt>\p{IsAlphabetic}</tt></td></tr>
636 * <tr><td><tt>\p{Digit}</tt></td>
637 * <td>A decimal digit character:<tt>p{IsDigit}</tt></td></tr>
638 * <tr><td><tt>\p{Alnum}</tt></td>
639 * <td>An alphanumeric character:<tt>[\p{IsAlphabetic}\p{IsDigit}]</tt></td></tr>
640 * <tr><td><tt>\p{Punct}</tt></td>
641 * <td>A punctuation character:<tt>p{IsPunctuation}</tt></td></tr>
642 * <tr><td><tt>\p{Graph}</tt></td>
643 * <td>A visible character: <tt>[^\p{IsWhite_Space}\p{gc=Cc}\p{gc=Cs}\p{gc=Cn}]</tt></td></tr>
644 * <tr><td><tt>\p{Print}</tt></td>
645 * <td>A printable character: {@code [\p{Graph}\p{Blank}&&[^\p{Cntrl}]]}</td></tr>
646 * <tr><td><tt>\p{Blank}</tt></td>
647 * <td>A space or a tab: {@code [\p{IsWhite_Space}&&[^\p{gc=Zl}\p{gc=Zp}\x0a\x0b\x0c\x0d\x85]]}</td></tr>
648 * <tr><td><tt>\p{Cntrl}</tt></td>
649 * <td>A control character: <tt>\p{gc=Cc}</tt></td></tr>
650 * <tr><td><tt>\p{XDigit}</tt></td>
651 * <td>A hexadecimal digit: <tt>[\p{gc=Nd}\p{IsHex_Digit}]</tt></td></tr>
652 * <tr><td><tt>\p{Space}</tt></td>
653 * <td>A whitespace character:<tt>\p{IsWhite_Space}</tt></td></tr>
654 * <tr><td><tt>\d</tt></td>
655 * <td>A digit: <tt>\p{IsDigit}</tt></td></tr>
656 * <tr><td><tt>\D</tt></td>
657 * <td>A non-digit: <tt>[^\d]</tt></td></tr>
658 * <tr><td><tt>\s</tt></td>
659 * <td>A whitespace character: <tt>\p{IsWhite_Space}</tt></td></tr>
660 * <tr><td><tt>\S</tt></td>
661 * <td>A non-whitespace character: <tt>[^\s]</tt></td></tr>
662 * <tr><td><tt>\w</tt></td>
663 * <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>
664 * <tr><td><tt>\W</tt></td>
665 * <td>A non-word character: <tt>[^\w]</tt></td></tr>
666 * </table>
667 * <p>
668 * <a name="jcc">
669 * Categories that behave like the java.lang.Character
670 * boolean is<i>methodname</i> methods (except for the deprecated ones) are
671 * available through the same <tt>\p{</tt><i>prop</i><tt>}</tt> syntax where
672 * the specified property has the name <tt>java<i>methodname</i></tt></a>.
673 *
674 * <h3> Comparison to Perl 5 </h3>
675 *
676 * <p>The <code>Pattern</code> engine performs traditional NFA-based matching
677 * with ordered alternation as occurs in Perl 5.
678 *
679 * <p> Perl constructs not supported by this class: </p>
680 *
681 * <ul>
682 * <li><p> Predefined character classes (Unicode character)
683 * <p><tt>\X </tt>Match Unicode
684 * <a href="http://www.unicode.org/reports/tr18/#Default_Grapheme_Clusters">
685 * <i>extended grapheme cluster</i></a>
686 * </p></li>
687 *
688 * <li><p> The backreference constructs, <tt>\g{</tt><i>n</i><tt>}</tt> for
689 * the <i>n</i><sup>th</sup><a href="#cg">capturing group</a> and
690 * <tt>\g{</tt><i>name</i><tt>}</tt> for
691 * <a href="#groupname">named-capturing group</a>.
692 * </p></li>
693 *
694 * <li><p> The named character construct, <tt>\N{</tt><i>name</i><tt>}</tt>
695 * for a Unicode character by its name.
696 * </p></li>
697 *
698 * <li><p> The conditional constructs
699 * <tt>(?(</tt><i>condition</i><tt>)</tt><i>X</i><tt>)</tt> and
700 * <tt>(?(</tt><i>condition</i><tt>)</tt><i>X</i><tt>|</tt><i>Y</i><tt>)</tt>,
701 * </p></li>
702 *
703 * <li><p> The embedded code constructs <tt>(?{</tt><i>code</i><tt>})</tt>
704 * and <tt>(??{</tt><i>code</i><tt>})</tt>,</p></li>
705 *
706 * <li><p> The embedded comment syntax <tt>(?#comment)</tt>, and </p></li>
707 *
708 * <li><p> The preprocessing operations <tt>\l</tt> <tt>\u</tt>,
709 * <tt>\L</tt>, and <tt>\U</tt>. </p></li>
710 *
711 * </ul>
712 *
713 * <p> Constructs supported by this class but not by Perl: </p>
714 *
715 * <ul>
716 *
717 * <li><p> Character-class union and intersection as described
718 * <a href="#cc">above</a>.</p></li>
719 *
720 * </ul>
721 *
722 * <p> Notable differences from Perl: </p>
723 *
724 * <ul>
725 *
726 * <li><p> In Perl, <tt>\1</tt> through <tt>\9</tt> are always interpreted
727 * as back references; a backslash-escaped number greater than <tt>9</tt> is
728 * treated as a back reference if at least that many subexpressions exist,
729 * otherwise it is interpreted, if possible, as an octal escape. In this
730 * class octal escapes must always begin with a zero. In this class,
731 * <tt>\1</tt> through <tt>\9</tt> are always interpreted as back
732 * references, and a larger number is accepted as a back reference if at
733 * least that many subexpressions exist at that point in the regular
734 * expression, otherwise the parser will drop digits until the number is
735 * smaller or equal to the existing number of groups or it is one digit.
736 * </p></li>
737 *
738 * <li><p> Perl uses the <tt>g</tt> flag to request a match that resumes
739 * where the last match left off. This functionality is provided implicitly
740 * by the {@link Matcher} class: Repeated invocations of the {@link
741 * Matcher#find find} method will resume where the last match left off,
742 * unless the matcher is reset. </p></li>
743 *
744 * <li><p> In Perl, embedded flags at the top level of an expression affect
745 * the whole expression. In this class, embedded flags always take effect
746 * at the point at which they appear, whether they are at the top level or
747 * within a group; in the latter case, flags are restored at the end of the
748 * group just as in Perl. </p></li>
749 *
750 * </ul>
751 *
752 *
753 * <p> For a more precise description of the behavior of regular expression
754 * constructs, please see <a href="http://www.oreilly.com/catalog/regex3/">
755 * <i>Mastering Regular Expressions, 3nd Edition</i>, Jeffrey E. F. Friedl,
756 * O'Reilly and Associates, 2006.</a>
757 * </p>
758 *
759 * @see java.lang.String#split(String, int)
760 * @see java.lang.String#split(String)
761 *
762 * @author Mike McCloskey
763 * @author Mark Reinhold
764 * @author JSR-51 Expert Group
765 * @since 1.4
766 * @spec JSR-51
767 */
768
769 public final class Pattern
770 implements java.io.Serializable
771 {
772
773 /**
774 * Regular expression modifier values. Instead of being passed as
775 * arguments, they can also be passed as inline modifiers.
776 * For example, the following statements have the same effect.
777 * <pre>
778 * RegExp r1 = RegExp.compile("abc", Pattern.I|Pattern.M);
779 * RegExp r2 = RegExp.compile("(?im)abc", 0);
780 * </pre>
781 *
782 * The flags are duplicated so that the familiar Perl match flag
783 * names are available.
784 */
785
786 /**
787 * Enables Unix lines mode.
788 *
789 * <p> In this mode, only the <tt>'\n'</tt> line terminator is recognized
790 * in the behavior of <tt>.</tt>, <tt>^</tt>, and <tt>$</tt>.
791 *
792 * <p> Unix lines mode can also be enabled via the embedded flag
793 * expression <tt>(?d)</tt>.
794 */
795 public static final int UNIX_LINES = 0x01;
796
797 /**
798 * Enables case-insensitive matching.
799 *
800 * <p> By default, case-insensitive matching assumes that only characters
801 * in the US-ASCII charset are being matched. Unicode-aware
802 * case-insensitive matching can be enabled by specifying the {@link
803 * #UNICODE_CASE} flag in conjunction with this flag.
804 *
805 * <p> Case-insensitive matching can also be enabled via the embedded flag
806 * expression <tt>(?i)</tt>.
807 *
808 * <p> Specifying this flag may impose a slight performance penalty. </p>
809 */
810 public static final int CASE_INSENSITIVE = 0x02;
811
812 /**
813 * Permits whitespace and comments in pattern.
814 *
815 * <p> In this mode, whitespace is ignored, and embedded comments starting
816 * with <tt>#</tt> are ignored until the end of a line.
817 *
818 * <p> Comments mode can also be enabled via the embedded flag
819 * expression <tt>(?x)</tt>.
820 */
821 public static final int COMMENTS = 0x04;
822
823 /**
824 * Enables multiline mode.
825 *
826 * <p> In multiline mode the expressions <tt>^</tt> and <tt>$</tt> match
827 * just after or just before, respectively, a line terminator or the end of
828 * the input sequence. By default these expressions only match at the
829 * beginning and the end of the entire input sequence.
830 *
831 * <p> Multiline mode can also be enabled via the embedded flag
832 * expression <tt>(?m)</tt>. </p>
833 */
834 public static final int MULTILINE = 0x08;
835
836 /**
837 * Enables literal parsing of the pattern.
838 *
839 * <p> When this flag is specified then the input string that specifies
840 * the pattern is treated as a sequence of literal characters.
841 * Metacharacters or escape sequences in the input sequence will be
842 * given no special meaning.
843 *
844 * <p>The flags CASE_INSENSITIVE and UNICODE_CASE retain their impact on
845 * matching when used in conjunction with this flag. The other flags
846 * become superfluous.
847 *
848 * <p> There is no embedded flag character for enabling literal parsing.
849 * @since 1.5
850 */
851 public static final int LITERAL = 0x10;
852
853 /**
854 * Enables dotall mode.
855 *
856 * <p> In dotall mode, the expression <tt>.</tt> matches any character,
857 * including a line terminator. By default this expression does not match
858 * line terminators.
859 *
860 * <p> Dotall mode can also be enabled via the embedded flag
861 * expression <tt>(?s)</tt>. (The <tt>s</tt> is a mnemonic for
862 * "single-line" mode, which is what this is called in Perl.) </p>
863 */
864 public static final int DOTALL = 0x20;
865
866 /**
867 * Enables Unicode-aware case folding.
868 *
869 * <p> When this flag is specified then case-insensitive matching, when
870 * enabled by the {@link #CASE_INSENSITIVE} flag, is done in a manner
871 * consistent with the Unicode Standard. By default, case-insensitive
872 * matching assumes that only characters in the US-ASCII charset are being
873 * matched.
874 *
875 * <p> Unicode-aware case folding can also be enabled via the embedded flag
876 * expression <tt>(?u)</tt>.
877 *
878 * <p> Specifying this flag may impose a performance penalty. </p>
879 */
880 public static final int UNICODE_CASE = 0x40;
881
882 /**
883 * Enables canonical equivalence.
884 *
885 * <p> When this flag is specified then two characters will be considered
886 * to match if, and only if, their full canonical decompositions match.
887 * The expression <tt>"a\u030A"</tt>, for example, will match the
888 * string <tt>"\u00E5"</tt> when this flag is specified. By default,
889 * matching does not take canonical equivalence into account.
890 *
891 * <p> There is no embedded flag character for enabling canonical
892 * equivalence.
893 *
894 * <p> Specifying this flag may impose a performance penalty. </p>
895 */
896 public static final int CANON_EQ = 0x80;
897
898 /**
899 * Enables the Unicode version of <i>Predefined character classes</i> and
900 * <i>POSIX character classes</i>.
901 *
902 * <p> When this flag is specified then the (US-ASCII only)
903 * <i>Predefined character classes</i> and <i>POSIX character classes</i>
904 * are in conformance with
905 * <a href="http://www.unicode.org/reports/tr18/"><i>Unicode Technical
906 * Standard #18: Unicode Regular Expression</i></a>
907 * <i>Annex C: Compatibility Properties</i>.
908 * <p>
909 * The UNICODE_CHARACTER_CLASS mode can also be enabled via the embedded
910 * flag expression <tt>(?U)</tt>.
911 * <p>
912 * The flag implies UNICODE_CASE, that is, it enables Unicode-aware case
913 * folding.
914 * <p>
915 * Specifying this flag may impose a performance penalty. </p>
916 * @since 1.7
917 */
918 public static final int UNICODE_CHARACTER_CLASS = 0x100;
919
920 /**
921 * Contains all possible flags for compile(regex, flags).
922 */
923 private static final int ALL_FLAGS = CASE_INSENSITIVE | MULTILINE |
924 DOTALL | UNICODE_CASE | CANON_EQ | UNIX_LINES | LITERAL |
925 UNICODE_CHARACTER_CLASS | COMMENTS;
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.
1027 *
1028 * @param regex
1029 * The expression to be compiled
1030 * @return the given regular expression compiled into a pattern
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.
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 * @return the given regular expression compiled into a pattern with the given flags
1053 * @throws IllegalArgumentException
1054 * If bit values other than those corresponding to the defined
1055 * match flags are set in <tt>flags</tt>
1056 *
1057 * @throws PatternSyntaxException
1058 * If the expression's syntax is invalid
1059 */
1060 public static Pattern compile(String regex, int flags) {
1061 return new Pattern(regex, flags);
1062 }
1063
1064 /**
1065 * Returns the regular expression from which this pattern was compiled.
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 *
1088 * @param input
1089 * The character sequence to be matched
1090 *
1091 * @return A new matcher for this pattern
1092 */
1093 public Matcher matcher(CharSequence input) {
1094 if (!compiled) {
1095 synchronized(this) {
1096 if (!compiled)
1097 compile();
1098 }
1099 }
1100 Matcher m = new Matcher(this, input);
1101 return m;
1102 }
1103
1104 /**
1105 * Returns this pattern's match flags.
1106 *
1107 * @return The match flags specified when this pattern was compiled
1108 */
1109 public int flags() {
1110 return flags;
1111 }
1112
1113 /**
1114 * Compiles the given regular expression and attempts to match the given
1115 * input against it.
1116 *
1117 * <p> An invocation of this convenience method of the form
1118 *
1119 * <blockquote><pre>
1120 * Pattern.matches(regex, input);</pre></blockquote>
1121 *
1122 * behaves in exactly the same way as the expression
1123 *
1124 * <blockquote><pre>
1125 * Pattern.compile(regex).matcher(input).matches()</pre></blockquote>
1126 *
1127 * <p> If a pattern is to be used multiple times, compiling it once and reusing
1128 * it will be more efficient than invoking this method each time. </p>
1129 *
1130 * @param regex
1131 * The expression to be compiled
1132 *
1133 * @param input
1134 * The character sequence to be matched
1135 * @return whether or not the regular expression matches on the input
1136 * @throws PatternSyntaxException
1137 * If the expression's syntax is invalid
1138 */
1139 public static boolean matches(String regex, CharSequence input) {
1140 Pattern p = Pattern.compile(regex);
1141 Matcher m = p.matcher(input);
1142 return m.matches();
1143 }
1144
1145 /**
1146 * Splits the given input sequence around matches of this pattern.
1147 *
1148 * <p> The array returned by this method contains each substring of the
1149 * input sequence that is terminated by another subsequence that matches
1150 * this pattern or is terminated by the end of the input sequence. The
1151 * substrings in the array are in the order in which they occur in the
1152 * input. If this pattern does not match any subsequence of the input then
1153 * the resulting array has just one element, namely the input sequence in
1154 * string form.
1155 *
1156 * <p> When there is a positive-width match at the beginning of the input
1157 * sequence then an empty leading substring is included at the beginning
1158 * of the resulting array. A zero-width match at the beginning however
1159 * never produces such empty leading substring.
1160 *
1161 * <p> The <tt>limit</tt> parameter controls the number of times the
1162 * pattern is applied and therefore affects the length of the resulting
1163 * array. If the limit <i>n</i> is greater than zero then the pattern
1164 * will be applied at most <i>n</i> - 1 times, the array's
1165 * length will be no greater than <i>n</i>, and the array's last entry
1166 * will contain all input beyond the last matched delimiter. If <i>n</i>
1167 * is non-positive then the pattern will be applied as many times as
1168 * possible and the array can have any length. If <i>n</i> is zero then
1169 * the pattern will be applied as many times as possible, the array can
1170 * have any length, and trailing empty strings will be discarded.
1171 *
1172 * <p> The input <tt>"boo:and:foo"</tt>, for example, yields the following
1173 * results with these parameters:
1174 *
1175 * <blockquote><table cellpadding=1 cellspacing=0
1176 * summary="Split examples showing regex, limit, and result">
1177 * <tr><th align="left"><i>Regex </i></th>
1178 * <th align="left"><i>Limit </i></th>
1179 * <th align="left"><i>Result </i></th></tr>
1180 * <tr><td align=center>:</td>
1181 * <td align=center>2</td>
1182 * <td><tt>{ "boo", "and:foo" }</tt></td></tr>
1183 * <tr><td align=center>:</td>
1184 * <td align=center>5</td>
1185 * <td><tt>{ "boo", "and", "foo" }</tt></td></tr>
1186 * <tr><td align=center>:</td>
1187 * <td align=center>-2</td>
1188 * <td><tt>{ "boo", "and", "foo" }</tt></td></tr>
1189 * <tr><td align=center>o</td>
1190 * <td align=center>5</td>
1191 * <td><tt>{ "b", "", ":and:f", "", "" }</tt></td></tr>
1192 * <tr><td align=center>o</td>
1193 * <td align=center>-2</td>
1194 * <td><tt>{ "b", "", ":and:f", "", "" }</tt></td></tr>
1195 * <tr><td align=center>o</td>
1196 * <td align=center>0</td>
1197 * <td><tt>{ "b", "", ":and:f" }</tt></td></tr>
1198 * </table></blockquote>
1199 *
1200 * @param input
1201 * The character sequence to be split
1202 *
1203 * @param limit
1204 * The result threshold, as described above
1205 *
1206 * @return The array of strings computed by splitting the input
1207 * around matches of this pattern
1208 */
1209 public String[] split(CharSequence input, int limit) {
1210 int index = 0;
1211 boolean matchLimited = limit > 0;
1212 ArrayList<String> matchList = new ArrayList<>();
1213 Matcher m = matcher(input);
1214
1215 // Add segments before each match found
1216 while(m.find()) {
1217 if (!matchLimited || matchList.size() < limit - 1) {
1218 if (index == 0 && index == m.start() && m.start() == m.end()) {
1219 // no empty leading substring included for zero-width match
1220 // at the beginning of the input char sequence.
1221 continue;
1222 }
1223 String match = input.subSequence(index, m.start()).toString();
1224 matchList.add(match);
1225 index = m.end();
1226 } else if (matchList.size() == limit - 1) { // last one
1227 String match = input.subSequence(index,
1228 input.length()).toString();
1229 matchList.add(match);
1230 index = m.end();
1231 }
1232 }
1233
1234 // If no match was found, return this
1235 if (index == 0)
1236 return new String[] {input.toString()};
1237
1238 // Add remaining segment
1239 if (!matchLimited || matchList.size() < limit)
1240 matchList.add(input.subSequence(index, input.length()).toString());
1241
1242 // Construct result
1243 int resultSize = matchList.size();
1244 if (limit == 0)
1245 while (resultSize > 0 && matchList.get(resultSize-1).equals(""))
1246 resultSize--;
1247 String[] result = new String[resultSize];
1248 return matchList.subList(0, resultSize).toArray(result);
1249 }
1250
1251 /**
1252 * Splits the given input sequence around matches of this pattern.
1253 *
1254 * <p> This method works as if by invoking the two-argument {@link
1255 * #split(java.lang.CharSequence, int) split} method with the given input
1256 * sequence and a limit argument of zero. Trailing empty strings are
1257 * therefore not included in the resulting array. </p>
1258 *
1259 * <p> The input <tt>"boo:and:foo"</tt>, for example, yields the following
1260 * results with these expressions:
1261 *
1262 * <blockquote><table cellpadding=1 cellspacing=0
1263 * summary="Split examples showing regex and result">
1264 * <tr><th align="left"><i>Regex </i></th>
1265 * <th align="left"><i>Result</i></th></tr>
1266 * <tr><td align=center>:</td>
1267 * <td><tt>{ "boo", "and", "foo" }</tt></td></tr>
1268 * <tr><td align=center>o</td>
1269 * <td><tt>{ "b", "", ":and:f" }</tt></td></tr>
1270 * </table></blockquote>
1271 *
1272 *
1273 * @param input
1274 * The character sequence to be split
1275 *
1276 * @return The array of strings computed by splitting the input
1277 * around matches of this pattern
1278 */
1279 public String[] split(CharSequence input) {
1280 return split(input, 0);
1281 }
1282
1283 /**
1284 * Returns a literal pattern <code>String</code> for the specified
1285 * <code>String</code>.
1286 *
1287 * <p>This method produces a <code>String</code> that can be used to
1288 * create a <code>Pattern</code> that would match the string
1289 * <code>s</code> as if it were a literal pattern.</p> Metacharacters
1290 * or escape sequences in the input sequence will be given no special
1291 * meaning.
1292 *
1293 * @param s The string to be literalized
1294 * @return A literal string replacement
1295 * @since 1.5
1296 */
1297 public static String quote(String s) {
1298 int slashEIndex = s.indexOf("\\E");
1299 if (slashEIndex == -1)
1300 return "\\Q" + s + "\\E";
1301
1302 StringBuilder sb = new StringBuilder(s.length() * 2);
1303 sb.append("\\Q");
1304 slashEIndex = 0;
1305 int current = 0;
1306 while ((slashEIndex = s.indexOf("\\E", current)) != -1) {
1307 sb.append(s.substring(current, slashEIndex));
1308 current = slashEIndex + 2;
1309 sb.append("\\E\\\\E\\Q");
1310 }
1311 sb.append(s.substring(current, s.length()));
1312 sb.append("\\E");
1313 return sb.toString();
1314 }
1315
1316 /**
1317 * Recompile the Pattern instance from a stream. The original pattern
1318 * string is read in and the object tree is recompiled from it.
1319 */
1320 private void readObject(java.io.ObjectInputStream s)
1321 throws java.io.IOException, ClassNotFoundException {
1322
1323 // Read in all fields
1324 s.defaultReadObject();
1325
1326 // Initialize counts
1327 capturingGroupCount = 1;
1328 localCount = 0;
1329
1330 // if length > 0, the Pattern is lazily compiled
1331 compiled = false;
1332 if (pattern.length() == 0) {
1333 root = new Start(lastAccept);
1334 matchRoot = lastAccept;
1335 compiled = true;
1336 }
1337 }
1338
1339 /**
1340 * This private constructor is used to create all Patterns. The pattern
1341 * string and match flags are all that is needed to completely describe
1342 * a Pattern. An empty pattern string results in an object tree with
1343 * only a Start node and a LastNode node.
1344 */
1345 private Pattern(String p, int f) {
1346 if ((f & ~ALL_FLAGS) != 0) {
1347 throw new IllegalArgumentException("Unknown flag 0x"
1348 + Integer.toHexString(f));
1349 }
1350 pattern = p;
1351 flags = f;
1352
1353 // to use UNICODE_CASE if UNICODE_CHARACTER_CLASS present
1354 if ((flags & UNICODE_CHARACTER_CLASS) != 0)
1355 flags |= UNICODE_CASE;
1356
1357 // Reset group index count
1358 capturingGroupCount = 1;
1359 localCount = 0;
1360
1361 if (pattern.length() > 0) {
1362 compile();
1363 } else {
1364 root = new Start(lastAccept);
1365 matchRoot = lastAccept;
1366 }
1367 }
1368
1369 /**
1370 * The pattern is converted to normalizedD form and then a pure group
1371 * is constructed to match canonical equivalences of the characters.
1372 */
1373 private void normalize() {
1374 boolean inCharClass = false;
1375 int lastCodePoint = -1;
1376
1377 // Convert pattern into normalizedD form
1378 normalizedPattern = Normalizer.normalize(pattern, Normalizer.Form.NFD);
1379 patternLength = normalizedPattern.length();
1380
1381 // Modify pattern to match canonical equivalences
1382 StringBuilder newPattern = new StringBuilder(patternLength);
1383 for(int i=0; i<patternLength; ) {
1384 int c = normalizedPattern.codePointAt(i);
1385 StringBuilder sequenceBuffer;
1386 if ((Character.getType(c) == Character.NON_SPACING_MARK)
1387 && (lastCodePoint != -1)) {
1388 sequenceBuffer = new StringBuilder();
1389 sequenceBuffer.appendCodePoint(lastCodePoint);
1390 sequenceBuffer.appendCodePoint(c);
1391 while(Character.getType(c) == Character.NON_SPACING_MARK) {
1392 i += Character.charCount(c);
1393 if (i >= patternLength)
1394 break;
1395 c = normalizedPattern.codePointAt(i);
1396 sequenceBuffer.appendCodePoint(c);
1397 }
1398 String ea = produceEquivalentAlternation(
1399 sequenceBuffer.toString());
1400 newPattern.setLength(newPattern.length()-Character.charCount(lastCodePoint));
1401 newPattern.append("(?:").append(ea).append(")");
1402 } else if (c == '[' && lastCodePoint != '\\') {
1403 i = normalizeCharClass(newPattern, i);
1404 } else {
1405 newPattern.appendCodePoint(c);
1406 }
1407 lastCodePoint = c;
1408 i += Character.charCount(c);
1409 }
1410 normalizedPattern = newPattern.toString();
1411 }
1412
1413 /**
1414 * Complete the character class being parsed and add a set
1415 * of alternations to it that will match the canonical equivalences
1416 * of the characters within the class.
1417 */
1418 private int normalizeCharClass(StringBuilder newPattern, int i) {
1419 StringBuilder charClass = new StringBuilder();
1420 StringBuilder eq = null;
1421 int lastCodePoint = -1;
1422 String result;
1423
1424 i++;
1425 charClass.append("[");
1426 while(true) {
1427 int c = normalizedPattern.codePointAt(i);
1428 StringBuilder sequenceBuffer;
1429
1430 if (c == ']' && lastCodePoint != '\\') {
1431 charClass.append((char)c);
1432 break;
1433 } else if (Character.getType(c) == Character.NON_SPACING_MARK) {
1434 sequenceBuffer = new StringBuilder();
1435 sequenceBuffer.appendCodePoint(lastCodePoint);
1436 while(Character.getType(c) == Character.NON_SPACING_MARK) {
1437 sequenceBuffer.appendCodePoint(c);
1438 i += Character.charCount(c);
1439 if (i >= normalizedPattern.length())
1440 break;
1441 c = normalizedPattern.codePointAt(i);
1442 }
1443 String ea = produceEquivalentAlternation(
1444 sequenceBuffer.toString());
1445
1446 charClass.setLength(charClass.length()-Character.charCount(lastCodePoint));
1447 if (eq == null)
1448 eq = new StringBuilder();
1449 eq.append('|');
1450 eq.append(ea);
1451 } else {
1452 charClass.appendCodePoint(c);
1453 i++;
1454 }
1455 if (i == normalizedPattern.length())
1456 throw error("Unclosed character class");
1457 lastCodePoint = c;
1458 }
1459
1460 if (eq != null) {
1461 result = "(?:"+charClass.toString()+eq.toString()+")";
1462 } else {
1463 result = charClass.toString();
1464 }
1465
1466 newPattern.append(result);
1467 return i;
1468 }
1469
1470 /**
1471 * Given a specific sequence composed of a regular character and
1472 * combining marks that follow it, produce the alternation that will
1473 * match all canonical equivalences of that sequence.
1474 */
1475 private String produceEquivalentAlternation(String source) {
1476 int len = countChars(source, 0, 1);
1477 if (source.length() == len)
1478 // source has one character.
1479 return source;
1480
1481 String base = source.substring(0,len);
1482 String combiningMarks = source.substring(len);
1483
1484 String[] perms = producePermutations(combiningMarks);
1485 StringBuilder result = new StringBuilder(source);
1486
1487 // Add combined permutations
1488 for(int x=0; x<perms.length; x++) {
1489 String next = base + perms[x];
1490 if (x>0)
1491 result.append('|').append(next);
1492 next = composeOneStep(next);
1493 if (next != null)
1494 result.append('|').append(produceEquivalentAlternation(next));
1495 }
1496 return result.toString();
1497 }
1498
1499 /**
1500 * Returns an array of strings that have all the possible
1501 * permutations of the characters in the input string.
1502 * This is used to get a list of all possible orderings
1503 * of a set of combining marks. Note that some of the permutations
1504 * are invalid because of combining class collisions, and these
1505 * possibilities must be removed because they are not canonically
1506 * equivalent.
1507 */
1508 private String[] producePermutations(String input) {
1509 if (input.length() == countChars(input, 0, 1))
1510 return new String[] {input};
1511
1512 if (input.length() == countChars(input, 0, 2)) {
1513 int c0 = Character.codePointAt(input, 0);
1514 int c1 = Character.codePointAt(input, Character.charCount(c0));
1515 if (getClass(c1) == getClass(c0)) {
1516 return new String[] {input};
1517 }
1518 String[] result = new String[2];
1519 result[0] = input;
1520 StringBuilder sb = new StringBuilder(2);
1521 sb.appendCodePoint(c1);
1522 sb.appendCodePoint(c0);
1523 result[1] = sb.toString();
1524 return result;
1525 }
1526
1527 int length = 1;
1528 int nCodePoints = countCodePoints(input);
1529 for(int x=1; x<nCodePoints; x++)
1530 length = length * (x+1);
1531
1532 String[] temp = new String[length];
1533
1534 int combClass[] = new int[nCodePoints];
1535 for(int x=0, i=0; x<nCodePoints; x++) {
1536 int c = Character.codePointAt(input, i);
1537 combClass[x] = getClass(c);
1538 i += Character.charCount(c);
1539 }
1540
1541 // For each char, take it out and add the permutations
1542 // of the remaining chars
1543 int index = 0;
1544 int len;
1545 // offset maintains the index in code units.
1546 loop: for(int x=0, offset=0; x<nCodePoints; x++, offset+=len) {
1547 len = countChars(input, offset, 1);
1548 boolean skip = false;
1549 for(int y=x-1; y>=0; y--) {
1550 if (combClass[y] == combClass[x]) {
1551 continue loop;
1552 }
1553 }
1554 StringBuilder sb = new StringBuilder(input);
1555 String otherChars = sb.delete(offset, offset+len).toString();
1556 String[] subResult = producePermutations(otherChars);
1557
1558 String prefix = input.substring(offset, offset+len);
1559 for (String sre : subResult)
1560 temp[index++] = prefix + sre;
1561 }
1562 String[] result = new String[index];
1563 for (int x=0; x<index; x++)
1564 result[x] = temp[x];
1565 return result;
1566 }
1567
1568 private int getClass(int c) {
1569 return sun.text.Normalizer.getCombiningClass(c);
1570 }
1571
1572 /**
1573 * Attempts to compose input by combining the first character
1574 * with the first combining mark following it. Returns a String
1575 * that is the composition of the leading character with its first
1576 * combining mark followed by the remaining combining marks. Returns
1577 * null if the first two characters cannot be further composed.
1578 */
1579 private String composeOneStep(String input) {
1580 int len = countChars(input, 0, 2);
1581 String firstTwoCharacters = input.substring(0, len);
1582 String result = Normalizer.normalize(firstTwoCharacters, Normalizer.Form.NFC);
1583
1584 if (result.equals(firstTwoCharacters))
1585 return null;
1586 else {
1587 String remainder = input.substring(len);
1588 return result + remainder;
1589 }
1590 }
1591
1592 /**
1593 * Preprocess any \Q...\E sequences in `temp', meta-quoting them.
1594 * See the description of `quotemeta' in perlfunc(1).
1595 */
1596 private void RemoveQEQuoting() {
1597 final int pLen = patternLength;
1598 int i = 0;
1599 while (i < pLen-1) {
1600 if (temp[i] != '\\')
1601 i += 1;
1602 else if (temp[i + 1] != 'Q')
1603 i += 2;
1604 else
1605 break;
1606 }
1607 if (i >= pLen - 1) // No \Q sequence found
1608 return;
1609 int j = i;
1610 i += 2;
1611 int[] newtemp = new int[j + 3*(pLen-i) + 2];
1612 System.arraycopy(temp, 0, newtemp, 0, j);
1613
1614 boolean inQuote = true;
1615 boolean beginQuote = true;
1616 while (i < pLen) {
1617 int c = temp[i++];
1618 if (!ASCII.isAscii(c) || ASCII.isAlpha(c)) {
1619 newtemp[j++] = c;
1620 } else if (ASCII.isDigit(c)) {
1621 if (beginQuote) {
1622 /*
1623 * A unicode escape \[0xu] could be before this quote,
1624 * and we don't want this numeric char to processed as
1625 * part of the escape.
1626 */
1627 newtemp[j++] = '\\';
1628 newtemp[j++] = 'x';
1629 newtemp[j++] = '3';
1630 }
1631 newtemp[j++] = c;
1632 } else if (c != '\\') {
1633 if (inQuote) newtemp[j++] = '\\';
1634 newtemp[j++] = c;
1635 } else if (inQuote) {
1636 if (temp[i] == 'E') {
1637 i++;
1638 inQuote = false;
1639 } else {
1640 newtemp[j++] = '\\';
1641 newtemp[j++] = '\\';
1642 }
1643 } else {
1644 if (temp[i] == 'Q') {
1645 i++;
1646 inQuote = true;
1647 beginQuote = true;
1648 continue;
1649 } else {
1650 newtemp[j++] = c;
1651 if (i != pLen)
1652 newtemp[j++] = temp[i++];
1653 }
1654 }
1655
1656 beginQuote = false;
1657 }
1658
1659 patternLength = j;
1660 temp = Arrays.copyOf(newtemp, j + 2); // double zero termination
1661 }
1662
1663 /**
1664 * Copies regular expression to an int array and invokes the parsing
1665 * of the expression which will create the object tree.
1666 */
1667 private void compile() {
1668 // Handle canonical equivalences
1669 if (has(CANON_EQ) && !has(LITERAL)) {
1670 normalize();
1671 } else {
1672 normalizedPattern = pattern;
1673 }
1674 patternLength = normalizedPattern.length();
1675
1676 // Copy pattern to int array for convenience
1677 // Use double zero to terminate pattern
1678 temp = new int[patternLength + 2];
1679
1680 hasSupplementary = false;
1681 int c, count = 0;
1682 // Convert all chars into code points
1683 for (int x = 0; x < patternLength; x += Character.charCount(c)) {
1684 c = normalizedPattern.codePointAt(x);
1685 if (isSupplementary(c)) {
1686 hasSupplementary = true;
1687 }
1688 temp[count++] = c;
1689 }
1690
1691 patternLength = count; // patternLength now in code points
1692
1693 if (! has(LITERAL))
1694 RemoveQEQuoting();
1695
1696 // Allocate all temporary objects here.
1697 buffer = new int[32];
1698 groupNodes = new GroupHead[10];
1699 namedGroups = null;
1700
1701 if (has(LITERAL)) {
1702 // Literal pattern handling
1703 matchRoot = newSlice(temp, patternLength, hasSupplementary);
1704 matchRoot.next = lastAccept;
1705 } else {
1706 // Start recursive descent parsing
1707 matchRoot = expr(lastAccept);
1708 // Check extra pattern characters
1709 if (patternLength != cursor) {
1710 if (peek() == ')') {
1711 throw error("Unmatched closing ')'");
1712 } else {
1713 throw error("Unexpected internal error");
1714 }
1715 }
1716 }
1717
1718 // Peephole optimization
1719 if (matchRoot instanceof Slice) {
1720 root = BnM.optimize(matchRoot);
1721 if (root == matchRoot) {
1722 root = hasSupplementary ? new StartS(matchRoot) : new Start(matchRoot);
1723 }
1724 } else if (matchRoot instanceof Begin || matchRoot instanceof First) {
1725 root = matchRoot;
1726 } else {
1727 root = hasSupplementary ? new StartS(matchRoot) : new Start(matchRoot);
1728 }
1729
1730 // Release temporary storage
1731 temp = null;
1732 buffer = null;
1733 groupNodes = null;
1734 patternLength = 0;
1735 compiled = true;
1736 }
1737
1738 Map<String, Integer> namedGroups() {
1739 if (namedGroups == null)
1740 namedGroups = new HashMap<>(2);
1741 return namedGroups;
1742 }
1743
1744 /**
1745 * Used to print out a subtree of the Pattern to help with debugging.
1746 */
1747 private static void printObjectTree(Node node) {
1748 while(node != null) {
1749 if (node instanceof Prolog) {
1750 System.out.println(node);
1751 printObjectTree(((Prolog)node).loop);
1752 System.out.println("**** end contents prolog loop");
1753 } else if (node instanceof Loop) {
1754 System.out.println(node);
1755 printObjectTree(((Loop)node).body);
1756 System.out.println("**** end contents Loop body");
1757 } else if (node instanceof Curly) {
1758 System.out.println(node);
1759 printObjectTree(((Curly)node).atom);
1760 System.out.println("**** end contents Curly body");
1761 } else if (node instanceof GroupCurly) {
1762 System.out.println(node);
1763 printObjectTree(((GroupCurly)node).atom);
1764 System.out.println("**** end contents GroupCurly body");
1765 } else if (node instanceof GroupTail) {
1766 System.out.println(node);
1767 System.out.println("Tail next is "+node.next);
1768 return;
1769 } else {
1770 System.out.println(node);
1771 }
1772 node = node.next;
1773 if (node != null)
1774 System.out.println("->next:");
1775 if (node == Pattern.accept) {
1776 System.out.println("Accept Node");
1777 node = null;
1778 }
1779 }
1780 }
1781
1782 /**
1783 * Used to accumulate information about a subtree of the object graph
1784 * so that optimizations can be applied to the subtree.
1785 */
1786 static final class TreeInfo {
1787 int minLength;
1788 int maxLength;
1789 boolean maxValid;
1790 boolean deterministic;
1791
1792 TreeInfo() {
1793 reset();
1794 }
1795 void reset() {
1796 minLength = 0;
1797 maxLength = 0;
1798 maxValid = true;
1799 deterministic = true;
1800 }
1801 }
1802
1803 /*
1804 * The following private methods are mainly used to improve the
1805 * readability of the code. In order to let the Java compiler easily
1806 * inline them, we should not put many assertions or error checks in them.
1807 */
1808
1809 /**
1810 * Indicates whether a particular flag is set or not.
1811 */
1812 private boolean has(int f) {
1813 return (flags & f) != 0;
1814 }
1815
1816 /**
1817 * Match next character, signal error if failed.
1818 */
1819 private void accept(int ch, String s) {
1820 int testChar = temp[cursor++];
1821 if (has(COMMENTS))
1822 testChar = parsePastWhitespace(testChar);
1823 if (ch != testChar) {
1824 throw error(s);
1825 }
1826 }
1827
1828 /**
1829 * Mark the end of pattern with a specific character.
1830 */
1831 private void mark(int c) {
1832 temp[patternLength] = c;
1833 }
1834
1835 /**
1836 * Peek the next character, and do not advance the cursor.
1837 */
1838 private int peek() {
1839 int ch = temp[cursor];
1840 if (has(COMMENTS))
1841 ch = peekPastWhitespace(ch);
1842 return ch;
1843 }
1844
1845 /**
1846 * Read the next character, and advance the cursor by one.
1847 */
1848 private int read() {
1849 int ch = temp[cursor++];
1850 if (has(COMMENTS))
1851 ch = parsePastWhitespace(ch);
1852 return ch;
1853 }
1854
1855 /**
1856 * Read the next character, and advance the cursor by one,
1857 * ignoring the COMMENTS setting
1858 */
1859 private int readEscaped() {
1860 int ch = temp[cursor++];
1861 return ch;
1862 }
1863
1864 /**
1865 * Advance the cursor by one, and peek the next character.
1866 */
1867 private int next() {
1868 int ch = temp[++cursor];
1869 if (has(COMMENTS))
1870 ch = peekPastWhitespace(ch);
1871 return ch;
1872 }
1873
1874 /**
1875 * Advance the cursor by one, and peek the next character,
1876 * ignoring the COMMENTS setting
1877 */
1878 private int nextEscaped() {
1879 int ch = temp[++cursor];
1880 return ch;
1881 }
1882
1883 /**
1884 * If in xmode peek past whitespace and comments.
1885 */
1886 private int peekPastWhitespace(int ch) {
1887 while (ASCII.isSpace(ch) || ch == '#') {
1888 while (ASCII.isSpace(ch))
1889 ch = temp[++cursor];
1890 if (ch == '#') {
1891 ch = peekPastLine();
1892 }
1893 }
1894 return ch;
1895 }
1896
1897 /**
1898 * If in xmode parse past whitespace and comments.
1899 */
1900 private int parsePastWhitespace(int ch) {
1901 while (ASCII.isSpace(ch) || ch == '#') {
1902 while (ASCII.isSpace(ch))
1903 ch = temp[cursor++];
1904 if (ch == '#')
1905 ch = parsePastLine();
1906 }
1907 return ch;
1908 }
1909
1910 /**
1911 * xmode parse past comment to end of line.
1912 */
1913 private int parsePastLine() {
1914 int ch = temp[cursor++];
1915 while (ch != 0 && !isLineSeparator(ch))
1916 ch = temp[cursor++];
1917 return ch;
1918 }
1919
1920 /**
1921 * xmode peek past comment to end of line.
1922 */
1923 private int peekPastLine() {
1924 int ch = temp[++cursor];
1925 while (ch != 0 && !isLineSeparator(ch))
1926 ch = temp[++cursor];
1927 return ch;
1928 }
1929
1930 /**
1931 * Determines if character is a line separator in the current mode
1932 */
1933 private boolean isLineSeparator(int ch) {
1934 if (has(UNIX_LINES)) {
1935 return ch == '\n';
1936 } else {
1937 return (ch == '\n' ||
1938 ch == '\r' ||
1939 (ch|1) == '\u2029' ||
1940 ch == '\u0085');
1941 }
1942 }
1943
1944 /**
1945 * Read the character after the next one, and advance the cursor by two.
1946 */
1947 private int skip() {
1948 int i = cursor;
1949 int ch = temp[i+1];
1950 cursor = i + 2;
1951 return ch;
1952 }
1953
1954 /**
1955 * Unread one next character, and retreat cursor by one.
1956 */
1957 private void unread() {
1958 cursor--;
1959 }
1960
1961 /**
1962 * Internal method used for handling all syntax errors. The pattern is
1963 * displayed with a pointer to aid in locating the syntax error.
1964 */
1965 private PatternSyntaxException error(String s) {
1966 return new PatternSyntaxException(s, normalizedPattern, cursor - 1);
1967 }
1968
1969 /**
1970 * Determines if there is any supplementary character or unpaired
1971 * surrogate in the specified range.
1972 */
1973 private boolean findSupplementary(int start, int end) {
1974 for (int i = start; i < end; i++) {
1975 if (isSupplementary(temp[i]))
1976 return true;
1977 }
1978 return false;
1979 }
1980
1981 /**
1982 * Determines if the specified code point is a supplementary
1983 * character or unpaired surrogate.
1984 */
1985 private static final boolean isSupplementary(int ch) {
1986 return ch >= Character.MIN_SUPPLEMENTARY_CODE_POINT ||
1987 Character.isSurrogate((char)ch);
1988 }
1989
1990 /**
1991 * The following methods handle the main parsing. They are sorted
1992 * according to their precedence order, the lowest one first.
1993 */
1994
1995 /**
1996 * The expression is parsed with branch nodes added for alternations.
1997 * This may be called recursively to parse sub expressions that may
1998 * contain alternations.
1999 */
2000 private Node expr(Node end) {
2001 Node prev = null;
2002 Node firstTail = null;
2003 Branch branch = null;
2004 Node branchConn = null;
2005
2006 for (;;) {
2007 Node node = sequence(end);
2008 Node nodeTail = root; //double return
2009 if (prev == null) {
2010 prev = node;
2011 firstTail = nodeTail;
2012 } else {
2013 // Branch
2014 if (branchConn == null) {
2015 branchConn = new BranchConn();
2016 branchConn.next = end;
2017 }
2018 if (node == end) {
2019 // if the node returned from sequence() is "end"
2020 // we have an empty expr, set a null atom into
2021 // the branch to indicate to go "next" directly.
2022 node = null;
2023 } else {
2024 // the "tail.next" of each atom goes to branchConn
2025 nodeTail.next = branchConn;
2026 }
2027 if (prev == branch) {
2028 branch.add(node);
2029 } else {
2030 if (prev == end) {
2031 prev = null;
2032 } else {
2033 // replace the "end" with "branchConn" at its tail.next
2034 // when put the "prev" into the branch as the first atom.
2035 firstTail.next = branchConn;
2036 }
2037 prev = branch = new Branch(prev, node, branchConn);
2038 }
2039 }
2040 if (peek() != '|') {
2041 return prev;
2042 }
2043 next();
2044 }
2045 }
2046
2047 @SuppressWarnings("fallthrough")
2048 /**
2049 * Parsing of sequences between alternations.
2050 */
2051 private Node sequence(Node end) {
2052 Node head = null;
2053 Node tail = null;
2054 Node node = null;
2055 LOOP:
2056 for (;;) {
2057 int ch = peek();
2058 switch (ch) {
2059 case '(':
2060 // Because group handles its own closure,
2061 // we need to treat it differently
2062 node = group0();
2063 // Check for comment or flag group
2064 if (node == null)
2065 continue;
2066 if (head == null)
2067 head = node;
2068 else
2069 tail.next = node;
2070 // Double return: Tail was returned in root
2071 tail = root;
2072 continue;
2073 case '[':
2074 node = clazz(true);
2075 break;
2076 case '\\':
2077 ch = nextEscaped();
2078 if (ch == 'p' || ch == 'P') {
2079 boolean oneLetter = true;
2080 boolean comp = (ch == 'P');
2081 ch = next(); // Consume { if present
2082 if (ch != '{') {
2083 unread();
2084 } else {
2085 oneLetter = false;
2086 }
2087 node = family(oneLetter, comp);
2088 } else {
2089 unread();
2090 node = atom();
2091 }
2092 break;
2093 case '^':
2094 next();
2095 if (has(MULTILINE)) {
2096 if (has(UNIX_LINES))
2097 node = new UnixCaret();
2098 else
2099 node = new Caret();
2100 } else {
2101 node = new Begin();
2102 }
2103 break;
2104 case '$':
2105 next();
2106 if (has(UNIX_LINES))
2107 node = new UnixDollar(has(MULTILINE));
2108 else
2109 node = new Dollar(has(MULTILINE));
2110 break;
2111 case '.':
2112 next();
2113 if (has(DOTALL)) {
2114 node = new All();
2115 } else {
2116 if (has(UNIX_LINES))
2117 node = new UnixDot();
2118 else {
2119 node = new Dot();
2120 }
2121 }
2122 break;
2123 case '|':
2124 case ')':
2125 break LOOP;
2126 case ']': // Now interpreting dangling ] and } as literals
2127 case '}':
2128 node = atom();
2129 break;
2130 case '?':
2131 case '*':
2132 case '+':
2133 next();
2134 throw error("Dangling meta character '" + ((char)ch) + "'");
2135 case 0:
2136 if (cursor >= patternLength) {
2137 break LOOP;
2138 }
2139 // Fall through
2140 default:
2141 node = atom();
2142 break;
2143 }
2144
2145 node = closure(node);
2146
2147 if (head == null) {
2148 head = tail = node;
2149 } else {
2150 tail.next = node;
2151 tail = node;
2152 }
2153 }
2154 if (head == null) {
2155 return end;
2156 }
2157 tail.next = end;
2158 root = tail; //double return
2159 return head;
2160 }
2161
2162 @SuppressWarnings("fallthrough")
2163 /**
2164 * Parse and add a new Single or Slice.
2165 */
2166 private Node atom() {
2167 int first = 0;
2168 int prev = -1;
2169 boolean hasSupplementary = false;
2170 int ch = peek();
2171 for (;;) {
2172 switch (ch) {
2173 case '*':
2174 case '+':
2175 case '?':
2176 case '{':
2177 if (first > 1) {
2178 cursor = prev; // Unwind one character
2179 first--;
2180 }
2181 break;
2182 case '$':
2183 case '.':
2184 case '^':
2185 case '(':
2186 case '[':
2187 case '|':
2188 case ')':
2189 break;
2190 case '\\':
2191 ch = nextEscaped();
2192 if (ch == 'p' || ch == 'P') { // Property
2193 if (first > 0) { // Slice is waiting; handle it first
2194 unread();
2195 break;
2196 } else { // No slice; just return the family node
2197 boolean comp = (ch == 'P');
2198 boolean oneLetter = true;
2199 ch = next(); // Consume { if present
2200 if (ch != '{')
2201 unread();
2202 else
2203 oneLetter = false;
2204 return family(oneLetter, comp);
2205 }
2206 }
2207 unread();
2208 prev = cursor;
2209 ch = escape(false, first == 0, false);
2210 if (ch >= 0) {
2211 append(ch, first);
2212 first++;
2213 if (isSupplementary(ch)) {
2214 hasSupplementary = true;
2215 }
2216 ch = peek();
2217 continue;
2218 } else if (first == 0) {
2219 return root;
2220 }
2221 // Unwind meta escape sequence
2222 cursor = prev;
2223 break;
2224 case 0:
2225 if (cursor >= patternLength) {
2226 break;
2227 }
2228 // Fall through
2229 default:
2230 prev = cursor;
2231 append(ch, first);
2232 first++;
2233 if (isSupplementary(ch)) {
2234 hasSupplementary = true;
2235 }
2236 ch = next();
2237 continue;
2238 }
2239 break;
2240 }
2241 if (first == 1) {
2242 return newSingle(buffer[0]);
2243 } else {
2244 return newSlice(buffer, first, hasSupplementary);
2245 }
2246 }
2247
2248 private void append(int ch, int len) {
2249 if (len >= buffer.length) {
2250 int[] tmp = new int[len+len];
2251 System.arraycopy(buffer, 0, tmp, 0, len);
2252 buffer = tmp;
2253 }
2254 buffer[len] = ch;
2255 }
2256
2257 /**
2258 * Parses a backref greedily, taking as many numbers as it
2259 * can. The first digit is always treated as a backref, but
2260 * multi digit numbers are only treated as a backref if at
2261 * least that many backrefs exist at this point in the regex.
2262 */
2263 private Node ref(int refNum) {
2264 boolean done = false;
2265 while(!done) {
2266 int ch = peek();
2267 switch(ch) {
2268 case '0':
2269 case '1':
2270 case '2':
2271 case '3':
2272 case '4':
2273 case '5':
2274 case '6':
2275 case '7':
2276 case '8':
2277 case '9':
2278 int newRefNum = (refNum * 10) + (ch - '0');
2279 // Add another number if it doesn't make a group
2280 // that doesn't exist
2281 if (capturingGroupCount - 1 < newRefNum) {
2282 done = true;
2283 break;
2284 }
2285 refNum = newRefNum;
2286 read();
2287 break;
2288 default:
2289 done = true;
2290 break;
2291 }
2292 }
2293 if (has(CASE_INSENSITIVE))
2294 return new CIBackRef(refNum, has(UNICODE_CASE));
2295 else
2296 return new BackRef(refNum);
2297 }
2298
2299 /**
2300 * Parses an escape sequence to determine the actual value that needs
2301 * to be matched.
2302 * If -1 is returned and create was true a new object was added to the tree
2303 * to handle the escape sequence.
2304 * If the returned value is greater than zero, it is the value that
2305 * matches the escape sequence.
2306 */
2307 private int escape(boolean inclass, boolean create, boolean isrange) {
2308 int ch = skip();
2309 switch (ch) {
2310 case '0':
2311 return o();
2312 case '1':
2313 case '2':
2314 case '3':
2315 case '4':
2316 case '5':
2317 case '6':
2318 case '7':
2319 case '8':
2320 case '9':
2321 if (inclass) break;
2322 if (create) {
2323 root = ref((ch - '0'));
2324 }
2325 return -1;
2326 case 'A':
2327 if (inclass) break;
2328 if (create) root = new Begin();
2329 return -1;
2330 case 'B':
2331 if (inclass) break;
2332 if (create) root = new Bound(Bound.NONE, has(UNICODE_CHARACTER_CLASS));
2333 return -1;
2334 case 'C':
2335 break;
2336 case 'D':
2337 if (create) root = has(UNICODE_CHARACTER_CLASS)
2338 ? new Utype(UnicodeProp.DIGIT).complement()
2339 : new Ctype(ASCII.DIGIT).complement();
2340 return -1;
2341 case 'E':
2342 case 'F':
2343 break;
2344 case 'G':
2345 if (inclass) break;
2346 if (create) root = new LastMatch();
2347 return -1;
2348 case 'H':
2349 if (create) root = new HorizWS().complement();
2350 return -1;
2351 case 'I':
2352 case 'J':
2353 case 'K':
2354 case 'L':
2355 case 'M':
2356 case 'N':
2357 case 'O':
2358 case 'P':
2359 case 'Q':
2360 break;
2361 case 'R':
2362 if (inclass) break;
2363 if (create) root = new LineEnding();
2364 return -1;
2365 case 'S':
2366 if (create) root = has(UNICODE_CHARACTER_CLASS)
2367 ? new Utype(UnicodeProp.WHITE_SPACE).complement()
2368 : new Ctype(ASCII.SPACE).complement();
2369 return -1;
2370 case 'T':
2371 case 'U':
2372 break;
2373 case 'V':
2374 if (create) root = new VertWS().complement();
2375 return -1;
2376 case 'W':
2377 if (create) root = has(UNICODE_CHARACTER_CLASS)
2378 ? new Utype(UnicodeProp.WORD).complement()
2379 : new Ctype(ASCII.WORD).complement();
2380 return -1;
2381 case 'X':
2382 case 'Y':
2383 break;
2384 case 'Z':
2385 if (inclass) break;
2386 if (create) {
2387 if (has(UNIX_LINES))
2388 root = new UnixDollar(false);
2389 else
2390 root = new Dollar(false);
2391 }
2392 return -1;
2393 case 'a':
2394 return '\007';
2395 case 'b':
2396 if (inclass) break;
2397 if (create) root = new Bound(Bound.BOTH, has(UNICODE_CHARACTER_CLASS));
2398 return -1;
2399 case 'c':
2400 return c();
2401 case 'd':
2402 if (create) root = has(UNICODE_CHARACTER_CLASS)
2403 ? new Utype(UnicodeProp.DIGIT)
2404 : new Ctype(ASCII.DIGIT);
2405 return -1;
2406 case 'e':
2407 return '\033';
2408 case 'f':
2409 return '\f';
2410 case 'g':
2411 break;
2412 case 'h':
2413 if (create) root = new HorizWS();
2414 return -1;
2415 case 'i':
2416 case 'j':
2417 break;
2418 case 'k':
2419 if (inclass)
2420 break;
2421 if (read() != '<')
2422 throw error("\\k is not followed by '<' for named capturing group");
2423 String name = groupname(read());
2424 if (!namedGroups().containsKey(name))
2425 throw error("(named capturing group <"+ name+"> does not exit");
2426 if (create) {
2427 if (has(CASE_INSENSITIVE))
2428 root = new CIBackRef(namedGroups().get(name), has(UNICODE_CASE));
2429 else
2430 root = new BackRef(namedGroups().get(name));
2431 }
2432 return -1;
2433 case 'l':
2434 case 'm':
2435 break;
2436 case 'n':
2437 return '\n';
2438 case 'o':
2439 case 'p':
2440 case 'q':
2441 break;
2442 case 'r':
2443 return '\r';
2444 case 's':
2445 if (create) root = has(UNICODE_CHARACTER_CLASS)
2446 ? new Utype(UnicodeProp.WHITE_SPACE)
2447 : new Ctype(ASCII.SPACE);
2448 return -1;
2449 case 't':
2450 return '\t';
2451 case 'u':
2452 return u();
2453 case 'v':
2454 // '\v' was implemented as VT/0x0B in releases < 1.8 (though
2455 // undocumented). In JDK8 '\v' is specified as a predefined
2456 // character class for all vertical whitespace characters.
2457 // So [-1, root=VertWS node] pair is returned (instead of a
2458 // single 0x0B). This breaks the range if '\v' is used as
2459 // the start or end value, such as [\v-...] or [...-\v], in
2460 // which a single definite value (0x0B) is expected. For
2461 // compatibility concern '\013'/0x0B is returned if isrange.
2462 if (isrange)
2463 return '\013';
2464 if (create) root = new VertWS();
2465 return -1;
2466 case 'w':
2467 if (create) root = has(UNICODE_CHARACTER_CLASS)
2468 ? new Utype(UnicodeProp.WORD)
2469 : new Ctype(ASCII.WORD);
2470 return -1;
2471 case 'x':
2472 return x();
2473 case 'y':
2474 break;
2475 case 'z':
2476 if (inclass) break;
2477 if (create) root = new End();
2478 return -1;
2479 default:
2480 return ch;
2481 }
2482 throw error("Illegal/unsupported escape sequence");
2483 }
2484
2485 /**
2486 * Parse a character class, and return the node that matches it.
2487 *
2488 * Consumes a ] on the way out if consume is true. Usually consume
2489 * is true except for the case of [abc&&def] where def is a separate
2490 * right hand node with "understood" brackets.
2491 */
2492 private CharProperty clazz(boolean consume) {
2493 CharProperty prev = null;
2494 CharProperty node = null;
2495 BitClass bits = new BitClass();
2496 boolean include = true;
2497 boolean firstInClass = true;
2498 int ch = next();
2499 for (;;) {
2500 switch (ch) {
2501 case '^':
2502 // Negates if first char in a class, otherwise literal
2503 if (firstInClass) {
2504 if (temp[cursor-1] != '[')
2505 break;
2506 ch = next();
2507 include = !include;
2508 continue;
2509 } else {
2510 // ^ not first in class, treat as literal
2511 break;
2512 }
2513 case '[':
2514 firstInClass = false;
2515 node = clazz(true);
2516 if (prev == null)
2517 prev = node;
2518 else
2519 prev = union(prev, node);
2520 ch = peek();
2521 continue;
2522 case '&':
2523 firstInClass = false;
2524 ch = next();
2525 if (ch == '&') {
2526 ch = next();
2527 CharProperty rightNode = null;
2528 while (ch != ']' && ch != '&') {
2529 if (ch == '[') {
2530 if (rightNode == null)
2531 rightNode = clazz(true);
2532 else
2533 rightNode = union(rightNode, clazz(true));
2534 } else { // abc&&def
2535 unread();
2536 rightNode = clazz(false);
2537 }
2538 ch = peek();
2539 }
2540 if (rightNode != null)
2541 node = rightNode;
2542 if (prev == null) {
2543 if (rightNode == null)
2544 throw error("Bad class syntax");
2545 else
2546 prev = rightNode;
2547 } else {
2548 prev = intersection(prev, node);
2549 }
2550 } else {
2551 // treat as a literal &
2552 unread();
2553 break;
2554 }
2555 continue;
2556 case 0:
2557 firstInClass = false;
2558 if (cursor >= patternLength)
2559 throw error("Unclosed character class");
2560 break;
2561 case ']':
2562 firstInClass = false;
2563 if (prev != null) {
2564 if (consume)
2565 next();
2566 return prev;
2567 }
2568 break;
2569 default:
2570 firstInClass = false;
2571 break;
2572 }
2573 node = range(bits);
2574 if (include) {
2575 if (prev == null) {
2576 prev = node;
2577 } else {
2578 if (prev != node)
2579 prev = union(prev, node);
2580 }
2581 } else {
2582 if (prev == null) {
2583 prev = node.complement();
2584 } else {
2585 if (prev != node)
2586 prev = setDifference(prev, node);
2587 }
2588 }
2589 ch = peek();
2590 }
2591 }
2592
2593 private CharProperty bitsOrSingle(BitClass bits, int ch) {
2594 /* Bits can only handle codepoints in [u+0000-u+00ff] range.
2595 Use "single" node instead of bits when dealing with unicode
2596 case folding for codepoints listed below.
2597 (1)Uppercase out of range: u+00ff, u+00b5
2598 toUpperCase(u+00ff) -> u+0178
2599 toUpperCase(u+00b5) -> u+039c
2600 (2)LatinSmallLetterLongS u+17f
2601 toUpperCase(u+017f) -> u+0053
2602 (3)LatinSmallLetterDotlessI u+131
2603 toUpperCase(u+0131) -> u+0049
2604 (4)LatinCapitalLetterIWithDotAbove u+0130
2605 toLowerCase(u+0130) -> u+0069
2606 (5)KelvinSign u+212a
2607 toLowerCase(u+212a) ==> u+006B
2608 (6)AngstromSign u+212b
2609 toLowerCase(u+212b) ==> u+00e5
2610 */
2611 int d;
2612 if (ch < 256 &&
2613 !(has(CASE_INSENSITIVE) && has(UNICODE_CASE) &&
2614 (ch == 0xff || ch == 0xb5 ||
2615 ch == 0x49 || ch == 0x69 || //I and i
2616 ch == 0x53 || ch == 0x73 || //S and s
2617 ch == 0x4b || ch == 0x6b || //K and k
2618 ch == 0xc5 || ch == 0xe5))) //A+ring
2619 return bits.add(ch, flags());
2620 return newSingle(ch);
2621 }
2622
2623 /**
2624 * Parse a single character or a character range in a character class
2625 * and return its representative node.
2626 */
2627 private CharProperty range(BitClass bits) {
2628 int ch = peek();
2629 if (ch == '\\') {
2630 ch = nextEscaped();
2631 if (ch == 'p' || ch == 'P') { // A property
2632 boolean comp = (ch == 'P');
2633 boolean oneLetter = true;
2634 // Consume { if present
2635 ch = next();
2636 if (ch != '{')
2637 unread();
2638 else
2639 oneLetter = false;
2640 return family(oneLetter, comp);
2641 } else { // ordinary escape
2642 boolean isrange = temp[cursor+1] == '-';
2643 unread();
2644 ch = escape(true, true, isrange);
2645 if (ch == -1)
2646 return (CharProperty) root;
2647 }
2648 } else {
2649 next();
2650 }
2651 if (ch >= 0) {
2652 if (peek() == '-') {
2653 int endRange = temp[cursor+1];
2654 if (endRange == '[') {
2655 return bitsOrSingle(bits, ch);
2656 }
2657 if (endRange != ']') {
2658 next();
2659 int m = peek();
2660 if (m == '\\') {
2661 m = escape(true, false, true);
2662 } else {
2663 next();
2664 }
2665 if (m < ch) {
2666 throw error("Illegal character range");
2667 }
2668 if (has(CASE_INSENSITIVE))
2669 return caseInsensitiveRangeFor(ch, m);
2670 else
2671 return rangeFor(ch, m);
2672 }
2673 }
2674 return bitsOrSingle(bits, ch);
2675 }
2676 throw error("Unexpected character '"+((char)ch)+"'");
2677 }
2678
2679 /**
2680 * Parses a Unicode character family and returns its representative node.
2681 */
2682 private CharProperty family(boolean singleLetter,
2683 boolean maybeComplement)
2684 {
2685 next();
2686 String name;
2687 CharProperty node = null;
2688
2689 if (singleLetter) {
2690 int c = temp[cursor];
2691 if (!Character.isSupplementaryCodePoint(c)) {
2692 name = String.valueOf((char)c);
2693 } else {
2694 name = new String(temp, cursor, 1);
2695 }
2696 read();
2697 } else {
2698 int i = cursor;
2699 mark('}');
2700 while(read() != '}') {
2701 }
2702 mark('\000');
2703 int j = cursor;
2704 if (j > patternLength)
2705 throw error("Unclosed character family");
2706 if (i + 1 >= j)
2707 throw error("Empty character family");
2708 name = new String(temp, i, j-i-1);
2709 }
2710
2711 int i = name.indexOf('=');
2712 if (i != -1) {
2713 // property construct \p{name=value}
2714 String value = name.substring(i + 1);
2715 name = name.substring(0, i).toLowerCase(Locale.ENGLISH);
2716 switch (name) {
2717 case "sc":
2718 case "script":
2719 node = unicodeScriptPropertyFor(value);
2720 break;
2721 case "blk":
2722 case "block":
2723 node = unicodeBlockPropertyFor(value);
2724 break;
2725 case "gc":
2726 case "general_category":
2727 node = charPropertyNodeFor(value);
2728 break;
2729 default:
2730 throw error("Unknown Unicode property {name=<" + name + ">, "
2731 + "value=<" + value + ">}");
2732 }
2733 } else {
2734 if (name.startsWith("In")) {
2735 // \p{inBlockName}
2736 node = unicodeBlockPropertyFor(name.substring(2));
2737 } else if (name.startsWith("Is")) {
2738 // \p{isGeneralCategory} and \p{isScriptName}
2739 name = name.substring(2);
2740 UnicodeProp uprop = UnicodeProp.forName(name);
2741 if (uprop != null)
2742 node = new Utype(uprop);
2743 if (node == null)
2744 node = CharPropertyNames.charPropertyFor(name);
2745 if (node == null)
2746 node = unicodeScriptPropertyFor(name);
2747 } else {
2748 if (has(UNICODE_CHARACTER_CLASS)) {
2749 UnicodeProp uprop = UnicodeProp.forPOSIXName(name);
2750 if (uprop != null)
2751 node = new Utype(uprop);
2752 }
2753 if (node == null)
2754 node = charPropertyNodeFor(name);
2755 }
2756 }
2757 if (maybeComplement) {
2758 if (node instanceof Category || node instanceof Block)
2759 hasSupplementary = true;
2760 node = node.complement();
2761 }
2762 return node;
2763 }
2764
2765
2766 /**
2767 * Returns a CharProperty matching all characters belong to
2768 * a UnicodeScript.
2769 */
2770 private CharProperty unicodeScriptPropertyFor(String name) {
2771 final Character.UnicodeScript script;
2772 try {
2773 script = Character.UnicodeScript.forName(name);
2774 } catch (IllegalArgumentException iae) {
2775 throw error("Unknown character script name {" + name + "}");
2776 }
2777 return new Script(script);
2778 }
2779
2780 /**
2781 * Returns a CharProperty matching all characters in a UnicodeBlock.
2782 */
2783 private CharProperty unicodeBlockPropertyFor(String name) {
2784 final Character.UnicodeBlock block;
2785 try {
2786 block = Character.UnicodeBlock.forName(name);
2787 } catch (IllegalArgumentException iae) {
2788 throw error("Unknown character block name {" + name + "}");
2789 }
2790 return new Block(block);
2791 }
2792
2793 /**
2794 * Returns a CharProperty matching all characters in a named property.
2795 */
2796 private CharProperty charPropertyNodeFor(String name) {
2797 CharProperty p = CharPropertyNames.charPropertyFor(name);
2798 if (p == null)
2799 throw error("Unknown character property name {" + name + "}");
2800 return p;
2801 }
2802
2803 /**
2804 * Parses and returns the name of a "named capturing group", the trailing
2805 * ">" is consumed after parsing.
2806 */
2807 private String groupname(int ch) {
2808 StringBuilder sb = new StringBuilder();
2809 sb.append(Character.toChars(ch));
2810 while (ASCII.isLower(ch=read()) || ASCII.isUpper(ch) ||
2811 ASCII.isDigit(ch)) {
2812 sb.append(Character.toChars(ch));
2813 }
2814 if (sb.length() == 0)
2815 throw error("named capturing group has 0 length name");
2816 if (ch != '>')
2817 throw error("named capturing group is missing trailing '>'");
2818 return sb.toString();
2819 }
2820
2821 /**
2822 * Parses a group and returns the head node of a set of nodes that process
2823 * the group. Sometimes a double return system is used where the tail is
2824 * returned in root.
2825 */
2826 private Node group0() {
2827 boolean capturingGroup = false;
2828 Node head = null;
2829 Node tail = null;
2830 int save = flags;
2831 root = null;
2832 int ch = next();
2833 if (ch == '?') {
2834 ch = skip();
2835 switch (ch) {
2836 case ':': // (?:xxx) pure group
2837 head = createGroup(true);
2838 tail = root;
2839 head.next = expr(tail);
2840 break;
2841 case '=': // (?=xxx) and (?!xxx) lookahead
2842 case '!':
2843 head = createGroup(true);
2844 tail = root;
2845 head.next = expr(tail);
2846 if (ch == '=') {
2847 head = tail = new Pos(head);
2848 } else {
2849 head = tail = new Neg(head);
2850 }
2851 break;
2852 case '>': // (?>xxx) independent group
2853 head = createGroup(true);
2854 tail = root;
2855 head.next = expr(tail);
2856 head = tail = new Ques(head, INDEPENDENT);
2857 break;
2858 case '<': // (?<xxx) look behind
2859 ch = read();
2860 if (ASCII.isLower(ch) || ASCII.isUpper(ch)) {
2861 // named captured group
2862 String name = groupname(ch);
2863 if (namedGroups().containsKey(name))
2864 throw error("Named capturing group <" + name
2865 + "> is already defined");
2866 capturingGroup = true;
2867 head = createGroup(false);
2868 tail = root;
2869 namedGroups().put(name, capturingGroupCount-1);
2870 head.next = expr(tail);
2871 break;
2872 }
2873 int start = cursor;
2874 head = createGroup(true);
2875 tail = root;
2876 head.next = expr(tail);
2877 tail.next = lookbehindEnd;
2878 TreeInfo info = new TreeInfo();
2879 head.study(info);
2880 if (info.maxValid == false) {
2881 throw error("Look-behind group does not have "
2882 + "an obvious maximum length");
2883 }
2884 boolean hasSupplementary = findSupplementary(start, patternLength);
2885 if (ch == '=') {
2886 head = tail = (hasSupplementary ?
2887 new BehindS(head, info.maxLength,
2888 info.minLength) :
2889 new Behind(head, info.maxLength,
2890 info.minLength));
2891 } else if (ch == '!') {
2892 head = tail = (hasSupplementary ?
2893 new NotBehindS(head, info.maxLength,
2894 info.minLength) :
2895 new NotBehind(head, info.maxLength,
2896 info.minLength));
2897 } else {
2898 throw error("Unknown look-behind group");
2899 }
2900 break;
2901 case '$':
2902 case '@':
2903 throw error("Unknown group type");
2904 default: // (?xxx:) inlined match flags
2905 unread();
2906 addFlag();
2907 ch = read();
2908 if (ch == ')') {
2909 return null; // Inline modifier only
2910 }
2911 if (ch != ':') {
2912 throw error("Unknown inline modifier");
2913 }
2914 head = createGroup(true);
2915 tail = root;
2916 head.next = expr(tail);
2917 break;
2918 }
2919 } else { // (xxx) a regular group
2920 capturingGroup = true;
2921 head = createGroup(false);
2922 tail = root;
2923 head.next = expr(tail);
2924 }
2925
2926 accept(')', "Unclosed group");
2927 flags = save;
2928
2929 // Check for quantifiers
2930 Node node = closure(head);
2931 if (node == head) { // No closure
2932 root = tail;
2933 return node; // Dual return
2934 }
2935 if (head == tail) { // Zero length assertion
2936 root = node;
2937 return node; // Dual return
2938 }
2939
2940 if (node instanceof Ques) {
2941 Ques ques = (Ques) node;
2942 if (ques.type == POSSESSIVE) {
2943 root = node;
2944 return node;
2945 }
2946 tail.next = new BranchConn();
2947 tail = tail.next;
2948 if (ques.type == GREEDY) {
2949 head = new Branch(head, null, tail);
2950 } else { // Reluctant quantifier
2951 head = new Branch(null, head, tail);
2952 }
2953 root = tail;
2954 return head;
2955 } else if (node instanceof Curly) {
2956 Curly curly = (Curly) node;
2957 if (curly.type == POSSESSIVE) {
2958 root = node;
2959 return node;
2960 }
2961 // Discover if the group is deterministic
2962 TreeInfo info = new TreeInfo();
2963 if (head.study(info)) { // Deterministic
2964 GroupTail temp = (GroupTail) tail;
2965 head = root = new GroupCurly(head.next, curly.cmin,
2966 curly.cmax, curly.type,
2967 ((GroupTail)tail).localIndex,
2968 ((GroupTail)tail).groupIndex,
2969 capturingGroup);
2970 return head;
2971 } else { // Non-deterministic
2972 int temp = ((GroupHead) head).localIndex;
2973 Loop loop;
2974 if (curly.type == GREEDY)
2975 loop = new Loop(this.localCount, temp);
2976 else // Reluctant Curly
2977 loop = new LazyLoop(this.localCount, temp);
2978 Prolog prolog = new Prolog(loop);
2979 this.localCount += 1;
2980 loop.cmin = curly.cmin;
2981 loop.cmax = curly.cmax;
2982 loop.body = head;
2983 tail.next = loop;
2984 root = loop;
2985 return prolog; // Dual return
2986 }
2987 }
2988 throw error("Internal logic error");
2989 }
2990
2991 /**
2992 * Create group head and tail nodes using double return. If the group is
2993 * created with anonymous true then it is a pure group and should not
2994 * affect group counting.
2995 */
2996 private Node createGroup(boolean anonymous) {
2997 int localIndex = localCount++;
2998 int groupIndex = 0;
2999 if (!anonymous)
3000 groupIndex = capturingGroupCount++;
3001 GroupHead head = new GroupHead(localIndex);
3002 root = new GroupTail(localIndex, groupIndex);
3003 if (!anonymous && groupIndex < 10)
3004 groupNodes[groupIndex] = head;
3005 return head;
3006 }
3007
3008 @SuppressWarnings("fallthrough")
3009 /**
3010 * Parses inlined match flags and set them appropriately.
3011 */
3012 private void addFlag() {
3013 int ch = peek();
3014 for (;;) {
3015 switch (ch) {
3016 case 'i':
3017 flags |= CASE_INSENSITIVE;
3018 break;
3019 case 'm':
3020 flags |= MULTILINE;
3021 break;
3022 case 's':
3023 flags |= DOTALL;
3024 break;
3025 case 'd':
3026 flags |= UNIX_LINES;
3027 break;
3028 case 'u':
3029 flags |= UNICODE_CASE;
3030 break;
3031 case 'c':
3032 flags |= CANON_EQ;
3033 break;
3034 case 'x':
3035 flags |= COMMENTS;
3036 break;
3037 case 'U':
3038 flags |= (UNICODE_CHARACTER_CLASS | UNICODE_CASE);
3039 break;
3040 case '-': // subFlag then fall through
3041 ch = next();
3042 subFlag();
3043 default:
3044 return;
3045 }
3046 ch = next();
3047 }
3048 }
3049
3050 @SuppressWarnings("fallthrough")
3051 /**
3052 * Parses the second part of inlined match flags and turns off
3053 * flags appropriately.
3054 */
3055 private void subFlag() {
3056 int ch = peek();
3057 for (;;) {
3058 switch (ch) {
3059 case 'i':
3060 flags &= ~CASE_INSENSITIVE;
3061 break;
3062 case 'm':
3063 flags &= ~MULTILINE;
3064 break;
3065 case 's':
3066 flags &= ~DOTALL;
3067 break;
3068 case 'd':
3069 flags &= ~UNIX_LINES;
3070 break;
3071 case 'u':
3072 flags &= ~UNICODE_CASE;
3073 break;
3074 case 'c':
3075 flags &= ~CANON_EQ;
3076 break;
3077 case 'x':
3078 flags &= ~COMMENTS;
3079 break;
3080 case 'U':
3081 flags &= ~(UNICODE_CHARACTER_CLASS | UNICODE_CASE);
3082 default:
3083 return;
3084 }
3085 ch = next();
3086 }
3087 }
3088
3089 static final int MAX_REPS = 0x7FFFFFFF;
3090
3091 static final int GREEDY = 0;
3092
3093 static final int LAZY = 1;
3094
3095 static final int POSSESSIVE = 2;
3096
3097 static final int INDEPENDENT = 3;
3098
3099 /**
3100 * Processes repetition. If the next character peeked is a quantifier
3101 * then new nodes must be appended to handle the repetition.
3102 * Prev could be a single or a group, so it could be a chain of nodes.
3103 */
3104 private Node closure(Node prev) {
3105 Node atom;
3106 int ch = peek();
3107 switch (ch) {
3108 case '?':
3109 ch = next();
3110 if (ch == '?') {
3111 next();
3112 return new Ques(prev, LAZY);
3113 } else if (ch == '+') {
3114 next();
3115 return new Ques(prev, POSSESSIVE);
3116 }
3117 return new Ques(prev, GREEDY);
3118 case '*':
3119 ch = next();
3120 if (ch == '?') {
3121 next();
3122 return new Curly(prev, 0, MAX_REPS, LAZY);
3123 } else if (ch == '+') {
3124 next();
3125 return new Curly(prev, 0, MAX_REPS, POSSESSIVE);
3126 }
3127 return new Curly(prev, 0, MAX_REPS, GREEDY);
3128 case '+':
3129 ch = next();
3130 if (ch == '?') {
3131 next();
3132 return new Curly(prev, 1, MAX_REPS, LAZY);
3133 } else if (ch == '+') {
3134 next();
3135 return new Curly(prev, 1, MAX_REPS, POSSESSIVE);
3136 }
3137 return new Curly(prev, 1, MAX_REPS, GREEDY);
3138 case '{':
3139 ch = temp[cursor+1];
3140 if (ASCII.isDigit(ch)) {
3141 skip();
3142 int cmin = 0;
3143 do {
3144 cmin = cmin * 10 + (ch - '0');
3145 } while (ASCII.isDigit(ch = read()));
3146 int cmax = cmin;
3147 if (ch == ',') {
3148 ch = read();
3149 cmax = MAX_REPS;
3150 if (ch != '}') {
3151 cmax = 0;
3152 while (ASCII.isDigit(ch)) {
3153 cmax = cmax * 10 + (ch - '0');
3154 ch = read();
3155 }
3156 }
3157 }
3158 if (ch != '}')
3159 throw error("Unclosed counted closure");
3160 if (((cmin) | (cmax) | (cmax - cmin)) < 0)
3161 throw error("Illegal repetition range");
3162 Curly curly;
3163 ch = peek();
3164 if (ch == '?') {
3165 next();
3166 curly = new Curly(prev, cmin, cmax, LAZY);
3167 } else if (ch == '+') {
3168 next();
3169 curly = new Curly(prev, cmin, cmax, POSSESSIVE);
3170 } else {
3171 curly = new Curly(prev, cmin, cmax, GREEDY);
3172 }
3173 return curly;
3174 } else {
3175 throw error("Illegal repetition");
3176 }
3177 default:
3178 return prev;
3179 }
3180 }
3181
3182 /**
3183 * Utility method for parsing control escape sequences.
3184 */
3185 private int c() {
3186 if (cursor < patternLength) {
3187 return read() ^ 64;
3188 }
3189 throw error("Illegal control escape sequence");
3190 }
3191
3192 /**
3193 * Utility method for parsing octal escape sequences.
3194 */
3195 private int o() {
3196 int n = read();
3197 if (((n-'0')|('7'-n)) >= 0) {
3198 int m = read();
3199 if (((m-'0')|('7'-m)) >= 0) {
3200 int o = read();
3201 if ((((o-'0')|('7'-o)) >= 0) && (((n-'0')|('3'-n)) >= 0)) {
3202 return (n - '0') * 64 + (m - '0') * 8 + (o - '0');
3203 }
3204 unread();
3205 return (n - '0') * 8 + (m - '0');
3206 }
3207 unread();
3208 return (n - '0');
3209 }
3210 throw error("Illegal octal escape sequence");
3211 }
3212
3213 /**
3214 * Utility method for parsing hexadecimal escape sequences.
3215 */
3216 private int x() {
3217 int n = read();
3218 if (ASCII.isHexDigit(n)) {
3219 int m = read();
3220 if (ASCII.isHexDigit(m)) {
3221 return ASCII.toDigit(n) * 16 + ASCII.toDigit(m);
3222 }
3223 } else if (n == '{' && ASCII.isHexDigit(peek())) {
3224 int ch = 0;
3225 while (ASCII.isHexDigit(n = read())) {
3226 ch = (ch << 4) + ASCII.toDigit(n);
3227 if (ch > Character.MAX_CODE_POINT)
3228 throw error("Hexadecimal codepoint is too big");
3229 }
3230 if (n != '}')
3231 throw error("Unclosed hexadecimal escape sequence");
3232 return ch;
3233 }
3234 throw error("Illegal hexadecimal escape sequence");
3235 }
3236
3237 /**
3238 * Utility method for parsing unicode escape sequences.
3239 */
3240 private int cursor() {
3241 return cursor;
3242 }
3243
3244 private void setcursor(int pos) {
3245 cursor = pos;
3246 }
3247
3248 private int uxxxx() {
3249 int n = 0;
3250 for (int i = 0; i < 4; i++) {
3251 int ch = read();
3252 if (!ASCII.isHexDigit(ch)) {
3253 throw error("Illegal Unicode escape sequence");
3254 }
3255 n = n * 16 + ASCII.toDigit(ch);
3256 }
3257 return n;
3258 }
3259
3260 private int u() {
3261 int n = uxxxx();
3262 if (Character.isHighSurrogate((char)n)) {
3263 int cur = cursor();
3264 if (read() == '\\' && read() == 'u') {
3265 int n2 = uxxxx();
3266 if (Character.isLowSurrogate((char)n2))
3267 return Character.toCodePoint((char)n, (char)n2);
3268 }
3269 setcursor(cur);
3270 }
3271 return n;
3272 }
3273
3274 //
3275 // Utility methods for code point support
3276 //
3277
3278 private static final int countChars(CharSequence seq, int index,
3279 int lengthInCodePoints) {
3280 // optimization
3281 if (lengthInCodePoints == 1 && !Character.isHighSurrogate(seq.charAt(index))) {
3282 assert (index >= 0 && index < seq.length());
3283 return 1;
3284 }
3285 int length = seq.length();
3286 int x = index;
3287 if (lengthInCodePoints >= 0) {
3288 assert (index >= 0 && index < length);
3289 for (int i = 0; x < length && i < lengthInCodePoints; i++) {
3290 if (Character.isHighSurrogate(seq.charAt(x++))) {
3291 if (x < length && Character.isLowSurrogate(seq.charAt(x))) {
3292 x++;
3293 }
3294 }
3295 }
3296 return x - index;
3297 }
3298
3299 assert (index >= 0 && index <= length);
3300 if (index == 0) {
3301 return 0;
3302 }
3303 int len = -lengthInCodePoints;
3304 for (int i = 0; x > 0 && i < len; i++) {
3305 if (Character.isLowSurrogate(seq.charAt(--x))) {
3306 if (x > 0 && Character.isHighSurrogate(seq.charAt(x-1))) {
3307 x--;
3308 }
3309 }
3310 }
3311 return index - x;
3312 }
3313
3314 private static final int countCodePoints(CharSequence seq) {
3315 int length = seq.length();
3316 int n = 0;
3317 for (int i = 0; i < length; ) {
3318 n++;
3319 if (Character.isHighSurrogate(seq.charAt(i++))) {
3320 if (i < length && Character.isLowSurrogate(seq.charAt(i))) {
3321 i++;
3322 }
3323 }
3324 }
3325 return n;
3326 }
3327
3328 /**
3329 * Creates a bit vector for matching Latin-1 values. A normal BitClass
3330 * never matches values above Latin-1, and a complemented BitClass always
3331 * matches values above Latin-1.
3332 */
3333 private static final class BitClass extends BmpCharProperty {
3334 final boolean[] bits;
3335 BitClass() { bits = new boolean[256]; }
3336 private BitClass(boolean[] bits) { this.bits = bits; }
3337 BitClass add(int c, int flags) {
3338 assert c >= 0 && c <= 255;
3339 if ((flags & CASE_INSENSITIVE) != 0) {
3340 if (ASCII.isAscii(c)) {
3341 bits[ASCII.toUpper(c)] = true;
3342 bits[ASCII.toLower(c)] = true;
3343 } else if ((flags & UNICODE_CASE) != 0) {
3344 bits[Character.toLowerCase(c)] = true;
3345 bits[Character.toUpperCase(c)] = true;
3346 }
3347 }
3348 bits[c] = true;
3349 return this;
3350 }
3351 boolean isSatisfiedBy(int ch) {
3352 return ch < 256 && bits[ch];
3353 }
3354 }
3355
3356 /**
3357 * Returns a suitably optimized, single character matcher.
3358 */
3359 private CharProperty newSingle(final int ch) {
3360 if (has(CASE_INSENSITIVE)) {
3361 int lower, upper;
3362 if (has(UNICODE_CASE)) {
3363 upper = Character.toUpperCase(ch);
3364 lower = Character.toLowerCase(upper);
3365 if (upper != lower)
3366 return new SingleU(lower);
3367 } else if (ASCII.isAscii(ch)) {
3368 lower = ASCII.toLower(ch);
3369 upper = ASCII.toUpper(ch);
3370 if (lower != upper)
3371 return new SingleI(lower, upper);
3372 }
3373 }
3374 if (isSupplementary(ch))
3375 return new SingleS(ch); // Match a given Unicode character
3376 return new Single(ch); // Match a given BMP character
3377 }
3378
3379 /**
3380 * Utility method for creating a string slice matcher.
3381 */
3382 private Node newSlice(int[] buf, int count, boolean hasSupplementary) {
3383 int[] tmp = new int[count];
3384 if (has(CASE_INSENSITIVE)) {
3385 if (has(UNICODE_CASE)) {
3386 for (int i = 0; i < count; i++) {
3387 tmp[i] = Character.toLowerCase(
3388 Character.toUpperCase(buf[i]));
3389 }
3390 return hasSupplementary? new SliceUS(tmp) : new SliceU(tmp);
3391 }
3392 for (int i = 0; i < count; i++) {
3393 tmp[i] = ASCII.toLower(buf[i]);
3394 }
3395 return hasSupplementary? new SliceIS(tmp) : new SliceI(tmp);
3396 }
3397 for (int i = 0; i < count; i++) {
3398 tmp[i] = buf[i];
3399 }
3400 return hasSupplementary ? new SliceS(tmp) : new Slice(tmp);
3401 }
3402
3403 /**
3404 * The following classes are the building components of the object
3405 * tree that represents a compiled regular expression. The object tree
3406 * is made of individual elements that handle constructs in the Pattern.
3407 * Each type of object knows how to match its equivalent construct with
3408 * the match() method.
3409 */
3410
3411 /**
3412 * Base class for all node classes. Subclasses should override the match()
3413 * method as appropriate. This class is an accepting node, so its match()
3414 * always returns true.
3415 */
3416 static class Node extends Object {
3417 Node next;
3418 Node() {
3419 next = Pattern.accept;
3420 }
3421 /**
3422 * This method implements the classic accept node.
3423 */
3424 boolean match(Matcher matcher, int i, CharSequence seq) {
3425 matcher.last = i;
3426 matcher.groups[0] = matcher.first;
3427 matcher.groups[1] = matcher.last;
3428 return true;
3429 }
3430 /**
3431 * This method is good for all zero length assertions.
3432 */
3433 boolean study(TreeInfo info) {
3434 if (next != null) {
3435 return next.study(info);
3436 } else {
3437 return info.deterministic;
3438 }
3439 }
3440 }
3441
3442 static class LastNode extends Node {
3443 /**
3444 * This method implements the classic accept node with
3445 * the addition of a check to see if the match occurred
3446 * using all of the input.
3447 */
3448 boolean match(Matcher matcher, int i, CharSequence seq) {
3449 if (matcher.acceptMode == Matcher.ENDANCHOR && i != matcher.to)
3450 return false;
3451 matcher.last = i;
3452 matcher.groups[0] = matcher.first;
3453 matcher.groups[1] = matcher.last;
3454 return true;
3455 }
3456 }
3457
3458 /**
3459 * Used for REs that can start anywhere within the input string.
3460 * This basically tries to match repeatedly at each spot in the
3461 * input string, moving forward after each try. An anchored search
3462 * or a BnM will bypass this node completely.
3463 */
3464 static class Start extends Node {
3465 int minLength;
3466 Start(Node node) {
3467 this.next = node;
3468 TreeInfo info = new TreeInfo();
3469 next.study(info);
3470 minLength = info.minLength;
3471 }
3472 boolean match(Matcher matcher, int i, CharSequence seq) {
3473 if (i > matcher.to - minLength) {
3474 matcher.hitEnd = true;
3475 return false;
3476 }
3477 int guard = matcher.to - minLength;
3478 for (; i <= guard; i++) {
3479 if (next.match(matcher, i, seq)) {
3480 matcher.first = i;
3481 matcher.groups[0] = matcher.first;
3482 matcher.groups[1] = matcher.last;
3483 return true;
3484 }
3485 }
3486 matcher.hitEnd = true;
3487 return false;
3488 }
3489 boolean study(TreeInfo info) {
3490 next.study(info);
3491 info.maxValid = false;
3492 info.deterministic = false;
3493 return false;
3494 }
3495 }
3496
3497 /*
3498 * StartS supports supplementary characters, including unpaired surrogates.
3499 */
3500 static final class StartS extends Start {
3501 StartS(Node node) {
3502 super(node);
3503 }
3504 boolean match(Matcher matcher, int i, CharSequence seq) {
3505 if (i > matcher.to - minLength) {
3506 matcher.hitEnd = true;
3507 return false;
3508 }
3509 int guard = matcher.to - minLength;
3510 while (i <= guard) {
3511 //if ((ret = next.match(matcher, i, seq)) || i == guard)
3512 if (next.match(matcher, i, seq)) {
3513 matcher.first = i;
3514 matcher.groups[0] = matcher.first;
3515 matcher.groups[1] = matcher.last;
3516 return true;
3517 }
3518 if (i == guard)
3519 break;
3520 // Optimization to move to the next character. This is
3521 // faster than countChars(seq, i, 1).
3522 if (Character.isHighSurrogate(seq.charAt(i++))) {
3523 if (i < seq.length() &&
3524 Character.isLowSurrogate(seq.charAt(i))) {
3525 i++;
3526 }
3527 }
3528 }
3529 matcher.hitEnd = true;
3530 return false;
3531 }
3532 }
3533
3534 /**
3535 * Node to anchor at the beginning of input. This object implements the
3536 * match for a \A sequence, and the caret anchor will use this if not in
3537 * multiline mode.
3538 */
3539 static final class Begin extends Node {
3540 boolean match(Matcher matcher, int i, CharSequence seq) {
3541 int fromIndex = (matcher.anchoringBounds) ?
3542 matcher.from : 0;
3543 if (i == fromIndex && next.match(matcher, i, seq)) {
3544 matcher.first = i;
3545 matcher.groups[0] = i;
3546 matcher.groups[1] = matcher.last;
3547 return true;
3548 } else {
3549 return false;
3550 }
3551 }
3552 }
3553
3554 /**
3555 * Node to anchor at the end of input. This is the absolute end, so this
3556 * should not match at the last newline before the end as $ will.
3557 */
3558 static final class End extends Node {
3559 boolean match(Matcher matcher, int i, CharSequence seq) {
3560 int endIndex = (matcher.anchoringBounds) ?
3561 matcher.to : matcher.getTextLength();
3562 if (i == endIndex) {
3563 matcher.hitEnd = true;
3564 return next.match(matcher, i, seq);
3565 }
3566 return false;
3567 }
3568 }
3569
3570 /**
3571 * Node to anchor at the beginning of a line. This is essentially the
3572 * object to match for the multiline ^.
3573 */
3574 static final class Caret extends Node {
3575 boolean match(Matcher matcher, int i, CharSequence seq) {
3576 int startIndex = matcher.from;
3577 int endIndex = matcher.to;
3578 if (!matcher.anchoringBounds) {
3579 startIndex = 0;
3580 endIndex = matcher.getTextLength();
3581 }
3582 // Perl does not match ^ at end of input even after newline
3583 if (i == endIndex) {
3584 matcher.hitEnd = true;
3585 return false;
3586 }
3587 if (i > startIndex) {
3588 char ch = seq.charAt(i-1);
3589 if (ch != '\n' && ch != '\r'
3590 && (ch|1) != '\u2029'
3591 && ch != '\u0085' ) {
3592 return false;
3593 }
3594 // Should treat /r/n as one newline
3595 if (ch == '\r' && seq.charAt(i) == '\n')
3596 return false;
3597 }
3598 return next.match(matcher, i, seq);
3599 }
3600 }
3601
3602 /**
3603 * Node to anchor at the beginning of a line when in unixdot mode.
3604 */
3605 static final class UnixCaret extends Node {
3606 boolean match(Matcher matcher, int i, CharSequence seq) {
3607 int startIndex = matcher.from;
3608 int endIndex = matcher.to;
3609 if (!matcher.anchoringBounds) {
3610 startIndex = 0;
3611 endIndex = matcher.getTextLength();
3612 }
3613 // Perl does not match ^ at end of input even after newline
3614 if (i == endIndex) {
3615 matcher.hitEnd = true;
3616 return false;
3617 }
3618 if (i > startIndex) {
3619 char ch = seq.charAt(i-1);
3620 if (ch != '\n') {
3621 return false;
3622 }
3623 }
3624 return next.match(matcher, i, seq);
3625 }
3626 }
3627
3628 /**
3629 * Node to match the location where the last match ended.
3630 * This is used for the \G construct.
3631 */
3632 static final class LastMatch extends Node {
3633 boolean match(Matcher matcher, int i, CharSequence seq) {
3634 if (i != matcher.oldLast)
3635 return false;
3636 return next.match(matcher, i, seq);
3637 }
3638 }
3639
3640 /**
3641 * Node to anchor at the end of a line or the end of input based on the
3642 * multiline mode.
3643 *
3644 * When not in multiline mode, the $ can only match at the very end
3645 * of the input, unless the input ends in a line terminator in which
3646 * it matches right before the last line terminator.
3647 *
3648 * Note that \r\n is considered an atomic line terminator.
3649 *
3650 * Like ^ the $ operator matches at a position, it does not match the
3651 * line terminators themselves.
3652 */
3653 static final class Dollar extends Node {
3654 boolean multiline;
3655 Dollar(boolean mul) {
3656 multiline = mul;
3657 }
3658 boolean match(Matcher matcher, int i, CharSequence seq) {
3659 int endIndex = (matcher.anchoringBounds) ?
3660 matcher.to : matcher.getTextLength();
3661 if (!multiline) {
3662 if (i < endIndex - 2)
3663 return false;
3664 if (i == endIndex - 2) {
3665 char ch = seq.charAt(i);
3666 if (ch != '\r')
3667 return false;
3668 ch = seq.charAt(i + 1);
3669 if (ch != '\n')
3670 return false;
3671 }
3672 }
3673 // Matches before any line terminator; also matches at the
3674 // end of input
3675 // Before line terminator:
3676 // If multiline, we match here no matter what
3677 // If not multiline, fall through so that the end
3678 // is marked as hit; this must be a /r/n or a /n
3679 // at the very end so the end was hit; more input
3680 // could make this not match here
3681 if (i < endIndex) {
3682 char ch = seq.charAt(i);
3683 if (ch == '\n') {
3684 // No match between \r\n
3685 if (i > 0 && seq.charAt(i-1) == '\r')
3686 return false;
3687 if (multiline)
3688 return next.match(matcher, i, seq);
3689 } else if (ch == '\r' || ch == '\u0085' ||
3690 (ch|1) == '\u2029') {
3691 if (multiline)
3692 return next.match(matcher, i, seq);
3693 } else { // No line terminator, no match
3694 return false;
3695 }
3696 }
3697 // Matched at current end so hit end
3698 matcher.hitEnd = true;
3699 // If a $ matches because of end of input, then more input
3700 // could cause it to fail!
3701 matcher.requireEnd = true;
3702 return next.match(matcher, i, seq);
3703 }
3704 boolean study(TreeInfo info) {
3705 next.study(info);
3706 return info.deterministic;
3707 }
3708 }
3709
3710 /**
3711 * Node to anchor at the end of a line or the end of input based on the
3712 * multiline mode when in unix lines mode.
3713 */
3714 static final class UnixDollar extends Node {
3715 boolean multiline;
3716 UnixDollar(boolean mul) {
3717 multiline = mul;
3718 }
3719 boolean match(Matcher matcher, int i, CharSequence seq) {
3720 int endIndex = (matcher.anchoringBounds) ?
3721 matcher.to : matcher.getTextLength();
3722 if (i < endIndex) {
3723 char ch = seq.charAt(i);
3724 if (ch == '\n') {
3725 // If not multiline, then only possible to
3726 // match at very end or one before end
3727 if (multiline == false && i != endIndex - 1)
3728 return false;
3729 // If multiline return next.match without setting
3730 // matcher.hitEnd
3731 if (multiline)
3732 return next.match(matcher, i, seq);
3733 } else {
3734 return false;
3735 }
3736 }
3737 // Matching because at the end or 1 before the end;
3738 // more input could change this so set hitEnd
3739 matcher.hitEnd = true;
3740 // If a $ matches because of end of input, then more input
3741 // could cause it to fail!
3742 matcher.requireEnd = true;
3743 return next.match(matcher, i, seq);
3744 }
3745 boolean study(TreeInfo info) {
3746 next.study(info);
3747 return info.deterministic;
3748 }
3749 }
3750
3751 /**
3752 * Node class that matches a Unicode line ending '\R'
3753 */
3754 static final class LineEnding extends Node {
3755 boolean match(Matcher matcher, int i, CharSequence seq) {
3756 // (u+000Du+000A|[u+000Au+000Bu+000Cu+000Du+0085u+2028u+2029])
3757 if (i < matcher.to) {
3758 int ch = seq.charAt(i);
3759 if (ch == 0x0A || ch == 0x0B || ch == 0x0C ||
3760 ch == 0x85 || ch == 0x2028 || ch == 0x2029)
3761 return next.match(matcher, i + 1, seq);
3762 if (ch == 0x0D) {
3763 i++;
3764 if (i < matcher.to && seq.charAt(i) == 0x0A)
3765 i++;
3766 return next.match(matcher, i, seq);
3767 }
3768 } else {
3769 matcher.hitEnd = true;
3770 }
3771 return false;
3772 }
3773 boolean study(TreeInfo info) {
3774 info.minLength++;
3775 info.maxLength += 2;
3776 return next.study(info);
3777 }
3778 }
3779
3780 /**
3781 * Abstract node class to match one character satisfying some
3782 * boolean property.
3783 */
3784 private static abstract class CharProperty extends Node {
3785 abstract boolean isSatisfiedBy(int ch);
3786 CharProperty complement() {
3787 return new CharProperty() {
3788 boolean isSatisfiedBy(int ch) {
3789 return ! CharProperty.this.isSatisfiedBy(ch);}};
3790 }
3791 boolean match(Matcher matcher, int i, CharSequence seq) {
3792 if (i < matcher.to) {
3793 int ch = Character.codePointAt(seq, i);
3794 return isSatisfiedBy(ch)
3795 && next.match(matcher, i+Character.charCount(ch), seq);
3796 } else {
3797 matcher.hitEnd = true;
3798 return false;
3799 }
3800 }
3801 boolean study(TreeInfo info) {
3802 info.minLength++;
3803 info.maxLength++;
3804 return next.study(info);
3805 }
3806 }
3807
3808 /**
3809 * Optimized version of CharProperty that works only for
3810 * properties never satisfied by Supplementary characters.
3811 */
3812 private static abstract class BmpCharProperty extends CharProperty {
3813 boolean match(Matcher matcher, int i, CharSequence seq) {
3814 if (i < matcher.to) {
3815 return isSatisfiedBy(seq.charAt(i))
3816 && next.match(matcher, i+1, seq);
3817 } else {
3818 matcher.hitEnd = true;
3819 return false;
3820 }
3821 }
3822 }
3823
3824 /**
3825 * Node class that matches a Supplementary Unicode character
3826 */
3827 static final class SingleS extends CharProperty {
3828 final int c;
3829 SingleS(int c) { this.c = c; }
3830 boolean isSatisfiedBy(int ch) {
3831 return ch == c;
3832 }
3833 }
3834
3835 /**
3836 * Optimization -- matches a given BMP character
3837 */
3838 static final class Single extends BmpCharProperty {
3839 final int c;
3840 Single(int c) { this.c = c; }
3841 boolean isSatisfiedBy(int ch) {
3842 return ch == c;
3843 }
3844 }
3845
3846 /**
3847 * Case insensitive matches a given BMP character
3848 */
3849 static final class SingleI extends BmpCharProperty {
3850 final int lower;
3851 final int upper;
3852 SingleI(int lower, int upper) {
3853 this.lower = lower;
3854 this.upper = upper;
3855 }
3856 boolean isSatisfiedBy(int ch) {
3857 return ch == lower || ch == upper;
3858 }
3859 }
3860
3861 /**
3862 * Unicode case insensitive matches a given Unicode character
3863 */
3864 static final class SingleU extends CharProperty {
3865 final int lower;
3866 SingleU(int lower) {
3867 this.lower = lower;
3868 }
3869 boolean isSatisfiedBy(int ch) {
3870 return lower == ch ||
3871 lower == Character.toLowerCase(Character.toUpperCase(ch));
3872 }
3873 }
3874
3875 /**
3876 * Node class that matches a Unicode block.
3877 */
3878 static final class Block extends CharProperty {
3879 final Character.UnicodeBlock block;
3880 Block(Character.UnicodeBlock block) {
3881 this.block = block;
3882 }
3883 boolean isSatisfiedBy(int ch) {
3884 return block == Character.UnicodeBlock.of(ch);
3885 }
3886 }
3887
3888 /**
3889 * Node class that matches a Unicode script
3890 */
3891 static final class Script extends CharProperty {
3892 final Character.UnicodeScript script;
3893 Script(Character.UnicodeScript script) {
3894 this.script = script;
3895 }
3896 boolean isSatisfiedBy(int ch) {
3897 return script == Character.UnicodeScript.of(ch);
3898 }
3899 }
3900
3901 /**
3902 * Node class that matches a Unicode category.
3903 */
3904 static final class Category extends CharProperty {
3905 final int typeMask;
3906 Category(int typeMask) { this.typeMask = typeMask; }
3907 boolean isSatisfiedBy(int ch) {
3908 return (typeMask & (1 << Character.getType(ch))) != 0;
3909 }
3910 }
3911
3912 /**
3913 * Node class that matches a Unicode "type"
3914 */
3915 static final class Utype extends CharProperty {
3916 final UnicodeProp uprop;
3917 Utype(UnicodeProp uprop) { this.uprop = uprop; }
3918 boolean isSatisfiedBy(int ch) {
3919 return uprop.is(ch);
3920 }
3921 }
3922
3923 /**
3924 * Node class that matches a POSIX type.
3925 */
3926 static final class Ctype extends BmpCharProperty {
3927 final int ctype;
3928 Ctype(int ctype) { this.ctype = ctype; }
3929 boolean isSatisfiedBy(int ch) {
3930 return ch < 128 && ASCII.isType(ch, ctype);
3931 }
3932 }
3933
3934 /**
3935 * Node class that matches a Perl vertical whitespace
3936 */
3937 static final class VertWS extends BmpCharProperty {
3938 boolean isSatisfiedBy(int cp) {
3939 return (cp >= 0x0A && cp <= 0x0D) ||
3940 cp == 0x85 || cp == 0x2028 || cp == 0x2029;
3941 }
3942 }
3943
3944 /**
3945 * Node class that matches a Perl horizontal whitespace
3946 */
3947 static final class HorizWS extends BmpCharProperty {
3948 boolean isSatisfiedBy(int cp) {
3949 return cp == 0x09 || cp == 0x20 || cp == 0xa0 ||
3950 cp == 0x1680 || cp == 0x180e ||
3951 cp >= 0x2000 && cp <= 0x200a ||
3952 cp == 0x202f || cp == 0x205f || cp == 0x3000;
3953 }
3954 }
3955
3956 /**
3957 * Base class for all Slice nodes
3958 */
3959 static class SliceNode extends Node {
3960 int[] buffer;
3961 SliceNode(int[] buf) {
3962 buffer = buf;
3963 }
3964 boolean study(TreeInfo info) {
3965 info.minLength += buffer.length;
3966 info.maxLength += buffer.length;
3967 return next.study(info);
3968 }
3969 }
3970
3971 /**
3972 * Node class for a case sensitive/BMP-only sequence of literal
3973 * characters.
3974 */
3975 static class Slice extends SliceNode {
3976 Slice(int[] buf) {
3977 super(buf);
3978 }
3979 boolean match(Matcher matcher, int i, CharSequence seq) {
3980 int[] buf = buffer;
3981 int len = buf.length;
3982 for (int j=0; j<len; j++) {
3983 if ((i+j) >= matcher.to) {
3984 matcher.hitEnd = true;
3985 return false;
3986 }
3987 if (buf[j] != seq.charAt(i+j))
3988 return false;
3989 }
3990 return next.match(matcher, i+len, seq);
3991 }
3992 }
3993
3994 /**
3995 * Node class for a case_insensitive/BMP-only sequence of literal
3996 * characters.
3997 */
3998 static class SliceI extends SliceNode {
3999 SliceI(int[] buf) {
4000 super(buf);
4001 }
4002 boolean match(Matcher matcher, int i, CharSequence seq) {
4003 int[] buf = buffer;
4004 int len = buf.length;
4005 for (int j=0; j<len; j++) {
4006 if ((i+j) >= matcher.to) {
4007 matcher.hitEnd = true;
4008 return false;
4009 }
4010 int c = seq.charAt(i+j);
4011 if (buf[j] != c &&
4012 buf[j] != ASCII.toLower(c))
4013 return false;
4014 }
4015 return next.match(matcher, i+len, seq);
4016 }
4017 }
4018
4019 /**
4020 * Node class for a unicode_case_insensitive/BMP-only sequence of
4021 * literal characters. Uses unicode case folding.
4022 */
4023 static final class SliceU extends SliceNode {
4024 SliceU(int[] buf) {
4025 super(buf);
4026 }
4027 boolean match(Matcher matcher, int i, CharSequence seq) {
4028 int[] buf = buffer;
4029 int len = buf.length;
4030 for (int j=0; j<len; j++) {
4031 if ((i+j) >= matcher.to) {
4032 matcher.hitEnd = true;
4033 return false;
4034 }
4035 int c = seq.charAt(i+j);
4036 if (buf[j] != c &&
4037 buf[j] != Character.toLowerCase(Character.toUpperCase(c)))
4038 return false;
4039 }
4040 return next.match(matcher, i+len, seq);
4041 }
4042 }
4043
4044 /**
4045 * Node class for a case sensitive sequence of literal characters
4046 * including supplementary characters.
4047 */
4048 static final class SliceS extends Slice {
4049 SliceS(int[] buf) {
4050 super(buf);
4051 }
4052 boolean match(Matcher matcher, int i, CharSequence seq) {
4053 int[] buf = buffer;
4054 int x = i;
4055 for (int j = 0; j < buf.length; j++) {
4056 if (x >= matcher.to) {
4057 matcher.hitEnd = true;
4058 return false;
4059 }
4060 int c = Character.codePointAt(seq, x);
4061 if (buf[j] != c)
4062 return false;
4063 x += Character.charCount(c);
4064 if (x > matcher.to) {
4065 matcher.hitEnd = true;
4066 return false;
4067 }
4068 }
4069 return next.match(matcher, x, seq);
4070 }
4071 }
4072
4073 /**
4074 * Node class for a case insensitive sequence of literal characters
4075 * including supplementary characters.
4076 */
4077 static class SliceIS extends SliceNode {
4078 SliceIS(int[] buf) {
4079 super(buf);
4080 }
4081 int toLower(int c) {
4082 return ASCII.toLower(c);
4083 }
4084 boolean match(Matcher matcher, int i, CharSequence seq) {
4085 int[] buf = buffer;
4086 int x = i;
4087 for (int j = 0; j < buf.length; j++) {
4088 if (x >= matcher.to) {
4089 matcher.hitEnd = true;
4090 return false;
4091 }
4092 int c = Character.codePointAt(seq, x);
4093 if (buf[j] != c && buf[j] != toLower(c))
4094 return false;
4095 x += Character.charCount(c);
4096 if (x > matcher.to) {
4097 matcher.hitEnd = true;
4098 return false;
4099 }
4100 }
4101 return next.match(matcher, x, seq);
4102 }
4103 }
4104
4105 /**
4106 * Node class for a case insensitive sequence of literal characters.
4107 * Uses unicode case folding.
4108 */
4109 static final class SliceUS extends SliceIS {
4110 SliceUS(int[] buf) {
4111 super(buf);
4112 }
4113 int toLower(int c) {
4114 return Character.toLowerCase(Character.toUpperCase(c));
4115 }
4116 }
4117
4118 private static boolean inRange(int lower, int ch, int upper) {
4119 return lower <= ch && ch <= upper;
4120 }
4121
4122 /**
4123 * Returns node for matching characters within an explicit value range.
4124 */
4125 private static CharProperty rangeFor(final int lower,
4126 final int upper) {
4127 return new CharProperty() {
4128 boolean isSatisfiedBy(int ch) {
4129 return inRange(lower, ch, upper);}};
4130 }
4131
4132 /**
4133 * Returns node for matching characters within an explicit value
4134 * range in a case insensitive manner.
4135 */
4136 private CharProperty caseInsensitiveRangeFor(final int lower,
4137 final int upper) {
4138 if (has(UNICODE_CASE))
4139 return new CharProperty() {
4140 boolean isSatisfiedBy(int ch) {
4141 if (inRange(lower, ch, upper))
4142 return true;
4143 int up = Character.toUpperCase(ch);
4144 return inRange(lower, up, upper) ||
4145 inRange(lower, Character.toLowerCase(up), upper);}};
4146 return new CharProperty() {
4147 boolean isSatisfiedBy(int ch) {
4148 return inRange(lower, ch, upper) ||
4149 ASCII.isAscii(ch) &&
4150 (inRange(lower, ASCII.toUpper(ch), upper) ||
4151 inRange(lower, ASCII.toLower(ch), upper));
4152 }};
4153 }
4154
4155 /**
4156 * Implements the Unicode category ALL and the dot metacharacter when
4157 * in dotall mode.
4158 */
4159 static final class All extends CharProperty {
4160 boolean isSatisfiedBy(int ch) {
4161 return true;
4162 }
4163 }
4164
4165 /**
4166 * Node class for the dot metacharacter when dotall is not enabled.
4167 */
4168 static final class Dot extends CharProperty {
4169 boolean isSatisfiedBy(int ch) {
4170 return (ch != '\n' && ch != '\r'
4171 && (ch|1) != '\u2029'
4172 && ch != '\u0085');
4173 }
4174 }
4175
4176 /**
4177 * Node class for the dot metacharacter when dotall is not enabled
4178 * but UNIX_LINES is enabled.
4179 */
4180 static final class UnixDot extends CharProperty {
4181 boolean isSatisfiedBy(int ch) {
4182 return ch != '\n';
4183 }
4184 }
4185
4186 /**
4187 * The 0 or 1 quantifier. This one class implements all three types.
4188 */
4189 static final class Ques extends Node {
4190 Node atom;
4191 int type;
4192 Ques(Node node, int type) {
4193 this.atom = node;
4194 this.type = type;
4195 }
4196 boolean match(Matcher matcher, int i, CharSequence seq) {
4197 switch (type) {
4198 case GREEDY:
4199 return (atom.match(matcher, i, seq) && next.match(matcher, matcher.last, seq))
4200 || next.match(matcher, i, seq);
4201 case LAZY:
4202 return next.match(matcher, i, seq)
4203 || (atom.match(matcher, i, seq) && next.match(matcher, matcher.last, seq));
4204 case POSSESSIVE:
4205 if (atom.match(matcher, i, seq)) i = matcher.last;
4206 return next.match(matcher, i, seq);
4207 default:
4208 return atom.match(matcher, i, seq) && next.match(matcher, matcher.last, seq);
4209 }
4210 }
4211 boolean study(TreeInfo info) {
4212 if (type != INDEPENDENT) {
4213 int minL = info.minLength;
4214 atom.study(info);
4215 info.minLength = minL;
4216 info.deterministic = false;
4217 return next.study(info);
4218 } else {
4219 atom.study(info);
4220 return next.study(info);
4221 }
4222 }
4223 }
4224
4225 /**
4226 * Handles the curly-brace style repetition with a specified minimum and
4227 * maximum occurrences. The * quantifier is handled as a special case.
4228 * This class handles the three types.
4229 */
4230 static final class Curly extends Node {
4231 Node atom;
4232 int type;
4233 int cmin;
4234 int cmax;
4235
4236 Curly(Node node, int cmin, int cmax, int type) {
4237 this.atom = node;
4238 this.type = type;
4239 this.cmin = cmin;
4240 this.cmax = cmax;
4241 }
4242 boolean match(Matcher matcher, int i, CharSequence seq) {
4243 int j;
4244 for (j = 0; j < cmin; j++) {
4245 if (atom.match(matcher, i, seq)) {
4246 i = matcher.last;
4247 continue;
4248 }
4249 return false;
4250 }
4251 if (type == GREEDY)
4252 return match0(matcher, i, j, seq);
4253 else if (type == LAZY)
4254 return match1(matcher, i, j, seq);
4255 else
4256 return match2(matcher, i, j, seq);
4257 }
4258 // Greedy match.
4259 // i is the index to start matching at
4260 // j is the number of atoms that have matched
4261 boolean match0(Matcher matcher, int i, int j, CharSequence seq) {
4262 if (j >= cmax) {
4263 // We have matched the maximum... continue with the rest of
4264 // the regular expression
4265 return next.match(matcher, i, seq);
4266 }
4267 int backLimit = j;
4268 while (atom.match(matcher, i, seq)) {
4269 // k is the length of this match
4270 int k = matcher.last - i;
4271 if (k == 0) // Zero length match
4272 break;
4273 // Move up index and number matched
4274 i = matcher.last;
4275 j++;
4276 // We are greedy so match as many as we can
4277 while (j < cmax) {
4278 if (!atom.match(matcher, i, seq))
4279 break;
4280 if (i + k != matcher.last) {
4281 if (match0(matcher, matcher.last, j+1, seq))
4282 return true;
4283 break;
4284 }
4285 i += k;
4286 j++;
4287 }
4288 // Handle backing off if match fails
4289 while (j >= backLimit) {
4290 if (next.match(matcher, i, seq))
4291 return true;
4292 i -= k;
4293 j--;
4294 }
4295 return false;
4296 }
4297 return next.match(matcher, i, seq);
4298 }
4299 // Reluctant match. At this point, the minimum has been satisfied.
4300 // i is the index to start matching at
4301 // j is the number of atoms that have matched
4302 boolean match1(Matcher matcher, int i, int j, CharSequence seq) {
4303 for (;;) {
4304 // Try finishing match without consuming any more
4305 if (next.match(matcher, i, seq))
4306 return true;
4307 // At the maximum, no match found
4308 if (j >= cmax)
4309 return false;
4310 // Okay, must try one more atom
4311 if (!atom.match(matcher, i, seq))
4312 return false;
4313 // If we haven't moved forward then must break out
4314 if (i == matcher.last)
4315 return false;
4316 // Move up index and number matched
4317 i = matcher.last;
4318 j++;
4319 }
4320 }
4321 boolean match2(Matcher matcher, int i, int j, CharSequence seq) {
4322 for (; j < cmax; j++) {
4323 if (!atom.match(matcher, i, seq))
4324 break;
4325 if (i == matcher.last)
4326 break;
4327 i = matcher.last;
4328 }
4329 return next.match(matcher, i, seq);
4330 }
4331 boolean study(TreeInfo info) {
4332 // Save original info
4333 int minL = info.minLength;
4334 int maxL = info.maxLength;
4335 boolean maxV = info.maxValid;
4336 boolean detm = info.deterministic;
4337 info.reset();
4338
4339 atom.study(info);
4340
4341 int temp = info.minLength * cmin + minL;
4342 if (temp < minL) {
4343 temp = 0xFFFFFFF; // arbitrary large number
4344 }
4345 info.minLength = temp;
4346
4347 if (maxV & info.maxValid) {
4348 temp = info.maxLength * cmax + maxL;
4349 info.maxLength = temp;
4350 if (temp < maxL) {
4351 info.maxValid = false;
4352 }
4353 } else {
4354 info.maxValid = false;
4355 }
4356
4357 if (info.deterministic && cmin == cmax)
4358 info.deterministic = detm;
4359 else
4360 info.deterministic = false;
4361 return next.study(info);
4362 }
4363 }
4364
4365 /**
4366 * Handles the curly-brace style repetition with a specified minimum and
4367 * maximum occurrences in deterministic cases. This is an iterative
4368 * optimization over the Prolog and Loop system which would handle this
4369 * in a recursive way. The * quantifier is handled as a special case.
4370 * If capture is true then this class saves group settings and ensures
4371 * that groups are unset when backing off of a group match.
4372 */
4373 static final class GroupCurly extends Node {
4374 Node atom;
4375 int type;
4376 int cmin;
4377 int cmax;
4378 int localIndex;
4379 int groupIndex;
4380 boolean capture;
4381
4382 GroupCurly(Node node, int cmin, int cmax, int type, int local,
4383 int group, boolean capture) {
4384 this.atom = node;
4385 this.type = type;
4386 this.cmin = cmin;
4387 this.cmax = cmax;
4388 this.localIndex = local;
4389 this.groupIndex = group;
4390 this.capture = capture;
4391 }
4392 boolean match(Matcher matcher, int i, CharSequence seq) {
4393 int[] groups = matcher.groups;
4394 int[] locals = matcher.locals;
4395 int save0 = locals[localIndex];
4396 int save1 = 0;
4397 int save2 = 0;
4398
4399 if (capture) {
4400 save1 = groups[groupIndex];
4401 save2 = groups[groupIndex+1];
4402 }
4403
4404 // Notify GroupTail there is no need to setup group info
4405 // because it will be set here
4406 locals[localIndex] = -1;
4407
4408 boolean ret = true;
4409 for (int j = 0; j < cmin; j++) {
4410 if (atom.match(matcher, i, seq)) {
4411 if (capture) {
4412 groups[groupIndex] = i;
4413 groups[groupIndex+1] = matcher.last;
4414 }
4415 i = matcher.last;
4416 } else {
4417 ret = false;
4418 break;
4419 }
4420 }
4421 if (ret) {
4422 if (type == GREEDY) {
4423 ret = match0(matcher, i, cmin, seq);
4424 } else if (type == LAZY) {
4425 ret = match1(matcher, i, cmin, seq);
4426 } else {
4427 ret = match2(matcher, i, cmin, seq);
4428 }
4429 }
4430 if (!ret) {
4431 locals[localIndex] = save0;
4432 if (capture) {
4433 groups[groupIndex] = save1;
4434 groups[groupIndex+1] = save2;
4435 }
4436 }
4437 return ret;
4438 }
4439 // Aggressive group match
4440 boolean match0(Matcher matcher, int i, int j, CharSequence seq) {
4441 // don't back off passing the starting "j"
4442 int min = j;
4443 int[] groups = matcher.groups;
4444 int save0 = 0;
4445 int save1 = 0;
4446 if (capture) {
4447 save0 = groups[groupIndex];
4448 save1 = groups[groupIndex+1];
4449 }
4450 for (;;) {
4451 if (j >= cmax)
4452 break;
4453 if (!atom.match(matcher, i, seq))
4454 break;
4455 int k = matcher.last - i;
4456 if (k <= 0) {
4457 if (capture) {
4458 groups[groupIndex] = i;
4459 groups[groupIndex+1] = i + k;
4460 }
4461 i = i + k;
4462 break;
4463 }
4464 for (;;) {
4465 if (capture) {
4466 groups[groupIndex] = i;
4467 groups[groupIndex+1] = i + k;
4468 }
4469 i = i + k;
4470 if (++j >= cmax)
4471 break;
4472 if (!atom.match(matcher, i, seq))
4473 break;
4474 if (i + k != matcher.last) {
4475 if (match0(matcher, i, j, seq))
4476 return true;
4477 break;
4478 }
4479 }
4480 while (j > min) {
4481 if (next.match(matcher, i, seq)) {
4482 if (capture) {
4483 groups[groupIndex+1] = i;
4484 groups[groupIndex] = i - k;
4485 }
4486 return true;
4487 }
4488 // backing off
4489 i = i - k;
4490 if (capture) {
4491 groups[groupIndex+1] = i;
4492 groups[groupIndex] = i - k;
4493 }
4494 j--;
4495
4496 }
4497 break;
4498 }
4499 if (capture) {
4500 groups[groupIndex] = save0;
4501 groups[groupIndex+1] = save1;
4502 }
4503 return next.match(matcher, i, seq);
4504 }
4505 // Reluctant matching
4506 boolean match1(Matcher matcher, int i, int j, CharSequence seq) {
4507 for (;;) {
4508 if (next.match(matcher, i, seq))
4509 return true;
4510 if (j >= cmax)
4511 return false;
4512 if (!atom.match(matcher, i, seq))
4513 return false;
4514 if (i == matcher.last)
4515 return false;
4516 if (capture) {
4517 matcher.groups[groupIndex] = i;
4518 matcher.groups[groupIndex+1] = matcher.last;
4519 }
4520 i = matcher.last;
4521 j++;
4522 }
4523 }
4524 // Possessive matching
4525 boolean match2(Matcher matcher, int i, int j, CharSequence seq) {
4526 for (; j < cmax; j++) {
4527 if (!atom.match(matcher, i, seq)) {
4528 break;
4529 }
4530 if (capture) {
4531 matcher.groups[groupIndex] = i;
4532 matcher.groups[groupIndex+1] = matcher.last;
4533 }
4534 if (i == matcher.last) {
4535 break;
4536 }
4537 i = matcher.last;
4538 }
4539 return next.match(matcher, i, seq);
4540 }
4541 boolean study(TreeInfo info) {
4542 // Save original info
4543 int minL = info.minLength;
4544 int maxL = info.maxLength;
4545 boolean maxV = info.maxValid;
4546 boolean detm = info.deterministic;
4547 info.reset();
4548
4549 atom.study(info);
4550
4551 int temp = info.minLength * cmin + minL;
4552 if (temp < minL) {
4553 temp = 0xFFFFFFF; // Arbitrary large number
4554 }
4555 info.minLength = temp;
4556
4557 if (maxV & info.maxValid) {
4558 temp = info.maxLength * cmax + maxL;
4559 info.maxLength = temp;
4560 if (temp < maxL) {
4561 info.maxValid = false;
4562 }
4563 } else {
4564 info.maxValid = false;
4565 }
4566
4567 if (info.deterministic && cmin == cmax) {
4568 info.deterministic = detm;
4569 } else {
4570 info.deterministic = false;
4571 }
4572 return next.study(info);
4573 }
4574 }
4575
4576 /**
4577 * A Guard node at the end of each atom node in a Branch. It
4578 * serves the purpose of chaining the "match" operation to
4579 * "next" but not the "study", so we can collect the TreeInfo
4580 * of each atom node without including the TreeInfo of the
4581 * "next".
4582 */
4583 static final class BranchConn extends Node {
4584 BranchConn() {};
4585 boolean match(Matcher matcher, int i, CharSequence seq) {
4586 return next.match(matcher, i, seq);
4587 }
4588 boolean study(TreeInfo info) {
4589 return info.deterministic;
4590 }
4591 }
4592
4593 /**
4594 * Handles the branching of alternations. Note this is also used for
4595 * the ? quantifier to branch between the case where it matches once
4596 * and where it does not occur.
4597 */
4598 static final class Branch extends Node {
4599 Node[] atoms = new Node[2];
4600 int size = 2;
4601 Node conn;
4602 Branch(Node first, Node second, Node branchConn) {
4603 conn = branchConn;
4604 atoms[0] = first;
4605 atoms[1] = second;
4606 }
4607
4608 void add(Node node) {
4609 if (size >= atoms.length) {
4610 Node[] tmp = new Node[atoms.length*2];
4611 System.arraycopy(atoms, 0, tmp, 0, atoms.length);
4612 atoms = tmp;
4613 }
4614 atoms[size++] = node;
4615 }
4616
4617 boolean match(Matcher matcher, int i, CharSequence seq) {
4618 for (int n = 0; n < size; n++) {
4619 if (atoms[n] == null) {
4620 if (conn.next.match(matcher, i, seq))
4621 return true;
4622 } else if (atoms[n].match(matcher, i, seq)) {
4623 return true;
4624 }
4625 }
4626 return false;
4627 }
4628
4629 boolean study(TreeInfo info) {
4630 int minL = info.minLength;
4631 int maxL = info.maxLength;
4632 boolean maxV = info.maxValid;
4633
4634 int minL2 = Integer.MAX_VALUE; //arbitrary large enough num
4635 int maxL2 = -1;
4636 for (int n = 0; n < size; n++) {
4637 info.reset();
4638 if (atoms[n] != null)
4639 atoms[n].study(info);
4640 minL2 = Math.min(minL2, info.minLength);
4641 maxL2 = Math.max(maxL2, info.maxLength);
4642 maxV = (maxV & info.maxValid);
4643 }
4644
4645 minL += minL2;
4646 maxL += maxL2;
4647
4648 info.reset();
4649 conn.next.study(info);
4650
4651 info.minLength += minL;
4652 info.maxLength += maxL;
4653 info.maxValid &= maxV;
4654 info.deterministic = false;
4655 return false;
4656 }
4657 }
4658
4659 /**
4660 * The GroupHead saves the location where the group begins in the locals
4661 * and restores them when the match is done.
4662 *
4663 * The matchRef is used when a reference to this group is accessed later
4664 * in the expression. The locals will have a negative value in them to
4665 * indicate that we do not want to unset the group if the reference
4666 * doesn't match.
4667 */
4668 static final class GroupHead extends Node {
4669 int localIndex;
4670 GroupHead(int localCount) {
4671 localIndex = localCount;
4672 }
4673 boolean match(Matcher matcher, int i, CharSequence seq) {
4674 int save = matcher.locals[localIndex];
4675 matcher.locals[localIndex] = i;
4676 boolean ret = next.match(matcher, i, seq);
4677 matcher.locals[localIndex] = save;
4678 return ret;
4679 }
4680 boolean matchRef(Matcher matcher, int i, CharSequence seq) {
4681 int save = matcher.locals[localIndex];
4682 matcher.locals[localIndex] = ~i; // HACK
4683 boolean ret = next.match(matcher, i, seq);
4684 matcher.locals[localIndex] = save;
4685 return ret;
4686 }
4687 }
4688
4689 /**
4690 * Recursive reference to a group in the regular expression. It calls
4691 * matchRef because if the reference fails to match we would not unset
4692 * the group.
4693 */
4694 static final class GroupRef extends Node {
4695 GroupHead head;
4696 GroupRef(GroupHead head) {
4697 this.head = head;
4698 }
4699 boolean match(Matcher matcher, int i, CharSequence seq) {
4700 return head.matchRef(matcher, i, seq)
4701 && next.match(matcher, matcher.last, seq);
4702 }
4703 boolean study(TreeInfo info) {
4704 info.maxValid = false;
4705 info.deterministic = false;
4706 return next.study(info);
4707 }
4708 }
4709
4710 /**
4711 * The GroupTail handles the setting of group beginning and ending
4712 * locations when groups are successfully matched. It must also be able to
4713 * unset groups that have to be backed off of.
4714 *
4715 * The GroupTail node is also used when a previous group is referenced,
4716 * and in that case no group information needs to be set.
4717 */
4718 static final class GroupTail extends Node {
4719 int localIndex;
4720 int groupIndex;
4721 GroupTail(int localCount, int groupCount) {
4722 localIndex = localCount;
4723 groupIndex = groupCount + groupCount;
4724 }
4725 boolean match(Matcher matcher, int i, CharSequence seq) {
4726 int tmp = matcher.locals[localIndex];
4727 if (tmp >= 0) { // This is the normal group case.
4728 // Save the group so we can unset it if it
4729 // backs off of a match.
4730 int groupStart = matcher.groups[groupIndex];
4731 int groupEnd = matcher.groups[groupIndex+1];
4732
4733 matcher.groups[groupIndex] = tmp;
4734 matcher.groups[groupIndex+1] = i;
4735 if (next.match(matcher, i, seq)) {
4736 return true;
4737 }
4738 matcher.groups[groupIndex] = groupStart;
4739 matcher.groups[groupIndex+1] = groupEnd;
4740 return false;
4741 } else {
4742 // This is a group reference case. We don't need to save any
4743 // group info because it isn't really a group.
4744 matcher.last = i;
4745 return true;
4746 }
4747 }
4748 }
4749
4750 /**
4751 * This sets up a loop to handle a recursive quantifier structure.
4752 */
4753 static final class Prolog extends Node {
4754 Loop loop;
4755 Prolog(Loop loop) {
4756 this.loop = loop;
4757 }
4758 boolean match(Matcher matcher, int i, CharSequence seq) {
4759 return loop.matchInit(matcher, i, seq);
4760 }
4761 boolean study(TreeInfo info) {
4762 return loop.study(info);
4763 }
4764 }
4765
4766 /**
4767 * Handles the repetition count for a greedy Curly. The matchInit
4768 * is called from the Prolog to save the index of where the group
4769 * beginning is stored. A zero length group check occurs in the
4770 * normal match but is skipped in the matchInit.
4771 */
4772 static class Loop extends Node {
4773 Node body;
4774 int countIndex; // local count index in matcher locals
4775 int beginIndex; // group beginning index
4776 int cmin, cmax;
4777 Loop(int countIndex, int beginIndex) {
4778 this.countIndex = countIndex;
4779 this.beginIndex = beginIndex;
4780 }
4781 boolean match(Matcher matcher, int i, CharSequence seq) {
4782 // Avoid infinite loop in zero-length case.
4783 if (i > matcher.locals[beginIndex]) {
4784 int count = matcher.locals[countIndex];
4785
4786 // This block is for before we reach the minimum
4787 // iterations required for the loop to match
4788 if (count < cmin) {
4789 matcher.locals[countIndex] = count + 1;
4790 boolean b = body.match(matcher, i, seq);
4791 // If match failed we must backtrack, so
4792 // the loop count should NOT be incremented
4793 if (!b)
4794 matcher.locals[countIndex] = count;
4795 // Return success or failure since we are under
4796 // minimum
4797 return b;
4798 }
4799 // This block is for after we have the minimum
4800 // iterations required for the loop to match
4801 if (count < cmax) {
4802 matcher.locals[countIndex] = count + 1;
4803 boolean b = body.match(matcher, i, seq);
4804 // If match failed we must backtrack, so
4805 // the loop count should NOT be incremented
4806 if (!b)
4807 matcher.locals[countIndex] = count;
4808 else
4809 return true;
4810 }
4811 }
4812 return next.match(matcher, i, seq);
4813 }
4814 boolean matchInit(Matcher matcher, int i, CharSequence seq) {
4815 int save = matcher.locals[countIndex];
4816 boolean ret = false;
4817 if (0 < cmin) {
4818 matcher.locals[countIndex] = 1;
4819 ret = body.match(matcher, i, seq);
4820 } else if (0 < cmax) {
4821 matcher.locals[countIndex] = 1;
4822 ret = body.match(matcher, i, seq);
4823 if (ret == false)
4824 ret = next.match(matcher, i, seq);
4825 } else {
4826 ret = next.match(matcher, i, seq);
4827 }
4828 matcher.locals[countIndex] = save;
4829 return ret;
4830 }
4831 boolean study(TreeInfo info) {
4832 info.maxValid = false;
4833 info.deterministic = false;
4834 return false;
4835 }
4836 }
4837
4838 /**
4839 * Handles the repetition count for a reluctant Curly. The matchInit
4840 * is called from the Prolog to save the index of where the group
4841 * beginning is stored. A zero length group check occurs in the
4842 * normal match but is skipped in the matchInit.
4843 */
4844 static final class LazyLoop extends Loop {
4845 LazyLoop(int countIndex, int beginIndex) {
4846 super(countIndex, beginIndex);
4847 }
4848 boolean match(Matcher matcher, int i, CharSequence seq) {
4849 // Check for zero length group
4850 if (i > matcher.locals[beginIndex]) {
4851 int count = matcher.locals[countIndex];
4852 if (count < cmin) {
4853 matcher.locals[countIndex] = count + 1;
4854 boolean result = body.match(matcher, i, seq);
4855 // If match failed we must backtrack, so
4856 // the loop count should NOT be incremented
4857 if (!result)
4858 matcher.locals[countIndex] = count;
4859 return result;
4860 }
4861 if (next.match(matcher, i, seq))
4862 return true;
4863 if (count < cmax) {
4864 matcher.locals[countIndex] = count + 1;
4865 boolean result = body.match(matcher, i, seq);
4866 // If match failed we must backtrack, so
4867 // the loop count should NOT be incremented
4868 if (!result)
4869 matcher.locals[countIndex] = count;
4870 return result;
4871 }
4872 return false;
4873 }
4874 return next.match(matcher, i, seq);
4875 }
4876 boolean matchInit(Matcher matcher, int i, CharSequence seq) {
4877 int save = matcher.locals[countIndex];
4878 boolean ret = false;
4879 if (0 < cmin) {
4880 matcher.locals[countIndex] = 1;
4881 ret = body.match(matcher, i, seq);
4882 } else if (next.match(matcher, i, seq)) {
4883 ret = true;
4884 } else if (0 < cmax) {
4885 matcher.locals[countIndex] = 1;
4886 ret = body.match(matcher, i, seq);
4887 }
4888 matcher.locals[countIndex] = save;
4889 return ret;
4890 }
4891 boolean study(TreeInfo info) {
4892 info.maxValid = false;
4893 info.deterministic = false;
4894 return false;
4895 }
4896 }
4897
4898 /**
4899 * Refers to a group in the regular expression. Attempts to match
4900 * whatever the group referred to last matched.
4901 */
4902 static class BackRef extends Node {
4903 int groupIndex;
4904 BackRef(int groupCount) {
4905 super();
4906 groupIndex = groupCount + groupCount;
4907 }
4908 boolean match(Matcher matcher, int i, CharSequence seq) {
4909 int j = matcher.groups[groupIndex];
4910 int k = matcher.groups[groupIndex+1];
4911
4912 int groupSize = k - j;
4913 // If the referenced group didn't match, neither can this
4914 if (j < 0)
4915 return false;
4916
4917 // If there isn't enough input left no match
4918 if (i + groupSize > matcher.to) {
4919 matcher.hitEnd = true;
4920 return false;
4921 }
4922 // Check each new char to make sure it matches what the group
4923 // referenced matched last time around
4924 for (int index=0; index<groupSize; index++)
4925 if (seq.charAt(i+index) != seq.charAt(j+index))
4926 return false;
4927
4928 return next.match(matcher, i+groupSize, seq);
4929 }
4930 boolean study(TreeInfo info) {
4931 info.maxValid = false;
4932 return next.study(info);
4933 }
4934 }
4935
4936 static class CIBackRef extends Node {
4937 int groupIndex;
4938 boolean doUnicodeCase;
4939 CIBackRef(int groupCount, boolean doUnicodeCase) {
4940 super();
4941 groupIndex = groupCount + groupCount;
4942 this.doUnicodeCase = doUnicodeCase;
4943 }
4944 boolean match(Matcher matcher, int i, CharSequence seq) {
4945 int j = matcher.groups[groupIndex];
4946 int k = matcher.groups[groupIndex+1];
4947
4948 int groupSize = k - j;
4949
4950 // If the referenced group didn't match, neither can this
4951 if (j < 0)
4952 return false;
4953
4954 // If there isn't enough input left no match
4955 if (i + groupSize > matcher.to) {
4956 matcher.hitEnd = true;
4957 return false;
4958 }
4959
4960 // Check each new char to make sure it matches what the group
4961 // referenced matched last time around
4962 int x = i;
4963 for (int index=0; index<groupSize; index++) {
4964 int c1 = Character.codePointAt(seq, x);
4965 int c2 = Character.codePointAt(seq, j);
4966 if (c1 != c2) {
4967 if (doUnicodeCase) {
4968 int cc1 = Character.toUpperCase(c1);
4969 int cc2 = Character.toUpperCase(c2);
4970 if (cc1 != cc2 &&
4971 Character.toLowerCase(cc1) !=
4972 Character.toLowerCase(cc2))
4973 return false;
4974 } else {
4975 if (ASCII.toLower(c1) != ASCII.toLower(c2))
4976 return false;
4977 }
4978 }
4979 x += Character.charCount(c1);
4980 j += Character.charCount(c2);
4981 }
4982
4983 return next.match(matcher, i+groupSize, seq);
4984 }
4985 boolean study(TreeInfo info) {
4986 info.maxValid = false;
4987 return next.study(info);
4988 }
4989 }
4990
4991 /**
4992 * Searches until the next instance of its atom. This is useful for
4993 * finding the atom efficiently without passing an instance of it
4994 * (greedy problem) and without a lot of wasted search time (reluctant
4995 * problem).
4996 */
4997 static final class First extends Node {
4998 Node atom;
4999 First(Node node) {
5000 this.atom = BnM.optimize(node);
5001 }
5002 boolean match(Matcher matcher, int i, CharSequence seq) {
5003 if (atom instanceof BnM) {
5004 return atom.match(matcher, i, seq)
5005 && next.match(matcher, matcher.last, seq);
5006 }
5007 for (;;) {
5008 if (i > matcher.to) {
5009 matcher.hitEnd = true;
5010 return false;
5011 }
5012 if (atom.match(matcher, i, seq)) {
5013 return next.match(matcher, matcher.last, seq);
5014 }
5015 i += countChars(seq, i, 1);
5016 matcher.first++;
5017 }
5018 }
5019 boolean study(TreeInfo info) {
5020 atom.study(info);
5021 info.maxValid = false;
5022 info.deterministic = false;
5023 return next.study(info);
5024 }
5025 }
5026
5027 static final class Conditional extends Node {
5028 Node cond, yes, not;
5029 Conditional(Node cond, Node yes, Node not) {
5030 this.cond = cond;
5031 this.yes = yes;
5032 this.not = not;
5033 }
5034 boolean match(Matcher matcher, int i, CharSequence seq) {
5035 if (cond.match(matcher, i, seq)) {
5036 return yes.match(matcher, i, seq);
5037 } else {
5038 return not.match(matcher, i, seq);
5039 }
5040 }
5041 boolean study(TreeInfo info) {
5042 int minL = info.minLength;
5043 int maxL = info.maxLength;
5044 boolean maxV = info.maxValid;
5045 info.reset();
5046 yes.study(info);
5047
5048 int minL2 = info.minLength;
5049 int maxL2 = info.maxLength;
5050 boolean maxV2 = info.maxValid;
5051 info.reset();
5052 not.study(info);
5053
5054 info.minLength = minL + Math.min(minL2, info.minLength);
5055 info.maxLength = maxL + Math.max(maxL2, info.maxLength);
5056 info.maxValid = (maxV & maxV2 & info.maxValid);
5057 info.deterministic = false;
5058 return next.study(info);
5059 }
5060 }
5061
5062 /**
5063 * Zero width positive lookahead.
5064 */
5065 static final class Pos extends Node {
5066 Node cond;
5067 Pos(Node cond) {
5068 this.cond = cond;
5069 }
5070 boolean match(Matcher matcher, int i, CharSequence seq) {
5071 int savedTo = matcher.to;
5072 boolean conditionMatched = false;
5073
5074 // Relax transparent region boundaries for lookahead
5075 if (matcher.transparentBounds)
5076 matcher.to = matcher.getTextLength();
5077 try {
5078 conditionMatched = cond.match(matcher, i, seq);
5079 } finally {
5080 // Reinstate region boundaries
5081 matcher.to = savedTo;
5082 }
5083 return conditionMatched && next.match(matcher, i, seq);
5084 }
5085 }
5086
5087 /**
5088 * Zero width negative lookahead.
5089 */
5090 static final class Neg extends Node {
5091 Node cond;
5092 Neg(Node cond) {
5093 this.cond = cond;
5094 }
5095 boolean match(Matcher matcher, int i, CharSequence seq) {
5096 int savedTo = matcher.to;
5097 boolean conditionMatched = false;
5098
5099 // Relax transparent region boundaries for lookahead
5100 if (matcher.transparentBounds)
5101 matcher.to = matcher.getTextLength();
5102 try {
5103 if (i < matcher.to) {
5104 conditionMatched = !cond.match(matcher, i, seq);
5105 } else {
5106 // If a negative lookahead succeeds then more input
5107 // could cause it to fail!
5108 matcher.requireEnd = true;
5109 conditionMatched = !cond.match(matcher, i, seq);
5110 }
5111 } finally {
5112 // Reinstate region boundaries
5113 matcher.to = savedTo;
5114 }
5115 return conditionMatched && next.match(matcher, i, seq);
5116 }
5117 }
5118
5119 /**
5120 * For use with lookbehinds; matches the position where the lookbehind
5121 * was encountered.
5122 */
5123 static Node lookbehindEnd = new Node() {
5124 boolean match(Matcher matcher, int i, CharSequence seq) {
5125 return i == matcher.lookbehindTo;
5126 }
5127 };
5128
5129 /**
5130 * Zero width positive lookbehind.
5131 */
5132 static class Behind extends Node {
5133 Node cond;
5134 int rmax, rmin;
5135 Behind(Node cond, int rmax, int rmin) {
5136 this.cond = cond;
5137 this.rmax = rmax;
5138 this.rmin = rmin;
5139 }
5140
5141 boolean match(Matcher matcher, int i, CharSequence seq) {
5142 int savedFrom = matcher.from;
5143 boolean conditionMatched = false;
5144 int startIndex = (!matcher.transparentBounds) ?
5145 matcher.from : 0;
5146 int from = Math.max(i - rmax, startIndex);
5147 // Set end boundary
5148 int savedLBT = matcher.lookbehindTo;
5149 matcher.lookbehindTo = i;
5150 // Relax transparent region boundaries for lookbehind
5151 if (matcher.transparentBounds)
5152 matcher.from = 0;
5153 for (int j = i - rmin; !conditionMatched && j >= from; j--) {
5154 conditionMatched = cond.match(matcher, j, seq);
5155 }
5156 matcher.from = savedFrom;
5157 matcher.lookbehindTo = savedLBT;
5158 return conditionMatched && next.match(matcher, i, seq);
5159 }
5160 }
5161
5162 /**
5163 * Zero width positive lookbehind, including supplementary
5164 * characters or unpaired surrogates.
5165 */
5166 static final class BehindS extends Behind {
5167 BehindS(Node cond, int rmax, int rmin) {
5168 super(cond, rmax, rmin);
5169 }
5170 boolean match(Matcher matcher, int i, CharSequence seq) {
5171 int rmaxChars = countChars(seq, i, -rmax);
5172 int rminChars = countChars(seq, i, -rmin);
5173 int savedFrom = matcher.from;
5174 int startIndex = (!matcher.transparentBounds) ?
5175 matcher.from : 0;
5176 boolean conditionMatched = false;
5177 int from = Math.max(i - rmaxChars, startIndex);
5178 // Set end boundary
5179 int savedLBT = matcher.lookbehindTo;
5180 matcher.lookbehindTo = i;
5181 // Relax transparent region boundaries for lookbehind
5182 if (matcher.transparentBounds)
5183 matcher.from = 0;
5184
5185 for (int j = i - rminChars;
5186 !conditionMatched && j >= from;
5187 j -= j>from ? countChars(seq, j, -1) : 1) {
5188 conditionMatched = cond.match(matcher, j, seq);
5189 }
5190 matcher.from = savedFrom;
5191 matcher.lookbehindTo = savedLBT;
5192 return conditionMatched && next.match(matcher, i, seq);
5193 }
5194 }
5195
5196 /**
5197 * Zero width negative lookbehind.
5198 */
5199 static class NotBehind extends Node {
5200 Node cond;
5201 int rmax, rmin;
5202 NotBehind(Node cond, int rmax, int rmin) {
5203 this.cond = cond;
5204 this.rmax = rmax;
5205 this.rmin = rmin;
5206 }
5207
5208 boolean match(Matcher matcher, int i, CharSequence seq) {
5209 int savedLBT = matcher.lookbehindTo;
5210 int savedFrom = matcher.from;
5211 boolean conditionMatched = false;
5212 int startIndex = (!matcher.transparentBounds) ?
5213 matcher.from : 0;
5214 int from = Math.max(i - rmax, startIndex);
5215 matcher.lookbehindTo = i;
5216 // Relax transparent region boundaries for lookbehind
5217 if (matcher.transparentBounds)
5218 matcher.from = 0;
5219 for (int j = i - rmin; !conditionMatched && j >= from; j--) {
5220 conditionMatched = cond.match(matcher, j, seq);
5221 }
5222 // Reinstate region boundaries
5223 matcher.from = savedFrom;
5224 matcher.lookbehindTo = savedLBT;
5225 return !conditionMatched && next.match(matcher, i, seq);
5226 }
5227 }
5228
5229 /**
5230 * Zero width negative lookbehind, including supplementary
5231 * characters or unpaired surrogates.
5232 */
5233 static final class NotBehindS extends NotBehind {
5234 NotBehindS(Node cond, int rmax, int rmin) {
5235 super(cond, rmax, rmin);
5236 }
5237 boolean match(Matcher matcher, int i, CharSequence seq) {
5238 int rmaxChars = countChars(seq, i, -rmax);
5239 int rminChars = countChars(seq, i, -rmin);
5240 int savedFrom = matcher.from;
5241 int savedLBT = matcher.lookbehindTo;
5242 boolean conditionMatched = false;
5243 int startIndex = (!matcher.transparentBounds) ?
5244 matcher.from : 0;
5245 int from = Math.max(i - rmaxChars, startIndex);
5246 matcher.lookbehindTo = i;
5247 // Relax transparent region boundaries for lookbehind
5248 if (matcher.transparentBounds)
5249 matcher.from = 0;
5250 for (int j = i - rminChars;
5251 !conditionMatched && j >= from;
5252 j -= j>from ? countChars(seq, j, -1) : 1) {
5253 conditionMatched = cond.match(matcher, j, seq);
5254 }
5255 //Reinstate region boundaries
5256 matcher.from = savedFrom;
5257 matcher.lookbehindTo = savedLBT;
5258 return !conditionMatched && next.match(matcher, i, seq);
5259 }
5260 }
5261
5262 /**
5263 * Returns the set union of two CharProperty nodes.
5264 */
5265 private static CharProperty union(final CharProperty lhs,
5266 final CharProperty rhs) {
5267 return new CharProperty() {
5268 boolean isSatisfiedBy(int ch) {
5269 return lhs.isSatisfiedBy(ch) || rhs.isSatisfiedBy(ch);}};
5270 }
5271
5272 /**
5273 * Returns the set intersection of two CharProperty nodes.
5274 */
5275 private static CharProperty intersection(final CharProperty lhs,
5276 final CharProperty rhs) {
5277 return new CharProperty() {
5278 boolean isSatisfiedBy(int ch) {
5279 return lhs.isSatisfiedBy(ch) && rhs.isSatisfiedBy(ch);}};
5280 }
5281
5282 /**
5283 * Returns the set difference of two CharProperty nodes.
5284 */
5285 private static CharProperty setDifference(final CharProperty lhs,
5286 final CharProperty rhs) {
5287 return new CharProperty() {
5288 boolean isSatisfiedBy(int ch) {
5289 return ! rhs.isSatisfiedBy(ch) && lhs.isSatisfiedBy(ch);}};
5290 }
5291
5292 /**
5293 * Handles word boundaries. Includes a field to allow this one class to
5294 * deal with the different types of word boundaries we can match. The word
5295 * characters include underscores, letters, and digits. Non spacing marks
5296 * can are also part of a word if they have a base character, otherwise
5297 * they are ignored for purposes of finding word boundaries.
5298 */
5299 static final class Bound extends Node {
5300 static int LEFT = 0x1;
5301 static int RIGHT= 0x2;
5302 static int BOTH = 0x3;
5303 static int NONE = 0x4;
5304 int type;
5305 boolean useUWORD;
5306 Bound(int n, boolean useUWORD) {
5307 type = n;
5308 this.useUWORD = useUWORD;
5309 }
5310
5311 boolean isWord(int ch) {
5312 return useUWORD ? UnicodeProp.WORD.is(ch)
5313 : (ch == '_' || Character.isLetterOrDigit(ch));
5314 }
5315
5316 int check(Matcher matcher, int i, CharSequence seq) {
5317 int ch;
5318 boolean left = false;
5319 int startIndex = matcher.from;
5320 int endIndex = matcher.to;
5321 if (matcher.transparentBounds) {
5322 startIndex = 0;
5323 endIndex = matcher.getTextLength();
5324 }
5325 if (i > startIndex) {
5326 ch = Character.codePointBefore(seq, i);
5327 left = (isWord(ch) ||
5328 ((Character.getType(ch) == Character.NON_SPACING_MARK)
5329 && hasBaseCharacter(matcher, i-1, seq)));
5330 }
5331 boolean right = false;
5332 if (i < endIndex) {
5333 ch = Character.codePointAt(seq, i);
5334 right = (isWord(ch) ||
5335 ((Character.getType(ch) == Character.NON_SPACING_MARK)
5336 && hasBaseCharacter(matcher, i, seq)));
5337 } else {
5338 // Tried to access char past the end
5339 matcher.hitEnd = true;
5340 // The addition of another char could wreck a boundary
5341 matcher.requireEnd = true;
5342 }
5343 return ((left ^ right) ? (right ? LEFT : RIGHT) : NONE);
5344 }
5345 boolean match(Matcher matcher, int i, CharSequence seq) {
5346 return (check(matcher, i, seq) & type) > 0
5347 && next.match(matcher, i, seq);
5348 }
5349 }
5350
5351 /**
5352 * Non spacing marks only count as word characters in bounds calculations
5353 * if they have a base character.
5354 */
5355 private static boolean hasBaseCharacter(Matcher matcher, int i,
5356 CharSequence seq)
5357 {
5358 int start = (!matcher.transparentBounds) ?
5359 matcher.from : 0;
5360 for (int x=i; x >= start; x--) {
5361 int ch = Character.codePointAt(seq, x);
5362 if (Character.isLetterOrDigit(ch))
5363 return true;
5364 if (Character.getType(ch) == Character.NON_SPACING_MARK)
5365 continue;
5366 return false;
5367 }
5368 return false;
5369 }
5370
5371 /**
5372 * Attempts to match a slice in the input using the Boyer-Moore string
5373 * matching algorithm. The algorithm is based on the idea that the
5374 * pattern can be shifted farther ahead in the search text if it is
5375 * matched right to left.
5376 * <p>
5377 * The pattern is compared to the input one character at a time, from
5378 * the rightmost character in the pattern to the left. If the characters
5379 * all match the pattern has been found. If a character does not match,
5380 * the pattern is shifted right a distance that is the maximum of two
5381 * functions, the bad character shift and the good suffix shift. This
5382 * shift moves the attempted match position through the input more
5383 * quickly than a naive one position at a time check.
5384 * <p>
5385 * The bad character shift is based on the character from the text that
5386 * did not match. If the character does not appear in the pattern, the
5387 * pattern can be shifted completely beyond the bad character. If the
5388 * character does occur in the pattern, the pattern can be shifted to
5389 * line the pattern up with the next occurrence of that character.
5390 * <p>
5391 * The good suffix shift is based on the idea that some subset on the right
5392 * side of the pattern has matched. When a bad character is found, the
5393 * pattern can be shifted right by the pattern length if the subset does
5394 * not occur again in pattern, or by the amount of distance to the
5395 * next occurrence of the subset in the pattern.
5396 *
5397 * Boyer-Moore search methods adapted from code by Amy Yu.
5398 */
5399 static class BnM extends Node {
5400 int[] buffer;
5401 int[] lastOcc;
5402 int[] optoSft;
5403
5404 /**
5405 * Pre calculates arrays needed to generate the bad character
5406 * shift and the good suffix shift. Only the last seven bits
5407 * are used to see if chars match; This keeps the tables small
5408 * and covers the heavily used ASCII range, but occasionally
5409 * results in an aliased match for the bad character shift.
5410 */
5411 static Node optimize(Node node) {
5412 if (!(node instanceof Slice)) {
5413 return node;
5414 }
5415
5416 int[] src = ((Slice) node).buffer;
5417 int patternLength = src.length;
5418 // The BM algorithm requires a bit of overhead;
5419 // If the pattern is short don't use it, since
5420 // a shift larger than the pattern length cannot
5421 // be used anyway.
5422 if (patternLength < 4) {
5423 return node;
5424 }
5425 int i, j, k;
5426 int[] lastOcc = new int[128];
5427 int[] optoSft = new int[patternLength];
5428 // Precalculate part of the bad character shift
5429 // It is a table for where in the pattern each
5430 // lower 7-bit value occurs
5431 for (i = 0; i < patternLength; i++) {
5432 lastOcc[src[i]&0x7F] = i + 1;
5433 }
5434 // Precalculate the good suffix shift
5435 // i is the shift amount being considered
5436 NEXT: for (i = patternLength; i > 0; i--) {
5437 // j is the beginning index of suffix being considered
5438 for (j = patternLength - 1; j >= i; j--) {
5439 // Testing for good suffix
5440 if (src[j] == src[j-i]) {
5441 // src[j..len] is a good suffix
5442 optoSft[j-1] = i;
5443 } else {
5444 // No match. The array has already been
5445 // filled up with correct values before.
5446 continue NEXT;
5447 }
5448 }
5449 // This fills up the remaining of optoSft
5450 // any suffix can not have larger shift amount
5451 // then its sub-suffix. Why???
5452 while (j > 0) {
5453 optoSft[--j] = i;
5454 }
5455 }
5456 // Set the guard value because of unicode compression
5457 optoSft[patternLength-1] = 1;
5458 if (node instanceof SliceS)
5459 return new BnMS(src, lastOcc, optoSft, node.next);
5460 return new BnM(src, lastOcc, optoSft, node.next);
5461 }
5462 BnM(int[] src, int[] lastOcc, int[] optoSft, Node next) {
5463 this.buffer = src;
5464 this.lastOcc = lastOcc;
5465 this.optoSft = optoSft;
5466 this.next = next;
5467 }
5468 boolean match(Matcher matcher, int i, CharSequence seq) {
5469 int[] src = buffer;
5470 int patternLength = src.length;
5471 int last = matcher.to - patternLength;
5472
5473 // Loop over all possible match positions in text
5474 NEXT: while (i <= last) {
5475 // Loop over pattern from right to left
5476 for (int j = patternLength - 1; j >= 0; j--) {
5477 int ch = seq.charAt(i+j);
5478 if (ch != src[j]) {
5479 // Shift search to the right by the maximum of the
5480 // bad character shift and the good suffix shift
5481 i += Math.max(j + 1 - lastOcc[ch&0x7F], optoSft[j]);
5482 continue NEXT;
5483 }
5484 }
5485 // Entire pattern matched starting at i
5486 matcher.first = i;
5487 boolean ret = next.match(matcher, i + patternLength, seq);
5488 if (ret) {
5489 matcher.first = i;
5490 matcher.groups[0] = matcher.first;
5491 matcher.groups[1] = matcher.last;
5492 return true;
5493 }
5494 i++;
5495 }
5496 // BnM is only used as the leading node in the unanchored case,
5497 // and it replaced its Start() which always searches to the end
5498 // if it doesn't find what it's looking for, so hitEnd is true.
5499 matcher.hitEnd = true;
5500 return false;
5501 }
5502 boolean study(TreeInfo info) {
5503 info.minLength += buffer.length;
5504 info.maxValid = false;
5505 return next.study(info);
5506 }
5507 }
5508
5509 /**
5510 * Supplementary support version of BnM(). Unpaired surrogates are
5511 * also handled by this class.
5512 */
5513 static final class BnMS extends BnM {
5514 int lengthInChars;
5515
5516 BnMS(int[] src, int[] lastOcc, int[] optoSft, Node next) {
5517 super(src, lastOcc, optoSft, next);
5518 for (int cp : buffer) {
5519 lengthInChars += Character.charCount(cp);
5520 }
5521 }
5522 boolean match(Matcher matcher, int i, CharSequence seq) {
5523 int[] src = buffer;
5524 int patternLength = src.length;
5525 int last = matcher.to - lengthInChars;
5526
5527 // Loop over all possible match positions in text
5528 NEXT: while (i <= last) {
5529 // Loop over pattern from right to left
5530 int ch;
5531 for (int j = countChars(seq, i, patternLength), x = patternLength - 1;
5532 j > 0; j -= Character.charCount(ch), x--) {
5533 ch = Character.codePointBefore(seq, i+j);
5534 if (ch != src[x]) {
5535 // Shift search to the right by the maximum of the
5536 // bad character shift and the good suffix shift
5537 int n = Math.max(x + 1 - lastOcc[ch&0x7F], optoSft[x]);
5538 i += countChars(seq, i, n);
5539 continue NEXT;
5540 }
5541 }
5542 // Entire pattern matched starting at i
5543 matcher.first = i;
5544 boolean ret = next.match(matcher, i + lengthInChars, seq);
5545 if (ret) {
5546 matcher.first = i;
5547 matcher.groups[0] = matcher.first;
5548 matcher.groups[1] = matcher.last;
5549 return true;
5550 }
5551 i += countChars(seq, i, 1);
5552 }
5553 matcher.hitEnd = true;
5554 return false;
5555 }
5556 }
5557
5558 ///////////////////////////////////////////////////////////////////////////////
5559 ///////////////////////////////////////////////////////////////////////////////
5560
5561 /**
5562 * This must be the very first initializer.
5563 */
5564 static Node accept = new Node();
5565
5566 static Node lastAccept = new LastNode();
5567
5568 private static class CharPropertyNames {
5569
5570 static CharProperty charPropertyFor(String name) {
5571 CharPropertyFactory m = map.get(name);
5572 return m == null ? null : m.make();
5573 }
5574
5575 private static abstract class CharPropertyFactory {
5576 abstract CharProperty make();
5577 }
5578
5579 private static void defCategory(String name,
5580 final int typeMask) {
5581 map.put(name, new CharPropertyFactory() {
5582 CharProperty make() { return new Category(typeMask);}});
5583 }
5584
5585 private static void defRange(String name,
5586 final int lower, final int upper) {
5587 map.put(name, new CharPropertyFactory() {
5588 CharProperty make() { return rangeFor(lower, upper);}});
5589 }
5590
5591 private static void defCtype(String name,
5592 final int ctype) {
5593 map.put(name, new CharPropertyFactory() {
5594 CharProperty make() { return new Ctype(ctype);}});
5595 }
5596
5597 private static abstract class CloneableProperty
5598 extends CharProperty implements Cloneable
5599 {
5600 public CloneableProperty clone() {
5601 try {
5602 return (CloneableProperty) super.clone();
5603 } catch (CloneNotSupportedException e) {
5604 throw new AssertionError(e);
5605 }
5606 }
5607 }
5608
5609 private static void defClone(String name,
5610 final CloneableProperty p) {
5611 map.put(name, new CharPropertyFactory() {
5612 CharProperty make() { return p.clone();}});
5613 }
5614
5615 private static final HashMap<String, CharPropertyFactory> map
5616 = new HashMap<>();
5617
5618 static {
5619 // Unicode character property aliases, defined in
5620 // http://www.unicode.org/Public/UNIDATA/PropertyValueAliases.txt
5621 defCategory("Cn", 1<<Character.UNASSIGNED);
5622 defCategory("Lu", 1<<Character.UPPERCASE_LETTER);
5623 defCategory("Ll", 1<<Character.LOWERCASE_LETTER);
5624 defCategory("Lt", 1<<Character.TITLECASE_LETTER);
5625 defCategory("Lm", 1<<Character.MODIFIER_LETTER);
5626 defCategory("Lo", 1<<Character.OTHER_LETTER);
5627 defCategory("Mn", 1<<Character.NON_SPACING_MARK);
5628 defCategory("Me", 1<<Character.ENCLOSING_MARK);
5629 defCategory("Mc", 1<<Character.COMBINING_SPACING_MARK);
5630 defCategory("Nd", 1<<Character.DECIMAL_DIGIT_NUMBER);
5631 defCategory("Nl", 1<<Character.LETTER_NUMBER);
5632 defCategory("No", 1<<Character.OTHER_NUMBER);
5633 defCategory("Zs", 1<<Character.SPACE_SEPARATOR);
5634 defCategory("Zl", 1<<Character.LINE_SEPARATOR);
5635 defCategory("Zp", 1<<Character.PARAGRAPH_SEPARATOR);
5636 defCategory("Cc", 1<<Character.CONTROL);
5637 defCategory("Cf", 1<<Character.FORMAT);
5638 defCategory("Co", 1<<Character.PRIVATE_USE);
5639 defCategory("Cs", 1<<Character.SURROGATE);
5640 defCategory("Pd", 1<<Character.DASH_PUNCTUATION);
5641 defCategory("Ps", 1<<Character.START_PUNCTUATION);
5642 defCategory("Pe", 1<<Character.END_PUNCTUATION);
5643 defCategory("Pc", 1<<Character.CONNECTOR_PUNCTUATION);
5644 defCategory("Po", 1<<Character.OTHER_PUNCTUATION);
5645 defCategory("Sm", 1<<Character.MATH_SYMBOL);
5646 defCategory("Sc", 1<<Character.CURRENCY_SYMBOL);
5647 defCategory("Sk", 1<<Character.MODIFIER_SYMBOL);
5648 defCategory("So", 1<<Character.OTHER_SYMBOL);
5649 defCategory("Pi", 1<<Character.INITIAL_QUOTE_PUNCTUATION);
5650 defCategory("Pf", 1<<Character.FINAL_QUOTE_PUNCTUATION);
5651 defCategory("L", ((1<<Character.UPPERCASE_LETTER) |
5652 (1<<Character.LOWERCASE_LETTER) |
5653 (1<<Character.TITLECASE_LETTER) |
5654 (1<<Character.MODIFIER_LETTER) |
5655 (1<<Character.OTHER_LETTER)));
5656 defCategory("M", ((1<<Character.NON_SPACING_MARK) |
5657 (1<<Character.ENCLOSING_MARK) |
5658 (1<<Character.COMBINING_SPACING_MARK)));
5659 defCategory("N", ((1<<Character.DECIMAL_DIGIT_NUMBER) |
5660 (1<<Character.LETTER_NUMBER) |
5661 (1<<Character.OTHER_NUMBER)));
5662 defCategory("Z", ((1<<Character.SPACE_SEPARATOR) |
5663 (1<<Character.LINE_SEPARATOR) |
5664 (1<<Character.PARAGRAPH_SEPARATOR)));
5665 defCategory("C", ((1<<Character.CONTROL) |
5666 (1<<Character.FORMAT) |
5667 (1<<Character.PRIVATE_USE) |
5668 (1<<Character.SURROGATE))); // Other
5669 defCategory("P", ((1<<Character.DASH_PUNCTUATION) |
5670 (1<<Character.START_PUNCTUATION) |
5671 (1<<Character.END_PUNCTUATION) |
5672 (1<<Character.CONNECTOR_PUNCTUATION) |
5673 (1<<Character.OTHER_PUNCTUATION) |
5674 (1<<Character.INITIAL_QUOTE_PUNCTUATION) |
5675 (1<<Character.FINAL_QUOTE_PUNCTUATION)));
5676 defCategory("S", ((1<<Character.MATH_SYMBOL) |
5677 (1<<Character.CURRENCY_SYMBOL) |
5678 (1<<Character.MODIFIER_SYMBOL) |
5679 (1<<Character.OTHER_SYMBOL)));
5680 defCategory("LC", ((1<<Character.UPPERCASE_LETTER) |
5681 (1<<Character.LOWERCASE_LETTER) |
5682 (1<<Character.TITLECASE_LETTER)));
5683 defCategory("LD", ((1<<Character.UPPERCASE_LETTER) |
5684 (1<<Character.LOWERCASE_LETTER) |
5685 (1<<Character.TITLECASE_LETTER) |
5686 (1<<Character.MODIFIER_LETTER) |
5687 (1<<Character.OTHER_LETTER) |
5688 (1<<Character.DECIMAL_DIGIT_NUMBER)));
5689 defRange("L1", 0x00, 0xFF); // Latin-1
5690 map.put("all", new CharPropertyFactory() {
5691 CharProperty make() { return new All(); }});
5692
5693 // Posix regular expression character classes, defined in
5694 // http://www.unix.org/onlinepubs/009695399/basedefs/xbd_chap09.html
5695 defRange("ASCII", 0x00, 0x7F); // ASCII
5696 defCtype("Alnum", ASCII.ALNUM); // Alphanumeric characters
5697 defCtype("Alpha", ASCII.ALPHA); // Alphabetic characters
5698 defCtype("Blank", ASCII.BLANK); // Space and tab characters
5699 defCtype("Cntrl", ASCII.CNTRL); // Control characters
5700 defRange("Digit", '0', '9'); // Numeric characters
5701 defCtype("Graph", ASCII.GRAPH); // printable and visible
5702 defRange("Lower", 'a', 'z'); // Lower-case alphabetic
5703 defRange("Print", 0x20, 0x7E); // Printable characters
5704 defCtype("Punct", ASCII.PUNCT); // Punctuation characters
5705 defCtype("Space", ASCII.SPACE); // Space characters
5706 defRange("Upper", 'A', 'Z'); // Upper-case alphabetic
5707 defCtype("XDigit",ASCII.XDIGIT); // hexadecimal digits
5708
5709 // Java character properties, defined by methods in Character.java
5710 defClone("javaLowerCase", new CloneableProperty() {
5711 boolean isSatisfiedBy(int ch) {
5712 return Character.isLowerCase(ch);}});
5713 defClone("javaUpperCase", new CloneableProperty() {
5714 boolean isSatisfiedBy(int ch) {
5715 return Character.isUpperCase(ch);}});
5716 defClone("javaAlphabetic", new CloneableProperty() {
5717 boolean isSatisfiedBy(int ch) {
5718 return Character.isAlphabetic(ch);}});
5719 defClone("javaIdeographic", new CloneableProperty() {
5720 boolean isSatisfiedBy(int ch) {
5721 return Character.isIdeographic(ch);}});
5722 defClone("javaTitleCase", new CloneableProperty() {
5723 boolean isSatisfiedBy(int ch) {
5724 return Character.isTitleCase(ch);}});
5725 defClone("javaDigit", new CloneableProperty() {
5726 boolean isSatisfiedBy(int ch) {
5727 return Character.isDigit(ch);}});
5728 defClone("javaDefined", new CloneableProperty() {
5729 boolean isSatisfiedBy(int ch) {
5730 return Character.isDefined(ch);}});
5731 defClone("javaLetter", new CloneableProperty() {
5732 boolean isSatisfiedBy(int ch) {
5733 return Character.isLetter(ch);}});
5734 defClone("javaLetterOrDigit", new CloneableProperty() {
5735 boolean isSatisfiedBy(int ch) {
5736 return Character.isLetterOrDigit(ch);}});
5737 defClone("javaJavaIdentifierStart", new CloneableProperty() {
5738 boolean isSatisfiedBy(int ch) {
5739 return Character.isJavaIdentifierStart(ch);}});
5740 defClone("javaJavaIdentifierPart", new CloneableProperty() {
5741 boolean isSatisfiedBy(int ch) {
5742 return Character.isJavaIdentifierPart(ch);}});
5743 defClone("javaUnicodeIdentifierStart", new CloneableProperty() {
5744 boolean isSatisfiedBy(int ch) {
5745 return Character.isUnicodeIdentifierStart(ch);}});
5746 defClone("javaUnicodeIdentifierPart", new CloneableProperty() {
5747 boolean isSatisfiedBy(int ch) {
5748 return Character.isUnicodeIdentifierPart(ch);}});
5749 defClone("javaIdentifierIgnorable", new CloneableProperty() {
5750 boolean isSatisfiedBy(int ch) {
5751 return Character.isIdentifierIgnorable(ch);}});
5752 defClone("javaSpaceChar", new CloneableProperty() {
5753 boolean isSatisfiedBy(int ch) {
5754 return Character.isSpaceChar(ch);}});
5755 defClone("javaWhitespace", new CloneableProperty() {
5756 boolean isSatisfiedBy(int ch) {
5757 return Character.isWhitespace(ch);}});
5758 defClone("javaISOControl", new CloneableProperty() {
5759 boolean isSatisfiedBy(int ch) {
5760 return Character.isISOControl(ch);}});
5761 defClone("javaMirrored", new CloneableProperty() {
5762 boolean isSatisfiedBy(int ch) {
5763 return Character.isMirrored(ch);}});
5764 }
5765 }
5766
5767 /**
5768 * Creates a predicate which can be used to match a string.
5769 *
5770 * @return The predicate which can be used for matching on a string
5771 * @since 1.8
5772 */
5773 public Predicate<String> asPredicate() {
5774 return s -> matcher(s).find();
5775 }
5776
5777 /**
5778 * Creates a stream from the given input sequence around matches of this
5779 * pattern.
5780 *
5781 * <p> The stream returned by this method contains each substring of the
5782 * input sequence that is terminated by another subsequence that matches
5783 * this pattern or is terminated by the end of the input sequence. The
5784 * substrings in the stream are in the order in which they occur in the
5785 * input. Trailing empty strings will be discarded and not encountered in
5786 * the stream.
5787 *
5788 * <p> If this pattern does not match any subsequence of the input then
5789 * the resulting stream has just one element, namely the input sequence in
5790 * string form.
5791 *
5792 * <p> When there is a positive-width match at the beginning of the input
5793 * sequence then an empty leading substring is included at the beginning
5794 * of the stream. A zero-width match at the beginning however never produces
5795 * such empty leading substring.
5796 *
5797 * <p> If the input sequence is mutable, it must remain constant during the
5798 * execution of the terminal stream operation. Otherwise, the result of the
5799 * terminal stream operation is undefined.
5800 *
5801 * @param input
5802 * The character sequence to be split
5803 *
5804 * @return The stream of strings computed by splitting the input
5805 * around matches of this pattern
5806 * @see #split(CharSequence)
5807 * @since 1.8
5808 */
5809 public Stream<String> splitAsStream(final CharSequence input) {
5810 class MatcherIterator implements Iterator<String> {
5811 private final Matcher matcher;
5812 // The start position of the next sub-sequence of input
5813 // when current == input.length there are no more elements
5814 private int current;
5815 // null if the next element, if any, needs to obtained
5816 private String nextElement;
5817 // > 0 if there are N next empty elements
5818 private int emptyElementCount;
5819
5820 MatcherIterator() {
5821 this.matcher = matcher(input);
5822 }
5823
5824 public String next() {
5825 if (!hasNext())
5826 throw new NoSuchElementException();
5827
5828 if (emptyElementCount == 0) {
5829 String n = nextElement;
5830 nextElement = null;
5831 return n;
5832 } else {
5833 emptyElementCount--;
5834 return "";
5835 }
5836 }
5837
5838 public boolean hasNext() {
5839 if (nextElement != null || emptyElementCount > 0)
5840 return true;
5841
5842 if (current == input.length())
5843 return false;
5844
5845 // Consume the next matching element
5846 // Count sequence of matching empty elements
5847 while (matcher.find()) {
5848 nextElement = input.subSequence(current, matcher.start()).toString();
5849 current = matcher.end();
5850 if (!nextElement.isEmpty()) {
5851 return true;
5852 } else if (current > 0) { // no empty leading substring for zero-width
5853 // match at the beginning of the input
5854 emptyElementCount++;
5855 }
5856 }
5857
5858 // Consume last matching element
5859 nextElement = input.subSequence(current, input.length()).toString();
5860 current = input.length();
5861 if (!nextElement.isEmpty()) {
5862 return true;
5863 } else {
5864 // Ignore a terminal sequence of matching empty elements
5865 emptyElementCount = 0;
5866 nextElement = null;
5867 return false;
5868 }
5869 }
5870 }
5871 return StreamSupport.stream(Spliterators.spliteratorUnknownSize(
5872 new MatcherIterator(), Spliterator.ORDERED | Spliterator.NONNULL), false);
5873 }
5874 }