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 int lenHint = s.length();
1303 lenHint = (lenHint < Integer.MAX_VALUE - 8 - lenHint) ?
1304 (lenHint << 1) : (Integer.MAX_VALUE - 8);
1305
1306 StringBuilder sb = new StringBuilder(lenHint);
1307 sb.append("\\Q");
1308 int current = 0;
1309 do {
1310 sb.append(s, current, slashEIndex)
1311 .append("\\E\\\\E\\Q");
1312 current = slashEIndex + 2;
1313 } while ((slashEIndex = s.indexOf("\\E", current)) != -1);
1314
1315 return sb.append(s, current, s.length())
1316 .append("\\E")
1317 .toString();
1318 }
1319
1320 /**
1321 * Recompile the Pattern instance from a stream. The original pattern
1322 * string is read in and the object tree is recompiled from it.
1323 */
1324 private void readObject(java.io.ObjectInputStream s)
1325 throws java.io.IOException, ClassNotFoundException {
1326
1327 // Read in all fields
1328 s.defaultReadObject();
1329
1330 // Initialize counts
1331 capturingGroupCount = 1;
1332 localCount = 0;
1333
1334 // if length > 0, the Pattern is lazily compiled
1335 compiled = false;
1336 if (pattern.length() == 0) {
1337 root = new Start(lastAccept);
1338 matchRoot = lastAccept;
1339 compiled = true;
1340 }
1341 }
1342
1343 /**
1344 * This private constructor is used to create all Patterns. The pattern
1345 * string and match flags are all that is needed to completely describe
1346 * a Pattern. An empty pattern string results in an object tree with
1347 * only a Start node and a LastNode node.
1348 */
1349 private Pattern(String p, int f) {
1350 if ((f & ~ALL_FLAGS) != 0) {
1351 throw new IllegalArgumentException("Unknown flag 0x"
1352 + Integer.toHexString(f));
1353 }
1354 pattern = p;
1355 flags = f;
1356
1357 // to use UNICODE_CASE if UNICODE_CHARACTER_CLASS present
1358 if ((flags & UNICODE_CHARACTER_CLASS) != 0)
1359 flags |= UNICODE_CASE;
1360
1361 // Reset group index count
1362 capturingGroupCount = 1;
1363 localCount = 0;
1364
1365 if (pattern.length() > 0) {
1366 compile();
1367 } else {
1368 root = new Start(lastAccept);
1369 matchRoot = lastAccept;
1370 }
1371 }
1372
1373 /**
1374 * The pattern is converted to normalized form and then a pure group
1375 * is constructed to match canonical equivalences of the characters.
1376 */
1377 private void normalize() {
1378 boolean inCharClass = false;
1379 int lastCodePoint = -1;
1380
1381 // Convert pattern into normalized form
1382 normalizedPattern = Normalizer.normalize(pattern, Normalizer.Form.NFD);
1383 patternLength = normalizedPattern.length();
1384
1385 // Modify pattern to match canonical equivalences
1386 StringBuilder newPattern = new StringBuilder(patternLength);
1387 for(int i=0; i<patternLength; ) {
1388 int c = normalizedPattern.codePointAt(i);
1389 StringBuilder sequenceBuffer;
1390 if ((Character.getType(c) == Character.NON_SPACING_MARK)
1391 && (lastCodePoint != -1)) {
1392 sequenceBuffer = new StringBuilder();
1393 sequenceBuffer.appendCodePoint(lastCodePoint);
1394 sequenceBuffer.appendCodePoint(c);
1395 while(Character.getType(c) == Character.NON_SPACING_MARK) {
1396 i += Character.charCount(c);
1397 if (i >= patternLength)
1398 break;
1399 c = normalizedPattern.codePointAt(i);
1400 sequenceBuffer.appendCodePoint(c);
1401 }
1402 String ea = produceEquivalentAlternation(
1403 sequenceBuffer.toString());
1404 newPattern.setLength(newPattern.length()-Character.charCount(lastCodePoint));
1405 newPattern.append("(?:").append(ea).append(")");
1406 } else if (c == '[' && lastCodePoint != '\\') {
1407 i = normalizeCharClass(newPattern, i);
1408 } else {
1409 newPattern.appendCodePoint(c);
1410 }
1411 lastCodePoint = c;
1412 i += Character.charCount(c);
1413 }
1414 normalizedPattern = newPattern.toString();
1415 }
1416
1417 /**
1418 * Complete the character class being parsed and add a set
1419 * of alternations to it that will match the canonical equivalences
1420 * of the characters within the class.
1421 */
1422 private int normalizeCharClass(StringBuilder newPattern, int i) {
1423 StringBuilder charClass = new StringBuilder();
1424 StringBuilder eq = null;
1425 int lastCodePoint = -1;
1426 String result;
1427
1428 i++;
1429 charClass.append("[");
1430 while(true) {
1431 int c = normalizedPattern.codePointAt(i);
1432 StringBuilder sequenceBuffer;
1433
1434 if (c == ']' && lastCodePoint != '\\') {
1435 charClass.append((char)c);
1436 break;
1437 } else if (Character.getType(c) == Character.NON_SPACING_MARK) {
1438 sequenceBuffer = new StringBuilder();
1439 sequenceBuffer.appendCodePoint(lastCodePoint);
1440 while(Character.getType(c) == Character.NON_SPACING_MARK) {
1441 sequenceBuffer.appendCodePoint(c);
1442 i += Character.charCount(c);
1443 if (i >= normalizedPattern.length())
1444 break;
1445 c = normalizedPattern.codePointAt(i);
1446 }
1447 String ea = produceEquivalentAlternation(
1448 sequenceBuffer.toString());
1449
1450 charClass.setLength(charClass.length()-Character.charCount(lastCodePoint));
1451 if (eq == null)
1452 eq = new StringBuilder();
1453 eq.append('|');
1454 eq.append(ea);
1455 } else {
1456 charClass.appendCodePoint(c);
1457 i++;
1458 }
1459 if (i == normalizedPattern.length())
1460 throw error("Unclosed character class");
1461 lastCodePoint = c;
1462 }
1463
1464 if (eq != null) {
1465 result = "(?:"+charClass.toString()+eq.toString()+")";
1466 } else {
1467 result = charClass.toString();
1468 }
1469
1470 newPattern.append(result);
1471 return i;
1472 }
1473
1474 /**
1475 * Given a specific sequence composed of a regular character and
1476 * combining marks that follow it, produce the alternation that will
1477 * match all canonical equivalences of that sequence.
1478 */
1479 private String produceEquivalentAlternation(String source) {
1480 int len = countChars(source, 0, 1);
1481 if (source.length() == len)
1482 // source has one character.
1483 return source;
1484
1485 String base = source.substring(0,len);
1486 String combiningMarks = source.substring(len);
1487
1488 String[] perms = producePermutations(combiningMarks);
1489 StringBuilder result = new StringBuilder(source);
1490
1491 // Add combined permutations
1492 for(int x=0; x<perms.length; x++) {
1493 String next = base + perms[x];
1494 if (x>0)
1495 result.append("|"+next);
1496 next = composeOneStep(next);
1497 if (next != null)
1498 result.append("|"+produceEquivalentAlternation(next));
1499 }
1500 return result.toString();
1501 }
1502
1503 /**
1504 * Returns an array of strings that have all the possible
1505 * permutations of the characters in the input string.
1506 * This is used to get a list of all possible orderings
1507 * of a set of combining marks. Note that some of the permutations
1508 * are invalid because of combining class collisions, and these
1509 * possibilities must be removed because they are not canonically
1510 * equivalent.
1511 */
1512 private String[] producePermutations(String input) {
1513 if (input.length() == countChars(input, 0, 1))
1514 return new String[] {input};
1515
1516 if (input.length() == countChars(input, 0, 2)) {
1517 int c0 = Character.codePointAt(input, 0);
1518 int c1 = Character.codePointAt(input, Character.charCount(c0));
1519 if (getClass(c1) == getClass(c0)) {
1520 return new String[] {input};
1521 }
1522 String[] result = new String[2];
1523 result[0] = input;
1524 StringBuilder sb = new StringBuilder(2);
1525 sb.appendCodePoint(c1);
1526 sb.appendCodePoint(c0);
1527 result[1] = sb.toString();
1528 return result;
1529 }
1530
1531 int length = 1;
1532 int nCodePoints = countCodePoints(input);
1533 for(int x=1; x<nCodePoints; x++)
1534 length = length * (x+1);
1535
1536 String[] temp = new String[length];
1537
1538 int combClass[] = new int[nCodePoints];
1539 for(int x=0, i=0; x<nCodePoints; x++) {
1540 int c = Character.codePointAt(input, i);
1541 combClass[x] = getClass(c);
1542 i += Character.charCount(c);
1543 }
1544
1545 // For each char, take it out and add the permutations
1546 // of the remaining chars
1547 int index = 0;
1548 int len;
1549 // offset maintains the index in code units.
1550 loop: for(int x=0, offset=0; x<nCodePoints; x++, offset+=len) {
1551 len = countChars(input, offset, 1);
1552 boolean skip = false;
1553 for(int y=x-1; y>=0; y--) {
1554 if (combClass[y] == combClass[x]) {
1555 continue loop;
1556 }
1557 }
1558 StringBuilder sb = new StringBuilder(input);
1559 String otherChars = sb.delete(offset, offset+len).toString();
1560 String[] subResult = producePermutations(otherChars);
1561
1562 String prefix = input.substring(offset, offset+len);
1563 for (String sre : subResult)
1564 temp[index++] = prefix + sre;
1565 }
1566 String[] result = new String[index];
1567 for (int x=0; x<index; x++)
1568 result[x] = temp[x];
1569 return result;
1570 }
1571
1572 private int getClass(int c) {
1573 return sun.text.Normalizer.getCombiningClass(c);
1574 }
1575
1576 /**
1577 * Attempts to compose input by combining the first character
1578 * with the first combining mark following it. Returns a String
1579 * that is the composition of the leading character with its first
1580 * combining mark followed by the remaining combining marks. Returns
1581 * null if the first two characters cannot be further composed.
1582 */
1583 private String composeOneStep(String input) {
1584 int len = countChars(input, 0, 2);
1585 String firstTwoCharacters = input.substring(0, len);
1586 String result = Normalizer.normalize(firstTwoCharacters, Normalizer.Form.NFC);
1587
1588 if (result.equals(firstTwoCharacters))
1589 return null;
1590 else {
1591 String remainder = input.substring(len);
1592 return result + remainder;
1593 }
1594 }
1595
1596 /**
1597 * Preprocess any \Q...\E sequences in `temp', meta-quoting them.
1598 * See the description of `quotemeta' in perlfunc(1).
1599 */
1600 private void RemoveQEQuoting() {
1601 final int pLen = patternLength;
1602 int i = 0;
1603 while (i < pLen-1) {
1604 if (temp[i] != '\\')
1605 i += 1;
1606 else if (temp[i + 1] != 'Q')
1607 i += 2;
1608 else
1609 break;
1610 }
1611 if (i >= pLen - 1) // No \Q sequence found
1612 return;
1613 int j = i;
1614 i += 2;
1615 int[] newtemp = new int[j + 3*(pLen-i) + 2];
1616 System.arraycopy(temp, 0, newtemp, 0, j);
1617
1618 boolean inQuote = true;
1619 boolean beginQuote = true;
1620 while (i < pLen) {
1621 int c = temp[i++];
1622 if (!ASCII.isAscii(c) || ASCII.isAlpha(c)) {
1623 newtemp[j++] = c;
1624 } else if (ASCII.isDigit(c)) {
1625 if (beginQuote) {
1626 /*
1627 * A unicode escape \[0xu] could be before this quote,
1628 * and we don't want this numeric char to processed as
1629 * part of the escape.
1630 */
1631 newtemp[j++] = '\\';
1632 newtemp[j++] = 'x';
1633 newtemp[j++] = '3';
1634 }
1635 newtemp[j++] = c;
1636 } else if (c != '\\') {
1637 if (inQuote) newtemp[j++] = '\\';
1638 newtemp[j++] = c;
1639 } else if (inQuote) {
1640 if (temp[i] == 'E') {
1641 i++;
1642 inQuote = false;
1643 } else {
1644 newtemp[j++] = '\\';
1645 newtemp[j++] = '\\';
1646 }
1647 } else {
1648 if (temp[i] == 'Q') {
1649 i++;
1650 inQuote = true;
1651 beginQuote = true;
1652 continue;
1653 } else {
1654 newtemp[j++] = c;
1655 if (i != pLen)
1656 newtemp[j++] = temp[i++];
1657 }
1658 }
1659
1660 beginQuote = false;
1661 }
1662
1663 patternLength = j;
1664 temp = Arrays.copyOf(newtemp, j + 2); // double zero termination
1665 }
1666
1667 /**
1668 * Copies regular expression to an int array and invokes the parsing
1669 * of the expression which will create the object tree.
1670 */
1671 private void compile() {
1672 // Handle canonical equivalences
1673 if (has(CANON_EQ) && !has(LITERAL)) {
1674 normalize();
1675 } else {
1676 normalizedPattern = pattern;
1677 }
1678 patternLength = normalizedPattern.length();
1679
1680 // Copy pattern to int array for convenience
1681 // Use double zero to terminate pattern
1682 temp = new int[patternLength + 2];
1683
1684 hasSupplementary = false;
1685 int c, count = 0;
1686 // Convert all chars into code points
1687 for (int x = 0; x < patternLength; x += Character.charCount(c)) {
1688 c = normalizedPattern.codePointAt(x);
1689 if (isSupplementary(c)) {
1690 hasSupplementary = true;
1691 }
1692 temp[count++] = c;
1693 }
1694
1695 patternLength = count; // patternLength now in code points
1696
1697 if (! has(LITERAL))
1698 RemoveQEQuoting();
1699
1700 // Allocate all temporary objects here.
1701 buffer = new int[32];
1702 groupNodes = new GroupHead[10];
1703 namedGroups = null;
1704
1705 if (has(LITERAL)) {
1706 // Literal pattern handling
1707 matchRoot = newSlice(temp, patternLength, hasSupplementary);
1708 matchRoot.next = lastAccept;
1709 } else {
1710 // Start recursive descent parsing
1711 matchRoot = expr(lastAccept);
1712 // Check extra pattern characters
1713 if (patternLength != cursor) {
1714 if (peek() == ')') {
1715 throw error("Unmatched closing ')'");
1716 } else {
1717 throw error("Unexpected internal error");
1718 }
1719 }
1720 }
1721
1722 // Peephole optimization
1723 if (matchRoot instanceof Slice) {
1724 root = BnM.optimize(matchRoot);
1725 if (root == matchRoot) {
1726 root = hasSupplementary ? new StartS(matchRoot) : new Start(matchRoot);
1727 }
1728 } else if (matchRoot instanceof Begin || matchRoot instanceof First) {
1729 root = matchRoot;
1730 } else {
1731 root = hasSupplementary ? new StartS(matchRoot) : new Start(matchRoot);
1732 }
1733
1734 // Release temporary storage
1735 temp = null;
1736 buffer = null;
1737 groupNodes = null;
1738 patternLength = 0;
1739 compiled = true;
1740 }
1741
1742 Map<String, Integer> namedGroups() {
1743 if (namedGroups == null)
1744 namedGroups = new HashMap<>(2);
1745 return namedGroups;
1746 }
1747
1748 /**
1749 * Used to print out a subtree of the Pattern to help with debugging.
1750 */
1751 private static void printObjectTree(Node node) {
1752 while(node != null) {
1753 if (node instanceof Prolog) {
1754 System.out.println(node);
1755 printObjectTree(((Prolog)node).loop);
1756 System.out.println("**** end contents prolog loop");
1757 } else if (node instanceof Loop) {
1758 System.out.println(node);
1759 printObjectTree(((Loop)node).body);
1760 System.out.println("**** end contents Loop body");
1761 } else if (node instanceof Curly) {
1762 System.out.println(node);
1763 printObjectTree(((Curly)node).atom);
1764 System.out.println("**** end contents Curly body");
1765 } else if (node instanceof GroupCurly) {
1766 System.out.println(node);
1767 printObjectTree(((GroupCurly)node).atom);
1768 System.out.println("**** end contents GroupCurly body");
1769 } else if (node instanceof GroupTail) {
1770 System.out.println(node);
1771 System.out.println("Tail next is "+node.next);
1772 return;
1773 } else {
1774 System.out.println(node);
1775 }
1776 node = node.next;
1777 if (node != null)
1778 System.out.println("->next:");
1779 if (node == Pattern.accept) {
1780 System.out.println("Accept Node");
1781 node = null;
1782 }
1783 }
1784 }
1785
1786 /**
1787 * Used to accumulate information about a subtree of the object graph
1788 * so that optimizations can be applied to the subtree.
1789 */
1790 static final class TreeInfo {
1791 int minLength;
1792 int maxLength;
1793 boolean maxValid;
1794 boolean deterministic;
1795
1796 TreeInfo() {
1797 reset();
1798 }
1799 void reset() {
1800 minLength = 0;
1801 maxLength = 0;
1802 maxValid = true;
1803 deterministic = true;
1804 }
1805 }
1806
1807 /*
1808 * The following private methods are mainly used to improve the
1809 * readability of the code. In order to let the Java compiler easily
1810 * inline them, we should not put many assertions or error checks in them.
1811 */
1812
1813 /**
1814 * Indicates whether a particular flag is set or not.
1815 */
1816 private boolean has(int f) {
1817 return (flags & f) != 0;
1818 }
1819
1820 /**
1821 * Match next character, signal error if failed.
1822 */
1823 private void accept(int ch, String s) {
1824 int testChar = temp[cursor++];
1825 if (has(COMMENTS))
1826 testChar = parsePastWhitespace(testChar);
1827 if (ch != testChar) {
1828 throw error(s);
1829 }
1830 }
1831
1832 /**
1833 * Mark the end of pattern with a specific character.
1834 */
1835 private void mark(int c) {
1836 temp[patternLength] = c;
1837 }
1838
1839 /**
1840 * Peek the next character, and do not advance the cursor.
1841 */
1842 private int peek() {
1843 int ch = temp[cursor];
1844 if (has(COMMENTS))
1845 ch = peekPastWhitespace(ch);
1846 return ch;
1847 }
1848
1849 /**
1850 * Read the next character, and advance the cursor by one.
1851 */
1852 private int read() {
1853 int ch = temp[cursor++];
1854 if (has(COMMENTS))
1855 ch = parsePastWhitespace(ch);
1856 return ch;
1857 }
1858
1859 /**
1860 * Read the next character, and advance the cursor by one,
1861 * ignoring the COMMENTS setting
1862 */
1863 private int readEscaped() {
1864 int ch = temp[cursor++];
1865 return ch;
1866 }
1867
1868 /**
1869 * Advance the cursor by one, and peek the next character.
1870 */
1871 private int next() {
1872 int ch = temp[++cursor];
1873 if (has(COMMENTS))
1874 ch = peekPastWhitespace(ch);
1875 return ch;
1876 }
1877
1878 /**
1879 * Advance the cursor by one, and peek the next character,
1880 * ignoring the COMMENTS setting
1881 */
1882 private int nextEscaped() {
1883 int ch = temp[++cursor];
1884 return ch;
1885 }
1886
1887 /**
1888 * If in xmode peek past whitespace and comments.
1889 */
1890 private int peekPastWhitespace(int ch) {
1891 while (ASCII.isSpace(ch) || ch == '#') {
1892 while (ASCII.isSpace(ch))
1893 ch = temp[++cursor];
1894 if (ch == '#') {
1895 ch = peekPastLine();
1896 }
1897 }
1898 return ch;
1899 }
1900
1901 /**
1902 * If in xmode parse past whitespace and comments.
1903 */
1904 private int parsePastWhitespace(int ch) {
1905 while (ASCII.isSpace(ch) || ch == '#') {
1906 while (ASCII.isSpace(ch))
1907 ch = temp[cursor++];
1908 if (ch == '#')
1909 ch = parsePastLine();
1910 }
1911 return ch;
1912 }
1913
1914 /**
1915 * xmode parse past comment to end of line.
1916 */
1917 private int parsePastLine() {
1918 int ch = temp[cursor++];
1919 while (ch != 0 && !isLineSeparator(ch))
1920 ch = temp[cursor++];
1921 return ch;
1922 }
1923
1924 /**
1925 * xmode peek past comment to end of line.
1926 */
1927 private int peekPastLine() {
1928 int ch = temp[++cursor];
1929 while (ch != 0 && !isLineSeparator(ch))
1930 ch = temp[++cursor];
1931 return ch;
1932 }
1933
1934 /**
1935 * Determines if character is a line separator in the current mode
1936 */
1937 private boolean isLineSeparator(int ch) {
1938 if (has(UNIX_LINES)) {
1939 return ch == '\n';
1940 } else {
1941 return (ch == '\n' ||
1942 ch == '\r' ||
1943 (ch|1) == '\u2029' ||
1944 ch == '\u0085');
1945 }
1946 }
1947
1948 /**
1949 * Read the character after the next one, and advance the cursor by two.
1950 */
1951 private int skip() {
1952 int i = cursor;
1953 int ch = temp[i+1];
1954 cursor = i + 2;
1955 return ch;
1956 }
1957
1958 /**
1959 * Unread one next character, and retreat cursor by one.
1960 */
1961 private void unread() {
1962 cursor--;
1963 }
1964
1965 /**
1966 * Internal method used for handling all syntax errors. The pattern is
1967 * displayed with a pointer to aid in locating the syntax error.
1968 */
1969 private PatternSyntaxException error(String s) {
1970 return new PatternSyntaxException(s, normalizedPattern, cursor - 1);
1971 }
1972
1973 /**
1974 * Determines if there is any supplementary character or unpaired
1975 * surrogate in the specified range.
1976 */
1977 private boolean findSupplementary(int start, int end) {
1978 for (int i = start; i < end; i++) {
1979 if (isSupplementary(temp[i]))
1980 return true;
1981 }
1982 return false;
1983 }
1984
1985 /**
1986 * Determines if the specified code point is a supplementary
1987 * character or unpaired surrogate.
1988 */
1989 private static final boolean isSupplementary(int ch) {
1990 return ch >= Character.MIN_SUPPLEMENTARY_CODE_POINT ||
1991 Character.isSurrogate((char)ch);
1992 }
1993
1994 /**
1995 * The following methods handle the main parsing. They are sorted
1996 * according to their precedence order, the lowest one first.
1997 */
1998
1999 /**
2000 * The expression is parsed with branch nodes added for alternations.
2001 * This may be called recursively to parse sub expressions that may
2002 * contain alternations.
2003 */
2004 private Node expr(Node end) {
2005 Node prev = null;
2006 Node firstTail = null;
2007 Branch branch = null;
2008 Node branchConn = null;
2009
2010 for (;;) {
2011 Node node = sequence(end);
2012 Node nodeTail = root; //double return
2013 if (prev == null) {
2014 prev = node;
2015 firstTail = nodeTail;
2016 } else {
2017 // Branch
2018 if (branchConn == null) {
2019 branchConn = new BranchConn();
2020 branchConn.next = end;
2021 }
2022 if (node == end) {
2023 // if the node returned from sequence() is "end"
2024 // we have an empty expr, set a null atom into
2025 // the branch to indicate to go "next" directly.
2026 node = null;
2027 } else {
2028 // the "tail.next" of each atom goes to branchConn
2029 nodeTail.next = branchConn;
2030 }
2031 if (prev == branch) {
2032 branch.add(node);
2033 } else {
2034 if (prev == end) {
2035 prev = null;
2036 } else {
2037 // replace the "end" with "branchConn" at its tail.next
2038 // when put the "prev" into the branch as the first atom.
2039 firstTail.next = branchConn;
2040 }
2041 prev = branch = new Branch(prev, node, branchConn);
2042 }
2043 }
2044 if (peek() != '|') {
2045 return prev;
2046 }
2047 next();
2048 }
2049 }
2050
2051 @SuppressWarnings("fallthrough")
2052 /**
2053 * Parsing of sequences between alternations.
2054 */
2055 private Node sequence(Node end) {
2056 Node head = null;
2057 Node tail = null;
2058 Node node = null;
2059 LOOP:
2060 for (;;) {
2061 int ch = peek();
2062 switch (ch) {
2063 case '(':
2064 // Because group handles its own closure,
2065 // we need to treat it differently
2066 node = group0();
2067 // Check for comment or flag group
2068 if (node == null)
2069 continue;
2070 if (head == null)
2071 head = node;
2072 else
2073 tail.next = node;
2074 // Double return: Tail was returned in root
2075 tail = root;
2076 continue;
2077 case '[':
2078 node = clazz(true);
2079 break;
2080 case '\\':
2081 ch = nextEscaped();
2082 if (ch == 'p' || ch == 'P') {
2083 boolean oneLetter = true;
2084 boolean comp = (ch == 'P');
2085 ch = next(); // Consume { if present
2086 if (ch != '{') {
2087 unread();
2088 } else {
2089 oneLetter = false;
2090 }
2091 node = family(oneLetter, comp);
2092 } else {
2093 unread();
2094 node = atom();
2095 }
2096 break;
2097 case '^':
2098 next();
2099 if (has(MULTILINE)) {
2100 if (has(UNIX_LINES))
2101 node = new UnixCaret();
2102 else
2103 node = new Caret();
2104 } else {
2105 node = new Begin();
2106 }
2107 break;
2108 case '$':
2109 next();
2110 if (has(UNIX_LINES))
2111 node = new UnixDollar(has(MULTILINE));
2112 else
2113 node = new Dollar(has(MULTILINE));
2114 break;
2115 case '.':
2116 next();
2117 if (has(DOTALL)) {
2118 node = new All();
2119 } else {
2120 if (has(UNIX_LINES))
2121 node = new UnixDot();
2122 else {
2123 node = new Dot();
2124 }
2125 }
2126 break;
2127 case '|':
2128 case ')':
2129 break LOOP;
2130 case ']': // Now interpreting dangling ] and } as literals
2131 case '}':
2132 node = atom();
2133 break;
2134 case '?':
2135 case '*':
2136 case '+':
2137 next();
2138 throw error("Dangling meta character '" + ((char)ch) + "'");
2139 case 0:
2140 if (cursor >= patternLength) {
2141 break LOOP;
2142 }
2143 // Fall through
2144 default:
2145 node = atom();
2146 break;
2147 }
2148
2149 node = closure(node);
2150
2151 if (head == null) {
2152 head = tail = node;
2153 } else {
2154 tail.next = node;
2155 tail = node;
2156 }
2157 }
2158 if (head == null) {
2159 return end;
2160 }
2161 tail.next = end;
2162 root = tail; //double return
2163 return head;
2164 }
2165
2166 @SuppressWarnings("fallthrough")
2167 /**
2168 * Parse and add a new Single or Slice.
2169 */
2170 private Node atom() {
2171 int first = 0;
2172 int prev = -1;
2173 boolean hasSupplementary = false;
2174 int ch = peek();
2175 for (;;) {
2176 switch (ch) {
2177 case '*':
2178 case '+':
2179 case '?':
2180 case '{':
2181 if (first > 1) {
2182 cursor = prev; // Unwind one character
2183 first--;
2184 }
2185 break;
2186 case '$':
2187 case '.':
2188 case '^':
2189 case '(':
2190 case '[':
2191 case '|':
2192 case ')':
2193 break;
2194 case '\\':
2195 ch = nextEscaped();
2196 if (ch == 'p' || ch == 'P') { // Property
2197 if (first > 0) { // Slice is waiting; handle it first
2198 unread();
2199 break;
2200 } else { // No slice; just return the family node
2201 boolean comp = (ch == 'P');
2202 boolean oneLetter = true;
2203 ch = next(); // Consume { if present
2204 if (ch != '{')
2205 unread();
2206 else
2207 oneLetter = false;
2208 return family(oneLetter, comp);
2209 }
2210 }
2211 unread();
2212 prev = cursor;
2213 ch = escape(false, first == 0, false);
2214 if (ch >= 0) {
2215 append(ch, first);
2216 first++;
2217 if (isSupplementary(ch)) {
2218 hasSupplementary = true;
2219 }
2220 ch = peek();
2221 continue;
2222 } else if (first == 0) {
2223 return root;
2224 }
2225 // Unwind meta escape sequence
2226 cursor = prev;
2227 break;
2228 case 0:
2229 if (cursor >= patternLength) {
2230 break;
2231 }
2232 // Fall through
2233 default:
2234 prev = cursor;
2235 append(ch, first);
2236 first++;
2237 if (isSupplementary(ch)) {
2238 hasSupplementary = true;
2239 }
2240 ch = next();
2241 continue;
2242 }
2243 break;
2244 }
2245 if (first == 1) {
2246 return newSingle(buffer[0]);
2247 } else {
2248 return newSlice(buffer, first, hasSupplementary);
2249 }
2250 }
2251
2252 private void append(int ch, int len) {
2253 if (len >= buffer.length) {
2254 int[] tmp = new int[len+len];
2255 System.arraycopy(buffer, 0, tmp, 0, len);
2256 buffer = tmp;
2257 }
2258 buffer[len] = ch;
2259 }
2260
2261 /**
2262 * Parses a backref greedily, taking as many numbers as it
2263 * can. The first digit is always treated as a backref, but
2264 * multi digit numbers are only treated as a backref if at
2265 * least that many backrefs exist at this point in the regex.
2266 */
2267 private Node ref(int refNum) {
2268 boolean done = false;
2269 while(!done) {
2270 int ch = peek();
2271 switch(ch) {
2272 case '0':
2273 case '1':
2274 case '2':
2275 case '3':
2276 case '4':
2277 case '5':
2278 case '6':
2279 case '7':
2280 case '8':
2281 case '9':
2282 int newRefNum = (refNum * 10) + (ch - '0');
2283 // Add another number if it doesn't make a group
2284 // that doesn't exist
2285 if (capturingGroupCount - 1 < newRefNum) {
2286 done = true;
2287 break;
2288 }
2289 refNum = newRefNum;
2290 read();
2291 break;
2292 default:
2293 done = true;
2294 break;
2295 }
2296 }
2297 if (has(CASE_INSENSITIVE))
2298 return new CIBackRef(refNum, has(UNICODE_CASE));
2299 else
2300 return new BackRef(refNum);
2301 }
2302
2303 /**
2304 * Parses an escape sequence to determine the actual value that needs
2305 * to be matched.
2306 * If -1 is returned and create was true a new object was added to the tree
2307 * to handle the escape sequence.
2308 * If the returned value is greater than zero, it is the value that
2309 * matches the escape sequence.
2310 */
2311 private int escape(boolean inclass, boolean create, boolean isrange) {
2312 int ch = skip();
2313 switch (ch) {
2314 case '0':
2315 return o();
2316 case '1':
2317 case '2':
2318 case '3':
2319 case '4':
2320 case '5':
2321 case '6':
2322 case '7':
2323 case '8':
2324 case '9':
2325 if (inclass) break;
2326 if (create) {
2327 root = ref((ch - '0'));
2328 }
2329 return -1;
2330 case 'A':
2331 if (inclass) break;
2332 if (create) root = new Begin();
2333 return -1;
2334 case 'B':
2335 if (inclass) break;
2336 if (create) root = new Bound(Bound.NONE, has(UNICODE_CHARACTER_CLASS));
2337 return -1;
2338 case 'C':
2339 break;
2340 case 'D':
2341 if (create) root = has(UNICODE_CHARACTER_CLASS)
2342 ? new Utype(UnicodeProp.DIGIT).complement()
2343 : new Ctype(ASCII.DIGIT).complement();
2344 return -1;
2345 case 'E':
2346 case 'F':
2347 break;
2348 case 'G':
2349 if (inclass) break;
2350 if (create) root = new LastMatch();
2351 return -1;
2352 case 'H':
2353 if (create) root = new HorizWS().complement();
2354 return -1;
2355 case 'I':
2356 case 'J':
2357 case 'K':
2358 case 'L':
2359 case 'M':
2360 case 'N':
2361 case 'O':
2362 case 'P':
2363 case 'Q':
2364 break;
2365 case 'R':
2366 if (inclass) break;
2367 if (create) root = new LineEnding();
2368 return -1;
2369 case 'S':
2370 if (create) root = has(UNICODE_CHARACTER_CLASS)
2371 ? new Utype(UnicodeProp.WHITE_SPACE).complement()
2372 : new Ctype(ASCII.SPACE).complement();
2373 return -1;
2374 case 'T':
2375 case 'U':
2376 break;
2377 case 'V':
2378 if (create) root = new VertWS().complement();
2379 return -1;
2380 case 'W':
2381 if (create) root = has(UNICODE_CHARACTER_CLASS)
2382 ? new Utype(UnicodeProp.WORD).complement()
2383 : new Ctype(ASCII.WORD).complement();
2384 return -1;
2385 case 'X':
2386 case 'Y':
2387 break;
2388 case 'Z':
2389 if (inclass) break;
2390 if (create) {
2391 if (has(UNIX_LINES))
2392 root = new UnixDollar(false);
2393 else
2394 root = new Dollar(false);
2395 }
2396 return -1;
2397 case 'a':
2398 return '\007';
2399 case 'b':
2400 if (inclass) break;
2401 if (create) root = new Bound(Bound.BOTH, has(UNICODE_CHARACTER_CLASS));
2402 return -1;
2403 case 'c':
2404 return c();
2405 case 'd':
2406 if (create) root = has(UNICODE_CHARACTER_CLASS)
2407 ? new Utype(UnicodeProp.DIGIT)
2408 : new Ctype(ASCII.DIGIT);
2409 return -1;
2410 case 'e':
2411 return '\033';
2412 case 'f':
2413 return '\f';
2414 case 'g':
2415 break;
2416 case 'h':
2417 if (create) root = new HorizWS();
2418 return -1;
2419 case 'i':
2420 case 'j':
2421 break;
2422 case 'k':
2423 if (inclass)
2424 break;
2425 if (read() != '<')
2426 throw error("\\k is not followed by '<' for named capturing group");
2427 String name = groupname(read());
2428 if (!namedGroups().containsKey(name))
2429 throw error("(named capturing group <"+ name+"> does not exit");
2430 if (create) {
2431 if (has(CASE_INSENSITIVE))
2432 root = new CIBackRef(namedGroups().get(name), has(UNICODE_CASE));
2433 else
2434 root = new BackRef(namedGroups().get(name));
2435 }
2436 return -1;
2437 case 'l':
2438 case 'm':
2439 break;
2440 case 'n':
2441 return '\n';
2442 case 'o':
2443 case 'p':
2444 case 'q':
2445 break;
2446 case 'r':
2447 return '\r';
2448 case 's':
2449 if (create) root = has(UNICODE_CHARACTER_CLASS)
2450 ? new Utype(UnicodeProp.WHITE_SPACE)
2451 : new Ctype(ASCII.SPACE);
2452 return -1;
2453 case 't':
2454 return '\t';
2455 case 'u':
2456 return u();
2457 case 'v':
2458 // '\v' was implemented as VT/0x0B in releases < 1.8 (though
2459 // undocumented). In JDK8 '\v' is specified as a predefined
2460 // character class for all vertical whitespace characters.
2461 // So [-1, root=VertWS node] pair is returned (instead of a
2462 // single 0x0B). This breaks the range if '\v' is used as
2463 // the start or end value, such as [\v-...] or [...-\v], in
2464 // which a single definite value (0x0B) is expected. For
2465 // compatibility concern '\013'/0x0B is returned if isrange.
2466 if (isrange)
2467 return '\013';
2468 if (create) root = new VertWS();
2469 return -1;
2470 case 'w':
2471 if (create) root = has(UNICODE_CHARACTER_CLASS)
2472 ? new Utype(UnicodeProp.WORD)
2473 : new Ctype(ASCII.WORD);
2474 return -1;
2475 case 'x':
2476 return x();
2477 case 'y':
2478 break;
2479 case 'z':
2480 if (inclass) break;
2481 if (create) root = new End();
2482 return -1;
2483 default:
2484 return ch;
2485 }
2486 throw error("Illegal/unsupported escape sequence");
2487 }
2488
2489 /**
2490 * Parse a character class, and return the node that matches it.
2491 *
2492 * Consumes a ] on the way out if consume is true. Usually consume
2493 * is true except for the case of [abc&&def] where def is a separate
2494 * right hand node with "understood" brackets.
2495 */
2496 private CharProperty clazz(boolean consume) {
2497 CharProperty prev = null;
2498 CharProperty node = null;
2499 BitClass bits = new BitClass();
2500 boolean include = true;
2501 boolean firstInClass = true;
2502 int ch = next();
2503 for (;;) {
2504 switch (ch) {
2505 case '^':
2506 // Negates if first char in a class, otherwise literal
2507 if (firstInClass) {
2508 if (temp[cursor-1] != '[')
2509 break;
2510 ch = next();
2511 include = !include;
2512 continue;
2513 } else {
2514 // ^ not first in class, treat as literal
2515 break;
2516 }
2517 case '[':
2518 firstInClass = false;
2519 node = clazz(true);
2520 if (prev == null)
2521 prev = node;
2522 else
2523 prev = union(prev, node);
2524 ch = peek();
2525 continue;
2526 case '&':
2527 firstInClass = false;
2528 ch = next();
2529 if (ch == '&') {
2530 ch = next();
2531 CharProperty rightNode = null;
2532 while (ch != ']' && ch != '&') {
2533 if (ch == '[') {
2534 if (rightNode == null)
2535 rightNode = clazz(true);
2536 else
2537 rightNode = union(rightNode, clazz(true));
2538 } else { // abc&&def
2539 unread();
2540 rightNode = clazz(false);
2541 }
2542 ch = peek();
2543 }
2544 if (rightNode != null)
2545 node = rightNode;
2546 if (prev == null) {
2547 if (rightNode == null)
2548 throw error("Bad class syntax");
2549 else
2550 prev = rightNode;
2551 } else {
2552 prev = intersection(prev, node);
2553 }
2554 } else {
2555 // treat as a literal &
2556 unread();
2557 break;
2558 }
2559 continue;
2560 case 0:
2561 firstInClass = false;
2562 if (cursor >= patternLength)
2563 throw error("Unclosed character class");
2564 break;
2565 case ']':
2566 firstInClass = false;
2567 if (prev != null) {
2568 if (consume)
2569 next();
2570 return prev;
2571 }
2572 break;
2573 default:
2574 firstInClass = false;
2575 break;
2576 }
2577 node = range(bits);
2578 if (include) {
2579 if (prev == null) {
2580 prev = node;
2581 } else {
2582 if (prev != node)
2583 prev = union(prev, node);
2584 }
2585 } else {
2586 if (prev == null) {
2587 prev = node.complement();
2588 } else {
2589 if (prev != node)
2590 prev = setDifference(prev, node);
2591 }
2592 }
2593 ch = peek();
2594 }
2595 }
2596
2597 private CharProperty bitsOrSingle(BitClass bits, int ch) {
2598 /* Bits can only handle codepoints in [u+0000-u+00ff] range.
2599 Use "single" node instead of bits when dealing with unicode
2600 case folding for codepoints listed below.
2601 (1)Uppercase out of range: u+00ff, u+00b5
2602 toUpperCase(u+00ff) -> u+0178
2603 toUpperCase(u+00b5) -> u+039c
2604 (2)LatinSmallLetterLongS u+17f
2605 toUpperCase(u+017f) -> u+0053
2606 (3)LatinSmallLetterDotlessI u+131
2607 toUpperCase(u+0131) -> u+0049
2608 (4)LatinCapitalLetterIWithDotAbove u+0130
2609 toLowerCase(u+0130) -> u+0069
2610 (5)KelvinSign u+212a
2611 toLowerCase(u+212a) ==> u+006B
2612 (6)AngstromSign u+212b
2613 toLowerCase(u+212b) ==> u+00e5
2614 */
2615 int d;
2616 if (ch < 256 &&
2617 !(has(CASE_INSENSITIVE) && has(UNICODE_CASE) &&
2618 (ch == 0xff || ch == 0xb5 ||
2619 ch == 0x49 || ch == 0x69 || //I and i
2620 ch == 0x53 || ch == 0x73 || //S and s
2621 ch == 0x4b || ch == 0x6b || //K and k
2622 ch == 0xc5 || ch == 0xe5))) //A+ring
2623 return bits.add(ch, flags());
2624 return newSingle(ch);
2625 }
2626
2627 /**
2628 * Parse a single character or a character range in a character class
2629 * and return its representative node.
2630 */
2631 private CharProperty range(BitClass bits) {
2632 int ch = peek();
2633 if (ch == '\\') {
2634 ch = nextEscaped();
2635 if (ch == 'p' || ch == 'P') { // A property
2636 boolean comp = (ch == 'P');
2637 boolean oneLetter = true;
2638 // Consume { if present
2639 ch = next();
2640 if (ch != '{')
2641 unread();
2642 else
2643 oneLetter = false;
2644 return family(oneLetter, comp);
2645 } else { // ordinary escape
2646 boolean isrange = temp[cursor+1] == '-';
2647 unread();
2648 ch = escape(true, true, isrange);
2649 if (ch == -1)
2650 return (CharProperty) root;
2651 }
2652 } else {
2653 next();
2654 }
2655 if (ch >= 0) {
2656 if (peek() == '-') {
2657 int endRange = temp[cursor+1];
2658 if (endRange == '[') {
2659 return bitsOrSingle(bits, ch);
2660 }
2661 if (endRange != ']') {
2662 next();
2663 int m = peek();
2664 if (m == '\\') {
2665 m = escape(true, false, true);
2666 } else {
2667 next();
2668 }
2669 if (m < ch) {
2670 throw error("Illegal character range");
2671 }
2672 if (has(CASE_INSENSITIVE))
2673 return caseInsensitiveRangeFor(ch, m);
2674 else
2675 return rangeFor(ch, m);
2676 }
2677 }
2678 return bitsOrSingle(bits, ch);
2679 }
2680 throw error("Unexpected character '"+((char)ch)+"'");
2681 }
2682
2683 /**
2684 * Parses a Unicode character family and returns its representative node.
2685 */
2686 private CharProperty family(boolean singleLetter,
2687 boolean maybeComplement)
2688 {
2689 next();
2690 String name;
2691 CharProperty node = null;
2692
2693 if (singleLetter) {
2694 int c = temp[cursor];
2695 if (!Character.isSupplementaryCodePoint(c)) {
2696 name = String.valueOf((char)c);
2697 } else {
2698 name = new String(temp, cursor, 1);
2699 }
2700 read();
2701 } else {
2702 int i = cursor;
2703 mark('}');
2704 while(read() != '}') {
2705 }
2706 mark('\000');
2707 int j = cursor;
2708 if (j > patternLength)
2709 throw error("Unclosed character family");
2710 if (i + 1 >= j)
2711 throw error("Empty character family");
2712 name = new String(temp, i, j-i-1);
2713 }
2714
2715 int i = name.indexOf('=');
2716 if (i != -1) {
2717 // property construct \p{name=value}
2718 String value = name.substring(i + 1);
2719 name = name.substring(0, i).toLowerCase(Locale.ENGLISH);
2720 switch (name) {
2721 case "sc":
2722 case "script":
2723 node = unicodeScriptPropertyFor(value);
2724 break;
2725 case "blk":
2726 case "block":
2727 node = unicodeBlockPropertyFor(value);
2728 break;
2729 case "gc":
2730 case "general_category":
2731 node = charPropertyNodeFor(value);
2732 break;
2733 default:
2734 throw error("Unknown Unicode property {name=<" + name + ">, "
2735 + "value=<" + value + ">}");
2736 }
2737 } else {
2738 if (name.startsWith("In")) {
2739 // \p{inBlockName}
2740 node = unicodeBlockPropertyFor(name.substring(2));
2741 } else if (name.startsWith("Is")) {
2742 // \p{isGeneralCategory} and \p{isScriptName}
2743 name = name.substring(2);
2744 UnicodeProp uprop = UnicodeProp.forName(name);
2745 if (uprop != null)
2746 node = new Utype(uprop);
2747 if (node == null)
2748 node = CharPropertyNames.charPropertyFor(name);
2749 if (node == null)
2750 node = unicodeScriptPropertyFor(name);
2751 } else {
2752 if (has(UNICODE_CHARACTER_CLASS)) {
2753 UnicodeProp uprop = UnicodeProp.forPOSIXName(name);
2754 if (uprop != null)
2755 node = new Utype(uprop);
2756 }
2757 if (node == null)
2758 node = charPropertyNodeFor(name);
2759 }
2760 }
2761 if (maybeComplement) {
2762 if (node instanceof Category || node instanceof Block)
2763 hasSupplementary = true;
2764 node = node.complement();
2765 }
2766 return node;
2767 }
2768
2769
2770 /**
2771 * Returns a CharProperty matching all characters belong to
2772 * a UnicodeScript.
2773 */
2774 private CharProperty unicodeScriptPropertyFor(String name) {
2775 final Character.UnicodeScript script;
2776 try {
2777 script = Character.UnicodeScript.forName(name);
2778 } catch (IllegalArgumentException iae) {
2779 throw error("Unknown character script name {" + name + "}");
2780 }
2781 return new Script(script);
2782 }
2783
2784 /**
2785 * Returns a CharProperty matching all characters in a UnicodeBlock.
2786 */
2787 private CharProperty unicodeBlockPropertyFor(String name) {
2788 final Character.UnicodeBlock block;
2789 try {
2790 block = Character.UnicodeBlock.forName(name);
2791 } catch (IllegalArgumentException iae) {
2792 throw error("Unknown character block name {" + name + "}");
2793 }
2794 return new Block(block);
2795 }
2796
2797 /**
2798 * Returns a CharProperty matching all characters in a named property.
2799 */
2800 private CharProperty charPropertyNodeFor(String name) {
2801 CharProperty p = CharPropertyNames.charPropertyFor(name);
2802 if (p == null)
2803 throw error("Unknown character property name {" + name + "}");
2804 return p;
2805 }
2806
2807 /**
2808 * Parses and returns the name of a "named capturing group", the trailing
2809 * ">" is consumed after parsing.
2810 */
2811 private String groupname(int ch) {
2812 StringBuilder sb = new StringBuilder();
2813 sb.append(Character.toChars(ch));
2814 while (ASCII.isLower(ch=read()) || ASCII.isUpper(ch) ||
2815 ASCII.isDigit(ch)) {
2816 sb.append(Character.toChars(ch));
2817 }
2818 if (sb.length() == 0)
2819 throw error("named capturing group has 0 length name");
2820 if (ch != '>')
2821 throw error("named capturing group is missing trailing '>'");
2822 return sb.toString();
2823 }
2824
2825 /**
2826 * Parses a group and returns the head node of a set of nodes that process
2827 * the group. Sometimes a double return system is used where the tail is
2828 * returned in root.
2829 */
2830 private Node group0() {
2831 boolean capturingGroup = false;
2832 Node head = null;
2833 Node tail = null;
2834 int save = flags;
2835 root = null;
2836 int ch = next();
2837 if (ch == '?') {
2838 ch = skip();
2839 switch (ch) {
2840 case ':': // (?:xxx) pure group
2841 head = createGroup(true);
2842 tail = root;
2843 head.next = expr(tail);
2844 break;
2845 case '=': // (?=xxx) and (?!xxx) lookahead
2846 case '!':
2847 head = createGroup(true);
2848 tail = root;
2849 head.next = expr(tail);
2850 if (ch == '=') {
2851 head = tail = new Pos(head);
2852 } else {
2853 head = tail = new Neg(head);
2854 }
2855 break;
2856 case '>': // (?>xxx) independent group
2857 head = createGroup(true);
2858 tail = root;
2859 head.next = expr(tail);
2860 head = tail = new Ques(head, INDEPENDENT);
2861 break;
2862 case '<': // (?<xxx) look behind
2863 ch = read();
2864 if (ASCII.isLower(ch) || ASCII.isUpper(ch)) {
2865 // named captured group
2866 String name = groupname(ch);
2867 if (namedGroups().containsKey(name))
2868 throw error("Named capturing group <" + name
2869 + "> is already defined");
2870 capturingGroup = true;
2871 head = createGroup(false);
2872 tail = root;
2873 namedGroups().put(name, capturingGroupCount-1);
2874 head.next = expr(tail);
2875 break;
2876 }
2877 int start = cursor;
2878 head = createGroup(true);
2879 tail = root;
2880 head.next = expr(tail);
2881 tail.next = lookbehindEnd;
2882 TreeInfo info = new TreeInfo();
2883 head.study(info);
2884 if (info.maxValid == false) {
2885 throw error("Look-behind group does not have "
2886 + "an obvious maximum length");
2887 }
2888 boolean hasSupplementary = findSupplementary(start, patternLength);
2889 if (ch == '=') {
2890 head = tail = (hasSupplementary ?
2891 new BehindS(head, info.maxLength,
2892 info.minLength) :
2893 new Behind(head, info.maxLength,
2894 info.minLength));
2895 } else if (ch == '!') {
2896 head = tail = (hasSupplementary ?
2897 new NotBehindS(head, info.maxLength,
2898 info.minLength) :
2899 new NotBehind(head, info.maxLength,
2900 info.minLength));
2901 } else {
2902 throw error("Unknown look-behind group");
2903 }
2904 break;
2905 case '$':
2906 case '@':
2907 throw error("Unknown group type");
2908 default: // (?xxx:) inlined match flags
2909 unread();
2910 addFlag();
2911 ch = read();
2912 if (ch == ')') {
2913 return null; // Inline modifier only
2914 }
2915 if (ch != ':') {
2916 throw error("Unknown inline modifier");
2917 }
2918 head = createGroup(true);
2919 tail = root;
2920 head.next = expr(tail);
2921 break;
2922 }
2923 } else { // (xxx) a regular group
2924 capturingGroup = true;
2925 head = createGroup(false);
2926 tail = root;
2927 head.next = expr(tail);
2928 }
2929
2930 accept(')', "Unclosed group");
2931 flags = save;
2932
2933 // Check for quantifiers
2934 Node node = closure(head);
2935 if (node == head) { // No closure
2936 root = tail;
2937 return node; // Dual return
2938 }
2939 if (head == tail) { // Zero length assertion
2940 root = node;
2941 return node; // Dual return
2942 }
2943
2944 if (node instanceof Ques) {
2945 Ques ques = (Ques) node;
2946 if (ques.type == POSSESSIVE) {
2947 root = node;
2948 return node;
2949 }
2950 tail.next = new BranchConn();
2951 tail = tail.next;
2952 if (ques.type == GREEDY) {
2953 head = new Branch(head, null, tail);
2954 } else { // Reluctant quantifier
2955 head = new Branch(null, head, tail);
2956 }
2957 root = tail;
2958 return head;
2959 } else if (node instanceof Curly) {
2960 Curly curly = (Curly) node;
2961 if (curly.type == POSSESSIVE) {
2962 root = node;
2963 return node;
2964 }
2965 // Discover if the group is deterministic
2966 TreeInfo info = new TreeInfo();
2967 if (head.study(info)) { // Deterministic
2968 GroupTail temp = (GroupTail) tail;
2969 head = root = new GroupCurly(head.next, curly.cmin,
2970 curly.cmax, curly.type,
2971 ((GroupTail)tail).localIndex,
2972 ((GroupTail)tail).groupIndex,
2973 capturingGroup);
2974 return head;
2975 } else { // Non-deterministic
2976 int temp = ((GroupHead) head).localIndex;
2977 Loop loop;
2978 if (curly.type == GREEDY)
2979 loop = new Loop(this.localCount, temp);
2980 else // Reluctant Curly
2981 loop = new LazyLoop(this.localCount, temp);
2982 Prolog prolog = new Prolog(loop);
2983 this.localCount += 1;
2984 loop.cmin = curly.cmin;
2985 loop.cmax = curly.cmax;
2986 loop.body = head;
2987 tail.next = loop;
2988 root = loop;
2989 return prolog; // Dual return
2990 }
2991 }
2992 throw error("Internal logic error");
2993 }
2994
2995 /**
2996 * Create group head and tail nodes using double return. If the group is
2997 * created with anonymous true then it is a pure group and should not
2998 * affect group counting.
2999 */
3000 private Node createGroup(boolean anonymous) {
3001 int localIndex = localCount++;
3002 int groupIndex = 0;
3003 if (!anonymous)
3004 groupIndex = capturingGroupCount++;
3005 GroupHead head = new GroupHead(localIndex);
3006 root = new GroupTail(localIndex, groupIndex);
3007 if (!anonymous && groupIndex < 10)
3008 groupNodes[groupIndex] = head;
3009 return head;
3010 }
3011
3012 @SuppressWarnings("fallthrough")
3013 /**
3014 * Parses inlined match flags and set them appropriately.
3015 */
3016 private void addFlag() {
3017 int ch = peek();
3018 for (;;) {
3019 switch (ch) {
3020 case 'i':
3021 flags |= CASE_INSENSITIVE;
3022 break;
3023 case 'm':
3024 flags |= MULTILINE;
3025 break;
3026 case 's':
3027 flags |= DOTALL;
3028 break;
3029 case 'd':
3030 flags |= UNIX_LINES;
3031 break;
3032 case 'u':
3033 flags |= UNICODE_CASE;
3034 break;
3035 case 'c':
3036 flags |= CANON_EQ;
3037 break;
3038 case 'x':
3039 flags |= COMMENTS;
3040 break;
3041 case 'U':
3042 flags |= (UNICODE_CHARACTER_CLASS | UNICODE_CASE);
3043 break;
3044 case '-': // subFlag then fall through
3045 ch = next();
3046 subFlag();
3047 default:
3048 return;
3049 }
3050 ch = next();
3051 }
3052 }
3053
3054 @SuppressWarnings("fallthrough")
3055 /**
3056 * Parses the second part of inlined match flags and turns off
3057 * flags appropriately.
3058 */
3059 private void subFlag() {
3060 int ch = peek();
3061 for (;;) {
3062 switch (ch) {
3063 case 'i':
3064 flags &= ~CASE_INSENSITIVE;
3065 break;
3066 case 'm':
3067 flags &= ~MULTILINE;
3068 break;
3069 case 's':
3070 flags &= ~DOTALL;
3071 break;
3072 case 'd':
3073 flags &= ~UNIX_LINES;
3074 break;
3075 case 'u':
3076 flags &= ~UNICODE_CASE;
3077 break;
3078 case 'c':
3079 flags &= ~CANON_EQ;
3080 break;
3081 case 'x':
3082 flags &= ~COMMENTS;
3083 break;
3084 case 'U':
3085 flags &= ~(UNICODE_CHARACTER_CLASS | UNICODE_CASE);
3086 default:
3087 return;
3088 }
3089 ch = next();
3090 }
3091 }
3092
3093 static final int MAX_REPS = 0x7FFFFFFF;
3094
3095 static final int GREEDY = 0;
3096
3097 static final int LAZY = 1;
3098
3099 static final int POSSESSIVE = 2;
3100
3101 static final int INDEPENDENT = 3;
3102
3103 /**
3104 * Processes repetition. If the next character peeked is a quantifier
3105 * then new nodes must be appended to handle the repetition.
3106 * Prev could be a single or a group, so it could be a chain of nodes.
3107 */
3108 private Node closure(Node prev) {
3109 Node atom;
3110 int ch = peek();
3111 switch (ch) {
3112 case '?':
3113 ch = next();
3114 if (ch == '?') {
3115 next();
3116 return new Ques(prev, LAZY);
3117 } else if (ch == '+') {
3118 next();
3119 return new Ques(prev, POSSESSIVE);
3120 }
3121 return new Ques(prev, GREEDY);
3122 case '*':
3123 ch = next();
3124 if (ch == '?') {
3125 next();
3126 return new Curly(prev, 0, MAX_REPS, LAZY);
3127 } else if (ch == '+') {
3128 next();
3129 return new Curly(prev, 0, MAX_REPS, POSSESSIVE);
3130 }
3131 return new Curly(prev, 0, MAX_REPS, GREEDY);
3132 case '+':
3133 ch = next();
3134 if (ch == '?') {
3135 next();
3136 return new Curly(prev, 1, MAX_REPS, LAZY);
3137 } else if (ch == '+') {
3138 next();
3139 return new Curly(prev, 1, MAX_REPS, POSSESSIVE);
3140 }
3141 return new Curly(prev, 1, MAX_REPS, GREEDY);
3142 case '{':
3143 ch = temp[cursor+1];
3144 if (ASCII.isDigit(ch)) {
3145 skip();
3146 int cmin = 0;
3147 do {
3148 cmin = cmin * 10 + (ch - '0');
3149 } while (ASCII.isDigit(ch = read()));
3150 int cmax = cmin;
3151 if (ch == ',') {
3152 ch = read();
3153 cmax = MAX_REPS;
3154 if (ch != '}') {
3155 cmax = 0;
3156 while (ASCII.isDigit(ch)) {
3157 cmax = cmax * 10 + (ch - '0');
3158 ch = read();
3159 }
3160 }
3161 }
3162 if (ch != '}')
3163 throw error("Unclosed counted closure");
3164 if (((cmin) | (cmax) | (cmax - cmin)) < 0)
3165 throw error("Illegal repetition range");
3166 Curly curly;
3167 ch = peek();
3168 if (ch == '?') {
3169 next();
3170 curly = new Curly(prev, cmin, cmax, LAZY);
3171 } else if (ch == '+') {
3172 next();
3173 curly = new Curly(prev, cmin, cmax, POSSESSIVE);
3174 } else {
3175 curly = new Curly(prev, cmin, cmax, GREEDY);
3176 }
3177 return curly;
3178 } else {
3179 throw error("Illegal repetition");
3180 }
3181 default:
3182 return prev;
3183 }
3184 }
3185
3186 /**
3187 * Utility method for parsing control escape sequences.
3188 */
3189 private int c() {
3190 if (cursor < patternLength) {
3191 return read() ^ 64;
3192 }
3193 throw error("Illegal control escape sequence");
3194 }
3195
3196 /**
3197 * Utility method for parsing octal escape sequences.
3198 */
3199 private int o() {
3200 int n = read();
3201 if (((n-'0')|('7'-n)) >= 0) {
3202 int m = read();
3203 if (((m-'0')|('7'-m)) >= 0) {
3204 int o = read();
3205 if ((((o-'0')|('7'-o)) >= 0) && (((n-'0')|('3'-n)) >= 0)) {
3206 return (n - '0') * 64 + (m - '0') * 8 + (o - '0');
3207 }
3208 unread();
3209 return (n - '0') * 8 + (m - '0');
3210 }
3211 unread();
3212 return (n - '0');
3213 }
3214 throw error("Illegal octal escape sequence");
3215 }
3216
3217 /**
3218 * Utility method for parsing hexadecimal escape sequences.
3219 */
3220 private int x() {
3221 int n = read();
3222 if (ASCII.isHexDigit(n)) {
3223 int m = read();
3224 if (ASCII.isHexDigit(m)) {
3225 return ASCII.toDigit(n) * 16 + ASCII.toDigit(m);
3226 }
3227 } else if (n == '{' && ASCII.isHexDigit(peek())) {
3228 int ch = 0;
3229 while (ASCII.isHexDigit(n = read())) {
3230 ch = (ch << 4) + ASCII.toDigit(n);
3231 if (ch > Character.MAX_CODE_POINT)
3232 throw error("Hexadecimal codepoint is too big");
3233 }
3234 if (n != '}')
3235 throw error("Unclosed hexadecimal escape sequence");
3236 return ch;
3237 }
3238 throw error("Illegal hexadecimal escape sequence");
3239 }
3240
3241 /**
3242 * Utility method for parsing unicode escape sequences.
3243 */
3244 private int cursor() {
3245 return cursor;
3246 }
3247
3248 private void setcursor(int pos) {
3249 cursor = pos;
3250 }
3251
3252 private int uxxxx() {
3253 int n = 0;
3254 for (int i = 0; i < 4; i++) {
3255 int ch = read();
3256 if (!ASCII.isHexDigit(ch)) {
3257 throw error("Illegal Unicode escape sequence");
3258 }
3259 n = n * 16 + ASCII.toDigit(ch);
3260 }
3261 return n;
3262 }
3263
3264 private int u() {
3265 int n = uxxxx();
3266 if (Character.isHighSurrogate((char)n)) {
3267 int cur = cursor();
3268 if (read() == '\\' && read() == 'u') {
3269 int n2 = uxxxx();
3270 if (Character.isLowSurrogate((char)n2))
3271 return Character.toCodePoint((char)n, (char)n2);
3272 }
3273 setcursor(cur);
3274 }
3275 return n;
3276 }
3277
3278 //
3279 // Utility methods for code point support
3280 //
3281
3282 private static final int countChars(CharSequence seq, int index,
3283 int lengthInCodePoints) {
3284 // optimization
3285 if (lengthInCodePoints == 1 && !Character.isHighSurrogate(seq.charAt(index))) {
3286 assert (index >= 0 && index < seq.length());
3287 return 1;
3288 }
3289 int length = seq.length();
3290 int x = index;
3291 if (lengthInCodePoints >= 0) {
3292 assert (index >= 0 && index < length);
3293 for (int i = 0; x < length && i < lengthInCodePoints; i++) {
3294 if (Character.isHighSurrogate(seq.charAt(x++))) {
3295 if (x < length && Character.isLowSurrogate(seq.charAt(x))) {
3296 x++;
3297 }
3298 }
3299 }
3300 return x - index;
3301 }
3302
3303 assert (index >= 0 && index <= length);
3304 if (index == 0) {
3305 return 0;
3306 }
3307 int len = -lengthInCodePoints;
3308 for (int i = 0; x > 0 && i < len; i++) {
3309 if (Character.isLowSurrogate(seq.charAt(--x))) {
3310 if (x > 0 && Character.isHighSurrogate(seq.charAt(x-1))) {
3311 x--;
3312 }
3313 }
3314 }
3315 return index - x;
3316 }
3317
3318 private static final int countCodePoints(CharSequence seq) {
3319 int length = seq.length();
3320 int n = 0;
3321 for (int i = 0; i < length; ) {
3322 n++;
3323 if (Character.isHighSurrogate(seq.charAt(i++))) {
3324 if (i < length && Character.isLowSurrogate(seq.charAt(i))) {
3325 i++;
3326 }
3327 }
3328 }
3329 return n;
3330 }
3331
3332 /**
3333 * Creates a bit vector for matching Latin-1 values. A normal BitClass
3334 * never matches values above Latin-1, and a complemented BitClass always
3335 * matches values above Latin-1.
3336 */
3337 private static final class BitClass extends BmpCharProperty {
3338 final boolean[] bits;
3339 BitClass() { bits = new boolean[256]; }
3340 private BitClass(boolean[] bits) { this.bits = bits; }
3341 BitClass add(int c, int flags) {
3342 assert c >= 0 && c <= 255;
3343 if ((flags & CASE_INSENSITIVE) != 0) {
3344 if (ASCII.isAscii(c)) {
3345 bits[ASCII.toUpper(c)] = true;
3346 bits[ASCII.toLower(c)] = true;
3347 } else if ((flags & UNICODE_CASE) != 0) {
3348 bits[Character.toLowerCase(c)] = true;
3349 bits[Character.toUpperCase(c)] = true;
3350 }
3351 }
3352 bits[c] = true;
3353 return this;
3354 }
3355 boolean isSatisfiedBy(int ch) {
3356 return ch < 256 && bits[ch];
3357 }
3358 }
3359
3360 /**
3361 * Returns a suitably optimized, single character matcher.
3362 */
3363 private CharProperty newSingle(final int ch) {
3364 if (has(CASE_INSENSITIVE)) {
3365 int lower, upper;
3366 if (has(UNICODE_CASE)) {
3367 upper = Character.toUpperCase(ch);
3368 lower = Character.toLowerCase(upper);
3369 if (upper != lower)
3370 return new SingleU(lower);
3371 } else if (ASCII.isAscii(ch)) {
3372 lower = ASCII.toLower(ch);
3373 upper = ASCII.toUpper(ch);
3374 if (lower != upper)
3375 return new SingleI(lower, upper);
3376 }
3377 }
3378 if (isSupplementary(ch))
3379 return new SingleS(ch); // Match a given Unicode character
3380 return new Single(ch); // Match a given BMP character
3381 }
3382
3383 /**
3384 * Utility method for creating a string slice matcher.
3385 */
3386 private Node newSlice(int[] buf, int count, boolean hasSupplementary) {
3387 int[] tmp = new int[count];
3388 if (has(CASE_INSENSITIVE)) {
3389 if (has(UNICODE_CASE)) {
3390 for (int i = 0; i < count; i++) {
3391 tmp[i] = Character.toLowerCase(
3392 Character.toUpperCase(buf[i]));
3393 }
3394 return hasSupplementary? new SliceUS(tmp) : new SliceU(tmp);
3395 }
3396 for (int i = 0; i < count; i++) {
3397 tmp[i] = ASCII.toLower(buf[i]);
3398 }
3399 return hasSupplementary? new SliceIS(tmp) : new SliceI(tmp);
3400 }
3401 for (int i = 0; i < count; i++) {
3402 tmp[i] = buf[i];
3403 }
3404 return hasSupplementary ? new SliceS(tmp) : new Slice(tmp);
3405 }
3406
3407 /**
3408 * The following classes are the building components of the object
3409 * tree that represents a compiled regular expression. The object tree
3410 * is made of individual elements that handle constructs in the Pattern.
3411 * Each type of object knows how to match its equivalent construct with
3412 * the match() method.
3413 */
3414
3415 /**
3416 * Base class for all node classes. Subclasses should override the match()
3417 * method as appropriate. This class is an accepting node, so its match()
3418 * always returns true.
3419 */
3420 static class Node extends Object {
3421 Node next;
3422 Node() {
3423 next = Pattern.accept;
3424 }
3425 /**
3426 * This method implements the classic accept node.
3427 */
3428 boolean match(Matcher matcher, int i, CharSequence seq) {
3429 matcher.last = i;
3430 matcher.groups[0] = matcher.first;
3431 matcher.groups[1] = matcher.last;
3432 return true;
3433 }
3434 /**
3435 * This method is good for all zero length assertions.
3436 */
3437 boolean study(TreeInfo info) {
3438 if (next != null) {
3439 return next.study(info);
3440 } else {
3441 return info.deterministic;
3442 }
3443 }
3444 }
3445
3446 static class LastNode extends Node {
3447 /**
3448 * This method implements the classic accept node with
3449 * the addition of a check to see if the match occurred
3450 * using all of the input.
3451 */
3452 boolean match(Matcher matcher, int i, CharSequence seq) {
3453 if (matcher.acceptMode == Matcher.ENDANCHOR && i != matcher.to)
3454 return false;
3455 matcher.last = i;
3456 matcher.groups[0] = matcher.first;
3457 matcher.groups[1] = matcher.last;
3458 return true;
3459 }
3460 }
3461
3462 /**
3463 * Used for REs that can start anywhere within the input string.
3464 * This basically tries to match repeatedly at each spot in the
3465 * input string, moving forward after each try. An anchored search
3466 * or a BnM will bypass this node completely.
3467 */
3468 static class Start extends Node {
3469 int minLength;
3470 Start(Node node) {
3471 this.next = node;
3472 TreeInfo info = new TreeInfo();
3473 next.study(info);
3474 minLength = info.minLength;
3475 }
3476 boolean match(Matcher matcher, int i, CharSequence seq) {
3477 if (i > matcher.to - minLength) {
3478 matcher.hitEnd = true;
3479 return false;
3480 }
3481 int guard = matcher.to - minLength;
3482 for (; i <= guard; i++) {
3483 if (next.match(matcher, i, seq)) {
3484 matcher.first = i;
3485 matcher.groups[0] = matcher.first;
3486 matcher.groups[1] = matcher.last;
3487 return true;
3488 }
3489 }
3490 matcher.hitEnd = true;
3491 return false;
3492 }
3493 boolean study(TreeInfo info) {
3494 next.study(info);
3495 info.maxValid = false;
3496 info.deterministic = false;
3497 return false;
3498 }
3499 }
3500
3501 /*
3502 * StartS supports supplementary characters, including unpaired surrogates.
3503 */
3504 static final class StartS extends Start {
3505 StartS(Node node) {
3506 super(node);
3507 }
3508 boolean match(Matcher matcher, int i, CharSequence seq) {
3509 if (i > matcher.to - minLength) {
3510 matcher.hitEnd = true;
3511 return false;
3512 }
3513 int guard = matcher.to - minLength;
3514 while (i <= guard) {
3515 //if ((ret = next.match(matcher, i, seq)) || i == guard)
3516 if (next.match(matcher, i, seq)) {
3517 matcher.first = i;
3518 matcher.groups[0] = matcher.first;
3519 matcher.groups[1] = matcher.last;
3520 return true;
3521 }
3522 if (i == guard)
3523 break;
3524 // Optimization to move to the next character. This is
3525 // faster than countChars(seq, i, 1).
3526 if (Character.isHighSurrogate(seq.charAt(i++))) {
3527 if (i < seq.length() &&
3528 Character.isLowSurrogate(seq.charAt(i))) {
3529 i++;
3530 }
3531 }
3532 }
3533 matcher.hitEnd = true;
3534 return false;
3535 }
3536 }
3537
3538 /**
3539 * Node to anchor at the beginning of input. This object implements the
3540 * match for a \A sequence, and the caret anchor will use this if not in
3541 * multiline mode.
3542 */
3543 static final class Begin extends Node {
3544 boolean match(Matcher matcher, int i, CharSequence seq) {
3545 int fromIndex = (matcher.anchoringBounds) ?
3546 matcher.from : 0;
3547 if (i == fromIndex && next.match(matcher, i, seq)) {
3548 matcher.first = i;
3549 matcher.groups[0] = i;
3550 matcher.groups[1] = matcher.last;
3551 return true;
3552 } else {
3553 return false;
3554 }
3555 }
3556 }
3557
3558 /**
3559 * Node to anchor at the end of input. This is the absolute end, so this
3560 * should not match at the last newline before the end as $ will.
3561 */
3562 static final class End extends Node {
3563 boolean match(Matcher matcher, int i, CharSequence seq) {
3564 int endIndex = (matcher.anchoringBounds) ?
3565 matcher.to : matcher.getTextLength();
3566 if (i == endIndex) {
3567 matcher.hitEnd = true;
3568 return next.match(matcher, i, seq);
3569 }
3570 return false;
3571 }
3572 }
3573
3574 /**
3575 * Node to anchor at the beginning of a line. This is essentially the
3576 * object to match for the multiline ^.
3577 */
3578 static final class Caret extends Node {
3579 boolean match(Matcher matcher, int i, CharSequence seq) {
3580 int startIndex = matcher.from;
3581 int endIndex = matcher.to;
3582 if (!matcher.anchoringBounds) {
3583 startIndex = 0;
3584 endIndex = matcher.getTextLength();
3585 }
3586 // Perl does not match ^ at end of input even after newline
3587 if (i == endIndex) {
3588 matcher.hitEnd = true;
3589 return false;
3590 }
3591 if (i > startIndex) {
3592 char ch = seq.charAt(i-1);
3593 if (ch != '\n' && ch != '\r'
3594 && (ch|1) != '\u2029'
3595 && ch != '\u0085' ) {
3596 return false;
3597 }
3598 // Should treat /r/n as one newline
3599 if (ch == '\r' && seq.charAt(i) == '\n')
3600 return false;
3601 }
3602 return next.match(matcher, i, seq);
3603 }
3604 }
3605
3606 /**
3607 * Node to anchor at the beginning of a line when in unixdot mode.
3608 */
3609 static final class UnixCaret extends Node {
3610 boolean match(Matcher matcher, int i, CharSequence seq) {
3611 int startIndex = matcher.from;
3612 int endIndex = matcher.to;
3613 if (!matcher.anchoringBounds) {
3614 startIndex = 0;
3615 endIndex = matcher.getTextLength();
3616 }
3617 // Perl does not match ^ at end of input even after newline
3618 if (i == endIndex) {
3619 matcher.hitEnd = true;
3620 return false;
3621 }
3622 if (i > startIndex) {
3623 char ch = seq.charAt(i-1);
3624 if (ch != '\n') {
3625 return false;
3626 }
3627 }
3628 return next.match(matcher, i, seq);
3629 }
3630 }
3631
3632 /**
3633 * Node to match the location where the last match ended.
3634 * This is used for the \G construct.
3635 */
3636 static final class LastMatch extends Node {
3637 boolean match(Matcher matcher, int i, CharSequence seq) {
3638 if (i != matcher.oldLast)
3639 return false;
3640 return next.match(matcher, i, seq);
3641 }
3642 }
3643
3644 /**
3645 * Node to anchor at the end of a line or the end of input based on the
3646 * multiline mode.
3647 *
3648 * When not in multiline mode, the $ can only match at the very end
3649 * of the input, unless the input ends in a line terminator in which
3650 * it matches right before the last line terminator.
3651 *
3652 * Note that \r\n is considered an atomic line terminator.
3653 *
3654 * Like ^ the $ operator matches at a position, it does not match the
3655 * line terminators themselves.
3656 */
3657 static final class Dollar extends Node {
3658 boolean multiline;
3659 Dollar(boolean mul) {
3660 multiline = mul;
3661 }
3662 boolean match(Matcher matcher, int i, CharSequence seq) {
3663 int endIndex = (matcher.anchoringBounds) ?
3664 matcher.to : matcher.getTextLength();
3665 if (!multiline) {
3666 if (i < endIndex - 2)
3667 return false;
3668 if (i == endIndex - 2) {
3669 char ch = seq.charAt(i);
3670 if (ch != '\r')
3671 return false;
3672 ch = seq.charAt(i + 1);
3673 if (ch != '\n')
3674 return false;
3675 }
3676 }
3677 // Matches before any line terminator; also matches at the
3678 // end of input
3679 // Before line terminator:
3680 // If multiline, we match here no matter what
3681 // If not multiline, fall through so that the end
3682 // is marked as hit; this must be a /r/n or a /n
3683 // at the very end so the end was hit; more input
3684 // could make this not match here
3685 if (i < endIndex) {
3686 char ch = seq.charAt(i);
3687 if (ch == '\n') {
3688 // No match between \r\n
3689 if (i > 0 && seq.charAt(i-1) == '\r')
3690 return false;
3691 if (multiline)
3692 return next.match(matcher, i, seq);
3693 } else if (ch == '\r' || ch == '\u0085' ||
3694 (ch|1) == '\u2029') {
3695 if (multiline)
3696 return next.match(matcher, i, seq);
3697 } else { // No line terminator, no match
3698 return false;
3699 }
3700 }
3701 // Matched at current end so hit end
3702 matcher.hitEnd = true;
3703 // If a $ matches because of end of input, then more input
3704 // could cause it to fail!
3705 matcher.requireEnd = true;
3706 return next.match(matcher, i, seq);
3707 }
3708 boolean study(TreeInfo info) {
3709 next.study(info);
3710 return info.deterministic;
3711 }
3712 }
3713
3714 /**
3715 * Node to anchor at the end of a line or the end of input based on the
3716 * multiline mode when in unix lines mode.
3717 */
3718 static final class UnixDollar extends Node {
3719 boolean multiline;
3720 UnixDollar(boolean mul) {
3721 multiline = mul;
3722 }
3723 boolean match(Matcher matcher, int i, CharSequence seq) {
3724 int endIndex = (matcher.anchoringBounds) ?
3725 matcher.to : matcher.getTextLength();
3726 if (i < endIndex) {
3727 char ch = seq.charAt(i);
3728 if (ch == '\n') {
3729 // If not multiline, then only possible to
3730 // match at very end or one before end
3731 if (multiline == false && i != endIndex - 1)
3732 return false;
3733 // If multiline return next.match without setting
3734 // matcher.hitEnd
3735 if (multiline)
3736 return next.match(matcher, i, seq);
3737 } else {
3738 return false;
3739 }
3740 }
3741 // Matching because at the end or 1 before the end;
3742 // more input could change this so set hitEnd
3743 matcher.hitEnd = true;
3744 // If a $ matches because of end of input, then more input
3745 // could cause it to fail!
3746 matcher.requireEnd = true;
3747 return next.match(matcher, i, seq);
3748 }
3749 boolean study(TreeInfo info) {
3750 next.study(info);
3751 return info.deterministic;
3752 }
3753 }
3754
3755 /**
3756 * Node class that matches a Unicode line ending '\R'
3757 */
3758 static final class LineEnding extends Node {
3759 boolean match(Matcher matcher, int i, CharSequence seq) {
3760 // (u+000Du+000A|[u+000Au+000Bu+000Cu+000Du+0085u+2028u+2029])
3761 if (i < matcher.to) {
3762 int ch = seq.charAt(i);
3763 if (ch == 0x0A || ch == 0x0B || ch == 0x0C ||
3764 ch == 0x85 || ch == 0x2028 || ch == 0x2029)
3765 return next.match(matcher, i + 1, seq);
3766 if (ch == 0x0D) {
3767 i++;
3768 if (i < matcher.to && seq.charAt(i) == 0x0A)
3769 i++;
3770 return next.match(matcher, i, seq);
3771 }
3772 } else {
3773 matcher.hitEnd = true;
3774 }
3775 return false;
3776 }
3777 boolean study(TreeInfo info) {
3778 info.minLength++;
3779 info.maxLength += 2;
3780 return next.study(info);
3781 }
3782 }
3783
3784 /**
3785 * Abstract node class to match one character satisfying some
3786 * boolean property.
3787 */
3788 private static abstract class CharProperty extends Node {
3789 abstract boolean isSatisfiedBy(int ch);
3790 CharProperty complement() {
3791 return new CharProperty() {
3792 boolean isSatisfiedBy(int ch) {
3793 return ! CharProperty.this.isSatisfiedBy(ch);}};
3794 }
3795 boolean match(Matcher matcher, int i, CharSequence seq) {
3796 if (i < matcher.to) {
3797 int ch = Character.codePointAt(seq, i);
3798 return isSatisfiedBy(ch)
3799 && next.match(matcher, i+Character.charCount(ch), seq);
3800 } else {
3801 matcher.hitEnd = true;
3802 return false;
3803 }
3804 }
3805 boolean study(TreeInfo info) {
3806 info.minLength++;
3807 info.maxLength++;
3808 return next.study(info);
3809 }
3810 }
3811
3812 /**
3813 * Optimized version of CharProperty that works only for
3814 * properties never satisfied by Supplementary characters.
3815 */
3816 private static abstract class BmpCharProperty extends CharProperty {
3817 boolean match(Matcher matcher, int i, CharSequence seq) {
3818 if (i < matcher.to) {
3819 return isSatisfiedBy(seq.charAt(i))
3820 && next.match(matcher, i+1, seq);
3821 } else {
3822 matcher.hitEnd = true;
3823 return false;
3824 }
3825 }
3826 }
3827
3828 /**
3829 * Node class that matches a Supplementary Unicode character
3830 */
3831 static final class SingleS extends CharProperty {
3832 final int c;
3833 SingleS(int c) { this.c = c; }
3834 boolean isSatisfiedBy(int ch) {
3835 return ch == c;
3836 }
3837 }
3838
3839 /**
3840 * Optimization -- matches a given BMP character
3841 */
3842 static final class Single extends BmpCharProperty {
3843 final int c;
3844 Single(int c) { this.c = c; }
3845 boolean isSatisfiedBy(int ch) {
3846 return ch == c;
3847 }
3848 }
3849
3850 /**
3851 * Case insensitive matches a given BMP character
3852 */
3853 static final class SingleI extends BmpCharProperty {
3854 final int lower;
3855 final int upper;
3856 SingleI(int lower, int upper) {
3857 this.lower = lower;
3858 this.upper = upper;
3859 }
3860 boolean isSatisfiedBy(int ch) {
3861 return ch == lower || ch == upper;
3862 }
3863 }
3864
3865 /**
3866 * Unicode case insensitive matches a given Unicode character
3867 */
3868 static final class SingleU extends CharProperty {
3869 final int lower;
3870 SingleU(int lower) {
3871 this.lower = lower;
3872 }
3873 boolean isSatisfiedBy(int ch) {
3874 return lower == ch ||
3875 lower == Character.toLowerCase(Character.toUpperCase(ch));
3876 }
3877 }
3878
3879 /**
3880 * Node class that matches a Unicode block.
3881 */
3882 static final class Block extends CharProperty {
3883 final Character.UnicodeBlock block;
3884 Block(Character.UnicodeBlock block) {
3885 this.block = block;
3886 }
3887 boolean isSatisfiedBy(int ch) {
3888 return block == Character.UnicodeBlock.of(ch);
3889 }
3890 }
3891
3892 /**
3893 * Node class that matches a Unicode script
3894 */
3895 static final class Script extends CharProperty {
3896 final Character.UnicodeScript script;
3897 Script(Character.UnicodeScript script) {
3898 this.script = script;
3899 }
3900 boolean isSatisfiedBy(int ch) {
3901 return script == Character.UnicodeScript.of(ch);
3902 }
3903 }
3904
3905 /**
3906 * Node class that matches a Unicode category.
3907 */
3908 static final class Category extends CharProperty {
3909 final int typeMask;
3910 Category(int typeMask) { this.typeMask = typeMask; }
3911 boolean isSatisfiedBy(int ch) {
3912 return (typeMask & (1 << Character.getType(ch))) != 0;
3913 }
3914 }
3915
3916 /**
3917 * Node class that matches a Unicode "type"
3918 */
3919 static final class Utype extends CharProperty {
3920 final UnicodeProp uprop;
3921 Utype(UnicodeProp uprop) { this.uprop = uprop; }
3922 boolean isSatisfiedBy(int ch) {
3923 return uprop.is(ch);
3924 }
3925 }
3926
3927 /**
3928 * Node class that matches a POSIX type.
3929 */
3930 static final class Ctype extends BmpCharProperty {
3931 final int ctype;
3932 Ctype(int ctype) { this.ctype = ctype; }
3933 boolean isSatisfiedBy(int ch) {
3934 return ch < 128 && ASCII.isType(ch, ctype);
3935 }
3936 }
3937
3938 /**
3939 * Node class that matches a Perl vertical whitespace
3940 */
3941 static final class VertWS extends BmpCharProperty {
3942 boolean isSatisfiedBy(int cp) {
3943 return (cp >= 0x0A && cp <= 0x0D) ||
3944 cp == 0x85 || cp == 0x2028 || cp == 0x2029;
3945 }
3946 }
3947
3948 /**
3949 * Node class that matches a Perl horizontal whitespace
3950 */
3951 static final class HorizWS extends BmpCharProperty {
3952 boolean isSatisfiedBy(int cp) {
3953 return cp == 0x09 || cp == 0x20 || cp == 0xa0 ||
3954 cp == 0x1680 || cp == 0x180e ||
3955 cp >= 0x2000 && cp <= 0x200a ||
3956 cp == 0x202f || cp == 0x205f || cp == 0x3000;
3957 }
3958 }
3959
3960 /**
3961 * Base class for all Slice nodes
3962 */
3963 static class SliceNode extends Node {
3964 int[] buffer;
3965 SliceNode(int[] buf) {
3966 buffer = buf;
3967 }
3968 boolean study(TreeInfo info) {
3969 info.minLength += buffer.length;
3970 info.maxLength += buffer.length;
3971 return next.study(info);
3972 }
3973 }
3974
3975 /**
3976 * Node class for a case sensitive/BMP-only sequence of literal
3977 * characters.
3978 */
3979 static class Slice extends SliceNode {
3980 Slice(int[] buf) {
3981 super(buf);
3982 }
3983 boolean match(Matcher matcher, int i, CharSequence seq) {
3984 int[] buf = buffer;
3985 int len = buf.length;
3986 for (int j=0; j<len; j++) {
3987 if ((i+j) >= matcher.to) {
3988 matcher.hitEnd = true;
3989 return false;
3990 }
3991 if (buf[j] != seq.charAt(i+j))
3992 return false;
3993 }
3994 return next.match(matcher, i+len, seq);
3995 }
3996 }
3997
3998 /**
3999 * Node class for a case_insensitive/BMP-only sequence of literal
4000 * characters.
4001 */
4002 static class SliceI extends SliceNode {
4003 SliceI(int[] buf) {
4004 super(buf);
4005 }
4006 boolean match(Matcher matcher, int i, CharSequence seq) {
4007 int[] buf = buffer;
4008 int len = buf.length;
4009 for (int j=0; j<len; j++) {
4010 if ((i+j) >= matcher.to) {
4011 matcher.hitEnd = true;
4012 return false;
4013 }
4014 int c = seq.charAt(i+j);
4015 if (buf[j] != c &&
4016 buf[j] != ASCII.toLower(c))
4017 return false;
4018 }
4019 return next.match(matcher, i+len, seq);
4020 }
4021 }
4022
4023 /**
4024 * Node class for a unicode_case_insensitive/BMP-only sequence of
4025 * literal characters. Uses unicode case folding.
4026 */
4027 static final class SliceU extends SliceNode {
4028 SliceU(int[] buf) {
4029 super(buf);
4030 }
4031 boolean match(Matcher matcher, int i, CharSequence seq) {
4032 int[] buf = buffer;
4033 int len = buf.length;
4034 for (int j=0; j<len; j++) {
4035 if ((i+j) >= matcher.to) {
4036 matcher.hitEnd = true;
4037 return false;
4038 }
4039 int c = seq.charAt(i+j);
4040 if (buf[j] != c &&
4041 buf[j] != Character.toLowerCase(Character.toUpperCase(c)))
4042 return false;
4043 }
4044 return next.match(matcher, i+len, seq);
4045 }
4046 }
4047
4048 /**
4049 * Node class for a case sensitive sequence of literal characters
4050 * including supplementary characters.
4051 */
4052 static final class SliceS extends Slice {
4053 SliceS(int[] buf) {
4054 super(buf);
4055 }
4056 boolean match(Matcher matcher, int i, CharSequence seq) {
4057 int[] buf = buffer;
4058 int x = i;
4059 for (int j = 0; j < buf.length; j++) {
4060 if (x >= matcher.to) {
4061 matcher.hitEnd = true;
4062 return false;
4063 }
4064 int c = Character.codePointAt(seq, x);
4065 if (buf[j] != c)
4066 return false;
4067 x += Character.charCount(c);
4068 if (x > matcher.to) {
4069 matcher.hitEnd = true;
4070 return false;
4071 }
4072 }
4073 return next.match(matcher, x, seq);
4074 }
4075 }
4076
4077 /**
4078 * Node class for a case insensitive sequence of literal characters
4079 * including supplementary characters.
4080 */
4081 static class SliceIS extends SliceNode {
4082 SliceIS(int[] buf) {
4083 super(buf);
4084 }
4085 int toLower(int c) {
4086 return ASCII.toLower(c);
4087 }
4088 boolean match(Matcher matcher, int i, CharSequence seq) {
4089 int[] buf = buffer;
4090 int x = i;
4091 for (int j = 0; j < buf.length; j++) {
4092 if (x >= matcher.to) {
4093 matcher.hitEnd = true;
4094 return false;
4095 }
4096 int c = Character.codePointAt(seq, x);
4097 if (buf[j] != c && buf[j] != toLower(c))
4098 return false;
4099 x += Character.charCount(c);
4100 if (x > matcher.to) {
4101 matcher.hitEnd = true;
4102 return false;
4103 }
4104 }
4105 return next.match(matcher, x, seq);
4106 }
4107 }
4108
4109 /**
4110 * Node class for a case insensitive sequence of literal characters.
4111 * Uses unicode case folding.
4112 */
4113 static final class SliceUS extends SliceIS {
4114 SliceUS(int[] buf) {
4115 super(buf);
4116 }
4117 int toLower(int c) {
4118 return Character.toLowerCase(Character.toUpperCase(c));
4119 }
4120 }
4121
4122 private static boolean inRange(int lower, int ch, int upper) {
4123 return lower <= ch && ch <= upper;
4124 }
4125
4126 /**
4127 * Returns node for matching characters within an explicit value range.
4128 */
4129 private static CharProperty rangeFor(final int lower,
4130 final int upper) {
4131 return new CharProperty() {
4132 boolean isSatisfiedBy(int ch) {
4133 return inRange(lower, ch, upper);}};
4134 }
4135
4136 /**
4137 * Returns node for matching characters within an explicit value
4138 * range in a case insensitive manner.
4139 */
4140 private CharProperty caseInsensitiveRangeFor(final int lower,
4141 final int upper) {
4142 if (has(UNICODE_CASE))
4143 return new CharProperty() {
4144 boolean isSatisfiedBy(int ch) {
4145 if (inRange(lower, ch, upper))
4146 return true;
4147 int up = Character.toUpperCase(ch);
4148 return inRange(lower, up, upper) ||
4149 inRange(lower, Character.toLowerCase(up), upper);}};
4150 return new CharProperty() {
4151 boolean isSatisfiedBy(int ch) {
4152 return inRange(lower, ch, upper) ||
4153 ASCII.isAscii(ch) &&
4154 (inRange(lower, ASCII.toUpper(ch), upper) ||
4155 inRange(lower, ASCII.toLower(ch), upper));
4156 }};
4157 }
4158
4159 /**
4160 * Implements the Unicode category ALL and the dot metacharacter when
4161 * in dotall mode.
4162 */
4163 static final class All extends CharProperty {
4164 boolean isSatisfiedBy(int ch) {
4165 return true;
4166 }
4167 }
4168
4169 /**
4170 * Node class for the dot metacharacter when dotall is not enabled.
4171 */
4172 static final class Dot extends CharProperty {
4173 boolean isSatisfiedBy(int ch) {
4174 return (ch != '\n' && ch != '\r'
4175 && (ch|1) != '\u2029'
4176 && ch != '\u0085');
4177 }
4178 }
4179
4180 /**
4181 * Node class for the dot metacharacter when dotall is not enabled
4182 * but UNIX_LINES is enabled.
4183 */
4184 static final class UnixDot extends CharProperty {
4185 boolean isSatisfiedBy(int ch) {
4186 return ch != '\n';
4187 }
4188 }
4189
4190 /**
4191 * The 0 or 1 quantifier. This one class implements all three types.
4192 */
4193 static final class Ques extends Node {
4194 Node atom;
4195 int type;
4196 Ques(Node node, int type) {
4197 this.atom = node;
4198 this.type = type;
4199 }
4200 boolean match(Matcher matcher, int i, CharSequence seq) {
4201 switch (type) {
4202 case GREEDY:
4203 return (atom.match(matcher, i, seq) && next.match(matcher, matcher.last, seq))
4204 || next.match(matcher, i, seq);
4205 case LAZY:
4206 return next.match(matcher, i, seq)
4207 || (atom.match(matcher, i, seq) && next.match(matcher, matcher.last, seq));
4208 case POSSESSIVE:
4209 if (atom.match(matcher, i, seq)) i = matcher.last;
4210 return next.match(matcher, i, seq);
4211 default:
4212 return atom.match(matcher, i, seq) && next.match(matcher, matcher.last, seq);
4213 }
4214 }
4215 boolean study(TreeInfo info) {
4216 if (type != INDEPENDENT) {
4217 int minL = info.minLength;
4218 atom.study(info);
4219 info.minLength = minL;
4220 info.deterministic = false;
4221 return next.study(info);
4222 } else {
4223 atom.study(info);
4224 return next.study(info);
4225 }
4226 }
4227 }
4228
4229 /**
4230 * Handles the curly-brace style repetition with a specified minimum and
4231 * maximum occurrences. The * quantifier is handled as a special case.
4232 * This class handles the three types.
4233 */
4234 static final class Curly extends Node {
4235 Node atom;
4236 int type;
4237 int cmin;
4238 int cmax;
4239
4240 Curly(Node node, int cmin, int cmax, int type) {
4241 this.atom = node;
4242 this.type = type;
4243 this.cmin = cmin;
4244 this.cmax = cmax;
4245 }
4246 boolean match(Matcher matcher, int i, CharSequence seq) {
4247 int j;
4248 for (j = 0; j < cmin; j++) {
4249 if (atom.match(matcher, i, seq)) {
4250 i = matcher.last;
4251 continue;
4252 }
4253 return false;
4254 }
4255 if (type == GREEDY)
4256 return match0(matcher, i, j, seq);
4257 else if (type == LAZY)
4258 return match1(matcher, i, j, seq);
4259 else
4260 return match2(matcher, i, j, seq);
4261 }
4262 // Greedy match.
4263 // i is the index to start matching at
4264 // j is the number of atoms that have matched
4265 boolean match0(Matcher matcher, int i, int j, CharSequence seq) {
4266 if (j >= cmax) {
4267 // We have matched the maximum... continue with the rest of
4268 // the regular expression
4269 return next.match(matcher, i, seq);
4270 }
4271 int backLimit = j;
4272 while (atom.match(matcher, i, seq)) {
4273 // k is the length of this match
4274 int k = matcher.last - i;
4275 if (k == 0) // Zero length match
4276 break;
4277 // Move up index and number matched
4278 i = matcher.last;
4279 j++;
4280 // We are greedy so match as many as we can
4281 while (j < cmax) {
4282 if (!atom.match(matcher, i, seq))
4283 break;
4284 if (i + k != matcher.last) {
4285 if (match0(matcher, matcher.last, j+1, seq))
4286 return true;
4287 break;
4288 }
4289 i += k;
4290 j++;
4291 }
4292 // Handle backing off if match fails
4293 while (j >= backLimit) {
4294 if (next.match(matcher, i, seq))
4295 return true;
4296 i -= k;
4297 j--;
4298 }
4299 return false;
4300 }
4301 return next.match(matcher, i, seq);
4302 }
4303 // Reluctant match. At this point, the minimum has been satisfied.
4304 // i is the index to start matching at
4305 // j is the number of atoms that have matched
4306 boolean match1(Matcher matcher, int i, int j, CharSequence seq) {
4307 for (;;) {
4308 // Try finishing match without consuming any more
4309 if (next.match(matcher, i, seq))
4310 return true;
4311 // At the maximum, no match found
4312 if (j >= cmax)
4313 return false;
4314 // Okay, must try one more atom
4315 if (!atom.match(matcher, i, seq))
4316 return false;
4317 // If we haven't moved forward then must break out
4318 if (i == matcher.last)
4319 return false;
4320 // Move up index and number matched
4321 i = matcher.last;
4322 j++;
4323 }
4324 }
4325 boolean match2(Matcher matcher, int i, int j, CharSequence seq) {
4326 for (; j < cmax; j++) {
4327 if (!atom.match(matcher, i, seq))
4328 break;
4329 if (i == matcher.last)
4330 break;
4331 i = matcher.last;
4332 }
4333 return next.match(matcher, i, seq);
4334 }
4335 boolean study(TreeInfo info) {
4336 // Save original info
4337 int minL = info.minLength;
4338 int maxL = info.maxLength;
4339 boolean maxV = info.maxValid;
4340 boolean detm = info.deterministic;
4341 info.reset();
4342
4343 atom.study(info);
4344
4345 int temp = info.minLength * cmin + minL;
4346 if (temp < minL) {
4347 temp = 0xFFFFFFF; // arbitrary large number
4348 }
4349 info.minLength = temp;
4350
4351 if (maxV & info.maxValid) {
4352 temp = info.maxLength * cmax + maxL;
4353 info.maxLength = temp;
4354 if (temp < maxL) {
4355 info.maxValid = false;
4356 }
4357 } else {
4358 info.maxValid = false;
4359 }
4360
4361 if (info.deterministic && cmin == cmax)
4362 info.deterministic = detm;
4363 else
4364 info.deterministic = false;
4365 return next.study(info);
4366 }
4367 }
4368
4369 /**
4370 * Handles the curly-brace style repetition with a specified minimum and
4371 * maximum occurrences in deterministic cases. This is an iterative
4372 * optimization over the Prolog and Loop system which would handle this
4373 * in a recursive way. The * quantifier is handled as a special case.
4374 * If capture is true then this class saves group settings and ensures
4375 * that groups are unset when backing off of a group match.
4376 */
4377 static final class GroupCurly extends Node {
4378 Node atom;
4379 int type;
4380 int cmin;
4381 int cmax;
4382 int localIndex;
4383 int groupIndex;
4384 boolean capture;
4385
4386 GroupCurly(Node node, int cmin, int cmax, int type, int local,
4387 int group, boolean capture) {
4388 this.atom = node;
4389 this.type = type;
4390 this.cmin = cmin;
4391 this.cmax = cmax;
4392 this.localIndex = local;
4393 this.groupIndex = group;
4394 this.capture = capture;
4395 }
4396 boolean match(Matcher matcher, int i, CharSequence seq) {
4397 int[] groups = matcher.groups;
4398 int[] locals = matcher.locals;
4399 int save0 = locals[localIndex];
4400 int save1 = 0;
4401 int save2 = 0;
4402
4403 if (capture) {
4404 save1 = groups[groupIndex];
4405 save2 = groups[groupIndex+1];
4406 }
4407
4408 // Notify GroupTail there is no need to setup group info
4409 // because it will be set here
4410 locals[localIndex] = -1;
4411
4412 boolean ret = true;
4413 for (int j = 0; j < cmin; j++) {
4414 if (atom.match(matcher, i, seq)) {
4415 if (capture) {
4416 groups[groupIndex] = i;
4417 groups[groupIndex+1] = matcher.last;
4418 }
4419 i = matcher.last;
4420 } else {
4421 ret = false;
4422 break;
4423 }
4424 }
4425 if (ret) {
4426 if (type == GREEDY) {
4427 ret = match0(matcher, i, cmin, seq);
4428 } else if (type == LAZY) {
4429 ret = match1(matcher, i, cmin, seq);
4430 } else {
4431 ret = match2(matcher, i, cmin, seq);
4432 }
4433 }
4434 if (!ret) {
4435 locals[localIndex] = save0;
4436 if (capture) {
4437 groups[groupIndex] = save1;
4438 groups[groupIndex+1] = save2;
4439 }
4440 }
4441 return ret;
4442 }
4443 // Aggressive group match
4444 boolean match0(Matcher matcher, int i, int j, CharSequence seq) {
4445 // don't back off passing the starting "j"
4446 int min = j;
4447 int[] groups = matcher.groups;
4448 int save0 = 0;
4449 int save1 = 0;
4450 if (capture) {
4451 save0 = groups[groupIndex];
4452 save1 = groups[groupIndex+1];
4453 }
4454 for (;;) {
4455 if (j >= cmax)
4456 break;
4457 if (!atom.match(matcher, i, seq))
4458 break;
4459 int k = matcher.last - i;
4460 if (k <= 0) {
4461 if (capture) {
4462 groups[groupIndex] = i;
4463 groups[groupIndex+1] = i + k;
4464 }
4465 i = i + k;
4466 break;
4467 }
4468 for (;;) {
4469 if (capture) {
4470 groups[groupIndex] = i;
4471 groups[groupIndex+1] = i + k;
4472 }
4473 i = i + k;
4474 if (++j >= cmax)
4475 break;
4476 if (!atom.match(matcher, i, seq))
4477 break;
4478 if (i + k != matcher.last) {
4479 if (match0(matcher, i, j, seq))
4480 return true;
4481 break;
4482 }
4483 }
4484 while (j > min) {
4485 if (next.match(matcher, i, seq)) {
4486 if (capture) {
4487 groups[groupIndex+1] = i;
4488 groups[groupIndex] = i - k;
4489 }
4490 return true;
4491 }
4492 // backing off
4493 i = i - k;
4494 if (capture) {
4495 groups[groupIndex+1] = i;
4496 groups[groupIndex] = i - k;
4497 }
4498 j--;
4499
4500 }
4501 break;
4502 }
4503 if (capture) {
4504 groups[groupIndex] = save0;
4505 groups[groupIndex+1] = save1;
4506 }
4507 return next.match(matcher, i, seq);
4508 }
4509 // Reluctant matching
4510 boolean match1(Matcher matcher, int i, int j, CharSequence seq) {
4511 for (;;) {
4512 if (next.match(matcher, i, seq))
4513 return true;
4514 if (j >= cmax)
4515 return false;
4516 if (!atom.match(matcher, i, seq))
4517 return false;
4518 if (i == matcher.last)
4519 return false;
4520 if (capture) {
4521 matcher.groups[groupIndex] = i;
4522 matcher.groups[groupIndex+1] = matcher.last;
4523 }
4524 i = matcher.last;
4525 j++;
4526 }
4527 }
4528 // Possessive matching
4529 boolean match2(Matcher matcher, int i, int j, CharSequence seq) {
4530 for (; j < cmax; j++) {
4531 if (!atom.match(matcher, i, seq)) {
4532 break;
4533 }
4534 if (capture) {
4535 matcher.groups[groupIndex] = i;
4536 matcher.groups[groupIndex+1] = matcher.last;
4537 }
4538 if (i == matcher.last) {
4539 break;
4540 }
4541 i = matcher.last;
4542 }
4543 return next.match(matcher, i, seq);
4544 }
4545 boolean study(TreeInfo info) {
4546 // Save original info
4547 int minL = info.minLength;
4548 int maxL = info.maxLength;
4549 boolean maxV = info.maxValid;
4550 boolean detm = info.deterministic;
4551 info.reset();
4552
4553 atom.study(info);
4554
4555 int temp = info.minLength * cmin + minL;
4556 if (temp < minL) {
4557 temp = 0xFFFFFFF; // Arbitrary large number
4558 }
4559 info.minLength = temp;
4560
4561 if (maxV & info.maxValid) {
4562 temp = info.maxLength * cmax + maxL;
4563 info.maxLength = temp;
4564 if (temp < maxL) {
4565 info.maxValid = false;
4566 }
4567 } else {
4568 info.maxValid = false;
4569 }
4570
4571 if (info.deterministic && cmin == cmax) {
4572 info.deterministic = detm;
4573 } else {
4574 info.deterministic = false;
4575 }
4576 return next.study(info);
4577 }
4578 }
4579
4580 /**
4581 * A Guard node at the end of each atom node in a Branch. It
4582 * serves the purpose of chaining the "match" operation to
4583 * "next" but not the "study", so we can collect the TreeInfo
4584 * of each atom node without including the TreeInfo of the
4585 * "next".
4586 */
4587 static final class BranchConn extends Node {
4588 BranchConn() {};
4589 boolean match(Matcher matcher, int i, CharSequence seq) {
4590 return next.match(matcher, i, seq);
4591 }
4592 boolean study(TreeInfo info) {
4593 return info.deterministic;
4594 }
4595 }
4596
4597 /**
4598 * Handles the branching of alternations. Note this is also used for
4599 * the ? quantifier to branch between the case where it matches once
4600 * and where it does not occur.
4601 */
4602 static final class Branch extends Node {
4603 Node[] atoms = new Node[2];
4604 int size = 2;
4605 Node conn;
4606 Branch(Node first, Node second, Node branchConn) {
4607 conn = branchConn;
4608 atoms[0] = first;
4609 atoms[1] = second;
4610 }
4611
4612 void add(Node node) {
4613 if (size >= atoms.length) {
4614 Node[] tmp = new Node[atoms.length*2];
4615 System.arraycopy(atoms, 0, tmp, 0, atoms.length);
4616 atoms = tmp;
4617 }
4618 atoms[size++] = node;
4619 }
4620
4621 boolean match(Matcher matcher, int i, CharSequence seq) {
4622 for (int n = 0; n < size; n++) {
4623 if (atoms[n] == null) {
4624 if (conn.next.match(matcher, i, seq))
4625 return true;
4626 } else if (atoms[n].match(matcher, i, seq)) {
4627 return true;
4628 }
4629 }
4630 return false;
4631 }
4632
4633 boolean study(TreeInfo info) {
4634 int minL = info.minLength;
4635 int maxL = info.maxLength;
4636 boolean maxV = info.maxValid;
4637
4638 int minL2 = Integer.MAX_VALUE; //arbitrary large enough num
4639 int maxL2 = -1;
4640 for (int n = 0; n < size; n++) {
4641 info.reset();
4642 if (atoms[n] != null)
4643 atoms[n].study(info);
4644 minL2 = Math.min(minL2, info.minLength);
4645 maxL2 = Math.max(maxL2, info.maxLength);
4646 maxV = (maxV & info.maxValid);
4647 }
4648
4649 minL += minL2;
4650 maxL += maxL2;
4651
4652 info.reset();
4653 conn.next.study(info);
4654
4655 info.minLength += minL;
4656 info.maxLength += maxL;
4657 info.maxValid &= maxV;
4658 info.deterministic = false;
4659 return false;
4660 }
4661 }
4662
4663 /**
4664 * The GroupHead saves the location where the group begins in the locals
4665 * and restores them when the match is done.
4666 *
4667 * The matchRef is used when a reference to this group is accessed later
4668 * in the expression. The locals will have a negative value in them to
4669 * indicate that we do not want to unset the group if the reference
4670 * doesn't match.
4671 */
4672 static final class GroupHead extends Node {
4673 int localIndex;
4674 GroupHead(int localCount) {
4675 localIndex = localCount;
4676 }
4677 boolean match(Matcher matcher, int i, CharSequence seq) {
4678 int save = matcher.locals[localIndex];
4679 matcher.locals[localIndex] = i;
4680 boolean ret = next.match(matcher, i, seq);
4681 matcher.locals[localIndex] = save;
4682 return ret;
4683 }
4684 boolean matchRef(Matcher matcher, int i, CharSequence seq) {
4685 int save = matcher.locals[localIndex];
4686 matcher.locals[localIndex] = ~i; // HACK
4687 boolean ret = next.match(matcher, i, seq);
4688 matcher.locals[localIndex] = save;
4689 return ret;
4690 }
4691 }
4692
4693 /**
4694 * Recursive reference to a group in the regular expression. It calls
4695 * matchRef because if the reference fails to match we would not unset
4696 * the group.
4697 */
4698 static final class GroupRef extends Node {
4699 GroupHead head;
4700 GroupRef(GroupHead head) {
4701 this.head = head;
4702 }
4703 boolean match(Matcher matcher, int i, CharSequence seq) {
4704 return head.matchRef(matcher, i, seq)
4705 && next.match(matcher, matcher.last, seq);
4706 }
4707 boolean study(TreeInfo info) {
4708 info.maxValid = false;
4709 info.deterministic = false;
4710 return next.study(info);
4711 }
4712 }
4713
4714 /**
4715 * The GroupTail handles the setting of group beginning and ending
4716 * locations when groups are successfully matched. It must also be able to
4717 * unset groups that have to be backed off of.
4718 *
4719 * The GroupTail node is also used when a previous group is referenced,
4720 * and in that case no group information needs to be set.
4721 */
4722 static final class GroupTail extends Node {
4723 int localIndex;
4724 int groupIndex;
4725 GroupTail(int localCount, int groupCount) {
4726 localIndex = localCount;
4727 groupIndex = groupCount + groupCount;
4728 }
4729 boolean match(Matcher matcher, int i, CharSequence seq) {
4730 int tmp = matcher.locals[localIndex];
4731 if (tmp >= 0) { // This is the normal group case.
4732 // Save the group so we can unset it if it
4733 // backs off of a match.
4734 int groupStart = matcher.groups[groupIndex];
4735 int groupEnd = matcher.groups[groupIndex+1];
4736
4737 matcher.groups[groupIndex] = tmp;
4738 matcher.groups[groupIndex+1] = i;
4739 if (next.match(matcher, i, seq)) {
4740 return true;
4741 }
4742 matcher.groups[groupIndex] = groupStart;
4743 matcher.groups[groupIndex+1] = groupEnd;
4744 return false;
4745 } else {
4746 // This is a group reference case. We don't need to save any
4747 // group info because it isn't really a group.
4748 matcher.last = i;
4749 return true;
4750 }
4751 }
4752 }
4753
4754 /**
4755 * This sets up a loop to handle a recursive quantifier structure.
4756 */
4757 static final class Prolog extends Node {
4758 Loop loop;
4759 Prolog(Loop loop) {
4760 this.loop = loop;
4761 }
4762 boolean match(Matcher matcher, int i, CharSequence seq) {
4763 return loop.matchInit(matcher, i, seq);
4764 }
4765 boolean study(TreeInfo info) {
4766 return loop.study(info);
4767 }
4768 }
4769
4770 /**
4771 * Handles the repetition count for a greedy Curly. The matchInit
4772 * is called from the Prolog to save the index of where the group
4773 * beginning is stored. A zero length group check occurs in the
4774 * normal match but is skipped in the matchInit.
4775 */
4776 static class Loop extends Node {
4777 Node body;
4778 int countIndex; // local count index in matcher locals
4779 int beginIndex; // group beginning index
4780 int cmin, cmax;
4781 Loop(int countIndex, int beginIndex) {
4782 this.countIndex = countIndex;
4783 this.beginIndex = beginIndex;
4784 }
4785 boolean match(Matcher matcher, int i, CharSequence seq) {
4786 // Avoid infinite loop in zero-length case.
4787 if (i > matcher.locals[beginIndex]) {
4788 int count = matcher.locals[countIndex];
4789
4790 // This block is for before we reach the minimum
4791 // iterations required for the loop to match
4792 if (count < cmin) {
4793 matcher.locals[countIndex] = count + 1;
4794 boolean b = body.match(matcher, i, seq);
4795 // If match failed we must backtrack, so
4796 // the loop count should NOT be incremented
4797 if (!b)
4798 matcher.locals[countIndex] = count;
4799 // Return success or failure since we are under
4800 // minimum
4801 return b;
4802 }
4803 // This block is for after we have the minimum
4804 // iterations required for the loop to match
4805 if (count < cmax) {
4806 matcher.locals[countIndex] = count + 1;
4807 boolean b = body.match(matcher, i, seq);
4808 // If match failed we must backtrack, so
4809 // the loop count should NOT be incremented
4810 if (!b)
4811 matcher.locals[countIndex] = count;
4812 else
4813 return true;
4814 }
4815 }
4816 return next.match(matcher, i, seq);
4817 }
4818 boolean matchInit(Matcher matcher, int i, CharSequence seq) {
4819 int save = matcher.locals[countIndex];
4820 boolean ret = false;
4821 if (0 < cmin) {
4822 matcher.locals[countIndex] = 1;
4823 ret = body.match(matcher, i, seq);
4824 } else if (0 < cmax) {
4825 matcher.locals[countIndex] = 1;
4826 ret = body.match(matcher, i, seq);
4827 if (ret == false)
4828 ret = next.match(matcher, i, seq);
4829 } else {
4830 ret = next.match(matcher, i, seq);
4831 }
4832 matcher.locals[countIndex] = save;
4833 return ret;
4834 }
4835 boolean study(TreeInfo info) {
4836 info.maxValid = false;
4837 info.deterministic = false;
4838 return false;
4839 }
4840 }
4841
4842 /**
4843 * Handles the repetition count for a reluctant Curly. The matchInit
4844 * is called from the Prolog to save the index of where the group
4845 * beginning is stored. A zero length group check occurs in the
4846 * normal match but is skipped in the matchInit.
4847 */
4848 static final class LazyLoop extends Loop {
4849 LazyLoop(int countIndex, int beginIndex) {
4850 super(countIndex, beginIndex);
4851 }
4852 boolean match(Matcher matcher, int i, CharSequence seq) {
4853 // Check for zero length group
4854 if (i > matcher.locals[beginIndex]) {
4855 int count = matcher.locals[countIndex];
4856 if (count < cmin) {
4857 matcher.locals[countIndex] = count + 1;
4858 boolean result = body.match(matcher, i, seq);
4859 // If match failed we must backtrack, so
4860 // the loop count should NOT be incremented
4861 if (!result)
4862 matcher.locals[countIndex] = count;
4863 return result;
4864 }
4865 if (next.match(matcher, i, seq))
4866 return true;
4867 if (count < cmax) {
4868 matcher.locals[countIndex] = count + 1;
4869 boolean result = body.match(matcher, i, seq);
4870 // If match failed we must backtrack, so
4871 // the loop count should NOT be incremented
4872 if (!result)
4873 matcher.locals[countIndex] = count;
4874 return result;
4875 }
4876 return false;
4877 }
4878 return next.match(matcher, i, seq);
4879 }
4880 boolean matchInit(Matcher matcher, int i, CharSequence seq) {
4881 int save = matcher.locals[countIndex];
4882 boolean ret = false;
4883 if (0 < cmin) {
4884 matcher.locals[countIndex] = 1;
4885 ret = body.match(matcher, i, seq);
4886 } else if (next.match(matcher, i, seq)) {
4887 ret = true;
4888 } else if (0 < cmax) {
4889 matcher.locals[countIndex] = 1;
4890 ret = body.match(matcher, i, seq);
4891 }
4892 matcher.locals[countIndex] = save;
4893 return ret;
4894 }
4895 boolean study(TreeInfo info) {
4896 info.maxValid = false;
4897 info.deterministic = false;
4898 return false;
4899 }
4900 }
4901
4902 /**
4903 * Refers to a group in the regular expression. Attempts to match
4904 * whatever the group referred to last matched.
4905 */
4906 static class BackRef extends Node {
4907 int groupIndex;
4908 BackRef(int groupCount) {
4909 super();
4910 groupIndex = groupCount + groupCount;
4911 }
4912 boolean match(Matcher matcher, int i, CharSequence seq) {
4913 int j = matcher.groups[groupIndex];
4914 int k = matcher.groups[groupIndex+1];
4915
4916 int groupSize = k - j;
4917 // If the referenced group didn't match, neither can this
4918 if (j < 0)
4919 return false;
4920
4921 // If there isn't enough input left no match
4922 if (i + groupSize > matcher.to) {
4923 matcher.hitEnd = true;
4924 return false;
4925 }
4926 // Check each new char to make sure it matches what the group
4927 // referenced matched last time around
4928 for (int index=0; index<groupSize; index++)
4929 if (seq.charAt(i+index) != seq.charAt(j+index))
4930 return false;
4931
4932 return next.match(matcher, i+groupSize, seq);
4933 }
4934 boolean study(TreeInfo info) {
4935 info.maxValid = false;
4936 return next.study(info);
4937 }
4938 }
4939
4940 static class CIBackRef extends Node {
4941 int groupIndex;
4942 boolean doUnicodeCase;
4943 CIBackRef(int groupCount, boolean doUnicodeCase) {
4944 super();
4945 groupIndex = groupCount + groupCount;
4946 this.doUnicodeCase = doUnicodeCase;
4947 }
4948 boolean match(Matcher matcher, int i, CharSequence seq) {
4949 int j = matcher.groups[groupIndex];
4950 int k = matcher.groups[groupIndex+1];
4951
4952 int groupSize = k - j;
4953
4954 // If the referenced group didn't match, neither can this
4955 if (j < 0)
4956 return false;
4957
4958 // If there isn't enough input left no match
4959 if (i + groupSize > matcher.to) {
4960 matcher.hitEnd = true;
4961 return false;
4962 }
4963
4964 // Check each new char to make sure it matches what the group
4965 // referenced matched last time around
4966 int x = i;
4967 for (int index=0; index<groupSize; index++) {
4968 int c1 = Character.codePointAt(seq, x);
4969 int c2 = Character.codePointAt(seq, j);
4970 if (c1 != c2) {
4971 if (doUnicodeCase) {
4972 int cc1 = Character.toUpperCase(c1);
4973 int cc2 = Character.toUpperCase(c2);
4974 if (cc1 != cc2 &&
4975 Character.toLowerCase(cc1) !=
4976 Character.toLowerCase(cc2))
4977 return false;
4978 } else {
4979 if (ASCII.toLower(c1) != ASCII.toLower(c2))
4980 return false;
4981 }
4982 }
4983 x += Character.charCount(c1);
4984 j += Character.charCount(c2);
4985 }
4986
4987 return next.match(matcher, i+groupSize, seq);
4988 }
4989 boolean study(TreeInfo info) {
4990 info.maxValid = false;
4991 return next.study(info);
4992 }
4993 }
4994
4995 /**
4996 * Searches until the next instance of its atom. This is useful for
4997 * finding the atom efficiently without passing an instance of it
4998 * (greedy problem) and without a lot of wasted search time (reluctant
4999 * problem).
5000 */
5001 static final class First extends Node {
5002 Node atom;
5003 First(Node node) {
5004 this.atom = BnM.optimize(node);
5005 }
5006 boolean match(Matcher matcher, int i, CharSequence seq) {
5007 if (atom instanceof BnM) {
5008 return atom.match(matcher, i, seq)
5009 && next.match(matcher, matcher.last, seq);
5010 }
5011 for (;;) {
5012 if (i > matcher.to) {
5013 matcher.hitEnd = true;
5014 return false;
5015 }
5016 if (atom.match(matcher, i, seq)) {
5017 return next.match(matcher, matcher.last, seq);
5018 }
5019 i += countChars(seq, i, 1);
5020 matcher.first++;
5021 }
5022 }
5023 boolean study(TreeInfo info) {
5024 atom.study(info);
5025 info.maxValid = false;
5026 info.deterministic = false;
5027 return next.study(info);
5028 }
5029 }
5030
5031 static final class Conditional extends Node {
5032 Node cond, yes, not;
5033 Conditional(Node cond, Node yes, Node not) {
5034 this.cond = cond;
5035 this.yes = yes;
5036 this.not = not;
5037 }
5038 boolean match(Matcher matcher, int i, CharSequence seq) {
5039 if (cond.match(matcher, i, seq)) {
5040 return yes.match(matcher, i, seq);
5041 } else {
5042 return not.match(matcher, i, seq);
5043 }
5044 }
5045 boolean study(TreeInfo info) {
5046 int minL = info.minLength;
5047 int maxL = info.maxLength;
5048 boolean maxV = info.maxValid;
5049 info.reset();
5050 yes.study(info);
5051
5052 int minL2 = info.minLength;
5053 int maxL2 = info.maxLength;
5054 boolean maxV2 = info.maxValid;
5055 info.reset();
5056 not.study(info);
5057
5058 info.minLength = minL + Math.min(minL2, info.minLength);
5059 info.maxLength = maxL + Math.max(maxL2, info.maxLength);
5060 info.maxValid = (maxV & maxV2 & info.maxValid);
5061 info.deterministic = false;
5062 return next.study(info);
5063 }
5064 }
5065
5066 /**
5067 * Zero width positive lookahead.
5068 */
5069 static final class Pos extends Node {
5070 Node cond;
5071 Pos(Node cond) {
5072 this.cond = cond;
5073 }
5074 boolean match(Matcher matcher, int i, CharSequence seq) {
5075 int savedTo = matcher.to;
5076 boolean conditionMatched = false;
5077
5078 // Relax transparent region boundaries for lookahead
5079 if (matcher.transparentBounds)
5080 matcher.to = matcher.getTextLength();
5081 try {
5082 conditionMatched = cond.match(matcher, i, seq);
5083 } finally {
5084 // Reinstate region boundaries
5085 matcher.to = savedTo;
5086 }
5087 return conditionMatched && next.match(matcher, i, seq);
5088 }
5089 }
5090
5091 /**
5092 * Zero width negative lookahead.
5093 */
5094 static final class Neg extends Node {
5095 Node cond;
5096 Neg(Node cond) {
5097 this.cond = cond;
5098 }
5099 boolean match(Matcher matcher, int i, CharSequence seq) {
5100 int savedTo = matcher.to;
5101 boolean conditionMatched = false;
5102
5103 // Relax transparent region boundaries for lookahead
5104 if (matcher.transparentBounds)
5105 matcher.to = matcher.getTextLength();
5106 try {
5107 if (i < matcher.to) {
5108 conditionMatched = !cond.match(matcher, i, seq);
5109 } else {
5110 // If a negative lookahead succeeds then more input
5111 // could cause it to fail!
5112 matcher.requireEnd = true;
5113 conditionMatched = !cond.match(matcher, i, seq);
5114 }
5115 } finally {
5116 // Reinstate region boundaries
5117 matcher.to = savedTo;
5118 }
5119 return conditionMatched && next.match(matcher, i, seq);
5120 }
5121 }
5122
5123 /**
5124 * For use with lookbehinds; matches the position where the lookbehind
5125 * was encountered.
5126 */
5127 static Node lookbehindEnd = new Node() {
5128 boolean match(Matcher matcher, int i, CharSequence seq) {
5129 return i == matcher.lookbehindTo;
5130 }
5131 };
5132
5133 /**
5134 * Zero width positive lookbehind.
5135 */
5136 static class Behind extends Node {
5137 Node cond;
5138 int rmax, rmin;
5139 Behind(Node cond, int rmax, int rmin) {
5140 this.cond = cond;
5141 this.rmax = rmax;
5142 this.rmin = rmin;
5143 }
5144
5145 boolean match(Matcher matcher, int i, CharSequence seq) {
5146 int savedFrom = matcher.from;
5147 boolean conditionMatched = false;
5148 int startIndex = (!matcher.transparentBounds) ?
5149 matcher.from : 0;
5150 int from = Math.max(i - rmax, startIndex);
5151 // Set end boundary
5152 int savedLBT = matcher.lookbehindTo;
5153 matcher.lookbehindTo = i;
5154 // Relax transparent region boundaries for lookbehind
5155 if (matcher.transparentBounds)
5156 matcher.from = 0;
5157 for (int j = i - rmin; !conditionMatched && j >= from; j--) {
5158 conditionMatched = cond.match(matcher, j, seq);
5159 }
5160 matcher.from = savedFrom;
5161 matcher.lookbehindTo = savedLBT;
5162 return conditionMatched && next.match(matcher, i, seq);
5163 }
5164 }
5165
5166 /**
5167 * Zero width positive lookbehind, including supplementary
5168 * characters or unpaired surrogates.
5169 */
5170 static final class BehindS extends Behind {
5171 BehindS(Node cond, int rmax, int rmin) {
5172 super(cond, rmax, rmin);
5173 }
5174 boolean match(Matcher matcher, int i, CharSequence seq) {
5175 int rmaxChars = countChars(seq, i, -rmax);
5176 int rminChars = countChars(seq, i, -rmin);
5177 int savedFrom = matcher.from;
5178 int startIndex = (!matcher.transparentBounds) ?
5179 matcher.from : 0;
5180 boolean conditionMatched = false;
5181 int from = Math.max(i - rmaxChars, startIndex);
5182 // Set end boundary
5183 int savedLBT = matcher.lookbehindTo;
5184 matcher.lookbehindTo = i;
5185 // Relax transparent region boundaries for lookbehind
5186 if (matcher.transparentBounds)
5187 matcher.from = 0;
5188
5189 for (int j = i - rminChars;
5190 !conditionMatched && j >= from;
5191 j -= j>from ? countChars(seq, j, -1) : 1) {
5192 conditionMatched = cond.match(matcher, j, seq);
5193 }
5194 matcher.from = savedFrom;
5195 matcher.lookbehindTo = savedLBT;
5196 return conditionMatched && next.match(matcher, i, seq);
5197 }
5198 }
5199
5200 /**
5201 * Zero width negative lookbehind.
5202 */
5203 static class NotBehind extends Node {
5204 Node cond;
5205 int rmax, rmin;
5206 NotBehind(Node cond, int rmax, int rmin) {
5207 this.cond = cond;
5208 this.rmax = rmax;
5209 this.rmin = rmin;
5210 }
5211
5212 boolean match(Matcher matcher, int i, CharSequence seq) {
5213 int savedLBT = matcher.lookbehindTo;
5214 int savedFrom = matcher.from;
5215 boolean conditionMatched = false;
5216 int startIndex = (!matcher.transparentBounds) ?
5217 matcher.from : 0;
5218 int from = Math.max(i - rmax, startIndex);
5219 matcher.lookbehindTo = i;
5220 // Relax transparent region boundaries for lookbehind
5221 if (matcher.transparentBounds)
5222 matcher.from = 0;
5223 for (int j = i - rmin; !conditionMatched && j >= from; j--) {
5224 conditionMatched = cond.match(matcher, j, seq);
5225 }
5226 // Reinstate region boundaries
5227 matcher.from = savedFrom;
5228 matcher.lookbehindTo = savedLBT;
5229 return !conditionMatched && next.match(matcher, i, seq);
5230 }
5231 }
5232
5233 /**
5234 * Zero width negative lookbehind, including supplementary
5235 * characters or unpaired surrogates.
5236 */
5237 static final class NotBehindS extends NotBehind {
5238 NotBehindS(Node cond, int rmax, int rmin) {
5239 super(cond, rmax, rmin);
5240 }
5241 boolean match(Matcher matcher, int i, CharSequence seq) {
5242 int rmaxChars = countChars(seq, i, -rmax);
5243 int rminChars = countChars(seq, i, -rmin);
5244 int savedFrom = matcher.from;
5245 int savedLBT = matcher.lookbehindTo;
5246 boolean conditionMatched = false;
5247 int startIndex = (!matcher.transparentBounds) ?
5248 matcher.from : 0;
5249 int from = Math.max(i - rmaxChars, startIndex);
5250 matcher.lookbehindTo = i;
5251 // Relax transparent region boundaries for lookbehind
5252 if (matcher.transparentBounds)
5253 matcher.from = 0;
5254 for (int j = i - rminChars;
5255 !conditionMatched && j >= from;
5256 j -= j>from ? countChars(seq, j, -1) : 1) {
5257 conditionMatched = cond.match(matcher, j, seq);
5258 }
5259 //Reinstate region boundaries
5260 matcher.from = savedFrom;
5261 matcher.lookbehindTo = savedLBT;
5262 return !conditionMatched && next.match(matcher, i, seq);
5263 }
5264 }
5265
5266 /**
5267 * Returns the set union of two CharProperty nodes.
5268 */
5269 private static CharProperty union(final CharProperty lhs,
5270 final CharProperty rhs) {
5271 return new CharProperty() {
5272 boolean isSatisfiedBy(int ch) {
5273 return lhs.isSatisfiedBy(ch) || rhs.isSatisfiedBy(ch);}};
5274 }
5275
5276 /**
5277 * Returns the set intersection of two CharProperty nodes.
5278 */
5279 private static CharProperty intersection(final CharProperty lhs,
5280 final CharProperty rhs) {
5281 return new CharProperty() {
5282 boolean isSatisfiedBy(int ch) {
5283 return lhs.isSatisfiedBy(ch) && rhs.isSatisfiedBy(ch);}};
5284 }
5285
5286 /**
5287 * Returns the set difference of two CharProperty nodes.
5288 */
5289 private static CharProperty setDifference(final CharProperty lhs,
5290 final CharProperty rhs) {
5291 return new CharProperty() {
5292 boolean isSatisfiedBy(int ch) {
5293 return ! rhs.isSatisfiedBy(ch) && lhs.isSatisfiedBy(ch);}};
5294 }
5295
5296 /**
5297 * Handles word boundaries. Includes a field to allow this one class to
5298 * deal with the different types of word boundaries we can match. The word
5299 * characters include underscores, letters, and digits. Non spacing marks
5300 * can are also part of a word if they have a base character, otherwise
5301 * they are ignored for purposes of finding word boundaries.
5302 */
5303 static final class Bound extends Node {
5304 static int LEFT = 0x1;
5305 static int RIGHT= 0x2;
5306 static int BOTH = 0x3;
5307 static int NONE = 0x4;
5308 int type;
5309 boolean useUWORD;
5310 Bound(int n, boolean useUWORD) {
5311 type = n;
5312 this.useUWORD = useUWORD;
5313 }
5314
5315 boolean isWord(int ch) {
5316 return useUWORD ? UnicodeProp.WORD.is(ch)
5317 : (ch == '_' || Character.isLetterOrDigit(ch));
5318 }
5319
5320 int check(Matcher matcher, int i, CharSequence seq) {
5321 int ch;
5322 boolean left = false;
5323 int startIndex = matcher.from;
5324 int endIndex = matcher.to;
5325 if (matcher.transparentBounds) {
5326 startIndex = 0;
5327 endIndex = matcher.getTextLength();
5328 }
5329 if (i > startIndex) {
5330 ch = Character.codePointBefore(seq, i);
5331 left = (isWord(ch) ||
5332 ((Character.getType(ch) == Character.NON_SPACING_MARK)
5333 && hasBaseCharacter(matcher, i-1, seq)));
5334 }
5335 boolean right = false;
5336 if (i < endIndex) {
5337 ch = Character.codePointAt(seq, i);
5338 right = (isWord(ch) ||
5339 ((Character.getType(ch) == Character.NON_SPACING_MARK)
5340 && hasBaseCharacter(matcher, i, seq)));
5341 } else {
5342 // Tried to access char past the end
5343 matcher.hitEnd = true;
5344 // The addition of another char could wreck a boundary
5345 matcher.requireEnd = true;
5346 }
5347 return ((left ^ right) ? (right ? LEFT : RIGHT) : NONE);
5348 }
5349 boolean match(Matcher matcher, int i, CharSequence seq) {
5350 return (check(matcher, i, seq) & type) > 0
5351 && next.match(matcher, i, seq);
5352 }
5353 }
5354
5355 /**
5356 * Non spacing marks only count as word characters in bounds calculations
5357 * if they have a base character.
5358 */
5359 private static boolean hasBaseCharacter(Matcher matcher, int i,
5360 CharSequence seq)
5361 {
5362 int start = (!matcher.transparentBounds) ?
5363 matcher.from : 0;
5364 for (int x=i; x >= start; x--) {
5365 int ch = Character.codePointAt(seq, x);
5366 if (Character.isLetterOrDigit(ch))
5367 return true;
5368 if (Character.getType(ch) == Character.NON_SPACING_MARK)
5369 continue;
5370 return false;
5371 }
5372 return false;
5373 }
5374
5375 /**
5376 * Attempts to match a slice in the input using the Boyer-Moore string
5377 * matching algorithm. The algorithm is based on the idea that the
5378 * pattern can be shifted farther ahead in the search text if it is
5379 * matched right to left.
5380 * <p>
5381 * The pattern is compared to the input one character at a time, from
5382 * the rightmost character in the pattern to the left. If the characters
5383 * all match the pattern has been found. If a character does not match,
5384 * the pattern is shifted right a distance that is the maximum of two
5385 * functions, the bad character shift and the good suffix shift. This
5386 * shift moves the attempted match position through the input more
5387 * quickly than a naive one position at a time check.
5388 * <p>
5389 * The bad character shift is based on the character from the text that
5390 * did not match. If the character does not appear in the pattern, the
5391 * pattern can be shifted completely beyond the bad character. If the
5392 * character does occur in the pattern, the pattern can be shifted to
5393 * line the pattern up with the next occurrence of that character.
5394 * <p>
5395 * The good suffix shift is based on the idea that some subset on the right
5396 * side of the pattern has matched. When a bad character is found, the
5397 * pattern can be shifted right by the pattern length if the subset does
5398 * not occur again in pattern, or by the amount of distance to the
5399 * next occurrence of the subset in the pattern.
5400 *
5401 * Boyer-Moore search methods adapted from code by Amy Yu.
5402 */
5403 static class BnM extends Node {
5404 int[] buffer;
5405 int[] lastOcc;
5406 int[] optoSft;
5407
5408 /**
5409 * Pre calculates arrays needed to generate the bad character
5410 * shift and the good suffix shift. Only the last seven bits
5411 * are used to see if chars match; This keeps the tables small
5412 * and covers the heavily used ASCII range, but occasionally
5413 * results in an aliased match for the bad character shift.
5414 */
5415 static Node optimize(Node node) {
5416 if (!(node instanceof Slice)) {
5417 return node;
5418 }
5419
5420 int[] src = ((Slice) node).buffer;
5421 int patternLength = src.length;
5422 // The BM algorithm requires a bit of overhead;
5423 // If the pattern is short don't use it, since
5424 // a shift larger than the pattern length cannot
5425 // be used anyway.
5426 if (patternLength < 4) {
5427 return node;
5428 }
5429 int i, j, k;
5430 int[] lastOcc = new int[128];
5431 int[] optoSft = new int[patternLength];
5432 // Precalculate part of the bad character shift
5433 // It is a table for where in the pattern each
5434 // lower 7-bit value occurs
5435 for (i = 0; i < patternLength; i++) {
5436 lastOcc[src[i]&0x7F] = i + 1;
5437 }
5438 // Precalculate the good suffix shift
5439 // i is the shift amount being considered
5440 NEXT: for (i = patternLength; i > 0; i--) {
5441 // j is the beginning index of suffix being considered
5442 for (j = patternLength - 1; j >= i; j--) {
5443 // Testing for good suffix
5444 if (src[j] == src[j-i]) {
5445 // src[j..len] is a good suffix
5446 optoSft[j-1] = i;
5447 } else {
5448 // No match. The array has already been
5449 // filled up with correct values before.
5450 continue NEXT;
5451 }
5452 }
5453 // This fills up the remaining of optoSft
5454 // any suffix can not have larger shift amount
5455 // then its sub-suffix. Why???
5456 while (j > 0) {
5457 optoSft[--j] = i;
5458 }
5459 }
5460 // Set the guard value because of unicode compression
5461 optoSft[patternLength-1] = 1;
5462 if (node instanceof SliceS)
5463 return new BnMS(src, lastOcc, optoSft, node.next);
5464 return new BnM(src, lastOcc, optoSft, node.next);
5465 }
5466 BnM(int[] src, int[] lastOcc, int[] optoSft, Node next) {
5467 this.buffer = src;
5468 this.lastOcc = lastOcc;
5469 this.optoSft = optoSft;
5470 this.next = next;
5471 }
5472 boolean match(Matcher matcher, int i, CharSequence seq) {
5473 int[] src = buffer;
5474 int patternLength = src.length;
5475 int last = matcher.to - patternLength;
5476
5477 // Loop over all possible match positions in text
5478 NEXT: while (i <= last) {
5479 // Loop over pattern from right to left
5480 for (int j = patternLength - 1; j >= 0; j--) {
5481 int ch = seq.charAt(i+j);
5482 if (ch != src[j]) {
5483 // Shift search to the right by the maximum of the
5484 // bad character shift and the good suffix shift
5485 i += Math.max(j + 1 - lastOcc[ch&0x7F], optoSft[j]);
5486 continue NEXT;
5487 }
5488 }
5489 // Entire pattern matched starting at i
5490 matcher.first = i;
5491 boolean ret = next.match(matcher, i + patternLength, seq);
5492 if (ret) {
5493 matcher.first = i;
5494 matcher.groups[0] = matcher.first;
5495 matcher.groups[1] = matcher.last;
5496 return true;
5497 }
5498 i++;
5499 }
5500 // BnM is only used as the leading node in the unanchored case,
5501 // and it replaced its Start() which always searches to the end
5502 // if it doesn't find what it's looking for, so hitEnd is true.
5503 matcher.hitEnd = true;
5504 return false;
5505 }
5506 boolean study(TreeInfo info) {
5507 info.minLength += buffer.length;
5508 info.maxValid = false;
5509 return next.study(info);
5510 }
5511 }
5512
5513 /**
5514 * Supplementary support version of BnM(). Unpaired surrogates are
5515 * also handled by this class.
5516 */
5517 static final class BnMS extends BnM {
5518 int lengthInChars;
5519
5520 BnMS(int[] src, int[] lastOcc, int[] optoSft, Node next) {
5521 super(src, lastOcc, optoSft, next);
5522 for (int cp : buffer) {
5523 lengthInChars += Character.charCount(cp);
5524 }
5525 }
5526 boolean match(Matcher matcher, int i, CharSequence seq) {
5527 int[] src = buffer;
5528 int patternLength = src.length;
5529 int last = matcher.to - lengthInChars;
5530
5531 // Loop over all possible match positions in text
5532 NEXT: while (i <= last) {
5533 // Loop over pattern from right to left
5534 int ch;
5535 for (int j = countChars(seq, i, patternLength), x = patternLength - 1;
5536 j > 0; j -= Character.charCount(ch), x--) {
5537 ch = Character.codePointBefore(seq, i+j);
5538 if (ch != src[x]) {
5539 // Shift search to the right by the maximum of the
5540 // bad character shift and the good suffix shift
5541 int n = Math.max(x + 1 - lastOcc[ch&0x7F], optoSft[x]);
5542 i += countChars(seq, i, n);
5543 continue NEXT;
5544 }
5545 }
5546 // Entire pattern matched starting at i
5547 matcher.first = i;
5548 boolean ret = next.match(matcher, i + lengthInChars, seq);
5549 if (ret) {
5550 matcher.first = i;
5551 matcher.groups[0] = matcher.first;
5552 matcher.groups[1] = matcher.last;
5553 return true;
5554 }
5555 i += countChars(seq, i, 1);
5556 }
5557 matcher.hitEnd = true;
5558 return false;
5559 }
5560 }
5561
5562 ///////////////////////////////////////////////////////////////////////////////
5563 ///////////////////////////////////////////////////////////////////////////////
5564
5565 /**
5566 * This must be the very first initializer.
5567 */
5568 static Node accept = new Node();
5569
5570 static Node lastAccept = new LastNode();
5571
5572 private static class CharPropertyNames {
5573
5574 static CharProperty charPropertyFor(String name) {
5575 CharPropertyFactory m = map.get(name);
5576 return m == null ? null : m.make();
5577 }
5578
5579 private static abstract class CharPropertyFactory {
5580 abstract CharProperty make();
5581 }
5582
5583 private static void defCategory(String name,
5584 final int typeMask) {
5585 map.put(name, new CharPropertyFactory() {
5586 CharProperty make() { return new Category(typeMask);}});
5587 }
5588
5589 private static void defRange(String name,
5590 final int lower, final int upper) {
5591 map.put(name, new CharPropertyFactory() {
5592 CharProperty make() { return rangeFor(lower, upper);}});
5593 }
5594
5595 private static void defCtype(String name,
5596 final int ctype) {
5597 map.put(name, new CharPropertyFactory() {
5598 CharProperty make() { return new Ctype(ctype);}});
5599 }
5600
5601 private static abstract class CloneableProperty
5602 extends CharProperty implements Cloneable
5603 {
5604 public CloneableProperty clone() {
5605 try {
5606 return (CloneableProperty) super.clone();
5607 } catch (CloneNotSupportedException e) {
5608 throw new AssertionError(e);
5609 }
5610 }
5611 }
5612
5613 private static void defClone(String name,
5614 final CloneableProperty p) {
5615 map.put(name, new CharPropertyFactory() {
5616 CharProperty make() { return p.clone();}});
5617 }
5618
5619 private static final HashMap<String, CharPropertyFactory> map
5620 = new HashMap<>();
5621
5622 static {
5623 // Unicode character property aliases, defined in
5624 // http://www.unicode.org/Public/UNIDATA/PropertyValueAliases.txt
5625 defCategory("Cn", 1<<Character.UNASSIGNED);
5626 defCategory("Lu", 1<<Character.UPPERCASE_LETTER);
5627 defCategory("Ll", 1<<Character.LOWERCASE_LETTER);
5628 defCategory("Lt", 1<<Character.TITLECASE_LETTER);
5629 defCategory("Lm", 1<<Character.MODIFIER_LETTER);
5630 defCategory("Lo", 1<<Character.OTHER_LETTER);
5631 defCategory("Mn", 1<<Character.NON_SPACING_MARK);
5632 defCategory("Me", 1<<Character.ENCLOSING_MARK);
5633 defCategory("Mc", 1<<Character.COMBINING_SPACING_MARK);
5634 defCategory("Nd", 1<<Character.DECIMAL_DIGIT_NUMBER);
5635 defCategory("Nl", 1<<Character.LETTER_NUMBER);
5636 defCategory("No", 1<<Character.OTHER_NUMBER);
5637 defCategory("Zs", 1<<Character.SPACE_SEPARATOR);
5638 defCategory("Zl", 1<<Character.LINE_SEPARATOR);
5639 defCategory("Zp", 1<<Character.PARAGRAPH_SEPARATOR);
5640 defCategory("Cc", 1<<Character.CONTROL);
5641 defCategory("Cf", 1<<Character.FORMAT);
5642 defCategory("Co", 1<<Character.PRIVATE_USE);
5643 defCategory("Cs", 1<<Character.SURROGATE);
5644 defCategory("Pd", 1<<Character.DASH_PUNCTUATION);
5645 defCategory("Ps", 1<<Character.START_PUNCTUATION);
5646 defCategory("Pe", 1<<Character.END_PUNCTUATION);
5647 defCategory("Pc", 1<<Character.CONNECTOR_PUNCTUATION);
5648 defCategory("Po", 1<<Character.OTHER_PUNCTUATION);
5649 defCategory("Sm", 1<<Character.MATH_SYMBOL);
5650 defCategory("Sc", 1<<Character.CURRENCY_SYMBOL);
5651 defCategory("Sk", 1<<Character.MODIFIER_SYMBOL);
5652 defCategory("So", 1<<Character.OTHER_SYMBOL);
5653 defCategory("Pi", 1<<Character.INITIAL_QUOTE_PUNCTUATION);
5654 defCategory("Pf", 1<<Character.FINAL_QUOTE_PUNCTUATION);
5655 defCategory("L", ((1<<Character.UPPERCASE_LETTER) |
5656 (1<<Character.LOWERCASE_LETTER) |
5657 (1<<Character.TITLECASE_LETTER) |
5658 (1<<Character.MODIFIER_LETTER) |
5659 (1<<Character.OTHER_LETTER)));
5660 defCategory("M", ((1<<Character.NON_SPACING_MARK) |
5661 (1<<Character.ENCLOSING_MARK) |
5662 (1<<Character.COMBINING_SPACING_MARK)));
5663 defCategory("N", ((1<<Character.DECIMAL_DIGIT_NUMBER) |
5664 (1<<Character.LETTER_NUMBER) |
5665 (1<<Character.OTHER_NUMBER)));
5666 defCategory("Z", ((1<<Character.SPACE_SEPARATOR) |
5667 (1<<Character.LINE_SEPARATOR) |
5668 (1<<Character.PARAGRAPH_SEPARATOR)));
5669 defCategory("C", ((1<<Character.CONTROL) |
5670 (1<<Character.FORMAT) |
5671 (1<<Character.PRIVATE_USE) |
5672 (1<<Character.SURROGATE))); // Other
5673 defCategory("P", ((1<<Character.DASH_PUNCTUATION) |
5674 (1<<Character.START_PUNCTUATION) |
5675 (1<<Character.END_PUNCTUATION) |
5676 (1<<Character.CONNECTOR_PUNCTUATION) |
5677 (1<<Character.OTHER_PUNCTUATION) |
5678 (1<<Character.INITIAL_QUOTE_PUNCTUATION) |
5679 (1<<Character.FINAL_QUOTE_PUNCTUATION)));
5680 defCategory("S", ((1<<Character.MATH_SYMBOL) |
5681 (1<<Character.CURRENCY_SYMBOL) |
5682 (1<<Character.MODIFIER_SYMBOL) |
5683 (1<<Character.OTHER_SYMBOL)));
5684 defCategory("LC", ((1<<Character.UPPERCASE_LETTER) |
5685 (1<<Character.LOWERCASE_LETTER) |
5686 (1<<Character.TITLECASE_LETTER)));
5687 defCategory("LD", ((1<<Character.UPPERCASE_LETTER) |
5688 (1<<Character.LOWERCASE_LETTER) |
5689 (1<<Character.TITLECASE_LETTER) |
5690 (1<<Character.MODIFIER_LETTER) |
5691 (1<<Character.OTHER_LETTER) |
5692 (1<<Character.DECIMAL_DIGIT_NUMBER)));
5693 defRange("L1", 0x00, 0xFF); // Latin-1
5694 map.put("all", new CharPropertyFactory() {
5695 CharProperty make() { return new All(); }});
5696
5697 // Posix regular expression character classes, defined in
5698 // http://www.unix.org/onlinepubs/009695399/basedefs/xbd_chap09.html
5699 defRange("ASCII", 0x00, 0x7F); // ASCII
5700 defCtype("Alnum", ASCII.ALNUM); // Alphanumeric characters
5701 defCtype("Alpha", ASCII.ALPHA); // Alphabetic characters
5702 defCtype("Blank", ASCII.BLANK); // Space and tab characters
5703 defCtype("Cntrl", ASCII.CNTRL); // Control characters
5704 defRange("Digit", '0', '9'); // Numeric characters
5705 defCtype("Graph", ASCII.GRAPH); // printable and visible
5706 defRange("Lower", 'a', 'z'); // Lower-case alphabetic
5707 defRange("Print", 0x20, 0x7E); // Printable characters
5708 defCtype("Punct", ASCII.PUNCT); // Punctuation characters
5709 defCtype("Space", ASCII.SPACE); // Space characters
5710 defRange("Upper", 'A', 'Z'); // Upper-case alphabetic
5711 defCtype("XDigit",ASCII.XDIGIT); // hexadecimal digits
5712
5713 // Java character properties, defined by methods in Character.java
5714 defClone("javaLowerCase", new CloneableProperty() {
5715 boolean isSatisfiedBy(int ch) {
5716 return Character.isLowerCase(ch);}});
5717 defClone("javaUpperCase", new CloneableProperty() {
5718 boolean isSatisfiedBy(int ch) {
5719 return Character.isUpperCase(ch);}});
5720 defClone("javaAlphabetic", new CloneableProperty() {
5721 boolean isSatisfiedBy(int ch) {
5722 return Character.isAlphabetic(ch);}});
5723 defClone("javaIdeographic", new CloneableProperty() {
5724 boolean isSatisfiedBy(int ch) {
5725 return Character.isIdeographic(ch);}});
5726 defClone("javaTitleCase", new CloneableProperty() {
5727 boolean isSatisfiedBy(int ch) {
5728 return Character.isTitleCase(ch);}});
5729 defClone("javaDigit", new CloneableProperty() {
5730 boolean isSatisfiedBy(int ch) {
5731 return Character.isDigit(ch);}});
5732 defClone("javaDefined", new CloneableProperty() {
5733 boolean isSatisfiedBy(int ch) {
5734 return Character.isDefined(ch);}});
5735 defClone("javaLetter", new CloneableProperty() {
5736 boolean isSatisfiedBy(int ch) {
5737 return Character.isLetter(ch);}});
5738 defClone("javaLetterOrDigit", new CloneableProperty() {
5739 boolean isSatisfiedBy(int ch) {
5740 return Character.isLetterOrDigit(ch);}});
5741 defClone("javaJavaIdentifierStart", new CloneableProperty() {
5742 boolean isSatisfiedBy(int ch) {
5743 return Character.isJavaIdentifierStart(ch);}});
5744 defClone("javaJavaIdentifierPart", new CloneableProperty() {
5745 boolean isSatisfiedBy(int ch) {
5746 return Character.isJavaIdentifierPart(ch);}});
5747 defClone("javaUnicodeIdentifierStart", new CloneableProperty() {
5748 boolean isSatisfiedBy(int ch) {
5749 return Character.isUnicodeIdentifierStart(ch);}});
5750 defClone("javaUnicodeIdentifierPart", new CloneableProperty() {
5751 boolean isSatisfiedBy(int ch) {
5752 return Character.isUnicodeIdentifierPart(ch);}});
5753 defClone("javaIdentifierIgnorable", new CloneableProperty() {
5754 boolean isSatisfiedBy(int ch) {
5755 return Character.isIdentifierIgnorable(ch);}});
5756 defClone("javaSpaceChar", new CloneableProperty() {
5757 boolean isSatisfiedBy(int ch) {
5758 return Character.isSpaceChar(ch);}});
5759 defClone("javaWhitespace", new CloneableProperty() {
5760 boolean isSatisfiedBy(int ch) {
5761 return Character.isWhitespace(ch);}});
5762 defClone("javaISOControl", new CloneableProperty() {
5763 boolean isSatisfiedBy(int ch) {
5764 return Character.isISOControl(ch);}});
5765 defClone("javaMirrored", new CloneableProperty() {
5766 boolean isSatisfiedBy(int ch) {
5767 return Character.isMirrored(ch);}});
5768 }
5769 }
5770
5771 /**
5772 * Creates a predicate which can be used to match a string.
5773 *
5774 * @return The predicate which can be used for matching on a string
5775 * @since 1.8
5776 */
5777 public Predicate<String> asPredicate() {
5778 return s -> matcher(s).find();
5779 }
5780
5781 /**
5782 * Creates a stream from the given input sequence around matches of this
5783 * pattern.
5784 *
5785 * <p> The stream returned by this method contains each substring of the
5786 * input sequence that is terminated by another subsequence that matches
5787 * this pattern or is terminated by the end of the input sequence. The
5788 * substrings in the stream are in the order in which they occur in the
5789 * input. Trailing empty strings will be discarded and not encountered in
5790 * the stream.
5791 *
5792 * <p> If this pattern does not match any subsequence of the input then
5793 * the resulting stream has just one element, namely the input sequence in
5794 * string form.
5795 *
5796 * <p> When there is a positive-width match at the beginning of the input
5797 * sequence then an empty leading substring is included at the beginning
5798 * of the stream. A zero-width match at the beginning however never produces
5799 * such empty leading substring.
5800 *
5801 * <p> If the input sequence is mutable, it must remain constant during the
5802 * execution of the terminal stream operation. Otherwise, the result of the
5803 * terminal stream operation is undefined.
5804 *
5805 * @param input
5806 * The character sequence to be split
5807 *
5808 * @return The stream of strings computed by splitting the input
5809 * around matches of this pattern
5810 * @see #split(CharSequence)
5811 * @since 1.8
5812 */
5813 public Stream<String> splitAsStream(final CharSequence input) {
5814 class MatcherIterator implements Iterator<String> {
5815 private final Matcher matcher;
5816 // The start position of the next sub-sequence of input
5817 // when current == input.length there are no more elements
5818 private int current;
5819 // null if the next element, if any, needs to obtained
5820 private String nextElement;
5821 // > 0 if there are N next empty elements
5822 private int emptyElementCount;
5823
5824 MatcherIterator() {
5825 this.matcher = matcher(input);
5826 // If the input is an empty string then the result can only be a
5827 // stream of the input. Induce that by setting the empty
5828 // element count to 1
5829 this.emptyElementCount = input.length() == 0 ? 1 : 0;
5830 }
5831
5832 public String next() {
5833 if (!hasNext())
5834 throw new NoSuchElementException();
5835
5836 if (emptyElementCount == 0) {
5837 String n = nextElement;
5838 nextElement = null;
5839 return n;
5840 } else {
5841 emptyElementCount--;
5842 return "";
5843 }
5844 }
5845
5846 public boolean hasNext() {
5847 if (nextElement != null || emptyElementCount > 0)
5848 return true;
5849
5850 if (current == input.length())
5851 return false;
5852
5853 // Consume the next matching element
5854 // Count sequence of matching empty elements
5855 while (matcher.find()) {
5856 nextElement = input.subSequence(current, matcher.start()).toString();
5857 current = matcher.end();
5858 if (!nextElement.isEmpty()) {
5859 return true;
5860 } else if (current > 0) { // no empty leading substring for zero-width
5861 // match at the beginning of the input
5862 emptyElementCount++;
5863 }
5864 }
5865
5866 // Consume last matching element
5867 nextElement = input.subSequence(current, input.length()).toString();
5868 current = input.length();
5869 if (!nextElement.isEmpty()) {
5870 return true;
5871 } else {
5872 // Ignore a terminal sequence of matching empty elements
5873 emptyElementCount = 0;
5874 nextElement = null;
5875 return false;
5876 }
5877 }
5878 }
5879 return StreamSupport.stream(Spliterators.spliteratorUnknownSize(
5880 new MatcherIterator(), Spliterator.ORDERED | Spliterator.NONNULL), false);
5881 }
5882 }