1 /*
2 * Copyright (c) 1999, 2017, 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 /* Pattern has only two serialized components: The pattern string
921 * and the flags, which are all that is needed to recompile the pattern
922 * when it is deserialized.
923 */
924
925 /** use serialVersionUID from Merlin b59 for interoperability */
926 private static final long serialVersionUID = 5073258162644648461L;
927
928 /**
929 * The original regular-expression pattern string.
930 *
931 * @serial
932 */
933 private String pattern;
934
935 /**
936 * The original pattern flags.
937 *
938 * @serial
939 */
940 private int flags;
941
942 /**
943 * Boolean indicating this Pattern is compiled; this is necessary in order
944 * to lazily compile deserialized Patterns.
945 */
946 private transient volatile boolean compiled = false;
947
948 /**
949 * The normalized pattern string.
950 */
951 private transient String normalizedPattern;
952
953 /**
954 * The starting point of state machine for the find operation. This allows
955 * a match to start anywhere in the input.
956 */
957 transient Node root;
958
959 /**
960 * The root of object tree for a match operation. The pattern is matched
961 * at the beginning. This may include a find that uses BnM or a First
962 * node.
963 */
964 transient Node matchRoot;
965
966 /**
967 * Temporary storage used by parsing pattern slice.
968 */
969 transient int[] buffer;
970
971 /**
972 * Map the "name" of the "named capturing group" to its group id
973 * node.
974 */
975 transient volatile Map<String, Integer> namedGroups;
976
977 /**
978 * Temporary storage used while parsing group references.
979 */
980 transient GroupHead[] groupNodes;
981
982 /**
983 * Temporary null terminated code point array used by pattern compiling.
984 */
985 private transient int[] temp;
986
987 /**
988 * The number of capturing groups in this Pattern. Used by matchers to
989 * allocate storage needed to perform a match.
990 */
991 transient int capturingGroupCount;
992
993 /**
994 * The local variable count used by parsing tree. Used by matchers to
995 * allocate storage needed to perform a match.
996 */
997 transient int localCount;
998
999 /**
1000 * Index into the pattern string that keeps track of how much has been
1001 * parsed.
1002 */
1003 private transient int cursor;
1004
1005 /**
1006 * Holds the length of the pattern string.
1007 */
1008 private transient int patternLength;
1009
1010 /**
1011 * If the Start node might possibly match supplementary characters.
1012 * It is set to true during compiling if
1013 * (1) There is supplementary char in pattern, or
1014 * (2) There is complement node of Category or Block
1015 */
1016 private transient boolean hasSupplementary;
1017
1018 /**
1019 * Compiles the given regular expression into a pattern.
1020 *
1021 * @param regex
1022 * The expression to be compiled
1023 * @return the given regular expression compiled into a pattern
1024 * @throws PatternSyntaxException
1025 * If the expression's syntax is invalid
1026 */
1027 public static Pattern compile(String regex) {
1028 return new Pattern(regex, 0);
1029 }
1030
1031 /**
1032 * Compiles the given regular expression into a pattern with the given
1033 * flags.
1034 *
1035 * @param regex
1036 * The expression to be compiled
1037 *
1038 * @param flags
1039 * Match flags, a bit mask that may include
1040 * {@link #CASE_INSENSITIVE}, {@link #MULTILINE}, {@link #DOTALL},
1041 * {@link #UNICODE_CASE}, {@link #CANON_EQ}, {@link #UNIX_LINES},
1042 * {@link #LITERAL}, {@link #UNICODE_CHARACTER_CLASS}
1043 * and {@link #COMMENTS}
1044 *
1045 * @return the given regular expression compiled into a pattern with the given flags
1046 * @throws IllegalArgumentException
1047 * If bit values other than those corresponding to the defined
1048 * match flags are set in <tt>flags</tt>
1049 *
1050 * @throws PatternSyntaxException
1051 * If the expression's syntax is invalid
1052 */
1053 public static Pattern compile(String regex, int flags) {
1054 return new Pattern(regex, flags);
1055 }
1056
1057 /**
1058 * Returns the regular expression from which this pattern was compiled.
1059 *
1060 * @return The source of this pattern
1061 */
1062 public String pattern() {
1063 return pattern;
1064 }
1065
1066 /**
1067 * <p>Returns the string representation of this pattern. This
1068 * is the regular expression from which this pattern was
1069 * compiled.</p>
1070 *
1071 * @return The string representation of this pattern
1072 * @since 1.5
1073 */
1074 public String toString() {
1075 return pattern;
1076 }
1077
1078 /**
1079 * Creates a matcher that will match the given input against this pattern.
1080 *
1081 * @param input
1082 * The character sequence to be matched
1083 *
1084 * @return A new matcher for this pattern
1085 */
1086 public Matcher matcher(CharSequence input) {
1087 if (!compiled) {
1088 synchronized(this) {
1089 if (!compiled)
1090 compile();
1091 }
1092 }
1093 Matcher m = new Matcher(this, input);
1094 return m;
1095 }
1096
1097 /**
1098 * Returns this pattern's match flags.
1099 *
1100 * @return The match flags specified when this pattern was compiled
1101 */
1102 public int flags() {
1103 return flags;
1104 }
1105
1106 /**
1107 * Compiles the given regular expression and attempts to match the given
1108 * input against it.
1109 *
1110 * <p> An invocation of this convenience method of the form
1111 *
1112 * <blockquote><pre>
1113 * Pattern.matches(regex, input);</pre></blockquote>
1114 *
1115 * behaves in exactly the same way as the expression
1116 *
1117 * <blockquote><pre>
1118 * Pattern.compile(regex).matcher(input).matches()</pre></blockquote>
1119 *
1120 * <p> If a pattern is to be used multiple times, compiling it once and reusing
1121 * it will be more efficient than invoking this method each time. </p>
1122 *
1123 * @param regex
1124 * The expression to be compiled
1125 *
1126 * @param input
1127 * The character sequence to be matched
1128 * @return whether or not the regular expression matches on the input
1129 * @throws PatternSyntaxException
1130 * If the expression's syntax is invalid
1131 */
1132 public static boolean matches(String regex, CharSequence input) {
1133 Pattern p = Pattern.compile(regex);
1134 Matcher m = p.matcher(input);
1135 return m.matches();
1136 }
1137
1138 /**
1139 * Splits the given input sequence around matches of this pattern.
1140 *
1141 * <p> The array returned by this method contains each substring of the
1142 * input sequence that is terminated by another subsequence that matches
1143 * this pattern or is terminated by the end of the input sequence. The
1144 * substrings in the array are in the order in which they occur in the
1145 * input. If this pattern does not match any subsequence of the input then
1146 * the resulting array has just one element, namely the input sequence in
1147 * string form.
1148 *
1149 * <p> When there is a positive-width match at the beginning of the input
1150 * sequence then an empty leading substring is included at the beginning
1151 * of the resulting array. A zero-width match at the beginning however
1152 * never produces such empty leading substring.
1153 *
1154 * <p> The <tt>limit</tt> parameter controls the number of times the
1155 * pattern is applied and therefore affects the length of the resulting
1156 * array. If the limit <i>n</i> is greater than zero then the pattern
1157 * will be applied at most <i>n</i> - 1 times, the array's
1158 * length will be no greater than <i>n</i>, and the array's last entry
1159 * will contain all input beyond the last matched delimiter. If <i>n</i>
1160 * is non-positive then the pattern will be applied as many times as
1161 * possible and the array can have any length. If <i>n</i> is zero then
1162 * the pattern will be applied as many times as possible, the array can
1163 * have any length, and trailing empty strings will be discarded.
1164 *
1165 * <p> The input <tt>"boo:and:foo"</tt>, for example, yields the following
1166 * results with these parameters:
1167 *
1168 * <blockquote><table cellpadding=1 cellspacing=0
1169 * summary="Split examples showing regex, limit, and result">
1170 * <tr><th align="left"><i>Regex </i></th>
1171 * <th align="left"><i>Limit </i></th>
1172 * <th align="left"><i>Result </i></th></tr>
1173 * <tr><td align=center>:</td>
1174 * <td align=center>2</td>
1175 * <td><tt>{ "boo", "and:foo" }</tt></td></tr>
1176 * <tr><td align=center>:</td>
1177 * <td align=center>5</td>
1178 * <td><tt>{ "boo", "and", "foo" }</tt></td></tr>
1179 * <tr><td align=center>:</td>
1180 * <td align=center>-2</td>
1181 * <td><tt>{ "boo", "and", "foo" }</tt></td></tr>
1182 * <tr><td align=center>o</td>
1183 * <td align=center>5</td>
1184 * <td><tt>{ "b", "", ":and:f", "", "" }</tt></td></tr>
1185 * <tr><td align=center>o</td>
1186 * <td align=center>-2</td>
1187 * <td><tt>{ "b", "", ":and:f", "", "" }</tt></td></tr>
1188 * <tr><td align=center>o</td>
1189 * <td align=center>0</td>
1190 * <td><tt>{ "b", "", ":and:f" }</tt></td></tr>
1191 * </table></blockquote>
1192 *
1193 * @param input
1194 * The character sequence to be split
1195 *
1196 * @param limit
1197 * The result threshold, as described above
1198 *
1199 * @return The array of strings computed by splitting the input
1200 * around matches of this pattern
1201 */
1202 public String[] split(CharSequence input, int limit) {
1203 int index = 0;
1204 boolean matchLimited = limit > 0;
1205 ArrayList<String> matchList = new ArrayList<>();
1206 Matcher m = matcher(input);
1207
1208 // Add segments before each match found
1209 while(m.find()) {
1210 if (!matchLimited || matchList.size() < limit - 1) {
1211 if (index == 0 && index == m.start() && m.start() == m.end()) {
1212 // no empty leading substring included for zero-width match
1213 // at the beginning of the input char sequence.
1214 continue;
1215 }
1216 String match = input.subSequence(index, m.start()).toString();
1217 matchList.add(match);
1218 index = m.end();
1219 } else if (matchList.size() == limit - 1) { // last one
1220 String match = input.subSequence(index,
1221 input.length()).toString();
1222 matchList.add(match);
1223 index = m.end();
1224 }
1225 }
1226
1227 // If no match was found, return this
1228 if (index == 0)
1229 return new String[] {input.toString()};
1230
1231 // Add remaining segment
1232 if (!matchLimited || matchList.size() < limit)
1233 matchList.add(input.subSequence(index, input.length()).toString());
1234
1235 // Construct result
1236 int resultSize = matchList.size();
1237 if (limit == 0)
1238 while (resultSize > 0 && matchList.get(resultSize-1).equals(""))
1239 resultSize--;
1240 String[] result = new String[resultSize];
1241 return matchList.subList(0, resultSize).toArray(result);
1242 }
1243
1244 /**
1245 * Splits the given input sequence around matches of this pattern.
1246 *
1247 * <p> This method works as if by invoking the two-argument {@link
1248 * #split(java.lang.CharSequence, int) split} method with the given input
1249 * sequence and a limit argument of zero. Trailing empty strings are
1250 * therefore not included in the resulting array. </p>
1251 *
1252 * <p> The input <tt>"boo:and:foo"</tt>, for example, yields the following
1253 * results with these expressions:
1254 *
1255 * <blockquote><table cellpadding=1 cellspacing=0
1256 * summary="Split examples showing regex and result">
1257 * <tr><th align="left"><i>Regex </i></th>
1258 * <th align="left"><i>Result</i></th></tr>
1259 * <tr><td align=center>:</td>
1260 * <td><tt>{ "boo", "and", "foo" }</tt></td></tr>
1261 * <tr><td align=center>o</td>
1262 * <td><tt>{ "b", "", ":and:f" }</tt></td></tr>
1263 * </table></blockquote>
1264 *
1265 *
1266 * @param input
1267 * The character sequence to be split
1268 *
1269 * @return The array of strings computed by splitting the input
1270 * around matches of this pattern
1271 */
1272 public String[] split(CharSequence input) {
1273 return split(input, 0);
1274 }
1275
1276 /**
1277 * Returns a literal pattern <code>String</code> for the specified
1278 * <code>String</code>.
1279 *
1280 * <p>This method produces a <code>String</code> that can be used to
1281 * create a <code>Pattern</code> that would match the string
1282 * <code>s</code> as if it were a literal pattern.</p> Metacharacters
1283 * or escape sequences in the input sequence will be given no special
1284 * meaning.
1285 *
1286 * @param s The string to be literalized
1287 * @return A literal string replacement
1288 * @since 1.5
1289 */
1290 public static String quote(String s) {
1291 int slashEIndex = s.indexOf("\\E");
1292 if (slashEIndex == -1)
1293 return "\\Q" + s + "\\E";
1294
1295 StringBuilder sb = new StringBuilder(s.length() * 2);
1296 sb.append("\\Q");
1297 slashEIndex = 0;
1298 int current = 0;
1299 while ((slashEIndex = s.indexOf("\\E", current)) != -1) {
1300 sb.append(s.substring(current, slashEIndex));
1301 current = slashEIndex + 2;
1302 sb.append("\\E\\\\E\\Q");
1303 }
1304 sb.append(s.substring(current, s.length()));
1305 sb.append("\\E");
1306 return sb.toString();
1307 }
1308
1309 /**
1310 * Recompile the Pattern instance from a stream. The original pattern
1311 * string is read in and the object tree is recompiled from it.
1312 */
1313 private void readObject(java.io.ObjectInputStream s)
1314 throws java.io.IOException, ClassNotFoundException {
1315
1316 // Read in all fields
1317 s.defaultReadObject();
1318
1319 // Initialize counts
1320 capturingGroupCount = 1;
1321 localCount = 0;
1322
1323 // if length > 0, the Pattern is lazily compiled
1324 compiled = false;
1325 if (pattern.length() == 0) {
1326 root = new Start(lastAccept);
1327 matchRoot = lastAccept;
1328 compiled = true;
1329 }
1330 }
1331
1332 /**
1333 * This private constructor is used to create all Patterns. The pattern
1334 * string and match flags are all that is needed to completely describe
1335 * a Pattern. An empty pattern string results in an object tree with
1336 * only a Start node and a LastNode node.
1337 */
1338 private Pattern(String p, int f) {
1339 pattern = p;
1340 flags = f;
1341
1342 // to use UNICODE_CASE if UNICODE_CHARACTER_CLASS present
1343 if ((flags & UNICODE_CHARACTER_CLASS) != 0)
1344 flags |= UNICODE_CASE;
1345
1346 // Reset group index count
1347 capturingGroupCount = 1;
1348 localCount = 0;
1349
1350 if (pattern.length() > 0) {
1351 compile();
1352 } else {
1353 root = new Start(lastAccept);
1354 matchRoot = lastAccept;
1355 }
1356 }
1357
1358 /**
1359 * The pattern is converted to normalizedD form and then a pure group
1360 * is constructed to match canonical equivalences of the characters.
1361 */
1362 private void normalize() {
1363 boolean inCharClass = false;
1364 int lastCodePoint = -1;
1365
1366 // Convert pattern into normalizedD form
1367 normalizedPattern = Normalizer.normalize(pattern, Normalizer.Form.NFD);
1368 patternLength = normalizedPattern.length();
1369
1370 // Modify pattern to match canonical equivalences
1371 StringBuilder newPattern = new StringBuilder(patternLength);
1372 for(int i=0; i<patternLength; ) {
1373 int c = normalizedPattern.codePointAt(i);
1374 StringBuilder sequenceBuffer;
1375 if ((Character.getType(c) == Character.NON_SPACING_MARK)
1376 && (lastCodePoint != -1)) {
1377 sequenceBuffer = new StringBuilder();
1378 sequenceBuffer.appendCodePoint(lastCodePoint);
1379 sequenceBuffer.appendCodePoint(c);
1380 while(Character.getType(c) == Character.NON_SPACING_MARK) {
1381 i += Character.charCount(c);
1382 if (i >= patternLength)
1383 break;
1384 c = normalizedPattern.codePointAt(i);
1385 sequenceBuffer.appendCodePoint(c);
1386 }
1387 String ea = produceEquivalentAlternation(
1388 sequenceBuffer.toString());
1389 newPattern.setLength(newPattern.length()-Character.charCount(lastCodePoint));
1390 newPattern.append("(?:").append(ea).append(")");
1391 } else if (c == '[' && lastCodePoint != '\\') {
1392 i = normalizeCharClass(newPattern, i);
1393 } else {
1394 newPattern.appendCodePoint(c);
1395 }
1396 lastCodePoint = c;
1397 i += Character.charCount(c);
1398 }
1399 normalizedPattern = newPattern.toString();
1400 }
1401
1402 /**
1403 * Complete the character class being parsed and add a set
1404 * of alternations to it that will match the canonical equivalences
1405 * of the characters within the class.
1406 */
1407 private int normalizeCharClass(StringBuilder newPattern, int i) {
1408 StringBuilder charClass = new StringBuilder();
1409 StringBuilder eq = null;
1410 int lastCodePoint = -1;
1411 String result;
1412
1413 i++;
1414 if (i == normalizedPattern.length())
1415 throw error("Unclosed character class");
1416 charClass.append("[");
1417 while(true) {
1418 int c = normalizedPattern.codePointAt(i);
1419 StringBuilder sequenceBuffer;
1420
1421 if (c == ']' && lastCodePoint != '\\') {
1422 charClass.append((char)c);
1423 break;
1424 } else if (Character.getType(c) == Character.NON_SPACING_MARK) {
1425 sequenceBuffer = new StringBuilder();
1426 sequenceBuffer.appendCodePoint(lastCodePoint);
1427 while(Character.getType(c) == Character.NON_SPACING_MARK) {
1428 sequenceBuffer.appendCodePoint(c);
1429 i += Character.charCount(c);
1430 if (i >= normalizedPattern.length())
1431 break;
1432 c = normalizedPattern.codePointAt(i);
1433 }
1434 String ea = produceEquivalentAlternation(
1435 sequenceBuffer.toString());
1436
1437 charClass.setLength(charClass.length()-Character.charCount(lastCodePoint));
1438 if (eq == null)
1439 eq = new StringBuilder();
1440 eq.append('|');
1441 eq.append(ea);
1442 } else {
1443 charClass.appendCodePoint(c);
1444 i++;
1445 }
1446 if (i == normalizedPattern.length())
1447 throw error("Unclosed character class");
1448 lastCodePoint = c;
1449 }
1450
1451 if (eq != null) {
1452 result = "(?:"+charClass.toString()+eq.toString()+")";
1453 } else {
1454 result = charClass.toString();
1455 }
1456
1457 newPattern.append(result);
1458 return i;
1459 }
1460
1461 /**
1462 * Given a specific sequence composed of a regular character and
1463 * combining marks that follow it, produce the alternation that will
1464 * match all canonical equivalences of that sequence.
1465 */
1466 private String produceEquivalentAlternation(String source) {
1467 int len = countChars(source, 0, 1);
1468 if (source.length() == len)
1469 // source has one character.
1470 return source;
1471
1472 String base = source.substring(0,len);
1473 String combiningMarks = source.substring(len);
1474
1475 String[] perms = producePermutations(combiningMarks);
1476 StringBuilder result = new StringBuilder(source);
1477
1478 // Add combined permutations
1479 for(int x=0; x<perms.length; x++) {
1480 String next = base + perms[x];
1481 if (x>0)
1482 result.append("|"+next);
1483 next = composeOneStep(next);
1484 if (next != null)
1485 result.append("|"+produceEquivalentAlternation(next));
1486 }
1487 return result.toString();
1488 }
1489
1490 /**
1491 * Returns an array of strings that have all the possible
1492 * permutations of the characters in the input string.
1493 * This is used to get a list of all possible orderings
1494 * of a set of combining marks. Note that some of the permutations
1495 * are invalid because of combining class collisions, and these
1496 * possibilities must be removed because they are not canonically
1497 * equivalent.
1498 */
1499 private String[] producePermutations(String input) {
1500 if (input.length() == countChars(input, 0, 1))
1501 return new String[] {input};
1502
1503 if (input.length() == countChars(input, 0, 2)) {
1504 int c0 = Character.codePointAt(input, 0);
1505 int c1 = Character.codePointAt(input, Character.charCount(c0));
1506 if (getClass(c1) == getClass(c0)) {
1507 return new String[] {input};
1508 }
1509 String[] result = new String[2];
1510 result[0] = input;
1511 StringBuilder sb = new StringBuilder(2);
1512 sb.appendCodePoint(c1);
1513 sb.appendCodePoint(c0);
1514 result[1] = sb.toString();
1515 return result;
1516 }
1517
1518 int length = 1;
1519 int nCodePoints = countCodePoints(input);
1520 for(int x=1; x<nCodePoints; x++)
1521 length = length * (x+1);
1522
1523 String[] temp = new String[length];
1524
1525 int combClass[] = new int[nCodePoints];
1526 for(int x=0, i=0; x<nCodePoints; x++) {
1527 int c = Character.codePointAt(input, i);
1528 combClass[x] = getClass(c);
1529 i += Character.charCount(c);
1530 }
1531
1532 // For each char, take it out and add the permutations
1533 // of the remaining chars
1534 int index = 0;
1535 int len;
1536 // offset maintains the index in code units.
1537 loop: for(int x=0, offset=0; x<nCodePoints; x++, offset+=len) {
1538 len = countChars(input, offset, 1);
1539 boolean skip = false;
1540 for(int y=x-1; y>=0; y--) {
1541 if (combClass[y] == combClass[x]) {
1542 continue loop;
1543 }
1544 }
1545 StringBuilder sb = new StringBuilder(input);
1546 String otherChars = sb.delete(offset, offset+len).toString();
1547 String[] subResult = producePermutations(otherChars);
1548
1549 String prefix = input.substring(offset, offset+len);
1550 for(int y=0; y<subResult.length; y++)
1551 temp[index++] = prefix + subResult[y];
1552 }
1553 String[] result = new String[index];
1554 for (int x=0; x<index; x++)
1555 result[x] = temp[x];
1556 return result;
1557 }
1558
1559 private int getClass(int c) {
1560 return sun.text.Normalizer.getCombiningClass(c);
1561 }
1562
1563 /**
1564 * Attempts to compose input by combining the first character
1565 * with the first combining mark following it. Returns a String
1566 * that is the composition of the leading character with its first
1567 * combining mark followed by the remaining combining marks. Returns
1568 * null if the first two characters cannot be further composed.
1569 */
1570 private String composeOneStep(String input) {
1571 int len = countChars(input, 0, 2);
1572 String firstTwoCharacters = input.substring(0, len);
1573 String result = Normalizer.normalize(firstTwoCharacters, Normalizer.Form.NFC);
1574
1575 if (result.equals(firstTwoCharacters))
1576 return null;
1577 else {
1578 String remainder = input.substring(len);
1579 return result + remainder;
1580 }
1581 }
1582
1583 /**
1584 * Preprocess any \Q...\E sequences in `temp', meta-quoting them.
1585 * See the description of `quotemeta' in perlfunc(1).
1586 */
1587 private void RemoveQEQuoting() {
1588 final int pLen = patternLength;
1589 int i = 0;
1590 while (i < pLen-1) {
1591 if (temp[i] != '\\')
1592 i += 1;
1593 else if (temp[i + 1] != 'Q')
1594 i += 2;
1595 else
1596 break;
1597 }
1598 if (i >= pLen - 1) // No \Q sequence found
1599 return;
1600 int j = i;
1601 i += 2;
1602 int[] newtemp = new int[j + 3*(pLen-i) + 2];
1603 System.arraycopy(temp, 0, newtemp, 0, j);
1604
1605 boolean inQuote = true;
1606 boolean beginQuote = true;
1607 while (i < pLen) {
1608 int c = temp[i++];
1609 if (!ASCII.isAscii(c) || ASCII.isAlpha(c)) {
1610 newtemp[j++] = c;
1611 } else if (ASCII.isDigit(c)) {
1612 if (beginQuote) {
1613 /*
1614 * A unicode escape \[0xu] could be before this quote,
1615 * and we don't want this numeric char to processed as
1616 * part of the escape.
1617 */
1618 newtemp[j++] = '\\';
1619 newtemp[j++] = 'x';
1620 newtemp[j++] = '3';
1621 }
1622 newtemp[j++] = c;
1623 } else if (c != '\\') {
1624 if (inQuote) newtemp[j++] = '\\';
1625 newtemp[j++] = c;
1626 } else if (inQuote) {
1627 if (temp[i] == 'E') {
1628 i++;
1629 inQuote = false;
1630 } else {
1631 newtemp[j++] = '\\';
1632 newtemp[j++] = '\\';
1633 }
1634 } else {
1635 if (temp[i] == 'Q') {
1636 i++;
1637 inQuote = true;
1638 beginQuote = true;
1639 continue;
1640 } else {
1641 newtemp[j++] = c;
1642 if (i != pLen)
1643 newtemp[j++] = temp[i++];
1644 }
1645 }
1646
1647 beginQuote = false;
1648 }
1649
1650 patternLength = j;
1651 temp = Arrays.copyOf(newtemp, j + 2); // double zero termination
1652 }
1653
1654 /**
1655 * Copies regular expression to an int array and invokes the parsing
1656 * of the expression which will create the object tree.
1657 */
1658 private void compile() {
1659 // Handle canonical equivalences
1660 if (has(CANON_EQ) && !has(LITERAL)) {
1661 normalize();
1662 } else {
1663 normalizedPattern = pattern;
1664 }
1665 patternLength = normalizedPattern.length();
1666
1667 // Copy pattern to int array for convenience
1668 // Use double zero to terminate pattern
1669 temp = new int[patternLength + 2];
1670
1671 hasSupplementary = false;
1672 int c, count = 0;
1673 // Convert all chars into code points
1674 for (int x = 0; x < patternLength; x += Character.charCount(c)) {
1675 c = normalizedPattern.codePointAt(x);
1676 if (isSupplementary(c)) {
1677 hasSupplementary = true;
1678 }
1679 temp[count++] = c;
1680 }
1681
1682 patternLength = count; // patternLength now in code points
1683
1684 if (! has(LITERAL))
1685 RemoveQEQuoting();
1686
1687 // Allocate all temporary objects here.
1688 buffer = new int[32];
1689 groupNodes = new GroupHead[10];
1690 namedGroups = null;
1691
1692 if (has(LITERAL)) {
1693 // Literal pattern handling
1694 matchRoot = newSlice(temp, patternLength, hasSupplementary);
1695 matchRoot.next = lastAccept;
1696 } else {
1697 // Start recursive descent parsing
1698 matchRoot = expr(lastAccept);
1699 // Check extra pattern characters
1700 if (patternLength != cursor) {
1701 if (peek() == ')') {
1702 throw error("Unmatched closing ')'");
1703 } else {
1704 throw error("Unexpected internal error");
1705 }
1706 }
1707 }
1708
1709 // Peephole optimization
1710 if (matchRoot instanceof Slice) {
1711 root = BnM.optimize(matchRoot);
1712 if (root == matchRoot) {
1713 root = hasSupplementary ? new StartS(matchRoot) : new Start(matchRoot);
1714 }
1715 } else if (matchRoot instanceof Begin || matchRoot instanceof First) {
1716 root = matchRoot;
1717 } else {
1718 root = hasSupplementary ? new StartS(matchRoot) : new Start(matchRoot);
1719 }
1720
1721 // Release temporary storage
1722 temp = null;
1723 buffer = null;
1724 groupNodes = null;
1725 patternLength = 0;
1726 compiled = true;
1727 }
1728
1729 Map<String, Integer> namedGroups() {
1730 if (namedGroups == null)
1731 namedGroups = new HashMap<>(2);
1732 return namedGroups;
1733 }
1734
1735 /**
1736 * Used to print out a subtree of the Pattern to help with debugging.
1737 */
1738 private static void printObjectTree(Node node) {
1739 while(node != null) {
1740 if (node instanceof Prolog) {
1741 System.out.println(node);
1742 printObjectTree(((Prolog)node).loop);
1743 System.out.println("**** end contents prolog loop");
1744 } else if (node instanceof Loop) {
1745 System.out.println(node);
1746 printObjectTree(((Loop)node).body);
1747 System.out.println("**** end contents Loop body");
1748 } else if (node instanceof Curly) {
1749 System.out.println(node);
1750 printObjectTree(((Curly)node).atom);
1751 System.out.println("**** end contents Curly body");
1752 } else if (node instanceof GroupCurly) {
1753 System.out.println(node);
1754 printObjectTree(((GroupCurly)node).atom);
1755 System.out.println("**** end contents GroupCurly body");
1756 } else if (node instanceof GroupTail) {
1757 System.out.println(node);
1758 System.out.println("Tail next is "+node.next);
1759 return;
1760 } else {
1761 System.out.println(node);
1762 }
1763 node = node.next;
1764 if (node != null)
1765 System.out.println("->next:");
1766 if (node == Pattern.accept) {
1767 System.out.println("Accept Node");
1768 node = null;
1769 }
1770 }
1771 }
1772
1773 /**
1774 * Used to accumulate information about a subtree of the object graph
1775 * so that optimizations can be applied to the subtree.
1776 */
1777 static final class TreeInfo {
1778 int minLength;
1779 int maxLength;
1780 boolean maxValid;
1781 boolean deterministic;
1782
1783 TreeInfo() {
1784 reset();
1785 }
1786 void reset() {
1787 minLength = 0;
1788 maxLength = 0;
1789 maxValid = true;
1790 deterministic = true;
1791 }
1792 }
1793
1794 /*
1795 * The following private methods are mainly used to improve the
1796 * readability of the code. In order to let the Java compiler easily
1797 * inline them, we should not put many assertions or error checks in them.
1798 */
1799
1800 /**
1801 * Indicates whether a particular flag is set or not.
1802 */
1803 private boolean has(int f) {
1804 return (flags & f) != 0;
1805 }
1806
1807 /**
1808 * Match next character, signal error if failed.
1809 */
1810 private void accept(int ch, String s) {
1811 int testChar = temp[cursor++];
1812 if (has(COMMENTS))
1813 testChar = parsePastWhitespace(testChar);
1814 if (ch != testChar) {
1815 throw error(s);
1816 }
1817 }
1818
1819 /**
1820 * Mark the end of pattern with a specific character.
1821 */
1822 private void mark(int c) {
1823 temp[patternLength] = c;
1824 }
1825
1826 /**
1827 * Peek the next character, and do not advance the cursor.
1828 */
1829 private int peek() {
1830 int ch = temp[cursor];
1831 if (has(COMMENTS))
1832 ch = peekPastWhitespace(ch);
1833 return ch;
1834 }
1835
1836 /**
1837 * Read the next character, and advance the cursor by one.
1838 */
1839 private int read() {
1840 int ch = temp[cursor++];
1841 if (has(COMMENTS))
1842 ch = parsePastWhitespace(ch);
1843 return ch;
1844 }
1845
1846 /**
1847 * Read the next character, and advance the cursor by one,
1848 * ignoring the COMMENTS setting
1849 */
1850 private int readEscaped() {
1851 int ch = temp[cursor++];
1852 return ch;
1853 }
1854
1855 /**
1856 * Advance the cursor by one, and peek the next character.
1857 */
1858 private int next() {
1859 int ch = temp[++cursor];
1860 if (has(COMMENTS))
1861 ch = peekPastWhitespace(ch);
1862 return ch;
1863 }
1864
1865 /**
1866 * Advance the cursor by one, and peek the next character,
1867 * ignoring the COMMENTS setting
1868 */
1869 private int nextEscaped() {
1870 int ch = temp[++cursor];
1871 return ch;
1872 }
1873
1874 /**
1875 * If in xmode peek past whitespace and comments.
1876 */
1877 private int peekPastWhitespace(int ch) {
1878 while (ASCII.isSpace(ch) || ch == '#') {
1879 while (ASCII.isSpace(ch))
1880 ch = temp[++cursor];
1881 if (ch == '#') {
1882 ch = peekPastLine();
1883 }
1884 }
1885 return ch;
1886 }
1887
1888 /**
1889 * If in xmode parse past whitespace and comments.
1890 */
1891 private int parsePastWhitespace(int ch) {
1892 while (ASCII.isSpace(ch) || ch == '#') {
1893 while (ASCII.isSpace(ch))
1894 ch = temp[cursor++];
1895 if (ch == '#')
1896 ch = parsePastLine();
1897 }
1898 return ch;
1899 }
1900
1901 /**
1902 * xmode parse past comment to end of line.
1903 */
1904 private int parsePastLine() {
1905 int ch = temp[cursor++];
1906 while (ch != 0 && !isLineSeparator(ch))
1907 ch = temp[cursor++];
1908 return ch;
1909 }
1910
1911 /**
1912 * xmode peek past comment to end of line.
1913 */
1914 private int peekPastLine() {
1915 int ch = temp[++cursor];
1916 while (ch != 0 && !isLineSeparator(ch))
1917 ch = temp[++cursor];
1918 return ch;
1919 }
1920
1921 /**
1922 * Determines if character is a line separator in the current mode
1923 */
1924 private boolean isLineSeparator(int ch) {
1925 if (has(UNIX_LINES)) {
1926 return ch == '\n';
1927 } else {
1928 return (ch == '\n' ||
1929 ch == '\r' ||
1930 (ch|1) == '\u2029' ||
1931 ch == '\u0085');
1932 }
1933 }
1934
1935 /**
1936 * Read the character after the next one, and advance the cursor by two.
1937 */
1938 private int skip() {
1939 int i = cursor;
1940 int ch = temp[i+1];
1941 cursor = i + 2;
1942 return ch;
1943 }
1944
1945 /**
1946 * Unread one next character, and retreat cursor by one.
1947 */
1948 private void unread() {
1949 cursor--;
1950 }
1951
1952 /**
1953 * Internal method used for handling all syntax errors. The pattern is
1954 * displayed with a pointer to aid in locating the syntax error.
1955 */
1956 private PatternSyntaxException error(String s) {
1957 return new PatternSyntaxException(s, normalizedPattern, cursor - 1);
1958 }
1959
1960 /**
1961 * Determines if there is any supplementary character or unpaired
1962 * surrogate in the specified range.
1963 */
1964 private boolean findSupplementary(int start, int end) {
1965 for (int i = start; i < end; i++) {
1966 if (isSupplementary(temp[i]))
1967 return true;
1968 }
1969 return false;
1970 }
1971
1972 /**
1973 * Determines if the specified code point is a supplementary
1974 * character or unpaired surrogate.
1975 */
1976 private static final boolean isSupplementary(int ch) {
1977 return ch >= Character.MIN_SUPPLEMENTARY_CODE_POINT ||
1978 Character.isSurrogate((char)ch);
1979 }
1980
1981 /**
1982 * The following methods handle the main parsing. They are sorted
1983 * according to their precedence order, the lowest one first.
1984 */
1985
1986 /**
1987 * The expression is parsed with branch nodes added for alternations.
1988 * This may be called recursively to parse sub expressions that may
1989 * contain alternations.
1990 */
1991 private Node expr(Node end) {
1992 Node prev = null;
1993 Node firstTail = null;
1994 Branch branch = null;
1995 Node branchConn = null;
1996
1997 for (;;) {
1998 Node node = sequence(end);
1999 Node nodeTail = root; //double return
2000 if (prev == null) {
2001 prev = node;
2002 firstTail = nodeTail;
2003 } else {
2004 // Branch
2005 if (branchConn == null) {
2006 branchConn = new BranchConn();
2007 branchConn.next = end;
2008 }
2009 if (node == end) {
2010 // if the node returned from sequence() is "end"
2011 // we have an empty expr, set a null atom into
2012 // the branch to indicate to go "next" directly.
2013 node = null;
2014 } else {
2015 // the "tail.next" of each atom goes to branchConn
2016 nodeTail.next = branchConn;
2017 }
2018 if (prev == branch) {
2019 branch.add(node);
2020 } else {
2021 if (prev == end) {
2022 prev = null;
2023 } else {
2024 // replace the "end" with "branchConn" at its tail.next
2025 // when put the "prev" into the branch as the first atom.
2026 firstTail.next = branchConn;
2027 }
2028 prev = branch = new Branch(prev, node, branchConn);
2029 }
2030 }
2031 if (peek() != '|') {
2032 return prev;
2033 }
2034 next();
2035 }
2036 }
2037
2038 @SuppressWarnings("fallthrough")
2039 /**
2040 * Parsing of sequences between alternations.
2041 */
2042 private Node sequence(Node end) {
2043 Node head = null;
2044 Node tail = null;
2045 Node node = null;
2046 LOOP:
2047 for (;;) {
2048 int ch = peek();
2049 switch (ch) {
2050 case '(':
2051 // Because group handles its own closure,
2052 // we need to treat it differently
2053 node = group0();
2054 // Check for comment or flag group
2055 if (node == null)
2056 continue;
2057 if (head == null)
2058 head = node;
2059 else
2060 tail.next = node;
2061 // Double return: Tail was returned in root
2062 tail = root;
2063 continue;
2064 case '[':
2065 node = clazz(true);
2066 break;
2067 case '\\':
2068 ch = nextEscaped();
2069 if (ch == 'p' || ch == 'P') {
2070 boolean oneLetter = true;
2071 boolean comp = (ch == 'P');
2072 ch = next(); // Consume { if present
2073 if (ch != '{') {
2074 unread();
2075 } else {
2076 oneLetter = false;
2077 }
2078 node = family(oneLetter, comp);
2079 } else {
2080 unread();
2081 node = atom();
2082 }
2083 break;
2084 case '^':
2085 next();
2086 if (has(MULTILINE)) {
2087 if (has(UNIX_LINES))
2088 node = new UnixCaret();
2089 else
2090 node = new Caret();
2091 } else {
2092 node = new Begin();
2093 }
2094 break;
2095 case '$':
2096 next();
2097 if (has(UNIX_LINES))
2098 node = new UnixDollar(has(MULTILINE));
2099 else
2100 node = new Dollar(has(MULTILINE));
2101 break;
2102 case '.':
2103 next();
2104 if (has(DOTALL)) {
2105 node = new All();
2106 } else {
2107 if (has(UNIX_LINES))
2108 node = new UnixDot();
2109 else {
2110 node = new Dot();
2111 }
2112 }
2113 break;
2114 case '|':
2115 case ')':
2116 break LOOP;
2117 case ']': // Now interpreting dangling ] and } as literals
2118 case '}':
2119 node = atom();
2120 break;
2121 case '?':
2122 case '*':
2123 case '+':
2124 next();
2125 throw error("Dangling meta character '" + ((char)ch) + "'");
2126 case 0:
2127 if (cursor >= patternLength) {
2128 break LOOP;
2129 }
2130 // Fall through
2131 default:
2132 node = atom();
2133 break;
2134 }
2135
2136 node = closure(node);
2137
2138 if (head == null) {
2139 head = tail = node;
2140 } else {
2141 tail.next = node;
2142 tail = node;
2143 }
2144 }
2145 if (head == null) {
2146 return end;
2147 }
2148 tail.next = end;
2149 root = tail; //double return
2150 return head;
2151 }
2152
2153 @SuppressWarnings("fallthrough")
2154 /**
2155 * Parse and add a new Single or Slice.
2156 */
2157 private Node atom() {
2158 int first = 0;
2159 int prev = -1;
2160 boolean hasSupplementary = false;
2161 int ch = peek();
2162 for (;;) {
2163 switch (ch) {
2164 case '*':
2165 case '+':
2166 case '?':
2167 case '{':
2168 if (first > 1) {
2169 cursor = prev; // Unwind one character
2170 first--;
2171 }
2172 break;
2173 case '$':
2174 case '.':
2175 case '^':
2176 case '(':
2177 case '[':
2178 case '|':
2179 case ')':
2180 break;
2181 case '\\':
2182 ch = nextEscaped();
2183 if (ch == 'p' || ch == 'P') { // Property
2184 if (first > 0) { // Slice is waiting; handle it first
2185 unread();
2186 break;
2187 } else { // No slice; just return the family node
2188 boolean comp = (ch == 'P');
2189 boolean oneLetter = true;
2190 ch = next(); // Consume { if present
2191 if (ch != '{')
2192 unread();
2193 else
2194 oneLetter = false;
2195 return family(oneLetter, comp);
2196 }
2197 }
2198 unread();
2199 prev = cursor;
2200 ch = escape(false, first == 0, false);
2201 if (ch >= 0) {
2202 append(ch, first);
2203 first++;
2204 if (isSupplementary(ch)) {
2205 hasSupplementary = true;
2206 }
2207 ch = peek();
2208 continue;
2209 } else if (first == 0) {
2210 return root;
2211 }
2212 // Unwind meta escape sequence
2213 cursor = prev;
2214 break;
2215 case 0:
2216 if (cursor >= patternLength) {
2217 break;
2218 }
2219 // Fall through
2220 default:
2221 prev = cursor;
2222 append(ch, first);
2223 first++;
2224 if (isSupplementary(ch)) {
2225 hasSupplementary = true;
2226 }
2227 ch = next();
2228 continue;
2229 }
2230 break;
2231 }
2232 if (first == 1) {
2233 return newSingle(buffer[0]);
2234 } else {
2235 return newSlice(buffer, first, hasSupplementary);
2236 }
2237 }
2238
2239 private void append(int ch, int len) {
2240 if (len >= buffer.length) {
2241 int[] tmp = new int[len+len];
2242 System.arraycopy(buffer, 0, tmp, 0, len);
2243 buffer = tmp;
2244 }
2245 buffer[len] = ch;
2246 }
2247
2248 /**
2249 * Parses a backref greedily, taking as many numbers as it
2250 * can. The first digit is always treated as a backref, but
2251 * multi digit numbers are only treated as a backref if at
2252 * least that many backrefs exist at this point in the regex.
2253 */
2254 private Node ref(int refNum) {
2255 boolean done = false;
2256 while(!done) {
2257 int ch = peek();
2258 switch(ch) {
2259 case '0':
2260 case '1':
2261 case '2':
2262 case '3':
2263 case '4':
2264 case '5':
2265 case '6':
2266 case '7':
2267 case '8':
2268 case '9':
2269 int newRefNum = (refNum * 10) + (ch - '0');
2270 // Add another number if it doesn't make a group
2271 // that doesn't exist
2272 if (capturingGroupCount - 1 < newRefNum) {
2273 done = true;
2274 break;
2275 }
2276 refNum = newRefNum;
2277 read();
2278 break;
2279 default:
2280 done = true;
2281 break;
2282 }
2283 }
2284 if (has(CASE_INSENSITIVE))
2285 return new CIBackRef(refNum, has(UNICODE_CASE));
2286 else
2287 return new BackRef(refNum);
2288 }
2289
2290 /**
2291 * Parses an escape sequence to determine the actual value that needs
2292 * to be matched.
2293 * If -1 is returned and create was true a new object was added to the tree
2294 * to handle the escape sequence.
2295 * If the returned value is greater than zero, it is the value that
2296 * matches the escape sequence.
2297 */
2298 private int escape(boolean inclass, boolean create, boolean isrange) {
2299 int ch = skip();
2300 switch (ch) {
2301 case '0':
2302 return o();
2303 case '1':
2304 case '2':
2305 case '3':
2306 case '4':
2307 case '5':
2308 case '6':
2309 case '7':
2310 case '8':
2311 case '9':
2312 if (inclass) break;
2313 if (create) {
2314 root = ref((ch - '0'));
2315 }
2316 return -1;
2317 case 'A':
2318 if (inclass) break;
2319 if (create) root = new Begin();
2320 return -1;
2321 case 'B':
2322 if (inclass) break;
2323 if (create) root = new Bound(Bound.NONE, has(UNICODE_CHARACTER_CLASS));
2324 return -1;
2325 case 'C':
2326 break;
2327 case 'D':
2328 if (create) root = has(UNICODE_CHARACTER_CLASS)
2329 ? new Utype(UnicodeProp.DIGIT).complement()
2330 : new Ctype(ASCII.DIGIT).complement();
2331 return -1;
2332 case 'E':
2333 case 'F':
2334 break;
2335 case 'G':
2336 if (inclass) break;
2337 if (create) root = new LastMatch();
2338 return -1;
2339 case 'H':
2340 if (create) root = new HorizWS().complement();
2341 return -1;
2342 case 'I':
2343 case 'J':
2344 case 'K':
2345 case 'L':
2346 case 'M':
2347 case 'N':
2348 case 'O':
2349 case 'P':
2350 case 'Q':
2351 break;
2352 case 'R':
2353 if (inclass) break;
2354 if (create) root = new LineEnding();
2355 return -1;
2356 case 'S':
2357 if (create) root = has(UNICODE_CHARACTER_CLASS)
2358 ? new Utype(UnicodeProp.WHITE_SPACE).complement()
2359 : new Ctype(ASCII.SPACE).complement();
2360 return -1;
2361 case 'T':
2362 case 'U':
2363 break;
2364 case 'V':
2365 if (create) root = new VertWS().complement();
2366 return -1;
2367 case 'W':
2368 if (create) root = has(UNICODE_CHARACTER_CLASS)
2369 ? new Utype(UnicodeProp.WORD).complement()
2370 : new Ctype(ASCII.WORD).complement();
2371 return -1;
2372 case 'X':
2373 case 'Y':
2374 break;
2375 case 'Z':
2376 if (inclass) break;
2377 if (create) {
2378 if (has(UNIX_LINES))
2379 root = new UnixDollar(false);
2380 else
2381 root = new Dollar(false);
2382 }
2383 return -1;
2384 case 'a':
2385 return '\007';
2386 case 'b':
2387 if (inclass) break;
2388 if (create) root = new Bound(Bound.BOTH, has(UNICODE_CHARACTER_CLASS));
2389 return -1;
2390 case 'c':
2391 return c();
2392 case 'd':
2393 if (create) root = has(UNICODE_CHARACTER_CLASS)
2394 ? new Utype(UnicodeProp.DIGIT)
2395 : new Ctype(ASCII.DIGIT);
2396 return -1;
2397 case 'e':
2398 return '\033';
2399 case 'f':
2400 return '\f';
2401 case 'g':
2402 break;
2403 case 'h':
2404 if (create) root = new HorizWS();
2405 return -1;
2406 case 'i':
2407 case 'j':
2408 break;
2409 case 'k':
2410 if (inclass)
2411 break;
2412 if (read() != '<')
2413 throw error("\\k is not followed by '<' for named capturing group");
2414 String name = groupname(read());
2415 if (!namedGroups().containsKey(name))
2416 throw error("(named capturing group <"+ name+"> does not exit");
2417 if (create) {
2418 if (has(CASE_INSENSITIVE))
2419 root = new CIBackRef(namedGroups().get(name), has(UNICODE_CASE));
2420 else
2421 root = new BackRef(namedGroups().get(name));
2422 }
2423 return -1;
2424 case 'l':
2425 case 'm':
2426 break;
2427 case 'n':
2428 return '\n';
2429 case 'o':
2430 case 'p':
2431 case 'q':
2432 break;
2433 case 'r':
2434 return '\r';
2435 case 's':
2436 if (create) root = has(UNICODE_CHARACTER_CLASS)
2437 ? new Utype(UnicodeProp.WHITE_SPACE)
2438 : new Ctype(ASCII.SPACE);
2439 return -1;
2440 case 't':
2441 return '\t';
2442 case 'u':
2443 return u();
2444 case 'v':
2445 // '\v' was implemented as VT/0x0B in releases < 1.8 (though
2446 // undocumented). In JDK8 '\v' is specified as a predefined
2447 // character class for all vertical whitespace characters.
2448 // So [-1, root=VertWS node] pair is returned (instead of a
2449 // single 0x0B). This breaks the range if '\v' is used as
2450 // the start or end value, such as [\v-...] or [...-\v], in
2451 // which a single definite value (0x0B) is expected. For
2452 // compatibility concern '\013'/0x0B is returned if isrange.
2453 if (isrange)
2454 return '\013';
2455 if (create) root = new VertWS();
2456 return -1;
2457 case 'w':
2458 if (create) root = has(UNICODE_CHARACTER_CLASS)
2459 ? new Utype(UnicodeProp.WORD)
2460 : new Ctype(ASCII.WORD);
2461 return -1;
2462 case 'x':
2463 return x();
2464 case 'y':
2465 break;
2466 case 'z':
2467 if (inclass) break;
2468 if (create) root = new End();
2469 return -1;
2470 default:
2471 return ch;
2472 }
2473 throw error("Illegal/unsupported escape sequence");
2474 }
2475
2476 /**
2477 * Parse a character class, and return the node that matches it.
2478 *
2479 * Consumes a ] on the way out if consume is true. Usually consume
2480 * is true except for the case of [abc&&def] where def is a separate
2481 * right hand node with "understood" brackets.
2482 */
2483 private CharProperty clazz(boolean consume) {
2484 CharProperty prev = null;
2485 CharProperty node = null;
2486 BitClass bits = new BitClass();
2487 boolean include = true;
2488 boolean firstInClass = true;
2489 int ch = next();
2490 for (;;) {
2491 switch (ch) {
2492 case '^':
2493 // Negates if first char in a class, otherwise literal
2494 if (firstInClass) {
2495 if (temp[cursor-1] != '[')
2496 break;
2497 ch = next();
2498 include = !include;
2499 continue;
2500 } else {
2501 // ^ not first in class, treat as literal
2502 break;
2503 }
2504 case '[':
2505 firstInClass = false;
2506 node = clazz(true);
2507 if (prev == null)
2508 prev = node;
2509 else
2510 prev = union(prev, node);
2511 ch = peek();
2512 continue;
2513 case '&':
2514 firstInClass = false;
2515 ch = next();
2516 if (ch == '&') {
2517 ch = next();
2518 CharProperty rightNode = null;
2519 while (ch != ']' && ch != '&') {
2520 if (ch == '[') {
2521 if (rightNode == null)
2522 rightNode = clazz(true);
2523 else
2524 rightNode = union(rightNode, clazz(true));
2525 } else { // abc&&def
2526 unread();
2527 rightNode = clazz(false);
2528 }
2529 ch = peek();
2530 }
2531 if (rightNode != null)
2532 node = rightNode;
2533 if (prev == null) {
2534 if (rightNode == null)
2535 throw error("Bad class syntax");
2536 else
2537 prev = rightNode;
2538 } else {
2539 prev = intersection(prev, node);
2540 }
2541 } else {
2542 // treat as a literal &
2543 unread();
2544 break;
2545 }
2546 continue;
2547 case 0:
2548 firstInClass = false;
2549 if (cursor >= patternLength)
2550 throw error("Unclosed character class");
2551 break;
2552 case ']':
2553 firstInClass = false;
2554 if (prev != null) {
2555 if (consume)
2556 next();
2557 return prev;
2558 }
2559 break;
2560 default:
2561 firstInClass = false;
2562 break;
2563 }
2564 node = range(bits);
2565 if (include) {
2566 if (prev == null) {
2567 prev = node;
2568 } else {
2569 if (prev != node)
2570 prev = union(prev, node);
2571 }
2572 } else {
2573 if (prev == null) {
2574 prev = node.complement();
2575 } else {
2576 if (prev != node)
2577 prev = setDifference(prev, node);
2578 }
2579 }
2580 ch = peek();
2581 }
2582 }
2583
2584 private CharProperty bitsOrSingle(BitClass bits, int ch) {
2585 /* Bits can only handle codepoints in [u+0000-u+00ff] range.
2586 Use "single" node instead of bits when dealing with unicode
2587 case folding for codepoints listed below.
2588 (1)Uppercase out of range: u+00ff, u+00b5
2589 toUpperCase(u+00ff) -> u+0178
2590 toUpperCase(u+00b5) -> u+039c
2591 (2)LatinSmallLetterLongS u+17f
2592 toUpperCase(u+017f) -> u+0053
2593 (3)LatinSmallLetterDotlessI u+131
2594 toUpperCase(u+0131) -> u+0049
2595 (4)LatinCapitalLetterIWithDotAbove u+0130
2596 toLowerCase(u+0130) -> u+0069
2597 (5)KelvinSign u+212a
2598 toLowerCase(u+212a) ==> u+006B
2599 (6)AngstromSign u+212b
2600 toLowerCase(u+212b) ==> u+00e5
2601 */
2602 int d;
2603 if (ch < 256 &&
2604 !(has(CASE_INSENSITIVE) && has(UNICODE_CASE) &&
2605 (ch == 0xff || ch == 0xb5 ||
2606 ch == 0x49 || ch == 0x69 || //I and i
2607 ch == 0x53 || ch == 0x73 || //S and s
2608 ch == 0x4b || ch == 0x6b || //K and k
2609 ch == 0xc5 || ch == 0xe5))) //A+ring
2610 return bits.add(ch, flags());
2611 return newSingle(ch);
2612 }
2613
2614 /**
2615 * Parse a single character or a character range in a character class
2616 * and return its representative node.
2617 */
2618 private CharProperty range(BitClass bits) {
2619 int ch = peek();
2620 if (ch == '\\') {
2621 ch = nextEscaped();
2622 if (ch == 'p' || ch == 'P') { // A property
2623 boolean comp = (ch == 'P');
2624 boolean oneLetter = true;
2625 // Consume { if present
2626 ch = next();
2627 if (ch != '{')
2628 unread();
2629 else
2630 oneLetter = false;
2631 return family(oneLetter, comp);
2632 } else { // ordinary escape
2633 boolean isrange = temp[cursor+1] == '-';
2634 unread();
2635 ch = escape(true, true, isrange);
2636 if (ch == -1)
2637 return (CharProperty) root;
2638 }
2639 } else {
2640 next();
2641 }
2642 if (ch >= 0) {
2643 if (peek() == '-') {
2644 int endRange = temp[cursor+1];
2645 if (endRange == '[') {
2646 return bitsOrSingle(bits, ch);
2647 }
2648 if (endRange != ']') {
2649 next();
2650 int m = peek();
2651 if (m == '\\') {
2652 m = escape(true, false, true);
2653 } else {
2654 next();
2655 }
2656 if (m < ch) {
2657 throw error("Illegal character range");
2658 }
2659 if (has(CASE_INSENSITIVE))
2660 return caseInsensitiveRangeFor(ch, m);
2661 else
2662 return rangeFor(ch, m);
2663 }
2664 }
2665 return bitsOrSingle(bits, ch);
2666 }
2667 throw error("Unexpected character '"+((char)ch)+"'");
2668 }
2669
2670 /**
2671 * Parses a Unicode character family and returns its representative node.
2672 */
2673 private CharProperty family(boolean singleLetter,
2674 boolean maybeComplement)
2675 {
2676 next();
2677 String name;
2678 CharProperty node = null;
2679
2680 if (singleLetter) {
2681 int c = temp[cursor];
2682 if (!Character.isSupplementaryCodePoint(c)) {
2683 name = String.valueOf((char)c);
2684 } else {
2685 name = new String(temp, cursor, 1);
2686 }
2687 read();
2688 } else {
2689 int i = cursor;
2690 mark('}');
2691 while(read() != '}') {
2692 }
2693 mark('\000');
2694 int j = cursor;
2695 if (j > patternLength)
2696 throw error("Unclosed character family");
2697 if (i + 1 >= j)
2698 throw error("Empty character family");
2699 name = new String(temp, i, j-i-1);
2700 }
2701
2702 int i = name.indexOf('=');
2703 if (i != -1) {
2704 // property construct \p{name=value}
2705 String value = name.substring(i + 1);
2706 name = name.substring(0, i).toLowerCase(Locale.ENGLISH);
2707 if ("sc".equals(name) || "script".equals(name)) {
2708 node = unicodeScriptPropertyFor(value);
2709 } else if ("blk".equals(name) || "block".equals(name)) {
2710 node = unicodeBlockPropertyFor(value);
2711 } else if ("gc".equals(name) || "general_category".equals(name)) {
2712 node = charPropertyNodeFor(value);
2713 } else {
2714 throw error("Unknown Unicode property {name=<" + name + ">, "
2715 + "value=<" + value + ">}");
2716 }
2717 } else {
2718 if (name.startsWith("In")) {
2719 // \p{inBlockName}
2720 node = unicodeBlockPropertyFor(name.substring(2));
2721 } else if (name.startsWith("Is")) {
2722 // \p{isGeneralCategory} and \p{isScriptName}
2723 name = name.substring(2);
2724 UnicodeProp uprop = UnicodeProp.forName(name);
2725 if (uprop != null)
2726 node = new Utype(uprop);
2727 if (node == null)
2728 node = CharPropertyNames.charPropertyFor(name);
2729 if (node == null)
2730 node = unicodeScriptPropertyFor(name);
2731 } else {
2732 if (has(UNICODE_CHARACTER_CLASS)) {
2733 UnicodeProp uprop = UnicodeProp.forPOSIXName(name);
2734 if (uprop != null)
2735 node = new Utype(uprop);
2736 }
2737 if (node == null)
2738 node = charPropertyNodeFor(name);
2739 }
2740 }
2741 if (maybeComplement) {
2742 if (node instanceof Category || node instanceof Block)
2743 hasSupplementary = true;
2744 node = node.complement();
2745 }
2746 return node;
2747 }
2748
2749
2750 /**
2751 * Returns a CharProperty matching all characters belong to
2752 * a UnicodeScript.
2753 */
2754 private CharProperty unicodeScriptPropertyFor(String name) {
2755 final Character.UnicodeScript script;
2756 try {
2757 script = Character.UnicodeScript.forName(name);
2758 } catch (IllegalArgumentException iae) {
2759 throw error("Unknown character script name {" + name + "}");
2760 }
2761 return new Script(script);
2762 }
2763
2764 /**
2765 * Returns a CharProperty matching all characters in a UnicodeBlock.
2766 */
2767 private CharProperty unicodeBlockPropertyFor(String name) {
2768 final Character.UnicodeBlock block;
2769 try {
2770 block = Character.UnicodeBlock.forName(name);
2771 } catch (IllegalArgumentException iae) {
2772 throw error("Unknown character block name {" + name + "}");
2773 }
2774 return new Block(block);
2775 }
2776
2777 /**
2778 * Returns a CharProperty matching all characters in a named property.
2779 */
2780 private CharProperty charPropertyNodeFor(String name) {
2781 CharProperty p = CharPropertyNames.charPropertyFor(name);
2782 if (p == null)
2783 throw error("Unknown character property name {" + name + "}");
2784 return p;
2785 }
2786
2787 /**
2788 * Parses and returns the name of a "named capturing group", the trailing
2789 * ">" is consumed after parsing.
2790 */
2791 private String groupname(int ch) {
2792 StringBuilder sb = new StringBuilder();
2793 sb.append(Character.toChars(ch));
2794 while (ASCII.isLower(ch=read()) || ASCII.isUpper(ch) ||
2795 ASCII.isDigit(ch)) {
2796 sb.append(Character.toChars(ch));
2797 }
2798 if (sb.length() == 0)
2799 throw error("named capturing group has 0 length name");
2800 if (ch != '>')
2801 throw error("named capturing group is missing trailing '>'");
2802 return sb.toString();
2803 }
2804
2805 /**
2806 * Parses a group and returns the head node of a set of nodes that process
2807 * the group. Sometimes a double return system is used where the tail is
2808 * returned in root.
2809 */
2810 private Node group0() {
2811 boolean capturingGroup = false;
2812 Node head = null;
2813 Node tail = null;
2814 int save = flags;
2815 root = null;
2816 int ch = next();
2817 if (ch == '?') {
2818 ch = skip();
2819 switch (ch) {
2820 case ':': // (?:xxx) pure group
2821 head = createGroup(true);
2822 tail = root;
2823 head.next = expr(tail);
2824 break;
2825 case '=': // (?=xxx) and (?!xxx) lookahead
2826 case '!':
2827 head = createGroup(true);
2828 tail = root;
2829 head.next = expr(tail);
2830 if (ch == '=') {
2831 head = tail = new Pos(head);
2832 } else {
2833 head = tail = new Neg(head);
2834 }
2835 break;
2836 case '>': // (?>xxx) independent group
2837 head = createGroup(true);
2838 tail = root;
2839 head.next = expr(tail);
2840 head = tail = new Ques(head, INDEPENDENT);
2841 break;
2842 case '<': // (?<xxx) look behind
2843 ch = read();
2844 if (ASCII.isLower(ch) || ASCII.isUpper(ch)) {
2845 // named captured group
2846 String name = groupname(ch);
2847 if (namedGroups().containsKey(name))
2848 throw error("Named capturing group <" + name
2849 + "> is already defined");
2850 capturingGroup = true;
2851 head = createGroup(false);
2852 tail = root;
2853 namedGroups().put(name, capturingGroupCount-1);
2854 head.next = expr(tail);
2855 break;
2856 }
2857 int start = cursor;
2858 head = createGroup(true);
2859 tail = root;
2860 head.next = expr(tail);
2861 tail.next = lookbehindEnd;
2862 TreeInfo info = new TreeInfo();
2863 head.study(info);
2864 if (info.maxValid == false) {
2865 throw error("Look-behind group does not have "
2866 + "an obvious maximum length");
2867 }
2868 boolean hasSupplementary = findSupplementary(start, patternLength);
2869 if (ch == '=') {
2870 head = tail = (hasSupplementary ?
2871 new BehindS(head, info.maxLength,
2872 info.minLength) :
2873 new Behind(head, info.maxLength,
2874 info.minLength));
2875 } else if (ch == '!') {
2876 head = tail = (hasSupplementary ?
2877 new NotBehindS(head, info.maxLength,
2878 info.minLength) :
2879 new NotBehind(head, info.maxLength,
2880 info.minLength));
2881 } else {
2882 throw error("Unknown look-behind group");
2883 }
2884 break;
2885 case '$':
2886 case '@':
2887 throw error("Unknown group type");
2888 default: // (?xxx:) inlined match flags
2889 unread();
2890 addFlag();
2891 ch = read();
2892 if (ch == ')') {
2893 return null; // Inline modifier only
2894 }
2895 if (ch != ':') {
2896 throw error("Unknown inline modifier");
2897 }
2898 head = createGroup(true);
2899 tail = root;
2900 head.next = expr(tail);
2901 break;
2902 }
2903 } else { // (xxx) a regular group
2904 capturingGroup = true;
2905 head = createGroup(false);
2906 tail = root;
2907 head.next = expr(tail);
2908 }
2909
2910 accept(')', "Unclosed group");
2911 flags = save;
2912
2913 // Check for quantifiers
2914 Node node = closure(head);
2915 if (node == head) { // No closure
2916 root = tail;
2917 return node; // Dual return
2918 }
2919 if (head == tail) { // Zero length assertion
2920 root = node;
2921 return node; // Dual return
2922 }
2923
2924 if (node instanceof Ques) {
2925 Ques ques = (Ques) node;
2926 if (ques.type == POSSESSIVE) {
2927 root = node;
2928 return node;
2929 }
2930 tail.next = new BranchConn();
2931 tail = tail.next;
2932 if (ques.type == GREEDY) {
2933 head = new Branch(head, null, tail);
2934 } else { // Reluctant quantifier
2935 head = new Branch(null, head, tail);
2936 }
2937 root = tail;
2938 return head;
2939 } else if (node instanceof Curly) {
2940 Curly curly = (Curly) node;
2941 if (curly.type == POSSESSIVE) {
2942 root = node;
2943 return node;
2944 }
2945 // Discover if the group is deterministic
2946 TreeInfo info = new TreeInfo();
2947 if (head.study(info)) { // Deterministic
2948 GroupTail temp = (GroupTail) tail;
2949 head = root = new GroupCurly(head.next, curly.cmin,
2950 curly.cmax, curly.type,
2951 ((GroupTail)tail).localIndex,
2952 ((GroupTail)tail).groupIndex,
2953 capturingGroup);
2954 return head;
2955 } else { // Non-deterministic
2956 int temp = ((GroupHead) head).localIndex;
2957 Loop loop;
2958 if (curly.type == GREEDY)
2959 loop = new Loop(this.localCount, temp);
2960 else // Reluctant Curly
2961 loop = new LazyLoop(this.localCount, temp);
2962 Prolog prolog = new Prolog(loop);
2963 this.localCount += 1;
2964 loop.cmin = curly.cmin;
2965 loop.cmax = curly.cmax;
2966 loop.body = head;
2967 tail.next = loop;
2968 root = loop;
2969 return prolog; // Dual return
2970 }
2971 }
2972 throw error("Internal logic error");
2973 }
2974
2975 /**
2976 * Create group head and tail nodes using double return. If the group is
2977 * created with anonymous true then it is a pure group and should not
2978 * affect group counting.
2979 */
2980 private Node createGroup(boolean anonymous) {
2981 int localIndex = localCount++;
2982 int groupIndex = 0;
2983 if (!anonymous)
2984 groupIndex = capturingGroupCount++;
2985 GroupHead head = new GroupHead(localIndex);
2986 root = new GroupTail(localIndex, groupIndex);
2987 if (!anonymous && groupIndex < 10)
2988 groupNodes[groupIndex] = head;
2989 return head;
2990 }
2991
2992 @SuppressWarnings("fallthrough")
2993 /**
2994 * Parses inlined match flags and set them appropriately.
2995 */
2996 private void addFlag() {
2997 int ch = peek();
2998 for (;;) {
2999 switch (ch) {
3000 case 'i':
3001 flags |= CASE_INSENSITIVE;
3002 break;
3003 case 'm':
3004 flags |= MULTILINE;
3005 break;
3006 case 's':
3007 flags |= DOTALL;
3008 break;
3009 case 'd':
3010 flags |= UNIX_LINES;
3011 break;
3012 case 'u':
3013 flags |= UNICODE_CASE;
3014 break;
3015 case 'c':
3016 flags |= CANON_EQ;
3017 break;
3018 case 'x':
3019 flags |= COMMENTS;
3020 break;
3021 case 'U':
3022 flags |= (UNICODE_CHARACTER_CLASS | UNICODE_CASE);
3023 break;
3024 case '-': // subFlag then fall through
3025 ch = next();
3026 subFlag();
3027 default:
3028 return;
3029 }
3030 ch = next();
3031 }
3032 }
3033
3034 @SuppressWarnings("fallthrough")
3035 /**
3036 * Parses the second part of inlined match flags and turns off
3037 * flags appropriately.
3038 */
3039 private void subFlag() {
3040 int ch = peek();
3041 for (;;) {
3042 switch (ch) {
3043 case 'i':
3044 flags &= ~CASE_INSENSITIVE;
3045 break;
3046 case 'm':
3047 flags &= ~MULTILINE;
3048 break;
3049 case 's':
3050 flags &= ~DOTALL;
3051 break;
3052 case 'd':
3053 flags &= ~UNIX_LINES;
3054 break;
3055 case 'u':
3056 flags &= ~UNICODE_CASE;
3057 break;
3058 case 'c':
3059 flags &= ~CANON_EQ;
3060 break;
3061 case 'x':
3062 flags &= ~COMMENTS;
3063 break;
3064 case 'U':
3065 flags &= ~(UNICODE_CHARACTER_CLASS | UNICODE_CASE);
3066 default:
3067 return;
3068 }
3069 ch = next();
3070 }
3071 }
3072
3073 static final int MAX_REPS = 0x7FFFFFFF;
3074
3075 static final int GREEDY = 0;
3076
3077 static final int LAZY = 1;
3078
3079 static final int POSSESSIVE = 2;
3080
3081 static final int INDEPENDENT = 3;
3082
3083 /**
3084 * Processes repetition. If the next character peeked is a quantifier
3085 * then new nodes must be appended to handle the repetition.
3086 * Prev could be a single or a group, so it could be a chain of nodes.
3087 */
3088 private Node closure(Node prev) {
3089 Node atom;
3090 int ch = peek();
3091 switch (ch) {
3092 case '?':
3093 ch = next();
3094 if (ch == '?') {
3095 next();
3096 return new Ques(prev, LAZY);
3097 } else if (ch == '+') {
3098 next();
3099 return new Ques(prev, POSSESSIVE);
3100 }
3101 return new Ques(prev, GREEDY);
3102 case '*':
3103 ch = next();
3104 if (ch == '?') {
3105 next();
3106 return new Curly(prev, 0, MAX_REPS, LAZY);
3107 } else if (ch == '+') {
3108 next();
3109 return new Curly(prev, 0, MAX_REPS, POSSESSIVE);
3110 }
3111 return new Curly(prev, 0, MAX_REPS, GREEDY);
3112 case '+':
3113 ch = next();
3114 if (ch == '?') {
3115 next();
3116 return new Curly(prev, 1, MAX_REPS, LAZY);
3117 } else if (ch == '+') {
3118 next();
3119 return new Curly(prev, 1, MAX_REPS, POSSESSIVE);
3120 }
3121 return new Curly(prev, 1, MAX_REPS, GREEDY);
3122 case '{':
3123 ch = temp[cursor+1];
3124 if (ASCII.isDigit(ch)) {
3125 skip();
3126 int cmin = 0;
3127 do {
3128 cmin = cmin * 10 + (ch - '0');
3129 } while (ASCII.isDigit(ch = read()));
3130 int cmax = cmin;
3131 if (ch == ',') {
3132 ch = read();
3133 cmax = MAX_REPS;
3134 if (ch != '}') {
3135 cmax = 0;
3136 while (ASCII.isDigit(ch)) {
3137 cmax = cmax * 10 + (ch - '0');
3138 ch = read();
3139 }
3140 }
3141 }
3142 if (ch != '}')
3143 throw error("Unclosed counted closure");
3144 if (((cmin) | (cmax) | (cmax - cmin)) < 0)
3145 throw error("Illegal repetition range");
3146 Curly curly;
3147 ch = peek();
3148 if (ch == '?') {
3149 next();
3150 curly = new Curly(prev, cmin, cmax, LAZY);
3151 } else if (ch == '+') {
3152 next();
3153 curly = new Curly(prev, cmin, cmax, POSSESSIVE);
3154 } else {
3155 curly = new Curly(prev, cmin, cmax, GREEDY);
3156 }
3157 return curly;
3158 } else {
3159 throw error("Illegal repetition");
3160 }
3161 default:
3162 return prev;
3163 }
3164 }
3165
3166 /**
3167 * Utility method for parsing control escape sequences.
3168 */
3169 private int c() {
3170 if (cursor < patternLength) {
3171 return read() ^ 64;
3172 }
3173 throw error("Illegal control escape sequence");
3174 }
3175
3176 /**
3177 * Utility method for parsing octal escape sequences.
3178 */
3179 private int o() {
3180 int n = read();
3181 if (((n-'0')|('7'-n)) >= 0) {
3182 int m = read();
3183 if (((m-'0')|('7'-m)) >= 0) {
3184 int o = read();
3185 if ((((o-'0')|('7'-o)) >= 0) && (((n-'0')|('3'-n)) >= 0)) {
3186 return (n - '0') * 64 + (m - '0') * 8 + (o - '0');
3187 }
3188 unread();
3189 return (n - '0') * 8 + (m - '0');
3190 }
3191 unread();
3192 return (n - '0');
3193 }
3194 throw error("Illegal octal escape sequence");
3195 }
3196
3197 /**
3198 * Utility method for parsing hexadecimal escape sequences.
3199 */
3200 private int x() {
3201 int n = read();
3202 if (ASCII.isHexDigit(n)) {
3203 int m = read();
3204 if (ASCII.isHexDigit(m)) {
3205 return ASCII.toDigit(n) * 16 + ASCII.toDigit(m);
3206 }
3207 } else if (n == '{' && ASCII.isHexDigit(peek())) {
3208 int ch = 0;
3209 while (ASCII.isHexDigit(n = read())) {
3210 ch = (ch << 4) + ASCII.toDigit(n);
3211 if (ch > Character.MAX_CODE_POINT)
3212 throw error("Hexadecimal codepoint is too big");
3213 }
3214 if (n != '}')
3215 throw error("Unclosed hexadecimal escape sequence");
3216 return ch;
3217 }
3218 throw error("Illegal hexadecimal escape sequence");
3219 }
3220
3221 /**
3222 * Utility method for parsing unicode escape sequences.
3223 */
3224 private int cursor() {
3225 return cursor;
3226 }
3227
3228 private void setcursor(int pos) {
3229 cursor = pos;
3230 }
3231
3232 private int uxxxx() {
3233 int n = 0;
3234 for (int i = 0; i < 4; i++) {
3235 int ch = read();
3236 if (!ASCII.isHexDigit(ch)) {
3237 throw error("Illegal Unicode escape sequence");
3238 }
3239 n = n * 16 + ASCII.toDigit(ch);
3240 }
3241 return n;
3242 }
3243
3244 private int u() {
3245 int n = uxxxx();
3246 if (Character.isHighSurrogate((char)n)) {
3247 int cur = cursor();
3248 if (read() == '\\' && read() == 'u') {
3249 int n2 = uxxxx();
3250 if (Character.isLowSurrogate((char)n2))
3251 return Character.toCodePoint((char)n, (char)n2);
3252 }
3253 setcursor(cur);
3254 }
3255 return n;
3256 }
3257
3258 //
3259 // Utility methods for code point support
3260 //
3261
3262 private static final int countChars(CharSequence seq, int index,
3263 int lengthInCodePoints) {
3264 // optimization
3265 if (lengthInCodePoints == 1 && !Character.isHighSurrogate(seq.charAt(index))) {
3266 assert (index >= 0 && index < seq.length());
3267 return 1;
3268 }
3269 int length = seq.length();
3270 int x = index;
3271 if (lengthInCodePoints >= 0) {
3272 assert (index >= 0 && index < length);
3273 for (int i = 0; x < length && i < lengthInCodePoints; i++) {
3274 if (Character.isHighSurrogate(seq.charAt(x++))) {
3275 if (x < length && Character.isLowSurrogate(seq.charAt(x))) {
3276 x++;
3277 }
3278 }
3279 }
3280 return x - index;
3281 }
3282
3283 assert (index >= 0 && index <= length);
3284 if (index == 0) {
3285 return 0;
3286 }
3287 int len = -lengthInCodePoints;
3288 for (int i = 0; x > 0 && i < len; i++) {
3289 if (Character.isLowSurrogate(seq.charAt(--x))) {
3290 if (x > 0 && Character.isHighSurrogate(seq.charAt(x-1))) {
3291 x--;
3292 }
3293 }
3294 }
3295 return index - x;
3296 }
3297
3298 private static final int countCodePoints(CharSequence seq) {
3299 int length = seq.length();
3300 int n = 0;
3301 for (int i = 0; i < length; ) {
3302 n++;
3303 if (Character.isHighSurrogate(seq.charAt(i++))) {
3304 if (i < length && Character.isLowSurrogate(seq.charAt(i))) {
3305 i++;
3306 }
3307 }
3308 }
3309 return n;
3310 }
3311
3312 /**
3313 * Creates a bit vector for matching Latin-1 values. A normal BitClass
3314 * never matches values above Latin-1, and a complemented BitClass always
3315 * matches values above Latin-1.
3316 */
3317 private static final class BitClass extends BmpCharProperty {
3318 final boolean[] bits;
3319 BitClass() { bits = new boolean[256]; }
3320 private BitClass(boolean[] bits) { this.bits = bits; }
3321 BitClass add(int c, int flags) {
3322 assert c >= 0 && c <= 255;
3323 if ((flags & CASE_INSENSITIVE) != 0) {
3324 if (ASCII.isAscii(c)) {
3325 bits[ASCII.toUpper(c)] = true;
3326 bits[ASCII.toLower(c)] = true;
3327 } else if ((flags & UNICODE_CASE) != 0) {
3328 bits[Character.toLowerCase(c)] = true;
3329 bits[Character.toUpperCase(c)] = true;
3330 }
3331 }
3332 bits[c] = true;
3333 return this;
3334 }
3335 boolean isSatisfiedBy(int ch) {
3336 return ch < 256 && bits[ch];
3337 }
3338 }
3339
3340 /**
3341 * Returns a suitably optimized, single character matcher.
3342 */
3343 private CharProperty newSingle(final int ch) {
3344 if (has(CASE_INSENSITIVE)) {
3345 int lower, upper;
3346 if (has(UNICODE_CASE)) {
3347 upper = Character.toUpperCase(ch);
3348 lower = Character.toLowerCase(upper);
3349 if (upper != lower)
3350 return new SingleU(lower);
3351 } else if (ASCII.isAscii(ch)) {
3352 lower = ASCII.toLower(ch);
3353 upper = ASCII.toUpper(ch);
3354 if (lower != upper)
3355 return new SingleI(lower, upper);
3356 }
3357 }
3358 if (isSupplementary(ch))
3359 return new SingleS(ch); // Match a given Unicode character
3360 return new Single(ch); // Match a given BMP character
3361 }
3362
3363 /**
3364 * Utility method for creating a string slice matcher.
3365 */
3366 private Node newSlice(int[] buf, int count, boolean hasSupplementary) {
3367 int[] tmp = new int[count];
3368 if (has(CASE_INSENSITIVE)) {
3369 if (has(UNICODE_CASE)) {
3370 for (int i = 0; i < count; i++) {
3371 tmp[i] = Character.toLowerCase(
3372 Character.toUpperCase(buf[i]));
3373 }
3374 return hasSupplementary? new SliceUS(tmp) : new SliceU(tmp);
3375 }
3376 for (int i = 0; i < count; i++) {
3377 tmp[i] = ASCII.toLower(buf[i]);
3378 }
3379 return hasSupplementary? new SliceIS(tmp) : new SliceI(tmp);
3380 }
3381 for (int i = 0; i < count; i++) {
3382 tmp[i] = buf[i];
3383 }
3384 return hasSupplementary ? new SliceS(tmp) : new Slice(tmp);
3385 }
3386
3387 /**
3388 * The following classes are the building components of the object
3389 * tree that represents a compiled regular expression. The object tree
3390 * is made of individual elements that handle constructs in the Pattern.
3391 * Each type of object knows how to match its equivalent construct with
3392 * the match() method.
3393 */
3394
3395 /**
3396 * Base class for all node classes. Subclasses should override the match()
3397 * method as appropriate. This class is an accepting node, so its match()
3398 * always returns true.
3399 */
3400 static class Node extends Object {
3401 Node next;
3402 Node() {
3403 next = Pattern.accept;
3404 }
3405 /**
3406 * This method implements the classic accept node.
3407 */
3408 boolean match(Matcher matcher, int i, CharSequence seq) {
3409 matcher.last = i;
3410 matcher.groups[0] = matcher.first;
3411 matcher.groups[1] = matcher.last;
3412 return true;
3413 }
3414 /**
3415 * This method is good for all zero length assertions.
3416 */
3417 boolean study(TreeInfo info) {
3418 if (next != null) {
3419 return next.study(info);
3420 } else {
3421 return info.deterministic;
3422 }
3423 }
3424 }
3425
3426 static class LastNode extends Node {
3427 /**
3428 * This method implements the classic accept node with
3429 * the addition of a check to see if the match occurred
3430 * using all of the input.
3431 */
3432 boolean match(Matcher matcher, int i, CharSequence seq) {
3433 if (matcher.acceptMode == Matcher.ENDANCHOR && i != matcher.to)
3434 return false;
3435 matcher.last = i;
3436 matcher.groups[0] = matcher.first;
3437 matcher.groups[1] = matcher.last;
3438 return true;
3439 }
3440 }
3441
3442 /**
3443 * Used for REs that can start anywhere within the input string.
3444 * This basically tries to match repeatedly at each spot in the
3445 * input string, moving forward after each try. An anchored search
3446 * or a BnM will bypass this node completely.
3447 */
3448 static class Start extends Node {
3449 int minLength;
3450 Start(Node node) {
3451 this.next = node;
3452 TreeInfo info = new TreeInfo();
3453 next.study(info);
3454 minLength = info.minLength;
3455 }
3456 boolean match(Matcher matcher, int i, CharSequence seq) {
3457 if (i > matcher.to - minLength) {
3458 matcher.hitEnd = true;
3459 return false;
3460 }
3461 int guard = matcher.to - minLength;
3462 for (; i <= guard; i++) {
3463 if (next.match(matcher, i, seq)) {
3464 matcher.first = i;
3465 matcher.groups[0] = matcher.first;
3466 matcher.groups[1] = matcher.last;
3467 return true;
3468 }
3469 }
3470 matcher.hitEnd = true;
3471 return false;
3472 }
3473 boolean study(TreeInfo info) {
3474 next.study(info);
3475 info.maxValid = false;
3476 info.deterministic = false;
3477 return false;
3478 }
3479 }
3480
3481 /*
3482 * StartS supports supplementary characters, including unpaired surrogates.
3483 */
3484 static final class StartS extends Start {
3485 StartS(Node node) {
3486 super(node);
3487 }
3488 boolean match(Matcher matcher, int i, CharSequence seq) {
3489 if (i > matcher.to - minLength) {
3490 matcher.hitEnd = true;
3491 return false;
3492 }
3493 int guard = matcher.to - minLength;
3494 while (i <= guard) {
3495 //if ((ret = next.match(matcher, i, seq)) || i == guard)
3496 if (next.match(matcher, i, seq)) {
3497 matcher.first = i;
3498 matcher.groups[0] = matcher.first;
3499 matcher.groups[1] = matcher.last;
3500 return true;
3501 }
3502 if (i == guard)
3503 break;
3504 // Optimization to move to the next character. This is
3505 // faster than countChars(seq, i, 1).
3506 if (Character.isHighSurrogate(seq.charAt(i++))) {
3507 if (i < seq.length() &&
3508 Character.isLowSurrogate(seq.charAt(i))) {
3509 i++;
3510 }
3511 }
3512 }
3513 matcher.hitEnd = true;
3514 return false;
3515 }
3516 }
3517
3518 /**
3519 * Node to anchor at the beginning of input. This object implements the
3520 * match for a \A sequence, and the caret anchor will use this if not in
3521 * multiline mode.
3522 */
3523 static final class Begin extends Node {
3524 boolean match(Matcher matcher, int i, CharSequence seq) {
3525 int fromIndex = (matcher.anchoringBounds) ?
3526 matcher.from : 0;
3527 if (i == fromIndex && next.match(matcher, i, seq)) {
3528 matcher.first = i;
3529 matcher.groups[0] = i;
3530 matcher.groups[1] = matcher.last;
3531 return true;
3532 } else {
3533 return false;
3534 }
3535 }
3536 }
3537
3538 /**
3539 * Node to anchor at the end of input. This is the absolute end, so this
3540 * should not match at the last newline before the end as $ will.
3541 */
3542 static final class End extends Node {
3543 boolean match(Matcher matcher, int i, CharSequence seq) {
3544 int endIndex = (matcher.anchoringBounds) ?
3545 matcher.to : matcher.getTextLength();
3546 if (i == endIndex) {
3547 matcher.hitEnd = true;
3548 return next.match(matcher, i, seq);
3549 }
3550 return false;
3551 }
3552 }
3553
3554 /**
3555 * Node to anchor at the beginning of a line. This is essentially the
3556 * object to match for the multiline ^.
3557 */
3558 static final class Caret extends Node {
3559 boolean match(Matcher matcher, int i, CharSequence seq) {
3560 int startIndex = matcher.from;
3561 int endIndex = matcher.to;
3562 if (!matcher.anchoringBounds) {
3563 startIndex = 0;
3564 endIndex = matcher.getTextLength();
3565 }
3566 // Perl does not match ^ at end of input even after newline
3567 if (i == endIndex) {
3568 matcher.hitEnd = true;
3569 return false;
3570 }
3571 if (i > startIndex) {
3572 char ch = seq.charAt(i-1);
3573 if (ch != '\n' && ch != '\r'
3574 && (ch|1) != '\u2029'
3575 && ch != '\u0085' ) {
3576 return false;
3577 }
3578 // Should treat /r/n as one newline
3579 if (ch == '\r' && seq.charAt(i) == '\n')
3580 return false;
3581 }
3582 return next.match(matcher, i, seq);
3583 }
3584 }
3585
3586 /**
3587 * Node to anchor at the beginning of a line when in unixdot mode.
3588 */
3589 static final class UnixCaret extends Node {
3590 boolean match(Matcher matcher, int i, CharSequence seq) {
3591 int startIndex = matcher.from;
3592 int endIndex = matcher.to;
3593 if (!matcher.anchoringBounds) {
3594 startIndex = 0;
3595 endIndex = matcher.getTextLength();
3596 }
3597 // Perl does not match ^ at end of input even after newline
3598 if (i == endIndex) {
3599 matcher.hitEnd = true;
3600 return false;
3601 }
3602 if (i > startIndex) {
3603 char ch = seq.charAt(i-1);
3604 if (ch != '\n') {
3605 return false;
3606 }
3607 }
3608 return next.match(matcher, i, seq);
3609 }
3610 }
3611
3612 /**
3613 * Node to match the location where the last match ended.
3614 * This is used for the \G construct.
3615 */
3616 static final class LastMatch extends Node {
3617 boolean match(Matcher matcher, int i, CharSequence seq) {
3618 if (i != matcher.oldLast)
3619 return false;
3620 return next.match(matcher, i, seq);
3621 }
3622 }
3623
3624 /**
3625 * Node to anchor at the end of a line or the end of input based on the
3626 * multiline mode.
3627 *
3628 * When not in multiline mode, the $ can only match at the very end
3629 * of the input, unless the input ends in a line terminator in which
3630 * it matches right before the last line terminator.
3631 *
3632 * Note that \r\n is considered an atomic line terminator.
3633 *
3634 * Like ^ the $ operator matches at a position, it does not match the
3635 * line terminators themselves.
3636 */
3637 static final class Dollar extends Node {
3638 boolean multiline;
3639 Dollar(boolean mul) {
3640 multiline = mul;
3641 }
3642 boolean match(Matcher matcher, int i, CharSequence seq) {
3643 int endIndex = (matcher.anchoringBounds) ?
3644 matcher.to : matcher.getTextLength();
3645 if (!multiline) {
3646 if (i < endIndex - 2)
3647 return false;
3648 if (i == endIndex - 2) {
3649 char ch = seq.charAt(i);
3650 if (ch != '\r')
3651 return false;
3652 ch = seq.charAt(i + 1);
3653 if (ch != '\n')
3654 return false;
3655 }
3656 }
3657 // Matches before any line terminator; also matches at the
3658 // end of input
3659 // Before line terminator:
3660 // If multiline, we match here no matter what
3661 // If not multiline, fall through so that the end
3662 // is marked as hit; this must be a /r/n or a /n
3663 // at the very end so the end was hit; more input
3664 // could make this not match here
3665 if (i < endIndex) {
3666 char ch = seq.charAt(i);
3667 if (ch == '\n') {
3668 // No match between \r\n
3669 if (i > 0 && seq.charAt(i-1) == '\r')
3670 return false;
3671 if (multiline)
3672 return next.match(matcher, i, seq);
3673 } else if (ch == '\r' || ch == '\u0085' ||
3674 (ch|1) == '\u2029') {
3675 if (multiline)
3676 return next.match(matcher, i, seq);
3677 } else { // No line terminator, no match
3678 return false;
3679 }
3680 }
3681 // Matched at current end so hit end
3682 matcher.hitEnd = true;
3683 // If a $ matches because of end of input, then more input
3684 // could cause it to fail!
3685 matcher.requireEnd = true;
3686 return next.match(matcher, i, seq);
3687 }
3688 boolean study(TreeInfo info) {
3689 next.study(info);
3690 return info.deterministic;
3691 }
3692 }
3693
3694 /**
3695 * Node to anchor at the end of a line or the end of input based on the
3696 * multiline mode when in unix lines mode.
3697 */
3698 static final class UnixDollar extends Node {
3699 boolean multiline;
3700 UnixDollar(boolean mul) {
3701 multiline = mul;
3702 }
3703 boolean match(Matcher matcher, int i, CharSequence seq) {
3704 int endIndex = (matcher.anchoringBounds) ?
3705 matcher.to : matcher.getTextLength();
3706 if (i < endIndex) {
3707 char ch = seq.charAt(i);
3708 if (ch == '\n') {
3709 // If not multiline, then only possible to
3710 // match at very end or one before end
3711 if (multiline == false && i != endIndex - 1)
3712 return false;
3713 // If multiline return next.match without setting
3714 // matcher.hitEnd
3715 if (multiline)
3716 return next.match(matcher, i, seq);
3717 } else {
3718 return false;
3719 }
3720 }
3721 // Matching because at the end or 1 before the end;
3722 // more input could change this so set hitEnd
3723 matcher.hitEnd = true;
3724 // If a $ matches because of end of input, then more input
3725 // could cause it to fail!
3726 matcher.requireEnd = true;
3727 return next.match(matcher, i, seq);
3728 }
3729 boolean study(TreeInfo info) {
3730 next.study(info);
3731 return info.deterministic;
3732 }
3733 }
3734
3735 /**
3736 * Node class that matches a Unicode line ending '\R'
3737 */
3738 static final class LineEnding extends Node {
3739 boolean match(Matcher matcher, int i, CharSequence seq) {
3740 // (u+000Du+000A|[u+000Au+000Bu+000Cu+000Du+0085u+2028u+2029])
3741 if (i < matcher.to) {
3742 int ch = seq.charAt(i);
3743 if (ch == 0x0A || ch == 0x0B || ch == 0x0C ||
3744 ch == 0x85 || ch == 0x2028 || ch == 0x2029)
3745 return next.match(matcher, i + 1, seq);
3746 if (ch == 0x0D) {
3747 i++;
3748 if (i < matcher.to && seq.charAt(i) == 0x0A)
3749 i++;
3750 return next.match(matcher, i, seq);
3751 }
3752 } else {
3753 matcher.hitEnd = true;
3754 }
3755 return false;
3756 }
3757 boolean study(TreeInfo info) {
3758 info.minLength++;
3759 info.maxLength += 2;
3760 return next.study(info);
3761 }
3762 }
3763
3764 /**
3765 * Abstract node class to match one character satisfying some
3766 * boolean property.
3767 */
3768 private static abstract class CharProperty extends Node {
3769 abstract boolean isSatisfiedBy(int ch);
3770 CharProperty complement() {
3771 return new CharProperty() {
3772 boolean isSatisfiedBy(int ch) {
3773 return ! CharProperty.this.isSatisfiedBy(ch);}};
3774 }
3775 boolean match(Matcher matcher, int i, CharSequence seq) {
3776 if (i < matcher.to) {
3777 int ch = Character.codePointAt(seq, i);
3778 return isSatisfiedBy(ch)
3779 && next.match(matcher, i+Character.charCount(ch), seq);
3780 } else {
3781 matcher.hitEnd = true;
3782 return false;
3783 }
3784 }
3785 boolean study(TreeInfo info) {
3786 info.minLength++;
3787 info.maxLength++;
3788 return next.study(info);
3789 }
3790 }
3791
3792 /**
3793 * Optimized version of CharProperty that works only for
3794 * properties never satisfied by Supplementary characters.
3795 */
3796 private static abstract class BmpCharProperty extends CharProperty {
3797 boolean match(Matcher matcher, int i, CharSequence seq) {
3798 if (i < matcher.to) {
3799 return isSatisfiedBy(seq.charAt(i))
3800 && next.match(matcher, i+1, seq);
3801 } else {
3802 matcher.hitEnd = true;
3803 return false;
3804 }
3805 }
3806 }
3807
3808 /**
3809 * Node class that matches a Supplementary Unicode character
3810 */
3811 static final class SingleS extends CharProperty {
3812 final int c;
3813 SingleS(int c) { this.c = c; }
3814 boolean isSatisfiedBy(int ch) {
3815 return ch == c;
3816 }
3817 }
3818
3819 /**
3820 * Optimization -- matches a given BMP character
3821 */
3822 static final class Single extends BmpCharProperty {
3823 final int c;
3824 Single(int c) { this.c = c; }
3825 boolean isSatisfiedBy(int ch) {
3826 return ch == c;
3827 }
3828 }
3829
3830 /**
3831 * Case insensitive matches a given BMP character
3832 */
3833 static final class SingleI extends BmpCharProperty {
3834 final int lower;
3835 final int upper;
3836 SingleI(int lower, int upper) {
3837 this.lower = lower;
3838 this.upper = upper;
3839 }
3840 boolean isSatisfiedBy(int ch) {
3841 return ch == lower || ch == upper;
3842 }
3843 }
3844
3845 /**
3846 * Unicode case insensitive matches a given Unicode character
3847 */
3848 static final class SingleU extends CharProperty {
3849 final int lower;
3850 SingleU(int lower) {
3851 this.lower = lower;
3852 }
3853 boolean isSatisfiedBy(int ch) {
3854 return lower == ch ||
3855 lower == Character.toLowerCase(Character.toUpperCase(ch));
3856 }
3857 }
3858
3859 /**
3860 * Node class that matches a Unicode block.
3861 */
3862 static final class Block extends CharProperty {
3863 final Character.UnicodeBlock block;
3864 Block(Character.UnicodeBlock block) {
3865 this.block = block;
3866 }
3867 boolean isSatisfiedBy(int ch) {
3868 return block == Character.UnicodeBlock.of(ch);
3869 }
3870 }
3871
3872 /**
3873 * Node class that matches a Unicode script
3874 */
3875 static final class Script extends CharProperty {
3876 final Character.UnicodeScript script;
3877 Script(Character.UnicodeScript script) {
3878 this.script = script;
3879 }
3880 boolean isSatisfiedBy(int ch) {
3881 return script == Character.UnicodeScript.of(ch);
3882 }
3883 }
3884
3885 /**
3886 * Node class that matches a Unicode category.
3887 */
3888 static final class Category extends CharProperty {
3889 final int typeMask;
3890 Category(int typeMask) { this.typeMask = typeMask; }
3891 boolean isSatisfiedBy(int ch) {
3892 return (typeMask & (1 << Character.getType(ch))) != 0;
3893 }
3894 }
3895
3896 /**
3897 * Node class that matches a Unicode "type"
3898 */
3899 static final class Utype extends CharProperty {
3900 final UnicodeProp uprop;
3901 Utype(UnicodeProp uprop) { this.uprop = uprop; }
3902 boolean isSatisfiedBy(int ch) {
3903 return uprop.is(ch);
3904 }
3905 }
3906
3907 /**
3908 * Node class that matches a POSIX type.
3909 */
3910 static final class Ctype extends BmpCharProperty {
3911 final int ctype;
3912 Ctype(int ctype) { this.ctype = ctype; }
3913 boolean isSatisfiedBy(int ch) {
3914 return ch < 128 && ASCII.isType(ch, ctype);
3915 }
3916 }
3917
3918 /**
3919 * Node class that matches a Perl vertical whitespace
3920 */
3921 static final class VertWS extends BmpCharProperty {
3922 boolean isSatisfiedBy(int cp) {
3923 return (cp >= 0x0A && cp <= 0x0D) ||
3924 cp == 0x85 || cp == 0x2028 || cp == 0x2029;
3925 }
3926 }
3927
3928 /**
3929 * Node class that matches a Perl horizontal whitespace
3930 */
3931 static final class HorizWS extends BmpCharProperty {
3932 boolean isSatisfiedBy(int cp) {
3933 return cp == 0x09 || cp == 0x20 || cp == 0xa0 ||
3934 cp == 0x1680 || cp == 0x180e ||
3935 cp >= 0x2000 && cp <= 0x200a ||
3936 cp == 0x202f || cp == 0x205f || cp == 0x3000;
3937 }
3938 }
3939
3940 /**
3941 * Base class for all Slice nodes
3942 */
3943 static class SliceNode extends Node {
3944 int[] buffer;
3945 SliceNode(int[] buf) {
3946 buffer = buf;
3947 }
3948 boolean study(TreeInfo info) {
3949 info.minLength += buffer.length;
3950 info.maxLength += buffer.length;
3951 return next.study(info);
3952 }
3953 }
3954
3955 /**
3956 * Node class for a case sensitive/BMP-only sequence of literal
3957 * characters.
3958 */
3959 static final class Slice extends SliceNode {
3960 Slice(int[] buf) {
3961 super(buf);
3962 }
3963 boolean match(Matcher matcher, int i, CharSequence seq) {
3964 int[] buf = buffer;
3965 int len = buf.length;
3966 for (int j=0; j<len; j++) {
3967 if ((i+j) >= matcher.to) {
3968 matcher.hitEnd = true;
3969 return false;
3970 }
3971 if (buf[j] != seq.charAt(i+j))
3972 return false;
3973 }
3974 return next.match(matcher, i+len, seq);
3975 }
3976 }
3977
3978 /**
3979 * Node class for a case_insensitive/BMP-only sequence of literal
3980 * characters.
3981 */
3982 static class SliceI extends SliceNode {
3983 SliceI(int[] buf) {
3984 super(buf);
3985 }
3986 boolean match(Matcher matcher, int i, CharSequence seq) {
3987 int[] buf = buffer;
3988 int len = buf.length;
3989 for (int j=0; j<len; j++) {
3990 if ((i+j) >= matcher.to) {
3991 matcher.hitEnd = true;
3992 return false;
3993 }
3994 int c = seq.charAt(i+j);
3995 if (buf[j] != c &&
3996 buf[j] != ASCII.toLower(c))
3997 return false;
3998 }
3999 return next.match(matcher, i+len, seq);
4000 }
4001 }
4002
4003 /**
4004 * Node class for a unicode_case_insensitive/BMP-only sequence of
4005 * literal characters. Uses unicode case folding.
4006 */
4007 static final class SliceU extends SliceNode {
4008 SliceU(int[] buf) {
4009 super(buf);
4010 }
4011 boolean match(Matcher matcher, int i, CharSequence seq) {
4012 int[] buf = buffer;
4013 int len = buf.length;
4014 for (int j=0; j<len; j++) {
4015 if ((i+j) >= matcher.to) {
4016 matcher.hitEnd = true;
4017 return false;
4018 }
4019 int c = seq.charAt(i+j);
4020 if (buf[j] != c &&
4021 buf[j] != Character.toLowerCase(Character.toUpperCase(c)))
4022 return false;
4023 }
4024 return next.match(matcher, i+len, seq);
4025 }
4026 }
4027
4028 /**
4029 * Node class for a case sensitive sequence of literal characters
4030 * including supplementary characters.
4031 */
4032 static final class SliceS extends SliceNode {
4033 SliceS(int[] buf) {
4034 super(buf);
4035 }
4036 boolean match(Matcher matcher, int i, CharSequence seq) {
4037 int[] buf = buffer;
4038 int x = i;
4039 for (int j = 0; j < buf.length; j++) {
4040 if (x >= matcher.to) {
4041 matcher.hitEnd = true;
4042 return false;
4043 }
4044 int c = Character.codePointAt(seq, x);
4045 if (buf[j] != c)
4046 return false;
4047 x += Character.charCount(c);
4048 if (x > matcher.to) {
4049 matcher.hitEnd = true;
4050 return false;
4051 }
4052 }
4053 return next.match(matcher, x, seq);
4054 }
4055 }
4056
4057 /**
4058 * Node class for a case insensitive sequence of literal characters
4059 * including supplementary characters.
4060 */
4061 static class SliceIS extends SliceNode {
4062 SliceIS(int[] buf) {
4063 super(buf);
4064 }
4065 int toLower(int c) {
4066 return ASCII.toLower(c);
4067 }
4068 boolean match(Matcher matcher, int i, CharSequence seq) {
4069 int[] buf = buffer;
4070 int x = i;
4071 for (int j = 0; j < buf.length; j++) {
4072 if (x >= matcher.to) {
4073 matcher.hitEnd = true;
4074 return false;
4075 }
4076 int c = Character.codePointAt(seq, x);
4077 if (buf[j] != c && buf[j] != toLower(c))
4078 return false;
4079 x += Character.charCount(c);
4080 if (x > matcher.to) {
4081 matcher.hitEnd = true;
4082 return false;
4083 }
4084 }
4085 return next.match(matcher, x, seq);
4086 }
4087 }
4088
4089 /**
4090 * Node class for a case insensitive sequence of literal characters.
4091 * Uses unicode case folding.
4092 */
4093 static final class SliceUS extends SliceIS {
4094 SliceUS(int[] buf) {
4095 super(buf);
4096 }
4097 int toLower(int c) {
4098 return Character.toLowerCase(Character.toUpperCase(c));
4099 }
4100 }
4101
4102 private static boolean inRange(int lower, int ch, int upper) {
4103 return lower <= ch && ch <= upper;
4104 }
4105
4106 /**
4107 * Returns node for matching characters within an explicit value range.
4108 */
4109 private static CharProperty rangeFor(final int lower,
4110 final int upper) {
4111 return new CharProperty() {
4112 boolean isSatisfiedBy(int ch) {
4113 return inRange(lower, ch, upper);}};
4114 }
4115
4116 /**
4117 * Returns node for matching characters within an explicit value
4118 * range in a case insensitive manner.
4119 */
4120 private CharProperty caseInsensitiveRangeFor(final int lower,
4121 final int upper) {
4122 if (has(UNICODE_CASE))
4123 return new CharProperty() {
4124 boolean isSatisfiedBy(int ch) {
4125 if (inRange(lower, ch, upper))
4126 return true;
4127 int up = Character.toUpperCase(ch);
4128 return inRange(lower, up, upper) ||
4129 inRange(lower, Character.toLowerCase(up), upper);}};
4130 return new CharProperty() {
4131 boolean isSatisfiedBy(int ch) {
4132 return inRange(lower, ch, upper) ||
4133 ASCII.isAscii(ch) &&
4134 (inRange(lower, ASCII.toUpper(ch), upper) ||
4135 inRange(lower, ASCII.toLower(ch), upper));
4136 }};
4137 }
4138
4139 /**
4140 * Implements the Unicode category ALL and the dot metacharacter when
4141 * in dotall mode.
4142 */
4143 static final class All extends CharProperty {
4144 boolean isSatisfiedBy(int ch) {
4145 return true;
4146 }
4147 }
4148
4149 /**
4150 * Node class for the dot metacharacter when dotall is not enabled.
4151 */
4152 static final class Dot extends CharProperty {
4153 boolean isSatisfiedBy(int ch) {
4154 return (ch != '\n' && ch != '\r'
4155 && (ch|1) != '\u2029'
4156 && ch != '\u0085');
4157 }
4158 }
4159
4160 /**
4161 * Node class for the dot metacharacter when dotall is not enabled
4162 * but UNIX_LINES is enabled.
4163 */
4164 static final class UnixDot extends CharProperty {
4165 boolean isSatisfiedBy(int ch) {
4166 return ch != '\n';
4167 }
4168 }
4169
4170 /**
4171 * The 0 or 1 quantifier. This one class implements all three types.
4172 */
4173 static final class Ques extends Node {
4174 Node atom;
4175 int type;
4176 Ques(Node node, int type) {
4177 this.atom = node;
4178 this.type = type;
4179 }
4180 boolean match(Matcher matcher, int i, CharSequence seq) {
4181 switch (type) {
4182 case GREEDY:
4183 return (atom.match(matcher, i, seq) && next.match(matcher, matcher.last, seq))
4184 || next.match(matcher, i, seq);
4185 case LAZY:
4186 return next.match(matcher, i, seq)
4187 || (atom.match(matcher, i, seq) && next.match(matcher, matcher.last, seq));
4188 case POSSESSIVE:
4189 if (atom.match(matcher, i, seq)) i = matcher.last;
4190 return next.match(matcher, i, seq);
4191 default:
4192 return atom.match(matcher, i, seq) && next.match(matcher, matcher.last, seq);
4193 }
4194 }
4195 boolean study(TreeInfo info) {
4196 if (type != INDEPENDENT) {
4197 int minL = info.minLength;
4198 atom.study(info);
4199 info.minLength = minL;
4200 info.deterministic = false;
4201 return next.study(info);
4202 } else {
4203 atom.study(info);
4204 return next.study(info);
4205 }
4206 }
4207 }
4208
4209 /**
4210 * Handles the curly-brace style repetition with a specified minimum and
4211 * maximum occurrences. The * quantifier is handled as a special case.
4212 * This class handles the three types.
4213 */
4214 static final class Curly extends Node {
4215 Node atom;
4216 int type;
4217 int cmin;
4218 int cmax;
4219
4220 Curly(Node node, int cmin, int cmax, int type) {
4221 this.atom = node;
4222 this.type = type;
4223 this.cmin = cmin;
4224 this.cmax = cmax;
4225 }
4226 boolean match(Matcher matcher, int i, CharSequence seq) {
4227 int j;
4228 for (j = 0; j < cmin; j++) {
4229 if (atom.match(matcher, i, seq)) {
4230 i = matcher.last;
4231 continue;
4232 }
4233 return false;
4234 }
4235 if (type == GREEDY)
4236 return match0(matcher, i, j, seq);
4237 else if (type == LAZY)
4238 return match1(matcher, i, j, seq);
4239 else
4240 return match2(matcher, i, j, seq);
4241 }
4242 // Greedy match.
4243 // i is the index to start matching at
4244 // j is the number of atoms that have matched
4245 boolean match0(Matcher matcher, int i, int j, CharSequence seq) {
4246 if (j >= cmax) {
4247 // We have matched the maximum... continue with the rest of
4248 // the regular expression
4249 return next.match(matcher, i, seq);
4250 }
4251 int backLimit = j;
4252 while (atom.match(matcher, i, seq)) {
4253 // k is the length of this match
4254 int k = matcher.last - i;
4255 if (k == 0) // Zero length match
4256 break;
4257 // Move up index and number matched
4258 i = matcher.last;
4259 j++;
4260 // We are greedy so match as many as we can
4261 while (j < cmax) {
4262 if (!atom.match(matcher, i, seq))
4263 break;
4264 if (i + k != matcher.last) {
4265 if (match0(matcher, matcher.last, j+1, seq))
4266 return true;
4267 break;
4268 }
4269 i += k;
4270 j++;
4271 }
4272 // Handle backing off if match fails
4273 while (j >= backLimit) {
4274 if (next.match(matcher, i, seq))
4275 return true;
4276 i -= k;
4277 j--;
4278 }
4279 return false;
4280 }
4281 return next.match(matcher, i, seq);
4282 }
4283 // Reluctant match. At this point, the minimum has been satisfied.
4284 // i is the index to start matching at
4285 // j is the number of atoms that have matched
4286 boolean match1(Matcher matcher, int i, int j, CharSequence seq) {
4287 for (;;) {
4288 // Try finishing match without consuming any more
4289 if (next.match(matcher, i, seq))
4290 return true;
4291 // At the maximum, no match found
4292 if (j >= cmax)
4293 return false;
4294 // Okay, must try one more atom
4295 if (!atom.match(matcher, i, seq))
4296 return false;
4297 // If we haven't moved forward then must break out
4298 if (i == matcher.last)
4299 return false;
4300 // Move up index and number matched
4301 i = matcher.last;
4302 j++;
4303 }
4304 }
4305 boolean match2(Matcher matcher, int i, int j, CharSequence seq) {
4306 for (; j < cmax; j++) {
4307 if (!atom.match(matcher, i, seq))
4308 break;
4309 if (i == matcher.last)
4310 break;
4311 i = matcher.last;
4312 }
4313 return next.match(matcher, i, seq);
4314 }
4315 boolean study(TreeInfo info) {
4316 // Save original info
4317 int minL = info.minLength;
4318 int maxL = info.maxLength;
4319 boolean maxV = info.maxValid;
4320 boolean detm = info.deterministic;
4321 info.reset();
4322
4323 atom.study(info);
4324
4325 int temp = info.minLength * cmin + minL;
4326 if (temp < minL) {
4327 temp = 0xFFFFFFF; // arbitrary large number
4328 }
4329 info.minLength = temp;
4330
4331 if (maxV & info.maxValid) {
4332 temp = info.maxLength * cmax + maxL;
4333 info.maxLength = temp;
4334 if (temp < maxL) {
4335 info.maxValid = false;
4336 }
4337 } else {
4338 info.maxValid = false;
4339 }
4340
4341 if (info.deterministic && cmin == cmax)
4342 info.deterministic = detm;
4343 else
4344 info.deterministic = false;
4345 return next.study(info);
4346 }
4347 }
4348
4349 /**
4350 * Handles the curly-brace style repetition with a specified minimum and
4351 * maximum occurrences in deterministic cases. This is an iterative
4352 * optimization over the Prolog and Loop system which would handle this
4353 * in a recursive way. The * quantifier is handled as a special case.
4354 * If capture is true then this class saves group settings and ensures
4355 * that groups are unset when backing off of a group match.
4356 */
4357 static final class GroupCurly extends Node {
4358 Node atom;
4359 int type;
4360 int cmin;
4361 int cmax;
4362 int localIndex;
4363 int groupIndex;
4364 boolean capture;
4365
4366 GroupCurly(Node node, int cmin, int cmax, int type, int local,
4367 int group, boolean capture) {
4368 this.atom = node;
4369 this.type = type;
4370 this.cmin = cmin;
4371 this.cmax = cmax;
4372 this.localIndex = local;
4373 this.groupIndex = group;
4374 this.capture = capture;
4375 }
4376 boolean match(Matcher matcher, int i, CharSequence seq) {
4377 int[] groups = matcher.groups;
4378 int[] locals = matcher.locals;
4379 int save0 = locals[localIndex];
4380 int save1 = 0;
4381 int save2 = 0;
4382
4383 if (capture) {
4384 save1 = groups[groupIndex];
4385 save2 = groups[groupIndex+1];
4386 }
4387
4388 // Notify GroupTail there is no need to setup group info
4389 // because it will be set here
4390 locals[localIndex] = -1;
4391
4392 boolean ret = true;
4393 for (int j = 0; j < cmin; j++) {
4394 if (atom.match(matcher, i, seq)) {
4395 if (capture) {
4396 groups[groupIndex] = i;
4397 groups[groupIndex+1] = matcher.last;
4398 }
4399 i = matcher.last;
4400 } else {
4401 ret = false;
4402 break;
4403 }
4404 }
4405 if (ret) {
4406 if (type == GREEDY) {
4407 ret = match0(matcher, i, cmin, seq);
4408 } else if (type == LAZY) {
4409 ret = match1(matcher, i, cmin, seq);
4410 } else {
4411 ret = match2(matcher, i, cmin, seq);
4412 }
4413 }
4414 if (!ret) {
4415 locals[localIndex] = save0;
4416 if (capture) {
4417 groups[groupIndex] = save1;
4418 groups[groupIndex+1] = save2;
4419 }
4420 }
4421 return ret;
4422 }
4423 // Aggressive group match
4424 boolean match0(Matcher matcher, int i, int j, CharSequence seq) {
4425 // don't back off passing the starting "j"
4426 int min = j;
4427 int[] groups = matcher.groups;
4428 int save0 = 0;
4429 int save1 = 0;
4430 if (capture) {
4431 save0 = groups[groupIndex];
4432 save1 = groups[groupIndex+1];
4433 }
4434 for (;;) {
4435 if (j >= cmax)
4436 break;
4437 if (!atom.match(matcher, i, seq))
4438 break;
4439 int k = matcher.last - i;
4440 if (k <= 0) {
4441 if (capture) {
4442 groups[groupIndex] = i;
4443 groups[groupIndex+1] = i + k;
4444 }
4445 i = i + k;
4446 break;
4447 }
4448 for (;;) {
4449 if (capture) {
4450 groups[groupIndex] = i;
4451 groups[groupIndex+1] = i + k;
4452 }
4453 i = i + k;
4454 if (++j >= cmax)
4455 break;
4456 if (!atom.match(matcher, i, seq))
4457 break;
4458 if (i + k != matcher.last) {
4459 if (match0(matcher, i, j, seq))
4460 return true;
4461 break;
4462 }
4463 }
4464 while (j > min) {
4465 if (next.match(matcher, i, seq)) {
4466 if (capture) {
4467 groups[groupIndex+1] = i;
4468 groups[groupIndex] = i - k;
4469 }
4470 return true;
4471 }
4472 // backing off
4473 i = i - k;
4474 if (capture) {
4475 groups[groupIndex+1] = i;
4476 groups[groupIndex] = i - k;
4477 }
4478 j--;
4479
4480 }
4481 break;
4482 }
4483 if (capture) {
4484 groups[groupIndex] = save0;
4485 groups[groupIndex+1] = save1;
4486 }
4487 return next.match(matcher, i, seq);
4488 }
4489 // Reluctant matching
4490 boolean match1(Matcher matcher, int i, int j, CharSequence seq) {
4491 for (;;) {
4492 if (next.match(matcher, i, seq))
4493 return true;
4494 if (j >= cmax)
4495 return false;
4496 if (!atom.match(matcher, i, seq))
4497 return false;
4498 if (i == matcher.last)
4499 return false;
4500 if (capture) {
4501 matcher.groups[groupIndex] = i;
4502 matcher.groups[groupIndex+1] = matcher.last;
4503 }
4504 i = matcher.last;
4505 j++;
4506 }
4507 }
4508 // Possessive matching
4509 boolean match2(Matcher matcher, int i, int j, CharSequence seq) {
4510 for (; j < cmax; j++) {
4511 if (!atom.match(matcher, i, seq)) {
4512 break;
4513 }
4514 if (capture) {
4515 matcher.groups[groupIndex] = i;
4516 matcher.groups[groupIndex+1] = matcher.last;
4517 }
4518 if (i == matcher.last) {
4519 break;
4520 }
4521 i = matcher.last;
4522 }
4523 return next.match(matcher, i, seq);
4524 }
4525 boolean study(TreeInfo info) {
4526 // Save original info
4527 int minL = info.minLength;
4528 int maxL = info.maxLength;
4529 boolean maxV = info.maxValid;
4530 boolean detm = info.deterministic;
4531 info.reset();
4532
4533 atom.study(info);
4534
4535 int temp = info.minLength * cmin + minL;
4536 if (temp < minL) {
4537 temp = 0xFFFFFFF; // Arbitrary large number
4538 }
4539 info.minLength = temp;
4540
4541 if (maxV & info.maxValid) {
4542 temp = info.maxLength * cmax + maxL;
4543 info.maxLength = temp;
4544 if (temp < maxL) {
4545 info.maxValid = false;
4546 }
4547 } else {
4548 info.maxValid = false;
4549 }
4550
4551 if (info.deterministic && cmin == cmax) {
4552 info.deterministic = detm;
4553 } else {
4554 info.deterministic = false;
4555 }
4556 return next.study(info);
4557 }
4558 }
4559
4560 /**
4561 * A Guard node at the end of each atom node in a Branch. It
4562 * serves the purpose of chaining the "match" operation to
4563 * "next" but not the "study", so we can collect the TreeInfo
4564 * of each atom node without including the TreeInfo of the
4565 * "next".
4566 */
4567 static final class BranchConn extends Node {
4568 BranchConn() {};
4569 boolean match(Matcher matcher, int i, CharSequence seq) {
4570 return next.match(matcher, i, seq);
4571 }
4572 boolean study(TreeInfo info) {
4573 return info.deterministic;
4574 }
4575 }
4576
4577 /**
4578 * Handles the branching of alternations. Note this is also used for
4579 * the ? quantifier to branch between the case where it matches once
4580 * and where it does not occur.
4581 */
4582 static final class Branch extends Node {
4583 Node[] atoms = new Node[2];
4584 int size = 2;
4585 Node conn;
4586 Branch(Node first, Node second, Node branchConn) {
4587 conn = branchConn;
4588 atoms[0] = first;
4589 atoms[1] = second;
4590 }
4591
4592 void add(Node node) {
4593 if (size >= atoms.length) {
4594 Node[] tmp = new Node[atoms.length*2];
4595 System.arraycopy(atoms, 0, tmp, 0, atoms.length);
4596 atoms = tmp;
4597 }
4598 atoms[size++] = node;
4599 }
4600
4601 boolean match(Matcher matcher, int i, CharSequence seq) {
4602 for (int n = 0; n < size; n++) {
4603 if (atoms[n] == null) {
4604 if (conn.next.match(matcher, i, seq))
4605 return true;
4606 } else if (atoms[n].match(matcher, i, seq)) {
4607 return true;
4608 }
4609 }
4610 return false;
4611 }
4612
4613 boolean study(TreeInfo info) {
4614 int minL = info.minLength;
4615 int maxL = info.maxLength;
4616 boolean maxV = info.maxValid;
4617
4618 int minL2 = Integer.MAX_VALUE; //arbitrary large enough num
4619 int maxL2 = -1;
4620 for (int n = 0; n < size; n++) {
4621 info.reset();
4622 if (atoms[n] != null)
4623 atoms[n].study(info);
4624 minL2 = Math.min(minL2, info.minLength);
4625 maxL2 = Math.max(maxL2, info.maxLength);
4626 maxV = (maxV & info.maxValid);
4627 }
4628
4629 minL += minL2;
4630 maxL += maxL2;
4631
4632 info.reset();
4633 conn.next.study(info);
4634
4635 info.minLength += minL;
4636 info.maxLength += maxL;
4637 info.maxValid &= maxV;
4638 info.deterministic = false;
4639 return false;
4640 }
4641 }
4642
4643 /**
4644 * The GroupHead saves the location where the group begins in the locals
4645 * and restores them when the match is done.
4646 *
4647 * The matchRef is used when a reference to this group is accessed later
4648 * in the expression. The locals will have a negative value in them to
4649 * indicate that we do not want to unset the group if the reference
4650 * doesn't match.
4651 */
4652 static final class GroupHead extends Node {
4653 int localIndex;
4654 GroupHead(int localCount) {
4655 localIndex = localCount;
4656 }
4657 boolean match(Matcher matcher, int i, CharSequence seq) {
4658 int save = matcher.locals[localIndex];
4659 matcher.locals[localIndex] = i;
4660 boolean ret = next.match(matcher, i, seq);
4661 matcher.locals[localIndex] = save;
4662 return ret;
4663 }
4664 boolean matchRef(Matcher matcher, int i, CharSequence seq) {
4665 int save = matcher.locals[localIndex];
4666 matcher.locals[localIndex] = ~i; // HACK
4667 boolean ret = next.match(matcher, i, seq);
4668 matcher.locals[localIndex] = save;
4669 return ret;
4670 }
4671 }
4672
4673 /**
4674 * Recursive reference to a group in the regular expression. It calls
4675 * matchRef because if the reference fails to match we would not unset
4676 * the group.
4677 */
4678 static final class GroupRef extends Node {
4679 GroupHead head;
4680 GroupRef(GroupHead head) {
4681 this.head = head;
4682 }
4683 boolean match(Matcher matcher, int i, CharSequence seq) {
4684 return head.matchRef(matcher, i, seq)
4685 && next.match(matcher, matcher.last, seq);
4686 }
4687 boolean study(TreeInfo info) {
4688 info.maxValid = false;
4689 info.deterministic = false;
4690 return next.study(info);
4691 }
4692 }
4693
4694 /**
4695 * The GroupTail handles the setting of group beginning and ending
4696 * locations when groups are successfully matched. It must also be able to
4697 * unset groups that have to be backed off of.
4698 *
4699 * The GroupTail node is also used when a previous group is referenced,
4700 * and in that case no group information needs to be set.
4701 */
4702 static final class GroupTail extends Node {
4703 int localIndex;
4704 int groupIndex;
4705 GroupTail(int localCount, int groupCount) {
4706 localIndex = localCount;
4707 groupIndex = groupCount + groupCount;
4708 }
4709 boolean match(Matcher matcher, int i, CharSequence seq) {
4710 int tmp = matcher.locals[localIndex];
4711 if (tmp >= 0) { // This is the normal group case.
4712 // Save the group so we can unset it if it
4713 // backs off of a match.
4714 int groupStart = matcher.groups[groupIndex];
4715 int groupEnd = matcher.groups[groupIndex+1];
4716
4717 matcher.groups[groupIndex] = tmp;
4718 matcher.groups[groupIndex+1] = i;
4719 if (next.match(matcher, i, seq)) {
4720 return true;
4721 }
4722 matcher.groups[groupIndex] = groupStart;
4723 matcher.groups[groupIndex+1] = groupEnd;
4724 return false;
4725 } else {
4726 // This is a group reference case. We don't need to save any
4727 // group info because it isn't really a group.
4728 matcher.last = i;
4729 return true;
4730 }
4731 }
4732 }
4733
4734 /**
4735 * This sets up a loop to handle a recursive quantifier structure.
4736 */
4737 static final class Prolog extends Node {
4738 Loop loop;
4739 Prolog(Loop loop) {
4740 this.loop = loop;
4741 }
4742 boolean match(Matcher matcher, int i, CharSequence seq) {
4743 return loop.matchInit(matcher, i, seq);
4744 }
4745 boolean study(TreeInfo info) {
4746 return loop.study(info);
4747 }
4748 }
4749
4750 /**
4751 * Handles the repetition count for a greedy Curly. The matchInit
4752 * is called from the Prolog to save the index of where the group
4753 * beginning is stored. A zero length group check occurs in the
4754 * normal match but is skipped in the matchInit.
4755 */
4756 static class Loop extends Node {
4757 Node body;
4758 int countIndex; // local count index in matcher locals
4759 int beginIndex; // group beginning index
4760 int cmin, cmax;
4761 Loop(int countIndex, int beginIndex) {
4762 this.countIndex = countIndex;
4763 this.beginIndex = beginIndex;
4764 }
4765 boolean match(Matcher matcher, int i, CharSequence seq) {
4766 // Avoid infinite loop in zero-length case.
4767 if (i > matcher.locals[beginIndex]) {
4768 int count = matcher.locals[countIndex];
4769
4770 // This block is for before we reach the minimum
4771 // iterations required for the loop to match
4772 if (count < cmin) {
4773 matcher.locals[countIndex] = count + 1;
4774 boolean b = body.match(matcher, i, seq);
4775 // If match failed we must backtrack, so
4776 // the loop count should NOT be incremented
4777 if (!b)
4778 matcher.locals[countIndex] = count;
4779 // Return success or failure since we are under
4780 // minimum
4781 return b;
4782 }
4783 // This block is for after we have the minimum
4784 // iterations required for the loop to match
4785 if (count < cmax) {
4786 matcher.locals[countIndex] = count + 1;
4787 boolean b = body.match(matcher, i, seq);
4788 // If match failed we must backtrack, so
4789 // the loop count should NOT be incremented
4790 if (!b)
4791 matcher.locals[countIndex] = count;
4792 else
4793 return true;
4794 }
4795 }
4796 return next.match(matcher, i, seq);
4797 }
4798 boolean matchInit(Matcher matcher, int i, CharSequence seq) {
4799 int save = matcher.locals[countIndex];
4800 boolean ret = false;
4801 if (0 < cmin) {
4802 matcher.locals[countIndex] = 1;
4803 ret = body.match(matcher, i, seq);
4804 } else if (0 < cmax) {
4805 matcher.locals[countIndex] = 1;
4806 ret = body.match(matcher, i, seq);
4807 if (ret == false)
4808 ret = next.match(matcher, i, seq);
4809 } else {
4810 ret = next.match(matcher, i, seq);
4811 }
4812 matcher.locals[countIndex] = save;
4813 return ret;
4814 }
4815 boolean study(TreeInfo info) {
4816 info.maxValid = false;
4817 info.deterministic = false;
4818 return false;
4819 }
4820 }
4821
4822 /**
4823 * Handles the repetition count for a reluctant Curly. The matchInit
4824 * is called from the Prolog to save the index of where the group
4825 * beginning is stored. A zero length group check occurs in the
4826 * normal match but is skipped in the matchInit.
4827 */
4828 static final class LazyLoop extends Loop {
4829 LazyLoop(int countIndex, int beginIndex) {
4830 super(countIndex, beginIndex);
4831 }
4832 boolean match(Matcher matcher, int i, CharSequence seq) {
4833 // Check for zero length group
4834 if (i > matcher.locals[beginIndex]) {
4835 int count = matcher.locals[countIndex];
4836 if (count < cmin) {
4837 matcher.locals[countIndex] = count + 1;
4838 boolean result = body.match(matcher, i, seq);
4839 // If match failed we must backtrack, so
4840 // the loop count should NOT be incremented
4841 if (!result)
4842 matcher.locals[countIndex] = count;
4843 return result;
4844 }
4845 if (next.match(matcher, i, seq))
4846 return true;
4847 if (count < cmax) {
4848 matcher.locals[countIndex] = count + 1;
4849 boolean result = body.match(matcher, i, seq);
4850 // If match failed we must backtrack, so
4851 // the loop count should NOT be incremented
4852 if (!result)
4853 matcher.locals[countIndex] = count;
4854 return result;
4855 }
4856 return false;
4857 }
4858 return next.match(matcher, i, seq);
4859 }
4860 boolean matchInit(Matcher matcher, int i, CharSequence seq) {
4861 int save = matcher.locals[countIndex];
4862 boolean ret = false;
4863 if (0 < cmin) {
4864 matcher.locals[countIndex] = 1;
4865 ret = body.match(matcher, i, seq);
4866 } else if (next.match(matcher, i, seq)) {
4867 ret = true;
4868 } else if (0 < cmax) {
4869 matcher.locals[countIndex] = 1;
4870 ret = body.match(matcher, i, seq);
4871 }
4872 matcher.locals[countIndex] = save;
4873 return ret;
4874 }
4875 boolean study(TreeInfo info) {
4876 info.maxValid = false;
4877 info.deterministic = false;
4878 return false;
4879 }
4880 }
4881
4882 /**
4883 * Refers to a group in the regular expression. Attempts to match
4884 * whatever the group referred to last matched.
4885 */
4886 static class BackRef extends Node {
4887 int groupIndex;
4888 BackRef(int groupCount) {
4889 super();
4890 groupIndex = groupCount + groupCount;
4891 }
4892 boolean match(Matcher matcher, int i, CharSequence seq) {
4893 int j = matcher.groups[groupIndex];
4894 int k = matcher.groups[groupIndex+1];
4895
4896 int groupSize = k - j;
4897 // If the referenced group didn't match, neither can this
4898 if (j < 0)
4899 return false;
4900
4901 // If there isn't enough input left no match
4902 if (i + groupSize > matcher.to) {
4903 matcher.hitEnd = true;
4904 return false;
4905 }
4906 // Check each new char to make sure it matches what the group
4907 // referenced matched last time around
4908 for (int index=0; index<groupSize; index++)
4909 if (seq.charAt(i+index) != seq.charAt(j+index))
4910 return false;
4911
4912 return next.match(matcher, i+groupSize, seq);
4913 }
4914 boolean study(TreeInfo info) {
4915 info.maxValid = false;
4916 return next.study(info);
4917 }
4918 }
4919
4920 static class CIBackRef extends Node {
4921 int groupIndex;
4922 boolean doUnicodeCase;
4923 CIBackRef(int groupCount, boolean doUnicodeCase) {
4924 super();
4925 groupIndex = groupCount + groupCount;
4926 this.doUnicodeCase = doUnicodeCase;
4927 }
4928 boolean match(Matcher matcher, int i, CharSequence seq) {
4929 int j = matcher.groups[groupIndex];
4930 int k = matcher.groups[groupIndex+1];
4931
4932 int groupSize = k - j;
4933
4934 // If the referenced group didn't match, neither can this
4935 if (j < 0)
4936 return false;
4937
4938 // If there isn't enough input left no match
4939 if (i + groupSize > matcher.to) {
4940 matcher.hitEnd = true;
4941 return false;
4942 }
4943
4944 // Check each new char to make sure it matches what the group
4945 // referenced matched last time around
4946 int x = i;
4947 for (int index=0; index<groupSize; index++) {
4948 int c1 = Character.codePointAt(seq, x);
4949 int c2 = Character.codePointAt(seq, j);
4950 if (c1 != c2) {
4951 if (doUnicodeCase) {
4952 int cc1 = Character.toUpperCase(c1);
4953 int cc2 = Character.toUpperCase(c2);
4954 if (cc1 != cc2 &&
4955 Character.toLowerCase(cc1) !=
4956 Character.toLowerCase(cc2))
4957 return false;
4958 } else {
4959 if (ASCII.toLower(c1) != ASCII.toLower(c2))
4960 return false;
4961 }
4962 }
4963 x += Character.charCount(c1);
4964 j += Character.charCount(c2);
4965 }
4966
4967 return next.match(matcher, i+groupSize, seq);
4968 }
4969 boolean study(TreeInfo info) {
4970 info.maxValid = false;
4971 return next.study(info);
4972 }
4973 }
4974
4975 /**
4976 * Searches until the next instance of its atom. This is useful for
4977 * finding the atom efficiently without passing an instance of it
4978 * (greedy problem) and without a lot of wasted search time (reluctant
4979 * problem).
4980 */
4981 static final class First extends Node {
4982 Node atom;
4983 First(Node node) {
4984 this.atom = BnM.optimize(node);
4985 }
4986 boolean match(Matcher matcher, int i, CharSequence seq) {
4987 if (atom instanceof BnM) {
4988 return atom.match(matcher, i, seq)
4989 && next.match(matcher, matcher.last, seq);
4990 }
4991 for (;;) {
4992 if (i > matcher.to) {
4993 matcher.hitEnd = true;
4994 return false;
4995 }
4996 if (atom.match(matcher, i, seq)) {
4997 return next.match(matcher, matcher.last, seq);
4998 }
4999 i += countChars(seq, i, 1);
5000 matcher.first++;
5001 }
5002 }
5003 boolean study(TreeInfo info) {
5004 atom.study(info);
5005 info.maxValid = false;
5006 info.deterministic = false;
5007 return next.study(info);
5008 }
5009 }
5010
5011 static final class Conditional extends Node {
5012 Node cond, yes, not;
5013 Conditional(Node cond, Node yes, Node not) {
5014 this.cond = cond;
5015 this.yes = yes;
5016 this.not = not;
5017 }
5018 boolean match(Matcher matcher, int i, CharSequence seq) {
5019 if (cond.match(matcher, i, seq)) {
5020 return yes.match(matcher, i, seq);
5021 } else {
5022 return not.match(matcher, i, seq);
5023 }
5024 }
5025 boolean study(TreeInfo info) {
5026 int minL = info.minLength;
5027 int maxL = info.maxLength;
5028 boolean maxV = info.maxValid;
5029 info.reset();
5030 yes.study(info);
5031
5032 int minL2 = info.minLength;
5033 int maxL2 = info.maxLength;
5034 boolean maxV2 = info.maxValid;
5035 info.reset();
5036 not.study(info);
5037
5038 info.minLength = minL + Math.min(minL2, info.minLength);
5039 info.maxLength = maxL + Math.max(maxL2, info.maxLength);
5040 info.maxValid = (maxV & maxV2 & info.maxValid);
5041 info.deterministic = false;
5042 return next.study(info);
5043 }
5044 }
5045
5046 /**
5047 * Zero width positive lookahead.
5048 */
5049 static final class Pos extends Node {
5050 Node cond;
5051 Pos(Node cond) {
5052 this.cond = cond;
5053 }
5054 boolean match(Matcher matcher, int i, CharSequence seq) {
5055 int savedTo = matcher.to;
5056 boolean conditionMatched = false;
5057
5058 // Relax transparent region boundaries for lookahead
5059 if (matcher.transparentBounds)
5060 matcher.to = matcher.getTextLength();
5061 try {
5062 conditionMatched = cond.match(matcher, i, seq);
5063 } finally {
5064 // Reinstate region boundaries
5065 matcher.to = savedTo;
5066 }
5067 return conditionMatched && next.match(matcher, i, seq);
5068 }
5069 }
5070
5071 /**
5072 * Zero width negative lookahead.
5073 */
5074 static final class Neg extends Node {
5075 Node cond;
5076 Neg(Node cond) {
5077 this.cond = cond;
5078 }
5079 boolean match(Matcher matcher, int i, CharSequence seq) {
5080 int savedTo = matcher.to;
5081 boolean conditionMatched = false;
5082
5083 // Relax transparent region boundaries for lookahead
5084 if (matcher.transparentBounds)
5085 matcher.to = matcher.getTextLength();
5086 try {
5087 if (i < matcher.to) {
5088 conditionMatched = !cond.match(matcher, i, seq);
5089 } else {
5090 // If a negative lookahead succeeds then more input
5091 // could cause it to fail!
5092 matcher.requireEnd = true;
5093 conditionMatched = !cond.match(matcher, i, seq);
5094 }
5095 } finally {
5096 // Reinstate region boundaries
5097 matcher.to = savedTo;
5098 }
5099 return conditionMatched && next.match(matcher, i, seq);
5100 }
5101 }
5102
5103 /**
5104 * For use with lookbehinds; matches the position where the lookbehind
5105 * was encountered.
5106 */
5107 static Node lookbehindEnd = new Node() {
5108 boolean match(Matcher matcher, int i, CharSequence seq) {
5109 return i == matcher.lookbehindTo;
5110 }
5111 };
5112
5113 /**
5114 * Zero width positive lookbehind.
5115 */
5116 static class Behind extends Node {
5117 Node cond;
5118 int rmax, rmin;
5119 Behind(Node cond, int rmax, int rmin) {
5120 this.cond = cond;
5121 this.rmax = rmax;
5122 this.rmin = rmin;
5123 }
5124
5125 boolean match(Matcher matcher, int i, CharSequence seq) {
5126 int savedFrom = matcher.from;
5127 boolean conditionMatched = false;
5128 int startIndex = (!matcher.transparentBounds) ?
5129 matcher.from : 0;
5130 int from = Math.max(i - rmax, startIndex);
5131 // Set end boundary
5132 int savedLBT = matcher.lookbehindTo;
5133 matcher.lookbehindTo = i;
5134 // Relax transparent region boundaries for lookbehind
5135 if (matcher.transparentBounds)
5136 matcher.from = 0;
5137 for (int j = i - rmin; !conditionMatched && j >= from; j--) {
5138 conditionMatched = cond.match(matcher, j, seq);
5139 }
5140 matcher.from = savedFrom;
5141 matcher.lookbehindTo = savedLBT;
5142 return conditionMatched && next.match(matcher, i, seq);
5143 }
5144 }
5145
5146 /**
5147 * Zero width positive lookbehind, including supplementary
5148 * characters or unpaired surrogates.
5149 */
5150 static final class BehindS extends Behind {
5151 BehindS(Node cond, int rmax, int rmin) {
5152 super(cond, rmax, rmin);
5153 }
5154 boolean match(Matcher matcher, int i, CharSequence seq) {
5155 int rmaxChars = countChars(seq, i, -rmax);
5156 int rminChars = countChars(seq, i, -rmin);
5157 int savedFrom = matcher.from;
5158 int startIndex = (!matcher.transparentBounds) ?
5159 matcher.from : 0;
5160 boolean conditionMatched = false;
5161 int from = Math.max(i - rmaxChars, startIndex);
5162 // Set end boundary
5163 int savedLBT = matcher.lookbehindTo;
5164 matcher.lookbehindTo = i;
5165 // Relax transparent region boundaries for lookbehind
5166 if (matcher.transparentBounds)
5167 matcher.from = 0;
5168
5169 for (int j = i - rminChars;
5170 !conditionMatched && j >= from;
5171 j -= j>from ? countChars(seq, j, -1) : 1) {
5172 conditionMatched = cond.match(matcher, j, seq);
5173 }
5174 matcher.from = savedFrom;
5175 matcher.lookbehindTo = savedLBT;
5176 return conditionMatched && next.match(matcher, i, seq);
5177 }
5178 }
5179
5180 /**
5181 * Zero width negative lookbehind.
5182 */
5183 static class NotBehind extends Node {
5184 Node cond;
5185 int rmax, rmin;
5186 NotBehind(Node cond, int rmax, int rmin) {
5187 this.cond = cond;
5188 this.rmax = rmax;
5189 this.rmin = rmin;
5190 }
5191
5192 boolean match(Matcher matcher, int i, CharSequence seq) {
5193 int savedLBT = matcher.lookbehindTo;
5194 int savedFrom = matcher.from;
5195 boolean conditionMatched = false;
5196 int startIndex = (!matcher.transparentBounds) ?
5197 matcher.from : 0;
5198 int from = Math.max(i - rmax, startIndex);
5199 matcher.lookbehindTo = i;
5200 // Relax transparent region boundaries for lookbehind
5201 if (matcher.transparentBounds)
5202 matcher.from = 0;
5203 for (int j = i - rmin; !conditionMatched && j >= from; j--) {
5204 conditionMatched = cond.match(matcher, j, seq);
5205 }
5206 // Reinstate region boundaries
5207 matcher.from = savedFrom;
5208 matcher.lookbehindTo = savedLBT;
5209 return !conditionMatched && next.match(matcher, i, seq);
5210 }
5211 }
5212
5213 /**
5214 * Zero width negative lookbehind, including supplementary
5215 * characters or unpaired surrogates.
5216 */
5217 static final class NotBehindS extends NotBehind {
5218 NotBehindS(Node cond, int rmax, int rmin) {
5219 super(cond, rmax, rmin);
5220 }
5221 boolean match(Matcher matcher, int i, CharSequence seq) {
5222 int rmaxChars = countChars(seq, i, -rmax);
5223 int rminChars = countChars(seq, i, -rmin);
5224 int savedFrom = matcher.from;
5225 int savedLBT = matcher.lookbehindTo;
5226 boolean conditionMatched = false;
5227 int startIndex = (!matcher.transparentBounds) ?
5228 matcher.from : 0;
5229 int from = Math.max(i - rmaxChars, startIndex);
5230 matcher.lookbehindTo = i;
5231 // Relax transparent region boundaries for lookbehind
5232 if (matcher.transparentBounds)
5233 matcher.from = 0;
5234 for (int j = i - rminChars;
5235 !conditionMatched && j >= from;
5236 j -= j>from ? countChars(seq, j, -1) : 1) {
5237 conditionMatched = cond.match(matcher, j, seq);
5238 }
5239 //Reinstate region boundaries
5240 matcher.from = savedFrom;
5241 matcher.lookbehindTo = savedLBT;
5242 return !conditionMatched && next.match(matcher, i, seq);
5243 }
5244 }
5245
5246 /**
5247 * Returns the set union of two CharProperty nodes.
5248 */
5249 private static CharProperty union(final CharProperty lhs,
5250 final CharProperty rhs) {
5251 return new CharProperty() {
5252 boolean isSatisfiedBy(int ch) {
5253 return lhs.isSatisfiedBy(ch) || rhs.isSatisfiedBy(ch);}};
5254 }
5255
5256 /**
5257 * Returns the set intersection of two CharProperty nodes.
5258 */
5259 private static CharProperty intersection(final CharProperty lhs,
5260 final CharProperty rhs) {
5261 return new CharProperty() {
5262 boolean isSatisfiedBy(int ch) {
5263 return lhs.isSatisfiedBy(ch) && rhs.isSatisfiedBy(ch);}};
5264 }
5265
5266 /**
5267 * Returns the set difference of two CharProperty nodes.
5268 */
5269 private static CharProperty setDifference(final CharProperty lhs,
5270 final CharProperty rhs) {
5271 return new CharProperty() {
5272 boolean isSatisfiedBy(int ch) {
5273 return ! rhs.isSatisfiedBy(ch) && lhs.isSatisfiedBy(ch);}};
5274 }
5275
5276 /**
5277 * Handles word boundaries. Includes a field to allow this one class to
5278 * deal with the different types of word boundaries we can match. The word
5279 * characters include underscores, letters, and digits. Non spacing marks
5280 * can are also part of a word if they have a base character, otherwise
5281 * they are ignored for purposes of finding word boundaries.
5282 */
5283 static final class Bound extends Node {
5284 static int LEFT = 0x1;
5285 static int RIGHT= 0x2;
5286 static int BOTH = 0x3;
5287 static int NONE = 0x4;
5288 int type;
5289 boolean useUWORD;
5290 Bound(int n, boolean useUWORD) {
5291 type = n;
5292 this.useUWORD = useUWORD;
5293 }
5294
5295 boolean isWord(int ch) {
5296 return useUWORD ? UnicodeProp.WORD.is(ch)
5297 : (ch == '_' || Character.isLetterOrDigit(ch));
5298 }
5299
5300 int check(Matcher matcher, int i, CharSequence seq) {
5301 int ch;
5302 boolean left = false;
5303 int startIndex = matcher.from;
5304 int endIndex = matcher.to;
5305 if (matcher.transparentBounds) {
5306 startIndex = 0;
5307 endIndex = matcher.getTextLength();
5308 }
5309 if (i > startIndex) {
5310 ch = Character.codePointBefore(seq, i);
5311 left = (isWord(ch) ||
5312 ((Character.getType(ch) == Character.NON_SPACING_MARK)
5313 && hasBaseCharacter(matcher, i-1, seq)));
5314 }
5315 boolean right = false;
5316 if (i < endIndex) {
5317 ch = Character.codePointAt(seq, i);
5318 right = (isWord(ch) ||
5319 ((Character.getType(ch) == Character.NON_SPACING_MARK)
5320 && hasBaseCharacter(matcher, i, seq)));
5321 } else {
5322 // Tried to access char past the end
5323 matcher.hitEnd = true;
5324 // The addition of another char could wreck a boundary
5325 matcher.requireEnd = true;
5326 }
5327 return ((left ^ right) ? (right ? LEFT : RIGHT) : NONE);
5328 }
5329 boolean match(Matcher matcher, int i, CharSequence seq) {
5330 return (check(matcher, i, seq) & type) > 0
5331 && next.match(matcher, i, seq);
5332 }
5333 }
5334
5335 /**
5336 * Non spacing marks only count as word characters in bounds calculations
5337 * if they have a base character.
5338 */
5339 private static boolean hasBaseCharacter(Matcher matcher, int i,
5340 CharSequence seq)
5341 {
5342 int start = (!matcher.transparentBounds) ?
5343 matcher.from : 0;
5344 for (int x=i; x >= start; x--) {
5345 int ch = Character.codePointAt(seq, x);
5346 if (Character.isLetterOrDigit(ch))
5347 return true;
5348 if (Character.getType(ch) == Character.NON_SPACING_MARK)
5349 continue;
5350 return false;
5351 }
5352 return false;
5353 }
5354
5355 /**
5356 * Attempts to match a slice in the input using the Boyer-Moore string
5357 * matching algorithm. The algorithm is based on the idea that the
5358 * pattern can be shifted farther ahead in the search text if it is
5359 * matched right to left.
5360 * <p>
5361 * The pattern is compared to the input one character at a time, from
5362 * the rightmost character in the pattern to the left. If the characters
5363 * all match the pattern has been found. If a character does not match,
5364 * the pattern is shifted right a distance that is the maximum of two
5365 * functions, the bad character shift and the good suffix shift. This
5366 * shift moves the attempted match position through the input more
5367 * quickly than a naive one position at a time check.
5368 * <p>
5369 * The bad character shift is based on the character from the text that
5370 * did not match. If the character does not appear in the pattern, the
5371 * pattern can be shifted completely beyond the bad character. If the
5372 * character does occur in the pattern, the pattern can be shifted to
5373 * line the pattern up with the next occurrence of that character.
5374 * <p>
5375 * The good suffix shift is based on the idea that some subset on the right
5376 * side of the pattern has matched. When a bad character is found, the
5377 * pattern can be shifted right by the pattern length if the subset does
5378 * not occur again in pattern, or by the amount of distance to the
5379 * next occurrence of the subset in the pattern.
5380 *
5381 * Boyer-Moore search methods adapted from code by Amy Yu.
5382 */
5383 static class BnM extends Node {
5384 int[] buffer;
5385 int[] lastOcc;
5386 int[] optoSft;
5387
5388 /**
5389 * Pre calculates arrays needed to generate the bad character
5390 * shift and the good suffix shift. Only the last seven bits
5391 * are used to see if chars match; This keeps the tables small
5392 * and covers the heavily used ASCII range, but occasionally
5393 * results in an aliased match for the bad character shift.
5394 */
5395 static Node optimize(Node node) {
5396 if (!(node instanceof Slice)) {
5397 return node;
5398 }
5399
5400 int[] src = ((Slice) node).buffer;
5401 int patternLength = src.length;
5402 // The BM algorithm requires a bit of overhead;
5403 // If the pattern is short don't use it, since
5404 // a shift larger than the pattern length cannot
5405 // be used anyway.
5406 if (patternLength < 4) {
5407 return node;
5408 }
5409 int i, j, k;
5410 int[] lastOcc = new int[128];
5411 int[] optoSft = new int[patternLength];
5412 // Precalculate part of the bad character shift
5413 // It is a table for where in the pattern each
5414 // lower 7-bit value occurs
5415 for (i = 0; i < patternLength; i++) {
5416 lastOcc[src[i]&0x7F] = i + 1;
5417 }
5418 // Precalculate the good suffix shift
5419 // i is the shift amount being considered
5420 NEXT: for (i = patternLength; i > 0; i--) {
5421 // j is the beginning index of suffix being considered
5422 for (j = patternLength - 1; j >= i; j--) {
5423 // Testing for good suffix
5424 if (src[j] == src[j-i]) {
5425 // src[j..len] is a good suffix
5426 optoSft[j-1] = i;
5427 } else {
5428 // No match. The array has already been
5429 // filled up with correct values before.
5430 continue NEXT;
5431 }
5432 }
5433 // This fills up the remaining of optoSft
5434 // any suffix can not have larger shift amount
5435 // then its sub-suffix. Why???
5436 while (j > 0) {
5437 optoSft[--j] = i;
5438 }
5439 }
5440 // Set the guard value because of unicode compression
5441 optoSft[patternLength-1] = 1;
5442 if (node instanceof SliceS)
5443 return new BnMS(src, lastOcc, optoSft, node.next);
5444 return new BnM(src, lastOcc, optoSft, node.next);
5445 }
5446 BnM(int[] src, int[] lastOcc, int[] optoSft, Node next) {
5447 this.buffer = src;
5448 this.lastOcc = lastOcc;
5449 this.optoSft = optoSft;
5450 this.next = next;
5451 }
5452 boolean match(Matcher matcher, int i, CharSequence seq) {
5453 int[] src = buffer;
5454 int patternLength = src.length;
5455 int last = matcher.to - patternLength;
5456
5457 // Loop over all possible match positions in text
5458 NEXT: while (i <= last) {
5459 // Loop over pattern from right to left
5460 for (int j = patternLength - 1; j >= 0; j--) {
5461 int ch = seq.charAt(i+j);
5462 if (ch != src[j]) {
5463 // Shift search to the right by the maximum of the
5464 // bad character shift and the good suffix shift
5465 i += Math.max(j + 1 - lastOcc[ch&0x7F], optoSft[j]);
5466 continue NEXT;
5467 }
5468 }
5469 // Entire pattern matched starting at i
5470 matcher.first = i;
5471 boolean ret = next.match(matcher, i + patternLength, seq);
5472 if (ret) {
5473 matcher.first = i;
5474 matcher.groups[0] = matcher.first;
5475 matcher.groups[1] = matcher.last;
5476 return true;
5477 }
5478 i++;
5479 }
5480 // BnM is only used as the leading node in the unanchored case,
5481 // and it replaced its Start() which always searches to the end
5482 // if it doesn't find what it's looking for, so hitEnd is true.
5483 matcher.hitEnd = true;
5484 return false;
5485 }
5486 boolean study(TreeInfo info) {
5487 info.minLength += buffer.length;
5488 info.maxValid = false;
5489 return next.study(info);
5490 }
5491 }
5492
5493 /**
5494 * Supplementary support version of BnM(). Unpaired surrogates are
5495 * also handled by this class.
5496 */
5497 static final class BnMS extends BnM {
5498 int lengthInChars;
5499
5500 BnMS(int[] src, int[] lastOcc, int[] optoSft, Node next) {
5501 super(src, lastOcc, optoSft, next);
5502 for (int x = 0; x < buffer.length; x++) {
5503 lengthInChars += Character.charCount(buffer[x]);
5504 }
5505 }
5506 boolean match(Matcher matcher, int i, CharSequence seq) {
5507 int[] src = buffer;
5508 int patternLength = src.length;
5509 int last = matcher.to - lengthInChars;
5510
5511 // Loop over all possible match positions in text
5512 NEXT: while (i <= last) {
5513 // Loop over pattern from right to left
5514 int ch;
5515 for (int j = countChars(seq, i, patternLength), x = patternLength - 1;
5516 j > 0; j -= Character.charCount(ch), x--) {
5517 ch = Character.codePointBefore(seq, i+j);
5518 if (ch != src[x]) {
5519 // Shift search to the right by the maximum of the
5520 // bad character shift and the good suffix shift
5521 int n = Math.max(x + 1 - lastOcc[ch&0x7F], optoSft[x]);
5522 i += countChars(seq, i, n);
5523 continue NEXT;
5524 }
5525 }
5526 // Entire pattern matched starting at i
5527 matcher.first = i;
5528 boolean ret = next.match(matcher, i + lengthInChars, seq);
5529 if (ret) {
5530 matcher.first = i;
5531 matcher.groups[0] = matcher.first;
5532 matcher.groups[1] = matcher.last;
5533 return true;
5534 }
5535 i += countChars(seq, i, 1);
5536 }
5537 matcher.hitEnd = true;
5538 return false;
5539 }
5540 }
5541
5542 ///////////////////////////////////////////////////////////////////////////////
5543 ///////////////////////////////////////////////////////////////////////////////
5544
5545 /**
5546 * This must be the very first initializer.
5547 */
5548 static Node accept = new Node();
5549
5550 static Node lastAccept = new LastNode();
5551
5552 private static class CharPropertyNames {
5553
5554 static CharProperty charPropertyFor(String name) {
5555 CharPropertyFactory m = map.get(name);
5556 return m == null ? null : m.make();
5557 }
5558
5559 private static abstract class CharPropertyFactory {
5560 abstract CharProperty make();
5561 }
5562
5563 private static void defCategory(String name,
5564 final int typeMask) {
5565 map.put(name, new CharPropertyFactory() {
5566 CharProperty make() { return new Category(typeMask);}});
5567 }
5568
5569 private static void defRange(String name,
5570 final int lower, final int upper) {
5571 map.put(name, new CharPropertyFactory() {
5572 CharProperty make() { return rangeFor(lower, upper);}});
5573 }
5574
5575 private static void defCtype(String name,
5576 final int ctype) {
5577 map.put(name, new CharPropertyFactory() {
5578 CharProperty make() { return new Ctype(ctype);}});
5579 }
5580
5581 private static abstract class CloneableProperty
5582 extends CharProperty implements Cloneable
5583 {
5584 public CloneableProperty clone() {
5585 try {
5586 return (CloneableProperty) super.clone();
5587 } catch (CloneNotSupportedException e) {
5588 throw new AssertionError(e);
5589 }
5590 }
5591 }
5592
5593 private static void defClone(String name,
5594 final CloneableProperty p) {
5595 map.put(name, new CharPropertyFactory() {
5596 CharProperty make() { return p.clone();}});
5597 }
5598
5599 private static final HashMap<String, CharPropertyFactory> map
5600 = new HashMap<>();
5601
5602 static {
5603 // Unicode character property aliases, defined in
5604 // http://www.unicode.org/Public/UNIDATA/PropertyValueAliases.txt
5605 defCategory("Cn", 1<<Character.UNASSIGNED);
5606 defCategory("Lu", 1<<Character.UPPERCASE_LETTER);
5607 defCategory("Ll", 1<<Character.LOWERCASE_LETTER);
5608 defCategory("Lt", 1<<Character.TITLECASE_LETTER);
5609 defCategory("Lm", 1<<Character.MODIFIER_LETTER);
5610 defCategory("Lo", 1<<Character.OTHER_LETTER);
5611 defCategory("Mn", 1<<Character.NON_SPACING_MARK);
5612 defCategory("Me", 1<<Character.ENCLOSING_MARK);
5613 defCategory("Mc", 1<<Character.COMBINING_SPACING_MARK);
5614 defCategory("Nd", 1<<Character.DECIMAL_DIGIT_NUMBER);
5615 defCategory("Nl", 1<<Character.LETTER_NUMBER);
5616 defCategory("No", 1<<Character.OTHER_NUMBER);
5617 defCategory("Zs", 1<<Character.SPACE_SEPARATOR);
5618 defCategory("Zl", 1<<Character.LINE_SEPARATOR);
5619 defCategory("Zp", 1<<Character.PARAGRAPH_SEPARATOR);
5620 defCategory("Cc", 1<<Character.CONTROL);
5621 defCategory("Cf", 1<<Character.FORMAT);
5622 defCategory("Co", 1<<Character.PRIVATE_USE);
5623 defCategory("Cs", 1<<Character.SURROGATE);
5624 defCategory("Pd", 1<<Character.DASH_PUNCTUATION);
5625 defCategory("Ps", 1<<Character.START_PUNCTUATION);
5626 defCategory("Pe", 1<<Character.END_PUNCTUATION);
5627 defCategory("Pc", 1<<Character.CONNECTOR_PUNCTUATION);
5628 defCategory("Po", 1<<Character.OTHER_PUNCTUATION);
5629 defCategory("Sm", 1<<Character.MATH_SYMBOL);
5630 defCategory("Sc", 1<<Character.CURRENCY_SYMBOL);
5631 defCategory("Sk", 1<<Character.MODIFIER_SYMBOL);
5632 defCategory("So", 1<<Character.OTHER_SYMBOL);
5633 defCategory("Pi", 1<<Character.INITIAL_QUOTE_PUNCTUATION);
5634 defCategory("Pf", 1<<Character.FINAL_QUOTE_PUNCTUATION);
5635 defCategory("L", ((1<<Character.UPPERCASE_LETTER) |
5636 (1<<Character.LOWERCASE_LETTER) |
5637 (1<<Character.TITLECASE_LETTER) |
5638 (1<<Character.MODIFIER_LETTER) |
5639 (1<<Character.OTHER_LETTER)));
5640 defCategory("M", ((1<<Character.NON_SPACING_MARK) |
5641 (1<<Character.ENCLOSING_MARK) |
5642 (1<<Character.COMBINING_SPACING_MARK)));
5643 defCategory("N", ((1<<Character.DECIMAL_DIGIT_NUMBER) |
5644 (1<<Character.LETTER_NUMBER) |
5645 (1<<Character.OTHER_NUMBER)));
5646 defCategory("Z", ((1<<Character.SPACE_SEPARATOR) |
5647 (1<<Character.LINE_SEPARATOR) |
5648 (1<<Character.PARAGRAPH_SEPARATOR)));
5649 defCategory("C", ((1<<Character.CONTROL) |
5650 (1<<Character.FORMAT) |
5651 (1<<Character.PRIVATE_USE) |
5652 (1<<Character.SURROGATE))); // Other
5653 defCategory("P", ((1<<Character.DASH_PUNCTUATION) |
5654 (1<<Character.START_PUNCTUATION) |
5655 (1<<Character.END_PUNCTUATION) |
5656 (1<<Character.CONNECTOR_PUNCTUATION) |
5657 (1<<Character.OTHER_PUNCTUATION) |
5658 (1<<Character.INITIAL_QUOTE_PUNCTUATION) |
5659 (1<<Character.FINAL_QUOTE_PUNCTUATION)));
5660 defCategory("S", ((1<<Character.MATH_SYMBOL) |
5661 (1<<Character.CURRENCY_SYMBOL) |
5662 (1<<Character.MODIFIER_SYMBOL) |
5663 (1<<Character.OTHER_SYMBOL)));
5664 defCategory("LC", ((1<<Character.UPPERCASE_LETTER) |
5665 (1<<Character.LOWERCASE_LETTER) |
5666 (1<<Character.TITLECASE_LETTER)));
5667 defCategory("LD", ((1<<Character.UPPERCASE_LETTER) |
5668 (1<<Character.LOWERCASE_LETTER) |
5669 (1<<Character.TITLECASE_LETTER) |
5670 (1<<Character.MODIFIER_LETTER) |
5671 (1<<Character.OTHER_LETTER) |
5672 (1<<Character.DECIMAL_DIGIT_NUMBER)));
5673 defRange("L1", 0x00, 0xFF); // Latin-1
5674 map.put("all", new CharPropertyFactory() {
5675 CharProperty make() { return new All(); }});
5676
5677 // Posix regular expression character classes, defined in
5678 // http://www.unix.org/onlinepubs/009695399/basedefs/xbd_chap09.html
5679 defRange("ASCII", 0x00, 0x7F); // ASCII
5680 defCtype("Alnum", ASCII.ALNUM); // Alphanumeric characters
5681 defCtype("Alpha", ASCII.ALPHA); // Alphabetic characters
5682 defCtype("Blank", ASCII.BLANK); // Space and tab characters
5683 defCtype("Cntrl", ASCII.CNTRL); // Control characters
5684 defRange("Digit", '0', '9'); // Numeric characters
5685 defCtype("Graph", ASCII.GRAPH); // printable and visible
5686 defRange("Lower", 'a', 'z'); // Lower-case alphabetic
5687 defRange("Print", 0x20, 0x7E); // Printable characters
5688 defCtype("Punct", ASCII.PUNCT); // Punctuation characters
5689 defCtype("Space", ASCII.SPACE); // Space characters
5690 defRange("Upper", 'A', 'Z'); // Upper-case alphabetic
5691 defCtype("XDigit",ASCII.XDIGIT); // hexadecimal digits
5692
5693 // Java character properties, defined by methods in Character.java
5694 defClone("javaLowerCase", new CloneableProperty() {
5695 boolean isSatisfiedBy(int ch) {
5696 return Character.isLowerCase(ch);}});
5697 defClone("javaUpperCase", new CloneableProperty() {
5698 boolean isSatisfiedBy(int ch) {
5699 return Character.isUpperCase(ch);}});
5700 defClone("javaAlphabetic", new CloneableProperty() {
5701 boolean isSatisfiedBy(int ch) {
5702 return Character.isAlphabetic(ch);}});
5703 defClone("javaIdeographic", new CloneableProperty() {
5704 boolean isSatisfiedBy(int ch) {
5705 return Character.isIdeographic(ch);}});
5706 defClone("javaTitleCase", new CloneableProperty() {
5707 boolean isSatisfiedBy(int ch) {
5708 return Character.isTitleCase(ch);}});
5709 defClone("javaDigit", new CloneableProperty() {
5710 boolean isSatisfiedBy(int ch) {
5711 return Character.isDigit(ch);}});
5712 defClone("javaDefined", new CloneableProperty() {
5713 boolean isSatisfiedBy(int ch) {
5714 return Character.isDefined(ch);}});
5715 defClone("javaLetter", new CloneableProperty() {
5716 boolean isSatisfiedBy(int ch) {
5717 return Character.isLetter(ch);}});
5718 defClone("javaLetterOrDigit", new CloneableProperty() {
5719 boolean isSatisfiedBy(int ch) {
5720 return Character.isLetterOrDigit(ch);}});
5721 defClone("javaJavaIdentifierStart", new CloneableProperty() {
5722 boolean isSatisfiedBy(int ch) {
5723 return Character.isJavaIdentifierStart(ch);}});
5724 defClone("javaJavaIdentifierPart", new CloneableProperty() {
5725 boolean isSatisfiedBy(int ch) {
5726 return Character.isJavaIdentifierPart(ch);}});
5727 defClone("javaUnicodeIdentifierStart", new CloneableProperty() {
5728 boolean isSatisfiedBy(int ch) {
5729 return Character.isUnicodeIdentifierStart(ch);}});
5730 defClone("javaUnicodeIdentifierPart", new CloneableProperty() {
5731 boolean isSatisfiedBy(int ch) {
5732 return Character.isUnicodeIdentifierPart(ch);}});
5733 defClone("javaIdentifierIgnorable", new CloneableProperty() {
5734 boolean isSatisfiedBy(int ch) {
5735 return Character.isIdentifierIgnorable(ch);}});
5736 defClone("javaSpaceChar", new CloneableProperty() {
5737 boolean isSatisfiedBy(int ch) {
5738 return Character.isSpaceChar(ch);}});
5739 defClone("javaWhitespace", new CloneableProperty() {
5740 boolean isSatisfiedBy(int ch) {
5741 return Character.isWhitespace(ch);}});
5742 defClone("javaISOControl", new CloneableProperty() {
5743 boolean isSatisfiedBy(int ch) {
5744 return Character.isISOControl(ch);}});
5745 defClone("javaMirrored", new CloneableProperty() {
5746 boolean isSatisfiedBy(int ch) {
5747 return Character.isMirrored(ch);}});
5748 }
5749 }
5750
5751 /**
5752 * Creates a predicate which can be used to match a string.
5753 *
5754 * @return The predicate which can be used for matching on a string
5755 * @since 1.8
5756 */
5757 public Predicate<String> asPredicate() {
5758 return s -> matcher(s).find();
5759 }
5760
5761 /**
5762 * Creates a stream from the given input sequence around matches of this
5763 * pattern.
5764 *
5765 * <p> The stream returned by this method contains each substring of the
5766 * input sequence that is terminated by another subsequence that matches
5767 * this pattern or is terminated by the end of the input sequence. The
5768 * substrings in the stream are in the order in which they occur in the
5769 * input. Trailing empty strings will be discarded and not encountered in
5770 * the stream.
5771 *
5772 * <p> If this pattern does not match any subsequence of the input then
5773 * the resulting stream has just one element, namely the input sequence in
5774 * string form.
5775 *
5776 * <p> When there is a positive-width match at the beginning of the input
5777 * sequence then an empty leading substring is included at the beginning
5778 * of the stream. A zero-width match at the beginning however never produces
5779 * such empty leading substring.
5780 *
5781 * <p> If the input sequence is mutable, it must remain constant during the
5782 * execution of the terminal stream operation. Otherwise, the result of the
5783 * terminal stream operation is undefined.
5784 *
5785 * @param input
5786 * The character sequence to be split
5787 *
5788 * @return The stream of strings computed by splitting the input
5789 * around matches of this pattern
5790 * @see #split(CharSequence)
5791 * @since 1.8
5792 */
5793 public Stream<String> splitAsStream(final CharSequence input) {
5794 class MatcherIterator implements Iterator<String> {
5795 private final Matcher matcher;
5796 // The start position of the next sub-sequence of input
5797 // when current == input.length there are no more elements
5798 private int current;
5799 // null if the next element, if any, needs to obtained
5800 private String nextElement;
5801 // > 0 if there are N next empty elements
5802 private int emptyElementCount;
5803
5804 MatcherIterator() {
5805 this.matcher = matcher(input);
5806 }
5807
5808 public String next() {
5809 if (!hasNext())
5810 throw new NoSuchElementException();
5811
5812 if (emptyElementCount == 0) {
5813 String n = nextElement;
5814 nextElement = null;
5815 return n;
5816 } else {
5817 emptyElementCount--;
5818 return "";
5819 }
5820 }
5821
5822 public boolean hasNext() {
5823 if (nextElement != null || emptyElementCount > 0)
5824 return true;
5825
5826 if (current == input.length())
5827 return false;
5828
5829 // Consume the next matching element
5830 // Count sequence of matching empty elements
5831 while (matcher.find()) {
5832 nextElement = input.subSequence(current, matcher.start()).toString();
5833 current = matcher.end();
5834 if (!nextElement.isEmpty()) {
5835 return true;
5836 } else if (current > 0) { // no empty leading substring for zero-width
5837 // match at the beginning of the input
5838 emptyElementCount++;
5839 }
5840 }
5841
5842 // Consume last matching element
5843 nextElement = input.subSequence(current, input.length()).toString();
5844 current = input.length();
5845 if (!nextElement.isEmpty()) {
5846 return true;
5847 } else {
5848 // Ignore a terminal sequence of matching empty elements
5849 emptyElementCount = 0;
5850 nextElement = null;
5851 return false;
5852 }
5853 }
5854 }
5855 return StreamSupport.stream(Spliterators.spliteratorUnknownSize(
5856 new MatcherIterator(), Spliterator.ORDERED | Spliterator.NONNULL), false);
5857 }
5858 }