1 /*
2 * Copyright (c) 1999, 2013, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation. Oracle designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Oracle in the LICENSE file that accompanied this code.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 */
25
26 package java.util.regex;
27
28 import java.text.Normalizer;
29 import java.util.Locale;
30 import java.util.Iterator;
31 import java.util.Map;
32 import java.util.ArrayList;
33 import java.util.HashMap;
34 import java.util.Arrays;
35 import java.util.NoSuchElementException;
36 import java.util.Spliterator;
37 import java.util.Spliterators;
38 import java.util.function.Predicate;
39 import java.util.stream.Stream;
40 import java.util.stream.StreamSupport;
41
42
43 /**
44 * A compiled representation of a regular expression.
45 *
46 * <p> A regular expression, specified as a string, must first be compiled into
47 * an instance of this class. The resulting pattern can then be used to create
48 * a {@link Matcher} object that can match arbitrary {@linkplain
49 * java.lang.CharSequence character sequences} against the regular
50 * expression. All of the state involved in performing a match resides in the
51 * matcher, so many matchers can share the same pattern.
52 *
53 * <p> A typical invocation sequence is thus
54 *
55 * <blockquote><pre>
56 * Pattern p = Pattern.{@link #compile compile}("a*b");
57 * Matcher m = p.{@link #matcher matcher}("aaaaab");
58 * boolean b = m.{@link Matcher#matches matches}();</pre></blockquote>
59 *
60 * <p> A {@link #matches matches} method is defined by this class as a
61 * convenience for when a regular expression is used just once. This method
62 * compiles an expression and matches an input sequence against it in a single
63 * invocation. The statement
64 *
65 * <blockquote><pre>
66 * boolean b = Pattern.matches("a*b", "aaaaab");</pre></blockquote>
67 *
68 * is equivalent to the three statements above, though for repeated matches it
69 * is less efficient since it does not allow the compiled pattern to be reused.
70 *
71 * <p> Instances of this class are immutable and are safe for use by multiple
72 * concurrent threads. Instances of the {@link Matcher} class are not safe for
73 * such use.
74 *
75 *
76 * <h3><a name="sum">Summary of regular-expression constructs</a></h3>
77 *
78 * <table border="0" cellpadding="1" cellspacing="0"
79 * summary="Regular expression constructs, and what they match">
80 *
81 * <tr align="left">
82 * <th align="left" id="construct">Construct</th>
83 * <th align="left" id="matches">Matches</th>
84 * </tr>
85 *
86 * <tr><th> </th></tr>
87 * <tr align="left"><th colspan="2" id="characters">Characters</th></tr>
88 *
89 * <tr><td valign="top" headers="construct characters"><i>x</i></td>
90 * <td headers="matches">The character <i>x</i></td></tr>
91 * <tr><td valign="top" headers="construct characters"><tt>\\</tt></td>
92 * <td headers="matches">The backslash character</td></tr>
93 * <tr><td valign="top" headers="construct characters"><tt>\0</tt><i>n</i></td>
94 * <td headers="matches">The character with octal value <tt>0</tt><i>n</i>
95 * (0 <tt><=</tt> <i>n</i> <tt><=</tt> 7)</td></tr>
96 * <tr><td valign="top" headers="construct characters"><tt>\0</tt><i>nn</i></td>
97 * <td headers="matches">The character with octal value <tt>0</tt><i>nn</i>
98 * (0 <tt><=</tt> <i>n</i> <tt><=</tt> 7)</td></tr>
99 * <tr><td valign="top" headers="construct characters"><tt>\0</tt><i>mnn</i></td>
100 * <td headers="matches">The character with octal value <tt>0</tt><i>mnn</i>
101 * (0 <tt><=</tt> <i>m</i> <tt><=</tt> 3,
102 * 0 <tt><=</tt> <i>n</i> <tt><=</tt> 7)</td></tr>
103 * <tr><td valign="top" headers="construct characters"><tt>\x</tt><i>hh</i></td>
104 * <td headers="matches">The character with hexadecimal value <tt>0x</tt><i>hh</i></td></tr>
105 * <tr><td valign="top" headers="construct characters"><tt>\u</tt><i>hhhh</i></td>
106 * <td headers="matches">The character with hexadecimal value <tt>0x</tt><i>hhhh</i></td></tr>
107 * <tr><td valign="top" headers="construct characters"><tt>\x</tt><i>{h...h}</i></td>
108 * <td headers="matches">The character with hexadecimal value <tt>0x</tt><i>h...h</i>
109 * ({@link java.lang.Character#MIN_CODE_POINT Character.MIN_CODE_POINT}
110 * <= <tt>0x</tt><i>h...h</i> <=
111 * {@link java.lang.Character#MAX_CODE_POINT Character.MAX_CODE_POINT})</td></tr>
112 * <tr><td valign="top" headers="matches"><tt>\t</tt></td>
113 * <td headers="matches">The tab character (<tt>'\u0009'</tt>)</td></tr>
114 * <tr><td valign="top" headers="construct characters"><tt>\n</tt></td>
115 * <td headers="matches">The newline (line feed) character (<tt>'\u000A'</tt>)</td></tr>
116 * <tr><td valign="top" headers="construct characters"><tt>\r</tt></td>
117 * <td headers="matches">The carriage-return character (<tt>'\u000D'</tt>)</td></tr>
118 * <tr><td valign="top" headers="construct characters"><tt>\f</tt></td>
119 * <td headers="matches">The form-feed character (<tt>'\u000C'</tt>)</td></tr>
120 * <tr><td valign="top" headers="construct characters"><tt>\a</tt></td>
121 * <td headers="matches">The alert (bell) character (<tt>'\u0007'</tt>)</td></tr>
122 * <tr><td valign="top" headers="construct characters"><tt>\e</tt></td>
123 * <td headers="matches">The escape character (<tt>'\u001B'</tt>)</td></tr>
124 * <tr><td valign="top" headers="construct characters"><tt>\c</tt><i>x</i></td>
125 * <td headers="matches">The control character corresponding to <i>x</i></td></tr>
126 *
127 * <tr><th> </th></tr>
128 * <tr align="left"><th colspan="2" id="classes">Character classes</th></tr>
129 *
130 * <tr><td valign="top" headers="construct classes">{@code [abc]}</td>
131 * <td headers="matches">{@code a}, {@code b}, or {@code c} (simple class)</td></tr>
132 * <tr><td valign="top" headers="construct classes">{@code [^abc]}</td>
133 * <td headers="matches">Any character except {@code a}, {@code b}, or {@code c} (negation)</td></tr>
134 * <tr><td valign="top" headers="construct classes">{@code [a-zA-Z]}</td>
135 * <td headers="matches">{@code a} through {@code z}
136 * or {@code A} through {@code Z}, inclusive (range)</td></tr>
137 * <tr><td valign="top" headers="construct classes">{@code [a-d[m-p]]}</td>
138 * <td headers="matches">{@code a} through {@code d},
139 * or {@code m} through {@code p}: {@code [a-dm-p]} (union)</td></tr>
140 * <tr><td valign="top" headers="construct classes">{@code [a-z&&[def]]}</td>
141 * <td headers="matches">{@code d}, {@code e}, or {@code f} (intersection)</tr>
142 * <tr><td valign="top" headers="construct classes">{@code [a-z&&[^bc]]}</td>
143 * <td headers="matches">{@code a} through {@code z},
144 * except for {@code b} and {@code c}: {@code [ad-z]} (subtraction)</td></tr>
145 * <tr><td valign="top" headers="construct classes">{@code [a-z&&[^m-p]]}</td>
146 * <td headers="matches">{@code a} through {@code z},
147 * and not {@code m} through {@code p}: {@code [a-lq-z]}(subtraction)</td></tr>
148 * <tr><th> </th></tr>
149 *
150 * <tr align="left"><th colspan="2" id="predef">Predefined character classes</th></tr>
151 *
152 * <tr><td valign="top" headers="construct predef"><tt>.</tt></td>
153 * <td headers="matches">Any character (may or may not match <a href="#lt">line terminators</a>)</td></tr>
154 * <tr><td valign="top" headers="construct predef"><tt>\d</tt></td>
155 * <td headers="matches">A digit: <tt>[0-9]</tt></td></tr>
156 * <tr><td valign="top" headers="construct predef"><tt>\D</tt></td>
157 * <td headers="matches">A non-digit: <tt>[^0-9]</tt></td></tr>
158 * <tr><td valign="top" headers="construct predef"><tt>\h</tt></td>
159 * <td headers="matches">A horizontal whitespace character:
160 * <tt>[ \t\xA0\u1680\u180e\u2000-\u200a\u202f\u205f\u3000]</tt></td></tr>
161 * <tr><td valign="top" headers="construct predef"><tt>\H</tt></td>
162 * <td headers="matches">A non-horizontal whitespace character: <tt>[^\h]</tt></td></tr>
163 * <tr><td valign="top" headers="construct predef"><tt>\s</tt></td>
164 * <td headers="matches">A whitespace character: <tt>[ \t\n\x0B\f\r]</tt></td></tr>
165 * <tr><td valign="top" headers="construct predef"><tt>\S</tt></td>
166 * <td headers="matches">A non-whitespace character: <tt>[^\s]</tt></td></tr>
167 * <tr><td valign="top" headers="construct predef"><tt>\v</tt></td>
168 * <td headers="matches">A vertical whitespace character: <tt>[\n\x0B\f\r\x85\u2028\u2029]</tt>
169 * </td></tr>
170 * <tr><td valign="top" headers="construct predef"><tt>\V</tt></td>
171 * <td headers="matches">A non-vertical whitespace character: <tt>[^\v]</tt></td></tr>
172 * <tr><td valign="top" headers="construct predef"><tt>\w</tt></td>
173 * <td headers="matches">A word character: <tt>[a-zA-Z_0-9]</tt></td></tr>
174 * <tr><td valign="top" headers="construct predef"><tt>\W</tt></td>
175 * <td headers="matches">A non-word character: <tt>[^\w]</tt></td></tr>
176 * <tr><th> </th></tr>
177 * <tr align="left"><th colspan="2" id="posix"><b>POSIX character classes (US-ASCII only)</b></th></tr>
178 *
179 * <tr><td valign="top" headers="construct posix">{@code \p{Lower}}</td>
180 * <td headers="matches">A lower-case alphabetic character: {@code [a-z]}</td></tr>
181 * <tr><td valign="top" headers="construct posix">{@code \p{Upper}}</td>
182 * <td headers="matches">An upper-case alphabetic character:{@code [A-Z]}</td></tr>
183 * <tr><td valign="top" headers="construct posix">{@code \p{ASCII}}</td>
184 * <td headers="matches">All ASCII:{@code [\x00-\x7F]}</td></tr>
185 * <tr><td valign="top" headers="construct posix">{@code \p{Alpha}}</td>
186 * <td headers="matches">An alphabetic character:{@code [\p{Lower}\p{Upper}]}</td></tr>
187 * <tr><td valign="top" headers="construct posix">{@code \p{Digit}}</td>
188 * <td headers="matches">A decimal digit: {@code [0-9]}</td></tr>
189 * <tr><td valign="top" headers="construct posix">{@code \p{Alnum}}</td>
190 * <td headers="matches">An alphanumeric character:{@code [\p{Alpha}\p{Digit}]}</td></tr>
191 * <tr><td valign="top" headers="construct posix">{@code \p{Punct}}</td>
192 * <td headers="matches">Punctuation: One of {@code !"#$%&'()*+,-./:;<=>?@[\]^_`{|}~}</td></tr>
193 * <!-- {@code [\!"#\$%&'\(\)\*\+,\-\./:;\<=\>\?@\[\\\]\^_`\{\|\}~]}
194 * {@code [\X21-\X2F\X31-\X40\X5B-\X60\X7B-\X7E]} -->
195 * <tr><td valign="top" headers="construct posix">{@code \p{Graph}}</td>
196 * <td headers="matches">A visible character: {@code [\p{Alnum}\p{Punct}]}</td></tr>
197 * <tr><td valign="top" headers="construct posix">{@code \p{Print}}</td>
198 * <td headers="matches">A printable character: {@code [\p{Graph}\x20]}</td></tr>
199 * <tr><td valign="top" headers="construct posix">{@code \p{Blank}}</td>
200 * <td headers="matches">A space or a tab: {@code [ \t]}</td></tr>
201 * <tr><td valign="top" headers="construct posix">{@code \p{Cntrl}}</td>
202 * <td headers="matches">A control character: {@code [\x00-\x1F\x7F]}</td></tr>
203 * <tr><td valign="top" headers="construct posix">{@code \p{XDigit}}</td>
204 * <td headers="matches">A hexadecimal digit: {@code [0-9a-fA-F]}</td></tr>
205 * <tr><td valign="top" headers="construct posix">{@code \p{Space}}</td>
206 * <td headers="matches">A whitespace character: {@code [ \t\n\x0B\f\r]}</td></tr>
207 *
208 * <tr><th> </th></tr>
209 * <tr align="left"><th colspan="2">java.lang.Character classes (simple <a href="#jcc">java character type</a>)</th></tr>
210 *
211 * <tr><td valign="top"><tt>\p{javaLowerCase}</tt></td>
212 * <td>Equivalent to java.lang.Character.isLowerCase()</td></tr>
213 * <tr><td valign="top"><tt>\p{javaUpperCase}</tt></td>
214 * <td>Equivalent to java.lang.Character.isUpperCase()</td></tr>
215 * <tr><td valign="top"><tt>\p{javaWhitespace}</tt></td>
216 * <td>Equivalent to java.lang.Character.isWhitespace()</td></tr>
217 * <tr><td valign="top"><tt>\p{javaMirrored}</tt></td>
218 * <td>Equivalent to java.lang.Character.isMirrored()</td></tr>
219 *
220 * <tr><th> </th></tr>
221 * <tr align="left"><th colspan="2" id="unicode">Classes for Unicode scripts, blocks, categories and binary properties</th></tr>
222 * <tr><td valign="top" headers="construct unicode">{@code \p{IsLatin}}</td>
223 * <td headers="matches">A Latin script character (<a href="#usc">script</a>)</td></tr>
224 * <tr><td valign="top" headers="construct unicode">{@code \p{InGreek}}</td>
225 * <td headers="matches">A character in the Greek block (<a href="#ubc">block</a>)</td></tr>
226 * <tr><td valign="top" headers="construct unicode">{@code \p{Lu}}</td>
227 * <td headers="matches">An uppercase letter (<a href="#ucc">category</a>)</td></tr>
228 * <tr><td valign="top" headers="construct unicode">{@code \p{IsAlphabetic}}</td>
229 * <td headers="matches">An alphabetic character (<a href="#ubpc">binary property</a>)</td></tr>
230 * <tr><td valign="top" headers="construct unicode">{@code \p{Sc}}</td>
231 * <td headers="matches">A currency symbol</td></tr>
232 * <tr><td valign="top" headers="construct unicode">{@code \P{InGreek}}</td>
233 * <td headers="matches">Any character except one in the Greek block (negation)</td></tr>
234 * <tr><td valign="top" headers="construct unicode">{@code [\p{L}&&[^\p{Lu}]]}</td>
235 * <td headers="matches">Any letter except an uppercase letter (subtraction)</td></tr>
236 *
237 * <tr><th> </th></tr>
238 * <tr align="left"><th colspan="2" id="bounds">Boundary matchers</th></tr>
239 *
240 * <tr><td valign="top" headers="construct bounds"><tt>^</tt></td>
241 * <td headers="matches">The beginning of a line</td></tr>
242 * <tr><td valign="top" headers="construct bounds"><tt>$</tt></td>
243 * <td headers="matches">The end of a line</td></tr>
244 * <tr><td valign="top" headers="construct bounds"><tt>\b</tt></td>
245 * <td headers="matches">A word boundary</td></tr>
246 * <tr><td valign="top" headers="construct bounds"><tt>\B</tt></td>
247 * <td headers="matches">A non-word boundary</td></tr>
248 * <tr><td valign="top" headers="construct bounds"><tt>\A</tt></td>
249 * <td headers="matches">The beginning of the input</td></tr>
250 * <tr><td valign="top" headers="construct bounds"><tt>\G</tt></td>
251 * <td headers="matches">The end of the previous match</td></tr>
252 * <tr><td valign="top" headers="construct bounds"><tt>\Z</tt></td>
253 * <td headers="matches">The end of the input but for the final
254 * <a href="#lt">terminator</a>, if any</td></tr>
255 * <tr><td valign="top" headers="construct bounds"><tt>\z</tt></td>
256 * <td headers="matches">The end of the input</td></tr>
257 *
258 * <tr><th> </th></tr>
259 * <tr align="left"><th colspan="2" id="lineending">Linebreak matcher</th></tr>
260 * <tr><td valign="top" headers="construct lineending"><tt>\R</tt></td>
261 * <td headers="matches">Any Unicode linebreak sequence, is equivalent to
262 * <tt>\u000D\u000A|[\u000A\u000B\u000C\u000D\u0085\u2028\u2029]
263 * </tt></td></tr>
264 *
265 * <tr><th> </th></tr>
266 * <tr align="left"><th colspan="2" id="greedy">Greedy quantifiers</th></tr>
267 *
268 * <tr><td valign="top" headers="construct greedy"><i>X</i><tt>?</tt></td>
269 * <td headers="matches"><i>X</i>, once or not at all</td></tr>
270 * <tr><td valign="top" headers="construct greedy"><i>X</i><tt>*</tt></td>
271 * <td headers="matches"><i>X</i>, zero or more times</td></tr>
272 * <tr><td valign="top" headers="construct greedy"><i>X</i><tt>+</tt></td>
273 * <td headers="matches"><i>X</i>, one or more times</td></tr>
274 * <tr><td valign="top" headers="construct greedy"><i>X</i><tt>{</tt><i>n</i><tt>}</tt></td>
275 * <td headers="matches"><i>X</i>, exactly <i>n</i> times</td></tr>
276 * <tr><td valign="top" headers="construct greedy"><i>X</i><tt>{</tt><i>n</i><tt>,}</tt></td>
277 * <td headers="matches"><i>X</i>, at least <i>n</i> times</td></tr>
278 * <tr><td valign="top" headers="construct greedy"><i>X</i><tt>{</tt><i>n</i><tt>,</tt><i>m</i><tt>}</tt></td>
279 * <td headers="matches"><i>X</i>, at least <i>n</i> but not more than <i>m</i> times</td></tr>
280 *
281 * <tr><th> </th></tr>
282 * <tr align="left"><th colspan="2" id="reluc">Reluctant quantifiers</th></tr>
283 *
284 * <tr><td valign="top" headers="construct reluc"><i>X</i><tt>??</tt></td>
285 * <td headers="matches"><i>X</i>, once or not at all</td></tr>
286 * <tr><td valign="top" headers="construct reluc"><i>X</i><tt>*?</tt></td>
287 * <td headers="matches"><i>X</i>, zero or more times</td></tr>
288 * <tr><td valign="top" headers="construct reluc"><i>X</i><tt>+?</tt></td>
289 * <td headers="matches"><i>X</i>, one or more times</td></tr>
290 * <tr><td valign="top" headers="construct reluc"><i>X</i><tt>{</tt><i>n</i><tt>}?</tt></td>
291 * <td headers="matches"><i>X</i>, exactly <i>n</i> times</td></tr>
292 * <tr><td valign="top" headers="construct reluc"><i>X</i><tt>{</tt><i>n</i><tt>,}?</tt></td>
293 * <td headers="matches"><i>X</i>, at least <i>n</i> times</td></tr>
294 * <tr><td valign="top" headers="construct reluc"><i>X</i><tt>{</tt><i>n</i><tt>,</tt><i>m</i><tt>}?</tt></td>
295 * <td headers="matches"><i>X</i>, at least <i>n</i> but not more than <i>m</i> times</td></tr>
296 *
297 * <tr><th> </th></tr>
298 * <tr align="left"><th colspan="2" id="poss">Possessive quantifiers</th></tr>
299 *
300 * <tr><td valign="top" headers="construct poss"><i>X</i><tt>?+</tt></td>
301 * <td headers="matches"><i>X</i>, once or not at all</td></tr>
302 * <tr><td valign="top" headers="construct poss"><i>X</i><tt>*+</tt></td>
303 * <td headers="matches"><i>X</i>, zero or more times</td></tr>
304 * <tr><td valign="top" headers="construct poss"><i>X</i><tt>++</tt></td>
305 * <td headers="matches"><i>X</i>, one or more times</td></tr>
306 * <tr><td valign="top" headers="construct poss"><i>X</i><tt>{</tt><i>n</i><tt>}+</tt></td>
307 * <td headers="matches"><i>X</i>, exactly <i>n</i> times</td></tr>
308 * <tr><td valign="top" headers="construct poss"><i>X</i><tt>{</tt><i>n</i><tt>,}+</tt></td>
309 * <td headers="matches"><i>X</i>, at least <i>n</i> times</td></tr>
310 * <tr><td valign="top" headers="construct poss"><i>X</i><tt>{</tt><i>n</i><tt>,</tt><i>m</i><tt>}+</tt></td>
311 * <td headers="matches"><i>X</i>, at least <i>n</i> but not more than <i>m</i> times</td></tr>
312 *
313 * <tr><th> </th></tr>
314 * <tr align="left"><th colspan="2" id="logical">Logical operators</th></tr>
315 *
316 * <tr><td valign="top" headers="construct logical"><i>XY</i></td>
317 * <td headers="matches"><i>X</i> followed by <i>Y</i></td></tr>
318 * <tr><td valign="top" headers="construct logical"><i>X</i><tt>|</tt><i>Y</i></td>
319 * <td headers="matches">Either <i>X</i> or <i>Y</i></td></tr>
320 * <tr><td valign="top" headers="construct logical"><tt>(</tt><i>X</i><tt>)</tt></td>
321 * <td headers="matches">X, as a <a href="#cg">capturing group</a></td></tr>
322 *
323 * <tr><th> </th></tr>
324 * <tr align="left"><th colspan="2" id="backref">Back references</th></tr>
325 *
326 * <tr><td valign="bottom" headers="construct backref"><tt>\</tt><i>n</i></td>
327 * <td valign="bottom" headers="matches">Whatever the <i>n</i><sup>th</sup>
328 * <a href="#cg">capturing group</a> matched</td></tr>
329 *
330 * <tr><td valign="bottom" headers="construct backref"><tt>\</tt><i>k</i><<i>name</i>></td>
331 * <td valign="bottom" headers="matches">Whatever the
332 * <a href="#groupname">named-capturing group</a> "name" matched</td></tr>
333 *
334 * <tr><th> </th></tr>
335 * <tr align="left"><th colspan="2" id="quot">Quotation</th></tr>
336 *
337 * <tr><td valign="top" headers="construct quot"><tt>\</tt></td>
338 * <td headers="matches">Nothing, but quotes the following character</td></tr>
339 * <tr><td valign="top" headers="construct quot"><tt>\Q</tt></td>
340 * <td headers="matches">Nothing, but quotes all characters until <tt>\E</tt></td></tr>
341 * <tr><td valign="top" headers="construct quot"><tt>\E</tt></td>
342 * <td headers="matches">Nothing, but ends quoting started by <tt>\Q</tt></td></tr>
343 * <!-- Metachars: !$()*+.<>?[\]^{|} -->
344 *
345 * <tr><th> </th></tr>
346 * <tr align="left"><th colspan="2" id="special">Special constructs (named-capturing and non-capturing)</th></tr>
347 *
348 * <tr><td valign="top" headers="construct special"><tt>(?<<a href="#groupname">name</a>></tt><i>X</i><tt>)</tt></td>
349 * <td headers="matches"><i>X</i>, as a named-capturing group</td></tr>
350 * <tr><td valign="top" headers="construct special"><tt>(?:</tt><i>X</i><tt>)</tt></td>
351 * <td headers="matches"><i>X</i>, as a non-capturing group</td></tr>
352 * <tr><td valign="top" headers="construct special"><tt>(?idmsuxU-idmsuxU) </tt></td>
353 * <td headers="matches">Nothing, but turns match flags <a href="#CASE_INSENSITIVE">i</a>
354 * <a href="#UNIX_LINES">d</a> <a href="#MULTILINE">m</a> <a href="#DOTALL">s</a>
355 * <a href="#UNICODE_CASE">u</a> <a href="#COMMENTS">x</a> <a href="#UNICODE_CHARACTER_CLASS">U</a>
356 * on - off</td></tr>
357 * <tr><td valign="top" headers="construct special"><tt>(?idmsux-idmsux:</tt><i>X</i><tt>)</tt> </td>
358 * <td headers="matches"><i>X</i>, as a <a href="#cg">non-capturing group</a> with the
359 * given flags <a href="#CASE_INSENSITIVE">i</a> <a href="#UNIX_LINES">d</a>
360 * <a href="#MULTILINE">m</a> <a href="#DOTALL">s</a> <a href="#UNICODE_CASE">u</a >
361 * <a href="#COMMENTS">x</a> on - off</td></tr>
362 * <tr><td valign="top" headers="construct special"><tt>(?=</tt><i>X</i><tt>)</tt></td>
363 * <td headers="matches"><i>X</i>, via zero-width positive lookahead</td></tr>
364 * <tr><td valign="top" headers="construct special"><tt>(?!</tt><i>X</i><tt>)</tt></td>
365 * <td headers="matches"><i>X</i>, via zero-width negative lookahead</td></tr>
366 * <tr><td valign="top" headers="construct special"><tt>(?<=</tt><i>X</i><tt>)</tt></td>
367 * <td headers="matches"><i>X</i>, via zero-width positive lookbehind</td></tr>
368 * <tr><td valign="top" headers="construct special"><tt>(?<!</tt><i>X</i><tt>)</tt></td>
369 * <td headers="matches"><i>X</i>, via zero-width negative lookbehind</td></tr>
370 * <tr><td valign="top" headers="construct special"><tt>(?></tt><i>X</i><tt>)</tt></td>
371 * <td headers="matches"><i>X</i>, as an independent, non-capturing group</td></tr>
372 *
373 * </table>
374 *
375 * <hr>
376 *
377 *
378 * <h3><a name="bs">Backslashes, escapes, and quoting</a></h3>
379 *
380 * <p> The backslash character (<tt>'\'</tt>) serves to introduce escaped
381 * constructs, as defined in the table above, as well as to quote characters
382 * that otherwise would be interpreted as unescaped constructs. Thus the
383 * expression <tt>\\</tt> matches a single backslash and <tt>\{</tt> matches a
384 * left brace.
385 *
386 * <p> It is an error to use a backslash prior to any alphabetic character that
387 * does not denote an escaped construct; these are reserved for future
388 * extensions to the regular-expression language. A backslash may be used
389 * prior to a non-alphabetic character regardless of whether that character is
390 * part of an unescaped construct.
391 *
392 * <p> Backslashes within string literals in Java source code are interpreted
393 * as required by
394 * <cite>The Java™ Language Specification</cite>
395 * as either Unicode escapes (section 3.3) or other character escapes (section 3.10.6)
396 * It is therefore necessary to double backslashes in string
397 * literals that represent regular expressions to protect them from
398 * interpretation by the Java bytecode compiler. The string literal
399 * <tt>"\b"</tt>, for example, matches a single backspace character when
400 * interpreted as a regular expression, while <tt>"\\b"</tt> matches a
401 * word boundary. The string literal <tt>"\(hello\)"</tt> is illegal
402 * and leads to a compile-time error; in order to match the string
403 * <tt>(hello)</tt> the string literal <tt>"\\(hello\\)"</tt>
404 * must be used.
405 *
406 * <h3><a name="cc">Character Classes</a></h3>
407 *
408 * <p> Character classes may appear within other character classes, and
409 * may be composed by the union operator (implicit) and the intersection
410 * operator (<tt>&&</tt>).
411 * The union operator denotes a class that contains every character that is
412 * in at least one of its operand classes. The intersection operator
413 * denotes a class that contains every character that is in both of its
414 * operand classes.
415 *
416 * <p> The precedence of character-class operators is as follows, from
417 * highest to lowest:
418 *
419 * <blockquote><table border="0" cellpadding="1" cellspacing="0"
420 * summary="Precedence of character class operators.">
421 * <tr><th>1 </th>
422 * <td>Literal escape </td>
423 * <td><tt>\x</tt></td></tr>
424 * <tr><th>2 </th>
425 * <td>Grouping</td>
426 * <td><tt>[...]</tt></td></tr>
427 * <tr><th>3 </th>
428 * <td>Range</td>
429 * <td><tt>a-z</tt></td></tr>
430 * <tr><th>4 </th>
431 * <td>Union</td>
432 * <td><tt>[a-e][i-u]</tt></td></tr>
433 * <tr><th>5 </th>
434 * <td>Intersection</td>
435 * <td>{@code [a-z&&[aeiou]]}</td></tr>
436 * </table></blockquote>
437 *
438 * <p> Note that a different set of metacharacters are in effect inside
439 * a character class than outside a character class. For instance, the
440 * regular expression <tt>.</tt> loses its special meaning inside a
441 * character class, while the expression <tt>-</tt> becomes a range
442 * forming metacharacter.
443 *
444 * <h3><a name="lt">Line terminators</a></h3>
445 *
446 * <p> A <i>line terminator</i> is a one- or two-character sequence that marks
447 * the end of a line of the input character sequence. The following are
448 * recognized as line terminators:
449 *
450 * <ul>
451 *
452 * <li> A newline (line feed) character (<tt>'\n'</tt>),
453 *
454 * <li> A carriage-return character followed immediately by a newline
455 * character (<tt>"\r\n"</tt>),
456 *
457 * <li> A standalone carriage-return character (<tt>'\r'</tt>),
458 *
459 * <li> A next-line character (<tt>'\u0085'</tt>),
460 *
461 * <li> A line-separator character (<tt>'\u2028'</tt>), or
462 *
463 * <li> A paragraph-separator character (<tt>'\u2029</tt>).
464 *
465 * </ul>
466 * <p>If {@link #UNIX_LINES} mode is activated, then the only line terminators
467 * recognized are newline characters.
468 *
469 * <p> The regular expression <tt>.</tt> matches any character except a line
470 * terminator unless the {@link #DOTALL} flag is specified.
471 *
472 * <p> By default, the regular expressions <tt>^</tt> and <tt>$</tt> ignore
473 * line terminators and only match at the beginning and the end, respectively,
474 * of the entire input sequence. If {@link #MULTILINE} mode is activated then
475 * <tt>^</tt> matches at the beginning of input and after any line terminator
476 * except at the end of input. When in {@link #MULTILINE} mode <tt>$</tt>
477 * matches just before a line terminator or the end of the input sequence.
478 *
479 * <h3><a name="cg">Groups and capturing</a></h3>
480 *
481 * <h4><a name="gnumber">Group number</a></h4>
482 * <p> Capturing groups are numbered by counting their opening parentheses from
483 * left to right. In the expression <tt>((A)(B(C)))</tt>, for example, there
484 * are four such groups: </p>
485 *
486 * <blockquote><table cellpadding=1 cellspacing=0 summary="Capturing group numberings">
487 * <tr><th>1 </th>
488 * <td><tt>((A)(B(C)))</tt></td></tr>
489 * <tr><th>2 </th>
490 * <td><tt>(A)</tt></td></tr>
491 * <tr><th>3 </th>
492 * <td><tt>(B(C))</tt></td></tr>
493 * <tr><th>4 </th>
494 * <td><tt>(C)</tt></td></tr>
495 * </table></blockquote>
496 *
497 * <p> Group zero always stands for the entire expression.
498 *
499 * <p> Capturing groups are so named because, during a match, each subsequence
500 * of the input sequence that matches such a group is saved. The captured
501 * subsequence may be used later in the expression, via a back reference, and
502 * may also be retrieved from the matcher once the match operation is complete.
503 *
504 * <h4><a name="groupname">Group name</a></h4>
505 * <p>A capturing group can also be assigned a "name", a <tt>named-capturing group</tt>,
506 * and then be back-referenced later by the "name". Group names are composed of
507 * the following characters. The first character must be a <tt>letter</tt>.
508 *
509 * <ul>
510 * <li> The uppercase letters <tt>'A'</tt> through <tt>'Z'</tt>
511 * (<tt>'\u0041'</tt> through <tt>'\u005a'</tt>),
512 * <li> The lowercase letters <tt>'a'</tt> through <tt>'z'</tt>
513 * (<tt>'\u0061'</tt> through <tt>'\u007a'</tt>),
514 * <li> The digits <tt>'0'</tt> through <tt>'9'</tt>
515 * (<tt>'\u0030'</tt> through <tt>'\u0039'</tt>),
516 * </ul>
517 *
518 * <p> A <tt>named-capturing group</tt> is still numbered as described in
519 * <a href="#gnumber">Group number</a>.
520 *
521 * <p> The captured input associated with a group is always the subsequence
522 * that the group most recently matched. If a group is evaluated a second time
523 * because of quantification then its previously-captured value, if any, will
524 * be retained if the second evaluation fails. Matching the string
525 * <tt>"aba"</tt> against the expression <tt>(a(b)?)+</tt>, for example, leaves
526 * group two set to <tt>"b"</tt>. All captured input is discarded at the
527 * beginning of each match.
528 *
529 * <p> Groups beginning with <tt>(?</tt> are either pure, <i>non-capturing</i> groups
530 * that do not capture text and do not count towards the group total, or
531 * <i>named-capturing</i> group.
532 *
533 * <h3> Unicode support </h3>
534 *
535 * <p> This class is in conformance with Level 1 of <a
536 * href="http://www.unicode.org/reports/tr18/"><i>Unicode Technical
537 * Standard #18: Unicode Regular Expression</i></a>, plus RL2.1
538 * Canonical Equivalents.
539 * <p>
540 * <b>Unicode escape sequences</b> such as <tt>\u2014</tt> in Java source code
541 * are processed as described in section 3.3 of
542 * <cite>The Java™ Language Specification</cite>.
543 * Such escape sequences are also implemented directly by the regular-expression
544 * parser so that Unicode escapes can be used in expressions that are read from
545 * files or from the keyboard. Thus the strings <tt>"\u2014"</tt> and
546 * <tt>"\\u2014"</tt>, while not equal, compile into the same pattern, which
547 * matches the character with hexadecimal value <tt>0x2014</tt>.
548 * <p>
549 * A Unicode character can also be represented in a regular-expression by
550 * using its <b>Hex notation</b>(hexadecimal code point value) directly as described in construct
551 * <tt>\x{...}</tt>, for example a supplementary character U+2011F
552 * can be specified as <tt>\x{2011F}</tt>, instead of two consecutive
553 * Unicode escape sequences of the surrogate pair
554 * <tt>\uD840</tt><tt>\uDD1F</tt>.
555 * <p>
556 * Unicode scripts, blocks, categories and binary properties are written with
557 * the <tt>\p</tt> and <tt>\P</tt> constructs as in Perl.
558 * <tt>\p{</tt><i>prop</i><tt>}</tt> matches if
559 * the input has the property <i>prop</i>, while <tt>\P{</tt><i>prop</i><tt>}</tt>
560 * does not match if the input has that property.
561 * <p>
562 * Scripts, blocks, categories and binary properties can be used both inside
563 * and outside of a character class.
564 *
565 * <p>
566 * <b><a name="usc">Scripts</a></b> are specified either with the prefix {@code Is}, as in
567 * {@code IsHiragana}, or by using the {@code script} keyword (or its short
568 * form {@code sc})as in {@code script=Hiragana} or {@code sc=Hiragana}.
569 * <p>
570 * The script names supported by <code>Pattern</code> are the valid script names
571 * accepted and defined by
572 * {@link java.lang.Character.UnicodeScript#forName(String) UnicodeScript.forName}.
573 *
574 * <p>
575 * <b><a name="ubc">Blocks</a></b> are specified with the prefix {@code In}, as in
576 * {@code InMongolian}, or by using the keyword {@code block} (or its short
577 * form {@code blk}) as in {@code block=Mongolian} or {@code blk=Mongolian}.
578 * <p>
579 * The block names supported by <code>Pattern</code> are the valid block names
580 * accepted and defined by
581 * {@link java.lang.Character.UnicodeBlock#forName(String) UnicodeBlock.forName}.
582 * <p>
583 *
584 * <b><a name="ucc">Categories</a></b> may be specified with the optional prefix {@code Is}:
585 * Both {@code \p{L}} and {@code \p{IsL}} denote the category of Unicode
586 * letters. Same as scripts and blocks, categories can also be specified
587 * by using the keyword {@code general_category} (or its short form
588 * {@code gc}) as in {@code general_category=Lu} or {@code gc=Lu}.
589 * <p>
590 * The supported categories are those of
591 * <a href="http://www.unicode.org/unicode/standard/standard.html">
592 * <i>The Unicode Standard</i></a> in the version specified by the
593 * {@link java.lang.Character Character} class. The category names are those
594 * defined in the Standard, both normative and informative.
595 * <p>
596 *
597 * <b><a name="ubpc">Binary properties</a></b> are specified with the prefix {@code Is}, as in
598 * {@code IsAlphabetic}. The supported binary properties by <code>Pattern</code>
599 * are
600 * <ul>
601 * <li> Alphabetic
602 * <li> Ideographic
603 * <li> Letter
604 * <li> Lowercase
605 * <li> Uppercase
606 * <li> Titlecase
607 * <li> Punctuation
608 * <Li> Control
609 * <li> White_Space
610 * <li> Digit
611 * <li> Hex_Digit
612 * <li> Join_Control
613 * <li> Noncharacter_Code_Point
614 * <li> Assigned
615 * </ul>
616 * <p>
617 * The following <b>Predefined Character classes</b> and <b>POSIX character classes</b>
618 * are in conformance with the recommendation of <i>Annex C: Compatibility Properties</i>
619 * of <a href="http://www.unicode.org/reports/tr18/"><i>Unicode Regular Expression
620 * </i></a>, when {@link #UNICODE_CHARACTER_CLASS} flag is specified.
621 *
622 * <table border="0" cellpadding="1" cellspacing="0"
623 * summary="predefined and posix character classes in Unicode mode">
624 * <tr align="left">
625 * <th align="left" id="predef_classes">Classes</th>
626 * <th align="left" id="predef_matches">Matches</th>
627 *</tr>
628 * <tr><td><tt>\p{Lower}</tt></td>
629 * <td>A lowercase character:<tt>\p{IsLowercase}</tt></td></tr>
630 * <tr><td><tt>\p{Upper}</tt></td>
631 * <td>An uppercase character:<tt>\p{IsUppercase}</tt></td></tr>
632 * <tr><td><tt>\p{ASCII}</tt></td>
633 * <td>All ASCII:<tt>[\x00-\x7F]</tt></td></tr>
634 * <tr><td><tt>\p{Alpha}</tt></td>
635 * <td>An alphabetic character:<tt>\p{IsAlphabetic}</tt></td></tr>
636 * <tr><td><tt>\p{Digit}</tt></td>
637 * <td>A decimal digit character:<tt>p{IsDigit}</tt></td></tr>
638 * <tr><td><tt>\p{Alnum}</tt></td>
639 * <td>An alphanumeric character:<tt>[\p{IsAlphabetic}\p{IsDigit}]</tt></td></tr>
640 * <tr><td><tt>\p{Punct}</tt></td>
641 * <td>A punctuation character:<tt>p{IsPunctuation}</tt></td></tr>
642 * <tr><td><tt>\p{Graph}</tt></td>
643 * <td>A visible character: <tt>[^\p{IsWhite_Space}\p{gc=Cc}\p{gc=Cs}\p{gc=Cn}]</tt></td></tr>
644 * <tr><td><tt>\p{Print}</tt></td>
645 * <td>A printable character: {@code [\p{Graph}\p{Blank}&&[^\p{Cntrl}]]}</td></tr>
646 * <tr><td><tt>\p{Blank}</tt></td>
647 * <td>A space or a tab: {@code [\p{IsWhite_Space}&&[^\p{gc=Zl}\p{gc=Zp}\x0a\x0b\x0c\x0d\x85]]}</td></tr>
648 * <tr><td><tt>\p{Cntrl}</tt></td>
649 * <td>A control character: <tt>\p{gc=Cc}</tt></td></tr>
650 * <tr><td><tt>\p{XDigit}</tt></td>
651 * <td>A hexadecimal digit: <tt>[\p{gc=Nd}\p{IsHex_Digit}]</tt></td></tr>
652 * <tr><td><tt>\p{Space}</tt></td>
653 * <td>A whitespace character:<tt>\p{IsWhite_Space}</tt></td></tr>
654 * <tr><td><tt>\d</tt></td>
655 * <td>A digit: <tt>\p{IsDigit}</tt></td></tr>
656 * <tr><td><tt>\D</tt></td>
657 * <td>A non-digit: <tt>[^\d]</tt></td></tr>
658 * <tr><td><tt>\s</tt></td>
659 * <td>A whitespace character: <tt>\p{IsWhite_Space}</tt></td></tr>
660 * <tr><td><tt>\S</tt></td>
661 * <td>A non-whitespace character: <tt>[^\s]</tt></td></tr>
662 * <tr><td><tt>\w</tt></td>
663 * <td>A word character: <tt>[\p{Alpha}\p{gc=Mn}\p{gc=Me}\p{gc=Mc}\p{Digit}\p{gc=Pc}\p{IsJoin_Control}]</tt></td></tr>
664 * <tr><td><tt>\W</tt></td>
665 * <td>A non-word character: <tt>[^\w]</tt></td></tr>
666 * </table>
667 * <p>
668 * <a name="jcc">
669 * Categories that behave like the java.lang.Character
670 * boolean is<i>methodname</i> methods (except for the deprecated ones) are
671 * available through the same <tt>\p{</tt><i>prop</i><tt>}</tt> syntax where
672 * the specified property has the name <tt>java<i>methodname</i></tt></a>.
673 *
674 * <h3> Comparison to Perl 5 </h3>
675 *
676 * <p>The <code>Pattern</code> engine performs traditional NFA-based matching
677 * with ordered alternation as occurs in Perl 5.
678 *
679 * <p> Perl constructs not supported by this class: </p>
680 *
681 * <ul>
682 * <li><p> Predefined character classes (Unicode character)
683 * <p><tt>\X </tt>Match Unicode
684 * <a href="http://www.unicode.org/reports/tr18/#Default_Grapheme_Clusters">
685 * <i>extended grapheme cluster</i></a>
686 * </p></li>
687 *
688 * <li><p> The backreference constructs, <tt>\g{</tt><i>n</i><tt>}</tt> for
689 * the <i>n</i><sup>th</sup><a href="#cg">capturing group</a> and
690 * <tt>\g{</tt><i>name</i><tt>}</tt> for
691 * <a href="#groupname">named-capturing group</a>.
692 * </p></li>
693 *
694 * <li><p> The named character construct, <tt>\N{</tt><i>name</i><tt>}</tt>
695 * for a Unicode character by its name.
696 * </p></li>
697 *
698 * <li><p> The conditional constructs
699 * <tt>(?(</tt><i>condition</i><tt>)</tt><i>X</i><tt>)</tt> and
700 * <tt>(?(</tt><i>condition</i><tt>)</tt><i>X</i><tt>|</tt><i>Y</i><tt>)</tt>,
701 * </p></li>
702 *
703 * <li><p> The embedded code constructs <tt>(?{</tt><i>code</i><tt>})</tt>
704 * and <tt>(??{</tt><i>code</i><tt>})</tt>,</p></li>
705 *
706 * <li><p> The embedded comment syntax <tt>(?#comment)</tt>, and </p></li>
707 *
708 * <li><p> The preprocessing operations <tt>\l</tt> <tt>\u</tt>,
709 * <tt>\L</tt>, and <tt>\U</tt>. </p></li>
710 *
711 * </ul>
712 *
713 * <p> Constructs supported by this class but not by Perl: </p>
714 *
715 * <ul>
716 *
717 * <li><p> Character-class union and intersection as described
718 * <a href="#cc">above</a>.</p></li>
719 *
720 * </ul>
721 *
722 * <p> Notable differences from Perl: </p>
723 *
724 * <ul>
725 *
726 * <li><p> In Perl, <tt>\1</tt> through <tt>\9</tt> are always interpreted
727 * as back references; a backslash-escaped number greater than <tt>9</tt> is
728 * treated as a back reference if at least that many subexpressions exist,
729 * otherwise it is interpreted, if possible, as an octal escape. In this
730 * class octal escapes must always begin with a zero. In this class,
731 * <tt>\1</tt> through <tt>\9</tt> are always interpreted as back
732 * references, and a larger number is accepted as a back reference if at
733 * least that many subexpressions exist at that point in the regular
734 * expression, otherwise the parser will drop digits until the number is
735 * smaller or equal to the existing number of groups or it is one digit.
736 * </p></li>
737 *
738 * <li><p> Perl uses the <tt>g</tt> flag to request a match that resumes
739 * where the last match left off. This functionality is provided implicitly
740 * by the {@link Matcher} class: Repeated invocations of the {@link
741 * Matcher#find find} method will resume where the last match left off,
742 * unless the matcher is reset. </p></li>
743 *
744 * <li><p> In Perl, embedded flags at the top level of an expression affect
745 * the whole expression. In this class, embedded flags always take effect
746 * at the point at which they appear, whether they are at the top level or
747 * within a group; in the latter case, flags are restored at the end of the
748 * group just as in Perl. </p></li>
749 *
750 * </ul>
751 *
752 *
753 * <p> For a more precise description of the behavior of regular expression
754 * constructs, please see <a href="http://www.oreilly.com/catalog/regex3/">
755 * <i>Mastering Regular Expressions, 3nd Edition</i>, Jeffrey E. F. Friedl,
756 * O'Reilly and Associates, 2006.</a>
757 * </p>
758 *
759 * @see java.lang.String#split(String, int)
760 * @see java.lang.String#split(String)
761 *
762 * @author Mike McCloskey
763 * @author Mark Reinhold
764 * @author JSR-51 Expert Group
765 * @since 1.4
766 * @spec JSR-51
767 */
768
769 public final class Pattern
770 implements java.io.Serializable
771 {
772
773 /**
774 * Regular expression modifier values. Instead of being passed as
775 * arguments, they can also be passed as inline modifiers.
776 * For example, the following statements have the same effect.
777 * <pre>
778 * RegExp r1 = RegExp.compile("abc", Pattern.I|Pattern.M);
779 * RegExp r2 = RegExp.compile("(?im)abc", 0);
780 * </pre>
781 *
782 * The flags are duplicated so that the familiar Perl match flag
783 * names are available.
784 */
785
786 /**
787 * Enables Unix lines mode.
788 *
789 * <p> In this mode, only the <tt>'\n'</tt> line terminator is recognized
790 * in the behavior of <tt>.</tt>, <tt>^</tt>, and <tt>$</tt>.
791 *
792 * <p> Unix lines mode can also be enabled via the embedded flag
793 * expression <tt>(?d)</tt>.
794 */
795 public static final int UNIX_LINES = 0x01;
796
797 /**
798 * Enables case-insensitive matching.
799 *
800 * <p> By default, case-insensitive matching assumes that only characters
801 * in the US-ASCII charset are being matched. Unicode-aware
802 * case-insensitive matching can be enabled by specifying the {@link
803 * #UNICODE_CASE} flag in conjunction with this flag.
804 *
805 * <p> Case-insensitive matching can also be enabled via the embedded flag
806 * expression <tt>(?i)</tt>.
807 *
808 * <p> Specifying this flag may impose a slight performance penalty. </p>
809 */
810 public static final int CASE_INSENSITIVE = 0x02;
811
812 /**
813 * Permits whitespace and comments in pattern.
814 *
815 * <p> In this mode, whitespace is ignored, and embedded comments starting
816 * with <tt>#</tt> are ignored until the end of a line.
817 *
818 * <p> Comments mode can also be enabled via the embedded flag
819 * expression <tt>(?x)</tt>.
820 */
821 public static final int COMMENTS = 0x04;
822
823 /**
824 * Enables multiline mode.
825 *
826 * <p> In multiline mode the expressions <tt>^</tt> and <tt>$</tt> match
827 * just after or just before, respectively, a line terminator or the end of
828 * the input sequence. By default these expressions only match at the
829 * beginning and the end of the entire input sequence.
830 *
831 * <p> Multiline mode can also be enabled via the embedded flag
832 * expression <tt>(?m)</tt>. </p>
833 */
834 public static final int MULTILINE = 0x08;
835
836 /**
837 * Enables literal parsing of the pattern.
838 *
839 * <p> When this flag is specified then the input string that specifies
840 * the pattern is treated as a sequence of literal characters.
841 * Metacharacters or escape sequences in the input sequence will be
842 * given no special meaning.
843 *
844 * <p>The flags CASE_INSENSITIVE and UNICODE_CASE retain their impact on
845 * matching when used in conjunction with this flag. The other flags
846 * become superfluous.
847 *
848 * <p> There is no embedded flag character for enabling literal parsing.
849 * @since 1.5
850 */
851 public static final int LITERAL = 0x10;
852
853 /**
854 * Enables dotall mode.
855 *
856 * <p> In dotall mode, the expression <tt>.</tt> matches any character,
857 * including a line terminator. By default this expression does not match
858 * line terminators.
859 *
860 * <p> Dotall mode can also be enabled via the embedded flag
861 * expression <tt>(?s)</tt>. (The <tt>s</tt> is a mnemonic for
862 * "single-line" mode, which is what this is called in Perl.) </p>
863 */
864 public static final int DOTALL = 0x20;
865
866 /**
867 * Enables Unicode-aware case folding.
868 *
869 * <p> When this flag is specified then case-insensitive matching, when
870 * enabled by the {@link #CASE_INSENSITIVE} flag, is done in a manner
871 * consistent with the Unicode Standard. By default, case-insensitive
872 * matching assumes that only characters in the US-ASCII charset are being
873 * matched.
874 *
875 * <p> Unicode-aware case folding can also be enabled via the embedded flag
876 * expression <tt>(?u)</tt>.
877 *
878 * <p> Specifying this flag may impose a performance penalty. </p>
879 */
880 public static final int UNICODE_CASE = 0x40;
881
882 /**
883 * Enables canonical equivalence.
884 *
885 * <p> When this flag is specified then two characters will be considered
886 * to match if, and only if, their full canonical decompositions match.
887 * The expression <tt>"a\u030A"</tt>, for example, will match the
888 * string <tt>"\u00E5"</tt> when this flag is specified. By default,
889 * matching does not take canonical equivalence into account.
890 *
891 * <p> There is no embedded flag character for enabling canonical
892 * equivalence.
893 *
894 * <p> Specifying this flag may impose a performance penalty. </p>
895 */
896 public static final int CANON_EQ = 0x80;
897
898 /**
899 * Enables the Unicode version of <i>Predefined character classes</i> and
900 * <i>POSIX character classes</i>.
901 *
902 * <p> When this flag is specified then the (US-ASCII only)
903 * <i>Predefined character classes</i> and <i>POSIX character classes</i>
904 * are in conformance with
905 * <a href="http://www.unicode.org/reports/tr18/"><i>Unicode Technical
906 * Standard #18: Unicode Regular Expression</i></a>
907 * <i>Annex C: Compatibility Properties</i>.
908 * <p>
909 * The UNICODE_CHARACTER_CLASS mode can also be enabled via the embedded
910 * flag expression <tt>(?U)</tt>.
911 * <p>
912 * The flag implies UNICODE_CASE, that is, it enables Unicode-aware case
913 * folding.
914 * <p>
915 * Specifying this flag may impose a performance penalty. </p>
916 * @since 1.7
917 */
918 public static final int UNICODE_CHARACTER_CLASS = 0x100;
919
920 /* 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 charClass.append("[");
1415 while(true) {
1416 int c = normalizedPattern.codePointAt(i);
1417 StringBuilder sequenceBuffer;
1418
1419 if (c == ']' && lastCodePoint != '\\') {
1420 charClass.append((char)c);
1421 break;
1422 } else if (Character.getType(c) == Character.NON_SPACING_MARK) {
1423 sequenceBuffer = new StringBuilder();
1424 sequenceBuffer.appendCodePoint(lastCodePoint);
1425 while(Character.getType(c) == Character.NON_SPACING_MARK) {
1426 sequenceBuffer.appendCodePoint(c);
1427 i += Character.charCount(c);
1428 if (i >= normalizedPattern.length())
1429 break;
1430 c = normalizedPattern.codePointAt(i);
1431 }
1432 String ea = produceEquivalentAlternation(
1433 sequenceBuffer.toString());
1434
1435 charClass.setLength(charClass.length()-Character.charCount(lastCodePoint));
1436 if (eq == null)
1437 eq = new StringBuilder();
1438 eq.append('|');
1439 eq.append(ea);
1440 } else {
1441 charClass.appendCodePoint(c);
1442 i++;
1443 }
1444 if (i == normalizedPattern.length())
1445 throw error("Unclosed character class");
1446 lastCodePoint = c;
1447 }
1448
1449 if (eq != null) {
1450 result = "(?:"+charClass.toString()+eq.toString()+")";
1451 } else {
1452 result = charClass.toString();
1453 }
1454
1455 newPattern.append(result);
1456 return i;
1457 }
1458
1459 /**
1460 * Given a specific sequence composed of a regular character and
1461 * combining marks that follow it, produce the alternation that will
1462 * match all canonical equivalences of that sequence.
1463 */
1464 private String produceEquivalentAlternation(String source) {
1465 int len = countChars(source, 0, 1);
1466 if (source.length() == len)
1467 // source has one character.
1468 return source;
1469
1470 String base = source.substring(0,len);
1471 String combiningMarks = source.substring(len);
1472
1473 String[] perms = producePermutations(combiningMarks);
1474 StringBuilder result = new StringBuilder(source);
1475
1476 // Add combined permutations
1477 for(int x=0; x<perms.length; x++) {
1478 String next = base + perms[x];
1479 if (x>0)
1480 result.append("|"+next);
1481 next = composeOneStep(next);
1482 if (next != null)
1483 result.append("|"+produceEquivalentAlternation(next));
1484 }
1485 return result.toString();
1486 }
1487
1488 /**
1489 * Returns an array of strings that have all the possible
1490 * permutations of the characters in the input string.
1491 * This is used to get a list of all possible orderings
1492 * of a set of combining marks. Note that some of the permutations
1493 * are invalid because of combining class collisions, and these
1494 * possibilities must be removed because they are not canonically
1495 * equivalent.
1496 */
1497 private String[] producePermutations(String input) {
1498 if (input.length() == countChars(input, 0, 1))
1499 return new String[] {input};
1500
1501 if (input.length() == countChars(input, 0, 2)) {
1502 int c0 = Character.codePointAt(input, 0);
1503 int c1 = Character.codePointAt(input, Character.charCount(c0));
1504 if (getClass(c1) == getClass(c0)) {
1505 return new String[] {input};
1506 }
1507 String[] result = new String[2];
1508 result[0] = input;
1509 StringBuilder sb = new StringBuilder(2);
1510 sb.appendCodePoint(c1);
1511 sb.appendCodePoint(c0);
1512 result[1] = sb.toString();
1513 return result;
1514 }
1515
1516 int length = 1;
1517 int nCodePoints = countCodePoints(input);
1518 for(int x=1; x<nCodePoints; x++)
1519 length = length * (x+1);
1520
1521 String[] temp = new String[length];
1522
1523 int combClass[] = new int[nCodePoints];
1524 for(int x=0, i=0; x<nCodePoints; x++) {
1525 int c = Character.codePointAt(input, i);
1526 combClass[x] = getClass(c);
1527 i += Character.charCount(c);
1528 }
1529
1530 // For each char, take it out and add the permutations
1531 // of the remaining chars
1532 int index = 0;
1533 int len;
1534 // offset maintains the index in code units.
1535 loop: for(int x=0, offset=0; x<nCodePoints; x++, offset+=len) {
1536 len = countChars(input, offset, 1);
1537 boolean skip = false;
1538 for(int y=x-1; y>=0; y--) {
1539 if (combClass[y] == combClass[x]) {
1540 continue loop;
1541 }
1542 }
1543 StringBuilder sb = new StringBuilder(input);
1544 String otherChars = sb.delete(offset, offset+len).toString();
1545 String[] subResult = producePermutations(otherChars);
1546
1547 String prefix = input.substring(offset, offset+len);
1548 for(int y=0; y<subResult.length; y++)
1549 temp[index++] = prefix + subResult[y];
1550 }
1551 String[] result = new String[index];
1552 for (int x=0; x<index; x++)
1553 result[x] = temp[x];
1554 return result;
1555 }
1556
1557 private int getClass(int c) {
1558 return sun.text.Normalizer.getCombiningClass(c);
1559 }
1560
1561 /**
1562 * Attempts to compose input by combining the first character
1563 * with the first combining mark following it. Returns a String
1564 * that is the composition of the leading character with its first
1565 * combining mark followed by the remaining combining marks. Returns
1566 * null if the first two characters cannot be further composed.
1567 */
1568 private String composeOneStep(String input) {
1569 int len = countChars(input, 0, 2);
1570 String firstTwoCharacters = input.substring(0, len);
1571 String result = Normalizer.normalize(firstTwoCharacters, Normalizer.Form.NFC);
1572
1573 if (result.equals(firstTwoCharacters))
1574 return null;
1575 else {
1576 String remainder = input.substring(len);
1577 return result + remainder;
1578 }
1579 }
1580
1581 /**
1582 * Preprocess any \Q...\E sequences in `temp', meta-quoting them.
1583 * See the description of `quotemeta' in perlfunc(1).
1584 */
1585 private void RemoveQEQuoting() {
1586 final int pLen = patternLength;
1587 int i = 0;
1588 while (i < pLen-1) {
1589 if (temp[i] != '\\')
1590 i += 1;
1591 else if (temp[i + 1] != 'Q')
1592 i += 2;
1593 else
1594 break;
1595 }
1596 if (i >= pLen - 1) // No \Q sequence found
1597 return;
1598 int j = i;
1599 i += 2;
1600 int[] newtemp = new int[j + 3*(pLen-i) + 2];
1601 System.arraycopy(temp, 0, newtemp, 0, j);
1602
1603 boolean inQuote = true;
1604 boolean beginQuote = true;
1605 while (i < pLen) {
1606 int c = temp[i++];
1607 if (!ASCII.isAscii(c) || ASCII.isAlpha(c)) {
1608 newtemp[j++] = c;
1609 } else if (ASCII.isDigit(c)) {
1610 if (beginQuote) {
1611 /*
1612 * A unicode escape \[0xu] could be before this quote,
1613 * and we don't want this numeric char to processed as
1614 * part of the escape.
1615 */
1616 newtemp[j++] = '\\';
1617 newtemp[j++] = 'x';
1618 newtemp[j++] = '3';
1619 }
1620 newtemp[j++] = c;
1621 } else if (c != '\\') {
1622 if (inQuote) newtemp[j++] = '\\';
1623 newtemp[j++] = c;
1624 } else if (inQuote) {
1625 if (temp[i] == 'E') {
1626 i++;
1627 inQuote = false;
1628 } else {
1629 newtemp[j++] = '\\';
1630 newtemp[j++] = '\\';
1631 }
1632 } else {
1633 if (temp[i] == 'Q') {
1634 i++;
1635 inQuote = true;
1636 beginQuote = true;
1637 continue;
1638 } else {
1639 newtemp[j++] = c;
1640 if (i != pLen)
1641 newtemp[j++] = temp[i++];
1642 }
1643 }
1644
1645 beginQuote = false;
1646 }
1647
1648 patternLength = j;
1649 temp = Arrays.copyOf(newtemp, j + 2); // double zero termination
1650 }
1651
1652 /**
1653 * Copies regular expression to an int array and invokes the parsing
1654 * of the expression which will create the object tree.
1655 */
1656 private void compile() {
1657 // Handle canonical equivalences
1658 if (has(CANON_EQ) && !has(LITERAL)) {
1659 normalize();
1660 } else {
1661 normalizedPattern = pattern;
1662 }
1663 patternLength = normalizedPattern.length();
1664
1665 // Copy pattern to int array for convenience
1666 // Use double zero to terminate pattern
1667 temp = new int[patternLength + 2];
1668
1669 hasSupplementary = false;
1670 int c, count = 0;
1671 // Convert all chars into code points
1672 for (int x = 0; x < patternLength; x += Character.charCount(c)) {
1673 c = normalizedPattern.codePointAt(x);
1674 if (isSupplementary(c)) {
1675 hasSupplementary = true;
1676 }
1677 temp[count++] = c;
1678 }
1679
1680 patternLength = count; // patternLength now in code points
1681
1682 if (! has(LITERAL))
1683 RemoveQEQuoting();
1684
1685 // Allocate all temporary objects here.
1686 buffer = new int[32];
1687 groupNodes = new GroupHead[10];
1688 namedGroups = null;
1689
1690 if (has(LITERAL)) {
1691 // Literal pattern handling
1692 matchRoot = newSlice(temp, patternLength, hasSupplementary);
1693 matchRoot.next = lastAccept;
1694 } else {
1695 // Start recursive descent parsing
1696 matchRoot = expr(lastAccept);
1697 // Check extra pattern characters
1698 if (patternLength != cursor) {
1699 if (peek() == ')') {
1700 throw error("Unmatched closing ')'");
1701 } else {
1702 throw error("Unexpected internal error");
1703 }
1704 }
1705 }
1706
1707 // Peephole optimization
1708 if (matchRoot instanceof Slice) {
1709 root = BnM.optimize(matchRoot);
1710 if (root == matchRoot) {
1711 root = hasSupplementary ? new StartS(matchRoot) : new Start(matchRoot);
1712 }
1713 } else if (matchRoot instanceof Begin || matchRoot instanceof First) {
1714 root = matchRoot;
1715 } else {
1716 root = hasSupplementary ? new StartS(matchRoot) : new Start(matchRoot);
1717 }
1718
1719 // Release temporary storage
1720 temp = null;
1721 buffer = null;
1722 groupNodes = null;
1723 patternLength = 0;
1724 compiled = true;
1725 }
1726
1727 Map<String, Integer> namedGroups() {
1728 if (namedGroups == null)
1729 namedGroups = new HashMap<>(2);
1730 return namedGroups;
1731 }
1732
1733 /**
1734 * Used to print out a subtree of the Pattern to help with debugging.
1735 */
1736 private static void printObjectTree(Node node) {
1737 while(node != null) {
1738 if (node instanceof Prolog) {
1739 System.out.println(node);
1740 printObjectTree(((Prolog)node).loop);
1741 System.out.println("**** end contents prolog loop");
1742 } else if (node instanceof Loop) {
1743 System.out.println(node);
1744 printObjectTree(((Loop)node).body);
1745 System.out.println("**** end contents Loop body");
1746 } else if (node instanceof Curly) {
1747 System.out.println(node);
1748 printObjectTree(((Curly)node).atom);
1749 System.out.println("**** end contents Curly body");
1750 } else if (node instanceof GroupCurly) {
1751 System.out.println(node);
1752 printObjectTree(((GroupCurly)node).atom);
1753 System.out.println("**** end contents GroupCurly body");
1754 } else if (node instanceof GroupTail) {
1755 System.out.println(node);
1756 System.out.println("Tail next is "+node.next);
1757 return;
1758 } else {
1759 System.out.println(node);
1760 }
1761 node = node.next;
1762 if (node != null)
1763 System.out.println("->next:");
1764 if (node == Pattern.accept) {
1765 System.out.println("Accept Node");
1766 node = null;
1767 }
1768 }
1769 }
1770
1771 /**
1772 * Used to accumulate information about a subtree of the object graph
1773 * so that optimizations can be applied to the subtree.
1774 */
1775 static final class TreeInfo {
1776 int minLength;
1777 int maxLength;
1778 boolean maxValid;
1779 boolean deterministic;
1780
1781 TreeInfo() {
1782 reset();
1783 }
1784 void reset() {
1785 minLength = 0;
1786 maxLength = 0;
1787 maxValid = true;
1788 deterministic = true;
1789 }
1790 }
1791
1792 /*
1793 * The following private methods are mainly used to improve the
1794 * readability of the code. In order to let the Java compiler easily
1795 * inline them, we should not put many assertions or error checks in them.
1796 */
1797
1798 /**
1799 * Indicates whether a particular flag is set or not.
1800 */
1801 private boolean has(int f) {
1802 return (flags & f) != 0;
1803 }
1804
1805 /**
1806 * Match next character, signal error if failed.
1807 */
1808 private void accept(int ch, String s) {
1809 int testChar = temp[cursor++];
1810 if (has(COMMENTS))
1811 testChar = parsePastWhitespace(testChar);
1812 if (ch != testChar) {
1813 throw error(s);
1814 }
1815 }
1816
1817 /**
1818 * Mark the end of pattern with a specific character.
1819 */
1820 private void mark(int c) {
1821 temp[patternLength] = c;
1822 }
1823
1824 /**
1825 * Peek the next character, and do not advance the cursor.
1826 */
1827 private int peek() {
1828 int ch = temp[cursor];
1829 if (has(COMMENTS))
1830 ch = peekPastWhitespace(ch);
1831 return ch;
1832 }
1833
1834 /**
1835 * Read the next character, and advance the cursor by one.
1836 */
1837 private int read() {
1838 int ch = temp[cursor++];
1839 if (has(COMMENTS))
1840 ch = parsePastWhitespace(ch);
1841 return ch;
1842 }
1843
1844 /**
1845 * Read the next character, and advance the cursor by one,
1846 * ignoring the COMMENTS setting
1847 */
1848 private int readEscaped() {
1849 int ch = temp[cursor++];
1850 return ch;
1851 }
1852
1853 /**
1854 * Advance the cursor by one, and peek the next character.
1855 */
1856 private int next() {
1857 int ch = temp[++cursor];
1858 if (has(COMMENTS))
1859 ch = peekPastWhitespace(ch);
1860 return ch;
1861 }
1862
1863 /**
1864 * Advance the cursor by one, and peek the next character,
1865 * ignoring the COMMENTS setting
1866 */
1867 private int nextEscaped() {
1868 int ch = temp[++cursor];
1869 return ch;
1870 }
1871
1872 /**
1873 * If in xmode peek past whitespace and comments.
1874 */
1875 private int peekPastWhitespace(int ch) {
1876 while (ASCII.isSpace(ch) || ch == '#') {
1877 while (ASCII.isSpace(ch))
1878 ch = temp[++cursor];
1879 if (ch == '#') {
1880 ch = peekPastLine();
1881 }
1882 }
1883 return ch;
1884 }
1885
1886 /**
1887 * If in xmode parse past whitespace and comments.
1888 */
1889 private int parsePastWhitespace(int ch) {
1890 while (ASCII.isSpace(ch) || ch == '#') {
1891 while (ASCII.isSpace(ch))
1892 ch = temp[cursor++];
1893 if (ch == '#')
1894 ch = parsePastLine();
1895 }
1896 return ch;
1897 }
1898
1899 /**
1900 * xmode parse past comment to end of line.
1901 */
1902 private int parsePastLine() {
1903 int ch = temp[cursor++];
1904 while (ch != 0 && !isLineSeparator(ch))
1905 ch = temp[cursor++];
1906 return ch;
1907 }
1908
1909 /**
1910 * xmode peek past comment to end of line.
1911 */
1912 private int peekPastLine() {
1913 int ch = temp[++cursor];
1914 while (ch != 0 && !isLineSeparator(ch))
1915 ch = temp[++cursor];
1916 return ch;
1917 }
1918
1919 /**
1920 * Determines if character is a line separator in the current mode
1921 */
1922 private boolean isLineSeparator(int ch) {
1923 if (has(UNIX_LINES)) {
1924 return ch == '\n';
1925 } else {
1926 return (ch == '\n' ||
1927 ch == '\r' ||
1928 (ch|1) == '\u2029' ||
1929 ch == '\u0085');
1930 }
1931 }
1932
1933 /**
1934 * Read the character after the next one, and advance the cursor by two.
1935 */
1936 private int skip() {
1937 int i = cursor;
1938 int ch = temp[i+1];
1939 cursor = i + 2;
1940 return ch;
1941 }
1942
1943 /**
1944 * Unread one next character, and retreat cursor by one.
1945 */
1946 private void unread() {
1947 cursor--;
1948 }
1949
1950 /**
1951 * Internal method used for handling all syntax errors. The pattern is
1952 * displayed with a pointer to aid in locating the syntax error.
1953 */
1954 private PatternSyntaxException error(String s) {
1955 return new PatternSyntaxException(s, normalizedPattern, cursor - 1);
1956 }
1957
1958 /**
1959 * Determines if there is any supplementary character or unpaired
1960 * surrogate in the specified range.
1961 */
1962 private boolean findSupplementary(int start, int end) {
1963 for (int i = start; i < end; i++) {
1964 if (isSupplementary(temp[i]))
1965 return true;
1966 }
1967 return false;
1968 }
1969
1970 /**
1971 * Determines if the specified code point is a supplementary
1972 * character or unpaired surrogate.
1973 */
1974 private static final boolean isSupplementary(int ch) {
1975 return ch >= Character.MIN_SUPPLEMENTARY_CODE_POINT ||
1976 Character.isSurrogate((char)ch);
1977 }
1978
1979 /**
1980 * The following methods handle the main parsing. They are sorted
1981 * according to their precedence order, the lowest one first.
1982 */
1983
1984 /**
1985 * The expression is parsed with branch nodes added for alternations.
1986 * This may be called recursively to parse sub expressions that may
1987 * contain alternations.
1988 */
1989 private Node expr(Node end) {
1990 Node prev = null;
1991 Node firstTail = null;
1992 Branch branch = null;
1993 Node branchConn = null;
1994
1995 for (;;) {
1996 Node node = sequence(end);
1997 Node nodeTail = root; //double return
1998 if (prev == null) {
1999 prev = node;
2000 firstTail = nodeTail;
2001 } else {
2002 // Branch
2003 if (branchConn == null) {
2004 branchConn = new BranchConn();
2005 branchConn.next = end;
2006 }
2007 if (node == end) {
2008 // if the node returned from sequence() is "end"
2009 // we have an empty expr, set a null atom into
2010 // the branch to indicate to go "next" directly.
2011 node = null;
2012 } else {
2013 // the "tail.next" of each atom goes to branchConn
2014 nodeTail.next = branchConn;
2015 }
2016 if (prev == branch) {
2017 branch.add(node);
2018 } else {
2019 if (prev == end) {
2020 prev = null;
2021 } else {
2022 // replace the "end" with "branchConn" at its tail.next
2023 // when put the "prev" into the branch as the first atom.
2024 firstTail.next = branchConn;
2025 }
2026 prev = branch = new Branch(prev, node, branchConn);
2027 }
2028 }
2029 if (peek() != '|') {
2030 return prev;
2031 }
2032 next();
2033 }
2034 }
2035
2036 @SuppressWarnings("fallthrough")
2037 /**
2038 * Parsing of sequences between alternations.
2039 */
2040 private Node sequence(Node end) {
2041 Node head = null;
2042 Node tail = null;
2043 Node node = null;
2044 LOOP:
2045 for (;;) {
2046 int ch = peek();
2047 switch (ch) {
2048 case '(':
2049 // Because group handles its own closure,
2050 // we need to treat it differently
2051 node = group0();
2052 // Check for comment or flag group
2053 if (node == null)
2054 continue;
2055 if (head == null)
2056 head = node;
2057 else
2058 tail.next = node;
2059 // Double return: Tail was returned in root
2060 tail = root;
2061 continue;
2062 case '[':
2063 node = clazz(true);
2064 break;
2065 case '\\':
2066 ch = nextEscaped();
2067 if (ch == 'p' || ch == 'P') {
2068 boolean oneLetter = true;
2069 boolean comp = (ch == 'P');
2070 ch = next(); // Consume { if present
2071 if (ch != '{') {
2072 unread();
2073 } else {
2074 oneLetter = false;
2075 }
2076 node = family(oneLetter, comp);
2077 } else {
2078 unread();
2079 node = atom();
2080 }
2081 break;
2082 case '^':
2083 next();
2084 if (has(MULTILINE)) {
2085 if (has(UNIX_LINES))
2086 node = new UnixCaret();
2087 else
2088 node = new Caret();
2089 } else {
2090 node = new Begin();
2091 }
2092 break;
2093 case '$':
2094 next();
2095 if (has(UNIX_LINES))
2096 node = new UnixDollar(has(MULTILINE));
2097 else
2098 node = new Dollar(has(MULTILINE));
2099 break;
2100 case '.':
2101 next();
2102 if (has(DOTALL)) {
2103 node = new All();
2104 } else {
2105 if (has(UNIX_LINES))
2106 node = new UnixDot();
2107 else {
2108 node = new Dot();
2109 }
2110 }
2111 break;
2112 case '|':
2113 case ')':
2114 break LOOP;
2115 case ']': // Now interpreting dangling ] and } as literals
2116 case '}':
2117 node = atom();
2118 break;
2119 case '?':
2120 case '*':
2121 case '+':
2122 next();
2123 throw error("Dangling meta character '" + ((char)ch) + "'");
2124 case 0:
2125 if (cursor >= patternLength) {
2126 break LOOP;
2127 }
2128 // Fall through
2129 default:
2130 node = atom();
2131 break;
2132 }
2133
2134 node = closure(node);
2135
2136 if (head == null) {
2137 head = tail = node;
2138 } else {
2139 tail.next = node;
2140 tail = node;
2141 }
2142 }
2143 if (head == null) {
2144 return end;
2145 }
2146 tail.next = end;
2147 root = tail; //double return
2148 return head;
2149 }
2150
2151 @SuppressWarnings("fallthrough")
2152 /**
2153 * Parse and add a new Single or Slice.
2154 */
2155 private Node atom() {
2156 int first = 0;
2157 int prev = -1;
2158 boolean hasSupplementary = false;
2159 int ch = peek();
2160 for (;;) {
2161 switch (ch) {
2162 case '*':
2163 case '+':
2164 case '?':
2165 case '{':
2166 if (first > 1) {
2167 cursor = prev; // Unwind one character
2168 first--;
2169 }
2170 break;
2171 case '$':
2172 case '.':
2173 case '^':
2174 case '(':
2175 case '[':
2176 case '|':
2177 case ')':
2178 break;
2179 case '\\':
2180 ch = nextEscaped();
2181 if (ch == 'p' || ch == 'P') { // Property
2182 if (first > 0) { // Slice is waiting; handle it first
2183 unread();
2184 break;
2185 } else { // No slice; just return the family node
2186 boolean comp = (ch == 'P');
2187 boolean oneLetter = true;
2188 ch = next(); // Consume { if present
2189 if (ch != '{')
2190 unread();
2191 else
2192 oneLetter = false;
2193 return family(oneLetter, comp);
2194 }
2195 }
2196 unread();
2197 prev = cursor;
2198 ch = escape(false, first == 0, false);
2199 if (ch >= 0) {
2200 append(ch, first);
2201 first++;
2202 if (isSupplementary(ch)) {
2203 hasSupplementary = true;
2204 }
2205 ch = peek();
2206 continue;
2207 } else if (first == 0) {
2208 return root;
2209 }
2210 // Unwind meta escape sequence
2211 cursor = prev;
2212 break;
2213 case 0:
2214 if (cursor >= patternLength) {
2215 break;
2216 }
2217 // Fall through
2218 default:
2219 prev = cursor;
2220 append(ch, first);
2221 first++;
2222 if (isSupplementary(ch)) {
2223 hasSupplementary = true;
2224 }
2225 ch = next();
2226 continue;
2227 }
2228 break;
2229 }
2230 if (first == 1) {
2231 return newSingle(buffer[0]);
2232 } else {
2233 return newSlice(buffer, first, hasSupplementary);
2234 }
2235 }
2236
2237 private void append(int ch, int len) {
2238 if (len >= buffer.length) {
2239 int[] tmp = new int[len+len];
2240 System.arraycopy(buffer, 0, tmp, 0, len);
2241 buffer = tmp;
2242 }
2243 buffer[len] = ch;
2244 }
2245
2246 /**
2247 * Parses a backref greedily, taking as many numbers as it
2248 * can. The first digit is always treated as a backref, but
2249 * multi digit numbers are only treated as a backref if at
2250 * least that many backrefs exist at this point in the regex.
2251 */
2252 private Node ref(int refNum) {
2253 boolean done = false;
2254 while(!done) {
2255 int ch = peek();
2256 switch(ch) {
2257 case '0':
2258 case '1':
2259 case '2':
2260 case '3':
2261 case '4':
2262 case '5':
2263 case '6':
2264 case '7':
2265 case '8':
2266 case '9':
2267 int newRefNum = (refNum * 10) + (ch - '0');
2268 // Add another number if it doesn't make a group
2269 // that doesn't exist
2270 if (capturingGroupCount - 1 < newRefNum) {
2271 done = true;
2272 break;
2273 }
2274 refNum = newRefNum;
2275 read();
2276 break;
2277 default:
2278 done = true;
2279 break;
2280 }
2281 }
2282 if (has(CASE_INSENSITIVE))
2283 return new CIBackRef(refNum, has(UNICODE_CASE));
2284 else
2285 return new BackRef(refNum);
2286 }
2287
2288 /**
2289 * Parses an escape sequence to determine the actual value that needs
2290 * to be matched.
2291 * If -1 is returned and create was true a new object was added to the tree
2292 * to handle the escape sequence.
2293 * If the returned value is greater than zero, it is the value that
2294 * matches the escape sequence.
2295 */
2296 private int escape(boolean inclass, boolean create, boolean isrange) {
2297 int ch = skip();
2298 switch (ch) {
2299 case '0':
2300 return o();
2301 case '1':
2302 case '2':
2303 case '3':
2304 case '4':
2305 case '5':
2306 case '6':
2307 case '7':
2308 case '8':
2309 case '9':
2310 if (inclass) break;
2311 if (create) {
2312 root = ref((ch - '0'));
2313 }
2314 return -1;
2315 case 'A':
2316 if (inclass) break;
2317 if (create) root = new Begin();
2318 return -1;
2319 case 'B':
2320 if (inclass) break;
2321 if (create) root = new Bound(Bound.NONE, has(UNICODE_CHARACTER_CLASS));
2322 return -1;
2323 case 'C':
2324 break;
2325 case 'D':
2326 if (create) root = has(UNICODE_CHARACTER_CLASS)
2327 ? new Utype(UnicodeProp.DIGIT).complement()
2328 : new Ctype(ASCII.DIGIT).complement();
2329 return -1;
2330 case 'E':
2331 case 'F':
2332 break;
2333 case 'G':
2334 if (inclass) break;
2335 if (create) root = new LastMatch();
2336 return -1;
2337 case 'H':
2338 if (create) root = new HorizWS().complement();
2339 return -1;
2340 case 'I':
2341 case 'J':
2342 case 'K':
2343 case 'L':
2344 case 'M':
2345 case 'N':
2346 case 'O':
2347 case 'P':
2348 case 'Q':
2349 break;
2350 case 'R':
2351 if (inclass) break;
2352 if (create) root = new LineEnding();
2353 return -1;
2354 case 'S':
2355 if (create) root = has(UNICODE_CHARACTER_CLASS)
2356 ? new Utype(UnicodeProp.WHITE_SPACE).complement()
2357 : new Ctype(ASCII.SPACE).complement();
2358 return -1;
2359 case 'T':
2360 case 'U':
2361 break;
2362 case 'V':
2363 if (create) root = new VertWS().complement();
2364 return -1;
2365 case 'W':
2366 if (create) root = has(UNICODE_CHARACTER_CLASS)
2367 ? new Utype(UnicodeProp.WORD).complement()
2368 : new Ctype(ASCII.WORD).complement();
2369 return -1;
2370 case 'X':
2371 case 'Y':
2372 break;
2373 case 'Z':
2374 if (inclass) break;
2375 if (create) {
2376 if (has(UNIX_LINES))
2377 root = new UnixDollar(false);
2378 else
2379 root = new Dollar(false);
2380 }
2381 return -1;
2382 case 'a':
2383 return '\007';
2384 case 'b':
2385 if (inclass) break;
2386 if (create) root = new Bound(Bound.BOTH, has(UNICODE_CHARACTER_CLASS));
2387 return -1;
2388 case 'c':
2389 return c();
2390 case 'd':
2391 if (create) root = has(UNICODE_CHARACTER_CLASS)
2392 ? new Utype(UnicodeProp.DIGIT)
2393 : new Ctype(ASCII.DIGIT);
2394 return -1;
2395 case 'e':
2396 return '\033';
2397 case 'f':
2398 return '\f';
2399 case 'g':
2400 break;
2401 case 'h':
2402 if (create) root = new HorizWS();
2403 return -1;
2404 case 'i':
2405 case 'j':
2406 break;
2407 case 'k':
2408 if (inclass)
2409 break;
2410 if (read() != '<')
2411 throw error("\\k is not followed by '<' for named capturing group");
2412 String name = groupname(read());
2413 if (!namedGroups().containsKey(name))
2414 throw error("(named capturing group <"+ name+"> does not exit");
2415 if (create) {
2416 if (has(CASE_INSENSITIVE))
2417 root = new CIBackRef(namedGroups().get(name), has(UNICODE_CASE));
2418 else
2419 root = new BackRef(namedGroups().get(name));
2420 }
2421 return -1;
2422 case 'l':
2423 case 'm':
2424 break;
2425 case 'n':
2426 return '\n';
2427 case 'o':
2428 case 'p':
2429 case 'q':
2430 break;
2431 case 'r':
2432 return '\r';
2433 case 's':
2434 if (create) root = has(UNICODE_CHARACTER_CLASS)
2435 ? new Utype(UnicodeProp.WHITE_SPACE)
2436 : new Ctype(ASCII.SPACE);
2437 return -1;
2438 case 't':
2439 return '\t';
2440 case 'u':
2441 return u();
2442 case 'v':
2443 // '\v' was implemented as VT/0x0B in releases < 1.8 (though
2444 // undocumented). In JDK8 '\v' is specified as a predefined
2445 // character class for all vertical whitespace characters.
2446 // So [-1, root=VertWS node] pair is returned (instead of a
2447 // single 0x0B). This breaks the range if '\v' is used as
2448 // the start or end value, such as [\v-...] or [...-\v], in
2449 // which a single definite value (0x0B) is expected. For
2450 // compatibility concern '\013'/0x0B is returned if isrange.
2451 if (isrange)
2452 return '\013';
2453 if (create) root = new VertWS();
2454 return -1;
2455 case 'w':
2456 if (create) root = has(UNICODE_CHARACTER_CLASS)
2457 ? new Utype(UnicodeProp.WORD)
2458 : new Ctype(ASCII.WORD);
2459 return -1;
2460 case 'x':
2461 return x();
2462 case 'y':
2463 break;
2464 case 'z':
2465 if (inclass) break;
2466 if (create) root = new End();
2467 return -1;
2468 default:
2469 return ch;
2470 }
2471 throw error("Illegal/unsupported escape sequence");
2472 }
2473
2474 /**
2475 * Parse a character class, and return the node that matches it.
2476 *
2477 * Consumes a ] on the way out if consume is true. Usually consume
2478 * is true except for the case of [abc&&def] where def is a separate
2479 * right hand node with "understood" brackets.
2480 */
2481 private CharProperty clazz(boolean consume) {
2482 CharProperty prev = null;
2483 CharProperty node = null;
2484 BitClass bits = new BitClass();
2485 boolean include = true;
2486 boolean firstInClass = true;
2487 int ch = next();
2488 for (;;) {
2489 switch (ch) {
2490 case '^':
2491 // Negates if first char in a class, otherwise literal
2492 if (firstInClass) {
2493 if (temp[cursor-1] != '[')
2494 break;
2495 ch = next();
2496 include = !include;
2497 continue;
2498 } else {
2499 // ^ not first in class, treat as literal
2500 break;
2501 }
2502 case '[':
2503 firstInClass = false;
2504 node = clazz(true);
2505 if (prev == null)
2506 prev = node;
2507 else
2508 prev = union(prev, node);
2509 ch = peek();
2510 continue;
2511 case '&':
2512 firstInClass = false;
2513 ch = next();
2514 if (ch == '&') {
2515 ch = next();
2516 CharProperty rightNode = null;
2517 while (ch != ']' && ch != '&') {
2518 if (ch == '[') {
2519 if (rightNode == null)
2520 rightNode = clazz(true);
2521 else
2522 rightNode = union(rightNode, clazz(true));
2523 } else { // abc&&def
2524 unread();
2525 rightNode = clazz(false);
2526 }
2527 ch = peek();
2528 }
2529 if (rightNode != null)
2530 node = rightNode;
2531 if (prev == null) {
2532 if (rightNode == null)
2533 throw error("Bad class syntax");
2534 else
2535 prev = rightNode;
2536 } else {
2537 prev = intersection(prev, node);
2538 }
2539 } else {
2540 // treat as a literal &
2541 unread();
2542 break;
2543 }
2544 continue;
2545 case 0:
2546 firstInClass = false;
2547 if (cursor >= patternLength)
2548 throw error("Unclosed character class");
2549 break;
2550 case ']':
2551 firstInClass = false;
2552 if (prev != null) {
2553 if (consume)
2554 next();
2555 return prev;
2556 }
2557 break;
2558 default:
2559 firstInClass = false;
2560 break;
2561 }
2562 node = range(bits);
2563 if (include) {
2564 if (prev == null) {
2565 prev = node;
2566 } else {
2567 if (prev != node)
2568 prev = union(prev, node);
2569 }
2570 } else {
2571 if (prev == null) {
2572 prev = node.complement();
2573 } else {
2574 if (prev != node)
2575 prev = setDifference(prev, node);
2576 }
2577 }
2578 ch = peek();
2579 }
2580 }
2581
2582 private CharProperty bitsOrSingle(BitClass bits, int ch) {
2583 /* Bits can only handle codepoints in [u+0000-u+00ff] range.
2584 Use "single" node instead of bits when dealing with unicode
2585 case folding for codepoints listed below.
2586 (1)Uppercase out of range: u+00ff, u+00b5
2587 toUpperCase(u+00ff) -> u+0178
2588 toUpperCase(u+00b5) -> u+039c
2589 (2)LatinSmallLetterLongS u+17f
2590 toUpperCase(u+017f) -> u+0053
2591 (3)LatinSmallLetterDotlessI u+131
2592 toUpperCase(u+0131) -> u+0049
2593 (4)LatinCapitalLetterIWithDotAbove u+0130
2594 toLowerCase(u+0130) -> u+0069
2595 (5)KelvinSign u+212a
2596 toLowerCase(u+212a) ==> u+006B
2597 (6)AngstromSign u+212b
2598 toLowerCase(u+212b) ==> u+00e5
2599 */
2600 int d;
2601 if (ch < 256 &&
2602 !(has(CASE_INSENSITIVE) && has(UNICODE_CASE) &&
2603 (ch == 0xff || ch == 0xb5 ||
2604 ch == 0x49 || ch == 0x69 || //I and i
2605 ch == 0x53 || ch == 0x73 || //S and s
2606 ch == 0x4b || ch == 0x6b || //K and k
2607 ch == 0xc5 || ch == 0xe5))) //A+ring
2608 return bits.add(ch, flags());
2609 return newSingle(ch);
2610 }
2611
2612 /**
2613 * Parse a single character or a character range in a character class
2614 * and return its representative node.
2615 */
2616 private CharProperty range(BitClass bits) {
2617 int ch = peek();
2618 if (ch == '\\') {
2619 ch = nextEscaped();
2620 if (ch == 'p' || ch == 'P') { // A property
2621 boolean comp = (ch == 'P');
2622 boolean oneLetter = true;
2623 // Consume { if present
2624 ch = next();
2625 if (ch != '{')
2626 unread();
2627 else
2628 oneLetter = false;
2629 return family(oneLetter, comp);
2630 } else { // ordinary escape
2631 boolean isrange = temp[cursor+1] == '-';
2632 unread();
2633 ch = escape(true, true, isrange);
2634 if (ch == -1)
2635 return (CharProperty) root;
2636 }
2637 } else {
2638 next();
2639 }
2640 if (ch >= 0) {
2641 if (peek() == '-') {
2642 int endRange = temp[cursor+1];
2643 if (endRange == '[') {
2644 return bitsOrSingle(bits, ch);
2645 }
2646 if (endRange != ']') {
2647 next();
2648 int m = peek();
2649 if (m == '\\') {
2650 m = escape(true, false, true);
2651 } else {
2652 next();
2653 }
2654 if (m < ch) {
2655 throw error("Illegal character range");
2656 }
2657 if (has(CASE_INSENSITIVE))
2658 return caseInsensitiveRangeFor(ch, m);
2659 else
2660 return rangeFor(ch, m);
2661 }
2662 }
2663 return bitsOrSingle(bits, ch);
2664 }
2665 throw error("Unexpected character '"+((char)ch)+"'");
2666 }
2667
2668 /**
2669 * Parses a Unicode character family and returns its representative node.
2670 */
2671 private CharProperty family(boolean singleLetter,
2672 boolean maybeComplement)
2673 {
2674 next();
2675 String name;
2676 CharProperty node = null;
2677
2678 if (singleLetter) {
2679 int c = temp[cursor];
2680 if (!Character.isSupplementaryCodePoint(c)) {
2681 name = String.valueOf((char)c);
2682 } else {
2683 name = new String(temp, cursor, 1);
2684 }
2685 read();
2686 } else {
2687 int i = cursor;
2688 mark('}');
2689 while(read() != '}') {
2690 }
2691 mark('\000');
2692 int j = cursor;
2693 if (j > patternLength)
2694 throw error("Unclosed character family");
2695 if (i + 1 >= j)
2696 throw error("Empty character family");
2697 name = new String(temp, i, j-i-1);
2698 }
2699
2700 int i = name.indexOf('=');
2701 if (i != -1) {
2702 // property construct \p{name=value}
2703 String value = name.substring(i + 1);
2704 name = name.substring(0, i).toLowerCase(Locale.ENGLISH);
2705 if ("sc".equals(name) || "script".equals(name)) {
2706 node = unicodeScriptPropertyFor(value);
2707 } else if ("blk".equals(name) || "block".equals(name)) {
2708 node = unicodeBlockPropertyFor(value);
2709 } else if ("gc".equals(name) || "general_category".equals(name)) {
2710 node = charPropertyNodeFor(value);
2711 } else {
2712 throw error("Unknown Unicode property {name=<" + name + ">, "
2713 + "value=<" + value + ">}");
2714 }
2715 } else {
2716 if (name.startsWith("In")) {
2717 // \p{inBlockName}
2718 node = unicodeBlockPropertyFor(name.substring(2));
2719 } else if (name.startsWith("Is")) {
2720 // \p{isGeneralCategory} and \p{isScriptName}
2721 name = name.substring(2);
2722 UnicodeProp uprop = UnicodeProp.forName(name);
2723 if (uprop != null)
2724 node = new Utype(uprop);
2725 if (node == null)
2726 node = CharPropertyNames.charPropertyFor(name);
2727 if (node == null)
2728 node = unicodeScriptPropertyFor(name);
2729 } else {
2730 if (has(UNICODE_CHARACTER_CLASS)) {
2731 UnicodeProp uprop = UnicodeProp.forPOSIXName(name);
2732 if (uprop != null)
2733 node = new Utype(uprop);
2734 }
2735 if (node == null)
2736 node = charPropertyNodeFor(name);
2737 }
2738 }
2739 if (maybeComplement) {
2740 if (node instanceof Category || node instanceof Block)
2741 hasSupplementary = true;
2742 node = node.complement();
2743 }
2744 return node;
2745 }
2746
2747
2748 /**
2749 * Returns a CharProperty matching all characters belong to
2750 * a UnicodeScript.
2751 */
2752 private CharProperty unicodeScriptPropertyFor(String name) {
2753 final Character.UnicodeScript script;
2754 try {
2755 script = Character.UnicodeScript.forName(name);
2756 } catch (IllegalArgumentException iae) {
2757 throw error("Unknown character script name {" + name + "}");
2758 }
2759 return new Script(script);
2760 }
2761
2762 /**
2763 * Returns a CharProperty matching all characters in a UnicodeBlock.
2764 */
2765 private CharProperty unicodeBlockPropertyFor(String name) {
2766 final Character.UnicodeBlock block;
2767 try {
2768 block = Character.UnicodeBlock.forName(name);
2769 } catch (IllegalArgumentException iae) {
2770 throw error("Unknown character block name {" + name + "}");
2771 }
2772 return new Block(block);
2773 }
2774
2775 /**
2776 * Returns a CharProperty matching all characters in a named property.
2777 */
2778 private CharProperty charPropertyNodeFor(String name) {
2779 CharProperty p = CharPropertyNames.charPropertyFor(name);
2780 if (p == null)
2781 throw error("Unknown character property name {" + name + "}");
2782 return p;
2783 }
2784
2785 /**
2786 * Parses and returns the name of a "named capturing group", the trailing
2787 * ">" is consumed after parsing.
2788 */
2789 private String groupname(int ch) {
2790 StringBuilder sb = new StringBuilder();
2791 sb.append(Character.toChars(ch));
2792 while (ASCII.isLower(ch=read()) || ASCII.isUpper(ch) ||
2793 ASCII.isDigit(ch)) {
2794 sb.append(Character.toChars(ch));
2795 }
2796 if (sb.length() == 0)
2797 throw error("named capturing group has 0 length name");
2798 if (ch != '>')
2799 throw error("named capturing group is missing trailing '>'");
2800 return sb.toString();
2801 }
2802
2803 /**
2804 * Parses a group and returns the head node of a set of nodes that process
2805 * the group. Sometimes a double return system is used where the tail is
2806 * returned in root.
2807 */
2808 private Node group0() {
2809 boolean capturingGroup = false;
2810 Node head = null;
2811 Node tail = null;
2812 int save = flags;
2813 root = null;
2814 int ch = next();
2815 if (ch == '?') {
2816 ch = skip();
2817 switch (ch) {
2818 case ':': // (?:xxx) pure group
2819 head = createGroup(true);
2820 tail = root;
2821 head.next = expr(tail);
2822 break;
2823 case '=': // (?=xxx) and (?!xxx) lookahead
2824 case '!':
2825 head = createGroup(true);
2826 tail = root;
2827 head.next = expr(tail);
2828 if (ch == '=') {
2829 head = tail = new Pos(head);
2830 } else {
2831 head = tail = new Neg(head);
2832 }
2833 break;
2834 case '>': // (?>xxx) independent group
2835 head = createGroup(true);
2836 tail = root;
2837 head.next = expr(tail);
2838 head = tail = new Ques(head, INDEPENDENT);
2839 break;
2840 case '<': // (?<xxx) look behind
2841 ch = read();
2842 if (ASCII.isLower(ch) || ASCII.isUpper(ch)) {
2843 // named captured group
2844 String name = groupname(ch);
2845 if (namedGroups().containsKey(name))
2846 throw error("Named capturing group <" + name
2847 + "> is already defined");
2848 capturingGroup = true;
2849 head = createGroup(false);
2850 tail = root;
2851 namedGroups().put(name, capturingGroupCount-1);
2852 head.next = expr(tail);
2853 break;
2854 }
2855 int start = cursor;
2856 head = createGroup(true);
2857 tail = root;
2858 head.next = expr(tail);
2859 tail.next = lookbehindEnd;
2860 TreeInfo info = new TreeInfo();
2861 head.study(info);
2862 if (info.maxValid == false) {
2863 throw error("Look-behind group does not have "
2864 + "an obvious maximum length");
2865 }
2866 boolean hasSupplementary = findSupplementary(start, patternLength);
2867 if (ch == '=') {
2868 head = tail = (hasSupplementary ?
2869 new BehindS(head, info.maxLength,
2870 info.minLength) :
2871 new Behind(head, info.maxLength,
2872 info.minLength));
2873 } else if (ch == '!') {
2874 head = tail = (hasSupplementary ?
2875 new NotBehindS(head, info.maxLength,
2876 info.minLength) :
2877 new NotBehind(head, info.maxLength,
2878 info.minLength));
2879 } else {
2880 throw error("Unknown look-behind group");
2881 }
2882 break;
2883 case '$':
2884 case '@':
2885 throw error("Unknown group type");
2886 default: // (?xxx:) inlined match flags
2887 unread();
2888 addFlag();
2889 ch = read();
2890 if (ch == ')') {
2891 return null; // Inline modifier only
2892 }
2893 if (ch != ':') {
2894 throw error("Unknown inline modifier");
2895 }
2896 head = createGroup(true);
2897 tail = root;
2898 head.next = expr(tail);
2899 break;
2900 }
2901 } else { // (xxx) a regular group
2902 capturingGroup = true;
2903 head = createGroup(false);
2904 tail = root;
2905 head.next = expr(tail);
2906 }
2907
2908 accept(')', "Unclosed group");
2909 flags = save;
2910
2911 // Check for quantifiers
2912 Node node = closure(head);
2913 if (node == head) { // No closure
2914 root = tail;
2915 return node; // Dual return
2916 }
2917 if (head == tail) { // Zero length assertion
2918 root = node;
2919 return node; // Dual return
2920 }
2921
2922 if (node instanceof Ques) {
2923 Ques ques = (Ques) node;
2924 if (ques.type == POSSESSIVE) {
2925 root = node;
2926 return node;
2927 }
2928 tail.next = new BranchConn();
2929 tail = tail.next;
2930 if (ques.type == GREEDY) {
2931 head = new Branch(head, null, tail);
2932 } else { // Reluctant quantifier
2933 head = new Branch(null, head, tail);
2934 }
2935 root = tail;
2936 return head;
2937 } else if (node instanceof Curly) {
2938 Curly curly = (Curly) node;
2939 if (curly.type == POSSESSIVE) {
2940 root = node;
2941 return node;
2942 }
2943 // Discover if the group is deterministic
2944 TreeInfo info = new TreeInfo();
2945 if (head.study(info)) { // Deterministic
2946 GroupTail temp = (GroupTail) tail;
2947 head = root = new GroupCurly(head.next, curly.cmin,
2948 curly.cmax, curly.type,
2949 ((GroupTail)tail).localIndex,
2950 ((GroupTail)tail).groupIndex,
2951 capturingGroup);
2952 return head;
2953 } else { // Non-deterministic
2954 int temp = ((GroupHead) head).localIndex;
2955 Loop loop;
2956 if (curly.type == GREEDY)
2957 loop = new Loop(this.localCount, temp);
2958 else // Reluctant Curly
2959 loop = new LazyLoop(this.localCount, temp);
2960 Prolog prolog = new Prolog(loop);
2961 this.localCount += 1;
2962 loop.cmin = curly.cmin;
2963 loop.cmax = curly.cmax;
2964 loop.body = head;
2965 tail.next = loop;
2966 root = loop;
2967 return prolog; // Dual return
2968 }
2969 }
2970 throw error("Internal logic error");
2971 }
2972
2973 /**
2974 * Create group head and tail nodes using double return. If the group is
2975 * created with anonymous true then it is a pure group and should not
2976 * affect group counting.
2977 */
2978 private Node createGroup(boolean anonymous) {
2979 int localIndex = localCount++;
2980 int groupIndex = 0;
2981 if (!anonymous)
2982 groupIndex = capturingGroupCount++;
2983 GroupHead head = new GroupHead(localIndex);
2984 root = new GroupTail(localIndex, groupIndex);
2985 if (!anonymous && groupIndex < 10)
2986 groupNodes[groupIndex] = head;
2987 return head;
2988 }
2989
2990 @SuppressWarnings("fallthrough")
2991 /**
2992 * Parses inlined match flags and set them appropriately.
2993 */
2994 private void addFlag() {
2995 int ch = peek();
2996 for (;;) {
2997 switch (ch) {
2998 case 'i':
2999 flags |= CASE_INSENSITIVE;
3000 break;
3001 case 'm':
3002 flags |= MULTILINE;
3003 break;
3004 case 's':
3005 flags |= DOTALL;
3006 break;
3007 case 'd':
3008 flags |= UNIX_LINES;
3009 break;
3010 case 'u':
3011 flags |= UNICODE_CASE;
3012 break;
3013 case 'c':
3014 flags |= CANON_EQ;
3015 break;
3016 case 'x':
3017 flags |= COMMENTS;
3018 break;
3019 case 'U':
3020 flags |= (UNICODE_CHARACTER_CLASS | UNICODE_CASE);
3021 break;
3022 case '-': // subFlag then fall through
3023 ch = next();
3024 subFlag();
3025 default:
3026 return;
3027 }
3028 ch = next();
3029 }
3030 }
3031
3032 @SuppressWarnings("fallthrough")
3033 /**
3034 * Parses the second part of inlined match flags and turns off
3035 * flags appropriately.
3036 */
3037 private void subFlag() {
3038 int ch = peek();
3039 for (;;) {
3040 switch (ch) {
3041 case 'i':
3042 flags &= ~CASE_INSENSITIVE;
3043 break;
3044 case 'm':
3045 flags &= ~MULTILINE;
3046 break;
3047 case 's':
3048 flags &= ~DOTALL;
3049 break;
3050 case 'd':
3051 flags &= ~UNIX_LINES;
3052 break;
3053 case 'u':
3054 flags &= ~UNICODE_CASE;
3055 break;
3056 case 'c':
3057 flags &= ~CANON_EQ;
3058 break;
3059 case 'x':
3060 flags &= ~COMMENTS;
3061 break;
3062 case 'U':
3063 flags &= ~(UNICODE_CHARACTER_CLASS | UNICODE_CASE);
3064 default:
3065 return;
3066 }
3067 ch = next();
3068 }
3069 }
3070
3071 static final int MAX_REPS = 0x7FFFFFFF;
3072
3073 static final int GREEDY = 0;
3074
3075 static final int LAZY = 1;
3076
3077 static final int POSSESSIVE = 2;
3078
3079 static final int INDEPENDENT = 3;
3080
3081 /**
3082 * Processes repetition. If the next character peeked is a quantifier
3083 * then new nodes must be appended to handle the repetition.
3084 * Prev could be a single or a group, so it could be a chain of nodes.
3085 */
3086 private Node closure(Node prev) {
3087 Node atom;
3088 int ch = peek();
3089 switch (ch) {
3090 case '?':
3091 ch = next();
3092 if (ch == '?') {
3093 next();
3094 return new Ques(prev, LAZY);
3095 } else if (ch == '+') {
3096 next();
3097 return new Ques(prev, POSSESSIVE);
3098 }
3099 return new Ques(prev, GREEDY);
3100 case '*':
3101 ch = next();
3102 if (ch == '?') {
3103 next();
3104 return new Curly(prev, 0, MAX_REPS, LAZY);
3105 } else if (ch == '+') {
3106 next();
3107 return new Curly(prev, 0, MAX_REPS, POSSESSIVE);
3108 }
3109 return new Curly(prev, 0, MAX_REPS, GREEDY);
3110 case '+':
3111 ch = next();
3112 if (ch == '?') {
3113 next();
3114 return new Curly(prev, 1, MAX_REPS, LAZY);
3115 } else if (ch == '+') {
3116 next();
3117 return new Curly(prev, 1, MAX_REPS, POSSESSIVE);
3118 }
3119 return new Curly(prev, 1, MAX_REPS, GREEDY);
3120 case '{':
3121 ch = temp[cursor+1];
3122 if (ASCII.isDigit(ch)) {
3123 skip();
3124 int cmin = 0;
3125 do {
3126 cmin = cmin * 10 + (ch - '0');
3127 } while (ASCII.isDigit(ch = read()));
3128 int cmax = cmin;
3129 if (ch == ',') {
3130 ch = read();
3131 cmax = MAX_REPS;
3132 if (ch != '}') {
3133 cmax = 0;
3134 while (ASCII.isDigit(ch)) {
3135 cmax = cmax * 10 + (ch - '0');
3136 ch = read();
3137 }
3138 }
3139 }
3140 if (ch != '}')
3141 throw error("Unclosed counted closure");
3142 if (((cmin) | (cmax) | (cmax - cmin)) < 0)
3143 throw error("Illegal repetition range");
3144 Curly curly;
3145 ch = peek();
3146 if (ch == '?') {
3147 next();
3148 curly = new Curly(prev, cmin, cmax, LAZY);
3149 } else if (ch == '+') {
3150 next();
3151 curly = new Curly(prev, cmin, cmax, POSSESSIVE);
3152 } else {
3153 curly = new Curly(prev, cmin, cmax, GREEDY);
3154 }
3155 return curly;
3156 } else {
3157 throw error("Illegal repetition");
3158 }
3159 default:
3160 return prev;
3161 }
3162 }
3163
3164 /**
3165 * Utility method for parsing control escape sequences.
3166 */
3167 private int c() {
3168 if (cursor < patternLength) {
3169 return read() ^ 64;
3170 }
3171 throw error("Illegal control escape sequence");
3172 }
3173
3174 /**
3175 * Utility method for parsing octal escape sequences.
3176 */
3177 private int o() {
3178 int n = read();
3179 if (((n-'0')|('7'-n)) >= 0) {
3180 int m = read();
3181 if (((m-'0')|('7'-m)) >= 0) {
3182 int o = read();
3183 if ((((o-'0')|('7'-o)) >= 0) && (((n-'0')|('3'-n)) >= 0)) {
3184 return (n - '0') * 64 + (m - '0') * 8 + (o - '0');
3185 }
3186 unread();
3187 return (n - '0') * 8 + (m - '0');
3188 }
3189 unread();
3190 return (n - '0');
3191 }
3192 throw error("Illegal octal escape sequence");
3193 }
3194
3195 /**
3196 * Utility method for parsing hexadecimal escape sequences.
3197 */
3198 private int x() {
3199 int n = read();
3200 if (ASCII.isHexDigit(n)) {
3201 int m = read();
3202 if (ASCII.isHexDigit(m)) {
3203 return ASCII.toDigit(n) * 16 + ASCII.toDigit(m);
3204 }
3205 } else if (n == '{' && ASCII.isHexDigit(peek())) {
3206 int ch = 0;
3207 while (ASCII.isHexDigit(n = read())) {
3208 ch = (ch << 4) + ASCII.toDigit(n);
3209 if (ch > Character.MAX_CODE_POINT)
3210 throw error("Hexadecimal codepoint is too big");
3211 }
3212 if (n != '}')
3213 throw error("Unclosed hexadecimal escape sequence");
3214 return ch;
3215 }
3216 throw error("Illegal hexadecimal escape sequence");
3217 }
3218
3219 /**
3220 * Utility method for parsing unicode escape sequences.
3221 */
3222 private int cursor() {
3223 return cursor;
3224 }
3225
3226 private void setcursor(int pos) {
3227 cursor = pos;
3228 }
3229
3230 private int uxxxx() {
3231 int n = 0;
3232 for (int i = 0; i < 4; i++) {
3233 int ch = read();
3234 if (!ASCII.isHexDigit(ch)) {
3235 throw error("Illegal Unicode escape sequence");
3236 }
3237 n = n * 16 + ASCII.toDigit(ch);
3238 }
3239 return n;
3240 }
3241
3242 private int u() {
3243 int n = uxxxx();
3244 if (Character.isHighSurrogate((char)n)) {
3245 int cur = cursor();
3246 if (read() == '\\' && read() == 'u') {
3247 int n2 = uxxxx();
3248 if (Character.isLowSurrogate((char)n2))
3249 return Character.toCodePoint((char)n, (char)n2);
3250 }
3251 setcursor(cur);
3252 }
3253 return n;
3254 }
3255
3256 //
3257 // Utility methods for code point support
3258 //
3259
3260 private static final int countChars(CharSequence seq, int index,
3261 int lengthInCodePoints) {
3262 // optimization
3263 if (lengthInCodePoints == 1 && !Character.isHighSurrogate(seq.charAt(index))) {
3264 assert (index >= 0 && index < seq.length());
3265 return 1;
3266 }
3267 int length = seq.length();
3268 int x = index;
3269 if (lengthInCodePoints >= 0) {
3270 assert (index >= 0 && index < length);
3271 for (int i = 0; x < length && i < lengthInCodePoints; i++) {
3272 if (Character.isHighSurrogate(seq.charAt(x++))) {
3273 if (x < length && Character.isLowSurrogate(seq.charAt(x))) {
3274 x++;
3275 }
3276 }
3277 }
3278 return x - index;
3279 }
3280
3281 assert (index >= 0 && index <= length);
3282 if (index == 0) {
3283 return 0;
3284 }
3285 int len = -lengthInCodePoints;
3286 for (int i = 0; x > 0 && i < len; i++) {
3287 if (Character.isLowSurrogate(seq.charAt(--x))) {
3288 if (x > 0 && Character.isHighSurrogate(seq.charAt(x-1))) {
3289 x--;
3290 }
3291 }
3292 }
3293 return index - x;
3294 }
3295
3296 private static final int countCodePoints(CharSequence seq) {
3297 int length = seq.length();
3298 int n = 0;
3299 for (int i = 0; i < length; ) {
3300 n++;
3301 if (Character.isHighSurrogate(seq.charAt(i++))) {
3302 if (i < length && Character.isLowSurrogate(seq.charAt(i))) {
3303 i++;
3304 }
3305 }
3306 }
3307 return n;
3308 }
3309
3310 /**
3311 * Creates a bit vector for matching Latin-1 values. A normal BitClass
3312 * never matches values above Latin-1, and a complemented BitClass always
3313 * matches values above Latin-1.
3314 */
3315 private static final class BitClass extends BmpCharProperty {
3316 final boolean[] bits;
3317 BitClass() { bits = new boolean[256]; }
3318 private BitClass(boolean[] bits) { this.bits = bits; }
3319 BitClass add(int c, int flags) {
3320 assert c >= 0 && c <= 255;
3321 if ((flags & CASE_INSENSITIVE) != 0) {
3322 if (ASCII.isAscii(c)) {
3323 bits[ASCII.toUpper(c)] = true;
3324 bits[ASCII.toLower(c)] = true;
3325 } else if ((flags & UNICODE_CASE) != 0) {
3326 bits[Character.toLowerCase(c)] = true;
3327 bits[Character.toUpperCase(c)] = true;
3328 }
3329 }
3330 bits[c] = true;
3331 return this;
3332 }
3333 boolean isSatisfiedBy(int ch) {
3334 return ch < 256 && bits[ch];
3335 }
3336 }
3337
3338 /**
3339 * Returns a suitably optimized, single character matcher.
3340 */
3341 private CharProperty newSingle(final int ch) {
3342 if (has(CASE_INSENSITIVE)) {
3343 int lower, upper;
3344 if (has(UNICODE_CASE)) {
3345 upper = Character.toUpperCase(ch);
3346 lower = Character.toLowerCase(upper);
3347 if (upper != lower)
3348 return new SingleU(lower);
3349 } else if (ASCII.isAscii(ch)) {
3350 lower = ASCII.toLower(ch);
3351 upper = ASCII.toUpper(ch);
3352 if (lower != upper)
3353 return new SingleI(lower, upper);
3354 }
3355 }
3356 if (isSupplementary(ch))
3357 return new SingleS(ch); // Match a given Unicode character
3358 return new Single(ch); // Match a given BMP character
3359 }
3360
3361 /**
3362 * Utility method for creating a string slice matcher.
3363 */
3364 private Node newSlice(int[] buf, int count, boolean hasSupplementary) {
3365 int[] tmp = new int[count];
3366 if (has(CASE_INSENSITIVE)) {
3367 if (has(UNICODE_CASE)) {
3368 for (int i = 0; i < count; i++) {
3369 tmp[i] = Character.toLowerCase(
3370 Character.toUpperCase(buf[i]));
3371 }
3372 return hasSupplementary? new SliceUS(tmp) : new SliceU(tmp);
3373 }
3374 for (int i = 0; i < count; i++) {
3375 tmp[i] = ASCII.toLower(buf[i]);
3376 }
3377 return hasSupplementary? new SliceIS(tmp) : new SliceI(tmp);
3378 }
3379 for (int i = 0; i < count; i++) {
3380 tmp[i] = buf[i];
3381 }
3382 return hasSupplementary ? new SliceS(tmp) : new Slice(tmp);
3383 }
3384
3385 /**
3386 * The following classes are the building components of the object
3387 * tree that represents a compiled regular expression. The object tree
3388 * is made of individual elements that handle constructs in the Pattern.
3389 * Each type of object knows how to match its equivalent construct with
3390 * the match() method.
3391 */
3392
3393 /**
3394 * Base class for all node classes. Subclasses should override the match()
3395 * method as appropriate. This class is an accepting node, so its match()
3396 * always returns true.
3397 */
3398 static class Node extends Object {
3399 Node next;
3400 Node() {
3401 next = Pattern.accept;
3402 }
3403 /**
3404 * This method implements the classic accept node.
3405 */
3406 boolean match(Matcher matcher, int i, CharSequence seq) {
3407 matcher.last = i;
3408 matcher.groups[0] = matcher.first;
3409 matcher.groups[1] = matcher.last;
3410 return true;
3411 }
3412 /**
3413 * This method is good for all zero length assertions.
3414 */
3415 boolean study(TreeInfo info) {
3416 if (next != null) {
3417 return next.study(info);
3418 } else {
3419 return info.deterministic;
3420 }
3421 }
3422 }
3423
3424 static class LastNode extends Node {
3425 /**
3426 * This method implements the classic accept node with
3427 * the addition of a check to see if the match occurred
3428 * using all of the input.
3429 */
3430 boolean match(Matcher matcher, int i, CharSequence seq) {
3431 if (matcher.acceptMode == Matcher.ENDANCHOR && i != matcher.to)
3432 return false;
3433 matcher.last = i;
3434 matcher.groups[0] = matcher.first;
3435 matcher.groups[1] = matcher.last;
3436 return true;
3437 }
3438 }
3439
3440 /**
3441 * Used for REs that can start anywhere within the input string.
3442 * This basically tries to match repeatedly at each spot in the
3443 * input string, moving forward after each try. An anchored search
3444 * or a BnM will bypass this node completely.
3445 */
3446 static class Start extends Node {
3447 int minLength;
3448 Start(Node node) {
3449 this.next = node;
3450 TreeInfo info = new TreeInfo();
3451 next.study(info);
3452 minLength = info.minLength;
3453 }
3454 boolean match(Matcher matcher, int i, CharSequence seq) {
3455 if (i > matcher.to - minLength) {
3456 matcher.hitEnd = true;
3457 return false;
3458 }
3459 int guard = matcher.to - minLength;
3460 for (; i <= guard; i++) {
3461 if (next.match(matcher, i, seq)) {
3462 matcher.first = i;
3463 matcher.groups[0] = matcher.first;
3464 matcher.groups[1] = matcher.last;
3465 return true;
3466 }
3467 }
3468 matcher.hitEnd = true;
3469 return false;
3470 }
3471 boolean study(TreeInfo info) {
3472 next.study(info);
3473 info.maxValid = false;
3474 info.deterministic = false;
3475 return false;
3476 }
3477 }
3478
3479 /*
3480 * StartS supports supplementary characters, including unpaired surrogates.
3481 */
3482 static final class StartS extends Start {
3483 StartS(Node node) {
3484 super(node);
3485 }
3486 boolean match(Matcher matcher, int i, CharSequence seq) {
3487 if (i > matcher.to - minLength) {
3488 matcher.hitEnd = true;
3489 return false;
3490 }
3491 int guard = matcher.to - minLength;
3492 while (i <= guard) {
3493 //if ((ret = next.match(matcher, i, seq)) || i == guard)
3494 if (next.match(matcher, i, seq)) {
3495 matcher.first = i;
3496 matcher.groups[0] = matcher.first;
3497 matcher.groups[1] = matcher.last;
3498 return true;
3499 }
3500 if (i == guard)
3501 break;
3502 // Optimization to move to the next character. This is
3503 // faster than countChars(seq, i, 1).
3504 if (Character.isHighSurrogate(seq.charAt(i++))) {
3505 if (i < seq.length() &&
3506 Character.isLowSurrogate(seq.charAt(i))) {
3507 i++;
3508 }
3509 }
3510 }
3511 matcher.hitEnd = true;
3512 return false;
3513 }
3514 }
3515
3516 /**
3517 * Node to anchor at the beginning of input. This object implements the
3518 * match for a \A sequence, and the caret anchor will use this if not in
3519 * multiline mode.
3520 */
3521 static final class Begin extends Node {
3522 boolean match(Matcher matcher, int i, CharSequence seq) {
3523 int fromIndex = (matcher.anchoringBounds) ?
3524 matcher.from : 0;
3525 if (i == fromIndex && next.match(matcher, i, seq)) {
3526 matcher.first = i;
3527 matcher.groups[0] = i;
3528 matcher.groups[1] = matcher.last;
3529 return true;
3530 } else {
3531 return false;
3532 }
3533 }
3534 }
3535
3536 /**
3537 * Node to anchor at the end of input. This is the absolute end, so this
3538 * should not match at the last newline before the end as $ will.
3539 */
3540 static final class End extends Node {
3541 boolean match(Matcher matcher, int i, CharSequence seq) {
3542 int endIndex = (matcher.anchoringBounds) ?
3543 matcher.to : matcher.getTextLength();
3544 if (i == endIndex) {
3545 matcher.hitEnd = true;
3546 return next.match(matcher, i, seq);
3547 }
3548 return false;
3549 }
3550 }
3551
3552 /**
3553 * Node to anchor at the beginning of a line. This is essentially the
3554 * object to match for the multiline ^.
3555 */
3556 static final class Caret extends Node {
3557 boolean match(Matcher matcher, int i, CharSequence seq) {
3558 int startIndex = matcher.from;
3559 int endIndex = matcher.to;
3560 if (!matcher.anchoringBounds) {
3561 startIndex = 0;
3562 endIndex = matcher.getTextLength();
3563 }
3564 // Perl does not match ^ at end of input even after newline
3565 if (i == endIndex) {
3566 matcher.hitEnd = true;
3567 return false;
3568 }
3569 if (i > startIndex) {
3570 char ch = seq.charAt(i-1);
3571 if (ch != '\n' && ch != '\r'
3572 && (ch|1) != '\u2029'
3573 && ch != '\u0085' ) {
3574 return false;
3575 }
3576 // Should treat /r/n as one newline
3577 if (ch == '\r' && seq.charAt(i) == '\n')
3578 return false;
3579 }
3580 return next.match(matcher, i, seq);
3581 }
3582 }
3583
3584 /**
3585 * Node to anchor at the beginning of a line when in unixdot mode.
3586 */
3587 static final class UnixCaret extends Node {
3588 boolean match(Matcher matcher, int i, CharSequence seq) {
3589 int startIndex = matcher.from;
3590 int endIndex = matcher.to;
3591 if (!matcher.anchoringBounds) {
3592 startIndex = 0;
3593 endIndex = matcher.getTextLength();
3594 }
3595 // Perl does not match ^ at end of input even after newline
3596 if (i == endIndex) {
3597 matcher.hitEnd = true;
3598 return false;
3599 }
3600 if (i > startIndex) {
3601 char ch = seq.charAt(i-1);
3602 if (ch != '\n') {
3603 return false;
3604 }
3605 }
3606 return next.match(matcher, i, seq);
3607 }
3608 }
3609
3610 /**
3611 * Node to match the location where the last match ended.
3612 * This is used for the \G construct.
3613 */
3614 static final class LastMatch extends Node {
3615 boolean match(Matcher matcher, int i, CharSequence seq) {
3616 if (i != matcher.oldLast)
3617 return false;
3618 return next.match(matcher, i, seq);
3619 }
3620 }
3621
3622 /**
3623 * Node to anchor at the end of a line or the end of input based on the
3624 * multiline mode.
3625 *
3626 * When not in multiline mode, the $ can only match at the very end
3627 * of the input, unless the input ends in a line terminator in which
3628 * it matches right before the last line terminator.
3629 *
3630 * Note that \r\n is considered an atomic line terminator.
3631 *
3632 * Like ^ the $ operator matches at a position, it does not match the
3633 * line terminators themselves.
3634 */
3635 static final class Dollar extends Node {
3636 boolean multiline;
3637 Dollar(boolean mul) {
3638 multiline = mul;
3639 }
3640 boolean match(Matcher matcher, int i, CharSequence seq) {
3641 int endIndex = (matcher.anchoringBounds) ?
3642 matcher.to : matcher.getTextLength();
3643 if (!multiline) {
3644 if (i < endIndex - 2)
3645 return false;
3646 if (i == endIndex - 2) {
3647 char ch = seq.charAt(i);
3648 if (ch != '\r')
3649 return false;
3650 ch = seq.charAt(i + 1);
3651 if (ch != '\n')
3652 return false;
3653 }
3654 }
3655 // Matches before any line terminator; also matches at the
3656 // end of input
3657 // Before line terminator:
3658 // If multiline, we match here no matter what
3659 // If not multiline, fall through so that the end
3660 // is marked as hit; this must be a /r/n or a /n
3661 // at the very end so the end was hit; more input
3662 // could make this not match here
3663 if (i < endIndex) {
3664 char ch = seq.charAt(i);
3665 if (ch == '\n') {
3666 // No match between \r\n
3667 if (i > 0 && seq.charAt(i-1) == '\r')
3668 return false;
3669 if (multiline)
3670 return next.match(matcher, i, seq);
3671 } else if (ch == '\r' || ch == '\u0085' ||
3672 (ch|1) == '\u2029') {
3673 if (multiline)
3674 return next.match(matcher, i, seq);
3675 } else { // No line terminator, no match
3676 return false;
3677 }
3678 }
3679 // Matched at current end so hit end
3680 matcher.hitEnd = true;
3681 // If a $ matches because of end of input, then more input
3682 // could cause it to fail!
3683 matcher.requireEnd = true;
3684 return next.match(matcher, i, seq);
3685 }
3686 boolean study(TreeInfo info) {
3687 next.study(info);
3688 return info.deterministic;
3689 }
3690 }
3691
3692 /**
3693 * Node to anchor at the end of a line or the end of input based on the
3694 * multiline mode when in unix lines mode.
3695 */
3696 static final class UnixDollar extends Node {
3697 boolean multiline;
3698 UnixDollar(boolean mul) {
3699 multiline = mul;
3700 }
3701 boolean match(Matcher matcher, int i, CharSequence seq) {
3702 int endIndex = (matcher.anchoringBounds) ?
3703 matcher.to : matcher.getTextLength();
3704 if (i < endIndex) {
3705 char ch = seq.charAt(i);
3706 if (ch == '\n') {
3707 // If not multiline, then only possible to
3708 // match at very end or one before end
3709 if (multiline == false && i != endIndex - 1)
3710 return false;
3711 // If multiline return next.match without setting
3712 // matcher.hitEnd
3713 if (multiline)
3714 return next.match(matcher, i, seq);
3715 } else {
3716 return false;
3717 }
3718 }
3719 // Matching because at the end or 1 before the end;
3720 // more input could change this so set hitEnd
3721 matcher.hitEnd = true;
3722 // If a $ matches because of end of input, then more input
3723 // could cause it to fail!
3724 matcher.requireEnd = true;
3725 return next.match(matcher, i, seq);
3726 }
3727 boolean study(TreeInfo info) {
3728 next.study(info);
3729 return info.deterministic;
3730 }
3731 }
3732
3733 /**
3734 * Node class that matches a Unicode line ending '\R'
3735 */
3736 static final class LineEnding extends Node {
3737 boolean match(Matcher matcher, int i, CharSequence seq) {
3738 // (u+000Du+000A|[u+000Au+000Bu+000Cu+000Du+0085u+2028u+2029])
3739 if (i < matcher.to) {
3740 int ch = seq.charAt(i);
3741 if (ch == 0x0A || ch == 0x0B || ch == 0x0C ||
3742 ch == 0x85 || ch == 0x2028 || ch == 0x2029)
3743 return next.match(matcher, i + 1, seq);
3744 if (ch == 0x0D) {
3745 i++;
3746 if (i < matcher.to && seq.charAt(i) == 0x0A)
3747 i++;
3748 return next.match(matcher, i, seq);
3749 }
3750 } else {
3751 matcher.hitEnd = true;
3752 }
3753 return false;
3754 }
3755 boolean study(TreeInfo info) {
3756 info.minLength++;
3757 info.maxLength += 2;
3758 return next.study(info);
3759 }
3760 }
3761
3762 /**
3763 * Abstract node class to match one character satisfying some
3764 * boolean property.
3765 */
3766 private static abstract class CharProperty extends Node {
3767 abstract boolean isSatisfiedBy(int ch);
3768 CharProperty complement() {
3769 return new CharProperty() {
3770 boolean isSatisfiedBy(int ch) {
3771 return ! CharProperty.this.isSatisfiedBy(ch);}};
3772 }
3773 boolean match(Matcher matcher, int i, CharSequence seq) {
3774 if (i < matcher.to) {
3775 int ch = Character.codePointAt(seq, i);
3776 return isSatisfiedBy(ch)
3777 && next.match(matcher, i+Character.charCount(ch), seq);
3778 } else {
3779 matcher.hitEnd = true;
3780 return false;
3781 }
3782 }
3783 boolean study(TreeInfo info) {
3784 info.minLength++;
3785 info.maxLength++;
3786 return next.study(info);
3787 }
3788 }
3789
3790 /**
3791 * Optimized version of CharProperty that works only for
3792 * properties never satisfied by Supplementary characters.
3793 */
3794 private static abstract class BmpCharProperty extends CharProperty {
3795 boolean match(Matcher matcher, int i, CharSequence seq) {
3796 if (i < matcher.to) {
3797 return isSatisfiedBy(seq.charAt(i))
3798 && next.match(matcher, i+1, seq);
3799 } else {
3800 matcher.hitEnd = true;
3801 return false;
3802 }
3803 }
3804 }
3805
3806 /**
3807 * Node class that matches a Supplementary Unicode character
3808 */
3809 static final class SingleS extends CharProperty {
3810 final int c;
3811 SingleS(int c) { this.c = c; }
3812 boolean isSatisfiedBy(int ch) {
3813 return ch == c;
3814 }
3815 }
3816
3817 /**
3818 * Optimization -- matches a given BMP character
3819 */
3820 static final class Single extends BmpCharProperty {
3821 final int c;
3822 Single(int c) { this.c = c; }
3823 boolean isSatisfiedBy(int ch) {
3824 return ch == c;
3825 }
3826 }
3827
3828 /**
3829 * Case insensitive matches a given BMP character
3830 */
3831 static final class SingleI extends BmpCharProperty {
3832 final int lower;
3833 final int upper;
3834 SingleI(int lower, int upper) {
3835 this.lower = lower;
3836 this.upper = upper;
3837 }
3838 boolean isSatisfiedBy(int ch) {
3839 return ch == lower || ch == upper;
3840 }
3841 }
3842
3843 /**
3844 * Unicode case insensitive matches a given Unicode character
3845 */
3846 static final class SingleU extends CharProperty {
3847 final int lower;
3848 SingleU(int lower) {
3849 this.lower = lower;
3850 }
3851 boolean isSatisfiedBy(int ch) {
3852 return lower == ch ||
3853 lower == Character.toLowerCase(Character.toUpperCase(ch));
3854 }
3855 }
3856
3857 /**
3858 * Node class that matches a Unicode block.
3859 */
3860 static final class Block extends CharProperty {
3861 final Character.UnicodeBlock block;
3862 Block(Character.UnicodeBlock block) {
3863 this.block = block;
3864 }
3865 boolean isSatisfiedBy(int ch) {
3866 return block == Character.UnicodeBlock.of(ch);
3867 }
3868 }
3869
3870 /**
3871 * Node class that matches a Unicode script
3872 */
3873 static final class Script extends CharProperty {
3874 final Character.UnicodeScript script;
3875 Script(Character.UnicodeScript script) {
3876 this.script = script;
3877 }
3878 boolean isSatisfiedBy(int ch) {
3879 return script == Character.UnicodeScript.of(ch);
3880 }
3881 }
3882
3883 /**
3884 * Node class that matches a Unicode category.
3885 */
3886 static final class Category extends CharProperty {
3887 final int typeMask;
3888 Category(int typeMask) { this.typeMask = typeMask; }
3889 boolean isSatisfiedBy(int ch) {
3890 return (typeMask & (1 << Character.getType(ch))) != 0;
3891 }
3892 }
3893
3894 /**
3895 * Node class that matches a Unicode "type"
3896 */
3897 static final class Utype extends CharProperty {
3898 final UnicodeProp uprop;
3899 Utype(UnicodeProp uprop) { this.uprop = uprop; }
3900 boolean isSatisfiedBy(int ch) {
3901 return uprop.is(ch);
3902 }
3903 }
3904
3905 /**
3906 * Node class that matches a POSIX type.
3907 */
3908 static final class Ctype extends BmpCharProperty {
3909 final int ctype;
3910 Ctype(int ctype) { this.ctype = ctype; }
3911 boolean isSatisfiedBy(int ch) {
3912 return ch < 128 && ASCII.isType(ch, ctype);
3913 }
3914 }
3915
3916 /**
3917 * Node class that matches a Perl vertical whitespace
3918 */
3919 static final class VertWS extends BmpCharProperty {
3920 boolean isSatisfiedBy(int cp) {
3921 return (cp >= 0x0A && cp <= 0x0D) ||
3922 cp == 0x85 || cp == 0x2028 || cp == 0x2029;
3923 }
3924 }
3925
3926 /**
3927 * Node class that matches a Perl horizontal whitespace
3928 */
3929 static final class HorizWS extends BmpCharProperty {
3930 boolean isSatisfiedBy(int cp) {
3931 return cp == 0x09 || cp == 0x20 || cp == 0xa0 ||
3932 cp == 0x1680 || cp == 0x180e ||
3933 cp >= 0x2000 && cp <= 0x200a ||
3934 cp == 0x202f || cp == 0x205f || cp == 0x3000;
3935 }
3936 }
3937
3938 /**
3939 * Base class for all Slice nodes
3940 */
3941 static class SliceNode extends Node {
3942 int[] buffer;
3943 SliceNode(int[] buf) {
3944 buffer = buf;
3945 }
3946 boolean study(TreeInfo info) {
3947 info.minLength += buffer.length;
3948 info.maxLength += buffer.length;
3949 return next.study(info);
3950 }
3951 }
3952
3953 /**
3954 * Node class for a case sensitive/BMP-only sequence of literal
3955 * characters.
3956 */
3957 static final class Slice extends SliceNode {
3958 Slice(int[] buf) {
3959 super(buf);
3960 }
3961 boolean match(Matcher matcher, int i, CharSequence seq) {
3962 int[] buf = buffer;
3963 int len = buf.length;
3964 for (int j=0; j<len; j++) {
3965 if ((i+j) >= matcher.to) {
3966 matcher.hitEnd = true;
3967 return false;
3968 }
3969 if (buf[j] != seq.charAt(i+j))
3970 return false;
3971 }
3972 return next.match(matcher, i+len, seq);
3973 }
3974 }
3975
3976 /**
3977 * Node class for a case_insensitive/BMP-only sequence of literal
3978 * characters.
3979 */
3980 static class SliceI extends SliceNode {
3981 SliceI(int[] buf) {
3982 super(buf);
3983 }
3984 boolean match(Matcher matcher, int i, CharSequence seq) {
3985 int[] buf = buffer;
3986 int len = buf.length;
3987 for (int j=0; j<len; j++) {
3988 if ((i+j) >= matcher.to) {
3989 matcher.hitEnd = true;
3990 return false;
3991 }
3992 int c = seq.charAt(i+j);
3993 if (buf[j] != c &&
3994 buf[j] != ASCII.toLower(c))
3995 return false;
3996 }
3997 return next.match(matcher, i+len, seq);
3998 }
3999 }
4000
4001 /**
4002 * Node class for a unicode_case_insensitive/BMP-only sequence of
4003 * literal characters. Uses unicode case folding.
4004 */
4005 static final class SliceU extends SliceNode {
4006 SliceU(int[] buf) {
4007 super(buf);
4008 }
4009 boolean match(Matcher matcher, int i, CharSequence seq) {
4010 int[] buf = buffer;
4011 int len = buf.length;
4012 for (int j=0; j<len; j++) {
4013 if ((i+j) >= matcher.to) {
4014 matcher.hitEnd = true;
4015 return false;
4016 }
4017 int c = seq.charAt(i+j);
4018 if (buf[j] != c &&
4019 buf[j] != Character.toLowerCase(Character.toUpperCase(c)))
4020 return false;
4021 }
4022 return next.match(matcher, i+len, seq);
4023 }
4024 }
4025
4026 /**
4027 * Node class for a case sensitive sequence of literal characters
4028 * including supplementary characters.
4029 */
4030 static final class SliceS extends SliceNode {
4031 SliceS(int[] buf) {
4032 super(buf);
4033 }
4034 boolean match(Matcher matcher, int i, CharSequence seq) {
4035 int[] buf = buffer;
4036 int x = i;
4037 for (int j = 0; j < buf.length; j++) {
4038 if (x >= matcher.to) {
4039 matcher.hitEnd = true;
4040 return false;
4041 }
4042 int c = Character.codePointAt(seq, x);
4043 if (buf[j] != c)
4044 return false;
4045 x += Character.charCount(c);
4046 if (x > matcher.to) {
4047 matcher.hitEnd = true;
4048 return false;
4049 }
4050 }
4051 return next.match(matcher, x, seq);
4052 }
4053 }
4054
4055 /**
4056 * Node class for a case insensitive sequence of literal characters
4057 * including supplementary characters.
4058 */
4059 static class SliceIS extends SliceNode {
4060 SliceIS(int[] buf) {
4061 super(buf);
4062 }
4063 int toLower(int c) {
4064 return ASCII.toLower(c);
4065 }
4066 boolean match(Matcher matcher, int i, CharSequence seq) {
4067 int[] buf = buffer;
4068 int x = i;
4069 for (int j = 0; j < buf.length; j++) {
4070 if (x >= matcher.to) {
4071 matcher.hitEnd = true;
4072 return false;
4073 }
4074 int c = Character.codePointAt(seq, x);
4075 if (buf[j] != c && buf[j] != toLower(c))
4076 return false;
4077 x += Character.charCount(c);
4078 if (x > matcher.to) {
4079 matcher.hitEnd = true;
4080 return false;
4081 }
4082 }
4083 return next.match(matcher, x, seq);
4084 }
4085 }
4086
4087 /**
4088 * Node class for a case insensitive sequence of literal characters.
4089 * Uses unicode case folding.
4090 */
4091 static final class SliceUS extends SliceIS {
4092 SliceUS(int[] buf) {
4093 super(buf);
4094 }
4095 int toLower(int c) {
4096 return Character.toLowerCase(Character.toUpperCase(c));
4097 }
4098 }
4099
4100 private static boolean inRange(int lower, int ch, int upper) {
4101 return lower <= ch && ch <= upper;
4102 }
4103
4104 /**
4105 * Returns node for matching characters within an explicit value range.
4106 */
4107 private static CharProperty rangeFor(final int lower,
4108 final int upper) {
4109 return new CharProperty() {
4110 boolean isSatisfiedBy(int ch) {
4111 return inRange(lower, ch, upper);}};
4112 }
4113
4114 /**
4115 * Returns node for matching characters within an explicit value
4116 * range in a case insensitive manner.
4117 */
4118 private CharProperty caseInsensitiveRangeFor(final int lower,
4119 final int upper) {
4120 if (has(UNICODE_CASE))
4121 return new CharProperty() {
4122 boolean isSatisfiedBy(int ch) {
4123 if (inRange(lower, ch, upper))
4124 return true;
4125 int up = Character.toUpperCase(ch);
4126 return inRange(lower, up, upper) ||
4127 inRange(lower, Character.toLowerCase(up), upper);}};
4128 return new CharProperty() {
4129 boolean isSatisfiedBy(int ch) {
4130 return inRange(lower, ch, upper) ||
4131 ASCII.isAscii(ch) &&
4132 (inRange(lower, ASCII.toUpper(ch), upper) ||
4133 inRange(lower, ASCII.toLower(ch), upper));
4134 }};
4135 }
4136
4137 /**
4138 * Implements the Unicode category ALL and the dot metacharacter when
4139 * in dotall mode.
4140 */
4141 static final class All extends CharProperty {
4142 boolean isSatisfiedBy(int ch) {
4143 return true;
4144 }
4145 }
4146
4147 /**
4148 * Node class for the dot metacharacter when dotall is not enabled.
4149 */
4150 static final class Dot extends CharProperty {
4151 boolean isSatisfiedBy(int ch) {
4152 return (ch != '\n' && ch != '\r'
4153 && (ch|1) != '\u2029'
4154 && ch != '\u0085');
4155 }
4156 }
4157
4158 /**
4159 * Node class for the dot metacharacter when dotall is not enabled
4160 * but UNIX_LINES is enabled.
4161 */
4162 static final class UnixDot extends CharProperty {
4163 boolean isSatisfiedBy(int ch) {
4164 return ch != '\n';
4165 }
4166 }
4167
4168 /**
4169 * The 0 or 1 quantifier. This one class implements all three types.
4170 */
4171 static final class Ques extends Node {
4172 Node atom;
4173 int type;
4174 Ques(Node node, int type) {
4175 this.atom = node;
4176 this.type = type;
4177 }
4178 boolean match(Matcher matcher, int i, CharSequence seq) {
4179 switch (type) {
4180 case GREEDY:
4181 return (atom.match(matcher, i, seq) && next.match(matcher, matcher.last, seq))
4182 || next.match(matcher, i, seq);
4183 case LAZY:
4184 return next.match(matcher, i, seq)
4185 || (atom.match(matcher, i, seq) && next.match(matcher, matcher.last, seq));
4186 case POSSESSIVE:
4187 if (atom.match(matcher, i, seq)) i = matcher.last;
4188 return next.match(matcher, i, seq);
4189 default:
4190 return atom.match(matcher, i, seq) && next.match(matcher, matcher.last, seq);
4191 }
4192 }
4193 boolean study(TreeInfo info) {
4194 if (type != INDEPENDENT) {
4195 int minL = info.minLength;
4196 atom.study(info);
4197 info.minLength = minL;
4198 info.deterministic = false;
4199 return next.study(info);
4200 } else {
4201 atom.study(info);
4202 return next.study(info);
4203 }
4204 }
4205 }
4206
4207 /**
4208 * Handles the curly-brace style repetition with a specified minimum and
4209 * maximum occurrences. The * quantifier is handled as a special case.
4210 * This class handles the three types.
4211 */
4212 static final class Curly extends Node {
4213 Node atom;
4214 int type;
4215 int cmin;
4216 int cmax;
4217
4218 Curly(Node node, int cmin, int cmax, int type) {
4219 this.atom = node;
4220 this.type = type;
4221 this.cmin = cmin;
4222 this.cmax = cmax;
4223 }
4224 boolean match(Matcher matcher, int i, CharSequence seq) {
4225 int j;
4226 for (j = 0; j < cmin; j++) {
4227 if (atom.match(matcher, i, seq)) {
4228 i = matcher.last;
4229 continue;
4230 }
4231 return false;
4232 }
4233 if (type == GREEDY)
4234 return match0(matcher, i, j, seq);
4235 else if (type == LAZY)
4236 return match1(matcher, i, j, seq);
4237 else
4238 return match2(matcher, i, j, seq);
4239 }
4240 // Greedy match.
4241 // i is the index to start matching at
4242 // j is the number of atoms that have matched
4243 boolean match0(Matcher matcher, int i, int j, CharSequence seq) {
4244 if (j >= cmax) {
4245 // We have matched the maximum... continue with the rest of
4246 // the regular expression
4247 return next.match(matcher, i, seq);
4248 }
4249 int backLimit = j;
4250 while (atom.match(matcher, i, seq)) {
4251 // k is the length of this match
4252 int k = matcher.last - i;
4253 if (k == 0) // Zero length match
4254 break;
4255 // Move up index and number matched
4256 i = matcher.last;
4257 j++;
4258 // We are greedy so match as many as we can
4259 while (j < cmax) {
4260 if (!atom.match(matcher, i, seq))
4261 break;
4262 if (i + k != matcher.last) {
4263 if (match0(matcher, matcher.last, j+1, seq))
4264 return true;
4265 break;
4266 }
4267 i += k;
4268 j++;
4269 }
4270 // Handle backing off if match fails
4271 while (j >= backLimit) {
4272 if (next.match(matcher, i, seq))
4273 return true;
4274 i -= k;
4275 j--;
4276 }
4277 return false;
4278 }
4279 return next.match(matcher, i, seq);
4280 }
4281 // Reluctant match. At this point, the minimum has been satisfied.
4282 // i is the index to start matching at
4283 // j is the number of atoms that have matched
4284 boolean match1(Matcher matcher, int i, int j, CharSequence seq) {
4285 for (;;) {
4286 // Try finishing match without consuming any more
4287 if (next.match(matcher, i, seq))
4288 return true;
4289 // At the maximum, no match found
4290 if (j >= cmax)
4291 return false;
4292 // Okay, must try one more atom
4293 if (!atom.match(matcher, i, seq))
4294 return false;
4295 // If we haven't moved forward then must break out
4296 if (i == matcher.last)
4297 return false;
4298 // Move up index and number matched
4299 i = matcher.last;
4300 j++;
4301 }
4302 }
4303 boolean match2(Matcher matcher, int i, int j, CharSequence seq) {
4304 for (; j < cmax; j++) {
4305 if (!atom.match(matcher, i, seq))
4306 break;
4307 if (i == matcher.last)
4308 break;
4309 i = matcher.last;
4310 }
4311 return next.match(matcher, i, seq);
4312 }
4313 boolean study(TreeInfo info) {
4314 // Save original info
4315 int minL = info.minLength;
4316 int maxL = info.maxLength;
4317 boolean maxV = info.maxValid;
4318 boolean detm = info.deterministic;
4319 info.reset();
4320
4321 atom.study(info);
4322
4323 int temp = info.minLength * cmin + minL;
4324 if (temp < minL) {
4325 temp = 0xFFFFFFF; // arbitrary large number
4326 }
4327 info.minLength = temp;
4328
4329 if (maxV & info.maxValid) {
4330 temp = info.maxLength * cmax + maxL;
4331 info.maxLength = temp;
4332 if (temp < maxL) {
4333 info.maxValid = false;
4334 }
4335 } else {
4336 info.maxValid = false;
4337 }
4338
4339 if (info.deterministic && cmin == cmax)
4340 info.deterministic = detm;
4341 else
4342 info.deterministic = false;
4343 return next.study(info);
4344 }
4345 }
4346
4347 /**
4348 * Handles the curly-brace style repetition with a specified minimum and
4349 * maximum occurrences in deterministic cases. This is an iterative
4350 * optimization over the Prolog and Loop system which would handle this
4351 * in a recursive way. The * quantifier is handled as a special case.
4352 * If capture is true then this class saves group settings and ensures
4353 * that groups are unset when backing off of a group match.
4354 */
4355 static final class GroupCurly extends Node {
4356 Node atom;
4357 int type;
4358 int cmin;
4359 int cmax;
4360 int localIndex;
4361 int groupIndex;
4362 boolean capture;
4363
4364 GroupCurly(Node node, int cmin, int cmax, int type, int local,
4365 int group, boolean capture) {
4366 this.atom = node;
4367 this.type = type;
4368 this.cmin = cmin;
4369 this.cmax = cmax;
4370 this.localIndex = local;
4371 this.groupIndex = group;
4372 this.capture = capture;
4373 }
4374 boolean match(Matcher matcher, int i, CharSequence seq) {
4375 int[] groups = matcher.groups;
4376 int[] locals = matcher.locals;
4377 int save0 = locals[localIndex];
4378 int save1 = 0;
4379 int save2 = 0;
4380
4381 if (capture) {
4382 save1 = groups[groupIndex];
4383 save2 = groups[groupIndex+1];
4384 }
4385
4386 // Notify GroupTail there is no need to setup group info
4387 // because it will be set here
4388 locals[localIndex] = -1;
4389
4390 boolean ret = true;
4391 for (int j = 0; j < cmin; j++) {
4392 if (atom.match(matcher, i, seq)) {
4393 if (capture) {
4394 groups[groupIndex] = i;
4395 groups[groupIndex+1] = matcher.last;
4396 }
4397 i = matcher.last;
4398 } else {
4399 ret = false;
4400 break;
4401 }
4402 }
4403 if (ret) {
4404 if (type == GREEDY) {
4405 ret = match0(matcher, i, cmin, seq);
4406 } else if (type == LAZY) {
4407 ret = match1(matcher, i, cmin, seq);
4408 } else {
4409 ret = match2(matcher, i, cmin, seq);
4410 }
4411 }
4412 if (!ret) {
4413 locals[localIndex] = save0;
4414 if (capture) {
4415 groups[groupIndex] = save1;
4416 groups[groupIndex+1] = save2;
4417 }
4418 }
4419 return ret;
4420 }
4421 // Aggressive group match
4422 boolean match0(Matcher matcher, int i, int j, CharSequence seq) {
4423 // don't back off passing the starting "j"
4424 int min = j;
4425 int[] groups = matcher.groups;
4426 int save0 = 0;
4427 int save1 = 0;
4428 if (capture) {
4429 save0 = groups[groupIndex];
4430 save1 = groups[groupIndex+1];
4431 }
4432 for (;;) {
4433 if (j >= cmax)
4434 break;
4435 if (!atom.match(matcher, i, seq))
4436 break;
4437 int k = matcher.last - i;
4438 if (k <= 0) {
4439 if (capture) {
4440 groups[groupIndex] = i;
4441 groups[groupIndex+1] = i + k;
4442 }
4443 i = i + k;
4444 break;
4445 }
4446 for (;;) {
4447 if (capture) {
4448 groups[groupIndex] = i;
4449 groups[groupIndex+1] = i + k;
4450 }
4451 i = i + k;
4452 if (++j >= cmax)
4453 break;
4454 if (!atom.match(matcher, i, seq))
4455 break;
4456 if (i + k != matcher.last) {
4457 if (match0(matcher, i, j, seq))
4458 return true;
4459 break;
4460 }
4461 }
4462 while (j > min) {
4463 if (next.match(matcher, i, seq)) {
4464 if (capture) {
4465 groups[groupIndex+1] = i;
4466 groups[groupIndex] = i - k;
4467 }
4468 return true;
4469 }
4470 // backing off
4471 i = i - k;
4472 if (capture) {
4473 groups[groupIndex+1] = i;
4474 groups[groupIndex] = i - k;
4475 }
4476 j--;
4477
4478 }
4479 break;
4480 }
4481 if (capture) {
4482 groups[groupIndex] = save0;
4483 groups[groupIndex+1] = save1;
4484 }
4485 return next.match(matcher, i, seq);
4486 }
4487 // Reluctant matching
4488 boolean match1(Matcher matcher, int i, int j, CharSequence seq) {
4489 for (;;) {
4490 if (next.match(matcher, i, seq))
4491 return true;
4492 if (j >= cmax)
4493 return false;
4494 if (!atom.match(matcher, i, seq))
4495 return false;
4496 if (i == matcher.last)
4497 return false;
4498 if (capture) {
4499 matcher.groups[groupIndex] = i;
4500 matcher.groups[groupIndex+1] = matcher.last;
4501 }
4502 i = matcher.last;
4503 j++;
4504 }
4505 }
4506 // Possessive matching
4507 boolean match2(Matcher matcher, int i, int j, CharSequence seq) {
4508 for (; j < cmax; j++) {
4509 if (!atom.match(matcher, i, seq)) {
4510 break;
4511 }
4512 if (capture) {
4513 matcher.groups[groupIndex] = i;
4514 matcher.groups[groupIndex+1] = matcher.last;
4515 }
4516 if (i == matcher.last) {
4517 break;
4518 }
4519 i = matcher.last;
4520 }
4521 return next.match(matcher, i, seq);
4522 }
4523 boolean study(TreeInfo info) {
4524 // Save original info
4525 int minL = info.minLength;
4526 int maxL = info.maxLength;
4527 boolean maxV = info.maxValid;
4528 boolean detm = info.deterministic;
4529 info.reset();
4530
4531 atom.study(info);
4532
4533 int temp = info.minLength * cmin + minL;
4534 if (temp < minL) {
4535 temp = 0xFFFFFFF; // Arbitrary large number
4536 }
4537 info.minLength = temp;
4538
4539 if (maxV & info.maxValid) {
4540 temp = info.maxLength * cmax + maxL;
4541 info.maxLength = temp;
4542 if (temp < maxL) {
4543 info.maxValid = false;
4544 }
4545 } else {
4546 info.maxValid = false;
4547 }
4548
4549 if (info.deterministic && cmin == cmax) {
4550 info.deterministic = detm;
4551 } else {
4552 info.deterministic = false;
4553 }
4554 return next.study(info);
4555 }
4556 }
4557
4558 /**
4559 * A Guard node at the end of each atom node in a Branch. It
4560 * serves the purpose of chaining the "match" operation to
4561 * "next" but not the "study", so we can collect the TreeInfo
4562 * of each atom node without including the TreeInfo of the
4563 * "next".
4564 */
4565 static final class BranchConn extends Node {
4566 BranchConn() {};
4567 boolean match(Matcher matcher, int i, CharSequence seq) {
4568 return next.match(matcher, i, seq);
4569 }
4570 boolean study(TreeInfo info) {
4571 return info.deterministic;
4572 }
4573 }
4574
4575 /**
4576 * Handles the branching of alternations. Note this is also used for
4577 * the ? quantifier to branch between the case where it matches once
4578 * and where it does not occur.
4579 */
4580 static final class Branch extends Node {
4581 Node[] atoms = new Node[2];
4582 int size = 2;
4583 Node conn;
4584 Branch(Node first, Node second, Node branchConn) {
4585 conn = branchConn;
4586 atoms[0] = first;
4587 atoms[1] = second;
4588 }
4589
4590 void add(Node node) {
4591 if (size >= atoms.length) {
4592 Node[] tmp = new Node[atoms.length*2];
4593 System.arraycopy(atoms, 0, tmp, 0, atoms.length);
4594 atoms = tmp;
4595 }
4596 atoms[size++] = node;
4597 }
4598
4599 boolean match(Matcher matcher, int i, CharSequence seq) {
4600 for (int n = 0; n < size; n++) {
4601 if (atoms[n] == null) {
4602 if (conn.next.match(matcher, i, seq))
4603 return true;
4604 } else if (atoms[n].match(matcher, i, seq)) {
4605 return true;
4606 }
4607 }
4608 return false;
4609 }
4610
4611 boolean study(TreeInfo info) {
4612 int minL = info.minLength;
4613 int maxL = info.maxLength;
4614 boolean maxV = info.maxValid;
4615
4616 int minL2 = Integer.MAX_VALUE; //arbitrary large enough num
4617 int maxL2 = -1;
4618 for (int n = 0; n < size; n++) {
4619 info.reset();
4620 if (atoms[n] != null)
4621 atoms[n].study(info);
4622 minL2 = Math.min(minL2, info.minLength);
4623 maxL2 = Math.max(maxL2, info.maxLength);
4624 maxV = (maxV & info.maxValid);
4625 }
4626
4627 minL += minL2;
4628 maxL += maxL2;
4629
4630 info.reset();
4631 conn.next.study(info);
4632
4633 info.minLength += minL;
4634 info.maxLength += maxL;
4635 info.maxValid &= maxV;
4636 info.deterministic = false;
4637 return false;
4638 }
4639 }
4640
4641 /**
4642 * The GroupHead saves the location where the group begins in the locals
4643 * and restores them when the match is done.
4644 *
4645 * The matchRef is used when a reference to this group is accessed later
4646 * in the expression. The locals will have a negative value in them to
4647 * indicate that we do not want to unset the group if the reference
4648 * doesn't match.
4649 */
4650 static final class GroupHead extends Node {
4651 int localIndex;
4652 GroupHead(int localCount) {
4653 localIndex = localCount;
4654 }
4655 boolean match(Matcher matcher, int i, CharSequence seq) {
4656 int save = matcher.locals[localIndex];
4657 matcher.locals[localIndex] = i;
4658 boolean ret = next.match(matcher, i, seq);
4659 matcher.locals[localIndex] = save;
4660 return ret;
4661 }
4662 boolean matchRef(Matcher matcher, int i, CharSequence seq) {
4663 int save = matcher.locals[localIndex];
4664 matcher.locals[localIndex] = ~i; // HACK
4665 boolean ret = next.match(matcher, i, seq);
4666 matcher.locals[localIndex] = save;
4667 return ret;
4668 }
4669 }
4670
4671 /**
4672 * Recursive reference to a group in the regular expression. It calls
4673 * matchRef because if the reference fails to match we would not unset
4674 * the group.
4675 */
4676 static final class GroupRef extends Node {
4677 GroupHead head;
4678 GroupRef(GroupHead head) {
4679 this.head = head;
4680 }
4681 boolean match(Matcher matcher, int i, CharSequence seq) {
4682 return head.matchRef(matcher, i, seq)
4683 && next.match(matcher, matcher.last, seq);
4684 }
4685 boolean study(TreeInfo info) {
4686 info.maxValid = false;
4687 info.deterministic = false;
4688 return next.study(info);
4689 }
4690 }
4691
4692 /**
4693 * The GroupTail handles the setting of group beginning and ending
4694 * locations when groups are successfully matched. It must also be able to
4695 * unset groups that have to be backed off of.
4696 *
4697 * The GroupTail node is also used when a previous group is referenced,
4698 * and in that case no group information needs to be set.
4699 */
4700 static final class GroupTail extends Node {
4701 int localIndex;
4702 int groupIndex;
4703 GroupTail(int localCount, int groupCount) {
4704 localIndex = localCount;
4705 groupIndex = groupCount + groupCount;
4706 }
4707 boolean match(Matcher matcher, int i, CharSequence seq) {
4708 int tmp = matcher.locals[localIndex];
4709 if (tmp >= 0) { // This is the normal group case.
4710 // Save the group so we can unset it if it
4711 // backs off of a match.
4712 int groupStart = matcher.groups[groupIndex];
4713 int groupEnd = matcher.groups[groupIndex+1];
4714
4715 matcher.groups[groupIndex] = tmp;
4716 matcher.groups[groupIndex+1] = i;
4717 if (next.match(matcher, i, seq)) {
4718 return true;
4719 }
4720 matcher.groups[groupIndex] = groupStart;
4721 matcher.groups[groupIndex+1] = groupEnd;
4722 return false;
4723 } else {
4724 // This is a group reference case. We don't need to save any
4725 // group info because it isn't really a group.
4726 matcher.last = i;
4727 return true;
4728 }
4729 }
4730 }
4731
4732 /**
4733 * This sets up a loop to handle a recursive quantifier structure.
4734 */
4735 static final class Prolog extends Node {
4736 Loop loop;
4737 Prolog(Loop loop) {
4738 this.loop = loop;
4739 }
4740 boolean match(Matcher matcher, int i, CharSequence seq) {
4741 return loop.matchInit(matcher, i, seq);
4742 }
4743 boolean study(TreeInfo info) {
4744 return loop.study(info);
4745 }
4746 }
4747
4748 /**
4749 * Handles the repetition count for a greedy Curly. The matchInit
4750 * is called from the Prolog to save the index of where the group
4751 * beginning is stored. A zero length group check occurs in the
4752 * normal match but is skipped in the matchInit.
4753 */
4754 static class Loop extends Node {
4755 Node body;
4756 int countIndex; // local count index in matcher locals
4757 int beginIndex; // group beginning index
4758 int cmin, cmax;
4759 Loop(int countIndex, int beginIndex) {
4760 this.countIndex = countIndex;
4761 this.beginIndex = beginIndex;
4762 }
4763 boolean match(Matcher matcher, int i, CharSequence seq) {
4764 // Avoid infinite loop in zero-length case.
4765 if (i > matcher.locals[beginIndex]) {
4766 int count = matcher.locals[countIndex];
4767
4768 // This block is for before we reach the minimum
4769 // iterations required for the loop to match
4770 if (count < cmin) {
4771 matcher.locals[countIndex] = count + 1;
4772 boolean b = body.match(matcher, i, seq);
4773 // If match failed we must backtrack, so
4774 // the loop count should NOT be incremented
4775 if (!b)
4776 matcher.locals[countIndex] = count;
4777 // Return success or failure since we are under
4778 // minimum
4779 return b;
4780 }
4781 // This block is for after we have the minimum
4782 // iterations required for the loop to match
4783 if (count < cmax) {
4784 matcher.locals[countIndex] = count + 1;
4785 boolean b = body.match(matcher, i, seq);
4786 // If match failed we must backtrack, so
4787 // the loop count should NOT be incremented
4788 if (!b)
4789 matcher.locals[countIndex] = count;
4790 else
4791 return true;
4792 }
4793 }
4794 return next.match(matcher, i, seq);
4795 }
4796 boolean matchInit(Matcher matcher, int i, CharSequence seq) {
4797 int save = matcher.locals[countIndex];
4798 boolean ret = false;
4799 if (0 < cmin) {
4800 matcher.locals[countIndex] = 1;
4801 ret = body.match(matcher, i, seq);
4802 } else if (0 < cmax) {
4803 matcher.locals[countIndex] = 1;
4804 ret = body.match(matcher, i, seq);
4805 if (ret == false)
4806 ret = next.match(matcher, i, seq);
4807 } else {
4808 ret = next.match(matcher, i, seq);
4809 }
4810 matcher.locals[countIndex] = save;
4811 return ret;
4812 }
4813 boolean study(TreeInfo info) {
4814 info.maxValid = false;
4815 info.deterministic = false;
4816 return false;
4817 }
4818 }
4819
4820 /**
4821 * Handles the repetition count for a reluctant Curly. The matchInit
4822 * is called from the Prolog to save the index of where the group
4823 * beginning is stored. A zero length group check occurs in the
4824 * normal match but is skipped in the matchInit.
4825 */
4826 static final class LazyLoop extends Loop {
4827 LazyLoop(int countIndex, int beginIndex) {
4828 super(countIndex, beginIndex);
4829 }
4830 boolean match(Matcher matcher, int i, CharSequence seq) {
4831 // Check for zero length group
4832 if (i > matcher.locals[beginIndex]) {
4833 int count = matcher.locals[countIndex];
4834 if (count < cmin) {
4835 matcher.locals[countIndex] = count + 1;
4836 boolean result = body.match(matcher, i, seq);
4837 // If match failed we must backtrack, so
4838 // the loop count should NOT be incremented
4839 if (!result)
4840 matcher.locals[countIndex] = count;
4841 return result;
4842 }
4843 if (next.match(matcher, i, seq))
4844 return true;
4845 if (count < cmax) {
4846 matcher.locals[countIndex] = count + 1;
4847 boolean result = body.match(matcher, i, seq);
4848 // If match failed we must backtrack, so
4849 // the loop count should NOT be incremented
4850 if (!result)
4851 matcher.locals[countIndex] = count;
4852 return result;
4853 }
4854 return false;
4855 }
4856 return next.match(matcher, i, seq);
4857 }
4858 boolean matchInit(Matcher matcher, int i, CharSequence seq) {
4859 int save = matcher.locals[countIndex];
4860 boolean ret = false;
4861 if (0 < cmin) {
4862 matcher.locals[countIndex] = 1;
4863 ret = body.match(matcher, i, seq);
4864 } else if (next.match(matcher, i, seq)) {
4865 ret = true;
4866 } else if (0 < cmax) {
4867 matcher.locals[countIndex] = 1;
4868 ret = body.match(matcher, i, seq);
4869 }
4870 matcher.locals[countIndex] = save;
4871 return ret;
4872 }
4873 boolean study(TreeInfo info) {
4874 info.maxValid = false;
4875 info.deterministic = false;
4876 return false;
4877 }
4878 }
4879
4880 /**
4881 * Refers to a group in the regular expression. Attempts to match
4882 * whatever the group referred to last matched.
4883 */
4884 static class BackRef extends Node {
4885 int groupIndex;
4886 BackRef(int groupCount) {
4887 super();
4888 groupIndex = groupCount + groupCount;
4889 }
4890 boolean match(Matcher matcher, int i, CharSequence seq) {
4891 int j = matcher.groups[groupIndex];
4892 int k = matcher.groups[groupIndex+1];
4893
4894 int groupSize = k - j;
4895 // If the referenced group didn't match, neither can this
4896 if (j < 0)
4897 return false;
4898
4899 // If there isn't enough input left no match
4900 if (i + groupSize > matcher.to) {
4901 matcher.hitEnd = true;
4902 return false;
4903 }
4904 // Check each new char to make sure it matches what the group
4905 // referenced matched last time around
4906 for (int index=0; index<groupSize; index++)
4907 if (seq.charAt(i+index) != seq.charAt(j+index))
4908 return false;
4909
4910 return next.match(matcher, i+groupSize, seq);
4911 }
4912 boolean study(TreeInfo info) {
4913 info.maxValid = false;
4914 return next.study(info);
4915 }
4916 }
4917
4918 static class CIBackRef extends Node {
4919 int groupIndex;
4920 boolean doUnicodeCase;
4921 CIBackRef(int groupCount, boolean doUnicodeCase) {
4922 super();
4923 groupIndex = groupCount + groupCount;
4924 this.doUnicodeCase = doUnicodeCase;
4925 }
4926 boolean match(Matcher matcher, int i, CharSequence seq) {
4927 int j = matcher.groups[groupIndex];
4928 int k = matcher.groups[groupIndex+1];
4929
4930 int groupSize = k - j;
4931
4932 // If the referenced group didn't match, neither can this
4933 if (j < 0)
4934 return false;
4935
4936 // If there isn't enough input left no match
4937 if (i + groupSize > matcher.to) {
4938 matcher.hitEnd = true;
4939 return false;
4940 }
4941
4942 // Check each new char to make sure it matches what the group
4943 // referenced matched last time around
4944 int x = i;
4945 for (int index=0; index<groupSize; index++) {
4946 int c1 = Character.codePointAt(seq, x);
4947 int c2 = Character.codePointAt(seq, j);
4948 if (c1 != c2) {
4949 if (doUnicodeCase) {
4950 int cc1 = Character.toUpperCase(c1);
4951 int cc2 = Character.toUpperCase(c2);
4952 if (cc1 != cc2 &&
4953 Character.toLowerCase(cc1) !=
4954 Character.toLowerCase(cc2))
4955 return false;
4956 } else {
4957 if (ASCII.toLower(c1) != ASCII.toLower(c2))
4958 return false;
4959 }
4960 }
4961 x += Character.charCount(c1);
4962 j += Character.charCount(c2);
4963 }
4964
4965 return next.match(matcher, i+groupSize, seq);
4966 }
4967 boolean study(TreeInfo info) {
4968 info.maxValid = false;
4969 return next.study(info);
4970 }
4971 }
4972
4973 /**
4974 * Searches until the next instance of its atom. This is useful for
4975 * finding the atom efficiently without passing an instance of it
4976 * (greedy problem) and without a lot of wasted search time (reluctant
4977 * problem).
4978 */
4979 static final class First extends Node {
4980 Node atom;
4981 First(Node node) {
4982 this.atom = BnM.optimize(node);
4983 }
4984 boolean match(Matcher matcher, int i, CharSequence seq) {
4985 if (atom instanceof BnM) {
4986 return atom.match(matcher, i, seq)
4987 && next.match(matcher, matcher.last, seq);
4988 }
4989 for (;;) {
4990 if (i > matcher.to) {
4991 matcher.hitEnd = true;
4992 return false;
4993 }
4994 if (atom.match(matcher, i, seq)) {
4995 return next.match(matcher, matcher.last, seq);
4996 }
4997 i += countChars(seq, i, 1);
4998 matcher.first++;
4999 }
5000 }
5001 boolean study(TreeInfo info) {
5002 atom.study(info);
5003 info.maxValid = false;
5004 info.deterministic = false;
5005 return next.study(info);
5006 }
5007 }
5008
5009 static final class Conditional extends Node {
5010 Node cond, yes, not;
5011 Conditional(Node cond, Node yes, Node not) {
5012 this.cond = cond;
5013 this.yes = yes;
5014 this.not = not;
5015 }
5016 boolean match(Matcher matcher, int i, CharSequence seq) {
5017 if (cond.match(matcher, i, seq)) {
5018 return yes.match(matcher, i, seq);
5019 } else {
5020 return not.match(matcher, i, seq);
5021 }
5022 }
5023 boolean study(TreeInfo info) {
5024 int minL = info.minLength;
5025 int maxL = info.maxLength;
5026 boolean maxV = info.maxValid;
5027 info.reset();
5028 yes.study(info);
5029
5030 int minL2 = info.minLength;
5031 int maxL2 = info.maxLength;
5032 boolean maxV2 = info.maxValid;
5033 info.reset();
5034 not.study(info);
5035
5036 info.minLength = minL + Math.min(minL2, info.minLength);
5037 info.maxLength = maxL + Math.max(maxL2, info.maxLength);
5038 info.maxValid = (maxV & maxV2 & info.maxValid);
5039 info.deterministic = false;
5040 return next.study(info);
5041 }
5042 }
5043
5044 /**
5045 * Zero width positive lookahead.
5046 */
5047 static final class Pos extends Node {
5048 Node cond;
5049 Pos(Node cond) {
5050 this.cond = cond;
5051 }
5052 boolean match(Matcher matcher, int i, CharSequence seq) {
5053 int savedTo = matcher.to;
5054 boolean conditionMatched = false;
5055
5056 // Relax transparent region boundaries for lookahead
5057 if (matcher.transparentBounds)
5058 matcher.to = matcher.getTextLength();
5059 try {
5060 conditionMatched = cond.match(matcher, i, seq);
5061 } finally {
5062 // Reinstate region boundaries
5063 matcher.to = savedTo;
5064 }
5065 return conditionMatched && next.match(matcher, i, seq);
5066 }
5067 }
5068
5069 /**
5070 * Zero width negative lookahead.
5071 */
5072 static final class Neg extends Node {
5073 Node cond;
5074 Neg(Node cond) {
5075 this.cond = cond;
5076 }
5077 boolean match(Matcher matcher, int i, CharSequence seq) {
5078 int savedTo = matcher.to;
5079 boolean conditionMatched = false;
5080
5081 // Relax transparent region boundaries for lookahead
5082 if (matcher.transparentBounds)
5083 matcher.to = matcher.getTextLength();
5084 try {
5085 if (i < matcher.to) {
5086 conditionMatched = !cond.match(matcher, i, seq);
5087 } else {
5088 // If a negative lookahead succeeds then more input
5089 // could cause it to fail!
5090 matcher.requireEnd = true;
5091 conditionMatched = !cond.match(matcher, i, seq);
5092 }
5093 } finally {
5094 // Reinstate region boundaries
5095 matcher.to = savedTo;
5096 }
5097 return conditionMatched && next.match(matcher, i, seq);
5098 }
5099 }
5100
5101 /**
5102 * For use with lookbehinds; matches the position where the lookbehind
5103 * was encountered.
5104 */
5105 static Node lookbehindEnd = new Node() {
5106 boolean match(Matcher matcher, int i, CharSequence seq) {
5107 return i == matcher.lookbehindTo;
5108 }
5109 };
5110
5111 /**
5112 * Zero width positive lookbehind.
5113 */
5114 static class Behind extends Node {
5115 Node cond;
5116 int rmax, rmin;
5117 Behind(Node cond, int rmax, int rmin) {
5118 this.cond = cond;
5119 this.rmax = rmax;
5120 this.rmin = rmin;
5121 }
5122
5123 boolean match(Matcher matcher, int i, CharSequence seq) {
5124 int savedFrom = matcher.from;
5125 boolean conditionMatched = false;
5126 int startIndex = (!matcher.transparentBounds) ?
5127 matcher.from : 0;
5128 int from = Math.max(i - rmax, startIndex);
5129 // Set end boundary
5130 int savedLBT = matcher.lookbehindTo;
5131 matcher.lookbehindTo = i;
5132 // Relax transparent region boundaries for lookbehind
5133 if (matcher.transparentBounds)
5134 matcher.from = 0;
5135 for (int j = i - rmin; !conditionMatched && j >= from; j--) {
5136 conditionMatched = cond.match(matcher, j, seq);
5137 }
5138 matcher.from = savedFrom;
5139 matcher.lookbehindTo = savedLBT;
5140 return conditionMatched && next.match(matcher, i, seq);
5141 }
5142 }
5143
5144 /**
5145 * Zero width positive lookbehind, including supplementary
5146 * characters or unpaired surrogates.
5147 */
5148 static final class BehindS extends Behind {
5149 BehindS(Node cond, int rmax, int rmin) {
5150 super(cond, rmax, rmin);
5151 }
5152 boolean match(Matcher matcher, int i, CharSequence seq) {
5153 int rmaxChars = countChars(seq, i, -rmax);
5154 int rminChars = countChars(seq, i, -rmin);
5155 int savedFrom = matcher.from;
5156 int startIndex = (!matcher.transparentBounds) ?
5157 matcher.from : 0;
5158 boolean conditionMatched = false;
5159 int from = Math.max(i - rmaxChars, startIndex);
5160 // Set end boundary
5161 int savedLBT = matcher.lookbehindTo;
5162 matcher.lookbehindTo = i;
5163 // Relax transparent region boundaries for lookbehind
5164 if (matcher.transparentBounds)
5165 matcher.from = 0;
5166
5167 for (int j = i - rminChars;
5168 !conditionMatched && j >= from;
5169 j -= j>from ? countChars(seq, j, -1) : 1) {
5170 conditionMatched = cond.match(matcher, j, seq);
5171 }
5172 matcher.from = savedFrom;
5173 matcher.lookbehindTo = savedLBT;
5174 return conditionMatched && next.match(matcher, i, seq);
5175 }
5176 }
5177
5178 /**
5179 * Zero width negative lookbehind.
5180 */
5181 static class NotBehind extends Node {
5182 Node cond;
5183 int rmax, rmin;
5184 NotBehind(Node cond, int rmax, int rmin) {
5185 this.cond = cond;
5186 this.rmax = rmax;
5187 this.rmin = rmin;
5188 }
5189
5190 boolean match(Matcher matcher, int i, CharSequence seq) {
5191 int savedLBT = matcher.lookbehindTo;
5192 int savedFrom = matcher.from;
5193 boolean conditionMatched = false;
5194 int startIndex = (!matcher.transparentBounds) ?
5195 matcher.from : 0;
5196 int from = Math.max(i - rmax, startIndex);
5197 matcher.lookbehindTo = i;
5198 // Relax transparent region boundaries for lookbehind
5199 if (matcher.transparentBounds)
5200 matcher.from = 0;
5201 for (int j = i - rmin; !conditionMatched && j >= from; j--) {
5202 conditionMatched = cond.match(matcher, j, seq);
5203 }
5204 // Reinstate region boundaries
5205 matcher.from = savedFrom;
5206 matcher.lookbehindTo = savedLBT;
5207 return !conditionMatched && next.match(matcher, i, seq);
5208 }
5209 }
5210
5211 /**
5212 * Zero width negative lookbehind, including supplementary
5213 * characters or unpaired surrogates.
5214 */
5215 static final class NotBehindS extends NotBehind {
5216 NotBehindS(Node cond, int rmax, int rmin) {
5217 super(cond, rmax, rmin);
5218 }
5219 boolean match(Matcher matcher, int i, CharSequence seq) {
5220 int rmaxChars = countChars(seq, i, -rmax);
5221 int rminChars = countChars(seq, i, -rmin);
5222 int savedFrom = matcher.from;
5223 int savedLBT = matcher.lookbehindTo;
5224 boolean conditionMatched = false;
5225 int startIndex = (!matcher.transparentBounds) ?
5226 matcher.from : 0;
5227 int from = Math.max(i - rmaxChars, startIndex);
5228 matcher.lookbehindTo = i;
5229 // Relax transparent region boundaries for lookbehind
5230 if (matcher.transparentBounds)
5231 matcher.from = 0;
5232 for (int j = i - rminChars;
5233 !conditionMatched && j >= from;
5234 j -= j>from ? countChars(seq, j, -1) : 1) {
5235 conditionMatched = cond.match(matcher, j, seq);
5236 }
5237 //Reinstate region boundaries
5238 matcher.from = savedFrom;
5239 matcher.lookbehindTo = savedLBT;
5240 return !conditionMatched && next.match(matcher, i, seq);
5241 }
5242 }
5243
5244 /**
5245 * Returns the set union of two CharProperty nodes.
5246 */
5247 private static CharProperty union(final CharProperty lhs,
5248 final CharProperty rhs) {
5249 return new CharProperty() {
5250 boolean isSatisfiedBy(int ch) {
5251 return lhs.isSatisfiedBy(ch) || rhs.isSatisfiedBy(ch);}};
5252 }
5253
5254 /**
5255 * Returns the set intersection of two CharProperty nodes.
5256 */
5257 private static CharProperty intersection(final CharProperty lhs,
5258 final CharProperty rhs) {
5259 return new CharProperty() {
5260 boolean isSatisfiedBy(int ch) {
5261 return lhs.isSatisfiedBy(ch) && rhs.isSatisfiedBy(ch);}};
5262 }
5263
5264 /**
5265 * Returns the set difference of two CharProperty nodes.
5266 */
5267 private static CharProperty setDifference(final CharProperty lhs,
5268 final CharProperty rhs) {
5269 return new CharProperty() {
5270 boolean isSatisfiedBy(int ch) {
5271 return ! rhs.isSatisfiedBy(ch) && lhs.isSatisfiedBy(ch);}};
5272 }
5273
5274 /**
5275 * Handles word boundaries. Includes a field to allow this one class to
5276 * deal with the different types of word boundaries we can match. The word
5277 * characters include underscores, letters, and digits. Non spacing marks
5278 * can are also part of a word if they have a base character, otherwise
5279 * they are ignored for purposes of finding word boundaries.
5280 */
5281 static final class Bound extends Node {
5282 static int LEFT = 0x1;
5283 static int RIGHT= 0x2;
5284 static int BOTH = 0x3;
5285 static int NONE = 0x4;
5286 int type;
5287 boolean useUWORD;
5288 Bound(int n, boolean useUWORD) {
5289 type = n;
5290 this.useUWORD = useUWORD;
5291 }
5292
5293 boolean isWord(int ch) {
5294 return useUWORD ? UnicodeProp.WORD.is(ch)
5295 : (ch == '_' || Character.isLetterOrDigit(ch));
5296 }
5297
5298 int check(Matcher matcher, int i, CharSequence seq) {
5299 int ch;
5300 boolean left = false;
5301 int startIndex = matcher.from;
5302 int endIndex = matcher.to;
5303 if (matcher.transparentBounds) {
5304 startIndex = 0;
5305 endIndex = matcher.getTextLength();
5306 }
5307 if (i > startIndex) {
5308 ch = Character.codePointBefore(seq, i);
5309 left = (isWord(ch) ||
5310 ((Character.getType(ch) == Character.NON_SPACING_MARK)
5311 && hasBaseCharacter(matcher, i-1, seq)));
5312 }
5313 boolean right = false;
5314 if (i < endIndex) {
5315 ch = Character.codePointAt(seq, i);
5316 right = (isWord(ch) ||
5317 ((Character.getType(ch) == Character.NON_SPACING_MARK)
5318 && hasBaseCharacter(matcher, i, seq)));
5319 } else {
5320 // Tried to access char past the end
5321 matcher.hitEnd = true;
5322 // The addition of another char could wreck a boundary
5323 matcher.requireEnd = true;
5324 }
5325 return ((left ^ right) ? (right ? LEFT : RIGHT) : NONE);
5326 }
5327 boolean match(Matcher matcher, int i, CharSequence seq) {
5328 return (check(matcher, i, seq) & type) > 0
5329 && next.match(matcher, i, seq);
5330 }
5331 }
5332
5333 /**
5334 * Non spacing marks only count as word characters in bounds calculations
5335 * if they have a base character.
5336 */
5337 private static boolean hasBaseCharacter(Matcher matcher, int i,
5338 CharSequence seq)
5339 {
5340 int start = (!matcher.transparentBounds) ?
5341 matcher.from : 0;
5342 for (int x=i; x >= start; x--) {
5343 int ch = Character.codePointAt(seq, x);
5344 if (Character.isLetterOrDigit(ch))
5345 return true;
5346 if (Character.getType(ch) == Character.NON_SPACING_MARK)
5347 continue;
5348 return false;
5349 }
5350 return false;
5351 }
5352
5353 /**
5354 * Attempts to match a slice in the input using the Boyer-Moore string
5355 * matching algorithm. The algorithm is based on the idea that the
5356 * pattern can be shifted farther ahead in the search text if it is
5357 * matched right to left.
5358 * <p>
5359 * The pattern is compared to the input one character at a time, from
5360 * the rightmost character in the pattern to the left. If the characters
5361 * all match the pattern has been found. If a character does not match,
5362 * the pattern is shifted right a distance that is the maximum of two
5363 * functions, the bad character shift and the good suffix shift. This
5364 * shift moves the attempted match position through the input more
5365 * quickly than a naive one position at a time check.
5366 * <p>
5367 * The bad character shift is based on the character from the text that
5368 * did not match. If the character does not appear in the pattern, the
5369 * pattern can be shifted completely beyond the bad character. If the
5370 * character does occur in the pattern, the pattern can be shifted to
5371 * line the pattern up with the next occurrence of that character.
5372 * <p>
5373 * The good suffix shift is based on the idea that some subset on the right
5374 * side of the pattern has matched. When a bad character is found, the
5375 * pattern can be shifted right by the pattern length if the subset does
5376 * not occur again in pattern, or by the amount of distance to the
5377 * next occurrence of the subset in the pattern.
5378 *
5379 * Boyer-Moore search methods adapted from code by Amy Yu.
5380 */
5381 static class BnM extends Node {
5382 int[] buffer;
5383 int[] lastOcc;
5384 int[] optoSft;
5385
5386 /**
5387 * Pre calculates arrays needed to generate the bad character
5388 * shift and the good suffix shift. Only the last seven bits
5389 * are used to see if chars match; This keeps the tables small
5390 * and covers the heavily used ASCII range, but occasionally
5391 * results in an aliased match for the bad character shift.
5392 */
5393 static Node optimize(Node node) {
5394 if (!(node instanceof Slice)) {
5395 return node;
5396 }
5397
5398 int[] src = ((Slice) node).buffer;
5399 int patternLength = src.length;
5400 // The BM algorithm requires a bit of overhead;
5401 // If the pattern is short don't use it, since
5402 // a shift larger than the pattern length cannot
5403 // be used anyway.
5404 if (patternLength < 4) {
5405 return node;
5406 }
5407 int i, j, k;
5408 int[] lastOcc = new int[128];
5409 int[] optoSft = new int[patternLength];
5410 // Precalculate part of the bad character shift
5411 // It is a table for where in the pattern each
5412 // lower 7-bit value occurs
5413 for (i = 0; i < patternLength; i++) {
5414 lastOcc[src[i]&0x7F] = i + 1;
5415 }
5416 // Precalculate the good suffix shift
5417 // i is the shift amount being considered
5418 NEXT: for (i = patternLength; i > 0; i--) {
5419 // j is the beginning index of suffix being considered
5420 for (j = patternLength - 1; j >= i; j--) {
5421 // Testing for good suffix
5422 if (src[j] == src[j-i]) {
5423 // src[j..len] is a good suffix
5424 optoSft[j-1] = i;
5425 } else {
5426 // No match. The array has already been
5427 // filled up with correct values before.
5428 continue NEXT;
5429 }
5430 }
5431 // This fills up the remaining of optoSft
5432 // any suffix can not have larger shift amount
5433 // then its sub-suffix. Why???
5434 while (j > 0) {
5435 optoSft[--j] = i;
5436 }
5437 }
5438 // Set the guard value because of unicode compression
5439 optoSft[patternLength-1] = 1;
5440 if (node instanceof SliceS)
5441 return new BnMS(src, lastOcc, optoSft, node.next);
5442 return new BnM(src, lastOcc, optoSft, node.next);
5443 }
5444 BnM(int[] src, int[] lastOcc, int[] optoSft, Node next) {
5445 this.buffer = src;
5446 this.lastOcc = lastOcc;
5447 this.optoSft = optoSft;
5448 this.next = next;
5449 }
5450 boolean match(Matcher matcher, int i, CharSequence seq) {
5451 int[] src = buffer;
5452 int patternLength = src.length;
5453 int last = matcher.to - patternLength;
5454
5455 // Loop over all possible match positions in text
5456 NEXT: while (i <= last) {
5457 // Loop over pattern from right to left
5458 for (int j = patternLength - 1; j >= 0; j--) {
5459 int ch = seq.charAt(i+j);
5460 if (ch != src[j]) {
5461 // Shift search to the right by the maximum of the
5462 // bad character shift and the good suffix shift
5463 i += Math.max(j + 1 - lastOcc[ch&0x7F], optoSft[j]);
5464 continue NEXT;
5465 }
5466 }
5467 // Entire pattern matched starting at i
5468 matcher.first = i;
5469 boolean ret = next.match(matcher, i + patternLength, seq);
5470 if (ret) {
5471 matcher.first = i;
5472 matcher.groups[0] = matcher.first;
5473 matcher.groups[1] = matcher.last;
5474 return true;
5475 }
5476 i++;
5477 }
5478 // BnM is only used as the leading node in the unanchored case,
5479 // and it replaced its Start() which always searches to the end
5480 // if it doesn't find what it's looking for, so hitEnd is true.
5481 matcher.hitEnd = true;
5482 return false;
5483 }
5484 boolean study(TreeInfo info) {
5485 info.minLength += buffer.length;
5486 info.maxValid = false;
5487 return next.study(info);
5488 }
5489 }
5490
5491 /**
5492 * Supplementary support version of BnM(). Unpaired surrogates are
5493 * also handled by this class.
5494 */
5495 static final class BnMS extends BnM {
5496 int lengthInChars;
5497
5498 BnMS(int[] src, int[] lastOcc, int[] optoSft, Node next) {
5499 super(src, lastOcc, optoSft, next);
5500 for (int x = 0; x < buffer.length; x++) {
5501 lengthInChars += Character.charCount(buffer[x]);
5502 }
5503 }
5504 boolean match(Matcher matcher, int i, CharSequence seq) {
5505 int[] src = buffer;
5506 int patternLength = src.length;
5507 int last = matcher.to - lengthInChars;
5508
5509 // Loop over all possible match positions in text
5510 NEXT: while (i <= last) {
5511 // Loop over pattern from right to left
5512 int ch;
5513 for (int j = countChars(seq, i, patternLength), x = patternLength - 1;
5514 j > 0; j -= Character.charCount(ch), x--) {
5515 ch = Character.codePointBefore(seq, i+j);
5516 if (ch != src[x]) {
5517 // Shift search to the right by the maximum of the
5518 // bad character shift and the good suffix shift
5519 int n = Math.max(x + 1 - lastOcc[ch&0x7F], optoSft[x]);
5520 i += countChars(seq, i, n);
5521 continue NEXT;
5522 }
5523 }
5524 // Entire pattern matched starting at i
5525 matcher.first = i;
5526 boolean ret = next.match(matcher, i + lengthInChars, seq);
5527 if (ret) {
5528 matcher.first = i;
5529 matcher.groups[0] = matcher.first;
5530 matcher.groups[1] = matcher.last;
5531 return true;
5532 }
5533 i += countChars(seq, i, 1);
5534 }
5535 matcher.hitEnd = true;
5536 return false;
5537 }
5538 }
5539
5540 ///////////////////////////////////////////////////////////////////////////////
5541 ///////////////////////////////////////////////////////////////////////////////
5542
5543 /**
5544 * This must be the very first initializer.
5545 */
5546 static Node accept = new Node();
5547
5548 static Node lastAccept = new LastNode();
5549
5550 private static class CharPropertyNames {
5551
5552 static CharProperty charPropertyFor(String name) {
5553 CharPropertyFactory m = map.get(name);
5554 return m == null ? null : m.make();
5555 }
5556
5557 private static abstract class CharPropertyFactory {
5558 abstract CharProperty make();
5559 }
5560
5561 private static void defCategory(String name,
5562 final int typeMask) {
5563 map.put(name, new CharPropertyFactory() {
5564 CharProperty make() { return new Category(typeMask);}});
5565 }
5566
5567 private static void defRange(String name,
5568 final int lower, final int upper) {
5569 map.put(name, new CharPropertyFactory() {
5570 CharProperty make() { return rangeFor(lower, upper);}});
5571 }
5572
5573 private static void defCtype(String name,
5574 final int ctype) {
5575 map.put(name, new CharPropertyFactory() {
5576 CharProperty make() { return new Ctype(ctype);}});
5577 }
5578
5579 private static abstract class CloneableProperty
5580 extends CharProperty implements Cloneable
5581 {
5582 public CloneableProperty clone() {
5583 try {
5584 return (CloneableProperty) super.clone();
5585 } catch (CloneNotSupportedException e) {
5586 throw new AssertionError(e);
5587 }
5588 }
5589 }
5590
5591 private static void defClone(String name,
5592 final CloneableProperty p) {
5593 map.put(name, new CharPropertyFactory() {
5594 CharProperty make() { return p.clone();}});
5595 }
5596
5597 private static final HashMap<String, CharPropertyFactory> map
5598 = new HashMap<>();
5599
5600 static {
5601 // Unicode character property aliases, defined in
5602 // http://www.unicode.org/Public/UNIDATA/PropertyValueAliases.txt
5603 defCategory("Cn", 1<<Character.UNASSIGNED);
5604 defCategory("Lu", 1<<Character.UPPERCASE_LETTER);
5605 defCategory("Ll", 1<<Character.LOWERCASE_LETTER);
5606 defCategory("Lt", 1<<Character.TITLECASE_LETTER);
5607 defCategory("Lm", 1<<Character.MODIFIER_LETTER);
5608 defCategory("Lo", 1<<Character.OTHER_LETTER);
5609 defCategory("Mn", 1<<Character.NON_SPACING_MARK);
5610 defCategory("Me", 1<<Character.ENCLOSING_MARK);
5611 defCategory("Mc", 1<<Character.COMBINING_SPACING_MARK);
5612 defCategory("Nd", 1<<Character.DECIMAL_DIGIT_NUMBER);
5613 defCategory("Nl", 1<<Character.LETTER_NUMBER);
5614 defCategory("No", 1<<Character.OTHER_NUMBER);
5615 defCategory("Zs", 1<<Character.SPACE_SEPARATOR);
5616 defCategory("Zl", 1<<Character.LINE_SEPARATOR);
5617 defCategory("Zp", 1<<Character.PARAGRAPH_SEPARATOR);
5618 defCategory("Cc", 1<<Character.CONTROL);
5619 defCategory("Cf", 1<<Character.FORMAT);
5620 defCategory("Co", 1<<Character.PRIVATE_USE);
5621 defCategory("Cs", 1<<Character.SURROGATE);
5622 defCategory("Pd", 1<<Character.DASH_PUNCTUATION);
5623 defCategory("Ps", 1<<Character.START_PUNCTUATION);
5624 defCategory("Pe", 1<<Character.END_PUNCTUATION);
5625 defCategory("Pc", 1<<Character.CONNECTOR_PUNCTUATION);
5626 defCategory("Po", 1<<Character.OTHER_PUNCTUATION);
5627 defCategory("Sm", 1<<Character.MATH_SYMBOL);
5628 defCategory("Sc", 1<<Character.CURRENCY_SYMBOL);
5629 defCategory("Sk", 1<<Character.MODIFIER_SYMBOL);
5630 defCategory("So", 1<<Character.OTHER_SYMBOL);
5631 defCategory("Pi", 1<<Character.INITIAL_QUOTE_PUNCTUATION);
5632 defCategory("Pf", 1<<Character.FINAL_QUOTE_PUNCTUATION);
5633 defCategory("L", ((1<<Character.UPPERCASE_LETTER) |
5634 (1<<Character.LOWERCASE_LETTER) |
5635 (1<<Character.TITLECASE_LETTER) |
5636 (1<<Character.MODIFIER_LETTER) |
5637 (1<<Character.OTHER_LETTER)));
5638 defCategory("M", ((1<<Character.NON_SPACING_MARK) |
5639 (1<<Character.ENCLOSING_MARK) |
5640 (1<<Character.COMBINING_SPACING_MARK)));
5641 defCategory("N", ((1<<Character.DECIMAL_DIGIT_NUMBER) |
5642 (1<<Character.LETTER_NUMBER) |
5643 (1<<Character.OTHER_NUMBER)));
5644 defCategory("Z", ((1<<Character.SPACE_SEPARATOR) |
5645 (1<<Character.LINE_SEPARATOR) |
5646 (1<<Character.PARAGRAPH_SEPARATOR)));
5647 defCategory("C", ((1<<Character.CONTROL) |
5648 (1<<Character.FORMAT) |
5649 (1<<Character.PRIVATE_USE) |
5650 (1<<Character.SURROGATE))); // Other
5651 defCategory("P", ((1<<Character.DASH_PUNCTUATION) |
5652 (1<<Character.START_PUNCTUATION) |
5653 (1<<Character.END_PUNCTUATION) |
5654 (1<<Character.CONNECTOR_PUNCTUATION) |
5655 (1<<Character.OTHER_PUNCTUATION) |
5656 (1<<Character.INITIAL_QUOTE_PUNCTUATION) |
5657 (1<<Character.FINAL_QUOTE_PUNCTUATION)));
5658 defCategory("S", ((1<<Character.MATH_SYMBOL) |
5659 (1<<Character.CURRENCY_SYMBOL) |
5660 (1<<Character.MODIFIER_SYMBOL) |
5661 (1<<Character.OTHER_SYMBOL)));
5662 defCategory("LC", ((1<<Character.UPPERCASE_LETTER) |
5663 (1<<Character.LOWERCASE_LETTER) |
5664 (1<<Character.TITLECASE_LETTER)));
5665 defCategory("LD", ((1<<Character.UPPERCASE_LETTER) |
5666 (1<<Character.LOWERCASE_LETTER) |
5667 (1<<Character.TITLECASE_LETTER) |
5668 (1<<Character.MODIFIER_LETTER) |
5669 (1<<Character.OTHER_LETTER) |
5670 (1<<Character.DECIMAL_DIGIT_NUMBER)));
5671 defRange("L1", 0x00, 0xFF); // Latin-1
5672 map.put("all", new CharPropertyFactory() {
5673 CharProperty make() { return new All(); }});
5674
5675 // Posix regular expression character classes, defined in
5676 // http://www.unix.org/onlinepubs/009695399/basedefs/xbd_chap09.html
5677 defRange("ASCII", 0x00, 0x7F); // ASCII
5678 defCtype("Alnum", ASCII.ALNUM); // Alphanumeric characters
5679 defCtype("Alpha", ASCII.ALPHA); // Alphabetic characters
5680 defCtype("Blank", ASCII.BLANK); // Space and tab characters
5681 defCtype("Cntrl", ASCII.CNTRL); // Control characters
5682 defRange("Digit", '0', '9'); // Numeric characters
5683 defCtype("Graph", ASCII.GRAPH); // printable and visible
5684 defRange("Lower", 'a', 'z'); // Lower-case alphabetic
5685 defRange("Print", 0x20, 0x7E); // Printable characters
5686 defCtype("Punct", ASCII.PUNCT); // Punctuation characters
5687 defCtype("Space", ASCII.SPACE); // Space characters
5688 defRange("Upper", 'A', 'Z'); // Upper-case alphabetic
5689 defCtype("XDigit",ASCII.XDIGIT); // hexadecimal digits
5690
5691 // Java character properties, defined by methods in Character.java
5692 defClone("javaLowerCase", new CloneableProperty() {
5693 boolean isSatisfiedBy(int ch) {
5694 return Character.isLowerCase(ch);}});
5695 defClone("javaUpperCase", new CloneableProperty() {
5696 boolean isSatisfiedBy(int ch) {
5697 return Character.isUpperCase(ch);}});
5698 defClone("javaAlphabetic", new CloneableProperty() {
5699 boolean isSatisfiedBy(int ch) {
5700 return Character.isAlphabetic(ch);}});
5701 defClone("javaIdeographic", new CloneableProperty() {
5702 boolean isSatisfiedBy(int ch) {
5703 return Character.isIdeographic(ch);}});
5704 defClone("javaTitleCase", new CloneableProperty() {
5705 boolean isSatisfiedBy(int ch) {
5706 return Character.isTitleCase(ch);}});
5707 defClone("javaDigit", new CloneableProperty() {
5708 boolean isSatisfiedBy(int ch) {
5709 return Character.isDigit(ch);}});
5710 defClone("javaDefined", new CloneableProperty() {
5711 boolean isSatisfiedBy(int ch) {
5712 return Character.isDefined(ch);}});
5713 defClone("javaLetter", new CloneableProperty() {
5714 boolean isSatisfiedBy(int ch) {
5715 return Character.isLetter(ch);}});
5716 defClone("javaLetterOrDigit", new CloneableProperty() {
5717 boolean isSatisfiedBy(int ch) {
5718 return Character.isLetterOrDigit(ch);}});
5719 defClone("javaJavaIdentifierStart", new CloneableProperty() {
5720 boolean isSatisfiedBy(int ch) {
5721 return Character.isJavaIdentifierStart(ch);}});
5722 defClone("javaJavaIdentifierPart", new CloneableProperty() {
5723 boolean isSatisfiedBy(int ch) {
5724 return Character.isJavaIdentifierPart(ch);}});
5725 defClone("javaUnicodeIdentifierStart", new CloneableProperty() {
5726 boolean isSatisfiedBy(int ch) {
5727 return Character.isUnicodeIdentifierStart(ch);}});
5728 defClone("javaUnicodeIdentifierPart", new CloneableProperty() {
5729 boolean isSatisfiedBy(int ch) {
5730 return Character.isUnicodeIdentifierPart(ch);}});
5731 defClone("javaIdentifierIgnorable", new CloneableProperty() {
5732 boolean isSatisfiedBy(int ch) {
5733 return Character.isIdentifierIgnorable(ch);}});
5734 defClone("javaSpaceChar", new CloneableProperty() {
5735 boolean isSatisfiedBy(int ch) {
5736 return Character.isSpaceChar(ch);}});
5737 defClone("javaWhitespace", new CloneableProperty() {
5738 boolean isSatisfiedBy(int ch) {
5739 return Character.isWhitespace(ch);}});
5740 defClone("javaISOControl", new CloneableProperty() {
5741 boolean isSatisfiedBy(int ch) {
5742 return Character.isISOControl(ch);}});
5743 defClone("javaMirrored", new CloneableProperty() {
5744 boolean isSatisfiedBy(int ch) {
5745 return Character.isMirrored(ch);}});
5746 }
5747 }
5748
5749 /**
5750 * Creates a predicate which can be used to match a string.
5751 *
5752 * @return The predicate which can be used for matching on a string
5753 * @since 1.8
5754 */
5755 public Predicate<String> asPredicate() {
5756 return s -> matcher(s).find();
5757 }
5758
5759 /**
5760 * Creates a stream from the given input sequence around matches of this
5761 * pattern.
5762 *
5763 * <p> The stream returned by this method contains each substring of the
5764 * input sequence that is terminated by another subsequence that matches
5765 * this pattern or is terminated by the end of the input sequence. The
5766 * substrings in the stream are in the order in which they occur in the
5767 * input. Trailing empty strings will be discarded and not encountered in
5768 * the stream.
5769 *
5770 * <p> If this pattern does not match any subsequence of the input then
5771 * the resulting stream has just one element, namely the input sequence in
5772 * string form.
5773 *
5774 * <p> When there is a positive-width match at the beginning of the input
5775 * sequence then an empty leading substring is included at the beginning
5776 * of the stream. A zero-width match at the beginning however never produces
5777 * such empty leading substring.
5778 *
5779 * <p> If the input sequence is mutable, it must remain constant during the
5780 * execution of the terminal stream operation. Otherwise, the result of the
5781 * terminal stream operation is undefined.
5782 *
5783 * @param input
5784 * The character sequence to be split
5785 *
5786 * @return The stream of strings computed by splitting the input
5787 * around matches of this pattern
5788 * @see #split(CharSequence)
5789 * @since 1.8
5790 */
5791 public Stream<String> splitAsStream(final CharSequence input) {
5792 class MatcherIterator implements Iterator<String> {
5793 private final Matcher matcher;
5794 // The start position of the next sub-sequence of input
5795 // when current == input.length there are no more elements
5796 private int current;
5797 // null if the next element, if any, needs to obtained
5798 private String nextElement;
5799 // > 0 if there are N next empty elements
5800 private int emptyElementCount;
5801
5802 MatcherIterator() {
5803 this.matcher = matcher(input);
5804 }
5805
5806 public String next() {
5807 if (!hasNext())
5808 throw new NoSuchElementException();
5809
5810 if (emptyElementCount == 0) {
5811 String n = nextElement;
5812 nextElement = null;
5813 return n;
5814 } else {
5815 emptyElementCount--;
5816 return "";
5817 }
5818 }
5819
5820 public boolean hasNext() {
5821 if (nextElement != null || emptyElementCount > 0)
5822 return true;
5823
5824 if (current == input.length())
5825 return false;
5826
5827 // Consume the next matching element
5828 // Count sequence of matching empty elements
5829 while (matcher.find()) {
5830 nextElement = input.subSequence(current, matcher.start()).toString();
5831 current = matcher.end();
5832 if (!nextElement.isEmpty()) {
5833 return true;
5834 } else if (current > 0) { // no empty leading substring for zero-width
5835 // match at the beginning of the input
5836 emptyElementCount++;
5837 }
5838 }
5839
5840 // Consume last matching element
5841 nextElement = input.subSequence(current, input.length()).toString();
5842 current = input.length();
5843 if (!nextElement.isEmpty()) {
5844 return true;
5845 } else {
5846 // Ignore a terminal sequence of matching empty elements
5847 emptyElementCount = 0;
5848 nextElement = null;
5849 return false;
5850 }
5851 }
5852 }
5853 return StreamSupport.stream(Spliterators.spliteratorUnknownSize(
5854 new MatcherIterator(), Spliterator.ORDERED | Spliterator.NONNULL), false);
5855 }
5856 }