1 /*
2 * Copyright (c) 1999, 2019, 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.text.Normalizer.Form;
30 import java.util.Locale;
31 import java.util.Iterator;
32 import java.util.Map;
33 import java.util.ArrayList;
34 import java.util.HashMap;
35 import java.util.LinkedHashSet;
36 import java.util.List;
37 import java.util.Set;
38 import java.util.Arrays;
39 import java.util.NoSuchElementException;
40 import java.util.Spliterator;
41 import java.util.Spliterators;
42 import java.util.function.Predicate;
43 import java.util.stream.Stream;
44 import java.util.stream.StreamSupport;
45
46 import jdk.internal.util.ArraysSupport;
47
48 import sun.security.action.GetPropertyAction;
49
50 /**
51 * A compiled representation of a regular expression.
52 *
53 * <p> A regular expression, specified as a string, must first be compiled into
54 * an instance of this class. The resulting pattern can then be used to create
55 * a {@link Matcher} object that can match arbitrary {@linkplain
56 * java.lang.CharSequence character sequences} against the regular
57 * expression. All of the state involved in performing a match resides in the
58 * matcher, so many matchers can share the same pattern.
59 *
60 * <p> A typical invocation sequence is thus
61 *
62 * <blockquote><pre>
63 * Pattern p = Pattern.{@link #compile compile}("a*b");
64 * Matcher m = p.{@link #matcher matcher}("aaaaab");
65 * boolean b = m.{@link Matcher#matches matches}();</pre></blockquote>
66 *
67 * <p> A {@link #matches matches} method is defined by this class as a
68 * convenience for when a regular expression is used just once. This method
69 * compiles an expression and matches an input sequence against it in a single
70 * invocation. The statement
71 *
72 * <blockquote><pre>
73 * boolean b = Pattern.matches("a*b", "aaaaab");</pre></blockquote>
74 *
75 * is equivalent to the three statements above, though for repeated matches it
76 * is less efficient since it does not allow the compiled pattern to be reused.
77 *
78 * <p> Instances of this class are immutable and are safe for use by multiple
79 * concurrent threads. Instances of the {@link Matcher} class are not safe for
80 * such use.
81 *
82 *
83 * <h2><a id="sum">Summary of regular-expression constructs</a></h2>
84 *
85 * <table class="borderless">
86 * <caption style="display:none">Regular expression constructs, and what they match</caption>
87 * <thead style="text-align:left">
88 * <tr>
89 * <th id="construct">Construct</th>
90 * <th id="matches">Matches</th>
91 * </tr>
92 * </thead>
93 * <tbody style="text-align:left">
94 *
95 * <tr><th colspan="2" style="padding-top:20px" id="characters">Characters</th></tr>
96 *
97 * <tr><th style="vertical-align:top; font-weight: normal" id="x"><i>x</i></th>
98 * <td headers="matches characters x">The character <i>x</i></td></tr>
99 * <tr><th style="vertical-align:top; font-weight: normal" id="backslash">{@code \\}</th>
100 * <td headers="matches characters backslash">The backslash character</td></tr>
101 * <tr><th style="vertical-align:top; font-weight: normal" id="octal_n">{@code \0}<i>n</i></th>
102 * <td headers="matches characters octal_n">The character with octal value {@code 0}<i>n</i>
103 * (0 {@code <=} <i>n</i> {@code <=} 7)</td></tr>
104 * <tr><th style="vertical-align:top; font-weight: normal" id="octal_nn">{@code \0}<i>nn</i></th>
105 * <td headers="matches characters octal_nn">The character with octal value {@code 0}<i>nn</i>
106 * (0 {@code <=} <i>n</i> {@code <=} 7)</td></tr>
107 * <tr><th style="vertical-align:top; font-weight: normal" id="octal_nnn">{@code \0}<i>mnn</i></th>
108 * <td headers="matches characters octal_nnn">The character with octal value {@code 0}<i>mnn</i>
109 * (0 {@code <=} <i>m</i> {@code <=} 3,
110 * 0 {@code <=} <i>n</i> {@code <=} 7)</td></tr>
111 * <tr><th style="vertical-align:top; font-weight: normal" id="hex_hh">{@code \x}<i>hh</i></th>
112 * <td headers="matches characters hex_hh">The character with hexadecimal value {@code 0x}<i>hh</i></td></tr>
113 * <tr><th style="vertical-align:top; font-weight: normal" id="hex_hhhh"><code>\u</code><i>hhhh</i></th>
114 * <td headers="matches characters hex_hhhh">The character with hexadecimal value {@code 0x}<i>hhhh</i></td></tr>
115 * <tr><th style="vertical-align:top; font-weight: normal" id="hex_h_h"><code>\x</code><i>{h...h}</i></th>
116 * <td headers="matches characters hex_h_h">The character with hexadecimal value {@code 0x}<i>h...h</i>
117 * ({@link java.lang.Character#MIN_CODE_POINT Character.MIN_CODE_POINT}
118 * <= {@code 0x}<i>h...h</i> <=
119 * {@link java.lang.Character#MAX_CODE_POINT Character.MAX_CODE_POINT})</td></tr>
120 * <tr><th style="vertical-align:top; font-weight: normal" id="unicode_name"><code>\N{</code><i>name</i><code>}</code></th>
121 * <td headers="matches characters unicode_name">The character with Unicode character name <i>'name'</i></td></tr>
122 * <tr><th style="vertical-align:top; font-weight:normal" id="tab">{@code \t}</th>
123 * <td headers="matches characters tab">The tab character (<code>'\u0009'</code>)</td></tr>
124 * <tr><th style="vertical-align:top; font-weight:normal" id="newline">{@code \n}</th>
125 * <td headers="matches characters newline">The newline (line feed) character (<code>'\u000A'</code>)</td></tr>
126 * <tr><th style="vertical-align:top; font-weight:normal" id="return">{@code \r}</th>
127 * <td headers="matches characters return">The carriage-return character (<code>'\u000D'</code>)</td></tr>
128 * <tr><th style="vertical-align:top; font-weight:normal" id="form_feed">{@code \f}</th>
129 * <td headers="matches characters form_feed">The form-feed character (<code>'\u000C'</code>)</td></tr>
130 * <tr><th style="vertical-align:top; font-weight:normal" id="bell">{@code \a}</th>
131 * <td headers="matches characters bell">The alert (bell) character (<code>'\u0007'</code>)</td></tr>
132 * <tr><th style="vertical-align:top; font-weight:normal" id="escape">{@code \e}</th>
133 * <td headers="matches characters escape">The escape character (<code>'\u001B'</code>)</td></tr>
134 * <tr><th style="vertical-align:top; font-weight:normal" id="ctrl_x">{@code \c}<i>x</i></th>
135 * <td headers="matches characters ctrl_x">The control character corresponding to <i>x</i>
136 * (<i>x</i> is either {@code A} through {@code Z} or one of
137 * {@code ?}, {@code @}, {@code [}, {@code \\}, {@code ]}, {@code ^}, {@code _})</td></tr>
138 *
139 * <tr><th colspan="2" style="padding-top:20px" id="classes">Character classes</th></tr>
140 *
141 * <tr><th style="vertical-align:top; font-weight:normal" id="simple">{@code [abc]}</th>
142 * <td headers="matches classes simple">{@code a}, {@code b}, or {@code c} (simple class)</td></tr>
143 * <tr><th style="vertical-align:top; font-weight:normal" id="negation">{@code [^abc]}</th>
144 * <td headers="matches classes negation">Any character except {@code a}, {@code b}, or {@code c} (negation)</td></tr>
145 * <tr><th style="vertical-align:top; font-weight:normal" id="range">{@code [a-zA-Z]}</th>
146 * <td headers="matches classes range">{@code a} through {@code z}
147 * or {@code A} through {@code Z}, inclusive (range)</td></tr>
148 * <tr><th style="vertical-align:top; font-weight:normal" id="union">{@code [a-d[m-p]]}</th>
149 * <td headers="matches classes union">{@code a} through {@code d},
150 * or {@code m} through {@code p}: {@code [a-dm-p]} (union)</td></tr>
151 * <tr><th style="vertical-align:top; font-weight:normal" id="intersection">{@code [a-z&&[def]]}</th>
152 * <td headers="matches classes intersection">{@code d}, {@code e}, or {@code f} (intersection)</tr>
153 * <tr><th style="vertical-align:top; font-weight:normal" id="subtraction1">{@code [a-z&&[^bc]]}</th>
154 * <td headers="matches classes subtraction1">{@code a} through {@code z},
155 * except for {@code b} and {@code c}: {@code [ad-z]} (subtraction)</td></tr>
156 * <tr><th style="vertical-align:top; font-weight:normal" id="subtraction2">{@code [a-z&&[^m-p]]}</th>
157 * <td headers="matches classes subtraction2">{@code a} through {@code z},
158 * and not {@code m} through {@code p}: {@code [a-lq-z]} (subtraction)</td></tr>
159 *
160 * <tr><th colspan="2" style="padding-top:20px" id="predef">Predefined character classes</th></tr>
161 *
162 * <tr><th style="vertical-align:top; font-weight:normal" id="any">{@code .}</th>
163 * <td headers="matches predef any">Any character (may or may not match <a href="#lt">line terminators</a>)</td></tr>
164 * <tr><th style="vertical-align:top; font-weight:normal" id="digit">{@code \d}</th>
165 * <td headers="matches predef digit">A digit: {@code [0-9]}</td></tr>
166 * <tr><th style="vertical-align:top; font-weight:normal" id="non_digit">{@code \D}</th>
167 * <td headers="matches predef non_digit">A non-digit: {@code [^0-9]}</td></tr>
168 * <tr><th style="vertical-align:top; font-weight:normal" id="horiz_white">{@code \h}</th>
169 * <td headers="matches predef horiz_white">A horizontal whitespace character:
170 * <code>[ \t\xA0\u1680\u180e\u2000-\u200a\u202f\u205f\u3000]</code></td></tr>
171 * <tr><th style="vertical-align:top; font-weight:normal" id="non_horiz_white">{@code \H}</th>
172 * <td headers="matches predef non_horiz_white">A non-horizontal whitespace character: {@code [^\h]}</td></tr>
173 * <tr><th style="vertical-align:top; font-weight:normal" id="white">{@code \s}</th>
174 * <td headers="matches predef white">A whitespace character: {@code [ \t\n\x0B\f\r]}</td></tr>
175 * <tr><th style="vertical-align:top; font-weight:normal" id="non_white">{@code \S}</th>
176 * <td headers="matches predef non_white">A non-whitespace character: {@code [^\s]}</td></tr>
177 * <tr><th style="vertical-align:top; font-weight:normal" id="vert_white">{@code \v}</th>
178 * <td headers="matches predef vert_white">A vertical whitespace character: <code>[\n\x0B\f\r\x85\u2028\u2029]</code>
179 * </td></tr>
180 * <tr><th style="vertical-align:top; font-weight:normal" id="non_vert_white">{@code \V}</th>
181 * <td headers="matches predef non_vert_white">A non-vertical whitespace character: {@code [^\v]}</td></tr>
182 * <tr><th style="vertical-align:top; font-weight:normal" id="word">{@code \w}</th>
183 * <td headers="matches predef word">A word character: {@code [a-zA-Z_0-9]}</td></tr>
184 * <tr><th style="vertical-align:top; font-weight:normal" id="non_word">{@code \W}</th>
185 * <td headers="matches predef non_word">A non-word character: {@code [^\w]}</td></tr>
186 *
187 * <tr><th colspan="2" style="padding-top:20px" id="posix"><b>POSIX character classes (US-ASCII only)</b></th></tr>
188 *
189 * <tr><th style="vertical-align:top; font-weight:normal" id="Lower">{@code \p{Lower}}</th>
190 * <td headers="matches posix Lower">A lower-case alphabetic character: {@code [a-z]}</td></tr>
191 * <tr><th style="vertical-align:top; font-weight:normal" id="Upper">{@code \p{Upper}}</th>
192 * <td headers="matches posix Upper">An upper-case alphabetic character:{@code [A-Z]}</td></tr>
193 * <tr><th style="vertical-align:top; font-weight:normal" id="ASCII">{@code \p{ASCII}}</th>
194 * <td headers="matches posix ASCII">All ASCII:{@code [\x00-\x7F]}</td></tr>
195 * <tr><th style="vertical-align:top; font-weight:normal" id="Alpha">{@code \p{Alpha}}</th>
196 * <td headers="matches posix Alpha">An alphabetic character:{@code [\p{Lower}\p{Upper}]}</td></tr>
197 * <tr><th style="vertical-align:top; font-weight:normal" id="Digit">{@code \p{Digit}}</th>
198 * <td headers="matches posix Digit">A decimal digit: {@code [0-9]}</td></tr>
199 * <tr><th style="vertical-align:top; font-weight:normal" id="Alnum">{@code \p{Alnum}}</th>
200 * <td headers="matches posix Alnum">An alphanumeric character:{@code [\p{Alpha}\p{Digit}]}</td></tr>
201 * <tr><th style="vertical-align:top; font-weight:normal" id="Punct">{@code \p{Punct}}</th>
202 * <td headers="matches posix Punct">Punctuation: One of {@code !"#$%&'()*+,-./:;<=>?@[\]^_`{|}~}</td></tr>
203 * <!-- {@code [\!"#\$%&'\(\)\*\+,\-\./:;\<=\>\?@\[\\\]\^_`\{\|\}~]}
204 * {@code [\X21-\X2F\X31-\X40\X5B-\X60\X7B-\X7E]} -->
205 * <tr><th style="vertical-align:top; font-weight:normal" id="Graph">{@code \p{Graph}}</th>
206 * <td headers="matches posix Graph">A visible character: {@code [\p{Alnum}\p{Punct}]}</td></tr>
207 * <tr><th style="vertical-align:top; font-weight:normal" id="Print">{@code \p{Print}}</th>
208 * <td headers="matches posix Print">A printable character: {@code [\p{Graph}\x20]}</td></tr>
209 * <tr><th style="vertical-align:top; font-weight:normal" id="Blank">{@code \p{Blank}}</th>
210 * <td headers="matches posix Blank">A space or a tab: {@code [ \t]}</td></tr>
211 * <tr><th style="vertical-align:top; font-weight:normal" id="Cntrl">{@code \p{Cntrl}}</th>
212 * <td headers="matches posix Cntrl">A control character: {@code [\x00-\x1F\x7F]}</td></tr>
213 * <tr><th style="vertical-align:top; font-weight:normal" id="XDigit">{@code \p{XDigit}}</th>
214 * <td headers="matches posix XDigit">A hexadecimal digit: {@code [0-9a-fA-F]}</td></tr>
215 * <tr><th style="vertical-align:top; font-weight:normal" id="Space">{@code \p{Space}}</th>
216 * <td headers="matches posix Space">A whitespace character: {@code [ \t\n\x0B\f\r]}</td></tr>
217 *
218 * <tr><th colspan="2" style="padding-top:20px" id="java">java.lang.Character classes (simple <a href="#jcc">java character type</a>)</th></tr>
219 *
220 * <tr><th style="vertical-align:top; font-weight:normal" id="javaLowerCase">{@code \p{javaLowerCase}}</th>
221 * <td headers="matches java javaLowerCase">Equivalent to java.lang.Character.isLowerCase()</td></tr>
222 * <tr><th style="vertical-align:top; font-weight:normal" id="javaUpperCase">{@code \p{javaUpperCase}}</th>
223 * <td headers="matches java javaUpperCase">Equivalent to java.lang.Character.isUpperCase()</td></tr>
224 * <tr><th style="vertical-align:top; font-weight:normal" id="javaWhitespace">{@code \p{javaWhitespace}}</th>
225 * <td headers="matches java javaWhitespace">Equivalent to java.lang.Character.isWhitespace()</td></tr>
226 * <tr><th style="vertical-align:top; font-weight:normal" id="javaMirrored">{@code \p{javaMirrored}}</th>
227 * <td headers="matches java javaMirrored">Equivalent to java.lang.Character.isMirrored()</td></tr>
228 *
229 * <tr><th colspan="2" style="padding-top:20px" id="unicode">Classes for Unicode scripts, blocks, categories and binary properties</th></tr>
230 *
231 * <tr><th style="vertical-align:top; font-weight:normal" id="IsLatin">{@code \p{IsLatin}}</th>
232 * <td headers="matches unicode IsLatin">A Latin script character (<a href="#usc">script</a>)</td></tr>
233 * <tr><th style="vertical-align:top; font-weight:normal" id="InGreek">{@code \p{InGreek}}</th>
234 * <td headers="matches unicode InGreek">A character in the Greek block (<a href="#ubc">block</a>)</td></tr>
235 * <tr><th style="vertical-align:top; font-weight:normal" id="Lu">{@code \p{Lu}}</th>
236 * <td headers="matches unicode Lu">An uppercase letter (<a href="#ucc">category</a>)</td></tr>
237 * <tr><th style="vertical-align:top; font-weight:normal" id="IsAlphabetic">{@code \p{IsAlphabetic}}</th>
238 * <td headers="matches unicode IsAlphabetic">An alphabetic character (<a href="#ubpc">binary property</a>)</td></tr>
239 * <tr><th style="vertical-align:top; font-weight:normal" id="Sc">{@code \p{Sc}}</th>
240 * <td headers="matches unicode Sc">A currency symbol</td></tr>
241 * <tr><th style="vertical-align:top; font-weight:normal" id="not_InGreek">{@code \P{InGreek}}</th>
242 * <td headers="matches unicode not_InGreek">Any character except one in the Greek block (negation)</td></tr>
243 * <tr><th style="vertical-align:top; font-weight:normal" id="not_uppercase">{@code [\p{L}&&[^\p{Lu}]]}</th>
244 * <td headers="matches unicode not_uppercase">Any letter except an uppercase letter (subtraction)</td></tr>
245 *
246 * <tr><th colspan="2" style="padding-top:20px" id="bounds">Boundary matchers</th></tr>
247 *
248 * <tr><th style="vertical-align:top; font-weight:normal" id="begin_line">{@code ^}</th>
249 * <td headers="matches bounds begin_line">The beginning of a line</td></tr>
250 * <tr><th style="vertical-align:top; font-weight:normal" id="end_line">{@code $}</th>
251 * <td headers="matches bounds end_line">The end of a line</td></tr>
252 * <tr><th style="vertical-align:top; font-weight:normal" id="word_boundary">{@code \b}</th>
253 * <td headers="matches bounds word_boundary">A word boundary</td></tr>
254 * <tr><th style="vertical-align:top; font-weight:normal" id="grapheme_cluster_boundary">{@code \b{g}}</th>
255 * <td headers="matches bounds grapheme_cluster_boundary">A Unicode extended grapheme cluster boundary</td></tr>
256 * <tr><th style="vertical-align:top; font-weight:normal" id="non_word_boundary">{@code \B}</th>
257 * <td headers="matches bounds non_word_boundary">A non-word boundary</td></tr>
258 * <tr><th style="vertical-align:top; font-weight:normal" id="begin_input">{@code \A}</th>
259 * <td headers="matches bounds begin_input">The beginning of the input</td></tr>
260 * <tr><th style="vertical-align:top; font-weight:normal" id="end_prev_match">{@code \G}</th>
261 * <td headers="matches bounds end_prev_match">The end of the previous match</td></tr>
262 * <tr><th style="vertical-align:top; font-weight:normal" id="end_input_except_term">{@code \Z}</th>
263 * <td headers="matches bounds end_input_except_term">The end of the input but for the final
264 * <a href="#lt">terminator</a>, if any</td></tr>
265 * <tr><th style="vertical-align:top; font-weight:normal" id="end_input">{@code \z}</th>
266 * <td headers="matches bounds end_input">The end of the input</td></tr>
267 *
268 * <tr><th colspan="2" style="padding-top:20px" id="linebreak">Linebreak matcher</th></tr>
269 *
270 * <tr><th style="vertical-align:top; font-weight:normal" id="any_unicode_linebreak">{@code \R}</th>
271 * <td headers="matches linebreak any_unicode_linebreak">Any Unicode linebreak sequence, is equivalent to
272 * <code>\u000D\u000A|[\u000A\u000B\u000C\u000D\u0085\u2028\u2029]
273 * </code></td></tr>
274 *
275 * <tr><th colspan="2" style="padding-top:20px" id="grapheme">Unicode Extended Grapheme matcher</th></tr>
276 *
277 * <tr><th style="vertical-align:top; font-weight:normal" id="grapheme_any">{@code \X}</th>
278 * <td headers="matches grapheme grapheme_any">Any Unicode extended grapheme cluster</td></tr>
279 *
280 * <tr><th colspan="2" style="padding-top:20px" id="greedy">Greedy quantifiers</th></tr>
281 *
282 * <tr><th style="vertical-align:top; font-weight:normal" id="greedy_once_or_not"><i>X</i>{@code ?}</th>
283 * <td headers="matches greedy greedy_once_or_not"><i>X</i>, once or not at all</td></tr>
284 * <tr><th style="vertical-align:top; font-weight:normal" id="greedy_zero_or_more"><i>X</i>{@code *}</th>
285 * <td headers="matches greedy greedy_zero_or_more"><i>X</i>, zero or more times</td></tr>
286 * <tr><th style="vertical-align:top; font-weight:normal" id="greedy_one_or_more"><i>X</i>{@code +}</th>
287 * <td headers="matches greedy greedy_one_or_more"><i>X</i>, one or more times</td></tr>
288 * <tr><th style="vertical-align:top; font-weight:normal" id="greedy_exactly"><i>X</i><code>{</code><i>n</i><code>}</code></th>
289 * <td headers="matches greedy greedy_exactly"><i>X</i>, exactly <i>n</i> times</td></tr>
290 * <tr><th style="vertical-align:top; font-weight:normal" id="greedy_at_least"><i>X</i><code>{</code><i>n</i>{@code ,}}</th>
291 * <td headers="matches greedy greedy_at_least"><i>X</i>, at least <i>n</i> times</td></tr>
292 * <tr><th style="vertical-align:top; font-weight:normal" id="greedy_at_least_up_to"><i>X</i><code>{</code><i>n</i>{@code ,}<i>m</i><code>}</code></th>
293 * <td headers="matches greedy greedy_at_least_up_to"><i>X</i>, at least <i>n</i> but not more than <i>m</i> times</td></tr>
294 *
295 * <tr><th colspan="2" style="padding-top:20px" id="reluc">Reluctant quantifiers</th></tr>
296 *
297 * <tr><th style="vertical-align:top; font-weight:normal" id="reluc_once_or_not"><i>X</i>{@code ??}</th>
298 * <td headers="matches reluc reluc_once_or_not"><i>X</i>, once or not at all</td></tr>
299 * <tr><th style="vertical-align:top; font-weight:normal" id="reluc_zero_or_more"><i>X</i>{@code *?}</th>
300 * <td headers="matches reluc reluc_zero_or_more"><i>X</i>, zero or more times</td></tr>
301 * <tr><th style="vertical-align:top; font-weight:normal" id="reluc_one_or_more"><i>X</i>{@code +?}</th>
302 * <td headers="matches reluc reluc_one_or_more"><i>X</i>, one or more times</td></tr>
303 * <tr><th style="vertical-align:top; font-weight:normal" id="reluc_exactly"><i>X</i><code>{</code><i>n</i><code>}?</code></th>
304 * <td headers="matches reluc reluc_exactly"><i>X</i>, exactly <i>n</i> times</td></tr>
305 * <tr><th style="vertical-align:top; font-weight:normal" id="reluc_at_least"><i>X</i><code>{</code><i>n</i><code>,}?</code></th>
306 * <td headers="matches reluc reluc_at_least"><i>X</i>, at least <i>n</i> times</td></tr>
307 * <tr><th style="vertical-align:top; font-weight:normal" id="reluc_at_least_up_to"><i>X</i><code>{</code><i>n</i>{@code ,}<i>m</i><code>}?</code></th>
308 * <td headers="matches reluc reluc_at_least_up_to"><i>X</i>, at least <i>n</i> but not more than <i>m</i> times</td></tr>
309 *
310 * <tr><th colspan="2" style="padding-top:20px" id="poss">Possessive quantifiers</th></tr>
311 *
312 * <tr><th style="vertical-align:top; font-weight:normal" id="poss_once_or_not"><i>X</i>{@code ?+}</th>
313 * <td headers="matches poss poss_once_or_not"><i>X</i>, once or not at all</td></tr>
314 * <tr><th style="vertical-align:top; font-weight:normal" id="poss_zero_or_more"><i>X</i>{@code *+}</th>
315 * <td headers="matches poss poss_zero_or_more"><i>X</i>, zero or more times</td></tr>
316 * <tr><th style="vertical-align:top; font-weight:normal" id="poss_one_or_more"><i>X</i>{@code ++}</th>
317 * <td headers="matches poss poss_one_or_more"><i>X</i>, one or more times</td></tr>
318 * <tr><th style="vertical-align:top; font-weight:normal" id="poss_exactly"><i>X</i><code>{</code><i>n</i><code>}+</code></th>
319 * <td headers="matches poss poss_exactly"><i>X</i>, exactly <i>n</i> times</td></tr>
320 * <tr><th style="vertical-align:top; font-weight:normal" id="poss_at_least"><i>X</i><code>{</code><i>n</i><code>,}+</code></th>
321 * <td headers="matches poss poss_at_least"><i>X</i>, at least <i>n</i> times</td></tr>
322 * <tr><th style="vertical-align:top; font-weight:normal" id="poss_at_least_up_to"><i>X</i><code>{</code><i>n</i>{@code ,}<i>m</i><code>}+</code></th>
323 * <td headers="matches poss poss_at_least_up_to"><i>X</i>, at least <i>n</i> but not more than <i>m</i> times</td></tr>
324 *
325 * <tr><th colspan="2" style="padding-top:20px" id="logical">Logical operators</th></tr>
326 *
327 * <tr><th style="vertical-align:top; font-weight:normal" id="concat"><i>XY</i></th>
328 * <td headers="matches logical concat"><i>X</i> followed by <i>Y</i></td></tr>
329 * <tr><th style="vertical-align:top; font-weight:normal" id="alternate"><i>X</i>{@code |}<i>Y</i></th>
330 * <td headers="matches logical alternate">Either <i>X</i> or <i>Y</i></td></tr>
331 * <tr><th style="vertical-align:top; font-weight:normal" id="group">{@code (}<i>X</i>{@code )}</th>
332 * <td headers="matches logical group">X, as a <a href="#cg">capturing group</a></td></tr>
333 *
334 * <tr><th colspan="2" style="padding-top:20px" id="backref">Back references</th></tr>
335 *
336 * <tr><th style="vertical-align:top; font-weight:normal" id="back_nth">{@code \}<i>n</i></th>
337 * <td headers="matches backref back_nth">Whatever the <i>n</i><sup>th</sup>
338 * <a href="#cg">capturing group</a> matched</td></tr>
339 * <tr><th style="vertical-align:top; font-weight:normal" id="back_named">{@code \}<i>k</i><<i>name</i>></th>
340 * <td headers="matches backref back_named">Whatever the
341 * <a href="#groupname">named-capturing group</a> "name" matched</td></tr>
342 *
343 * <tr><th colspan="2" style="padding-top:20px" id="quote">Quotation</th></tr>
344 *
345 * <tr><th style="vertical-align:top; font-weight:normal" id="quote_follow">{@code \}</th>
346 * <td headers="matches quote quote_follow">Nothing, but quotes the following character</td></tr>
347 * <tr><th style="vertical-align:top; font-weight:normal" id="quote_begin">{@code \Q}</th>
348 * <td headers="matches quote quote_begin">Nothing, but quotes all characters until {@code \E}</td></tr>
349 * <tr><th style="vertical-align:top; font-weight:normal" id="quote_end">{@code \E}</th>
350 * <td headers="matches quote quote_end">Nothing, but ends quoting started by {@code \Q}</td></tr>
351 * <!-- Metachars: !$()*+.<>?[\]^{|} -->
352 *
353 * <tr><th colspan="2" style="padding-top:20px" id="special">Special constructs (named-capturing and non-capturing)</th></tr>
354 *
355 * <tr><th style="vertical-align:top; font-weight:normal" id="named_group"><code>(?<<a href="#groupname">name</a>></code><i>X</i>{@code )}</th>
356 * <td headers="matches special named_group"><i>X</i>, as a named-capturing group</td></tr>
357 * <tr><th style="vertical-align:top; font-weight:normal" id="non_capture_group">{@code (?:}<i>X</i>{@code )}</th>
358 * <td headers="matches special non_capture_group"><i>X</i>, as a non-capturing group</td></tr>
359 * <tr><th style="vertical-align:top; font-weight:normal" id="flags"><code>(?idmsuxU-idmsuxU) </code></th>
360 * <td headers="matches special flags">Nothing, but turns match flags <a href="#CASE_INSENSITIVE">i</a>
361 * <a href="#UNIX_LINES">d</a> <a href="#MULTILINE">m</a> <a href="#DOTALL">s</a>
362 * <a href="#UNICODE_CASE">u</a> <a href="#COMMENTS">x</a> <a href="#UNICODE_CHARACTER_CLASS">U</a>
363 * on - off</td></tr>
364 * <tr><th style="vertical-align:top; font-weight:normal" id="non_capture_group_flags"><code>(?idmsuxU-idmsuxU:</code><i>X</i>{@code )} </th>
365 * <td headers="matches special non_capture_group_flags"><i>X</i>, as a <a href="#cg">non-capturing group</a> with the
366 * given flags <a href="#CASE_INSENSITIVE">i</a> <a href="#UNIX_LINES">d</a>
367 * <a href="#MULTILINE">m</a> <a href="#DOTALL">s</a> <a href="#UNICODE_CASE">u</a >
368 * <a href="#COMMENTS">x</a> <a href="#UNICODE_CHARACTER_CLASS">U</a> on - off</td></tr>
369 * <tr><th style="vertical-align:top; font-weight:normal" id="pos_lookahead">{@code (?=}<i>X</i>{@code )}</th>
370 * <td headers="matches special pos_lookahead"><i>X</i>, via zero-width positive lookahead</td></tr>
371 * <tr><th style="vertical-align:top; font-weight:normal" id="neg_lookahead">{@code (?!}<i>X</i>{@code )}</th>
372 * <td headers="matches special neg_lookahead"><i>X</i>, via zero-width negative lookahead</td></tr>
373 * <tr><th style="vertical-align:top; font-weight:normal" id="pos_lookbehind">{@code (?<=}<i>X</i>{@code )}</th>
374 * <td headers="matches special pos_lookbehind"><i>X</i>, via zero-width positive lookbehind</td></tr>
375 * <tr><th style="vertical-align:top; font-weight:normal" id="neg_lookbehind">{@code (?<!}<i>X</i>{@code )}</th>
376 * <td headers="matches special neg_lookbehind"><i>X</i>, via zero-width negative lookbehind</td></tr>
377 * <tr><th style="vertical-align:top; font-weight:normal" id="indep_non_capture_group">{@code (?>}<i>X</i>{@code )}</th>
378 * <td headers="matches special indep_non_capture_group"><i>X</i>, as an independent, non-capturing group</td></tr>
379 *
380 * </tbody>
381 * </table>
382 *
383 * <hr>
384 *
385 *
386 * <h2><a id="bs">Backslashes, escapes, and quoting</a></h2>
387 *
388 * <p> The backslash character ({@code '\'}) serves to introduce escaped
389 * constructs, as defined in the table above, as well as to quote characters
390 * that otherwise would be interpreted as unescaped constructs. Thus the
391 * expression {@code \\} matches a single backslash and <code>\{</code> matches a
392 * left brace.
393 *
394 * <p> It is an error to use a backslash prior to any alphabetic character that
395 * does not denote an escaped construct; these are reserved for future
396 * extensions to the regular-expression language. A backslash may be used
397 * prior to a non-alphabetic character regardless of whether that character is
398 * part of an unescaped construct.
399 *
400 * <p> Backslashes within string literals in Java source code are interpreted
401 * as required by
402 * <cite>The Java™ Language Specification</cite>
403 * as either Unicode escapes (section 3.3) or other character escapes (section 3.10.6)
404 * It is therefore necessary to double backslashes in string
405 * literals that represent regular expressions to protect them from
406 * interpretation by the Java bytecode compiler. The string literal
407 * <code>"\b"</code>, for example, matches a single backspace character when
408 * interpreted as a regular expression, while {@code "\\b"} matches a
409 * word boundary. The string literal {@code "\(hello\)"} is illegal
410 * and leads to a compile-time error; in order to match the string
411 * {@code (hello)} the string literal {@code "\\(hello\\)"}
412 * must be used.
413 *
414 * <h2><a id="cc">Character Classes</a></h2>
415 *
416 * <p> Character classes may appear within other character classes, and
417 * may be composed by the union operator (implicit) and the intersection
418 * operator ({@code &&}).
419 * The union operator denotes a class that contains every character that is
420 * in at least one of its operand classes. The intersection operator
421 * denotes a class that contains every character that is in both of its
422 * operand classes.
423 *
424 * <p> The precedence of character-class operators is as follows, from
425 * highest to lowest:
426 *
427 * <table class="striped" style="margin-left: 2em;">
428 * <caption style="display:none">Precedence of character class operators.</caption>
429 * <thead>
430 * <tr><th scope="col">Precedence<th scope="col">Name<th scope="col">Example
431 * </thead>
432 * <tbody>
433 * <tr><th scope="row">1</th>
434 * <td>Literal escape </td>
435 * <td>{@code \x}</td></tr>
436 * <tr><th scope="row">2</th>
437 * <td>Grouping</td>
438 * <td>{@code [...]}</td></tr>
439 * <tr><th scope="row">3</th>
440 * <td>Range</td>
441 * <td>{@code a-z}</td></tr>
442 * <tr><th scope="row">4</th>
443 * <td>Union</td>
444 * <td>{@code [a-e][i-u]}</td></tr>
445 * <tr><th scope="row">5</th>
446 * <td>Intersection</td>
447 * <td>{@code [a-z&&[aeiou]]}</td></tr>
448 * </tbody>
449 * </table>
450 *
451 * <p> Note that a different set of metacharacters are in effect inside
452 * a character class than outside a character class. For instance, the
453 * regular expression {@code .} loses its special meaning inside a
454 * character class, while the expression {@code -} becomes a range
455 * forming metacharacter.
456 *
457 * <h2><a id="lt">Line terminators</a></h2>
458 *
459 * <p> A <i>line terminator</i> is a one- or two-character sequence that marks
460 * the end of a line of the input character sequence. The following are
461 * recognized as line terminators:
462 *
463 * <ul>
464 *
465 * <li> A newline (line feed) character ({@code '\n'}),
466 *
467 * <li> A carriage-return character followed immediately by a newline
468 * character ({@code "\r\n"}),
469 *
470 * <li> A standalone carriage-return character ({@code '\r'}),
471 *
472 * <li> A next-line character (<code>'\u0085'</code>),
473 *
474 * <li> A line-separator character (<code>'\u2028'</code>), or
475 *
476 * <li> A paragraph-separator character (<code>'\u2029'</code>).
477 *
478 * </ul>
479 * <p>If {@link #UNIX_LINES} mode is activated, then the only line terminators
480 * recognized are newline characters.
481 *
482 * <p> The regular expression {@code .} matches any character except a line
483 * terminator unless the {@link #DOTALL} flag is specified.
484 *
485 * <p> By default, the regular expressions {@code ^} and {@code $} ignore
486 * line terminators and only match at the beginning and the end, respectively,
487 * of the entire input sequence. If {@link #MULTILINE} mode is activated then
488 * {@code ^} matches at the beginning of input and after any line terminator
489 * except at the end of input. When in {@link #MULTILINE} mode {@code $}
490 * matches just before a line terminator or the end of the input sequence.
491 *
492 * <h2><a id="cg">Groups and capturing</a></h2>
493 *
494 * <h3><a id="gnumber">Group number</a></h3>
495 * <p> Capturing groups are numbered by counting their opening parentheses from
496 * left to right. In the expression {@code ((A)(B(C)))}, for example, there
497 * are four such groups: </p>
498 *
499 * <ol style="margin-left:2em;">
500 * <li> {@code ((A)(B(C)))}
501 * <li> {@code (A)}
502 * <li> {@code (B(C))}
503 * <li> {@code (C)}
504 * </ol>
505 *
506 * <p> Group zero always stands for the entire expression.
507 *
508 * <p> Capturing groups are so named because, during a match, each subsequence
509 * of the input sequence that matches such a group is saved. The captured
510 * subsequence may be used later in the expression, via a back reference, and
511 * may also be retrieved from the matcher once the match operation is complete.
512 *
513 * <h3><a id="groupname">Group name</a></h3>
514 * <p>A capturing group can also be assigned a "name", a {@code named-capturing group},
515 * and then be back-referenced later by the "name". Group names are composed of
516 * the following characters. The first character must be a {@code letter}.
517 *
518 * <ul>
519 * <li> The uppercase letters {@code 'A'} through {@code 'Z'}
520 * (<code>'\u0041'</code> through <code>'\u005a'</code>),
521 * <li> The lowercase letters {@code 'a'} through {@code 'z'}
522 * (<code>'\u0061'</code> through <code>'\u007a'</code>),
523 * <li> The digits {@code '0'} through {@code '9'}
524 * (<code>'\u0030'</code> through <code>'\u0039'</code>),
525 * </ul>
526 *
527 * <p> A {@code named-capturing group} is still numbered as described in
528 * <a href="#gnumber">Group number</a>.
529 *
530 * <p> The captured input associated with a group is always the subsequence
531 * that the group most recently matched. If a group is evaluated a second time
532 * because of quantification then its previously-captured value, if any, will
533 * be retained if the second evaluation fails. Matching the string
534 * {@code "aba"} against the expression {@code (a(b)?)+}, for example, leaves
535 * group two set to {@code "b"}. All captured input is discarded at the
536 * beginning of each match.
537 *
538 * <p> Groups beginning with {@code (?} are either pure, <i>non-capturing</i> groups
539 * that do not capture text and do not count towards the group total, or
540 * <i>named-capturing</i> group.
541 *
542 * <h2> Unicode support </h2>
543 *
544 * <p> This class is in conformance with Level 1 of <a
545 * href="http://www.unicode.org/reports/tr18/"><i>Unicode Technical
546 * Standard #18: Unicode Regular Expression</i></a>, plus RL2.1
547 * Canonical Equivalents and RL2.2 Extended Grapheme Clusters.
548 * <p>
549 * <b>Unicode escape sequences</b> such as <code>\u2014</code> in Java source code
550 * are processed as described in section 3.3 of
551 * <cite>The Java™ Language Specification</cite>.
552 * Such escape sequences are also implemented directly by the regular-expression
553 * parser so that Unicode escapes can be used in expressions that are read from
554 * files or from the keyboard. Thus the strings <code>"\u2014"</code> and
555 * {@code "\\u2014"}, while not equal, compile into the same pattern, which
556 * matches the character with hexadecimal value {@code 0x2014}.
557 * <p>
558 * A Unicode character can also be represented by using its <b>Hex notation</b>
559 * (hexadecimal code point value) directly as described in construct
560 * <code>\x{...}</code>, for example a supplementary character U+2011F can be
561 * specified as <code>\x{2011F}</code>, instead of two consecutive Unicode escape
562 * sequences of the surrogate pair <code>\uD840</code><code>\uDD1F</code>.
563 * <p>
564 * <b>Unicode character names</b> are supported by the named character construct
565 * <code>\N{</code>...<code>}</code>, for example, <code>\N{WHITE SMILING FACE}</code>
566 * specifies character <code>\u263A</code>. The character names supported
567 * by this class are the valid Unicode character names matched by
568 * {@link java.lang.Character#codePointOf(String) Character.codePointOf(name)}.
569 * <p>
570 * <a href="http://www.unicode.org/reports/tr18/#Default_Grapheme_Clusters">
571 * <b>Unicode extended grapheme clusters</b></a> are supported by the grapheme
572 * cluster matcher {@code \X} and the corresponding boundary matcher {@code \b{g}}.
573 * <p>
574 * Unicode scripts, blocks, categories and binary properties are written with
575 * the {@code \p} and {@code \P} constructs as in Perl.
576 * <code>\p{</code><i>prop</i><code>}</code> matches if
577 * the input has the property <i>prop</i>, while <code>\P{</code><i>prop</i><code>}</code>
578 * does not match if the input has that property.
579 * <p>
580 * Scripts, blocks, categories and binary properties can be used both inside
581 * and outside of a character class.
582 *
583 * <p>
584 * <b><a id="usc">Scripts</a></b> are specified either with the prefix {@code Is}, as in
585 * {@code IsHiragana}, or by using the {@code script} keyword (or its short
586 * form {@code sc}) as in {@code script=Hiragana} or {@code sc=Hiragana}.
587 * <p>
588 * The script names supported by {@code Pattern} are the valid script names
589 * accepted and defined by
590 * {@link java.lang.Character.UnicodeScript#forName(String) UnicodeScript.forName}.
591 *
592 * <p>
593 * <b><a id="ubc">Blocks</a></b> are specified with the prefix {@code In}, as in
594 * {@code InMongolian}, or by using the keyword {@code block} (or its short
595 * form {@code blk}) as in {@code block=Mongolian} or {@code blk=Mongolian}.
596 * <p>
597 * The block names supported by {@code Pattern} are the valid block names
598 * accepted and defined by
599 * {@link java.lang.Character.UnicodeBlock#forName(String) UnicodeBlock.forName}.
600 * <p>
601 *
602 * <b><a id="ucc">Categories</a></b> may be specified with the optional prefix {@code Is}:
603 * Both {@code \p{L}} and {@code \p{IsL}} denote the category of Unicode
604 * letters. Same as scripts and blocks, categories can also be specified
605 * by using the keyword {@code general_category} (or its short form
606 * {@code gc}) as in {@code general_category=Lu} or {@code gc=Lu}.
607 * <p>
608 * The supported categories are those of
609 * <a href="http://www.unicode.org/unicode/standard/standard.html">
610 * <i>The Unicode Standard</i></a> in the version specified by the
611 * {@link java.lang.Character Character} class. The category names are those
612 * defined in the Standard, both normative and informative.
613 * <p>
614 *
615 * <b><a id="ubpc">Binary properties</a></b> are specified with the prefix {@code Is}, as in
616 * {@code IsAlphabetic}. The supported binary properties by {@code Pattern}
617 * are
618 * <ul>
619 * <li> Alphabetic
620 * <li> Ideographic
621 * <li> Letter
622 * <li> Lowercase
623 * <li> Uppercase
624 * <li> Titlecase
625 * <li> Punctuation
626 * <Li> Control
627 * <li> White_Space
628 * <li> Digit
629 * <li> Hex_Digit
630 * <li> Join_Control
631 * <li> Noncharacter_Code_Point
632 * <li> Assigned
633 * </ul>
634 * <p>
635 * The following <b>Predefined Character classes</b> and <b>POSIX character classes</b>
636 * are in conformance with the recommendation of <i>Annex C: Compatibility Properties</i>
637 * of <a href="http://www.unicode.org/reports/tr18/"><i>Unicode Regular Expression
638 * </i></a>, when {@link #UNICODE_CHARACTER_CLASS} flag is specified.
639 *
640 * <table class="striped">
641 * <caption style="display:none">predefined and posix character classes in Unicode mode</caption>
642 * <thead>
643 * <tr>
644 * <th scope="col" id="predef_classes">Classes</th>
645 * <th scope="col" id="predef_matches">Matches</th>
646 * </tr>
647 * </thead>
648 * <tbody>
649 * <tr><th scope="row">{@code \p{Lower}}</th>
650 * <td>A lowercase character:{@code \p{IsLowercase}}</td></tr>
651 * <tr><th scope="row">{@code \p{Upper}}</th>
652 * <td>An uppercase character:{@code \p{IsUppercase}}</td></tr>
653 * <tr><th scope="row">{@code \p{ASCII}}</th>
654 * <td>All ASCII:{@code [\x00-\x7F]}</td></tr>
655 * <tr><th scope="row">{@code \p{Alpha}}</th>
656 * <td>An alphabetic character:{@code \p{IsAlphabetic}}</td></tr>
657 * <tr><th scope="row">{@code \p{Digit}}</th>
658 * <td>A decimal digit character:{@code \p{IsDigit}}</td></tr>
659 * <tr><th scope="row">{@code \p{Alnum}}</th>
660 * <td>An alphanumeric character:{@code [\p{IsAlphabetic}\p{IsDigit}]}</td></tr>
661 * <tr><th scope="row">{@code \p{Punct}}</th>
662 * <td>A punctuation character:{@code \p{IsPunctuation}}</td></tr>
663 * <tr><th scope="row">{@code \p{Graph}}</th>
664 * <td>A visible character: {@code [^\p{IsWhite_Space}\p{gc=Cc}\p{gc=Cs}\p{gc=Cn}]}</td></tr>
665 * <tr><th scope="row">{@code \p{Print}}</th>
666 * <td>A printable character: {@code [\p{Graph}\p{Blank}&&[^\p{Cntrl}]]}</td></tr>
667 * <tr><th scope="row">{@code \p{Blank}}</th>
668 * <td>A space or a tab: {@code [\p{IsWhite_Space}&&[^\p{gc=Zl}\p{gc=Zp}\x0a\x0b\x0c\x0d\x85]]}</td></tr>
669 * <tr><th scope="row">{@code \p{Cntrl}}</th>
670 * <td>A control character: {@code \p{gc=Cc}}</td></tr>
671 * <tr><th scope="row">{@code \p{XDigit}}</th>
672 * <td>A hexadecimal digit: {@code [\p{gc=Nd}\p{IsHex_Digit}]}</td></tr>
673 * <tr><th scope="row">{@code \p{Space}}</th>
674 * <td>A whitespace character:{@code \p{IsWhite_Space}}</td></tr>
675 * <tr><th scope="row">{@code \d}</th>
676 * <td>A digit: {@code \p{IsDigit}}</td></tr>
677 * <tr><th scope="row">{@code \D}</th>
678 * <td>A non-digit: {@code [^\d]}</td></tr>
679 * <tr><th scope="row">{@code \s}</th>
680 * <td>A whitespace character: {@code \p{IsWhite_Space}}</td></tr>
681 * <tr><th scope="row">{@code \S}</th>
682 * <td>A non-whitespace character: {@code [^\s]}</td></tr>
683 * <tr><th scope="row">{@code \w}</th>
684 * <td>A word character: {@code [\p{Alpha}\p{gc=Mn}\p{gc=Me}\p{gc=Mc}\p{Digit}\p{gc=Pc}\p{IsJoin_Control}]}</td></tr>
685 * <tr><th scope="row">{@code \W}</th>
686 * <td>A non-word character: {@code [^\w]}</td></tr>
687 * </tbody>
688 * </table>
689 * <p>
690 * <a id="jcc">
691 * Categories that behave like the java.lang.Character
692 * boolean is<i>methodname</i> methods (except for the deprecated ones) are
693 * available through the same <code>\p{</code><i>prop</i><code>}</code> syntax where
694 * the specified property has the name <code>java<i>methodname</i></code></a>.
695 *
696 * <h2> Comparison to Perl 5 </h2>
697 *
698 * <p>The {@code Pattern} engine performs traditional NFA-based matching
699 * with ordered alternation as occurs in Perl 5.
700 *
701 * <p> Perl constructs not supported by this class: </p>
702 *
703 * <ul>
704 * <li><p> The backreference constructs, <code>\g{</code><i>n</i><code>}</code> for
705 * the <i>n</i><sup>th</sup><a href="#cg">capturing group</a> and
706 * <code>\g{</code><i>name</i><code>}</code> for
707 * <a href="#groupname">named-capturing group</a>.
708 * </p></li>
709 *
710 * <li><p> The conditional constructs
711 * {@code (?(}<i>condition</i>{@code )}<i>X</i>{@code )} and
712 * {@code (?(}<i>condition</i>{@code )}<i>X</i>{@code |}<i>Y</i>{@code )},
713 * </p></li>
714 *
715 * <li><p> The embedded code constructs <code>(?{</code><i>code</i><code>})</code>
716 * and <code>(??{</code><i>code</i><code>})</code>,</p></li>
717 *
718 * <li><p> The embedded comment syntax {@code (?#comment)}, and </p></li>
719 *
720 * <li><p> The preprocessing operations {@code \l} <code>\u</code>,
721 * {@code \L}, and {@code \U}. </p></li>
722 *
723 * </ul>
724 *
725 * <p> Constructs supported by this class but not by Perl: </p>
726 *
727 * <ul>
728 *
729 * <li><p> Character-class union and intersection as described
730 * <a href="#cc">above</a>.</p></li>
731 *
732 * </ul>
733 *
734 * <p> Notable differences from Perl: </p>
735 *
736 * <ul>
737 *
738 * <li><p> In Perl, {@code \1} through {@code \9} are always interpreted
739 * as back references; a backslash-escaped number greater than {@code 9} is
740 * treated as a back reference if at least that many subexpressions exist,
741 * otherwise it is interpreted, if possible, as an octal escape. In this
742 * class octal escapes must always begin with a zero. In this class,
743 * {@code \1} through {@code \9} are always interpreted as back
744 * references, and a larger number is accepted as a back reference if at
745 * least that many subexpressions exist at that point in the regular
746 * expression, otherwise the parser will drop digits until the number is
747 * smaller or equal to the existing number of groups or it is one digit.
748 * </p></li>
749 *
750 * <li><p> Perl uses the {@code g} flag to request a match that resumes
751 * where the last match left off. This functionality is provided implicitly
752 * by the {@link Matcher} class: Repeated invocations of the {@link
753 * Matcher#find find} method will resume where the last match left off,
754 * unless the matcher is reset. </p></li>
755 *
756 * <li><p> In Perl, embedded flags at the top level of an expression affect
757 * the whole expression. In this class, embedded flags always take effect
758 * at the point at which they appear, whether they are at the top level or
759 * within a group; in the latter case, flags are restored at the end of the
760 * group just as in Perl. </p></li>
761 *
762 * </ul>
763 *
764 *
765 * <p> For a more precise description of the behavior of regular expression
766 * constructs, please see <a href="http://www.oreilly.com/catalog/regex3/">
767 * <i>Mastering Regular Expressions, 3nd Edition</i>, Jeffrey E. F. Friedl,
768 * O'Reilly and Associates, 2006.</a>
769 * </p>
770 *
771 * @see java.lang.String#split(String, int)
772 * @see java.lang.String#split(String)
773 *
774 * @author Mike McCloskey
775 * @author Mark Reinhold
776 * @author JSR-51 Expert Group
777 * @since 1.4
778 * @spec JSR-51
779 */
780
781 public final class Pattern
782 implements java.io.Serializable
783 {
784
785 /**
786 * Regular expression modifier values. Instead of being passed as
787 * arguments, they can also be passed as inline modifiers.
788 * For example, the following statements have the same effect.
789 * <pre>
790 * Pattern p1 = Pattern.compile("abc", Pattern.CASE_INSENSITIVE|Pattern.MULTILINE);
791 * Pattern p2 = Pattern.compile("(?im)abc", 0);
792 * </pre>
793 */
794
795 /**
796 * Enables Unix lines mode.
797 *
798 * <p> In this mode, only the {@code '\n'} line terminator is recognized
799 * in the behavior of {@code .}, {@code ^}, and {@code $}.
800 *
801 * <p> Unix lines mode can also be enabled via the embedded flag
802 * expression {@code (?d)}.
803 */
804 public static final int UNIX_LINES = 0x01;
805
806 /**
807 * Enables case-insensitive matching.
808 *
809 * <p> By default, case-insensitive matching assumes that only characters
810 * in the US-ASCII charset are being matched. Unicode-aware
811 * case-insensitive matching can be enabled by specifying the {@link
812 * #UNICODE_CASE} flag in conjunction with this flag.
813 *
814 * <p> Case-insensitive matching can also be enabled via the embedded flag
815 * expression {@code (?i)}.
816 *
817 * <p> Specifying this flag may impose a slight performance penalty. </p>
818 */
819 public static final int CASE_INSENSITIVE = 0x02;
820
821 /**
822 * Permits whitespace and comments in pattern.
823 *
824 * <p> In this mode, whitespace is ignored, and embedded comments starting
825 * with {@code #} are ignored until the end of a line.
826 *
827 * <p> Comments mode can also be enabled via the embedded flag
828 * expression {@code (?x)}.
829 */
830 public static final int COMMENTS = 0x04;
831
832 /**
833 * Enables multiline mode.
834 *
835 * <p> In multiline mode the expressions {@code ^} and {@code $} match
836 * just after or just before, respectively, a line terminator or the end of
837 * the input sequence. By default these expressions only match at the
838 * beginning and the end of the entire input sequence.
839 *
840 * <p> Multiline mode can also be enabled via the embedded flag
841 * expression {@code (?m)}. </p>
842 */
843 public static final int MULTILINE = 0x08;
844
845 /**
846 * Enables literal parsing of the pattern.
847 *
848 * <p> When this flag is specified then the input string that specifies
849 * the pattern is treated as a sequence of literal characters.
850 * Metacharacters or escape sequences in the input sequence will be
851 * given no special meaning.
852 *
853 * <p>The flags CASE_INSENSITIVE and UNICODE_CASE retain their impact on
854 * matching when used in conjunction with this flag. The other flags
855 * become superfluous.
856 *
857 * <p> There is no embedded flag character for enabling literal parsing.
858 * @since 1.5
859 */
860 public static final int LITERAL = 0x10;
861
862 /**
863 * Enables dotall mode.
864 *
865 * <p> In dotall mode, the expression {@code .} matches any character,
866 * including a line terminator. By default this expression does not match
867 * line terminators.
868 *
869 * <p> Dotall mode can also be enabled via the embedded flag
870 * expression {@code (?s)}. (The {@code s} is a mnemonic for
871 * "single-line" mode, which is what this is called in Perl.) </p>
872 */
873 public static final int DOTALL = 0x20;
874
875 /**
876 * Enables Unicode-aware case folding.
877 *
878 * <p> When this flag is specified then case-insensitive matching, when
879 * enabled by the {@link #CASE_INSENSITIVE} flag, is done in a manner
880 * consistent with the Unicode Standard. By default, case-insensitive
881 * matching assumes that only characters in the US-ASCII charset are being
882 * matched.
883 *
884 * <p> Unicode-aware case folding can also be enabled via the embedded flag
885 * expression {@code (?u)}.
886 *
887 * <p> Specifying this flag may impose a performance penalty. </p>
888 */
889 public static final int UNICODE_CASE = 0x40;
890
891 /**
892 * Enables canonical equivalence.
893 *
894 * <p> When this flag is specified then two characters will be considered
895 * to match if, and only if, their full canonical decompositions match.
896 * The expression <code>"a\u030A"</code>, for example, will match the
897 * string <code>"\u00E5"</code> when this flag is specified. By default,
898 * matching does not take canonical equivalence into account.
899 *
900 * <p> There is no embedded flag character for enabling canonical
901 * equivalence.
902 *
903 * <p> Specifying this flag may impose a performance penalty. </p>
904 */
905 public static final int CANON_EQ = 0x80;
906
907 /**
908 * Enables the Unicode version of <i>Predefined character classes</i> and
909 * <i>POSIX character classes</i>.
910 *
911 * <p> When this flag is specified then the (US-ASCII only)
912 * <i>Predefined character classes</i> and <i>POSIX character classes</i>
913 * are in conformance with
914 * <a href="http://www.unicode.org/reports/tr18/"><i>Unicode Technical
915 * Standard #18: Unicode Regular Expression</i></a>
916 * <i>Annex C: Compatibility Properties</i>.
917 * <p>
918 * The UNICODE_CHARACTER_CLASS mode can also be enabled via the embedded
919 * flag expression {@code (?U)}.
920 * <p>
921 * The flag implies UNICODE_CASE, that is, it enables Unicode-aware case
922 * folding.
923 * <p>
924 * Specifying this flag may impose a performance penalty. </p>
925 * @since 1.7
926 */
927 public static final int UNICODE_CHARACTER_CLASS = 0x100;
928
929 /**
930 * Contains all possible flags for compile(regex, flags).
931 */
932 private static final int ALL_FLAGS = CASE_INSENSITIVE | MULTILINE |
933 DOTALL | UNICODE_CASE | CANON_EQ | UNIX_LINES | LITERAL |
934 UNICODE_CHARACTER_CLASS | COMMENTS;
935
936 /* Pattern has only two serialized components: The pattern string
937 * and the flags, which are all that is needed to recompile the pattern
938 * when it is deserialized.
939 */
940
941 /** use serialVersionUID from Merlin b59 for interoperability */
942 @java.io.Serial
943 private static final long serialVersionUID = 5073258162644648461L;
944
945 /**
946 * The original regular-expression pattern string.
947 *
948 * @serial
949 */
950 private String pattern;
951
952 /**
953 * The original pattern flags.
954 *
955 * @serial
956 */
957 private int flags;
958
959 /**
960 * The temporary pattern flags used during compiling. The flags might be turn
961 * on and off by embedded flag.
962 */
963 private transient int flags0;
964
965 /**
966 * Boolean indicating this Pattern is compiled; this is necessary in order
967 * to lazily compile deserialized Patterns.
968 */
969 private transient volatile boolean compiled;
970
971 /**
972 * The normalized pattern string.
973 */
974 private transient String normalizedPattern;
975
976 /**
977 * The starting point of state machine for the find operation. This allows
978 * a match to start anywhere in the input.
979 */
980 transient Node root;
981
982 /**
983 * The root of object tree for a match operation. The pattern is matched
984 * at the beginning. This may include a find that uses BnM or a First
985 * node.
986 */
987 transient Node matchRoot;
988
989 /**
990 * Temporary storage used by parsing pattern slice.
991 */
992 transient int[] buffer;
993
994 /**
995 * A temporary storage used for predicate for double return.
996 */
997 transient CharPredicate predicate;
998
999 /**
1000 * Map the "name" of the "named capturing group" to its group id
1001 * node.
1002 */
1003 transient volatile Map<String, Integer> namedGroups;
1004
1005 /**
1006 * Temporary storage used while parsing group references.
1007 */
1008 transient GroupHead[] groupNodes;
1009
1010 /**
1011 * Temporary storage used to store the top level closure nodes.
1012 */
1013 transient List<Node> topClosureNodes;
1014
1015 /**
1016 * The number of top greedy closure nodes in this Pattern. Used by
1017 * matchers to allocate storage needed for a IntHashSet to keep the
1018 * beginning pos {@code i} of all failed match.
1019 */
1020 transient int localTCNCount;
1021
1022 /*
1023 * Turn off the stop-exponential-backtracking optimization if there
1024 * is a group ref in the pattern.
1025 */
1026 transient boolean hasGroupRef;
1027
1028 /**
1029 * Temporary null terminated code point array used by pattern compiling.
1030 */
1031 private transient int[] temp;
1032
1033 /**
1034 * The number of capturing groups in this Pattern. Used by matchers to
1035 * allocate storage needed to perform a match.
1036 */
1037 transient int capturingGroupCount;
1038
1039 /**
1040 * The local variable count used by parsing tree. Used by matchers to
1041 * allocate storage needed to perform a match.
1042 */
1043 transient int localCount;
1044
1045 /**
1046 * Index into the pattern string that keeps track of how much has been
1047 * parsed.
1048 */
1049 private transient int cursor;
1050
1051 /**
1052 * Holds the length of the pattern string.
1053 */
1054 private transient int patternLength;
1055
1056 /**
1057 * If the Start node might possibly match supplementary characters.
1058 * It is set to true during compiling if
1059 * (1) There is supplementary char in pattern, or
1060 * (2) There is complement node of a "family" CharProperty
1061 */
1062 private transient boolean hasSupplementary;
1063
1064 /**
1065 * If {@code true} then only limited list of chars is accepted as
1066 * control-character IDs in regular expressions of form "\\cX":
1067 * 'A' through 'Z', '?', '@', '[', '\\', ']', '^', '_'.
1068 * Otherwise, no restrictions on the IDs are exposed.
1069 */
1070 private static final boolean RESTRICTED_CONTROL_CHAR_IDS = Boolean.valueOf(
1071 GetPropertyAction.privilegedGetProperty(
1072 "jdk.util.regex.restrictedControlCharIds", "true"));
1073
1074 /**
1075 * If {@code true} then lower-case control-character ids are mapped to the
1076 * their upper-case counterparts.
1077 * For example, "\\ca" will be the same as "\\cA".
1078 */
1079 private static final boolean ALLOW_LOWERCASE_CONTROL_CHAR_IDS = Boolean.valueOf(
1080 GetPropertyAction.privilegedGetProperty(
1081 "jdk.util.regex.allowLowerCaseControlCharIds", "false"));
1082
1083 /**
1084 * Compiles the given regular expression into a pattern.
1085 *
1086 * @param regex
1087 * The expression to be compiled
1088 * @return the given regular expression compiled into a pattern
1089 * @throws PatternSyntaxException
1090 * If the expression's syntax is invalid
1091 */
1092 public static Pattern compile(String regex) {
1093 return new Pattern(regex, 0);
1094 }
1095
1096 /**
1097 * Compiles the given regular expression into a pattern with the given
1098 * flags.
1099 *
1100 * @param regex
1101 * The expression to be compiled
1102 *
1103 * @param flags
1104 * Match flags, a bit mask that may include
1105 * {@link #CASE_INSENSITIVE}, {@link #MULTILINE}, {@link #DOTALL},
1106 * {@link #UNICODE_CASE}, {@link #CANON_EQ}, {@link #UNIX_LINES},
1107 * {@link #LITERAL}, {@link #UNICODE_CHARACTER_CLASS}
1108 * and {@link #COMMENTS}
1109 *
1110 * @return the given regular expression compiled into a pattern with the given flags
1111 * @throws IllegalArgumentException
1112 * If bit values other than those corresponding to the defined
1113 * match flags are set in {@code flags}
1114 *
1115 * @throws PatternSyntaxException
1116 * If the expression's syntax is invalid
1117 */
1118 public static Pattern compile(String regex, int flags) {
1119 return new Pattern(regex, flags);
1120 }
1121
1122 /**
1123 * Returns the regular expression from which this pattern was compiled.
1124 *
1125 * @return The source of this pattern
1126 */
1127 public String pattern() {
1128 return pattern;
1129 }
1130
1131 /**
1132 * <p>Returns the string representation of this pattern. This
1133 * is the regular expression from which this pattern was
1134 * compiled.</p>
1135 *
1136 * @return The string representation of this pattern
1137 * @since 1.5
1138 */
1139 public String toString() {
1140 return pattern;
1141 }
1142
1143 /**
1144 * Creates a matcher that will match the given input against this pattern.
1145 *
1146 * @param input
1147 * The character sequence to be matched
1148 *
1149 * @return A new matcher for this pattern
1150 */
1151 public Matcher matcher(CharSequence input) {
1152 if (!compiled) {
1153 synchronized(this) {
1154 if (!compiled)
1155 compile();
1156 }
1157 }
1158 Matcher m = new Matcher(this, input);
1159 return m;
1160 }
1161
1162 /**
1163 * Returns this pattern's match flags.
1164 *
1165 * @return The match flags specified when this pattern was compiled
1166 */
1167 public int flags() {
1168 return flags0;
1169 }
1170
1171 /**
1172 * Compiles the given regular expression and attempts to match the given
1173 * input against it.
1174 *
1175 * <p> An invocation of this convenience method of the form
1176 *
1177 * <blockquote><pre>
1178 * Pattern.matches(regex, input);</pre></blockquote>
1179 *
1180 * behaves in exactly the same way as the expression
1181 *
1182 * <blockquote><pre>
1183 * Pattern.compile(regex).matcher(input).matches()</pre></blockquote>
1184 *
1185 * <p> If a pattern is to be used multiple times, compiling it once and reusing
1186 * it will be more efficient than invoking this method each time. </p>
1187 *
1188 * @param regex
1189 * The expression to be compiled
1190 *
1191 * @param input
1192 * The character sequence to be matched
1193 * @return whether or not the regular expression matches on the input
1194 * @throws PatternSyntaxException
1195 * If the expression's syntax is invalid
1196 */
1197 public static boolean matches(String regex, CharSequence input) {
1198 Pattern p = Pattern.compile(regex);
1199 Matcher m = p.matcher(input);
1200 return m.matches();
1201 }
1202
1203 /**
1204 * Splits the given input sequence around matches of this pattern.
1205 *
1206 * <p> The array returned by this method contains each substring of the
1207 * input sequence that is terminated by another subsequence that matches
1208 * this pattern or is terminated by the end of the input sequence. The
1209 * substrings in the array are in the order in which they occur in the
1210 * input. If this pattern does not match any subsequence of the input then
1211 * the resulting array has just one element, namely the input sequence in
1212 * string form.
1213 *
1214 * <p> When there is a positive-width match at the beginning of the input
1215 * sequence then an empty leading substring is included at the beginning
1216 * of the resulting array. A zero-width match at the beginning however
1217 * never produces such empty leading substring.
1218 *
1219 * <p> The {@code limit} parameter controls the number of times the
1220 * pattern is applied and therefore affects the length of the resulting
1221 * array.
1222 * <ul>
1223 * <li><p>
1224 * If the <i>limit</i> is positive then the pattern will be applied
1225 * at most <i>limit</i> - 1 times, the array's length will be
1226 * no greater than <i>limit</i>, and the array's last entry will contain
1227 * all input beyond the last matched delimiter.</p></li>
1228 *
1229 * <li><p>
1230 * If the <i>limit</i> is zero then the pattern will be applied as
1231 * many times as possible, the array can have any length, and trailing
1232 * empty strings will be discarded.</p></li>
1233 *
1234 * <li><p>
1235 * If the <i>limit</i> is negative then the pattern will be applied
1236 * as many times as possible and the array can have any length.</p></li>
1237 * </ul>
1238 *
1239 * <p> The input {@code "boo:and:foo"}, for example, yields the following
1240 * results with these parameters:
1241 *
1242 * <table class="plain" style="margin-left:2em;">
1243 * <caption style="display:none">Split example showing regex, limit, and result</caption>
1244 * <thead>
1245 * <tr>
1246 * <th scope="col">Regex</th>
1247 * <th scope="col">Limit</th>
1248 * <th scope="col">Result</th>
1249 * </tr>
1250 * </thead>
1251 * <tbody>
1252 * <tr><th scope="row" rowspan="3" style="font-weight:normal">:</th>
1253 * <th scope="row" style="font-weight:normal; text-align:right; padding-right:1em">2</th>
1254 * <td>{@code { "boo", "and:foo" }}</td></tr>
1255 * <tr><!-- : -->
1256 * <th scope="row" style="font-weight:normal; text-align:right; padding-right:1em">5</th>
1257 * <td>{@code { "boo", "and", "foo" }}</td></tr>
1258 * <tr><!-- : -->
1259 * <th scope="row" style="font-weight:normal; text-align:right; padding-right:1em">-2</th>
1260 * <td>{@code { "boo", "and", "foo" }}</td></tr>
1261 * <tr><th scope="row" rowspan="3" style="font-weight:normal">o</th>
1262 * <th scope="row" style="font-weight:normal; text-align:right; padding-right:1em">5</th>
1263 * <td>{@code { "b", "", ":and:f", "", "" }}</td></tr>
1264 * <tr><!-- o -->
1265 * <th scope="row" style="font-weight:normal; text-align:right; padding-right:1em">-2</th>
1266 * <td>{@code { "b", "", ":and:f", "", "" }}</td></tr>
1267 * <tr><!-- o -->
1268 * <th scope="row" style="font-weight:normal; text-align:right; padding-right:1em">0</th>
1269 * <td>{@code { "b", "", ":and:f" }}</td></tr>
1270 * </tbody>
1271 * </table>
1272 *
1273 * @param input
1274 * The character sequence to be split
1275 *
1276 * @param limit
1277 * The result threshold, as described above
1278 *
1279 * @return The array of strings computed by splitting the input
1280 * around matches of this pattern
1281 */
1282 public String[] split(CharSequence input, int limit) {
1283 int index = 0;
1284 boolean matchLimited = limit > 0;
1285 ArrayList<String> matchList = new ArrayList<>();
1286 Matcher m = matcher(input);
1287
1288 // Add segments before each match found
1289 while(m.find()) {
1290 if (!matchLimited || matchList.size() < limit - 1) {
1291 if (index == 0 && index == m.start() && m.start() == m.end()) {
1292 // no empty leading substring included for zero-width match
1293 // at the beginning of the input char sequence.
1294 continue;
1295 }
1296 String match = input.subSequence(index, m.start()).toString();
1297 matchList.add(match);
1298 index = m.end();
1299 } else if (matchList.size() == limit - 1) { // last one
1300 String match = input.subSequence(index,
1301 input.length()).toString();
1302 matchList.add(match);
1303 index = m.end();
1304 }
1305 }
1306
1307 // If no match was found, return this
1308 if (index == 0)
1309 return new String[] {input.toString()};
1310
1311 // Add remaining segment
1312 if (!matchLimited || matchList.size() < limit)
1313 matchList.add(input.subSequence(index, input.length()).toString());
1314
1315 // Construct result
1316 int resultSize = matchList.size();
1317 if (limit == 0)
1318 while (resultSize > 0 && matchList.get(resultSize-1).isEmpty())
1319 resultSize--;
1320 String[] result = new String[resultSize];
1321 return matchList.subList(0, resultSize).toArray(result);
1322 }
1323
1324 /**
1325 * Splits the given input sequence around matches of this pattern.
1326 *
1327 * <p> This method works as if by invoking the two-argument {@link
1328 * #split(java.lang.CharSequence, int) split} method with the given input
1329 * sequence and a limit argument of zero. Trailing empty strings are
1330 * therefore not included in the resulting array. </p>
1331 *
1332 * <p> The input {@code "boo:and:foo"}, for example, yields the following
1333 * results with these expressions:
1334 *
1335 * <table class="plain" style="margin-left:2em">
1336 * <caption style="display:none">Split examples showing regex and result</caption>
1337 * <thead>
1338 * <tr>
1339 * <th scope="col">Regex</th>
1340 * <th scope="col">Result</th>
1341 * </tr>
1342 * </thead>
1343 * <tbody>
1344 * <tr><th scope="row" style="text-weight:normal">:</th>
1345 * <td>{@code { "boo", "and", "foo" }}</td></tr>
1346 * <tr><th scope="row" style="text-weight:normal">o</th>
1347 * <td>{@code { "b", "", ":and:f" }}</td></tr>
1348 * </tbody>
1349 * </table>
1350 *
1351 *
1352 * @param input
1353 * The character sequence to be split
1354 *
1355 * @return The array of strings computed by splitting the input
1356 * around matches of this pattern
1357 */
1358 public String[] split(CharSequence input) {
1359 return split(input, 0);
1360 }
1361
1362 /**
1363 * Returns a literal pattern {@code String} for the specified
1364 * {@code String}.
1365 *
1366 * <p>This method produces a {@code String} that can be used to
1367 * create a {@code Pattern} that would match the string
1368 * {@code s} as if it were a literal pattern.</p> Metacharacters
1369 * or escape sequences in the input sequence will be given no special
1370 * meaning.
1371 *
1372 * @param s The string to be literalized
1373 * @return A literal string replacement
1374 * @since 1.5
1375 */
1376 public static String quote(String s) {
1377 int slashEIndex = s.indexOf("\\E");
1378 if (slashEIndex == -1)
1379 return "\\Q" + s + "\\E";
1380
1381 int lenHint = s.length();
1382 lenHint = (lenHint < Integer.MAX_VALUE - 8 - lenHint) ?
1383 (lenHint << 1) : (Integer.MAX_VALUE - 8);
1384
1385 StringBuilder sb = new StringBuilder(lenHint);
1386 sb.append("\\Q");
1387 int current = 0;
1388 do {
1389 sb.append(s, current, slashEIndex)
1390 .append("\\E\\\\E\\Q");
1391 current = slashEIndex + 2;
1392 } while ((slashEIndex = s.indexOf("\\E", current)) != -1);
1393
1394 return sb.append(s, current, s.length())
1395 .append("\\E")
1396 .toString();
1397 }
1398
1399 /**
1400 * Recompile the Pattern instance from a stream. The original pattern
1401 * string is read in and the object tree is recompiled from it.
1402 */
1403 @java.io.Serial
1404 private void readObject(java.io.ObjectInputStream s)
1405 throws java.io.IOException, ClassNotFoundException {
1406
1407 // Read in all fields
1408 s.defaultReadObject();
1409
1410 // reset the flags
1411 flags0 = flags;
1412
1413 // Initialize counts
1414 capturingGroupCount = 1;
1415 localCount = 0;
1416 localTCNCount = 0;
1417
1418 // if length > 0, the Pattern is lazily compiled
1419 if (pattern.isEmpty()) {
1420 root = new Start(lastAccept);
1421 matchRoot = lastAccept;
1422 compiled = true;
1423 }
1424 }
1425
1426 /**
1427 * This private constructor is used to create all Patterns. The pattern
1428 * string and match flags are all that is needed to completely describe
1429 * a Pattern. An empty pattern string results in an object tree with
1430 * only a Start node and a LastNode node.
1431 */
1432 private Pattern(String p, int f) {
1433 if ((f & ~ALL_FLAGS) != 0) {
1434 throw new IllegalArgumentException("Unknown flag 0x"
1435 + Integer.toHexString(f));
1436 }
1437 pattern = p;
1438 flags = f;
1439
1440 // to use UNICODE_CASE if UNICODE_CHARACTER_CLASS present
1441 if ((flags & UNICODE_CHARACTER_CLASS) != 0)
1442 flags |= UNICODE_CASE;
1443
1444 // 'flags' for compiling
1445 flags0 = flags;
1446
1447 // Reset group index count
1448 capturingGroupCount = 1;
1449 localCount = 0;
1450 localTCNCount = 0;
1451
1452 if (!pattern.isEmpty()) {
1453 compile();
1454 } else {
1455 root = new Start(lastAccept);
1456 matchRoot = lastAccept;
1457 }
1458 }
1459
1460 /**
1461 * The pattern is converted to normalized form ({@link
1462 * java.text.Normalizer.Form#NFC NFC}, canonical decomposition,
1463 * followed by canonical composition for the character class
1464 * part, and {@link java.text.Normalizer.Form#NFD NFD},
1465 * canonical decomposition for the rest), and then a pure
1466 * group is constructed to match canonical equivalences of the
1467 * characters.
1468 */
1469 private static String normalize(String pattern) {
1470 int plen = pattern.length();
1471 StringBuilder pbuf = new StringBuilder(plen);
1472 char last = 0;
1473 int lastStart = 0;
1474 char cc = 0;
1475 for (int i = 0; i < plen;) {
1476 char c = pattern.charAt(i);
1477 if (cc == 0 && // top level
1478 c == '\\' && i + 1 < plen && pattern.charAt(i + 1) == '\\') {
1479 i += 2; last = 0;
1480 continue;
1481 }
1482 if (c == '[' && last != '\\') {
1483 if (cc == 0) {
1484 if (lastStart < i)
1485 normalizeSlice(pattern, lastStart, i, pbuf);
1486 lastStart = i;
1487 }
1488 cc++;
1489 } else if (c == ']' && last != '\\') {
1490 cc--;
1491 if (cc == 0) {
1492 normalizeClazz(pattern, lastStart, i + 1, pbuf);
1493 lastStart = i + 1;
1494 }
1495 }
1496 last = c;
1497 i++;
1498 }
1499 assert (cc == 0);
1500 if (lastStart < plen)
1501 normalizeSlice(pattern, lastStart, plen, pbuf);
1502 return pbuf.toString();
1503 }
1504
1505 private static void normalizeSlice(String src, int off, int limit,
1506 StringBuilder dst)
1507 {
1508 int len = src.length();
1509 int off0 = off;
1510 while (off < limit && ASCII.isAscii(src.charAt(off))) {
1511 off++;
1512 }
1513 if (off == limit) {
1514 dst.append(src, off0, limit);
1515 return;
1516 }
1517 off--;
1518 if (off < off0)
1519 off = off0;
1520 else
1521 dst.append(src, off0, off);
1522 while (off < limit) {
1523 int ch0 = src.codePointAt(off);
1524 if (".$|()[]{}^?*+\\".indexOf(ch0) != -1) {
1525 dst.append((char)ch0);
1526 off++;
1527 continue;
1528 }
1529 int j = Grapheme.nextBoundary(src, off, limit);
1530 int ch1;
1531 String seq = src.substring(off, j);
1532 String nfd = Normalizer.normalize(seq, Normalizer.Form.NFD);
1533 off = j;
1534 if (nfd.codePointCount(0, nfd.length()) > 1) {
1535 ch0 = nfd.codePointAt(0);
1536 ch1 = nfd.codePointAt(Character.charCount(ch0));
1537 if (Character.getType(ch1) == Character.NON_SPACING_MARK) {
1538 Set<String> altns = new LinkedHashSet<>();
1539 altns.add(seq);
1540 produceEquivalentAlternation(nfd, altns);
1541 dst.append("(?:");
1542 altns.forEach( s -> dst.append(s).append('|'));
1543 dst.delete(dst.length() - 1, dst.length());
1544 dst.append(")");
1545 continue;
1546 }
1547 }
1548 String nfc = Normalizer.normalize(seq, Normalizer.Form.NFC);
1549 if (!seq.equals(nfc) && !nfd.equals(nfc))
1550 dst.append("(?:" + seq + "|" + nfd + "|" + nfc + ")");
1551 else if (!seq.equals(nfd))
1552 dst.append("(?:" + seq + "|" + nfd + ")");
1553 else
1554 dst.append(seq);
1555 }
1556 }
1557
1558 private static void normalizeClazz(String src, int off, int limit,
1559 StringBuilder dst)
1560 {
1561 dst.append(Normalizer.normalize(src.substring(off, limit), Form.NFC));
1562 }
1563
1564 /**
1565 * Given a specific sequence composed of a regular character and
1566 * combining marks that follow it, produce the alternation that will
1567 * match all canonical equivalences of that sequence.
1568 */
1569 private static void produceEquivalentAlternation(String src,
1570 Set<String> dst)
1571 {
1572 int len = countChars(src, 0, 1);
1573 if (src.length() == len) {
1574 dst.add(src); // source has one character.
1575 return;
1576 }
1577 String base = src.substring(0,len);
1578 String combiningMarks = src.substring(len);
1579 String[] perms = producePermutations(combiningMarks);
1580 // Add combined permutations
1581 for(int x = 0; x < perms.length; x++) {
1582 String next = base + perms[x];
1583 dst.add(next);
1584 next = composeOneStep(next);
1585 if (next != null) {
1586 produceEquivalentAlternation(next, dst);
1587 }
1588 }
1589 }
1590
1591 /**
1592 * Returns an array of strings that have all the possible
1593 * permutations of the characters in the input string.
1594 * This is used to get a list of all possible orderings
1595 * of a set of combining marks. Note that some of the permutations
1596 * are invalid because of combining class collisions, and these
1597 * possibilities must be removed because they are not canonically
1598 * equivalent.
1599 */
1600 private static String[] producePermutations(String input) {
1601 if (input.length() == countChars(input, 0, 1))
1602 return new String[] {input};
1603
1604 if (input.length() == countChars(input, 0, 2)) {
1605 int c0 = Character.codePointAt(input, 0);
1606 int c1 = Character.codePointAt(input, Character.charCount(c0));
1607 if (getClass(c1) == getClass(c0)) {
1608 return new String[] {input};
1609 }
1610 String[] result = new String[2];
1611 result[0] = input;
1612 StringBuilder sb = new StringBuilder(2);
1613 sb.appendCodePoint(c1);
1614 sb.appendCodePoint(c0);
1615 result[1] = sb.toString();
1616 return result;
1617 }
1618
1619 int length = 1;
1620 int nCodePoints = countCodePoints(input);
1621 for(int x=1; x<nCodePoints; x++)
1622 length = length * (x+1);
1623
1624 String[] temp = new String[length];
1625
1626 int combClass[] = new int[nCodePoints];
1627 for(int x=0, i=0; x<nCodePoints; x++) {
1628 int c = Character.codePointAt(input, i);
1629 combClass[x] = getClass(c);
1630 i += Character.charCount(c);
1631 }
1632
1633 // For each char, take it out and add the permutations
1634 // of the remaining chars
1635 int index = 0;
1636 int len;
1637 // offset maintains the index in code units.
1638 loop: for(int x=0, offset=0; x<nCodePoints; x++, offset+=len) {
1639 len = countChars(input, offset, 1);
1640 for(int y=x-1; y>=0; y--) {
1641 if (combClass[y] == combClass[x]) {
1642 continue loop;
1643 }
1644 }
1645 StringBuilder sb = new StringBuilder(input);
1646 String otherChars = sb.delete(offset, offset+len).toString();
1647 String[] subResult = producePermutations(otherChars);
1648
1649 String prefix = input.substring(offset, offset+len);
1650 for (String sre : subResult)
1651 temp[index++] = prefix + sre;
1652 }
1653 String[] result = new String[index];
1654 System.arraycopy(temp, 0, result, 0, index);
1655 return result;
1656 }
1657
1658 private static int getClass(int c) {
1659 return sun.text.Normalizer.getCombiningClass(c);
1660 }
1661
1662 /**
1663 * Attempts to compose input by combining the first character
1664 * with the first combining mark following it. Returns a String
1665 * that is the composition of the leading character with its first
1666 * combining mark followed by the remaining combining marks. Returns
1667 * null if the first two characters cannot be further composed.
1668 */
1669 private static String composeOneStep(String input) {
1670 int len = countChars(input, 0, 2);
1671 String firstTwoCharacters = input.substring(0, len);
1672 String result = Normalizer.normalize(firstTwoCharacters, Normalizer.Form.NFC);
1673 if (result.equals(firstTwoCharacters))
1674 return null;
1675 else {
1676 String remainder = input.substring(len);
1677 return result + remainder;
1678 }
1679 }
1680
1681 /**
1682 * Preprocess any \Q...\E sequences in `temp', meta-quoting them.
1683 * See the description of `quotemeta' in perlfunc(1).
1684 */
1685 private void RemoveQEQuoting() {
1686 final int pLen = patternLength;
1687 int i = 0;
1688 while (i < pLen-1) {
1689 if (temp[i] != '\\')
1690 i += 1;
1691 else if (temp[i + 1] != 'Q')
1692 i += 2;
1693 else
1694 break;
1695 }
1696 if (i >= pLen - 1) // No \Q sequence found
1697 return;
1698 int j = i;
1699 i += 2;
1700 int newTempLen;
1701 try {
1702 newTempLen = Math.addExact(j + 2, Math.multiplyExact(3, pLen - i));
1703 } catch (ArithmeticException ae) {
1704 throw new OutOfMemoryError();
1705 }
1706 int[] newtemp = new int[newTempLen];
1707 System.arraycopy(temp, 0, newtemp, 0, j);
1708
1709 boolean inQuote = true;
1710 boolean beginQuote = true;
1711 while (i < pLen) {
1712 int c = temp[i++];
1713 if (!ASCII.isAscii(c) || ASCII.isAlpha(c)) {
1714 newtemp[j++] = c;
1715 } else if (ASCII.isDigit(c)) {
1716 if (beginQuote) {
1717 /*
1718 * A unicode escape \[0xu] could be before this quote,
1719 * and we don't want this numeric char to processed as
1720 * part of the escape.
1721 */
1722 newtemp[j++] = '\\';
1723 newtemp[j++] = 'x';
1724 newtemp[j++] = '3';
1725 }
1726 newtemp[j++] = c;
1727 } else if (c != '\\') {
1728 if (inQuote) newtemp[j++] = '\\';
1729 newtemp[j++] = c;
1730 } else if (inQuote) {
1731 if (temp[i] == 'E') {
1732 i++;
1733 inQuote = false;
1734 } else {
1735 newtemp[j++] = '\\';
1736 newtemp[j++] = '\\';
1737 }
1738 } else {
1739 if (temp[i] == 'Q') {
1740 i++;
1741 inQuote = true;
1742 beginQuote = true;
1743 continue;
1744 } else {
1745 newtemp[j++] = c;
1746 if (i != pLen)
1747 newtemp[j++] = temp[i++];
1748 }
1749 }
1750
1751 beginQuote = false;
1752 }
1753
1754 patternLength = j;
1755 temp = Arrays.copyOf(newtemp, j + 2); // double zero termination
1756 }
1757
1758 /**
1759 * Copies regular expression to an int array and invokes the parsing
1760 * of the expression which will create the object tree.
1761 */
1762 private void compile() {
1763 // Handle canonical equivalences
1764 if (has(CANON_EQ) && !has(LITERAL)) {
1765 normalizedPattern = normalize(pattern);
1766 } else {
1767 normalizedPattern = pattern;
1768 }
1769 patternLength = normalizedPattern.length();
1770
1771 // Copy pattern to int array for convenience
1772 // Use double zero to terminate pattern
1773 temp = new int[patternLength + 2];
1774
1775 hasSupplementary = false;
1776 int c, count = 0;
1777 // Convert all chars into code points
1778 for (int x = 0; x < patternLength; x += Character.charCount(c)) {
1779 c = normalizedPattern.codePointAt(x);
1780 if (isSupplementary(c)) {
1781 hasSupplementary = true;
1782 }
1783 temp[count++] = c;
1784 }
1785
1786 patternLength = count; // patternLength now in code points
1787
1788 if (! has(LITERAL))
1789 RemoveQEQuoting();
1790
1791 // Allocate all temporary objects here.
1792 buffer = new int[32];
1793 groupNodes = new GroupHead[10];
1794 namedGroups = null;
1795 topClosureNodes = new ArrayList<>(10);
1796
1797 if (has(LITERAL)) {
1798 // Literal pattern handling
1799 matchRoot = newSlice(temp, patternLength, hasSupplementary);
1800 matchRoot.next = lastAccept;
1801 } else {
1802 // Start recursive descent parsing
1803 matchRoot = expr(lastAccept);
1804 // Check extra pattern characters
1805 if (patternLength != cursor) {
1806 if (peek() == ')') {
1807 throw error("Unmatched closing ')'");
1808 } else {
1809 throw error("Unexpected internal error");
1810 }
1811 }
1812 }
1813
1814 // Peephole optimization
1815 if (matchRoot instanceof Slice) {
1816 root = BnM.optimize(matchRoot);
1817 if (root == matchRoot) {
1818 root = hasSupplementary ? new StartS(matchRoot) : new Start(matchRoot);
1819 }
1820 } else if (matchRoot instanceof Begin || matchRoot instanceof First) {
1821 root = matchRoot;
1822 } else {
1823 root = hasSupplementary ? new StartS(matchRoot) : new Start(matchRoot);
1824 }
1825
1826 // Optimize the greedy Loop to prevent exponential backtracking, IF there
1827 // is no group ref in this pattern. With a non-negative localTCNCount value,
1828 // the greedy type Loop, Curly will skip the backtracking for any starting
1829 // position "i" that failed in the past.
1830 if (!hasGroupRef) {
1831 for (Node node : topClosureNodes) {
1832 if (node instanceof Loop) {
1833 // non-deterministic-greedy-group
1834 ((Loop)node).posIndex = localTCNCount++;
1835 }
1836 }
1837 }
1838
1839 // Release temporary storage
1840 temp = null;
1841 buffer = null;
1842 groupNodes = null;
1843 patternLength = 0;
1844 compiled = true;
1845 topClosureNodes = null;
1846 }
1847
1848 Map<String, Integer> namedGroups() {
1849 Map<String, Integer> groups = namedGroups;
1850 if (groups == null) {
1851 namedGroups = groups = new HashMap<>(2);
1852 }
1853 return groups;
1854 }
1855
1856 /**
1857 * Used to accumulate information about a subtree of the object graph
1858 * so that optimizations can be applied to the subtree.
1859 */
1860 static final class TreeInfo {
1861 int minLength;
1862 int maxLength;
1863 boolean maxValid;
1864 boolean deterministic;
1865
1866 TreeInfo() {
1867 reset();
1868 }
1869 void reset() {
1870 minLength = 0;
1871 maxLength = 0;
1872 maxValid = true;
1873 deterministic = true;
1874 }
1875 }
1876
1877 /*
1878 * The following private methods are mainly used to improve the
1879 * readability of the code. In order to let the Java compiler easily
1880 * inline them, we should not put many assertions or error checks in them.
1881 */
1882
1883 /**
1884 * Indicates whether a particular flag is set or not.
1885 */
1886 private boolean has(int f) {
1887 return (flags0 & f) != 0;
1888 }
1889
1890 /**
1891 * Match next character, signal error if failed.
1892 */
1893 private void accept(int ch, String s) {
1894 int testChar = temp[cursor++];
1895 if (has(COMMENTS))
1896 testChar = parsePastWhitespace(testChar);
1897 if (ch != testChar) {
1898 throw error(s);
1899 }
1900 }
1901
1902 /**
1903 * Mark the end of pattern with a specific character.
1904 */
1905 private void mark(int c) {
1906 temp[patternLength] = c;
1907 }
1908
1909 /**
1910 * Peek the next character, and do not advance the cursor.
1911 */
1912 private int peek() {
1913 int ch = temp[cursor];
1914 if (has(COMMENTS))
1915 ch = peekPastWhitespace(ch);
1916 return ch;
1917 }
1918
1919 /**
1920 * Read the next character, and advance the cursor by one.
1921 */
1922 private int read() {
1923 int ch = temp[cursor++];
1924 if (has(COMMENTS))
1925 ch = parsePastWhitespace(ch);
1926 return ch;
1927 }
1928
1929 /**
1930 * Read the next character, and advance the cursor by one,
1931 * ignoring the COMMENTS setting
1932 */
1933 private int readEscaped() {
1934 int ch = temp[cursor++];
1935 return ch;
1936 }
1937
1938 /**
1939 * Advance the cursor by one, and peek the next character.
1940 */
1941 private int next() {
1942 int ch = temp[++cursor];
1943 if (has(COMMENTS))
1944 ch = peekPastWhitespace(ch);
1945 return ch;
1946 }
1947
1948 /**
1949 * Advance the cursor by one, and peek the next character,
1950 * ignoring the COMMENTS setting
1951 */
1952 private int nextEscaped() {
1953 int ch = temp[++cursor];
1954 return ch;
1955 }
1956
1957 /**
1958 * If in xmode peek past whitespace and comments.
1959 */
1960 private int peekPastWhitespace(int ch) {
1961 while (ASCII.isSpace(ch) || ch == '#') {
1962 while (ASCII.isSpace(ch))
1963 ch = temp[++cursor];
1964 if (ch == '#') {
1965 ch = peekPastLine();
1966 }
1967 }
1968 return ch;
1969 }
1970
1971 /**
1972 * If in xmode parse past whitespace and comments.
1973 */
1974 private int parsePastWhitespace(int ch) {
1975 while (ASCII.isSpace(ch) || ch == '#') {
1976 while (ASCII.isSpace(ch))
1977 ch = temp[cursor++];
1978 if (ch == '#')
1979 ch = parsePastLine();
1980 }
1981 return ch;
1982 }
1983
1984 /**
1985 * xmode parse past comment to end of line.
1986 */
1987 private int parsePastLine() {
1988 int ch = temp[cursor++];
1989 while (ch != 0 && !isLineSeparator(ch))
1990 ch = temp[cursor++];
1991 return ch;
1992 }
1993
1994 /**
1995 * xmode peek past comment to end of line.
1996 */
1997 private int peekPastLine() {
1998 int ch = temp[++cursor];
1999 while (ch != 0 && !isLineSeparator(ch))
2000 ch = temp[++cursor];
2001 return ch;
2002 }
2003
2004 /**
2005 * Determines if character is a line separator in the current mode
2006 */
2007 private boolean isLineSeparator(int ch) {
2008 if (has(UNIX_LINES)) {
2009 return ch == '\n';
2010 } else {
2011 return (ch == '\n' ||
2012 ch == '\r' ||
2013 (ch|1) == '\u2029' ||
2014 ch == '\u0085');
2015 }
2016 }
2017
2018 /**
2019 * Read the character after the next one, and advance the cursor by two.
2020 */
2021 private int skip() {
2022 int i = cursor;
2023 int ch = temp[i+1];
2024 cursor = i + 2;
2025 return ch;
2026 }
2027
2028 /**
2029 * Unread one next character, and retreat cursor by one.
2030 */
2031 private void unread() {
2032 cursor--;
2033 }
2034
2035 /**
2036 * Internal method used for handling all syntax errors. The pattern is
2037 * displayed with a pointer to aid in locating the syntax error.
2038 */
2039 private PatternSyntaxException error(String s) {
2040 return new PatternSyntaxException(s, normalizedPattern, cursor - 1);
2041 }
2042
2043 /**
2044 * Determines if there is any supplementary character or unpaired
2045 * surrogate in the specified range.
2046 */
2047 private boolean findSupplementary(int start, int end) {
2048 for (int i = start; i < end; i++) {
2049 if (isSupplementary(temp[i]))
2050 return true;
2051 }
2052 return false;
2053 }
2054
2055 /**
2056 * Determines if the specified code point is a supplementary
2057 * character or unpaired surrogate.
2058 */
2059 private static final boolean isSupplementary(int ch) {
2060 return ch >= Character.MIN_SUPPLEMENTARY_CODE_POINT ||
2061 Character.isSurrogate((char)ch);
2062 }
2063
2064 /**
2065 * The following methods handle the main parsing. They are sorted
2066 * according to their precedence order, the lowest one first.
2067 */
2068
2069 /**
2070 * The expression is parsed with branch nodes added for alternations.
2071 * This may be called recursively to parse sub expressions that may
2072 * contain alternations.
2073 */
2074 private Node expr(Node end) {
2075 Node prev = null;
2076 Node firstTail = null;
2077 Branch branch = null;
2078 Node branchConn = null;
2079
2080 for (;;) {
2081 Node node = sequence(end);
2082 Node nodeTail = root; //double return
2083 if (prev == null) {
2084 prev = node;
2085 firstTail = nodeTail;
2086 } else {
2087 // Branch
2088 if (branchConn == null) {
2089 branchConn = new BranchConn();
2090 branchConn.next = end;
2091 }
2092 if (node == end) {
2093 // if the node returned from sequence() is "end"
2094 // we have an empty expr, set a null atom into
2095 // the branch to indicate to go "next" directly.
2096 node = null;
2097 } else {
2098 // the "tail.next" of each atom goes to branchConn
2099 nodeTail.next = branchConn;
2100 }
2101 if (prev == branch) {
2102 branch.add(node);
2103 } else {
2104 if (prev == end) {
2105 prev = null;
2106 } else {
2107 // replace the "end" with "branchConn" at its tail.next
2108 // when put the "prev" into the branch as the first atom.
2109 firstTail.next = branchConn;
2110 }
2111 prev = branch = new Branch(prev, node, branchConn);
2112 }
2113 }
2114 if (peek() != '|') {
2115 return prev;
2116 }
2117 next();
2118 }
2119 }
2120
2121 @SuppressWarnings("fallthrough")
2122 /**
2123 * Parsing of sequences between alternations.
2124 */
2125 private Node sequence(Node end) {
2126 Node head = null;
2127 Node tail = null;
2128 Node node;
2129 LOOP:
2130 for (;;) {
2131 int ch = peek();
2132 switch (ch) {
2133 case '(':
2134 // Because group handles its own closure,
2135 // we need to treat it differently
2136 node = group0();
2137 // Check for comment or flag group
2138 if (node == null)
2139 continue;
2140 if (head == null)
2141 head = node;
2142 else
2143 tail.next = node;
2144 // Double return: Tail was returned in root
2145 tail = root;
2146 continue;
2147 case '[':
2148 if (has(CANON_EQ) && !has(LITERAL))
2149 node = new NFCCharProperty(clazz(true));
2150 else
2151 node = newCharProperty(clazz(true));
2152 break;
2153 case '\\':
2154 ch = nextEscaped();
2155 if (ch == 'p' || ch == 'P') {
2156 boolean oneLetter = true;
2157 boolean comp = (ch == 'P');
2158 ch = next(); // Consume { if present
2159 if (ch != '{') {
2160 unread();
2161 } else {
2162 oneLetter = false;
2163 }
2164 // node = newCharProperty(family(oneLetter, comp));
2165 if (has(CANON_EQ) && !has(LITERAL))
2166 node = new NFCCharProperty(family(oneLetter, comp));
2167 else
2168 node = newCharProperty(family(oneLetter, comp));
2169 } else {
2170 unread();
2171 node = atom();
2172 }
2173 break;
2174 case '^':
2175 next();
2176 if (has(MULTILINE)) {
2177 if (has(UNIX_LINES))
2178 node = new UnixCaret();
2179 else
2180 node = new Caret();
2181 } else {
2182 node = new Begin();
2183 }
2184 break;
2185 case '$':
2186 next();
2187 if (has(UNIX_LINES))
2188 node = new UnixDollar(has(MULTILINE));
2189 else
2190 node = new Dollar(has(MULTILINE));
2191 break;
2192 case '.':
2193 next();
2194 if (has(DOTALL)) {
2195 node = new CharProperty(ALL());
2196 } else {
2197 if (has(UNIX_LINES)) {
2198 node = new CharProperty(UNIXDOT());
2199 } else {
2200 node = new CharProperty(DOT());
2201 }
2202 }
2203 break;
2204 case '|':
2205 case ')':
2206 break LOOP;
2207 case ']': // Now interpreting dangling ] and } as literals
2208 case '}':
2209 node = atom();
2210 break;
2211 case '?':
2212 case '*':
2213 case '+':
2214 next();
2215 throw error("Dangling meta character '" + ((char)ch) + "'");
2216 case 0:
2217 if (cursor >= patternLength) {
2218 break LOOP;
2219 }
2220 // Fall through
2221 default:
2222 node = atom();
2223 break;
2224 }
2225
2226 node = closure(node);
2227 /* save the top dot-greedy nodes (.*, .+) as well
2228 if (node instanceof GreedyCharProperty &&
2229 ((GreedyCharProperty)node).cp instanceof Dot) {
2230 topClosureNodes.add(node);
2231 }
2232 */
2233 if (head == null) {
2234 head = tail = node;
2235 } else {
2236 tail.next = node;
2237 tail = node;
2238 }
2239 }
2240 if (head == null) {
2241 return end;
2242 }
2243 tail.next = end;
2244 root = tail; //double return
2245 return head;
2246 }
2247
2248 @SuppressWarnings("fallthrough")
2249 /**
2250 * Parse and add a new Single or Slice.
2251 */
2252 private Node atom() {
2253 int first = 0;
2254 int prev = -1;
2255 boolean hasSupplementary = false;
2256 int ch = peek();
2257 for (;;) {
2258 switch (ch) {
2259 case '*':
2260 case '+':
2261 case '?':
2262 case '{':
2263 if (first > 1) {
2264 cursor = prev; // Unwind one character
2265 first--;
2266 }
2267 break;
2268 case '$':
2269 case '.':
2270 case '^':
2271 case '(':
2272 case '[':
2273 case '|':
2274 case ')':
2275 break;
2276 case '\\':
2277 ch = nextEscaped();
2278 if (ch == 'p' || ch == 'P') { // Property
2279 if (first > 0) { // Slice is waiting; handle it first
2280 unread();
2281 break;
2282 } else { // No slice; just return the family node
2283 boolean comp = (ch == 'P');
2284 boolean oneLetter = true;
2285 ch = next(); // Consume { if present
2286 if (ch != '{')
2287 unread();
2288 else
2289 oneLetter = false;
2290 if (has(CANON_EQ) && !has(LITERAL))
2291 return new NFCCharProperty(family(oneLetter, comp));
2292 else
2293 return newCharProperty(family(oneLetter, comp));
2294 }
2295 }
2296 unread();
2297 prev = cursor;
2298 ch = escape(false, first == 0, false);
2299 if (ch >= 0) {
2300 append(ch, first);
2301 first++;
2302 if (isSupplementary(ch)) {
2303 hasSupplementary = true;
2304 }
2305 ch = peek();
2306 continue;
2307 } else if (first == 0) {
2308 return root;
2309 }
2310 // Unwind meta escape sequence
2311 cursor = prev;
2312 break;
2313 case 0:
2314 if (cursor >= patternLength) {
2315 break;
2316 }
2317 // Fall through
2318 default:
2319 prev = cursor;
2320 append(ch, first);
2321 first++;
2322 if (isSupplementary(ch)) {
2323 hasSupplementary = true;
2324 }
2325 ch = next();
2326 continue;
2327 }
2328 break;
2329 }
2330 if (first == 1) {
2331 return newCharProperty(single(buffer[0]));
2332 } else {
2333 return newSlice(buffer, first, hasSupplementary);
2334 }
2335 }
2336
2337 private void append(int ch, int index) {
2338 int len = buffer.length;
2339 if (index - len >= 0) {
2340 len = ArraysSupport.newLength(len,
2341 1 + index - len, /* minimum growth */
2342 len /* preferred growth */);
2343 buffer = Arrays.copyOf(buffer, len);
2344 }
2345 buffer[index] = ch;
2346 }
2347
2348 /**
2349 * Parses a backref greedily, taking as many numbers as it
2350 * can. The first digit is always treated as a backref, but
2351 * multi digit numbers are only treated as a backref if at
2352 * least that many backrefs exist at this point in the regex.
2353 */
2354 private Node ref(int refNum) {
2355 boolean done = false;
2356 while(!done) {
2357 int ch = peek();
2358 switch(ch) {
2359 case '0':
2360 case '1':
2361 case '2':
2362 case '3':
2363 case '4':
2364 case '5':
2365 case '6':
2366 case '7':
2367 case '8':
2368 case '9':
2369 int newRefNum = (refNum * 10) + (ch - '0');
2370 // Add another number if it doesn't make a group
2371 // that doesn't exist
2372 if (capturingGroupCount - 1 < newRefNum) {
2373 done = true;
2374 break;
2375 }
2376 refNum = newRefNum;
2377 read();
2378 break;
2379 default:
2380 done = true;
2381 break;
2382 }
2383 }
2384 hasGroupRef = true;
2385 if (has(CASE_INSENSITIVE))
2386 return new CIBackRef(refNum, has(UNICODE_CASE));
2387 else
2388 return new BackRef(refNum);
2389 }
2390
2391 /**
2392 * Parses an escape sequence to determine the actual value that needs
2393 * to be matched.
2394 * If -1 is returned and create was true a new object was added to the tree
2395 * to handle the escape sequence.
2396 * If the returned value is greater than zero, it is the value that
2397 * matches the escape sequence.
2398 */
2399 private int escape(boolean inclass, boolean create, boolean isrange) {
2400 int ch = skip();
2401 switch (ch) {
2402 case '0':
2403 return o();
2404 case '1':
2405 case '2':
2406 case '3':
2407 case '4':
2408 case '5':
2409 case '6':
2410 case '7':
2411 case '8':
2412 case '9':
2413 if (inclass) break;
2414 if (create) {
2415 root = ref((ch - '0'));
2416 }
2417 return -1;
2418 case 'A':
2419 if (inclass) break;
2420 if (create) root = new Begin();
2421 return -1;
2422 case 'B':
2423 if (inclass) break;
2424 if (create) root = new Bound(Bound.NONE, has(UNICODE_CHARACTER_CLASS));
2425 return -1;
2426 case 'C':
2427 break;
2428 case 'D':
2429 if (create) {
2430 predicate = has(UNICODE_CHARACTER_CLASS) ?
2431 CharPredicates.DIGIT() : CharPredicates.ASCII_DIGIT();
2432 predicate = predicate.negate();
2433 if (!inclass)
2434 root = newCharProperty(predicate);
2435 }
2436 return -1;
2437 case 'E':
2438 case 'F':
2439 break;
2440 case 'G':
2441 if (inclass) break;
2442 if (create) root = new LastMatch();
2443 return -1;
2444 case 'H':
2445 if (create) {
2446 predicate = HorizWS().negate();
2447 if (!inclass)
2448 root = newCharProperty(predicate);
2449 }
2450 return -1;
2451 case 'I':
2452 case 'J':
2453 case 'K':
2454 case 'L':
2455 case 'M':
2456 break;
2457 case 'N':
2458 return N();
2459 case 'O':
2460 case 'P':
2461 case 'Q':
2462 break;
2463 case 'R':
2464 if (inclass) break;
2465 if (create) root = new LineEnding();
2466 return -1;
2467 case 'S':
2468 if (create) {
2469 predicate = has(UNICODE_CHARACTER_CLASS) ?
2470 CharPredicates.WHITE_SPACE() : CharPredicates.ASCII_SPACE();
2471 predicate = predicate.negate();
2472 if (!inclass)
2473 root = newCharProperty(predicate);
2474 }
2475 return -1;
2476 case 'T':
2477 case 'U':
2478 break;
2479 case 'V':
2480 if (create) {
2481 predicate = VertWS().negate();
2482 if (!inclass)
2483 root = newCharProperty(predicate);
2484 }
2485 return -1;
2486 case 'W':
2487 if (create) {
2488 predicate = has(UNICODE_CHARACTER_CLASS) ?
2489 CharPredicates.WORD() : CharPredicates.ASCII_WORD();
2490 predicate = predicate.negate();
2491 if (!inclass)
2492 root = newCharProperty(predicate);
2493 }
2494 return -1;
2495 case 'X':
2496 if (inclass) break;
2497 if (create) {
2498 root = new XGrapheme();
2499 }
2500 return -1;
2501 case 'Y':
2502 break;
2503 case 'Z':
2504 if (inclass) break;
2505 if (create) {
2506 if (has(UNIX_LINES))
2507 root = new UnixDollar(false);
2508 else
2509 root = new Dollar(false);
2510 }
2511 return -1;
2512 case 'a':
2513 return '\007';
2514 case 'b':
2515 if (inclass) break;
2516 if (create) {
2517 if (peek() == '{') {
2518 if (skip() == 'g') {
2519 if (read() == '}') {
2520 root = new GraphemeBound();
2521 return -1;
2522 }
2523 break; // error missing trailing }
2524 }
2525 unread(); unread();
2526 }
2527 root = new Bound(Bound.BOTH, has(UNICODE_CHARACTER_CLASS));
2528 }
2529 return -1;
2530 case 'c':
2531 return c();
2532 case 'd':
2533 if (create) {
2534 predicate = has(UNICODE_CHARACTER_CLASS) ?
2535 CharPredicates.DIGIT() : CharPredicates.ASCII_DIGIT();
2536 if (!inclass)
2537 root = newCharProperty(predicate);
2538 }
2539 return -1;
2540 case 'e':
2541 return '\033';
2542 case 'f':
2543 return '\f';
2544 case 'g':
2545 break;
2546 case 'h':
2547 if (create) {
2548 predicate = HorizWS();
2549 if (!inclass)
2550 root = newCharProperty(predicate);
2551 }
2552 return -1;
2553 case 'i':
2554 case 'j':
2555 break;
2556 case 'k':
2557 if (inclass)
2558 break;
2559 if (read() != '<')
2560 throw error("\\k is not followed by '<' for named capturing group");
2561 String name = groupname(read());
2562 if (!namedGroups().containsKey(name))
2563 throw error("named capturing group <" + name + "> does not exist");
2564 if (create) {
2565 hasGroupRef = true;
2566 if (has(CASE_INSENSITIVE))
2567 root = new CIBackRef(namedGroups().get(name), has(UNICODE_CASE));
2568 else
2569 root = new BackRef(namedGroups().get(name));
2570 }
2571 return -1;
2572 case 'l':
2573 case 'm':
2574 break;
2575 case 'n':
2576 return '\n';
2577 case 'o':
2578 case 'p':
2579 case 'q':
2580 break;
2581 case 'r':
2582 return '\r';
2583 case 's':
2584 if (create) {
2585 predicate = has(UNICODE_CHARACTER_CLASS) ?
2586 CharPredicates.WHITE_SPACE() : CharPredicates.ASCII_SPACE();
2587 if (!inclass)
2588 root = newCharProperty(predicate);
2589 }
2590 return -1;
2591 case 't':
2592 return '\t';
2593 case 'u':
2594 return u();
2595 case 'v':
2596 // '\v' was implemented as VT/0x0B in releases < 1.8 (though
2597 // undocumented). In JDK8 '\v' is specified as a predefined
2598 // character class for all vertical whitespace characters.
2599 // So [-1, root=VertWS node] pair is returned (instead of a
2600 // single 0x0B). This breaks the range if '\v' is used as
2601 // the start or end value, such as [\v-...] or [...-\v], in
2602 // which a single definite value (0x0B) is expected. For
2603 // compatibility concern '\013'/0x0B is returned if isrange.
2604 if (isrange)
2605 return '\013';
2606 if (create) {
2607 predicate = VertWS();
2608 if (!inclass)
2609 root = newCharProperty(predicate);
2610 }
2611 return -1;
2612 case 'w':
2613 if (create) {
2614 predicate = has(UNICODE_CHARACTER_CLASS) ?
2615 CharPredicates.WORD() : CharPredicates.ASCII_WORD();
2616 if (!inclass)
2617 root = newCharProperty(predicate);
2618 }
2619 return -1;
2620 case 'x':
2621 return x();
2622 case 'y':
2623 break;
2624 case 'z':
2625 if (inclass) break;
2626 if (create) root = new End();
2627 return -1;
2628 default:
2629 return ch;
2630 }
2631 throw error("Illegal/unsupported escape sequence");
2632 }
2633
2634 /**
2635 * Parse a character class, and return the node that matches it.
2636 *
2637 * Consumes a ] on the way out if consume is true. Usually consume
2638 * is true except for the case of [abc&&def] where def is a separate
2639 * right hand node with "understood" brackets.
2640 */
2641 private CharPredicate clazz(boolean consume) {
2642 CharPredicate prev = null;
2643 CharPredicate curr = null;
2644 BitClass bits = new BitClass();
2645
2646 boolean isNeg = false;
2647 boolean hasBits = false;
2648 int ch = next();
2649
2650 // Negates if first char in a class, otherwise literal
2651 if (ch == '^' && temp[cursor-1] == '[') {
2652 ch = next();
2653 isNeg = true;
2654 }
2655 for (;;) {
2656 switch (ch) {
2657 case '[':
2658 curr = clazz(true);
2659 if (prev == null)
2660 prev = curr;
2661 else
2662 prev = prev.union(curr);
2663 ch = peek();
2664 continue;
2665 case '&':
2666 ch = next();
2667 if (ch == '&') {
2668 ch = next();
2669 CharPredicate right = null;
2670 while (ch != ']' && ch != '&') {
2671 if (ch == '[') {
2672 if (right == null)
2673 right = clazz(true);
2674 else
2675 right = right.union(clazz(true));
2676 } else { // abc&&def
2677 unread();
2678 right = clazz(false);
2679 }
2680 ch = peek();
2681 }
2682 if (hasBits) {
2683 // bits used, union has high precedence
2684 if (prev == null) {
2685 prev = curr = bits;
2686 } else {
2687 prev = prev.union(bits);
2688 }
2689 hasBits = false;
2690 }
2691 if (right != null)
2692 curr = right;
2693 if (prev == null) {
2694 if (right == null)
2695 throw error("Bad class syntax");
2696 else
2697 prev = right;
2698 } else {
2699 prev = prev.and(curr);
2700 }
2701 } else {
2702 // treat as a literal &
2703 unread();
2704 break;
2705 }
2706 continue;
2707 case 0:
2708 if (cursor >= patternLength)
2709 throw error("Unclosed character class");
2710 break;
2711 case ']':
2712 if (prev != null || hasBits) {
2713 if (consume)
2714 next();
2715 if (prev == null)
2716 prev = bits;
2717 else if (hasBits)
2718 prev = prev.union(bits);
2719 if (isNeg)
2720 return prev.negate();
2721 return prev;
2722 }
2723 break;
2724 default:
2725 break;
2726 }
2727 curr = range(bits);
2728 if (curr == null) { // the bits used
2729 hasBits = true;
2730 } else {
2731 if (prev == null)
2732 prev = curr;
2733 else if (prev != curr)
2734 prev = prev.union(curr);
2735 }
2736 ch = peek();
2737 }
2738 }
2739
2740 private CharPredicate bitsOrSingle(BitClass bits, int ch) {
2741 /* Bits can only handle codepoints in [u+0000-u+00ff] range.
2742 Use "single" node instead of bits when dealing with unicode
2743 case folding for codepoints listed below.
2744 (1)Uppercase out of range: u+00ff, u+00b5
2745 toUpperCase(u+00ff) -> u+0178
2746 toUpperCase(u+00b5) -> u+039c
2747 (2)LatinSmallLetterLongS u+17f
2748 toUpperCase(u+017f) -> u+0053
2749 (3)LatinSmallLetterDotlessI u+131
2750 toUpperCase(u+0131) -> u+0049
2751 (4)LatinCapitalLetterIWithDotAbove u+0130
2752 toLowerCase(u+0130) -> u+0069
2753 (5)KelvinSign u+212a
2754 toLowerCase(u+212a) ==> u+006B
2755 (6)AngstromSign u+212b
2756 toLowerCase(u+212b) ==> u+00e5
2757 */
2758 if (ch < 256 &&
2759 !(has(CASE_INSENSITIVE) && has(UNICODE_CASE) &&
2760 (ch == 0xff || ch == 0xb5 ||
2761 ch == 0x49 || ch == 0x69 || //I and i
2762 ch == 0x53 || ch == 0x73 || //S and s
2763 ch == 0x4b || ch == 0x6b || //K and k
2764 ch == 0xc5 || ch == 0xe5))) { //A+ring
2765 bits.add(ch, flags0);
2766 return null;
2767 }
2768 return single(ch);
2769 }
2770
2771 /**
2772 * Returns a suitably optimized, single character predicate
2773 */
2774 private CharPredicate single(final int ch) {
2775 if (has(CASE_INSENSITIVE)) {
2776 int lower, upper;
2777 if (has(UNICODE_CASE)) {
2778 upper = Character.toUpperCase(ch);
2779 lower = Character.toLowerCase(upper);
2780 // Unicode case insensitive matches
2781 if (upper != lower)
2782 return SingleU(lower);
2783 } else if (ASCII.isAscii(ch)) {
2784 lower = ASCII.toLower(ch);
2785 upper = ASCII.toUpper(ch);
2786 // Case insensitive matches a given BMP character
2787 if (lower != upper)
2788 return SingleI(lower, upper);
2789 }
2790 }
2791 if (isSupplementary(ch))
2792 return SingleS(ch);
2793 return Single(ch); // Match a given BMP character
2794 }
2795
2796 /**
2797 * Parse a single character or a character range in a character class
2798 * and return its representative node.
2799 */
2800 private CharPredicate range(BitClass bits) {
2801 int ch = peek();
2802 if (ch == '\\') {
2803 ch = nextEscaped();
2804 if (ch == 'p' || ch == 'P') { // A property
2805 boolean comp = (ch == 'P');
2806 boolean oneLetter = true;
2807 // Consume { if present
2808 ch = next();
2809 if (ch != '{')
2810 unread();
2811 else
2812 oneLetter = false;
2813 return family(oneLetter, comp);
2814 } else { // ordinary escape
2815 boolean isrange = temp[cursor+1] == '-';
2816 unread();
2817 ch = escape(true, true, isrange);
2818 if (ch == -1)
2819 return predicate;
2820 }
2821 } else {
2822 next();
2823 }
2824 if (ch >= 0) {
2825 if (peek() == '-') {
2826 int endRange = temp[cursor+1];
2827 if (endRange == '[') {
2828 return bitsOrSingle(bits, ch);
2829 }
2830 if (endRange != ']') {
2831 next();
2832 int m = peek();
2833 if (m == '\\') {
2834 m = escape(true, false, true);
2835 } else {
2836 next();
2837 }
2838 if (m < ch) {
2839 throw error("Illegal character range");
2840 }
2841 if (has(CASE_INSENSITIVE)) {
2842 if (has(UNICODE_CASE))
2843 return CIRangeU(ch, m);
2844 return CIRange(ch, m);
2845 } else {
2846 return Range(ch, m);
2847 }
2848 }
2849 }
2850 return bitsOrSingle(bits, ch);
2851 }
2852 throw error("Unexpected character '"+((char)ch)+"'");
2853 }
2854
2855 /**
2856 * Parses a Unicode character family and returns its representative node.
2857 */
2858 private CharPredicate family(boolean singleLetter, boolean isComplement) {
2859 next();
2860 String name;
2861 CharPredicate p = null;
2862
2863 if (singleLetter) {
2864 int c = temp[cursor];
2865 if (!Character.isSupplementaryCodePoint(c)) {
2866 name = String.valueOf((char)c);
2867 } else {
2868 name = new String(temp, cursor, 1);
2869 }
2870 read();
2871 } else {
2872 int i = cursor;
2873 mark('}');
2874 while(read() != '}') {
2875 }
2876 mark('\000');
2877 int j = cursor;
2878 if (j > patternLength)
2879 throw error("Unclosed character family");
2880 if (i + 1 >= j)
2881 throw error("Empty character family");
2882 name = new String(temp, i, j-i-1);
2883 }
2884
2885 int i = name.indexOf('=');
2886 if (i != -1) {
2887 // property construct \p{name=value}
2888 String value = name.substring(i + 1);
2889 name = name.substring(0, i).toLowerCase(Locale.ENGLISH);
2890 switch (name) {
2891 case "sc":
2892 case "script":
2893 p = CharPredicates.forUnicodeScript(value);
2894 break;
2895 case "blk":
2896 case "block":
2897 p = CharPredicates.forUnicodeBlock(value);
2898 break;
2899 case "gc":
2900 case "general_category":
2901 p = CharPredicates.forProperty(value);
2902 break;
2903 default:
2904 break;
2905 }
2906 if (p == null)
2907 throw error("Unknown Unicode property {name=<" + name + ">, "
2908 + "value=<" + value + ">}");
2909
2910 } else {
2911 if (name.startsWith("In")) {
2912 // \p{InBlockName}
2913 p = CharPredicates.forUnicodeBlock(name.substring(2));
2914 } else if (name.startsWith("Is")) {
2915 // \p{IsGeneralCategory} and \p{IsScriptName}
2916 String shortName = name.substring(2);
2917 p = CharPredicates.forUnicodeProperty(shortName);
2918 if (p == null)
2919 p = CharPredicates.forProperty(shortName);
2920 if (p == null)
2921 p = CharPredicates.forUnicodeScript(shortName);
2922 } else {
2923 if (has(UNICODE_CHARACTER_CLASS)) {
2924 p = CharPredicates.forPOSIXName(name);
2925 }
2926 if (p == null)
2927 p = CharPredicates.forProperty(name);
2928 }
2929 if (p == null)
2930 throw error("Unknown character property name {" + name + "}");
2931 }
2932 if (isComplement) {
2933 // it might be too expensive to detect if a complement of
2934 // CharProperty can match "certain" supplementary. So just
2935 // go with StartS.
2936 hasSupplementary = true;
2937 p = p.negate();
2938 }
2939 return p;
2940 }
2941
2942 private CharProperty newCharProperty(CharPredicate p) {
2943 if (p == null)
2944 return null;
2945 if (p instanceof BmpCharPredicate)
2946 return new BmpCharProperty((BmpCharPredicate)p);
2947 else
2948 return new CharProperty(p);
2949 }
2950
2951 /**
2952 * Parses and returns the name of a "named capturing group", the trailing
2953 * ">" is consumed after parsing.
2954 */
2955 private String groupname(int ch) {
2956 StringBuilder sb = new StringBuilder();
2957 if (!ASCII.isAlpha(ch))
2958 throw error("capturing group name does not start with a Latin letter");
2959 do {
2960 sb.append((char) ch);
2961 } while (ASCII.isAlnum(ch=read()));
2962 if (ch != '>')
2963 throw error("named capturing group is missing trailing '>'");
2964 return sb.toString();
2965 }
2966
2967 /**
2968 * Parses a group and returns the head node of a set of nodes that process
2969 * the group. Sometimes a double return system is used where the tail is
2970 * returned in root.
2971 */
2972 private Node group0() {
2973 boolean capturingGroup = false;
2974 Node head;
2975 Node tail;
2976 int save = flags0;
2977 int saveTCNCount = topClosureNodes.size();
2978 root = null;
2979 int ch = next();
2980 if (ch == '?') {
2981 ch = skip();
2982 switch (ch) {
2983 case ':': // (?:xxx) pure group
2984 head = createGroup(true);
2985 tail = root;
2986 head.next = expr(tail);
2987 break;
2988 case '=': // (?=xxx) and (?!xxx) lookahead
2989 case '!':
2990 head = createGroup(true);
2991 tail = root;
2992 head.next = expr(tail);
2993 if (ch == '=') {
2994 head = tail = new Pos(head);
2995 } else {
2996 head = tail = new Neg(head);
2997 }
2998 break;
2999 case '>': // (?>xxx) independent group
3000 head = createGroup(true);
3001 tail = root;
3002 head.next = expr(tail);
3003 head = tail = new Ques(head, Qtype.INDEPENDENT);
3004 break;
3005 case '<': // (?<xxx) look behind
3006 ch = read();
3007 if (ch != '=' && ch != '!') {
3008 // named captured group
3009 String name = groupname(ch);
3010 if (namedGroups().containsKey(name))
3011 throw error("Named capturing group <" + name
3012 + "> is already defined");
3013 capturingGroup = true;
3014 head = createGroup(false);
3015 tail = root;
3016 namedGroups().put(name, capturingGroupCount-1);
3017 head.next = expr(tail);
3018 break;
3019 }
3020 int start = cursor;
3021 head = createGroup(true);
3022 tail = root;
3023 head.next = expr(tail);
3024 tail.next = LookBehindEndNode.INSTANCE;
3025 TreeInfo info = new TreeInfo();
3026 head.study(info);
3027 if (info.maxValid == false) {
3028 throw error("Look-behind group does not have "
3029 + "an obvious maximum length");
3030 }
3031 boolean hasSupplementary = findSupplementary(start, patternLength);
3032 if (ch == '=') {
3033 head = tail = (hasSupplementary ?
3034 new BehindS(head, info.maxLength,
3035 info.minLength) :
3036 new Behind(head, info.maxLength,
3037 info.minLength));
3038 } else { // if (ch == '!')
3039 head = tail = (hasSupplementary ?
3040 new NotBehindS(head, info.maxLength,
3041 info.minLength) :
3042 new NotBehind(head, info.maxLength,
3043 info.minLength));
3044 }
3045 // clear all top-closure-nodes inside lookbehind
3046 if (saveTCNCount < topClosureNodes.size())
3047 topClosureNodes.subList(saveTCNCount, topClosureNodes.size()).clear();
3048 break;
3049 case '$':
3050 case '@':
3051 throw error("Unknown group type");
3052 default: // (?xxx:) inlined match flags
3053 unread();
3054 addFlag();
3055 ch = read();
3056 if (ch == ')') {
3057 return null; // Inline modifier only
3058 }
3059 if (ch != ':') {
3060 throw error("Unknown inline modifier");
3061 }
3062 head = createGroup(true);
3063 tail = root;
3064 head.next = expr(tail);
3065 break;
3066 }
3067 } else { // (xxx) a regular group
3068 capturingGroup = true;
3069 head = createGroup(false);
3070 tail = root;
3071 head.next = expr(tail);
3072 }
3073
3074 accept(')', "Unclosed group");
3075 flags0 = save;
3076
3077 // Check for quantifiers
3078 Node node = closure(head);
3079 if (node == head) { // No closure
3080 root = tail;
3081 return node; // Dual return
3082 }
3083 if (head == tail) { // Zero length assertion
3084 root = node;
3085 return node; // Dual return
3086 }
3087
3088 // have group closure, clear all inner closure nodes from the
3089 // top list (no backtracking stopper optimization for inner
3090 if (saveTCNCount < topClosureNodes.size())
3091 topClosureNodes.subList(saveTCNCount, topClosureNodes.size()).clear();
3092
3093 if (node instanceof Ques) {
3094 Ques ques = (Ques) node;
3095 if (ques.type == Qtype.POSSESSIVE) {
3096 root = node;
3097 return node;
3098 }
3099 tail.next = new BranchConn();
3100 tail = tail.next;
3101 if (ques.type == Qtype.GREEDY) {
3102 head = new Branch(head, null, tail);
3103 } else { // Reluctant quantifier
3104 head = new Branch(null, head, tail);
3105 }
3106 root = tail;
3107 return head;
3108 } else if (node instanceof Curly) {
3109 Curly curly = (Curly) node;
3110 if (curly.type == Qtype.POSSESSIVE) {
3111 root = node;
3112 return node;
3113 }
3114 // Discover if the group is deterministic
3115 TreeInfo info = new TreeInfo();
3116 if (head.study(info)) { // Deterministic
3117 GroupTail temp = (GroupTail) tail;
3118 head = root = new GroupCurly(head.next, curly.cmin,
3119 curly.cmax, curly.type,
3120 ((GroupTail)tail).localIndex,
3121 ((GroupTail)tail).groupIndex,
3122 capturingGroup);
3123 return head;
3124 } else { // Non-deterministic
3125 int temp = ((GroupHead) head).localIndex;
3126 Loop loop;
3127 if (curly.type == Qtype.GREEDY) {
3128 loop = new Loop(this.localCount, temp);
3129 // add the max_reps greedy to the top-closure-node list
3130 if (curly.cmax == MAX_REPS)
3131 topClosureNodes.add(loop);
3132 } else { // Reluctant Curly
3133 loop = new LazyLoop(this.localCount, temp);
3134 }
3135 Prolog prolog = new Prolog(loop);
3136 this.localCount += 1;
3137 loop.cmin = curly.cmin;
3138 loop.cmax = curly.cmax;
3139 loop.body = head;
3140 tail.next = loop;
3141 root = loop;
3142 return prolog; // Dual return
3143 }
3144 }
3145 throw error("Internal logic error");
3146 }
3147
3148 /**
3149 * Create group head and tail nodes using double return. If the group is
3150 * created with anonymous true then it is a pure group and should not
3151 * affect group counting.
3152 */
3153 private Node createGroup(boolean anonymous) {
3154 int localIndex = localCount++;
3155 int groupIndex = 0;
3156 if (!anonymous)
3157 groupIndex = capturingGroupCount++;
3158 GroupHead head = new GroupHead(localIndex);
3159 root = new GroupTail(localIndex, groupIndex);
3160
3161 // for debug/print only, head.match does NOT need the "tail" info
3162 head.tail = (GroupTail)root;
3163
3164 if (!anonymous && groupIndex < 10)
3165 groupNodes[groupIndex] = head;
3166 return head;
3167 }
3168
3169 @SuppressWarnings("fallthrough")
3170 /**
3171 * Parses inlined match flags and set them appropriately.
3172 */
3173 private void addFlag() {
3174 int ch = peek();
3175 for (;;) {
3176 switch (ch) {
3177 case 'i':
3178 flags0 |= CASE_INSENSITIVE;
3179 break;
3180 case 'm':
3181 flags0 |= MULTILINE;
3182 break;
3183 case 's':
3184 flags0 |= DOTALL;
3185 break;
3186 case 'd':
3187 flags0 |= UNIX_LINES;
3188 break;
3189 case 'u':
3190 flags0 |= UNICODE_CASE;
3191 break;
3192 case 'c':
3193 flags0 |= CANON_EQ;
3194 break;
3195 case 'x':
3196 flags0 |= COMMENTS;
3197 break;
3198 case 'U':
3199 flags0 |= (UNICODE_CHARACTER_CLASS | UNICODE_CASE);
3200 break;
3201 case '-': // subFlag then fall through
3202 ch = next();
3203 subFlag();
3204 default:
3205 return;
3206 }
3207 ch = next();
3208 }
3209 }
3210
3211 @SuppressWarnings("fallthrough")
3212 /**
3213 * Parses the second part of inlined match flags and turns off
3214 * flags appropriately.
3215 */
3216 private void subFlag() {
3217 int ch = peek();
3218 for (;;) {
3219 switch (ch) {
3220 case 'i':
3221 flags0 &= ~CASE_INSENSITIVE;
3222 break;
3223 case 'm':
3224 flags0 &= ~MULTILINE;
3225 break;
3226 case 's':
3227 flags0 &= ~DOTALL;
3228 break;
3229 case 'd':
3230 flags0 &= ~UNIX_LINES;
3231 break;
3232 case 'u':
3233 flags0 &= ~UNICODE_CASE;
3234 break;
3235 case 'c':
3236 flags0 &= ~CANON_EQ;
3237 break;
3238 case 'x':
3239 flags0 &= ~COMMENTS;
3240 break;
3241 case 'U':
3242 flags0 &= ~(UNICODE_CHARACTER_CLASS | UNICODE_CASE);
3243 break;
3244 default:
3245 return;
3246 }
3247 ch = next();
3248 }
3249 }
3250
3251 static final int MAX_REPS = 0x7FFFFFFF;
3252
3253 static enum Qtype {
3254 GREEDY, LAZY, POSSESSIVE, INDEPENDENT
3255 }
3256
3257 private Node curly(Node prev, int cmin) {
3258 int ch = next();
3259 if (ch == '?') {
3260 next();
3261 return new Curly(prev, cmin, MAX_REPS, Qtype.LAZY);
3262 } else if (ch == '+') {
3263 next();
3264 return new Curly(prev, cmin, MAX_REPS, Qtype.POSSESSIVE);
3265 }
3266 if (prev instanceof BmpCharProperty) {
3267 return new BmpCharPropertyGreedy((BmpCharProperty)prev, cmin);
3268 } else if (prev instanceof CharProperty) {
3269 return new CharPropertyGreedy((CharProperty)prev, cmin);
3270 }
3271 return new Curly(prev, cmin, MAX_REPS, Qtype.GREEDY);
3272 }
3273
3274 /**
3275 * Processes repetition. If the next character peeked is a quantifier
3276 * then new nodes must be appended to handle the repetition.
3277 * Prev could be a single or a group, so it could be a chain of nodes.
3278 */
3279 private Node closure(Node prev) {
3280 int ch = peek();
3281 switch (ch) {
3282 case '?':
3283 ch = next();
3284 if (ch == '?') {
3285 next();
3286 return new Ques(prev, Qtype.LAZY);
3287 } else if (ch == '+') {
3288 next();
3289 return new Ques(prev, Qtype.POSSESSIVE);
3290 }
3291 return new Ques(prev, Qtype.GREEDY);
3292 case '*':
3293 return curly(prev, 0);
3294 case '+':
3295 return curly(prev, 1);
3296 case '{':
3297 ch = skip();
3298 if (ASCII.isDigit(ch)) {
3299 int cmin = 0, cmax;
3300 try {
3301 do {
3302 cmin = Math.addExact(Math.multiplyExact(cmin, 10),
3303 ch - '0');
3304 } while (ASCII.isDigit(ch = read()));
3305 if (ch == ',') {
3306 ch = read();
3307 if (ch == '}') {
3308 unread();
3309 return curly(prev, cmin);
3310 } else {
3311 cmax = 0;
3312 while (ASCII.isDigit(ch)) {
3313 cmax = Math.addExact(Math.multiplyExact(cmax, 10),
3314 ch - '0');
3315 ch = read();
3316 }
3317 }
3318 } else {
3319 cmax = cmin;
3320 }
3321 } catch (ArithmeticException ae) {
3322 throw error("Illegal repetition range");
3323 }
3324 if (ch != '}')
3325 throw error("Unclosed counted closure");
3326 if (cmax < cmin)
3327 throw error("Illegal repetition range");
3328 ch = peek();
3329 if (ch == '?') {
3330 next();
3331 return new Curly(prev, cmin, cmax, Qtype.LAZY);
3332 } else if (ch == '+') {
3333 next();
3334 return new Curly(prev, cmin, cmax, Qtype.POSSESSIVE);
3335 } else {
3336 return new Curly(prev, cmin, cmax, Qtype.GREEDY);
3337 }
3338 } else {
3339 throw error("Illegal repetition");
3340 }
3341 default:
3342 return prev;
3343 }
3344 }
3345
3346 /**
3347 * Utility method for parsing control escape sequences.
3348 */
3349 private int c() {
3350 if (cursor < patternLength) {
3351 int ch = read();
3352 if (ALLOW_LOWERCASE_CONTROL_CHAR_IDS && ASCII.isLower(ch))
3353 return ch ^ 0x60;
3354 if (!RESTRICTED_CONTROL_CHAR_IDS || ASCII.isCntrlId(ch))
3355 return ch ^ 0x40;
3356 }
3357 throw error("Illegal control escape sequence");
3358 }
3359
3360 /**
3361 * Utility method for parsing octal escape sequences.
3362 */
3363 private int o() {
3364 int n = read();
3365 if (((n-'0')|('7'-n)) >= 0) {
3366 int m = read();
3367 if (((m-'0')|('7'-m)) >= 0) {
3368 int o = read();
3369 if ((((o-'0')|('7'-o)) >= 0) && (((n-'0')|('3'-n)) >= 0)) {
3370 return (n - '0') * 64 + (m - '0') * 8 + (o - '0');
3371 }
3372 unread();
3373 return (n - '0') * 8 + (m - '0');
3374 }
3375 unread();
3376 return (n - '0');
3377 }
3378 throw error("Illegal octal escape sequence");
3379 }
3380
3381 /**
3382 * Utility method for parsing hexadecimal escape sequences.
3383 */
3384 private int x() {
3385 int n = read();
3386 if (ASCII.isHexDigit(n)) {
3387 int m = read();
3388 if (ASCII.isHexDigit(m)) {
3389 return ASCII.toDigit(n) * 16 + ASCII.toDigit(m);
3390 }
3391 } else if (n == '{' && ASCII.isHexDigit(peek())) {
3392 int ch = 0;
3393 while (ASCII.isHexDigit(n = read())) {
3394 ch = (ch << 4) + ASCII.toDigit(n);
3395 if (ch > Character.MAX_CODE_POINT)
3396 throw error("Hexadecimal codepoint is too big");
3397 }
3398 if (n != '}')
3399 throw error("Unclosed hexadecimal escape sequence");
3400 return ch;
3401 }
3402 throw error("Illegal hexadecimal escape sequence");
3403 }
3404
3405 /**
3406 * Utility method for parsing unicode escape sequences.
3407 */
3408 private int cursor() {
3409 return cursor;
3410 }
3411
3412 private void setcursor(int pos) {
3413 cursor = pos;
3414 }
3415
3416 private int uxxxx() {
3417 int n = 0;
3418 for (int i = 0; i < 4; i++) {
3419 int ch = read();
3420 if (!ASCII.isHexDigit(ch)) {
3421 throw error("Illegal Unicode escape sequence");
3422 }
3423 n = n * 16 + ASCII.toDigit(ch);
3424 }
3425 return n;
3426 }
3427
3428 private int u() {
3429 int n = uxxxx();
3430 if (Character.isHighSurrogate((char)n)) {
3431 int cur = cursor();
3432 if (read() == '\\' && read() == 'u') {
3433 int n2 = uxxxx();
3434 if (Character.isLowSurrogate((char)n2))
3435 return Character.toCodePoint((char)n, (char)n2);
3436 }
3437 setcursor(cur);
3438 }
3439 return n;
3440 }
3441
3442 private int N() {
3443 if (read() == '{') {
3444 int i = cursor;
3445 while (cursor < patternLength && read() != '}') {}
3446 if (cursor > patternLength)
3447 throw error("Unclosed character name escape sequence");
3448 String name = new String(temp, i, cursor - i - 1);
3449 try {
3450 return Character.codePointOf(name);
3451 } catch (IllegalArgumentException x) {
3452 throw error("Unknown character name [" + name + "]");
3453 }
3454 }
3455 throw error("Illegal character name escape sequence");
3456 }
3457
3458 //
3459 // Utility methods for code point support
3460 //
3461 private static final int countChars(CharSequence seq, int index,
3462 int lengthInCodePoints) {
3463 // optimization
3464 if (lengthInCodePoints == 1 && !Character.isHighSurrogate(seq.charAt(index))) {
3465 assert (index >= 0 && index < seq.length());
3466 return 1;
3467 }
3468 int length = seq.length();
3469 int x = index;
3470 if (lengthInCodePoints >= 0) {
3471 assert (index >= 0 && index < length);
3472 for (int i = 0; x < length && i < lengthInCodePoints; i++) {
3473 if (Character.isHighSurrogate(seq.charAt(x++))) {
3474 if (x < length && Character.isLowSurrogate(seq.charAt(x))) {
3475 x++;
3476 }
3477 }
3478 }
3479 return x - index;
3480 }
3481
3482 assert (index >= 0 && index <= length);
3483 if (index == 0) {
3484 return 0;
3485 }
3486 int len = -lengthInCodePoints;
3487 for (int i = 0; x > 0 && i < len; i++) {
3488 if (Character.isLowSurrogate(seq.charAt(--x))) {
3489 if (x > 0 && Character.isHighSurrogate(seq.charAt(x-1))) {
3490 x--;
3491 }
3492 }
3493 }
3494 return index - x;
3495 }
3496
3497 private static final int countCodePoints(CharSequence seq) {
3498 int length = seq.length();
3499 int n = 0;
3500 for (int i = 0; i < length; ) {
3501 n++;
3502 if (Character.isHighSurrogate(seq.charAt(i++))) {
3503 if (i < length && Character.isLowSurrogate(seq.charAt(i))) {
3504 i++;
3505 }
3506 }
3507 }
3508 return n;
3509 }
3510
3511 /**
3512 * Creates a bit vector for matching Latin-1 values. A normal BitClass
3513 * never matches values above Latin-1, and a complemented BitClass always
3514 * matches values above Latin-1.
3515 */
3516 static final class BitClass implements BmpCharPredicate {
3517 final boolean[] bits;
3518 BitClass() {
3519 bits = new boolean[256];
3520 }
3521 BitClass add(int c, int flags) {
3522 assert c >= 0 && c <= 255;
3523 if ((flags & CASE_INSENSITIVE) != 0) {
3524 if (ASCII.isAscii(c)) {
3525 bits[ASCII.toUpper(c)] = true;
3526 bits[ASCII.toLower(c)] = true;
3527 } else if ((flags & UNICODE_CASE) != 0) {
3528 bits[Character.toLowerCase(c)] = true;
3529 bits[Character.toUpperCase(c)] = true;
3530 }
3531 }
3532 bits[c] = true;
3533 return this;
3534 }
3535 public boolean is(int ch) {
3536 return ch < 256 && bits[ch];
3537 }
3538 }
3539
3540
3541 /**
3542 * Utility method for creating a string slice matcher.
3543 */
3544 private Node newSlice(int[] buf, int count, boolean hasSupplementary) {
3545 int[] tmp = new int[count];
3546 if (has(CASE_INSENSITIVE)) {
3547 if (has(UNICODE_CASE)) {
3548 for (int i = 0; i < count; i++) {
3549 tmp[i] = Character.toLowerCase(
3550 Character.toUpperCase(buf[i]));
3551 }
3552 return hasSupplementary? new SliceUS(tmp) : new SliceU(tmp);
3553 }
3554 for (int i = 0; i < count; i++) {
3555 tmp[i] = ASCII.toLower(buf[i]);
3556 }
3557 return hasSupplementary? new SliceIS(tmp) : new SliceI(tmp);
3558 }
3559 for (int i = 0; i < count; i++) {
3560 tmp[i] = buf[i];
3561 }
3562 return hasSupplementary ? new SliceS(tmp) : new Slice(tmp);
3563 }
3564
3565 /**
3566 * The following classes are the building components of the object
3567 * tree that represents a compiled regular expression. The object tree
3568 * is made of individual elements that handle constructs in the Pattern.
3569 * Each type of object knows how to match its equivalent construct with
3570 * the match() method.
3571 */
3572
3573 /**
3574 * Base class for all node classes. Subclasses should override the match()
3575 * method as appropriate. This class is an accepting node, so its match()
3576 * always returns true.
3577 */
3578 static class Node extends Object {
3579 Node next;
3580 Node() {
3581 next = Pattern.accept;
3582 }
3583 /**
3584 * This method implements the classic accept node.
3585 */
3586 boolean match(Matcher matcher, int i, CharSequence seq) {
3587 matcher.last = i;
3588 matcher.groups[0] = matcher.first;
3589 matcher.groups[1] = matcher.last;
3590 return true;
3591 }
3592 /**
3593 * This method is good for all zero length assertions.
3594 */
3595 boolean study(TreeInfo info) {
3596 if (next != null) {
3597 return next.study(info);
3598 } else {
3599 return info.deterministic;
3600 }
3601 }
3602 }
3603
3604 static class LastNode extends Node {
3605 /**
3606 * This method implements the classic accept node with
3607 * the addition of a check to see if the match occurred
3608 * using all of the input.
3609 */
3610 boolean match(Matcher matcher, int i, CharSequence seq) {
3611 if (matcher.acceptMode == Matcher.ENDANCHOR && i != matcher.to)
3612 return false;
3613 matcher.last = i;
3614 matcher.groups[0] = matcher.first;
3615 matcher.groups[1] = matcher.last;
3616 return true;
3617 }
3618 }
3619
3620 /**
3621 * Used for REs that can start anywhere within the input string.
3622 * This basically tries to match repeatedly at each spot in the
3623 * input string, moving forward after each try. An anchored search
3624 * or a BnM will bypass this node completely.
3625 */
3626 static class Start extends Node {
3627 int minLength;
3628 Start(Node node) {
3629 this.next = node;
3630 TreeInfo info = new TreeInfo();
3631 next.study(info);
3632 minLength = info.minLength;
3633 }
3634 boolean match(Matcher matcher, int i, CharSequence seq) {
3635 if (i > matcher.to - minLength) {
3636 matcher.hitEnd = true;
3637 return false;
3638 }
3639 int guard = matcher.to - minLength;
3640 for (; i <= guard; i++) {
3641 if (next.match(matcher, i, seq)) {
3642 matcher.first = i;
3643 matcher.groups[0] = matcher.first;
3644 matcher.groups[1] = matcher.last;
3645 return true;
3646 }
3647 }
3648 matcher.hitEnd = true;
3649 return false;
3650 }
3651 boolean study(TreeInfo info) {
3652 next.study(info);
3653 info.maxValid = false;
3654 info.deterministic = false;
3655 return false;
3656 }
3657 }
3658
3659 /*
3660 * StartS supports supplementary characters, including unpaired surrogates.
3661 */
3662 static final class StartS extends Start {
3663 StartS(Node node) {
3664 super(node);
3665 }
3666 boolean match(Matcher matcher, int i, CharSequence seq) {
3667 if (i > matcher.to - minLength) {
3668 matcher.hitEnd = true;
3669 return false;
3670 }
3671 int guard = matcher.to - minLength;
3672 while (i <= guard) {
3673 //if ((ret = next.match(matcher, i, seq)) || i == guard)
3674 if (next.match(matcher, i, seq)) {
3675 matcher.first = i;
3676 matcher.groups[0] = matcher.first;
3677 matcher.groups[1] = matcher.last;
3678 return true;
3679 }
3680 if (i == guard)
3681 break;
3682 // Optimization to move to the next character. This is
3683 // faster than countChars(seq, i, 1).
3684 if (Character.isHighSurrogate(seq.charAt(i++))) {
3685 if (i < seq.length() &&
3686 Character.isLowSurrogate(seq.charAt(i))) {
3687 i++;
3688 }
3689 }
3690 }
3691 matcher.hitEnd = true;
3692 return false;
3693 }
3694 }
3695
3696 /**
3697 * Node to anchor at the beginning of input. This object implements the
3698 * match for a \A sequence, and the caret anchor will use this if not in
3699 * multiline mode.
3700 */
3701 static final class Begin extends Node {
3702 boolean match(Matcher matcher, int i, CharSequence seq) {
3703 int fromIndex = (matcher.anchoringBounds) ?
3704 matcher.from : 0;
3705 if (i == fromIndex && next.match(matcher, i, seq)) {
3706 matcher.first = i;
3707 matcher.groups[0] = i;
3708 matcher.groups[1] = matcher.last;
3709 return true;
3710 } else {
3711 return false;
3712 }
3713 }
3714 }
3715
3716 /**
3717 * Node to anchor at the end of input. This is the absolute end, so this
3718 * should not match at the last newline before the end as $ will.
3719 */
3720 static final class End extends Node {
3721 boolean match(Matcher matcher, int i, CharSequence seq) {
3722 int endIndex = (matcher.anchoringBounds) ?
3723 matcher.to : matcher.getTextLength();
3724 if (i == endIndex) {
3725 matcher.hitEnd = true;
3726 return next.match(matcher, i, seq);
3727 }
3728 return false;
3729 }
3730 }
3731
3732 /**
3733 * Node to anchor at the beginning of a line. This is essentially the
3734 * object to match for the multiline ^.
3735 */
3736 static final class Caret extends Node {
3737 boolean match(Matcher matcher, int i, CharSequence seq) {
3738 int startIndex = matcher.from;
3739 int endIndex = matcher.to;
3740 if (!matcher.anchoringBounds) {
3741 startIndex = 0;
3742 endIndex = matcher.getTextLength();
3743 }
3744 // Perl does not match ^ at end of input even after newline
3745 if (i == endIndex) {
3746 matcher.hitEnd = true;
3747 return false;
3748 }
3749 if (i > startIndex) {
3750 char ch = seq.charAt(i-1);
3751 if (ch != '\n' && ch != '\r'
3752 && (ch|1) != '\u2029'
3753 && ch != '\u0085' ) {
3754 return false;
3755 }
3756 // Should treat /r/n as one newline
3757 if (ch == '\r' && seq.charAt(i) == '\n')
3758 return false;
3759 }
3760 return next.match(matcher, i, seq);
3761 }
3762 }
3763
3764 /**
3765 * Node to anchor at the beginning of a line when in unixdot mode.
3766 */
3767 static final class UnixCaret extends Node {
3768 boolean match(Matcher matcher, int i, CharSequence seq) {
3769 int startIndex = matcher.from;
3770 int endIndex = matcher.to;
3771 if (!matcher.anchoringBounds) {
3772 startIndex = 0;
3773 endIndex = matcher.getTextLength();
3774 }
3775 // Perl does not match ^ at end of input even after newline
3776 if (i == endIndex) {
3777 matcher.hitEnd = true;
3778 return false;
3779 }
3780 if (i > startIndex) {
3781 char ch = seq.charAt(i-1);
3782 if (ch != '\n') {
3783 return false;
3784 }
3785 }
3786 return next.match(matcher, i, seq);
3787 }
3788 }
3789
3790 /**
3791 * Node to match the location where the last match ended.
3792 * This is used for the \G construct.
3793 */
3794 static final class LastMatch extends Node {
3795 boolean match(Matcher matcher, int i, CharSequence seq) {
3796 if (i != matcher.oldLast)
3797 return false;
3798 return next.match(matcher, i, seq);
3799 }
3800 }
3801
3802 /**
3803 * Node to anchor at the end of a line or the end of input based on the
3804 * multiline mode.
3805 *
3806 * When not in multiline mode, the $ can only match at the very end
3807 * of the input, unless the input ends in a line terminator in which
3808 * it matches right before the last line terminator.
3809 *
3810 * Note that \r\n is considered an atomic line terminator.
3811 *
3812 * Like ^ the $ operator matches at a position, it does not match the
3813 * line terminators themselves.
3814 */
3815 static final class Dollar extends Node {
3816 boolean multiline;
3817 Dollar(boolean mul) {
3818 multiline = mul;
3819 }
3820 boolean match(Matcher matcher, int i, CharSequence seq) {
3821 int endIndex = (matcher.anchoringBounds) ?
3822 matcher.to : matcher.getTextLength();
3823 if (!multiline) {
3824 if (i < endIndex - 2)
3825 return false;
3826 if (i == endIndex - 2) {
3827 char ch = seq.charAt(i);
3828 if (ch != '\r')
3829 return false;
3830 ch = seq.charAt(i + 1);
3831 if (ch != '\n')
3832 return false;
3833 }
3834 }
3835 // Matches before any line terminator; also matches at the
3836 // end of input
3837 // Before line terminator:
3838 // If multiline, we match here no matter what
3839 // If not multiline, fall through so that the end
3840 // is marked as hit; this must be a /r/n or a /n
3841 // at the very end so the end was hit; more input
3842 // could make this not match here
3843 if (i < endIndex) {
3844 char ch = seq.charAt(i);
3845 if (ch == '\n') {
3846 // No match between \r\n
3847 if (i > 0 && seq.charAt(i-1) == '\r')
3848 return false;
3849 if (multiline)
3850 return next.match(matcher, i, seq);
3851 } else if (ch == '\r' || ch == '\u0085' ||
3852 (ch|1) == '\u2029') {
3853 if (multiline)
3854 return next.match(matcher, i, seq);
3855 } else { // No line terminator, no match
3856 return false;
3857 }
3858 }
3859 // Matched at current end so hit end
3860 matcher.hitEnd = true;
3861 // If a $ matches because of end of input, then more input
3862 // could cause it to fail!
3863 matcher.requireEnd = true;
3864 return next.match(matcher, i, seq);
3865 }
3866 boolean study(TreeInfo info) {
3867 next.study(info);
3868 return info.deterministic;
3869 }
3870 }
3871
3872 /**
3873 * Node to anchor at the end of a line or the end of input based on the
3874 * multiline mode when in unix lines mode.
3875 */
3876 static final class UnixDollar extends Node {
3877 boolean multiline;
3878 UnixDollar(boolean mul) {
3879 multiline = mul;
3880 }
3881 boolean match(Matcher matcher, int i, CharSequence seq) {
3882 int endIndex = (matcher.anchoringBounds) ?
3883 matcher.to : matcher.getTextLength();
3884 if (i < endIndex) {
3885 char ch = seq.charAt(i);
3886 if (ch == '\n') {
3887 // If not multiline, then only possible to
3888 // match at very end or one before end
3889 if (multiline == false && i != endIndex - 1)
3890 return false;
3891 // If multiline return next.match without setting
3892 // matcher.hitEnd
3893 if (multiline)
3894 return next.match(matcher, i, seq);
3895 } else {
3896 return false;
3897 }
3898 }
3899 // Matching because at the end or 1 before the end;
3900 // more input could change this so set hitEnd
3901 matcher.hitEnd = true;
3902 // If a $ matches because of end of input, then more input
3903 // could cause it to fail!
3904 matcher.requireEnd = true;
3905 return next.match(matcher, i, seq);
3906 }
3907 boolean study(TreeInfo info) {
3908 next.study(info);
3909 return info.deterministic;
3910 }
3911 }
3912
3913 /**
3914 * Node class that matches a Unicode line ending '\R'
3915 */
3916 static final class LineEnding extends Node {
3917 boolean match(Matcher matcher, int i, CharSequence seq) {
3918 // (u+000Du+000A|[u+000Au+000Bu+000Cu+000Du+0085u+2028u+2029])
3919 if (i < matcher.to) {
3920 int ch = seq.charAt(i);
3921 if (ch == 0x0A || ch == 0x0B || ch == 0x0C ||
3922 ch == 0x85 || ch == 0x2028 || ch == 0x2029)
3923 return next.match(matcher, i + 1, seq);
3924 if (ch == 0x0D) {
3925 i++;
3926 if (i < matcher.to) {
3927 if (seq.charAt(i) == 0x0A &&
3928 next.match(matcher, i + 1, seq)) {
3929 return true;
3930 }
3931 } else {
3932 matcher.hitEnd = true;
3933 }
3934 return next.match(matcher, i, seq);
3935 }
3936 } else {
3937 matcher.hitEnd = true;
3938 }
3939 return false;
3940 }
3941 boolean study(TreeInfo info) {
3942 info.minLength++;
3943 info.maxLength += 2;
3944 return next.study(info);
3945 }
3946 }
3947
3948 /**
3949 * Abstract node class to match one character satisfying some
3950 * boolean property.
3951 */
3952 static class CharProperty extends Node {
3953 final CharPredicate predicate;
3954
3955 CharProperty (CharPredicate predicate) {
3956 this.predicate = predicate;
3957 }
3958 boolean match(Matcher matcher, int i, CharSequence seq) {
3959 if (i < matcher.to) {
3960 int ch = Character.codePointAt(seq, i);
3961 return predicate.is(ch) &&
3962 next.match(matcher, i + Character.charCount(ch), seq);
3963 } else {
3964 matcher.hitEnd = true;
3965 return false;
3966 }
3967 }
3968 boolean study(TreeInfo info) {
3969 info.minLength++;
3970 info.maxLength++;
3971 return next.study(info);
3972 }
3973 }
3974
3975 /**
3976 * Optimized version of CharProperty that works only for
3977 * properties never satisfied by Supplementary characters.
3978 */
3979 private static class BmpCharProperty extends CharProperty {
3980 BmpCharProperty (BmpCharPredicate predicate) {
3981 super(predicate);
3982 }
3983 boolean match(Matcher matcher, int i, CharSequence seq) {
3984 if (i < matcher.to) {
3985 return predicate.is(seq.charAt(i)) &&
3986 next.match(matcher, i + 1, seq);
3987 } else {
3988 matcher.hitEnd = true;
3989 return false;
3990 }
3991 }
3992 }
3993
3994 private static class NFCCharProperty extends Node {
3995 CharPredicate predicate;
3996 NFCCharProperty (CharPredicate predicate) {
3997 this.predicate = predicate;
3998 }
3999
4000 boolean match(Matcher matcher, int i, CharSequence seq) {
4001 if (i < matcher.to) {
4002 int ch0 = Character.codePointAt(seq, i);
4003 int n = Character.charCount(ch0);
4004 int j = i + n;
4005 // Fast check if it's necessary to call Normalizer;
4006 // testing Grapheme.isBoundary is enough for this case
4007 while (j < matcher.to) {
4008 int ch1 = Character.codePointAt(seq, j);
4009 if (Grapheme.isBoundary(ch0, ch1))
4010 break;
4011 ch0 = ch1;
4012 j += Character.charCount(ch1);
4013 }
4014 if (i + n == j) { // single, assume nfc cp
4015 if (predicate.is(ch0))
4016 return next.match(matcher, j, seq);
4017 } else {
4018 while (i + n < j) {
4019 String nfc = Normalizer.normalize(
4020 seq.toString().substring(i, j), Normalizer.Form.NFC);
4021 if (nfc.codePointCount(0, nfc.length()) == 1) {
4022 if (predicate.is(nfc.codePointAt(0)) &&
4023 next.match(matcher, j, seq)) {
4024 return true;
4025 }
4026 }
4027
4028 ch0 = Character.codePointBefore(seq, j);
4029 j -= Character.charCount(ch0);
4030 }
4031 }
4032 if (j < matcher.to)
4033 return false;
4034 }
4035 matcher.hitEnd = true;
4036 return false;
4037 }
4038
4039 boolean study(TreeInfo info) {
4040 info.minLength++;
4041 info.deterministic = false;
4042 return next.study(info);
4043 }
4044 }
4045
4046 /**
4047 * Node class that matches an unicode extended grapheme cluster
4048 */
4049 static class XGrapheme extends Node {
4050 boolean match(Matcher matcher, int i, CharSequence seq) {
4051 if (i < matcher.to) {
4052 i = Grapheme.nextBoundary(seq, i, matcher.to);
4053 return next.match(matcher, i, seq);
4054 }
4055 matcher.hitEnd = true;
4056 return false;
4057 }
4058
4059 boolean study(TreeInfo info) {
4060 info.minLength++;
4061 info.deterministic = false;
4062 return next.study(info);
4063 }
4064 }
4065
4066 /**
4067 * Node class that handles grapheme boundaries
4068 */
4069 static class GraphemeBound extends Node {
4070 boolean match(Matcher matcher, int i, CharSequence seq) {
4071 int startIndex = matcher.from;
4072 int endIndex = matcher.to;
4073 if (matcher.transparentBounds) {
4074 startIndex = 0;
4075 endIndex = matcher.getTextLength();
4076 }
4077 if (i == startIndex) {
4078 return next.match(matcher, i, seq);
4079 }
4080 if (i < endIndex) {
4081 if (Character.isSurrogatePair(seq.charAt(i-1), seq.charAt(i)) ||
4082 Grapheme.nextBoundary(seq,
4083 i - Character.charCount(Character.codePointBefore(seq, i)),
4084 i + Character.charCount(Character.codePointAt(seq, i))) > i) {
4085 return false;
4086 }
4087 } else {
4088 matcher.hitEnd = true;
4089 matcher.requireEnd = true;
4090 }
4091 return next.match(matcher, i, seq);
4092 }
4093 }
4094
4095 /**
4096 * Base class for all Slice nodes
4097 */
4098 static class SliceNode extends Node {
4099 int[] buffer;
4100 SliceNode(int[] buf) {
4101 buffer = buf;
4102 }
4103 boolean study(TreeInfo info) {
4104 info.minLength += buffer.length;
4105 info.maxLength += buffer.length;
4106 return next.study(info);
4107 }
4108 }
4109
4110 /**
4111 * Node class for a case sensitive/BMP-only sequence of literal
4112 * characters.
4113 */
4114 static class Slice extends SliceNode {
4115 Slice(int[] buf) {
4116 super(buf);
4117 }
4118 boolean match(Matcher matcher, int i, CharSequence seq) {
4119 int[] buf = buffer;
4120 int len = buf.length;
4121 for (int j=0; j<len; j++) {
4122 if ((i+j) >= matcher.to) {
4123 matcher.hitEnd = true;
4124 return false;
4125 }
4126 if (buf[j] != seq.charAt(i+j))
4127 return false;
4128 }
4129 return next.match(matcher, i+len, seq);
4130 }
4131 }
4132
4133 /**
4134 * Node class for a case_insensitive/BMP-only sequence of literal
4135 * characters.
4136 */
4137 static class SliceI extends SliceNode {
4138 SliceI(int[] buf) {
4139 super(buf);
4140 }
4141 boolean match(Matcher matcher, int i, CharSequence seq) {
4142 int[] buf = buffer;
4143 int len = buf.length;
4144 for (int j=0; j<len; j++) {
4145 if ((i+j) >= matcher.to) {
4146 matcher.hitEnd = true;
4147 return false;
4148 }
4149 int c = seq.charAt(i+j);
4150 if (buf[j] != c &&
4151 buf[j] != ASCII.toLower(c))
4152 return false;
4153 }
4154 return next.match(matcher, i+len, seq);
4155 }
4156 }
4157
4158 /**
4159 * Node class for a unicode_case_insensitive/BMP-only sequence of
4160 * literal characters. Uses unicode case folding.
4161 */
4162 static final class SliceU extends SliceNode {
4163 SliceU(int[] buf) {
4164 super(buf);
4165 }
4166 boolean match(Matcher matcher, int i, CharSequence seq) {
4167 int[] buf = buffer;
4168 int len = buf.length;
4169 for (int j=0; j<len; j++) {
4170 if ((i+j) >= matcher.to) {
4171 matcher.hitEnd = true;
4172 return false;
4173 }
4174 int c = seq.charAt(i+j);
4175 if (buf[j] != c &&
4176 buf[j] != Character.toLowerCase(Character.toUpperCase(c)))
4177 return false;
4178 }
4179 return next.match(matcher, i+len, seq);
4180 }
4181 }
4182
4183 /**
4184 * Node class for a case sensitive sequence of literal characters
4185 * including supplementary characters.
4186 */
4187 static final class SliceS extends Slice {
4188 SliceS(int[] buf) {
4189 super(buf);
4190 }
4191 boolean match(Matcher matcher, int i, CharSequence seq) {
4192 int[] buf = buffer;
4193 int x = i;
4194 for (int j = 0; j < buf.length; j++) {
4195 if (x >= matcher.to) {
4196 matcher.hitEnd = true;
4197 return false;
4198 }
4199 int c = Character.codePointAt(seq, x);
4200 if (buf[j] != c)
4201 return false;
4202 x += Character.charCount(c);
4203 if (x > matcher.to) {
4204 matcher.hitEnd = true;
4205 return false;
4206 }
4207 }
4208 return next.match(matcher, x, seq);
4209 }
4210 }
4211
4212 /**
4213 * Node class for a case insensitive sequence of literal characters
4214 * including supplementary characters.
4215 */
4216 static class SliceIS extends SliceNode {
4217 SliceIS(int[] buf) {
4218 super(buf);
4219 }
4220 int toLower(int c) {
4221 return ASCII.toLower(c);
4222 }
4223 boolean match(Matcher matcher, int i, CharSequence seq) {
4224 int[] buf = buffer;
4225 int x = i;
4226 for (int j = 0; j < buf.length; j++) {
4227 if (x >= matcher.to) {
4228 matcher.hitEnd = true;
4229 return false;
4230 }
4231 int c = Character.codePointAt(seq, x);
4232 if (buf[j] != c && buf[j] != toLower(c))
4233 return false;
4234 x += Character.charCount(c);
4235 if (x > matcher.to) {
4236 matcher.hitEnd = true;
4237 return false;
4238 }
4239 }
4240 return next.match(matcher, x, seq);
4241 }
4242 }
4243
4244 /**
4245 * Node class for a case insensitive sequence of literal characters.
4246 * Uses unicode case folding.
4247 */
4248 static final class SliceUS extends SliceIS {
4249 SliceUS(int[] buf) {
4250 super(buf);
4251 }
4252 int toLower(int c) {
4253 return Character.toLowerCase(Character.toUpperCase(c));
4254 }
4255 }
4256
4257 /**
4258 * The 0 or 1 quantifier. This one class implements all three types.
4259 */
4260 static final class Ques extends Node {
4261 Node atom;
4262 Qtype type;
4263 Ques(Node node, Qtype type) {
4264 this.atom = node;
4265 this.type = type;
4266 }
4267 boolean match(Matcher matcher, int i, CharSequence seq) {
4268 switch (type) {
4269 case GREEDY:
4270 return (atom.match(matcher, i, seq) && next.match(matcher, matcher.last, seq))
4271 || next.match(matcher, i, seq);
4272 case LAZY:
4273 return next.match(matcher, i, seq)
4274 || (atom.match(matcher, i, seq) && next.match(matcher, matcher.last, seq));
4275 case POSSESSIVE:
4276 if (atom.match(matcher, i, seq)) i = matcher.last;
4277 return next.match(matcher, i, seq);
4278 default:
4279 return atom.match(matcher, i, seq) && next.match(matcher, matcher.last, seq);
4280 }
4281 }
4282 boolean study(TreeInfo info) {
4283 if (type != Qtype.INDEPENDENT) {
4284 int minL = info.minLength;
4285 atom.study(info);
4286 info.minLength = minL;
4287 info.deterministic = false;
4288 return next.study(info);
4289 } else {
4290 atom.study(info);
4291 return next.study(info);
4292 }
4293 }
4294 }
4295
4296 /**
4297 * Handles the greedy style repetition with the specified minimum
4298 * and the maximum equal to MAX_REPS, for *, + and {N,} quantifiers.
4299 */
4300 static class CharPropertyGreedy extends Node {
4301 final CharPredicate predicate;
4302 final int cmin;
4303
4304 CharPropertyGreedy(CharProperty cp, int cmin) {
4305 this.predicate = cp.predicate;
4306 this.cmin = cmin;
4307 }
4308 boolean match(Matcher matcher, int i, CharSequence seq) {
4309 int n = 0;
4310 int to = matcher.to;
4311 // greedy, all the way down
4312 while (i < to) {
4313 int ch = Character.codePointAt(seq, i);
4314 if (!predicate.is(ch))
4315 break;
4316 i += Character.charCount(ch);
4317 n++;
4318 }
4319 if (i >= to) {
4320 matcher.hitEnd = true;
4321 }
4322 while (n >= cmin) {
4323 if (next.match(matcher, i, seq))
4324 return true;
4325 if (n == cmin)
4326 return false;
4327 // backing off if match fails
4328 int ch = Character.codePointBefore(seq, i);
4329 i -= Character.charCount(ch);
4330 n--;
4331 }
4332 return false;
4333 }
4334
4335 boolean study(TreeInfo info) {
4336 info.minLength += cmin;
4337 if (info.maxValid) {
4338 info.maxLength += MAX_REPS;
4339 }
4340 info.deterministic = false;
4341 return next.study(info);
4342 }
4343 }
4344
4345 static final class BmpCharPropertyGreedy extends CharPropertyGreedy {
4346
4347 BmpCharPropertyGreedy(BmpCharProperty bcp, int cmin) {
4348 super(bcp, cmin);
4349 }
4350
4351 boolean match(Matcher matcher, int i, CharSequence seq) {
4352 int n = 0;
4353 int to = matcher.to;
4354 while (i < to && predicate.is(seq.charAt(i))) {
4355 i++; n++;
4356 }
4357 if (i >= to) {
4358 matcher.hitEnd = true;
4359 }
4360 while (n >= cmin) {
4361 if (next.match(matcher, i, seq))
4362 return true;
4363 i--; n--; // backing off if match fails
4364 }
4365 return false;
4366 }
4367 }
4368
4369 /**
4370 * Handles the curly-brace style repetition with a specified minimum and
4371 * maximum occurrences. The * quantifier is handled as a special case.
4372 * This class handles the three types.
4373 */
4374 static final class Curly extends Node {
4375 Node atom;
4376 Qtype type;
4377 int cmin;
4378 int cmax;
4379
4380 Curly(Node node, int cmin, int cmax, Qtype type) {
4381 this.atom = node;
4382 this.type = type;
4383 this.cmin = cmin;
4384 this.cmax = cmax;
4385 }
4386 boolean match(Matcher matcher, int i, CharSequence seq) {
4387 int j;
4388 for (j = 0; j < cmin; j++) {
4389 if (atom.match(matcher, i, seq)) {
4390 i = matcher.last;
4391 continue;
4392 }
4393 return false;
4394 }
4395 if (type == Qtype.GREEDY)
4396 return match0(matcher, i, j, seq);
4397 else if (type == Qtype.LAZY)
4398 return match1(matcher, i, j, seq);
4399 else
4400 return match2(matcher, i, j, seq);
4401 }
4402 // Greedy match.
4403 // i is the index to start matching at
4404 // j is the number of atoms that have matched
4405 boolean match0(Matcher matcher, int i, int j, CharSequence seq) {
4406 if (j >= cmax) {
4407 // We have matched the maximum... continue with the rest of
4408 // the regular expression
4409 return next.match(matcher, i, seq);
4410 }
4411 int backLimit = j;
4412 while (atom.match(matcher, i, seq)) {
4413 // k is the length of this match
4414 int k = matcher.last - i;
4415 if (k == 0) // Zero length match
4416 break;
4417 // Move up index and number matched
4418 i = matcher.last;
4419 j++;
4420 // We are greedy so match as many as we can
4421 while (j < cmax) {
4422 if (!atom.match(matcher, i, seq))
4423 break;
4424 if (i + k != matcher.last) {
4425 if (match0(matcher, matcher.last, j+1, seq))
4426 return true;
4427 break;
4428 }
4429 i += k;
4430 j++;
4431 }
4432 // Handle backing off if match fails
4433 while (j >= backLimit) {
4434 if (next.match(matcher, i, seq))
4435 return true;
4436 i -= k;
4437 j--;
4438 }
4439 return false;
4440 }
4441 return next.match(matcher, i, seq);
4442 }
4443 // Reluctant match. At this point, the minimum has been satisfied.
4444 // i is the index to start matching at
4445 // j is the number of atoms that have matched
4446 boolean match1(Matcher matcher, int i, int j, CharSequence seq) {
4447 for (;;) {
4448 // Try finishing match without consuming any more
4449 if (next.match(matcher, i, seq))
4450 return true;
4451 // At the maximum, no match found
4452 if (j >= cmax)
4453 return false;
4454 // Okay, must try one more atom
4455 if (!atom.match(matcher, i, seq))
4456 return false;
4457 // If we haven't moved forward then must break out
4458 if (i == matcher.last)
4459 return false;
4460 // Move up index and number matched
4461 i = matcher.last;
4462 j++;
4463 }
4464 }
4465 boolean match2(Matcher matcher, int i, int j, CharSequence seq) {
4466 for (; j < cmax; j++) {
4467 if (!atom.match(matcher, i, seq))
4468 break;
4469 if (i == matcher.last)
4470 break;
4471 i = matcher.last;
4472 }
4473 return next.match(matcher, i, seq);
4474 }
4475 boolean study(TreeInfo info) {
4476 // Save original info
4477 int minL = info.minLength;
4478 int maxL = info.maxLength;
4479 boolean maxV = info.maxValid;
4480 boolean detm = info.deterministic;
4481 info.reset();
4482
4483 atom.study(info);
4484
4485 int temp = info.minLength * cmin + minL;
4486 if (temp < minL) {
4487 temp = 0xFFFFFFF; // arbitrary large number
4488 }
4489 info.minLength = temp;
4490
4491 if (maxV & info.maxValid) {
4492 temp = info.maxLength * cmax + maxL;
4493 info.maxLength = temp;
4494 if (temp < maxL) {
4495 info.maxValid = false;
4496 }
4497 } else {
4498 info.maxValid = false;
4499 }
4500
4501 if (info.deterministic && cmin == cmax)
4502 info.deterministic = detm;
4503 else
4504 info.deterministic = false;
4505 return next.study(info);
4506 }
4507 }
4508
4509 /**
4510 * Handles the curly-brace style repetition with a specified minimum and
4511 * maximum occurrences in deterministic cases. This is an iterative
4512 * optimization over the Prolog and Loop system which would handle this
4513 * in a recursive way. The * quantifier is handled as a special case.
4514 * If capture is true then this class saves group settings and ensures
4515 * that groups are unset when backing off of a group match.
4516 */
4517 static final class GroupCurly extends Node {
4518 Node atom;
4519 Qtype type;
4520 int cmin;
4521 int cmax;
4522 int localIndex;
4523 int groupIndex;
4524 boolean capture;
4525
4526 GroupCurly(Node node, int cmin, int cmax, Qtype type, int local,
4527 int group, boolean capture) {
4528 this.atom = node;
4529 this.type = type;
4530 this.cmin = cmin;
4531 this.cmax = cmax;
4532 this.localIndex = local;
4533 this.groupIndex = group;
4534 this.capture = capture;
4535 }
4536 boolean match(Matcher matcher, int i, CharSequence seq) {
4537 int[] groups = matcher.groups;
4538 int[] locals = matcher.locals;
4539 int save0 = locals[localIndex];
4540 int save1 = 0;
4541 int save2 = 0;
4542
4543 if (capture) {
4544 save1 = groups[groupIndex];
4545 save2 = groups[groupIndex+1];
4546 }
4547
4548 // Notify GroupTail there is no need to setup group info
4549 // because it will be set here
4550 locals[localIndex] = -1;
4551
4552 boolean ret = true;
4553 for (int j = 0; j < cmin; j++) {
4554 if (atom.match(matcher, i, seq)) {
4555 if (capture) {
4556 groups[groupIndex] = i;
4557 groups[groupIndex+1] = matcher.last;
4558 }
4559 i = matcher.last;
4560 } else {
4561 ret = false;
4562 break;
4563 }
4564 }
4565 if (ret) {
4566 if (type == Qtype.GREEDY) {
4567 ret = match0(matcher, i, cmin, seq);
4568 } else if (type == Qtype.LAZY) {
4569 ret = match1(matcher, i, cmin, seq);
4570 } else {
4571 ret = match2(matcher, i, cmin, seq);
4572 }
4573 }
4574 if (!ret) {
4575 locals[localIndex] = save0;
4576 if (capture) {
4577 groups[groupIndex] = save1;
4578 groups[groupIndex+1] = save2;
4579 }
4580 }
4581 return ret;
4582 }
4583 // Aggressive group match
4584 boolean match0(Matcher matcher, int i, int j, CharSequence seq) {
4585 // don't back off passing the starting "j"
4586 int min = j;
4587 int[] groups = matcher.groups;
4588 int save0 = 0;
4589 int save1 = 0;
4590 if (capture) {
4591 save0 = groups[groupIndex];
4592 save1 = groups[groupIndex+1];
4593 }
4594 for (;;) {
4595 if (j >= cmax)
4596 break;
4597 if (!atom.match(matcher, i, seq))
4598 break;
4599 int k = matcher.last - i;
4600 if (k <= 0) {
4601 if (capture) {
4602 groups[groupIndex] = i;
4603 groups[groupIndex+1] = i + k;
4604 }
4605 i = i + k;
4606 break;
4607 }
4608 for (;;) {
4609 if (capture) {
4610 groups[groupIndex] = i;
4611 groups[groupIndex+1] = i + k;
4612 }
4613 i = i + k;
4614 if (++j >= cmax)
4615 break;
4616 if (!atom.match(matcher, i, seq))
4617 break;
4618 if (i + k != matcher.last) {
4619 if (match0(matcher, i, j, seq))
4620 return true;
4621 break;
4622 }
4623 }
4624 while (j > min) {
4625 if (next.match(matcher, i, seq)) {
4626 if (capture) {
4627 groups[groupIndex+1] = i;
4628 groups[groupIndex] = i - k;
4629 }
4630 return true;
4631 }
4632 // backing off
4633 i = i - k;
4634 if (capture) {
4635 groups[groupIndex+1] = i;
4636 groups[groupIndex] = i - k;
4637 }
4638 j--;
4639
4640 }
4641 break;
4642 }
4643 if (capture) {
4644 groups[groupIndex] = save0;
4645 groups[groupIndex+1] = save1;
4646 }
4647 return next.match(matcher, i, seq);
4648 }
4649 // Reluctant matching
4650 boolean match1(Matcher matcher, int i, int j, CharSequence seq) {
4651 for (;;) {
4652 if (next.match(matcher, i, seq))
4653 return true;
4654 if (j >= cmax)
4655 return false;
4656 if (!atom.match(matcher, i, seq))
4657 return false;
4658 if (i == matcher.last)
4659 return false;
4660 if (capture) {
4661 matcher.groups[groupIndex] = i;
4662 matcher.groups[groupIndex+1] = matcher.last;
4663 }
4664 i = matcher.last;
4665 j++;
4666 }
4667 }
4668 // Possessive matching
4669 boolean match2(Matcher matcher, int i, int j, CharSequence seq) {
4670 for (; j < cmax; j++) {
4671 if (!atom.match(matcher, i, seq)) {
4672 break;
4673 }
4674 if (capture) {
4675 matcher.groups[groupIndex] = i;
4676 matcher.groups[groupIndex+1] = matcher.last;
4677 }
4678 if (i == matcher.last) {
4679 break;
4680 }
4681 i = matcher.last;
4682 }
4683 return next.match(matcher, i, seq);
4684 }
4685 boolean study(TreeInfo info) {
4686 // Save original info
4687 int minL = info.minLength;
4688 int maxL = info.maxLength;
4689 boolean maxV = info.maxValid;
4690 boolean detm = info.deterministic;
4691 info.reset();
4692
4693 atom.study(info);
4694
4695 int temp = info.minLength * cmin + minL;
4696 if (temp < minL) {
4697 temp = 0xFFFFFFF; // Arbitrary large number
4698 }
4699 info.minLength = temp;
4700
4701 if (maxV & info.maxValid) {
4702 temp = info.maxLength * cmax + maxL;
4703 info.maxLength = temp;
4704 if (temp < maxL) {
4705 info.maxValid = false;
4706 }
4707 } else {
4708 info.maxValid = false;
4709 }
4710
4711 if (info.deterministic && cmin == cmax) {
4712 info.deterministic = detm;
4713 } else {
4714 info.deterministic = false;
4715 }
4716 return next.study(info);
4717 }
4718 }
4719
4720 /**
4721 * A Guard node at the end of each atom node in a Branch. It
4722 * serves the purpose of chaining the "match" operation to
4723 * "next" but not the "study", so we can collect the TreeInfo
4724 * of each atom node without including the TreeInfo of the
4725 * "next".
4726 */
4727 static final class BranchConn extends Node {
4728 BranchConn() {}
4729 boolean match(Matcher matcher, int i, CharSequence seq) {
4730 return next.match(matcher, i, seq);
4731 }
4732 boolean study(TreeInfo info) {
4733 return info.deterministic;
4734 }
4735 }
4736
4737 /**
4738 * Handles the branching of alternations. Note this is also used for
4739 * the ? quantifier to branch between the case where it matches once
4740 * and where it does not occur.
4741 */
4742 static final class Branch extends Node {
4743 Node[] atoms = new Node[2];
4744 int size = 2;
4745 Node conn;
4746 Branch(Node first, Node second, Node branchConn) {
4747 conn = branchConn;
4748 atoms[0] = first;
4749 atoms[1] = second;
4750 }
4751
4752 void add(Node node) {
4753 if (size >= atoms.length) {
4754 Node[] tmp = new Node[atoms.length*2];
4755 System.arraycopy(atoms, 0, tmp, 0, atoms.length);
4756 atoms = tmp;
4757 }
4758 atoms[size++] = node;
4759 }
4760
4761 boolean match(Matcher matcher, int i, CharSequence seq) {
4762 for (int n = 0; n < size; n++) {
4763 if (atoms[n] == null) {
4764 if (conn.next.match(matcher, i, seq))
4765 return true;
4766 } else if (atoms[n].match(matcher, i, seq)) {
4767 return true;
4768 }
4769 }
4770 return false;
4771 }
4772
4773 boolean study(TreeInfo info) {
4774 int minL = info.minLength;
4775 int maxL = info.maxLength;
4776 boolean maxV = info.maxValid;
4777
4778 int minL2 = Integer.MAX_VALUE; //arbitrary large enough num
4779 int maxL2 = -1;
4780 for (int n = 0; n < size; n++) {
4781 info.reset();
4782 if (atoms[n] != null)
4783 atoms[n].study(info);
4784 minL2 = Math.min(minL2, info.minLength);
4785 maxL2 = Math.max(maxL2, info.maxLength);
4786 maxV = (maxV & info.maxValid);
4787 }
4788
4789 minL += minL2;
4790 maxL += maxL2;
4791
4792 info.reset();
4793 conn.next.study(info);
4794
4795 info.minLength += minL;
4796 info.maxLength += maxL;
4797 info.maxValid &= maxV;
4798 info.deterministic = false;
4799 return false;
4800 }
4801 }
4802
4803 /**
4804 * The GroupHead saves the location where the group begins in the locals
4805 * and restores them when the match is done.
4806 *
4807 * The matchRef is used when a reference to this group is accessed later
4808 * in the expression. The locals will have a negative value in them to
4809 * indicate that we do not want to unset the group if the reference
4810 * doesn't match.
4811 */
4812 static final class GroupHead extends Node {
4813 int localIndex;
4814 GroupTail tail; // for debug/print only, match does not need to know
4815 GroupHead(int localCount) {
4816 localIndex = localCount;
4817 }
4818 boolean match(Matcher matcher, int i, CharSequence seq) {
4819 int save = matcher.locals[localIndex];
4820 matcher.locals[localIndex] = i;
4821 boolean ret = next.match(matcher, i, seq);
4822 matcher.locals[localIndex] = save;
4823 return ret;
4824 }
4825 }
4826
4827 /**
4828 * The GroupTail handles the setting of group beginning and ending
4829 * locations when groups are successfully matched. It must also be able to
4830 * unset groups that have to be backed off of.
4831 *
4832 * The GroupTail node is also used when a previous group is referenced,
4833 * and in that case no group information needs to be set.
4834 */
4835 static final class GroupTail extends Node {
4836 int localIndex;
4837 int groupIndex;
4838 GroupTail(int localCount, int groupCount) {
4839 localIndex = localCount;
4840 groupIndex = groupCount + groupCount;
4841 }
4842 boolean match(Matcher matcher, int i, CharSequence seq) {
4843 int tmp = matcher.locals[localIndex];
4844 if (tmp >= 0) { // This is the normal group case.
4845 // Save the group so we can unset it if it
4846 // backs off of a match.
4847 int groupStart = matcher.groups[groupIndex];
4848 int groupEnd = matcher.groups[groupIndex+1];
4849
4850 matcher.groups[groupIndex] = tmp;
4851 matcher.groups[groupIndex+1] = i;
4852 if (next.match(matcher, i, seq)) {
4853 return true;
4854 }
4855 matcher.groups[groupIndex] = groupStart;
4856 matcher.groups[groupIndex+1] = groupEnd;
4857 return false;
4858 } else {
4859 // This is a group reference case. We don't need to save any
4860 // group info because it isn't really a group.
4861 matcher.last = i;
4862 return true;
4863 }
4864 }
4865 }
4866
4867 /**
4868 * This sets up a loop to handle a recursive quantifier structure.
4869 */
4870 static final class Prolog extends Node {
4871 Loop loop;
4872 Prolog(Loop loop) {
4873 this.loop = loop;
4874 }
4875 boolean match(Matcher matcher, int i, CharSequence seq) {
4876 return loop.matchInit(matcher, i, seq);
4877 }
4878 boolean study(TreeInfo info) {
4879 return loop.study(info);
4880 }
4881 }
4882
4883 /**
4884 * Handles the repetition count for a greedy Curly. The matchInit
4885 * is called from the Prolog to save the index of where the group
4886 * beginning is stored. A zero length group check occurs in the
4887 * normal match but is skipped in the matchInit.
4888 */
4889 static class Loop extends Node {
4890 Node body;
4891 int countIndex; // local count index in matcher locals
4892 int beginIndex; // group beginning index
4893 int cmin, cmax;
4894 int posIndex;
4895 Loop(int countIndex, int beginIndex) {
4896 this.countIndex = countIndex;
4897 this.beginIndex = beginIndex;
4898 this.posIndex = -1;
4899 }
4900 boolean match(Matcher matcher, int i, CharSequence seq) {
4901 // Avoid infinite loop in zero-length case.
4902 if (i > matcher.locals[beginIndex]) {
4903 int count = matcher.locals[countIndex];
4904
4905 // This block is for before we reach the minimum
4906 // iterations required for the loop to match
4907 if (count < cmin) {
4908 matcher.locals[countIndex] = count + 1;
4909 boolean b = body.match(matcher, i, seq);
4910 // If match failed we must backtrack, so
4911 // the loop count should NOT be incremented
4912 if (!b)
4913 matcher.locals[countIndex] = count;
4914 // Return success or failure since we are under
4915 // minimum
4916 return b;
4917 }
4918 // This block is for after we have the minimum
4919 // iterations required for the loop to match
4920 if (count < cmax) {
4921 // Let's check if we have already tried and failed
4922 // at this starting position "i" in the past.
4923 // If yes, then just return false wihtout trying
4924 // again, to stop the exponential backtracking.
4925 if (posIndex != -1 &&
4926 matcher.localsPos[posIndex].contains(i)) {
4927 return next.match(matcher, i, seq);
4928 }
4929 matcher.locals[countIndex] = count + 1;
4930 boolean b = body.match(matcher, i, seq);
4931 // If match failed we must backtrack, so
4932 // the loop count should NOT be incremented
4933 if (b)
4934 return true;
4935 matcher.locals[countIndex] = count;
4936 // save the failed position
4937 if (posIndex != -1) {
4938 matcher.localsPos[posIndex].add(i);
4939 }
4940 }
4941 }
4942 return next.match(matcher, i, seq);
4943 }
4944 boolean matchInit(Matcher matcher, int i, CharSequence seq) {
4945 int save = matcher.locals[countIndex];
4946 boolean ret;
4947 if (posIndex != -1 && matcher.localsPos[posIndex] == null) {
4948 matcher.localsPos[posIndex] = new IntHashSet();
4949 }
4950 if (0 < cmin) {
4951 matcher.locals[countIndex] = 1;
4952 ret = body.match(matcher, i, seq);
4953 } else if (0 < cmax) {
4954 matcher.locals[countIndex] = 1;
4955 ret = body.match(matcher, i, seq);
4956 if (ret == false)
4957 ret = next.match(matcher, i, seq);
4958 } else {
4959 ret = next.match(matcher, i, seq);
4960 }
4961 matcher.locals[countIndex] = save;
4962 return ret;
4963 }
4964 boolean study(TreeInfo info) {
4965 info.maxValid = false;
4966 info.deterministic = false;
4967 return false;
4968 }
4969 }
4970
4971 /**
4972 * Handles the repetition count for a reluctant Curly. The matchInit
4973 * is called from the Prolog to save the index of where the group
4974 * beginning is stored. A zero length group check occurs in the
4975 * normal match but is skipped in the matchInit.
4976 */
4977 static final class LazyLoop extends Loop {
4978 LazyLoop(int countIndex, int beginIndex) {
4979 super(countIndex, beginIndex);
4980 }
4981 boolean match(Matcher matcher, int i, CharSequence seq) {
4982 // Check for zero length group
4983 if (i > matcher.locals[beginIndex]) {
4984 int count = matcher.locals[countIndex];
4985 if (count < cmin) {
4986 matcher.locals[countIndex] = count + 1;
4987 boolean result = body.match(matcher, i, seq);
4988 // If match failed we must backtrack, so
4989 // the loop count should NOT be incremented
4990 if (!result)
4991 matcher.locals[countIndex] = count;
4992 return result;
4993 }
4994 if (next.match(matcher, i, seq))
4995 return true;
4996 if (count < cmax) {
4997 matcher.locals[countIndex] = count + 1;
4998 boolean result = body.match(matcher, i, seq);
4999 // If match failed we must backtrack, so
5000 // the loop count should NOT be incremented
5001 if (!result)
5002 matcher.locals[countIndex] = count;
5003 return result;
5004 }
5005 return false;
5006 }
5007 return next.match(matcher, i, seq);
5008 }
5009 boolean matchInit(Matcher matcher, int i, CharSequence seq) {
5010 int save = matcher.locals[countIndex];
5011 boolean ret = false;
5012 if (0 < cmin) {
5013 matcher.locals[countIndex] = 1;
5014 ret = body.match(matcher, i, seq);
5015 } else if (next.match(matcher, i, seq)) {
5016 ret = true;
5017 } else if (0 < cmax) {
5018 matcher.locals[countIndex] = 1;
5019 ret = body.match(matcher, i, seq);
5020 }
5021 matcher.locals[countIndex] = save;
5022 return ret;
5023 }
5024 boolean study(TreeInfo info) {
5025 info.maxValid = false;
5026 info.deterministic = false;
5027 return false;
5028 }
5029 }
5030
5031 /**
5032 * Refers to a group in the regular expression. Attempts to match
5033 * whatever the group referred to last matched.
5034 */
5035 static class BackRef extends Node {
5036 int groupIndex;
5037 BackRef(int groupCount) {
5038 super();
5039 groupIndex = groupCount + groupCount;
5040 }
5041 boolean match(Matcher matcher, int i, CharSequence seq) {
5042 int j = matcher.groups[groupIndex];
5043 int k = matcher.groups[groupIndex+1];
5044
5045 int groupSize = k - j;
5046 // If the referenced group didn't match, neither can this
5047 if (j < 0)
5048 return false;
5049
5050 // If there isn't enough input left no match
5051 if (i + groupSize > matcher.to) {
5052 matcher.hitEnd = true;
5053 return false;
5054 }
5055 // Check each new char to make sure it matches what the group
5056 // referenced matched last time around
5057 for (int index=0; index<groupSize; index++)
5058 if (seq.charAt(i+index) != seq.charAt(j+index))
5059 return false;
5060
5061 return next.match(matcher, i+groupSize, seq);
5062 }
5063 boolean study(TreeInfo info) {
5064 info.maxValid = false;
5065 return next.study(info);
5066 }
5067 }
5068
5069 static class CIBackRef extends Node {
5070 int groupIndex;
5071 boolean doUnicodeCase;
5072 CIBackRef(int groupCount, boolean doUnicodeCase) {
5073 super();
5074 groupIndex = groupCount + groupCount;
5075 this.doUnicodeCase = doUnicodeCase;
5076 }
5077 boolean match(Matcher matcher, int i, CharSequence seq) {
5078 int j = matcher.groups[groupIndex];
5079 int k = matcher.groups[groupIndex+1];
5080
5081 int groupSize = k - j;
5082
5083 // If the referenced group didn't match, neither can this
5084 if (j < 0)
5085 return false;
5086
5087 // If there isn't enough input left no match
5088 if (i + groupSize > matcher.to) {
5089 matcher.hitEnd = true;
5090 return false;
5091 }
5092
5093 // Check each new char to make sure it matches what the group
5094 // referenced matched last time around
5095 int x = i;
5096 for (int index=0; index<groupSize; index++) {
5097 int c1 = Character.codePointAt(seq, x);
5098 int c2 = Character.codePointAt(seq, j);
5099 if (c1 != c2) {
5100 if (doUnicodeCase) {
5101 int cc1 = Character.toUpperCase(c1);
5102 int cc2 = Character.toUpperCase(c2);
5103 if (cc1 != cc2 &&
5104 Character.toLowerCase(cc1) !=
5105 Character.toLowerCase(cc2))
5106 return false;
5107 } else {
5108 if (ASCII.toLower(c1) != ASCII.toLower(c2))
5109 return false;
5110 }
5111 }
5112 x += Character.charCount(c1);
5113 j += Character.charCount(c2);
5114 }
5115
5116 return next.match(matcher, i+groupSize, seq);
5117 }
5118 boolean study(TreeInfo info) {
5119 info.maxValid = false;
5120 return next.study(info);
5121 }
5122 }
5123
5124 /**
5125 * Searches until the next instance of its atom. This is useful for
5126 * finding the atom efficiently without passing an instance of it
5127 * (greedy problem) and without a lot of wasted search time (reluctant
5128 * problem).
5129 */
5130 static final class First extends Node {
5131 Node atom;
5132 First(Node node) {
5133 this.atom = BnM.optimize(node);
5134 }
5135 boolean match(Matcher matcher, int i, CharSequence seq) {
5136 if (atom instanceof BnM) {
5137 return atom.match(matcher, i, seq)
5138 && next.match(matcher, matcher.last, seq);
5139 }
5140 for (;;) {
5141 if (i > matcher.to) {
5142 matcher.hitEnd = true;
5143 return false;
5144 }
5145 if (atom.match(matcher, i, seq)) {
5146 return next.match(matcher, matcher.last, seq);
5147 }
5148 i += countChars(seq, i, 1);
5149 matcher.first++;
5150 }
5151 }
5152 boolean study(TreeInfo info) {
5153 atom.study(info);
5154 info.maxValid = false;
5155 info.deterministic = false;
5156 return next.study(info);
5157 }
5158 }
5159
5160 /**
5161 * Zero width positive lookahead.
5162 */
5163 static final class Pos extends Node {
5164 Node cond;
5165 Pos(Node cond) {
5166 this.cond = cond;
5167 }
5168 boolean match(Matcher matcher, int i, CharSequence seq) {
5169 int savedTo = matcher.to;
5170 boolean conditionMatched;
5171
5172 // Relax transparent region boundaries for lookahead
5173 if (matcher.transparentBounds)
5174 matcher.to = matcher.getTextLength();
5175 try {
5176 conditionMatched = cond.match(matcher, i, seq);
5177 } finally {
5178 // Reinstate region boundaries
5179 matcher.to = savedTo;
5180 }
5181 return conditionMatched && next.match(matcher, i, seq);
5182 }
5183 }
5184
5185 /**
5186 * Zero width negative lookahead.
5187 */
5188 static final class Neg extends Node {
5189 Node cond;
5190 Neg(Node cond) {
5191 this.cond = cond;
5192 }
5193 boolean match(Matcher matcher, int i, CharSequence seq) {
5194 int savedTo = matcher.to;
5195 boolean conditionMatched;
5196
5197 // Relax transparent region boundaries for lookahead
5198 if (matcher.transparentBounds)
5199 matcher.to = matcher.getTextLength();
5200 try {
5201 if (i < matcher.to) {
5202 conditionMatched = !cond.match(matcher, i, seq);
5203 } else {
5204 // If a negative lookahead succeeds then more input
5205 // could cause it to fail!
5206 matcher.requireEnd = true;
5207 conditionMatched = !cond.match(matcher, i, seq);
5208 }
5209 } finally {
5210 // Reinstate region boundaries
5211 matcher.to = savedTo;
5212 }
5213 return conditionMatched && next.match(matcher, i, seq);
5214 }
5215 }
5216
5217 /**
5218 * For use with lookbehinds; matches the position where the lookbehind
5219 * was encountered.
5220 */
5221 static class LookBehindEndNode extends Node {
5222 private LookBehindEndNode() {} // Singleton
5223
5224 static LookBehindEndNode INSTANCE = new LookBehindEndNode();
5225
5226 boolean match(Matcher matcher, int i, CharSequence seq) {
5227 return i == matcher.lookbehindTo;
5228 }
5229 }
5230
5231 /**
5232 * Zero width positive lookbehind.
5233 */
5234 static class Behind extends Node {
5235 Node cond;
5236 int rmax, rmin;
5237 Behind(Node cond, int rmax, int rmin) {
5238 this.cond = cond;
5239 this.rmax = rmax;
5240 this.rmin = rmin;
5241 }
5242
5243 boolean match(Matcher matcher, int i, CharSequence seq) {
5244 int savedFrom = matcher.from;
5245 boolean conditionMatched = false;
5246 int startIndex = (!matcher.transparentBounds) ?
5247 matcher.from : 0;
5248 int from = Math.max(i - rmax, startIndex);
5249 // Set end boundary
5250 int savedLBT = matcher.lookbehindTo;
5251 matcher.lookbehindTo = i;
5252 // Relax transparent region boundaries for lookbehind
5253 if (matcher.transparentBounds)
5254 matcher.from = 0;
5255 for (int j = i - rmin; !conditionMatched && j >= from; j--) {
5256 conditionMatched = cond.match(matcher, j, seq);
5257 }
5258 matcher.from = savedFrom;
5259 matcher.lookbehindTo = savedLBT;
5260 return conditionMatched && next.match(matcher, i, seq);
5261 }
5262 }
5263
5264 /**
5265 * Zero width positive lookbehind, including supplementary
5266 * characters or unpaired surrogates.
5267 */
5268 static final class BehindS extends Behind {
5269 BehindS(Node cond, int rmax, int rmin) {
5270 super(cond, rmax, rmin);
5271 }
5272 boolean match(Matcher matcher, int i, CharSequence seq) {
5273 int rmaxChars = countChars(seq, i, -rmax);
5274 int rminChars = countChars(seq, i, -rmin);
5275 int savedFrom = matcher.from;
5276 int startIndex = (!matcher.transparentBounds) ?
5277 matcher.from : 0;
5278 boolean conditionMatched = false;
5279 int from = Math.max(i - rmaxChars, startIndex);
5280 // Set end boundary
5281 int savedLBT = matcher.lookbehindTo;
5282 matcher.lookbehindTo = i;
5283 // Relax transparent region boundaries for lookbehind
5284 if (matcher.transparentBounds)
5285 matcher.from = 0;
5286
5287 for (int j = i - rminChars;
5288 !conditionMatched && j >= from;
5289 j -= j>from ? countChars(seq, j, -1) : 1) {
5290 conditionMatched = cond.match(matcher, j, seq);
5291 }
5292 matcher.from = savedFrom;
5293 matcher.lookbehindTo = savedLBT;
5294 return conditionMatched && next.match(matcher, i, seq);
5295 }
5296 }
5297
5298 /**
5299 * Zero width negative lookbehind.
5300 */
5301 static class NotBehind extends Node {
5302 Node cond;
5303 int rmax, rmin;
5304 NotBehind(Node cond, int rmax, int rmin) {
5305 this.cond = cond;
5306 this.rmax = rmax;
5307 this.rmin = rmin;
5308 }
5309
5310 boolean match(Matcher matcher, int i, CharSequence seq) {
5311 int savedLBT = matcher.lookbehindTo;
5312 int savedFrom = matcher.from;
5313 boolean conditionMatched = false;
5314 int startIndex = (!matcher.transparentBounds) ?
5315 matcher.from : 0;
5316 int from = Math.max(i - rmax, startIndex);
5317 matcher.lookbehindTo = i;
5318 // Relax transparent region boundaries for lookbehind
5319 if (matcher.transparentBounds)
5320 matcher.from = 0;
5321 for (int j = i - rmin; !conditionMatched && j >= from; j--) {
5322 conditionMatched = cond.match(matcher, j, seq);
5323 }
5324 // Reinstate region boundaries
5325 matcher.from = savedFrom;
5326 matcher.lookbehindTo = savedLBT;
5327 return !conditionMatched && next.match(matcher, i, seq);
5328 }
5329 }
5330
5331 /**
5332 * Zero width negative lookbehind, including supplementary
5333 * characters or unpaired surrogates.
5334 */
5335 static final class NotBehindS extends NotBehind {
5336 NotBehindS(Node cond, int rmax, int rmin) {
5337 super(cond, rmax, rmin);
5338 }
5339 boolean match(Matcher matcher, int i, CharSequence seq) {
5340 int rmaxChars = countChars(seq, i, -rmax);
5341 int rminChars = countChars(seq, i, -rmin);
5342 int savedFrom = matcher.from;
5343 int savedLBT = matcher.lookbehindTo;
5344 boolean conditionMatched = false;
5345 int startIndex = (!matcher.transparentBounds) ?
5346 matcher.from : 0;
5347 int from = Math.max(i - rmaxChars, startIndex);
5348 matcher.lookbehindTo = i;
5349 // Relax transparent region boundaries for lookbehind
5350 if (matcher.transparentBounds)
5351 matcher.from = 0;
5352 for (int j = i - rminChars;
5353 !conditionMatched && j >= from;
5354 j -= j>from ? countChars(seq, j, -1) : 1) {
5355 conditionMatched = cond.match(matcher, j, seq);
5356 }
5357 //Reinstate region boundaries
5358 matcher.from = savedFrom;
5359 matcher.lookbehindTo = savedLBT;
5360 return !conditionMatched && next.match(matcher, i, seq);
5361 }
5362 }
5363
5364 /**
5365 * Handles word boundaries. Includes a field to allow this one class to
5366 * deal with the different types of word boundaries we can match. The word
5367 * characters include underscores, letters, and digits. Non spacing marks
5368 * can are also part of a word if they have a base character, otherwise
5369 * they are ignored for purposes of finding word boundaries.
5370 */
5371 static final class Bound extends Node {
5372 static int LEFT = 0x1;
5373 static int RIGHT= 0x2;
5374 static int BOTH = 0x3;
5375 static int NONE = 0x4;
5376 int type;
5377 boolean useUWORD;
5378 Bound(int n, boolean useUWORD) {
5379 type = n;
5380 this.useUWORD = useUWORD;
5381 }
5382
5383 boolean isWord(int ch) {
5384 return useUWORD ? CharPredicates.WORD().is(ch)
5385 : (ch == '_' || Character.isLetterOrDigit(ch));
5386 }
5387
5388 int check(Matcher matcher, int i, CharSequence seq) {
5389 int ch;
5390 boolean left = false;
5391 int startIndex = matcher.from;
5392 int endIndex = matcher.to;
5393 if (matcher.transparentBounds) {
5394 startIndex = 0;
5395 endIndex = matcher.getTextLength();
5396 }
5397 if (i > startIndex) {
5398 ch = Character.codePointBefore(seq, i);
5399 left = (isWord(ch) ||
5400 ((Character.getType(ch) == Character.NON_SPACING_MARK)
5401 && hasBaseCharacter(matcher, i-1, seq)));
5402 }
5403 boolean right = false;
5404 if (i < endIndex) {
5405 ch = Character.codePointAt(seq, i);
5406 right = (isWord(ch) ||
5407 ((Character.getType(ch) == Character.NON_SPACING_MARK)
5408 && hasBaseCharacter(matcher, i, seq)));
5409 } else {
5410 // Tried to access char past the end
5411 matcher.hitEnd = true;
5412 // The addition of another char could wreck a boundary
5413 matcher.requireEnd = true;
5414 }
5415 return ((left ^ right) ? (right ? LEFT : RIGHT) : NONE);
5416 }
5417 boolean match(Matcher matcher, int i, CharSequence seq) {
5418 return (check(matcher, i, seq) & type) > 0
5419 && next.match(matcher, i, seq);
5420 }
5421 }
5422
5423 /**
5424 * Non spacing marks only count as word characters in bounds calculations
5425 * if they have a base character.
5426 */
5427 private static boolean hasBaseCharacter(Matcher matcher, int i,
5428 CharSequence seq)
5429 {
5430 int start = (!matcher.transparentBounds) ?
5431 matcher.from : 0;
5432 for (int x=i; x >= start; x--) {
5433 int ch = Character.codePointAt(seq, x);
5434 if (Character.isLetterOrDigit(ch))
5435 return true;
5436 if (Character.getType(ch) == Character.NON_SPACING_MARK)
5437 continue;
5438 return false;
5439 }
5440 return false;
5441 }
5442
5443 /**
5444 * Attempts to match a slice in the input using the Boyer-Moore string
5445 * matching algorithm. The algorithm is based on the idea that the
5446 * pattern can be shifted farther ahead in the search text if it is
5447 * matched right to left.
5448 * <p>
5449 * The pattern is compared to the input one character at a time, from
5450 * the rightmost character in the pattern to the left. If the characters
5451 * all match the pattern has been found. If a character does not match,
5452 * the pattern is shifted right a distance that is the maximum of two
5453 * functions, the bad character shift and the good suffix shift. This
5454 * shift moves the attempted match position through the input more
5455 * quickly than a naive one position at a time check.
5456 * <p>
5457 * The bad character shift is based on the character from the text that
5458 * did not match. If the character does not appear in the pattern, the
5459 * pattern can be shifted completely beyond the bad character. If the
5460 * character does occur in the pattern, the pattern can be shifted to
5461 * line the pattern up with the next occurrence of that character.
5462 * <p>
5463 * The good suffix shift is based on the idea that some subset on the right
5464 * side of the pattern has matched. When a bad character is found, the
5465 * pattern can be shifted right by the pattern length if the subset does
5466 * not occur again in pattern, or by the amount of distance to the
5467 * next occurrence of the subset in the pattern.
5468 *
5469 * Boyer-Moore search methods adapted from code by Amy Yu.
5470 */
5471 static class BnM extends Node {
5472 int[] buffer;
5473 int[] lastOcc;
5474 int[] optoSft;
5475
5476 /**
5477 * Pre calculates arrays needed to generate the bad character
5478 * shift and the good suffix shift. Only the last seven bits
5479 * are used to see if chars match; This keeps the tables small
5480 * and covers the heavily used ASCII range, but occasionally
5481 * results in an aliased match for the bad character shift.
5482 */
5483 static Node optimize(Node node) {
5484 if (!(node instanceof Slice)) {
5485 return node;
5486 }
5487
5488 int[] src = ((Slice) node).buffer;
5489 int patternLength = src.length;
5490 // The BM algorithm requires a bit of overhead;
5491 // If the pattern is short don't use it, since
5492 // a shift larger than the pattern length cannot
5493 // be used anyway.
5494 if (patternLength < 4) {
5495 return node;
5496 }
5497 int i, j;
5498 int[] lastOcc = new int[128];
5499 int[] optoSft = new int[patternLength];
5500 // Precalculate part of the bad character shift
5501 // It is a table for where in the pattern each
5502 // lower 7-bit value occurs
5503 for (i = 0; i < patternLength; i++) {
5504 lastOcc[src[i]&0x7F] = i + 1;
5505 }
5506 // Precalculate the good suffix shift
5507 // i is the shift amount being considered
5508 NEXT: for (i = patternLength; i > 0; i--) {
5509 // j is the beginning index of suffix being considered
5510 for (j = patternLength - 1; j >= i; j--) {
5511 // Testing for good suffix
5512 if (src[j] == src[j-i]) {
5513 // src[j..len] is a good suffix
5514 optoSft[j-1] = i;
5515 } else {
5516 // No match. The array has already been
5517 // filled up with correct values before.
5518 continue NEXT;
5519 }
5520 }
5521 // This fills up the remaining of optoSft
5522 // any suffix can not have larger shift amount
5523 // then its sub-suffix. Why???
5524 while (j > 0) {
5525 optoSft[--j] = i;
5526 }
5527 }
5528 // Set the guard value because of unicode compression
5529 optoSft[patternLength-1] = 1;
5530 if (node instanceof SliceS)
5531 return new BnMS(src, lastOcc, optoSft, node.next);
5532 return new BnM(src, lastOcc, optoSft, node.next);
5533 }
5534 BnM(int[] src, int[] lastOcc, int[] optoSft, Node next) {
5535 this.buffer = src;
5536 this.lastOcc = lastOcc;
5537 this.optoSft = optoSft;
5538 this.next = next;
5539 }
5540 boolean match(Matcher matcher, int i, CharSequence seq) {
5541 int[] src = buffer;
5542 int patternLength = src.length;
5543 int last = matcher.to - patternLength;
5544
5545 // Loop over all possible match positions in text
5546 NEXT: while (i <= last) {
5547 // Loop over pattern from right to left
5548 for (int j = patternLength - 1; j >= 0; j--) {
5549 int ch = seq.charAt(i+j);
5550 if (ch != src[j]) {
5551 // Shift search to the right by the maximum of the
5552 // bad character shift and the good suffix shift
5553 i += Math.max(j + 1 - lastOcc[ch&0x7F], optoSft[j]);
5554 continue NEXT;
5555 }
5556 }
5557 // Entire pattern matched starting at i
5558 matcher.first = i;
5559 boolean ret = next.match(matcher, i + patternLength, seq);
5560 if (ret) {
5561 matcher.first = i;
5562 matcher.groups[0] = matcher.first;
5563 matcher.groups[1] = matcher.last;
5564 return true;
5565 }
5566 i++;
5567 }
5568 // BnM is only used as the leading node in the unanchored case,
5569 // and it replaced its Start() which always searches to the end
5570 // if it doesn't find what it's looking for, so hitEnd is true.
5571 matcher.hitEnd = true;
5572 return false;
5573 }
5574 boolean study(TreeInfo info) {
5575 info.minLength += buffer.length;
5576 info.maxValid = false;
5577 return next.study(info);
5578 }
5579 }
5580
5581 /**
5582 * Supplementary support version of BnM(). Unpaired surrogates are
5583 * also handled by this class.
5584 */
5585 static final class BnMS extends BnM {
5586 int lengthInChars;
5587
5588 BnMS(int[] src, int[] lastOcc, int[] optoSft, Node next) {
5589 super(src, lastOcc, optoSft, next);
5590 for (int cp : buffer) {
5591 lengthInChars += Character.charCount(cp);
5592 }
5593 }
5594 boolean match(Matcher matcher, int i, CharSequence seq) {
5595 int[] src = buffer;
5596 int patternLength = src.length;
5597 int last = matcher.to - lengthInChars;
5598
5599 // Loop over all possible match positions in text
5600 NEXT: while (i <= last) {
5601 // Loop over pattern from right to left
5602 int ch;
5603 for (int j = countChars(seq, i, patternLength), x = patternLength - 1;
5604 j > 0; j -= Character.charCount(ch), x--) {
5605 ch = Character.codePointBefore(seq, i+j);
5606 if (ch != src[x]) {
5607 // Shift search to the right by the maximum of the
5608 // bad character shift and the good suffix shift
5609 int n = Math.max(x + 1 - lastOcc[ch&0x7F], optoSft[x]);
5610 i += countChars(seq, i, n);
5611 continue NEXT;
5612 }
5613 }
5614 // Entire pattern matched starting at i
5615 matcher.first = i;
5616 boolean ret = next.match(matcher, i + lengthInChars, seq);
5617 if (ret) {
5618 matcher.first = i;
5619 matcher.groups[0] = matcher.first;
5620 matcher.groups[1] = matcher.last;
5621 return true;
5622 }
5623 i += countChars(seq, i, 1);
5624 }
5625 matcher.hitEnd = true;
5626 return false;
5627 }
5628 }
5629
5630 @FunctionalInterface
5631 static interface CharPredicate {
5632 boolean is(int ch);
5633
5634 default CharPredicate and(CharPredicate p) {
5635 return ch -> is(ch) && p.is(ch);
5636 }
5637 default CharPredicate union(CharPredicate p) {
5638 return ch -> is(ch) || p.is(ch);
5639 }
5640 default CharPredicate union(CharPredicate p1,
5641 CharPredicate p2 ) {
5642 return ch -> is(ch) || p1.is(ch) || p2.is(ch);
5643 }
5644 default CharPredicate negate() {
5645 return ch -> !is(ch);
5646 }
5647 }
5648
5649 static interface BmpCharPredicate extends CharPredicate {
5650
5651 default CharPredicate and(CharPredicate p) {
5652 if (p instanceof BmpCharPredicate)
5653 return (BmpCharPredicate)(ch -> is(ch) && p.is(ch));
5654 return ch -> is(ch) && p.is(ch);
5655 }
5656 default CharPredicate union(CharPredicate p) {
5657 if (p instanceof BmpCharPredicate)
5658 return (BmpCharPredicate)(ch -> is(ch) || p.is(ch));
5659 return ch -> is(ch) || p.is(ch);
5660 }
5661 static CharPredicate union(CharPredicate... predicates) {
5662 CharPredicate cp = ch -> {
5663 for (CharPredicate p : predicates) {
5664 if (!p.is(ch))
5665 return false;
5666 }
5667 return true;
5668 };
5669 for (CharPredicate p : predicates) {
5670 if (! (p instanceof BmpCharPredicate))
5671 return cp;
5672 }
5673 return (BmpCharPredicate)cp;
5674 }
5675 }
5676
5677 /**
5678 * matches a Perl vertical whitespace
5679 */
5680 static BmpCharPredicate VertWS() {
5681 return cp -> (cp >= 0x0A && cp <= 0x0D) ||
5682 cp == 0x85 || cp == 0x2028 || cp == 0x2029;
5683 }
5684
5685 /**
5686 * matches a Perl horizontal whitespace
5687 */
5688 static BmpCharPredicate HorizWS() {
5689 return cp ->
5690 cp == 0x09 || cp == 0x20 || cp == 0xa0 || cp == 0x1680 ||
5691 cp == 0x180e || cp >= 0x2000 && cp <= 0x200a || cp == 0x202f ||
5692 cp == 0x205f || cp == 0x3000;
5693 }
5694
5695 /**
5696 * for the Unicode category ALL and the dot metacharacter when
5697 * in dotall mode.
5698 */
5699 static CharPredicate ALL() {
5700 return ch -> true;
5701 }
5702
5703 /**
5704 * for the dot metacharacter when dotall is not enabled.
5705 */
5706 static CharPredicate DOT() {
5707 return ch ->
5708 (ch != '\n' && ch != '\r'
5709 && (ch|1) != '\u2029'
5710 && ch != '\u0085');
5711 }
5712
5713 /**
5714 * the dot metacharacter when dotall is not enabled but UNIX_LINES is enabled.
5715 */
5716 static CharPredicate UNIXDOT() {
5717 return ch -> ch != '\n';
5718 }
5719
5720 /**
5721 * Indicate that matches a Supplementary Unicode character
5722 */
5723 static CharPredicate SingleS(int c) {
5724 return ch -> ch == c;
5725 }
5726
5727 /**
5728 * A bmp/optimized predicate of single
5729 */
5730 static BmpCharPredicate Single(int c) {
5731 return ch -> ch == c;
5732 }
5733
5734 /**
5735 * Case insensitive matches a given BMP character
5736 */
5737 static BmpCharPredicate SingleI(int lower, int upper) {
5738 return ch -> ch == lower || ch == upper;
5739 }
5740
5741 /**
5742 * Unicode case insensitive matches a given Unicode character
5743 */
5744 static CharPredicate SingleU(int lower) {
5745 return ch -> lower == ch ||
5746 lower == Character.toLowerCase(Character.toUpperCase(ch));
5747 }
5748
5749 private static boolean inRange(int lower, int ch, int upper) {
5750 return lower <= ch && ch <= upper;
5751 }
5752
5753 /**
5754 * Charactrs within a explicit value range
5755 */
5756 static CharPredicate Range(int lower, int upper) {
5757 if (upper < Character.MIN_HIGH_SURROGATE ||
5758 lower > Character.MAX_HIGH_SURROGATE &&
5759 upper < Character.MIN_SUPPLEMENTARY_CODE_POINT)
5760 return (BmpCharPredicate)(ch -> inRange(lower, ch, upper));
5761 return ch -> inRange(lower, ch, upper);
5762 }
5763
5764 /**
5765 * Charactrs within a explicit value range in a case insensitive manner.
5766 */
5767 static CharPredicate CIRange(int lower, int upper) {
5768 return ch -> inRange(lower, ch, upper) ||
5769 ASCII.isAscii(ch) &&
5770 (inRange(lower, ASCII.toUpper(ch), upper) ||
5771 inRange(lower, ASCII.toLower(ch), upper));
5772 }
5773
5774 static CharPredicate CIRangeU(int lower, int upper) {
5775 return ch -> {
5776 if (inRange(lower, ch, upper))
5777 return true;
5778 int up = Character.toUpperCase(ch);
5779 return inRange(lower, up, upper) ||
5780 inRange(lower, Character.toLowerCase(up), upper);
5781 };
5782 }
5783
5784 /**
5785 * This must be the very first initializer.
5786 */
5787 static final Node accept = new Node();
5788
5789 static final Node lastAccept = new LastNode();
5790
5791 /**
5792 * Creates a predicate that tests if this pattern is found in a given input
5793 * string.
5794 *
5795 * @apiNote
5796 * This method creates a predicate that behaves as if it creates a matcher
5797 * from the input sequence and then calls {@code find}, for example a
5798 * predicate of the form:
5799 * <pre>{@code
5800 * s -> matcher(s).find();
5801 * }</pre>
5802 *
5803 * @return The predicate which can be used for finding a match on a
5804 * subsequence of a string
5805 * @since 1.8
5806 * @see Matcher#find
5807 */
5808 public Predicate<String> asPredicate() {
5809 return s -> matcher(s).find();
5810 }
5811
5812 /**
5813 * Creates a predicate that tests if this pattern matches a given input string.
5814 *
5815 * @apiNote
5816 * This method creates a predicate that behaves as if it creates a matcher
5817 * from the input sequence and then calls {@code matches}, for example a
5818 * predicate of the form:
5819 * <pre>{@code
5820 * s -> matcher(s).matches();
5821 * }</pre>
5822 *
5823 * @return The predicate which can be used for matching an input string
5824 * against this pattern.
5825 * @since 11
5826 * @see Matcher#matches
5827 */
5828 public Predicate<String> asMatchPredicate() {
5829 return s -> matcher(s).matches();
5830 }
5831
5832 /**
5833 * Creates a stream from the given input sequence around matches of this
5834 * pattern.
5835 *
5836 * <p> The stream returned by this method contains each substring of the
5837 * input sequence that is terminated by another subsequence that matches
5838 * this pattern or is terminated by the end of the input sequence. The
5839 * substrings in the stream are in the order in which they occur in the
5840 * input. Trailing empty strings will be discarded and not encountered in
5841 * the stream.
5842 *
5843 * <p> If this pattern does not match any subsequence of the input then
5844 * the resulting stream has just one element, namely the input sequence in
5845 * string form.
5846 *
5847 * <p> When there is a positive-width match at the beginning of the input
5848 * sequence then an empty leading substring is included at the beginning
5849 * of the stream. A zero-width match at the beginning however never produces
5850 * such empty leading substring.
5851 *
5852 * <p> If the input sequence is mutable, it must remain constant during the
5853 * execution of the terminal stream operation. Otherwise, the result of the
5854 * terminal stream operation is undefined.
5855 *
5856 * @param input
5857 * The character sequence to be split
5858 *
5859 * @return The stream of strings computed by splitting the input
5860 * around matches of this pattern
5861 * @see #split(CharSequence)
5862 * @since 1.8
5863 */
5864 public Stream<String> splitAsStream(final CharSequence input) {
5865 class MatcherIterator implements Iterator<String> {
5866 private Matcher matcher;
5867 // The start position of the next sub-sequence of input
5868 // when current == input.length there are no more elements
5869 private int current;
5870 // null if the next element, if any, needs to obtained
5871 private String nextElement;
5872 // > 0 if there are N next empty elements
5873 private int emptyElementCount;
5874
5875 public String next() {
5876 if (!hasNext())
5877 throw new NoSuchElementException();
5878
5879 if (emptyElementCount == 0) {
5880 String n = nextElement;
5881 nextElement = null;
5882 return n;
5883 } else {
5884 emptyElementCount--;
5885 return "";
5886 }
5887 }
5888
5889 public boolean hasNext() {
5890 if (matcher == null) {
5891 matcher = matcher(input);
5892 // If the input is an empty string then the result can only be a
5893 // stream of the input. Induce that by setting the empty
5894 // element count to 1
5895 emptyElementCount = input.length() == 0 ? 1 : 0;
5896 }
5897 if (nextElement != null || emptyElementCount > 0)
5898 return true;
5899
5900 if (current == input.length())
5901 return false;
5902
5903 // Consume the next matching element
5904 // Count sequence of matching empty elements
5905 while (matcher.find()) {
5906 nextElement = input.subSequence(current, matcher.start()).toString();
5907 current = matcher.end();
5908 if (!nextElement.isEmpty()) {
5909 return true;
5910 } else if (current > 0) { // no empty leading substring for zero-width
5911 // match at the beginning of the input
5912 emptyElementCount++;
5913 }
5914 }
5915
5916 // Consume last matching element
5917 nextElement = input.subSequence(current, input.length()).toString();
5918 current = input.length();
5919 if (!nextElement.isEmpty()) {
5920 return true;
5921 } else {
5922 // Ignore a terminal sequence of matching empty elements
5923 emptyElementCount = 0;
5924 nextElement = null;
5925 return false;
5926 }
5927 }
5928 }
5929 return StreamSupport.stream(Spliterators.spliteratorUnknownSize(
5930 new MatcherIterator(), Spliterator.ORDERED | Spliterator.NONNULL), false);
5931 }
5932 }