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 /**
49 * A compiled representation of a regular expression.
50 *
51 * <p> A regular expression, specified as a string, must first be compiled into
52 * an instance of this class. The resulting pattern can then be used to create
53 * a {@link Matcher} object that can match arbitrary {@linkplain
54 * java.lang.CharSequence character sequences} against the regular
55 * expression. All of the state involved in performing a match resides in the
56 * matcher, so many matchers can share the same pattern.
57 *
58 * <p> A typical invocation sequence is thus
59 *
60 * <blockquote><pre>
61 * Pattern p = Pattern.{@link #compile compile}("a*b");
62 * Matcher m = p.{@link #matcher matcher}("aaaaab");
63 * boolean b = m.{@link Matcher#matches matches}();</pre></blockquote>
64 *
65 * <p> A {@link #matches matches} method is defined by this class as a
66 * convenience for when a regular expression is used just once. This method
67 * compiles an expression and matches an input sequence against it in a single
68 * invocation. The statement
69 *
70 * <blockquote><pre>
71 * boolean b = Pattern.matches("a*b", "aaaaab");</pre></blockquote>
72 *
73 * is equivalent to the three statements above, though for repeated matches it
74 * is less efficient since it does not allow the compiled pattern to be reused.
75 *
76 * <p> Instances of this class are immutable and are safe for use by multiple
77 * concurrent threads. Instances of the {@link Matcher} class are not safe for
78 * such use.
79 *
80 *
81 * <h2><a id="sum">Summary of regular-expression constructs</a></h2>
82 *
83 * <table class="borderless">
84 * <caption style="display:none">Regular expression constructs, and what they match</caption>
85 * <thead style="text-align:left">
86 * <tr>
87 * <th id="construct">Construct</th>
88 * <th id="matches">Matches</th>
89 * </tr>
90 * </thead>
91 * <tbody style="text-align:left">
92 *
93 * <tr><th colspan="2" style="padding-top:20px" id="characters">Characters</th></tr>
94 *
95 * <tr><th style="vertical-align:top; font-weight: normal" id="x"><i>x</i></th>
96 * <td headers="matches characters x">The character <i>x</i></td></tr>
97 * <tr><th style="vertical-align:top; font-weight: normal" id="backslash">{@code \\}</th>
98 * <td headers="matches characters backslash">The backslash character</td></tr>
99 * <tr><th style="vertical-align:top; font-weight: normal" id="octal_n">{@code \0}<i>n</i></th>
100 * <td headers="matches characters octal_n">The character with octal value {@code 0}<i>n</i>
101 * (0 {@code <=} <i>n</i> {@code <=} 7)</td></tr>
102 * <tr><th style="vertical-align:top; font-weight: normal" id="octal_nn">{@code \0}<i>nn</i></th>
103 * <td headers="matches characters octal_nn">The character with octal value {@code 0}<i>nn</i>
104 * (0 {@code <=} <i>n</i> {@code <=} 7)</td></tr>
105 * <tr><th style="vertical-align:top; font-weight: normal" id="octal_nnn">{@code \0}<i>mnn</i></th>
106 * <td headers="matches characters octal_nnn">The character with octal value {@code 0}<i>mnn</i>
107 * (0 {@code <=} <i>m</i> {@code <=} 3,
108 * 0 {@code <=} <i>n</i> {@code <=} 7)</td></tr>
109 * <tr><th style="vertical-align:top; font-weight: normal" id="hex_hh">{@code \x}<i>hh</i></th>
110 * <td headers="matches characters hex_hh">The character with hexadecimal value {@code 0x}<i>hh</i></td></tr>
111 * <tr><th style="vertical-align:top; font-weight: normal" id="hex_hhhh"><code>\u</code><i>hhhh</i></th>
112 * <td headers="matches characters hex_hhhh">The character with hexadecimal value {@code 0x}<i>hhhh</i></td></tr>
113 * <tr><th style="vertical-align:top; font-weight: normal" id="hex_h_h"><code>\x</code><i>{h...h}</i></th>
114 * <td headers="matches characters hex_h_h">The character with hexadecimal value {@code 0x}<i>h...h</i>
115 * ({@link java.lang.Character#MIN_CODE_POINT Character.MIN_CODE_POINT}
116 * <= {@code 0x}<i>h...h</i> <=
117 * {@link java.lang.Character#MAX_CODE_POINT Character.MAX_CODE_POINT})</td></tr>
118 * <tr><th style="vertical-align:top; font-weight: normal" id="unicode_name"><code>\N{</code><i>name</i><code>}</code></th>
119 * <td headers="matches characters unicode_name">The character with Unicode character name <i>'name'</i></td></tr>
120 * <tr><th style="vertical-align:top; font-weight:normal" id="tab">{@code \t}</th>
121 * <td headers="matches characters tab">The tab character (<code>'\u0009'</code>)</td></tr>
122 * <tr><th style="vertical-align:top; font-weight:normal" id="newline">{@code \n}</th>
123 * <td headers="matches characters newline">The newline (line feed) character (<code>'\u000A'</code>)</td></tr>
124 * <tr><th style="vertical-align:top; font-weight:normal" id="return">{@code \r}</th>
125 * <td headers="matches characters return">The carriage-return character (<code>'\u000D'</code>)</td></tr>
126 * <tr><th style="vertical-align:top; font-weight:normal" id="form_feed">{@code \f}</th>
127 * <td headers="matches characters form_feed">The form-feed character (<code>'\u000C'</code>)</td></tr>
128 * <tr><th style="vertical-align:top; font-weight:normal" id="bell">{@code \a}</th>
129 * <td headers="matches characters bell">The alert (bell) character (<code>'\u0007'</code>)</td></tr>
130 * <tr><th style="vertical-align:top; font-weight:normal" id="escape">{@code \e}</th>
131 * <td headers="matches characters escape">The escape character (<code>'\u001B'</code>)</td></tr>
132 * <tr><th style="vertical-align:top; font-weight:normal" id="ctrl_x">{@code \c}<i>x</i></th>
133 * <td headers="matches characters ctrl_x">The control character corresponding to <i>x</i></td></tr>
134 *
135 * <tr><th colspan="2" style="padding-top:20px" id="classes">Character classes</th></tr>
136 *
137 * <tr><th style="vertical-align:top; font-weight:normal" id="simple">{@code [abc]}</th>
138 * <td headers="matches classes simple">{@code a}, {@code b}, or {@code c} (simple class)</td></tr>
139 * <tr><th style="vertical-align:top; font-weight:normal" id="negation">{@code [^abc]}</th>
140 * <td headers="matches classes negation">Any character except {@code a}, {@code b}, or {@code c} (negation)</td></tr>
141 * <tr><th style="vertical-align:top; font-weight:normal" id="range">{@code [a-zA-Z]}</th>
142 * <td headers="matches classes range">{@code a} through {@code z}
143 * or {@code A} through {@code Z}, inclusive (range)</td></tr>
144 * <tr><th style="vertical-align:top; font-weight:normal" id="union">{@code [a-d[m-p]]}</th>
145 * <td headers="matches classes union">{@code a} through {@code d},
146 * or {@code m} through {@code p}: {@code [a-dm-p]} (union)</td></tr>
147 * <tr><th style="vertical-align:top; font-weight:normal" id="intersection">{@code [a-z&&[def]]}</th>
148 * <td headers="matches classes intersection">{@code d}, {@code e}, or {@code f} (intersection)</tr>
149 * <tr><th style="vertical-align:top; font-weight:normal" id="subtraction1">{@code [a-z&&[^bc]]}</th>
150 * <td headers="matches classes subtraction1">{@code a} through {@code z},
151 * except for {@code b} and {@code c}: {@code [ad-z]} (subtraction)</td></tr>
152 * <tr><th style="vertical-align:top; font-weight:normal" id="subtraction2">{@code [a-z&&[^m-p]]}</th>
153 * <td headers="matches classes subtraction2">{@code a} through {@code z},
154 * and not {@code m} through {@code p}: {@code [a-lq-z]}(subtraction)</td></tr>
155 *
156 * <tr><th colspan="2" style="padding-top:20px" id="predef">Predefined character classes</th></tr>
157 *
158 * <tr><th style="vertical-align:top; font-weight:normal" id="any">{@code .}</th>
159 * <td headers="matches predef any">Any character (may or may not match <a href="#lt">line terminators</a>)</td></tr>
160 * <tr><th style="vertical-align:top; font-weight:normal" id="digit">{@code \d}</th>
161 * <td headers="matches predef digit">A digit: {@code [0-9]}</td></tr>
162 * <tr><th style="vertical-align:top; font-weight:normal" id="non_digit">{@code \D}</th>
163 * <td headers="matches predef non_digit">A non-digit: {@code [^0-9]}</td></tr>
164 * <tr><th style="vertical-align:top; font-weight:normal" id="horiz_white">{@code \h}</th>
165 * <td headers="matches predef horiz_white">A horizontal whitespace character:
166 * <code>[ \t\xA0\u1680\u180e\u2000-\u200a\u202f\u205f\u3000]</code></td></tr>
167 * <tr><th style="vertical-align:top; font-weight:normal" id="non_horiz_white">{@code \H}</th>
168 * <td headers="matches predef non_horiz_white">A non-horizontal whitespace character: {@code [^\h]}</td></tr>
169 * <tr><th style="vertical-align:top; font-weight:normal" id="white">{@code \s}</th>
170 * <td headers="matches predef white">A whitespace character: {@code [ \t\n\x0B\f\r]}</td></tr>
171 * <tr><th style="vertical-align:top; font-weight:normal" id="non_white">{@code \S}</th>
172 * <td headers="matches predef non_white">A non-whitespace character: {@code [^\s]}</td></tr>
173 * <tr><th style="vertical-align:top; font-weight:normal" id="vert_white">{@code \v}</th>
174 * <td headers="matches predef vert_white">A vertical whitespace character: <code>[\n\x0B\f\r\x85\u2028\u2029]</code>
175 * </td></tr>
176 * <tr><th style="vertical-align:top; font-weight:normal" id="non_vert_white">{@code \V}</th>
177 * <td headers="matches predef non_vert_white">A non-vertical whitespace character: {@code [^\v]}</td></tr>
178 * <tr><th style="vertical-align:top; font-weight:normal" id="word">{@code \w}</th>
179 * <td headers="matches predef word">A word character: {@code [a-zA-Z_0-9]}</td></tr>
180 * <tr><th style="vertical-align:top; font-weight:normal" id="non_word">{@code \W}</th>
181 * <td headers="matches predef non_word">A non-word character: {@code [^\w]}</td></tr>
182 *
183 * <tr><th colspan="2" style="padding-top:20px" id="posix"><b>POSIX character classes (US-ASCII only)</b></th></tr>
184 *
185 * <tr><th style="vertical-align:top; font-weight:normal" id="Lower">{@code \p{Lower}}</th>
186 * <td headers="matches posix Lower">A lower-case alphabetic character: {@code [a-z]}</td></tr>
187 * <tr><th style="vertical-align:top; font-weight:normal" id="Upper">{@code \p{Upper}}</th>
188 * <td headers="matches posix Upper">An upper-case alphabetic character:{@code [A-Z]}</td></tr>
189 * <tr><th style="vertical-align:top; font-weight:normal" id="ASCII">{@code \p{ASCII}}</th>
190 * <td headers="matches posix ASCII">All ASCII:{@code [\x00-\x7F]}</td></tr>
191 * <tr><th style="vertical-align:top; font-weight:normal" id="Alpha">{@code \p{Alpha}}</th>
192 * <td headers="matches posix Alpha">An alphabetic character:{@code [\p{Lower}\p{Upper}]}</td></tr>
193 * <tr><th style="vertical-align:top; font-weight:normal" id="Digit">{@code \p{Digit}}</th>
194 * <td headers="matches posix Digit">A decimal digit: {@code [0-9]}</td></tr>
195 * <tr><th style="vertical-align:top; font-weight:normal" id="Alnum">{@code \p{Alnum}}</th>
196 * <td headers="matches posix Alnum">An alphanumeric character:{@code [\p{Alpha}\p{Digit}]}</td></tr>
197 * <tr><th style="vertical-align:top; font-weight:normal" id="Punct">{@code \p{Punct}}</th>
198 * <td headers="matches posix Punct">Punctuation: One of {@code !"#$%&'()*+,-./:;<=>?@[\]^_`{|}~}</td></tr>
199 * <!-- {@code [\!"#\$%&'\(\)\*\+,\-\./:;\<=\>\?@\[\\\]\^_`\{\|\}~]}
200 * {@code [\X21-\X2F\X31-\X40\X5B-\X60\X7B-\X7E]} -->
201 * <tr><th style="vertical-align:top; font-weight:normal" id="Graph">{@code \p{Graph}}</th>
202 * <td headers="matches posix Graph">A visible character: {@code [\p{Alnum}\p{Punct}]}</td></tr>
203 * <tr><th style="vertical-align:top; font-weight:normal" id="Print">{@code \p{Print}}</th>
204 * <td headers="matches posix Print">A printable character: {@code [\p{Graph}\x20]}</td></tr>
205 * <tr><th style="vertical-align:top; font-weight:normal" id="Blank">{@code \p{Blank}}</th>
206 * <td headers="matches posix Blank">A space or a tab: {@code [ \t]}</td></tr>
207 * <tr><th style="vertical-align:top; font-weight:normal" id="Cntrl">{@code \p{Cntrl}}</th>
208 * <td headers="matches posix Cntrl">A control character: {@code [\x00-\x1F\x7F]}</td></tr>
209 * <tr><th style="vertical-align:top; font-weight:normal" id="XDigit">{@code \p{XDigit}}</th>
210 * <td headers="matches posix XDigit">A hexadecimal digit: {@code [0-9a-fA-F]}</td></tr>
211 * <tr><th style="vertical-align:top; font-weight:normal" id="Space">{@code \p{Space}}</th>
212 * <td headers="matches posix Space">A whitespace character: {@code [ \t\n\x0B\f\r]}</td></tr>
213 *
214 * <tr><th colspan="2" style="padding-top:20px" id="java">java.lang.Character classes (simple <a href="#jcc">java character type</a>)</th></tr>
215 *
216 * <tr><th style="vertical-align:top; font-weight:normal" id="javaLowerCase">{@code \p{javaLowerCase}}</th>
217 * <td headers="matches java javaLowerCase">Equivalent to java.lang.Character.isLowerCase()</td></tr>
218 * <tr><th style="vertical-align:top; font-weight:normal" id="javaUpperCase">{@code \p{javaUpperCase}}</th>
219 * <td headers="matches java javaUpperCase">Equivalent to java.lang.Character.isUpperCase()</td></tr>
220 * <tr><th style="vertical-align:top; font-weight:normal" id="javaWhitespace">{@code \p{javaWhitespace}}</th>
221 * <td headers="matches java javaWhitespace">Equivalent to java.lang.Character.isWhitespace()</td></tr>
222 * <tr><th style="vertical-align:top; font-weight:normal" id="javaMirrored">{@code \p{javaMirrored}}</th>
223 * <td headers="matches java javaMirrored">Equivalent to java.lang.Character.isMirrored()</td></tr>
224 *
225 * <tr><th colspan="2" style="padding-top:20px" id="unicode">Classes for Unicode scripts, blocks, categories and binary properties</th></tr>
226 *
227 * <tr><th style="vertical-align:top; font-weight:normal" id="IsLatin">{@code \p{IsLatin}}</th>
228 * <td headers="matches unicode IsLatin">A Latin script character (<a href="#usc">script</a>)</td></tr>
229 * <tr><th style="vertical-align:top; font-weight:normal" id="InGreek">{@code \p{InGreek}}</th>
230 * <td headers="matches unicode InGreek">A character in the Greek block (<a href="#ubc">block</a>)</td></tr>
231 * <tr><th style="vertical-align:top; font-weight:normal" id="Lu">{@code \p{Lu}}</th>
232 * <td headers="matches unicode Lu">An uppercase letter (<a href="#ucc">category</a>)</td></tr>
233 * <tr><th style="vertical-align:top; font-weight:normal" id="IsAlphabetic">{@code \p{IsAlphabetic}}</th>
234 * <td headers="matches unicode IsAlphabetic">An alphabetic character (<a href="#ubpc">binary property</a>)</td></tr>
235 * <tr><th style="vertical-align:top; font-weight:normal" id="Sc">{@code \p{Sc}}</th>
236 * <td headers="matches unicode Sc">A currency symbol</td></tr>
237 * <tr><th style="vertical-align:top; font-weight:normal" id="not_InGreek">{@code \P{InGreek}}</th>
238 * <td headers="matches unicode not_InGreek">Any character except one in the Greek block (negation)</td></tr>
239 * <tr><th style="vertical-align:top; font-weight:normal" id="not_uppercase">{@code [\p{L}&&[^\p{Lu}]]}</th>
240 * <td headers="matches unicode not_uppercase">Any letter except an uppercase letter (subtraction)</td></tr>
241 *
242 * <tr><th colspan="2" style="padding-top:20px" id="bounds">Boundary matchers</th></tr>
243 *
244 * <tr><th style="vertical-align:top; font-weight:normal" id="begin_line">{@code ^}</th>
245 * <td headers="matches bounds begin_line">The beginning of a line</td></tr>
246 * <tr><th style="vertical-align:top; font-weight:normal" id="end_line">{@code $}</th>
247 * <td headers="matches bounds end_line">The end of a line</td></tr>
248 * <tr><th style="vertical-align:top; font-weight:normal" id="word_boundary">{@code \b}</th>
249 * <td headers="matches bounds word_boundary">A word boundary</td></tr>
250 * <tr><th style="vertical-align:top; font-weight:normal" id="grapheme_cluster_boundary">{@code \b{g}}</th>
251 * <td headers="matches bounds grapheme_cluster_boundary">A Unicode extended grapheme cluster boundary</td></tr>
252 * <tr><th style="vertical-align:top; font-weight:normal" id="non_word_boundary">{@code \B}</th>
253 * <td headers="matches bounds non_word_boundary">A non-word boundary</td></tr>
254 * <tr><th style="vertical-align:top; font-weight:normal" id="begin_input">{@code \A}</th>
255 * <td headers="matches bounds begin_input">The beginning of the input</td></tr>
256 * <tr><th style="vertical-align:top; font-weight:normal" id="end_prev_match">{@code \G}</th>
257 * <td headers="matches bounds end_prev_match">The end of the previous match</td></tr>
258 * <tr><th style="vertical-align:top; font-weight:normal" id="end_input_except_term">{@code \Z}</th>
259 * <td headers="matches bounds end_input_except_term">The end of the input but for the final
260 * <a href="#lt">terminator</a>, if any</td></tr>
261 * <tr><th style="vertical-align:top; font-weight:normal" id="end_input">{@code \z}</th>
262 * <td headers="matches bounds end_input">The end of the input</td></tr>
263 *
264 * <tr><th colspan="2" style="padding-top:20px" id="linebreak">Linebreak matcher</th></tr>
265 *
266 * <tr><th style="vertical-align:top; font-weight:normal" id="any_unicode_linebreak">{@code \R}</th>
267 * <td headers="matches linebreak any_unicode_linebreak">Any Unicode linebreak sequence, is equivalent to
268 * <code>\u000D\u000A|[\u000A\u000B\u000C\u000D\u0085\u2028\u2029]
269 * </code></td></tr>
270 *
271 * <tr><th colspan="2" style="padding-top:20px" id="grapheme">Unicode Extended Grapheme matcher</th></tr>
272 *
273 * <tr><th style="vertical-align:top; font-weight:normal" id="grapheme_any">{@code \X}</th>
274 * <td headers="matches grapheme grapheme_any">Any Unicode extended grapheme cluster</td></tr>
275 *
276 * <tr><th colspan="2" style="padding-top:20px" id="greedy">Greedy quantifiers</th></tr>
277 *
278 * <tr><th style="vertical-align:top; font-weight:normal" id="greedy_once_or_not"><i>X</i>{@code ?}</th>
279 * <td headers="matches greedy greedy_once_or_not"><i>X</i>, once or not at all</td></tr>
280 * <tr><th style="vertical-align:top; font-weight:normal" id="greedy_zero_or_more"><i>X</i>{@code *}</th>
281 * <td headers="matches greedy greedy_zero_or_more"><i>X</i>, zero or more times</td></tr>
282 * <tr><th style="vertical-align:top; font-weight:normal" id="greedy_one_or_more"><i>X</i>{@code +}</th>
283 * <td headers="matches greedy greedy_one_or_more"><i>X</i>, one or more times</td></tr>
284 * <tr><th style="vertical-align:top; font-weight:normal" id="greedy_exactly"><i>X</i><code>{</code><i>n</i><code>}</code></th>
285 * <td headers="matches greedy greedy_exactly"><i>X</i>, exactly <i>n</i> times</td></tr>
286 * <tr><th style="vertical-align:top; font-weight:normal" id="greedy_at_least"><i>X</i><code>{</code><i>n</i>{@code ,}}</th>
287 * <td headers="matches greedy greedy_at_least"><i>X</i>, at least <i>n</i> times</td></tr>
288 * <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>
289 * <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>
290 *
291 * <tr><th colspan="2" style="padding-top:20px" id="reluc">Reluctant quantifiers</th></tr>
292 *
293 * <tr><th style="vertical-align:top; font-weight:normal" id="reluc_once_or_not"><i>X</i>{@code ??}</th>
294 * <td headers="matches reluc reluc_once_or_not"><i>X</i>, once or not at all</td></tr>
295 * <tr><th style="vertical-align:top; font-weight:normal" id="reluc_zero_or_more"><i>X</i>{@code *?}</th>
296 * <td headers="matches reluc reluc_zero_or_more"><i>X</i>, zero or more times</td></tr>
297 * <tr><th style="vertical-align:top; font-weight:normal" id="reluc_one_or_more"><i>X</i>{@code +?}</th>
298 * <td headers="matches reluc reluc_one_or_more"><i>X</i>, one or more times</td></tr>
299 * <tr><th style="vertical-align:top; font-weight:normal" id="reluc_exactly"><i>X</i><code>{</code><i>n</i><code>}?</code></th>
300 * <td headers="matches reluc reluc_exactly"><i>X</i>, exactly <i>n</i> times</td></tr>
301 * <tr><th style="vertical-align:top; font-weight:normal" id="reluc_at_least"><i>X</i><code>{</code><i>n</i><code>,}?</code></th>
302 * <td headers="matches reluc reluc_at_least"><i>X</i>, at least <i>n</i> times</td></tr>
303 * <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>
304 * <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>
305 *
306 * <tr><th colspan="2" style="padding-top:20px" id="poss">Possessive quantifiers</th></tr>
307 *
308 * <tr><th style="vertical-align:top; font-weight:normal" id="poss_once_or_not"><i>X</i>{@code ?+}</th>
309 * <td headers="matches poss poss_once_or_not"><i>X</i>, once or not at all</td></tr>
310 * <tr><th style="vertical-align:top; font-weight:normal" id="poss_zero_or_more"><i>X</i>{@code *+}</th>
311 * <td headers="matches poss poss_zero_or_more"><i>X</i>, zero or more times</td></tr>
312 * <tr><th style="vertical-align:top; font-weight:normal" id="poss_one_or_more"><i>X</i>{@code ++}</th>
313 * <td headers="matches poss poss_one_or_more"><i>X</i>, one or more times</td></tr>
314 * <tr><th style="vertical-align:top; font-weight:normal" id="poss_exactly"><i>X</i><code>{</code><i>n</i><code>}+</code></th>
315 * <td headers="matches poss poss_exactly"><i>X</i>, exactly <i>n</i> times</td></tr>
316 * <tr><th style="vertical-align:top; font-weight:normal" id="poss_at_least"><i>X</i><code>{</code><i>n</i><code>,}+</code></th>
317 * <td headers="matches poss poss_at_least"><i>X</i>, at least <i>n</i> times</td></tr>
318 * <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>
319 * <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>
320 *
321 * <tr><th colspan="2" style="padding-top:20px" id="logical">Logical operators</th></tr>
322 *
323 * <tr><th style="vertical-align:top; font-weight:normal" id="concat"><i>XY</i></th>
324 * <td headers="matches logical concat"><i>X</i> followed by <i>Y</i></td></tr>
325 * <tr><th style="vertical-align:top; font-weight:normal" id="alternate"><i>X</i>{@code |}<i>Y</i></th>
326 * <td headers="matches logical alternate">Either <i>X</i> or <i>Y</i></td></tr>
327 * <tr><th style="vertical-align:top; font-weight:normal" id="group">{@code (}<i>X</i>{@code )}</th>
328 * <td headers="matches logical group">X, as a <a href="#cg">capturing group</a></td></tr>
329 *
330 * <tr><th colspan="2" style="padding-top:20px" id="backref">Back references</th></tr>
331 *
332 * <tr><th style="vertical-align:top; font-weight:normal" id="back_nth">{@code \}<i>n</i></th>
333 * <td headers="matches backref back_nth">Whatever the <i>n</i><sup>th</sup>
334 * <a href="#cg">capturing group</a> matched</td></tr>
335 * <tr><th style="vertical-align:top; font-weight:normal" id="back_named">{@code \}<i>k</i><<i>name</i>></th>
336 * <td headers="matches backref back_named">Whatever the
337 * <a href="#groupname">named-capturing group</a> "name" matched</td></tr>
338 *
339 * <tr><th colspan="2" style="padding-top:20px" id="quote">Quotation</th></tr>
340 *
341 * <tr><th style="vertical-align:top; font-weight:normal" id="quote_follow">{@code \}</th>
342 * <td headers="matches quote quote_follow">Nothing, but quotes the following character</td></tr>
343 * <tr><th style="vertical-align:top; font-weight:normal" id="quote_begin">{@code \Q}</th>
344 * <td headers="matches quote quote_begin">Nothing, but quotes all characters until {@code \E}</td></tr>
345 * <tr><th style="vertical-align:top; font-weight:normal" id="quote_end">{@code \E}</th>
346 * <td headers="matches quote quote_end">Nothing, but ends quoting started by {@code \Q}</td></tr>
347 * <!-- Metachars: !$()*+.<>?[\]^{|} -->
348 *
349 * <tr><th colspan="2" style="padding-top:20px" id="special">Special constructs (named-capturing and non-capturing)</th></tr>
350 *
351 * <tr><th style="vertical-align:top; font-weight:normal" id="named_group"><code>(?<<a href="#groupname">name</a>></code><i>X</i>{@code )}</th>
352 * <td headers="matches special named_group"><i>X</i>, as a named-capturing group</td></tr>
353 * <tr><th style="vertical-align:top; font-weight:normal" id="non_capture_group">{@code (?:}<i>X</i>{@code )}</th>
354 * <td headers="matches special non_capture_group"><i>X</i>, as a non-capturing group</td></tr>
355 * <tr><th style="vertical-align:top; font-weight:normal" id="flags"><code>(?idmsuxU-idmsuxU) </code></th>
356 * <td headers="matches special flags">Nothing, but turns match flags <a href="#CASE_INSENSITIVE">i</a>
357 * <a href="#UNIX_LINES">d</a> <a href="#MULTILINE">m</a> <a href="#DOTALL">s</a>
358 * <a href="#UNICODE_CASE">u</a> <a href="#COMMENTS">x</a> <a href="#UNICODE_CHARACTER_CLASS">U</a>
359 * on - off</td></tr>
360 * <tr><th style="vertical-align:top; font-weight:normal" id="non_capture_group_flags"><code>(?idmsux-idmsux:</code><i>X</i>{@code )} </th>
361 * <td headers="matches special non_capture_group_flags"><i>X</i>, as a <a href="#cg">non-capturing group</a> with the
362 * given flags <a href="#CASE_INSENSITIVE">i</a> <a href="#UNIX_LINES">d</a>
363 * <a href="#MULTILINE">m</a> <a href="#DOTALL">s</a> <a href="#UNICODE_CASE">u</a >
364 * <a href="#COMMENTS">x</a> on - off</td></tr>
365 * <tr><th style="vertical-align:top; font-weight:normal" id="pos_lookahead">{@code (?=}<i>X</i>{@code )}</th>
366 * <td headers="matches special pos_lookahead"><i>X</i>, via zero-width positive lookahead</td></tr>
367 * <tr><th style="vertical-align:top; font-weight:normal" id="neg_lookahead">{@code (?!}<i>X</i>{@code )}</th>
368 * <td headers="matches special neg_lookahead"><i>X</i>, via zero-width negative lookahead</td></tr>
369 * <tr><th style="vertical-align:top; font-weight:normal" id="pos_lookbehind">{@code (?<=}<i>X</i>{@code )}</th>
370 * <td headers="matches special pos_lookbehind"><i>X</i>, via zero-width positive lookbehind</td></tr>
371 * <tr><th style="vertical-align:top; font-weight:normal" id="neg_lookbehind">{@code (?<!}<i>X</i>{@code )}</th>
372 * <td headers="matches special neg_lookbehind"><i>X</i>, via zero-width negative lookbehind</td></tr>
373 * <tr><th style="vertical-align:top; font-weight:normal" id="indep_non_capture_group">{@code (?>}<i>X</i>{@code )}</th>
374 * <td headers="matches special indep_non_capture_group"><i>X</i>, as an independent, non-capturing group</td></tr>
375 *
376 * </tbody>
377 * </table>
378 *
379 * <hr>
380 *
381 *
382 * <h2><a id="bs">Backslashes, escapes, and quoting</a></h2>
383 *
384 * <p> The backslash character ({@code '\'}) serves to introduce escaped
385 * constructs, as defined in the table above, as well as to quote characters
386 * that otherwise would be interpreted as unescaped constructs. Thus the
387 * expression {@code \\} matches a single backslash and <code>\{</code> matches a
388 * left brace.
389 *
390 * <p> It is an error to use a backslash prior to any alphabetic character that
391 * does not denote an escaped construct; these are reserved for future
392 * extensions to the regular-expression language. A backslash may be used
393 * prior to a non-alphabetic character regardless of whether that character is
394 * part of an unescaped construct.
395 *
396 * <p> Backslashes within string literals in Java source code are interpreted
397 * as required by
398 * <cite>The Java™ Language Specification</cite>
399 * as either Unicode escapes (section 3.3) or other character escapes (section 3.10.6)
400 * It is therefore necessary to double backslashes in string
401 * literals that represent regular expressions to protect them from
402 * interpretation by the Java bytecode compiler. The string literal
403 * <code>"\b"</code>, for example, matches a single backspace character when
404 * interpreted as a regular expression, while {@code "\\b"} matches a
405 * word boundary. The string literal {@code "\(hello\)"} is illegal
406 * and leads to a compile-time error; in order to match the string
407 * {@code (hello)} the string literal {@code "\\(hello\\)"}
408 * must be used.
409 *
410 * <h2><a id="cc">Character Classes</a></h2>
411 *
412 * <p> Character classes may appear within other character classes, and
413 * may be composed by the union operator (implicit) and the intersection
414 * operator ({@code &&}).
415 * The union operator denotes a class that contains every character that is
416 * in at least one of its operand classes. The intersection operator
417 * denotes a class that contains every character that is in both of its
418 * operand classes.
419 *
420 * <p> The precedence of character-class operators is as follows, from
421 * highest to lowest:
422 *
423 * <table class="striped" style="margin-left: 2em;">
424 * <caption style="display:none">Precedence of character class operators.</caption>
425 * <thead>
426 * <tr><th scope="col">Precedence<th scope="col">Name<th scope="col">Example
427 * </thead>
428 * <tbody>
429 * <tr><th scope="row">1</th>
430 * <td>Literal escape </td>
431 * <td>{@code \x}</td></tr>
432 * <tr><th scope="row">2</th>
433 * <td>Grouping</td>
434 * <td>{@code [...]}</td></tr>
435 * <tr><th scope="row">3</th>
436 * <td>Range</td>
437 * <td>{@code a-z}</td></tr>
438 * <tr><th scope="row">4</th>
439 * <td>Union</td>
440 * <td>{@code [a-e][i-u]}</td></tr>
441 * <tr><th scope="row">5</th>
442 * <td>Intersection</td>
443 * <td>{@code [a-z&&[aeiou]]}</td></tr>
444 * </tbody>
445 * </table>
446 *
447 * <p> Note that a different set of metacharacters are in effect inside
448 * a character class than outside a character class. For instance, the
449 * regular expression {@code .} loses its special meaning inside a
450 * character class, while the expression {@code -} becomes a range
451 * forming metacharacter.
452 *
453 * <h2><a id="lt">Line terminators</a></h2>
454 *
455 * <p> A <i>line terminator</i> is a one- or two-character sequence that marks
456 * the end of a line of the input character sequence. The following are
457 * recognized as line terminators:
458 *
459 * <ul>
460 *
461 * <li> A newline (line feed) character ({@code '\n'}),
462 *
463 * <li> A carriage-return character followed immediately by a newline
464 * character ({@code "\r\n"}),
465 *
466 * <li> A standalone carriage-return character ({@code '\r'}),
467 *
468 * <li> A next-line character (<code>'\u0085'</code>),
469 *
470 * <li> A line-separator character (<code>'\u2028'</code>), or
471 *
472 * <li> A paragraph-separator character (<code>'\u2029'</code>).
473 *
474 * </ul>
475 * <p>If {@link #UNIX_LINES} mode is activated, then the only line terminators
476 * recognized are newline characters.
477 *
478 * <p> The regular expression {@code .} matches any character except a line
479 * terminator unless the {@link #DOTALL} flag is specified.
480 *
481 * <p> By default, the regular expressions {@code ^} and {@code $} ignore
482 * line terminators and only match at the beginning and the end, respectively,
483 * of the entire input sequence. If {@link #MULTILINE} mode is activated then
484 * {@code ^} matches at the beginning of input and after any line terminator
485 * except at the end of input. When in {@link #MULTILINE} mode {@code $}
486 * matches just before a line terminator or the end of the input sequence.
487 *
488 * <h2><a id="cg">Groups and capturing</a></h2>
489 *
490 * <h3><a id="gnumber">Group number</a></h3>
491 * <p> Capturing groups are numbered by counting their opening parentheses from
492 * left to right. In the expression {@code ((A)(B(C)))}, for example, there
493 * are four such groups: </p>
494 *
495 * <ol style="margin-left:2em;">
496 * <li> {@code ((A)(B(C)))}
497 * <li> {@code (A)}
498 * <li> {@code (B(C))}
499 * <li> {@code (C)}
500 * </ol>
501 *
502 * <p> Group zero always stands for the entire expression.
503 *
504 * <p> Capturing groups are so named because, during a match, each subsequence
505 * of the input sequence that matches such a group is saved. The captured
506 * subsequence may be used later in the expression, via a back reference, and
507 * may also be retrieved from the matcher once the match operation is complete.
508 *
509 * <h3><a id="groupname">Group name</a></h3>
510 * <p>A capturing group can also be assigned a "name", a {@code named-capturing group},
511 * and then be back-referenced later by the "name". Group names are composed of
512 * the following characters. The first character must be a {@code letter}.
513 *
514 * <ul>
515 * <li> The uppercase letters {@code 'A'} through {@code 'Z'}
516 * (<code>'\u0041'</code> through <code>'\u005a'</code>),
517 * <li> The lowercase letters {@code 'a'} through {@code 'z'}
518 * (<code>'\u0061'</code> through <code>'\u007a'</code>),
519 * <li> The digits {@code '0'} through {@code '9'}
520 * (<code>'\u0030'</code> through <code>'\u0039'</code>),
521 * </ul>
522 *
523 * <p> A {@code named-capturing group} is still numbered as described in
524 * <a href="#gnumber">Group number</a>.
525 *
526 * <p> The captured input associated with a group is always the subsequence
527 * that the group most recently matched. If a group is evaluated a second time
528 * because of quantification then its previously-captured value, if any, will
529 * be retained if the second evaluation fails. Matching the string
530 * {@code "aba"} against the expression {@code (a(b)?)+}, for example, leaves
531 * group two set to {@code "b"}. All captured input is discarded at the
532 * beginning of each match.
533 *
534 * <p> Groups beginning with {@code (?} are either pure, <i>non-capturing</i> groups
535 * that do not capture text and do not count towards the group total, or
536 * <i>named-capturing</i> group.
537 *
538 * <h2> Unicode support </h2>
539 *
540 * <p> This class is in conformance with Level 1 of <a
541 * href="http://www.unicode.org/reports/tr18/"><i>Unicode Technical
542 * Standard #18: Unicode Regular Expression</i></a>, plus RL2.1
543 * Canonical Equivalents.
544 * <p>
545 * <b>Unicode escape sequences</b> such as <code>\u2014</code> in Java source code
546 * are processed as described in section 3.3 of
547 * <cite>The Java™ Language Specification</cite>.
548 * Such escape sequences are also implemented directly by the regular-expression
549 * parser so that Unicode escapes can be used in expressions that are read from
550 * files or from the keyboard. Thus the strings <code>"\u2014"</code> and
551 * {@code "\\u2014"}, while not equal, compile into the same pattern, which
552 * matches the character with hexadecimal value {@code 0x2014}.
553 * <p>
554 * A Unicode character can also be represented by using its <b>Hex notation</b>
555 * (hexadecimal code point value) directly as described in construct
556 * <code>\x{...}</code>, for example a supplementary character U+2011F can be
557 * specified as <code>\x{2011F}</code>, instead of two consecutive Unicode escape
558 * sequences of the surrogate pair <code>\uD840</code><code>\uDD1F</code>.
559 * <p>
560 * <b>Unicode character names</b> are supported by the named character construct
561 * <code>\N{</code>...<code>}</code>, for example, <code>\N{WHITE SMILING FACE}</code>
562 * specifies character <code>\u263A</code>. The character names supported
563 * by this class are the valid Unicode character names matched by
564 * {@link java.lang.Character#codePointOf(String) Character.codePointOf(name)}.
565 * <p>
566 * <a href="http://www.unicode.org/reports/tr18/#Default_Grapheme_Clusters">
567 * <b>Unicode extended grapheme clusters</b></a> are supported by the grapheme
568 * cluster matcher {@code \X} and the corresponding boundary matcher {@code \b{g}}.
569 * <p>
570 * Unicode scripts, blocks, categories and binary properties are written with
571 * the {@code \p} and {@code \P} constructs as in Perl.
572 * <code>\p{</code><i>prop</i><code>}</code> matches if
573 * the input has the property <i>prop</i>, while <code>\P{</code><i>prop</i><code>}</code>
574 * does not match if the input has that property.
575 * <p>
576 * Scripts, blocks, categories and binary properties can be used both inside
577 * and outside of a character class.
578 *
579 * <p>
580 * <b><a id="usc">Scripts</a></b> are specified either with the prefix {@code Is}, as in
581 * {@code IsHiragana}, or by using the {@code script} keyword (or its short
582 * form {@code sc}) as in {@code script=Hiragana} or {@code sc=Hiragana}.
583 * <p>
584 * The script names supported by {@code Pattern} are the valid script names
585 * accepted and defined by
586 * {@link java.lang.Character.UnicodeScript#forName(String) UnicodeScript.forName}.
587 *
588 * <p>
589 * <b><a id="ubc">Blocks</a></b> are specified with the prefix {@code In}, as in
590 * {@code InMongolian}, or by using the keyword {@code block} (or its short
591 * form {@code blk}) as in {@code block=Mongolian} or {@code blk=Mongolian}.
592 * <p>
593 * The block names supported by {@code Pattern} are the valid block names
594 * accepted and defined by
595 * {@link java.lang.Character.UnicodeBlock#forName(String) UnicodeBlock.forName}.
596 * <p>
597 *
598 * <b><a id="ucc">Categories</a></b> may be specified with the optional prefix {@code Is}:
599 * Both {@code \p{L}} and {@code \p{IsL}} denote the category of Unicode
600 * letters. Same as scripts and blocks, categories can also be specified
601 * by using the keyword {@code general_category} (or its short form
602 * {@code gc}) as in {@code general_category=Lu} or {@code gc=Lu}.
603 * <p>
604 * The supported categories are those of
605 * <a href="http://www.unicode.org/unicode/standard/standard.html">
606 * <i>The Unicode Standard</i></a> in the version specified by the
607 * {@link java.lang.Character Character} class. The category names are those
608 * defined in the Standard, both normative and informative.
609 * <p>
610 *
611 * <b><a id="ubpc">Binary properties</a></b> are specified with the prefix {@code Is}, as in
612 * {@code IsAlphabetic}. The supported binary properties by {@code Pattern}
613 * are
614 * <ul>
615 * <li> Alphabetic
616 * <li> Ideographic
617 * <li> Letter
618 * <li> Lowercase
619 * <li> Uppercase
620 * <li> Titlecase
621 * <li> Punctuation
622 * <Li> Control
623 * <li> White_Space
624 * <li> Digit
625 * <li> Hex_Digit
626 * <li> Join_Control
627 * <li> Noncharacter_Code_Point
628 * <li> Assigned
629 * </ul>
630 * <p>
631 * The following <b>Predefined Character classes</b> and <b>POSIX character classes</b>
632 * are in conformance with the recommendation of <i>Annex C: Compatibility Properties</i>
633 * of <a href="http://www.unicode.org/reports/tr18/"><i>Unicode Regular Expression
634 * </i></a>, when {@link #UNICODE_CHARACTER_CLASS} flag is specified.
635 *
636 * <table class="striped">
637 * <caption style="display:none">predefined and posix character classes in Unicode mode</caption>
638 * <thead>
639 * <tr>
640 * <th scope="col" id="predef_classes">Classes</th>
641 * <th scope="col" id="predef_matches">Matches</th>
642 * </tr>
643 * </thead>
644 * <tbody>
645 * <tr><th scope="row">{@code \p{Lower}}</th>
646 * <td>A lowercase character:{@code \p{IsLowercase}}</td></tr>
647 * <tr><th scope="row">{@code \p{Upper}}</th>
648 * <td>An uppercase character:{@code \p{IsUppercase}}</td></tr>
649 * <tr><th scope="row">{@code \p{ASCII}}</th>
650 * <td>All ASCII:{@code [\x00-\x7F]}</td></tr>
651 * <tr><th scope="row">{@code \p{Alpha}}</th>
652 * <td>An alphabetic character:{@code \p{IsAlphabetic}}</td></tr>
653 * <tr><th scope="row">{@code \p{Digit}}</th>
654 * <td>A decimal digit character:{@code \p{IsDigit}}</td></tr>
655 * <tr><th scope="row">{@code \p{Alnum}}</th>
656 * <td>An alphanumeric character:{@code [\p{IsAlphabetic}\p{IsDigit}]}</td></tr>
657 * <tr><th scope="row">{@code \p{Punct}}</th>
658 * <td>A punctuation character:{@code \p{IsPunctuation}}</td></tr>
659 * <tr><th scope="row">{@code \p{Graph}}</th>
660 * <td>A visible character: {@code [^\p{IsWhite_Space}\p{gc=Cc}\p{gc=Cs}\p{gc=Cn}]}</td></tr>
661 * <tr><th scope="row">{@code \p{Print}}</th>
662 * <td>A printable character: {@code [\p{Graph}\p{Blank}&&[^\p{Cntrl}]]}</td></tr>
663 * <tr><th scope="row">{@code \p{Blank}}</th>
664 * <td>A space or a tab: {@code [\p{IsWhite_Space}&&[^\p{gc=Zl}\p{gc=Zp}\x0a\x0b\x0c\x0d\x85]]}</td></tr>
665 * <tr><th scope="row">{@code \p{Cntrl}}</th>
666 * <td>A control character: {@code \p{gc=Cc}}</td></tr>
667 * <tr><th scope="row">{@code \p{XDigit}}</th>
668 * <td>A hexadecimal digit: {@code [\p{gc=Nd}\p{IsHex_Digit}]}</td></tr>
669 * <tr><th scope="row">{@code \p{Space}}</th>
670 * <td>A whitespace character:{@code \p{IsWhite_Space}}</td></tr>
671 * <tr><th scope="row">{@code \d}</th>
672 * <td>A digit: {@code \p{IsDigit}}</td></tr>
673 * <tr><th scope="row">{@code \D}</th>
674 * <td>A non-digit: {@code [^\d]}</td></tr>
675 * <tr><th scope="row">{@code \s}</th>
676 * <td>A whitespace character: {@code \p{IsWhite_Space}}</td></tr>
677 * <tr><th scope="row">{@code \S}</th>
678 * <td>A non-whitespace character: {@code [^\s]}</td></tr>
679 * <tr><th scope="row">{@code \w}</th>
680 * <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>
681 * <tr><th scope="row">{@code \W}</th>
682 * <td>A non-word character: {@code [^\w]}</td></tr>
683 * </tbody>
684 * </table>
685 * <p>
686 * <a id="jcc">
687 * Categories that behave like the java.lang.Character
688 * boolean is<i>methodname</i> methods (except for the deprecated ones) are
689 * available through the same <code>\p{</code><i>prop</i><code>}</code> syntax where
690 * the specified property has the name <code>java<i>methodname</i></code></a>.
691 *
692 * <h2> Comparison to Perl 5 </h2>
693 *
694 * <p>The {@code Pattern} engine performs traditional NFA-based matching
695 * with ordered alternation as occurs in Perl 5.
696 *
697 * <p> Perl constructs not supported by this class: </p>
698 *
699 * <ul>
700 * <li><p> The backreference constructs, <code>\g{</code><i>n</i><code>}</code> for
701 * the <i>n</i><sup>th</sup><a href="#cg">capturing group</a> and
702 * <code>\g{</code><i>name</i><code>}</code> for
703 * <a href="#groupname">named-capturing group</a>.
704 * </p></li>
705 *
706 * <li><p> The conditional constructs
707 * {@code (?(}<i>condition</i>{@code )}<i>X</i>{@code )} and
708 * {@code (?(}<i>condition</i>{@code )}<i>X</i>{@code |}<i>Y</i>{@code )},
709 * </p></li>
710 *
711 * <li><p> The embedded code constructs <code>(?{</code><i>code</i><code>})</code>
712 * and <code>(??{</code><i>code</i><code>})</code>,</p></li>
713 *
714 * <li><p> The embedded comment syntax {@code (?#comment)}, and </p></li>
715 *
716 * <li><p> The preprocessing operations {@code \l} <code>\u</code>,
717 * {@code \L}, and {@code \U}. </p></li>
718 *
719 * </ul>
720 *
721 * <p> Constructs supported by this class but not by Perl: </p>
722 *
723 * <ul>
724 *
725 * <li><p> Character-class union and intersection as described
726 * <a href="#cc">above</a>.</p></li>
727 *
728 * </ul>
729 *
730 * <p> Notable differences from Perl: </p>
731 *
732 * <ul>
733 *
734 * <li><p> In Perl, {@code \1} through {@code \9} are always interpreted
735 * as back references; a backslash-escaped number greater than {@code 9} is
736 * treated as a back reference if at least that many subexpressions exist,
737 * otherwise it is interpreted, if possible, as an octal escape. In this
738 * class octal escapes must always begin with a zero. In this class,
739 * {@code \1} through {@code \9} are always interpreted as back
740 * references, and a larger number is accepted as a back reference if at
741 * least that many subexpressions exist at that point in the regular
742 * expression, otherwise the parser will drop digits until the number is
743 * smaller or equal to the existing number of groups or it is one digit.
744 * </p></li>
745 *
746 * <li><p> Perl uses the {@code g} flag to request a match that resumes
747 * where the last match left off. This functionality is provided implicitly
748 * by the {@link Matcher} class: Repeated invocations of the {@link
749 * Matcher#find find} method will resume where the last match left off,
750 * unless the matcher is reset. </p></li>
751 *
752 * <li><p> In Perl, embedded flags at the top level of an expression affect
753 * the whole expression. In this class, embedded flags always take effect
754 * at the point at which they appear, whether they are at the top level or
755 * within a group; in the latter case, flags are restored at the end of the
756 * group just as in Perl. </p></li>
757 *
758 * </ul>
759 *
760 *
761 * <p> For a more precise description of the behavior of regular expression
762 * constructs, please see <a href="http://www.oreilly.com/catalog/regex3/">
763 * <i>Mastering Regular Expressions, 3nd Edition</i>, Jeffrey E. F. Friedl,
764 * O'Reilly and Associates, 2006.</a>
765 * </p>
766 *
767 * @see java.lang.String#split(String, int)
768 * @see java.lang.String#split(String)
769 *
770 * @author Mike McCloskey
771 * @author Mark Reinhold
772 * @author JSR-51 Expert Group
773 * @since 1.4
774 * @spec JSR-51
775 */
776
777 public final class Pattern
778 implements java.io.Serializable
779 {
780
781 /**
782 * Regular expression modifier values. Instead of being passed as
783 * arguments, they can also be passed as inline modifiers.
784 * For example, the following statements have the same effect.
785 * <pre>
786 * Pattern p1 = Pattern.compile("abc", Pattern.CASE_INSENSITIVE|Pattern.MULTILINE);
787 * Pattern p2 = Pattern.compile("(?im)abc", 0);
788 * </pre>
789 */
790
791 /**
792 * Enables Unix lines mode.
793 *
794 * <p> In this mode, only the {@code '\n'} line terminator is recognized
795 * in the behavior of {@code .}, {@code ^}, and {@code $}.
796 *
797 * <p> Unix lines mode can also be enabled via the embedded flag
798 * expression {@code (?d)}.
799 */
800 public static final int UNIX_LINES = 0x01;
801
802 /**
803 * Enables case-insensitive matching.
804 *
805 * <p> By default, case-insensitive matching assumes that only characters
806 * in the US-ASCII charset are being matched. Unicode-aware
807 * case-insensitive matching can be enabled by specifying the {@link
808 * #UNICODE_CASE} flag in conjunction with this flag.
809 *
810 * <p> Case-insensitive matching can also be enabled via the embedded flag
811 * expression {@code (?i)}.
812 *
813 * <p> Specifying this flag may impose a slight performance penalty. </p>
814 */
815 public static final int CASE_INSENSITIVE = 0x02;
816
817 /**
818 * Permits whitespace and comments in pattern.
819 *
820 * <p> In this mode, whitespace is ignored, and embedded comments starting
821 * with {@code #} are ignored until the end of a line.
822 *
823 * <p> Comments mode can also be enabled via the embedded flag
824 * expression {@code (?x)}.
825 */
826 public static final int COMMENTS = 0x04;
827
828 /**
829 * Enables multiline mode.
830 *
831 * <p> In multiline mode the expressions {@code ^} and {@code $} match
832 * just after or just before, respectively, a line terminator or the end of
833 * the input sequence. By default these expressions only match at the
834 * beginning and the end of the entire input sequence.
835 *
836 * <p> Multiline mode can also be enabled via the embedded flag
837 * expression {@code (?m)}. </p>
838 */
839 public static final int MULTILINE = 0x08;
840
841 /**
842 * Enables literal parsing of the pattern.
843 *
844 * <p> When this flag is specified then the input string that specifies
845 * the pattern is treated as a sequence of literal characters.
846 * Metacharacters or escape sequences in the input sequence will be
847 * given no special meaning.
848 *
849 * <p>The flags CASE_INSENSITIVE and UNICODE_CASE retain their impact on
850 * matching when used in conjunction with this flag. The other flags
851 * become superfluous.
852 *
853 * <p> There is no embedded flag character for enabling literal parsing.
854 * @since 1.5
855 */
856 public static final int LITERAL = 0x10;
857
858 /**
859 * Enables dotall mode.
860 *
861 * <p> In dotall mode, the expression {@code .} matches any character,
862 * including a line terminator. By default this expression does not match
863 * line terminators.
864 *
865 * <p> Dotall mode can also be enabled via the embedded flag
866 * expression {@code (?s)}. (The {@code s} is a mnemonic for
867 * "single-line" mode, which is what this is called in Perl.) </p>
868 */
869 public static final int DOTALL = 0x20;
870
871 /**
872 * Enables Unicode-aware case folding.
873 *
874 * <p> When this flag is specified then case-insensitive matching, when
875 * enabled by the {@link #CASE_INSENSITIVE} flag, is done in a manner
876 * consistent with the Unicode Standard. By default, case-insensitive
877 * matching assumes that only characters in the US-ASCII charset are being
878 * matched.
879 *
880 * <p> Unicode-aware case folding can also be enabled via the embedded flag
881 * expression {@code (?u)}.
882 *
883 * <p> Specifying this flag may impose a performance penalty. </p>
884 */
885 public static final int UNICODE_CASE = 0x40;
886
887 /**
888 * Enables canonical equivalence.
889 *
890 * <p> When this flag is specified then two characters will be considered
891 * to match if, and only if, their full canonical decompositions match.
892 * The expression <code>"a\u030A"</code>, for example, will match the
893 * string <code>"\u00E5"</code> when this flag is specified. By default,
894 * matching does not take canonical equivalence into account.
895 *
896 * <p> There is no embedded flag character for enabling canonical
897 * equivalence.
898 *
899 * <p> Specifying this flag may impose a performance penalty. </p>
900 */
901 public static final int CANON_EQ = 0x80;
902
903 /**
904 * Enables the Unicode version of <i>Predefined character classes</i> and
905 * <i>POSIX character classes</i>.
906 *
907 * <p> When this flag is specified then the (US-ASCII only)
908 * <i>Predefined character classes</i> and <i>POSIX character classes</i>
909 * are in conformance with
910 * <a href="http://www.unicode.org/reports/tr18/"><i>Unicode Technical
911 * Standard #18: Unicode Regular Expression</i></a>
912 * <i>Annex C: Compatibility Properties</i>.
913 * <p>
914 * The UNICODE_CHARACTER_CLASS mode can also be enabled via the embedded
915 * flag expression {@code (?U)}.
916 * <p>
917 * The flag implies UNICODE_CASE, that is, it enables Unicode-aware case
918 * folding.
919 * <p>
920 * Specifying this flag may impose a performance penalty. </p>
921 * @since 1.7
922 */
923 public static final int UNICODE_CHARACTER_CLASS = 0x100;
924
925 /**
926 * Contains all possible flags for compile(regex, flags).
927 */
928 private static final int ALL_FLAGS = CASE_INSENSITIVE | MULTILINE |
929 DOTALL | UNICODE_CASE | CANON_EQ | UNIX_LINES | LITERAL |
930 UNICODE_CHARACTER_CLASS | COMMENTS;
931
932 /* Pattern has only two serialized components: The pattern string
933 * and the flags, which are all that is needed to recompile the pattern
934 * when it is deserialized.
935 */
936
937 /** use serialVersionUID from Merlin b59 for interoperability */
938 private static final long serialVersionUID = 5073258162644648461L;
939
940 /**
941 * The original regular-expression pattern string.
942 *
943 * @serial
944 */
945 private String pattern;
946
947 /**
948 * The original pattern flags.
949 *
950 * @serial
951 */
952 private int flags;
953
954 /**
955 * The temporary pattern flags used during compiling. The flags might be turn
956 * on and off by embedded flag.
957 */
958 private transient int flags0;
959
960 /**
961 * Boolean indicating this Pattern is compiled; this is necessary in order
962 * to lazily compile deserialized Patterns.
963 */
964 private transient volatile boolean compiled;
965
966 /**
967 * The normalized pattern string.
968 */
969 private transient String normalizedPattern;
970
971 /**
972 * The starting point of state machine for the find operation. This allows
973 * a match to start anywhere in the input.
974 */
975 transient Node root;
976
977 /**
978 * The root of object tree for a match operation. The pattern is matched
979 * at the beginning. This may include a find that uses BnM or a First
980 * node.
981 */
982 transient Node matchRoot;
983
984 /**
985 * Temporary storage used by parsing pattern slice.
986 */
987 transient int[] buffer;
988
989 /**
990 * A temporary storage used for predicate for double return.
991 */
992 transient CharPredicate predicate;
993
994 /**
995 * Map the "name" of the "named capturing group" to its group id
996 * node.
997 */
998 transient volatile Map<String, Integer> namedGroups;
999
1000 /**
1001 * Temporary storage used while parsing group references.
1002 */
1003 transient GroupHead[] groupNodes;
1004
1005 /**
1006 * Temporary storage used to store the top level closure nodes.
1007 */
1008 transient List<Node> topClosureNodes;
1009
1010 /**
1011 * The number of top greedy closure nodes in this Pattern. Used by
1012 * matchers to allocate storage needed for a IntHashSet to keep the
1013 * beginning pos {@code i} of all failed match.
1014 */
1015 transient int localTCNCount;
1016
1017 /*
1018 * Turn off the stop-exponential-backtracking optimization if there
1019 * is a group ref in the pattern.
1020 */
1021 transient boolean hasGroupRef;
1022
1023 /**
1024 * Temporary null terminated code point array used by pattern compiling.
1025 */
1026 private transient int[] temp;
1027
1028 /**
1029 * The number of capturing groups in this Pattern. Used by matchers to
1030 * allocate storage needed to perform a match.
1031 */
1032 transient int capturingGroupCount;
1033
1034 /**
1035 * The local variable count used by parsing tree. Used by matchers to
1036 * allocate storage needed to perform a match.
1037 */
1038 transient int localCount;
1039
1040 /**
1041 * Index into the pattern string that keeps track of how much has been
1042 * parsed.
1043 */
1044 private transient int cursor;
1045
1046 /**
1047 * Holds the length of the pattern string.
1048 */
1049 private transient int patternLength;
1050
1051 /**
1052 * If the Start node might possibly match supplementary characters.
1053 * It is set to true during compiling if
1054 * (1) There is supplementary char in pattern, or
1055 * (2) There is complement node of a "family" CharProperty
1056 */
1057 private transient boolean hasSupplementary;
1058
1059 /**
1060 * Compiles the given regular expression into a pattern.
1061 *
1062 * @param regex
1063 * The expression to be compiled
1064 * @return the given regular expression compiled into a pattern
1065 * @throws PatternSyntaxException
1066 * If the expression's syntax is invalid
1067 */
1068 public static Pattern compile(String regex) {
1069 return new Pattern(regex, 0);
1070 }
1071
1072 /**
1073 * Compiles the given regular expression into a pattern with the given
1074 * flags.
1075 *
1076 * @param regex
1077 * The expression to be compiled
1078 *
1079 * @param flags
1080 * Match flags, a bit mask that may include
1081 * {@link #CASE_INSENSITIVE}, {@link #MULTILINE}, {@link #DOTALL},
1082 * {@link #UNICODE_CASE}, {@link #CANON_EQ}, {@link #UNIX_LINES},
1083 * {@link #LITERAL}, {@link #UNICODE_CHARACTER_CLASS}
1084 * and {@link #COMMENTS}
1085 *
1086 * @return the given regular expression compiled into a pattern with the given flags
1087 * @throws IllegalArgumentException
1088 * If bit values other than those corresponding to the defined
1089 * match flags are set in {@code flags}
1090 *
1091 * @throws PatternSyntaxException
1092 * If the expression's syntax is invalid
1093 */
1094 public static Pattern compile(String regex, int flags) {
1095 return new Pattern(regex, flags);
1096 }
1097
1098 /**
1099 * Returns the regular expression from which this pattern was compiled.
1100 *
1101 * @return The source of this pattern
1102 */
1103 public String pattern() {
1104 return pattern;
1105 }
1106
1107 /**
1108 * <p>Returns the string representation of this pattern. This
1109 * is the regular expression from which this pattern was
1110 * compiled.</p>
1111 *
1112 * @return The string representation of this pattern
1113 * @since 1.5
1114 */
1115 public String toString() {
1116 return pattern;
1117 }
1118
1119 /**
1120 * Creates a matcher that will match the given input against this pattern.
1121 *
1122 * @param input
1123 * The character sequence to be matched
1124 *
1125 * @return A new matcher for this pattern
1126 */
1127 public Matcher matcher(CharSequence input) {
1128 if (!compiled) {
1129 synchronized(this) {
1130 if (!compiled)
1131 compile();
1132 }
1133 }
1134 Matcher m = new Matcher(this, input);
1135 return m;
1136 }
1137
1138 /**
1139 * Returns this pattern's match flags.
1140 *
1141 * @return The match flags specified when this pattern was compiled
1142 */
1143 public int flags() {
1144 return flags0;
1145 }
1146
1147 /**
1148 * Compiles the given regular expression and attempts to match the given
1149 * input against it.
1150 *
1151 * <p> An invocation of this convenience method of the form
1152 *
1153 * <blockquote><pre>
1154 * Pattern.matches(regex, input);</pre></blockquote>
1155 *
1156 * behaves in exactly the same way as the expression
1157 *
1158 * <blockquote><pre>
1159 * Pattern.compile(regex).matcher(input).matches()</pre></blockquote>
1160 *
1161 * <p> If a pattern is to be used multiple times, compiling it once and reusing
1162 * it will be more efficient than invoking this method each time. </p>
1163 *
1164 * @param regex
1165 * The expression to be compiled
1166 *
1167 * @param input
1168 * The character sequence to be matched
1169 * @return whether or not the regular expression matches on the input
1170 * @throws PatternSyntaxException
1171 * If the expression's syntax is invalid
1172 */
1173 public static boolean matches(String regex, CharSequence input) {
1174 Pattern p = Pattern.compile(regex);
1175 Matcher m = p.matcher(input);
1176 return m.matches();
1177 }
1178
1179 /**
1180 * Splits the given input sequence around matches of this pattern.
1181 *
1182 * <p> The array returned by this method contains each substring of the
1183 * input sequence that is terminated by another subsequence that matches
1184 * this pattern or is terminated by the end of the input sequence. The
1185 * substrings in the array are in the order in which they occur in the
1186 * input. If this pattern does not match any subsequence of the input then
1187 * the resulting array has just one element, namely the input sequence in
1188 * string form.
1189 *
1190 * <p> When there is a positive-width match at the beginning of the input
1191 * sequence then an empty leading substring is included at the beginning
1192 * of the resulting array. A zero-width match at the beginning however
1193 * never produces such empty leading substring.
1194 *
1195 * <p> The {@code limit} parameter controls the number of times the
1196 * pattern is applied and therefore affects the length of the resulting
1197 * array.
1198 * <ul>
1199 * <li><p>
1200 * If the <i>limit</i> is positive then the pattern will be applied
1201 * at most <i>limit</i> - 1 times, the array's length will be
1202 * no greater than <i>limit</i>, and the array's last entry will contain
1203 * all input beyond the last matched delimiter.</p></li>
1204 *
1205 * <li><p>
1206 * If the <i>limit</i> is zero then the pattern will be applied as
1207 * many times as possible, the array can have any length, and trailing
1208 * empty strings will be discarded.</p></li>
1209 *
1210 * <li><p>
1211 * If the <i>limit</i> is negative then the pattern will be applied
1212 * as many times as possible and the array can have any length.</p></li>
1213 * </ul>
1214 *
1215 * <p> The input {@code "boo:and:foo"}, for example, yields the following
1216 * results with these parameters:
1217 *
1218 * <table class="plain" style="margin-left:2em;">
1219 * <caption style="display:none">Split example showing regex, limit, and result</caption>
1220 * <thead>
1221 * <tr>
1222 * <th scope="col">Regex</th>
1223 * <th scope="col">Limit</th>
1224 * <th scope="col">Result</th>
1225 * </tr>
1226 * </thead>
1227 * <tbody>
1228 * <tr><th scope="row" rowspan="3" style="font-weight:normal">:</th>
1229 * <th scope="row" style="font-weight:normal; text-align:right; padding-right:1em">2</th>
1230 * <td>{@code { "boo", "and:foo" }}</td></tr>
1231 * <tr><!-- : -->
1232 * <th scope="row" style="font-weight:normal; text-align:right; padding-right:1em">5</th>
1233 * <td>{@code { "boo", "and", "foo" }}</td></tr>
1234 * <tr><!-- : -->
1235 * <th scope="row" style="font-weight:normal; text-align:right; padding-right:1em">-2</th>
1236 * <td>{@code { "boo", "and", "foo" }}</td></tr>
1237 * <tr><th scope="row" rowspan="3" style="font-weight:normal">o</th>
1238 * <th scope="row" style="font-weight:normal; text-align:right; padding-right:1em">5</th>
1239 * <td>{@code { "b", "", ":and:f", "", "" }}</td></tr>
1240 * <tr><!-- o -->
1241 * <th scope="row" style="font-weight:normal; text-align:right; padding-right:1em">-2</th>
1242 * <td>{@code { "b", "", ":and:f", "", "" }}</td></tr>
1243 * <tr><!-- o -->
1244 * <th scope="row" style="font-weight:normal; text-align:right; padding-right:1em">0</th>
1245 * <td>{@code { "b", "", ":and:f" }}</td></tr>
1246 * </tbody>
1247 * </table>
1248 *
1249 * @param input
1250 * The character sequence to be split
1251 *
1252 * @param limit
1253 * The result threshold, as described above
1254 *
1255 * @return The array of strings computed by splitting the input
1256 * around matches of this pattern
1257 */
1258 public String[] split(CharSequence input, int limit) {
1259 int index = 0;
1260 boolean matchLimited = limit > 0;
1261 ArrayList<String> matchList = new ArrayList<>();
1262 Matcher m = matcher(input);
1263
1264 // Add segments before each match found
1265 while(m.find()) {
1266 if (!matchLimited || matchList.size() < limit - 1) {
1267 if (index == 0 && index == m.start() && m.start() == m.end()) {
1268 // no empty leading substring included for zero-width match
1269 // at the beginning of the input char sequence.
1270 continue;
1271 }
1272 String match = input.subSequence(index, m.start()).toString();
1273 matchList.add(match);
1274 index = m.end();
1275 } else if (matchList.size() == limit - 1) { // last one
1276 String match = input.subSequence(index,
1277 input.length()).toString();
1278 matchList.add(match);
1279 index = m.end();
1280 }
1281 }
1282
1283 // If no match was found, return this
1284 if (index == 0)
1285 return new String[] {input.toString()};
1286
1287 // Add remaining segment
1288 if (!matchLimited || matchList.size() < limit)
1289 matchList.add(input.subSequence(index, input.length()).toString());
1290
1291 // Construct result
1292 int resultSize = matchList.size();
1293 if (limit == 0)
1294 while (resultSize > 0 && matchList.get(resultSize-1).isEmpty())
1295 resultSize--;
1296 String[] result = new String[resultSize];
1297 return matchList.subList(0, resultSize).toArray(result);
1298 }
1299
1300 /**
1301 * Splits the given input sequence around matches of this pattern.
1302 *
1303 * <p> This method works as if by invoking the two-argument {@link
1304 * #split(java.lang.CharSequence, int) split} method with the given input
1305 * sequence and a limit argument of zero. Trailing empty strings are
1306 * therefore not included in the resulting array. </p>
1307 *
1308 * <p> The input {@code "boo:and:foo"}, for example, yields the following
1309 * results with these expressions:
1310 *
1311 * <table class="plain" style="margin-left:2em">
1312 * <caption style="display:none">Split examples showing regex and result</caption>
1313 * <thead>
1314 * <tr>
1315 * <th scope="col">Regex</th>
1316 * <th scope="col">Result</th>
1317 * </tr>
1318 * </thead>
1319 * <tbody>
1320 * <tr><th scope="row" style="text-weight:normal">:</th>
1321 * <td>{@code { "boo", "and", "foo" }}</td></tr>
1322 * <tr><th scope="row" style="text-weight:normal">o</th>
1323 * <td>{@code { "b", "", ":and:f" }}</td></tr>
1324 * </tbody>
1325 * </table>
1326 *
1327 *
1328 * @param input
1329 * The character sequence to be split
1330 *
1331 * @return The array of strings computed by splitting the input
1332 * around matches of this pattern
1333 */
1334 public String[] split(CharSequence input) {
1335 return split(input, 0);
1336 }
1337
1338 /**
1339 * Returns a literal pattern {@code String} for the specified
1340 * {@code String}.
1341 *
1342 * <p>This method produces a {@code String} that can be used to
1343 * create a {@code Pattern} that would match the string
1344 * {@code s} as if it were a literal pattern.</p> Metacharacters
1345 * or escape sequences in the input sequence will be given no special
1346 * meaning.
1347 *
1348 * @param s The string to be literalized
1349 * @return A literal string replacement
1350 * @since 1.5
1351 */
1352 public static String quote(String s) {
1353 int slashEIndex = s.indexOf("\\E");
1354 if (slashEIndex == -1)
1355 return "\\Q" + s + "\\E";
1356
1357 int lenHint = s.length();
1358 lenHint = (lenHint < Integer.MAX_VALUE - 8 - lenHint) ?
1359 (lenHint << 1) : (Integer.MAX_VALUE - 8);
1360
1361 StringBuilder sb = new StringBuilder(lenHint);
1362 sb.append("\\Q");
1363 int current = 0;
1364 do {
1365 sb.append(s, current, slashEIndex)
1366 .append("\\E\\\\E\\Q");
1367 current = slashEIndex + 2;
1368 } while ((slashEIndex = s.indexOf("\\E", current)) != -1);
1369
1370 return sb.append(s, current, s.length())
1371 .append("\\E")
1372 .toString();
1373 }
1374
1375 /**
1376 * Recompile the Pattern instance from a stream. The original pattern
1377 * string is read in and the object tree is recompiled from it.
1378 */
1379 private void readObject(java.io.ObjectInputStream s)
1380 throws java.io.IOException, ClassNotFoundException {
1381
1382 // Read in all fields
1383 s.defaultReadObject();
1384
1385 // reset the flags
1386 flags0 = flags;
1387
1388 // Initialize counts
1389 capturingGroupCount = 1;
1390 localCount = 0;
1391 localTCNCount = 0;
1392
1393 // if length > 0, the Pattern is lazily compiled
1394 if (pattern.isEmpty()) {
1395 root = new Start(lastAccept);
1396 matchRoot = lastAccept;
1397 compiled = true;
1398 }
1399 }
1400
1401 /**
1402 * This private constructor is used to create all Patterns. The pattern
1403 * string and match flags are all that is needed to completely describe
1404 * a Pattern. An empty pattern string results in an object tree with
1405 * only a Start node and a LastNode node.
1406 */
1407 private Pattern(String p, int f) {
1408 if ((f & ~ALL_FLAGS) != 0) {
1409 throw new IllegalArgumentException("Unknown flag 0x"
1410 + Integer.toHexString(f));
1411 }
1412 pattern = p;
1413 flags = f;
1414
1415 // to use UNICODE_CASE if UNICODE_CHARACTER_CLASS present
1416 if ((flags & UNICODE_CHARACTER_CLASS) != 0)
1417 flags |= UNICODE_CASE;
1418
1419 // 'flags' for compiling
1420 flags0 = flags;
1421
1422 // Reset group index count
1423 capturingGroupCount = 1;
1424 localCount = 0;
1425 localTCNCount = 0;
1426
1427 if (!pattern.isEmpty()) {
1428 compile();
1429 } else {
1430 root = new Start(lastAccept);
1431 matchRoot = lastAccept;
1432 }
1433 }
1434
1435 /**
1436 * The pattern is converted to normalized form ({@link
1437 * java.text.Normalizer.Form#NFC NFC}, canonical decomposition,
1438 * followed by canonical composition for the character class
1439 * part, and {@link java.text.Normalizer.Form#NFD NFD},
1440 * canonical decomposition for the rest), and then a pure
1441 * group is constructed to match canonical equivalences of the
1442 * characters.
1443 */
1444 private static String normalize(String pattern) {
1445 int plen = pattern.length();
1446 StringBuilder pbuf = new StringBuilder(plen);
1447 char last = 0;
1448 int lastStart = 0;
1449 char cc = 0;
1450 for (int i = 0; i < plen;) {
1451 char c = pattern.charAt(i);
1452 if (cc == 0 && // top level
1453 c == '\\' && i + 1 < plen && pattern.charAt(i + 1) == '\\') {
1454 i += 2; last = 0;
1455 continue;
1456 }
1457 if (c == '[' && last != '\\') {
1458 if (cc == 0) {
1459 if (lastStart < i)
1460 normalizeSlice(pattern, lastStart, i, pbuf);
1461 lastStart = i;
1462 }
1463 cc++;
1464 } else if (c == ']' && last != '\\') {
1465 cc--;
1466 if (cc == 0) {
1467 normalizeClazz(pattern, lastStart, i + 1, pbuf);
1468 lastStart = i + 1;
1469 }
1470 }
1471 last = c;
1472 i++;
1473 }
1474 assert (cc == 0);
1475 if (lastStart < plen)
1476 normalizeSlice(pattern, lastStart, plen, pbuf);
1477 return pbuf.toString();
1478 }
1479
1480 private static void normalizeSlice(String src, int off, int limit,
1481 StringBuilder dst)
1482 {
1483 int len = src.length();
1484 int off0 = off;
1485 while (off < limit && ASCII.isAscii(src.charAt(off))) {
1486 off++;
1487 }
1488 if (off == limit) {
1489 dst.append(src, off0, limit);
1490 return;
1491 }
1492 off--;
1493 if (off < off0)
1494 off = off0;
1495 else
1496 dst.append(src, off0, off);
1497 while (off < limit) {
1498 int ch0 = src.codePointAt(off);
1499 if (".$|()[]{}^?*+\\".indexOf(ch0) != -1) {
1500 dst.append((char)ch0);
1501 off++;
1502 continue;
1503 }
1504 int j = off + Character.charCount(ch0);
1505 int ch1;
1506 while (j < limit) {
1507 ch1 = src.codePointAt(j);
1508 if (Grapheme.isBoundary(ch0, ch1))
1509 break;
1510 ch0 = ch1;
1511 j += Character.charCount(ch1);
1512 }
1513 String seq = src.substring(off, j);
1514 String nfd = Normalizer.normalize(seq, Normalizer.Form.NFD);
1515 off = j;
1516 if (nfd.length() > 1) {
1517 ch0 = nfd.codePointAt(0);
1518 ch1 = nfd.codePointAt(Character.charCount(ch0));
1519 if (Character.getType(ch1) == Character.NON_SPACING_MARK) {
1520 Set<String> altns = new LinkedHashSet<>();
1521 altns.add(seq);
1522 produceEquivalentAlternation(nfd, altns);
1523 dst.append("(?:");
1524 altns.forEach( s -> dst.append(s).append('|'));
1525 dst.delete(dst.length() - 1, dst.length());
1526 dst.append(")");
1527 continue;
1528 }
1529 }
1530 String nfc = Normalizer.normalize(seq, Normalizer.Form.NFC);
1531 if (!seq.equals(nfc) && !nfd.equals(nfc))
1532 dst.append("(?:" + seq + "|" + nfd + "|" + nfc + ")");
1533 else if (!seq.equals(nfd))
1534 dst.append("(?:" + seq + "|" + nfd + ")");
1535 else
1536 dst.append(seq);
1537 }
1538 }
1539
1540 private static void normalizeClazz(String src, int off, int limit,
1541 StringBuilder dst)
1542 {
1543 dst.append(Normalizer.normalize(src.substring(off, limit), Form.NFC));
1544 }
1545
1546 /**
1547 * Given a specific sequence composed of a regular character and
1548 * combining marks that follow it, produce the alternation that will
1549 * match all canonical equivalences of that sequence.
1550 */
1551 private static void produceEquivalentAlternation(String src,
1552 Set<String> dst)
1553 {
1554 int len = countChars(src, 0, 1);
1555 if (src.length() == len) {
1556 dst.add(src); // source has one character.
1557 return;
1558 }
1559 String base = src.substring(0,len);
1560 String combiningMarks = src.substring(len);
1561 String[] perms = producePermutations(combiningMarks);
1562 // Add combined permutations
1563 for(int x = 0; x < perms.length; x++) {
1564 String next = base + perms[x];
1565 dst.add(next);
1566 next = composeOneStep(next);
1567 if (next != null) {
1568 produceEquivalentAlternation(next, dst);
1569 }
1570 }
1571 }
1572
1573 /**
1574 * Returns an array of strings that have all the possible
1575 * permutations of the characters in the input string.
1576 * This is used to get a list of all possible orderings
1577 * of a set of combining marks. Note that some of the permutations
1578 * are invalid because of combining class collisions, and these
1579 * possibilities must be removed because they are not canonically
1580 * equivalent.
1581 */
1582 private static String[] producePermutations(String input) {
1583 if (input.length() == countChars(input, 0, 1))
1584 return new String[] {input};
1585
1586 if (input.length() == countChars(input, 0, 2)) {
1587 int c0 = Character.codePointAt(input, 0);
1588 int c1 = Character.codePointAt(input, Character.charCount(c0));
1589 if (getClass(c1) == getClass(c0)) {
1590 return new String[] {input};
1591 }
1592 String[] result = new String[2];
1593 result[0] = input;
1594 StringBuilder sb = new StringBuilder(2);
1595 sb.appendCodePoint(c1);
1596 sb.appendCodePoint(c0);
1597 result[1] = sb.toString();
1598 return result;
1599 }
1600
1601 int length = 1;
1602 int nCodePoints = countCodePoints(input);
1603 for(int x=1; x<nCodePoints; x++)
1604 length = length * (x+1);
1605
1606 String[] temp = new String[length];
1607
1608 int combClass[] = new int[nCodePoints];
1609 for(int x=0, i=0; x<nCodePoints; x++) {
1610 int c = Character.codePointAt(input, i);
1611 combClass[x] = getClass(c);
1612 i += Character.charCount(c);
1613 }
1614
1615 // For each char, take it out and add the permutations
1616 // of the remaining chars
1617 int index = 0;
1618 int len;
1619 // offset maintains the index in code units.
1620 loop: for(int x=0, offset=0; x<nCodePoints; x++, offset+=len) {
1621 len = countChars(input, offset, 1);
1622 for(int y=x-1; y>=0; y--) {
1623 if (combClass[y] == combClass[x]) {
1624 continue loop;
1625 }
1626 }
1627 StringBuilder sb = new StringBuilder(input);
1628 String otherChars = sb.delete(offset, offset+len).toString();
1629 String[] subResult = producePermutations(otherChars);
1630
1631 String prefix = input.substring(offset, offset+len);
1632 for (String sre : subResult)
1633 temp[index++] = prefix + sre;
1634 }
1635 String[] result = new String[index];
1636 System.arraycopy(temp, 0, result, 0, index);
1637 return result;
1638 }
1639
1640 private static int getClass(int c) {
1641 return sun.text.Normalizer.getCombiningClass(c);
1642 }
1643
1644 /**
1645 * Attempts to compose input by combining the first character
1646 * with the first combining mark following it. Returns a String
1647 * that is the composition of the leading character with its first
1648 * combining mark followed by the remaining combining marks. Returns
1649 * null if the first two characters cannot be further composed.
1650 */
1651 private static String composeOneStep(String input) {
1652 int len = countChars(input, 0, 2);
1653 String firstTwoCharacters = input.substring(0, len);
1654 String result = Normalizer.normalize(firstTwoCharacters, Normalizer.Form.NFC);
1655 if (result.equals(firstTwoCharacters))
1656 return null;
1657 else {
1658 String remainder = input.substring(len);
1659 return result + remainder;
1660 }
1661 }
1662
1663 /**
1664 * Preprocess any \Q...\E sequences in `temp', meta-quoting them.
1665 * See the description of `quotemeta' in perlfunc(1).
1666 */
1667 private void RemoveQEQuoting() {
1668 final int pLen = patternLength;
1669 int i = 0;
1670 while (i < pLen-1) {
1671 if (temp[i] != '\\')
1672 i += 1;
1673 else if (temp[i + 1] != 'Q')
1674 i += 2;
1675 else
1676 break;
1677 }
1678 if (i >= pLen - 1) // No \Q sequence found
1679 return;
1680 int j = i;
1681 i += 2;
1682 int newTempLen;
1683 try {
1684 newTempLen = Math.addExact(j + 2, Math.multiplyExact(3, pLen - i));
1685 } catch (ArithmeticException ae) {
1686 throw new OutOfMemoryError();
1687 }
1688 int[] newtemp = new int[newTempLen];
1689 System.arraycopy(temp, 0, newtemp, 0, j);
1690
1691 boolean inQuote = true;
1692 boolean beginQuote = true;
1693 while (i < pLen) {
1694 int c = temp[i++];
1695 if (!ASCII.isAscii(c) || ASCII.isAlpha(c)) {
1696 newtemp[j++] = c;
1697 } else if (ASCII.isDigit(c)) {
1698 if (beginQuote) {
1699 /*
1700 * A unicode escape \[0xu] could be before this quote,
1701 * and we don't want this numeric char to processed as
1702 * part of the escape.
1703 */
1704 newtemp[j++] = '\\';
1705 newtemp[j++] = 'x';
1706 newtemp[j++] = '3';
1707 }
1708 newtemp[j++] = c;
1709 } else if (c != '\\') {
1710 if (inQuote) newtemp[j++] = '\\';
1711 newtemp[j++] = c;
1712 } else if (inQuote) {
1713 if (temp[i] == 'E') {
1714 i++;
1715 inQuote = false;
1716 } else {
1717 newtemp[j++] = '\\';
1718 newtemp[j++] = '\\';
1719 }
1720 } else {
1721 if (temp[i] == 'Q') {
1722 i++;
1723 inQuote = true;
1724 beginQuote = true;
1725 continue;
1726 } else {
1727 newtemp[j++] = c;
1728 if (i != pLen)
1729 newtemp[j++] = temp[i++];
1730 }
1731 }
1732
1733 beginQuote = false;
1734 }
1735
1736 patternLength = j;
1737 temp = Arrays.copyOf(newtemp, j + 2); // double zero termination
1738 }
1739
1740 /**
1741 * Copies regular expression to an int array and invokes the parsing
1742 * of the expression which will create the object tree.
1743 */
1744 private void compile() {
1745 // Handle canonical equivalences
1746 if (has(CANON_EQ) && !has(LITERAL)) {
1747 normalizedPattern = normalize(pattern);
1748 } else {
1749 normalizedPattern = pattern;
1750 }
1751 patternLength = normalizedPattern.length();
1752
1753 // Copy pattern to int array for convenience
1754 // Use double zero to terminate pattern
1755 temp = new int[patternLength + 2];
1756
1757 hasSupplementary = false;
1758 int c, count = 0;
1759 // Convert all chars into code points
1760 for (int x = 0; x < patternLength; x += Character.charCount(c)) {
1761 c = normalizedPattern.codePointAt(x);
1762 if (isSupplementary(c)) {
1763 hasSupplementary = true;
1764 }
1765 temp[count++] = c;
1766 }
1767
1768 patternLength = count; // patternLength now in code points
1769
1770 if (! has(LITERAL))
1771 RemoveQEQuoting();
1772
1773 // Allocate all temporary objects here.
1774 buffer = new int[32];
1775 groupNodes = new GroupHead[10];
1776 namedGroups = null;
1777 topClosureNodes = new ArrayList<>(10);
1778
1779 if (has(LITERAL)) {
1780 // Literal pattern handling
1781 matchRoot = newSlice(temp, patternLength, hasSupplementary);
1782 matchRoot.next = lastAccept;
1783 } else {
1784 // Start recursive descent parsing
1785 matchRoot = expr(lastAccept);
1786 // Check extra pattern characters
1787 if (patternLength != cursor) {
1788 if (peek() == ')') {
1789 throw error("Unmatched closing ')'");
1790 } else {
1791 throw error("Unexpected internal error");
1792 }
1793 }
1794 }
1795
1796 // Peephole optimization
1797 if (matchRoot instanceof Slice) {
1798 root = BnM.optimize(matchRoot);
1799 if (root == matchRoot) {
1800 root = hasSupplementary ? new StartS(matchRoot) : new Start(matchRoot);
1801 }
1802 } else if (matchRoot instanceof Begin || matchRoot instanceof First) {
1803 root = matchRoot;
1804 } else {
1805 root = hasSupplementary ? new StartS(matchRoot) : new Start(matchRoot);
1806 }
1807
1808 // Optimize the greedy Loop to prevent exponential backtracking, IF there
1809 // is no group ref in this pattern. With a non-negative localTCNCount value,
1810 // the greedy type Loop, Curly will skip the backtracking for any starting
1811 // position "i" that failed in the past.
1812 if (!hasGroupRef) {
1813 for (Node node : topClosureNodes) {
1814 if (node instanceof Loop) {
1815 // non-deterministic-greedy-group
1816 ((Loop)node).posIndex = localTCNCount++;
1817 }
1818 }
1819 }
1820
1821 // Release temporary storage
1822 temp = null;
1823 buffer = null;
1824 groupNodes = null;
1825 patternLength = 0;
1826 compiled = true;
1827 topClosureNodes = null;
1828 }
1829
1830 Map<String, Integer> namedGroups() {
1831 Map<String, Integer> groups = namedGroups;
1832 if (groups == null) {
1833 namedGroups = groups = new HashMap<>(2);
1834 }
1835 return groups;
1836 }
1837
1838 /**
1839 * Used to accumulate information about a subtree of the object graph
1840 * so that optimizations can be applied to the subtree.
1841 */
1842 static final class TreeInfo {
1843 int minLength;
1844 int maxLength;
1845 boolean maxValid;
1846 boolean deterministic;
1847
1848 TreeInfo() {
1849 reset();
1850 }
1851 void reset() {
1852 minLength = 0;
1853 maxLength = 0;
1854 maxValid = true;
1855 deterministic = true;
1856 }
1857 }
1858
1859 /*
1860 * The following private methods are mainly used to improve the
1861 * readability of the code. In order to let the Java compiler easily
1862 * inline them, we should not put many assertions or error checks in them.
1863 */
1864
1865 /**
1866 * Indicates whether a particular flag is set or not.
1867 */
1868 private boolean has(int f) {
1869 return (flags0 & f) != 0;
1870 }
1871
1872 /**
1873 * Match next character, signal error if failed.
1874 */
1875 private void accept(int ch, String s) {
1876 int testChar = temp[cursor++];
1877 if (has(COMMENTS))
1878 testChar = parsePastWhitespace(testChar);
1879 if (ch != testChar) {
1880 throw error(s);
1881 }
1882 }
1883
1884 /**
1885 * Mark the end of pattern with a specific character.
1886 */
1887 private void mark(int c) {
1888 temp[patternLength] = c;
1889 }
1890
1891 /**
1892 * Peek the next character, and do not advance the cursor.
1893 */
1894 private int peek() {
1895 int ch = temp[cursor];
1896 if (has(COMMENTS))
1897 ch = peekPastWhitespace(ch);
1898 return ch;
1899 }
1900
1901 /**
1902 * Read the next character, and advance the cursor by one.
1903 */
1904 private int read() {
1905 int ch = temp[cursor++];
1906 if (has(COMMENTS))
1907 ch = parsePastWhitespace(ch);
1908 return ch;
1909 }
1910
1911 /**
1912 * Read the next character, and advance the cursor by one,
1913 * ignoring the COMMENTS setting
1914 */
1915 private int readEscaped() {
1916 int ch = temp[cursor++];
1917 return ch;
1918 }
1919
1920 /**
1921 * Advance the cursor by one, and peek the next character.
1922 */
1923 private int next() {
1924 int ch = temp[++cursor];
1925 if (has(COMMENTS))
1926 ch = peekPastWhitespace(ch);
1927 return ch;
1928 }
1929
1930 /**
1931 * Advance the cursor by one, and peek the next character,
1932 * ignoring the COMMENTS setting
1933 */
1934 private int nextEscaped() {
1935 int ch = temp[++cursor];
1936 return ch;
1937 }
1938
1939 /**
1940 * If in xmode peek past whitespace and comments.
1941 */
1942 private int peekPastWhitespace(int ch) {
1943 while (ASCII.isSpace(ch) || ch == '#') {
1944 while (ASCII.isSpace(ch))
1945 ch = temp[++cursor];
1946 if (ch == '#') {
1947 ch = peekPastLine();
1948 }
1949 }
1950 return ch;
1951 }
1952
1953 /**
1954 * If in xmode parse past whitespace and comments.
1955 */
1956 private int parsePastWhitespace(int ch) {
1957 while (ASCII.isSpace(ch) || ch == '#') {
1958 while (ASCII.isSpace(ch))
1959 ch = temp[cursor++];
1960 if (ch == '#')
1961 ch = parsePastLine();
1962 }
1963 return ch;
1964 }
1965
1966 /**
1967 * xmode parse past comment to end of line.
1968 */
1969 private int parsePastLine() {
1970 int ch = temp[cursor++];
1971 while (ch != 0 && !isLineSeparator(ch))
1972 ch = temp[cursor++];
1973 return ch;
1974 }
1975
1976 /**
1977 * xmode peek past comment to end of line.
1978 */
1979 private int peekPastLine() {
1980 int ch = temp[++cursor];
1981 while (ch != 0 && !isLineSeparator(ch))
1982 ch = temp[++cursor];
1983 return ch;
1984 }
1985
1986 /**
1987 * Determines if character is a line separator in the current mode
1988 */
1989 private boolean isLineSeparator(int ch) {
1990 if (has(UNIX_LINES)) {
1991 return ch == '\n';
1992 } else {
1993 return (ch == '\n' ||
1994 ch == '\r' ||
1995 (ch|1) == '\u2029' ||
1996 ch == '\u0085');
1997 }
1998 }
1999
2000 /**
2001 * Read the character after the next one, and advance the cursor by two.
2002 */
2003 private int skip() {
2004 int i = cursor;
2005 int ch = temp[i+1];
2006 cursor = i + 2;
2007 return ch;
2008 }
2009
2010 /**
2011 * Unread one next character, and retreat cursor by one.
2012 */
2013 private void unread() {
2014 cursor--;
2015 }
2016
2017 /**
2018 * Internal method used for handling all syntax errors. The pattern is
2019 * displayed with a pointer to aid in locating the syntax error.
2020 */
2021 private PatternSyntaxException error(String s) {
2022 return new PatternSyntaxException(s, normalizedPattern, cursor - 1);
2023 }
2024
2025 /**
2026 * Determines if there is any supplementary character or unpaired
2027 * surrogate in the specified range.
2028 */
2029 private boolean findSupplementary(int start, int end) {
2030 for (int i = start; i < end; i++) {
2031 if (isSupplementary(temp[i]))
2032 return true;
2033 }
2034 return false;
2035 }
2036
2037 /**
2038 * Determines if the specified code point is a supplementary
2039 * character or unpaired surrogate.
2040 */
2041 private static final boolean isSupplementary(int ch) {
2042 return ch >= Character.MIN_SUPPLEMENTARY_CODE_POINT ||
2043 Character.isSurrogate((char)ch);
2044 }
2045
2046 /**
2047 * The following methods handle the main parsing. They are sorted
2048 * according to their precedence order, the lowest one first.
2049 */
2050
2051 /**
2052 * The expression is parsed with branch nodes added for alternations.
2053 * This may be called recursively to parse sub expressions that may
2054 * contain alternations.
2055 */
2056 private Node expr(Node end) {
2057 Node prev = null;
2058 Node firstTail = null;
2059 Branch branch = null;
2060 Node branchConn = null;
2061
2062 for (;;) {
2063 Node node = sequence(end);
2064 Node nodeTail = root; //double return
2065 if (prev == null) {
2066 prev = node;
2067 firstTail = nodeTail;
2068 } else {
2069 // Branch
2070 if (branchConn == null) {
2071 branchConn = new BranchConn();
2072 branchConn.next = end;
2073 }
2074 if (node == end) {
2075 // if the node returned from sequence() is "end"
2076 // we have an empty expr, set a null atom into
2077 // the branch to indicate to go "next" directly.
2078 node = null;
2079 } else {
2080 // the "tail.next" of each atom goes to branchConn
2081 nodeTail.next = branchConn;
2082 }
2083 if (prev == branch) {
2084 branch.add(node);
2085 } else {
2086 if (prev == end) {
2087 prev = null;
2088 } else {
2089 // replace the "end" with "branchConn" at its tail.next
2090 // when put the "prev" into the branch as the first atom.
2091 firstTail.next = branchConn;
2092 }
2093 prev = branch = new Branch(prev, node, branchConn);
2094 }
2095 }
2096 if (peek() != '|') {
2097 return prev;
2098 }
2099 next();
2100 }
2101 }
2102
2103 @SuppressWarnings("fallthrough")
2104 /**
2105 * Parsing of sequences between alternations.
2106 */
2107 private Node sequence(Node end) {
2108 Node head = null;
2109 Node tail = null;
2110 Node node = null;
2111 LOOP:
2112 for (;;) {
2113 int ch = peek();
2114 switch (ch) {
2115 case '(':
2116 // Because group handles its own closure,
2117 // we need to treat it differently
2118 node = group0();
2119 // Check for comment or flag group
2120 if (node == null)
2121 continue;
2122 if (head == null)
2123 head = node;
2124 else
2125 tail.next = node;
2126 // Double return: Tail was returned in root
2127 tail = root;
2128 continue;
2129 case '[':
2130 if (has(CANON_EQ) && !has(LITERAL))
2131 node = new NFCCharProperty(clazz(true));
2132 else
2133 node = newCharProperty(clazz(true));
2134 break;
2135 case '\\':
2136 ch = nextEscaped();
2137 if (ch == 'p' || ch == 'P') {
2138 boolean oneLetter = true;
2139 boolean comp = (ch == 'P');
2140 ch = next(); // Consume { if present
2141 if (ch != '{') {
2142 unread();
2143 } else {
2144 oneLetter = false;
2145 }
2146 // node = newCharProperty(family(oneLetter, comp));
2147 if (has(CANON_EQ) && !has(LITERAL))
2148 node = new NFCCharProperty(family(oneLetter, comp));
2149 else
2150 node = newCharProperty(family(oneLetter, comp));
2151 } else {
2152 unread();
2153 node = atom();
2154 }
2155 break;
2156 case '^':
2157 next();
2158 if (has(MULTILINE)) {
2159 if (has(UNIX_LINES))
2160 node = new UnixCaret();
2161 else
2162 node = new Caret();
2163 } else {
2164 node = new Begin();
2165 }
2166 break;
2167 case '$':
2168 next();
2169 if (has(UNIX_LINES))
2170 node = new UnixDollar(has(MULTILINE));
2171 else
2172 node = new Dollar(has(MULTILINE));
2173 break;
2174 case '.':
2175 next();
2176 if (has(DOTALL)) {
2177 node = new CharProperty(ALL());
2178 } else {
2179 if (has(UNIX_LINES)) {
2180 node = new CharProperty(UNIXDOT());
2181 } else {
2182 node = new CharProperty(DOT());
2183 }
2184 }
2185 break;
2186 case '|':
2187 case ')':
2188 break LOOP;
2189 case ']': // Now interpreting dangling ] and } as literals
2190 case '}':
2191 node = atom();
2192 break;
2193 case '?':
2194 case '*':
2195 case '+':
2196 next();
2197 throw error("Dangling meta character '" + ((char)ch) + "'");
2198 case 0:
2199 if (cursor >= patternLength) {
2200 break LOOP;
2201 }
2202 // Fall through
2203 default:
2204 node = atom();
2205 break;
2206 }
2207
2208 node = closure(node);
2209 /* save the top dot-greedy nodes (.*, .+) as well
2210 if (node instanceof GreedyCharProperty &&
2211 ((GreedyCharProperty)node).cp instanceof Dot) {
2212 topClosureNodes.add(node);
2213 }
2214 */
2215 if (head == null) {
2216 head = tail = node;
2217 } else {
2218 tail.next = node;
2219 tail = node;
2220 }
2221 }
2222 if (head == null) {
2223 return end;
2224 }
2225 tail.next = end;
2226 root = tail; //double return
2227 return head;
2228 }
2229
2230 @SuppressWarnings("fallthrough")
2231 /**
2232 * Parse and add a new Single or Slice.
2233 */
2234 private Node atom() {
2235 int first = 0;
2236 int prev = -1;
2237 boolean hasSupplementary = false;
2238 int ch = peek();
2239 for (;;) {
2240 switch (ch) {
2241 case '*':
2242 case '+':
2243 case '?':
2244 case '{':
2245 if (first > 1) {
2246 cursor = prev; // Unwind one character
2247 first--;
2248 }
2249 break;
2250 case '$':
2251 case '.':
2252 case '^':
2253 case '(':
2254 case '[':
2255 case '|':
2256 case ')':
2257 break;
2258 case '\\':
2259 ch = nextEscaped();
2260 if (ch == 'p' || ch == 'P') { // Property
2261 if (first > 0) { // Slice is waiting; handle it first
2262 unread();
2263 break;
2264 } else { // No slice; just return the family node
2265 boolean comp = (ch == 'P');
2266 boolean oneLetter = true;
2267 ch = next(); // Consume { if present
2268 if (ch != '{')
2269 unread();
2270 else
2271 oneLetter = false;
2272 if (has(CANON_EQ) && !has(LITERAL))
2273 return new NFCCharProperty(family(oneLetter, comp));
2274 else
2275 return newCharProperty(family(oneLetter, comp));
2276 }
2277 }
2278 unread();
2279 prev = cursor;
2280 ch = escape(false, first == 0, false);
2281 if (ch >= 0) {
2282 append(ch, first);
2283 first++;
2284 if (isSupplementary(ch)) {
2285 hasSupplementary = true;
2286 }
2287 ch = peek();
2288 continue;
2289 } else if (first == 0) {
2290 return root;
2291 }
2292 // Unwind meta escape sequence
2293 cursor = prev;
2294 break;
2295 case 0:
2296 if (cursor >= patternLength) {
2297 break;
2298 }
2299 // Fall through
2300 default:
2301 prev = cursor;
2302 append(ch, first);
2303 first++;
2304 if (isSupplementary(ch)) {
2305 hasSupplementary = true;
2306 }
2307 ch = next();
2308 continue;
2309 }
2310 break;
2311 }
2312 if (first == 1) {
2313 return newCharProperty(single(buffer[0]));
2314 } else {
2315 return newSlice(buffer, first, hasSupplementary);
2316 }
2317 }
2318
2319 private void append(int ch, int index) {
2320 int len = buffer.length;
2321 if (index - len >= 0) {
2322 len = ArraysSupport.newLength(len,
2323 1 + index - len, /* minimum growth */
2324 len /* preferred growth */);
2325 buffer = Arrays.copyOf(buffer, len);
2326 }
2327 buffer[index] = ch;
2328 }
2329
2330 /**
2331 * Parses a backref greedily, taking as many numbers as it
2332 * can. The first digit is always treated as a backref, but
2333 * multi digit numbers are only treated as a backref if at
2334 * least that many backrefs exist at this point in the regex.
2335 */
2336 private Node ref(int refNum) {
2337 boolean done = false;
2338 while(!done) {
2339 int ch = peek();
2340 switch(ch) {
2341 case '0':
2342 case '1':
2343 case '2':
2344 case '3':
2345 case '4':
2346 case '5':
2347 case '6':
2348 case '7':
2349 case '8':
2350 case '9':
2351 int newRefNum = (refNum * 10) + (ch - '0');
2352 // Add another number if it doesn't make a group
2353 // that doesn't exist
2354 if (capturingGroupCount - 1 < newRefNum) {
2355 done = true;
2356 break;
2357 }
2358 refNum = newRefNum;
2359 read();
2360 break;
2361 default:
2362 done = true;
2363 break;
2364 }
2365 }
2366 hasGroupRef = true;
2367 if (has(CASE_INSENSITIVE))
2368 return new CIBackRef(refNum, has(UNICODE_CASE));
2369 else
2370 return new BackRef(refNum);
2371 }
2372
2373 /**
2374 * Parses an escape sequence to determine the actual value that needs
2375 * to be matched.
2376 * If -1 is returned and create was true a new object was added to the tree
2377 * to handle the escape sequence.
2378 * If the returned value is greater than zero, it is the value that
2379 * matches the escape sequence.
2380 */
2381 private int escape(boolean inclass, boolean create, boolean isrange) {
2382 int ch = skip();
2383 switch (ch) {
2384 case '0':
2385 return o();
2386 case '1':
2387 case '2':
2388 case '3':
2389 case '4':
2390 case '5':
2391 case '6':
2392 case '7':
2393 case '8':
2394 case '9':
2395 if (inclass) break;
2396 if (create) {
2397 root = ref((ch - '0'));
2398 }
2399 return -1;
2400 case 'A':
2401 if (inclass) break;
2402 if (create) root = new Begin();
2403 return -1;
2404 case 'B':
2405 if (inclass) break;
2406 if (create) root = new Bound(Bound.NONE, has(UNICODE_CHARACTER_CLASS));
2407 return -1;
2408 case 'C':
2409 break;
2410 case 'D':
2411 if (create) {
2412 predicate = has(UNICODE_CHARACTER_CLASS) ?
2413 CharPredicates.DIGIT() : CharPredicates.ASCII_DIGIT();
2414 predicate = predicate.negate();
2415 if (!inclass)
2416 root = newCharProperty(predicate);
2417 }
2418 return -1;
2419 case 'E':
2420 case 'F':
2421 break;
2422 case 'G':
2423 if (inclass) break;
2424 if (create) root = new LastMatch();
2425 return -1;
2426 case 'H':
2427 if (create) {
2428 predicate = HorizWS().negate();
2429 if (!inclass)
2430 root = newCharProperty(predicate);
2431 }
2432 return -1;
2433 case 'I':
2434 case 'J':
2435 case 'K':
2436 case 'L':
2437 case 'M':
2438 break;
2439 case 'N':
2440 return N();
2441 case 'O':
2442 case 'P':
2443 case 'Q':
2444 break;
2445 case 'R':
2446 if (inclass) break;
2447 if (create) root = new LineEnding();
2448 return -1;
2449 case 'S':
2450 if (create) {
2451 predicate = has(UNICODE_CHARACTER_CLASS) ?
2452 CharPredicates.WHITE_SPACE() : CharPredicates.ASCII_SPACE();
2453 predicate = predicate.negate();
2454 if (!inclass)
2455 root = newCharProperty(predicate);
2456 }
2457 return -1;
2458 case 'T':
2459 case 'U':
2460 break;
2461 case 'V':
2462 if (create) {
2463 predicate = VertWS().negate();
2464 if (!inclass)
2465 root = newCharProperty(predicate);
2466 }
2467 return -1;
2468 case 'W':
2469 if (create) {
2470 predicate = has(UNICODE_CHARACTER_CLASS) ?
2471 CharPredicates.WORD() : CharPredicates.ASCII_WORD();
2472 predicate = predicate.negate();
2473 if (!inclass)
2474 root = newCharProperty(predicate);
2475 }
2476 return -1;
2477 case 'X':
2478 if (inclass) break;
2479 if (create) {
2480 root = new XGrapheme();
2481 }
2482 return -1;
2483 case 'Y':
2484 break;
2485 case 'Z':
2486 if (inclass) break;
2487 if (create) {
2488 if (has(UNIX_LINES))
2489 root = new UnixDollar(false);
2490 else
2491 root = new Dollar(false);
2492 }
2493 return -1;
2494 case 'a':
2495 return '\007';
2496 case 'b':
2497 if (inclass) break;
2498 if (create) {
2499 if (peek() == '{') {
2500 if (skip() == 'g') {
2501 if (read() == '}') {
2502 root = new GraphemeBound();
2503 return -1;
2504 }
2505 break; // error missing trailing }
2506 }
2507 unread(); unread();
2508 }
2509 root = new Bound(Bound.BOTH, has(UNICODE_CHARACTER_CLASS));
2510 }
2511 return -1;
2512 case 'c':
2513 return c();
2514 case 'd':
2515 if (create) {
2516 predicate = has(UNICODE_CHARACTER_CLASS) ?
2517 CharPredicates.DIGIT() : CharPredicates.ASCII_DIGIT();
2518 if (!inclass)
2519 root = newCharProperty(predicate);
2520 }
2521 return -1;
2522 case 'e':
2523 return '\033';
2524 case 'f':
2525 return '\f';
2526 case 'g':
2527 break;
2528 case 'h':
2529 if (create) {
2530 predicate = HorizWS();
2531 if (!inclass)
2532 root = newCharProperty(predicate);
2533 }
2534 return -1;
2535 case 'i':
2536 case 'j':
2537 break;
2538 case 'k':
2539 if (inclass)
2540 break;
2541 if (read() != '<')
2542 throw error("\\k is not followed by '<' for named capturing group");
2543 String name = groupname(read());
2544 if (!namedGroups().containsKey(name))
2545 throw error("named capturing group <" + name + "> does not exist");
2546 if (create) {
2547 hasGroupRef = true;
2548 if (has(CASE_INSENSITIVE))
2549 root = new CIBackRef(namedGroups().get(name), has(UNICODE_CASE));
2550 else
2551 root = new BackRef(namedGroups().get(name));
2552 }
2553 return -1;
2554 case 'l':
2555 case 'm':
2556 break;
2557 case 'n':
2558 return '\n';
2559 case 'o':
2560 case 'p':
2561 case 'q':
2562 break;
2563 case 'r':
2564 return '\r';
2565 case 's':
2566 if (create) {
2567 predicate = has(UNICODE_CHARACTER_CLASS) ?
2568 CharPredicates.WHITE_SPACE() : CharPredicates.ASCII_SPACE();
2569 if (!inclass)
2570 root = newCharProperty(predicate);
2571 }
2572 return -1;
2573 case 't':
2574 return '\t';
2575 case 'u':
2576 return u();
2577 case 'v':
2578 // '\v' was implemented as VT/0x0B in releases < 1.8 (though
2579 // undocumented). In JDK8 '\v' is specified as a predefined
2580 // character class for all vertical whitespace characters.
2581 // So [-1, root=VertWS node] pair is returned (instead of a
2582 // single 0x0B). This breaks the range if '\v' is used as
2583 // the start or end value, such as [\v-...] or [...-\v], in
2584 // which a single definite value (0x0B) is expected. For
2585 // compatibility concern '\013'/0x0B is returned if isrange.
2586 if (isrange)
2587 return '\013';
2588 if (create) {
2589 predicate = VertWS();
2590 if (!inclass)
2591 root = newCharProperty(predicate);
2592 }
2593 return -1;
2594 case 'w':
2595 if (create) {
2596 predicate = has(UNICODE_CHARACTER_CLASS) ?
2597 CharPredicates.WORD() : CharPredicates.ASCII_WORD();
2598 if (!inclass)
2599 root = newCharProperty(predicate);
2600 }
2601 return -1;
2602 case 'x':
2603 return x();
2604 case 'y':
2605 break;
2606 case 'z':
2607 if (inclass) break;
2608 if (create) root = new End();
2609 return -1;
2610 default:
2611 return ch;
2612 }
2613 throw error("Illegal/unsupported escape sequence");
2614 }
2615
2616 /**
2617 * Parse a character class, and return the node that matches it.
2618 *
2619 * Consumes a ] on the way out if consume is true. Usually consume
2620 * is true except for the case of [abc&&def] where def is a separate
2621 * right hand node with "understood" brackets.
2622 */
2623 private CharPredicate clazz(boolean consume) {
2624 CharPredicate prev = null;
2625 CharPredicate curr = null;
2626 BitClass bits = new BitClass();
2627 BmpCharPredicate bitsP = ch -> ch < 256 && bits.bits[ch];
2628
2629 boolean isNeg = false;
2630 boolean hasBits = false;
2631 int ch = next();
2632
2633 // Negates if first char in a class, otherwise literal
2634 if (ch == '^' && temp[cursor-1] == '[') {
2635 ch = next();
2636 isNeg = true;
2637 }
2638 for (;;) {
2639 switch (ch) {
2640 case '[':
2641 curr = clazz(true);
2642 if (prev == null)
2643 prev = curr;
2644 else
2645 prev = prev.union(curr);
2646 ch = peek();
2647 continue;
2648 case '&':
2649 ch = next();
2650 if (ch == '&') {
2651 ch = next();
2652 CharPredicate right = null;
2653 while (ch != ']' && ch != '&') {
2654 if (ch == '[') {
2655 if (right == null)
2656 right = clazz(true);
2657 else
2658 right = right.union(clazz(true));
2659 } else { // abc&&def
2660 unread();
2661 right = clazz(false);
2662 }
2663 ch = peek();
2664 }
2665 if (hasBits) {
2666 // bits used, union has high precedence
2667 if (prev == null) {
2668 prev = curr = bitsP;
2669 } else {
2670 prev = prev.union(bitsP);
2671 }
2672 hasBits = false;
2673 }
2674 if (right != null)
2675 curr = right;
2676 if (prev == null) {
2677 if (right == null)
2678 throw error("Bad class syntax");
2679 else
2680 prev = right;
2681 } else {
2682 prev = prev.and(curr);
2683 }
2684 } else {
2685 // treat as a literal &
2686 unread();
2687 break;
2688 }
2689 continue;
2690 case 0:
2691 if (cursor >= patternLength)
2692 throw error("Unclosed character class");
2693 break;
2694 case ']':
2695 if (prev != null || hasBits) {
2696 if (consume)
2697 next();
2698 if (prev == null)
2699 prev = bitsP;
2700 else if (hasBits)
2701 prev = prev.union(bitsP);
2702 if (isNeg)
2703 return prev.negate();
2704 return prev;
2705 }
2706 break;
2707 default:
2708 break;
2709 }
2710 curr = range(bits);
2711 if (curr == null) { // the bits used
2712 hasBits = true;
2713 } else {
2714 if (prev == null)
2715 prev = curr;
2716 else if (prev != curr)
2717 prev = prev.union(curr);
2718 }
2719 ch = peek();
2720 }
2721 }
2722
2723 private CharPredicate bitsOrSingle(BitClass bits, int ch) {
2724 /* Bits can only handle codepoints in [u+0000-u+00ff] range.
2725 Use "single" node instead of bits when dealing with unicode
2726 case folding for codepoints listed below.
2727 (1)Uppercase out of range: u+00ff, u+00b5
2728 toUpperCase(u+00ff) -> u+0178
2729 toUpperCase(u+00b5) -> u+039c
2730 (2)LatinSmallLetterLongS u+17f
2731 toUpperCase(u+017f) -> u+0053
2732 (3)LatinSmallLetterDotlessI u+131
2733 toUpperCase(u+0131) -> u+0049
2734 (4)LatinCapitalLetterIWithDotAbove u+0130
2735 toLowerCase(u+0130) -> u+0069
2736 (5)KelvinSign u+212a
2737 toLowerCase(u+212a) ==> u+006B
2738 (6)AngstromSign u+212b
2739 toLowerCase(u+212b) ==> u+00e5
2740 */
2741 if (ch < 256 &&
2742 !(has(CASE_INSENSITIVE) && has(UNICODE_CASE) &&
2743 (ch == 0xff || ch == 0xb5 ||
2744 ch == 0x49 || ch == 0x69 || //I and i
2745 ch == 0x53 || ch == 0x73 || //S and s
2746 ch == 0x4b || ch == 0x6b || //K and k
2747 ch == 0xc5 || ch == 0xe5))) { //A+ring
2748 bits.add(ch, flags0);
2749 return null;
2750 }
2751 return single(ch);
2752 }
2753
2754 /**
2755 * Returns a suitably optimized, single character predicate
2756 */
2757 private CharPredicate single(final int ch) {
2758 if (has(CASE_INSENSITIVE)) {
2759 int lower, upper;
2760 if (has(UNICODE_CASE)) {
2761 upper = Character.toUpperCase(ch);
2762 lower = Character.toLowerCase(upper);
2763 // Unicode case insensitive matches
2764 if (upper != lower)
2765 return SingleU(lower);
2766 } else if (ASCII.isAscii(ch)) {
2767 lower = ASCII.toLower(ch);
2768 upper = ASCII.toUpper(ch);
2769 // Case insensitive matches a given BMP character
2770 if (lower != upper)
2771 return SingleI(lower, upper);
2772 }
2773 }
2774 if (isSupplementary(ch))
2775 return SingleS(ch);
2776 return Single(ch); // Match a given BMP character
2777 }
2778
2779 /**
2780 * Parse a single character or a character range in a character class
2781 * and return its representative node.
2782 */
2783 private CharPredicate range(BitClass bits) {
2784 int ch = peek();
2785 if (ch == '\\') {
2786 ch = nextEscaped();
2787 if (ch == 'p' || ch == 'P') { // A property
2788 boolean comp = (ch == 'P');
2789 boolean oneLetter = true;
2790 // Consume { if present
2791 ch = next();
2792 if (ch != '{')
2793 unread();
2794 else
2795 oneLetter = false;
2796 return family(oneLetter, comp);
2797 } else { // ordinary escape
2798 boolean isrange = temp[cursor+1] == '-';
2799 unread();
2800 ch = escape(true, true, isrange);
2801 if (ch == -1)
2802 return predicate;
2803 }
2804 } else {
2805 next();
2806 }
2807 if (ch >= 0) {
2808 if (peek() == '-') {
2809 int endRange = temp[cursor+1];
2810 if (endRange == '[') {
2811 return bitsOrSingle(bits, ch);
2812 }
2813 if (endRange != ']') {
2814 next();
2815 int m = peek();
2816 if (m == '\\') {
2817 m = escape(true, false, true);
2818 } else {
2819 next();
2820 }
2821 if (m < ch) {
2822 throw error("Illegal character range");
2823 }
2824 if (has(CASE_INSENSITIVE)) {
2825 if (has(UNICODE_CASE))
2826 return CIRangeU(ch, m);
2827 return CIRange(ch, m);
2828 } else {
2829 return Range(ch, m);
2830 }
2831 }
2832 }
2833 return bitsOrSingle(bits, ch);
2834 }
2835 throw error("Unexpected character '"+((char)ch)+"'");
2836 }
2837
2838 /**
2839 * Parses a Unicode character family and returns its representative node.
2840 */
2841 private CharPredicate family(boolean singleLetter, boolean isComplement) {
2842 next();
2843 String name;
2844 CharPredicate p = null;
2845
2846 if (singleLetter) {
2847 int c = temp[cursor];
2848 if (!Character.isSupplementaryCodePoint(c)) {
2849 name = String.valueOf((char)c);
2850 } else {
2851 name = new String(temp, cursor, 1);
2852 }
2853 read();
2854 } else {
2855 int i = cursor;
2856 mark('}');
2857 while(read() != '}') {
2858 }
2859 mark('\000');
2860 int j = cursor;
2861 if (j > patternLength)
2862 throw error("Unclosed character family");
2863 if (i + 1 >= j)
2864 throw error("Empty character family");
2865 name = new String(temp, i, j-i-1);
2866 }
2867
2868 int i = name.indexOf('=');
2869 if (i != -1) {
2870 // property construct \p{name=value}
2871 String value = name.substring(i + 1);
2872 name = name.substring(0, i).toLowerCase(Locale.ENGLISH);
2873 switch (name) {
2874 case "sc":
2875 case "script":
2876 p = CharPredicates.forUnicodeScript(value);
2877 break;
2878 case "blk":
2879 case "block":
2880 p = CharPredicates.forUnicodeBlock(value);
2881 break;
2882 case "gc":
2883 case "general_category":
2884 p = CharPredicates.forProperty(value);
2885 break;
2886 default:
2887 break;
2888 }
2889 if (p == null)
2890 throw error("Unknown Unicode property {name=<" + name + ">, "
2891 + "value=<" + value + ">}");
2892
2893 } else {
2894 if (name.startsWith("In")) {
2895 // \p{InBlockName}
2896 p = CharPredicates.forUnicodeBlock(name.substring(2));
2897 } else if (name.startsWith("Is")) {
2898 // \p{IsGeneralCategory} and \p{IsScriptName}
2899 name = name.substring(2);
2900 p = CharPredicates.forUnicodeProperty(name);
2901 if (p == null)
2902 p = CharPredicates.forProperty(name);
2903 if (p == null)
2904 p = CharPredicates.forUnicodeScript(name);
2905 } else {
2906 if (has(UNICODE_CHARACTER_CLASS)) {
2907 p = CharPredicates.forPOSIXName(name);
2908 }
2909 if (p == null)
2910 p = CharPredicates.forProperty(name);
2911 }
2912 if (p == null)
2913 throw error("Unknown character property name {In/Is" + name + "}");
2914 }
2915 if (isComplement) {
2916 // it might be too expensive to detect if a complement of
2917 // CharProperty can match "certain" supplementary. So just
2918 // go with StartS.
2919 hasSupplementary = true;
2920 p = p.negate();
2921 }
2922 return p;
2923 }
2924
2925 private CharProperty newCharProperty(CharPredicate p) {
2926 if (p == null)
2927 return null;
2928 if (p instanceof BmpCharPredicate)
2929 return new BmpCharProperty((BmpCharPredicate)p);
2930 else
2931 return new CharProperty(p);
2932 }
2933
2934 /**
2935 * Parses and returns the name of a "named capturing group", the trailing
2936 * ">" is consumed after parsing.
2937 */
2938 private String groupname(int ch) {
2939 StringBuilder sb = new StringBuilder();
2940 if (!ASCII.isAlpha(ch))
2941 throw error("capturing group name does not start with a Latin letter");
2942 do {
2943 sb.append((char) ch);
2944 } while (ASCII.isAlnum(ch=read()));
2945 if (ch != '>')
2946 throw error("named capturing group is missing trailing '>'");
2947 return sb.toString();
2948 }
2949
2950 /**
2951 * Parses a group and returns the head node of a set of nodes that process
2952 * the group. Sometimes a double return system is used where the tail is
2953 * returned in root.
2954 */
2955 private Node group0() {
2956 boolean capturingGroup = false;
2957 Node head = null;
2958 Node tail = null;
2959 int save = flags0;
2960 int saveTCNCount = topClosureNodes.size();
2961 root = null;
2962 int ch = next();
2963 if (ch == '?') {
2964 ch = skip();
2965 switch (ch) {
2966 case ':': // (?:xxx) pure group
2967 head = createGroup(true);
2968 tail = root;
2969 head.next = expr(tail);
2970 break;
2971 case '=': // (?=xxx) and (?!xxx) lookahead
2972 case '!':
2973 head = createGroup(true);
2974 tail = root;
2975 head.next = expr(tail);
2976 if (ch == '=') {
2977 head = tail = new Pos(head);
2978 } else {
2979 head = tail = new Neg(head);
2980 }
2981 break;
2982 case '>': // (?>xxx) independent group
2983 head = createGroup(true);
2984 tail = root;
2985 head.next = expr(tail);
2986 head = tail = new Ques(head, Qtype.INDEPENDENT);
2987 break;
2988 case '<': // (?<xxx) look behind
2989 ch = read();
2990 if (ch != '=' && ch != '!') {
2991 // named captured group
2992 String name = groupname(ch);
2993 if (namedGroups().containsKey(name))
2994 throw error("Named capturing group <" + name
2995 + "> is already defined");
2996 capturingGroup = true;
2997 head = createGroup(false);
2998 tail = root;
2999 namedGroups().put(name, capturingGroupCount-1);
3000 head.next = expr(tail);
3001 break;
3002 }
3003 int start = cursor;
3004 head = createGroup(true);
3005 tail = root;
3006 head.next = expr(tail);
3007 tail.next = lookbehindEnd;
3008 TreeInfo info = new TreeInfo();
3009 head.study(info);
3010 if (info.maxValid == false) {
3011 throw error("Look-behind group does not have "
3012 + "an obvious maximum length");
3013 }
3014 boolean hasSupplementary = findSupplementary(start, patternLength);
3015 if (ch == '=') {
3016 head = tail = (hasSupplementary ?
3017 new BehindS(head, info.maxLength,
3018 info.minLength) :
3019 new Behind(head, info.maxLength,
3020 info.minLength));
3021 } else { // if (ch == '!')
3022 head = tail = (hasSupplementary ?
3023 new NotBehindS(head, info.maxLength,
3024 info.minLength) :
3025 new NotBehind(head, info.maxLength,
3026 info.minLength));
3027 }
3028 // clear all top-closure-nodes inside lookbehind
3029 if (saveTCNCount < topClosureNodes.size())
3030 topClosureNodes.subList(saveTCNCount, topClosureNodes.size()).clear();
3031 break;
3032 case '$':
3033 case '@':
3034 throw error("Unknown group type");
3035 default: // (?xxx:) inlined match flags
3036 unread();
3037 addFlag();
3038 ch = read();
3039 if (ch == ')') {
3040 return null; // Inline modifier only
3041 }
3042 if (ch != ':') {
3043 throw error("Unknown inline modifier");
3044 }
3045 head = createGroup(true);
3046 tail = root;
3047 head.next = expr(tail);
3048 break;
3049 }
3050 } else { // (xxx) a regular group
3051 capturingGroup = true;
3052 head = createGroup(false);
3053 tail = root;
3054 head.next = expr(tail);
3055 }
3056
3057 accept(')', "Unclosed group");
3058 flags0 = save;
3059
3060 // Check for quantifiers
3061 Node node = closure(head);
3062 if (node == head) { // No closure
3063 root = tail;
3064 return node; // Dual return
3065 }
3066 if (head == tail) { // Zero length assertion
3067 root = node;
3068 return node; // Dual return
3069 }
3070
3071 // have group closure, clear all inner closure nodes from the
3072 // top list (no backtracking stopper optimization for inner
3073 if (saveTCNCount < topClosureNodes.size())
3074 topClosureNodes.subList(saveTCNCount, topClosureNodes.size()).clear();
3075
3076 if (node instanceof Ques) {
3077 Ques ques = (Ques) node;
3078 if (ques.type == Qtype.POSSESSIVE) {
3079 root = node;
3080 return node;
3081 }
3082 tail.next = new BranchConn();
3083 tail = tail.next;
3084 if (ques.type == Qtype.GREEDY) {
3085 head = new Branch(head, null, tail);
3086 } else { // Reluctant quantifier
3087 head = new Branch(null, head, tail);
3088 }
3089 root = tail;
3090 return head;
3091 } else if (node instanceof Curly) {
3092 Curly curly = (Curly) node;
3093 if (curly.type == Qtype.POSSESSIVE) {
3094 root = node;
3095 return node;
3096 }
3097 // Discover if the group is deterministic
3098 TreeInfo info = new TreeInfo();
3099 if (head.study(info)) { // Deterministic
3100 GroupTail temp = (GroupTail) tail;
3101 head = root = new GroupCurly(head.next, curly.cmin,
3102 curly.cmax, curly.type,
3103 ((GroupTail)tail).localIndex,
3104 ((GroupTail)tail).groupIndex,
3105 capturingGroup);
3106 return head;
3107 } else { // Non-deterministic
3108 int temp = ((GroupHead) head).localIndex;
3109 Loop loop;
3110 if (curly.type == Qtype.GREEDY) {
3111 loop = new Loop(this.localCount, temp);
3112 // add the max_reps greedy to the top-closure-node list
3113 if (curly.cmax == MAX_REPS)
3114 topClosureNodes.add(loop);
3115 } else { // Reluctant Curly
3116 loop = new LazyLoop(this.localCount, temp);
3117 }
3118 Prolog prolog = new Prolog(loop);
3119 this.localCount += 1;
3120 loop.cmin = curly.cmin;
3121 loop.cmax = curly.cmax;
3122 loop.body = head;
3123 tail.next = loop;
3124 root = loop;
3125 return prolog; // Dual return
3126 }
3127 }
3128 throw error("Internal logic error");
3129 }
3130
3131 /**
3132 * Create group head and tail nodes using double return. If the group is
3133 * created with anonymous true then it is a pure group and should not
3134 * affect group counting.
3135 */
3136 private Node createGroup(boolean anonymous) {
3137 int localIndex = localCount++;
3138 int groupIndex = 0;
3139 if (!anonymous)
3140 groupIndex = capturingGroupCount++;
3141 GroupHead head = new GroupHead(localIndex);
3142 root = new GroupTail(localIndex, groupIndex);
3143
3144 // for debug/print only, head.match does NOT need the "tail" info
3145 head.tail = (GroupTail)root;
3146
3147 if (!anonymous && groupIndex < 10)
3148 groupNodes[groupIndex] = head;
3149 return head;
3150 }
3151
3152 @SuppressWarnings("fallthrough")
3153 /**
3154 * Parses inlined match flags and set them appropriately.
3155 */
3156 private void addFlag() {
3157 int ch = peek();
3158 for (;;) {
3159 switch (ch) {
3160 case 'i':
3161 flags0 |= CASE_INSENSITIVE;
3162 break;
3163 case 'm':
3164 flags0 |= MULTILINE;
3165 break;
3166 case 's':
3167 flags0 |= DOTALL;
3168 break;
3169 case 'd':
3170 flags0 |= UNIX_LINES;
3171 break;
3172 case 'u':
3173 flags0 |= UNICODE_CASE;
3174 break;
3175 case 'c':
3176 flags0 |= CANON_EQ;
3177 break;
3178 case 'x':
3179 flags0 |= COMMENTS;
3180 break;
3181 case 'U':
3182 flags0 |= (UNICODE_CHARACTER_CLASS | UNICODE_CASE);
3183 break;
3184 case '-': // subFlag then fall through
3185 ch = next();
3186 subFlag();
3187 default:
3188 return;
3189 }
3190 ch = next();
3191 }
3192 }
3193
3194 @SuppressWarnings("fallthrough")
3195 /**
3196 * Parses the second part of inlined match flags and turns off
3197 * flags appropriately.
3198 */
3199 private void subFlag() {
3200 int ch = peek();
3201 for (;;) {
3202 switch (ch) {
3203 case 'i':
3204 flags0 &= ~CASE_INSENSITIVE;
3205 break;
3206 case 'm':
3207 flags0 &= ~MULTILINE;
3208 break;
3209 case 's':
3210 flags0 &= ~DOTALL;
3211 break;
3212 case 'd':
3213 flags0 &= ~UNIX_LINES;
3214 break;
3215 case 'u':
3216 flags0 &= ~UNICODE_CASE;
3217 break;
3218 case 'c':
3219 flags0 &= ~CANON_EQ;
3220 break;
3221 case 'x':
3222 flags0 &= ~COMMENTS;
3223 break;
3224 case 'U':
3225 flags0 &= ~(UNICODE_CHARACTER_CLASS | UNICODE_CASE);
3226 break;
3227 default:
3228 return;
3229 }
3230 ch = next();
3231 }
3232 }
3233
3234 static final int MAX_REPS = 0x7FFFFFFF;
3235
3236 static enum Qtype {
3237 GREEDY, LAZY, POSSESSIVE, INDEPENDENT
3238 }
3239
3240 private Node curly(Node prev, int cmin) {
3241 int ch = next();
3242 if (ch == '?') {
3243 next();
3244 return new Curly(prev, cmin, MAX_REPS, Qtype.LAZY);
3245 } else if (ch == '+') {
3246 next();
3247 return new Curly(prev, cmin, MAX_REPS, Qtype.POSSESSIVE);
3248 }
3249 if (prev instanceof BmpCharProperty) {
3250 return new BmpCharPropertyGreedy((BmpCharProperty)prev, cmin);
3251 } else if (prev instanceof CharProperty) {
3252 return new CharPropertyGreedy((CharProperty)prev, cmin);
3253 }
3254 return new Curly(prev, cmin, MAX_REPS, Qtype.GREEDY);
3255 }
3256
3257 /**
3258 * Processes repetition. If the next character peeked is a quantifier
3259 * then new nodes must be appended to handle the repetition.
3260 * Prev could be a single or a group, so it could be a chain of nodes.
3261 */
3262 private Node closure(Node prev) {
3263 Node atom;
3264 int ch = peek();
3265 switch (ch) {
3266 case '?':
3267 ch = next();
3268 if (ch == '?') {
3269 next();
3270 return new Ques(prev, Qtype.LAZY);
3271 } else if (ch == '+') {
3272 next();
3273 return new Ques(prev, Qtype.POSSESSIVE);
3274 }
3275 return new Ques(prev, Qtype.GREEDY);
3276 case '*':
3277 return curly(prev, 0);
3278 case '+':
3279 return curly(prev, 1);
3280 case '{':
3281 ch = temp[cursor+1];
3282 if (ASCII.isDigit(ch)) {
3283 skip();
3284 int cmin = 0;
3285 do {
3286 cmin = cmin * 10 + (ch - '0');
3287 } while (ASCII.isDigit(ch = read()));
3288 int cmax = cmin;
3289 if (ch == ',') {
3290 ch = read();
3291 cmax = MAX_REPS;
3292 if (ch != '}') {
3293 cmax = 0;
3294 while (ASCII.isDigit(ch)) {
3295 cmax = cmax * 10 + (ch - '0');
3296 ch = read();
3297 }
3298 }
3299 }
3300 if (ch != '}')
3301 throw error("Unclosed counted closure");
3302 if (((cmin) | (cmax) | (cmax - cmin)) < 0)
3303 throw error("Illegal repetition range");
3304 Curly curly;
3305 ch = peek();
3306 if (ch == '?') {
3307 next();
3308 curly = new Curly(prev, cmin, cmax, Qtype.LAZY);
3309 } else if (ch == '+') {
3310 next();
3311 curly = new Curly(prev, cmin, cmax, Qtype.POSSESSIVE);
3312 } else {
3313 curly = new Curly(prev, cmin, cmax, Qtype.GREEDY);
3314 }
3315 return curly;
3316 } else {
3317 throw error("Illegal repetition");
3318 }
3319 default:
3320 return prev;
3321 }
3322 }
3323
3324 /**
3325 * Utility method for parsing control escape sequences.
3326 */
3327 private int c() {
3328 if (cursor < patternLength) {
3329 return read() ^ 64;
3330 }
3331 throw error("Illegal control escape sequence");
3332 }
3333
3334 /**
3335 * Utility method for parsing octal escape sequences.
3336 */
3337 private int o() {
3338 int n = read();
3339 if (((n-'0')|('7'-n)) >= 0) {
3340 int m = read();
3341 if (((m-'0')|('7'-m)) >= 0) {
3342 int o = read();
3343 if ((((o-'0')|('7'-o)) >= 0) && (((n-'0')|('3'-n)) >= 0)) {
3344 return (n - '0') * 64 + (m - '0') * 8 + (o - '0');
3345 }
3346 unread();
3347 return (n - '0') * 8 + (m - '0');
3348 }
3349 unread();
3350 return (n - '0');
3351 }
3352 throw error("Illegal octal escape sequence");
3353 }
3354
3355 /**
3356 * Utility method for parsing hexadecimal escape sequences.
3357 */
3358 private int x() {
3359 int n = read();
3360 if (ASCII.isHexDigit(n)) {
3361 int m = read();
3362 if (ASCII.isHexDigit(m)) {
3363 return ASCII.toDigit(n) * 16 + ASCII.toDigit(m);
3364 }
3365 } else if (n == '{' && ASCII.isHexDigit(peek())) {
3366 int ch = 0;
3367 while (ASCII.isHexDigit(n = read())) {
3368 ch = (ch << 4) + ASCII.toDigit(n);
3369 if (ch > Character.MAX_CODE_POINT)
3370 throw error("Hexadecimal codepoint is too big");
3371 }
3372 if (n != '}')
3373 throw error("Unclosed hexadecimal escape sequence");
3374 return ch;
3375 }
3376 throw error("Illegal hexadecimal escape sequence");
3377 }
3378
3379 /**
3380 * Utility method for parsing unicode escape sequences.
3381 */
3382 private int cursor() {
3383 return cursor;
3384 }
3385
3386 private void setcursor(int pos) {
3387 cursor = pos;
3388 }
3389
3390 private int uxxxx() {
3391 int n = 0;
3392 for (int i = 0; i < 4; i++) {
3393 int ch = read();
3394 if (!ASCII.isHexDigit(ch)) {
3395 throw error("Illegal Unicode escape sequence");
3396 }
3397 n = n * 16 + ASCII.toDigit(ch);
3398 }
3399 return n;
3400 }
3401
3402 private int u() {
3403 int n = uxxxx();
3404 if (Character.isHighSurrogate((char)n)) {
3405 int cur = cursor();
3406 if (read() == '\\' && read() == 'u') {
3407 int n2 = uxxxx();
3408 if (Character.isLowSurrogate((char)n2))
3409 return Character.toCodePoint((char)n, (char)n2);
3410 }
3411 setcursor(cur);
3412 }
3413 return n;
3414 }
3415
3416 private int N() {
3417 if (read() == '{') {
3418 int i = cursor;
3419 while (cursor < patternLength && read() != '}') {}
3420 if (cursor > patternLength)
3421 throw error("Unclosed character name escape sequence");
3422 String name = new String(temp, i, cursor - i - 1);
3423 try {
3424 return Character.codePointOf(name);
3425 } catch (IllegalArgumentException x) {
3426 throw error("Unknown character name [" + name + "]");
3427 }
3428 }
3429 throw error("Illegal character name escape sequence");
3430 }
3431
3432 //
3433 // Utility methods for code point support
3434 //
3435 private static final int countChars(CharSequence seq, int index,
3436 int lengthInCodePoints) {
3437 // optimization
3438 if (lengthInCodePoints == 1 && !Character.isHighSurrogate(seq.charAt(index))) {
3439 assert (index >= 0 && index < seq.length());
3440 return 1;
3441 }
3442 int length = seq.length();
3443 int x = index;
3444 if (lengthInCodePoints >= 0) {
3445 assert (index >= 0 && index < length);
3446 for (int i = 0; x < length && i < lengthInCodePoints; i++) {
3447 if (Character.isHighSurrogate(seq.charAt(x++))) {
3448 if (x < length && Character.isLowSurrogate(seq.charAt(x))) {
3449 x++;
3450 }
3451 }
3452 }
3453 return x - index;
3454 }
3455
3456 assert (index >= 0 && index <= length);
3457 if (index == 0) {
3458 return 0;
3459 }
3460 int len = -lengthInCodePoints;
3461 for (int i = 0; x > 0 && i < len; i++) {
3462 if (Character.isLowSurrogate(seq.charAt(--x))) {
3463 if (x > 0 && Character.isHighSurrogate(seq.charAt(x-1))) {
3464 x--;
3465 }
3466 }
3467 }
3468 return index - x;
3469 }
3470
3471 private static final int countCodePoints(CharSequence seq) {
3472 int length = seq.length();
3473 int n = 0;
3474 for (int i = 0; i < length; ) {
3475 n++;
3476 if (Character.isHighSurrogate(seq.charAt(i++))) {
3477 if (i < length && Character.isLowSurrogate(seq.charAt(i))) {
3478 i++;
3479 }
3480 }
3481 }
3482 return n;
3483 }
3484
3485 /**
3486 * Creates a bit vector for matching Latin-1 values. A normal BitClass
3487 * never matches values above Latin-1, and a complemented BitClass always
3488 * matches values above Latin-1.
3489 */
3490 static final class BitClass extends BmpCharProperty {
3491 final boolean[] bits;
3492 BitClass() {
3493 this(new boolean[256]);
3494 }
3495 private BitClass(boolean[] bits) {
3496 super( ch -> ch < 256 && bits[ch]);
3497 this.bits = bits;
3498 }
3499 BitClass add(int c, int flags) {
3500 assert c >= 0 && c <= 255;
3501 if ((flags & CASE_INSENSITIVE) != 0) {
3502 if (ASCII.isAscii(c)) {
3503 bits[ASCII.toUpper(c)] = true;
3504 bits[ASCII.toLower(c)] = true;
3505 } else if ((flags & UNICODE_CASE) != 0) {
3506 bits[Character.toLowerCase(c)] = true;
3507 bits[Character.toUpperCase(c)] = true;
3508 }
3509 }
3510 bits[c] = true;
3511 return this;
3512 }
3513 }
3514
3515 /**
3516 * Utility method for creating a string slice matcher.
3517 */
3518 private Node newSlice(int[] buf, int count, boolean hasSupplementary) {
3519 int[] tmp = new int[count];
3520 if (has(CASE_INSENSITIVE)) {
3521 if (has(UNICODE_CASE)) {
3522 for (int i = 0; i < count; i++) {
3523 tmp[i] = Character.toLowerCase(
3524 Character.toUpperCase(buf[i]));
3525 }
3526 return hasSupplementary? new SliceUS(tmp) : new SliceU(tmp);
3527 }
3528 for (int i = 0; i < count; i++) {
3529 tmp[i] = ASCII.toLower(buf[i]);
3530 }
3531 return hasSupplementary? new SliceIS(tmp) : new SliceI(tmp);
3532 }
3533 for (int i = 0; i < count; i++) {
3534 tmp[i] = buf[i];
3535 }
3536 return hasSupplementary ? new SliceS(tmp) : new Slice(tmp);
3537 }
3538
3539 /**
3540 * The following classes are the building components of the object
3541 * tree that represents a compiled regular expression. The object tree
3542 * is made of individual elements that handle constructs in the Pattern.
3543 * Each type of object knows how to match its equivalent construct with
3544 * the match() method.
3545 */
3546
3547 /**
3548 * Base class for all node classes. Subclasses should override the match()
3549 * method as appropriate. This class is an accepting node, so its match()
3550 * always returns true.
3551 */
3552 static class Node extends Object {
3553 Node next;
3554 Node() {
3555 next = Pattern.accept;
3556 }
3557 /**
3558 * This method implements the classic accept node.
3559 */
3560 boolean match(Matcher matcher, int i, CharSequence seq) {
3561 matcher.last = i;
3562 matcher.groups[0] = matcher.first;
3563 matcher.groups[1] = matcher.last;
3564 return true;
3565 }
3566 /**
3567 * This method is good for all zero length assertions.
3568 */
3569 boolean study(TreeInfo info) {
3570 if (next != null) {
3571 return next.study(info);
3572 } else {
3573 return info.deterministic;
3574 }
3575 }
3576 }
3577
3578 static class LastNode extends Node {
3579 /**
3580 * This method implements the classic accept node with
3581 * the addition of a check to see if the match occurred
3582 * using all of the input.
3583 */
3584 boolean match(Matcher matcher, int i, CharSequence seq) {
3585 if (matcher.acceptMode == Matcher.ENDANCHOR && i != matcher.to)
3586 return false;
3587 matcher.last = i;
3588 matcher.groups[0] = matcher.first;
3589 matcher.groups[1] = matcher.last;
3590 return true;
3591 }
3592 }
3593
3594 /**
3595 * Used for REs that can start anywhere within the input string.
3596 * This basically tries to match repeatedly at each spot in the
3597 * input string, moving forward after each try. An anchored search
3598 * or a BnM will bypass this node completely.
3599 */
3600 static class Start extends Node {
3601 int minLength;
3602 Start(Node node) {
3603 this.next = node;
3604 TreeInfo info = new TreeInfo();
3605 next.study(info);
3606 minLength = info.minLength;
3607 }
3608 boolean match(Matcher matcher, int i, CharSequence seq) {
3609 if (i > matcher.to - minLength) {
3610 matcher.hitEnd = true;
3611 return false;
3612 }
3613 int guard = matcher.to - minLength;
3614 for (; i <= guard; i++) {
3615 if (next.match(matcher, i, seq)) {
3616 matcher.first = i;
3617 matcher.groups[0] = matcher.first;
3618 matcher.groups[1] = matcher.last;
3619 return true;
3620 }
3621 }
3622 matcher.hitEnd = true;
3623 return false;
3624 }
3625 boolean study(TreeInfo info) {
3626 next.study(info);
3627 info.maxValid = false;
3628 info.deterministic = false;
3629 return false;
3630 }
3631 }
3632
3633 /*
3634 * StartS supports supplementary characters, including unpaired surrogates.
3635 */
3636 static final class StartS extends Start {
3637 StartS(Node node) {
3638 super(node);
3639 }
3640 boolean match(Matcher matcher, int i, CharSequence seq) {
3641 if (i > matcher.to - minLength) {
3642 matcher.hitEnd = true;
3643 return false;
3644 }
3645 int guard = matcher.to - minLength;
3646 while (i <= guard) {
3647 //if ((ret = next.match(matcher, i, seq)) || i == guard)
3648 if (next.match(matcher, i, seq)) {
3649 matcher.first = i;
3650 matcher.groups[0] = matcher.first;
3651 matcher.groups[1] = matcher.last;
3652 return true;
3653 }
3654 if (i == guard)
3655 break;
3656 // Optimization to move to the next character. This is
3657 // faster than countChars(seq, i, 1).
3658 if (Character.isHighSurrogate(seq.charAt(i++))) {
3659 if (i < seq.length() &&
3660 Character.isLowSurrogate(seq.charAt(i))) {
3661 i++;
3662 }
3663 }
3664 }
3665 matcher.hitEnd = true;
3666 return false;
3667 }
3668 }
3669
3670 /**
3671 * Node to anchor at the beginning of input. This object implements the
3672 * match for a \A sequence, and the caret anchor will use this if not in
3673 * multiline mode.
3674 */
3675 static final class Begin extends Node {
3676 boolean match(Matcher matcher, int i, CharSequence seq) {
3677 int fromIndex = (matcher.anchoringBounds) ?
3678 matcher.from : 0;
3679 if (i == fromIndex && next.match(matcher, i, seq)) {
3680 matcher.first = i;
3681 matcher.groups[0] = i;
3682 matcher.groups[1] = matcher.last;
3683 return true;
3684 } else {
3685 return false;
3686 }
3687 }
3688 }
3689
3690 /**
3691 * Node to anchor at the end of input. This is the absolute end, so this
3692 * should not match at the last newline before the end as $ will.
3693 */
3694 static final class End extends Node {
3695 boolean match(Matcher matcher, int i, CharSequence seq) {
3696 int endIndex = (matcher.anchoringBounds) ?
3697 matcher.to : matcher.getTextLength();
3698 if (i == endIndex) {
3699 matcher.hitEnd = true;
3700 return next.match(matcher, i, seq);
3701 }
3702 return false;
3703 }
3704 }
3705
3706 /**
3707 * Node to anchor at the beginning of a line. This is essentially the
3708 * object to match for the multiline ^.
3709 */
3710 static final class Caret extends Node {
3711 boolean match(Matcher matcher, int i, CharSequence seq) {
3712 int startIndex = matcher.from;
3713 int endIndex = matcher.to;
3714 if (!matcher.anchoringBounds) {
3715 startIndex = 0;
3716 endIndex = matcher.getTextLength();
3717 }
3718 // Perl does not match ^ at end of input even after newline
3719 if (i == endIndex) {
3720 matcher.hitEnd = true;
3721 return false;
3722 }
3723 if (i > startIndex) {
3724 char ch = seq.charAt(i-1);
3725 if (ch != '\n' && ch != '\r'
3726 && (ch|1) != '\u2029'
3727 && ch != '\u0085' ) {
3728 return false;
3729 }
3730 // Should treat /r/n as one newline
3731 if (ch == '\r' && seq.charAt(i) == '\n')
3732 return false;
3733 }
3734 return next.match(matcher, i, seq);
3735 }
3736 }
3737
3738 /**
3739 * Node to anchor at the beginning of a line when in unixdot mode.
3740 */
3741 static final class UnixCaret extends Node {
3742 boolean match(Matcher matcher, int i, CharSequence seq) {
3743 int startIndex = matcher.from;
3744 int endIndex = matcher.to;
3745 if (!matcher.anchoringBounds) {
3746 startIndex = 0;
3747 endIndex = matcher.getTextLength();
3748 }
3749 // Perl does not match ^ at end of input even after newline
3750 if (i == endIndex) {
3751 matcher.hitEnd = true;
3752 return false;
3753 }
3754 if (i > startIndex) {
3755 char ch = seq.charAt(i-1);
3756 if (ch != '\n') {
3757 return false;
3758 }
3759 }
3760 return next.match(matcher, i, seq);
3761 }
3762 }
3763
3764 /**
3765 * Node to match the location where the last match ended.
3766 * This is used for the \G construct.
3767 */
3768 static final class LastMatch extends Node {
3769 boolean match(Matcher matcher, int i, CharSequence seq) {
3770 if (i != matcher.oldLast)
3771 return false;
3772 return next.match(matcher, i, seq);
3773 }
3774 }
3775
3776 /**
3777 * Node to anchor at the end of a line or the end of input based on the
3778 * multiline mode.
3779 *
3780 * When not in multiline mode, the $ can only match at the very end
3781 * of the input, unless the input ends in a line terminator in which
3782 * it matches right before the last line terminator.
3783 *
3784 * Note that \r\n is considered an atomic line terminator.
3785 *
3786 * Like ^ the $ operator matches at a position, it does not match the
3787 * line terminators themselves.
3788 */
3789 static final class Dollar extends Node {
3790 boolean multiline;
3791 Dollar(boolean mul) {
3792 multiline = mul;
3793 }
3794 boolean match(Matcher matcher, int i, CharSequence seq) {
3795 int endIndex = (matcher.anchoringBounds) ?
3796 matcher.to : matcher.getTextLength();
3797 if (!multiline) {
3798 if (i < endIndex - 2)
3799 return false;
3800 if (i == endIndex - 2) {
3801 char ch = seq.charAt(i);
3802 if (ch != '\r')
3803 return false;
3804 ch = seq.charAt(i + 1);
3805 if (ch != '\n')
3806 return false;
3807 }
3808 }
3809 // Matches before any line terminator; also matches at the
3810 // end of input
3811 // Before line terminator:
3812 // If multiline, we match here no matter what
3813 // If not multiline, fall through so that the end
3814 // is marked as hit; this must be a /r/n or a /n
3815 // at the very end so the end was hit; more input
3816 // could make this not match here
3817 if (i < endIndex) {
3818 char ch = seq.charAt(i);
3819 if (ch == '\n') {
3820 // No match between \r\n
3821 if (i > 0 && seq.charAt(i-1) == '\r')
3822 return false;
3823 if (multiline)
3824 return next.match(matcher, i, seq);
3825 } else if (ch == '\r' || ch == '\u0085' ||
3826 (ch|1) == '\u2029') {
3827 if (multiline)
3828 return next.match(matcher, i, seq);
3829 } else { // No line terminator, no match
3830 return false;
3831 }
3832 }
3833 // Matched at current end so hit end
3834 matcher.hitEnd = true;
3835 // If a $ matches because of end of input, then more input
3836 // could cause it to fail!
3837 matcher.requireEnd = true;
3838 return next.match(matcher, i, seq);
3839 }
3840 boolean study(TreeInfo info) {
3841 next.study(info);
3842 return info.deterministic;
3843 }
3844 }
3845
3846 /**
3847 * Node to anchor at the end of a line or the end of input based on the
3848 * multiline mode when in unix lines mode.
3849 */
3850 static final class UnixDollar extends Node {
3851 boolean multiline;
3852 UnixDollar(boolean mul) {
3853 multiline = mul;
3854 }
3855 boolean match(Matcher matcher, int i, CharSequence seq) {
3856 int endIndex = (matcher.anchoringBounds) ?
3857 matcher.to : matcher.getTextLength();
3858 if (i < endIndex) {
3859 char ch = seq.charAt(i);
3860 if (ch == '\n') {
3861 // If not multiline, then only possible to
3862 // match at very end or one before end
3863 if (multiline == false && i != endIndex - 1)
3864 return false;
3865 // If multiline return next.match without setting
3866 // matcher.hitEnd
3867 if (multiline)
3868 return next.match(matcher, i, seq);
3869 } else {
3870 return false;
3871 }
3872 }
3873 // Matching because at the end or 1 before the end;
3874 // more input could change this so set hitEnd
3875 matcher.hitEnd = true;
3876 // If a $ matches because of end of input, then more input
3877 // could cause it to fail!
3878 matcher.requireEnd = true;
3879 return next.match(matcher, i, seq);
3880 }
3881 boolean study(TreeInfo info) {
3882 next.study(info);
3883 return info.deterministic;
3884 }
3885 }
3886
3887 /**
3888 * Node class that matches a Unicode line ending '\R'
3889 */
3890 static final class LineEnding extends Node {
3891 boolean match(Matcher matcher, int i, CharSequence seq) {
3892 // (u+000Du+000A|[u+000Au+000Bu+000Cu+000Du+0085u+2028u+2029])
3893 if (i < matcher.to) {
3894 int ch = seq.charAt(i);
3895 if (ch == 0x0A || ch == 0x0B || ch == 0x0C ||
3896 ch == 0x85 || ch == 0x2028 || ch == 0x2029)
3897 return next.match(matcher, i + 1, seq);
3898 if (ch == 0x0D) {
3899 i++;
3900 if (i < matcher.to) {
3901 if (seq.charAt(i) == 0x0A &&
3902 next.match(matcher, i + 1, seq)) {
3903 return true;
3904 }
3905 } else {
3906 matcher.hitEnd = true;
3907 }
3908 return next.match(matcher, i, seq);
3909 }
3910 } else {
3911 matcher.hitEnd = true;
3912 }
3913 return false;
3914 }
3915 boolean study(TreeInfo info) {
3916 info.minLength++;
3917 info.maxLength += 2;
3918 return next.study(info);
3919 }
3920 }
3921
3922 /**
3923 * Abstract node class to match one character satisfying some
3924 * boolean property.
3925 */
3926 static class CharProperty extends Node {
3927 CharPredicate predicate;
3928
3929 CharProperty (CharPredicate predicate) {
3930 this.predicate = predicate;
3931 }
3932 boolean match(Matcher matcher, int i, CharSequence seq) {
3933 if (i < matcher.to) {
3934 int ch = Character.codePointAt(seq, i);
3935 return predicate.is(ch) &&
3936 next.match(matcher, i + Character.charCount(ch), seq);
3937 } else {
3938 matcher.hitEnd = true;
3939 return false;
3940 }
3941 }
3942 boolean study(TreeInfo info) {
3943 info.minLength++;
3944 info.maxLength++;
3945 return next.study(info);
3946 }
3947 }
3948
3949 /**
3950 * Optimized version of CharProperty that works only for
3951 * properties never satisfied by Supplementary characters.
3952 */
3953 private static class BmpCharProperty extends CharProperty {
3954 BmpCharProperty (BmpCharPredicate predicate) {
3955 super(predicate);
3956 }
3957 boolean match(Matcher matcher, int i, CharSequence seq) {
3958 if (i < matcher.to) {
3959 return predicate.is(seq.charAt(i)) &&
3960 next.match(matcher, i + 1, seq);
3961 } else {
3962 matcher.hitEnd = true;
3963 return false;
3964 }
3965 }
3966 }
3967
3968 private static class NFCCharProperty extends Node {
3969 CharPredicate predicate;
3970 NFCCharProperty (CharPredicate predicate) {
3971 this.predicate = predicate;
3972 }
3973
3974 boolean match(Matcher matcher, int i, CharSequence seq) {
3975 if (i < matcher.to) {
3976 int ch0 = Character.codePointAt(seq, i);
3977 int n = Character.charCount(ch0);
3978 int j = i + n;
3979 while (j < matcher.to) {
3980 int ch1 = Character.codePointAt(seq, j);
3981 if (Grapheme.isBoundary(ch0, ch1))
3982 break;
3983 ch0 = ch1;
3984 j += Character.charCount(ch1);
3985 }
3986 if (i + n == j) { // single, assume nfc cp
3987 if (predicate.is(ch0))
3988 return next.match(matcher, j, seq);
3989 } else {
3990 while (i + n < j) {
3991 String nfc = Normalizer.normalize(
3992 seq.toString().substring(i, j), Normalizer.Form.NFC);
3993 if (nfc.codePointCount(0, nfc.length()) == 1) {
3994 if (predicate.is(nfc.codePointAt(0)) &&
3995 next.match(matcher, j, seq)) {
3996 return true;
3997 }
3998 }
3999
4000 ch0 = Character.codePointBefore(seq, j);
4001 j -= Character.charCount(ch0);
4002 }
4003 }
4004 if (j < matcher.to)
4005 return false;
4006 }
4007 matcher.hitEnd = true;
4008 return false;
4009 }
4010
4011 boolean study(TreeInfo info) {
4012 info.minLength++;
4013 info.deterministic = false;
4014 return next.study(info);
4015 }
4016 }
4017
4018 /**
4019 * Node class that matches an unicode extended grapheme cluster
4020 */
4021 static class XGrapheme extends Node {
4022 boolean match(Matcher matcher, int i, CharSequence seq) {
4023 if (i < matcher.to) {
4024 int ch0 = Character.codePointAt(seq, i);
4025 i += Character.charCount(ch0);
4026 while (i < matcher.to) {
4027 int ch1 = Character.codePointAt(seq, i);
4028 if (Grapheme.isBoundary(ch0, ch1))
4029 break;
4030 ch0 = ch1;
4031 i += Character.charCount(ch1);
4032 }
4033 return next.match(matcher, i, seq);
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 handles grapheme boundaries
4048 */
4049 static class GraphemeBound extends Node {
4050 boolean match(Matcher matcher, int i, CharSequence seq) {
4051 int startIndex = matcher.from;
4052 int endIndex = matcher.to;
4053 if (matcher.transparentBounds) {
4054 startIndex = 0;
4055 endIndex = matcher.getTextLength();
4056 }
4057 if (i == startIndex) {
4058 return next.match(matcher, i, seq);
4059 }
4060 if (i < endIndex) {
4061 if (Character.isSurrogatePair(seq.charAt(i-1), seq.charAt(i)) ||
4062 !Grapheme.isBoundary(Character.codePointBefore(seq, i),
4063 Character.codePointAt(seq, i))) {
4064 return false;
4065 }
4066 } else {
4067 matcher.hitEnd = true;
4068 matcher.requireEnd = true;
4069 }
4070 return next.match(matcher, i, seq);
4071 }
4072 }
4073
4074 /**
4075 * Base class for all Slice nodes
4076 */
4077 static class SliceNode extends Node {
4078 int[] buffer;
4079 SliceNode(int[] buf) {
4080 buffer = buf;
4081 }
4082 boolean study(TreeInfo info) {
4083 info.minLength += buffer.length;
4084 info.maxLength += buffer.length;
4085 return next.study(info);
4086 }
4087 }
4088
4089 /**
4090 * Node class for a case sensitive/BMP-only sequence of literal
4091 * characters.
4092 */
4093 static class Slice extends SliceNode {
4094 Slice(int[] buf) {
4095 super(buf);
4096 }
4097 boolean match(Matcher matcher, int i, CharSequence seq) {
4098 int[] buf = buffer;
4099 int len = buf.length;
4100 for (int j=0; j<len; j++) {
4101 if ((i+j) >= matcher.to) {
4102 matcher.hitEnd = true;
4103 return false;
4104 }
4105 if (buf[j] != seq.charAt(i+j))
4106 return false;
4107 }
4108 return next.match(matcher, i+len, seq);
4109 }
4110 }
4111
4112 /**
4113 * Node class for a case_insensitive/BMP-only sequence of literal
4114 * characters.
4115 */
4116 static class SliceI extends SliceNode {
4117 SliceI(int[] buf) {
4118 super(buf);
4119 }
4120 boolean match(Matcher matcher, int i, CharSequence seq) {
4121 int[] buf = buffer;
4122 int len = buf.length;
4123 for (int j=0; j<len; j++) {
4124 if ((i+j) >= matcher.to) {
4125 matcher.hitEnd = true;
4126 return false;
4127 }
4128 int c = seq.charAt(i+j);
4129 if (buf[j] != c &&
4130 buf[j] != ASCII.toLower(c))
4131 return false;
4132 }
4133 return next.match(matcher, i+len, seq);
4134 }
4135 }
4136
4137 /**
4138 * Node class for a unicode_case_insensitive/BMP-only sequence of
4139 * literal characters. Uses unicode case folding.
4140 */
4141 static final class SliceU extends SliceNode {
4142 SliceU(int[] buf) {
4143 super(buf);
4144 }
4145 boolean match(Matcher matcher, int i, CharSequence seq) {
4146 int[] buf = buffer;
4147 int len = buf.length;
4148 for (int j=0; j<len; j++) {
4149 if ((i+j) >= matcher.to) {
4150 matcher.hitEnd = true;
4151 return false;
4152 }
4153 int c = seq.charAt(i+j);
4154 if (buf[j] != c &&
4155 buf[j] != Character.toLowerCase(Character.toUpperCase(c)))
4156 return false;
4157 }
4158 return next.match(matcher, i+len, seq);
4159 }
4160 }
4161
4162 /**
4163 * Node class for a case sensitive sequence of literal characters
4164 * including supplementary characters.
4165 */
4166 static final class SliceS extends Slice {
4167 SliceS(int[] buf) {
4168 super(buf);
4169 }
4170 boolean match(Matcher matcher, int i, CharSequence seq) {
4171 int[] buf = buffer;
4172 int x = i;
4173 for (int j = 0; j < buf.length; j++) {
4174 if (x >= matcher.to) {
4175 matcher.hitEnd = true;
4176 return false;
4177 }
4178 int c = Character.codePointAt(seq, x);
4179 if (buf[j] != c)
4180 return false;
4181 x += Character.charCount(c);
4182 if (x > matcher.to) {
4183 matcher.hitEnd = true;
4184 return false;
4185 }
4186 }
4187 return next.match(matcher, x, seq);
4188 }
4189 }
4190
4191 /**
4192 * Node class for a case insensitive sequence of literal characters
4193 * including supplementary characters.
4194 */
4195 static class SliceIS extends SliceNode {
4196 SliceIS(int[] buf) {
4197 super(buf);
4198 }
4199 int toLower(int c) {
4200 return ASCII.toLower(c);
4201 }
4202 boolean match(Matcher matcher, int i, CharSequence seq) {
4203 int[] buf = buffer;
4204 int x = i;
4205 for (int j = 0; j < buf.length; j++) {
4206 if (x >= matcher.to) {
4207 matcher.hitEnd = true;
4208 return false;
4209 }
4210 int c = Character.codePointAt(seq, x);
4211 if (buf[j] != c && buf[j] != toLower(c))
4212 return false;
4213 x += Character.charCount(c);
4214 if (x > matcher.to) {
4215 matcher.hitEnd = true;
4216 return false;
4217 }
4218 }
4219 return next.match(matcher, x, seq);
4220 }
4221 }
4222
4223 /**
4224 * Node class for a case insensitive sequence of literal characters.
4225 * Uses unicode case folding.
4226 */
4227 static final class SliceUS extends SliceIS {
4228 SliceUS(int[] buf) {
4229 super(buf);
4230 }
4231 int toLower(int c) {
4232 return Character.toLowerCase(Character.toUpperCase(c));
4233 }
4234 }
4235
4236 /**
4237 * The 0 or 1 quantifier. This one class implements all three types.
4238 */
4239 static final class Ques extends Node {
4240 Node atom;
4241 Qtype type;
4242 Ques(Node node, Qtype type) {
4243 this.atom = node;
4244 this.type = type;
4245 }
4246 boolean match(Matcher matcher, int i, CharSequence seq) {
4247 switch (type) {
4248 case GREEDY:
4249 return (atom.match(matcher, i, seq) && next.match(matcher, matcher.last, seq))
4250 || next.match(matcher, i, seq);
4251 case LAZY:
4252 return next.match(matcher, i, seq)
4253 || (atom.match(matcher, i, seq) && next.match(matcher, matcher.last, seq));
4254 case POSSESSIVE:
4255 if (atom.match(matcher, i, seq)) i = matcher.last;
4256 return next.match(matcher, i, seq);
4257 default:
4258 return atom.match(matcher, i, seq) && next.match(matcher, matcher.last, seq);
4259 }
4260 }
4261 boolean study(TreeInfo info) {
4262 if (type != Qtype.INDEPENDENT) {
4263 int minL = info.minLength;
4264 atom.study(info);
4265 info.minLength = minL;
4266 info.deterministic = false;
4267 return next.study(info);
4268 } else {
4269 atom.study(info);
4270 return next.study(info);
4271 }
4272 }
4273 }
4274
4275 /**
4276 * Handles the greedy style repetition with the minimum either be
4277 * 0 or 1 and the maximum be MAX_REPS, for * and + quantifier.
4278 */
4279 static class CharPropertyGreedy extends Node {
4280 final CharPredicate predicate;
4281 final int cmin;
4282
4283 CharPropertyGreedy(CharProperty cp, int cmin) {
4284 this.predicate = cp.predicate;
4285 this.cmin = cmin;
4286 }
4287 boolean match(Matcher matcher, int i, CharSequence seq) {
4288 int n = 0;
4289 int to = matcher.to;
4290 // greedy, all the way down
4291 while (i < to) {
4292 int ch = Character.codePointAt(seq, i);
4293 if (!predicate.is(ch))
4294 break;
4295 i += Character.charCount(ch);
4296 n++;
4297 }
4298 if (i >= to) {
4299 matcher.hitEnd = true;
4300 }
4301 while (n >= cmin) {
4302 if (next.match(matcher, i, seq))
4303 return true;
4304 if (n == cmin)
4305 return false;
4306 // backing off if match fails
4307 int ch = Character.codePointBefore(seq, i);
4308 i -= Character.charCount(ch);
4309 n--;
4310 }
4311 return false;
4312 }
4313
4314 boolean study(TreeInfo info) {
4315 info.minLength += cmin;
4316 if (info.maxValid) {
4317 info.maxLength += MAX_REPS;
4318 }
4319 info.deterministic = false;
4320 return next.study(info);
4321 }
4322 }
4323
4324 static final class BmpCharPropertyGreedy extends CharPropertyGreedy {
4325
4326 BmpCharPropertyGreedy(BmpCharProperty bcp, int cmin) {
4327 super(bcp, cmin);
4328 }
4329
4330 boolean match(Matcher matcher, int i, CharSequence seq) {
4331 int n = 0;
4332 int to = matcher.to;
4333 while (i < to && predicate.is(seq.charAt(i))) {
4334 i++; n++;
4335 }
4336 if (i >= to) {
4337 matcher.hitEnd = true;
4338 }
4339 while (n >= cmin) {
4340 if (next.match(matcher, i, seq))
4341 return true;
4342 i--; n--; // backing off if match fails
4343 }
4344 return false;
4345 }
4346 }
4347
4348 /**
4349 * Handles the curly-brace style repetition with a specified minimum and
4350 * maximum occurrences. The * quantifier is handled as a special case.
4351 * This class handles the three types.
4352 */
4353 static final class Curly extends Node {
4354 Node atom;
4355 Qtype type;
4356 int cmin;
4357 int cmax;
4358
4359 Curly(Node node, int cmin, int cmax, Qtype type) {
4360 this.atom = node;
4361 this.type = type;
4362 this.cmin = cmin;
4363 this.cmax = cmax;
4364 }
4365 boolean match(Matcher matcher, int i, CharSequence seq) {
4366 int j;
4367 for (j = 0; j < cmin; j++) {
4368 if (atom.match(matcher, i, seq)) {
4369 i = matcher.last;
4370 continue;
4371 }
4372 return false;
4373 }
4374 if (type == Qtype.GREEDY)
4375 return match0(matcher, i, j, seq);
4376 else if (type == Qtype.LAZY)
4377 return match1(matcher, i, j, seq);
4378 else
4379 return match2(matcher, i, j, seq);
4380 }
4381 // Greedy match.
4382 // i is the index to start matching at
4383 // j is the number of atoms that have matched
4384 boolean match0(Matcher matcher, int i, int j, CharSequence seq) {
4385 if (j >= cmax) {
4386 // We have matched the maximum... continue with the rest of
4387 // the regular expression
4388 return next.match(matcher, i, seq);
4389 }
4390 int backLimit = j;
4391 while (atom.match(matcher, i, seq)) {
4392 // k is the length of this match
4393 int k = matcher.last - i;
4394 if (k == 0) // Zero length match
4395 break;
4396 // Move up index and number matched
4397 i = matcher.last;
4398 j++;
4399 // We are greedy so match as many as we can
4400 while (j < cmax) {
4401 if (!atom.match(matcher, i, seq))
4402 break;
4403 if (i + k != matcher.last) {
4404 if (match0(matcher, matcher.last, j+1, seq))
4405 return true;
4406 break;
4407 }
4408 i += k;
4409 j++;
4410 }
4411 // Handle backing off if match fails
4412 while (j >= backLimit) {
4413 if (next.match(matcher, i, seq))
4414 return true;
4415 i -= k;
4416 j--;
4417 }
4418 return false;
4419 }
4420 return next.match(matcher, i, seq);
4421 }
4422 // Reluctant match. At this point, the minimum has been satisfied.
4423 // i is the index to start matching at
4424 // j is the number of atoms that have matched
4425 boolean match1(Matcher matcher, int i, int j, CharSequence seq) {
4426 for (;;) {
4427 // Try finishing match without consuming any more
4428 if (next.match(matcher, i, seq))
4429 return true;
4430 // At the maximum, no match found
4431 if (j >= cmax)
4432 return false;
4433 // Okay, must try one more atom
4434 if (!atom.match(matcher, i, seq))
4435 return false;
4436 // If we haven't moved forward then must break out
4437 if (i == matcher.last)
4438 return false;
4439 // Move up index and number matched
4440 i = matcher.last;
4441 j++;
4442 }
4443 }
4444 boolean match2(Matcher matcher, int i, int j, CharSequence seq) {
4445 for (; j < cmax; j++) {
4446 if (!atom.match(matcher, i, seq))
4447 break;
4448 if (i == matcher.last)
4449 break;
4450 i = matcher.last;
4451 }
4452 return next.match(matcher, i, seq);
4453 }
4454 boolean study(TreeInfo info) {
4455 // Save original info
4456 int minL = info.minLength;
4457 int maxL = info.maxLength;
4458 boolean maxV = info.maxValid;
4459 boolean detm = info.deterministic;
4460 info.reset();
4461
4462 atom.study(info);
4463
4464 int temp = info.minLength * cmin + minL;
4465 if (temp < minL) {
4466 temp = 0xFFFFFFF; // arbitrary large number
4467 }
4468 info.minLength = temp;
4469
4470 if (maxV & info.maxValid) {
4471 temp = info.maxLength * cmax + maxL;
4472 info.maxLength = temp;
4473 if (temp < maxL) {
4474 info.maxValid = false;
4475 }
4476 } else {
4477 info.maxValid = false;
4478 }
4479
4480 if (info.deterministic && cmin == cmax)
4481 info.deterministic = detm;
4482 else
4483 info.deterministic = false;
4484 return next.study(info);
4485 }
4486 }
4487
4488 /**
4489 * Handles the curly-brace style repetition with a specified minimum and
4490 * maximum occurrences in deterministic cases. This is an iterative
4491 * optimization over the Prolog and Loop system which would handle this
4492 * in a recursive way. The * quantifier is handled as a special case.
4493 * If capture is true then this class saves group settings and ensures
4494 * that groups are unset when backing off of a group match.
4495 */
4496 static final class GroupCurly extends Node {
4497 Node atom;
4498 Qtype type;
4499 int cmin;
4500 int cmax;
4501 int localIndex;
4502 int groupIndex;
4503 boolean capture;
4504
4505 GroupCurly(Node node, int cmin, int cmax, Qtype type, int local,
4506 int group, boolean capture) {
4507 this.atom = node;
4508 this.type = type;
4509 this.cmin = cmin;
4510 this.cmax = cmax;
4511 this.localIndex = local;
4512 this.groupIndex = group;
4513 this.capture = capture;
4514 }
4515 boolean match(Matcher matcher, int i, CharSequence seq) {
4516 int[] groups = matcher.groups;
4517 int[] locals = matcher.locals;
4518 int save0 = locals[localIndex];
4519 int save1 = 0;
4520 int save2 = 0;
4521
4522 if (capture) {
4523 save1 = groups[groupIndex];
4524 save2 = groups[groupIndex+1];
4525 }
4526
4527 // Notify GroupTail there is no need to setup group info
4528 // because it will be set here
4529 locals[localIndex] = -1;
4530
4531 boolean ret = true;
4532 for (int j = 0; j < cmin; j++) {
4533 if (atom.match(matcher, i, seq)) {
4534 if (capture) {
4535 groups[groupIndex] = i;
4536 groups[groupIndex+1] = matcher.last;
4537 }
4538 i = matcher.last;
4539 } else {
4540 ret = false;
4541 break;
4542 }
4543 }
4544 if (ret) {
4545 if (type == Qtype.GREEDY) {
4546 ret = match0(matcher, i, cmin, seq);
4547 } else if (type == Qtype.LAZY) {
4548 ret = match1(matcher, i, cmin, seq);
4549 } else {
4550 ret = match2(matcher, i, cmin, seq);
4551 }
4552 }
4553 if (!ret) {
4554 locals[localIndex] = save0;
4555 if (capture) {
4556 groups[groupIndex] = save1;
4557 groups[groupIndex+1] = save2;
4558 }
4559 }
4560 return ret;
4561 }
4562 // Aggressive group match
4563 boolean match0(Matcher matcher, int i, int j, CharSequence seq) {
4564 // don't back off passing the starting "j"
4565 int min = j;
4566 int[] groups = matcher.groups;
4567 int save0 = 0;
4568 int save1 = 0;
4569 if (capture) {
4570 save0 = groups[groupIndex];
4571 save1 = groups[groupIndex+1];
4572 }
4573 for (;;) {
4574 if (j >= cmax)
4575 break;
4576 if (!atom.match(matcher, i, seq))
4577 break;
4578 int k = matcher.last - i;
4579 if (k <= 0) {
4580 if (capture) {
4581 groups[groupIndex] = i;
4582 groups[groupIndex+1] = i + k;
4583 }
4584 i = i + k;
4585 break;
4586 }
4587 for (;;) {
4588 if (capture) {
4589 groups[groupIndex] = i;
4590 groups[groupIndex+1] = i + k;
4591 }
4592 i = i + k;
4593 if (++j >= cmax)
4594 break;
4595 if (!atom.match(matcher, i, seq))
4596 break;
4597 if (i + k != matcher.last) {
4598 if (match0(matcher, i, j, seq))
4599 return true;
4600 break;
4601 }
4602 }
4603 while (j > min) {
4604 if (next.match(matcher, i, seq)) {
4605 if (capture) {
4606 groups[groupIndex+1] = i;
4607 groups[groupIndex] = i - k;
4608 }
4609 return true;
4610 }
4611 // backing off
4612 i = i - k;
4613 if (capture) {
4614 groups[groupIndex+1] = i;
4615 groups[groupIndex] = i - k;
4616 }
4617 j--;
4618
4619 }
4620 break;
4621 }
4622 if (capture) {
4623 groups[groupIndex] = save0;
4624 groups[groupIndex+1] = save1;
4625 }
4626 return next.match(matcher, i, seq);
4627 }
4628 // Reluctant matching
4629 boolean match1(Matcher matcher, int i, int j, CharSequence seq) {
4630 for (;;) {
4631 if (next.match(matcher, i, seq))
4632 return true;
4633 if (j >= cmax)
4634 return false;
4635 if (!atom.match(matcher, i, seq))
4636 return false;
4637 if (i == matcher.last)
4638 return false;
4639 if (capture) {
4640 matcher.groups[groupIndex] = i;
4641 matcher.groups[groupIndex+1] = matcher.last;
4642 }
4643 i = matcher.last;
4644 j++;
4645 }
4646 }
4647 // Possessive matching
4648 boolean match2(Matcher matcher, int i, int j, CharSequence seq) {
4649 for (; j < cmax; j++) {
4650 if (!atom.match(matcher, i, seq)) {
4651 break;
4652 }
4653 if (capture) {
4654 matcher.groups[groupIndex] = i;
4655 matcher.groups[groupIndex+1] = matcher.last;
4656 }
4657 if (i == matcher.last) {
4658 break;
4659 }
4660 i = matcher.last;
4661 }
4662 return next.match(matcher, i, seq);
4663 }
4664 boolean study(TreeInfo info) {
4665 // Save original info
4666 int minL = info.minLength;
4667 int maxL = info.maxLength;
4668 boolean maxV = info.maxValid;
4669 boolean detm = info.deterministic;
4670 info.reset();
4671
4672 atom.study(info);
4673
4674 int temp = info.minLength * cmin + minL;
4675 if (temp < minL) {
4676 temp = 0xFFFFFFF; // Arbitrary large number
4677 }
4678 info.minLength = temp;
4679
4680 if (maxV & info.maxValid) {
4681 temp = info.maxLength * cmax + maxL;
4682 info.maxLength = temp;
4683 if (temp < maxL) {
4684 info.maxValid = false;
4685 }
4686 } else {
4687 info.maxValid = false;
4688 }
4689
4690 if (info.deterministic && cmin == cmax) {
4691 info.deterministic = detm;
4692 } else {
4693 info.deterministic = false;
4694 }
4695 return next.study(info);
4696 }
4697 }
4698
4699 /**
4700 * A Guard node at the end of each atom node in a Branch. It
4701 * serves the purpose of chaining the "match" operation to
4702 * "next" but not the "study", so we can collect the TreeInfo
4703 * of each atom node without including the TreeInfo of the
4704 * "next".
4705 */
4706 static final class BranchConn extends Node {
4707 BranchConn() {};
4708 boolean match(Matcher matcher, int i, CharSequence seq) {
4709 return next.match(matcher, i, seq);
4710 }
4711 boolean study(TreeInfo info) {
4712 return info.deterministic;
4713 }
4714 }
4715
4716 /**
4717 * Handles the branching of alternations. Note this is also used for
4718 * the ? quantifier to branch between the case where it matches once
4719 * and where it does not occur.
4720 */
4721 static final class Branch extends Node {
4722 Node[] atoms = new Node[2];
4723 int size = 2;
4724 Node conn;
4725 Branch(Node first, Node second, Node branchConn) {
4726 conn = branchConn;
4727 atoms[0] = first;
4728 atoms[1] = second;
4729 }
4730
4731 void add(Node node) {
4732 if (size >= atoms.length) {
4733 Node[] tmp = new Node[atoms.length*2];
4734 System.arraycopy(atoms, 0, tmp, 0, atoms.length);
4735 atoms = tmp;
4736 }
4737 atoms[size++] = node;
4738 }
4739
4740 boolean match(Matcher matcher, int i, CharSequence seq) {
4741 for (int n = 0; n < size; n++) {
4742 if (atoms[n] == null) {
4743 if (conn.next.match(matcher, i, seq))
4744 return true;
4745 } else if (atoms[n].match(matcher, i, seq)) {
4746 return true;
4747 }
4748 }
4749 return false;
4750 }
4751
4752 boolean study(TreeInfo info) {
4753 int minL = info.minLength;
4754 int maxL = info.maxLength;
4755 boolean maxV = info.maxValid;
4756
4757 int minL2 = Integer.MAX_VALUE; //arbitrary large enough num
4758 int maxL2 = -1;
4759 for (int n = 0; n < size; n++) {
4760 info.reset();
4761 if (atoms[n] != null)
4762 atoms[n].study(info);
4763 minL2 = Math.min(minL2, info.minLength);
4764 maxL2 = Math.max(maxL2, info.maxLength);
4765 maxV = (maxV & info.maxValid);
4766 }
4767
4768 minL += minL2;
4769 maxL += maxL2;
4770
4771 info.reset();
4772 conn.next.study(info);
4773
4774 info.minLength += minL;
4775 info.maxLength += maxL;
4776 info.maxValid &= maxV;
4777 info.deterministic = false;
4778 return false;
4779 }
4780 }
4781
4782 /**
4783 * The GroupHead saves the location where the group begins in the locals
4784 * and restores them when the match is done.
4785 *
4786 * The matchRef is used when a reference to this group is accessed later
4787 * in the expression. The locals will have a negative value in them to
4788 * indicate that we do not want to unset the group if the reference
4789 * doesn't match.
4790 */
4791 static final class GroupHead extends Node {
4792 int localIndex;
4793 GroupTail tail; // for debug/print only, match does not need to know
4794 GroupHead(int localCount) {
4795 localIndex = localCount;
4796 }
4797 boolean match(Matcher matcher, int i, CharSequence seq) {
4798 int save = matcher.locals[localIndex];
4799 matcher.locals[localIndex] = i;
4800 boolean ret = next.match(matcher, i, seq);
4801 matcher.locals[localIndex] = save;
4802 return ret;
4803 }
4804 boolean matchRef(Matcher matcher, int i, CharSequence seq) {
4805 int save = matcher.locals[localIndex];
4806 matcher.locals[localIndex] = ~i; // HACK
4807 boolean ret = next.match(matcher, i, seq);
4808 matcher.locals[localIndex] = save;
4809 return ret;
4810 }
4811 }
4812
4813 /**
4814 * Recursive reference to a group in the regular expression. It calls
4815 * matchRef because if the reference fails to match we would not unset
4816 * the group.
4817 */
4818 static final class GroupRef extends Node {
4819 GroupHead head;
4820 GroupRef(GroupHead head) {
4821 this.head = head;
4822 }
4823 boolean match(Matcher matcher, int i, CharSequence seq) {
4824 return head.matchRef(matcher, i, seq)
4825 && next.match(matcher, matcher.last, seq);
4826 }
4827 boolean study(TreeInfo info) {
4828 info.maxValid = false;
4829 info.deterministic = false;
4830 return next.study(info);
4831 }
4832 }
4833
4834 /**
4835 * The GroupTail handles the setting of group beginning and ending
4836 * locations when groups are successfully matched. It must also be able to
4837 * unset groups that have to be backed off of.
4838 *
4839 * The GroupTail node is also used when a previous group is referenced,
4840 * and in that case no group information needs to be set.
4841 */
4842 static final class GroupTail extends Node {
4843 int localIndex;
4844 int groupIndex;
4845 GroupTail(int localCount, int groupCount) {
4846 localIndex = localCount;
4847 groupIndex = groupCount + groupCount;
4848 }
4849 boolean match(Matcher matcher, int i, CharSequence seq) {
4850 int tmp = matcher.locals[localIndex];
4851 if (tmp >= 0) { // This is the normal group case.
4852 // Save the group so we can unset it if it
4853 // backs off of a match.
4854 int groupStart = matcher.groups[groupIndex];
4855 int groupEnd = matcher.groups[groupIndex+1];
4856
4857 matcher.groups[groupIndex] = tmp;
4858 matcher.groups[groupIndex+1] = i;
4859 if (next.match(matcher, i, seq)) {
4860 return true;
4861 }
4862 matcher.groups[groupIndex] = groupStart;
4863 matcher.groups[groupIndex+1] = groupEnd;
4864 return false;
4865 } else {
4866 // This is a group reference case. We don't need to save any
4867 // group info because it isn't really a group.
4868 matcher.last = i;
4869 return true;
4870 }
4871 }
4872 }
4873
4874 /**
4875 * This sets up a loop to handle a recursive quantifier structure.
4876 */
4877 static final class Prolog extends Node {
4878 Loop loop;
4879 Prolog(Loop loop) {
4880 this.loop = loop;
4881 }
4882 boolean match(Matcher matcher, int i, CharSequence seq) {
4883 return loop.matchInit(matcher, i, seq);
4884 }
4885 boolean study(TreeInfo info) {
4886 return loop.study(info);
4887 }
4888 }
4889
4890 /**
4891 * Handles the repetition count for a greedy Curly. The matchInit
4892 * is called from the Prolog to save the index of where the group
4893 * beginning is stored. A zero length group check occurs in the
4894 * normal match but is skipped in the matchInit.
4895 */
4896 static class Loop extends Node {
4897 Node body;
4898 int countIndex; // local count index in matcher locals
4899 int beginIndex; // group beginning index
4900 int cmin, cmax;
4901 int posIndex;
4902 Loop(int countIndex, int beginIndex) {
4903 this.countIndex = countIndex;
4904 this.beginIndex = beginIndex;
4905 this.posIndex = -1;
4906 }
4907 boolean match(Matcher matcher, int i, CharSequence seq) {
4908 // Avoid infinite loop in zero-length case.
4909 if (i > matcher.locals[beginIndex]) {
4910 int count = matcher.locals[countIndex];
4911
4912 // This block is for before we reach the minimum
4913 // iterations required for the loop to match
4914 if (count < cmin) {
4915 matcher.locals[countIndex] = count + 1;
4916 boolean b = body.match(matcher, i, seq);
4917 // If match failed we must backtrack, so
4918 // the loop count should NOT be incremented
4919 if (!b)
4920 matcher.locals[countIndex] = count;
4921 // Return success or failure since we are under
4922 // minimum
4923 return b;
4924 }
4925 // This block is for after we have the minimum
4926 // iterations required for the loop to match
4927 if (count < cmax) {
4928 // Let's check if we have already tried and failed
4929 // at this starting position "i" in the past.
4930 // If yes, then just return false wihtout trying
4931 // again, to stop the exponential backtracking.
4932 if (posIndex != -1 &&
4933 matcher.localsPos[posIndex].contains(i)) {
4934 return next.match(matcher, i, seq);
4935 }
4936 matcher.locals[countIndex] = count + 1;
4937 boolean b = body.match(matcher, i, seq);
4938 // If match failed we must backtrack, so
4939 // the loop count should NOT be incremented
4940 if (b)
4941 return true;
4942 matcher.locals[countIndex] = count;
4943 // save the failed position
4944 if (posIndex != -1) {
4945 matcher.localsPos[posIndex].add(i);
4946 }
4947 }
4948 }
4949 return next.match(matcher, i, seq);
4950 }
4951 boolean matchInit(Matcher matcher, int i, CharSequence seq) {
4952 int save = matcher.locals[countIndex];
4953 boolean ret = false;
4954 if (posIndex != -1 && matcher.localsPos[posIndex] == null) {
4955 matcher.localsPos[posIndex] = new IntHashSet();
4956 }
4957 if (0 < cmin) {
4958 matcher.locals[countIndex] = 1;
4959 ret = body.match(matcher, i, seq);
4960 } else if (0 < cmax) {
4961 matcher.locals[countIndex] = 1;
4962 ret = body.match(matcher, i, seq);
4963 if (ret == false)
4964 ret = next.match(matcher, i, seq);
4965 } else {
4966 ret = next.match(matcher, i, seq);
4967 }
4968 matcher.locals[countIndex] = save;
4969 return ret;
4970 }
4971 boolean study(TreeInfo info) {
4972 info.maxValid = false;
4973 info.deterministic = false;
4974 return false;
4975 }
4976 }
4977
4978 /**
4979 * Handles the repetition count for a reluctant Curly. The matchInit
4980 * is called from the Prolog to save the index of where the group
4981 * beginning is stored. A zero length group check occurs in the
4982 * normal match but is skipped in the matchInit.
4983 */
4984 static final class LazyLoop extends Loop {
4985 LazyLoop(int countIndex, int beginIndex) {
4986 super(countIndex, beginIndex);
4987 }
4988 boolean match(Matcher matcher, int i, CharSequence seq) {
4989 // Check for zero length group
4990 if (i > matcher.locals[beginIndex]) {
4991 int count = matcher.locals[countIndex];
4992 if (count < cmin) {
4993 matcher.locals[countIndex] = count + 1;
4994 boolean result = body.match(matcher, i, seq);
4995 // If match failed we must backtrack, so
4996 // the loop count should NOT be incremented
4997 if (!result)
4998 matcher.locals[countIndex] = count;
4999 return result;
5000 }
5001 if (next.match(matcher, i, seq))
5002 return true;
5003 if (count < cmax) {
5004 matcher.locals[countIndex] = count + 1;
5005 boolean result = body.match(matcher, i, seq);
5006 // If match failed we must backtrack, so
5007 // the loop count should NOT be incremented
5008 if (!result)
5009 matcher.locals[countIndex] = count;
5010 return result;
5011 }
5012 return false;
5013 }
5014 return next.match(matcher, i, seq);
5015 }
5016 boolean matchInit(Matcher matcher, int i, CharSequence seq) {
5017 int save = matcher.locals[countIndex];
5018 boolean ret = false;
5019 if (0 < cmin) {
5020 matcher.locals[countIndex] = 1;
5021 ret = body.match(matcher, i, seq);
5022 } else if (next.match(matcher, i, seq)) {
5023 ret = true;
5024 } else if (0 < cmax) {
5025 matcher.locals[countIndex] = 1;
5026 ret = body.match(matcher, i, seq);
5027 }
5028 matcher.locals[countIndex] = save;
5029 return ret;
5030 }
5031 boolean study(TreeInfo info) {
5032 info.maxValid = false;
5033 info.deterministic = false;
5034 return false;
5035 }
5036 }
5037
5038 /**
5039 * Refers to a group in the regular expression. Attempts to match
5040 * whatever the group referred to last matched.
5041 */
5042 static class BackRef extends Node {
5043 int groupIndex;
5044 BackRef(int groupCount) {
5045 super();
5046 groupIndex = groupCount + groupCount;
5047 }
5048 boolean match(Matcher matcher, int i, CharSequence seq) {
5049 int j = matcher.groups[groupIndex];
5050 int k = matcher.groups[groupIndex+1];
5051
5052 int groupSize = k - j;
5053 // If the referenced group didn't match, neither can this
5054 if (j < 0)
5055 return false;
5056
5057 // If there isn't enough input left no match
5058 if (i + groupSize > matcher.to) {
5059 matcher.hitEnd = true;
5060 return false;
5061 }
5062 // Check each new char to make sure it matches what the group
5063 // referenced matched last time around
5064 for (int index=0; index<groupSize; index++)
5065 if (seq.charAt(i+index) != seq.charAt(j+index))
5066 return false;
5067
5068 return next.match(matcher, i+groupSize, seq);
5069 }
5070 boolean study(TreeInfo info) {
5071 info.maxValid = false;
5072 return next.study(info);
5073 }
5074 }
5075
5076 static class CIBackRef extends Node {
5077 int groupIndex;
5078 boolean doUnicodeCase;
5079 CIBackRef(int groupCount, boolean doUnicodeCase) {
5080 super();
5081 groupIndex = groupCount + groupCount;
5082 this.doUnicodeCase = doUnicodeCase;
5083 }
5084 boolean match(Matcher matcher, int i, CharSequence seq) {
5085 int j = matcher.groups[groupIndex];
5086 int k = matcher.groups[groupIndex+1];
5087
5088 int groupSize = k - j;
5089
5090 // If the referenced group didn't match, neither can this
5091 if (j < 0)
5092 return false;
5093
5094 // If there isn't enough input left no match
5095 if (i + groupSize > matcher.to) {
5096 matcher.hitEnd = true;
5097 return false;
5098 }
5099
5100 // Check each new char to make sure it matches what the group
5101 // referenced matched last time around
5102 int x = i;
5103 for (int index=0; index<groupSize; index++) {
5104 int c1 = Character.codePointAt(seq, x);
5105 int c2 = Character.codePointAt(seq, j);
5106 if (c1 != c2) {
5107 if (doUnicodeCase) {
5108 int cc1 = Character.toUpperCase(c1);
5109 int cc2 = Character.toUpperCase(c2);
5110 if (cc1 != cc2 &&
5111 Character.toLowerCase(cc1) !=
5112 Character.toLowerCase(cc2))
5113 return false;
5114 } else {
5115 if (ASCII.toLower(c1) != ASCII.toLower(c2))
5116 return false;
5117 }
5118 }
5119 x += Character.charCount(c1);
5120 j += Character.charCount(c2);
5121 }
5122
5123 return next.match(matcher, i+groupSize, seq);
5124 }
5125 boolean study(TreeInfo info) {
5126 info.maxValid = false;
5127 return next.study(info);
5128 }
5129 }
5130
5131 /**
5132 * Searches until the next instance of its atom. This is useful for
5133 * finding the atom efficiently without passing an instance of it
5134 * (greedy problem) and without a lot of wasted search time (reluctant
5135 * problem).
5136 */
5137 static final class First extends Node {
5138 Node atom;
5139 First(Node node) {
5140 this.atom = BnM.optimize(node);
5141 }
5142 boolean match(Matcher matcher, int i, CharSequence seq) {
5143 if (atom instanceof BnM) {
5144 return atom.match(matcher, i, seq)
5145 && next.match(matcher, matcher.last, seq);
5146 }
5147 for (;;) {
5148 if (i > matcher.to) {
5149 matcher.hitEnd = true;
5150 return false;
5151 }
5152 if (atom.match(matcher, i, seq)) {
5153 return next.match(matcher, matcher.last, seq);
5154 }
5155 i += countChars(seq, i, 1);
5156 matcher.first++;
5157 }
5158 }
5159 boolean study(TreeInfo info) {
5160 atom.study(info);
5161 info.maxValid = false;
5162 info.deterministic = false;
5163 return next.study(info);
5164 }
5165 }
5166
5167 static final class Conditional extends Node {
5168 Node cond, yes, not;
5169 Conditional(Node cond, Node yes, Node not) {
5170 this.cond = cond;
5171 this.yes = yes;
5172 this.not = not;
5173 }
5174 boolean match(Matcher matcher, int i, CharSequence seq) {
5175 if (cond.match(matcher, i, seq)) {
5176 return yes.match(matcher, i, seq);
5177 } else {
5178 return not.match(matcher, i, seq);
5179 }
5180 }
5181 boolean study(TreeInfo info) {
5182 int minL = info.minLength;
5183 int maxL = info.maxLength;
5184 boolean maxV = info.maxValid;
5185 info.reset();
5186 yes.study(info);
5187
5188 int minL2 = info.minLength;
5189 int maxL2 = info.maxLength;
5190 boolean maxV2 = info.maxValid;
5191 info.reset();
5192 not.study(info);
5193
5194 info.minLength = minL + Math.min(minL2, info.minLength);
5195 info.maxLength = maxL + Math.max(maxL2, info.maxLength);
5196 info.maxValid = (maxV & maxV2 & info.maxValid);
5197 info.deterministic = false;
5198 return next.study(info);
5199 }
5200 }
5201
5202 /**
5203 * Zero width positive lookahead.
5204 */
5205 static final class Pos extends Node {
5206 Node cond;
5207 Pos(Node cond) {
5208 this.cond = cond;
5209 }
5210 boolean match(Matcher matcher, int i, CharSequence seq) {
5211 int savedTo = matcher.to;
5212 boolean conditionMatched = false;
5213
5214 // Relax transparent region boundaries for lookahead
5215 if (matcher.transparentBounds)
5216 matcher.to = matcher.getTextLength();
5217 try {
5218 conditionMatched = cond.match(matcher, i, seq);
5219 } finally {
5220 // Reinstate region boundaries
5221 matcher.to = savedTo;
5222 }
5223 return conditionMatched && next.match(matcher, i, seq);
5224 }
5225 }
5226
5227 /**
5228 * Zero width negative lookahead.
5229 */
5230 static final class Neg extends Node {
5231 Node cond;
5232 Neg(Node cond) {
5233 this.cond = cond;
5234 }
5235 boolean match(Matcher matcher, int i, CharSequence seq) {
5236 int savedTo = matcher.to;
5237 boolean conditionMatched = false;
5238
5239 // Relax transparent region boundaries for lookahead
5240 if (matcher.transparentBounds)
5241 matcher.to = matcher.getTextLength();
5242 try {
5243 if (i < matcher.to) {
5244 conditionMatched = !cond.match(matcher, i, seq);
5245 } else {
5246 // If a negative lookahead succeeds then more input
5247 // could cause it to fail!
5248 matcher.requireEnd = true;
5249 conditionMatched = !cond.match(matcher, i, seq);
5250 }
5251 } finally {
5252 // Reinstate region boundaries
5253 matcher.to = savedTo;
5254 }
5255 return conditionMatched && next.match(matcher, i, seq);
5256 }
5257 }
5258
5259 /**
5260 * For use with lookbehinds; matches the position where the lookbehind
5261 * was encountered.
5262 */
5263 static Node lookbehindEnd = new Node() {
5264 boolean match(Matcher matcher, int i, CharSequence seq) {
5265 return i == matcher.lookbehindTo;
5266 }
5267 };
5268
5269 /**
5270 * Zero width positive lookbehind.
5271 */
5272 static class Behind extends Node {
5273 Node cond;
5274 int rmax, rmin;
5275 Behind(Node cond, int rmax, int rmin) {
5276 this.cond = cond;
5277 this.rmax = rmax;
5278 this.rmin = rmin;
5279 }
5280
5281 boolean match(Matcher matcher, int i, CharSequence seq) {
5282 int savedFrom = matcher.from;
5283 boolean conditionMatched = false;
5284 int startIndex = (!matcher.transparentBounds) ?
5285 matcher.from : 0;
5286 int from = Math.max(i - rmax, startIndex);
5287 // Set end boundary
5288 int savedLBT = matcher.lookbehindTo;
5289 matcher.lookbehindTo = i;
5290 // Relax transparent region boundaries for lookbehind
5291 if (matcher.transparentBounds)
5292 matcher.from = 0;
5293 for (int j = i - rmin; !conditionMatched && j >= from; j--) {
5294 conditionMatched = cond.match(matcher, j, seq);
5295 }
5296 matcher.from = savedFrom;
5297 matcher.lookbehindTo = savedLBT;
5298 return conditionMatched && next.match(matcher, i, seq);
5299 }
5300 }
5301
5302 /**
5303 * Zero width positive lookbehind, including supplementary
5304 * characters or unpaired surrogates.
5305 */
5306 static final class BehindS extends Behind {
5307 BehindS(Node cond, int rmax, int rmin) {
5308 super(cond, rmax, rmin);
5309 }
5310 boolean match(Matcher matcher, int i, CharSequence seq) {
5311 int rmaxChars = countChars(seq, i, -rmax);
5312 int rminChars = countChars(seq, i, -rmin);
5313 int savedFrom = matcher.from;
5314 int startIndex = (!matcher.transparentBounds) ?
5315 matcher.from : 0;
5316 boolean conditionMatched = false;
5317 int from = Math.max(i - rmaxChars, startIndex);
5318 // Set end boundary
5319 int savedLBT = matcher.lookbehindTo;
5320 matcher.lookbehindTo = i;
5321 // Relax transparent region boundaries for lookbehind
5322 if (matcher.transparentBounds)
5323 matcher.from = 0;
5324
5325 for (int j = i - rminChars;
5326 !conditionMatched && j >= from;
5327 j -= j>from ? countChars(seq, j, -1) : 1) {
5328 conditionMatched = cond.match(matcher, j, seq);
5329 }
5330 matcher.from = savedFrom;
5331 matcher.lookbehindTo = savedLBT;
5332 return conditionMatched && next.match(matcher, i, seq);
5333 }
5334 }
5335
5336 /**
5337 * Zero width negative lookbehind.
5338 */
5339 static class NotBehind extends Node {
5340 Node cond;
5341 int rmax, rmin;
5342 NotBehind(Node cond, int rmax, int rmin) {
5343 this.cond = cond;
5344 this.rmax = rmax;
5345 this.rmin = rmin;
5346 }
5347
5348 boolean match(Matcher matcher, int i, CharSequence seq) {
5349 int savedLBT = matcher.lookbehindTo;
5350 int savedFrom = matcher.from;
5351 boolean conditionMatched = false;
5352 int startIndex = (!matcher.transparentBounds) ?
5353 matcher.from : 0;
5354 int from = Math.max(i - rmax, startIndex);
5355 matcher.lookbehindTo = i;
5356 // Relax transparent region boundaries for lookbehind
5357 if (matcher.transparentBounds)
5358 matcher.from = 0;
5359 for (int j = i - rmin; !conditionMatched && j >= from; j--) {
5360 conditionMatched = cond.match(matcher, j, seq);
5361 }
5362 // Reinstate region boundaries
5363 matcher.from = savedFrom;
5364 matcher.lookbehindTo = savedLBT;
5365 return !conditionMatched && next.match(matcher, i, seq);
5366 }
5367 }
5368
5369 /**
5370 * Zero width negative lookbehind, including supplementary
5371 * characters or unpaired surrogates.
5372 */
5373 static final class NotBehindS extends NotBehind {
5374 NotBehindS(Node cond, int rmax, int rmin) {
5375 super(cond, rmax, rmin);
5376 }
5377 boolean match(Matcher matcher, int i, CharSequence seq) {
5378 int rmaxChars = countChars(seq, i, -rmax);
5379 int rminChars = countChars(seq, i, -rmin);
5380 int savedFrom = matcher.from;
5381 int savedLBT = matcher.lookbehindTo;
5382 boolean conditionMatched = false;
5383 int startIndex = (!matcher.transparentBounds) ?
5384 matcher.from : 0;
5385 int from = Math.max(i - rmaxChars, startIndex);
5386 matcher.lookbehindTo = i;
5387 // Relax transparent region boundaries for lookbehind
5388 if (matcher.transparentBounds)
5389 matcher.from = 0;
5390 for (int j = i - rminChars;
5391 !conditionMatched && j >= from;
5392 j -= j>from ? countChars(seq, j, -1) : 1) {
5393 conditionMatched = cond.match(matcher, j, seq);
5394 }
5395 //Reinstate region boundaries
5396 matcher.from = savedFrom;
5397 matcher.lookbehindTo = savedLBT;
5398 return !conditionMatched && next.match(matcher, i, seq);
5399 }
5400 }
5401
5402 /**
5403 * Handles word boundaries. Includes a field to allow this one class to
5404 * deal with the different types of word boundaries we can match. The word
5405 * characters include underscores, letters, and digits. Non spacing marks
5406 * can are also part of a word if they have a base character, otherwise
5407 * they are ignored for purposes of finding word boundaries.
5408 */
5409 static final class Bound extends Node {
5410 static int LEFT = 0x1;
5411 static int RIGHT= 0x2;
5412 static int BOTH = 0x3;
5413 static int NONE = 0x4;
5414 int type;
5415 boolean useUWORD;
5416 Bound(int n, boolean useUWORD) {
5417 type = n;
5418 this.useUWORD = useUWORD;
5419 }
5420
5421 boolean isWord(int ch) {
5422 return useUWORD ? CharPredicates.WORD().is(ch)
5423 : (ch == '_' || Character.isLetterOrDigit(ch));
5424 }
5425
5426 int check(Matcher matcher, int i, CharSequence seq) {
5427 int ch;
5428 boolean left = false;
5429 int startIndex = matcher.from;
5430 int endIndex = matcher.to;
5431 if (matcher.transparentBounds) {
5432 startIndex = 0;
5433 endIndex = matcher.getTextLength();
5434 }
5435 if (i > startIndex) {
5436 ch = Character.codePointBefore(seq, i);
5437 left = (isWord(ch) ||
5438 ((Character.getType(ch) == Character.NON_SPACING_MARK)
5439 && hasBaseCharacter(matcher, i-1, seq)));
5440 }
5441 boolean right = false;
5442 if (i < endIndex) {
5443 ch = Character.codePointAt(seq, i);
5444 right = (isWord(ch) ||
5445 ((Character.getType(ch) == Character.NON_SPACING_MARK)
5446 && hasBaseCharacter(matcher, i, seq)));
5447 } else {
5448 // Tried to access char past the end
5449 matcher.hitEnd = true;
5450 // The addition of another char could wreck a boundary
5451 matcher.requireEnd = true;
5452 }
5453 return ((left ^ right) ? (right ? LEFT : RIGHT) : NONE);
5454 }
5455 boolean match(Matcher matcher, int i, CharSequence seq) {
5456 return (check(matcher, i, seq) & type) > 0
5457 && next.match(matcher, i, seq);
5458 }
5459 }
5460
5461 /**
5462 * Non spacing marks only count as word characters in bounds calculations
5463 * if they have a base character.
5464 */
5465 private static boolean hasBaseCharacter(Matcher matcher, int i,
5466 CharSequence seq)
5467 {
5468 int start = (!matcher.transparentBounds) ?
5469 matcher.from : 0;
5470 for (int x=i; x >= start; x--) {
5471 int ch = Character.codePointAt(seq, x);
5472 if (Character.isLetterOrDigit(ch))
5473 return true;
5474 if (Character.getType(ch) == Character.NON_SPACING_MARK)
5475 continue;
5476 return false;
5477 }
5478 return false;
5479 }
5480
5481 /**
5482 * Attempts to match a slice in the input using the Boyer-Moore string
5483 * matching algorithm. The algorithm is based on the idea that the
5484 * pattern can be shifted farther ahead in the search text if it is
5485 * matched right to left.
5486 * <p>
5487 * The pattern is compared to the input one character at a time, from
5488 * the rightmost character in the pattern to the left. If the characters
5489 * all match the pattern has been found. If a character does not match,
5490 * the pattern is shifted right a distance that is the maximum of two
5491 * functions, the bad character shift and the good suffix shift. This
5492 * shift moves the attempted match position through the input more
5493 * quickly than a naive one position at a time check.
5494 * <p>
5495 * The bad character shift is based on the character from the text that
5496 * did not match. If the character does not appear in the pattern, the
5497 * pattern can be shifted completely beyond the bad character. If the
5498 * character does occur in the pattern, the pattern can be shifted to
5499 * line the pattern up with the next occurrence of that character.
5500 * <p>
5501 * The good suffix shift is based on the idea that some subset on the right
5502 * side of the pattern has matched. When a bad character is found, the
5503 * pattern can be shifted right by the pattern length if the subset does
5504 * not occur again in pattern, or by the amount of distance to the
5505 * next occurrence of the subset in the pattern.
5506 *
5507 * Boyer-Moore search methods adapted from code by Amy Yu.
5508 */
5509 static class BnM extends Node {
5510 int[] buffer;
5511 int[] lastOcc;
5512 int[] optoSft;
5513
5514 /**
5515 * Pre calculates arrays needed to generate the bad character
5516 * shift and the good suffix shift. Only the last seven bits
5517 * are used to see if chars match; This keeps the tables small
5518 * and covers the heavily used ASCII range, but occasionally
5519 * results in an aliased match for the bad character shift.
5520 */
5521 static Node optimize(Node node) {
5522 if (!(node instanceof Slice)) {
5523 return node;
5524 }
5525
5526 int[] src = ((Slice) node).buffer;
5527 int patternLength = src.length;
5528 // The BM algorithm requires a bit of overhead;
5529 // If the pattern is short don't use it, since
5530 // a shift larger than the pattern length cannot
5531 // be used anyway.
5532 if (patternLength < 4) {
5533 return node;
5534 }
5535 int i, j, k;
5536 int[] lastOcc = new int[128];
5537 int[] optoSft = new int[patternLength];
5538 // Precalculate part of the bad character shift
5539 // It is a table for where in the pattern each
5540 // lower 7-bit value occurs
5541 for (i = 0; i < patternLength; i++) {
5542 lastOcc[src[i]&0x7F] = i + 1;
5543 }
5544 // Precalculate the good suffix shift
5545 // i is the shift amount being considered
5546 NEXT: for (i = patternLength; i > 0; i--) {
5547 // j is the beginning index of suffix being considered
5548 for (j = patternLength - 1; j >= i; j--) {
5549 // Testing for good suffix
5550 if (src[j] == src[j-i]) {
5551 // src[j..len] is a good suffix
5552 optoSft[j-1] = i;
5553 } else {
5554 // No match. The array has already been
5555 // filled up with correct values before.
5556 continue NEXT;
5557 }
5558 }
5559 // This fills up the remaining of optoSft
5560 // any suffix can not have larger shift amount
5561 // then its sub-suffix. Why???
5562 while (j > 0) {
5563 optoSft[--j] = i;
5564 }
5565 }
5566 // Set the guard value because of unicode compression
5567 optoSft[patternLength-1] = 1;
5568 if (node instanceof SliceS)
5569 return new BnMS(src, lastOcc, optoSft, node.next);
5570 return new BnM(src, lastOcc, optoSft, node.next);
5571 }
5572 BnM(int[] src, int[] lastOcc, int[] optoSft, Node next) {
5573 this.buffer = src;
5574 this.lastOcc = lastOcc;
5575 this.optoSft = optoSft;
5576 this.next = next;
5577 }
5578 boolean match(Matcher matcher, int i, CharSequence seq) {
5579 int[] src = buffer;
5580 int patternLength = src.length;
5581 int last = matcher.to - patternLength;
5582
5583 // Loop over all possible match positions in text
5584 NEXT: while (i <= last) {
5585 // Loop over pattern from right to left
5586 for (int j = patternLength - 1; j >= 0; j--) {
5587 int ch = seq.charAt(i+j);
5588 if (ch != src[j]) {
5589 // Shift search to the right by the maximum of the
5590 // bad character shift and the good suffix shift
5591 i += Math.max(j + 1 - lastOcc[ch&0x7F], optoSft[j]);
5592 continue NEXT;
5593 }
5594 }
5595 // Entire pattern matched starting at i
5596 matcher.first = i;
5597 boolean ret = next.match(matcher, i + patternLength, seq);
5598 if (ret) {
5599 matcher.first = i;
5600 matcher.groups[0] = matcher.first;
5601 matcher.groups[1] = matcher.last;
5602 return true;
5603 }
5604 i++;
5605 }
5606 // BnM is only used as the leading node in the unanchored case,
5607 // and it replaced its Start() which always searches to the end
5608 // if it doesn't find what it's looking for, so hitEnd is true.
5609 matcher.hitEnd = true;
5610 return false;
5611 }
5612 boolean study(TreeInfo info) {
5613 info.minLength += buffer.length;
5614 info.maxValid = false;
5615 return next.study(info);
5616 }
5617 }
5618
5619 /**
5620 * Supplementary support version of BnM(). Unpaired surrogates are
5621 * also handled by this class.
5622 */
5623 static final class BnMS extends BnM {
5624 int lengthInChars;
5625
5626 BnMS(int[] src, int[] lastOcc, int[] optoSft, Node next) {
5627 super(src, lastOcc, optoSft, next);
5628 for (int cp : buffer) {
5629 lengthInChars += Character.charCount(cp);
5630 }
5631 }
5632 boolean match(Matcher matcher, int i, CharSequence seq) {
5633 int[] src = buffer;
5634 int patternLength = src.length;
5635 int last = matcher.to - lengthInChars;
5636
5637 // Loop over all possible match positions in text
5638 NEXT: while (i <= last) {
5639 // Loop over pattern from right to left
5640 int ch;
5641 for (int j = countChars(seq, i, patternLength), x = patternLength - 1;
5642 j > 0; j -= Character.charCount(ch), x--) {
5643 ch = Character.codePointBefore(seq, i+j);
5644 if (ch != src[x]) {
5645 // Shift search to the right by the maximum of the
5646 // bad character shift and the good suffix shift
5647 int n = Math.max(x + 1 - lastOcc[ch&0x7F], optoSft[x]);
5648 i += countChars(seq, i, n);
5649 continue NEXT;
5650 }
5651 }
5652 // Entire pattern matched starting at i
5653 matcher.first = i;
5654 boolean ret = next.match(matcher, i + lengthInChars, seq);
5655 if (ret) {
5656 matcher.first = i;
5657 matcher.groups[0] = matcher.first;
5658 matcher.groups[1] = matcher.last;
5659 return true;
5660 }
5661 i += countChars(seq, i, 1);
5662 }
5663 matcher.hitEnd = true;
5664 return false;
5665 }
5666 }
5667
5668 @FunctionalInterface
5669 static interface CharPredicate {
5670 boolean is(int ch);
5671
5672 default CharPredicate and(CharPredicate p) {
5673 return ch -> is(ch) && p.is(ch);
5674 }
5675 default CharPredicate union(CharPredicate p) {
5676 return ch -> is(ch) || p.is(ch);
5677 }
5678 default CharPredicate union(CharPredicate p1,
5679 CharPredicate p2 ) {
5680 return ch -> is(ch) || p1.is(ch) || p2.is(ch);
5681 }
5682 default CharPredicate negate() {
5683 return ch -> !is(ch);
5684 }
5685 }
5686
5687 static interface BmpCharPredicate extends CharPredicate {
5688
5689 default CharPredicate and(CharPredicate p) {
5690 if(p instanceof BmpCharPredicate)
5691 return (BmpCharPredicate)(ch -> is(ch) && p.is(ch));
5692 return ch -> is(ch) && p.is(ch);
5693 }
5694 default CharPredicate union(CharPredicate p) {
5695 if (p instanceof BmpCharPredicate)
5696 return (BmpCharPredicate)(ch -> is(ch) || p.is(ch));
5697 return ch -> is(ch) || p.is(ch);
5698 }
5699 static CharPredicate union(CharPredicate... predicates) {
5700 CharPredicate cp = ch -> {
5701 for (CharPredicate p : predicates) {
5702 if (!p.is(ch))
5703 return false;
5704 }
5705 return true;
5706 };
5707 for (CharPredicate p : predicates) {
5708 if (! (p instanceof BmpCharPredicate))
5709 return cp;
5710 }
5711 return (BmpCharPredicate)cp;
5712 }
5713 }
5714
5715 /**
5716 * matches a Perl vertical whitespace
5717 */
5718 static BmpCharPredicate VertWS() {
5719 return cp -> (cp >= 0x0A && cp <= 0x0D) ||
5720 cp == 0x85 || cp == 0x2028 || cp == 0x2029;
5721 }
5722
5723 /**
5724 * matches a Perl horizontal whitespace
5725 */
5726 static BmpCharPredicate HorizWS() {
5727 return cp ->
5728 cp == 0x09 || cp == 0x20 || cp == 0xa0 || cp == 0x1680 ||
5729 cp == 0x180e || cp >= 0x2000 && cp <= 0x200a || cp == 0x202f ||
5730 cp == 0x205f || cp == 0x3000;
5731 }
5732
5733 /**
5734 * for the Unicode category ALL and the dot metacharacter when
5735 * in dotall mode.
5736 */
5737 static CharPredicate ALL() {
5738 return ch -> true;
5739 }
5740
5741 /**
5742 * for the dot metacharacter when dotall is not enabled.
5743 */
5744 static CharPredicate DOT() {
5745 return ch ->
5746 (ch != '\n' && ch != '\r'
5747 && (ch|1) != '\u2029'
5748 && ch != '\u0085');
5749 }
5750
5751 /**
5752 * the dot metacharacter when dotall is not enabled but UNIX_LINES is enabled.
5753 */
5754 static CharPredicate UNIXDOT() {
5755 return ch -> ch != '\n';
5756 }
5757
5758 /**
5759 * Indicate that matches a Supplementary Unicode character
5760 */
5761 static CharPredicate SingleS(int c) {
5762 return ch -> ch == c;
5763 }
5764
5765 /**
5766 * A bmp/optimized predicate of single
5767 */
5768 static BmpCharPredicate Single(int c) {
5769 return ch -> ch == c;
5770 }
5771
5772 /**
5773 * Case insensitive matches a given BMP character
5774 */
5775 static BmpCharPredicate SingleI(int lower, int upper) {
5776 return ch -> ch == lower || ch == upper;
5777 }
5778
5779 /**
5780 * Unicode case insensitive matches a given Unicode character
5781 */
5782 static CharPredicate SingleU(int lower) {
5783 return ch -> lower == ch ||
5784 lower == Character.toLowerCase(Character.toUpperCase(ch));
5785 }
5786
5787 private static boolean inRange(int lower, int ch, int upper) {
5788 return lower <= ch && ch <= upper;
5789 }
5790
5791 /**
5792 * Charactrs within a explicit value range
5793 */
5794 static CharPredicate Range(int lower, int upper) {
5795 if (upper < Character.MIN_HIGH_SURROGATE ||
5796 lower > Character.MAX_HIGH_SURROGATE &&
5797 upper < Character.MIN_SUPPLEMENTARY_CODE_POINT)
5798 return (BmpCharPredicate)(ch -> inRange(lower, ch, upper));
5799 return ch -> inRange(lower, ch, upper);
5800 }
5801
5802 /**
5803 * Charactrs within a explicit value range in a case insensitive manner.
5804 */
5805 static CharPredicate CIRange(int lower, int upper) {
5806 return ch -> inRange(lower, ch, upper) ||
5807 ASCII.isAscii(ch) &&
5808 (inRange(lower, ASCII.toUpper(ch), upper) ||
5809 inRange(lower, ASCII.toLower(ch), upper));
5810 }
5811
5812 static CharPredicate CIRangeU(int lower, int upper) {
5813 return ch -> {
5814 if (inRange(lower, ch, upper))
5815 return true;
5816 int up = Character.toUpperCase(ch);
5817 return inRange(lower, up, upper) ||
5818 inRange(lower, Character.toLowerCase(up), upper);
5819 };
5820 }
5821
5822 /**
5823 * This must be the very first initializer.
5824 */
5825 static final Node accept = new Node();
5826
5827 static final Node lastAccept = new LastNode();
5828
5829 /**
5830 * Creates a predicate that tests if this pattern is found in a given input
5831 * string.
5832 *
5833 * @apiNote
5834 * This method creates a predicate that behaves as if it creates a matcher
5835 * from the input sequence and then calls {@code find}, for example a
5836 * predicate of the form:
5837 * <pre>{@code
5838 * s -> matcher(s).find();
5839 * }</pre>
5840 *
5841 * @return The predicate which can be used for finding a match on a
5842 * subsequence of a string
5843 * @since 1.8
5844 * @see Matcher#find
5845 */
5846 public Predicate<String> asPredicate() {
5847 return s -> matcher(s).find();
5848 }
5849
5850 /**
5851 * Creates a predicate that tests if this pattern matches a given input string.
5852 *
5853 * @apiNote
5854 * This method creates a predicate that behaves as if it creates a matcher
5855 * from the input sequence and then calls {@code matches}, for example a
5856 * predicate of the form:
5857 * <pre>{@code
5858 * s -> matcher(s).matches();
5859 * }</pre>
5860 *
5861 * @return The predicate which can be used for matching an input string
5862 * against this pattern.
5863 * @since 11
5864 * @see Matcher#matches
5865 */
5866 public Predicate<String> asMatchPredicate() {
5867 return s -> matcher(s).matches();
5868 }
5869
5870 /**
5871 * Creates a stream from the given input sequence around matches of this
5872 * pattern.
5873 *
5874 * <p> The stream returned by this method contains each substring of the
5875 * input sequence that is terminated by another subsequence that matches
5876 * this pattern or is terminated by the end of the input sequence. The
5877 * substrings in the stream are in the order in which they occur in the
5878 * input. Trailing empty strings will be discarded and not encountered in
5879 * the stream.
5880 *
5881 * <p> If this pattern does not match any subsequence of the input then
5882 * the resulting stream has just one element, namely the input sequence in
5883 * string form.
5884 *
5885 * <p> When there is a positive-width match at the beginning of the input
5886 * sequence then an empty leading substring is included at the beginning
5887 * of the stream. A zero-width match at the beginning however never produces
5888 * such empty leading substring.
5889 *
5890 * <p> If the input sequence is mutable, it must remain constant during the
5891 * execution of the terminal stream operation. Otherwise, the result of the
5892 * terminal stream operation is undefined.
5893 *
5894 * @param input
5895 * The character sequence to be split
5896 *
5897 * @return The stream of strings computed by splitting the input
5898 * around matches of this pattern
5899 * @see #split(CharSequence)
5900 * @since 1.8
5901 */
5902 public Stream<String> splitAsStream(final CharSequence input) {
5903 class MatcherIterator implements Iterator<String> {
5904 private Matcher matcher;
5905 // The start position of the next sub-sequence of input
5906 // when current == input.length there are no more elements
5907 private int current;
5908 // null if the next element, if any, needs to obtained
5909 private String nextElement;
5910 // > 0 if there are N next empty elements
5911 private int emptyElementCount;
5912
5913 public String next() {
5914 if (!hasNext())
5915 throw new NoSuchElementException();
5916
5917 if (emptyElementCount == 0) {
5918 String n = nextElement;
5919 nextElement = null;
5920 return n;
5921 } else {
5922 emptyElementCount--;
5923 return "";
5924 }
5925 }
5926
5927 public boolean hasNext() {
5928 if (matcher == null) {
5929 matcher = matcher(input);
5930 // If the input is an empty string then the result can only be a
5931 // stream of the input. Induce that by setting the empty
5932 // element count to 1
5933 emptyElementCount = input.length() == 0 ? 1 : 0;
5934 }
5935 if (nextElement != null || emptyElementCount > 0)
5936 return true;
5937
5938 if (current == input.length())
5939 return false;
5940
5941 // Consume the next matching element
5942 // Count sequence of matching empty elements
5943 while (matcher.find()) {
5944 nextElement = input.subSequence(current, matcher.start()).toString();
5945 current = matcher.end();
5946 if (!nextElement.isEmpty()) {
5947 return true;
5948 } else if (current > 0) { // no empty leading substring for zero-width
5949 // match at the beginning of the input
5950 emptyElementCount++;
5951 }
5952 }
5953
5954 // Consume last matching element
5955 nextElement = input.subSequence(current, input.length()).toString();
5956 current = input.length();
5957 if (!nextElement.isEmpty()) {
5958 return true;
5959 } else {
5960 // Ignore a terminal sequence of matching empty elements
5961 emptyElementCount = 0;
5962 nextElement = null;
5963 return false;
5964 }
5965 }
5966 }
5967 return StreamSupport.stream(Spliterators.spliteratorUnknownSize(
5968 new MatcherIterator(), Spliterator.ORDERED | Spliterator.NONNULL), false);
5969 }
5970 }