1 /*
2 * Copyright (c) 1999, 2018, 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
47 /**
48 * A compiled representation of a regular expression.
49 *
50 * <p> A regular expression, specified as a string, must first be compiled into
51 * an instance of this class. The resulting pattern can then be used to create
52 * a {@link Matcher} object that can match arbitrary {@linkplain
53 * java.lang.CharSequence character sequences} against the regular
54 * expression. All of the state involved in performing a match resides in the
55 * matcher, so many matchers can share the same pattern.
56 *
57 * <p> A typical invocation sequence is thus
58 *
59 * <blockquote><pre>
60 * Pattern p = Pattern.{@link #compile compile}("a*b");
61 * Matcher m = p.{@link #matcher matcher}("aaaaab");
62 * boolean b = m.{@link Matcher#matches matches}();</pre></blockquote>
63 *
64 * <p> A {@link #matches matches} method is defined by this class as a
65 * convenience for when a regular expression is used just once. This method
66 * compiles an expression and matches an input sequence against it in a single
67 * invocation. The statement
68 *
69 * <blockquote><pre>
70 * boolean b = Pattern.matches("a*b", "aaaaab");</pre></blockquote>
71 *
72 * is equivalent to the three statements above, though for repeated matches it
73 * is less efficient since it does not allow the compiled pattern to be reused.
74 *
75 * <p> Instances of this class are immutable and are safe for use by multiple
76 * concurrent threads. Instances of the {@link Matcher} class are not safe for
77 * such use.
78 *
79 *
80 * <h3><a id="sum">Summary of regular-expression constructs</a></h3>
81 *
82 * <table class="borderless">
83 * <caption style="display:none">Regular expression constructs, and what they match</caption>
84 * <thead style="text-align:left">
85 * <tr>
86 * <th id="construct">Construct</th>
87 * <th id="matches">Matches</th>
88 * </tr>
89 * </thead>
90 * <tbody style="text-align:left">
91 *
92 * <tr><th colspan="2" style="padding-top:20px" id="characters">Characters</th></tr>
93 *
94 * <tr><th style="vertical-align:top; font-weight: normal" id="x"><i>x</i></th>
95 * <td headers="matches characters x">The character <i>x</i></td></tr>
96 * <tr><th style="vertical-align:top; font-weight: normal" id="backslash">{@code \\}</th>
97 * <td headers="matches characters backslash">The backslash character</td></tr>
98 * <tr><th style="vertical-align:top; font-weight: normal" id="octal_n">{@code \0}<i>n</i></th>
99 * <td headers="matches characters octal_n">The character with octal value {@code 0}<i>n</i>
100 * (0 {@code <=} <i>n</i> {@code <=} 7)</td></tr>
101 * <tr><th style="vertical-align:top; font-weight: normal" id="octal_nn">{@code \0}<i>nn</i></th>
102 * <td headers="matches characters octal_nn">The character with octal value {@code 0}<i>nn</i>
103 * (0 {@code <=} <i>n</i> {@code <=} 7)</td></tr>
104 * <tr><th style="vertical-align:top; font-weight: normal" id="octal_nnn">{@code \0}<i>mnn</i></th>
105 * <td headers="matches characters octal_nnn">The character with octal value {@code 0}<i>mnn</i>
106 * (0 {@code <=} <i>m</i> {@code <=} 3,
107 * 0 {@code <=} <i>n</i> {@code <=} 7)</td></tr>
108 * <tr><th style="vertical-align:top; font-weight: normal" id="hex_hh">{@code \x}<i>hh</i></th>
109 * <td headers="matches characters hex_hh">The character with hexadecimal value {@code 0x}<i>hh</i></td></tr>
110 * <tr><th style="vertical-align:top; font-weight: normal" id="hex_hhhh"><code>\u</code><i>hhhh</i></th>
111 * <td headers="matches characters hex_hhhh">The character with hexadecimal value {@code 0x}<i>hhhh</i></td></tr>
112 * <tr><th style="vertical-align:top; font-weight: normal" id="hex_h_h"><code>\x</code><i>{h...h}</i></th>
113 * <td headers="matches characters hex_h_h">The character with hexadecimal value {@code 0x}<i>h...h</i>
114 * ({@link java.lang.Character#MIN_CODE_POINT Character.MIN_CODE_POINT}
115 * <= {@code 0x}<i>h...h</i> <=
116 * {@link java.lang.Character#MAX_CODE_POINT Character.MAX_CODE_POINT})</td></tr>
117 * <tr><th style="vertical-align:top; font-weight: normal" id="unicode_name"><code>\N{</code><i>name</i><code>}</code></th>
118 * <td headers="matches characters unicode_name">The character with Unicode character name <i>'name'</i></td></tr>
119 * <tr><th style="vertical-align:top; font-weight:normal" id="tab">{@code \t}</th>
120 * <td headers="matches characters tab">The tab character (<code>'\u0009'</code>)</td></tr>
121 * <tr><th style="vertical-align:top; font-weight:normal" id="newline">{@code \n}</th>
122 * <td headers="matches characters newline">The newline (line feed) character (<code>'\u000A'</code>)</td></tr>
123 * <tr><th style="vertical-align:top; font-weight:normal" id="return">{@code \r}</th>
124 * <td headers="matches characters return">The carriage-return character (<code>'\u000D'</code>)</td></tr>
125 * <tr><th style="vertical-align:top; font-weight:normal" id="form_feed">{@code \f}</th>
126 * <td headers="matches characters form_feed">The form-feed character (<code>'\u000C'</code>)</td></tr>
127 * <tr><th style="vertical-align:top; font-weight:normal" id="bell">{@code \a}</th>
128 * <td headers="matches characters bell">The alert (bell) character (<code>'\u0007'</code>)</td></tr>
129 * <tr><th style="vertical-align:top; font-weight:normal" id="escape">{@code \e}</th>
130 * <td headers="matches characters escape">The escape character (<code>'\u001B'</code>)</td></tr>
131 * <tr><th style="vertical-align:top; font-weight:normal" id="ctrl_x">{@code \c}<i>x</i></th>
132 * <td headers="matches characters ctrl_x">The control character corresponding to <i>x</i></td></tr>
133 *
134 * <tr><th colspan="2" style="padding-top:20px" id="classes">Character classes</th></tr>
135 *
136 * <tr><th style="vertical-align:top; font-weight:normal" id="simple">{@code [abc]}</th>
137 * <td headers="matches classes simple">{@code a}, {@code b}, or {@code c} (simple class)</td></tr>
138 * <tr><th style="vertical-align:top; font-weight:normal" id="negation">{@code [^abc]}</th>
139 * <td headers="matches classes negation">Any character except {@code a}, {@code b}, or {@code c} (negation)</td></tr>
140 * <tr><th style="vertical-align:top; font-weight:normal" id="range">{@code [a-zA-Z]}</th>
141 * <td headers="matches classes range">{@code a} through {@code z}
142 * or {@code A} through {@code Z}, inclusive (range)</td></tr>
143 * <tr><th style="vertical-align:top; font-weight:normal" id="union">{@code [a-d[m-p]]}</th>
144 * <td headers="matches classes union">{@code a} through {@code d},
145 * or {@code m} through {@code p}: {@code [a-dm-p]} (union)</td></tr>
146 * <tr><th style="vertical-align:top; font-weight:normal" id="intersection">{@code [a-z&&[def]]}</th>
147 * <td headers="matches classes intersection">{@code d}, {@code e}, or {@code f} (intersection)</tr>
148 * <tr><th style="vertical-align:top; font-weight:normal" id="subtraction1">{@code [a-z&&[^bc]]}</th>
149 * <td headers="matches classes subtraction1">{@code a} through {@code z},
150 * except for {@code b} and {@code c}: {@code [ad-z]} (subtraction)</td></tr>
151 * <tr><th style="vertical-align:top; font-weight:normal" id="subtraction2">{@code [a-z&&[^m-p]]}</th>
152 * <td headers="matches classes subtraction2">{@code a} through {@code z},
153 * and not {@code m} through {@code p}: {@code [a-lq-z]}(subtraction)</td></tr>
154 *
155 * <tr><th colspan="2" style="padding-top:20px" id="predef">Predefined character classes</th></tr>
156 *
157 * <tr><th style="vertical-align:top; font-weight:normal" id="any">{@code .}</th>
158 * <td headers="matches predef any">Any character (may or may not match <a href="#lt">line terminators</a>)</td></tr>
159 * <tr><th style="vertical-align:top; font-weight:normal" id="digit">{@code \d}</th>
160 * <td headers="matches predef digit">A digit: {@code [0-9]}</td></tr>
161 * <tr><th style="vertical-align:top; font-weight:normal" id="non_digit">{@code \D}</th>
162 * <td headers="matches predef non_digit">A non-digit: {@code [^0-9]}</td></tr>
163 * <tr><th style="vertical-align:top; font-weight:normal" id="horiz_white">{@code \h}</th>
164 * <td headers="matches predef horiz_white">A horizontal whitespace character:
165 * <code>[ \t\xA0\u1680\u180e\u2000-\u200a\u202f\u205f\u3000]</code></td></tr>
166 * <tr><th style="vertical-align:top; font-weight:normal" id="non_horiz_white">{@code \H}</th>
167 * <td headers="matches predef non_horiz_white">A non-horizontal whitespace character: {@code [^\h]}</td></tr>
168 * <tr><th style="vertical-align:top; font-weight:normal" id="white">{@code \s}</th>
169 * <td headers="matches predef white">A whitespace character: {@code [ \t\n\x0B\f\r]}</td></tr>
170 * <tr><th style="vertical-align:top; font-weight:normal" id="non_white">{@code \S}</th>
171 * <td headers="matches predef non_white">A non-whitespace character: {@code [^\s]}</td></tr>
172 * <tr><th style="vertical-align:top; font-weight:normal" id="vert_white">{@code \v}</th>
173 * <td headers="matches predef vert_white">A vertical whitespace character: <code>[\n\x0B\f\r\x85\u2028\u2029]</code>
174 * </td></tr>
175 * <tr><th style="vertical-align:top; font-weight:normal" id="non_vert_white">{@code \V}</th>
176 * <td headers="matches predef non_vert_white">A non-vertical whitespace character: {@code [^\v]}</td></tr>
177 * <tr><th style="vertical-align:top; font-weight:normal" id="word">{@code \w}</th>
178 * <td headers="matches predef word">A word character: {@code [a-zA-Z_0-9]}</td></tr>
179 * <tr><th style="vertical-align:top; font-weight:normal" id="non_word">{@code \W}</th>
180 * <td headers="matches predef non_word">A non-word character: {@code [^\w]}</td></tr>
181 *
182 * <tr><th colspan="2" style="padding-top:20px" id="posix"><b>POSIX character classes (US-ASCII only)</b></th></tr>
183 *
184 * <tr><th style="vertical-align:top; font-weight:normal" id="Lower">{@code \p{Lower}}</th>
185 * <td headers="matches posix Lower">A lower-case alphabetic character: {@code [a-z]}</td></tr>
186 * <tr><th style="vertical-align:top; font-weight:normal" id="Upper">{@code \p{Upper}}</th>
187 * <td headers="matches posix Upper">An upper-case alphabetic character:{@code [A-Z]}</td></tr>
188 * <tr><th style="vertical-align:top; font-weight:normal" id="ASCII">{@code \p{ASCII}}</th>
189 * <td headers="matches posix ASCII">All ASCII:{@code [\x00-\x7F]}</td></tr>
190 * <tr><th style="vertical-align:top; font-weight:normal" id="Alpha">{@code \p{Alpha}}</th>
191 * <td headers="matches posix Alpha">An alphabetic character:{@code [\p{Lower}\p{Upper}]}</td></tr>
192 * <tr><th style="vertical-align:top; font-weight:normal" id="Digit">{@code \p{Digit}}</th>
193 * <td headers="matches posix Digit">A decimal digit: {@code [0-9]}</td></tr>
194 * <tr><th style="vertical-align:top; font-weight:normal" id="Alnum">{@code \p{Alnum}}</th>
195 * <td headers="matches posix Alnum">An alphanumeric character:{@code [\p{Alpha}\p{Digit}]}</td></tr>
196 * <tr><th style="vertical-align:top; font-weight:normal" id="Punct">{@code \p{Punct}}</th>
197 * <td headers="matches posix Punct">Punctuation: One of {@code !"#$%&'()*+,-./:;<=>?@[\]^_`{|}~}</td></tr>
198 * <!-- {@code [\!"#\$%&'\(\)\*\+,\-\./:;\<=\>\?@\[\\\]\^_`\{\|\}~]}
199 * {@code [\X21-\X2F\X31-\X40\X5B-\X60\X7B-\X7E]} -->
200 * <tr><th style="vertical-align:top; font-weight:normal" id="Graph">{@code \p{Graph}}</th>
201 * <td headers="matches posix Graph">A visible character: {@code [\p{Alnum}\p{Punct}]}</td></tr>
202 * <tr><th style="vertical-align:top; font-weight:normal" id="Print">{@code \p{Print}}</th>
203 * <td headers="matches posix Print">A printable character: {@code [\p{Graph}\x20]}</td></tr>
204 * <tr><th style="vertical-align:top; font-weight:normal" id="Blank">{@code \p{Blank}}</th>
205 * <td headers="matches posix Blank">A space or a tab: {@code [ \t]}</td></tr>
206 * <tr><th style="vertical-align:top; font-weight:normal" id="Cntrl">{@code \p{Cntrl}}</th>
207 * <td headers="matches posix Cntrl">A control character: {@code [\x00-\x1F\x7F]}</td></tr>
208 * <tr><th style="vertical-align:top; font-weight:normal" id="XDigit">{@code \p{XDigit}}</th>
209 * <td headers="matches posix XDigit">A hexadecimal digit: {@code [0-9a-fA-F]}</td></tr>
210 * <tr><th style="vertical-align:top; font-weight:normal" id="Space">{@code \p{Space}}</th>
211 * <td headers="matches posix Space">A whitespace character: {@code [ \t\n\x0B\f\r]}</td></tr>
212 *
213 * <tr><th colspan="2" style="padding-top:20px" id="java">java.lang.Character classes (simple <a href="#jcc">java character type</a>)</th></tr>
214 *
215 * <tr><th style="vertical-align:top; font-weight:normal" id="javaLowerCase">{@code \p{javaLowerCase}}</th>
216 * <td headers="matches java javaLowerCase">Equivalent to java.lang.Character.isLowerCase()</td></tr>
217 * <tr><th style="vertical-align:top; font-weight:normal" id="javaUpperCase">{@code \p{javaUpperCase}}</th>
218 * <td headers="matches java javaUpperCase">Equivalent to java.lang.Character.isUpperCase()</td></tr>
219 * <tr><th style="vertical-align:top; font-weight:normal" id="javaWhitespace">{@code \p{javaWhitespace}}</th>
220 * <td headers="matches java javaWhitespace">Equivalent to java.lang.Character.isWhitespace()</td></tr>
221 * <tr><th style="vertical-align:top; font-weight:normal" id="javaMirrored">{@code \p{javaMirrored}}</th>
222 * <td headers="matches java javaMirrored">Equivalent to java.lang.Character.isMirrored()</td></tr>
223 *
224 * <tr><th colspan="2" style="padding-top:20px" id="unicode">Classes for Unicode scripts, blocks, categories and binary properties</th></tr>
225 *
226 * <tr><th style="vertical-align:top; font-weight:normal" id="IsLatin">{@code \p{IsLatin}}</th>
227 * <td headers="matches unicode IsLatin">A Latin script character (<a href="#usc">script</a>)</td></tr>
228 * <tr><th style="vertical-align:top; font-weight:normal" id="InGreek">{@code \p{InGreek}}</th>
229 * <td headers="matches unicode InGreek">A character in the Greek block (<a href="#ubc">block</a>)</td></tr>
230 * <tr><th style="vertical-align:top; font-weight:normal" id="Lu">{@code \p{Lu}}</th>
231 * <td headers="matches unicode Lu">An uppercase letter (<a href="#ucc">category</a>)</td></tr>
232 * <tr><th style="vertical-align:top; font-weight:normal" id="IsAlphabetic">{@code \p{IsAlphabetic}}</th>
233 * <td headers="matches unicode IsAlphabetic">An alphabetic character (<a href="#ubpc">binary property</a>)</td></tr>
234 * <tr><th style="vertical-align:top; font-weight:normal" id="Sc">{@code \p{Sc}}</th>
235 * <td headers="matches unicode Sc">A currency symbol</td></tr>
236 * <tr><th style="vertical-align:top; font-weight:normal" id="not_InGreek">{@code \P{InGreek}}</th>
237 * <td headers="matches unicode not_InGreek">Any character except one in the Greek block (negation)</td></tr>
238 * <tr><th style="vertical-align:top; font-weight:normal" id="not_uppercase">{@code [\p{L}&&[^\p{Lu}]]}</th>
239 * <td headers="matches unicode not_uppercase">Any letter except an uppercase letter (subtraction)</td></tr>
240 *
241 * <tr><th colspan="2" style="padding-top:20px" id="bounds">Boundary matchers</th></tr>
242 *
243 * <tr><th style="vertical-align:top; font-weight:normal" id="begin_line">{@code ^}</th>
244 * <td headers="matches bounds begin_line">The beginning of a line</td></tr>
245 * <tr><th style="vertical-align:top; font-weight:normal" id="end_line">{@code $}</th>
246 * <td headers="matches bounds end_line">The end of a line</td></tr>
247 * <tr><th style="vertical-align:top; font-weight:normal" id="word_boundary">{@code \b}</th>
248 * <td headers="matches bounds word_boundary">A word boundary</td></tr>
249 * <tr><th style="vertical-align:top; font-weight:normal" id="grapheme_cluster_boundary">{@code \b{g}}</th>
250 * <td headers="matches bounds grapheme_cluster_boundary">A Unicode extended grapheme cluster boundary</td></tr>
251 * <tr><th style="vertical-align:top; font-weight:normal" id="non_word_boundary">{@code \B}</th>
252 * <td headers="matches bounds non_word_boundary">A non-word boundary</td></tr>
253 * <tr><th style="vertical-align:top; font-weight:normal" id="begin_input">{@code \A}</th>
254 * <td headers="matches bounds begin_input">The beginning of the input</td></tr>
255 * <tr><th style="vertical-align:top; font-weight:normal" id="end_prev_match">{@code \G}</th>
256 * <td headers="matches bounds end_prev_match">The end of the previous match</td></tr>
257 * <tr><th style="vertical-align:top; font-weight:normal" id="end_input_except_term">{@code \Z}</th>
258 * <td headers="matches bounds end_input_except_term">The end of the input but for the final
259 * <a href="#lt">terminator</a>, if any</td></tr>
260 * <tr><th style="vertical-align:top; font-weight:normal" id="end_input">{@code \z}</th>
261 * <td headers="matches bounds end_input">The end of the input</td></tr>
262 *
263 * <tr><th colspan="2" style="padding-top:20px" id="linebreak">Linebreak matcher</th></tr>
264 *
265 * <tr><th style="vertical-align:top; font-weight:normal" id="any_unicode_linebreak">{@code \R}</th>
266 * <td headers="matches linebreak any_unicode_linebreak">Any Unicode linebreak sequence, is equivalent to
267 * <code>\u000D\u000A|[\u000A\u000B\u000C\u000D\u0085\u2028\u2029]
268 * </code></td></tr>
269 *
270 * <tr><th colspan="2" style="padding-top:20px" id="grapheme">Unicode Extended Grapheme matcher</th></tr>
271 *
272 * <tr><th style="vertical-align:top; font-weight:normal" id="grapheme_any">{@code \X}</th>
273 * <td headers="matches grapheme grapheme_any">Any Unicode extended grapheme cluster</td></tr>
274 *
275 * <tr><th colspan="2" style="padding-top:20px" id="greedy">Greedy quantifiers</th></tr>
276 *
277 * <tr><th style="vertical-align:top; font-weight:normal" id="greedy_once_or_not"><i>X</i>{@code ?}</th>
278 * <td headers="matches greedy greedy_once_or_not"><i>X</i>, once or not at all</td></tr>
279 * <tr><th style="vertical-align:top; font-weight:normal" id="greedy_zero_or_more"><i>X</i>{@code *}</th>
280 * <td headers="matches greedy greedy_zero_or_more"><i>X</i>, zero or more times</td></tr>
281 * <tr><th style="vertical-align:top; font-weight:normal" id="greedy_one_or_more"><i>X</i>{@code +}</th>
282 * <td headers="matches greedy greedy_one_or_more"><i>X</i>, one or more times</td></tr>
283 * <tr><th style="vertical-align:top; font-weight:normal" id="greedy_exactly"><i>X</i><code>{</code><i>n</i><code>}</code></th>
284 * <td headers="matches greedy greedy_exactly"><i>X</i>, exactly <i>n</i> times</td></tr>
285 * <tr><th style="vertical-align:top; font-weight:normal" id="greedy_at_least"><i>X</i><code>{</code><i>n</i>{@code ,}}</th>
286 * <td headers="matches greedy greedy_at_least"><i>X</i>, at least <i>n</i> times</td></tr>
287 * <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>
288 * <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>
289 *
290 * <tr><th colspan="2" style="padding-top:20px" id="reluc">Reluctant quantifiers</th></tr>
291 *
292 * <tr><th style="vertical-align:top; font-weight:normal" id="reluc_once_or_not"><i>X</i>{@code ??}</th>
293 * <td headers="matches reluc reluc_once_or_not"><i>X</i>, once or not at all</td></tr>
294 * <tr><th style="vertical-align:top; font-weight:normal" id="reluc_zero_or_more"><i>X</i>{@code *?}</th>
295 * <td headers="matches reluc reluc_zero_or_more"><i>X</i>, zero or more times</td></tr>
296 * <tr><th style="vertical-align:top; font-weight:normal" id="reluc_one_or_more"><i>X</i>{@code +?}</th>
297 * <td headers="matches reluc reluc_one_or_more"><i>X</i>, one or more times</td></tr>
298 * <tr><th style="vertical-align:top; font-weight:normal" id="reluc_exactly"><i>X</i><code>{</code><i>n</i><code>}?</code></th>
299 * <td headers="matches reluc reluc_exactly"><i>X</i>, exactly <i>n</i> times</td></tr>
300 * <tr><th style="vertical-align:top; font-weight:normal" id="reluc_at_least"><i>X</i><code>{</code><i>n</i><code>,}?</code></th>
301 * <td headers="matches reluc reluc_at_least"><i>X</i>, at least <i>n</i> times</td></tr>
302 * <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>
303 * <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>
304 *
305 * <tr><th colspan="2" style="padding-top:20px" id="poss">Possessive quantifiers</th></tr>
306 *
307 * <tr><th style="vertical-align:top; font-weight:normal" id="poss_once_or_not"><i>X</i>{@code ?+}</th>
308 * <td headers="matches poss poss_once_or_not"><i>X</i>, once or not at all</td></tr>
309 * <tr><th style="vertical-align:top; font-weight:normal" id="poss_zero_or_more"><i>X</i>{@code *+}</th>
310 * <td headers="matches poss poss_zero_or_more"><i>X</i>, zero or more times</td></tr>
311 * <tr><th style="vertical-align:top; font-weight:normal" id="poss_one_or_more"><i>X</i>{@code ++}</th>
312 * <td headers="matches poss poss_one_or_more"><i>X</i>, one or more times</td></tr>
313 * <tr><th style="vertical-align:top; font-weight:normal" id="poss_exactly"><i>X</i><code>{</code><i>n</i><code>}+</code></th>
314 * <td headers="matches poss poss_exactly"><i>X</i>, exactly <i>n</i> times</td></tr>
315 * <tr><th style="vertical-align:top; font-weight:normal" id="poss_at_least"><i>X</i><code>{</code><i>n</i><code>,}+</code></th>
316 * <td headers="matches poss poss_at_least"><i>X</i>, at least <i>n</i> times</td></tr>
317 * <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>
318 * <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>
319 *
320 * <tr><th colspan="2" style="padding-top:20px" id="logical">Logical operators</th></tr>
321 *
322 * <tr><th style="vertical-align:top; font-weight:normal" id="concat"><i>XY</i></th>
323 * <td headers="matches logical concat"><i>X</i> followed by <i>Y</i></td></tr>
324 * <tr><th style="vertical-align:top; font-weight:normal" id="alternate"><i>X</i>{@code |}<i>Y</i></th>
325 * <td headers="matches logical alternate">Either <i>X</i> or <i>Y</i></td></tr>
326 * <tr><th style="vertical-align:top; font-weight:normal" id="group">{@code (}<i>X</i>{@code )}</th>
327 * <td headers="matches logical group">X, as a <a href="#cg">capturing group</a></td></tr>
328 *
329 * <tr><th colspan="2" style="padding-top:20px" id="backref">Back references</th></tr>
330 *
331 * <tr><th style="vertical-align:top; font-weight:normal" id="back_nth">{@code \}<i>n</i></th>
332 * <td headers="matches backref back_nth">Whatever the <i>n</i><sup>th</sup>
333 * <a href="#cg">capturing group</a> matched</td></tr>
334 * <tr><th style="vertical-align:top; font-weight:normal" id="back_named">{@code \}<i>k</i><<i>name</i>></th>
335 * <td headers="matches backref back_named">Whatever the
336 * <a href="#groupname">named-capturing group</a> "name" matched</td></tr>
337 *
338 * <tr><th colspan="2" style="padding-top:20px" id="quote">Quotation</th></tr>
339 *
340 * <tr><th style="vertical-align:top; font-weight:normal" id="quote_follow">{@code \}</th>
341 * <td headers="matches quote quote_follow">Nothing, but quotes the following character</td></tr>
342 * <tr><th style="vertical-align:top; font-weight:normal" id="quote_begin">{@code \Q}</th>
343 * <td headers="matches quote quote_begin">Nothing, but quotes all characters until {@code \E}</td></tr>
344 * <tr><th style="vertical-align:top; font-weight:normal" id="quote_end">{@code \E}</th>
345 * <td headers="matches quote quote_end">Nothing, but ends quoting started by {@code \Q}</td></tr>
346 * <!-- Metachars: !$()*+.<>?[\]^{|} -->
347 *
348 * <tr><th colspan="2" style="padding-top:20px" id="special">Special constructs (named-capturing and non-capturing)</th></tr>
349 *
350 * <tr><th style="vertical-align:top; font-weight:normal" id="named_group"><code>(?<<a href="#groupname">name</a>></code><i>X</i>{@code )}</th>
351 * <td headers="matches special named_group"><i>X</i>, as a named-capturing group</td></tr>
352 * <tr><th style="vertical-align:top; font-weight:normal" id="non_capture_group">{@code (?:}<i>X</i>{@code )}</th>
353 * <td headers="matches special non_capture_group"><i>X</i>, as a non-capturing group</td></tr>
354 * <tr><th style="vertical-align:top; font-weight:normal" id="flags"><code>(?idmsuxU-idmsuxU) </code></th>
355 * <td headers="matches special flags">Nothing, but turns match flags <a href="#CASE_INSENSITIVE">i</a>
356 * <a href="#UNIX_LINES">d</a> <a href="#MULTILINE">m</a> <a href="#DOTALL">s</a>
357 * <a href="#UNICODE_CASE">u</a> <a href="#COMMENTS">x</a> <a href="#UNICODE_CHARACTER_CLASS">U</a>
358 * on - off</td></tr>
359 * <tr><th style="vertical-align:top; font-weight:normal" id="non_capture_group_flags"><code>(?idmsux-idmsux:</code><i>X</i>{@code )} </th>
360 * <td headers="matches special non_capture_group_flags"><i>X</i>, as a <a href="#cg">non-capturing group</a> with the
361 * given flags <a href="#CASE_INSENSITIVE">i</a> <a href="#UNIX_LINES">d</a>
362 * <a href="#MULTILINE">m</a> <a href="#DOTALL">s</a> <a href="#UNICODE_CASE">u</a >
363 * <a href="#COMMENTS">x</a> on - off</td></tr>
364 * <tr><th style="vertical-align:top; font-weight:normal" id="pos_lookahead">{@code (?=}<i>X</i>{@code )}</th>
365 * <td headers="matches special pos_lookahead"><i>X</i>, via zero-width positive lookahead</td></tr>
366 * <tr><th style="vertical-align:top; font-weight:normal" id="neg_lookahead">{@code (?!}<i>X</i>{@code )}</th>
367 * <td headers="matches special neg_lookahead"><i>X</i>, via zero-width negative lookahead</td></tr>
368 * <tr><th style="vertical-align:top; font-weight:normal" id="pos_lookbehind">{@code (?<=}<i>X</i>{@code )}</th>
369 * <td headers="matches special pos_lookbehind"><i>X</i>, via zero-width positive lookbehind</td></tr>
370 * <tr><th style="vertical-align:top; font-weight:normal" id="neg_lookbehind">{@code (?<!}<i>X</i>{@code )}</th>
371 * <td headers="matches special neg_lookbehind"><i>X</i>, via zero-width negative lookbehind</td></tr>
372 * <tr><th style="vertical-align:top; font-weight:normal" id="indep_non_capture_group">{@code (?>}<i>X</i>{@code )}</th>
373 * <td headers="matches special indep_non_capture_group"><i>X</i>, as an independent, non-capturing group</td></tr>
374 *
375 * </tbody>
376 * </table>
377 *
378 * <hr>
379 *
380 *
381 * <h3><a id="bs">Backslashes, escapes, and quoting</a></h3>
382 *
383 * <p> The backslash character ({@code '\'}) serves to introduce escaped
384 * constructs, as defined in the table above, as well as to quote characters
385 * that otherwise would be interpreted as unescaped constructs. Thus the
386 * expression {@code \\} matches a single backslash and <code>\{</code> matches a
387 * left brace.
388 *
389 * <p> It is an error to use a backslash prior to any alphabetic character that
390 * does not denote an escaped construct; these are reserved for future
391 * extensions to the regular-expression language. A backslash may be used
392 * prior to a non-alphabetic character regardless of whether that character is
393 * part of an unescaped construct.
394 *
395 * <p> Backslashes within string literals in Java source code are interpreted
396 * as required by
397 * <cite>The Java™ Language Specification</cite>
398 * as either Unicode escapes (section 3.3) or other character escapes (section 3.10.6)
399 * It is therefore necessary to double backslashes in string
400 * literals that represent regular expressions to protect them from
401 * interpretation by the Java bytecode compiler. The string literal
402 * <code>"\b"</code>, for example, matches a single backspace character when
403 * interpreted as a regular expression, while {@code "\\b"} matches a
404 * word boundary. The string literal {@code "\(hello\)"} is illegal
405 * and leads to a compile-time error; in order to match the string
406 * {@code (hello)} the string literal {@code "\\(hello\\)"}
407 * must be used.
408 *
409 * <h3><a id="cc">Character Classes</a></h3>
410 *
411 * <p> Character classes may appear within other character classes, and
412 * may be composed by the union operator (implicit) and the intersection
413 * operator ({@code &&}).
414 * The union operator denotes a class that contains every character that is
415 * in at least one of its operand classes. The intersection operator
416 * denotes a class that contains every character that is in both of its
417 * operand classes.
418 *
419 * <p> The precedence of character-class operators is as follows, from
420 * highest to lowest:
421 *
422 * <table class="striped" style="margin-left: 2em;">
423 * <caption style="display:none">Precedence of character class operators.</caption>
424 * <thead>
425 * <tr><th scope="col">Precedence<th scope="col">Name<th scope="col">Example
426 * </thead>
427 * <tbody>
428 * <tr><th scope="row">1</th>
429 * <td>Literal escape </td>
430 * <td>{@code \x}</td></tr>
431 * <tr><th scope="row">2</th>
432 * <td>Grouping</td>
433 * <td>{@code [...]}</td></tr>
434 * <tr><th scope="row">3</th>
435 * <td>Range</td>
436 * <td>{@code a-z}</td></tr>
437 * <tr><th scope="row">4</th>
438 * <td>Union</td>
439 * <td>{@code [a-e][i-u]}</td></tr>
440 * <tr><th scope="row">5</th>
441 * <td>Intersection</td>
442 * <td>{@code [a-z&&[aeiou]]}</td></tr>
443 * </tbody>
444 * </table>
445 *
446 * <p> Note that a different set of metacharacters are in effect inside
447 * a character class than outside a character class. For instance, the
448 * regular expression {@code .} loses its special meaning inside a
449 * character class, while the expression {@code -} becomes a range
450 * forming metacharacter.
451 *
452 * <h3><a id="lt">Line terminators</a></h3>
453 *
454 * <p> A <i>line terminator</i> is a one- or two-character sequence that marks
455 * the end of a line of the input character sequence. The following are
456 * recognized as line terminators:
457 *
458 * <ul>
459 *
460 * <li> A newline (line feed) character ({@code '\n'}),
461 *
462 * <li> A carriage-return character followed immediately by a newline
463 * character ({@code "\r\n"}),
464 *
465 * <li> A standalone carriage-return character ({@code '\r'}),
466 *
467 * <li> A next-line character (<code>'\u0085'</code>),
468 *
469 * <li> A line-separator character (<code>'\u2028'</code>), or
470 *
471 * <li> A paragraph-separator character (<code>'\u2029'</code>).
472 *
473 * </ul>
474 * <p>If {@link #UNIX_LINES} mode is activated, then the only line terminators
475 * recognized are newline characters.
476 *
477 * <p> The regular expression {@code .} matches any character except a line
478 * terminator unless the {@link #DOTALL} flag is specified.
479 *
480 * <p> By default, the regular expressions {@code ^} and {@code $} ignore
481 * line terminators and only match at the beginning and the end, respectively,
482 * of the entire input sequence. If {@link #MULTILINE} mode is activated then
483 * {@code ^} matches at the beginning of input and after any line terminator
484 * except at the end of input. When in {@link #MULTILINE} mode {@code $}
485 * matches just before a line terminator or the end of the input sequence.
486 *
487 * <h3><a id="cg">Groups and capturing</a></h3>
488 *
489 * <h4><a id="gnumber">Group number</a></h4>
490 * <p> Capturing groups are numbered by counting their opening parentheses from
491 * left to right. In the expression {@code ((A)(B(C)))}, for example, there
492 * are four such groups: </p>
493 *
494 * <ol style="margin-left:2em;">
495 * <li> {@code ((A)(B(C)))}
496 * <li> {@code (A)}
497 * <li> {@code (B(C))}
498 * <li> {@code (C)}
499 * </ol>
500 *
501 * <p> Group zero always stands for the entire expression.
502 *
503 * <p> Capturing groups are so named because, during a match, each subsequence
504 * of the input sequence that matches such a group is saved. The captured
505 * subsequence may be used later in the expression, via a back reference, and
506 * may also be retrieved from the matcher once the match operation is complete.
507 *
508 * <h4><a id="groupname">Group name</a></h4>
509 * <p>A capturing group can also be assigned a "name", a {@code named-capturing group},
510 * and then be back-referenced later by the "name". Group names are composed of
511 * the following characters. The first character must be a {@code letter}.
512 *
513 * <ul>
514 * <li> The uppercase letters {@code 'A'} through {@code 'Z'}
515 * (<code>'\u0041'</code> through <code>'\u005a'</code>),
516 * <li> The lowercase letters {@code 'a'} through {@code 'z'}
517 * (<code>'\u0061'</code> through <code>'\u007a'</code>),
518 * <li> The digits {@code '0'} through {@code '9'}
519 * (<code>'\u0030'</code> through <code>'\u0039'</code>),
520 * </ul>
521 *
522 * <p> A {@code named-capturing group} is still numbered as described in
523 * <a href="#gnumber">Group number</a>.
524 *
525 * <p> The captured input associated with a group is always the subsequence
526 * that the group most recently matched. If a group is evaluated a second time
527 * because of quantification then its previously-captured value, if any, will
528 * be retained if the second evaluation fails. Matching the string
529 * {@code "aba"} against the expression {@code (a(b)?)+}, for example, leaves
530 * group two set to {@code "b"}. All captured input is discarded at the
531 * beginning of each match.
532 *
533 * <p> Groups beginning with {@code (?} are either pure, <i>non-capturing</i> groups
534 * that do not capture text and do not count towards the group total, or
535 * <i>named-capturing</i> group.
536 *
537 * <h3> Unicode support </h3>
538 *
539 * <p> This class is in conformance with Level 1 of <a
540 * href="http://www.unicode.org/reports/tr18/"><i>Unicode Technical
541 * Standard #18: Unicode Regular Expression</i></a>, plus RL2.1
542 * Canonical Equivalents.
543 * <p>
544 * <b>Unicode escape sequences</b> such as <code>\u2014</code> in Java source code
545 * are processed as described in section 3.3 of
546 * <cite>The Java™ Language Specification</cite>.
547 * Such escape sequences are also implemented directly by the regular-expression
548 * parser so that Unicode escapes can be used in expressions that are read from
549 * files or from the keyboard. Thus the strings <code>"\u2014"</code> and
550 * {@code "\\u2014"}, while not equal, compile into the same pattern, which
551 * matches the character with hexadecimal value {@code 0x2014}.
552 * <p>
553 * A Unicode character can also be represented by using its <b>Hex notation</b>
554 * (hexadecimal code point value) directly as described in construct
555 * <code>\x{...}</code>, for example a supplementary character U+2011F can be
556 * specified as <code>\x{2011F}</code>, instead of two consecutive Unicode escape
557 * sequences of the surrogate pair <code>\uD840</code><code>\uDD1F</code>.
558 * <p>
559 * <b>Unicode character names</b> are supported by the named character construct
560 * <code>\N{</code>...<code>}</code>, for example, <code>\N{WHITE SMILING FACE}</code>
561 * specifies character <code>\u263A</code>. The character names supported
562 * by this class are the valid Unicode character names matched by
563 * {@link java.lang.Character#codePointOf(String) Character.codePointOf(name)}.
564 * <p>
565 * <a href="http://www.unicode.org/reports/tr18/#Default_Grapheme_Clusters">
566 * <b>Unicode extended grapheme clusters</b></a> are supported by the grapheme
567 * cluster matcher {@code \X} and the corresponding boundary matcher {@code \b{g}}.
568 * <p>
569 * Unicode scripts, blocks, categories and binary properties are written with
570 * the {@code \p} and {@code \P} constructs as in Perl.
571 * <code>\p{</code><i>prop</i><code>}</code> matches if
572 * the input has the property <i>prop</i>, while <code>\P{</code><i>prop</i><code>}</code>
573 * does not match if the input has that property.
574 * <p>
575 * Scripts, blocks, categories and binary properties can be used both inside
576 * and outside of a character class.
577 *
578 * <p>
579 * <b><a id="usc">Scripts</a></b> are specified either with the prefix {@code Is}, as in
580 * {@code IsHiragana}, or by using the {@code script} keyword (or its short
581 * form {@code sc}) as in {@code script=Hiragana} or {@code sc=Hiragana}.
582 * <p>
583 * The script names supported by {@code Pattern} are the valid script names
584 * accepted and defined by
585 * {@link java.lang.Character.UnicodeScript#forName(String) UnicodeScript.forName}.
586 *
587 * <p>
588 * <b><a id="ubc">Blocks</a></b> are specified with the prefix {@code In}, as in
589 * {@code InMongolian}, or by using the keyword {@code block} (or its short
590 * form {@code blk}) as in {@code block=Mongolian} or {@code blk=Mongolian}.
591 * <p>
592 * The block names supported by {@code Pattern} are the valid block names
593 * accepted and defined by
594 * {@link java.lang.Character.UnicodeBlock#forName(String) UnicodeBlock.forName}.
595 * <p>
596 *
597 * <b><a id="ucc">Categories</a></b> may be specified with the optional prefix {@code Is}:
598 * Both {@code \p{L}} and {@code \p{IsL}} denote the category of Unicode
599 * letters. Same as scripts and blocks, categories can also be specified
600 * by using the keyword {@code general_category} (or its short form
601 * {@code gc}) as in {@code general_category=Lu} or {@code gc=Lu}.
602 * <p>
603 * The supported categories are those of
604 * <a href="http://www.unicode.org/unicode/standard/standard.html">
605 * <i>The Unicode Standard</i></a> in the version specified by the
606 * {@link java.lang.Character Character} class. The category names are those
607 * defined in the Standard, both normative and informative.
608 * <p>
609 *
610 * <b><a id="ubpc">Binary properties</a></b> are specified with the prefix {@code Is}, as in
611 * {@code IsAlphabetic}. The supported binary properties by {@code Pattern}
612 * are
613 * <ul>
614 * <li> Alphabetic
615 * <li> Ideographic
616 * <li> Letter
617 * <li> Lowercase
618 * <li> Uppercase
619 * <li> Titlecase
620 * <li> Punctuation
621 * <Li> Control
622 * <li> White_Space
623 * <li> Digit
624 * <li> Hex_Digit
625 * <li> Join_Control
626 * <li> Noncharacter_Code_Point
627 * <li> Assigned
628 * </ul>
629 * <p>
630 * The following <b>Predefined Character classes</b> and <b>POSIX character classes</b>
631 * are in conformance with the recommendation of <i>Annex C: Compatibility Properties</i>
632 * of <a href="http://www.unicode.org/reports/tr18/"><i>Unicode Regular Expression
633 * </i></a>, when {@link #UNICODE_CHARACTER_CLASS} flag is specified.
634 *
635 * <table class="striped">
636 * <caption style="display:none">predefined and posix character classes in Unicode mode</caption>
637 * <thead>
638 * <tr>
639 * <th scope="col" id="predef_classes">Classes</th>
640 * <th scope="col" id="predef_matches">Matches</th>
641 * </tr>
642 * </thead>
643 * <tbody>
644 * <tr><th scope="row">{@code \p{Lower}}</th>
645 * <td>A lowercase character:{@code \p{IsLowercase}}</td></tr>
646 * <tr><th scope="row">{@code \p{Upper}}</th>
647 * <td>An uppercase character:{@code \p{IsUppercase}}</td></tr>
648 * <tr><th scope="row">{@code \p{ASCII}}</th>
649 * <td>All ASCII:{@code [\x00-\x7F]}</td></tr>
650 * <tr><th scope="row">{@code \p{Alpha}}</th>
651 * <td>An alphabetic character:{@code \p{IsAlphabetic}}</td></tr>
652 * <tr><th scope="row">{@code \p{Digit}}</th>
653 * <td>A decimal digit character:{@code \p{IsDigit}}</td></tr>
654 * <tr><th scope="row">{@code \p{Alnum}}</th>
655 * <td>An alphanumeric character:{@code [\p{IsAlphabetic}\p{IsDigit}]}</td></tr>
656 * <tr><th scope="row">{@code \p{Punct}}</th>
657 * <td>A punctuation character:{@code \p{IsPunctuation}}</td></tr>
658 * <tr><th scope="row">{@code \p{Graph}}</th>
659 * <td>A visible character: {@code [^\p{IsWhite_Space}\p{gc=Cc}\p{gc=Cs}\p{gc=Cn}]}</td></tr>
660 * <tr><th scope="row">{@code \p{Print}}</th>
661 * <td>A printable character: {@code [\p{Graph}\p{Blank}&&[^\p{Cntrl}]]}</td></tr>
662 * <tr><th scope="row">{@code \p{Blank}}</th>
663 * <td>A space or a tab: {@code [\p{IsWhite_Space}&&[^\p{gc=Zl}\p{gc=Zp}\x0a\x0b\x0c\x0d\x85]]}</td></tr>
664 * <tr><th scope="row">{@code \p{Cntrl}}</th>
665 * <td>A control character: {@code \p{gc=Cc}}</td></tr>
666 * <tr><th scope="row">{@code \p{XDigit}}</th>
667 * <td>A hexadecimal digit: {@code [\p{gc=Nd}\p{IsHex_Digit}]}</td></tr>
668 * <tr><th scope="row">{@code \p{Space}}</th>
669 * <td>A whitespace character:{@code \p{IsWhite_Space}}</td></tr>
670 * <tr><th scope="row">{@code \d}</th>
671 * <td>A digit: {@code \p{IsDigit}}</td></tr>
672 * <tr><th scope="row">{@code \D}</th>
673 * <td>A non-digit: {@code [^\d]}</td></tr>
674 * <tr><th scope="row">{@code \s}</th>
675 * <td>A whitespace character: {@code \p{IsWhite_Space}}</td></tr>
676 * <tr><th scope="row">{@code \S}</th>
677 * <td>A non-whitespace character: {@code [^\s]}</td></tr>
678 * <tr><th scope="row">{@code \w}</th>
679 * <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>
680 * <tr><th scope="row">{@code \W}</th>
681 * <td>A non-word character: {@code [^\w]}</td></tr>
682 * </tbody>
683 * </table>
684 * <p>
685 * <a id="jcc">
686 * Categories that behave like the java.lang.Character
687 * boolean is<i>methodname</i> methods (except for the deprecated ones) are
688 * available through the same <code>\p{</code><i>prop</i><code>}</code> syntax where
689 * the specified property has the name <code>java<i>methodname</i></code></a>.
690 *
691 * <h3> Comparison to Perl 5 </h3>
692 *
693 * <p>The {@code Pattern} engine performs traditional NFA-based matching
694 * with ordered alternation as occurs in Perl 5.
695 *
696 * <p> Perl constructs not supported by this class: </p>
697 *
698 * <ul>
699 * <li><p> The backreference constructs, <code>\g{</code><i>n</i><code>}</code> for
700 * the <i>n</i><sup>th</sup><a href="#cg">capturing group</a> and
701 * <code>\g{</code><i>name</i><code>}</code> for
702 * <a href="#groupname">named-capturing group</a>.
703 * </p></li>
704 *
705 * <li><p> The conditional constructs
706 * {@code (?(}<i>condition</i>{@code )}<i>X</i>{@code )} and
707 * {@code (?(}<i>condition</i>{@code )}<i>X</i>{@code |}<i>Y</i>{@code )},
708 * </p></li>
709 *
710 * <li><p> The embedded code constructs <code>(?{</code><i>code</i><code>})</code>
711 * and <code>(??{</code><i>code</i><code>})</code>,</p></li>
712 *
713 * <li><p> The embedded comment syntax {@code (?#comment)}, and </p></li>
714 *
715 * <li><p> The preprocessing operations {@code \l} <code>\u</code>,
716 * {@code \L}, and {@code \U}. </p></li>
717 *
718 * </ul>
719 *
720 * <p> Constructs supported by this class but not by Perl: </p>
721 *
722 * <ul>
723 *
724 * <li><p> Character-class union and intersection as described
725 * <a href="#cc">above</a>.</p></li>
726 *
727 * </ul>
728 *
729 * <p> Notable differences from Perl: </p>
730 *
731 * <ul>
732 *
733 * <li><p> In Perl, {@code \1} through {@code \9} are always interpreted
734 * as back references; a backslash-escaped number greater than {@code 9} is
735 * treated as a back reference if at least that many subexpressions exist,
736 * otherwise it is interpreted, if possible, as an octal escape. In this
737 * class octal escapes must always begin with a zero. In this class,
738 * {@code \1} through {@code \9} are always interpreted as back
739 * references, and a larger number is accepted as a back reference if at
740 * least that many subexpressions exist at that point in the regular
741 * expression, otherwise the parser will drop digits until the number is
742 * smaller or equal to the existing number of groups or it is one digit.
743 * </p></li>
744 *
745 * <li><p> Perl uses the {@code g} flag to request a match that resumes
746 * where the last match left off. This functionality is provided implicitly
747 * by the {@link Matcher} class: Repeated invocations of the {@link
748 * Matcher#find find} method will resume where the last match left off,
749 * unless the matcher is reset. </p></li>
750 *
751 * <li><p> In Perl, embedded flags at the top level of an expression affect
752 * the whole expression. In this class, embedded flags always take effect
753 * at the point at which they appear, whether they are at the top level or
754 * within a group; in the latter case, flags are restored at the end of the
755 * group just as in Perl. </p></li>
756 *
757 * </ul>
758 *
759 *
760 * <p> For a more precise description of the behavior of regular expression
761 * constructs, please see <a href="http://www.oreilly.com/catalog/regex3/">
762 * <i>Mastering Regular Expressions, 3nd Edition</i>, Jeffrey E. F. Friedl,
763 * O'Reilly and Associates, 2006.</a>
764 * </p>
765 *
766 * @see java.lang.String#split(String, int)
767 * @see java.lang.String#split(String)
768 *
769 * @author Mike McCloskey
770 * @author Mark Reinhold
771 * @author JSR-51 Expert Group
772 * @since 1.4
773 * @spec JSR-51
774 */
775
776 public final class Pattern
777 implements java.io.Serializable
778 {
779
780 /**
781 * Regular expression modifier values. Instead of being passed as
782 * arguments, they can also be passed as inline modifiers.
783 * For example, the following statements have the same effect.
784 * <pre>
785 * RegExp r1 = RegExp.compile("abc", Pattern.I|Pattern.M);
786 * RegExp r2 = RegExp.compile("(?im)abc", 0);
787 * </pre>
788 *
789 * The flags are duplicated so that the familiar Perl match flag
790 * names are available.
791 */
792
793 /**
794 * Enables Unix lines mode.
795 *
796 * <p> In this mode, only the {@code '\n'} line terminator is recognized
797 * in the behavior of {@code .}, {@code ^}, and {@code $}.
798 *
799 * <p> Unix lines mode can also be enabled via the embedded flag
800 * expression {@code (?d)}.
801 */
802 public static final int UNIX_LINES = 0x01;
803
804 /**
805 * Enables case-insensitive matching.
806 *
807 * <p> By default, case-insensitive matching assumes that only characters
808 * in the US-ASCII charset are being matched. Unicode-aware
809 * case-insensitive matching can be enabled by specifying the {@link
810 * #UNICODE_CASE} flag in conjunction with this flag.
811 *
812 * <p> Case-insensitive matching can also be enabled via the embedded flag
813 * expression {@code (?i)}.
814 *
815 * <p> Specifying this flag may impose a slight performance penalty. </p>
816 */
817 public static final int CASE_INSENSITIVE = 0x02;
818
819 /**
820 * Permits whitespace and comments in pattern.
821 *
822 * <p> In this mode, whitespace is ignored, and embedded comments starting
823 * with {@code #} are ignored until the end of a line.
824 *
825 * <p> Comments mode can also be enabled via the embedded flag
826 * expression {@code (?x)}.
827 */
828 public static final int COMMENTS = 0x04;
829
830 /**
831 * Enables multiline mode.
832 *
833 * <p> In multiline mode the expressions {@code ^} and {@code $} match
834 * just after or just before, respectively, a line terminator or the end of
835 * the input sequence. By default these expressions only match at the
836 * beginning and the end of the entire input sequence.
837 *
838 * <p> Multiline mode can also be enabled via the embedded flag
839 * expression {@code (?m)}. </p>
840 */
841 public static final int MULTILINE = 0x08;
842
843 /**
844 * Enables literal parsing of the pattern.
845 *
846 * <p> When this flag is specified then the input string that specifies
847 * the pattern is treated as a sequence of literal characters.
848 * Metacharacters or escape sequences in the input sequence will be
849 * given no special meaning.
850 *
851 * <p>The flags CASE_INSENSITIVE and UNICODE_CASE retain their impact on
852 * matching when used in conjunction with this flag. The other flags
853 * become superfluous.
854 *
855 * <p> There is no embedded flag character for enabling literal parsing.
856 * @since 1.5
857 */
858 public static final int LITERAL = 0x10;
859
860 /**
861 * Enables dotall mode.
862 *
863 * <p> In dotall mode, the expression {@code .} matches any character,
864 * including a line terminator. By default this expression does not match
865 * line terminators.
866 *
867 * <p> Dotall mode can also be enabled via the embedded flag
868 * expression {@code (?s)}. (The {@code s} is a mnemonic for
869 * "single-line" mode, which is what this is called in Perl.) </p>
870 */
871 public static final int DOTALL = 0x20;
872
873 /**
874 * Enables Unicode-aware case folding.
875 *
876 * <p> When this flag is specified then case-insensitive matching, when
877 * enabled by the {@link #CASE_INSENSITIVE} flag, is done in a manner
878 * consistent with the Unicode Standard. By default, case-insensitive
879 * matching assumes that only characters in the US-ASCII charset are being
880 * matched.
881 *
882 * <p> Unicode-aware case folding can also be enabled via the embedded flag
883 * expression {@code (?u)}.
884 *
885 * <p> Specifying this flag may impose a performance penalty. </p>
886 */
887 public static final int UNICODE_CASE = 0x40;
888
889 /**
890 * Enables canonical equivalence.
891 *
892 * <p> When this flag is specified then two characters will be considered
893 * to match if, and only if, their full canonical decompositions match.
894 * The expression <code>"a\u030A"</code>, for example, will match the
895 * string <code>"\u00E5"</code> when this flag is specified. By default,
896 * matching does not take canonical equivalence into account.
897 *
898 * <p> There is no embedded flag character for enabling canonical
899 * equivalence.
900 *
901 * <p> Specifying this flag may impose a performance penalty. </p>
902 */
903 public static final int CANON_EQ = 0x80;
904
905 /**
906 * Enables the Unicode version of <i>Predefined character classes</i> and
907 * <i>POSIX character classes</i>.
908 *
909 * <p> When this flag is specified then the (US-ASCII only)
910 * <i>Predefined character classes</i> and <i>POSIX character classes</i>
911 * are in conformance with
912 * <a href="http://www.unicode.org/reports/tr18/"><i>Unicode Technical
913 * Standard #18: Unicode Regular Expression</i></a>
914 * <i>Annex C: Compatibility Properties</i>.
915 * <p>
916 * The UNICODE_CHARACTER_CLASS mode can also be enabled via the embedded
917 * flag expression {@code (?U)}.
918 * <p>
919 * The flag implies UNICODE_CASE, that is, it enables Unicode-aware case
920 * folding.
921 * <p>
922 * Specifying this flag may impose a performance penalty. </p>
923 * @since 1.7
924 */
925 public static final int UNICODE_CHARACTER_CLASS = 0x100;
926
927 /**
928 * Contains all possible flags for compile(regex, flags).
929 */
930 private static final int ALL_FLAGS = CASE_INSENSITIVE | MULTILINE |
931 DOTALL | UNICODE_CASE | CANON_EQ | UNIX_LINES | LITERAL |
932 UNICODE_CHARACTER_CLASS | COMMENTS;
933
934 /* Pattern has only two serialized components: The pattern string
935 * and the flags, which are all that is needed to recompile the pattern
936 * when it is deserialized.
937 */
938
939 /** use serialVersionUID from Merlin b59 for interoperability */
940 private static final long serialVersionUID = 5073258162644648461L;
941
942 /**
943 * The original regular-expression pattern string.
944 *
945 * @serial
946 */
947 private String pattern;
948
949 /**
950 * The original pattern flags.
951 *
952 * @serial
953 */
954 private int flags;
955
956 /**
957 * The temporary pattern flags used during compiling. The flags might be turn
958 * on and off by embedded flag.
959 */
960 private transient int flags0;
961
962 /**
963 * Boolean indicating this Pattern is compiled; this is necessary in order
964 * to lazily compile deserialized Patterns.
965 */
966 private transient volatile boolean compiled;
967
968 /**
969 * The normalized pattern string.
970 */
971 private transient String normalizedPattern;
972
973 /**
974 * The starting point of state machine for the find operation. This allows
975 * a match to start anywhere in the input.
976 */
977 transient Node root;
978
979 /**
980 * The root of object tree for a match operation. The pattern is matched
981 * at the beginning. This may include a find that uses BnM or a First
982 * node.
983 */
984 transient Node matchRoot;
985
986 /**
987 * Temporary storage used by parsing pattern slice.
988 */
989 transient int[] buffer;
990
991 /**
992 * A temporary storage used for predicate for double return.
993 */
994 transient CharPredicate predicate;
995
996 /**
997 * Map the "name" of the "named capturing group" to its group id
998 * node.
999 */
1000 transient volatile Map<String, Integer> namedGroups;
1001
1002 /**
1003 * Temporary storage used while parsing group references.
1004 */
1005 transient GroupHead[] groupNodes;
1006
1007 /**
1008 * Temporary storage used to store the top level closure nodes.
1009 */
1010 transient List<Node> topClosureNodes;
1011
1012 /**
1013 * The number of top greedy closure nodes in this Pattern. Used by
1014 * matchers to allocate storage needed for a IntHashSet to keep the
1015 * beginning pos {@code i} of all failed match.
1016 */
1017 transient int localTCNCount;
1018
1019 /*
1020 * Turn off the stop-exponential-backtracking optimization if there
1021 * is a group ref in the pattern.
1022 */
1023 transient boolean hasGroupRef;
1024
1025 /**
1026 * Temporary null terminated code point array used by pattern compiling.
1027 */
1028 private transient int[] temp;
1029
1030 /**
1031 * The number of capturing groups in this Pattern. Used by matchers to
1032 * allocate storage needed to perform a match.
1033 */
1034 transient int capturingGroupCount;
1035
1036 /**
1037 * The local variable count used by parsing tree. Used by matchers to
1038 * allocate storage needed to perform a match.
1039 */
1040 transient int localCount;
1041
1042 /**
1043 * Index into the pattern string that keeps track of how much has been
1044 * parsed.
1045 */
1046 private transient int cursor;
1047
1048 /**
1049 * Holds the length of the pattern string.
1050 */
1051 private transient int patternLength;
1052
1053 /**
1054 * If the Start node might possibly match supplementary characters.
1055 * It is set to true during compiling if
1056 * (1) There is supplementary char in pattern, or
1057 * (2) There is complement node of a "family" CharProperty
1058 */
1059 private transient boolean hasSupplementary;
1060
1061 /**
1062 * Compiles the given regular expression into a pattern.
1063 *
1064 * @param regex
1065 * The expression to be compiled
1066 * @return the given regular expression compiled into a pattern
1067 * @throws PatternSyntaxException
1068 * If the expression's syntax is invalid
1069 */
1070 public static Pattern compile(String regex) {
1071 return new Pattern(regex, 0);
1072 }
1073
1074 /**
1075 * Compiles the given regular expression into a pattern with the given
1076 * flags.
1077 *
1078 * @param regex
1079 * The expression to be compiled
1080 *
1081 * @param flags
1082 * Match flags, a bit mask that may include
1083 * {@link #CASE_INSENSITIVE}, {@link #MULTILINE}, {@link #DOTALL},
1084 * {@link #UNICODE_CASE}, {@link #CANON_EQ}, {@link #UNIX_LINES},
1085 * {@link #LITERAL}, {@link #UNICODE_CHARACTER_CLASS}
1086 * and {@link #COMMENTS}
1087 *
1088 * @return the given regular expression compiled into a pattern with the given flags
1089 * @throws IllegalArgumentException
1090 * If bit values other than those corresponding to the defined
1091 * match flags are set in {@code flags}
1092 *
1093 * @throws PatternSyntaxException
1094 * If the expression's syntax is invalid
1095 */
1096 public static Pattern compile(String regex, int flags) {
1097 return new Pattern(regex, flags);
1098 }
1099
1100 /**
1101 * Returns the regular expression from which this pattern was compiled.
1102 *
1103 * @return The source of this pattern
1104 */
1105 public String pattern() {
1106 return pattern;
1107 }
1108
1109 /**
1110 * <p>Returns the string representation of this pattern. This
1111 * is the regular expression from which this pattern was
1112 * compiled.</p>
1113 *
1114 * @return The string representation of this pattern
1115 * @since 1.5
1116 */
1117 public String toString() {
1118 return pattern;
1119 }
1120
1121 /**
1122 * Creates a matcher that will match the given input against this pattern.
1123 *
1124 * @param input
1125 * The character sequence to be matched
1126 *
1127 * @return A new matcher for this pattern
1128 */
1129 public Matcher matcher(CharSequence input) {
1130 if (!compiled) {
1131 synchronized(this) {
1132 if (!compiled)
1133 compile();
1134 }
1135 }
1136 Matcher m = new Matcher(this, input);
1137 return m;
1138 }
1139
1140 /**
1141 * Returns this pattern's match flags.
1142 *
1143 * @return The match flags specified when this pattern was compiled
1144 */
1145 public int flags() {
1146 return flags0;
1147 }
1148
1149 /**
1150 * Compiles the given regular expression and attempts to match the given
1151 * input against it.
1152 *
1153 * <p> An invocation of this convenience method of the form
1154 *
1155 * <blockquote><pre>
1156 * Pattern.matches(regex, input);</pre></blockquote>
1157 *
1158 * behaves in exactly the same way as the expression
1159 *
1160 * <blockquote><pre>
1161 * Pattern.compile(regex).matcher(input).matches()</pre></blockquote>
1162 *
1163 * <p> If a pattern is to be used multiple times, compiling it once and reusing
1164 * it will be more efficient than invoking this method each time. </p>
1165 *
1166 * @param regex
1167 * The expression to be compiled
1168 *
1169 * @param input
1170 * The character sequence to be matched
1171 * @return whether or not the regular expression matches on the input
1172 * @throws PatternSyntaxException
1173 * If the expression's syntax is invalid
1174 */
1175 public static boolean matches(String regex, CharSequence input) {
1176 Pattern p = Pattern.compile(regex);
1177 Matcher m = p.matcher(input);
1178 return m.matches();
1179 }
1180
1181 /**
1182 * Splits the given input sequence around matches of this pattern.
1183 *
1184 * <p> The array returned by this method contains each substring of the
1185 * input sequence that is terminated by another subsequence that matches
1186 * this pattern or is terminated by the end of the input sequence. The
1187 * substrings in the array are in the order in which they occur in the
1188 * input. If this pattern does not match any subsequence of the input then
1189 * the resulting array has just one element, namely the input sequence in
1190 * string form.
1191 *
1192 * <p> When there is a positive-width match at the beginning of the input
1193 * sequence then an empty leading substring is included at the beginning
1194 * of the resulting array. A zero-width match at the beginning however
1195 * never produces such empty leading substring.
1196 *
1197 * <p> The {@code limit} parameter controls the number of times the
1198 * pattern is applied and therefore affects the length of the resulting
1199 * array. If the limit <i>n</i> is greater than zero then the pattern
1200 * will be applied at most <i>n</i> - 1 times, the array's
1201 * length will be no greater than <i>n</i>, and the array's last entry
1202 * will contain all input beyond the last matched delimiter. If <i>n</i>
1203 * is non-positive then the pattern will be applied as many times as
1204 * possible and the array can have any length. If <i>n</i> is zero then
1205 * the pattern will be applied as many times as possible, the array can
1206 * have any length, and trailing empty strings will be discarded.
1207 *
1208 * <p> The input {@code "boo:and:foo"}, for example, yields the following
1209 * results with these parameters:
1210 *
1211 * <table class="plain" style="margin-left:2em;">
1212 * <caption style="display:none">Split example showing regex, limit, and result</caption>
1213 * <thead>
1214 * <tr>
1215 * <th scope="col">Regex</th>
1216 * <th scope="col">Limit</th>
1217 * <th scope="col">Result</th>
1218 * </tr>
1219 * </thead>
1220 * <tbody>
1221 * <tr><th scope="row" rowspan="3" style="font-weight:normal">:</th>
1222 * <th scope="row" style="font-weight:normal; text-align:right; padding-right:1em">2</th>
1223 * <td>{@code { "boo", "and:foo" }}</td></tr>
1224 * <tr><!-- : -->
1225 * <th scope="row" style="font-weight:normal; text-align:right; padding-right:1em">5</th>
1226 * <td>{@code { "boo", "and", "foo" }}</td></tr>
1227 * <tr><!-- : -->
1228 * <th scope="row" style="font-weight:normal; text-align:right; padding-right:1em">-2</th>
1229 * <td>{@code { "boo", "and", "foo" }}</td></tr>
1230 * <tr><th scope="row" rowspan="3" style="font-weight:normal">o</th>
1231 * <th scope="row" style="font-weight:normal; text-align:right; padding-right:1em">5</th>
1232 * <td>{@code { "b", "", ":and:f", "", "" }}</td></tr>
1233 * <tr><!-- o -->
1234 * <th scope="row" style="font-weight:normal; text-align:right; padding-right:1em">-2</th>
1235 * <td>{@code { "b", "", ":and:f", "", "" }}</td></tr>
1236 * <tr><!-- o -->
1237 * <th scope="row" style="font-weight:normal; text-align:right; padding-right:1em">0</th>
1238 * <td>{@code { "b", "", ":and:f" }}</td></tr>
1239 * </tbody>
1240 * </table>
1241 *
1242 * @param input
1243 * The character sequence to be split
1244 *
1245 * @param limit
1246 * The result threshold, as described above
1247 *
1248 * @return The array of strings computed by splitting the input
1249 * around matches of this pattern
1250 */
1251 public String[] split(CharSequence input, int limit) {
1252 int index = 0;
1253 boolean matchLimited = limit > 0;
1254 ArrayList<String> matchList = new ArrayList<>();
1255 Matcher m = matcher(input);
1256
1257 // Add segments before each match found
1258 while(m.find()) {
1259 if (!matchLimited || matchList.size() < limit - 1) {
1260 if (index == 0 && index == m.start() && m.start() == m.end()) {
1261 // no empty leading substring included for zero-width match
1262 // at the beginning of the input char sequence.
1263 continue;
1264 }
1265 String match = input.subSequence(index, m.start()).toString();
1266 matchList.add(match);
1267 index = m.end();
1268 } else if (matchList.size() == limit - 1) { // last one
1269 String match = input.subSequence(index,
1270 input.length()).toString();
1271 matchList.add(match);
1272 index = m.end();
1273 }
1274 }
1275
1276 // If no match was found, return this
1277 if (index == 0)
1278 return new String[] {input.toString()};
1279
1280 // Add remaining segment
1281 if (!matchLimited || matchList.size() < limit)
1282 matchList.add(input.subSequence(index, input.length()).toString());
1283
1284 // Construct result
1285 int resultSize = matchList.size();
1286 if (limit == 0)
1287 while (resultSize > 0 && matchList.get(resultSize-1).equals(""))
1288 resultSize--;
1289 String[] result = new String[resultSize];
1290 return matchList.subList(0, resultSize).toArray(result);
1291 }
1292
1293 /**
1294 * Splits the given input sequence around matches of this pattern.
1295 *
1296 * <p> This method works as if by invoking the two-argument {@link
1297 * #split(java.lang.CharSequence, int) split} method with the given input
1298 * sequence and a limit argument of zero. Trailing empty strings are
1299 * therefore not included in the resulting array. </p>
1300 *
1301 * <p> The input {@code "boo:and:foo"}, for example, yields the following
1302 * results with these expressions:
1303 *
1304 * <table class="plain" style="margin-left:2em">
1305 * <caption style="display:none">Split examples showing regex and result</caption>
1306 * <thead>
1307 * <tr>
1308 * <th scope="col">Regex</th>
1309 * <th scope="col">Result</th>
1310 * </tr>
1311 * </thead>
1312 * <tbody>
1313 * <tr><th scope="row" style="text-weight:normal">:</th>
1314 * <td>{@code { "boo", "and", "foo" }}</td></tr>
1315 * <tr><th scope="row" style="text-weight:normal">o</th>
1316 * <td>{@code { "b", "", ":and:f" }}</td></tr>
1317 * </tbody>
1318 * </table>
1319 *
1320 *
1321 * @param input
1322 * The character sequence to be split
1323 *
1324 * @return The array of strings computed by splitting the input
1325 * around matches of this pattern
1326 */
1327 public String[] split(CharSequence input) {
1328 return split(input, 0);
1329 }
1330
1331 /**
1332 * Returns a literal pattern {@code String} for the specified
1333 * {@code String}.
1334 *
1335 * <p>This method produces a {@code String} that can be used to
1336 * create a {@code Pattern} that would match the string
1337 * {@code s} as if it were a literal pattern.</p> Metacharacters
1338 * or escape sequences in the input sequence will be given no special
1339 * meaning.
1340 *
1341 * @param s The string to be literalized
1342 * @return A literal string replacement
1343 * @since 1.5
1344 */
1345 public static String quote(String s) {
1346 int slashEIndex = s.indexOf("\\E");
1347 if (slashEIndex == -1)
1348 return "\\Q" + s + "\\E";
1349
1350 int lenHint = s.length();
1351 lenHint = (lenHint < Integer.MAX_VALUE - 8 - lenHint) ?
1352 (lenHint << 1) : (Integer.MAX_VALUE - 8);
1353
1354 StringBuilder sb = new StringBuilder(lenHint);
1355 sb.append("\\Q");
1356 int current = 0;
1357 do {
1358 sb.append(s, current, slashEIndex)
1359 .append("\\E\\\\E\\Q");
1360 current = slashEIndex + 2;
1361 } while ((slashEIndex = s.indexOf("\\E", current)) != -1);
1362
1363 return sb.append(s, current, s.length())
1364 .append("\\E")
1365 .toString();
1366 }
1367
1368 /**
1369 * Recompile the Pattern instance from a stream. The original pattern
1370 * string is read in and the object tree is recompiled from it.
1371 */
1372 private void readObject(java.io.ObjectInputStream s)
1373 throws java.io.IOException, ClassNotFoundException {
1374
1375 // Read in all fields
1376 s.defaultReadObject();
1377
1378 // reset the flags
1379 flags0 = flags;
1380
1381 // Initialize counts
1382 capturingGroupCount = 1;
1383 localCount = 0;
1384 localTCNCount = 0;
1385
1386 // if length > 0, the Pattern is lazily compiled
1387 if (pattern.length() == 0) {
1388 root = new Start(lastAccept);
1389 matchRoot = lastAccept;
1390 compiled = true;
1391 }
1392 }
1393
1394 /**
1395 * This private constructor is used to create all Patterns. The pattern
1396 * string and match flags are all that is needed to completely describe
1397 * a Pattern. An empty pattern string results in an object tree with
1398 * only a Start node and a LastNode node.
1399 */
1400 private Pattern(String p, int f) {
1401 if ((f & ~ALL_FLAGS) != 0) {
1402 throw new IllegalArgumentException("Unknown flag 0x"
1403 + Integer.toHexString(f));
1404 }
1405 pattern = p;
1406 flags = f;
1407
1408 // to use UNICODE_CASE if UNICODE_CHARACTER_CLASS present
1409 if ((flags & UNICODE_CHARACTER_CLASS) != 0)
1410 flags |= UNICODE_CASE;
1411
1412 // 'flags' for compiling
1413 flags0 = flags;
1414
1415 // Reset group index count
1416 capturingGroupCount = 1;
1417 localCount = 0;
1418 localTCNCount = 0;
1419
1420 if (pattern.length() > 0) {
1421 compile();
1422 } else {
1423 root = new Start(lastAccept);
1424 matchRoot = lastAccept;
1425 }
1426 }
1427
1428 /**
1429 * The pattern is converted to normalized form ({@link
1430 * java.text.Normalizer.Form.NFC NFC}, canonical decomposition,
1431 * followed by canonical composition for the character class
1432 * part, and {@link java.text.Normalizer.Form.NFD NFD},
1433 * canonical decomposition) for the rest), and then a pure
1434 * group is constructed to match canonical equivalences of the
1435 * characters.
1436 */
1437 private static String normalize(String pattern) {
1438 int plen = pattern.length();
1439 StringBuilder pbuf = new StringBuilder(plen);
1440 char last = 0;
1441 int lastStart = 0;
1442 char cc = 0;
1443 for (int i = 0; i < plen;) {
1444 char c = pattern.charAt(i);
1445 if (cc == 0 && // top level
1446 c == '\\' && i + 1 < plen && pattern.charAt(i + 1) == '\\') {
1447 i += 2; last = 0;
1448 continue;
1449 }
1450 if (c == '[' && last != '\\') {
1451 if (cc == 0) {
1452 if (lastStart < i)
1453 normalizeSlice(pattern, lastStart, i, pbuf);
1454 lastStart = i;
1455 }
1456 cc++;
1457 } else if (c == ']' && last != '\\') {
1458 cc--;
1459 if (cc == 0) {
1460 normalizeClazz(pattern, lastStart, i + 1, pbuf);
1461 lastStart = i + 1;
1462 }
1463 }
1464 last = c;
1465 i++;
1466 }
1467 assert (cc == 0);
1468 if (lastStart < plen)
1469 normalizeSlice(pattern, lastStart, plen, pbuf);
1470 return pbuf.toString();
1471 }
1472
1473 private static void normalizeSlice(String src, int off, int limit,
1474 StringBuilder dst)
1475 {
1476 int len = src.length();
1477 int off0 = off;
1478 while (off < limit && ASCII.isAscii(src.charAt(off))) {
1479 off++;
1480 }
1481 if (off == limit) {
1482 dst.append(src, off0, limit);
1483 return;
1484 }
1485 off--;
1486 if (off < off0)
1487 off = off0;
1488 else
1489 dst.append(src, off0, off);
1490 while (off < limit) {
1491 int ch0 = src.codePointAt(off);
1492 if (".$|()[]{}^?*+\\".indexOf(ch0) != -1) {
1493 dst.append((char)ch0);
1494 off++;
1495 continue;
1496 }
1497 int j = off + Character.charCount(ch0);
1498 int ch1;
1499 while (j < limit) {
1500 ch1 = src.codePointAt(j);
1501 if (Grapheme.isBoundary(ch0, ch1))
1502 break;
1503 ch0 = ch1;
1504 j += Character.charCount(ch1);
1505 }
1506 String seq = src.substring(off, j);
1507 String nfd = Normalizer.normalize(seq, Normalizer.Form.NFD);
1508 off = j;
1509 if (nfd.length() > 1) {
1510 ch0 = nfd.codePointAt(0);
1511 ch1 = nfd.codePointAt(Character.charCount(ch0));
1512 if (Character.getType(ch1) == Character.NON_SPACING_MARK) {
1513 Set<String> altns = new LinkedHashSet<>();
1514 altns.add(seq);
1515 produceEquivalentAlternation(nfd, altns);
1516 dst.append("(?:");
1517 altns.forEach( s -> dst.append(s).append('|'));
1518 dst.delete(dst.length() - 1, dst.length());
1519 dst.append(")");
1520 continue;
1521 }
1522 }
1523 String nfc = Normalizer.normalize(seq, Normalizer.Form.NFC);
1524 if (!seq.equals(nfc) && !nfd.equals(nfc))
1525 dst.append("(?:" + seq + "|" + nfd + "|" + nfc + ")");
1526 else if (!seq.equals(nfd))
1527 dst.append("(?:" + seq + "|" + nfd + ")");
1528 else
1529 dst.append(seq);
1530 }
1531 }
1532
1533 private static void normalizeClazz(String src, int off, int limit,
1534 StringBuilder dst)
1535 {
1536 dst.append(Normalizer.normalize(src.substring(off, limit), Form.NFC));
1537 }
1538
1539 /**
1540 * Given a specific sequence composed of a regular character and
1541 * combining marks that follow it, produce the alternation that will
1542 * match all canonical equivalences of that sequence.
1543 */
1544 private static void produceEquivalentAlternation(String src,
1545 Set<String> dst)
1546 {
1547 int len = countChars(src, 0, 1);
1548 if (src.length() == len) {
1549 dst.add(src); // source has one character.
1550 return;
1551 }
1552 String base = src.substring(0,len);
1553 String combiningMarks = src.substring(len);
1554 String[] perms = producePermutations(combiningMarks);
1555 // Add combined permutations
1556 for(int x = 0; x < perms.length; x++) {
1557 String next = base + perms[x];
1558 dst.add(next);
1559 next = composeOneStep(next);
1560 if (next != null) {
1561 produceEquivalentAlternation(next, dst);
1562 }
1563 }
1564 }
1565
1566 /**
1567 * Returns an array of strings that have all the possible
1568 * permutations of the characters in the input string.
1569 * This is used to get a list of all possible orderings
1570 * of a set of combining marks. Note that some of the permutations
1571 * are invalid because of combining class collisions, and these
1572 * possibilities must be removed because they are not canonically
1573 * equivalent.
1574 */
1575 private static String[] producePermutations(String input) {
1576 if (input.length() == countChars(input, 0, 1))
1577 return new String[] {input};
1578
1579 if (input.length() == countChars(input, 0, 2)) {
1580 int c0 = Character.codePointAt(input, 0);
1581 int c1 = Character.codePointAt(input, Character.charCount(c0));
1582 if (getClass(c1) == getClass(c0)) {
1583 return new String[] {input};
1584 }
1585 String[] result = new String[2];
1586 result[0] = input;
1587 StringBuilder sb = new StringBuilder(2);
1588 sb.appendCodePoint(c1);
1589 sb.appendCodePoint(c0);
1590 result[1] = sb.toString();
1591 return result;
1592 }
1593
1594 int length = 1;
1595 int nCodePoints = countCodePoints(input);
1596 for(int x=1; x<nCodePoints; x++)
1597 length = length * (x+1);
1598
1599 String[] temp = new String[length];
1600
1601 int combClass[] = new int[nCodePoints];
1602 for(int x=0, i=0; x<nCodePoints; x++) {
1603 int c = Character.codePointAt(input, i);
1604 combClass[x] = getClass(c);
1605 i += Character.charCount(c);
1606 }
1607
1608 // For each char, take it out and add the permutations
1609 // of the remaining chars
1610 int index = 0;
1611 int len;
1612 // offset maintains the index in code units.
1613 loop: for(int x=0, offset=0; x<nCodePoints; x++, offset+=len) {
1614 len = countChars(input, offset, 1);
1615 for(int y=x-1; y>=0; y--) {
1616 if (combClass[y] == combClass[x]) {
1617 continue loop;
1618 }
1619 }
1620 StringBuilder sb = new StringBuilder(input);
1621 String otherChars = sb.delete(offset, offset+len).toString();
1622 String[] subResult = producePermutations(otherChars);
1623
1624 String prefix = input.substring(offset, offset+len);
1625 for (String sre : subResult)
1626 temp[index++] = prefix + sre;
1627 }
1628 String[] result = new String[index];
1629 System.arraycopy(temp, 0, result, 0, index);
1630 return result;
1631 }
1632
1633 private static int getClass(int c) {
1634 return sun.text.Normalizer.getCombiningClass(c);
1635 }
1636
1637 /**
1638 * Attempts to compose input by combining the first character
1639 * with the first combining mark following it. Returns a String
1640 * that is the composition of the leading character with its first
1641 * combining mark followed by the remaining combining marks. Returns
1642 * null if the first two characters cannot be further composed.
1643 */
1644 private static String composeOneStep(String input) {
1645 int len = countChars(input, 0, 2);
1646 String firstTwoCharacters = input.substring(0, len);
1647 String result = Normalizer.normalize(firstTwoCharacters, Normalizer.Form.NFC);
1648 if (result.equals(firstTwoCharacters))
1649 return null;
1650 else {
1651 String remainder = input.substring(len);
1652 return result + remainder;
1653 }
1654 }
1655
1656 /**
1657 * Preprocess any \Q...\E sequences in `temp', meta-quoting them.
1658 * See the description of `quotemeta' in perlfunc(1).
1659 */
1660 private void RemoveQEQuoting() {
1661 final int pLen = patternLength;
1662 int i = 0;
1663 while (i < pLen-1) {
1664 if (temp[i] != '\\')
1665 i += 1;
1666 else if (temp[i + 1] != 'Q')
1667 i += 2;
1668 else
1669 break;
1670 }
1671 if (i >= pLen - 1) // No \Q sequence found
1672 return;
1673 int j = i;
1674 i += 2;
1675 int[] newtemp = new int[j + 3*(pLen-i) + 2];
1676 System.arraycopy(temp, 0, newtemp, 0, j);
1677
1678 boolean inQuote = true;
1679 boolean beginQuote = true;
1680 while (i < pLen) {
1681 int c = temp[i++];
1682 if (!ASCII.isAscii(c) || ASCII.isAlpha(c)) {
1683 newtemp[j++] = c;
1684 } else if (ASCII.isDigit(c)) {
1685 if (beginQuote) {
1686 /*
1687 * A unicode escape \[0xu] could be before this quote,
1688 * and we don't want this numeric char to processed as
1689 * part of the escape.
1690 */
1691 newtemp[j++] = '\\';
1692 newtemp[j++] = 'x';
1693 newtemp[j++] = '3';
1694 }
1695 newtemp[j++] = c;
1696 } else if (c != '\\') {
1697 if (inQuote) newtemp[j++] = '\\';
1698 newtemp[j++] = c;
1699 } else if (inQuote) {
1700 if (temp[i] == 'E') {
1701 i++;
1702 inQuote = false;
1703 } else {
1704 newtemp[j++] = '\\';
1705 newtemp[j++] = '\\';
1706 }
1707 } else {
1708 if (temp[i] == 'Q') {
1709 i++;
1710 inQuote = true;
1711 beginQuote = true;
1712 continue;
1713 } else {
1714 newtemp[j++] = c;
1715 if (i != pLen)
1716 newtemp[j++] = temp[i++];
1717 }
1718 }
1719
1720 beginQuote = false;
1721 }
1722
1723 patternLength = j;
1724 temp = Arrays.copyOf(newtemp, j + 2); // double zero termination
1725 }
1726
1727 /**
1728 * Copies regular expression to an int array and invokes the parsing
1729 * of the expression which will create the object tree.
1730 */
1731 private void compile() {
1732 // Handle canonical equivalences
1733 if (has(CANON_EQ) && !has(LITERAL)) {
1734 normalizedPattern = normalize(pattern);
1735 } else {
1736 normalizedPattern = pattern;
1737 }
1738 patternLength = normalizedPattern.length();
1739
1740 // Copy pattern to int array for convenience
1741 // Use double zero to terminate pattern
1742 temp = new int[patternLength + 2];
1743
1744 hasSupplementary = false;
1745 int c, count = 0;
1746 // Convert all chars into code points
1747 for (int x = 0; x < patternLength; x += Character.charCount(c)) {
1748 c = normalizedPattern.codePointAt(x);
1749 if (isSupplementary(c)) {
1750 hasSupplementary = true;
1751 }
1752 temp[count++] = c;
1753 }
1754
1755 patternLength = count; // patternLength now in code points
1756
1757 if (! has(LITERAL))
1758 RemoveQEQuoting();
1759
1760 // Allocate all temporary objects here.
1761 buffer = new int[32];
1762 groupNodes = new GroupHead[10];
1763 namedGroups = null;
1764 topClosureNodes = new ArrayList<>(10);
1765
1766 if (has(LITERAL)) {
1767 // Literal pattern handling
1768 matchRoot = newSlice(temp, patternLength, hasSupplementary);
1769 matchRoot.next = lastAccept;
1770 } else {
1771 // Start recursive descent parsing
1772 matchRoot = expr(lastAccept);
1773 // Check extra pattern characters
1774 if (patternLength != cursor) {
1775 if (peek() == ')') {
1776 throw error("Unmatched closing ')'");
1777 } else {
1778 throw error("Unexpected internal error");
1779 }
1780 }
1781 }
1782
1783 // Peephole optimization
1784 if (matchRoot instanceof Slice) {
1785 root = BnM.optimize(matchRoot);
1786 if (root == matchRoot) {
1787 root = hasSupplementary ? new StartS(matchRoot) : new Start(matchRoot);
1788 }
1789 } else if (matchRoot instanceof Begin || matchRoot instanceof First) {
1790 root = matchRoot;
1791 } else {
1792 root = hasSupplementary ? new StartS(matchRoot) : new Start(matchRoot);
1793 }
1794
1795 // Optimize the greedy Loop to prevent exponential backtracking, IF there
1796 // is no group ref in this pattern. With a non-negative localTCNCount value,
1797 // the greedy type Loop, Curly will skip the backtracking for any starting
1798 // position "i" that failed in the past.
1799 if (!hasGroupRef) {
1800 for (Node node : topClosureNodes) {
1801 if (node instanceof Loop) {
1802 // non-deterministic-greedy-group
1803 ((Loop)node).posIndex = localTCNCount++;
1804 }
1805 }
1806 }
1807
1808 // Release temporary storage
1809 temp = null;
1810 buffer = null;
1811 groupNodes = null;
1812 patternLength = 0;
1813 compiled = true;
1814 topClosureNodes = null;
1815 }
1816
1817 Map<String, Integer> namedGroups() {
1818 Map<String, Integer> groups = namedGroups;
1819 if (groups == null) {
1820 namedGroups = groups = new HashMap<>(2);
1821 }
1822 return groups;
1823 }
1824
1825 /**
1826 * Used to accumulate information about a subtree of the object graph
1827 * so that optimizations can be applied to the subtree.
1828 */
1829 static final class TreeInfo {
1830 int minLength;
1831 int maxLength;
1832 boolean maxValid;
1833 boolean deterministic;
1834
1835 TreeInfo() {
1836 reset();
1837 }
1838 void reset() {
1839 minLength = 0;
1840 maxLength = 0;
1841 maxValid = true;
1842 deterministic = true;
1843 }
1844 }
1845
1846 /*
1847 * The following private methods are mainly used to improve the
1848 * readability of the code. In order to let the Java compiler easily
1849 * inline them, we should not put many assertions or error checks in them.
1850 */
1851
1852 /**
1853 * Indicates whether a particular flag is set or not.
1854 */
1855 private boolean has(int f) {
1856 return (flags0 & f) != 0;
1857 }
1858
1859 /**
1860 * Match next character, signal error if failed.
1861 */
1862 private void accept(int ch, String s) {
1863 int testChar = temp[cursor++];
1864 if (has(COMMENTS))
1865 testChar = parsePastWhitespace(testChar);
1866 if (ch != testChar) {
1867 throw error(s);
1868 }
1869 }
1870
1871 /**
1872 * Mark the end of pattern with a specific character.
1873 */
1874 private void mark(int c) {
1875 temp[patternLength] = c;
1876 }
1877
1878 /**
1879 * Peek the next character, and do not advance the cursor.
1880 */
1881 private int peek() {
1882 int ch = temp[cursor];
1883 if (has(COMMENTS))
1884 ch = peekPastWhitespace(ch);
1885 return ch;
1886 }
1887
1888 /**
1889 * Read the next character, and advance the cursor by one.
1890 */
1891 private int read() {
1892 int ch = temp[cursor++];
1893 if (has(COMMENTS))
1894 ch = parsePastWhitespace(ch);
1895 return ch;
1896 }
1897
1898 /**
1899 * Read the next character, and advance the cursor by one,
1900 * ignoring the COMMENTS setting
1901 */
1902 private int readEscaped() {
1903 int ch = temp[cursor++];
1904 return ch;
1905 }
1906
1907 /**
1908 * Advance the cursor by one, and peek the next character.
1909 */
1910 private int next() {
1911 int ch = temp[++cursor];
1912 if (has(COMMENTS))
1913 ch = peekPastWhitespace(ch);
1914 return ch;
1915 }
1916
1917 /**
1918 * Advance the cursor by one, and peek the next character,
1919 * ignoring the COMMENTS setting
1920 */
1921 private int nextEscaped() {
1922 int ch = temp[++cursor];
1923 return ch;
1924 }
1925
1926 /**
1927 * If in xmode peek past whitespace and comments.
1928 */
1929 private int peekPastWhitespace(int ch) {
1930 while (ASCII.isSpace(ch) || ch == '#') {
1931 while (ASCII.isSpace(ch))
1932 ch = temp[++cursor];
1933 if (ch == '#') {
1934 ch = peekPastLine();
1935 }
1936 }
1937 return ch;
1938 }
1939
1940 /**
1941 * If in xmode parse past whitespace and comments.
1942 */
1943 private int parsePastWhitespace(int ch) {
1944 while (ASCII.isSpace(ch) || ch == '#') {
1945 while (ASCII.isSpace(ch))
1946 ch = temp[cursor++];
1947 if (ch == '#')
1948 ch = parsePastLine();
1949 }
1950 return ch;
1951 }
1952
1953 /**
1954 * xmode parse past comment to end of line.
1955 */
1956 private int parsePastLine() {
1957 int ch = temp[cursor++];
1958 while (ch != 0 && !isLineSeparator(ch))
1959 ch = temp[cursor++];
1960 return ch;
1961 }
1962
1963 /**
1964 * xmode peek past comment to end of line.
1965 */
1966 private int peekPastLine() {
1967 int ch = temp[++cursor];
1968 while (ch != 0 && !isLineSeparator(ch))
1969 ch = temp[++cursor];
1970 return ch;
1971 }
1972
1973 /**
1974 * Determines if character is a line separator in the current mode
1975 */
1976 private boolean isLineSeparator(int ch) {
1977 if (has(UNIX_LINES)) {
1978 return ch == '\n';
1979 } else {
1980 return (ch == '\n' ||
1981 ch == '\r' ||
1982 (ch|1) == '\u2029' ||
1983 ch == '\u0085');
1984 }
1985 }
1986
1987 /**
1988 * Read the character after the next one, and advance the cursor by two.
1989 */
1990 private int skip() {
1991 int i = cursor;
1992 int ch = temp[i+1];
1993 cursor = i + 2;
1994 return ch;
1995 }
1996
1997 /**
1998 * Unread one next character, and retreat cursor by one.
1999 */
2000 private void unread() {
2001 cursor--;
2002 }
2003
2004 /**
2005 * Internal method used for handling all syntax errors. The pattern is
2006 * displayed with a pointer to aid in locating the syntax error.
2007 */
2008 private PatternSyntaxException error(String s) {
2009 return new PatternSyntaxException(s, normalizedPattern, cursor - 1);
2010 }
2011
2012 /**
2013 * Determines if there is any supplementary character or unpaired
2014 * surrogate in the specified range.
2015 */
2016 private boolean findSupplementary(int start, int end) {
2017 for (int i = start; i < end; i++) {
2018 if (isSupplementary(temp[i]))
2019 return true;
2020 }
2021 return false;
2022 }
2023
2024 /**
2025 * Determines if the specified code point is a supplementary
2026 * character or unpaired surrogate.
2027 */
2028 private static final boolean isSupplementary(int ch) {
2029 return ch >= Character.MIN_SUPPLEMENTARY_CODE_POINT ||
2030 Character.isSurrogate((char)ch);
2031 }
2032
2033 /**
2034 * The following methods handle the main parsing. They are sorted
2035 * according to their precedence order, the lowest one first.
2036 */
2037
2038 /**
2039 * The expression is parsed with branch nodes added for alternations.
2040 * This may be called recursively to parse sub expressions that may
2041 * contain alternations.
2042 */
2043 private Node expr(Node end) {
2044 Node prev = null;
2045 Node firstTail = null;
2046 Branch branch = null;
2047 Node branchConn = null;
2048
2049 for (;;) {
2050 Node node = sequence(end);
2051 Node nodeTail = root; //double return
2052 if (prev == null) {
2053 prev = node;
2054 firstTail = nodeTail;
2055 } else {
2056 // Branch
2057 if (branchConn == null) {
2058 branchConn = new BranchConn();
2059 branchConn.next = end;
2060 }
2061 if (node == end) {
2062 // if the node returned from sequence() is "end"
2063 // we have an empty expr, set a null atom into
2064 // the branch to indicate to go "next" directly.
2065 node = null;
2066 } else {
2067 // the "tail.next" of each atom goes to branchConn
2068 nodeTail.next = branchConn;
2069 }
2070 if (prev == branch) {
2071 branch.add(node);
2072 } else {
2073 if (prev == end) {
2074 prev = null;
2075 } else {
2076 // replace the "end" with "branchConn" at its tail.next
2077 // when put the "prev" into the branch as the first atom.
2078 firstTail.next = branchConn;
2079 }
2080 prev = branch = new Branch(prev, node, branchConn);
2081 }
2082 }
2083 if (peek() != '|') {
2084 return prev;
2085 }
2086 next();
2087 }
2088 }
2089
2090 @SuppressWarnings("fallthrough")
2091 /**
2092 * Parsing of sequences between alternations.
2093 */
2094 private Node sequence(Node end) {
2095 Node head = null;
2096 Node tail = null;
2097 Node node = null;
2098 LOOP:
2099 for (;;) {
2100 int ch = peek();
2101 switch (ch) {
2102 case '(':
2103 // Because group handles its own closure,
2104 // we need to treat it differently
2105 node = group0();
2106 // Check for comment or flag group
2107 if (node == null)
2108 continue;
2109 if (head == null)
2110 head = node;
2111 else
2112 tail.next = node;
2113 // Double return: Tail was returned in root
2114 tail = root;
2115 continue;
2116 case '[':
2117 if (has(CANON_EQ) && !has(LITERAL))
2118 node = new NFCCharProperty(clazz(true));
2119 else
2120 node = newCharProperty(clazz(true));
2121 break;
2122 case '\\':
2123 ch = nextEscaped();
2124 if (ch == 'p' || ch == 'P') {
2125 boolean oneLetter = true;
2126 boolean comp = (ch == 'P');
2127 ch = next(); // Consume { if present
2128 if (ch != '{') {
2129 unread();
2130 } else {
2131 oneLetter = false;
2132 }
2133 // node = newCharProperty(family(oneLetter, comp));
2134 if (has(CANON_EQ) && !has(LITERAL))
2135 node = new NFCCharProperty(family(oneLetter, comp));
2136 else
2137 node = newCharProperty(family(oneLetter, comp));
2138 } else {
2139 unread();
2140 node = atom();
2141 }
2142 break;
2143 case '^':
2144 next();
2145 if (has(MULTILINE)) {
2146 if (has(UNIX_LINES))
2147 node = new UnixCaret();
2148 else
2149 node = new Caret();
2150 } else {
2151 node = new Begin();
2152 }
2153 break;
2154 case '$':
2155 next();
2156 if (has(UNIX_LINES))
2157 node = new UnixDollar(has(MULTILINE));
2158 else
2159 node = new Dollar(has(MULTILINE));
2160 break;
2161 case '.':
2162 next();
2163 if (has(DOTALL)) {
2164 node = new CharProperty(ALL());
2165 } else {
2166 if (has(UNIX_LINES)) {
2167 node = new CharProperty(UNIXDOT());
2168 } else {
2169 node = new CharProperty(DOT());
2170 }
2171 }
2172 break;
2173 case '|':
2174 case ')':
2175 break LOOP;
2176 case ']': // Now interpreting dangling ] and } as literals
2177 case '}':
2178 node = atom();
2179 break;
2180 case '?':
2181 case '*':
2182 case '+':
2183 next();
2184 throw error("Dangling meta character '" + ((char)ch) + "'");
2185 case 0:
2186 if (cursor >= patternLength) {
2187 break LOOP;
2188 }
2189 // Fall through
2190 default:
2191 node = atom();
2192 break;
2193 }
2194
2195 node = closure(node);
2196 /* save the top dot-greedy nodes (.*, .+) as well
2197 if (node instanceof GreedyCharProperty &&
2198 ((GreedyCharProperty)node).cp instanceof Dot) {
2199 topClosureNodes.add(node);
2200 }
2201 */
2202 if (head == null) {
2203 head = tail = node;
2204 } else {
2205 tail.next = node;
2206 tail = node;
2207 }
2208 }
2209 if (head == null) {
2210 return end;
2211 }
2212 tail.next = end;
2213 root = tail; //double return
2214 return head;
2215 }
2216
2217 @SuppressWarnings("fallthrough")
2218 /**
2219 * Parse and add a new Single or Slice.
2220 */
2221 private Node atom() {
2222 int first = 0;
2223 int prev = -1;
2224 boolean hasSupplementary = false;
2225 int ch = peek();
2226 for (;;) {
2227 switch (ch) {
2228 case '*':
2229 case '+':
2230 case '?':
2231 case '{':
2232 if (first > 1) {
2233 cursor = prev; // Unwind one character
2234 first--;
2235 }
2236 break;
2237 case '$':
2238 case '.':
2239 case '^':
2240 case '(':
2241 case '[':
2242 case '|':
2243 case ')':
2244 break;
2245 case '\\':
2246 ch = nextEscaped();
2247 if (ch == 'p' || ch == 'P') { // Property
2248 if (first > 0) { // Slice is waiting; handle it first
2249 unread();
2250 break;
2251 } else { // No slice; just return the family node
2252 boolean comp = (ch == 'P');
2253 boolean oneLetter = true;
2254 ch = next(); // Consume { if present
2255 if (ch != '{')
2256 unread();
2257 else
2258 oneLetter = false;
2259 if (has(CANON_EQ) && !has(LITERAL))
2260 return new NFCCharProperty(family(oneLetter, comp));
2261 else
2262 return newCharProperty(family(oneLetter, comp));
2263 }
2264 }
2265 unread();
2266 prev = cursor;
2267 ch = escape(false, first == 0, false);
2268 if (ch >= 0) {
2269 append(ch, first);
2270 first++;
2271 if (isSupplementary(ch)) {
2272 hasSupplementary = true;
2273 }
2274 ch = peek();
2275 continue;
2276 } else if (first == 0) {
2277 return root;
2278 }
2279 // Unwind meta escape sequence
2280 cursor = prev;
2281 break;
2282 case 0:
2283 if (cursor >= patternLength) {
2284 break;
2285 }
2286 // Fall through
2287 default:
2288 prev = cursor;
2289 append(ch, first);
2290 first++;
2291 if (isSupplementary(ch)) {
2292 hasSupplementary = true;
2293 }
2294 ch = next();
2295 continue;
2296 }
2297 break;
2298 }
2299 if (first == 1) {
2300 return newCharProperty(single(buffer[0]));
2301 } else {
2302 return newSlice(buffer, first, hasSupplementary);
2303 }
2304 }
2305
2306 private void append(int ch, int len) {
2307 if (len >= buffer.length) {
2308 int[] tmp = new int[len+len];
2309 System.arraycopy(buffer, 0, tmp, 0, len);
2310 buffer = tmp;
2311 }
2312 buffer[len] = ch;
2313 }
2314
2315 /**
2316 * Parses a backref greedily, taking as many numbers as it
2317 * can. The first digit is always treated as a backref, but
2318 * multi digit numbers are only treated as a backref if at
2319 * least that many backrefs exist at this point in the regex.
2320 */
2321 private Node ref(int refNum) {
2322 boolean done = false;
2323 while(!done) {
2324 int ch = peek();
2325 switch(ch) {
2326 case '0':
2327 case '1':
2328 case '2':
2329 case '3':
2330 case '4':
2331 case '5':
2332 case '6':
2333 case '7':
2334 case '8':
2335 case '9':
2336 int newRefNum = (refNum * 10) + (ch - '0');
2337 // Add another number if it doesn't make a group
2338 // that doesn't exist
2339 if (capturingGroupCount - 1 < newRefNum) {
2340 done = true;
2341 break;
2342 }
2343 refNum = newRefNum;
2344 read();
2345 break;
2346 default:
2347 done = true;
2348 break;
2349 }
2350 }
2351 hasGroupRef = true;
2352 if (has(CASE_INSENSITIVE))
2353 return new CIBackRef(refNum, has(UNICODE_CASE));
2354 else
2355 return new BackRef(refNum);
2356 }
2357
2358 /**
2359 * Parses an escape sequence to determine the actual value that needs
2360 * to be matched.
2361 * If -1 is returned and create was true a new object was added to the tree
2362 * to handle the escape sequence.
2363 * If the returned value is greater than zero, it is the value that
2364 * matches the escape sequence.
2365 */
2366 private int escape(boolean inclass, boolean create, boolean isrange) {
2367 int ch = skip();
2368 switch (ch) {
2369 case '0':
2370 return o();
2371 case '1':
2372 case '2':
2373 case '3':
2374 case '4':
2375 case '5':
2376 case '6':
2377 case '7':
2378 case '8':
2379 case '9':
2380 if (inclass) break;
2381 if (create) {
2382 root = ref((ch - '0'));
2383 }
2384 return -1;
2385 case 'A':
2386 if (inclass) break;
2387 if (create) root = new Begin();
2388 return -1;
2389 case 'B':
2390 if (inclass) break;
2391 if (create) root = new Bound(Bound.NONE, has(UNICODE_CHARACTER_CLASS));
2392 return -1;
2393 case 'C':
2394 break;
2395 case 'D':
2396 if (create) {
2397 predicate = has(UNICODE_CHARACTER_CLASS) ?
2398 CharPredicates.DIGIT() : CharPredicates.ASCII_DIGIT();
2399 predicate = predicate.negate();
2400 if (!inclass)
2401 root = newCharProperty(predicate);
2402 }
2403 return -1;
2404 case 'E':
2405 case 'F':
2406 break;
2407 case 'G':
2408 if (inclass) break;
2409 if (create) root = new LastMatch();
2410 return -1;
2411 case 'H':
2412 if (create) {
2413 predicate = HorizWS().negate();
2414 if (!inclass)
2415 root = newCharProperty(predicate);
2416 }
2417 return -1;
2418 case 'I':
2419 case 'J':
2420 case 'K':
2421 case 'L':
2422 case 'M':
2423 break;
2424 case 'N':
2425 return N();
2426 case 'O':
2427 case 'P':
2428 case 'Q':
2429 break;
2430 case 'R':
2431 if (inclass) break;
2432 if (create) root = new LineEnding();
2433 return -1;
2434 case 'S':
2435 if (create) {
2436 predicate = has(UNICODE_CHARACTER_CLASS) ?
2437 CharPredicates.WHITE_SPACE() : CharPredicates.ASCII_SPACE();
2438 predicate = predicate.negate();
2439 if (!inclass)
2440 root = newCharProperty(predicate);
2441 }
2442 return -1;
2443 case 'T':
2444 case 'U':
2445 break;
2446 case 'V':
2447 if (create) {
2448 predicate = VertWS().negate();
2449 if (!inclass)
2450 root = newCharProperty(predicate);
2451 }
2452 return -1;
2453 case 'W':
2454 if (create) {
2455 predicate = has(UNICODE_CHARACTER_CLASS) ?
2456 CharPredicates.WORD() : CharPredicates.ASCII_WORD();
2457 predicate = predicate.negate();
2458 if (!inclass)
2459 root = newCharProperty(predicate);
2460 }
2461 return -1;
2462 case 'X':
2463 if (inclass) break;
2464 if (create) {
2465 root = new XGrapheme();
2466 }
2467 return -1;
2468 case 'Y':
2469 break;
2470 case 'Z':
2471 if (inclass) break;
2472 if (create) {
2473 if (has(UNIX_LINES))
2474 root = new UnixDollar(false);
2475 else
2476 root = new Dollar(false);
2477 }
2478 return -1;
2479 case 'a':
2480 return '\007';
2481 case 'b':
2482 if (inclass) break;
2483 if (create) {
2484 if (peek() == '{') {
2485 if (skip() == 'g') {
2486 if (read() == '}') {
2487 root = new GraphemeBound();
2488 return -1;
2489 }
2490 break; // error missing trailing }
2491 }
2492 unread(); unread();
2493 }
2494 root = new Bound(Bound.BOTH, has(UNICODE_CHARACTER_CLASS));
2495 }
2496 return -1;
2497 case 'c':
2498 return c();
2499 case 'd':
2500 if (create) {
2501 predicate = has(UNICODE_CHARACTER_CLASS) ?
2502 CharPredicates.DIGIT() : CharPredicates.ASCII_DIGIT();
2503 if (!inclass)
2504 root = newCharProperty(predicate);
2505 }
2506 return -1;
2507 case 'e':
2508 return '\033';
2509 case 'f':
2510 return '\f';
2511 case 'g':
2512 break;
2513 case 'h':
2514 if (create) {
2515 predicate = HorizWS();
2516 if (!inclass)
2517 root = newCharProperty(predicate);
2518 }
2519 return -1;
2520 case 'i':
2521 case 'j':
2522 break;
2523 case 'k':
2524 if (inclass)
2525 break;
2526 if (read() != '<')
2527 throw error("\\k is not followed by '<' for named capturing group");
2528 String name = groupname(read());
2529 if (!namedGroups().containsKey(name))
2530 throw error("(named capturing group <"+ name+"> does not exit");
2531 if (create) {
2532 hasGroupRef = true;
2533 if (has(CASE_INSENSITIVE))
2534 root = new CIBackRef(namedGroups().get(name), has(UNICODE_CASE));
2535 else
2536 root = new BackRef(namedGroups().get(name));
2537 }
2538 return -1;
2539 case 'l':
2540 case 'm':
2541 break;
2542 case 'n':
2543 return '\n';
2544 case 'o':
2545 case 'p':
2546 case 'q':
2547 break;
2548 case 'r':
2549 return '\r';
2550 case 's':
2551 if (create) {
2552 predicate = has(UNICODE_CHARACTER_CLASS) ?
2553 CharPredicates.WHITE_SPACE() : CharPredicates.ASCII_SPACE();
2554 if (!inclass)
2555 root = newCharProperty(predicate);
2556 }
2557 return -1;
2558 case 't':
2559 return '\t';
2560 case 'u':
2561 return u();
2562 case 'v':
2563 // '\v' was implemented as VT/0x0B in releases < 1.8 (though
2564 // undocumented). In JDK8 '\v' is specified as a predefined
2565 // character class for all vertical whitespace characters.
2566 // So [-1, root=VertWS node] pair is returned (instead of a
2567 // single 0x0B). This breaks the range if '\v' is used as
2568 // the start or end value, such as [\v-...] or [...-\v], in
2569 // which a single definite value (0x0B) is expected. For
2570 // compatibility concern '\013'/0x0B is returned if isrange.
2571 if (isrange)
2572 return '\013';
2573 if (create) {
2574 predicate = VertWS();
2575 if (!inclass)
2576 root = newCharProperty(predicate);
2577 }
2578 return -1;
2579 case 'w':
2580 if (create) {
2581 predicate = has(UNICODE_CHARACTER_CLASS) ?
2582 CharPredicates.WORD() : CharPredicates.ASCII_WORD();
2583 if (!inclass)
2584 root = newCharProperty(predicate);
2585 }
2586 return -1;
2587 case 'x':
2588 return x();
2589 case 'y':
2590 break;
2591 case 'z':
2592 if (inclass) break;
2593 if (create) root = new End();
2594 return -1;
2595 default:
2596 return ch;
2597 }
2598 throw error("Illegal/unsupported escape sequence");
2599 }
2600
2601 /**
2602 * Parse a character class, and return the node that matches it.
2603 *
2604 * Consumes a ] on the way out if consume is true. Usually consume
2605 * is true except for the case of [abc&&def] where def is a separate
2606 * right hand node with "understood" brackets.
2607 */
2608 private CharPredicate clazz(boolean consume) {
2609 CharPredicate prev = null;
2610 CharPredicate curr = null;
2611 BitClass bits = new BitClass();
2612 BmpCharPredicate bitsP = ch -> ch < 256 && bits.bits[ch];
2613
2614 boolean isNeg = false;
2615 boolean hasBits = false;
2616 int ch = next();
2617
2618 // Negates if first char in a class, otherwise literal
2619 if (ch == '^' && temp[cursor-1] == '[') {
2620 ch = next();
2621 isNeg = true;
2622 }
2623 for (;;) {
2624 switch (ch) {
2625 case '[':
2626 curr = clazz(true);
2627 if (prev == null)
2628 prev = curr;
2629 else
2630 prev = prev.union(curr);
2631 ch = peek();
2632 continue;
2633 case '&':
2634 ch = next();
2635 if (ch == '&') {
2636 ch = next();
2637 CharPredicate right = null;
2638 while (ch != ']' && ch != '&') {
2639 if (ch == '[') {
2640 if (right == null)
2641 right = clazz(true);
2642 else
2643 right = right.union(clazz(true));
2644 } else { // abc&&def
2645 unread();
2646 right = clazz(false);
2647 }
2648 ch = peek();
2649 }
2650 if (hasBits) {
2651 // bits used, union has high precedence
2652 if (prev == null) {
2653 prev = curr = bitsP;
2654 } else {
2655 prev = prev.union(bitsP);
2656 }
2657 hasBits = false;
2658 }
2659 if (right != null)
2660 curr = right;
2661 if (prev == null) {
2662 if (right == null)
2663 throw error("Bad class syntax");
2664 else
2665 prev = right;
2666 } else {
2667 prev = prev.and(curr);
2668 }
2669 } else {
2670 // treat as a literal &
2671 unread();
2672 break;
2673 }
2674 continue;
2675 case 0:
2676 if (cursor >= patternLength)
2677 throw error("Unclosed character class");
2678 break;
2679 case ']':
2680 if (prev != null || hasBits) {
2681 if (consume)
2682 next();
2683 if (prev == null)
2684 prev = bitsP;
2685 else if (hasBits)
2686 prev = prev.union(bitsP);
2687 if (isNeg)
2688 return prev.negate();
2689 return prev;
2690 }
2691 break;
2692 default:
2693 break;
2694 }
2695 curr = range(bits);
2696 if (curr == null) { // the bits used
2697 hasBits = true;
2698 } else {
2699 if (prev == null)
2700 prev = curr;
2701 else if (prev != curr)
2702 prev = prev.union(curr);
2703 }
2704 ch = peek();
2705 }
2706 }
2707
2708 private CharPredicate bitsOrSingle(BitClass bits, int ch) {
2709 /* Bits can only handle codepoints in [u+0000-u+00ff] range.
2710 Use "single" node instead of bits when dealing with unicode
2711 case folding for codepoints listed below.
2712 (1)Uppercase out of range: u+00ff, u+00b5
2713 toUpperCase(u+00ff) -> u+0178
2714 toUpperCase(u+00b5) -> u+039c
2715 (2)LatinSmallLetterLongS u+17f
2716 toUpperCase(u+017f) -> u+0053
2717 (3)LatinSmallLetterDotlessI u+131
2718 toUpperCase(u+0131) -> u+0049
2719 (4)LatinCapitalLetterIWithDotAbove u+0130
2720 toLowerCase(u+0130) -> u+0069
2721 (5)KelvinSign u+212a
2722 toLowerCase(u+212a) ==> u+006B
2723 (6)AngstromSign u+212b
2724 toLowerCase(u+212b) ==> u+00e5
2725 */
2726 if (ch < 256 &&
2727 !(has(CASE_INSENSITIVE) && has(UNICODE_CASE) &&
2728 (ch == 0xff || ch == 0xb5 ||
2729 ch == 0x49 || ch == 0x69 || //I and i
2730 ch == 0x53 || ch == 0x73 || //S and s
2731 ch == 0x4b || ch == 0x6b || //K and k
2732 ch == 0xc5 || ch == 0xe5))) { //A+ring
2733 bits.add(ch, flags0);
2734 return null;
2735 }
2736 return single(ch);
2737 }
2738
2739 /**
2740 * Returns a suitably optimized, single character predicate
2741 */
2742 private CharPredicate single(final int ch) {
2743 if (has(CASE_INSENSITIVE)) {
2744 int lower, upper;
2745 if (has(UNICODE_CASE)) {
2746 upper = Character.toUpperCase(ch);
2747 lower = Character.toLowerCase(upper);
2748 // Unicode case insensitive matches
2749 if (upper != lower)
2750 return SingleU(lower);
2751 } else if (ASCII.isAscii(ch)) {
2752 lower = ASCII.toLower(ch);
2753 upper = ASCII.toUpper(ch);
2754 // Case insensitive matches a given BMP character
2755 if (lower != upper)
2756 return SingleI(lower, upper);
2757 }
2758 }
2759 if (isSupplementary(ch))
2760 return SingleS(ch);
2761 return Single(ch); // Match a given BMP character
2762 }
2763
2764 /**
2765 * Parse a single character or a character range in a character class
2766 * and return its representative node.
2767 */
2768 private CharPredicate range(BitClass bits) {
2769 int ch = peek();
2770 if (ch == '\\') {
2771 ch = nextEscaped();
2772 if (ch == 'p' || ch == 'P') { // A property
2773 boolean comp = (ch == 'P');
2774 boolean oneLetter = true;
2775 // Consume { if present
2776 ch = next();
2777 if (ch != '{')
2778 unread();
2779 else
2780 oneLetter = false;
2781 return family(oneLetter, comp);
2782 } else { // ordinary escape
2783 boolean isrange = temp[cursor+1] == '-';
2784 unread();
2785 ch = escape(true, true, isrange);
2786 if (ch == -1)
2787 return predicate;
2788 }
2789 } else {
2790 next();
2791 }
2792 if (ch >= 0) {
2793 if (peek() == '-') {
2794 int endRange = temp[cursor+1];
2795 if (endRange == '[') {
2796 return bitsOrSingle(bits, ch);
2797 }
2798 if (endRange != ']') {
2799 next();
2800 int m = peek();
2801 if (m == '\\') {
2802 m = escape(true, false, true);
2803 } else {
2804 next();
2805 }
2806 if (m < ch) {
2807 throw error("Illegal character range");
2808 }
2809 if (has(CASE_INSENSITIVE)) {
2810 if (has(UNICODE_CASE))
2811 return CIRangeU(ch, m);
2812 return CIRange(ch, m);
2813 } else {
2814 return Range(ch, m);
2815 }
2816 }
2817 }
2818 return bitsOrSingle(bits, ch);
2819 }
2820 throw error("Unexpected character '"+((char)ch)+"'");
2821 }
2822
2823 /**
2824 * Parses a Unicode character family and returns its representative node.
2825 */
2826 private CharPredicate family(boolean singleLetter, boolean isComplement) {
2827 next();
2828 String name;
2829 CharPredicate p = null;
2830
2831 if (singleLetter) {
2832 int c = temp[cursor];
2833 if (!Character.isSupplementaryCodePoint(c)) {
2834 name = String.valueOf((char)c);
2835 } else {
2836 name = new String(temp, cursor, 1);
2837 }
2838 read();
2839 } else {
2840 int i = cursor;
2841 mark('}');
2842 while(read() != '}') {
2843 }
2844 mark('\000');
2845 int j = cursor;
2846 if (j > patternLength)
2847 throw error("Unclosed character family");
2848 if (i + 1 >= j)
2849 throw error("Empty character family");
2850 name = new String(temp, i, j-i-1);
2851 }
2852
2853 int i = name.indexOf('=');
2854 if (i != -1) {
2855 // property construct \p{name=value}
2856 String value = name.substring(i + 1);
2857 name = name.substring(0, i).toLowerCase(Locale.ENGLISH);
2858 switch (name) {
2859 case "sc":
2860 case "script":
2861 p = CharPredicates.forUnicodeScript(value);
2862 break;
2863 case "blk":
2864 case "block":
2865 p = CharPredicates.forUnicodeBlock(value);
2866 break;
2867 case "gc":
2868 case "general_category":
2869 p = CharPredicates.forProperty(value);
2870 break;
2871 default:
2872 break;
2873 }
2874 if (p == null)
2875 throw error("Unknown Unicode property {name=<" + name + ">, "
2876 + "value=<" + value + ">}");
2877
2878 } else {
2879 if (name.startsWith("In")) {
2880 // \p{InBlockName}
2881 p = CharPredicates.forUnicodeBlock(name.substring(2));
2882 } else if (name.startsWith("Is")) {
2883 // \p{IsGeneralCategory} and \p{IsScriptName}
2884 name = name.substring(2);
2885 p = CharPredicates.forUnicodeProperty(name);
2886 if (p == null)
2887 p = CharPredicates.forProperty(name);
2888 if (p == null)
2889 p = CharPredicates.forUnicodeScript(name);
2890 } else {
2891 if (has(UNICODE_CHARACTER_CLASS)) {
2892 p = CharPredicates.forPOSIXName(name);
2893 }
2894 if (p == null)
2895 p = CharPredicates.forProperty(name);
2896 }
2897 if (p == null)
2898 throw error("Unknown character property name {In/Is" + name + "}");
2899 }
2900 if (isComplement) {
2901 // it might be too expensive to detect if a complement of
2902 // CharProperty can match "certain" supplementary. So just
2903 // go with StartS.
2904 hasSupplementary = true;
2905 p = p.negate();
2906 }
2907 return p;
2908 }
2909
2910 private CharProperty newCharProperty(CharPredicate p) {
2911 if (p == null)
2912 return null;
2913 if (p instanceof BmpCharPredicate)
2914 return new BmpCharProperty((BmpCharPredicate)p);
2915 else
2916 return new CharProperty(p);
2917 }
2918
2919 /**
2920 * Parses and returns the name of a "named capturing group", the trailing
2921 * ">" is consumed after parsing.
2922 */
2923 private String groupname(int ch) {
2924 StringBuilder sb = new StringBuilder();
2925 sb.append(Character.toChars(ch));
2926 while (ASCII.isLower(ch=read()) || ASCII.isUpper(ch) ||
2927 ASCII.isDigit(ch)) {
2928 sb.append(Character.toChars(ch));
2929 }
2930 if (sb.length() == 0)
2931 throw error("named capturing group has 0 length name");
2932 if (ch != '>')
2933 throw error("named capturing group is missing trailing '>'");
2934 return sb.toString();
2935 }
2936
2937 /**
2938 * Parses a group and returns the head node of a set of nodes that process
2939 * the group. Sometimes a double return system is used where the tail is
2940 * returned in root.
2941 */
2942 private Node group0() {
2943 boolean capturingGroup = false;
2944 Node head = null;
2945 Node tail = null;
2946 int save = flags0;
2947 int saveTCNCount = topClosureNodes.size();
2948 root = null;
2949 int ch = next();
2950 if (ch == '?') {
2951 ch = skip();
2952 switch (ch) {
2953 case ':': // (?:xxx) pure group
2954 head = createGroup(true);
2955 tail = root;
2956 head.next = expr(tail);
2957 break;
2958 case '=': // (?=xxx) and (?!xxx) lookahead
2959 case '!':
2960 head = createGroup(true);
2961 tail = root;
2962 head.next = expr(tail);
2963 if (ch == '=') {
2964 head = tail = new Pos(head);
2965 } else {
2966 head = tail = new Neg(head);
2967 }
2968 break;
2969 case '>': // (?>xxx) independent group
2970 head = createGroup(true);
2971 tail = root;
2972 head.next = expr(tail);
2973 head = tail = new Ques(head, Qtype.INDEPENDENT);
2974 break;
2975 case '<': // (?<xxx) look behind
2976 ch = read();
2977 if (ASCII.isLower(ch) || ASCII.isUpper(ch)) {
2978 // named captured group
2979 String name = groupname(ch);
2980 if (namedGroups().containsKey(name))
2981 throw error("Named capturing group <" + name
2982 + "> is already defined");
2983 capturingGroup = true;
2984 head = createGroup(false);
2985 tail = root;
2986 namedGroups().put(name, capturingGroupCount-1);
2987 head.next = expr(tail);
2988 break;
2989 }
2990 int start = cursor;
2991 head = createGroup(true);
2992 tail = root;
2993 head.next = expr(tail);
2994 tail.next = lookbehindEnd;
2995 TreeInfo info = new TreeInfo();
2996 head.study(info);
2997 if (info.maxValid == false) {
2998 throw error("Look-behind group does not have "
2999 + "an obvious maximum length");
3000 }
3001 boolean hasSupplementary = findSupplementary(start, patternLength);
3002 if (ch == '=') {
3003 head = tail = (hasSupplementary ?
3004 new BehindS(head, info.maxLength,
3005 info.minLength) :
3006 new Behind(head, info.maxLength,
3007 info.minLength));
3008 } else if (ch == '!') {
3009 head = tail = (hasSupplementary ?
3010 new NotBehindS(head, info.maxLength,
3011 info.minLength) :
3012 new NotBehind(head, info.maxLength,
3013 info.minLength));
3014 } else {
3015 throw error("Unknown look-behind group");
3016 }
3017 // clear all top-closure-nodes inside lookbehind
3018 if (saveTCNCount < topClosureNodes.size())
3019 topClosureNodes.subList(saveTCNCount, topClosureNodes.size()).clear();
3020 break;
3021 case '$':
3022 case '@':
3023 throw error("Unknown group type");
3024 default: // (?xxx:) inlined match flags
3025 unread();
3026 addFlag();
3027 ch = read();
3028 if (ch == ')') {
3029 return null; // Inline modifier only
3030 }
3031 if (ch != ':') {
3032 throw error("Unknown inline modifier");
3033 }
3034 head = createGroup(true);
3035 tail = root;
3036 head.next = expr(tail);
3037 break;
3038 }
3039 } else { // (xxx) a regular group
3040 capturingGroup = true;
3041 head = createGroup(false);
3042 tail = root;
3043 head.next = expr(tail);
3044 }
3045
3046 accept(')', "Unclosed group");
3047 flags0 = save;
3048
3049 // Check for quantifiers
3050 Node node = closure(head);
3051 if (node == head) { // No closure
3052 root = tail;
3053 return node; // Dual return
3054 }
3055 if (head == tail) { // Zero length assertion
3056 root = node;
3057 return node; // Dual return
3058 }
3059
3060 // have group closure, clear all inner closure nodes from the
3061 // top list (no backtracking stopper optimization for inner
3062 if (saveTCNCount < topClosureNodes.size())
3063 topClosureNodes.subList(saveTCNCount, topClosureNodes.size()).clear();
3064
3065 if (node instanceof Ques) {
3066 Ques ques = (Ques) node;
3067 if (ques.type == Qtype.POSSESSIVE) {
3068 root = node;
3069 return node;
3070 }
3071 tail.next = new BranchConn();
3072 tail = tail.next;
3073 if (ques.type == Qtype.GREEDY) {
3074 head = new Branch(head, null, tail);
3075 } else { // Reluctant quantifier
3076 head = new Branch(null, head, tail);
3077 }
3078 root = tail;
3079 return head;
3080 } else if (node instanceof Curly) {
3081 Curly curly = (Curly) node;
3082 if (curly.type == Qtype.POSSESSIVE) {
3083 root = node;
3084 return node;
3085 }
3086 // Discover if the group is deterministic
3087 TreeInfo info = new TreeInfo();
3088 if (head.study(info)) { // Deterministic
3089 GroupTail temp = (GroupTail) tail;
3090 head = root = new GroupCurly(head.next, curly.cmin,
3091 curly.cmax, curly.type,
3092 ((GroupTail)tail).localIndex,
3093 ((GroupTail)tail).groupIndex,
3094 capturingGroup);
3095 return head;
3096 } else { // Non-deterministic
3097 int temp = ((GroupHead) head).localIndex;
3098 Loop loop;
3099 if (curly.type == Qtype.GREEDY) {
3100 loop = new Loop(this.localCount, temp);
3101 // add the max_reps greedy to the top-closure-node list
3102 if (curly.cmax == MAX_REPS)
3103 topClosureNodes.add(loop);
3104 } else { // Reluctant Curly
3105 loop = new LazyLoop(this.localCount, temp);
3106 }
3107 Prolog prolog = new Prolog(loop);
3108 this.localCount += 1;
3109 loop.cmin = curly.cmin;
3110 loop.cmax = curly.cmax;
3111 loop.body = head;
3112 tail.next = loop;
3113 root = loop;
3114 return prolog; // Dual return
3115 }
3116 }
3117 throw error("Internal logic error");
3118 }
3119
3120 /**
3121 * Create group head and tail nodes using double return. If the group is
3122 * created with anonymous true then it is a pure group and should not
3123 * affect group counting.
3124 */
3125 private Node createGroup(boolean anonymous) {
3126 int localIndex = localCount++;
3127 int groupIndex = 0;
3128 if (!anonymous)
3129 groupIndex = capturingGroupCount++;
3130 GroupHead head = new GroupHead(localIndex);
3131 root = new GroupTail(localIndex, groupIndex);
3132
3133 // for debug/print only, head.match does NOT need the "tail" info
3134 head.tail = (GroupTail)root;
3135
3136 if (!anonymous && groupIndex < 10)
3137 groupNodes[groupIndex] = head;
3138 return head;
3139 }
3140
3141 @SuppressWarnings("fallthrough")
3142 /**
3143 * Parses inlined match flags and set them appropriately.
3144 */
3145 private void addFlag() {
3146 int ch = peek();
3147 for (;;) {
3148 switch (ch) {
3149 case 'i':
3150 flags0 |= CASE_INSENSITIVE;
3151 break;
3152 case 'm':
3153 flags0 |= MULTILINE;
3154 break;
3155 case 's':
3156 flags0 |= DOTALL;
3157 break;
3158 case 'd':
3159 flags0 |= UNIX_LINES;
3160 break;
3161 case 'u':
3162 flags0 |= UNICODE_CASE;
3163 break;
3164 case 'c':
3165 flags0 |= CANON_EQ;
3166 break;
3167 case 'x':
3168 flags0 |= COMMENTS;
3169 break;
3170 case 'U':
3171 flags0 |= (UNICODE_CHARACTER_CLASS | UNICODE_CASE);
3172 break;
3173 case '-': // subFlag then fall through
3174 ch = next();
3175 subFlag();
3176 default:
3177 return;
3178 }
3179 ch = next();
3180 }
3181 }
3182
3183 @SuppressWarnings("fallthrough")
3184 /**
3185 * Parses the second part of inlined match flags and turns off
3186 * flags appropriately.
3187 */
3188 private void subFlag() {
3189 int ch = peek();
3190 for (;;) {
3191 switch (ch) {
3192 case 'i':
3193 flags0 &= ~CASE_INSENSITIVE;
3194 break;
3195 case 'm':
3196 flags0 &= ~MULTILINE;
3197 break;
3198 case 's':
3199 flags0 &= ~DOTALL;
3200 break;
3201 case 'd':
3202 flags0 &= ~UNIX_LINES;
3203 break;
3204 case 'u':
3205 flags0 &= ~UNICODE_CASE;
3206 break;
3207 case 'c':
3208 flags0 &= ~CANON_EQ;
3209 break;
3210 case 'x':
3211 flags0 &= ~COMMENTS;
3212 break;
3213 case 'U':
3214 flags0 &= ~(UNICODE_CHARACTER_CLASS | UNICODE_CASE);
3215 break;
3216 default:
3217 return;
3218 }
3219 ch = next();
3220 }
3221 }
3222
3223 static final int MAX_REPS = 0x7FFFFFFF;
3224
3225 static enum Qtype {
3226 GREEDY, LAZY, POSSESSIVE, INDEPENDENT
3227 }
3228
3229 private Node curly(Node prev, int cmin) {
3230 int ch = next();
3231 if (ch == '?') {
3232 next();
3233 return new Curly(prev, cmin, MAX_REPS, Qtype.LAZY);
3234 } else if (ch == '+') {
3235 next();
3236 return new Curly(prev, cmin, MAX_REPS, Qtype.POSSESSIVE);
3237 }
3238 if (prev instanceof BmpCharProperty) {
3239 return new BmpCharPropertyGreedy((BmpCharProperty)prev, cmin);
3240 } else if (prev instanceof CharProperty) {
3241 return new CharPropertyGreedy((CharProperty)prev, cmin);
3242 }
3243 return new Curly(prev, cmin, MAX_REPS, Qtype.GREEDY);
3244 }
3245
3246 /**
3247 * Processes repetition. If the next character peeked is a quantifier
3248 * then new nodes must be appended to handle the repetition.
3249 * Prev could be a single or a group, so it could be a chain of nodes.
3250 */
3251 private Node closure(Node prev) {
3252 Node atom;
3253 int ch = peek();
3254 switch (ch) {
3255 case '?':
3256 ch = next();
3257 if (ch == '?') {
3258 next();
3259 return new Ques(prev, Qtype.LAZY);
3260 } else if (ch == '+') {
3261 next();
3262 return new Ques(prev, Qtype.POSSESSIVE);
3263 }
3264 return new Ques(prev, Qtype.GREEDY);
3265 case '*':
3266 return curly(prev, 0);
3267 case '+':
3268 return curly(prev, 1);
3269 case '{':
3270 ch = temp[cursor+1];
3271 if (ASCII.isDigit(ch)) {
3272 skip();
3273 int cmin = 0;
3274 do {
3275 cmin = cmin * 10 + (ch - '0');
3276 } while (ASCII.isDigit(ch = read()));
3277 int cmax = cmin;
3278 if (ch == ',') {
3279 ch = read();
3280 cmax = MAX_REPS;
3281 if (ch != '}') {
3282 cmax = 0;
3283 while (ASCII.isDigit(ch)) {
3284 cmax = cmax * 10 + (ch - '0');
3285 ch = read();
3286 }
3287 }
3288 }
3289 if (ch != '}')
3290 throw error("Unclosed counted closure");
3291 if (((cmin) | (cmax) | (cmax - cmin)) < 0)
3292 throw error("Illegal repetition range");
3293 Curly curly;
3294 ch = peek();
3295 if (ch == '?') {
3296 next();
3297 curly = new Curly(prev, cmin, cmax, Qtype.LAZY);
3298 } else if (ch == '+') {
3299 next();
3300 curly = new Curly(prev, cmin, cmax, Qtype.POSSESSIVE);
3301 } else {
3302 curly = new Curly(prev, cmin, cmax, Qtype.GREEDY);
3303 }
3304 return curly;
3305 } else {
3306 throw error("Illegal repetition");
3307 }
3308 default:
3309 return prev;
3310 }
3311 }
3312
3313 /**
3314 * Utility method for parsing control escape sequences.
3315 */
3316 private int c() {
3317 if (cursor < patternLength) {
3318 return read() ^ 64;
3319 }
3320 throw error("Illegal control escape sequence");
3321 }
3322
3323 /**
3324 * Utility method for parsing octal escape sequences.
3325 */
3326 private int o() {
3327 int n = read();
3328 if (((n-'0')|('7'-n)) >= 0) {
3329 int m = read();
3330 if (((m-'0')|('7'-m)) >= 0) {
3331 int o = read();
3332 if ((((o-'0')|('7'-o)) >= 0) && (((n-'0')|('3'-n)) >= 0)) {
3333 return (n - '0') * 64 + (m - '0') * 8 + (o - '0');
3334 }
3335 unread();
3336 return (n - '0') * 8 + (m - '0');
3337 }
3338 unread();
3339 return (n - '0');
3340 }
3341 throw error("Illegal octal escape sequence");
3342 }
3343
3344 /**
3345 * Utility method for parsing hexadecimal escape sequences.
3346 */
3347 private int x() {
3348 int n = read();
3349 if (ASCII.isHexDigit(n)) {
3350 int m = read();
3351 if (ASCII.isHexDigit(m)) {
3352 return ASCII.toDigit(n) * 16 + ASCII.toDigit(m);
3353 }
3354 } else if (n == '{' && ASCII.isHexDigit(peek())) {
3355 int ch = 0;
3356 while (ASCII.isHexDigit(n = read())) {
3357 ch = (ch << 4) + ASCII.toDigit(n);
3358 if (ch > Character.MAX_CODE_POINT)
3359 throw error("Hexadecimal codepoint is too big");
3360 }
3361 if (n != '}')
3362 throw error("Unclosed hexadecimal escape sequence");
3363 return ch;
3364 }
3365 throw error("Illegal hexadecimal escape sequence");
3366 }
3367
3368 /**
3369 * Utility method for parsing unicode escape sequences.
3370 */
3371 private int cursor() {
3372 return cursor;
3373 }
3374
3375 private void setcursor(int pos) {
3376 cursor = pos;
3377 }
3378
3379 private int uxxxx() {
3380 int n = 0;
3381 for (int i = 0; i < 4; i++) {
3382 int ch = read();
3383 if (!ASCII.isHexDigit(ch)) {
3384 throw error("Illegal Unicode escape sequence");
3385 }
3386 n = n * 16 + ASCII.toDigit(ch);
3387 }
3388 return n;
3389 }
3390
3391 private int u() {
3392 int n = uxxxx();
3393 if (Character.isHighSurrogate((char)n)) {
3394 int cur = cursor();
3395 if (read() == '\\' && read() == 'u') {
3396 int n2 = uxxxx();
3397 if (Character.isLowSurrogate((char)n2))
3398 return Character.toCodePoint((char)n, (char)n2);
3399 }
3400 setcursor(cur);
3401 }
3402 return n;
3403 }
3404
3405 private int N() {
3406 if (read() == '{') {
3407 int i = cursor;
3408 while (cursor < patternLength && read() != '}') {}
3409 if (cursor > patternLength)
3410 throw error("Unclosed character name escape sequence");
3411 String name = new String(temp, i, cursor - i - 1);
3412 try {
3413 return Character.codePointOf(name);
3414 } catch (IllegalArgumentException x) {
3415 throw error("Unknown character name [" + name + "]");
3416 }
3417 }
3418 throw error("Illegal character name escape sequence");
3419 }
3420
3421 //
3422 // Utility methods for code point support
3423 //
3424 private static final int countChars(CharSequence seq, int index,
3425 int lengthInCodePoints) {
3426 // optimization
3427 if (lengthInCodePoints == 1 && !Character.isHighSurrogate(seq.charAt(index))) {
3428 assert (index >= 0 && index < seq.length());
3429 return 1;
3430 }
3431 int length = seq.length();
3432 int x = index;
3433 if (lengthInCodePoints >= 0) {
3434 assert (index >= 0 && index < length);
3435 for (int i = 0; x < length && i < lengthInCodePoints; i++) {
3436 if (Character.isHighSurrogate(seq.charAt(x++))) {
3437 if (x < length && Character.isLowSurrogate(seq.charAt(x))) {
3438 x++;
3439 }
3440 }
3441 }
3442 return x - index;
3443 }
3444
3445 assert (index >= 0 && index <= length);
3446 if (index == 0) {
3447 return 0;
3448 }
3449 int len = -lengthInCodePoints;
3450 for (int i = 0; x > 0 && i < len; i++) {
3451 if (Character.isLowSurrogate(seq.charAt(--x))) {
3452 if (x > 0 && Character.isHighSurrogate(seq.charAt(x-1))) {
3453 x--;
3454 }
3455 }
3456 }
3457 return index - x;
3458 }
3459
3460 private static final int countCodePoints(CharSequence seq) {
3461 int length = seq.length();
3462 int n = 0;
3463 for (int i = 0; i < length; ) {
3464 n++;
3465 if (Character.isHighSurrogate(seq.charAt(i++))) {
3466 if (i < length && Character.isLowSurrogate(seq.charAt(i))) {
3467 i++;
3468 }
3469 }
3470 }
3471 return n;
3472 }
3473
3474 /**
3475 * Creates a bit vector for matching Latin-1 values. A normal BitClass
3476 * never matches values above Latin-1, and a complemented BitClass always
3477 * matches values above Latin-1.
3478 */
3479 static final class BitClass extends BmpCharProperty {
3480 final boolean[] bits;
3481 BitClass() {
3482 this(new boolean[256]);
3483 }
3484 private BitClass(boolean[] bits) {
3485 super( ch -> ch < 256 && bits[ch]);
3486 this.bits = bits;
3487 }
3488 BitClass add(int c, int flags) {
3489 assert c >= 0 && c <= 255;
3490 if ((flags & CASE_INSENSITIVE) != 0) {
3491 if (ASCII.isAscii(c)) {
3492 bits[ASCII.toUpper(c)] = true;
3493 bits[ASCII.toLower(c)] = true;
3494 } else if ((flags & UNICODE_CASE) != 0) {
3495 bits[Character.toLowerCase(c)] = true;
3496 bits[Character.toUpperCase(c)] = true;
3497 }
3498 }
3499 bits[c] = true;
3500 return this;
3501 }
3502 }
3503
3504 /**
3505 * Utility method for creating a string slice matcher.
3506 */
3507 private Node newSlice(int[] buf, int count, boolean hasSupplementary) {
3508 int[] tmp = new int[count];
3509 if (has(CASE_INSENSITIVE)) {
3510 if (has(UNICODE_CASE)) {
3511 for (int i = 0; i < count; i++) {
3512 tmp[i] = Character.toLowerCase(
3513 Character.toUpperCase(buf[i]));
3514 }
3515 return hasSupplementary? new SliceUS(tmp) : new SliceU(tmp);
3516 }
3517 for (int i = 0; i < count; i++) {
3518 tmp[i] = ASCII.toLower(buf[i]);
3519 }
3520 return hasSupplementary? new SliceIS(tmp) : new SliceI(tmp);
3521 }
3522 for (int i = 0; i < count; i++) {
3523 tmp[i] = buf[i];
3524 }
3525 return hasSupplementary ? new SliceS(tmp) : new Slice(tmp);
3526 }
3527
3528 /**
3529 * The following classes are the building components of the object
3530 * tree that represents a compiled regular expression. The object tree
3531 * is made of individual elements that handle constructs in the Pattern.
3532 * Each type of object knows how to match its equivalent construct with
3533 * the match() method.
3534 */
3535
3536 /**
3537 * Base class for all node classes. Subclasses should override the match()
3538 * method as appropriate. This class is an accepting node, so its match()
3539 * always returns true.
3540 */
3541 static class Node extends Object {
3542 Node next;
3543 Node() {
3544 next = Pattern.accept;
3545 }
3546 /**
3547 * This method implements the classic accept node.
3548 */
3549 boolean match(Matcher matcher, int i, CharSequence seq) {
3550 matcher.last = i;
3551 matcher.groups[0] = matcher.first;
3552 matcher.groups[1] = matcher.last;
3553 return true;
3554 }
3555 /**
3556 * This method is good for all zero length assertions.
3557 */
3558 boolean study(TreeInfo info) {
3559 if (next != null) {
3560 return next.study(info);
3561 } else {
3562 return info.deterministic;
3563 }
3564 }
3565 }
3566
3567 static class LastNode extends Node {
3568 /**
3569 * This method implements the classic accept node with
3570 * the addition of a check to see if the match occurred
3571 * using all of the input.
3572 */
3573 boolean match(Matcher matcher, int i, CharSequence seq) {
3574 if (matcher.acceptMode == Matcher.ENDANCHOR && i != matcher.to)
3575 return false;
3576 matcher.last = i;
3577 matcher.groups[0] = matcher.first;
3578 matcher.groups[1] = matcher.last;
3579 return true;
3580 }
3581 }
3582
3583 /**
3584 * Used for REs that can start anywhere within the input string.
3585 * This basically tries to match repeatedly at each spot in the
3586 * input string, moving forward after each try. An anchored search
3587 * or a BnM will bypass this node completely.
3588 */
3589 static class Start extends Node {
3590 int minLength;
3591 Start(Node node) {
3592 this.next = node;
3593 TreeInfo info = new TreeInfo();
3594 next.study(info);
3595 minLength = info.minLength;
3596 }
3597 boolean match(Matcher matcher, int i, CharSequence seq) {
3598 if (i > matcher.to - minLength) {
3599 matcher.hitEnd = true;
3600 return false;
3601 }
3602 int guard = matcher.to - minLength;
3603 for (; i <= guard; i++) {
3604 if (next.match(matcher, i, seq)) {
3605 matcher.first = i;
3606 matcher.groups[0] = matcher.first;
3607 matcher.groups[1] = matcher.last;
3608 return true;
3609 }
3610 }
3611 matcher.hitEnd = true;
3612 return false;
3613 }
3614 boolean study(TreeInfo info) {
3615 next.study(info);
3616 info.maxValid = false;
3617 info.deterministic = false;
3618 return false;
3619 }
3620 }
3621
3622 /*
3623 * StartS supports supplementary characters, including unpaired surrogates.
3624 */
3625 static final class StartS extends Start {
3626 StartS(Node node) {
3627 super(node);
3628 }
3629 boolean match(Matcher matcher, int i, CharSequence seq) {
3630 if (i > matcher.to - minLength) {
3631 matcher.hitEnd = true;
3632 return false;
3633 }
3634 int guard = matcher.to - minLength;
3635 while (i <= guard) {
3636 //if ((ret = next.match(matcher, i, seq)) || i == guard)
3637 if (next.match(matcher, i, seq)) {
3638 matcher.first = i;
3639 matcher.groups[0] = matcher.first;
3640 matcher.groups[1] = matcher.last;
3641 return true;
3642 }
3643 if (i == guard)
3644 break;
3645 // Optimization to move to the next character. This is
3646 // faster than countChars(seq, i, 1).
3647 if (Character.isHighSurrogate(seq.charAt(i++))) {
3648 if (i < seq.length() &&
3649 Character.isLowSurrogate(seq.charAt(i))) {
3650 i++;
3651 }
3652 }
3653 }
3654 matcher.hitEnd = true;
3655 return false;
3656 }
3657 }
3658
3659 /**
3660 * Node to anchor at the beginning of input. This object implements the
3661 * match for a \A sequence, and the caret anchor will use this if not in
3662 * multiline mode.
3663 */
3664 static final class Begin extends Node {
3665 boolean match(Matcher matcher, int i, CharSequence seq) {
3666 int fromIndex = (matcher.anchoringBounds) ?
3667 matcher.from : 0;
3668 if (i == fromIndex && next.match(matcher, i, seq)) {
3669 matcher.first = i;
3670 matcher.groups[0] = i;
3671 matcher.groups[1] = matcher.last;
3672 return true;
3673 } else {
3674 return false;
3675 }
3676 }
3677 }
3678
3679 /**
3680 * Node to anchor at the end of input. This is the absolute end, so this
3681 * should not match at the last newline before the end as $ will.
3682 */
3683 static final class End extends Node {
3684 boolean match(Matcher matcher, int i, CharSequence seq) {
3685 int endIndex = (matcher.anchoringBounds) ?
3686 matcher.to : matcher.getTextLength();
3687 if (i == endIndex) {
3688 matcher.hitEnd = true;
3689 return next.match(matcher, i, seq);
3690 }
3691 return false;
3692 }
3693 }
3694
3695 /**
3696 * Node to anchor at the beginning of a line. This is essentially the
3697 * object to match for the multiline ^.
3698 */
3699 static final class Caret extends Node {
3700 boolean match(Matcher matcher, int i, CharSequence seq) {
3701 int startIndex = matcher.from;
3702 int endIndex = matcher.to;
3703 if (!matcher.anchoringBounds) {
3704 startIndex = 0;
3705 endIndex = matcher.getTextLength();
3706 }
3707 // Perl does not match ^ at end of input even after newline
3708 if (i == endIndex) {
3709 matcher.hitEnd = true;
3710 return false;
3711 }
3712 if (i > startIndex) {
3713 char ch = seq.charAt(i-1);
3714 if (ch != '\n' && ch != '\r'
3715 && (ch|1) != '\u2029'
3716 && ch != '\u0085' ) {
3717 return false;
3718 }
3719 // Should treat /r/n as one newline
3720 if (ch == '\r' && seq.charAt(i) == '\n')
3721 return false;
3722 }
3723 return next.match(matcher, i, seq);
3724 }
3725 }
3726
3727 /**
3728 * Node to anchor at the beginning of a line when in unixdot mode.
3729 */
3730 static final class UnixCaret extends Node {
3731 boolean match(Matcher matcher, int i, CharSequence seq) {
3732 int startIndex = matcher.from;
3733 int endIndex = matcher.to;
3734 if (!matcher.anchoringBounds) {
3735 startIndex = 0;
3736 endIndex = matcher.getTextLength();
3737 }
3738 // Perl does not match ^ at end of input even after newline
3739 if (i == endIndex) {
3740 matcher.hitEnd = true;
3741 return false;
3742 }
3743 if (i > startIndex) {
3744 char ch = seq.charAt(i-1);
3745 if (ch != '\n') {
3746 return false;
3747 }
3748 }
3749 return next.match(matcher, i, seq);
3750 }
3751 }
3752
3753 /**
3754 * Node to match the location where the last match ended.
3755 * This is used for the \G construct.
3756 */
3757 static final class LastMatch extends Node {
3758 boolean match(Matcher matcher, int i, CharSequence seq) {
3759 if (i != matcher.oldLast)
3760 return false;
3761 return next.match(matcher, i, seq);
3762 }
3763 }
3764
3765 /**
3766 * Node to anchor at the end of a line or the end of input based on the
3767 * multiline mode.
3768 *
3769 * When not in multiline mode, the $ can only match at the very end
3770 * of the input, unless the input ends in a line terminator in which
3771 * it matches right before the last line terminator.
3772 *
3773 * Note that \r\n is considered an atomic line terminator.
3774 *
3775 * Like ^ the $ operator matches at a position, it does not match the
3776 * line terminators themselves.
3777 */
3778 static final class Dollar extends Node {
3779 boolean multiline;
3780 Dollar(boolean mul) {
3781 multiline = mul;
3782 }
3783 boolean match(Matcher matcher, int i, CharSequence seq) {
3784 int endIndex = (matcher.anchoringBounds) ?
3785 matcher.to : matcher.getTextLength();
3786 if (!multiline) {
3787 if (i < endIndex - 2)
3788 return false;
3789 if (i == endIndex - 2) {
3790 char ch = seq.charAt(i);
3791 if (ch != '\r')
3792 return false;
3793 ch = seq.charAt(i + 1);
3794 if (ch != '\n')
3795 return false;
3796 }
3797 }
3798 // Matches before any line terminator; also matches at the
3799 // end of input
3800 // Before line terminator:
3801 // If multiline, we match here no matter what
3802 // If not multiline, fall through so that the end
3803 // is marked as hit; this must be a /r/n or a /n
3804 // at the very end so the end was hit; more input
3805 // could make this not match here
3806 if (i < endIndex) {
3807 char ch = seq.charAt(i);
3808 if (ch == '\n') {
3809 // No match between \r\n
3810 if (i > 0 && seq.charAt(i-1) == '\r')
3811 return false;
3812 if (multiline)
3813 return next.match(matcher, i, seq);
3814 } else if (ch == '\r' || ch == '\u0085' ||
3815 (ch|1) == '\u2029') {
3816 if (multiline)
3817 return next.match(matcher, i, seq);
3818 } else { // No line terminator, no match
3819 return false;
3820 }
3821 }
3822 // Matched at current end so hit end
3823 matcher.hitEnd = true;
3824 // If a $ matches because of end of input, then more input
3825 // could cause it to fail!
3826 matcher.requireEnd = true;
3827 return next.match(matcher, i, seq);
3828 }
3829 boolean study(TreeInfo info) {
3830 next.study(info);
3831 return info.deterministic;
3832 }
3833 }
3834
3835 /**
3836 * Node to anchor at the end of a line or the end of input based on the
3837 * multiline mode when in unix lines mode.
3838 */
3839 static final class UnixDollar extends Node {
3840 boolean multiline;
3841 UnixDollar(boolean mul) {
3842 multiline = mul;
3843 }
3844 boolean match(Matcher matcher, int i, CharSequence seq) {
3845 int endIndex = (matcher.anchoringBounds) ?
3846 matcher.to : matcher.getTextLength();
3847 if (i < endIndex) {
3848 char ch = seq.charAt(i);
3849 if (ch == '\n') {
3850 // If not multiline, then only possible to
3851 // match at very end or one before end
3852 if (multiline == false && i != endIndex - 1)
3853 return false;
3854 // If multiline return next.match without setting
3855 // matcher.hitEnd
3856 if (multiline)
3857 return next.match(matcher, i, seq);
3858 } else {
3859 return false;
3860 }
3861 }
3862 // Matching because at the end or 1 before the end;
3863 // more input could change this so set hitEnd
3864 matcher.hitEnd = true;
3865 // If a $ matches because of end of input, then more input
3866 // could cause it to fail!
3867 matcher.requireEnd = true;
3868 return next.match(matcher, i, seq);
3869 }
3870 boolean study(TreeInfo info) {
3871 next.study(info);
3872 return info.deterministic;
3873 }
3874 }
3875
3876 /**
3877 * Node class that matches a Unicode line ending '\R'
3878 */
3879 static final class LineEnding extends Node {
3880 boolean match(Matcher matcher, int i, CharSequence seq) {
3881 // (u+000Du+000A|[u+000Au+000Bu+000Cu+000Du+0085u+2028u+2029])
3882 if (i < matcher.to) {
3883 int ch = seq.charAt(i);
3884 if (ch == 0x0A || ch == 0x0B || ch == 0x0C ||
3885 ch == 0x85 || ch == 0x2028 || ch == 0x2029)
3886 return next.match(matcher, i + 1, seq);
3887 if (ch == 0x0D) {
3888 i++;
3889 if (i < matcher.to) {
3890 if (seq.charAt(i) == 0x0A &&
3891 next.match(matcher, i + 1, seq)) {
3892 return true;
3893 }
3894 } else {
3895 matcher.hitEnd = true;
3896 }
3897 return next.match(matcher, i, seq);
3898 }
3899 } else {
3900 matcher.hitEnd = true;
3901 }
3902 return false;
3903 }
3904 boolean study(TreeInfo info) {
3905 info.minLength++;
3906 info.maxLength += 2;
3907 return next.study(info);
3908 }
3909 }
3910
3911 /**
3912 * Abstract node class to match one character satisfying some
3913 * boolean property.
3914 */
3915 static class CharProperty extends Node {
3916 CharPredicate predicate;
3917
3918 CharProperty (CharPredicate predicate) {
3919 this.predicate = predicate;
3920 }
3921 boolean match(Matcher matcher, int i, CharSequence seq) {
3922 if (i < matcher.to) {
3923 int ch = Character.codePointAt(seq, i);
3924 return predicate.is(ch) &&
3925 next.match(matcher, i + Character.charCount(ch), seq);
3926 } else {
3927 matcher.hitEnd = true;
3928 return false;
3929 }
3930 }
3931 boolean study(TreeInfo info) {
3932 info.minLength++;
3933 info.maxLength++;
3934 return next.study(info);
3935 }
3936 }
3937
3938 /**
3939 * Optimized version of CharProperty that works only for
3940 * properties never satisfied by Supplementary characters.
3941 */
3942 private static class BmpCharProperty extends CharProperty {
3943 BmpCharProperty (BmpCharPredicate predicate) {
3944 super(predicate);
3945 }
3946 boolean match(Matcher matcher, int i, CharSequence seq) {
3947 if (i < matcher.to) {
3948 return predicate.is(seq.charAt(i)) &&
3949 next.match(matcher, i + 1, seq);
3950 } else {
3951 matcher.hitEnd = true;
3952 return false;
3953 }
3954 }
3955 }
3956
3957 private static class NFCCharProperty extends Node {
3958 CharPredicate predicate;
3959 NFCCharProperty (CharPredicate predicate) {
3960 this.predicate = predicate;
3961 }
3962
3963 boolean match(Matcher matcher, int i, CharSequence seq) {
3964 if (i < matcher.to) {
3965 int ch0 = Character.codePointAt(seq, i);
3966 int n = Character.charCount(ch0);
3967 int j = i + n;
3968 while (j < matcher.to) {
3969 int ch1 = Character.codePointAt(seq, j);
3970 if (Grapheme.isBoundary(ch0, ch1))
3971 break;
3972 ch0 = ch1;
3973 j += Character.charCount(ch1);
3974 }
3975 if (i + n == j) { // single, assume nfc cp
3976 if (predicate.is(ch0))
3977 return next.match(matcher, j, seq);
3978 } else {
3979 while (i + n < j) {
3980 String nfc = Normalizer.normalize(
3981 seq.toString().substring(i, j), Normalizer.Form.NFC);
3982 if (nfc.codePointCount(0, nfc.length()) == 1) {
3983 if (predicate.is(nfc.codePointAt(0)) &&
3984 next.match(matcher, j, seq)) {
3985 return true;
3986 }
3987 }
3988
3989 ch0 = Character.codePointBefore(seq, j);
3990 j -= Character.charCount(ch0);
3991 }
3992 }
3993 if (j < matcher.to)
3994 return false;
3995 }
3996 matcher.hitEnd = true;
3997 return false;
3998 }
3999
4000 boolean study(TreeInfo info) {
4001 info.minLength++;
4002 info.deterministic = false;
4003 return next.study(info);
4004 }
4005 }
4006
4007 /**
4008 * Node class that matches an unicode extended grapheme cluster
4009 */
4010 static class XGrapheme extends Node {
4011 boolean match(Matcher matcher, int i, CharSequence seq) {
4012 if (i < matcher.to) {
4013 int ch0 = Character.codePointAt(seq, i);
4014 i += Character.charCount(ch0);
4015 while (i < matcher.to) {
4016 int ch1 = Character.codePointAt(seq, i);
4017 if (Grapheme.isBoundary(ch0, ch1))
4018 break;
4019 ch0 = ch1;
4020 i += Character.charCount(ch1);
4021 }
4022 return next.match(matcher, i, seq);
4023 }
4024 matcher.hitEnd = true;
4025 return false;
4026 }
4027
4028 boolean study(TreeInfo info) {
4029 info.minLength++;
4030 info.deterministic = false;
4031 return next.study(info);
4032 }
4033 }
4034
4035 /**
4036 * Node class that handles grapheme boundaries
4037 */
4038 static class GraphemeBound extends Node {
4039 boolean match(Matcher matcher, int i, CharSequence seq) {
4040 int startIndex = matcher.from;
4041 int endIndex = matcher.to;
4042 if (matcher.transparentBounds) {
4043 startIndex = 0;
4044 endIndex = matcher.getTextLength();
4045 }
4046 if (i == startIndex) {
4047 return next.match(matcher, i, seq);
4048 }
4049 if (i < endIndex) {
4050 if (Character.isSurrogatePair(seq.charAt(i-1), seq.charAt(i)) ||
4051 !Grapheme.isBoundary(Character.codePointBefore(seq, i),
4052 Character.codePointAt(seq, i))) {
4053 return false;
4054 }
4055 } else {
4056 matcher.hitEnd = true;
4057 matcher.requireEnd = true;
4058 }
4059 return next.match(matcher, i, seq);
4060 }
4061 }
4062
4063 /**
4064 * Base class for all Slice nodes
4065 */
4066 static class SliceNode extends Node {
4067 int[] buffer;
4068 SliceNode(int[] buf) {
4069 buffer = buf;
4070 }
4071 boolean study(TreeInfo info) {
4072 info.minLength += buffer.length;
4073 info.maxLength += buffer.length;
4074 return next.study(info);
4075 }
4076 }
4077
4078 /**
4079 * Node class for a case sensitive/BMP-only sequence of literal
4080 * characters.
4081 */
4082 static class Slice extends SliceNode {
4083 Slice(int[] buf) {
4084 super(buf);
4085 }
4086 boolean match(Matcher matcher, int i, CharSequence seq) {
4087 int[] buf = buffer;
4088 int len = buf.length;
4089 for (int j=0; j<len; j++) {
4090 if ((i+j) >= matcher.to) {
4091 matcher.hitEnd = true;
4092 return false;
4093 }
4094 if (buf[j] != seq.charAt(i+j))
4095 return false;
4096 }
4097 return next.match(matcher, i+len, seq);
4098 }
4099 }
4100
4101 /**
4102 * Node class for a case_insensitive/BMP-only sequence of literal
4103 * characters.
4104 */
4105 static class SliceI extends SliceNode {
4106 SliceI(int[] buf) {
4107 super(buf);
4108 }
4109 boolean match(Matcher matcher, int i, CharSequence seq) {
4110 int[] buf = buffer;
4111 int len = buf.length;
4112 for (int j=0; j<len; j++) {
4113 if ((i+j) >= matcher.to) {
4114 matcher.hitEnd = true;
4115 return false;
4116 }
4117 int c = seq.charAt(i+j);
4118 if (buf[j] != c &&
4119 buf[j] != ASCII.toLower(c))
4120 return false;
4121 }
4122 return next.match(matcher, i+len, seq);
4123 }
4124 }
4125
4126 /**
4127 * Node class for a unicode_case_insensitive/BMP-only sequence of
4128 * literal characters. Uses unicode case folding.
4129 */
4130 static final class SliceU extends SliceNode {
4131 SliceU(int[] buf) {
4132 super(buf);
4133 }
4134 boolean match(Matcher matcher, int i, CharSequence seq) {
4135 int[] buf = buffer;
4136 int len = buf.length;
4137 for (int j=0; j<len; j++) {
4138 if ((i+j) >= matcher.to) {
4139 matcher.hitEnd = true;
4140 return false;
4141 }
4142 int c = seq.charAt(i+j);
4143 if (buf[j] != c &&
4144 buf[j] != Character.toLowerCase(Character.toUpperCase(c)))
4145 return false;
4146 }
4147 return next.match(matcher, i+len, seq);
4148 }
4149 }
4150
4151 /**
4152 * Node class for a case sensitive sequence of literal characters
4153 * including supplementary characters.
4154 */
4155 static final class SliceS extends Slice {
4156 SliceS(int[] buf) {
4157 super(buf);
4158 }
4159 boolean match(Matcher matcher, int i, CharSequence seq) {
4160 int[] buf = buffer;
4161 int x = i;
4162 for (int j = 0; j < buf.length; j++) {
4163 if (x >= matcher.to) {
4164 matcher.hitEnd = true;
4165 return false;
4166 }
4167 int c = Character.codePointAt(seq, x);
4168 if (buf[j] != c)
4169 return false;
4170 x += Character.charCount(c);
4171 if (x > matcher.to) {
4172 matcher.hitEnd = true;
4173 return false;
4174 }
4175 }
4176 return next.match(matcher, x, seq);
4177 }
4178 }
4179
4180 /**
4181 * Node class for a case insensitive sequence of literal characters
4182 * including supplementary characters.
4183 */
4184 static class SliceIS extends SliceNode {
4185 SliceIS(int[] buf) {
4186 super(buf);
4187 }
4188 int toLower(int c) {
4189 return ASCII.toLower(c);
4190 }
4191 boolean match(Matcher matcher, int i, CharSequence seq) {
4192 int[] buf = buffer;
4193 int x = i;
4194 for (int j = 0; j < buf.length; j++) {
4195 if (x >= matcher.to) {
4196 matcher.hitEnd = true;
4197 return false;
4198 }
4199 int c = Character.codePointAt(seq, x);
4200 if (buf[j] != c && buf[j] != toLower(c))
4201 return false;
4202 x += Character.charCount(c);
4203 if (x > matcher.to) {
4204 matcher.hitEnd = true;
4205 return false;
4206 }
4207 }
4208 return next.match(matcher, x, seq);
4209 }
4210 }
4211
4212 /**
4213 * Node class for a case insensitive sequence of literal characters.
4214 * Uses unicode case folding.
4215 */
4216 static final class SliceUS extends SliceIS {
4217 SliceUS(int[] buf) {
4218 super(buf);
4219 }
4220 int toLower(int c) {
4221 return Character.toLowerCase(Character.toUpperCase(c));
4222 }
4223 }
4224
4225 /**
4226 * The 0 or 1 quantifier. This one class implements all three types.
4227 */
4228 static final class Ques extends Node {
4229 Node atom;
4230 Qtype type;
4231 Ques(Node node, Qtype type) {
4232 this.atom = node;
4233 this.type = type;
4234 }
4235 boolean match(Matcher matcher, int i, CharSequence seq) {
4236 switch (type) {
4237 case GREEDY:
4238 return (atom.match(matcher, i, seq) && next.match(matcher, matcher.last, seq))
4239 || next.match(matcher, i, seq);
4240 case LAZY:
4241 return next.match(matcher, i, seq)
4242 || (atom.match(matcher, i, seq) && next.match(matcher, matcher.last, seq));
4243 case POSSESSIVE:
4244 if (atom.match(matcher, i, seq)) i = matcher.last;
4245 return next.match(matcher, i, seq);
4246 default:
4247 return atom.match(matcher, i, seq) && next.match(matcher, matcher.last, seq);
4248 }
4249 }
4250 boolean study(TreeInfo info) {
4251 if (type != Qtype.INDEPENDENT) {
4252 int minL = info.minLength;
4253 atom.study(info);
4254 info.minLength = minL;
4255 info.deterministic = false;
4256 return next.study(info);
4257 } else {
4258 atom.study(info);
4259 return next.study(info);
4260 }
4261 }
4262 }
4263
4264 /**
4265 * Handles the greedy style repetition with the minimum either be
4266 * 0 or 1 and the maximum be MAX_REPS, for * and + quantifier.
4267 */
4268 static class CharPropertyGreedy extends Node {
4269 final CharPredicate predicate;
4270 final int cmin;
4271
4272 CharPropertyGreedy(CharProperty cp, int cmin) {
4273 this.predicate = cp.predicate;
4274 this.cmin = cmin;
4275 }
4276 boolean match(Matcher matcher, int i, CharSequence seq) {
4277 int n = 0;
4278 int to = matcher.to;
4279 // greedy, all the way down
4280 while (i < to) {
4281 int ch = Character.codePointAt(seq, i);
4282 if (!predicate.is(ch))
4283 break;
4284 i += Character.charCount(ch);
4285 n++;
4286 }
4287 if (i >= to) {
4288 matcher.hitEnd = true;
4289 }
4290 while (n >= cmin) {
4291 if (next.match(matcher, i, seq))
4292 return true;
4293 if (n == cmin)
4294 return false;
4295 // backing off if match fails
4296 int ch = Character.codePointBefore(seq, i);
4297 i -= Character.charCount(ch);
4298 n--;
4299 }
4300 return false;
4301 }
4302
4303 boolean study(TreeInfo info) {
4304 info.minLength += cmin;
4305 if (info.maxValid) {
4306 info.maxLength += MAX_REPS;
4307 }
4308 info.deterministic = false;
4309 return next.study(info);
4310 }
4311 }
4312
4313 static final class BmpCharPropertyGreedy extends CharPropertyGreedy {
4314
4315 BmpCharPropertyGreedy(BmpCharProperty bcp, int cmin) {
4316 super(bcp, cmin);
4317 }
4318
4319 boolean match(Matcher matcher, int i, CharSequence seq) {
4320 int n = 0;
4321 int to = matcher.to;
4322 while (i < to && predicate.is(seq.charAt(i))) {
4323 i++; n++;
4324 }
4325 if (i >= to) {
4326 matcher.hitEnd = true;
4327 }
4328 while (n >= cmin) {
4329 if (next.match(matcher, i, seq))
4330 return true;
4331 i--; n--; // backing off if match fails
4332 }
4333 return false;
4334 }
4335 }
4336
4337 /**
4338 * Handles the curly-brace style repetition with a specified minimum and
4339 * maximum occurrences. The * quantifier is handled as a special case.
4340 * This class handles the three types.
4341 */
4342 static final class Curly extends Node {
4343 Node atom;
4344 Qtype type;
4345 int cmin;
4346 int cmax;
4347
4348 Curly(Node node, int cmin, int cmax, Qtype type) {
4349 this.atom = node;
4350 this.type = type;
4351 this.cmin = cmin;
4352 this.cmax = cmax;
4353 }
4354 boolean match(Matcher matcher, int i, CharSequence seq) {
4355 int j;
4356 for (j = 0; j < cmin; j++) {
4357 if (atom.match(matcher, i, seq)) {
4358 i = matcher.last;
4359 continue;
4360 }
4361 return false;
4362 }
4363 if (type == Qtype.GREEDY)
4364 return match0(matcher, i, j, seq);
4365 else if (type == Qtype.LAZY)
4366 return match1(matcher, i, j, seq);
4367 else
4368 return match2(matcher, i, j, seq);
4369 }
4370 // Greedy match.
4371 // i is the index to start matching at
4372 // j is the number of atoms that have matched
4373 boolean match0(Matcher matcher, int i, int j, CharSequence seq) {
4374 if (j >= cmax) {
4375 // We have matched the maximum... continue with the rest of
4376 // the regular expression
4377 return next.match(matcher, i, seq);
4378 }
4379 int backLimit = j;
4380 while (atom.match(matcher, i, seq)) {
4381 // k is the length of this match
4382 int k = matcher.last - i;
4383 if (k == 0) // Zero length match
4384 break;
4385 // Move up index and number matched
4386 i = matcher.last;
4387 j++;
4388 // We are greedy so match as many as we can
4389 while (j < cmax) {
4390 if (!atom.match(matcher, i, seq))
4391 break;
4392 if (i + k != matcher.last) {
4393 if (match0(matcher, matcher.last, j+1, seq))
4394 return true;
4395 break;
4396 }
4397 i += k;
4398 j++;
4399 }
4400 // Handle backing off if match fails
4401 while (j >= backLimit) {
4402 if (next.match(matcher, i, seq))
4403 return true;
4404 i -= k;
4405 j--;
4406 }
4407 return false;
4408 }
4409 return next.match(matcher, i, seq);
4410 }
4411 // Reluctant match. At this point, the minimum has been satisfied.
4412 // i is the index to start matching at
4413 // j is the number of atoms that have matched
4414 boolean match1(Matcher matcher, int i, int j, CharSequence seq) {
4415 for (;;) {
4416 // Try finishing match without consuming any more
4417 if (next.match(matcher, i, seq))
4418 return true;
4419 // At the maximum, no match found
4420 if (j >= cmax)
4421 return false;
4422 // Okay, must try one more atom
4423 if (!atom.match(matcher, i, seq))
4424 return false;
4425 // If we haven't moved forward then must break out
4426 if (i == matcher.last)
4427 return false;
4428 // Move up index and number matched
4429 i = matcher.last;
4430 j++;
4431 }
4432 }
4433 boolean match2(Matcher matcher, int i, int j, CharSequence seq) {
4434 for (; j < cmax; j++) {
4435 if (!atom.match(matcher, i, seq))
4436 break;
4437 if (i == matcher.last)
4438 break;
4439 i = matcher.last;
4440 }
4441 return next.match(matcher, i, seq);
4442 }
4443 boolean study(TreeInfo info) {
4444 // Save original info
4445 int minL = info.minLength;
4446 int maxL = info.maxLength;
4447 boolean maxV = info.maxValid;
4448 boolean detm = info.deterministic;
4449 info.reset();
4450
4451 atom.study(info);
4452
4453 int temp = info.minLength * cmin + minL;
4454 if (temp < minL) {
4455 temp = 0xFFFFFFF; // arbitrary large number
4456 }
4457 info.minLength = temp;
4458
4459 if (maxV & info.maxValid) {
4460 temp = info.maxLength * cmax + maxL;
4461 info.maxLength = temp;
4462 if (temp < maxL) {
4463 info.maxValid = false;
4464 }
4465 } else {
4466 info.maxValid = false;
4467 }
4468
4469 if (info.deterministic && cmin == cmax)
4470 info.deterministic = detm;
4471 else
4472 info.deterministic = false;
4473 return next.study(info);
4474 }
4475 }
4476
4477 /**
4478 * Handles the curly-brace style repetition with a specified minimum and
4479 * maximum occurrences in deterministic cases. This is an iterative
4480 * optimization over the Prolog and Loop system which would handle this
4481 * in a recursive way. The * quantifier is handled as a special case.
4482 * If capture is true then this class saves group settings and ensures
4483 * that groups are unset when backing off of a group match.
4484 */
4485 static final class GroupCurly extends Node {
4486 Node atom;
4487 Qtype type;
4488 int cmin;
4489 int cmax;
4490 int localIndex;
4491 int groupIndex;
4492 boolean capture;
4493
4494 GroupCurly(Node node, int cmin, int cmax, Qtype type, int local,
4495 int group, boolean capture) {
4496 this.atom = node;
4497 this.type = type;
4498 this.cmin = cmin;
4499 this.cmax = cmax;
4500 this.localIndex = local;
4501 this.groupIndex = group;
4502 this.capture = capture;
4503 }
4504 boolean match(Matcher matcher, int i, CharSequence seq) {
4505 int[] groups = matcher.groups;
4506 int[] locals = matcher.locals;
4507 int save0 = locals[localIndex];
4508 int save1 = 0;
4509 int save2 = 0;
4510
4511 if (capture) {
4512 save1 = groups[groupIndex];
4513 save2 = groups[groupIndex+1];
4514 }
4515
4516 // Notify GroupTail there is no need to setup group info
4517 // because it will be set here
4518 locals[localIndex] = -1;
4519
4520 boolean ret = true;
4521 for (int j = 0; j < cmin; j++) {
4522 if (atom.match(matcher, i, seq)) {
4523 if (capture) {
4524 groups[groupIndex] = i;
4525 groups[groupIndex+1] = matcher.last;
4526 }
4527 i = matcher.last;
4528 } else {
4529 ret = false;
4530 break;
4531 }
4532 }
4533 if (ret) {
4534 if (type == Qtype.GREEDY) {
4535 ret = match0(matcher, i, cmin, seq);
4536 } else if (type == Qtype.LAZY) {
4537 ret = match1(matcher, i, cmin, seq);
4538 } else {
4539 ret = match2(matcher, i, cmin, seq);
4540 }
4541 }
4542 if (!ret) {
4543 locals[localIndex] = save0;
4544 if (capture) {
4545 groups[groupIndex] = save1;
4546 groups[groupIndex+1] = save2;
4547 }
4548 }
4549 return ret;
4550 }
4551 // Aggressive group match
4552 boolean match0(Matcher matcher, int i, int j, CharSequence seq) {
4553 // don't back off passing the starting "j"
4554 int min = j;
4555 int[] groups = matcher.groups;
4556 int save0 = 0;
4557 int save1 = 0;
4558 if (capture) {
4559 save0 = groups[groupIndex];
4560 save1 = groups[groupIndex+1];
4561 }
4562 for (;;) {
4563 if (j >= cmax)
4564 break;
4565 if (!atom.match(matcher, i, seq))
4566 break;
4567 int k = matcher.last - i;
4568 if (k <= 0) {
4569 if (capture) {
4570 groups[groupIndex] = i;
4571 groups[groupIndex+1] = i + k;
4572 }
4573 i = i + k;
4574 break;
4575 }
4576 for (;;) {
4577 if (capture) {
4578 groups[groupIndex] = i;
4579 groups[groupIndex+1] = i + k;
4580 }
4581 i = i + k;
4582 if (++j >= cmax)
4583 break;
4584 if (!atom.match(matcher, i, seq))
4585 break;
4586 if (i + k != matcher.last) {
4587 if (match0(matcher, i, j, seq))
4588 return true;
4589 break;
4590 }
4591 }
4592 while (j > min) {
4593 if (next.match(matcher, i, seq)) {
4594 if (capture) {
4595 groups[groupIndex+1] = i;
4596 groups[groupIndex] = i - k;
4597 }
4598 return true;
4599 }
4600 // backing off
4601 i = i - k;
4602 if (capture) {
4603 groups[groupIndex+1] = i;
4604 groups[groupIndex] = i - k;
4605 }
4606 j--;
4607
4608 }
4609 break;
4610 }
4611 if (capture) {
4612 groups[groupIndex] = save0;
4613 groups[groupIndex+1] = save1;
4614 }
4615 return next.match(matcher, i, seq);
4616 }
4617 // Reluctant matching
4618 boolean match1(Matcher matcher, int i, int j, CharSequence seq) {
4619 for (;;) {
4620 if (next.match(matcher, i, seq))
4621 return true;
4622 if (j >= cmax)
4623 return false;
4624 if (!atom.match(matcher, i, seq))
4625 return false;
4626 if (i == matcher.last)
4627 return false;
4628 if (capture) {
4629 matcher.groups[groupIndex] = i;
4630 matcher.groups[groupIndex+1] = matcher.last;
4631 }
4632 i = matcher.last;
4633 j++;
4634 }
4635 }
4636 // Possessive matching
4637 boolean match2(Matcher matcher, int i, int j, CharSequence seq) {
4638 for (; j < cmax; j++) {
4639 if (!atom.match(matcher, i, seq)) {
4640 break;
4641 }
4642 if (capture) {
4643 matcher.groups[groupIndex] = i;
4644 matcher.groups[groupIndex+1] = matcher.last;
4645 }
4646 if (i == matcher.last) {
4647 break;
4648 }
4649 i = matcher.last;
4650 }
4651 return next.match(matcher, i, seq);
4652 }
4653 boolean study(TreeInfo info) {
4654 // Save original info
4655 int minL = info.minLength;
4656 int maxL = info.maxLength;
4657 boolean maxV = info.maxValid;
4658 boolean detm = info.deterministic;
4659 info.reset();
4660
4661 atom.study(info);
4662
4663 int temp = info.minLength * cmin + minL;
4664 if (temp < minL) {
4665 temp = 0xFFFFFFF; // Arbitrary large number
4666 }
4667 info.minLength = temp;
4668
4669 if (maxV & info.maxValid) {
4670 temp = info.maxLength * cmax + maxL;
4671 info.maxLength = temp;
4672 if (temp < maxL) {
4673 info.maxValid = false;
4674 }
4675 } else {
4676 info.maxValid = false;
4677 }
4678
4679 if (info.deterministic && cmin == cmax) {
4680 info.deterministic = detm;
4681 } else {
4682 info.deterministic = false;
4683 }
4684 return next.study(info);
4685 }
4686 }
4687
4688 /**
4689 * A Guard node at the end of each atom node in a Branch. It
4690 * serves the purpose of chaining the "match" operation to
4691 * "next" but not the "study", so we can collect the TreeInfo
4692 * of each atom node without including the TreeInfo of the
4693 * "next".
4694 */
4695 static final class BranchConn extends Node {
4696 BranchConn() {};
4697 boolean match(Matcher matcher, int i, CharSequence seq) {
4698 return next.match(matcher, i, seq);
4699 }
4700 boolean study(TreeInfo info) {
4701 return info.deterministic;
4702 }
4703 }
4704
4705 /**
4706 * Handles the branching of alternations. Note this is also used for
4707 * the ? quantifier to branch between the case where it matches once
4708 * and where it does not occur.
4709 */
4710 static final class Branch extends Node {
4711 Node[] atoms = new Node[2];
4712 int size = 2;
4713 Node conn;
4714 Branch(Node first, Node second, Node branchConn) {
4715 conn = branchConn;
4716 atoms[0] = first;
4717 atoms[1] = second;
4718 }
4719
4720 void add(Node node) {
4721 if (size >= atoms.length) {
4722 Node[] tmp = new Node[atoms.length*2];
4723 System.arraycopy(atoms, 0, tmp, 0, atoms.length);
4724 atoms = tmp;
4725 }
4726 atoms[size++] = node;
4727 }
4728
4729 boolean match(Matcher matcher, int i, CharSequence seq) {
4730 for (int n = 0; n < size; n++) {
4731 if (atoms[n] == null) {
4732 if (conn.next.match(matcher, i, seq))
4733 return true;
4734 } else if (atoms[n].match(matcher, i, seq)) {
4735 return true;
4736 }
4737 }
4738 return false;
4739 }
4740
4741 boolean study(TreeInfo info) {
4742 int minL = info.minLength;
4743 int maxL = info.maxLength;
4744 boolean maxV = info.maxValid;
4745
4746 int minL2 = Integer.MAX_VALUE; //arbitrary large enough num
4747 int maxL2 = -1;
4748 for (int n = 0; n < size; n++) {
4749 info.reset();
4750 if (atoms[n] != null)
4751 atoms[n].study(info);
4752 minL2 = Math.min(minL2, info.minLength);
4753 maxL2 = Math.max(maxL2, info.maxLength);
4754 maxV = (maxV & info.maxValid);
4755 }
4756
4757 minL += minL2;
4758 maxL += maxL2;
4759
4760 info.reset();
4761 conn.next.study(info);
4762
4763 info.minLength += minL;
4764 info.maxLength += maxL;
4765 info.maxValid &= maxV;
4766 info.deterministic = false;
4767 return false;
4768 }
4769 }
4770
4771 /**
4772 * The GroupHead saves the location where the group begins in the locals
4773 * and restores them when the match is done.
4774 *
4775 * The matchRef is used when a reference to this group is accessed later
4776 * in the expression. The locals will have a negative value in them to
4777 * indicate that we do not want to unset the group if the reference
4778 * doesn't match.
4779 */
4780 static final class GroupHead extends Node {
4781 int localIndex;
4782 GroupTail tail; // for debug/print only, match does not need to know
4783 GroupHead(int localCount) {
4784 localIndex = localCount;
4785 }
4786 boolean match(Matcher matcher, int i, CharSequence seq) {
4787 int save = matcher.locals[localIndex];
4788 matcher.locals[localIndex] = i;
4789 boolean ret = next.match(matcher, i, seq);
4790 matcher.locals[localIndex] = save;
4791 return ret;
4792 }
4793 boolean matchRef(Matcher matcher, int i, CharSequence seq) {
4794 int save = matcher.locals[localIndex];
4795 matcher.locals[localIndex] = ~i; // HACK
4796 boolean ret = next.match(matcher, i, seq);
4797 matcher.locals[localIndex] = save;
4798 return ret;
4799 }
4800 }
4801
4802 /**
4803 * Recursive reference to a group in the regular expression. It calls
4804 * matchRef because if the reference fails to match we would not unset
4805 * the group.
4806 */
4807 static final class GroupRef extends Node {
4808 GroupHead head;
4809 GroupRef(GroupHead head) {
4810 this.head = head;
4811 }
4812 boolean match(Matcher matcher, int i, CharSequence seq) {
4813 return head.matchRef(matcher, i, seq)
4814 && next.match(matcher, matcher.last, seq);
4815 }
4816 boolean study(TreeInfo info) {
4817 info.maxValid = false;
4818 info.deterministic = false;
4819 return next.study(info);
4820 }
4821 }
4822
4823 /**
4824 * The GroupTail handles the setting of group beginning and ending
4825 * locations when groups are successfully matched. It must also be able to
4826 * unset groups that have to be backed off of.
4827 *
4828 * The GroupTail node is also used when a previous group is referenced,
4829 * and in that case no group information needs to be set.
4830 */
4831 static final class GroupTail extends Node {
4832 int localIndex;
4833 int groupIndex;
4834 GroupTail(int localCount, int groupCount) {
4835 localIndex = localCount;
4836 groupIndex = groupCount + groupCount;
4837 }
4838 boolean match(Matcher matcher, int i, CharSequence seq) {
4839 int tmp = matcher.locals[localIndex];
4840 if (tmp >= 0) { // This is the normal group case.
4841 // Save the group so we can unset it if it
4842 // backs off of a match.
4843 int groupStart = matcher.groups[groupIndex];
4844 int groupEnd = matcher.groups[groupIndex+1];
4845
4846 matcher.groups[groupIndex] = tmp;
4847 matcher.groups[groupIndex+1] = i;
4848 if (next.match(matcher, i, seq)) {
4849 return true;
4850 }
4851 matcher.groups[groupIndex] = groupStart;
4852 matcher.groups[groupIndex+1] = groupEnd;
4853 return false;
4854 } else {
4855 // This is a group reference case. We don't need to save any
4856 // group info because it isn't really a group.
4857 matcher.last = i;
4858 return true;
4859 }
4860 }
4861 }
4862
4863 /**
4864 * This sets up a loop to handle a recursive quantifier structure.
4865 */
4866 static final class Prolog extends Node {
4867 Loop loop;
4868 Prolog(Loop loop) {
4869 this.loop = loop;
4870 }
4871 boolean match(Matcher matcher, int i, CharSequence seq) {
4872 return loop.matchInit(matcher, i, seq);
4873 }
4874 boolean study(TreeInfo info) {
4875 return loop.study(info);
4876 }
4877 }
4878
4879 /**
4880 * Handles the repetition count for a greedy Curly. The matchInit
4881 * is called from the Prolog to save the index of where the group
4882 * beginning is stored. A zero length group check occurs in the
4883 * normal match but is skipped in the matchInit.
4884 */
4885 static class Loop extends Node {
4886 Node body;
4887 int countIndex; // local count index in matcher locals
4888 int beginIndex; // group beginning index
4889 int cmin, cmax;
4890 int posIndex;
4891 Loop(int countIndex, int beginIndex) {
4892 this.countIndex = countIndex;
4893 this.beginIndex = beginIndex;
4894 this.posIndex = -1;
4895 }
4896 boolean match(Matcher matcher, int i, CharSequence seq) {
4897 // Avoid infinite loop in zero-length case.
4898 if (i > matcher.locals[beginIndex]) {
4899 int count = matcher.locals[countIndex];
4900
4901 // This block is for before we reach the minimum
4902 // iterations required for the loop to match
4903 if (count < cmin) {
4904 matcher.locals[countIndex] = count + 1;
4905 boolean b = body.match(matcher, i, seq);
4906 // If match failed we must backtrack, so
4907 // the loop count should NOT be incremented
4908 if (!b)
4909 matcher.locals[countIndex] = count;
4910 // Return success or failure since we are under
4911 // minimum
4912 return b;
4913 }
4914 // This block is for after we have the minimum
4915 // iterations required for the loop to match
4916 if (count < cmax) {
4917 // Let's check if we have already tried and failed
4918 // at this starting position "i" in the past.
4919 // If yes, then just return false wihtout trying
4920 // again, to stop the exponential backtracking.
4921 if (posIndex != -1 &&
4922 matcher.localsPos[posIndex].contains(i)) {
4923 return next.match(matcher, i, seq);
4924 }
4925 matcher.locals[countIndex] = count + 1;
4926 boolean b = body.match(matcher, i, seq);
4927 // If match failed we must backtrack, so
4928 // the loop count should NOT be incremented
4929 if (b)
4930 return true;
4931 matcher.locals[countIndex] = count;
4932 // save the failed position
4933 if (posIndex != -1) {
4934 matcher.localsPos[posIndex].add(i);
4935 }
4936 }
4937 }
4938 return next.match(matcher, i, seq);
4939 }
4940 boolean matchInit(Matcher matcher, int i, CharSequence seq) {
4941 int save = matcher.locals[countIndex];
4942 boolean ret = false;
4943 if (posIndex != -1 && matcher.localsPos[posIndex] == null) {
4944 matcher.localsPos[posIndex] = new IntHashSet();
4945 }
4946 if (0 < cmin) {
4947 matcher.locals[countIndex] = 1;
4948 ret = body.match(matcher, i, seq);
4949 } else if (0 < cmax) {
4950 matcher.locals[countIndex] = 1;
4951 ret = body.match(matcher, i, seq);
4952 if (ret == false)
4953 ret = next.match(matcher, i, seq);
4954 } else {
4955 ret = next.match(matcher, i, seq);
4956 }
4957 matcher.locals[countIndex] = save;
4958 return ret;
4959 }
4960 boolean study(TreeInfo info) {
4961 info.maxValid = false;
4962 info.deterministic = false;
4963 return false;
4964 }
4965 }
4966
4967 /**
4968 * Handles the repetition count for a reluctant Curly. The matchInit
4969 * is called from the Prolog to save the index of where the group
4970 * beginning is stored. A zero length group check occurs in the
4971 * normal match but is skipped in the matchInit.
4972 */
4973 static final class LazyLoop extends Loop {
4974 LazyLoop(int countIndex, int beginIndex) {
4975 super(countIndex, beginIndex);
4976 }
4977 boolean match(Matcher matcher, int i, CharSequence seq) {
4978 // Check for zero length group
4979 if (i > matcher.locals[beginIndex]) {
4980 int count = matcher.locals[countIndex];
4981 if (count < cmin) {
4982 matcher.locals[countIndex] = count + 1;
4983 boolean result = body.match(matcher, i, seq);
4984 // If match failed we must backtrack, so
4985 // the loop count should NOT be incremented
4986 if (!result)
4987 matcher.locals[countIndex] = count;
4988 return result;
4989 }
4990 if (next.match(matcher, i, seq))
4991 return true;
4992 if (count < cmax) {
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 return false;
5002 }
5003 return next.match(matcher, i, seq);
5004 }
5005 boolean matchInit(Matcher matcher, int i, CharSequence seq) {
5006 int save = matcher.locals[countIndex];
5007 boolean ret = false;
5008 if (0 < cmin) {
5009 matcher.locals[countIndex] = 1;
5010 ret = body.match(matcher, i, seq);
5011 } else if (next.match(matcher, i, seq)) {
5012 ret = true;
5013 } else if (0 < cmax) {
5014 matcher.locals[countIndex] = 1;
5015 ret = body.match(matcher, i, seq);
5016 }
5017 matcher.locals[countIndex] = save;
5018 return ret;
5019 }
5020 boolean study(TreeInfo info) {
5021 info.maxValid = false;
5022 info.deterministic = false;
5023 return false;
5024 }
5025 }
5026
5027 /**
5028 * Refers to a group in the regular expression. Attempts to match
5029 * whatever the group referred to last matched.
5030 */
5031 static class BackRef extends Node {
5032 int groupIndex;
5033 BackRef(int groupCount) {
5034 super();
5035 groupIndex = groupCount + groupCount;
5036 }
5037 boolean match(Matcher matcher, int i, CharSequence seq) {
5038 int j = matcher.groups[groupIndex];
5039 int k = matcher.groups[groupIndex+1];
5040
5041 int groupSize = k - j;
5042 // If the referenced group didn't match, neither can this
5043 if (j < 0)
5044 return false;
5045
5046 // If there isn't enough input left no match
5047 if (i + groupSize > matcher.to) {
5048 matcher.hitEnd = true;
5049 return false;
5050 }
5051 // Check each new char to make sure it matches what the group
5052 // referenced matched last time around
5053 for (int index=0; index<groupSize; index++)
5054 if (seq.charAt(i+index) != seq.charAt(j+index))
5055 return false;
5056
5057 return next.match(matcher, i+groupSize, seq);
5058 }
5059 boolean study(TreeInfo info) {
5060 info.maxValid = false;
5061 return next.study(info);
5062 }
5063 }
5064
5065 static class CIBackRef extends Node {
5066 int groupIndex;
5067 boolean doUnicodeCase;
5068 CIBackRef(int groupCount, boolean doUnicodeCase) {
5069 super();
5070 groupIndex = groupCount + groupCount;
5071 this.doUnicodeCase = doUnicodeCase;
5072 }
5073 boolean match(Matcher matcher, int i, CharSequence seq) {
5074 int j = matcher.groups[groupIndex];
5075 int k = matcher.groups[groupIndex+1];
5076
5077 int groupSize = k - j;
5078
5079 // If the referenced group didn't match, neither can this
5080 if (j < 0)
5081 return false;
5082
5083 // If there isn't enough input left no match
5084 if (i + groupSize > matcher.to) {
5085 matcher.hitEnd = true;
5086 return false;
5087 }
5088
5089 // Check each new char to make sure it matches what the group
5090 // referenced matched last time around
5091 int x = i;
5092 for (int index=0; index<groupSize; index++) {
5093 int c1 = Character.codePointAt(seq, x);
5094 int c2 = Character.codePointAt(seq, j);
5095 if (c1 != c2) {
5096 if (doUnicodeCase) {
5097 int cc1 = Character.toUpperCase(c1);
5098 int cc2 = Character.toUpperCase(c2);
5099 if (cc1 != cc2 &&
5100 Character.toLowerCase(cc1) !=
5101 Character.toLowerCase(cc2))
5102 return false;
5103 } else {
5104 if (ASCII.toLower(c1) != ASCII.toLower(c2))
5105 return false;
5106 }
5107 }
5108 x += Character.charCount(c1);
5109 j += Character.charCount(c2);
5110 }
5111
5112 return next.match(matcher, i+groupSize, seq);
5113 }
5114 boolean study(TreeInfo info) {
5115 info.maxValid = false;
5116 return next.study(info);
5117 }
5118 }
5119
5120 /**
5121 * Searches until the next instance of its atom. This is useful for
5122 * finding the atom efficiently without passing an instance of it
5123 * (greedy problem) and without a lot of wasted search time (reluctant
5124 * problem).
5125 */
5126 static final class First extends Node {
5127 Node atom;
5128 First(Node node) {
5129 this.atom = BnM.optimize(node);
5130 }
5131 boolean match(Matcher matcher, int i, CharSequence seq) {
5132 if (atom instanceof BnM) {
5133 return atom.match(matcher, i, seq)
5134 && next.match(matcher, matcher.last, seq);
5135 }
5136 for (;;) {
5137 if (i > matcher.to) {
5138 matcher.hitEnd = true;
5139 return false;
5140 }
5141 if (atom.match(matcher, i, seq)) {
5142 return next.match(matcher, matcher.last, seq);
5143 }
5144 i += countChars(seq, i, 1);
5145 matcher.first++;
5146 }
5147 }
5148 boolean study(TreeInfo info) {
5149 atom.study(info);
5150 info.maxValid = false;
5151 info.deterministic = false;
5152 return next.study(info);
5153 }
5154 }
5155
5156 static final class Conditional extends Node {
5157 Node cond, yes, not;
5158 Conditional(Node cond, Node yes, Node not) {
5159 this.cond = cond;
5160 this.yes = yes;
5161 this.not = not;
5162 }
5163 boolean match(Matcher matcher, int i, CharSequence seq) {
5164 if (cond.match(matcher, i, seq)) {
5165 return yes.match(matcher, i, seq);
5166 } else {
5167 return not.match(matcher, i, seq);
5168 }
5169 }
5170 boolean study(TreeInfo info) {
5171 int minL = info.minLength;
5172 int maxL = info.maxLength;
5173 boolean maxV = info.maxValid;
5174 info.reset();
5175 yes.study(info);
5176
5177 int minL2 = info.minLength;
5178 int maxL2 = info.maxLength;
5179 boolean maxV2 = info.maxValid;
5180 info.reset();
5181 not.study(info);
5182
5183 info.minLength = minL + Math.min(minL2, info.minLength);
5184 info.maxLength = maxL + Math.max(maxL2, info.maxLength);
5185 info.maxValid = (maxV & maxV2 & info.maxValid);
5186 info.deterministic = false;
5187 return next.study(info);
5188 }
5189 }
5190
5191 /**
5192 * Zero width positive lookahead.
5193 */
5194 static final class Pos extends Node {
5195 Node cond;
5196 Pos(Node cond) {
5197 this.cond = cond;
5198 }
5199 boolean match(Matcher matcher, int i, CharSequence seq) {
5200 int savedTo = matcher.to;
5201 boolean conditionMatched = false;
5202
5203 // Relax transparent region boundaries for lookahead
5204 if (matcher.transparentBounds)
5205 matcher.to = matcher.getTextLength();
5206 try {
5207 conditionMatched = cond.match(matcher, i, seq);
5208 } finally {
5209 // Reinstate region boundaries
5210 matcher.to = savedTo;
5211 }
5212 return conditionMatched && next.match(matcher, i, seq);
5213 }
5214 }
5215
5216 /**
5217 * Zero width negative lookahead.
5218 */
5219 static final class Neg extends Node {
5220 Node cond;
5221 Neg(Node cond) {
5222 this.cond = cond;
5223 }
5224 boolean match(Matcher matcher, int i, CharSequence seq) {
5225 int savedTo = matcher.to;
5226 boolean conditionMatched = false;
5227
5228 // Relax transparent region boundaries for lookahead
5229 if (matcher.transparentBounds)
5230 matcher.to = matcher.getTextLength();
5231 try {
5232 if (i < matcher.to) {
5233 conditionMatched = !cond.match(matcher, i, seq);
5234 } else {
5235 // If a negative lookahead succeeds then more input
5236 // could cause it to fail!
5237 matcher.requireEnd = true;
5238 conditionMatched = !cond.match(matcher, i, seq);
5239 }
5240 } finally {
5241 // Reinstate region boundaries
5242 matcher.to = savedTo;
5243 }
5244 return conditionMatched && next.match(matcher, i, seq);
5245 }
5246 }
5247
5248 /**
5249 * For use with lookbehinds; matches the position where the lookbehind
5250 * was encountered.
5251 */
5252 static Node lookbehindEnd = new Node() {
5253 boolean match(Matcher matcher, int i, CharSequence seq) {
5254 return i == matcher.lookbehindTo;
5255 }
5256 };
5257
5258 /**
5259 * Zero width positive lookbehind.
5260 */
5261 static class Behind extends Node {
5262 Node cond;
5263 int rmax, rmin;
5264 Behind(Node cond, int rmax, int rmin) {
5265 this.cond = cond;
5266 this.rmax = rmax;
5267 this.rmin = rmin;
5268 }
5269
5270 boolean match(Matcher matcher, int i, CharSequence seq) {
5271 int savedFrom = matcher.from;
5272 boolean conditionMatched = false;
5273 int startIndex = (!matcher.transparentBounds) ?
5274 matcher.from : 0;
5275 int from = Math.max(i - rmax, startIndex);
5276 // Set end boundary
5277 int savedLBT = matcher.lookbehindTo;
5278 matcher.lookbehindTo = i;
5279 // Relax transparent region boundaries for lookbehind
5280 if (matcher.transparentBounds)
5281 matcher.from = 0;
5282 for (int j = i - rmin; !conditionMatched && j >= from; j--) {
5283 conditionMatched = cond.match(matcher, j, seq);
5284 }
5285 matcher.from = savedFrom;
5286 matcher.lookbehindTo = savedLBT;
5287 return conditionMatched && next.match(matcher, i, seq);
5288 }
5289 }
5290
5291 /**
5292 * Zero width positive lookbehind, including supplementary
5293 * characters or unpaired surrogates.
5294 */
5295 static final class BehindS extends Behind {
5296 BehindS(Node cond, int rmax, int rmin) {
5297 super(cond, rmax, rmin);
5298 }
5299 boolean match(Matcher matcher, int i, CharSequence seq) {
5300 int rmaxChars = countChars(seq, i, -rmax);
5301 int rminChars = countChars(seq, i, -rmin);
5302 int savedFrom = matcher.from;
5303 int startIndex = (!matcher.transparentBounds) ?
5304 matcher.from : 0;
5305 boolean conditionMatched = false;
5306 int from = Math.max(i - rmaxChars, startIndex);
5307 // Set end boundary
5308 int savedLBT = matcher.lookbehindTo;
5309 matcher.lookbehindTo = i;
5310 // Relax transparent region boundaries for lookbehind
5311 if (matcher.transparentBounds)
5312 matcher.from = 0;
5313
5314 for (int j = i - rminChars;
5315 !conditionMatched && j >= from;
5316 j -= j>from ? countChars(seq, j, -1) : 1) {
5317 conditionMatched = cond.match(matcher, j, seq);
5318 }
5319 matcher.from = savedFrom;
5320 matcher.lookbehindTo = savedLBT;
5321 return conditionMatched && next.match(matcher, i, seq);
5322 }
5323 }
5324
5325 /**
5326 * Zero width negative lookbehind.
5327 */
5328 static class NotBehind extends Node {
5329 Node cond;
5330 int rmax, rmin;
5331 NotBehind(Node cond, int rmax, int rmin) {
5332 this.cond = cond;
5333 this.rmax = rmax;
5334 this.rmin = rmin;
5335 }
5336
5337 boolean match(Matcher matcher, int i, CharSequence seq) {
5338 int savedLBT = matcher.lookbehindTo;
5339 int savedFrom = matcher.from;
5340 boolean conditionMatched = false;
5341 int startIndex = (!matcher.transparentBounds) ?
5342 matcher.from : 0;
5343 int from = Math.max(i - rmax, startIndex);
5344 matcher.lookbehindTo = i;
5345 // Relax transparent region boundaries for lookbehind
5346 if (matcher.transparentBounds)
5347 matcher.from = 0;
5348 for (int j = i - rmin; !conditionMatched && j >= from; j--) {
5349 conditionMatched = cond.match(matcher, j, seq);
5350 }
5351 // Reinstate region boundaries
5352 matcher.from = savedFrom;
5353 matcher.lookbehindTo = savedLBT;
5354 return !conditionMatched && next.match(matcher, i, seq);
5355 }
5356 }
5357
5358 /**
5359 * Zero width negative lookbehind, including supplementary
5360 * characters or unpaired surrogates.
5361 */
5362 static final class NotBehindS extends NotBehind {
5363 NotBehindS(Node cond, int rmax, int rmin) {
5364 super(cond, rmax, rmin);
5365 }
5366 boolean match(Matcher matcher, int i, CharSequence seq) {
5367 int rmaxChars = countChars(seq, i, -rmax);
5368 int rminChars = countChars(seq, i, -rmin);
5369 int savedFrom = matcher.from;
5370 int savedLBT = matcher.lookbehindTo;
5371 boolean conditionMatched = false;
5372 int startIndex = (!matcher.transparentBounds) ?
5373 matcher.from : 0;
5374 int from = Math.max(i - rmaxChars, startIndex);
5375 matcher.lookbehindTo = i;
5376 // Relax transparent region boundaries for lookbehind
5377 if (matcher.transparentBounds)
5378 matcher.from = 0;
5379 for (int j = i - rminChars;
5380 !conditionMatched && j >= from;
5381 j -= j>from ? countChars(seq, j, -1) : 1) {
5382 conditionMatched = cond.match(matcher, j, seq);
5383 }
5384 //Reinstate region boundaries
5385 matcher.from = savedFrom;
5386 matcher.lookbehindTo = savedLBT;
5387 return !conditionMatched && next.match(matcher, i, seq);
5388 }
5389 }
5390
5391 /**
5392 * Handles word boundaries. Includes a field to allow this one class to
5393 * deal with the different types of word boundaries we can match. The word
5394 * characters include underscores, letters, and digits. Non spacing marks
5395 * can are also part of a word if they have a base character, otherwise
5396 * they are ignored for purposes of finding word boundaries.
5397 */
5398 static final class Bound extends Node {
5399 static int LEFT = 0x1;
5400 static int RIGHT= 0x2;
5401 static int BOTH = 0x3;
5402 static int NONE = 0x4;
5403 int type;
5404 boolean useUWORD;
5405 Bound(int n, boolean useUWORD) {
5406 type = n;
5407 this.useUWORD = useUWORD;
5408 }
5409
5410 boolean isWord(int ch) {
5411 return useUWORD ? CharPredicates.WORD().is(ch)
5412 : (ch == '_' || Character.isLetterOrDigit(ch));
5413 }
5414
5415 int check(Matcher matcher, int i, CharSequence seq) {
5416 int ch;
5417 boolean left = false;
5418 int startIndex = matcher.from;
5419 int endIndex = matcher.to;
5420 if (matcher.transparentBounds) {
5421 startIndex = 0;
5422 endIndex = matcher.getTextLength();
5423 }
5424 if (i > startIndex) {
5425 ch = Character.codePointBefore(seq, i);
5426 left = (isWord(ch) ||
5427 ((Character.getType(ch) == Character.NON_SPACING_MARK)
5428 && hasBaseCharacter(matcher, i-1, seq)));
5429 }
5430 boolean right = false;
5431 if (i < endIndex) {
5432 ch = Character.codePointAt(seq, i);
5433 right = (isWord(ch) ||
5434 ((Character.getType(ch) == Character.NON_SPACING_MARK)
5435 && hasBaseCharacter(matcher, i, seq)));
5436 } else {
5437 // Tried to access char past the end
5438 matcher.hitEnd = true;
5439 // The addition of another char could wreck a boundary
5440 matcher.requireEnd = true;
5441 }
5442 return ((left ^ right) ? (right ? LEFT : RIGHT) : NONE);
5443 }
5444 boolean match(Matcher matcher, int i, CharSequence seq) {
5445 return (check(matcher, i, seq) & type) > 0
5446 && next.match(matcher, i, seq);
5447 }
5448 }
5449
5450 /**
5451 * Non spacing marks only count as word characters in bounds calculations
5452 * if they have a base character.
5453 */
5454 private static boolean hasBaseCharacter(Matcher matcher, int i,
5455 CharSequence seq)
5456 {
5457 int start = (!matcher.transparentBounds) ?
5458 matcher.from : 0;
5459 for (int x=i; x >= start; x--) {
5460 int ch = Character.codePointAt(seq, x);
5461 if (Character.isLetterOrDigit(ch))
5462 return true;
5463 if (Character.getType(ch) == Character.NON_SPACING_MARK)
5464 continue;
5465 return false;
5466 }
5467 return false;
5468 }
5469
5470 /**
5471 * Attempts to match a slice in the input using the Boyer-Moore string
5472 * matching algorithm. The algorithm is based on the idea that the
5473 * pattern can be shifted farther ahead in the search text if it is
5474 * matched right to left.
5475 * <p>
5476 * The pattern is compared to the input one character at a time, from
5477 * the rightmost character in the pattern to the left. If the characters
5478 * all match the pattern has been found. If a character does not match,
5479 * the pattern is shifted right a distance that is the maximum of two
5480 * functions, the bad character shift and the good suffix shift. This
5481 * shift moves the attempted match position through the input more
5482 * quickly than a naive one position at a time check.
5483 * <p>
5484 * The bad character shift is based on the character from the text that
5485 * did not match. If the character does not appear in the pattern, the
5486 * pattern can be shifted completely beyond the bad character. If the
5487 * character does occur in the pattern, the pattern can be shifted to
5488 * line the pattern up with the next occurrence of that character.
5489 * <p>
5490 * The good suffix shift is based on the idea that some subset on the right
5491 * side of the pattern has matched. When a bad character is found, the
5492 * pattern can be shifted right by the pattern length if the subset does
5493 * not occur again in pattern, or by the amount of distance to the
5494 * next occurrence of the subset in the pattern.
5495 *
5496 * Boyer-Moore search methods adapted from code by Amy Yu.
5497 */
5498 static class BnM extends Node {
5499 int[] buffer;
5500 int[] lastOcc;
5501 int[] optoSft;
5502
5503 /**
5504 * Pre calculates arrays needed to generate the bad character
5505 * shift and the good suffix shift. Only the last seven bits
5506 * are used to see if chars match; This keeps the tables small
5507 * and covers the heavily used ASCII range, but occasionally
5508 * results in an aliased match for the bad character shift.
5509 */
5510 static Node optimize(Node node) {
5511 if (!(node instanceof Slice)) {
5512 return node;
5513 }
5514
5515 int[] src = ((Slice) node).buffer;
5516 int patternLength = src.length;
5517 // The BM algorithm requires a bit of overhead;
5518 // If the pattern is short don't use it, since
5519 // a shift larger than the pattern length cannot
5520 // be used anyway.
5521 if (patternLength < 4) {
5522 return node;
5523 }
5524 int i, j, k;
5525 int[] lastOcc = new int[128];
5526 int[] optoSft = new int[patternLength];
5527 // Precalculate part of the bad character shift
5528 // It is a table for where in the pattern each
5529 // lower 7-bit value occurs
5530 for (i = 0; i < patternLength; i++) {
5531 lastOcc[src[i]&0x7F] = i + 1;
5532 }
5533 // Precalculate the good suffix shift
5534 // i is the shift amount being considered
5535 NEXT: for (i = patternLength; i > 0; i--) {
5536 // j is the beginning index of suffix being considered
5537 for (j = patternLength - 1; j >= i; j--) {
5538 // Testing for good suffix
5539 if (src[j] == src[j-i]) {
5540 // src[j..len] is a good suffix
5541 optoSft[j-1] = i;
5542 } else {
5543 // No match. The array has already been
5544 // filled up with correct values before.
5545 continue NEXT;
5546 }
5547 }
5548 // This fills up the remaining of optoSft
5549 // any suffix can not have larger shift amount
5550 // then its sub-suffix. Why???
5551 while (j > 0) {
5552 optoSft[--j] = i;
5553 }
5554 }
5555 // Set the guard value because of unicode compression
5556 optoSft[patternLength-1] = 1;
5557 if (node instanceof SliceS)
5558 return new BnMS(src, lastOcc, optoSft, node.next);
5559 return new BnM(src, lastOcc, optoSft, node.next);
5560 }
5561 BnM(int[] src, int[] lastOcc, int[] optoSft, Node next) {
5562 this.buffer = src;
5563 this.lastOcc = lastOcc;
5564 this.optoSft = optoSft;
5565 this.next = next;
5566 }
5567 boolean match(Matcher matcher, int i, CharSequence seq) {
5568 int[] src = buffer;
5569 int patternLength = src.length;
5570 int last = matcher.to - patternLength;
5571
5572 // Loop over all possible match positions in text
5573 NEXT: while (i <= last) {
5574 // Loop over pattern from right to left
5575 for (int j = patternLength - 1; j >= 0; j--) {
5576 int ch = seq.charAt(i+j);
5577 if (ch != src[j]) {
5578 // Shift search to the right by the maximum of the
5579 // bad character shift and the good suffix shift
5580 i += Math.max(j + 1 - lastOcc[ch&0x7F], optoSft[j]);
5581 continue NEXT;
5582 }
5583 }
5584 // Entire pattern matched starting at i
5585 matcher.first = i;
5586 boolean ret = next.match(matcher, i + patternLength, seq);
5587 if (ret) {
5588 matcher.first = i;
5589 matcher.groups[0] = matcher.first;
5590 matcher.groups[1] = matcher.last;
5591 return true;
5592 }
5593 i++;
5594 }
5595 // BnM is only used as the leading node in the unanchored case,
5596 // and it replaced its Start() which always searches to the end
5597 // if it doesn't find what it's looking for, so hitEnd is true.
5598 matcher.hitEnd = true;
5599 return false;
5600 }
5601 boolean study(TreeInfo info) {
5602 info.minLength += buffer.length;
5603 info.maxValid = false;
5604 return next.study(info);
5605 }
5606 }
5607
5608 /**
5609 * Supplementary support version of BnM(). Unpaired surrogates are
5610 * also handled by this class.
5611 */
5612 static final class BnMS extends BnM {
5613 int lengthInChars;
5614
5615 BnMS(int[] src, int[] lastOcc, int[] optoSft, Node next) {
5616 super(src, lastOcc, optoSft, next);
5617 for (int cp : buffer) {
5618 lengthInChars += Character.charCount(cp);
5619 }
5620 }
5621 boolean match(Matcher matcher, int i, CharSequence seq) {
5622 int[] src = buffer;
5623 int patternLength = src.length;
5624 int last = matcher.to - lengthInChars;
5625
5626 // Loop over all possible match positions in text
5627 NEXT: while (i <= last) {
5628 // Loop over pattern from right to left
5629 int ch;
5630 for (int j = countChars(seq, i, patternLength), x = patternLength - 1;
5631 j > 0; j -= Character.charCount(ch), x--) {
5632 ch = Character.codePointBefore(seq, i+j);
5633 if (ch != src[x]) {
5634 // Shift search to the right by the maximum of the
5635 // bad character shift and the good suffix shift
5636 int n = Math.max(x + 1 - lastOcc[ch&0x7F], optoSft[x]);
5637 i += countChars(seq, i, n);
5638 continue NEXT;
5639 }
5640 }
5641 // Entire pattern matched starting at i
5642 matcher.first = i;
5643 boolean ret = next.match(matcher, i + lengthInChars, seq);
5644 if (ret) {
5645 matcher.first = i;
5646 matcher.groups[0] = matcher.first;
5647 matcher.groups[1] = matcher.last;
5648 return true;
5649 }
5650 i += countChars(seq, i, 1);
5651 }
5652 matcher.hitEnd = true;
5653 return false;
5654 }
5655 }
5656
5657 @FunctionalInterface
5658 static interface CharPredicate {
5659 boolean is(int ch);
5660
5661 default CharPredicate and(CharPredicate p) {
5662 return ch -> is(ch) && p.is(ch);
5663 }
5664 default CharPredicate union(CharPredicate p) {
5665 return ch -> is(ch) || p.is(ch);
5666 }
5667 default CharPredicate union(CharPredicate p1,
5668 CharPredicate p2 ) {
5669 return ch -> is(ch) || p1.is(ch) || p2.is(ch);
5670 }
5671 default CharPredicate negate() {
5672 return ch -> !is(ch);
5673 }
5674 }
5675
5676 static interface BmpCharPredicate extends CharPredicate {
5677
5678 default CharPredicate and(CharPredicate p) {
5679 if(p instanceof BmpCharPredicate)
5680 return (BmpCharPredicate)(ch -> is(ch) && p.is(ch));
5681 return ch -> is(ch) && p.is(ch);
5682 }
5683 default CharPredicate union(CharPredicate p) {
5684 if (p instanceof BmpCharPredicate)
5685 return (BmpCharPredicate)(ch -> is(ch) || p.is(ch));
5686 return ch -> is(ch) || p.is(ch);
5687 }
5688 static CharPredicate union(CharPredicate... predicates) {
5689 CharPredicate cp = ch -> {
5690 for (CharPredicate p : predicates) {
5691 if (!p.is(ch))
5692 return false;
5693 }
5694 return true;
5695 };
5696 for (CharPredicate p : predicates) {
5697 if (! (p instanceof BmpCharPredicate))
5698 return cp;
5699 }
5700 return (BmpCharPredicate)cp;
5701 }
5702 }
5703
5704 /**
5705 * matches a Perl vertical whitespace
5706 */
5707 static BmpCharPredicate VertWS() {
5708 return cp -> (cp >= 0x0A && cp <= 0x0D) ||
5709 cp == 0x85 || cp == 0x2028 || cp == 0x2029;
5710 }
5711
5712 /**
5713 * matches a Perl horizontal whitespace
5714 */
5715 static BmpCharPredicate HorizWS() {
5716 return cp ->
5717 cp == 0x09 || cp == 0x20 || cp == 0xa0 || cp == 0x1680 ||
5718 cp == 0x180e || cp >= 0x2000 && cp <= 0x200a || cp == 0x202f ||
5719 cp == 0x205f || cp == 0x3000;
5720 }
5721
5722 /**
5723 * for the Unicode category ALL and the dot metacharacter when
5724 * in dotall mode.
5725 */
5726 static CharPredicate ALL() {
5727 return ch -> true;
5728 }
5729
5730 /**
5731 * for the dot metacharacter when dotall is not enabled.
5732 */
5733 static CharPredicate DOT() {
5734 return ch ->
5735 (ch != '\n' && ch != '\r'
5736 && (ch|1) != '\u2029'
5737 && ch != '\u0085');
5738 }
5739
5740 /**
5741 * the dot metacharacter when dotall is not enabled but UNIX_LINES is enabled.
5742 */
5743 static CharPredicate UNIXDOT() {
5744 return ch -> ch != '\n';
5745 }
5746
5747 /**
5748 * Indicate that matches a Supplementary Unicode character
5749 */
5750 static CharPredicate SingleS(int c) {
5751 return ch -> ch == c;
5752 }
5753
5754 /**
5755 * A bmp/optimized predicate of single
5756 */
5757 static BmpCharPredicate Single(int c) {
5758 return ch -> ch == c;
5759 }
5760
5761 /**
5762 * Case insensitive matches a given BMP character
5763 */
5764 static BmpCharPredicate SingleI(int lower, int upper) {
5765 return ch -> ch == lower || ch == upper;
5766 }
5767
5768 /**
5769 * Unicode case insensitive matches a given Unicode character
5770 */
5771 static CharPredicate SingleU(int lower) {
5772 return ch -> lower == ch ||
5773 lower == Character.toLowerCase(Character.toUpperCase(ch));
5774 }
5775
5776 private static boolean inRange(int lower, int ch, int upper) {
5777 return lower <= ch && ch <= upper;
5778 }
5779
5780 /**
5781 * Charactrs within a explicit value range
5782 */
5783 static CharPredicate Range(int lower, int upper) {
5784 if (upper < Character.MIN_HIGH_SURROGATE ||
5785 lower > Character.MAX_HIGH_SURROGATE &&
5786 upper < Character.MIN_SUPPLEMENTARY_CODE_POINT)
5787 return (BmpCharPredicate)(ch -> inRange(lower, ch, upper));
5788 return ch -> inRange(lower, ch, upper);
5789 }
5790
5791 /**
5792 * Charactrs within a explicit value range in a case insensitive manner.
5793 */
5794 static CharPredicate CIRange(int lower, int upper) {
5795 return ch -> inRange(lower, ch, upper) ||
5796 ASCII.isAscii(ch) &&
5797 (inRange(lower, ASCII.toUpper(ch), upper) ||
5798 inRange(lower, ASCII.toLower(ch), upper));
5799 }
5800
5801 static CharPredicate CIRangeU(int lower, int upper) {
5802 return ch -> {
5803 if (inRange(lower, ch, upper))
5804 return true;
5805 int up = Character.toUpperCase(ch);
5806 return inRange(lower, up, upper) ||
5807 inRange(lower, Character.toLowerCase(up), upper);
5808 };
5809 }
5810
5811 /**
5812 * This must be the very first initializer.
5813 */
5814 static final Node accept = new Node();
5815
5816 static final Node lastAccept = new LastNode();
5817
5818 /**
5819 * Creates a predicate which can be used to match a string.
5820 *
5821 * @return The predicate which can be used for matching on a string
5822 * @since 1.8
5823 */
5824 public Predicate<String> asPredicate() {
5825 return s -> matcher(s).find();
5826 }
5827
5828 /**
5829 * Creates a stream from the given input sequence around matches of this
5830 * pattern.
5831 *
5832 * <p> The stream returned by this method contains each substring of the
5833 * input sequence that is terminated by another subsequence that matches
5834 * this pattern or is terminated by the end of the input sequence. The
5835 * substrings in the stream are in the order in which they occur in the
5836 * input. Trailing empty strings will be discarded and not encountered in
5837 * the stream.
5838 *
5839 * <p> If this pattern does not match any subsequence of the input then
5840 * the resulting stream has just one element, namely the input sequence in
5841 * string form.
5842 *
5843 * <p> When there is a positive-width match at the beginning of the input
5844 * sequence then an empty leading substring is included at the beginning
5845 * of the stream. A zero-width match at the beginning however never produces
5846 * such empty leading substring.
5847 *
5848 * <p> If the input sequence is mutable, it must remain constant during the
5849 * execution of the terminal stream operation. Otherwise, the result of the
5850 * terminal stream operation is undefined.
5851 *
5852 * @param input
5853 * The character sequence to be split
5854 *
5855 * @return The stream of strings computed by splitting the input
5856 * around matches of this pattern
5857 * @see #split(CharSequence)
5858 * @since 1.8
5859 */
5860 public Stream<String> splitAsStream(final CharSequence input) {
5861 class MatcherIterator implements Iterator<String> {
5862 private Matcher matcher;
5863 // The start position of the next sub-sequence of input
5864 // when current == input.length there are no more elements
5865 private int current;
5866 // null if the next element, if any, needs to obtained
5867 private String nextElement;
5868 // > 0 if there are N next empty elements
5869 private int emptyElementCount;
5870
5871 public String next() {
5872 if (!hasNext())
5873 throw new NoSuchElementException();
5874
5875 if (emptyElementCount == 0) {
5876 String n = nextElement;
5877 nextElement = null;
5878 return n;
5879 } else {
5880 emptyElementCount--;
5881 return "";
5882 }
5883 }
5884
5885 public boolean hasNext() {
5886 if (matcher == null) {
5887 matcher = matcher(input);
5888 // If the input is an empty string then the result can only be a
5889 // stream of the input. Induce that by setting the empty
5890 // element count to 1
5891 emptyElementCount = input.length() == 0 ? 1 : 0;
5892 }
5893 if (nextElement != null || emptyElementCount > 0)
5894 return true;
5895
5896 if (current == input.length())
5897 return false;
5898
5899 // Consume the next matching element
5900 // Count sequence of matching empty elements
5901 while (matcher.find()) {
5902 nextElement = input.subSequence(current, matcher.start()).toString();
5903 current = matcher.end();
5904 if (!nextElement.isEmpty()) {
5905 return true;
5906 } else if (current > 0) { // no empty leading substring for zero-width
5907 // match at the beginning of the input
5908 emptyElementCount++;
5909 }
5910 }
5911
5912 // Consume last matching element
5913 nextElement = input.subSequence(current, input.length()).toString();
5914 current = input.length();
5915 if (!nextElement.isEmpty()) {
5916 return true;
5917 } else {
5918 // Ignore a terminal sequence of matching empty elements
5919 emptyElementCount = 0;
5920 nextElement = null;
5921 return false;
5922 }
5923 }
5924 }
5925 return StreamSupport.stream(Spliterators.spliteratorUnknownSize(
5926 new MatcherIterator(), Spliterator.ORDERED | Spliterator.NONNULL), false);
5927 }
5928 }