1 /* 2 * Copyright (c) 1999, 2015, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. Oracle designates this 8 * particular file as subject to the "Classpath" exception as provided 9 * by Oracle in the LICENSE file that accompanied this code. 10 * 11 * This code is distributed in the hope that it will be useful, but WITHOUT 12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 14 * version 2 for more details (a copy is included in the LICENSE file that 15 * accompanied this code). 16 * 17 * You should have received a copy of the GNU General Public License version 18 * 2 along with this work; if not, write to the Free Software Foundation, 19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 20 * 21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 22 * or visit www.oracle.com if you need additional information or have any 23 * questions. 24 */ 25 26 package java.util.regex; 27 28 import java.text.Normalizer; 29 import java.util.Locale; 30 import java.util.Iterator; 31 import java.util.Map; 32 import java.util.ArrayList; 33 import java.util.HashMap; 34 import java.util.Arrays; 35 import java.util.NoSuchElementException; 36 import java.util.Spliterator; 37 import java.util.Spliterators; 38 import java.util.function.Predicate; 39 import java.util.stream.Stream; 40 import java.util.stream.StreamSupport; 41 42 43 /** 44 * A compiled representation of a regular expression. 45 * 46 * <p> A regular expression, specified as a string, must first be compiled into 47 * an instance of this class. The resulting pattern can then be used to create 48 * a {@link Matcher} object that can match arbitrary {@linkplain 49 * java.lang.CharSequence character sequences} against the regular 50 * expression. All of the state involved in performing a match resides in the 51 * matcher, so many matchers can share the same pattern. 52 * 53 * <p> A typical invocation sequence is thus 54 * 55 * <blockquote><pre> 56 * Pattern p = Pattern.{@link #compile compile}("a*b"); 57 * Matcher m = p.{@link #matcher matcher}("aaaaab"); 58 * boolean b = m.{@link Matcher#matches matches}();</pre></blockquote> 59 * 60 * <p> A {@link #matches matches} method is defined by this class as a 61 * convenience for when a regular expression is used just once. This method 62 * compiles an expression and matches an input sequence against it in a single 63 * invocation. The statement 64 * 65 * <blockquote><pre> 66 * boolean b = Pattern.matches("a*b", "aaaaab");</pre></blockquote> 67 * 68 * is equivalent to the three statements above, though for repeated matches it 69 * is less efficient since it does not allow the compiled pattern to be reused. 70 * 71 * <p> Instances of this class are immutable and are safe for use by multiple 72 * concurrent threads. Instances of the {@link Matcher} class are not safe for 73 * such use. 74 * 75 * 76 * <h3><a name="sum">Summary of regular-expression constructs</a></h3> 77 * 78 * <table border="0" cellpadding="1" cellspacing="0" 79 * summary="Regular expression constructs, and what they match"> 80 * 81 * <tr align="left"> 82 * <th align="left" id="construct">Construct</th> 83 * <th align="left" id="matches">Matches</th> 84 * </tr> 85 * 86 * <tr><th> </th></tr> 87 * <tr align="left"><th colspan="2" id="characters">Characters</th></tr> 88 * 89 * <tr><td valign="top" headers="construct characters"><i>x</i></td> 90 * <td headers="matches">The character <i>x</i></td></tr> 91 * <tr><td valign="top" headers="construct characters">{@code \\}</td> 92 * <td headers="matches">The backslash character</td></tr> 93 * <tr><td valign="top" headers="construct characters">{@code \0}<i>n</i></td> 94 * <td headers="matches">The character with octal value {@code 0}<i>n</i> 95 * (0 {@code <=} <i>n</i> {@code <=} 7)</td></tr> 96 * <tr><td valign="top" headers="construct characters">{@code \0}<i>nn</i></td> 97 * <td headers="matches">The character with octal value {@code 0}<i>nn</i> 98 * (0 {@code <=} <i>n</i> {@code <=} 7)</td></tr> 99 * <tr><td valign="top" headers="construct characters">{@code \0}<i>mnn</i></td> 100 * <td headers="matches">The character with octal value {@code 0}<i>mnn</i> 101 * (0 {@code <=} <i>m</i> {@code <=} 3, 102 * 0 {@code <=} <i>n</i> {@code <=} 7)</td></tr> 103 * <tr><td valign="top" headers="construct characters">{@code \x}<i>hh</i></td> 104 * <td headers="matches">The character with hexadecimal value {@code 0x}<i>hh</i></td></tr> 105 * <tr><td valign="top" headers="construct characters"><code>\u</code><i>hhhh</i></td> 106 * <td headers="matches">The character with hexadecimal value {@code 0x}<i>hhhh</i></td></tr> 107 * <tr><td valign="top" headers="construct characters"><code>\x</code><i>{h...h}</i></td> 108 * <td headers="matches">The character with hexadecimal value {@code 0x}<i>h...h</i> 109 * ({@link java.lang.Character#MIN_CODE_POINT Character.MIN_CODE_POINT} 110 * <= {@code 0x}<i>h...h</i> <= 111 * {@link java.lang.Character#MAX_CODE_POINT Character.MAX_CODE_POINT})</td></tr> 112 * <tr><td valign="top" headers="construct characters"><code>\N{</code><i>name</i><code>}</code></td> 113 * <td headers="matches">The character with Unicode character name <i>'name'</i></td></tr> 114 * <tr><td valign="top" headers="matches">{@code \t}</td> 115 * <td headers="matches">The tab character (<code>'\u0009'</code>)</td></tr> 116 * <tr><td valign="top" headers="construct characters">{@code \n}</td> 117 * <td headers="matches">The newline (line feed) character (<code>'\u000A'</code>)</td></tr> 118 * <tr><td valign="top" headers="construct characters">{@code \r}</td> 119 * <td headers="matches">The carriage-return character (<code>'\u000D'</code>)</td></tr> 120 * <tr><td valign="top" headers="construct characters">{@code \f}</td> 121 * <td headers="matches">The form-feed character (<code>'\u000C'</code>)</td></tr> 122 * <tr><td valign="top" headers="construct characters">{@code \a}</td> 123 * <td headers="matches">The alert (bell) character (<code>'\u0007'</code>)</td></tr> 124 * <tr><td valign="top" headers="construct characters">{@code \e}</td> 125 * <td headers="matches">The escape character (<code>'\u001B'</code>)</td></tr> 126 * <tr><td valign="top" headers="construct characters">{@code \c}<i>x</i></td> 127 * <td headers="matches">The control character corresponding to <i>x</i></td></tr> 128 * 129 * <tr><th> </th></tr> 130 * <tr align="left"><th colspan="2" id="classes">Character classes</th></tr> 131 * 132 * <tr><td valign="top" headers="construct classes">{@code [abc]}</td> 133 * <td headers="matches">{@code a}, {@code b}, or {@code c} (simple class)</td></tr> 134 * <tr><td valign="top" headers="construct classes">{@code [^abc]}</td> 135 * <td headers="matches">Any character except {@code a}, {@code b}, or {@code c} (negation)</td></tr> 136 * <tr><td valign="top" headers="construct classes">{@code [a-zA-Z]}</td> 137 * <td headers="matches">{@code a} through {@code z} 138 * or {@code A} through {@code Z}, inclusive (range)</td></tr> 139 * <tr><td valign="top" headers="construct classes">{@code [a-d[m-p]]}</td> 140 * <td headers="matches">{@code a} through {@code d}, 141 * or {@code m} through {@code p}: {@code [a-dm-p]} (union)</td></tr> 142 * <tr><td valign="top" headers="construct classes">{@code [a-z&&[def]]}</td> 143 * <td headers="matches">{@code d}, {@code e}, or {@code f} (intersection)</tr> 144 * <tr><td valign="top" headers="construct classes">{@code [a-z&&[^bc]]}</td> 145 * <td headers="matches">{@code a} through {@code z}, 146 * except for {@code b} and {@code c}: {@code [ad-z]} (subtraction)</td></tr> 147 * <tr><td valign="top" headers="construct classes">{@code [a-z&&[^m-p]]}</td> 148 * <td headers="matches">{@code a} through {@code z}, 149 * and not {@code m} through {@code p}: {@code [a-lq-z]}(subtraction)</td></tr> 150 * <tr><th> </th></tr> 151 * 152 * <tr align="left"><th colspan="2" id="predef">Predefined character classes</th></tr> 153 * 154 * <tr><td valign="top" headers="construct predef">{@code .}</td> 155 * <td headers="matches">Any character (may or may not match <a href="#lt">line terminators</a>)</td></tr> 156 * <tr><td valign="top" headers="construct predef">{@code \d}</td> 157 * <td headers="matches">A digit: {@code [0-9]}</td></tr> 158 * <tr><td valign="top" headers="construct predef">{@code \D}</td> 159 * <td headers="matches">A non-digit: {@code [^0-9]}</td></tr> 160 * <tr><td valign="top" headers="construct predef">{@code \h}</td> 161 * <td headers="matches">A horizontal whitespace character: 162 * <code>[ \t\xA0\u1680\u180e\u2000-\u200a\u202f\u205f\u3000]</code></td></tr> 163 * <tr><td valign="top" headers="construct predef">{@code \H}</td> 164 * <td headers="matches">A non-horizontal whitespace character: {@code [^\h]}</td></tr> 165 * <tr><td valign="top" headers="construct predef">{@code \s}</td> 166 * <td headers="matches">A whitespace character: {@code [ \t\n\x0B\f\r]}</td></tr> 167 * <tr><td valign="top" headers="construct predef">{@code \S}</td> 168 * <td headers="matches">A non-whitespace character: {@code [^\s]}</td></tr> 169 * <tr><td valign="top" headers="construct predef">{@code \v}</td> 170 * <td headers="matches">A vertical whitespace character: <code>[\n\x0B\f\r\x85\u2028\u2029]</code> 171 * </td></tr> 172 * <tr><td valign="top" headers="construct predef">{@code \V}</td> 173 * <td headers="matches">A non-vertical whitespace character: {@code [^\v]}</td></tr> 174 * <tr><td valign="top" headers="construct predef">{@code \w}</td> 175 * <td headers="matches">A word character: {@code [a-zA-Z_0-9]}</td></tr> 176 * <tr><td valign="top" headers="construct predef">{@code \W}</td> 177 * <td headers="matches">A non-word character: {@code [^\w]}</td></tr> 178 * <tr><th> </th></tr> 179 * <tr align="left"><th colspan="2" id="posix"><b>POSIX character classes (US-ASCII only)</b></th></tr> 180 * 181 * <tr><td valign="top" headers="construct posix">{@code \p{Lower}}</td> 182 * <td headers="matches">A lower-case alphabetic character: {@code [a-z]}</td></tr> 183 * <tr><td valign="top" headers="construct posix">{@code \p{Upper}}</td> 184 * <td headers="matches">An upper-case alphabetic character:{@code [A-Z]}</td></tr> 185 * <tr><td valign="top" headers="construct posix">{@code \p{ASCII}}</td> 186 * <td headers="matches">All ASCII:{@code [\x00-\x7F]}</td></tr> 187 * <tr><td valign="top" headers="construct posix">{@code \p{Alpha}}</td> 188 * <td headers="matches">An alphabetic character:{@code [\p{Lower}\p{Upper}]}</td></tr> 189 * <tr><td valign="top" headers="construct posix">{@code \p{Digit}}</td> 190 * <td headers="matches">A decimal digit: {@code [0-9]}</td></tr> 191 * <tr><td valign="top" headers="construct posix">{@code \p{Alnum}}</td> 192 * <td headers="matches">An alphanumeric character:{@code [\p{Alpha}\p{Digit}]}</td></tr> 193 * <tr><td valign="top" headers="construct posix">{@code \p{Punct}}</td> 194 * <td headers="matches">Punctuation: One of {@code !"#$%&'()*+,-./:;<=>?@[\]^_`{|}~}</td></tr> 195 * <!-- {@code [\!"#\$%&'\(\)\*\+,\-\./:;\<=\>\?@\[\\\]\^_`\{\|\}~]} 196 * {@code [\X21-\X2F\X31-\X40\X5B-\X60\X7B-\X7E]} --> 197 * <tr><td valign="top" headers="construct posix">{@code \p{Graph}}</td> 198 * <td headers="matches">A visible character: {@code [\p{Alnum}\p{Punct}]}</td></tr> 199 * <tr><td valign="top" headers="construct posix">{@code \p{Print}}</td> 200 * <td headers="matches">A printable character: {@code [\p{Graph}\x20]}</td></tr> 201 * <tr><td valign="top" headers="construct posix">{@code \p{Blank}}</td> 202 * <td headers="matches">A space or a tab: {@code [ \t]}</td></tr> 203 * <tr><td valign="top" headers="construct posix">{@code \p{Cntrl}}</td> 204 * <td headers="matches">A control character: {@code [\x00-\x1F\x7F]}</td></tr> 205 * <tr><td valign="top" headers="construct posix">{@code \p{XDigit}}</td> 206 * <td headers="matches">A hexadecimal digit: {@code [0-9a-fA-F]}</td></tr> 207 * <tr><td valign="top" headers="construct posix">{@code \p{Space}}</td> 208 * <td headers="matches">A whitespace character: {@code [ \t\n\x0B\f\r]}</td></tr> 209 * 210 * <tr><th> </th></tr> 211 * <tr align="left"><th colspan="2">java.lang.Character classes (simple <a href="#jcc">java character type</a>)</th></tr> 212 * 213 * <tr><td valign="top">{@code \p{javaLowerCase}}</td> 214 * <td>Equivalent to java.lang.Character.isLowerCase()</td></tr> 215 * <tr><td valign="top">{@code \p{javaUpperCase}}</td> 216 * <td>Equivalent to java.lang.Character.isUpperCase()</td></tr> 217 * <tr><td valign="top">{@code \p{javaWhitespace}}</td> 218 * <td>Equivalent to java.lang.Character.isWhitespace()</td></tr> 219 * <tr><td valign="top">{@code \p{javaMirrored}}</td> 220 * <td>Equivalent to java.lang.Character.isMirrored()</td></tr> 221 * 222 * <tr><th> </th></tr> 223 * <tr align="left"><th colspan="2" id="unicode">Classes for Unicode scripts, blocks, categories and binary properties</th></tr> 224 * <tr><td valign="top" headers="construct unicode">{@code \p{IsLatin}}</td> 225 * <td headers="matches">A Latin script character (<a href="#usc">script</a>)</td></tr> 226 * <tr><td valign="top" headers="construct unicode">{@code \p{InGreek}}</td> 227 * <td headers="matches">A character in the Greek block (<a href="#ubc">block</a>)</td></tr> 228 * <tr><td valign="top" headers="construct unicode">{@code \p{Lu}}</td> 229 * <td headers="matches">An uppercase letter (<a href="#ucc">category</a>)</td></tr> 230 * <tr><td valign="top" headers="construct unicode">{@code \p{IsAlphabetic}}</td> 231 * <td headers="matches">An alphabetic character (<a href="#ubpc">binary property</a>)</td></tr> 232 * <tr><td valign="top" headers="construct unicode">{@code \p{Sc}}</td> 233 * <td headers="matches">A currency symbol</td></tr> 234 * <tr><td valign="top" headers="construct unicode">{@code \P{InGreek}}</td> 235 * <td headers="matches">Any character except one in the Greek block (negation)</td></tr> 236 * <tr><td valign="top" headers="construct unicode">{@code [\p{L}&&[^\p{Lu}]]}</td> 237 * <td headers="matches">Any letter except an uppercase letter (subtraction)</td></tr> 238 * 239 * <tr><th> </th></tr> 240 * <tr align="left"><th colspan="2" id="bounds">Boundary matchers</th></tr> 241 * 242 * <tr><td valign="top" headers="construct bounds">{@code ^}</td> 243 * <td headers="matches">The beginning of a line</td></tr> 244 * <tr><td valign="top" headers="construct bounds">{@code $}</td> 245 * <td headers="matches">The end of a line</td></tr> 246 * <tr><td valign="top" headers="construct bounds">{@code \b}</td> 247 * <td headers="matches">A word boundary</td></tr> 248 * <tr><td valign="top" headers="construct bounds">{@code \b{g}}</td> 249 * <td headers="matches">A Unicode extended grapheme cluster boundary</td></tr> 250 * <tr><td valign="top" headers="construct bounds">{@code \B}</td> 251 * <td headers="matches">A non-word boundary</td></tr> 252 * <tr><td valign="top" headers="construct bounds">{@code \A}</td> 253 * <td headers="matches">The beginning of the input</td></tr> 254 * <tr><td valign="top" headers="construct bounds">{@code \G}</td> 255 * <td headers="matches">The end of the previous match</td></tr> 256 * <tr><td valign="top" headers="construct bounds">{@code \Z}</td> 257 * <td headers="matches">The end of the input but for the final 258 * <a href="#lt">terminator</a>, if any</td></tr> 259 * <tr><td valign="top" headers="construct bounds">{@code \z}</td> 260 * <td headers="matches">The end of the input</td></tr> 261 * 262 * <tr><th> </th></tr> 263 * <tr align="left"><th colspan="2" id="lineending">Linebreak matcher</th></tr> 264 * <tr><td valign="top" headers="construct lineending">{@code \R}</td> 265 * <td headers="matches">Any Unicode linebreak sequence, is equivalent to 266 * <code>\u000D\u000A|[\u000A\u000B\u000C\u000D\u0085\u2028\u2029] 267 * </code></td></tr> 268 * 269 * <tr><th> </th></tr> 270 * <tr align="left"><th colspan="2" id="grapheme">Unicode Extended Grapheme matcher</th></tr> 271 * <tr><td valign="top" headers="construct grapheme">{@code \X}</td> 272 * <td headers="matches">Any Unicode extended grapheme cluster</td></tr> 273 * 274 * <tr><th> </th></tr> 275 * <tr align="left"><th colspan="2" id="greedy">Greedy quantifiers</th></tr> 276 * 277 * <tr><td valign="top" headers="construct greedy"><i>X</i>{@code ?}</td> 278 * <td headers="matches"><i>X</i>, once or not at all</td></tr> 279 * <tr><td valign="top" headers="construct greedy"><i>X</i>{@code *}</td> 280 * <td headers="matches"><i>X</i>, zero or more times</td></tr> 281 * <tr><td valign="top" headers="construct greedy"><i>X</i>{@code +}</td> 282 * <td headers="matches"><i>X</i>, one or more times</td></tr> 283 * <tr><td valign="top" headers="construct greedy"><i>X</i><code>{</code><i>n</i><code>}</code></td> 284 * <td headers="matches"><i>X</i>, exactly <i>n</i> times</td></tr> 285 * <tr><td valign="top" headers="construct greedy"><i>X</i><code>{</code><i>n</i>{@code ,}}</td> 286 * <td headers="matches"><i>X</i>, at least <i>n</i> times</td></tr> 287 * <tr><td valign="top" headers="construct greedy"><i>X</i><code>{</code><i>n</i>{@code ,}<i>m</i><code>}</code></td> 288 * <td headers="matches"><i>X</i>, at least <i>n</i> but not more than <i>m</i> times</td></tr> 289 * 290 * <tr><th> </th></tr> 291 * <tr align="left"><th colspan="2" id="reluc">Reluctant quantifiers</th></tr> 292 * 293 * <tr><td valign="top" headers="construct reluc"><i>X</i>{@code ??}</td> 294 * <td headers="matches"><i>X</i>, once or not at all</td></tr> 295 * <tr><td valign="top" headers="construct reluc"><i>X</i>{@code *?}</td> 296 * <td headers="matches"><i>X</i>, zero or more times</td></tr> 297 * <tr><td valign="top" headers="construct reluc"><i>X</i>{@code +?}</td> 298 * <td headers="matches"><i>X</i>, one or more times</td></tr> 299 * <tr><td valign="top" headers="construct reluc"><i>X</i><code>{</code><i>n</i><code>}?</code></td> 300 * <td headers="matches"><i>X</i>, exactly <i>n</i> times</td></tr> 301 * <tr><td valign="top" headers="construct reluc"><i>X</i><code>{</code><i>n</i><code>,}?</code></td> 302 * <td headers="matches"><i>X</i>, at least <i>n</i> times</td></tr> 303 * <tr><td valign="top" headers="construct reluc"><i>X</i><code>{</code><i>n</i>{@code ,}<i>m</i><code>}?</code></td> 304 * <td headers="matches"><i>X</i>, at least <i>n</i> but not more than <i>m</i> times</td></tr> 305 * 306 * <tr><th> </th></tr> 307 * <tr align="left"><th colspan="2" id="poss">Possessive quantifiers</th></tr> 308 * 309 * <tr><td valign="top" headers="construct poss"><i>X</i>{@code ?+}</td> 310 * <td headers="matches"><i>X</i>, once or not at all</td></tr> 311 * <tr><td valign="top" headers="construct poss"><i>X</i>{@code *+}</td> 312 * <td headers="matches"><i>X</i>, zero or more times</td></tr> 313 * <tr><td valign="top" headers="construct poss"><i>X</i>{@code ++}</td> 314 * <td headers="matches"><i>X</i>, one or more times</td></tr> 315 * <tr><td valign="top" headers="construct poss"><i>X</i><code>{</code><i>n</i><code>}+</code></td> 316 * <td headers="matches"><i>X</i>, exactly <i>n</i> times</td></tr> 317 * <tr><td valign="top" headers="construct poss"><i>X</i><code>{</code><i>n</i><code>,}+</code></td> 318 * <td headers="matches"><i>X</i>, at least <i>n</i> times</td></tr> 319 * <tr><td valign="top" headers="construct poss"><i>X</i><code>{</code><i>n</i>{@code ,}<i>m</i><code>}+</code></td> 320 * <td headers="matches"><i>X</i>, at least <i>n</i> but not more than <i>m</i> times</td></tr> 321 * 322 * <tr><th> </th></tr> 323 * <tr align="left"><th colspan="2" id="logical">Logical operators</th></tr> 324 * 325 * <tr><td valign="top" headers="construct logical"><i>XY</i></td> 326 * <td headers="matches"><i>X</i> followed by <i>Y</i></td></tr> 327 * <tr><td valign="top" headers="construct logical"><i>X</i>{@code |}<i>Y</i></td> 328 * <td headers="matches">Either <i>X</i> or <i>Y</i></td></tr> 329 * <tr><td valign="top" headers="construct logical">{@code (}<i>X</i>{@code )}</td> 330 * <td headers="matches">X, as a <a href="#cg">capturing group</a></td></tr> 331 * 332 * <tr><th> </th></tr> 333 * <tr align="left"><th colspan="2" id="backref">Back references</th></tr> 334 * 335 * <tr><td valign="bottom" headers="construct backref">{@code \}<i>n</i></td> 336 * <td valign="bottom" headers="matches">Whatever the <i>n</i><sup>th</sup> 337 * <a href="#cg">capturing group</a> matched</td></tr> 338 * 339 * <tr><td valign="bottom" headers="construct backref">{@code \}<i>k</i><<i>name</i>></td> 340 * <td valign="bottom" headers="matches">Whatever the 341 * <a href="#groupname">named-capturing group</a> "name" matched</td></tr> 342 * 343 * <tr><th> </th></tr> 344 * <tr align="left"><th colspan="2" id="quot">Quotation</th></tr> 345 * 346 * <tr><td valign="top" headers="construct quot">{@code \}</td> 347 * <td headers="matches">Nothing, but quotes the following character</td></tr> 348 * <tr><td valign="top" headers="construct quot">{@code \Q}</td> 349 * <td headers="matches">Nothing, but quotes all characters until {@code \E}</td></tr> 350 * <tr><td valign="top" headers="construct quot">{@code \E}</td> 351 * <td headers="matches">Nothing, but ends quoting started by {@code \Q}</td></tr> 352 * <!-- Metachars: !$()*+.<>?[\]^{|} --> 353 * 354 * <tr><th> </th></tr> 355 * <tr align="left"><th colspan="2" id="special">Special constructs (named-capturing and non-capturing)</th></tr> 356 * 357 * <tr><td valign="top" headers="construct special"><code>(?<<a href="#groupname">name</a>></code><i>X</i>{@code )}</td> 358 * <td headers="matches"><i>X</i>, as a named-capturing group</td></tr> 359 * <tr><td valign="top" headers="construct special">{@code (?:}<i>X</i>{@code )}</td> 360 * <td headers="matches"><i>X</i>, as a non-capturing group</td></tr> 361 * <tr><td valign="top" headers="construct special"><code>(?idmsuxU-idmsuxU) </code></td> 362 * <td headers="matches">Nothing, but turns match flags <a href="#CASE_INSENSITIVE">i</a> 363 * <a href="#UNIX_LINES">d</a> <a href="#MULTILINE">m</a> <a href="#DOTALL">s</a> 364 * <a href="#UNICODE_CASE">u</a> <a href="#COMMENTS">x</a> <a href="#UNICODE_CHARACTER_CLASS">U</a> 365 * on - off</td></tr> 366 * <tr><td valign="top" headers="construct special"><code>(?idmsux-idmsux:</code><i>X</i>{@code )} </td> 367 * <td headers="matches"><i>X</i>, as a <a href="#cg">non-capturing group</a> with the 368 * given flags <a href="#CASE_INSENSITIVE">i</a> <a href="#UNIX_LINES">d</a> 369 * <a href="#MULTILINE">m</a> <a href="#DOTALL">s</a> <a href="#UNICODE_CASE">u</a > 370 * <a href="#COMMENTS">x</a> on - off</td></tr> 371 * <tr><td valign="top" headers="construct special">{@code (?=}<i>X</i>{@code )}</td> 372 * <td headers="matches"><i>X</i>, via zero-width positive lookahead</td></tr> 373 * <tr><td valign="top" headers="construct special">{@code (?!}<i>X</i>{@code )}</td> 374 * <td headers="matches"><i>X</i>, via zero-width negative lookahead</td></tr> 375 * <tr><td valign="top" headers="construct special">{@code (?<=}<i>X</i>{@code )}</td> 376 * <td headers="matches"><i>X</i>, via zero-width positive lookbehind</td></tr> 377 * <tr><td valign="top" headers="construct special">{@code (?<!}<i>X</i>{@code )}</td> 378 * <td headers="matches"><i>X</i>, via zero-width negative lookbehind</td></tr> 379 * <tr><td valign="top" headers="construct special">{@code (?>}<i>X</i>{@code )}</td> 380 * <td headers="matches"><i>X</i>, as an independent, non-capturing group</td></tr> 381 * 382 * </table> 383 * 384 * <hr> 385 * 386 * 387 * <h3><a name="bs">Backslashes, escapes, and quoting</a></h3> 388 * 389 * <p> The backslash character ({@code '\'}) serves to introduce escaped 390 * constructs, as defined in the table above, as well as to quote characters 391 * that otherwise would be interpreted as unescaped constructs. Thus the 392 * expression {@code \\} matches a single backslash and <code>\{</code> matches a 393 * left brace. 394 * 395 * <p> It is an error to use a backslash prior to any alphabetic character that 396 * does not denote an escaped construct; these are reserved for future 397 * extensions to the regular-expression language. A backslash may be used 398 * prior to a non-alphabetic character regardless of whether that character is 399 * part of an unescaped construct. 400 * 401 * <p> Backslashes within string literals in Java source code are interpreted 402 * as required by 403 * <cite>The Java™ Language Specification</cite> 404 * as either Unicode escapes (section 3.3) or other character escapes (section 3.10.6) 405 * It is therefore necessary to double backslashes in string 406 * literals that represent regular expressions to protect them from 407 * interpretation by the Java bytecode compiler. The string literal 408 * <code>"\b"</code>, for example, matches a single backspace character when 409 * interpreted as a regular expression, while {@code "\\b"} matches a 410 * word boundary. The string literal {@code "\(hello\)"} is illegal 411 * and leads to a compile-time error; in order to match the string 412 * {@code (hello)} the string literal {@code "\\(hello\\)"} 413 * must be used. 414 * 415 * <h3><a name="cc">Character Classes</a></h3> 416 * 417 * <p> Character classes may appear within other character classes, and 418 * may be composed by the union operator (implicit) and the intersection 419 * operator ({@code &&}). 420 * The union operator denotes a class that contains every character that is 421 * in at least one of its operand classes. The intersection operator 422 * denotes a class that contains every character that is in both of its 423 * operand classes. 424 * 425 * <p> The precedence of character-class operators is as follows, from 426 * highest to lowest: 427 * 428 * <blockquote><table border="0" cellpadding="1" cellspacing="0" 429 * summary="Precedence of character class operators."> 430 * <tr><th>1 </th> 431 * <td>Literal escape </td> 432 * <td>{@code \x}</td></tr> 433 * <tr><th>2 </th> 434 * <td>Grouping</td> 435 * <td>{@code [...]}</td></tr> 436 * <tr><th>3 </th> 437 * <td>Range</td> 438 * <td>{@code a-z}</td></tr> 439 * <tr><th>4 </th> 440 * <td>Union</td> 441 * <td>{@code [a-e][i-u]}</td></tr> 442 * <tr><th>5 </th> 443 * <td>Intersection</td> 444 * <td>{@code [a-z&&[aeiou]]}</td></tr> 445 * </table></blockquote> 446 * 447 * <p> Note that a different set of metacharacters are in effect inside 448 * a character class than outside a character class. For instance, the 449 * regular expression {@code .} loses its special meaning inside a 450 * character class, while the expression {@code -} becomes a range 451 * forming metacharacter. 452 * 453 * <h3><a name="lt">Line terminators</a></h3> 454 * 455 * <p> A <i>line terminator</i> is a one- or two-character sequence that marks 456 * the end of a line of the input character sequence. The following are 457 * recognized as line terminators: 458 * 459 * <ul> 460 * 461 * <li> A newline (line feed) character ({@code '\n'}), 462 * 463 * <li> A carriage-return character followed immediately by a newline 464 * character ({@code "\r\n"}), 465 * 466 * <li> A standalone carriage-return character ({@code '\r'}), 467 * 468 * <li> A next-line character (<code>'\u0085'</code>), 469 * 470 * <li> A line-separator character (<code>'\u2028'</code>), or 471 * 472 * <li> A paragraph-separator character (<code>'\u2029</code>). 473 * 474 * </ul> 475 * <p>If {@link #UNIX_LINES} mode is activated, then the only line terminators 476 * recognized are newline characters. 477 * 478 * <p> The regular expression {@code .} matches any character except a line 479 * terminator unless the {@link #DOTALL} flag is specified. 480 * 481 * <p> By default, the regular expressions {@code ^} and {@code $} ignore 482 * line terminators and only match at the beginning and the end, respectively, 483 * of the entire input sequence. If {@link #MULTILINE} mode is activated then 484 * {@code ^} matches at the beginning of input and after any line terminator 485 * except at the end of input. When in {@link #MULTILINE} mode {@code $} 486 * matches just before a line terminator or the end of the input sequence. 487 * 488 * <h3><a name="cg">Groups and capturing</a></h3> 489 * 490 * <h4><a name="gnumber">Group number</a></h4> 491 * <p> Capturing groups are numbered by counting their opening parentheses from 492 * left to right. In the expression {@code ((A)(B(C)))}, for example, there 493 * are four such groups: </p> 494 * 495 * <blockquote><table cellpadding=1 cellspacing=0 summary="Capturing group numberings"> 496 * <tr><th>1 </th> 497 * <td>{@code ((A)(B(C)))}</td></tr> 498 * <tr><th>2 </th> 499 * <td>{@code (A)}</td></tr> 500 * <tr><th>3 </th> 501 * <td>{@code (B(C))}</td></tr> 502 * <tr><th>4 </th> 503 * <td>{@code (C)}</td></tr> 504 * </table></blockquote> 505 * 506 * <p> Group zero always stands for the entire expression. 507 * 508 * <p> Capturing groups are so named because, during a match, each subsequence 509 * of the input sequence that matches such a group is saved. The captured 510 * subsequence may be used later in the expression, via a back reference, and 511 * may also be retrieved from the matcher once the match operation is complete. 512 * 513 * <h4><a name="groupname">Group name</a></h4> 514 * <p>A capturing group can also be assigned a "name", a {@code named-capturing group}, 515 * and then be back-referenced later by the "name". Group names are composed of 516 * the following characters. The first character must be a {@code letter}. 517 * 518 * <ul> 519 * <li> The uppercase letters {@code 'A'} through {@code 'Z'} 520 * (<code>'\u0041'</code> through <code>'\u005a'</code>), 521 * <li> The lowercase letters {@code 'a'} through {@code 'z'} 522 * (<code>'\u0061'</code> through <code>'\u007a'</code>), 523 * <li> The digits {@code '0'} through {@code '9'} 524 * (<code>'\u0030'</code> through <code>'\u0039'</code>), 525 * </ul> 526 * 527 * <p> A {@code named-capturing group} is still numbered as described in 528 * <a href="#gnumber">Group number</a>. 529 * 530 * <p> The captured input associated with a group is always the subsequence 531 * that the group most recently matched. If a group is evaluated a second time 532 * because of quantification then its previously-captured value, if any, will 533 * be retained if the second evaluation fails. Matching the string 534 * {@code "aba"} against the expression {@code (a(b)?)+}, for example, leaves 535 * group two set to {@code "b"}. All captured input is discarded at the 536 * beginning of each match. 537 * 538 * <p> Groups beginning with {@code (?} are either pure, <i>non-capturing</i> groups 539 * that do not capture text and do not count towards the group total, or 540 * <i>named-capturing</i> group. 541 * 542 * <h3> Unicode support </h3> 543 * 544 * <p> This class is in conformance with Level 1 of <a 545 * href="http://www.unicode.org/reports/tr18/"><i>Unicode Technical 546 * Standard #18: Unicode Regular Expression</i></a>, plus RL2.1 547 * Canonical Equivalents. 548 * <p> 549 * <b>Unicode escape sequences</b> such as <code>\u2014</code> in Java source code 550 * are processed as described in section 3.3 of 551 * <cite>The Java™ Language Specification</cite>. 552 * Such escape sequences are also implemented directly by the regular-expression 553 * parser so that Unicode escapes can be used in expressions that are read from 554 * files or from the keyboard. Thus the strings <code>"\u2014"</code> and 555 * {@code "\\u2014"}, while not equal, compile into the same pattern, which 556 * matches the character with hexadecimal value {@code 0x2014}. 557 * <p> 558 * A Unicode character can also be represented by using its <b>Hex notation</b> 559 * (hexadecimal code point value) directly as described in construct 560 * <code>\x{...}</code>, for example a supplementary character U+2011F can be 561 * specified as <code>\x{2011F}</code>, instead of two consecutive Unicode escape 562 * sequences of the surrogate pair <code>\uD840</code><code>\uDD1F</code>. 563 * <p> 564 * <b>Unicode character names</b> are supported by the named character construct 565 * <code>\N{</code>...<code>}</code>, for example, <code>\N{WHITE SMILING FACE}</code> 566 * specifies character <code>\u263A</code>. The character names supported 567 * by this class are the valid Unicode character names matched by 568 * {@link java.lang.Character#codePointOf(String) Character.codePointOf(name)}. 569 * <p> 570 * <a href="http://www.unicode.org/reports/tr18/#Default_Grapheme_Clusters"> 571 * <b>Unicode extended grapheme clusters</b></a> are supported by the grapheme 572 * cluster matcher {@code \X} and the corresponding boundary matcher {@code \b{g}}. 573 * <p> 574 * Unicode scripts, blocks, categories and binary properties are written with 575 * the {@code \p} and {@code \P} constructs as in Perl. 576 * <code>\p{</code><i>prop</i><code>}</code> matches if 577 * the input has the property <i>prop</i>, while <code>\P{</code><i>prop</i><code>}</code> 578 * does not match if the input has that property. 579 * <p> 580 * Scripts, blocks, categories and binary properties can be used both inside 581 * and outside of a character class. 582 * 583 * <p> 584 * <b><a name="usc">Scripts</a></b> are specified either with the prefix {@code Is}, as in 585 * {@code IsHiragana}, or by using the {@code script} keyword (or its short 586 * form {@code sc}) as in {@code script=Hiragana} or {@code sc=Hiragana}. 587 * <p> 588 * The script names supported by {@code Pattern} are the valid script names 589 * accepted and defined by 590 * {@link java.lang.Character.UnicodeScript#forName(String) UnicodeScript.forName}. 591 * 592 * <p> 593 * <b><a name="ubc">Blocks</a></b> are specified with the prefix {@code In}, as in 594 * {@code InMongolian}, or by using the keyword {@code block} (or its short 595 * form {@code blk}) as in {@code block=Mongolian} or {@code blk=Mongolian}. 596 * <p> 597 * The block names supported by {@code Pattern} are the valid block names 598 * accepted and defined by 599 * {@link java.lang.Character.UnicodeBlock#forName(String) UnicodeBlock.forName}. 600 * <p> 601 * 602 * <b><a name="ucc">Categories</a></b> may be specified with the optional prefix {@code Is}: 603 * Both {@code \p{L}} and {@code \p{IsL}} denote the category of Unicode 604 * letters. Same as scripts and blocks, categories can also be specified 605 * by using the keyword {@code general_category} (or its short form 606 * {@code gc}) as in {@code general_category=Lu} or {@code gc=Lu}. 607 * <p> 608 * The supported categories are those of 609 * <a href="http://www.unicode.org/unicode/standard/standard.html"> 610 * <i>The Unicode Standard</i></a> in the version specified by the 611 * {@link java.lang.Character Character} class. The category names are those 612 * defined in the Standard, both normative and informative. 613 * <p> 614 * 615 * <b><a name="ubpc">Binary properties</a></b> are specified with the prefix {@code Is}, as in 616 * {@code IsAlphabetic}. The supported binary properties by {@code Pattern} 617 * are 618 * <ul> 619 * <li> Alphabetic 620 * <li> Ideographic 621 * <li> Letter 622 * <li> Lowercase 623 * <li> Uppercase 624 * <li> Titlecase 625 * <li> Punctuation 626 * <Li> Control 627 * <li> White_Space 628 * <li> Digit 629 * <li> Hex_Digit 630 * <li> Join_Control 631 * <li> Noncharacter_Code_Point 632 * <li> Assigned 633 * </ul> 634 * <p> 635 * The following <b>Predefined Character classes</b> and <b>POSIX character classes</b> 636 * are in conformance with the recommendation of <i>Annex C: Compatibility Properties</i> 637 * of <a href="http://www.unicode.org/reports/tr18/"><i>Unicode Regular Expression 638 * </i></a>, when {@link #UNICODE_CHARACTER_CLASS} flag is specified. 639 * 640 * <table border="0" cellpadding="1" cellspacing="0" 641 * summary="predefined and posix character classes in Unicode mode"> 642 * <tr align="left"> 643 * <th align="left" id="predef_classes">Classes</th> 644 * <th align="left" id="predef_matches">Matches</th> 645 *</tr> 646 * <tr><td>{@code \p{Lower}}</td> 647 * <td>A lowercase character:{@code \p{IsLowercase}}</td></tr> 648 * <tr><td>{@code \p{Upper}}</td> 649 * <td>An uppercase character:{@code \p{IsUppercase}}</td></tr> 650 * <tr><td>{@code \p{ASCII}}</td> 651 * <td>All ASCII:{@code [\x00-\x7F]}</td></tr> 652 * <tr><td>{@code \p{Alpha}}</td> 653 * <td>An alphabetic character:{@code \p{IsAlphabetic}}</td></tr> 654 * <tr><td>{@code \p{Digit}}</td> 655 * <td>A decimal digit character:{@code p{IsDigit}}</td></tr> 656 * <tr><td>{@code \p{Alnum}}</td> 657 * <td>An alphanumeric character:{@code [\p{IsAlphabetic}\p{IsDigit}]}</td></tr> 658 * <tr><td>{@code \p{Punct}}</td> 659 * <td>A punctuation character:{@code p{IsPunctuation}}</td></tr> 660 * <tr><td>{@code \p{Graph}}</td> 661 * <td>A visible character: {@code [^\p{IsWhite_Space}\p{gc=Cc}\p{gc=Cs}\p{gc=Cn}]}</td></tr> 662 * <tr><td>{@code \p{Print}}</td> 663 * <td>A printable character: {@code [\p{Graph}\p{Blank}&&[^\p{Cntrl}]]}</td></tr> 664 * <tr><td>{@code \p{Blank}}</td> 665 * <td>A space or a tab: {@code [\p{IsWhite_Space}&&[^\p{gc=Zl}\p{gc=Zp}\x0a\x0b\x0c\x0d\x85]]}</td></tr> 666 * <tr><td>{@code \p{Cntrl}}</td> 667 * <td>A control character: {@code \p{gc=Cc}}</td></tr> 668 * <tr><td>{@code \p{XDigit}}</td> 669 * <td>A hexadecimal digit: {@code [\p{gc=Nd}\p{IsHex_Digit}]}</td></tr> 670 * <tr><td>{@code \p{Space}}</td> 671 * <td>A whitespace character:{@code \p{IsWhite_Space}}</td></tr> 672 * <tr><td>{@code \d}</td> 673 * <td>A digit: {@code \p{IsDigit}}</td></tr> 674 * <tr><td>{@code \D}</td> 675 * <td>A non-digit: {@code [^\d]}</td></tr> 676 * <tr><td>{@code \s}</td> 677 * <td>A whitespace character: {@code \p{IsWhite_Space}}</td></tr> 678 * <tr><td>{@code \S}</td> 679 * <td>A non-whitespace character: {@code [^\s]}</td></tr> 680 * <tr><td>{@code \w}</td> 681 * <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> 682 * <tr><td>{@code \W}</td> 683 * <td>A non-word character: {@code [^\w]}</td></tr> 684 * </table> 685 * <p> 686 * <a name="jcc"> 687 * Categories that behave like the java.lang.Character 688 * boolean is<i>methodname</i> methods (except for the deprecated ones) are 689 * available through the same <code>\p{</code><i>prop</i><code>}</code> syntax where 690 * the specified property has the name <code>java<i>methodname</i></code></a>. 691 * 692 * <h3> Comparison to Perl 5 </h3> 693 * 694 * <p>The {@code Pattern} engine performs traditional NFA-based matching 695 * with ordered alternation as occurs in Perl 5. 696 * 697 * <p> Perl constructs not supported by this class: </p> 698 * 699 * <ul> 700 * <li><p> The backreference constructs, <code>\g{</code><i>n</i><code>}</code> for 701 * the <i>n</i><sup>th</sup><a href="#cg">capturing group</a> and 702 * <code>\g{</code><i>name</i><code>}</code> for 703 * <a href="#groupname">named-capturing group</a>. 704 * </p></li> 705 * 706 * <li><p> The conditional constructs 707 * {@code (?(}<i>condition</i>{@code )}<i>X</i>{@code )} and 708 * {@code (?(}<i>condition</i>{@code )}<i>X</i>{@code |}<i>Y</i>{@code )}, 709 * </p></li> 710 * 711 * <li><p> The embedded code constructs <code>(?{</code><i>code</i><code>})</code> 712 * and <code>(??{</code><i>code</i><code>})</code>,</p></li> 713 * 714 * <li><p> The embedded comment syntax {@code (?#comment)}, and </p></li> 715 * 716 * <li><p> The preprocessing operations {@code \l} <code>\u</code>, 717 * {@code \L}, and {@code \U}. </p></li> 718 * 719 * </ul> 720 * 721 * <p> Constructs supported by this class but not by Perl: </p> 722 * 723 * <ul> 724 * 725 * <li><p> Character-class union and intersection as described 726 * <a href="#cc">above</a>.</p></li> 727 * 728 * </ul> 729 * 730 * <p> Notable differences from Perl: </p> 731 * 732 * <ul> 733 * 734 * <li><p> In Perl, {@code \1} through {@code \9} are always interpreted 735 * as back references; a backslash-escaped number greater than {@code 9} is 736 * treated as a back reference if at least that many subexpressions exist, 737 * otherwise it is interpreted, if possible, as an octal escape. In this 738 * class octal escapes must always begin with a zero. In this class, 739 * {@code \1} through {@code \9} are always interpreted as back 740 * references, and a larger number is accepted as a back reference if at 741 * least that many subexpressions exist at that point in the regular 742 * expression, otherwise the parser will drop digits until the number is 743 * smaller or equal to the existing number of groups or it is one digit. 744 * </p></li> 745 * 746 * <li><p> Perl uses the {@code g} flag to request a match that resumes 747 * where the last match left off. This functionality is provided implicitly 748 * by the {@link Matcher} class: Repeated invocations of the {@link 749 * Matcher#find find} method will resume where the last match left off, 750 * unless the matcher is reset. </p></li> 751 * 752 * <li><p> In Perl, embedded flags at the top level of an expression affect 753 * the whole expression. In this class, embedded flags always take effect 754 * at the point at which they appear, whether they are at the top level or 755 * within a group; in the latter case, flags are restored at the end of the 756 * group just as in Perl. </p></li> 757 * 758 * </ul> 759 * 760 * 761 * <p> For a more precise description of the behavior of regular expression 762 * constructs, please see <a href="http://www.oreilly.com/catalog/regex3/"> 763 * <i>Mastering Regular Expressions, 3nd Edition</i>, Jeffrey E. F. Friedl, 764 * O'Reilly and Associates, 2006.</a> 765 * </p> 766 * 767 * @see java.lang.String#split(String, int) 768 * @see java.lang.String#split(String) 769 * 770 * @author Mike McCloskey 771 * @author Mark Reinhold 772 * @author JSR-51 Expert Group 773 * @since 1.4 774 * @spec JSR-51 775 */ 776 777 public final class Pattern 778 implements java.io.Serializable 779 { 780 781 /** 782 * Regular expression modifier values. Instead of being passed as 783 * arguments, they can also be passed as inline modifiers. 784 * For example, the following statements have the same effect. 785 * <pre> 786 * RegExp r1 = RegExp.compile("abc", Pattern.I|Pattern.M); 787 * RegExp r2 = RegExp.compile("(?im)abc", 0); 788 * </pre> 789 * 790 * The flags are duplicated so that the familiar Perl match flag 791 * names are available. 792 */ 793 794 /** 795 * Enables Unix lines mode. 796 * 797 * <p> In this mode, only the {@code '\n'} line terminator is recognized 798 * in the behavior of {@code .}, {@code ^}, and {@code $}. 799 * 800 * <p> Unix lines mode can also be enabled via the embedded flag 801 * expression {@code (?d)}. 802 */ 803 public static final int UNIX_LINES = 0x01; 804 805 /** 806 * Enables case-insensitive matching. 807 * 808 * <p> By default, case-insensitive matching assumes that only characters 809 * in the US-ASCII charset are being matched. Unicode-aware 810 * case-insensitive matching can be enabled by specifying the {@link 811 * #UNICODE_CASE} flag in conjunction with this flag. 812 * 813 * <p> Case-insensitive matching can also be enabled via the embedded flag 814 * expression {@code (?i)}. 815 * 816 * <p> Specifying this flag may impose a slight performance penalty. </p> 817 */ 818 public static final int CASE_INSENSITIVE = 0x02; 819 820 /** 821 * Permits whitespace and comments in pattern. 822 * 823 * <p> In this mode, whitespace is ignored, and embedded comments starting 824 * with {@code #} are ignored until the end of a line. 825 * 826 * <p> Comments mode can also be enabled via the embedded flag 827 * expression {@code (?x)}. 828 */ 829 public static final int COMMENTS = 0x04; 830 831 /** 832 * Enables multiline mode. 833 * 834 * <p> In multiline mode the expressions {@code ^} and {@code $} match 835 * just after or just before, respectively, a line terminator or the end of 836 * the input sequence. By default these expressions only match at the 837 * beginning and the end of the entire input sequence. 838 * 839 * <p> Multiline mode can also be enabled via the embedded flag 840 * expression {@code (?m)}. </p> 841 */ 842 public static final int MULTILINE = 0x08; 843 844 /** 845 * Enables literal parsing of the pattern. 846 * 847 * <p> When this flag is specified then the input string that specifies 848 * the pattern is treated as a sequence of literal characters. 849 * Metacharacters or escape sequences in the input sequence will be 850 * given no special meaning. 851 * 852 * <p>The flags CASE_INSENSITIVE and UNICODE_CASE retain their impact on 853 * matching when used in conjunction with this flag. The other flags 854 * become superfluous. 855 * 856 * <p> There is no embedded flag character for enabling literal parsing. 857 * @since 1.5 858 */ 859 public static final int LITERAL = 0x10; 860 861 /** 862 * Enables dotall mode. 863 * 864 * <p> In dotall mode, the expression {@code .} matches any character, 865 * including a line terminator. By default this expression does not match 866 * line terminators. 867 * 868 * <p> Dotall mode can also be enabled via the embedded flag 869 * expression {@code (?s)}. (The {@code s} is a mnemonic for 870 * "single-line" mode, which is what this is called in Perl.) </p> 871 */ 872 public static final int DOTALL = 0x20; 873 874 /** 875 * Enables Unicode-aware case folding. 876 * 877 * <p> When this flag is specified then case-insensitive matching, when 878 * enabled by the {@link #CASE_INSENSITIVE} flag, is done in a manner 879 * consistent with the Unicode Standard. By default, case-insensitive 880 * matching assumes that only characters in the US-ASCII charset are being 881 * matched. 882 * 883 * <p> Unicode-aware case folding can also be enabled via the embedded flag 884 * expression {@code (?u)}. 885 * 886 * <p> Specifying this flag may impose a performance penalty. </p> 887 */ 888 public static final int UNICODE_CASE = 0x40; 889 890 /** 891 * Enables canonical equivalence. 892 * 893 * <p> When this flag is specified then two characters will be considered 894 * to match if, and only if, their full canonical decompositions match. 895 * The expression <code>"a\u030A"</code>, for example, will match the 896 * string <code>"\u00E5"</code> when this flag is specified. By default, 897 * matching does not take canonical equivalence into account. 898 * 899 * <p> There is no embedded flag character for enabling canonical 900 * equivalence. 901 * 902 * <p> Specifying this flag may impose a performance penalty. </p> 903 */ 904 public static final int CANON_EQ = 0x80; 905 906 /** 907 * Enables the Unicode version of <i>Predefined character classes</i> and 908 * <i>POSIX character classes</i>. 909 * 910 * <p> When this flag is specified then the (US-ASCII only) 911 * <i>Predefined character classes</i> and <i>POSIX character classes</i> 912 * are in conformance with 913 * <a href="http://www.unicode.org/reports/tr18/"><i>Unicode Technical 914 * Standard #18: Unicode Regular Expression</i></a> 915 * <i>Annex C: Compatibility Properties</i>. 916 * <p> 917 * The UNICODE_CHARACTER_CLASS mode can also be enabled via the embedded 918 * flag expression {@code (?U)}. 919 * <p> 920 * The flag implies UNICODE_CASE, that is, it enables Unicode-aware case 921 * folding. 922 * <p> 923 * Specifying this flag may impose a performance penalty. </p> 924 * @since 1.7 925 */ 926 public static final int UNICODE_CHARACTER_CLASS = 0x100; 927 928 /** 929 * Contains all possible flags for compile(regex, flags). 930 */ 931 private static final int ALL_FLAGS = CASE_INSENSITIVE | MULTILINE | 932 DOTALL | UNICODE_CASE | CANON_EQ | UNIX_LINES | LITERAL | 933 UNICODE_CHARACTER_CLASS | COMMENTS; 934 935 /* Pattern has only two serialized components: The pattern string 936 * and the flags, which are all that is needed to recompile the pattern 937 * when it is deserialized. 938 */ 939 940 /** use serialVersionUID from Merlin b59 for interoperability */ 941 private static final long serialVersionUID = 5073258162644648461L; 942 943 /** 944 * The original regular-expression pattern string. 945 * 946 * @serial 947 */ 948 private String pattern; 949 950 /** 951 * The original pattern flags. 952 * 953 * @serial 954 */ 955 private int flags; 956 957 /** 958 * Boolean indicating this Pattern is compiled; this is necessary in order 959 * to lazily compile deserialized Patterns. 960 */ 961 private transient volatile boolean compiled; 962 963 /** 964 * The normalized pattern string. 965 */ 966 private transient String normalizedPattern; 967 968 /** 969 * The starting point of state machine for the find operation. This allows 970 * a match to start anywhere in the input. 971 */ 972 transient Node root; 973 974 /** 975 * The root of object tree for a match operation. The pattern is matched 976 * at the beginning. This may include a find that uses BnM or a First 977 * node. 978 */ 979 transient Node matchRoot; 980 981 /** 982 * Temporary storage used by parsing pattern slice. 983 */ 984 transient int[] buffer; 985 986 /** 987 * Map the "name" of the "named capturing group" to its group id 988 * node. 989 */ 990 transient volatile Map<String, Integer> namedGroups; 991 992 /** 993 * Temporary storage used while parsing group references. 994 */ 995 transient GroupHead[] groupNodes; 996 997 /** 998 * Temporary null terminated code point array used by pattern compiling. 999 */ 1000 private transient int[] temp; 1001 1002 /** 1003 * The number of capturing groups in this Pattern. Used by matchers to 1004 * allocate storage needed to perform a match. 1005 */ 1006 transient int capturingGroupCount; 1007 1008 /** 1009 * The local variable count used by parsing tree. Used by matchers to 1010 * allocate storage needed to perform a match. 1011 */ 1012 transient int localCount; 1013 1014 /** 1015 * Index into the pattern string that keeps track of how much has been 1016 * parsed. 1017 */ 1018 private transient int cursor; 1019 1020 /** 1021 * Holds the length of the pattern string. 1022 */ 1023 private transient int patternLength; 1024 1025 /** 1026 * If the Start node might possibly match supplementary characters. 1027 * It is set to true during compiling if 1028 * (1) There is supplementary char in pattern, or 1029 * (2) There is complement node of Category or Block 1030 */ 1031 private transient boolean hasSupplementary; 1032 1033 /** 1034 * Compiles the given regular expression into a pattern. 1035 * 1036 * @param regex 1037 * The expression to be compiled 1038 * @return the given regular expression compiled into a pattern 1039 * @throws PatternSyntaxException 1040 * If the expression's syntax is invalid 1041 */ 1042 public static Pattern compile(String regex) { 1043 return new Pattern(regex, 0); 1044 } 1045 1046 /** 1047 * Compiles the given regular expression into a pattern with the given 1048 * flags. 1049 * 1050 * @param regex 1051 * The expression to be compiled 1052 * 1053 * @param flags 1054 * Match flags, a bit mask that may include 1055 * {@link #CASE_INSENSITIVE}, {@link #MULTILINE}, {@link #DOTALL}, 1056 * {@link #UNICODE_CASE}, {@link #CANON_EQ}, {@link #UNIX_LINES}, 1057 * {@link #LITERAL}, {@link #UNICODE_CHARACTER_CLASS} 1058 * and {@link #COMMENTS} 1059 * 1060 * @return the given regular expression compiled into a pattern with the given flags 1061 * @throws IllegalArgumentException 1062 * If bit values other than those corresponding to the defined 1063 * match flags are set in {@code flags} 1064 * 1065 * @throws PatternSyntaxException 1066 * If the expression's syntax is invalid 1067 */ 1068 public static Pattern compile(String regex, int flags) { 1069 return new Pattern(regex, flags); 1070 } 1071 1072 /** 1073 * Returns the regular expression from which this pattern was compiled. 1074 * 1075 * @return The source of this pattern 1076 */ 1077 public String pattern() { 1078 return pattern; 1079 } 1080 1081 /** 1082 * <p>Returns the string representation of this pattern. This 1083 * is the regular expression from which this pattern was 1084 * compiled.</p> 1085 * 1086 * @return The string representation of this pattern 1087 * @since 1.5 1088 */ 1089 public String toString() { 1090 return pattern; 1091 } 1092 1093 /** 1094 * Creates a matcher that will match the given input against this pattern. 1095 * 1096 * @param input 1097 * The character sequence to be matched 1098 * 1099 * @return A new matcher for this pattern 1100 */ 1101 public Matcher matcher(CharSequence input) { 1102 if (!compiled) { 1103 synchronized(this) { 1104 if (!compiled) 1105 compile(); 1106 } 1107 } 1108 Matcher m = new Matcher(this, input); 1109 return m; 1110 } 1111 1112 /** 1113 * Returns this pattern's match flags. 1114 * 1115 * @return The match flags specified when this pattern was compiled 1116 */ 1117 public int flags() { 1118 return flags; 1119 } 1120 1121 /** 1122 * Compiles the given regular expression and attempts to match the given 1123 * input against it. 1124 * 1125 * <p> An invocation of this convenience method of the form 1126 * 1127 * <blockquote><pre> 1128 * Pattern.matches(regex, input);</pre></blockquote> 1129 * 1130 * behaves in exactly the same way as the expression 1131 * 1132 * <blockquote><pre> 1133 * Pattern.compile(regex).matcher(input).matches()</pre></blockquote> 1134 * 1135 * <p> If a pattern is to be used multiple times, compiling it once and reusing 1136 * it will be more efficient than invoking this method each time. </p> 1137 * 1138 * @param regex 1139 * The expression to be compiled 1140 * 1141 * @param input 1142 * The character sequence to be matched 1143 * @return whether or not the regular expression matches on the input 1144 * @throws PatternSyntaxException 1145 * If the expression's syntax is invalid 1146 */ 1147 public static boolean matches(String regex, CharSequence input) { 1148 Pattern p = Pattern.compile(regex); 1149 Matcher m = p.matcher(input); 1150 return m.matches(); 1151 } 1152 1153 /** 1154 * Splits the given input sequence around matches of this pattern. 1155 * 1156 * <p> The array returned by this method contains each substring of the 1157 * input sequence that is terminated by another subsequence that matches 1158 * this pattern or is terminated by the end of the input sequence. The 1159 * substrings in the array are in the order in which they occur in the 1160 * input. If this pattern does not match any subsequence of the input then 1161 * the resulting array has just one element, namely the input sequence in 1162 * string form. 1163 * 1164 * <p> When there is a positive-width match at the beginning of the input 1165 * sequence then an empty leading substring is included at the beginning 1166 * of the resulting array. A zero-width match at the beginning however 1167 * never produces such empty leading substring. 1168 * 1169 * <p> The {@code limit} parameter controls the number of times the 1170 * pattern is applied and therefore affects the length of the resulting 1171 * array. If the limit <i>n</i> is greater than zero then the pattern 1172 * will be applied at most <i>n</i> - 1 times, the array's 1173 * length will be no greater than <i>n</i>, and the array's last entry 1174 * will contain all input beyond the last matched delimiter. If <i>n</i> 1175 * is non-positive then the pattern will be applied as many times as 1176 * possible and the array can have any length. If <i>n</i> is zero then 1177 * the pattern will be applied as many times as possible, the array can 1178 * have any length, and trailing empty strings will be discarded. 1179 * 1180 * <p> The input {@code "boo:and:foo"}, for example, yields the following 1181 * results with these parameters: 1182 * 1183 * <blockquote><table cellpadding=1 cellspacing=0 1184 * summary="Split examples showing regex, limit, and result"> 1185 * <tr><th align="left"><i>Regex </i></th> 1186 * <th align="left"><i>Limit </i></th> 1187 * <th align="left"><i>Result </i></th></tr> 1188 * <tr><td align=center>:</td> 1189 * <td align=center>2</td> 1190 * <td>{@code { "boo", "and:foo" }}</td></tr> 1191 * <tr><td align=center>:</td> 1192 * <td align=center>5</td> 1193 * <td>{@code { "boo", "and", "foo" }}</td></tr> 1194 * <tr><td align=center>:</td> 1195 * <td align=center>-2</td> 1196 * <td>{@code { "boo", "and", "foo" }}</td></tr> 1197 * <tr><td align=center>o</td> 1198 * <td align=center>5</td> 1199 * <td>{@code { "b", "", ":and:f", "", "" }}</td></tr> 1200 * <tr><td align=center>o</td> 1201 * <td align=center>-2</td> 1202 * <td>{@code { "b", "", ":and:f", "", "" }}</td></tr> 1203 * <tr><td align=center>o</td> 1204 * <td align=center>0</td> 1205 * <td>{@code { "b", "", ":and:f" }}</td></tr> 1206 * </table></blockquote> 1207 * 1208 * @param input 1209 * The character sequence to be split 1210 * 1211 * @param limit 1212 * The result threshold, as described above 1213 * 1214 * @return The array of strings computed by splitting the input 1215 * around matches of this pattern 1216 */ 1217 public String[] split(CharSequence input, int limit) { 1218 int index = 0; 1219 boolean matchLimited = limit > 0; 1220 ArrayList<String> matchList = new ArrayList<>(); 1221 Matcher m = matcher(input); 1222 1223 // Add segments before each match found 1224 while(m.find()) { 1225 if (!matchLimited || matchList.size() < limit - 1) { 1226 if (index == 0 && index == m.start() && m.start() == m.end()) { 1227 // no empty leading substring included for zero-width match 1228 // at the beginning of the input char sequence. 1229 continue; 1230 } 1231 String match = input.subSequence(index, m.start()).toString(); 1232 matchList.add(match); 1233 index = m.end(); 1234 } else if (matchList.size() == limit - 1) { // last one 1235 String match = input.subSequence(index, 1236 input.length()).toString(); 1237 matchList.add(match); 1238 index = m.end(); 1239 } 1240 } 1241 1242 // If no match was found, return this 1243 if (index == 0) 1244 return new String[] {input.toString()}; 1245 1246 // Add remaining segment 1247 if (!matchLimited || matchList.size() < limit) 1248 matchList.add(input.subSequence(index, input.length()).toString()); 1249 1250 // Construct result 1251 int resultSize = matchList.size(); 1252 if (limit == 0) 1253 while (resultSize > 0 && matchList.get(resultSize-1).equals("")) 1254 resultSize--; 1255 String[] result = new String[resultSize]; 1256 return matchList.subList(0, resultSize).toArray(result); 1257 } 1258 1259 /** 1260 * Splits the given input sequence around matches of this pattern. 1261 * 1262 * <p> This method works as if by invoking the two-argument {@link 1263 * #split(java.lang.CharSequence, int) split} method with the given input 1264 * sequence and a limit argument of zero. Trailing empty strings are 1265 * therefore not included in the resulting array. </p> 1266 * 1267 * <p> The input {@code "boo:and:foo"}, for example, yields the following 1268 * results with these expressions: 1269 * 1270 * <blockquote><table cellpadding=1 cellspacing=0 1271 * summary="Split examples showing regex and result"> 1272 * <tr><th align="left"><i>Regex </i></th> 1273 * <th align="left"><i>Result</i></th></tr> 1274 * <tr><td align=center>:</td> 1275 * <td>{@code { "boo", "and", "foo" }}</td></tr> 1276 * <tr><td align=center>o</td> 1277 * <td>{@code { "b", "", ":and:f" }}</td></tr> 1278 * </table></blockquote> 1279 * 1280 * 1281 * @param input 1282 * The character sequence to be split 1283 * 1284 * @return The array of strings computed by splitting the input 1285 * around matches of this pattern 1286 */ 1287 public String[] split(CharSequence input) { 1288 return split(input, 0); 1289 } 1290 1291 /** 1292 * Returns a literal pattern {@code String} for the specified 1293 * {@code String}. 1294 * 1295 * <p>This method produces a {@code String} that can be used to 1296 * create a {@code Pattern} that would match the string 1297 * {@code s} as if it were a literal pattern.</p> Metacharacters 1298 * or escape sequences in the input sequence will be given no special 1299 * meaning. 1300 * 1301 * @param s The string to be literalized 1302 * @return A literal string replacement 1303 * @since 1.5 1304 */ 1305 public static String quote(String s) { 1306 int slashEIndex = s.indexOf("\\E"); 1307 if (slashEIndex == -1) 1308 return "\\Q" + s + "\\E"; 1309 1310 int lenHint = s.length(); 1311 lenHint = (lenHint < Integer.MAX_VALUE - 8 - lenHint) ? 1312 (lenHint << 1) : (Integer.MAX_VALUE - 8); 1313 1314 StringBuilder sb = new StringBuilder(lenHint); 1315 sb.append("\\Q"); 1316 int current = 0; 1317 do { 1318 sb.append(s, current, slashEIndex) 1319 .append("\\E\\\\E\\Q"); 1320 current = slashEIndex + 2; 1321 } while ((slashEIndex = s.indexOf("\\E", current)) != -1); 1322 1323 return sb.append(s, current, s.length()) 1324 .append("\\E") 1325 .toString(); 1326 } 1327 1328 /** 1329 * Recompile the Pattern instance from a stream. The original pattern 1330 * string is read in and the object tree is recompiled from it. 1331 */ 1332 private void readObject(java.io.ObjectInputStream s) 1333 throws java.io.IOException, ClassNotFoundException { 1334 1335 // Read in all fields 1336 s.defaultReadObject(); 1337 1338 // Initialize counts 1339 capturingGroupCount = 1; 1340 localCount = 0; 1341 1342 // if length > 0, the Pattern is lazily compiled 1343 if (pattern.length() == 0) { 1344 root = new Start(lastAccept); 1345 matchRoot = lastAccept; 1346 compiled = true; 1347 } 1348 } 1349 1350 /** 1351 * This private constructor is used to create all Patterns. The pattern 1352 * string and match flags are all that is needed to completely describe 1353 * a Pattern. An empty pattern string results in an object tree with 1354 * only a Start node and a LastNode node. 1355 */ 1356 private Pattern(String p, int f) { 1357 if ((f & ~ALL_FLAGS) != 0) { 1358 throw new IllegalArgumentException("Unknown flag 0x" 1359 + Integer.toHexString(f)); 1360 } 1361 pattern = p; 1362 flags = f; 1363 1364 // to use UNICODE_CASE if UNICODE_CHARACTER_CLASS present 1365 if ((flags & UNICODE_CHARACTER_CLASS) != 0) 1366 flags |= UNICODE_CASE; 1367 1368 // Reset group index count 1369 capturingGroupCount = 1; 1370 localCount = 0; 1371 1372 if (pattern.length() > 0) { 1373 compile(); 1374 } else { 1375 root = new Start(lastAccept); 1376 matchRoot = lastAccept; 1377 } 1378 } 1379 1380 /** 1381 * The pattern is converted to normalized form ({@linkplain 1382 * java.text.Normalizer.Form.NFD NFD}, canonical decomposition) 1383 * and then a pure group is constructed to match canonical 1384 * equivalences of the characters. 1385 */ 1386 private void normalize() { 1387 int lastCodePoint = -1; 1388 1389 // Convert pattern into normalized form 1390 normalizedPattern = Normalizer.normalize(pattern, Normalizer.Form.NFD); 1391 patternLength = normalizedPattern.length(); 1392 1393 // Modify pattern to match canonical equivalences 1394 StringBuilder newPattern = new StringBuilder(patternLength); 1395 for(int i=0; i<patternLength; ) { 1396 int c = normalizedPattern.codePointAt(i); 1397 StringBuilder sequenceBuffer; 1398 if ((Character.getType(c) == Character.NON_SPACING_MARK) 1399 && (lastCodePoint != -1)) { 1400 sequenceBuffer = new StringBuilder(); 1401 sequenceBuffer.appendCodePoint(lastCodePoint); 1402 sequenceBuffer.appendCodePoint(c); 1403 while(Character.getType(c) == Character.NON_SPACING_MARK) { 1404 i += Character.charCount(c); 1405 if (i >= patternLength) 1406 break; 1407 c = normalizedPattern.codePointAt(i); 1408 sequenceBuffer.appendCodePoint(c); 1409 } 1410 String ea = produceEquivalentAlternation( 1411 sequenceBuffer.toString()); 1412 newPattern.setLength(newPattern.length()-Character.charCount(lastCodePoint)); 1413 newPattern.append("(?:").append(ea).append(")"); 1414 } else if (c == '[' && lastCodePoint != '\\') { 1415 i = normalizeCharClass(newPattern, i); 1416 } else { 1417 newPattern.appendCodePoint(c); 1418 } 1419 lastCodePoint = c; 1420 i += Character.charCount(c); 1421 } 1422 normalizedPattern = newPattern.toString(); 1423 } 1424 1425 /** 1426 * Complete the character class being parsed and add a set 1427 * of alternations to it that will match the canonical equivalences 1428 * of the characters within the class. 1429 */ 1430 private int normalizeCharClass(StringBuilder newPattern, int i) { 1431 StringBuilder charClass = new StringBuilder(); 1432 StringBuilder eq = null; 1433 int lastCodePoint = -1; 1434 String result; 1435 1436 i++; 1437 charClass.append("["); 1438 while(true) { 1439 int c = normalizedPattern.codePointAt(i); 1440 StringBuilder sequenceBuffer; 1441 1442 if (c == ']' && lastCodePoint != '\\') { 1443 charClass.append((char)c); 1444 break; 1445 } else if (Character.getType(c) == Character.NON_SPACING_MARK) { 1446 sequenceBuffer = new StringBuilder(); 1447 sequenceBuffer.appendCodePoint(lastCodePoint); 1448 while(Character.getType(c) == Character.NON_SPACING_MARK) { 1449 sequenceBuffer.appendCodePoint(c); 1450 i += Character.charCount(c); 1451 if (i >= normalizedPattern.length()) 1452 break; 1453 c = normalizedPattern.codePointAt(i); 1454 } 1455 String ea = produceEquivalentAlternation( 1456 sequenceBuffer.toString()); 1457 1458 charClass.setLength(charClass.length()-Character.charCount(lastCodePoint)); 1459 if (eq == null) 1460 eq = new StringBuilder(); 1461 eq.append('|'); 1462 eq.append(ea); 1463 } else { 1464 charClass.appendCodePoint(c); 1465 i++; 1466 } 1467 if (i == normalizedPattern.length()) 1468 throw error("Unclosed character class"); 1469 lastCodePoint = c; 1470 } 1471 1472 if (eq != null) { 1473 result = "(?:"+charClass.toString()+eq.toString()+")"; 1474 } else { 1475 result = charClass.toString(); 1476 } 1477 1478 newPattern.append(result); 1479 return i; 1480 } 1481 1482 /** 1483 * Given a specific sequence composed of a regular character and 1484 * combining marks that follow it, produce the alternation that will 1485 * match all canonical equivalences of that sequence. 1486 */ 1487 private String produceEquivalentAlternation(String source) { 1488 int len = countChars(source, 0, 1); 1489 if (source.length() == len) 1490 // source has one character. 1491 return source; 1492 1493 String base = source.substring(0,len); 1494 String combiningMarks = source.substring(len); 1495 1496 String[] perms = producePermutations(combiningMarks); 1497 StringBuilder result = new StringBuilder(source); 1498 1499 // Add combined permutations 1500 for(int x=0; x<perms.length; x++) { 1501 String next = base + perms[x]; 1502 if (x>0) 1503 result.append("|"+next); 1504 next = composeOneStep(next); 1505 if (next != null) 1506 result.append("|"+produceEquivalentAlternation(next)); 1507 } 1508 return result.toString(); 1509 } 1510 1511 /** 1512 * Returns an array of strings that have all the possible 1513 * permutations of the characters in the input string. 1514 * This is used to get a list of all possible orderings 1515 * of a set of combining marks. Note that some of the permutations 1516 * are invalid because of combining class collisions, and these 1517 * possibilities must be removed because they are not canonically 1518 * equivalent. 1519 */ 1520 private String[] producePermutations(String input) { 1521 if (input.length() == countChars(input, 0, 1)) 1522 return new String[] {input}; 1523 1524 if (input.length() == countChars(input, 0, 2)) { 1525 int c0 = Character.codePointAt(input, 0); 1526 int c1 = Character.codePointAt(input, Character.charCount(c0)); 1527 if (getClass(c1) == getClass(c0)) { 1528 return new String[] {input}; 1529 } 1530 String[] result = new String[2]; 1531 result[0] = input; 1532 StringBuilder sb = new StringBuilder(2); 1533 sb.appendCodePoint(c1); 1534 sb.appendCodePoint(c0); 1535 result[1] = sb.toString(); 1536 return result; 1537 } 1538 1539 int length = 1; 1540 int nCodePoints = countCodePoints(input); 1541 for(int x=1; x<nCodePoints; x++) 1542 length = length * (x+1); 1543 1544 String[] temp = new String[length]; 1545 1546 int combClass[] = new int[nCodePoints]; 1547 for(int x=0, i=0; x<nCodePoints; x++) { 1548 int c = Character.codePointAt(input, i); 1549 combClass[x] = getClass(c); 1550 i += Character.charCount(c); 1551 } 1552 1553 // For each char, take it out and add the permutations 1554 // of the remaining chars 1555 int index = 0; 1556 int len; 1557 // offset maintains the index in code units. 1558 loop: for(int x=0, offset=0; x<nCodePoints; x++, offset+=len) { 1559 len = countChars(input, offset, 1); 1560 for(int y=x-1; y>=0; y--) { 1561 if (combClass[y] == combClass[x]) { 1562 continue loop; 1563 } 1564 } 1565 StringBuilder sb = new StringBuilder(input); 1566 String otherChars = sb.delete(offset, offset+len).toString(); 1567 String[] subResult = producePermutations(otherChars); 1568 1569 String prefix = input.substring(offset, offset+len); 1570 for (String sre : subResult) 1571 temp[index++] = prefix + sre; 1572 } 1573 String[] result = new String[index]; 1574 System.arraycopy(temp, 0, result, 0, index); 1575 return result; 1576 } 1577 1578 private int getClass(int c) { 1579 return sun.text.Normalizer.getCombiningClass(c); 1580 } 1581 1582 /** 1583 * Attempts to compose input by combining the first character 1584 * with the first combining mark following it. Returns a String 1585 * that is the composition of the leading character with its first 1586 * combining mark followed by the remaining combining marks. Returns 1587 * null if the first two characters cannot be further composed. 1588 */ 1589 private String composeOneStep(String input) { 1590 int len = countChars(input, 0, 2); 1591 String firstTwoCharacters = input.substring(0, len); 1592 String result = Normalizer.normalize(firstTwoCharacters, Normalizer.Form.NFC); 1593 1594 if (result.equals(firstTwoCharacters)) 1595 return null; 1596 else { 1597 String remainder = input.substring(len); 1598 return result + remainder; 1599 } 1600 } 1601 1602 /** 1603 * Preprocess any \Q...\E sequences in `temp', meta-quoting them. 1604 * See the description of `quotemeta' in perlfunc(1). 1605 */ 1606 private void RemoveQEQuoting() { 1607 final int pLen = patternLength; 1608 int i = 0; 1609 while (i < pLen-1) { 1610 if (temp[i] != '\\') 1611 i += 1; 1612 else if (temp[i + 1] != 'Q') 1613 i += 2; 1614 else 1615 break; 1616 } 1617 if (i >= pLen - 1) // No \Q sequence found 1618 return; 1619 int j = i; 1620 i += 2; 1621 int[] newtemp = new int[j + 3*(pLen-i) + 2]; 1622 System.arraycopy(temp, 0, newtemp, 0, j); 1623 1624 boolean inQuote = true; 1625 boolean beginQuote = true; 1626 while (i < pLen) { 1627 int c = temp[i++]; 1628 if (!ASCII.isAscii(c) || ASCII.isAlpha(c)) { 1629 newtemp[j++] = c; 1630 } else if (ASCII.isDigit(c)) { 1631 if (beginQuote) { 1632 /* 1633 * A unicode escape \[0xu] could be before this quote, 1634 * and we don't want this numeric char to processed as 1635 * part of the escape. 1636 */ 1637 newtemp[j++] = '\\'; 1638 newtemp[j++] = 'x'; 1639 newtemp[j++] = '3'; 1640 } 1641 newtemp[j++] = c; 1642 } else if (c != '\\') { 1643 if (inQuote) newtemp[j++] = '\\'; 1644 newtemp[j++] = c; 1645 } else if (inQuote) { 1646 if (temp[i] == 'E') { 1647 i++; 1648 inQuote = false; 1649 } else { 1650 newtemp[j++] = '\\'; 1651 newtemp[j++] = '\\'; 1652 } 1653 } else { 1654 if (temp[i] == 'Q') { 1655 i++; 1656 inQuote = true; 1657 beginQuote = true; 1658 continue; 1659 } else { 1660 newtemp[j++] = c; 1661 if (i != pLen) 1662 newtemp[j++] = temp[i++]; 1663 } 1664 } 1665 1666 beginQuote = false; 1667 } 1668 1669 patternLength = j; 1670 temp = Arrays.copyOf(newtemp, j + 2); // double zero termination 1671 } 1672 1673 /** 1674 * Copies regular expression to an int array and invokes the parsing 1675 * of the expression which will create the object tree. 1676 */ 1677 private void compile() { 1678 // Handle canonical equivalences 1679 if (has(CANON_EQ) && !has(LITERAL)) { 1680 normalize(); 1681 } else { 1682 normalizedPattern = pattern; 1683 } 1684 patternLength = normalizedPattern.length(); 1685 1686 // Copy pattern to int array for convenience 1687 // Use double zero to terminate pattern 1688 temp = new int[patternLength + 2]; 1689 1690 hasSupplementary = false; 1691 int c, count = 0; 1692 // Convert all chars into code points 1693 for (int x = 0; x < patternLength; x += Character.charCount(c)) { 1694 c = normalizedPattern.codePointAt(x); 1695 if (isSupplementary(c)) { 1696 hasSupplementary = true; 1697 } 1698 temp[count++] = c; 1699 } 1700 1701 patternLength = count; // patternLength now in code points 1702 1703 if (! has(LITERAL)) 1704 RemoveQEQuoting(); 1705 1706 // Allocate all temporary objects here. 1707 buffer = new int[32]; 1708 groupNodes = new GroupHead[10]; 1709 namedGroups = null; 1710 1711 if (has(LITERAL)) { 1712 // Literal pattern handling 1713 matchRoot = newSlice(temp, patternLength, hasSupplementary); 1714 matchRoot.next = lastAccept; 1715 } else { 1716 // Start recursive descent parsing 1717 matchRoot = expr(lastAccept); 1718 // Check extra pattern characters 1719 if (patternLength != cursor) { 1720 if (peek() == ')') { 1721 throw error("Unmatched closing ')'"); 1722 } else { 1723 throw error("Unexpected internal error"); 1724 } 1725 } 1726 } 1727 1728 // Peephole optimization 1729 if (matchRoot instanceof Slice) { 1730 root = BnM.optimize(matchRoot); 1731 if (root == matchRoot) { 1732 root = hasSupplementary ? new StartS(matchRoot) : new Start(matchRoot); 1733 } 1734 } else if (matchRoot instanceof Begin || matchRoot instanceof First) { 1735 root = matchRoot; 1736 } else { 1737 root = hasSupplementary ? new StartS(matchRoot) : new Start(matchRoot); 1738 } 1739 1740 // Release temporary storage 1741 temp = null; 1742 buffer = null; 1743 groupNodes = null; 1744 patternLength = 0; 1745 compiled = true; 1746 } 1747 1748 Map<String, Integer> namedGroups() { 1749 Map<String, Integer> groups = namedGroups; 1750 if (groups == null) { 1751 namedGroups = groups = new HashMap<>(2); 1752 } 1753 return groups; 1754 } 1755 1756 /** 1757 * Used to print out a subtree of the Pattern to help with debugging. 1758 */ 1759 private static void printObjectTree(Node node) { 1760 while(node != null) { 1761 if (node instanceof Prolog) { 1762 System.out.println(node); 1763 printObjectTree(((Prolog)node).loop); 1764 System.out.println("**** end contents prolog loop"); 1765 } else if (node instanceof Loop) { 1766 System.out.println(node); 1767 printObjectTree(((Loop)node).body); 1768 System.out.println("**** end contents Loop body"); 1769 } else if (node instanceof Curly) { 1770 System.out.println(node); 1771 printObjectTree(((Curly)node).atom); 1772 System.out.println("**** end contents Curly body"); 1773 } else if (node instanceof GroupCurly) { 1774 System.out.println(node); 1775 printObjectTree(((GroupCurly)node).atom); 1776 System.out.println("**** end contents GroupCurly body"); 1777 } else if (node instanceof GroupTail) { 1778 System.out.println(node); 1779 System.out.println("Tail next is "+node.next); 1780 return; 1781 } else { 1782 System.out.println(node); 1783 } 1784 node = node.next; 1785 if (node != null) 1786 System.out.println("->next:"); 1787 if (node == Pattern.accept) { 1788 System.out.println("Accept Node"); 1789 node = null; 1790 } 1791 } 1792 } 1793 1794 /** 1795 * Used to accumulate information about a subtree of the object graph 1796 * so that optimizations can be applied to the subtree. 1797 */ 1798 static final class TreeInfo { 1799 int minLength; 1800 int maxLength; 1801 boolean maxValid; 1802 boolean deterministic; 1803 1804 TreeInfo() { 1805 reset(); 1806 } 1807 void reset() { 1808 minLength = 0; 1809 maxLength = 0; 1810 maxValid = true; 1811 deterministic = true; 1812 } 1813 } 1814 1815 /* 1816 * The following private methods are mainly used to improve the 1817 * readability of the code. In order to let the Java compiler easily 1818 * inline them, we should not put many assertions or error checks in them. 1819 */ 1820 1821 /** 1822 * Indicates whether a particular flag is set or not. 1823 */ 1824 private boolean has(int f) { 1825 return (flags & f) != 0; 1826 } 1827 1828 /** 1829 * Match next character, signal error if failed. 1830 */ 1831 private void accept(int ch, String s) { 1832 int testChar = temp[cursor++]; 1833 if (has(COMMENTS)) 1834 testChar = parsePastWhitespace(testChar); 1835 if (ch != testChar) { 1836 throw error(s); 1837 } 1838 } 1839 1840 /** 1841 * Mark the end of pattern with a specific character. 1842 */ 1843 private void mark(int c) { 1844 temp[patternLength] = c; 1845 } 1846 1847 /** 1848 * Peek the next character, and do not advance the cursor. 1849 */ 1850 private int peek() { 1851 int ch = temp[cursor]; 1852 if (has(COMMENTS)) 1853 ch = peekPastWhitespace(ch); 1854 return ch; 1855 } 1856 1857 /** 1858 * Read the next character, and advance the cursor by one. 1859 */ 1860 private int read() { 1861 int ch = temp[cursor++]; 1862 if (has(COMMENTS)) 1863 ch = parsePastWhitespace(ch); 1864 return ch; 1865 } 1866 1867 /** 1868 * Read the next character, and advance the cursor by one, 1869 * ignoring the COMMENTS setting 1870 */ 1871 private int readEscaped() { 1872 int ch = temp[cursor++]; 1873 return ch; 1874 } 1875 1876 /** 1877 * Advance the cursor by one, and peek the next character. 1878 */ 1879 private int next() { 1880 int ch = temp[++cursor]; 1881 if (has(COMMENTS)) 1882 ch = peekPastWhitespace(ch); 1883 return ch; 1884 } 1885 1886 /** 1887 * Advance the cursor by one, and peek the next character, 1888 * ignoring the COMMENTS setting 1889 */ 1890 private int nextEscaped() { 1891 int ch = temp[++cursor]; 1892 return ch; 1893 } 1894 1895 /** 1896 * If in xmode peek past whitespace and comments. 1897 */ 1898 private int peekPastWhitespace(int ch) { 1899 while (ASCII.isSpace(ch) || ch == '#') { 1900 while (ASCII.isSpace(ch)) 1901 ch = temp[++cursor]; 1902 if (ch == '#') { 1903 ch = peekPastLine(); 1904 } 1905 } 1906 return ch; 1907 } 1908 1909 /** 1910 * If in xmode parse past whitespace and comments. 1911 */ 1912 private int parsePastWhitespace(int ch) { 1913 while (ASCII.isSpace(ch) || ch == '#') { 1914 while (ASCII.isSpace(ch)) 1915 ch = temp[cursor++]; 1916 if (ch == '#') 1917 ch = parsePastLine(); 1918 } 1919 return ch; 1920 } 1921 1922 /** 1923 * xmode parse past comment to end of line. 1924 */ 1925 private int parsePastLine() { 1926 int ch = temp[cursor++]; 1927 while (ch != 0 && !isLineSeparator(ch)) 1928 ch = temp[cursor++]; 1929 return ch; 1930 } 1931 1932 /** 1933 * xmode peek past comment to end of line. 1934 */ 1935 private int peekPastLine() { 1936 int ch = temp[++cursor]; 1937 while (ch != 0 && !isLineSeparator(ch)) 1938 ch = temp[++cursor]; 1939 return ch; 1940 } 1941 1942 /** 1943 * Determines if character is a line separator in the current mode 1944 */ 1945 private boolean isLineSeparator(int ch) { 1946 if (has(UNIX_LINES)) { 1947 return ch == '\n'; 1948 } else { 1949 return (ch == '\n' || 1950 ch == '\r' || 1951 (ch|1) == '\u2029' || 1952 ch == '\u0085'); 1953 } 1954 } 1955 1956 /** 1957 * Read the character after the next one, and advance the cursor by two. 1958 */ 1959 private int skip() { 1960 int i = cursor; 1961 int ch = temp[i+1]; 1962 cursor = i + 2; 1963 return ch; 1964 } 1965 1966 /** 1967 * Unread one next character, and retreat cursor by one. 1968 */ 1969 private void unread() { 1970 cursor--; 1971 } 1972 1973 /** 1974 * Internal method used for handling all syntax errors. The pattern is 1975 * displayed with a pointer to aid in locating the syntax error. 1976 */ 1977 private PatternSyntaxException error(String s) { 1978 return new PatternSyntaxException(s, normalizedPattern, cursor - 1); 1979 } 1980 1981 /** 1982 * Determines if there is any supplementary character or unpaired 1983 * surrogate in the specified range. 1984 */ 1985 private boolean findSupplementary(int start, int end) { 1986 for (int i = start; i < end; i++) { 1987 if (isSupplementary(temp[i])) 1988 return true; 1989 } 1990 return false; 1991 } 1992 1993 /** 1994 * Determines if the specified code point is a supplementary 1995 * character or unpaired surrogate. 1996 */ 1997 private static final boolean isSupplementary(int ch) { 1998 return ch >= Character.MIN_SUPPLEMENTARY_CODE_POINT || 1999 Character.isSurrogate((char)ch); 2000 } 2001 2002 /** 2003 * The following methods handle the main parsing. They are sorted 2004 * according to their precedence order, the lowest one first. 2005 */ 2006 2007 /** 2008 * The expression is parsed with branch nodes added for alternations. 2009 * This may be called recursively to parse sub expressions that may 2010 * contain alternations. 2011 */ 2012 private Node expr(Node end) { 2013 Node prev = null; 2014 Node firstTail = null; 2015 Branch branch = null; 2016 Node branchConn = null; 2017 2018 for (;;) { 2019 Node node = sequence(end); 2020 Node nodeTail = root; //double return 2021 if (prev == null) { 2022 prev = node; 2023 firstTail = nodeTail; 2024 } else { 2025 // Branch 2026 if (branchConn == null) { 2027 branchConn = new BranchConn(); 2028 branchConn.next = end; 2029 } 2030 if (node == end) { 2031 // if the node returned from sequence() is "end" 2032 // we have an empty expr, set a null atom into 2033 // the branch to indicate to go "next" directly. 2034 node = null; 2035 } else { 2036 // the "tail.next" of each atom goes to branchConn 2037 nodeTail.next = branchConn; 2038 } 2039 if (prev == branch) { 2040 branch.add(node); 2041 } else { 2042 if (prev == end) { 2043 prev = null; 2044 } else { 2045 // replace the "end" with "branchConn" at its tail.next 2046 // when put the "prev" into the branch as the first atom. 2047 firstTail.next = branchConn; 2048 } 2049 prev = branch = new Branch(prev, node, branchConn); 2050 } 2051 } 2052 if (peek() != '|') { 2053 return prev; 2054 } 2055 next(); 2056 } 2057 } 2058 2059 @SuppressWarnings("fallthrough") 2060 /** 2061 * Parsing of sequences between alternations. 2062 */ 2063 private Node sequence(Node end) { 2064 Node head = null; 2065 Node tail = null; 2066 Node node = null; 2067 LOOP: 2068 for (;;) { 2069 int ch = peek(); 2070 switch (ch) { 2071 case '(': 2072 // Because group handles its own closure, 2073 // we need to treat it differently 2074 node = group0(); 2075 // Check for comment or flag group 2076 if (node == null) 2077 continue; 2078 if (head == null) 2079 head = node; 2080 else 2081 tail.next = node; 2082 // Double return: Tail was returned in root 2083 tail = root; 2084 continue; 2085 case '[': 2086 node = clazz(true); 2087 break; 2088 case '\\': 2089 ch = nextEscaped(); 2090 if (ch == 'p' || ch == 'P') { 2091 boolean oneLetter = true; 2092 boolean comp = (ch == 'P'); 2093 ch = next(); // Consume { if present 2094 if (ch != '{') { 2095 unread(); 2096 } else { 2097 oneLetter = false; 2098 } 2099 node = family(oneLetter, comp); 2100 } else { 2101 unread(); 2102 node = atom(); 2103 } 2104 break; 2105 case '^': 2106 next(); 2107 if (has(MULTILINE)) { 2108 if (has(UNIX_LINES)) 2109 node = new UnixCaret(); 2110 else 2111 node = new Caret(); 2112 } else { 2113 node = new Begin(); 2114 } 2115 break; 2116 case '$': 2117 next(); 2118 if (has(UNIX_LINES)) 2119 node = new UnixDollar(has(MULTILINE)); 2120 else 2121 node = new Dollar(has(MULTILINE)); 2122 break; 2123 case '.': 2124 next(); 2125 if (has(DOTALL)) { 2126 node = new All(); 2127 } else { 2128 if (has(UNIX_LINES)) 2129 node = new UnixDot(); 2130 else { 2131 node = new Dot(); 2132 } 2133 } 2134 break; 2135 case '|': 2136 case ')': 2137 break LOOP; 2138 case ']': // Now interpreting dangling ] and } as literals 2139 case '}': 2140 node = atom(); 2141 break; 2142 case '?': 2143 case '*': 2144 case '+': 2145 next(); 2146 throw error("Dangling meta character '" + ((char)ch) + "'"); 2147 case 0: 2148 if (cursor >= patternLength) { 2149 break LOOP; 2150 } 2151 // Fall through 2152 default: 2153 node = atom(); 2154 break; 2155 } 2156 2157 node = closure(node); 2158 2159 if (head == null) { 2160 head = tail = node; 2161 } else { 2162 tail.next = node; 2163 tail = node; 2164 } 2165 } 2166 if (head == null) { 2167 return end; 2168 } 2169 tail.next = end; 2170 root = tail; //double return 2171 return head; 2172 } 2173 2174 @SuppressWarnings("fallthrough") 2175 /** 2176 * Parse and add a new Single or Slice. 2177 */ 2178 private Node atom() { 2179 int first = 0; 2180 int prev = -1; 2181 boolean hasSupplementary = false; 2182 int ch = peek(); 2183 for (;;) { 2184 switch (ch) { 2185 case '*': 2186 case '+': 2187 case '?': 2188 case '{': 2189 if (first > 1) { 2190 cursor = prev; // Unwind one character 2191 first--; 2192 } 2193 break; 2194 case '$': 2195 case '.': 2196 case '^': 2197 case '(': 2198 case '[': 2199 case '|': 2200 case ')': 2201 break; 2202 case '\\': 2203 ch = nextEscaped(); 2204 if (ch == 'p' || ch == 'P') { // Property 2205 if (first > 0) { // Slice is waiting; handle it first 2206 unread(); 2207 break; 2208 } else { // No slice; just return the family node 2209 boolean comp = (ch == 'P'); 2210 boolean oneLetter = true; 2211 ch = next(); // Consume { if present 2212 if (ch != '{') 2213 unread(); 2214 else 2215 oneLetter = false; 2216 return family(oneLetter, comp); 2217 } 2218 } 2219 unread(); 2220 prev = cursor; 2221 ch = escape(false, first == 0, false); 2222 if (ch >= 0) { 2223 append(ch, first); 2224 first++; 2225 if (isSupplementary(ch)) { 2226 hasSupplementary = true; 2227 } 2228 ch = peek(); 2229 continue; 2230 } else if (first == 0) { 2231 return root; 2232 } 2233 // Unwind meta escape sequence 2234 cursor = prev; 2235 break; 2236 case 0: 2237 if (cursor >= patternLength) { 2238 break; 2239 } 2240 // Fall through 2241 default: 2242 prev = cursor; 2243 append(ch, first); 2244 first++; 2245 if (isSupplementary(ch)) { 2246 hasSupplementary = true; 2247 } 2248 ch = next(); 2249 continue; 2250 } 2251 break; 2252 } 2253 if (first == 1) { 2254 return newSingle(buffer[0]); 2255 } else { 2256 return newSlice(buffer, first, hasSupplementary); 2257 } 2258 } 2259 2260 private void append(int ch, int len) { 2261 if (len >= buffer.length) { 2262 int[] tmp = new int[len+len]; 2263 System.arraycopy(buffer, 0, tmp, 0, len); 2264 buffer = tmp; 2265 } 2266 buffer[len] = ch; 2267 } 2268 2269 /** 2270 * Parses a backref greedily, taking as many numbers as it 2271 * can. The first digit is always treated as a backref, but 2272 * multi digit numbers are only treated as a backref if at 2273 * least that many backrefs exist at this point in the regex. 2274 */ 2275 private Node ref(int refNum) { 2276 boolean done = false; 2277 while(!done) { 2278 int ch = peek(); 2279 switch(ch) { 2280 case '0': 2281 case '1': 2282 case '2': 2283 case '3': 2284 case '4': 2285 case '5': 2286 case '6': 2287 case '7': 2288 case '8': 2289 case '9': 2290 int newRefNum = (refNum * 10) + (ch - '0'); 2291 // Add another number if it doesn't make a group 2292 // that doesn't exist 2293 if (capturingGroupCount - 1 < newRefNum) { 2294 done = true; 2295 break; 2296 } 2297 refNum = newRefNum; 2298 read(); 2299 break; 2300 default: 2301 done = true; 2302 break; 2303 } 2304 } 2305 if (has(CASE_INSENSITIVE)) 2306 return new CIBackRef(refNum, has(UNICODE_CASE)); 2307 else 2308 return new BackRef(refNum); 2309 } 2310 2311 /** 2312 * Parses an escape sequence to determine the actual value that needs 2313 * to be matched. 2314 * If -1 is returned and create was true a new object was added to the tree 2315 * to handle the escape sequence. 2316 * If the returned value is greater than zero, it is the value that 2317 * matches the escape sequence. 2318 */ 2319 private int escape(boolean inclass, boolean create, boolean isrange) { 2320 int ch = skip(); 2321 switch (ch) { 2322 case '0': 2323 return o(); 2324 case '1': 2325 case '2': 2326 case '3': 2327 case '4': 2328 case '5': 2329 case '6': 2330 case '7': 2331 case '8': 2332 case '9': 2333 if (inclass) break; 2334 if (create) { 2335 root = ref((ch - '0')); 2336 } 2337 return -1; 2338 case 'A': 2339 if (inclass) break; 2340 if (create) root = new Begin(); 2341 return -1; 2342 case 'B': 2343 if (inclass) break; 2344 if (create) root = new Bound(Bound.NONE, has(UNICODE_CHARACTER_CLASS)); 2345 return -1; 2346 case 'C': 2347 break; 2348 case 'D': 2349 if (create) root = has(UNICODE_CHARACTER_CLASS) 2350 ? new Utype(UnicodeProp.DIGIT).complement() 2351 : new Ctype(ASCII.DIGIT).complement(); 2352 return -1; 2353 case 'E': 2354 case 'F': 2355 break; 2356 case 'G': 2357 if (inclass) break; 2358 if (create) root = new LastMatch(); 2359 return -1; 2360 case 'H': 2361 if (create) root = new HorizWS().complement(); 2362 return -1; 2363 case 'I': 2364 case 'J': 2365 case 'K': 2366 case 'L': 2367 case 'M': 2368 break; 2369 case 'N': 2370 return N(); 2371 case 'O': 2372 case 'P': 2373 case 'Q': 2374 break; 2375 case 'R': 2376 if (inclass) break; 2377 if (create) root = new LineEnding(); 2378 return -1; 2379 case 'S': 2380 if (create) root = has(UNICODE_CHARACTER_CLASS) 2381 ? new Utype(UnicodeProp.WHITE_SPACE).complement() 2382 : new Ctype(ASCII.SPACE).complement(); 2383 return -1; 2384 case 'T': 2385 case 'U': 2386 break; 2387 case 'V': 2388 if (create) root = new VertWS().complement(); 2389 return -1; 2390 case 'W': 2391 if (create) root = has(UNICODE_CHARACTER_CLASS) 2392 ? new Utype(UnicodeProp.WORD).complement() 2393 : new Ctype(ASCII.WORD).complement(); 2394 return -1; 2395 case 'X': 2396 if (inclass) break; 2397 if (create) { 2398 root = new XGrapheme(); 2399 } 2400 return -1; 2401 case 'Y': 2402 break; 2403 case 'Z': 2404 if (inclass) break; 2405 if (create) { 2406 if (has(UNIX_LINES)) 2407 root = new UnixDollar(false); 2408 else 2409 root = new Dollar(false); 2410 } 2411 return -1; 2412 case 'a': 2413 return '\007'; 2414 case 'b': 2415 if (inclass) break; 2416 if (create) { 2417 if (peek() == '{') { 2418 if (skip() == 'g') { 2419 if (read() == '}') { 2420 root = new GraphemeBound(); 2421 return -1; 2422 } 2423 break; // error missing trailing } 2424 } 2425 unread(); unread(); 2426 } 2427 root = new Bound(Bound.BOTH, has(UNICODE_CHARACTER_CLASS)); 2428 } 2429 return -1; 2430 case 'c': 2431 return c(); 2432 case 'd': 2433 if (create) root = has(UNICODE_CHARACTER_CLASS) 2434 ? new Utype(UnicodeProp.DIGIT) 2435 : new Ctype(ASCII.DIGIT); 2436 return -1; 2437 case 'e': 2438 return '\033'; 2439 case 'f': 2440 return '\f'; 2441 case 'g': 2442 break; 2443 case 'h': 2444 if (create) root = new HorizWS(); 2445 return -1; 2446 case 'i': 2447 case 'j': 2448 break; 2449 case 'k': 2450 if (inclass) 2451 break; 2452 if (read() != '<') 2453 throw error("\\k is not followed by '<' for named capturing group"); 2454 String name = groupname(read()); 2455 if (!namedGroups().containsKey(name)) 2456 throw error("(named capturing group <"+ name+"> does not exit"); 2457 if (create) { 2458 if (has(CASE_INSENSITIVE)) 2459 root = new CIBackRef(namedGroups().get(name), has(UNICODE_CASE)); 2460 else 2461 root = new BackRef(namedGroups().get(name)); 2462 } 2463 return -1; 2464 case 'l': 2465 case 'm': 2466 break; 2467 case 'n': 2468 return '\n'; 2469 case 'o': 2470 case 'p': 2471 case 'q': 2472 break; 2473 case 'r': 2474 return '\r'; 2475 case 's': 2476 if (create) root = has(UNICODE_CHARACTER_CLASS) 2477 ? new Utype(UnicodeProp.WHITE_SPACE) 2478 : new Ctype(ASCII.SPACE); 2479 return -1; 2480 case 't': 2481 return '\t'; 2482 case 'u': 2483 return u(); 2484 case 'v': 2485 // '\v' was implemented as VT/0x0B in releases < 1.8 (though 2486 // undocumented). In JDK8 '\v' is specified as a predefined 2487 // character class for all vertical whitespace characters. 2488 // So [-1, root=VertWS node] pair is returned (instead of a 2489 // single 0x0B). This breaks the range if '\v' is used as 2490 // the start or end value, such as [\v-...] or [...-\v], in 2491 // which a single definite value (0x0B) is expected. For 2492 // compatibility concern '\013'/0x0B is returned if isrange. 2493 if (isrange) 2494 return '\013'; 2495 if (create) root = new VertWS(); 2496 return -1; 2497 case 'w': 2498 if (create) root = has(UNICODE_CHARACTER_CLASS) 2499 ? new Utype(UnicodeProp.WORD) 2500 : new Ctype(ASCII.WORD); 2501 return -1; 2502 case 'x': 2503 return x(); 2504 case 'y': 2505 break; 2506 case 'z': 2507 if (inclass) break; 2508 if (create) root = new End(); 2509 return -1; 2510 default: 2511 return ch; 2512 } 2513 throw error("Illegal/unsupported escape sequence"); 2514 } 2515 2516 /** 2517 * Parse a character class, and return the node that matches it. 2518 * 2519 * Consumes a ] on the way out if consume is true. Usually consume 2520 * is true except for the case of [abc&&def] where def is a separate 2521 * right hand node with "understood" brackets. 2522 */ 2523 private CharProperty clazz(boolean consume) { 2524 CharProperty prev = null; 2525 CharProperty node = null; 2526 BitClass bits = new BitClass(); 2527 boolean include = true; 2528 boolean firstInClass = true; 2529 int ch = next(); 2530 for (;;) { 2531 switch (ch) { 2532 case '^': 2533 // Negates if first char in a class, otherwise literal 2534 if (firstInClass) { 2535 if (temp[cursor-1] != '[') 2536 break; 2537 ch = next(); 2538 include = !include; 2539 continue; 2540 } else { 2541 // ^ not first in class, treat as literal 2542 break; 2543 } 2544 case '[': 2545 firstInClass = false; 2546 node = clazz(true); 2547 if (prev == null) 2548 prev = node; 2549 else 2550 prev = union(prev, node); 2551 ch = peek(); 2552 continue; 2553 case '&': 2554 firstInClass = false; 2555 ch = next(); 2556 if (ch == '&') { 2557 ch = next(); 2558 CharProperty rightNode = null; 2559 while (ch != ']' && ch != '&') { 2560 if (ch == '[') { 2561 if (rightNode == null) 2562 rightNode = clazz(true); 2563 else 2564 rightNode = union(rightNode, clazz(true)); 2565 } else { // abc&&def 2566 unread(); 2567 rightNode = clazz(false); 2568 } 2569 ch = peek(); 2570 } 2571 if (rightNode != null) 2572 node = rightNode; 2573 if (prev == null) { 2574 if (rightNode == null) 2575 throw error("Bad class syntax"); 2576 else 2577 prev = rightNode; 2578 } else { 2579 prev = intersection(prev, node); 2580 } 2581 } else { 2582 // treat as a literal & 2583 unread(); 2584 break; 2585 } 2586 continue; 2587 case 0: 2588 firstInClass = false; 2589 if (cursor >= patternLength) 2590 throw error("Unclosed character class"); 2591 break; 2592 case ']': 2593 firstInClass = false; 2594 if (prev != null) { 2595 if (consume) 2596 next(); 2597 return prev; 2598 } 2599 break; 2600 default: 2601 firstInClass = false; 2602 break; 2603 } 2604 node = range(bits); 2605 if (include) { 2606 if (prev == null) { 2607 prev = node; 2608 } else { 2609 if (prev != node) 2610 prev = union(prev, node); 2611 } 2612 } else { 2613 if (prev == null) { 2614 prev = node.complement(); 2615 } else { 2616 if (prev != node) 2617 prev = setDifference(prev, node); 2618 } 2619 } 2620 ch = peek(); 2621 } 2622 } 2623 2624 private CharProperty bitsOrSingle(BitClass bits, int ch) { 2625 /* Bits can only handle codepoints in [u+0000-u+00ff] range. 2626 Use "single" node instead of bits when dealing with unicode 2627 case folding for codepoints listed below. 2628 (1)Uppercase out of range: u+00ff, u+00b5 2629 toUpperCase(u+00ff) -> u+0178 2630 toUpperCase(u+00b5) -> u+039c 2631 (2)LatinSmallLetterLongS u+17f 2632 toUpperCase(u+017f) -> u+0053 2633 (3)LatinSmallLetterDotlessI u+131 2634 toUpperCase(u+0131) -> u+0049 2635 (4)LatinCapitalLetterIWithDotAbove u+0130 2636 toLowerCase(u+0130) -> u+0069 2637 (5)KelvinSign u+212a 2638 toLowerCase(u+212a) ==> u+006B 2639 (6)AngstromSign u+212b 2640 toLowerCase(u+212b) ==> u+00e5 2641 */ 2642 int d; 2643 if (ch < 256 && 2644 !(has(CASE_INSENSITIVE) && has(UNICODE_CASE) && 2645 (ch == 0xff || ch == 0xb5 || 2646 ch == 0x49 || ch == 0x69 || //I and i 2647 ch == 0x53 || ch == 0x73 || //S and s 2648 ch == 0x4b || ch == 0x6b || //K and k 2649 ch == 0xc5 || ch == 0xe5))) //A+ring 2650 return bits.add(ch, flags()); 2651 return newSingle(ch); 2652 } 2653 2654 /** 2655 * Parse a single character or a character range in a character class 2656 * and return its representative node. 2657 */ 2658 private CharProperty range(BitClass bits) { 2659 int ch = peek(); 2660 if (ch == '\\') { 2661 ch = nextEscaped(); 2662 if (ch == 'p' || ch == 'P') { // A property 2663 boolean comp = (ch == 'P'); 2664 boolean oneLetter = true; 2665 // Consume { if present 2666 ch = next(); 2667 if (ch != '{') 2668 unread(); 2669 else 2670 oneLetter = false; 2671 return family(oneLetter, comp); 2672 } else { // ordinary escape 2673 boolean isrange = temp[cursor+1] == '-'; 2674 unread(); 2675 ch = escape(true, true, isrange); 2676 if (ch == -1) 2677 return (CharProperty) root; 2678 } 2679 } else { 2680 next(); 2681 } 2682 if (ch >= 0) { 2683 if (peek() == '-') { 2684 int endRange = temp[cursor+1]; 2685 if (endRange == '[') { 2686 return bitsOrSingle(bits, ch); 2687 } 2688 if (endRange != ']') { 2689 next(); 2690 int m = peek(); 2691 if (m == '\\') { 2692 m = escape(true, false, true); 2693 } else { 2694 next(); 2695 } 2696 if (m < ch) { 2697 throw error("Illegal character range"); 2698 } 2699 if (has(CASE_INSENSITIVE)) 2700 return caseInsensitiveRangeFor(ch, m); 2701 else 2702 return rangeFor(ch, m); 2703 } 2704 } 2705 return bitsOrSingle(bits, ch); 2706 } 2707 throw error("Unexpected character '"+((char)ch)+"'"); 2708 } 2709 2710 /** 2711 * Parses a Unicode character family and returns its representative node. 2712 */ 2713 private CharProperty family(boolean singleLetter, 2714 boolean maybeComplement) 2715 { 2716 next(); 2717 String name; 2718 CharProperty node = null; 2719 2720 if (singleLetter) { 2721 int c = temp[cursor]; 2722 if (!Character.isSupplementaryCodePoint(c)) { 2723 name = String.valueOf((char)c); 2724 } else { 2725 name = new String(temp, cursor, 1); 2726 } 2727 read(); 2728 } else { 2729 int i = cursor; 2730 mark('}'); 2731 while(read() != '}') { 2732 } 2733 mark('\000'); 2734 int j = cursor; 2735 if (j > patternLength) 2736 throw error("Unclosed character family"); 2737 if (i + 1 >= j) 2738 throw error("Empty character family"); 2739 name = new String(temp, i, j-i-1); 2740 } 2741 2742 int i = name.indexOf('='); 2743 if (i != -1) { 2744 // property construct \p{name=value} 2745 String value = name.substring(i + 1); 2746 name = name.substring(0, i).toLowerCase(Locale.ENGLISH); 2747 switch (name) { 2748 case "sc": 2749 case "script": 2750 node = unicodeScriptPropertyFor(value); 2751 break; 2752 case "blk": 2753 case "block": 2754 node = unicodeBlockPropertyFor(value); 2755 break; 2756 case "gc": 2757 case "general_category": 2758 node = charPropertyNodeFor(value); 2759 break; 2760 default: 2761 throw error("Unknown Unicode property {name=<" + name + ">, " 2762 + "value=<" + value + ">}"); 2763 } 2764 } else { 2765 if (name.startsWith("In")) { 2766 // \p{inBlockName} 2767 node = unicodeBlockPropertyFor(name.substring(2)); 2768 } else if (name.startsWith("Is")) { 2769 // \p{isGeneralCategory} and \p{isScriptName} 2770 name = name.substring(2); 2771 UnicodeProp uprop = UnicodeProp.forName(name); 2772 if (uprop != null) 2773 node = new Utype(uprop); 2774 if (node == null) 2775 node = CharPropertyNames.charPropertyFor(name); 2776 if (node == null) 2777 node = unicodeScriptPropertyFor(name); 2778 } else { 2779 if (has(UNICODE_CHARACTER_CLASS)) { 2780 UnicodeProp uprop = UnicodeProp.forPOSIXName(name); 2781 if (uprop != null) 2782 node = new Utype(uprop); 2783 } 2784 if (node == null) 2785 node = charPropertyNodeFor(name); 2786 } 2787 } 2788 if (maybeComplement) { 2789 if (node instanceof Category || node instanceof Block) 2790 hasSupplementary = true; 2791 node = node.complement(); 2792 } 2793 return node; 2794 } 2795 2796 2797 /** 2798 * Returns a CharProperty matching all characters belong to 2799 * a UnicodeScript. 2800 */ 2801 private CharProperty unicodeScriptPropertyFor(String name) { 2802 final Character.UnicodeScript script; 2803 try { 2804 script = Character.UnicodeScript.forName(name); 2805 } catch (IllegalArgumentException iae) { 2806 throw error("Unknown character script name {" + name + "}"); 2807 } 2808 return new Script(script); 2809 } 2810 2811 /** 2812 * Returns a CharProperty matching all characters in a UnicodeBlock. 2813 */ 2814 private CharProperty unicodeBlockPropertyFor(String name) { 2815 final Character.UnicodeBlock block; 2816 try { 2817 block = Character.UnicodeBlock.forName(name); 2818 } catch (IllegalArgumentException iae) { 2819 throw error("Unknown character block name {" + name + "}"); 2820 } 2821 return new Block(block); 2822 } 2823 2824 /** 2825 * Returns a CharProperty matching all characters in a named property. 2826 */ 2827 private CharProperty charPropertyNodeFor(String name) { 2828 CharProperty p = CharPropertyNames.charPropertyFor(name); 2829 if (p == null) 2830 throw error("Unknown character property name {" + name + "}"); 2831 return p; 2832 } 2833 2834 /** 2835 * Parses and returns the name of a "named capturing group", the trailing 2836 * ">" is consumed after parsing. 2837 */ 2838 private String groupname(int ch) { 2839 StringBuilder sb = new StringBuilder(); 2840 sb.append(Character.toChars(ch)); 2841 while (ASCII.isLower(ch=read()) || ASCII.isUpper(ch) || 2842 ASCII.isDigit(ch)) { 2843 sb.append(Character.toChars(ch)); 2844 } 2845 if (sb.length() == 0) 2846 throw error("named capturing group has 0 length name"); 2847 if (ch != '>') 2848 throw error("named capturing group is missing trailing '>'"); 2849 return sb.toString(); 2850 } 2851 2852 /** 2853 * Parses a group and returns the head node of a set of nodes that process 2854 * the group. Sometimes a double return system is used where the tail is 2855 * returned in root. 2856 */ 2857 private Node group0() { 2858 boolean capturingGroup = false; 2859 Node head = null; 2860 Node tail = null; 2861 int save = flags; 2862 root = null; 2863 int ch = next(); 2864 if (ch == '?') { 2865 ch = skip(); 2866 switch (ch) { 2867 case ':': // (?:xxx) pure group 2868 head = createGroup(true); 2869 tail = root; 2870 head.next = expr(tail); 2871 break; 2872 case '=': // (?=xxx) and (?!xxx) lookahead 2873 case '!': 2874 head = createGroup(true); 2875 tail = root; 2876 head.next = expr(tail); 2877 if (ch == '=') { 2878 head = tail = new Pos(head); 2879 } else { 2880 head = tail = new Neg(head); 2881 } 2882 break; 2883 case '>': // (?>xxx) independent group 2884 head = createGroup(true); 2885 tail = root; 2886 head.next = expr(tail); 2887 head = tail = new Ques(head, INDEPENDENT); 2888 break; 2889 case '<': // (?<xxx) look behind 2890 ch = read(); 2891 if (ASCII.isLower(ch) || ASCII.isUpper(ch)) { 2892 // named captured group 2893 String name = groupname(ch); 2894 if (namedGroups().containsKey(name)) 2895 throw error("Named capturing group <" + name 2896 + "> is already defined"); 2897 capturingGroup = true; 2898 head = createGroup(false); 2899 tail = root; 2900 namedGroups().put(name, capturingGroupCount-1); 2901 head.next = expr(tail); 2902 break; 2903 } 2904 int start = cursor; 2905 head = createGroup(true); 2906 tail = root; 2907 head.next = expr(tail); 2908 tail.next = lookbehindEnd; 2909 TreeInfo info = new TreeInfo(); 2910 head.study(info); 2911 if (info.maxValid == false) { 2912 throw error("Look-behind group does not have " 2913 + "an obvious maximum length"); 2914 } 2915 boolean hasSupplementary = findSupplementary(start, patternLength); 2916 if (ch == '=') { 2917 head = tail = (hasSupplementary ? 2918 new BehindS(head, info.maxLength, 2919 info.minLength) : 2920 new Behind(head, info.maxLength, 2921 info.minLength)); 2922 } else if (ch == '!') { 2923 head = tail = (hasSupplementary ? 2924 new NotBehindS(head, info.maxLength, 2925 info.minLength) : 2926 new NotBehind(head, info.maxLength, 2927 info.minLength)); 2928 } else { 2929 throw error("Unknown look-behind group"); 2930 } 2931 break; 2932 case '$': 2933 case '@': 2934 throw error("Unknown group type"); 2935 default: // (?xxx:) inlined match flags 2936 unread(); 2937 addFlag(); 2938 ch = read(); 2939 if (ch == ')') { 2940 return null; // Inline modifier only 2941 } 2942 if (ch != ':') { 2943 throw error("Unknown inline modifier"); 2944 } 2945 head = createGroup(true); 2946 tail = root; 2947 head.next = expr(tail); 2948 break; 2949 } 2950 } else { // (xxx) a regular group 2951 capturingGroup = true; 2952 head = createGroup(false); 2953 tail = root; 2954 head.next = expr(tail); 2955 } 2956 2957 accept(')', "Unclosed group"); 2958 flags = save; 2959 2960 // Check for quantifiers 2961 Node node = closure(head); 2962 if (node == head) { // No closure 2963 root = tail; 2964 return node; // Dual return 2965 } 2966 if (head == tail) { // Zero length assertion 2967 root = node; 2968 return node; // Dual return 2969 } 2970 2971 if (node instanceof Ques) { 2972 Ques ques = (Ques) node; 2973 if (ques.type == POSSESSIVE) { 2974 root = node; 2975 return node; 2976 } 2977 tail.next = new BranchConn(); 2978 tail = tail.next; 2979 if (ques.type == GREEDY) { 2980 head = new Branch(head, null, tail); 2981 } else { // Reluctant quantifier 2982 head = new Branch(null, head, tail); 2983 } 2984 root = tail; 2985 return head; 2986 } else if (node instanceof Curly) { 2987 Curly curly = (Curly) node; 2988 if (curly.type == POSSESSIVE) { 2989 root = node; 2990 return node; 2991 } 2992 // Discover if the group is deterministic 2993 TreeInfo info = new TreeInfo(); 2994 if (head.study(info)) { // Deterministic 2995 GroupTail temp = (GroupTail) tail; 2996 head = root = new GroupCurly(head.next, curly.cmin, 2997 curly.cmax, curly.type, 2998 ((GroupTail)tail).localIndex, 2999 ((GroupTail)tail).groupIndex, 3000 capturingGroup); 3001 return head; 3002 } else { // Non-deterministic 3003 int temp = ((GroupHead) head).localIndex; 3004 Loop loop; 3005 if (curly.type == GREEDY) 3006 loop = new Loop(this.localCount, temp); 3007 else // Reluctant Curly 3008 loop = new LazyLoop(this.localCount, temp); 3009 Prolog prolog = new Prolog(loop); 3010 this.localCount += 1; 3011 loop.cmin = curly.cmin; 3012 loop.cmax = curly.cmax; 3013 loop.body = head; 3014 tail.next = loop; 3015 root = loop; 3016 return prolog; // Dual return 3017 } 3018 } 3019 throw error("Internal logic error"); 3020 } 3021 3022 /** 3023 * Create group head and tail nodes using double return. If the group is 3024 * created with anonymous true then it is a pure group and should not 3025 * affect group counting. 3026 */ 3027 private Node createGroup(boolean anonymous) { 3028 int localIndex = localCount++; 3029 int groupIndex = 0; 3030 if (!anonymous) 3031 groupIndex = capturingGroupCount++; 3032 GroupHead head = new GroupHead(localIndex); 3033 root = new GroupTail(localIndex, groupIndex); 3034 if (!anonymous && groupIndex < 10) 3035 groupNodes[groupIndex] = head; 3036 return head; 3037 } 3038 3039 @SuppressWarnings("fallthrough") 3040 /** 3041 * Parses inlined match flags and set them appropriately. 3042 */ 3043 private void addFlag() { 3044 int ch = peek(); 3045 for (;;) { 3046 switch (ch) { 3047 case 'i': 3048 flags |= CASE_INSENSITIVE; 3049 break; 3050 case 'm': 3051 flags |= MULTILINE; 3052 break; 3053 case 's': 3054 flags |= DOTALL; 3055 break; 3056 case 'd': 3057 flags |= UNIX_LINES; 3058 break; 3059 case 'u': 3060 flags |= UNICODE_CASE; 3061 break; 3062 case 'c': 3063 flags |= CANON_EQ; 3064 break; 3065 case 'x': 3066 flags |= COMMENTS; 3067 break; 3068 case 'U': 3069 flags |= (UNICODE_CHARACTER_CLASS | UNICODE_CASE); 3070 break; 3071 case '-': // subFlag then fall through 3072 ch = next(); 3073 subFlag(); 3074 default: 3075 return; 3076 } 3077 ch = next(); 3078 } 3079 } 3080 3081 @SuppressWarnings("fallthrough") 3082 /** 3083 * Parses the second part of inlined match flags and turns off 3084 * flags appropriately. 3085 */ 3086 private void subFlag() { 3087 int ch = peek(); 3088 for (;;) { 3089 switch (ch) { 3090 case 'i': 3091 flags &= ~CASE_INSENSITIVE; 3092 break; 3093 case 'm': 3094 flags &= ~MULTILINE; 3095 break; 3096 case 's': 3097 flags &= ~DOTALL; 3098 break; 3099 case 'd': 3100 flags &= ~UNIX_LINES; 3101 break; 3102 case 'u': 3103 flags &= ~UNICODE_CASE; 3104 break; 3105 case 'c': 3106 flags &= ~CANON_EQ; 3107 break; 3108 case 'x': 3109 flags &= ~COMMENTS; 3110 break; 3111 case 'U': 3112 flags &= ~(UNICODE_CHARACTER_CLASS | UNICODE_CASE); 3113 default: 3114 return; 3115 } 3116 ch = next(); 3117 } 3118 } 3119 3120 static final int MAX_REPS = 0x7FFFFFFF; 3121 3122 static final int GREEDY = 0; 3123 3124 static final int LAZY = 1; 3125 3126 static final int POSSESSIVE = 2; 3127 3128 static final int INDEPENDENT = 3; 3129 3130 /** 3131 * Processes repetition. If the next character peeked is a quantifier 3132 * then new nodes must be appended to handle the repetition. 3133 * Prev could be a single or a group, so it could be a chain of nodes. 3134 */ 3135 private Node closure(Node prev) { 3136 Node atom; 3137 int ch = peek(); 3138 switch (ch) { 3139 case '?': 3140 ch = next(); 3141 if (ch == '?') { 3142 next(); 3143 return new Ques(prev, LAZY); 3144 } else if (ch == '+') { 3145 next(); 3146 return new Ques(prev, POSSESSIVE); 3147 } 3148 return new Ques(prev, GREEDY); 3149 case '*': 3150 ch = next(); 3151 if (ch == '?') { 3152 next(); 3153 return new Curly(prev, 0, MAX_REPS, LAZY); 3154 } else if (ch == '+') { 3155 next(); 3156 return new Curly(prev, 0, MAX_REPS, POSSESSIVE); 3157 } 3158 return new Curly(prev, 0, MAX_REPS, GREEDY); 3159 case '+': 3160 ch = next(); 3161 if (ch == '?') { 3162 next(); 3163 return new Curly(prev, 1, MAX_REPS, LAZY); 3164 } else if (ch == '+') { 3165 next(); 3166 return new Curly(prev, 1, MAX_REPS, POSSESSIVE); 3167 } 3168 return new Curly(prev, 1, MAX_REPS, GREEDY); 3169 case '{': 3170 ch = temp[cursor+1]; 3171 if (ASCII.isDigit(ch)) { 3172 skip(); 3173 int cmin = 0; 3174 do { 3175 cmin = cmin * 10 + (ch - '0'); 3176 } while (ASCII.isDigit(ch = read())); 3177 int cmax = cmin; 3178 if (ch == ',') { 3179 ch = read(); 3180 cmax = MAX_REPS; 3181 if (ch != '}') { 3182 cmax = 0; 3183 while (ASCII.isDigit(ch)) { 3184 cmax = cmax * 10 + (ch - '0'); 3185 ch = read(); 3186 } 3187 } 3188 } 3189 if (ch != '}') 3190 throw error("Unclosed counted closure"); 3191 if (((cmin) | (cmax) | (cmax - cmin)) < 0) 3192 throw error("Illegal repetition range"); 3193 Curly curly; 3194 ch = peek(); 3195 if (ch == '?') { 3196 next(); 3197 curly = new Curly(prev, cmin, cmax, LAZY); 3198 } else if (ch == '+') { 3199 next(); 3200 curly = new Curly(prev, cmin, cmax, POSSESSIVE); 3201 } else { 3202 curly = new Curly(prev, cmin, cmax, GREEDY); 3203 } 3204 return curly; 3205 } else { 3206 throw error("Illegal repetition"); 3207 } 3208 default: 3209 return prev; 3210 } 3211 } 3212 3213 /** 3214 * Utility method for parsing control escape sequences. 3215 */ 3216 private int c() { 3217 if (cursor < patternLength) { 3218 return read() ^ 64; 3219 } 3220 throw error("Illegal control escape sequence"); 3221 } 3222 3223 /** 3224 * Utility method for parsing octal escape sequences. 3225 */ 3226 private int o() { 3227 int n = read(); 3228 if (((n-'0')|('7'-n)) >= 0) { 3229 int m = read(); 3230 if (((m-'0')|('7'-m)) >= 0) { 3231 int o = read(); 3232 if ((((o-'0')|('7'-o)) >= 0) && (((n-'0')|('3'-n)) >= 0)) { 3233 return (n - '0') * 64 + (m - '0') * 8 + (o - '0'); 3234 } 3235 unread(); 3236 return (n - '0') * 8 + (m - '0'); 3237 } 3238 unread(); 3239 return (n - '0'); 3240 } 3241 throw error("Illegal octal escape sequence"); 3242 } 3243 3244 /** 3245 * Utility method for parsing hexadecimal escape sequences. 3246 */ 3247 private int x() { 3248 int n = read(); 3249 if (ASCII.isHexDigit(n)) { 3250 int m = read(); 3251 if (ASCII.isHexDigit(m)) { 3252 return ASCII.toDigit(n) * 16 + ASCII.toDigit(m); 3253 } 3254 } else if (n == '{' && ASCII.isHexDigit(peek())) { 3255 int ch = 0; 3256 while (ASCII.isHexDigit(n = read())) { 3257 ch = (ch << 4) + ASCII.toDigit(n); 3258 if (ch > Character.MAX_CODE_POINT) 3259 throw error("Hexadecimal codepoint is too big"); 3260 } 3261 if (n != '}') 3262 throw error("Unclosed hexadecimal escape sequence"); 3263 return ch; 3264 } 3265 throw error("Illegal hexadecimal escape sequence"); 3266 } 3267 3268 /** 3269 * Utility method for parsing unicode escape sequences. 3270 */ 3271 private int cursor() { 3272 return cursor; 3273 } 3274 3275 private void setcursor(int pos) { 3276 cursor = pos; 3277 } 3278 3279 private int uxxxx() { 3280 int n = 0; 3281 for (int i = 0; i < 4; i++) { 3282 int ch = read(); 3283 if (!ASCII.isHexDigit(ch)) { 3284 throw error("Illegal Unicode escape sequence"); 3285 } 3286 n = n * 16 + ASCII.toDigit(ch); 3287 } 3288 return n; 3289 } 3290 3291 private int u() { 3292 int n = uxxxx(); 3293 if (Character.isHighSurrogate((char)n)) { 3294 int cur = cursor(); 3295 if (read() == '\\' && read() == 'u') { 3296 int n2 = uxxxx(); 3297 if (Character.isLowSurrogate((char)n2)) 3298 return Character.toCodePoint((char)n, (char)n2); 3299 } 3300 setcursor(cur); 3301 } 3302 return n; 3303 } 3304 3305 private int N() { 3306 if (read() == '{') { 3307 int i = cursor; 3308 while (cursor < patternLength && read() != '}') {} 3309 if (cursor > patternLength) 3310 throw error("Unclosed character name escape sequence"); 3311 String name = new String(temp, i, cursor - i - 1); 3312 try { 3313 return Character.codePointOf(name); 3314 } catch (IllegalArgumentException x) { 3315 throw error("Unknown character name [" + name + "]"); 3316 } 3317 } 3318 throw error("Illegal character name escape sequence"); 3319 } 3320 3321 // 3322 // Utility methods for code point support 3323 // 3324 private static final int countChars(CharSequence seq, int index, 3325 int lengthInCodePoints) { 3326 // optimization 3327 if (lengthInCodePoints == 1 && !Character.isHighSurrogate(seq.charAt(index))) { 3328 assert (index >= 0 && index < seq.length()); 3329 return 1; 3330 } 3331 int length = seq.length(); 3332 int x = index; 3333 if (lengthInCodePoints >= 0) { 3334 assert (index >= 0 && index < length); 3335 for (int i = 0; x < length && i < lengthInCodePoints; i++) { 3336 if (Character.isHighSurrogate(seq.charAt(x++))) { 3337 if (x < length && Character.isLowSurrogate(seq.charAt(x))) { 3338 x++; 3339 } 3340 } 3341 } 3342 return x - index; 3343 } 3344 3345 assert (index >= 0 && index <= length); 3346 if (index == 0) { 3347 return 0; 3348 } 3349 int len = -lengthInCodePoints; 3350 for (int i = 0; x > 0 && i < len; i++) { 3351 if (Character.isLowSurrogate(seq.charAt(--x))) { 3352 if (x > 0 && Character.isHighSurrogate(seq.charAt(x-1))) { 3353 x--; 3354 } 3355 } 3356 } 3357 return index - x; 3358 } 3359 3360 private static final int countCodePoints(CharSequence seq) { 3361 int length = seq.length(); 3362 int n = 0; 3363 for (int i = 0; i < length; ) { 3364 n++; 3365 if (Character.isHighSurrogate(seq.charAt(i++))) { 3366 if (i < length && Character.isLowSurrogate(seq.charAt(i))) { 3367 i++; 3368 } 3369 } 3370 } 3371 return n; 3372 } 3373 3374 /** 3375 * Creates a bit vector for matching Latin-1 values. A normal BitClass 3376 * never matches values above Latin-1, and a complemented BitClass always 3377 * matches values above Latin-1. 3378 */ 3379 private static final class BitClass extends BmpCharProperty { 3380 final boolean[] bits; 3381 BitClass() { bits = new boolean[256]; } 3382 private BitClass(boolean[] bits) { this.bits = bits; } 3383 BitClass add(int c, int flags) { 3384 assert c >= 0 && c <= 255; 3385 if ((flags & CASE_INSENSITIVE) != 0) { 3386 if (ASCII.isAscii(c)) { 3387 bits[ASCII.toUpper(c)] = true; 3388 bits[ASCII.toLower(c)] = true; 3389 } else if ((flags & UNICODE_CASE) != 0) { 3390 bits[Character.toLowerCase(c)] = true; 3391 bits[Character.toUpperCase(c)] = true; 3392 } 3393 } 3394 bits[c] = true; 3395 return this; 3396 } 3397 boolean isSatisfiedBy(int ch) { 3398 return ch < 256 && bits[ch]; 3399 } 3400 } 3401 3402 /** 3403 * Returns a suitably optimized, single character matcher. 3404 */ 3405 private CharProperty newSingle(final int ch) { 3406 if (has(CASE_INSENSITIVE)) { 3407 int lower, upper; 3408 if (has(UNICODE_CASE)) { 3409 upper = Character.toUpperCase(ch); 3410 lower = Character.toLowerCase(upper); 3411 if (upper != lower) 3412 return new SingleU(lower); 3413 } else if (ASCII.isAscii(ch)) { 3414 lower = ASCII.toLower(ch); 3415 upper = ASCII.toUpper(ch); 3416 if (lower != upper) 3417 return new SingleI(lower, upper); 3418 } 3419 } 3420 if (isSupplementary(ch)) 3421 return new SingleS(ch); // Match a given Unicode character 3422 return new Single(ch); // Match a given BMP character 3423 } 3424 3425 /** 3426 * Utility method for creating a string slice matcher. 3427 */ 3428 private Node newSlice(int[] buf, int count, boolean hasSupplementary) { 3429 int[] tmp = new int[count]; 3430 if (has(CASE_INSENSITIVE)) { 3431 if (has(UNICODE_CASE)) { 3432 for (int i = 0; i < count; i++) { 3433 tmp[i] = Character.toLowerCase( 3434 Character.toUpperCase(buf[i])); 3435 } 3436 return hasSupplementary? new SliceUS(tmp) : new SliceU(tmp); 3437 } 3438 for (int i = 0; i < count; i++) { 3439 tmp[i] = ASCII.toLower(buf[i]); 3440 } 3441 return hasSupplementary? new SliceIS(tmp) : new SliceI(tmp); 3442 } 3443 for (int i = 0; i < count; i++) { 3444 tmp[i] = buf[i]; 3445 } 3446 return hasSupplementary ? new SliceS(tmp) : new Slice(tmp); 3447 } 3448 3449 /** 3450 * The following classes are the building components of the object 3451 * tree that represents a compiled regular expression. The object tree 3452 * is made of individual elements that handle constructs in the Pattern. 3453 * Each type of object knows how to match its equivalent construct with 3454 * the match() method. 3455 */ 3456 3457 /** 3458 * Base class for all node classes. Subclasses should override the match() 3459 * method as appropriate. This class is an accepting node, so its match() 3460 * always returns true. 3461 */ 3462 static class Node extends Object { 3463 Node next; 3464 Node() { 3465 next = Pattern.accept; 3466 } 3467 /** 3468 * This method implements the classic accept node. 3469 */ 3470 boolean match(Matcher matcher, int i, CharSequence seq) { 3471 matcher.last = i; 3472 matcher.groups[0] = matcher.first; 3473 matcher.groups[1] = matcher.last; 3474 return true; 3475 } 3476 /** 3477 * This method is good for all zero length assertions. 3478 */ 3479 boolean study(TreeInfo info) { 3480 if (next != null) { 3481 return next.study(info); 3482 } else { 3483 return info.deterministic; 3484 } 3485 } 3486 } 3487 3488 static class LastNode extends Node { 3489 /** 3490 * This method implements the classic accept node with 3491 * the addition of a check to see if the match occurred 3492 * using all of the input. 3493 */ 3494 boolean match(Matcher matcher, int i, CharSequence seq) { 3495 if (matcher.acceptMode == Matcher.ENDANCHOR && i != matcher.to) 3496 return false; 3497 matcher.last = i; 3498 matcher.groups[0] = matcher.first; 3499 matcher.groups[1] = matcher.last; 3500 return true; 3501 } 3502 } 3503 3504 /** 3505 * Used for REs that can start anywhere within the input string. 3506 * This basically tries to match repeatedly at each spot in the 3507 * input string, moving forward after each try. An anchored search 3508 * or a BnM will bypass this node completely. 3509 */ 3510 static class Start extends Node { 3511 int minLength; 3512 Start(Node node) { 3513 this.next = node; 3514 TreeInfo info = new TreeInfo(); 3515 next.study(info); 3516 minLength = info.minLength; 3517 } 3518 boolean match(Matcher matcher, int i, CharSequence seq) { 3519 if (i > matcher.to - minLength) { 3520 matcher.hitEnd = true; 3521 return false; 3522 } 3523 int guard = matcher.to - minLength; 3524 for (; i <= guard; i++) { 3525 if (next.match(matcher, i, seq)) { 3526 matcher.first = i; 3527 matcher.groups[0] = matcher.first; 3528 matcher.groups[1] = matcher.last; 3529 return true; 3530 } 3531 } 3532 matcher.hitEnd = true; 3533 return false; 3534 } 3535 boolean study(TreeInfo info) { 3536 next.study(info); 3537 info.maxValid = false; 3538 info.deterministic = false; 3539 return false; 3540 } 3541 } 3542 3543 /* 3544 * StartS supports supplementary characters, including unpaired surrogates. 3545 */ 3546 static final class StartS extends Start { 3547 StartS(Node node) { 3548 super(node); 3549 } 3550 boolean match(Matcher matcher, int i, CharSequence seq) { 3551 if (i > matcher.to - minLength) { 3552 matcher.hitEnd = true; 3553 return false; 3554 } 3555 int guard = matcher.to - minLength; 3556 while (i <= guard) { 3557 //if ((ret = next.match(matcher, i, seq)) || i == guard) 3558 if (next.match(matcher, i, seq)) { 3559 matcher.first = i; 3560 matcher.groups[0] = matcher.first; 3561 matcher.groups[1] = matcher.last; 3562 return true; 3563 } 3564 if (i == guard) 3565 break; 3566 // Optimization to move to the next character. This is 3567 // faster than countChars(seq, i, 1). 3568 if (Character.isHighSurrogate(seq.charAt(i++))) { 3569 if (i < seq.length() && 3570 Character.isLowSurrogate(seq.charAt(i))) { 3571 i++; 3572 } 3573 } 3574 } 3575 matcher.hitEnd = true; 3576 return false; 3577 } 3578 } 3579 3580 /** 3581 * Node to anchor at the beginning of input. This object implements the 3582 * match for a \A sequence, and the caret anchor will use this if not in 3583 * multiline mode. 3584 */ 3585 static final class Begin extends Node { 3586 boolean match(Matcher matcher, int i, CharSequence seq) { 3587 int fromIndex = (matcher.anchoringBounds) ? 3588 matcher.from : 0; 3589 if (i == fromIndex && next.match(matcher, i, seq)) { 3590 matcher.first = i; 3591 matcher.groups[0] = i; 3592 matcher.groups[1] = matcher.last; 3593 return true; 3594 } else { 3595 return false; 3596 } 3597 } 3598 } 3599 3600 /** 3601 * Node to anchor at the end of input. This is the absolute end, so this 3602 * should not match at the last newline before the end as $ will. 3603 */ 3604 static final class End extends Node { 3605 boolean match(Matcher matcher, int i, CharSequence seq) { 3606 int endIndex = (matcher.anchoringBounds) ? 3607 matcher.to : matcher.getTextLength(); 3608 if (i == endIndex) { 3609 matcher.hitEnd = true; 3610 return next.match(matcher, i, seq); 3611 } 3612 return false; 3613 } 3614 } 3615 3616 /** 3617 * Node to anchor at the beginning of a line. This is essentially the 3618 * object to match for the multiline ^. 3619 */ 3620 static final class Caret extends Node { 3621 boolean match(Matcher matcher, int i, CharSequence seq) { 3622 int startIndex = matcher.from; 3623 int endIndex = matcher.to; 3624 if (!matcher.anchoringBounds) { 3625 startIndex = 0; 3626 endIndex = matcher.getTextLength(); 3627 } 3628 // Perl does not match ^ at end of input even after newline 3629 if (i == endIndex) { 3630 matcher.hitEnd = true; 3631 return false; 3632 } 3633 if (i > startIndex) { 3634 char ch = seq.charAt(i-1); 3635 if (ch != '\n' && ch != '\r' 3636 && (ch|1) != '\u2029' 3637 && ch != '\u0085' ) { 3638 return false; 3639 } 3640 // Should treat /r/n as one newline 3641 if (ch == '\r' && seq.charAt(i) == '\n') 3642 return false; 3643 } 3644 return next.match(matcher, i, seq); 3645 } 3646 } 3647 3648 /** 3649 * Node to anchor at the beginning of a line when in unixdot mode. 3650 */ 3651 static final class UnixCaret extends Node { 3652 boolean match(Matcher matcher, int i, CharSequence seq) { 3653 int startIndex = matcher.from; 3654 int endIndex = matcher.to; 3655 if (!matcher.anchoringBounds) { 3656 startIndex = 0; 3657 endIndex = matcher.getTextLength(); 3658 } 3659 // Perl does not match ^ at end of input even after newline 3660 if (i == endIndex) { 3661 matcher.hitEnd = true; 3662 return false; 3663 } 3664 if (i > startIndex) { 3665 char ch = seq.charAt(i-1); 3666 if (ch != '\n') { 3667 return false; 3668 } 3669 } 3670 return next.match(matcher, i, seq); 3671 } 3672 } 3673 3674 /** 3675 * Node to match the location where the last match ended. 3676 * This is used for the \G construct. 3677 */ 3678 static final class LastMatch extends Node { 3679 boolean match(Matcher matcher, int i, CharSequence seq) { 3680 if (i != matcher.oldLast) 3681 return false; 3682 return next.match(matcher, i, seq); 3683 } 3684 } 3685 3686 /** 3687 * Node to anchor at the end of a line or the end of input based on the 3688 * multiline mode. 3689 * 3690 * When not in multiline mode, the $ can only match at the very end 3691 * of the input, unless the input ends in a line terminator in which 3692 * it matches right before the last line terminator. 3693 * 3694 * Note that \r\n is considered an atomic line terminator. 3695 * 3696 * Like ^ the $ operator matches at a position, it does not match the 3697 * line terminators themselves. 3698 */ 3699 static final class Dollar extends Node { 3700 boolean multiline; 3701 Dollar(boolean mul) { 3702 multiline = mul; 3703 } 3704 boolean match(Matcher matcher, int i, CharSequence seq) { 3705 int endIndex = (matcher.anchoringBounds) ? 3706 matcher.to : matcher.getTextLength(); 3707 if (!multiline) { 3708 if (i < endIndex - 2) 3709 return false; 3710 if (i == endIndex - 2) { 3711 char ch = seq.charAt(i); 3712 if (ch != '\r') 3713 return false; 3714 ch = seq.charAt(i + 1); 3715 if (ch != '\n') 3716 return false; 3717 } 3718 } 3719 // Matches before any line terminator; also matches at the 3720 // end of input 3721 // Before line terminator: 3722 // If multiline, we match here no matter what 3723 // If not multiline, fall through so that the end 3724 // is marked as hit; this must be a /r/n or a /n 3725 // at the very end so the end was hit; more input 3726 // could make this not match here 3727 if (i < endIndex) { 3728 char ch = seq.charAt(i); 3729 if (ch == '\n') { 3730 // No match between \r\n 3731 if (i > 0 && seq.charAt(i-1) == '\r') 3732 return false; 3733 if (multiline) 3734 return next.match(matcher, i, seq); 3735 } else if (ch == '\r' || ch == '\u0085' || 3736 (ch|1) == '\u2029') { 3737 if (multiline) 3738 return next.match(matcher, i, seq); 3739 } else { // No line terminator, no match 3740 return false; 3741 } 3742 } 3743 // Matched at current end so hit end 3744 matcher.hitEnd = true; 3745 // If a $ matches because of end of input, then more input 3746 // could cause it to fail! 3747 matcher.requireEnd = true; 3748 return next.match(matcher, i, seq); 3749 } 3750 boolean study(TreeInfo info) { 3751 next.study(info); 3752 return info.deterministic; 3753 } 3754 } 3755 3756 /** 3757 * Node to anchor at the end of a line or the end of input based on the 3758 * multiline mode when in unix lines mode. 3759 */ 3760 static final class UnixDollar extends Node { 3761 boolean multiline; 3762 UnixDollar(boolean mul) { 3763 multiline = mul; 3764 } 3765 boolean match(Matcher matcher, int i, CharSequence seq) { 3766 int endIndex = (matcher.anchoringBounds) ? 3767 matcher.to : matcher.getTextLength(); 3768 if (i < endIndex) { 3769 char ch = seq.charAt(i); 3770 if (ch == '\n') { 3771 // If not multiline, then only possible to 3772 // match at very end or one before end 3773 if (multiline == false && i != endIndex - 1) 3774 return false; 3775 // If multiline return next.match without setting 3776 // matcher.hitEnd 3777 if (multiline) 3778 return next.match(matcher, i, seq); 3779 } else { 3780 return false; 3781 } 3782 } 3783 // Matching because at the end or 1 before the end; 3784 // more input could change this so set hitEnd 3785 matcher.hitEnd = true; 3786 // If a $ matches because of end of input, then more input 3787 // could cause it to fail! 3788 matcher.requireEnd = true; 3789 return next.match(matcher, i, seq); 3790 } 3791 boolean study(TreeInfo info) { 3792 next.study(info); 3793 return info.deterministic; 3794 } 3795 } 3796 3797 /** 3798 * Node class that matches a Unicode line ending '\R' 3799 */ 3800 static final class LineEnding extends Node { 3801 boolean match(Matcher matcher, int i, CharSequence seq) { 3802 // (u+000Du+000A|[u+000Au+000Bu+000Cu+000Du+0085u+2028u+2029]) 3803 if (i < matcher.to) { 3804 int ch = seq.charAt(i); 3805 if (ch == 0x0A || ch == 0x0B || ch == 0x0C || 3806 ch == 0x85 || ch == 0x2028 || ch == 0x2029) 3807 return next.match(matcher, i + 1, seq); 3808 if (ch == 0x0D) { 3809 i++; 3810 if (i < matcher.to && seq.charAt(i) == 0x0A) 3811 i++; 3812 return next.match(matcher, i, seq); 3813 } 3814 } else { 3815 matcher.hitEnd = true; 3816 } 3817 return false; 3818 } 3819 boolean study(TreeInfo info) { 3820 info.minLength++; 3821 info.maxLength += 2; 3822 return next.study(info); 3823 } 3824 } 3825 3826 /** 3827 * Abstract node class to match one character satisfying some 3828 * boolean property. 3829 */ 3830 private abstract static class CharProperty extends Node { 3831 abstract boolean isSatisfiedBy(int ch); 3832 CharProperty complement() { 3833 return new CharProperty() { 3834 boolean isSatisfiedBy(int ch) { 3835 return ! CharProperty.this.isSatisfiedBy(ch);}}; 3836 } 3837 boolean match(Matcher matcher, int i, CharSequence seq) { 3838 if (i < matcher.to) { 3839 int ch = Character.codePointAt(seq, i); 3840 return isSatisfiedBy(ch) 3841 && next.match(matcher, i+Character.charCount(ch), seq); 3842 } else { 3843 matcher.hitEnd = true; 3844 return false; 3845 } 3846 } 3847 boolean study(TreeInfo info) { 3848 info.minLength++; 3849 info.maxLength++; 3850 return next.study(info); 3851 } 3852 } 3853 3854 /** 3855 * Optimized version of CharProperty that works only for 3856 * properties never satisfied by Supplementary characters. 3857 */ 3858 private abstract static class BmpCharProperty extends CharProperty { 3859 boolean match(Matcher matcher, int i, CharSequence seq) { 3860 if (i < matcher.to) { 3861 return isSatisfiedBy(seq.charAt(i)) 3862 && next.match(matcher, i+1, seq); 3863 } else { 3864 matcher.hitEnd = true; 3865 return false; 3866 } 3867 } 3868 } 3869 3870 /** 3871 * Node class that matches a Supplementary Unicode character 3872 */ 3873 static final class SingleS extends CharProperty { 3874 final int c; 3875 SingleS(int c) { this.c = c; } 3876 boolean isSatisfiedBy(int ch) { 3877 return ch == c; 3878 } 3879 } 3880 3881 /** 3882 * Optimization -- matches a given BMP character 3883 */ 3884 static final class Single extends BmpCharProperty { 3885 final int c; 3886 Single(int c) { this.c = c; } 3887 boolean isSatisfiedBy(int ch) { 3888 return ch == c; 3889 } 3890 } 3891 3892 /** 3893 * Case insensitive matches a given BMP character 3894 */ 3895 static final class SingleI extends BmpCharProperty { 3896 final int lower; 3897 final int upper; 3898 SingleI(int lower, int upper) { 3899 this.lower = lower; 3900 this.upper = upper; 3901 } 3902 boolean isSatisfiedBy(int ch) { 3903 return ch == lower || ch == upper; 3904 } 3905 } 3906 3907 /** 3908 * Unicode case insensitive matches a given Unicode character 3909 */ 3910 static final class SingleU extends CharProperty { 3911 final int lower; 3912 SingleU(int lower) { 3913 this.lower = lower; 3914 } 3915 boolean isSatisfiedBy(int ch) { 3916 return lower == ch || 3917 lower == Character.toLowerCase(Character.toUpperCase(ch)); 3918 } 3919 } 3920 3921 /** 3922 * Node class that matches a Unicode block. 3923 */ 3924 static final class Block extends CharProperty { 3925 final Character.UnicodeBlock block; 3926 Block(Character.UnicodeBlock block) { 3927 this.block = block; 3928 } 3929 boolean isSatisfiedBy(int ch) { 3930 return block == Character.UnicodeBlock.of(ch); 3931 } 3932 } 3933 3934 /** 3935 * Node class that matches a Unicode script 3936 */ 3937 static final class Script extends CharProperty { 3938 final Character.UnicodeScript script; 3939 Script(Character.UnicodeScript script) { 3940 this.script = script; 3941 } 3942 boolean isSatisfiedBy(int ch) { 3943 return script == Character.UnicodeScript.of(ch); 3944 } 3945 } 3946 3947 /** 3948 * Node class that matches a Unicode category. 3949 */ 3950 static final class Category extends CharProperty { 3951 final int typeMask; 3952 Category(int typeMask) { this.typeMask = typeMask; } 3953 boolean isSatisfiedBy(int ch) { 3954 return (typeMask & (1 << Character.getType(ch))) != 0; 3955 } 3956 } 3957 3958 /** 3959 * Node class that matches a Unicode "type" 3960 */ 3961 static final class Utype extends CharProperty { 3962 final UnicodeProp uprop; 3963 Utype(UnicodeProp uprop) { this.uprop = uprop; } 3964 boolean isSatisfiedBy(int ch) { 3965 return uprop.is(ch); 3966 } 3967 } 3968 3969 /** 3970 * Node class that matches a POSIX type. 3971 */ 3972 static final class Ctype extends BmpCharProperty { 3973 final int ctype; 3974 Ctype(int ctype) { this.ctype = ctype; } 3975 boolean isSatisfiedBy(int ch) { 3976 return ch < 128 && ASCII.isType(ch, ctype); 3977 } 3978 } 3979 3980 /** 3981 * Node class that matches a Perl vertical whitespace 3982 */ 3983 static final class VertWS extends BmpCharProperty { 3984 boolean isSatisfiedBy(int cp) { 3985 return (cp >= 0x0A && cp <= 0x0D) || 3986 cp == 0x85 || cp == 0x2028 || cp == 0x2029; 3987 } 3988 } 3989 3990 /** 3991 * Node class that matches a Perl horizontal whitespace 3992 */ 3993 static final class HorizWS extends BmpCharProperty { 3994 boolean isSatisfiedBy(int cp) { 3995 return cp == 0x09 || cp == 0x20 || cp == 0xa0 || 3996 cp == 0x1680 || cp == 0x180e || 3997 cp >= 0x2000 && cp <= 0x200a || 3998 cp == 0x202f || cp == 0x205f || cp == 0x3000; 3999 } 4000 } 4001 4002 /** 4003 * Node class that matches an unicode extended grapheme cluster 4004 */ 4005 static class XGrapheme extends Node { 4006 boolean match(Matcher matcher, int i, CharSequence seq) { 4007 if (i < matcher.to) { 4008 int ch0 = Character.codePointAt(seq, i); 4009 i += Character.charCount(ch0); 4010 while (i < matcher.to) { 4011 int ch1 = Character.codePointAt(seq, i); 4012 if (Grapheme.isBoundary(ch0, ch1)) 4013 break; 4014 ch0 = ch1; 4015 i += Character.charCount(ch1); 4016 } 4017 return next.match(matcher, i, seq); 4018 } 4019 matcher.hitEnd = true; 4020 return false; 4021 } 4022 4023 boolean study(TreeInfo info) { 4024 info.minLength++; 4025 info.deterministic = false; 4026 return next.study(info); 4027 } 4028 } 4029 4030 /** 4031 * Node class that handles grapheme boundaries 4032 */ 4033 static class GraphemeBound extends Node { 4034 boolean match(Matcher matcher, int i, CharSequence seq) { 4035 int startIndex = matcher.from; 4036 int endIndex = matcher.to; 4037 if (matcher.transparentBounds) { 4038 startIndex = 0; 4039 endIndex = matcher.getTextLength(); 4040 } 4041 if (i == startIndex) { 4042 return next.match(matcher, i, seq); 4043 } 4044 if (i < endIndex) { 4045 if (Character.isSurrogatePair(seq.charAt(i-1), seq.charAt(i)) || 4046 !Grapheme.isBoundary(Character.codePointBefore(seq, i), 4047 Character.codePointAt(seq, i))) { 4048 return false; 4049 } 4050 } else { 4051 matcher.hitEnd = true; 4052 matcher.requireEnd = true; 4053 } 4054 return next.match(matcher, i, seq); 4055 } 4056 } 4057 4058 /** 4059 * Base class for all Slice nodes 4060 */ 4061 static class SliceNode extends Node { 4062 int[] buffer; 4063 SliceNode(int[] buf) { 4064 buffer = buf; 4065 } 4066 boolean study(TreeInfo info) { 4067 info.minLength += buffer.length; 4068 info.maxLength += buffer.length; 4069 return next.study(info); 4070 } 4071 } 4072 4073 /** 4074 * Node class for a case sensitive/BMP-only sequence of literal 4075 * characters. 4076 */ 4077 static class Slice extends SliceNode { 4078 Slice(int[] buf) { 4079 super(buf); 4080 } 4081 boolean match(Matcher matcher, int i, CharSequence seq) { 4082 int[] buf = buffer; 4083 int len = buf.length; 4084 for (int j=0; j<len; j++) { 4085 if ((i+j) >= matcher.to) { 4086 matcher.hitEnd = true; 4087 return false; 4088 } 4089 if (buf[j] != seq.charAt(i+j)) 4090 return false; 4091 } 4092 return next.match(matcher, i+len, seq); 4093 } 4094 } 4095 4096 /** 4097 * Node class for a case_insensitive/BMP-only sequence of literal 4098 * characters. 4099 */ 4100 static class SliceI extends SliceNode { 4101 SliceI(int[] buf) { 4102 super(buf); 4103 } 4104 boolean match(Matcher matcher, int i, CharSequence seq) { 4105 int[] buf = buffer; 4106 int len = buf.length; 4107 for (int j=0; j<len; j++) { 4108 if ((i+j) >= matcher.to) { 4109 matcher.hitEnd = true; 4110 return false; 4111 } 4112 int c = seq.charAt(i+j); 4113 if (buf[j] != c && 4114 buf[j] != ASCII.toLower(c)) 4115 return false; 4116 } 4117 return next.match(matcher, i+len, seq); 4118 } 4119 } 4120 4121 /** 4122 * Node class for a unicode_case_insensitive/BMP-only sequence of 4123 * literal characters. Uses unicode case folding. 4124 */ 4125 static final class SliceU extends SliceNode { 4126 SliceU(int[] buf) { 4127 super(buf); 4128 } 4129 boolean match(Matcher matcher, int i, CharSequence seq) { 4130 int[] buf = buffer; 4131 int len = buf.length; 4132 for (int j=0; j<len; j++) { 4133 if ((i+j) >= matcher.to) { 4134 matcher.hitEnd = true; 4135 return false; 4136 } 4137 int c = seq.charAt(i+j); 4138 if (buf[j] != c && 4139 buf[j] != Character.toLowerCase(Character.toUpperCase(c))) 4140 return false; 4141 } 4142 return next.match(matcher, i+len, seq); 4143 } 4144 } 4145 4146 /** 4147 * Node class for a case sensitive sequence of literal characters 4148 * including supplementary characters. 4149 */ 4150 static final class SliceS extends Slice { 4151 SliceS(int[] buf) { 4152 super(buf); 4153 } 4154 boolean match(Matcher matcher, int i, CharSequence seq) { 4155 int[] buf = buffer; 4156 int x = i; 4157 for (int j = 0; j < buf.length; j++) { 4158 if (x >= matcher.to) { 4159 matcher.hitEnd = true; 4160 return false; 4161 } 4162 int c = Character.codePointAt(seq, x); 4163 if (buf[j] != c) 4164 return false; 4165 x += Character.charCount(c); 4166 if (x > matcher.to) { 4167 matcher.hitEnd = true; 4168 return false; 4169 } 4170 } 4171 return next.match(matcher, x, seq); 4172 } 4173 } 4174 4175 /** 4176 * Node class for a case insensitive sequence of literal characters 4177 * including supplementary characters. 4178 */ 4179 static class SliceIS extends SliceNode { 4180 SliceIS(int[] buf) { 4181 super(buf); 4182 } 4183 int toLower(int c) { 4184 return ASCII.toLower(c); 4185 } 4186 boolean match(Matcher matcher, int i, CharSequence seq) { 4187 int[] buf = buffer; 4188 int x = i; 4189 for (int j = 0; j < buf.length; j++) { 4190 if (x >= matcher.to) { 4191 matcher.hitEnd = true; 4192 return false; 4193 } 4194 int c = Character.codePointAt(seq, x); 4195 if (buf[j] != c && buf[j] != toLower(c)) 4196 return false; 4197 x += Character.charCount(c); 4198 if (x > matcher.to) { 4199 matcher.hitEnd = true; 4200 return false; 4201 } 4202 } 4203 return next.match(matcher, x, seq); 4204 } 4205 } 4206 4207 /** 4208 * Node class for a case insensitive sequence of literal characters. 4209 * Uses unicode case folding. 4210 */ 4211 static final class SliceUS extends SliceIS { 4212 SliceUS(int[] buf) { 4213 super(buf); 4214 } 4215 int toLower(int c) { 4216 return Character.toLowerCase(Character.toUpperCase(c)); 4217 } 4218 } 4219 4220 private static boolean inRange(int lower, int ch, int upper) { 4221 return lower <= ch && ch <= upper; 4222 } 4223 4224 /** 4225 * Returns node for matching characters within an explicit value range. 4226 */ 4227 private static CharProperty rangeFor(final int lower, 4228 final int upper) { 4229 return new CharProperty() { 4230 boolean isSatisfiedBy(int ch) { 4231 return inRange(lower, ch, upper);}}; 4232 } 4233 4234 /** 4235 * Returns node for matching characters within an explicit value 4236 * range in a case insensitive manner. 4237 */ 4238 private CharProperty caseInsensitiveRangeFor(final int lower, 4239 final int upper) { 4240 if (has(UNICODE_CASE)) 4241 return new CharProperty() { 4242 boolean isSatisfiedBy(int ch) { 4243 if (inRange(lower, ch, upper)) 4244 return true; 4245 int up = Character.toUpperCase(ch); 4246 return inRange(lower, up, upper) || 4247 inRange(lower, Character.toLowerCase(up), upper);}}; 4248 return new CharProperty() { 4249 boolean isSatisfiedBy(int ch) { 4250 return inRange(lower, ch, upper) || 4251 ASCII.isAscii(ch) && 4252 (inRange(lower, ASCII.toUpper(ch), upper) || 4253 inRange(lower, ASCII.toLower(ch), upper)); 4254 }}; 4255 } 4256 4257 /** 4258 * Implements the Unicode category ALL and the dot metacharacter when 4259 * in dotall mode. 4260 */ 4261 static final class All extends CharProperty { 4262 boolean isSatisfiedBy(int ch) { 4263 return true; 4264 } 4265 } 4266 4267 /** 4268 * Node class for the dot metacharacter when dotall is not enabled. 4269 */ 4270 static final class Dot extends CharProperty { 4271 boolean isSatisfiedBy(int ch) { 4272 return (ch != '\n' && ch != '\r' 4273 && (ch|1) != '\u2029' 4274 && ch != '\u0085'); 4275 } 4276 } 4277 4278 /** 4279 * Node class for the dot metacharacter when dotall is not enabled 4280 * but UNIX_LINES is enabled. 4281 */ 4282 static final class UnixDot extends CharProperty { 4283 boolean isSatisfiedBy(int ch) { 4284 return ch != '\n'; 4285 } 4286 } 4287 4288 /** 4289 * The 0 or 1 quantifier. This one class implements all three types. 4290 */ 4291 static final class Ques extends Node { 4292 Node atom; 4293 int type; 4294 Ques(Node node, int type) { 4295 this.atom = node; 4296 this.type = type; 4297 } 4298 boolean match(Matcher matcher, int i, CharSequence seq) { 4299 switch (type) { 4300 case GREEDY: 4301 return (atom.match(matcher, i, seq) && next.match(matcher, matcher.last, seq)) 4302 || next.match(matcher, i, seq); 4303 case LAZY: 4304 return next.match(matcher, i, seq) 4305 || (atom.match(matcher, i, seq) && next.match(matcher, matcher.last, seq)); 4306 case POSSESSIVE: 4307 if (atom.match(matcher, i, seq)) i = matcher.last; 4308 return next.match(matcher, i, seq); 4309 default: 4310 return atom.match(matcher, i, seq) && next.match(matcher, matcher.last, seq); 4311 } 4312 } 4313 boolean study(TreeInfo info) { 4314 if (type != INDEPENDENT) { 4315 int minL = info.minLength; 4316 atom.study(info); 4317 info.minLength = minL; 4318 info.deterministic = false; 4319 return next.study(info); 4320 } else { 4321 atom.study(info); 4322 return next.study(info); 4323 } 4324 } 4325 } 4326 4327 /** 4328 * Handles the curly-brace style repetition with a specified minimum and 4329 * maximum occurrences. The * quantifier is handled as a special case. 4330 * This class handles the three types. 4331 */ 4332 static final class Curly extends Node { 4333 Node atom; 4334 int type; 4335 int cmin; 4336 int cmax; 4337 4338 Curly(Node node, int cmin, int cmax, int type) { 4339 this.atom = node; 4340 this.type = type; 4341 this.cmin = cmin; 4342 this.cmax = cmax; 4343 } 4344 boolean match(Matcher matcher, int i, CharSequence seq) { 4345 int j; 4346 for (j = 0; j < cmin; j++) { 4347 if (atom.match(matcher, i, seq)) { 4348 i = matcher.last; 4349 continue; 4350 } 4351 return false; 4352 } 4353 if (type == GREEDY) 4354 return match0(matcher, i, j, seq); 4355 else if (type == LAZY) 4356 return match1(matcher, i, j, seq); 4357 else 4358 return match2(matcher, i, j, seq); 4359 } 4360 // Greedy match. 4361 // i is the index to start matching at 4362 // j is the number of atoms that have matched 4363 boolean match0(Matcher matcher, int i, int j, CharSequence seq) { 4364 if (j >= cmax) { 4365 // We have matched the maximum... continue with the rest of 4366 // the regular expression 4367 return next.match(matcher, i, seq); 4368 } 4369 int backLimit = j; 4370 while (atom.match(matcher, i, seq)) { 4371 // k is the length of this match 4372 int k = matcher.last - i; 4373 if (k == 0) // Zero length match 4374 break; 4375 // Move up index and number matched 4376 i = matcher.last; 4377 j++; 4378 // We are greedy so match as many as we can 4379 while (j < cmax) { 4380 if (!atom.match(matcher, i, seq)) 4381 break; 4382 if (i + k != matcher.last) { 4383 if (match0(matcher, matcher.last, j+1, seq)) 4384 return true; 4385 break; 4386 } 4387 i += k; 4388 j++; 4389 } 4390 // Handle backing off if match fails 4391 while (j >= backLimit) { 4392 if (next.match(matcher, i, seq)) 4393 return true; 4394 i -= k; 4395 j--; 4396 } 4397 return false; 4398 } 4399 return next.match(matcher, i, seq); 4400 } 4401 // Reluctant match. At this point, the minimum has been satisfied. 4402 // i is the index to start matching at 4403 // j is the number of atoms that have matched 4404 boolean match1(Matcher matcher, int i, int j, CharSequence seq) { 4405 for (;;) { 4406 // Try finishing match without consuming any more 4407 if (next.match(matcher, i, seq)) 4408 return true; 4409 // At the maximum, no match found 4410 if (j >= cmax) 4411 return false; 4412 // Okay, must try one more atom 4413 if (!atom.match(matcher, i, seq)) 4414 return false; 4415 // If we haven't moved forward then must break out 4416 if (i == matcher.last) 4417 return false; 4418 // Move up index and number matched 4419 i = matcher.last; 4420 j++; 4421 } 4422 } 4423 boolean match2(Matcher matcher, int i, int j, CharSequence seq) { 4424 for (; j < cmax; j++) { 4425 if (!atom.match(matcher, i, seq)) 4426 break; 4427 if (i == matcher.last) 4428 break; 4429 i = matcher.last; 4430 } 4431 return next.match(matcher, i, seq); 4432 } 4433 boolean study(TreeInfo info) { 4434 // Save original info 4435 int minL = info.minLength; 4436 int maxL = info.maxLength; 4437 boolean maxV = info.maxValid; 4438 boolean detm = info.deterministic; 4439 info.reset(); 4440 4441 atom.study(info); 4442 4443 int temp = info.minLength * cmin + minL; 4444 if (temp < minL) { 4445 temp = 0xFFFFFFF; // arbitrary large number 4446 } 4447 info.minLength = temp; 4448 4449 if (maxV & info.maxValid) { 4450 temp = info.maxLength * cmax + maxL; 4451 info.maxLength = temp; 4452 if (temp < maxL) { 4453 info.maxValid = false; 4454 } 4455 } else { 4456 info.maxValid = false; 4457 } 4458 4459 if (info.deterministic && cmin == cmax) 4460 info.deterministic = detm; 4461 else 4462 info.deterministic = false; 4463 return next.study(info); 4464 } 4465 } 4466 4467 /** 4468 * Handles the curly-brace style repetition with a specified minimum and 4469 * maximum occurrences in deterministic cases. This is an iterative 4470 * optimization over the Prolog and Loop system which would handle this 4471 * in a recursive way. The * quantifier is handled as a special case. 4472 * If capture is true then this class saves group settings and ensures 4473 * that groups are unset when backing off of a group match. 4474 */ 4475 static final class GroupCurly extends Node { 4476 Node atom; 4477 int type; 4478 int cmin; 4479 int cmax; 4480 int localIndex; 4481 int groupIndex; 4482 boolean capture; 4483 4484 GroupCurly(Node node, int cmin, int cmax, int type, int local, 4485 int group, boolean capture) { 4486 this.atom = node; 4487 this.type = type; 4488 this.cmin = cmin; 4489 this.cmax = cmax; 4490 this.localIndex = local; 4491 this.groupIndex = group; 4492 this.capture = capture; 4493 } 4494 boolean match(Matcher matcher, int i, CharSequence seq) { 4495 int[] groups = matcher.groups; 4496 int[] locals = matcher.locals; 4497 int save0 = locals[localIndex]; 4498 int save1 = 0; 4499 int save2 = 0; 4500 4501 if (capture) { 4502 save1 = groups[groupIndex]; 4503 save2 = groups[groupIndex+1]; 4504 } 4505 4506 // Notify GroupTail there is no need to setup group info 4507 // because it will be set here 4508 locals[localIndex] = -1; 4509 4510 boolean ret = true; 4511 for (int j = 0; j < cmin; j++) { 4512 if (atom.match(matcher, i, seq)) { 4513 if (capture) { 4514 groups[groupIndex] = i; 4515 groups[groupIndex+1] = matcher.last; 4516 } 4517 i = matcher.last; 4518 } else { 4519 ret = false; 4520 break; 4521 } 4522 } 4523 if (ret) { 4524 if (type == GREEDY) { 4525 ret = match0(matcher, i, cmin, seq); 4526 } else if (type == LAZY) { 4527 ret = match1(matcher, i, cmin, seq); 4528 } else { 4529 ret = match2(matcher, i, cmin, seq); 4530 } 4531 } 4532 if (!ret) { 4533 locals[localIndex] = save0; 4534 if (capture) { 4535 groups[groupIndex] = save1; 4536 groups[groupIndex+1] = save2; 4537 } 4538 } 4539 return ret; 4540 } 4541 // Aggressive group match 4542 boolean match0(Matcher matcher, int i, int j, CharSequence seq) { 4543 // don't back off passing the starting "j" 4544 int min = j; 4545 int[] groups = matcher.groups; 4546 int save0 = 0; 4547 int save1 = 0; 4548 if (capture) { 4549 save0 = groups[groupIndex]; 4550 save1 = groups[groupIndex+1]; 4551 } 4552 for (;;) { 4553 if (j >= cmax) 4554 break; 4555 if (!atom.match(matcher, i, seq)) 4556 break; 4557 int k = matcher.last - i; 4558 if (k <= 0) { 4559 if (capture) { 4560 groups[groupIndex] = i; 4561 groups[groupIndex+1] = i + k; 4562 } 4563 i = i + k; 4564 break; 4565 } 4566 for (;;) { 4567 if (capture) { 4568 groups[groupIndex] = i; 4569 groups[groupIndex+1] = i + k; 4570 } 4571 i = i + k; 4572 if (++j >= cmax) 4573 break; 4574 if (!atom.match(matcher, i, seq)) 4575 break; 4576 if (i + k != matcher.last) { 4577 if (match0(matcher, i, j, seq)) 4578 return true; 4579 break; 4580 } 4581 } 4582 while (j > min) { 4583 if (next.match(matcher, i, seq)) { 4584 if (capture) { 4585 groups[groupIndex+1] = i; 4586 groups[groupIndex] = i - k; 4587 } 4588 return true; 4589 } 4590 // backing off 4591 i = i - k; 4592 if (capture) { 4593 groups[groupIndex+1] = i; 4594 groups[groupIndex] = i - k; 4595 } 4596 j--; 4597 4598 } 4599 break; 4600 } 4601 if (capture) { 4602 groups[groupIndex] = save0; 4603 groups[groupIndex+1] = save1; 4604 } 4605 return next.match(matcher, i, seq); 4606 } 4607 // Reluctant matching 4608 boolean match1(Matcher matcher, int i, int j, CharSequence seq) { 4609 for (;;) { 4610 if (next.match(matcher, i, seq)) 4611 return true; 4612 if (j >= cmax) 4613 return false; 4614 if (!atom.match(matcher, i, seq)) 4615 return false; 4616 if (i == matcher.last) 4617 return false; 4618 if (capture) { 4619 matcher.groups[groupIndex] = i; 4620 matcher.groups[groupIndex+1] = matcher.last; 4621 } 4622 i = matcher.last; 4623 j++; 4624 } 4625 } 4626 // Possessive matching 4627 boolean match2(Matcher matcher, int i, int j, CharSequence seq) { 4628 for (; j < cmax; j++) { 4629 if (!atom.match(matcher, i, seq)) { 4630 break; 4631 } 4632 if (capture) { 4633 matcher.groups[groupIndex] = i; 4634 matcher.groups[groupIndex+1] = matcher.last; 4635 } 4636 if (i == matcher.last) { 4637 break; 4638 } 4639 i = matcher.last; 4640 } 4641 return next.match(matcher, i, seq); 4642 } 4643 boolean study(TreeInfo info) { 4644 // Save original info 4645 int minL = info.minLength; 4646 int maxL = info.maxLength; 4647 boolean maxV = info.maxValid; 4648 boolean detm = info.deterministic; 4649 info.reset(); 4650 4651 atom.study(info); 4652 4653 int temp = info.minLength * cmin + minL; 4654 if (temp < minL) { 4655 temp = 0xFFFFFFF; // Arbitrary large number 4656 } 4657 info.minLength = temp; 4658 4659 if (maxV & info.maxValid) { 4660 temp = info.maxLength * cmax + maxL; 4661 info.maxLength = temp; 4662 if (temp < maxL) { 4663 info.maxValid = false; 4664 } 4665 } else { 4666 info.maxValid = false; 4667 } 4668 4669 if (info.deterministic && cmin == cmax) { 4670 info.deterministic = detm; 4671 } else { 4672 info.deterministic = false; 4673 } 4674 return next.study(info); 4675 } 4676 } 4677 4678 /** 4679 * A Guard node at the end of each atom node in a Branch. It 4680 * serves the purpose of chaining the "match" operation to 4681 * "next" but not the "study", so we can collect the TreeInfo 4682 * of each atom node without including the TreeInfo of the 4683 * "next". 4684 */ 4685 static final class BranchConn extends Node { 4686 BranchConn() {}; 4687 boolean match(Matcher matcher, int i, CharSequence seq) { 4688 return next.match(matcher, i, seq); 4689 } 4690 boolean study(TreeInfo info) { 4691 return info.deterministic; 4692 } 4693 } 4694 4695 /** 4696 * Handles the branching of alternations. Note this is also used for 4697 * the ? quantifier to branch between the case where it matches once 4698 * and where it does not occur. 4699 */ 4700 static final class Branch extends Node { 4701 Node[] atoms = new Node[2]; 4702 int size = 2; 4703 Node conn; 4704 Branch(Node first, Node second, Node branchConn) { 4705 conn = branchConn; 4706 atoms[0] = first; 4707 atoms[1] = second; 4708 } 4709 4710 void add(Node node) { 4711 if (size >= atoms.length) { 4712 Node[] tmp = new Node[atoms.length*2]; 4713 System.arraycopy(atoms, 0, tmp, 0, atoms.length); 4714 atoms = tmp; 4715 } 4716 atoms[size++] = node; 4717 } 4718 4719 boolean match(Matcher matcher, int i, CharSequence seq) { 4720 for (int n = 0; n < size; n++) { 4721 if (atoms[n] == null) { 4722 if (conn.next.match(matcher, i, seq)) 4723 return true; 4724 } else if (atoms[n].match(matcher, i, seq)) { 4725 return true; 4726 } 4727 } 4728 return false; 4729 } 4730 4731 boolean study(TreeInfo info) { 4732 int minL = info.minLength; 4733 int maxL = info.maxLength; 4734 boolean maxV = info.maxValid; 4735 4736 int minL2 = Integer.MAX_VALUE; //arbitrary large enough num 4737 int maxL2 = -1; 4738 for (int n = 0; n < size; n++) { 4739 info.reset(); 4740 if (atoms[n] != null) 4741 atoms[n].study(info); 4742 minL2 = Math.min(minL2, info.minLength); 4743 maxL2 = Math.max(maxL2, info.maxLength); 4744 maxV = (maxV & info.maxValid); 4745 } 4746 4747 minL += minL2; 4748 maxL += maxL2; 4749 4750 info.reset(); 4751 conn.next.study(info); 4752 4753 info.minLength += minL; 4754 info.maxLength += maxL; 4755 info.maxValid &= maxV; 4756 info.deterministic = false; 4757 return false; 4758 } 4759 } 4760 4761 /** 4762 * The GroupHead saves the location where the group begins in the locals 4763 * and restores them when the match is done. 4764 * 4765 * The matchRef is used when a reference to this group is accessed later 4766 * in the expression. The locals will have a negative value in them to 4767 * indicate that we do not want to unset the group if the reference 4768 * doesn't match. 4769 */ 4770 static final class GroupHead extends Node { 4771 int localIndex; 4772 GroupHead(int localCount) { 4773 localIndex = localCount; 4774 } 4775 boolean match(Matcher matcher, int i, CharSequence seq) { 4776 int save = matcher.locals[localIndex]; 4777 matcher.locals[localIndex] = i; 4778 boolean ret = next.match(matcher, i, seq); 4779 matcher.locals[localIndex] = save; 4780 return ret; 4781 } 4782 boolean matchRef(Matcher matcher, int i, CharSequence seq) { 4783 int save = matcher.locals[localIndex]; 4784 matcher.locals[localIndex] = ~i; // HACK 4785 boolean ret = next.match(matcher, i, seq); 4786 matcher.locals[localIndex] = save; 4787 return ret; 4788 } 4789 } 4790 4791 /** 4792 * Recursive reference to a group in the regular expression. It calls 4793 * matchRef because if the reference fails to match we would not unset 4794 * the group. 4795 */ 4796 static final class GroupRef extends Node { 4797 GroupHead head; 4798 GroupRef(GroupHead head) { 4799 this.head = head; 4800 } 4801 boolean match(Matcher matcher, int i, CharSequence seq) { 4802 return head.matchRef(matcher, i, seq) 4803 && next.match(matcher, matcher.last, seq); 4804 } 4805 boolean study(TreeInfo info) { 4806 info.maxValid = false; 4807 info.deterministic = false; 4808 return next.study(info); 4809 } 4810 } 4811 4812 /** 4813 * The GroupTail handles the setting of group beginning and ending 4814 * locations when groups are successfully matched. It must also be able to 4815 * unset groups that have to be backed off of. 4816 * 4817 * The GroupTail node is also used when a previous group is referenced, 4818 * and in that case no group information needs to be set. 4819 */ 4820 static final class GroupTail extends Node { 4821 int localIndex; 4822 int groupIndex; 4823 GroupTail(int localCount, int groupCount) { 4824 localIndex = localCount; 4825 groupIndex = groupCount + groupCount; 4826 } 4827 boolean match(Matcher matcher, int i, CharSequence seq) { 4828 int tmp = matcher.locals[localIndex]; 4829 if (tmp >= 0) { // This is the normal group case. 4830 // Save the group so we can unset it if it 4831 // backs off of a match. 4832 int groupStart = matcher.groups[groupIndex]; 4833 int groupEnd = matcher.groups[groupIndex+1]; 4834 4835 matcher.groups[groupIndex] = tmp; 4836 matcher.groups[groupIndex+1] = i; 4837 if (next.match(matcher, i, seq)) { 4838 return true; 4839 } 4840 matcher.groups[groupIndex] = groupStart; 4841 matcher.groups[groupIndex+1] = groupEnd; 4842 return false; 4843 } else { 4844 // This is a group reference case. We don't need to save any 4845 // group info because it isn't really a group. 4846 matcher.last = i; 4847 return true; 4848 } 4849 } 4850 } 4851 4852 /** 4853 * This sets up a loop to handle a recursive quantifier structure. 4854 */ 4855 static final class Prolog extends Node { 4856 Loop loop; 4857 Prolog(Loop loop) { 4858 this.loop = loop; 4859 } 4860 boolean match(Matcher matcher, int i, CharSequence seq) { 4861 return loop.matchInit(matcher, i, seq); 4862 } 4863 boolean study(TreeInfo info) { 4864 return loop.study(info); 4865 } 4866 } 4867 4868 /** 4869 * Handles the repetition count for a greedy Curly. The matchInit 4870 * is called from the Prolog to save the index of where the group 4871 * beginning is stored. A zero length group check occurs in the 4872 * normal match but is skipped in the matchInit. 4873 */ 4874 static class Loop extends Node { 4875 Node body; 4876 int countIndex; // local count index in matcher locals 4877 int beginIndex; // group beginning index 4878 int cmin, cmax; 4879 Loop(int countIndex, int beginIndex) { 4880 this.countIndex = countIndex; 4881 this.beginIndex = beginIndex; 4882 } 4883 boolean match(Matcher matcher, int i, CharSequence seq) { 4884 // Avoid infinite loop in zero-length case. 4885 if (i > matcher.locals[beginIndex]) { 4886 int count = matcher.locals[countIndex]; 4887 4888 // This block is for before we reach the minimum 4889 // iterations required for the loop to match 4890 if (count < cmin) { 4891 matcher.locals[countIndex] = count + 1; 4892 boolean b = body.match(matcher, i, seq); 4893 // If match failed we must backtrack, so 4894 // the loop count should NOT be incremented 4895 if (!b) 4896 matcher.locals[countIndex] = count; 4897 // Return success or failure since we are under 4898 // minimum 4899 return b; 4900 } 4901 // This block is for after we have the minimum 4902 // iterations required for the loop to match 4903 if (count < cmax) { 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 else 4911 return true; 4912 } 4913 } 4914 return next.match(matcher, i, seq); 4915 } 4916 boolean matchInit(Matcher matcher, int i, CharSequence seq) { 4917 int save = matcher.locals[countIndex]; 4918 boolean ret = false; 4919 if (0 < cmin) { 4920 matcher.locals[countIndex] = 1; 4921 ret = body.match(matcher, i, seq); 4922 } else if (0 < cmax) { 4923 matcher.locals[countIndex] = 1; 4924 ret = body.match(matcher, i, seq); 4925 if (ret == false) 4926 ret = next.match(matcher, i, seq); 4927 } else { 4928 ret = next.match(matcher, i, seq); 4929 } 4930 matcher.locals[countIndex] = save; 4931 return ret; 4932 } 4933 boolean study(TreeInfo info) { 4934 info.maxValid = false; 4935 info.deterministic = false; 4936 return false; 4937 } 4938 } 4939 4940 /** 4941 * Handles the repetition count for a reluctant Curly. The matchInit 4942 * is called from the Prolog to save the index of where the group 4943 * beginning is stored. A zero length group check occurs in the 4944 * normal match but is skipped in the matchInit. 4945 */ 4946 static final class LazyLoop extends Loop { 4947 LazyLoop(int countIndex, int beginIndex) { 4948 super(countIndex, beginIndex); 4949 } 4950 boolean match(Matcher matcher, int i, CharSequence seq) { 4951 // Check for zero length group 4952 if (i > matcher.locals[beginIndex]) { 4953 int count = matcher.locals[countIndex]; 4954 if (count < cmin) { 4955 matcher.locals[countIndex] = count + 1; 4956 boolean result = body.match(matcher, i, seq); 4957 // If match failed we must backtrack, so 4958 // the loop count should NOT be incremented 4959 if (!result) 4960 matcher.locals[countIndex] = count; 4961 return result; 4962 } 4963 if (next.match(matcher, i, seq)) 4964 return true; 4965 if (count < cmax) { 4966 matcher.locals[countIndex] = count + 1; 4967 boolean result = body.match(matcher, i, seq); 4968 // If match failed we must backtrack, so 4969 // the loop count should NOT be incremented 4970 if (!result) 4971 matcher.locals[countIndex] = count; 4972 return result; 4973 } 4974 return false; 4975 } 4976 return next.match(matcher, i, seq); 4977 } 4978 boolean matchInit(Matcher matcher, int i, CharSequence seq) { 4979 int save = matcher.locals[countIndex]; 4980 boolean ret = false; 4981 if (0 < cmin) { 4982 matcher.locals[countIndex] = 1; 4983 ret = body.match(matcher, i, seq); 4984 } else if (next.match(matcher, i, seq)) { 4985 ret = true; 4986 } else if (0 < cmax) { 4987 matcher.locals[countIndex] = 1; 4988 ret = body.match(matcher, i, seq); 4989 } 4990 matcher.locals[countIndex] = save; 4991 return ret; 4992 } 4993 boolean study(TreeInfo info) { 4994 info.maxValid = false; 4995 info.deterministic = false; 4996 return false; 4997 } 4998 } 4999 5000 /** 5001 * Refers to a group in the regular expression. Attempts to match 5002 * whatever the group referred to last matched. 5003 */ 5004 static class BackRef extends Node { 5005 int groupIndex; 5006 BackRef(int groupCount) { 5007 super(); 5008 groupIndex = groupCount + groupCount; 5009 } 5010 boolean match(Matcher matcher, int i, CharSequence seq) { 5011 int j = matcher.groups[groupIndex]; 5012 int k = matcher.groups[groupIndex+1]; 5013 5014 int groupSize = k - j; 5015 // If the referenced group didn't match, neither can this 5016 if (j < 0) 5017 return false; 5018 5019 // If there isn't enough input left no match 5020 if (i + groupSize > matcher.to) { 5021 matcher.hitEnd = true; 5022 return false; 5023 } 5024 // Check each new char to make sure it matches what the group 5025 // referenced matched last time around 5026 for (int index=0; index<groupSize; index++) 5027 if (seq.charAt(i+index) != seq.charAt(j+index)) 5028 return false; 5029 5030 return next.match(matcher, i+groupSize, seq); 5031 } 5032 boolean study(TreeInfo info) { 5033 info.maxValid = false; 5034 return next.study(info); 5035 } 5036 } 5037 5038 static class CIBackRef extends Node { 5039 int groupIndex; 5040 boolean doUnicodeCase; 5041 CIBackRef(int groupCount, boolean doUnicodeCase) { 5042 super(); 5043 groupIndex = groupCount + groupCount; 5044 this.doUnicodeCase = doUnicodeCase; 5045 } 5046 boolean match(Matcher matcher, int i, CharSequence seq) { 5047 int j = matcher.groups[groupIndex]; 5048 int k = matcher.groups[groupIndex+1]; 5049 5050 int groupSize = k - j; 5051 5052 // If the referenced group didn't match, neither can this 5053 if (j < 0) 5054 return false; 5055 5056 // If there isn't enough input left no match 5057 if (i + groupSize > matcher.to) { 5058 matcher.hitEnd = true; 5059 return false; 5060 } 5061 5062 // Check each new char to make sure it matches what the group 5063 // referenced matched last time around 5064 int x = i; 5065 for (int index=0; index<groupSize; index++) { 5066 int c1 = Character.codePointAt(seq, x); 5067 int c2 = Character.codePointAt(seq, j); 5068 if (c1 != c2) { 5069 if (doUnicodeCase) { 5070 int cc1 = Character.toUpperCase(c1); 5071 int cc2 = Character.toUpperCase(c2); 5072 if (cc1 != cc2 && 5073 Character.toLowerCase(cc1) != 5074 Character.toLowerCase(cc2)) 5075 return false; 5076 } else { 5077 if (ASCII.toLower(c1) != ASCII.toLower(c2)) 5078 return false; 5079 } 5080 } 5081 x += Character.charCount(c1); 5082 j += Character.charCount(c2); 5083 } 5084 5085 return next.match(matcher, i+groupSize, seq); 5086 } 5087 boolean study(TreeInfo info) { 5088 info.maxValid = false; 5089 return next.study(info); 5090 } 5091 } 5092 5093 /** 5094 * Searches until the next instance of its atom. This is useful for 5095 * finding the atom efficiently without passing an instance of it 5096 * (greedy problem) and without a lot of wasted search time (reluctant 5097 * problem). 5098 */ 5099 static final class First extends Node { 5100 Node atom; 5101 First(Node node) { 5102 this.atom = BnM.optimize(node); 5103 } 5104 boolean match(Matcher matcher, int i, CharSequence seq) { 5105 if (atom instanceof BnM) { 5106 return atom.match(matcher, i, seq) 5107 && next.match(matcher, matcher.last, seq); 5108 } 5109 for (;;) { 5110 if (i > matcher.to) { 5111 matcher.hitEnd = true; 5112 return false; 5113 } 5114 if (atom.match(matcher, i, seq)) { 5115 return next.match(matcher, matcher.last, seq); 5116 } 5117 i += countChars(seq, i, 1); 5118 matcher.first++; 5119 } 5120 } 5121 boolean study(TreeInfo info) { 5122 atom.study(info); 5123 info.maxValid = false; 5124 info.deterministic = false; 5125 return next.study(info); 5126 } 5127 } 5128 5129 static final class Conditional extends Node { 5130 Node cond, yes, not; 5131 Conditional(Node cond, Node yes, Node not) { 5132 this.cond = cond; 5133 this.yes = yes; 5134 this.not = not; 5135 } 5136 boolean match(Matcher matcher, int i, CharSequence seq) { 5137 if (cond.match(matcher, i, seq)) { 5138 return yes.match(matcher, i, seq); 5139 } else { 5140 return not.match(matcher, i, seq); 5141 } 5142 } 5143 boolean study(TreeInfo info) { 5144 int minL = info.minLength; 5145 int maxL = info.maxLength; 5146 boolean maxV = info.maxValid; 5147 info.reset(); 5148 yes.study(info); 5149 5150 int minL2 = info.minLength; 5151 int maxL2 = info.maxLength; 5152 boolean maxV2 = info.maxValid; 5153 info.reset(); 5154 not.study(info); 5155 5156 info.minLength = minL + Math.min(minL2, info.minLength); 5157 info.maxLength = maxL + Math.max(maxL2, info.maxLength); 5158 info.maxValid = (maxV & maxV2 & info.maxValid); 5159 info.deterministic = false; 5160 return next.study(info); 5161 } 5162 } 5163 5164 /** 5165 * Zero width positive lookahead. 5166 */ 5167 static final class Pos extends Node { 5168 Node cond; 5169 Pos(Node cond) { 5170 this.cond = cond; 5171 } 5172 boolean match(Matcher matcher, int i, CharSequence seq) { 5173 int savedTo = matcher.to; 5174 boolean conditionMatched = false; 5175 5176 // Relax transparent region boundaries for lookahead 5177 if (matcher.transparentBounds) 5178 matcher.to = matcher.getTextLength(); 5179 try { 5180 conditionMatched = cond.match(matcher, i, seq); 5181 } finally { 5182 // Reinstate region boundaries 5183 matcher.to = savedTo; 5184 } 5185 return conditionMatched && next.match(matcher, i, seq); 5186 } 5187 } 5188 5189 /** 5190 * Zero width negative lookahead. 5191 */ 5192 static final class Neg extends Node { 5193 Node cond; 5194 Neg(Node cond) { 5195 this.cond = cond; 5196 } 5197 boolean match(Matcher matcher, int i, CharSequence seq) { 5198 int savedTo = matcher.to; 5199 boolean conditionMatched = false; 5200 5201 // Relax transparent region boundaries for lookahead 5202 if (matcher.transparentBounds) 5203 matcher.to = matcher.getTextLength(); 5204 try { 5205 if (i < matcher.to) { 5206 conditionMatched = !cond.match(matcher, i, seq); 5207 } else { 5208 // If a negative lookahead succeeds then more input 5209 // could cause it to fail! 5210 matcher.requireEnd = true; 5211 conditionMatched = !cond.match(matcher, i, seq); 5212 } 5213 } finally { 5214 // Reinstate region boundaries 5215 matcher.to = savedTo; 5216 } 5217 return conditionMatched && next.match(matcher, i, seq); 5218 } 5219 } 5220 5221 /** 5222 * For use with lookbehinds; matches the position where the lookbehind 5223 * was encountered. 5224 */ 5225 static Node lookbehindEnd = new Node() { 5226 boolean match(Matcher matcher, int i, CharSequence seq) { 5227 return i == matcher.lookbehindTo; 5228 } 5229 }; 5230 5231 /** 5232 * Zero width positive lookbehind. 5233 */ 5234 static class Behind extends Node { 5235 Node cond; 5236 int rmax, rmin; 5237 Behind(Node cond, int rmax, int rmin) { 5238 this.cond = cond; 5239 this.rmax = rmax; 5240 this.rmin = rmin; 5241 } 5242 5243 boolean match(Matcher matcher, int i, CharSequence seq) { 5244 int savedFrom = matcher.from; 5245 boolean conditionMatched = false; 5246 int startIndex = (!matcher.transparentBounds) ? 5247 matcher.from : 0; 5248 int from = Math.max(i - rmax, startIndex); 5249 // Set end boundary 5250 int savedLBT = matcher.lookbehindTo; 5251 matcher.lookbehindTo = i; 5252 // Relax transparent region boundaries for lookbehind 5253 if (matcher.transparentBounds) 5254 matcher.from = 0; 5255 for (int j = i - rmin; !conditionMatched && j >= from; j--) { 5256 conditionMatched = cond.match(matcher, j, seq); 5257 } 5258 matcher.from = savedFrom; 5259 matcher.lookbehindTo = savedLBT; 5260 return conditionMatched && next.match(matcher, i, seq); 5261 } 5262 } 5263 5264 /** 5265 * Zero width positive lookbehind, including supplementary 5266 * characters or unpaired surrogates. 5267 */ 5268 static final class BehindS extends Behind { 5269 BehindS(Node cond, int rmax, int rmin) { 5270 super(cond, rmax, rmin); 5271 } 5272 boolean match(Matcher matcher, int i, CharSequence seq) { 5273 int rmaxChars = countChars(seq, i, -rmax); 5274 int rminChars = countChars(seq, i, -rmin); 5275 int savedFrom = matcher.from; 5276 int startIndex = (!matcher.transparentBounds) ? 5277 matcher.from : 0; 5278 boolean conditionMatched = false; 5279 int from = Math.max(i - rmaxChars, startIndex); 5280 // Set end boundary 5281 int savedLBT = matcher.lookbehindTo; 5282 matcher.lookbehindTo = i; 5283 // Relax transparent region boundaries for lookbehind 5284 if (matcher.transparentBounds) 5285 matcher.from = 0; 5286 5287 for (int j = i - rminChars; 5288 !conditionMatched && j >= from; 5289 j -= j>from ? countChars(seq, j, -1) : 1) { 5290 conditionMatched = cond.match(matcher, j, seq); 5291 } 5292 matcher.from = savedFrom; 5293 matcher.lookbehindTo = savedLBT; 5294 return conditionMatched && next.match(matcher, i, seq); 5295 } 5296 } 5297 5298 /** 5299 * Zero width negative lookbehind. 5300 */ 5301 static class NotBehind extends Node { 5302 Node cond; 5303 int rmax, rmin; 5304 NotBehind(Node cond, int rmax, int rmin) { 5305 this.cond = cond; 5306 this.rmax = rmax; 5307 this.rmin = rmin; 5308 } 5309 5310 boolean match(Matcher matcher, int i, CharSequence seq) { 5311 int savedLBT = matcher.lookbehindTo; 5312 int savedFrom = matcher.from; 5313 boolean conditionMatched = false; 5314 int startIndex = (!matcher.transparentBounds) ? 5315 matcher.from : 0; 5316 int from = Math.max(i - rmax, startIndex); 5317 matcher.lookbehindTo = i; 5318 // Relax transparent region boundaries for lookbehind 5319 if (matcher.transparentBounds) 5320 matcher.from = 0; 5321 for (int j = i - rmin; !conditionMatched && j >= from; j--) { 5322 conditionMatched = cond.match(matcher, j, seq); 5323 } 5324 // Reinstate region boundaries 5325 matcher.from = savedFrom; 5326 matcher.lookbehindTo = savedLBT; 5327 return !conditionMatched && next.match(matcher, i, seq); 5328 } 5329 } 5330 5331 /** 5332 * Zero width negative lookbehind, including supplementary 5333 * characters or unpaired surrogates. 5334 */ 5335 static final class NotBehindS extends NotBehind { 5336 NotBehindS(Node cond, int rmax, int rmin) { 5337 super(cond, rmax, rmin); 5338 } 5339 boolean match(Matcher matcher, int i, CharSequence seq) { 5340 int rmaxChars = countChars(seq, i, -rmax); 5341 int rminChars = countChars(seq, i, -rmin); 5342 int savedFrom = matcher.from; 5343 int savedLBT = matcher.lookbehindTo; 5344 boolean conditionMatched = false; 5345 int startIndex = (!matcher.transparentBounds) ? 5346 matcher.from : 0; 5347 int from = Math.max(i - rmaxChars, startIndex); 5348 matcher.lookbehindTo = i; 5349 // Relax transparent region boundaries for lookbehind 5350 if (matcher.transparentBounds) 5351 matcher.from = 0; 5352 for (int j = i - rminChars; 5353 !conditionMatched && j >= from; 5354 j -= j>from ? countChars(seq, j, -1) : 1) { 5355 conditionMatched = cond.match(matcher, j, seq); 5356 } 5357 //Reinstate region boundaries 5358 matcher.from = savedFrom; 5359 matcher.lookbehindTo = savedLBT; 5360 return !conditionMatched && next.match(matcher, i, seq); 5361 } 5362 } 5363 5364 /** 5365 * Returns the set union of two CharProperty nodes. 5366 */ 5367 private static CharProperty union(final CharProperty lhs, 5368 final CharProperty rhs) { 5369 return new CharProperty() { 5370 boolean isSatisfiedBy(int ch) { 5371 return lhs.isSatisfiedBy(ch) || rhs.isSatisfiedBy(ch);}}; 5372 } 5373 5374 /** 5375 * Returns the set intersection of two CharProperty nodes. 5376 */ 5377 private static CharProperty intersection(final CharProperty lhs, 5378 final CharProperty rhs) { 5379 return new CharProperty() { 5380 boolean isSatisfiedBy(int ch) { 5381 return lhs.isSatisfiedBy(ch) && rhs.isSatisfiedBy(ch);}}; 5382 } 5383 5384 /** 5385 * Returns the set difference of two CharProperty nodes. 5386 */ 5387 private static CharProperty setDifference(final CharProperty lhs, 5388 final CharProperty rhs) { 5389 return new CharProperty() { 5390 boolean isSatisfiedBy(int ch) { 5391 return ! rhs.isSatisfiedBy(ch) && lhs.isSatisfiedBy(ch);}}; 5392 } 5393 5394 /** 5395 * Handles word boundaries. Includes a field to allow this one class to 5396 * deal with the different types of word boundaries we can match. The word 5397 * characters include underscores, letters, and digits. Non spacing marks 5398 * can are also part of a word if they have a base character, otherwise 5399 * they are ignored for purposes of finding word boundaries. 5400 */ 5401 static final class Bound extends Node { 5402 static int LEFT = 0x1; 5403 static int RIGHT= 0x2; 5404 static int BOTH = 0x3; 5405 static int NONE = 0x4; 5406 int type; 5407 boolean useUWORD; 5408 Bound(int n, boolean useUWORD) { 5409 type = n; 5410 this.useUWORD = useUWORD; 5411 } 5412 5413 boolean isWord(int ch) { 5414 return useUWORD ? UnicodeProp.WORD.is(ch) 5415 : (ch == '_' || Character.isLetterOrDigit(ch)); 5416 } 5417 5418 int check(Matcher matcher, int i, CharSequence seq) { 5419 int ch; 5420 boolean left = false; 5421 int startIndex = matcher.from; 5422 int endIndex = matcher.to; 5423 if (matcher.transparentBounds) { 5424 startIndex = 0; 5425 endIndex = matcher.getTextLength(); 5426 } 5427 if (i > startIndex) { 5428 ch = Character.codePointBefore(seq, i); 5429 left = (isWord(ch) || 5430 ((Character.getType(ch) == Character.NON_SPACING_MARK) 5431 && hasBaseCharacter(matcher, i-1, seq))); 5432 } 5433 boolean right = false; 5434 if (i < endIndex) { 5435 ch = Character.codePointAt(seq, i); 5436 right = (isWord(ch) || 5437 ((Character.getType(ch) == Character.NON_SPACING_MARK) 5438 && hasBaseCharacter(matcher, i, seq))); 5439 } else { 5440 // Tried to access char past the end 5441 matcher.hitEnd = true; 5442 // The addition of another char could wreck a boundary 5443 matcher.requireEnd = true; 5444 } 5445 return ((left ^ right) ? (right ? LEFT : RIGHT) : NONE); 5446 } 5447 boolean match(Matcher matcher, int i, CharSequence seq) { 5448 return (check(matcher, i, seq) & type) > 0 5449 && next.match(matcher, i, seq); 5450 } 5451 } 5452 5453 /** 5454 * Non spacing marks only count as word characters in bounds calculations 5455 * if they have a base character. 5456 */ 5457 private static boolean hasBaseCharacter(Matcher matcher, int i, 5458 CharSequence seq) 5459 { 5460 int start = (!matcher.transparentBounds) ? 5461 matcher.from : 0; 5462 for (int x=i; x >= start; x--) { 5463 int ch = Character.codePointAt(seq, x); 5464 if (Character.isLetterOrDigit(ch)) 5465 return true; 5466 if (Character.getType(ch) == Character.NON_SPACING_MARK) 5467 continue; 5468 return false; 5469 } 5470 return false; 5471 } 5472 5473 /** 5474 * Attempts to match a slice in the input using the Boyer-Moore string 5475 * matching algorithm. The algorithm is based on the idea that the 5476 * pattern can be shifted farther ahead in the search text if it is 5477 * matched right to left. 5478 * <p> 5479 * The pattern is compared to the input one character at a time, from 5480 * the rightmost character in the pattern to the left. If the characters 5481 * all match the pattern has been found. If a character does not match, 5482 * the pattern is shifted right a distance that is the maximum of two 5483 * functions, the bad character shift and the good suffix shift. This 5484 * shift moves the attempted match position through the input more 5485 * quickly than a naive one position at a time check. 5486 * <p> 5487 * The bad character shift is based on the character from the text that 5488 * did not match. If the character does not appear in the pattern, the 5489 * pattern can be shifted completely beyond the bad character. If the 5490 * character does occur in the pattern, the pattern can be shifted to 5491 * line the pattern up with the next occurrence of that character. 5492 * <p> 5493 * The good suffix shift is based on the idea that some subset on the right 5494 * side of the pattern has matched. When a bad character is found, the 5495 * pattern can be shifted right by the pattern length if the subset does 5496 * not occur again in pattern, or by the amount of distance to the 5497 * next occurrence of the subset in the pattern. 5498 * 5499 * Boyer-Moore search methods adapted from code by Amy Yu. 5500 */ 5501 static class BnM extends Node { 5502 int[] buffer; 5503 int[] lastOcc; 5504 int[] optoSft; 5505 5506 /** 5507 * Pre calculates arrays needed to generate the bad character 5508 * shift and the good suffix shift. Only the last seven bits 5509 * are used to see if chars match; This keeps the tables small 5510 * and covers the heavily used ASCII range, but occasionally 5511 * results in an aliased match for the bad character shift. 5512 */ 5513 static Node optimize(Node node) { 5514 if (!(node instanceof Slice)) { 5515 return node; 5516 } 5517 5518 int[] src = ((Slice) node).buffer; 5519 int patternLength = src.length; 5520 // The BM algorithm requires a bit of overhead; 5521 // If the pattern is short don't use it, since 5522 // a shift larger than the pattern length cannot 5523 // be used anyway. 5524 if (patternLength < 4) { 5525 return node; 5526 } 5527 int i, j, k; 5528 int[] lastOcc = new int[128]; 5529 int[] optoSft = new int[patternLength]; 5530 // Precalculate part of the bad character shift 5531 // It is a table for where in the pattern each 5532 // lower 7-bit value occurs 5533 for (i = 0; i < patternLength; i++) { 5534 lastOcc[src[i]&0x7F] = i + 1; 5535 } 5536 // Precalculate the good suffix shift 5537 // i is the shift amount being considered 5538 NEXT: for (i = patternLength; i > 0; i--) { 5539 // j is the beginning index of suffix being considered 5540 for (j = patternLength - 1; j >= i; j--) { 5541 // Testing for good suffix 5542 if (src[j] == src[j-i]) { 5543 // src[j..len] is a good suffix 5544 optoSft[j-1] = i; 5545 } else { 5546 // No match. The array has already been 5547 // filled up with correct values before. 5548 continue NEXT; 5549 } 5550 } 5551 // This fills up the remaining of optoSft 5552 // any suffix can not have larger shift amount 5553 // then its sub-suffix. Why??? 5554 while (j > 0) { 5555 optoSft[--j] = i; 5556 } 5557 } 5558 // Set the guard value because of unicode compression 5559 optoSft[patternLength-1] = 1; 5560 if (node instanceof SliceS) 5561 return new BnMS(src, lastOcc, optoSft, node.next); 5562 return new BnM(src, lastOcc, optoSft, node.next); 5563 } 5564 BnM(int[] src, int[] lastOcc, int[] optoSft, Node next) { 5565 this.buffer = src; 5566 this.lastOcc = lastOcc; 5567 this.optoSft = optoSft; 5568 this.next = next; 5569 } 5570 boolean match(Matcher matcher, int i, CharSequence seq) { 5571 int[] src = buffer; 5572 int patternLength = src.length; 5573 int last = matcher.to - patternLength; 5574 5575 // Loop over all possible match positions in text 5576 NEXT: while (i <= last) { 5577 // Loop over pattern from right to left 5578 for (int j = patternLength - 1; j >= 0; j--) { 5579 int ch = seq.charAt(i+j); 5580 if (ch != src[j]) { 5581 // Shift search to the right by the maximum of the 5582 // bad character shift and the good suffix shift 5583 i += Math.max(j + 1 - lastOcc[ch&0x7F], optoSft[j]); 5584 continue NEXT; 5585 } 5586 } 5587 // Entire pattern matched starting at i 5588 matcher.first = i; 5589 boolean ret = next.match(matcher, i + patternLength, seq); 5590 if (ret) { 5591 matcher.first = i; 5592 matcher.groups[0] = matcher.first; 5593 matcher.groups[1] = matcher.last; 5594 return true; 5595 } 5596 i++; 5597 } 5598 // BnM is only used as the leading node in the unanchored case, 5599 // and it replaced its Start() which always searches to the end 5600 // if it doesn't find what it's looking for, so hitEnd is true. 5601 matcher.hitEnd = true; 5602 return false; 5603 } 5604 boolean study(TreeInfo info) { 5605 info.minLength += buffer.length; 5606 info.maxValid = false; 5607 return next.study(info); 5608 } 5609 } 5610 5611 /** 5612 * Supplementary support version of BnM(). Unpaired surrogates are 5613 * also handled by this class. 5614 */ 5615 static final class BnMS extends BnM { 5616 int lengthInChars; 5617 5618 BnMS(int[] src, int[] lastOcc, int[] optoSft, Node next) { 5619 super(src, lastOcc, optoSft, next); 5620 for (int cp : buffer) { 5621 lengthInChars += Character.charCount(cp); 5622 } 5623 } 5624 boolean match(Matcher matcher, int i, CharSequence seq) { 5625 int[] src = buffer; 5626 int patternLength = src.length; 5627 int last = matcher.to - lengthInChars; 5628 5629 // Loop over all possible match positions in text 5630 NEXT: while (i <= last) { 5631 // Loop over pattern from right to left 5632 int ch; 5633 for (int j = countChars(seq, i, patternLength), x = patternLength - 1; 5634 j > 0; j -= Character.charCount(ch), x--) { 5635 ch = Character.codePointBefore(seq, i+j); 5636 if (ch != src[x]) { 5637 // Shift search to the right by the maximum of the 5638 // bad character shift and the good suffix shift 5639 int n = Math.max(x + 1 - lastOcc[ch&0x7F], optoSft[x]); 5640 i += countChars(seq, i, n); 5641 continue NEXT; 5642 } 5643 } 5644 // Entire pattern matched starting at i 5645 matcher.first = i; 5646 boolean ret = next.match(matcher, i + lengthInChars, seq); 5647 if (ret) { 5648 matcher.first = i; 5649 matcher.groups[0] = matcher.first; 5650 matcher.groups[1] = matcher.last; 5651 return true; 5652 } 5653 i += countChars(seq, i, 1); 5654 } 5655 matcher.hitEnd = true; 5656 return false; 5657 } 5658 } 5659 5660 /////////////////////////////////////////////////////////////////////////////// 5661 /////////////////////////////////////////////////////////////////////////////// 5662 5663 /** 5664 * This must be the very first initializer. 5665 */ 5666 static Node accept = new Node(); 5667 5668 static Node lastAccept = new LastNode(); 5669 5670 private static class CharPropertyNames { 5671 5672 static CharProperty charPropertyFor(String name) { 5673 CharPropertyFactory m = map.get(name); 5674 return m == null ? null : m.make(); 5675 } 5676 5677 private abstract static class CharPropertyFactory { 5678 abstract CharProperty make(); 5679 } 5680 5681 private static void defCategory(String name, 5682 final int typeMask) { 5683 map.put(name, new CharPropertyFactory() { 5684 CharProperty make() { return new Category(typeMask);}}); 5685 } 5686 5687 private static void defRange(String name, 5688 final int lower, final int upper) { 5689 map.put(name, new CharPropertyFactory() { 5690 CharProperty make() { return rangeFor(lower, upper);}}); 5691 } 5692 5693 private static void defCtype(String name, 5694 final int ctype) { 5695 map.put(name, new CharPropertyFactory() { 5696 CharProperty make() { return new Ctype(ctype);}}); 5697 } 5698 5699 private abstract static class CloneableProperty 5700 extends CharProperty implements Cloneable 5701 { 5702 public CloneableProperty clone() { 5703 try { 5704 return (CloneableProperty) super.clone(); 5705 } catch (CloneNotSupportedException e) { 5706 throw new AssertionError(e); 5707 } 5708 } 5709 } 5710 5711 private static void defClone(String name, 5712 final CloneableProperty p) { 5713 map.put(name, new CharPropertyFactory() { 5714 CharProperty make() { return p.clone();}}); 5715 } 5716 5717 private static final HashMap<String, CharPropertyFactory> map 5718 = new HashMap<>(); 5719 5720 static { 5721 // Unicode character property aliases, defined in 5722 // http://www.unicode.org/Public/UNIDATA/PropertyValueAliases.txt 5723 defCategory("Cn", 1<<Character.UNASSIGNED); 5724 defCategory("Lu", 1<<Character.UPPERCASE_LETTER); 5725 defCategory("Ll", 1<<Character.LOWERCASE_LETTER); 5726 defCategory("Lt", 1<<Character.TITLECASE_LETTER); 5727 defCategory("Lm", 1<<Character.MODIFIER_LETTER); 5728 defCategory("Lo", 1<<Character.OTHER_LETTER); 5729 defCategory("Mn", 1<<Character.NON_SPACING_MARK); 5730 defCategory("Me", 1<<Character.ENCLOSING_MARK); 5731 defCategory("Mc", 1<<Character.COMBINING_SPACING_MARK); 5732 defCategory("Nd", 1<<Character.DECIMAL_DIGIT_NUMBER); 5733 defCategory("Nl", 1<<Character.LETTER_NUMBER); 5734 defCategory("No", 1<<Character.OTHER_NUMBER); 5735 defCategory("Zs", 1<<Character.SPACE_SEPARATOR); 5736 defCategory("Zl", 1<<Character.LINE_SEPARATOR); 5737 defCategory("Zp", 1<<Character.PARAGRAPH_SEPARATOR); 5738 defCategory("Cc", 1<<Character.CONTROL); 5739 defCategory("Cf", 1<<Character.FORMAT); 5740 defCategory("Co", 1<<Character.PRIVATE_USE); 5741 defCategory("Cs", 1<<Character.SURROGATE); 5742 defCategory("Pd", 1<<Character.DASH_PUNCTUATION); 5743 defCategory("Ps", 1<<Character.START_PUNCTUATION); 5744 defCategory("Pe", 1<<Character.END_PUNCTUATION); 5745 defCategory("Pc", 1<<Character.CONNECTOR_PUNCTUATION); 5746 defCategory("Po", 1<<Character.OTHER_PUNCTUATION); 5747 defCategory("Sm", 1<<Character.MATH_SYMBOL); 5748 defCategory("Sc", 1<<Character.CURRENCY_SYMBOL); 5749 defCategory("Sk", 1<<Character.MODIFIER_SYMBOL); 5750 defCategory("So", 1<<Character.OTHER_SYMBOL); 5751 defCategory("Pi", 1<<Character.INITIAL_QUOTE_PUNCTUATION); 5752 defCategory("Pf", 1<<Character.FINAL_QUOTE_PUNCTUATION); 5753 defCategory("L", ((1<<Character.UPPERCASE_LETTER) | 5754 (1<<Character.LOWERCASE_LETTER) | 5755 (1<<Character.TITLECASE_LETTER) | 5756 (1<<Character.MODIFIER_LETTER) | 5757 (1<<Character.OTHER_LETTER))); 5758 defCategory("M", ((1<<Character.NON_SPACING_MARK) | 5759 (1<<Character.ENCLOSING_MARK) | 5760 (1<<Character.COMBINING_SPACING_MARK))); 5761 defCategory("N", ((1<<Character.DECIMAL_DIGIT_NUMBER) | 5762 (1<<Character.LETTER_NUMBER) | 5763 (1<<Character.OTHER_NUMBER))); 5764 defCategory("Z", ((1<<Character.SPACE_SEPARATOR) | 5765 (1<<Character.LINE_SEPARATOR) | 5766 (1<<Character.PARAGRAPH_SEPARATOR))); 5767 defCategory("C", ((1<<Character.CONTROL) | 5768 (1<<Character.FORMAT) | 5769 (1<<Character.PRIVATE_USE) | 5770 (1<<Character.SURROGATE))); // Other 5771 defCategory("P", ((1<<Character.DASH_PUNCTUATION) | 5772 (1<<Character.START_PUNCTUATION) | 5773 (1<<Character.END_PUNCTUATION) | 5774 (1<<Character.CONNECTOR_PUNCTUATION) | 5775 (1<<Character.OTHER_PUNCTUATION) | 5776 (1<<Character.INITIAL_QUOTE_PUNCTUATION) | 5777 (1<<Character.FINAL_QUOTE_PUNCTUATION))); 5778 defCategory("S", ((1<<Character.MATH_SYMBOL) | 5779 (1<<Character.CURRENCY_SYMBOL) | 5780 (1<<Character.MODIFIER_SYMBOL) | 5781 (1<<Character.OTHER_SYMBOL))); 5782 defCategory("LC", ((1<<Character.UPPERCASE_LETTER) | 5783 (1<<Character.LOWERCASE_LETTER) | 5784 (1<<Character.TITLECASE_LETTER))); 5785 defCategory("LD", ((1<<Character.UPPERCASE_LETTER) | 5786 (1<<Character.LOWERCASE_LETTER) | 5787 (1<<Character.TITLECASE_LETTER) | 5788 (1<<Character.MODIFIER_LETTER) | 5789 (1<<Character.OTHER_LETTER) | 5790 (1<<Character.DECIMAL_DIGIT_NUMBER))); 5791 defRange("L1", 0x00, 0xFF); // Latin-1 5792 map.put("all", new CharPropertyFactory() { 5793 CharProperty make() { return new All(); }}); 5794 5795 // Posix regular expression character classes, defined in 5796 // http://www.unix.org/onlinepubs/009695399/basedefs/xbd_chap09.html 5797 defRange("ASCII", 0x00, 0x7F); // ASCII 5798 defCtype("Alnum", ASCII.ALNUM); // Alphanumeric characters 5799 defCtype("Alpha", ASCII.ALPHA); // Alphabetic characters 5800 defCtype("Blank", ASCII.BLANK); // Space and tab characters 5801 defCtype("Cntrl", ASCII.CNTRL); // Control characters 5802 defRange("Digit", '0', '9'); // Numeric characters 5803 defCtype("Graph", ASCII.GRAPH); // printable and visible 5804 defRange("Lower", 'a', 'z'); // Lower-case alphabetic 5805 defRange("Print", 0x20, 0x7E); // Printable characters 5806 defCtype("Punct", ASCII.PUNCT); // Punctuation characters 5807 defCtype("Space", ASCII.SPACE); // Space characters 5808 defRange("Upper", 'A', 'Z'); // Upper-case alphabetic 5809 defCtype("XDigit",ASCII.XDIGIT); // hexadecimal digits 5810 5811 // Java character properties, defined by methods in Character.java 5812 defClone("javaLowerCase", new CloneableProperty() { 5813 boolean isSatisfiedBy(int ch) { 5814 return Character.isLowerCase(ch);}}); 5815 defClone("javaUpperCase", new CloneableProperty() { 5816 boolean isSatisfiedBy(int ch) { 5817 return Character.isUpperCase(ch);}}); 5818 defClone("javaAlphabetic", new CloneableProperty() { 5819 boolean isSatisfiedBy(int ch) { 5820 return Character.isAlphabetic(ch);}}); 5821 defClone("javaIdeographic", new CloneableProperty() { 5822 boolean isSatisfiedBy(int ch) { 5823 return Character.isIdeographic(ch);}}); 5824 defClone("javaTitleCase", new CloneableProperty() { 5825 boolean isSatisfiedBy(int ch) { 5826 return Character.isTitleCase(ch);}}); 5827 defClone("javaDigit", new CloneableProperty() { 5828 boolean isSatisfiedBy(int ch) { 5829 return Character.isDigit(ch);}}); 5830 defClone("javaDefined", new CloneableProperty() { 5831 boolean isSatisfiedBy(int ch) { 5832 return Character.isDefined(ch);}}); 5833 defClone("javaLetter", new CloneableProperty() { 5834 boolean isSatisfiedBy(int ch) { 5835 return Character.isLetter(ch);}}); 5836 defClone("javaLetterOrDigit", new CloneableProperty() { 5837 boolean isSatisfiedBy(int ch) { 5838 return Character.isLetterOrDigit(ch);}}); 5839 defClone("javaJavaIdentifierStart", new CloneableProperty() { 5840 boolean isSatisfiedBy(int ch) { 5841 return Character.isJavaIdentifierStart(ch);}}); 5842 defClone("javaJavaIdentifierPart", new CloneableProperty() { 5843 boolean isSatisfiedBy(int ch) { 5844 return Character.isJavaIdentifierPart(ch);}}); 5845 defClone("javaUnicodeIdentifierStart", new CloneableProperty() { 5846 boolean isSatisfiedBy(int ch) { 5847 return Character.isUnicodeIdentifierStart(ch);}}); 5848 defClone("javaUnicodeIdentifierPart", new CloneableProperty() { 5849 boolean isSatisfiedBy(int ch) { 5850 return Character.isUnicodeIdentifierPart(ch);}}); 5851 defClone("javaIdentifierIgnorable", new CloneableProperty() { 5852 boolean isSatisfiedBy(int ch) { 5853 return Character.isIdentifierIgnorable(ch);}}); 5854 defClone("javaSpaceChar", new CloneableProperty() { 5855 boolean isSatisfiedBy(int ch) { 5856 return Character.isSpaceChar(ch);}}); 5857 defClone("javaWhitespace", new CloneableProperty() { 5858 boolean isSatisfiedBy(int ch) { 5859 return Character.isWhitespace(ch);}}); 5860 defClone("javaISOControl", new CloneableProperty() { 5861 boolean isSatisfiedBy(int ch) { 5862 return Character.isISOControl(ch);}}); 5863 defClone("javaMirrored", new CloneableProperty() { 5864 boolean isSatisfiedBy(int ch) { 5865 return Character.isMirrored(ch);}}); 5866 } 5867 } 5868 5869 /** 5870 * Creates a predicate which can be used to match a string. 5871 * 5872 * @return The predicate which can be used for matching on a string 5873 * @since 1.8 5874 */ 5875 public Predicate<String> asPredicate() { 5876 return s -> matcher(s).find(); 5877 } 5878 5879 /** 5880 * Creates a stream from the given input sequence around matches of this 5881 * pattern. 5882 * 5883 * <p> The stream returned by this method contains each substring of the 5884 * input sequence that is terminated by another subsequence that matches 5885 * this pattern or is terminated by the end of the input sequence. The 5886 * substrings in the stream are in the order in which they occur in the 5887 * input. Trailing empty strings will be discarded and not encountered in 5888 * the stream. 5889 * 5890 * <p> If this pattern does not match any subsequence of the input then 5891 * the resulting stream has just one element, namely the input sequence in 5892 * string form. 5893 * 5894 * <p> When there is a positive-width match at the beginning of the input 5895 * sequence then an empty leading substring is included at the beginning 5896 * of the stream. A zero-width match at the beginning however never produces 5897 * such empty leading substring. 5898 * 5899 * <p> If the input sequence is mutable, it must remain constant during the 5900 * execution of the terminal stream operation. Otherwise, the result of the 5901 * terminal stream operation is undefined. 5902 * 5903 * @param input 5904 * The character sequence to be split 5905 * 5906 * @return The stream of strings computed by splitting the input 5907 * around matches of this pattern 5908 * @see #split(CharSequence) 5909 * @since 1.8 5910 */ 5911 public Stream<String> splitAsStream(final CharSequence input) { 5912 class MatcherIterator implements Iterator<String> { 5913 private Matcher matcher; 5914 // The start position of the next sub-sequence of input 5915 // when current == input.length there are no more elements 5916 private int current; 5917 // null if the next element, if any, needs to obtained 5918 private String nextElement; 5919 // > 0 if there are N next empty elements 5920 private int emptyElementCount; 5921 5922 public String next() { 5923 if (!hasNext()) 5924 throw new NoSuchElementException(); 5925 5926 if (emptyElementCount == 0) { 5927 String n = nextElement; 5928 nextElement = null; 5929 return n; 5930 } else { 5931 emptyElementCount--; 5932 return ""; 5933 } 5934 } 5935 5936 public boolean hasNext() { 5937 if (matcher == null) { 5938 matcher = matcher(input); 5939 // If the input is an empty string then the result can only be a 5940 // stream of the input. Induce that by setting the empty 5941 // element count to 1 5942 emptyElementCount = input.length() == 0 ? 1 : 0; 5943 } 5944 if (nextElement != null || emptyElementCount > 0) 5945 return true; 5946 5947 if (current == input.length()) 5948 return false; 5949 5950 // Consume the next matching element 5951 // Count sequence of matching empty elements 5952 while (matcher.find()) { 5953 nextElement = input.subSequence(current, matcher.start()).toString(); 5954 current = matcher.end(); 5955 if (!nextElement.isEmpty()) { 5956 return true; 5957 } else if (current > 0) { // no empty leading substring for zero-width 5958 // match at the beginning of the input 5959 emptyElementCount++; 5960 } 5961 } 5962 5963 // Consume last matching element 5964 nextElement = input.subSequence(current, input.length()).toString(); 5965 current = input.length(); 5966 if (!nextElement.isEmpty()) { 5967 return true; 5968 } else { 5969 // Ignore a terminal sequence of matching empty elements 5970 emptyElementCount = 0; 5971 nextElement = null; 5972 return false; 5973 } 5974 } 5975 } 5976 return StreamSupport.stream(Spliterators.spliteratorUnknownSize( 5977 new MatcherIterator(), Spliterator.ORDERED | Spliterator.NONNULL), false); 5978 } 5979 }