| /* |
| * Copyright (C) 2014 The Android Open Source Project |
| * Copyright (c) 1999, 2013, Oracle and/or its affiliates. All rights reserved. |
| * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| * |
| * This code is free software; you can redistribute it and/or modify it |
| * under the terms of the GNU General Public License version 2 only, as |
| * published by the Free Software Foundation. Oracle designates this |
| * particular file as subject to the "Classpath" exception as provided |
| * by Oracle in the LICENSE file that accompanied this code. |
| * |
| * This code is distributed in the hope that it will be useful, but WITHOUT |
| * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| * version 2 for more details (a copy is included in the LICENSE file that |
| * accompanied this code). |
| * |
| * You should have received a copy of the GNU General Public License version |
| * 2 along with this work; if not, write to the Free Software Foundation, |
| * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| * |
| * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
| * or visit www.oracle.com if you need additional information or have any |
| * questions. |
| */ |
| |
| package java.util.regex; |
| |
| import dalvik.annotation.optimization.ReachabilitySensitive; |
| import libcore.util.NativeAllocationRegistry; |
| |
| import java.util.Iterator; |
| import java.util.ArrayList; |
| import java.util.NoSuchElementException; |
| import java.util.Spliterator; |
| import java.util.Spliterators; |
| import java.util.function.Predicate; |
| import java.util.stream.Stream; |
| import java.util.stream.StreamSupport; |
| |
| import libcore.util.EmptyArray; |
| |
| /** |
| * A compiled representation of a regular expression. |
| * |
| * <p> A regular expression, specified as a string, must first be compiled into |
| * an instance of this class. The resulting pattern can then be used to create |
| * a {@link Matcher} object that can match arbitrary {@link |
| * java.lang.CharSequence </code>character sequences<code>} against the regular |
| * expression. All of the state involved in performing a match resides in the |
| * matcher, so many matchers can share the same pattern. |
| * |
| * <p> A typical invocation sequence is thus |
| * |
| * <blockquote><pre> |
| * Pattern p = Pattern.{@link #compile compile}("a*b"); |
| * Matcher m = p.{@link #matcher matcher}("aaaaab"); |
| * boolean b = m.{@link Matcher#matches matches}();</pre></blockquote> |
| * |
| * <p> A {@link #matches matches} method is defined by this class as a |
| * convenience for when a regular expression is used just once. This method |
| * compiles an expression and matches an input sequence against it in a single |
| * invocation. The statement |
| * |
| * <blockquote><pre> |
| * boolean b = Pattern.matches("a*b", "aaaaab");</pre></blockquote> |
| * |
| * is equivalent to the three statements above, though for repeated matches it |
| * is less efficient since it does not allow the compiled pattern to be reused. |
| * |
| * <p> Instances of this class are immutable and are safe for use by multiple |
| * concurrent threads. Instances of the {@link Matcher} class are not safe for |
| * such use. |
| * |
| * |
| * <a name="sum"> |
| * <h4> Summary of regular-expression constructs </h4> |
| * |
| * <table border="0" cellpadding="1" cellspacing="0" |
| * summary="Regular expression constructs, and what they match"> |
| * |
| * <tr align="left"> |
| * <th bgcolor="#CCCCFF" align="left" id="construct">Construct</th> |
| * <th bgcolor="#CCCCFF" align="left" id="matches">Matches</th> |
| * </tr> |
| * |
| * <tr><th> </th></tr> |
| * <tr align="left"><th colspan="2" id="characters">Characters</th></tr> |
| * |
| * <tr><td valign="top" headers="construct characters"><i>x</i></td> |
| * <td headers="matches">The character <i>x</i></td></tr> |
| * <tr><td valign="top" headers="construct characters"><tt>\\</tt></td> |
| * <td headers="matches">The backslash character</td></tr> |
| * <tr><td valign="top" headers="construct characters"><tt>\0</tt><i>n</i></td> |
| * <td headers="matches">The character with octal value <tt>0</tt><i>n</i> |
| * (0 <tt><=</tt> <i>n</i> <tt><=</tt> 7)</td></tr> |
| * <tr><td valign="top" headers="construct characters"><tt>\0</tt><i>nn</i></td> |
| * <td headers="matches">The character with octal value <tt>0</tt><i>nn</i> |
| * (0 <tt><=</tt> <i>n</i> <tt><=</tt> 7)</td></tr> |
| * <tr><td valign="top" headers="construct characters"><tt>\0</tt><i>mnn</i></td> |
| * <td headers="matches">The character with octal value <tt>0</tt><i>mnn</i> |
| * (0 <tt><=</tt> <i>m</i> <tt><=</tt> 3, |
| * 0 <tt><=</tt> <i>n</i> <tt><=</tt> 7)</td></tr> |
| * <tr><td valign="top" headers="construct characters"><tt>\x</tt><i>hh</i></td> |
| * <td headers="matches">The character with hexadecimal value <tt>0x</tt><i>hh</i></td></tr> |
| * <tr><td valign="top" headers="construct characters"><tt>\u</tt><i>hhhh</i></td> |
| * <td headers="matches">The character with hexadecimal value <tt>0x</tt><i>hhhh</i></td></tr> |
| * <tr><td valign="top" headers="construct characters"><tt>\x</tt><i>{h...h}</i></td> |
| * <td headers="matches">The character with hexadecimal value <tt>0x</tt><i>h...h</i> |
| * ({@link java.lang.Character#MIN_CODE_POINT Character.MIN_CODE_POINT} |
| * <= <tt>0x</tt><i>h...h</i> <=  |
| * {@link java.lang.Character#MAX_CODE_POINT Character.MAX_CODE_POINT})</td></tr> |
| * <tr><td valign="top" headers="matches"><tt>\t</tt></td> |
| * <td headers="matches">The tab character (<tt>'\u0009'</tt>)</td></tr> |
| * <tr><td valign="top" headers="construct characters"><tt>\n</tt></td> |
| * <td headers="matches">The newline (line feed) character (<tt>'\u000A'</tt>)</td></tr> |
| * <tr><td valign="top" headers="construct characters"><tt>\r</tt></td> |
| * <td headers="matches">The carriage-return character (<tt>'\u000D'</tt>)</td></tr> |
| * <tr><td valign="top" headers="construct characters"><tt>\f</tt></td> |
| * <td headers="matches">The form-feed character (<tt>'\u000C'</tt>)</td></tr> |
| * <tr><td valign="top" headers="construct characters"><tt>\a</tt></td> |
| * <td headers="matches">The alert (bell) character (<tt>'\u0007'</tt>)</td></tr> |
| * <tr><td valign="top" headers="construct characters"><tt>\e</tt></td> |
| * <td headers="matches">The escape character (<tt>'\u001B'</tt>)</td></tr> |
| * <tr><td valign="top" headers="construct characters"><tt>\c</tt><i>x</i></td> |
| * <td headers="matches">The control character corresponding to <i>x</i></td></tr> |
| * |
| * <tr><th> </th></tr> |
| * <tr align="left"><th colspan="2" id="classes">Character classes</th></tr> |
| * |
| * <tr><td valign="top" headers="construct classes"><tt>[abc]</tt></td> |
| * <td headers="matches"><tt>a</tt>, <tt>b</tt>, or <tt>c</tt> (simple class)</td></tr> |
| * <tr><td valign="top" headers="construct classes"><tt>[^abc]</tt></td> |
| * <td headers="matches">Any character except <tt>a</tt>, <tt>b</tt>, or <tt>c</tt> (negation)</td></tr> |
| * <tr><td valign="top" headers="construct classes"><tt>[a-zA-Z]</tt></td> |
| * <td headers="matches"><tt>a</tt> through <tt>z</tt> |
| * or <tt>A</tt> through <tt>Z</tt>, inclusive (range)</td></tr> |
| * <tr><td valign="top" headers="construct classes"><tt>[a-d[m-p]]</tt></td> |
| * <td headers="matches"><tt>a</tt> through <tt>d</tt>, |
| * or <tt>m</tt> through <tt>p</tt>: <tt>[a-dm-p]</tt> (union)</td></tr> |
| * <tr><td valign="top" headers="construct classes"><tt>[a-z&&[def]]</tt></td> |
| * <td headers="matches"><tt>d</tt>, <tt>e</tt>, or <tt>f</tt> (intersection)</tr> |
| * <tr><td valign="top" headers="construct classes"><tt>[a-z&&[^bc]]</tt></td> |
| * <td headers="matches"><tt>a</tt> through <tt>z</tt>, |
| * except for <tt>b</tt> and <tt>c</tt>: <tt>[ad-z]</tt> (subtraction)</td></tr> |
| * <tr><td valign="top" headers="construct classes"><tt>[a-z&&[^m-p]]</tt></td> |
| * <td headers="matches"><tt>a</tt> through <tt>z</tt>, |
| * and not <tt>m</tt> through <tt>p</tt>: <tt>[a-lq-z]</tt>(subtraction)</td></tr> |
| * <tr><th> </th></tr> |
| * |
| * <tr align="left"><th colspan="2" id="predef">Predefined character classes</th></tr> |
| * |
| * <tr><td valign="top" headers="construct predef"><tt>.</tt></td> |
| * <td headers="matches">Any character (may or may not match <a href="#lt">line terminators</a>)</td></tr> |
| * <tr><td valign="top" headers="construct predef"><tt>\d</tt></td> |
| * <td headers="matches">A digit: <tt>[0-9]</tt></td></tr> |
| * <tr><td valign="top" headers="construct predef"><tt>\D</tt></td> |
| * <td headers="matches">A non-digit: <tt>[^0-9]</tt></td></tr> |
| * <tr><td valign="top" headers="construct predef"><tt>\s</tt></td> |
| * <td headers="matches">A whitespace character: <tt>[ \t\n\x0B\f\r]</tt></td></tr> |
| * <tr><td valign="top" headers="construct predef"><tt>\S</tt></td> |
| * <td headers="matches">A non-whitespace character: <tt>[^\s]</tt></td></tr> |
| * <tr><td valign="top" headers="construct predef"><tt>\w</tt></td> |
| * <td headers="matches">A word character: <tt>[a-zA-Z_0-9]</tt></td></tr> |
| * <tr><td valign="top" headers="construct predef"><tt>\W</tt></td> |
| * <td headers="matches">A non-word character: <tt>[^\w]</tt></td></tr> |
| * |
| * <tr><th> </th></tr> |
| * <tr align="left"><th colspan="2" id="posix">POSIX character classes</b> (US-ASCII only)<b></th></tr> |
| * |
| * <tr><td valign="top" headers="construct posix"><tt>\p{Lower}</tt></td> |
| * <td headers="matches">A lower-case alphabetic character: <tt>[a-z]</tt></td></tr> |
| * <tr><td valign="top" headers="construct posix"><tt>\p{Upper}</tt></td> |
| * <td headers="matches">An upper-case alphabetic character:<tt>[A-Z]</tt></td></tr> |
| * <tr><td valign="top" headers="construct posix"><tt>\p{ASCII}</tt></td> |
| * <td headers="matches">All ASCII:<tt>[\x00-\x7F]</tt></td></tr> |
| * <tr><td valign="top" headers="construct posix"><tt>\p{Alpha}</tt></td> |
| * <td headers="matches">An alphabetic character:<tt>[\p{Lower}\p{Upper}]</tt></td></tr> |
| * <tr><td valign="top" headers="construct posix"><tt>\p{Digit}</tt></td> |
| * <td headers="matches">A decimal digit: <tt>[0-9]</tt></td></tr> |
| * <tr><td valign="top" headers="construct posix"><tt>\p{Alnum}</tt></td> |
| * <td headers="matches">An alphanumeric character:<tt>[\p{Alpha}\p{Digit}]</tt></td></tr> |
| * <tr><td valign="top" headers="construct posix"><tt>\p{Punct}</tt></td> |
| * <td headers="matches">Punctuation: One of <tt>!"#$%&'()*+,-./:;<=>?@[\]^_`{|}~</tt></td></tr> |
| * <!-- <tt>[\!"#\$%&'\(\)\*\+,\-\./:;\<=\>\?@\[\\\]\^_`\{\|\}~]</tt> |
| * <tt>[\X21-\X2F\X31-\X40\X5B-\X60\X7B-\X7E]</tt> --> |
| * <tr><td valign="top" headers="construct posix"><tt>\p{Graph}</tt></td> |
| * <td headers="matches">A visible character: <tt>[\p{Alnum}\p{Punct}]</tt></td></tr> |
| * <tr><td valign="top" headers="construct posix"><tt>\p{Print}</tt></td> |
| * <td headers="matches">A printable character: <tt>[\p{Graph}\x20]</tt></td></tr> |
| * <tr><td valign="top" headers="construct posix"><tt>\p{Blank}</tt></td> |
| * <td headers="matches">A space or a tab: <tt>[ \t]</tt></td></tr> |
| * <tr><td valign="top" headers="construct posix"><tt>\p{Cntrl}</tt></td> |
| * <td headers="matches">A control character: <tt>[\x00-\x1F\x7F]</tt></td></tr> |
| * <tr><td valign="top" headers="construct posix"><tt>\p{XDigit}</tt></td> |
| * <td headers="matches">A hexadecimal digit: <tt>[0-9a-fA-F]</tt></td></tr> |
| * <tr><td valign="top" headers="construct posix"><tt>\p{Space}</tt></td> |
| * <td headers="matches">A whitespace character: <tt>[ \t\n\x0B\f\r]</tt></td></tr> |
| * |
| * <tr><th> </th></tr> |
| * <tr align="left"><th colspan="2">java.lang.Character classes (simple <a href="#jcc">java character type</a>)</th></tr> |
| * |
| * <tr><td valign="top"><tt>\p{javaLowerCase}</tt></td> |
| * <td>Equivalent to java.lang.Character.isLowerCase()</td></tr> |
| * <tr><td valign="top"><tt>\p{javaUpperCase}</tt></td> |
| * <td>Equivalent to java.lang.Character.isUpperCase()</td></tr> |
| * <tr><td valign="top"><tt>\p{javaWhitespace}</tt></td> |
| * <td>Equivalent to java.lang.Character.isWhitespace()</td></tr> |
| * <tr><td valign="top"><tt>\p{javaMirrored}</tt></td> |
| * <td>Equivalent to java.lang.Character.isMirrored()</td></tr> |
| * |
| * <tr><th> </th></tr> |
| * <tr align="left"><th colspan="2" id="unicode">Classes for Unicode scripts, blocks, categories and binary properties</th></tr> |
| * * <tr><td valign="top" headers="construct unicode"><tt>\p{IsLatin}</tt></td> |
| * <td headers="matches">A Latin script character (<a href="#usc">script</a>)</td></tr> |
| * <tr><td valign="top" headers="construct unicode"><tt>\p{InGreek}</tt></td> |
| * <td headers="matches">A character in the Greek block (<a href="#ubc">block</a>)</td></tr> |
| * <tr><td valign="top" headers="construct unicode"><tt>\p{Lu}</tt></td> |
| * <td headers="matches">An uppercase letter (<a href="#ucc">category</a>)</td></tr> |
| * <tr><td valign="top" headers="construct unicode"><tt>\p{IsAlphabetic}</tt></td> |
| * <td headers="matches">An alphabetic character (<a href="#ubpc">binary property</a>)</td></tr> |
| * <tr><td valign="top" headers="construct unicode"><tt>\p{Sc}</tt></td> |
| * <td headers="matches">A currency symbol</td></tr> |
| * <tr><td valign="top" headers="construct unicode"><tt>\P{InGreek}</tt></td> |
| * <td headers="matches">Any character except one in the Greek block (negation)</td></tr> |
| * <tr><td valign="top" headers="construct unicode"><tt>[\p{L}&&[^\p{Lu}]] </tt></td> |
| * <td headers="matches">Any letter except an uppercase letter (subtraction)</td></tr> |
| * |
| * <tr><th> </th></tr> |
| * <tr align="left"><th colspan="2" id="bounds">Boundary matchers</th></tr> |
| * |
| * <tr><td valign="top" headers="construct bounds"><tt>^</tt></td> |
| * <td headers="matches">The beginning of a line</td></tr> |
| * <tr><td valign="top" headers="construct bounds"><tt>$</tt></td> |
| * <td headers="matches">The end of a line</td></tr> |
| * <tr><td valign="top" headers="construct bounds"><tt>\b</tt></td> |
| * <td headers="matches">A word boundary</td></tr> |
| * <tr><td valign="top" headers="construct bounds"><tt>\B</tt></td> |
| * <td headers="matches">A non-word boundary</td></tr> |
| * <tr><td valign="top" headers="construct bounds"><tt>\A</tt></td> |
| * <td headers="matches">The beginning of the input</td></tr> |
| * <tr><td valign="top" headers="construct bounds"><tt>\G</tt></td> |
| * <td headers="matches">The end of the previous match</td></tr> |
| * <tr><td valign="top" headers="construct bounds"><tt>\Z</tt></td> |
| * <td headers="matches">The end of the input but for the final |
| * <a href="#lt">terminator</a>, if any</td></tr> |
| * <tr><td valign="top" headers="construct bounds"><tt>\z</tt></td> |
| * <td headers="matches">The end of the input</td></tr> |
| * |
| * <tr><th> </th></tr> |
| * <tr align="left"><th colspan="2" id="greedy">Greedy quantifiers</th></tr> |
| * |
| * <tr><td valign="top" headers="construct greedy"><i>X</i><tt>?</tt></td> |
| * <td headers="matches"><i>X</i>, once or not at all</td></tr> |
| * <tr><td valign="top" headers="construct greedy"><i>X</i><tt>*</tt></td> |
| * <td headers="matches"><i>X</i>, zero or more times</td></tr> |
| * <tr><td valign="top" headers="construct greedy"><i>X</i><tt>+</tt></td> |
| * <td headers="matches"><i>X</i>, one or more times</td></tr> |
| * <tr><td valign="top" headers="construct greedy"><i>X</i><tt>{</tt><i>n</i><tt>}</tt></td> |
| * <td headers="matches"><i>X</i>, exactly <i>n</i> times</td></tr> |
| * <tr><td valign="top" headers="construct greedy"><i>X</i><tt>{</tt><i>n</i><tt>,}</tt></td> |
| * <td headers="matches"><i>X</i>, at least <i>n</i> times</td></tr> |
| * <tr><td valign="top" headers="construct greedy"><i>X</i><tt>{</tt><i>n</i><tt>,</tt><i>m</i><tt>}</tt></td> |
| * <td headers="matches"><i>X</i>, at least <i>n</i> but not more than <i>m</i> times</td></tr> |
| * |
| * <tr><th> </th></tr> |
| * <tr align="left"><th colspan="2" id="reluc">Reluctant quantifiers</th></tr> |
| * |
| * <tr><td valign="top" headers="construct reluc"><i>X</i><tt>??</tt></td> |
| * <td headers="matches"><i>X</i>, once or not at all</td></tr> |
| * <tr><td valign="top" headers="construct reluc"><i>X</i><tt>*?</tt></td> |
| * <td headers="matches"><i>X</i>, zero or more times</td></tr> |
| * <tr><td valign="top" headers="construct reluc"><i>X</i><tt>+?</tt></td> |
| * <td headers="matches"><i>X</i>, one or more times</td></tr> |
| * <tr><td valign="top" headers="construct reluc"><i>X</i><tt>{</tt><i>n</i><tt>}?</tt></td> |
| * <td headers="matches"><i>X</i>, exactly <i>n</i> times</td></tr> |
| * <tr><td valign="top" headers="construct reluc"><i>X</i><tt>{</tt><i>n</i><tt>,}?</tt></td> |
| * <td headers="matches"><i>X</i>, at least <i>n</i> times</td></tr> |
| * <tr><td valign="top" headers="construct reluc"><i>X</i><tt>{</tt><i>n</i><tt>,</tt><i>m</i><tt>}?</tt></td> |
| * <td headers="matches"><i>X</i>, at least <i>n</i> but not more than <i>m</i> times</td></tr> |
| * |
| * <tr><th> </th></tr> |
| * <tr align="left"><th colspan="2" id="poss">Possessive quantifiers</th></tr> |
| * |
| * <tr><td valign="top" headers="construct poss"><i>X</i><tt>?+</tt></td> |
| * <td headers="matches"><i>X</i>, once or not at all</td></tr> |
| * <tr><td valign="top" headers="construct poss"><i>X</i><tt>*+</tt></td> |
| * <td headers="matches"><i>X</i>, zero or more times</td></tr> |
| * <tr><td valign="top" headers="construct poss"><i>X</i><tt>++</tt></td> |
| * <td headers="matches"><i>X</i>, one or more times</td></tr> |
| * <tr><td valign="top" headers="construct poss"><i>X</i><tt>{</tt><i>n</i><tt>}+</tt></td> |
| * <td headers="matches"><i>X</i>, exactly <i>n</i> times</td></tr> |
| * <tr><td valign="top" headers="construct poss"><i>X</i><tt>{</tt><i>n</i><tt>,}+</tt></td> |
| * <td headers="matches"><i>X</i>, at least <i>n</i> times</td></tr> |
| * <tr><td valign="top" headers="construct poss"><i>X</i><tt>{</tt><i>n</i><tt>,</tt><i>m</i><tt>}+</tt></td> |
| * <td headers="matches"><i>X</i>, at least <i>n</i> but not more than <i>m</i> times</td></tr> |
| * |
| * <tr><th> </th></tr> |
| * <tr align="left"><th colspan="2" id="logical">Logical operators</th></tr> |
| * |
| * <tr><td valign="top" headers="construct logical"><i>XY</i></td> |
| * <td headers="matches"><i>X</i> followed by <i>Y</i></td></tr> |
| * <tr><td valign="top" headers="construct logical"><i>X</i><tt>|</tt><i>Y</i></td> |
| * <td headers="matches">Either <i>X</i> or <i>Y</i></td></tr> |
| * <tr><td valign="top" headers="construct logical"><tt>(</tt><i>X</i><tt>)</tt></td> |
| * <td headers="matches">X, as a <a href="#cg">capturing group</a></td></tr> |
| * |
| * <tr><th> </th></tr> |
| * <tr align="left"><th colspan="2" id="backref">Back references</th></tr> |
| * |
| * <tr><td valign="bottom" headers="construct backref"><tt>\</tt><i>n</i></td> |
| * <td valign="bottom" headers="matches">Whatever the <i>n</i><sup>th</sup> |
| * <a href="#cg">capturing group</a> matched</td></tr> |
| * |
| * <tr><td valign="bottom" headers="construct backref"><tt>\</tt><i>k</i><<i>name</i>></td> |
| * <td valign="bottom" headers="matches">Whatever the |
| * <a href="#groupname">named-capturing group</a> "name" matched</td></tr> |
| * |
| * <tr><th> </th></tr> |
| * <tr align="left"><th colspan="2" id="quot">Quotation</th></tr> |
| * |
| * <tr><td valign="top" headers="construct quot"><tt>\</tt></td> |
| * <td headers="matches">Nothing, but quotes the following character</td></tr> |
| * <tr><td valign="top" headers="construct quot"><tt>\Q</tt></td> |
| * <td headers="matches">Nothing, but quotes all characters until <tt>\E</tt></td></tr> |
| * <tr><td valign="top" headers="construct quot"><tt>\E</tt></td> |
| * <td headers="matches">Nothing, but ends quoting started by <tt>\Q</tt></td></tr> |
| * <!-- Metachars: !$()*+.<>?[\]^{|} --> |
| * |
| * <tr><th> </th></tr> |
| * <tr align="left"><th colspan="2" id="special">Special constructs (named-capturing and non-capturing)</th></tr> |
| * |
| * <tr><td valign="top" headers="construct special"><tt>(?<<a href="#groupname">name</a>></tt><i>X</i><tt>)</tt></td> |
| * <td headers="matches"><i>X</i>, as a named-capturing group</td></tr> |
| * <tr><td valign="top" headers="construct special"><tt>(?:</tt><i>X</i><tt>)</tt></td> |
| * <td headers="matches"><i>X</i>, as a non-capturing group</td></tr> |
| * <tr><td valign="top" headers="construct special"><tt>(?idmsuxU-idmsuxU) </tt></td> |
| * <td headers="matches">Nothing, but turns match flags <a href="#CASE_INSENSITIVE">i</a> |
| * <a href="#UNIX_LINES">d</a> <a href="#MULTILINE">m</a> <a href="#DOTALL">s</a> |
| * <a href="#UNICODE_CASE">u</a> <a href="#COMMENTS">x</a> <a href="#UNICODE_CHARACTER_CLASS">U</a> |
| * on - off</td></tr> |
| * <tr><td valign="top" headers="construct special"><tt>(?idmsux-idmsux:</tt><i>X</i><tt>)</tt> </td> |
| * <td headers="matches"><i>X</i>, as a <a href="#cg">non-capturing group</a> with the |
| * given flags <a href="#CASE_INSENSITIVE">i</a> <a href="#UNIX_LINES">d</a> |
| * <a href="#MULTILINE">m</a> <a href="#DOTALL">s</a> <a href="#UNICODE_CASE">u</a > |
| * <a href="#COMMENTS">x</a> on - off</td></tr> |
| * <tr><td valign="top" headers="construct special"><tt>(?=</tt><i>X</i><tt>)</tt></td> |
| * <td headers="matches"><i>X</i>, via zero-width positive lookahead</td></tr> |
| * <tr><td valign="top" headers="construct special"><tt>(?!</tt><i>X</i><tt>)</tt></td> |
| * <td headers="matches"><i>X</i>, via zero-width negative lookahead</td></tr> |
| * <tr><td valign="top" headers="construct special"><tt>(?<=</tt><i>X</i><tt>)</tt></td> |
| * <td headers="matches"><i>X</i>, via zero-width positive lookbehind</td></tr> |
| * <tr><td valign="top" headers="construct special"><tt>(?<!</tt><i>X</i><tt>)</tt></td> |
| * <td headers="matches"><i>X</i>, via zero-width negative lookbehind</td></tr> |
| * <tr><td valign="top" headers="construct special"><tt>(?></tt><i>X</i><tt>)</tt></td> |
| * <td headers="matches"><i>X</i>, as an independent, non-capturing group</td></tr> |
| * |
| * </table> |
| * |
| * <hr> |
| * |
| * |
| * <a name="bs"> |
| * <h4> Backslashes, escapes, and quoting </h4> |
| * |
| * <p> The backslash character (<tt>'\'</tt>) serves to introduce escaped |
| * constructs, as defined in the table above, as well as to quote characters |
| * that otherwise would be interpreted as unescaped constructs. Thus the |
| * expression <tt>\\</tt> matches a single backslash and <tt>\{</tt> matches a |
| * left brace. |
| * |
| * <p> It is an error to use a backslash prior to any alphabetic character that |
| * does not denote an escaped construct; these are reserved for future |
| * extensions to the regular-expression language. A backslash may be used |
| * prior to a non-alphabetic character regardless of whether that character is |
| * part of an unescaped construct. |
| * |
| * <p> Backslashes within string literals in Java source code are interpreted |
| * as required by |
| * <cite>The Java™ Language Specification</cite> |
| * as either Unicode escapes (section 3.3) or other character escapes (section 3.10.6) |
| * It is therefore necessary to double backslashes in string |
| * literals that represent regular expressions to protect them from |
| * interpretation by the Java bytecode compiler. The string literal |
| * <tt>"\b"</tt>, for example, matches a single backspace character when |
| * interpreted as a regular expression, while <tt>"\\b"</tt> matches a |
| * word boundary. The string literal <tt>"\(hello\)"</tt> is illegal |
| * and leads to a compile-time error; in order to match the string |
| * <tt>(hello)</tt> the string literal <tt>"\\(hello\\)"</tt> |
| * must be used. |
| * |
| * <a name="cc"> |
| * <h4> Character Classes </h4> |
| * |
| * <p> Character classes may appear within other character classes, and |
| * may be composed by the union operator (implicit) and the intersection |
| * operator (<tt>&&</tt>). |
| * The union operator denotes a class that contains every character that is |
| * in at least one of its operand classes. The intersection operator |
| * denotes a class that contains every character that is in both of its |
| * operand classes. |
| * |
| * <p> The precedence of character-class operators is as follows, from |
| * highest to lowest: |
| * |
| * <blockquote><table border="0" cellpadding="1" cellspacing="0" |
| * summary="Precedence of character class operators."> |
| * <tr><th>1 </th> |
| * <td>Literal escape </td> |
| * <td><tt>\x</tt></td></tr> |
| * <tr><th>2 </th> |
| * <td>Grouping</td> |
| * <td><tt>[...]</tt></td></tr> |
| * <tr><th>3 </th> |
| * <td>Range</td> |
| * <td><tt>a-z</tt></td></tr> |
| * <tr><th>4 </th> |
| * <td>Union</td> |
| * <td><tt>[a-e][i-u]</tt></td></tr> |
| * <tr><th>5 </th> |
| * <td>Intersection</td> |
| * <td><tt>[a-z&&[aeiou]]</tt></td></tr> |
| * </table></blockquote> |
| * |
| * <p> Note that a different set of metacharacters are in effect inside |
| * a character class than outside a character class. For instance, the |
| * regular expression <tt>.</tt> loses its special meaning inside a |
| * character class, while the expression <tt>-</tt> becomes a range |
| * forming metacharacter. |
| * |
| * <a name="lt"> |
| * <h4> Line terminators </h4> |
| * |
| * <p> A <i>line terminator</i> is a one- or two-character sequence that marks |
| * the end of a line of the input character sequence. The following are |
| * recognized as line terminators: |
| * |
| * <ul> |
| * |
| * <li> A newline (line feed) character (<tt>'\n'</tt>), |
| * |
| * <li> A carriage-return character followed immediately by a newline |
| * character (<tt>"\r\n"</tt>), |
| * |
| * <li> A standalone carriage-return character (<tt>'\r'</tt>), |
| * |
| * <li> A next-line character (<tt>'\u0085'</tt>), |
| * |
| * <li> A line-separator character (<tt>'\u2028'</tt>), or |
| * |
| * <li> A paragraph-separator character (<tt>'\u2029</tt>). |
| * |
| * </ul> |
| * <p>If {@link #UNIX_LINES} mode is activated, then the only line terminators |
| * recognized are newline characters. |
| * |
| * <p> The regular expression <tt>.</tt> matches any character except a line |
| * terminator unless the {@link #DOTALL} flag is specified. |
| * |
| * <p> By default, the regular expressions <tt>^</tt> and <tt>$</tt> ignore |
| * line terminators and only match at the beginning and the end, respectively, |
| * of the entire input sequence. If {@link #MULTILINE} mode is activated then |
| * <tt>^</tt> matches at the beginning of input and after any line terminator |
| * except at the end of input. When in {@link #MULTILINE} mode <tt>$</tt> |
| * matches just before a line terminator or the end of the input sequence. |
| * |
| * <a name="cg"> |
| * <h4> Groups and capturing </h4> |
| * |
| * <a name="gnumber"> |
| * <h5> Group number </h5> |
| * <p> Capturing groups are numbered by counting their opening parentheses from |
| * left to right. In the expression <tt>((A)(B(C)))</tt>, for example, there |
| * are four such groups: </p> |
| * |
| * <blockquote><table cellpadding=1 cellspacing=0 summary="Capturing group numberings"> |
| * <tr><th>1 </th> |
| * <td><tt>((A)(B(C)))</tt></td></tr> |
| * <tr><th>2 </th> |
| * <td><tt>(A)</tt></td></tr> |
| * <tr><th>3 </th> |
| * <td><tt>(B(C))</tt></td></tr> |
| * <tr><th>4 </th> |
| * <td><tt>(C)</tt></td></tr> |
| * </table></blockquote> |
| * |
| * <p> Group zero always stands for the entire expression. |
| * |
| * <p> Capturing groups are so named because, during a match, each subsequence |
| * of the input sequence that matches such a group is saved. The captured |
| * subsequence may be used later in the expression, via a back reference, and |
| * may also be retrieved from the matcher once the match operation is complete. |
| * |
| * <a name="groupname"> |
| * <h5> Group name </h5> |
| * <p>A capturing group can also be assigned a "name", a <tt>named-capturing group</tt>, |
| * and then be back-referenced later by the "name". Group names are composed of |
| * the following characters. The first character must be a <tt>letter</tt>. |
| * |
| * <ul> |
| * <li> The uppercase letters <tt>'A'</tt> through <tt>'Z'</tt> |
| * (<tt>'\u0041'</tt> through <tt>'\u005a'</tt>), |
| * <li> The lowercase letters <tt>'a'</tt> through <tt>'z'</tt> |
| * (<tt>'\u0061'</tt> through <tt>'\u007a'</tt>), |
| * <li> The digits <tt>'0'</tt> through <tt>'9'</tt> |
| * (<tt>'\u0030'</tt> through <tt>'\u0039'</tt>), |
| * </ul> |
| * |
| * <p> A <tt>named-capturing group</tt> is still numbered as described in |
| * <a href="#gnumber">Group number</a>. |
| * |
| * <p> The captured input associated with a group is always the subsequence |
| * that the group most recently matched. If a group is evaluated a second time |
| * because of quantification then its previously-captured value, if any, will |
| * be retained if the second evaluation fails. Matching the string |
| * <tt>"aba"</tt> against the expression <tt>(a(b)?)+</tt>, for example, leaves |
| * group two set to <tt>"b"</tt>. All captured input is discarded at the |
| * beginning of each match. |
| * |
| * <p> Groups beginning with <tt>(?</tt> are either pure, <i>non-capturing</i> groups |
| * that do not capture text and do not count towards the group total, or |
| * <i>named-capturing</i> group. |
| * |
| * <h4> Unicode support </h4> |
| * |
| * <p> This class is in conformance with Level 1 of <a |
| * href="http://www.unicode.org/reports/tr18/"><i>Unicode Technical |
| * Standard #18: Unicode Regular Expression</i></a>, plus RL2.1 |
| * Canonical Equivalents. |
| * <p> |
| * <b>Unicode escape sequences</b> such as <tt>\u2014</tt> in Java source code |
| * are processed as described in section 3.3 of |
| * <cite>The Java™ Language Specification</cite>. |
| * Such escape sequences are also implemented directly by the regular-expression |
| * parser so that Unicode escapes can be used in expressions that are read from |
| * files or from the keyboard. Thus the strings <tt>"\u2014"</tt> and |
| * <tt>"\\u2014"</tt>, while not equal, compile into the same pattern, which |
| * matches the character with hexadecimal value <tt>0x2014</tt>. |
| * <p> |
| * A Unicode character can also be represented in a regular-expression by |
| * using its <b>Hex notation</b>(hexadecimal code point value) directly as described in construct |
| * <tt>\x{...}</tt>, for example a supplementary character U+2011F |
| * can be specified as <tt>\x{2011F}</tt>, instead of two consecutive |
| * Unicode escape sequences of the surrogate pair |
| * <tt>\uD840</tt><tt>\uDD1F</tt>. |
| * <p> |
| * Unicode scripts, blocks, categories and binary properties are written with |
| * the <tt>\p</tt> and <tt>\P</tt> constructs as in Perl. |
| * <tt>\p{</tt><i>prop</i><tt>}</tt> matches if |
| * the input has the property <i>prop</i>, while <tt>\P{</tt><i>prop</i><tt>}</tt> |
| * does not match if the input has that property. |
| * <p> |
| * Scripts, blocks, categories and binary properties can be used both inside |
| * and outside of a character class. |
| * <a name="usc"> |
| * <p> |
| * <b>Scripts</b> are specified either with the prefix {@code Is}, as in |
| * {@code IsHiragana}, or by using the {@code script} keyword (or its short |
| * form {@code sc})as in {@code script=Hiragana} or {@code sc=Hiragana}. |
| * <p> |
| * The script names supported by <code>Pattern</code> are the valid script names |
| * accepted and defined by |
| * {@link java.lang.Character.UnicodeScript#forName(String) UnicodeScript.forName}. |
| * <a name="ubc"> |
| * <p> |
| * <b>Blocks</b> are specified with the prefix {@code In}, as in |
| * {@code InMongolian}, or by using the keyword {@code block} (or its short |
| * form {@code blk}) as in {@code block=Mongolian} or {@code blk=Mongolian}. |
| * <p> |
| * The block names supported by <code>Pattern</code> are the valid block names |
| * accepted and defined by |
| * {@link java.lang.Character.UnicodeBlock#forName(String) UnicodeBlock.forName}. |
| * <p> |
| * <a name="ucc"> |
| * <b>Categories</b> may be specified with the optional prefix {@code Is}: |
| * Both {@code \p{L}} and {@code \p{IsL}} denote the category of Unicode |
| * letters. Same as scripts and blocks, categories can also be specified |
| * by using the keyword {@code general_category} (or its short form |
| * {@code gc}) as in {@code general_category=Lu} or {@code gc=Lu}. |
| * <p> |
| * The supported categories are those of |
| * <a href="http://www.unicode.org/unicode/standard/standard.html"> |
| * <i>The Unicode Standard</i></a> in the version specified by the |
| * {@link java.lang.Character Character} class. The category names are those |
| * defined in the Standard, both normative and informative. |
| * <p> |
| * <a name="ubpc"> |
| * <b>Binary properties</b> are specified with the prefix {@code Is}, as in |
| * {@code IsAlphabetic}. The supported binary properties by <code>Pattern</code> |
| * are |
| * <ul> |
| * <li> Alphabetic |
| * <li> Ideographic |
| * <li> Letter |
| * <li> Lowercase |
| * <li> Uppercase |
| * <li> Titlecase |
| * <li> Punctuation |
| * <Li> Control |
| * <li> White_Space |
| * <li> Digit |
| * <li> Hex_Digit |
| * <li> Noncharacter_Code_Point |
| * <li> Assigned |
| * </ul> |
| |
| |
| * <p> |
| * <b>Predefined Character classes</b> and <b>POSIX character classes</b> are in |
| * conformance with the recommendation of <i>Annex C: Compatibility Properties</i> |
| * of <a href="http://www.unicode.org/reports/tr18/"><i>Unicode Regular Expression |
| * </i></a>. |
| * <p> |
| * <table border="0" cellpadding="1" cellspacing="0" |
| * summary="predefined and posix character classes in Unicode mode"> |
| * <tr align="left"> |
| * <th bgcolor="#CCCCFF" align="left" id="classes">Classes</th> |
| * <th bgcolor="#CCCCFF" align="left" id="matches">Matches</th> |
| *</tr> |
| * <tr><td><tt>\p{Lower}</tt></td> |
| * <td>A lowercase character:<tt>\p{IsLowercase}</tt></td></tr> |
| * <tr><td><tt>\p{Upper}</tt></td> |
| * <td>An uppercase character:<tt>\p{IsUppercase}</tt></td></tr> |
| * <tr><td><tt>\p{ASCII}</tt></td> |
| * <td>All ASCII:<tt>[\x00-\x7F]</tt></td></tr> |
| * <tr><td><tt>\p{Alpha}</tt></td> |
| * <td>An alphabetic character:<tt>\p{IsAlphabetic}</tt></td></tr> |
| * <tr><td><tt>\p{Digit}</tt></td> |
| * <td>A decimal digit character:<tt>p{IsDigit}</tt></td></tr> |
| * <tr><td><tt>\p{Alnum}</tt></td> |
| * <td>An alphanumeric character:<tt>[\p{IsAlphabetic}\p{IsDigit}]</tt></td></tr> |
| * <tr><td><tt>\p{Punct}</tt></td> |
| * <td>A punctuation character:<tt>p{IsPunctuation}</tt></td></tr> |
| * <tr><td><tt>\p{Graph}</tt></td> |
| * <td>A visible character: <tt>[^\p{IsWhite_Space}\p{gc=Cc}\p{gc=Cs}\p{gc=Cn}]</tt></td></tr> |
| * <tr><td><tt>\p{Print}</tt></td> |
| * <td>A printable character: <tt>[\p{Graph}\p{Blank}&&[^\p{Cntrl}]]</tt></td></tr> |
| * <tr><td><tt>\p{Blank}</tt></td> |
| * <td>A space or a tab: <tt>[\p{IsWhite_Space}&&[^\p{gc=Zl}\p{gc=Zp}\x0a\x0b\x0c\x0d\x85]]</tt></td></tr> |
| * <tr><td><tt>\p{Cntrl}</tt></td> |
| * <td>A control character: <tt>\p{gc=Cc}</tt></td></tr> |
| * <tr><td><tt>\p{XDigit}</tt></td> |
| * <td>A hexadecimal digit: <tt>[\p{gc=Nd}\p{IsHex_Digit}]</tt></td></tr> |
| * <tr><td><tt>\p{Space}</tt></td> |
| * <td>A whitespace character:<tt>\p{IsWhite_Space}</tt></td></tr> |
| * <tr><td><tt>\d</tt></td> |
| * <td>A digit: <tt>\p{IsDigit}</tt></td></tr> |
| * <tr><td><tt>\D</tt></td> |
| * <td>A non-digit: <tt>[^\d]</tt></td></tr> |
| * <tr><td><tt>\s</tt></td> |
| * <td>A whitespace character: <tt>\p{IsWhite_Space}</tt></td></tr> |
| * <tr><td><tt>\S</tt></td> |
| * <td>A non-whitespace character: <tt>[^\s]</tt></td></tr> |
| * <tr><td><tt>\w</tt></td> |
| * <td>A word character: <tt>[\p{Alpha}\p{gc=Mn}\p{gc=Me}\p{gc=Mc}\p{Digit}\p{gc=Pc}]</tt></td></tr> |
| * <tr><td><tt>\W</tt></td> |
| * <td>A non-word character: <tt>[^\w]</tt></td></tr> |
| * </table> |
| * <p> |
| * <a name="jcc"> |
| * Categories that behave like the java.lang.Character |
| * boolean is<i>methodname</i> methods (except for the deprecated ones) are |
| * available through the same <tt>\p{</tt><i>prop</i><tt>}</tt> syntax where |
| * the specified property has the name <tt>java<i>methodname</i></tt>. |
| * |
| * <h4> Comparison to Perl 5 </h4> |
| * |
| * <p>The <code>Pattern</code> engine performs traditional NFA-based matching |
| * with ordered alternation as occurs in Perl 5. |
| * |
| * <p> Perl constructs not supported by this class: </p> |
| * |
| * <ul> |
| * <li><p> Predefined character classes (Unicode character) |
| * <p><tt>\h </tt>A horizontal whitespace |
| * <p><tt>\H </tt>A non horizontal whitespace |
| * <p><tt>\v </tt>A vertical whitespace |
| * <p><tt>\V </tt>A non vertical whitespace |
| * <p><tt>\R </tt>Any Unicode linebreak sequence |
| * <tt>\u005cu000D\u005cu000A|[\u005cu000A\u005cu000B\u005cu000C\u005cu000D\u005cu0085\u005cu2028\u005cu2029]</tt> |
| * <p><tt>\X </tt>Match Unicode |
| * <a href="http://www.unicode.org/reports/tr18/#Default_Grapheme_Clusters"> |
| * <i>extended grapheme cluster</i></a> |
| * </p></li> |
| * |
| * <li><p> The backreference constructs, <tt>\g{</tt><i>n</i><tt>}</tt> for |
| * the <i>n</i><sup>th</sup><a href="#cg">capturing group</a> and |
| * <tt>\g{</tt><i>name</i><tt>}</tt> for |
| * <a href="#groupname">named-capturing group</a>. |
| * </p></li> |
| * |
| * <li><p> The named character construct, <tt>\N{</tt><i>name</i><tt>}</tt> |
| * for a Unicode character by its name. |
| * </p></li> |
| * |
| * <li><p> The conditional constructs |
| * <tt>(?(</tt><i>condition</i><tt>)</tt><i>X</i><tt>)</tt> and |
| * <tt>(?(</tt><i>condition</i><tt>)</tt><i>X</i><tt>|</tt><i>Y</i><tt>)</tt>, |
| * </p></li> |
| * |
| * <li><p> The embedded code constructs <tt>(?{</tt><i>code</i><tt>})</tt> |
| * and <tt>(??{</tt><i>code</i><tt>})</tt>,</p></li> |
| * |
| * <li><p> The embedded comment syntax <tt>(?#comment)</tt>, and </p></li> |
| * |
| * <li><p> The preprocessing operations <tt>\l</tt> <tt>\u</tt>, |
| * <tt>\L</tt>, and <tt>\U</tt>. </p></li> |
| * |
| * </ul> |
| * |
| * <p> Constructs supported by this class but not by Perl: </p> |
| * |
| * <ul> |
| * |
| * <li><p> Character-class union and intersection as described |
| * <a href="#cc">above</a>.</p></li> |
| * |
| * </ul> |
| * |
| * <p> Notable differences from Perl: </p> |
| * |
| * <ul> |
| * |
| * <li><p> In Perl, <tt>\1</tt> through <tt>\9</tt> are always interpreted |
| * as back references; a backslash-escaped number greater than <tt>9</tt> is |
| * treated as a back reference if at least that many subexpressions exist, |
| * otherwise it is interpreted, if possible, as an octal escape. In this |
| * class octal escapes must always begin with a zero. In this class, |
| * <tt>\1</tt> through <tt>\9</tt> are always interpreted as back |
| * references, and a larger number is accepted as a back reference if at |
| * least that many subexpressions exist at that point in the regular |
| * expression, otherwise the parser will drop digits until the number is |
| * smaller or equal to the existing number of groups or it is one digit. |
| * </p></li> |
| * |
| * <li><p> Perl uses the <tt>g</tt> flag to request a match that resumes |
| * where the last match left off. This functionality is provided implicitly |
| * by the {@link Matcher} class: Repeated invocations of the {@link |
| * Matcher#find find} method will resume where the last match left off, |
| * unless the matcher is reset. </p></li> |
| * |
| * <li><p> In Perl, embedded flags at the top level of an expression affect |
| * the whole expression. In this class, embedded flags always take effect |
| * at the point at which they appear, whether they are at the top level or |
| * within a group; in the latter case, flags are restored at the end of the |
| * group just as in Perl. </p></li> |
| * |
| * </ul> |
| * |
| * |
| * <p> For a more precise description of the behavior of regular expression |
| * constructs, please see <a href="http://www.oreilly.com/catalog/regex3/"> |
| * <i>Mastering Regular Expressions, 3nd Edition</i>, Jeffrey E. F. Friedl, |
| * O'Reilly and Associates, 2006.</a> |
| * </p> |
| * |
| * @see java.lang.String#split(String, int) |
| * @see java.lang.String#split(String) |
| * |
| * @author Mike McCloskey |
| * @author Mark Reinhold |
| * @author JSR-51 Expert Group |
| * @since 1.4 |
| * @spec JSR-51 |
| */ |
| |
| public final class Pattern implements java.io.Serializable |
| { |
| |
| /** |
| * Regular expression modifier values. Instead of being passed as |
| * arguments, they can also be passed as inline modifiers. |
| * For example, the following statements have the same effect. |
| * <pre> |
| * RegExp r1 = RegExp.compile("abc", Pattern.I|Pattern.M); |
| * RegExp r2 = RegExp.compile("(?im)abc", 0); |
| * </pre> |
| * |
| * The flags are duplicated so that the familiar Perl match flag |
| * names are available. |
| */ |
| |
| /** |
| * Enables Unix lines mode. |
| * |
| * <p> In this mode, only the <tt>'\n'</tt> line terminator is recognized |
| * in the behavior of <tt>.</tt>, <tt>^</tt>, and <tt>$</tt>. |
| * |
| * <p> Unix lines mode can also be enabled via the embedded flag |
| * expression <tt>(?d)</tt>. |
| */ |
| public static final int UNIX_LINES = 0x01; |
| |
| /** |
| * Enables case-insensitive matching. |
| * |
| * <p> By default, case-insensitive matching assumes that only characters |
| * in the US-ASCII charset are being matched. Unicode-aware |
| * case-insensitive matching can be enabled by specifying the {@link |
| * #UNICODE_CASE} flag in conjunction with this flag. |
| * |
| * <p> Case-insensitive matching can also be enabled via the embedded flag |
| * expression <tt>(?i)</tt>. |
| * |
| * <p> Specifying this flag may impose a slight performance penalty. </p> |
| */ |
| public static final int CASE_INSENSITIVE = 0x02; |
| |
| /** |
| * Permits whitespace and comments in pattern. |
| * |
| * <p> In this mode, whitespace is ignored, and embedded comments starting |
| * with <tt>#</tt> are ignored until the end of a line. |
| * |
| * <p> Comments mode can also be enabled via the embedded flag |
| * expression <tt>(?x)</tt>. |
| */ |
| public static final int COMMENTS = 0x04; |
| |
| /** |
| * Enables multiline mode. |
| * |
| * <p> In multiline mode the expressions <tt>^</tt> and <tt>$</tt> match |
| * just after or just before, respectively, a line terminator or the end of |
| * the input sequence. By default these expressions only match at the |
| * beginning and the end of the entire input sequence. |
| * |
| * <p> Multiline mode can also be enabled via the embedded flag |
| * expression <tt>(?m)</tt>. </p> |
| */ |
| public static final int MULTILINE = 0x08; |
| |
| /** |
| * Enables literal parsing of the pattern. |
| * |
| * <p> When this flag is specified then the input string that specifies |
| * the pattern is treated as a sequence of literal characters. |
| * Metacharacters or escape sequences in the input sequence will be |
| * given no special meaning. |
| * |
| * <p>The flags CASE_INSENSITIVE and UNICODE_CASE retain their impact on |
| * matching when used in conjunction with this flag. The other flags |
| * become superfluous. |
| * |
| * <p> There is no embedded flag character for enabling literal parsing. |
| * @since 1.5 |
| */ |
| public static final int LITERAL = 0x10; |
| |
| /** |
| * Enables dotall mode. |
| * |
| * <p> In dotall mode, the expression <tt>.</tt> matches any character, |
| * including a line terminator. By default this expression does not match |
| * line terminators. |
| * |
| * <p> Dotall mode can also be enabled via the embedded flag |
| * expression <tt>(?s)</tt>. (The <tt>s</tt> is a mnemonic for |
| * "single-line" mode, which is what this is called in Perl.) </p> |
| */ |
| public static final int DOTALL = 0x20; |
| |
| /** |
| * Enables Unicode-aware case folding. |
| * |
| * <p> When this flag is specified then case-insensitive matching, when |
| * enabled by the {@link #CASE_INSENSITIVE} flag, is done in a manner |
| * consistent with the Unicode Standard. By default, case-insensitive |
| * matching assumes that only characters in the US-ASCII charset are being |
| * matched. |
| * |
| * <p> Unicode-aware case folding can also be enabled via the embedded flag |
| * expression <tt>(?u)</tt>. |
| * |
| * <p> Specifying this flag may impose a performance penalty. </p> |
| */ |
| public static final int UNICODE_CASE = 0x40; |
| |
| /** |
| * Enables canonical equivalence. |
| * |
| * <p> When this flag is specified then two characters will be considered |
| * to match if, and only if, their full canonical decompositions match. |
| * The expression <tt>"a\u030A"</tt>, for example, will match the |
| * string <tt>"\u00E5"</tt> when this flag is specified. By default, |
| * matching does not take canonical equivalence into account. |
| * |
| * <p> There is no embedded flag character for enabling canonical |
| * equivalence. |
| * |
| * <p> Specifying this flag may impose a performance penalty. </p> |
| */ |
| public static final int CANON_EQ = 0x80; |
| |
| /** |
| * Enables the Unicode version of <i>Predefined character classes</i> and |
| * <i>POSIX character classes</i> as eefined by <a href="http://www.unicode.org/reports/tr18/"><i>Unicode Technical |
| * Standard #18: Unicode Regular Expression</i></a> |
| * <i>Annex C: Compatibility Properties</i>. |
| * <p> |
| * |
| * This flag has no effect on Android, unicode character classes are always |
| * used. |
| * |
| * @since 1.7 |
| */ |
| public static final int UNICODE_CHARACTER_CLASS = 0x100; |
| |
| /* Pattern has only two serialized components: The pattern string |
| * and the flags, which are all that is needed to recompile the pattern |
| * when it is deserialized. |
| */ |
| |
| /** use serialVersionUID from Merlin b59 for interoperability */ |
| private static final long serialVersionUID = 5073258162644648461L; |
| |
| /** |
| * The original regular-expression pattern string. |
| * |
| * @serial |
| */ |
| private final String pattern; |
| |
| /** |
| * The original pattern flags. |
| * |
| * @serial |
| */ |
| private final int flags; |
| |
| @ReachabilitySensitive |
| transient long address; |
| |
| private static final NativeAllocationRegistry registry = new NativeAllocationRegistry( |
| Pattern.class.getClassLoader(), getNativeFinalizer(), nativeSize()); |
| |
| |
| /** |
| * Compiles the given regular expression into a pattern. </p> |
| * |
| * @param regex |
| * The expression to be compiled |
| * |
| * @throws PatternSyntaxException |
| * If the expression's syntax is invalid |
| */ |
| public static Pattern compile(String regex) { |
| return new Pattern(regex, 0); |
| } |
| |
| /** |
| * Compiles the given regular expression into a pattern with the given |
| * flags. </p> |
| * |
| * @param regex |
| * The expression to be compiled |
| * |
| * @param flags |
| * Match flags, a bit mask that may include |
| * {@link #CASE_INSENSITIVE}, {@link #MULTILINE}, {@link #DOTALL}, |
| * {@link #UNICODE_CASE}, {@link #CANON_EQ}, {@link #UNIX_LINES}, |
| * {@link #LITERAL}, {@link #UNICODE_CHARACTER_CLASS} |
| * and {@link #COMMENTS} |
| * |
| * @throws IllegalArgumentException |
| * If bit values other than those corresponding to the defined |
| * match flags are set in <tt>flags</tt> |
| * |
| * @throws PatternSyntaxException |
| * If the expression's syntax is invalid |
| */ |
| public static Pattern compile(String regex, int flags) throws PatternSyntaxException { |
| return new Pattern(regex, flags); |
| } |
| |
| /** |
| * Returns the regular expression from which this pattern was compiled. |
| * </p> |
| * |
| * @return The source of this pattern |
| */ |
| public String pattern() { |
| return pattern; |
| } |
| |
| /** |
| * <p>Returns the string representation of this pattern. This |
| * is the regular expression from which this pattern was |
| * compiled.</p> |
| * |
| * @return The string representation of this pattern |
| * @since 1.5 |
| */ |
| public String toString() { |
| return pattern; |
| } |
| |
| /** |
| * Creates a matcher that will match the given input against this pattern. |
| * </p> |
| * |
| * @param input |
| * The character sequence to be matched |
| * |
| * @return A new matcher for this pattern |
| */ |
| public Matcher matcher(CharSequence input) { |
| Matcher m = new Matcher(this, input); |
| return m; |
| } |
| |
| /** |
| * Returns this pattern's match flags. </p> |
| * |
| * @return The match flags specified when this pattern was compiled |
| */ |
| public int flags() { |
| return flags; |
| } |
| |
| /** |
| * Compiles the given regular expression and attempts to match the given |
| * input against it. |
| * |
| * <p> An invocation of this convenience method of the form |
| * |
| * <blockquote><pre> |
| * Pattern.matches(regex, input);</pre></blockquote> |
| * |
| * behaves in exactly the same way as the expression |
| * |
| * <blockquote><pre> |
| * Pattern.compile(regex).matcher(input).matches()</pre></blockquote> |
| * |
| * <p> If a pattern is to be used multiple times, compiling it once and reusing |
| * it will be more efficient than invoking this method each time. </p> |
| * |
| * @param regex |
| * The expression to be compiled |
| * |
| * @param input |
| * The character sequence to be matched |
| * |
| * @throws PatternSyntaxException |
| * If the expression's syntax is invalid |
| */ |
| public static boolean matches(String regex, CharSequence input) { |
| Pattern p = Pattern.compile(regex); |
| Matcher m = p.matcher(input); |
| return m.matches(); |
| } |
| |
| /** |
| * Splits the given input sequence around matches of this pattern. |
| * |
| * <p> The array returned by this method contains each substring of the |
| * input sequence that is terminated by another subsequence that matches |
| * this pattern or is terminated by the end of the input sequence. The |
| * substrings in the array are in the order in which they occur in the |
| * input. If this pattern does not match any subsequence of the input then |
| * the resulting array has just one element, namely the input sequence in |
| * string form. |
| * |
| * <p> The <tt>limit</tt> parameter controls the number of times the |
| * pattern is applied and therefore affects the length of the resulting |
| * array. If the limit <i>n</i> is greater than zero then the pattern |
| * will be applied at most <i>n</i> - 1 times, the array's |
| * length will be no greater than <i>n</i>, and the array's last entry |
| * will contain all input beyond the last matched delimiter. If <i>n</i> |
| * is non-positive then the pattern will be applied as many times as |
| * possible and the array can have any length. If <i>n</i> is zero then |
| * the pattern will be applied as many times as possible, the array can |
| * have any length, and trailing empty strings will be discarded. |
| * |
| * <p> The input <tt>"boo:and:foo"</tt>, for example, yields the following |
| * results with these parameters: |
| * |
| * <blockquote><table cellpadding=1 cellspacing=0 |
| * summary="Split examples showing regex, limit, and result"> |
| * <tr><th><P align="left"><i>Regex </i></th> |
| * <th><P align="left"><i>Limit </i></th> |
| * <th><P align="left"><i>Result </i></th></tr> |
| * <tr><td align=center>:</td> |
| * <td align=center>2</td> |
| * <td><tt>{ "boo", "and:foo" }</tt></td></tr> |
| * <tr><td align=center>:</td> |
| * <td align=center>5</td> |
| * <td><tt>{ "boo", "and", "foo" }</tt></td></tr> |
| * <tr><td align=center>:</td> |
| * <td align=center>-2</td> |
| * <td><tt>{ "boo", "and", "foo" }</tt></td></tr> |
| * <tr><td align=center>o</td> |
| * <td align=center>5</td> |
| * <td><tt>{ "b", "", ":and:f", "", "" }</tt></td></tr> |
| * <tr><td align=center>o</td> |
| * <td align=center>-2</td> |
| * <td><tt>{ "b", "", ":and:f", "", "" }</tt></td></tr> |
| * <tr><td align=center>o</td> |
| * <td align=center>0</td> |
| * <td><tt>{ "b", "", ":and:f" }</tt></td></tr> |
| * </table></blockquote> |
| * |
| * |
| * @param input |
| * The character sequence to be split |
| * |
| * @param limit |
| * The result threshold, as described above |
| * |
| * @return The array of strings computed by splitting the input |
| * around matches of this pattern |
| */ |
| public String[] split(CharSequence input, int limit) { |
| String[] fast = fastSplit(pattern, input.toString(), limit); |
| if (fast != null) { |
| return fast; |
| } |
| |
| int index = 0; |
| boolean matchLimited = limit > 0; |
| ArrayList<String> matchList = new ArrayList<>(); |
| Matcher m = matcher(input); |
| |
| // Add segments before each match found |
| while(m.find()) { |
| if (!matchLimited || matchList.size() < limit - 1) { |
| String match = input.subSequence(index, m.start()).toString(); |
| matchList.add(match); |
| index = m.end(); |
| } else if (matchList.size() == limit - 1) { // last one |
| String match = input.subSequence(index, |
| input.length()).toString(); |
| matchList.add(match); |
| index = m.end(); |
| } |
| } |
| |
| // If no match was found, return this |
| if (index == 0) |
| return new String[] {input.toString()}; |
| |
| // Add remaining segment |
| if (!matchLimited || matchList.size() < limit) |
| matchList.add(input.subSequence(index, input.length()).toString()); |
| |
| // Construct result |
| int resultSize = matchList.size(); |
| if (limit == 0) |
| while (resultSize > 0 && matchList.get(resultSize-1).equals("")) |
| resultSize--; |
| String[] result = new String[resultSize]; |
| return matchList.subList(0, resultSize).toArray(result); |
| } |
| |
| private static final String FASTSPLIT_METACHARACTERS = "\\?*+[](){}^$.|"; |
| |
| /** |
| * Returns a result equivalent to {@code s.split(separator, limit)} if it's able |
| * to compute it more cheaply than native impl, or null if the caller should fall back to |
| * using native impl. |
| * |
| * fastpath will work if the regex is a |
| * (1)one-char String and this character is not one of the |
| * RegEx's meta characters ".$|()[{^?*+\\", or |
| * (2)two-char String and the first char is the backslash and |
| * the second is one of regEx's meta characters ".$|()[{^?*+\\". |
| * @hide |
| */ |
| public static String[] fastSplit(String re, String input, int limit) { |
| // Can we do it cheaply? |
| int len = re.length(); |
| if (len == 0) { |
| return null; |
| } |
| char ch = re.charAt(0); |
| if (len == 1 && FASTSPLIT_METACHARACTERS.indexOf(ch) == -1) { |
| // We're looking for a single non-metacharacter. Easy. |
| } else if (len == 2 && ch == '\\') { |
| // We're looking for a quoted character. |
| // Quoted metacharacters are effectively single non-metacharacters. |
| ch = re.charAt(1); |
| if (FASTSPLIT_METACHARACTERS.indexOf(ch) == -1) { |
| return null; |
| } |
| } else { |
| return null; |
| } |
| |
| // We can do this cheaply... |
| |
| // Unlike Perl, which considers the result of splitting the empty string to be the empty |
| // array, Java returns an array containing the empty string. |
| if (input.isEmpty()) { |
| return new String[] { "" }; |
| } |
| |
| // Count separators |
| int separatorCount = 0; |
| int begin = 0; |
| int end; |
| while (separatorCount + 1 != limit && (end = input.indexOf(ch, begin)) != -1) { |
| ++separatorCount; |
| begin = end + 1; |
| } |
| int lastPartEnd = input.length(); |
| if (limit == 0 && begin == lastPartEnd) { |
| // Last part is empty for limit == 0, remove all trailing empty matches. |
| if (separatorCount == lastPartEnd) { |
| // Input contains only separators. |
| return EmptyArray.STRING; |
| } |
| // Find the beginning of trailing separators. |
| do { |
| --begin; |
| } while (input.charAt(begin - 1) == ch); |
| // Reduce separatorCount and fix lastPartEnd. |
| separatorCount -= input.length() - begin; |
| lastPartEnd = begin; |
| } |
| |
| // Collect the result parts. |
| String[] result = new String[separatorCount + 1]; |
| begin = 0; |
| for (int i = 0; i != separatorCount; ++i) { |
| end = input.indexOf(ch, begin); |
| result[i] = input.substring(begin, end); |
| begin = end + 1; |
| } |
| // Add last part. |
| result[separatorCount] = input.substring(begin, lastPartEnd); |
| return result; |
| } |
| |
| /** |
| * Splits the given input sequence around matches of this pattern. |
| * |
| * <p> This method works as if by invoking the two-argument {@link |
| * #split(java.lang.CharSequence, int) split} method with the given input |
| * sequence and a limit argument of zero. Trailing empty strings are |
| * therefore not included in the resulting array. </p> |
| * |
| * <p> The input <tt>"boo:and:foo"</tt>, for example, yields the following |
| * results with these expressions: |
| * |
| * <blockquote><table cellpadding=1 cellspacing=0 |
| * summary="Split examples showing regex and result"> |
| * <tr><th><P align="left"><i>Regex </i></th> |
| * <th><P align="left"><i>Result</i></th></tr> |
| * <tr><td align=center>:</td> |
| * <td><tt>{ "boo", "and", "foo" }</tt></td></tr> |
| * <tr><td align=center>o</td> |
| * <td><tt>{ "b", "", ":and:f" }</tt></td></tr> |
| * </table></blockquote> |
| * |
| * |
| * @param input |
| * The character sequence to be split |
| * |
| * @return The array of strings computed by splitting the input |
| * around matches of this pattern |
| */ |
| public String[] split(CharSequence input) { |
| return split(input, 0); |
| } |
| |
| /** |
| * Returns a literal pattern <code>String</code> for the specified |
| * <code>String</code>. |
| * |
| * <p>This method produces a <code>String</code> that can be used to |
| * create a <code>Pattern</code> that would match the string |
| * <code>s</code> as if it were a literal pattern.</p> Metacharacters |
| * or escape sequences in the input sequence will be given no special |
| * meaning. |
| * |
| * @param s The string to be literalized |
| * @return A literal string replacement |
| * @since 1.5 |
| */ |
| public static String quote(String s) { |
| int slashEIndex = s.indexOf("\\E"); |
| if (slashEIndex == -1) |
| return "\\Q" + s + "\\E"; |
| |
| StringBuilder sb = new StringBuilder(s.length() * 2); |
| sb.append("\\Q"); |
| slashEIndex = 0; |
| int current = 0; |
| while ((slashEIndex = s.indexOf("\\E", current)) != -1) { |
| sb.append(s.substring(current, slashEIndex)); |
| current = slashEIndex + 2; |
| sb.append("\\E\\\\E\\Q"); |
| } |
| sb.append(s.substring(current, s.length())); |
| sb.append("\\E"); |
| return sb.toString(); |
| } |
| |
| /** |
| * Recompile the Pattern instance from a stream. The original pattern |
| * string is read in and the object tree is recompiled from it. |
| */ |
| private void readObject(java.io.ObjectInputStream s) |
| throws java.io.IOException, ClassNotFoundException { |
| |
| // Read in all fields |
| s.defaultReadObject(); |
| compile(); |
| } |
| |
| /** |
| * This private constructor is used to create all Patterns. The pattern |
| * string and match flags are all that is needed to completely describe |
| * a Pattern. |
| */ |
| private Pattern(String p, int f) { |
| if ((f & CANON_EQ) != 0) { |
| throw new UnsupportedOperationException("CANON_EQ flag not supported"); |
| } |
| int supportedFlags = CASE_INSENSITIVE | COMMENTS | DOTALL | LITERAL | MULTILINE | UNICODE_CASE | UNIX_LINES; |
| if ((f & ~supportedFlags) != 0) { |
| throw new IllegalArgumentException("Unsupported flags: " + (f & ~supportedFlags)); |
| } |
| this.pattern = p; |
| this.flags = f; |
| compile(); |
| } |
| |
| private void compile() throws PatternSyntaxException { |
| if (pattern == null) { |
| throw new NullPointerException("pattern == null"); |
| } |
| |
| String icuPattern = pattern; |
| if ((flags & LITERAL) != 0) { |
| icuPattern = quote(pattern); |
| } |
| |
| // These are the flags natively supported by ICU. |
| // They even have the same value in native code. |
| int icuFlags = flags & (CASE_INSENSITIVE | COMMENTS | MULTILINE | DOTALL | UNIX_LINES); |
| address = compileImpl(icuPattern, icuFlags); |
| registry.registerNativeAllocation(this, address); |
| } |
| |
| private static native long compileImpl(String regex, int flags); |
| private static native long getNativeFinalizer(); |
| private static native int nativeSize(); |
| |
| /** |
| * Creates a predicate which can be used to match a string. |
| * |
| * @return The predicate which can be used for matching on a string |
| * @since 1.8 |
| */ |
| public Predicate<String> asPredicate() { |
| return s -> matcher(s).find(); |
| } |
| |
| /** |
| * Creates a stream from the given input sequence around matches of this |
| * pattern. |
| * |
| * <p> The stream returned by this method contains each substring of the |
| * input sequence that is terminated by another subsequence that matches |
| * this pattern or is terminated by the end of the input sequence. The |
| * substrings in the stream are in the order in which they occur in the |
| * input. Trailing empty strings will be discarded and not encountered in |
| * the stream. |
| * |
| * <p> If this pattern does not match any subsequence of the input then |
| * the resulting stream has just one element, namely the input sequence in |
| * string form. |
| * |
| * <p> When there is a positive-width match at the beginning of the input |
| * sequence then an empty leading substring is included at the beginning |
| * of the stream. A zero-width match at the beginning however never produces |
| * such empty leading substring. |
| * |
| * <p> If the input sequence is mutable, it must remain constant during the |
| * execution of the terminal stream operation. Otherwise, the result of the |
| * terminal stream operation is undefined. |
| * |
| * @param input |
| * The character sequence to be split |
| * |
| * @return The stream of strings computed by splitting the input |
| * around matches of this pattern |
| * @see #split(CharSequence) |
| * @since 1.8 |
| */ |
| public Stream<String> splitAsStream(final CharSequence input) { |
| class MatcherIterator implements Iterator<String> { |
| private final Matcher matcher; |
| // The start position of the next sub-sequence of input |
| // when current == input.length there are no more elements |
| private int current; |
| // null if the next element, if any, needs to obtained |
| private String nextElement; |
| // > 0 if there are N next empty elements |
| private int emptyElementCount; |
| |
| MatcherIterator() { |
| this.matcher = matcher(input); |
| } |
| |
| public String next() { |
| if (!hasNext()) |
| throw new NoSuchElementException(); |
| |
| if (emptyElementCount == 0) { |
| String n = nextElement; |
| nextElement = null; |
| return n; |
| } else { |
| emptyElementCount--; |
| return ""; |
| } |
| } |
| |
| public boolean hasNext() { |
| if (nextElement != null || emptyElementCount > 0) |
| return true; |
| |
| if (current == input.length()) |
| return false; |
| |
| // Consume the next matching element |
| // Count sequence of matching empty elements |
| while (matcher.find()) { |
| nextElement = input.subSequence(current, matcher.start()).toString(); |
| current = matcher.end(); |
| if (!nextElement.isEmpty()) { |
| return true; |
| } else if (current > 0) { // no empty leading substring for zero-width |
| // match at the beginning of the input |
| emptyElementCount++; |
| } |
| } |
| |
| // Consume last matching element |
| nextElement = input.subSequence(current, input.length()).toString(); |
| current = input.length(); |
| if (!nextElement.isEmpty()) { |
| return true; |
| } else { |
| // Ignore a terminal sequence of matching empty elements |
| emptyElementCount = 0; |
| nextElement = null; |
| return false; |
| } |
| } |
| } |
| return StreamSupport.stream(Spliterators.spliteratorUnknownSize( |
| new MatcherIterator(), Spliterator.ORDERED | Spliterator.NONNULL), false); |
| } |
| } |
