giteadmin/script-astra
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity
master
script-astra/Android/Sdk/sources/android-35/java/util/regex/Pattern.java
localadmin 4380f00a78 init
2025-01-20 18:15:20 +03:00

5802 lines
218 KiB
Java
Raw Permalink Blame History

/*
* Copyright (C) 2014 The Android Open Source Project
* Copyright (c) 1999, 2021, 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 android.compat.Compatibility;
import android.compat.annotation.ChangeId;
import android.compat.annotation.EnabledSince;
import com.android.icu.util.regex.PatternNative;
import dalvik.annotation.compat.VersionCodes;
import dalvik.system.VMRuntime;
import java.util.ArrayList;
import java.util.Iterator;
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;
// Android-changed: Document that named capturing is only available from API 26.
// Android-changed: Android always uses unicode character classes.
// Android-changed: Remove reference to Character.codePointOf(String) until it's implemented.
// Android-changed: UNICODE_CHARACTER_CLASS causes IllegalArgumentException on Android.
// Android-changed: POSIX character classes are Unicode-aware.
// Android-changed: Throw PatternSyntaxException for non-existent back references.
// Android-changed: Remove "Compatibility Properties of Unicode Regular Expression" table.
// Android-changed: Remove supported \b{g} Unicode extended grapheme cluster boundary.
// Android-changed: Prefix "Is" is supported since Android 10. http://b/110364810
/**
* 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 {@linkplain
* java.lang.CharSequence character sequences} 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.
*
*
* <h2><a id="sum">Summary of regular-expression constructs</a></h2>
*
* <table class="borderless">
* <caption style="display:none">Regular expression constructs, and what they match</caption>
* <thead style="text-align:left">
* <tr>
* <th id="construct">Construct</th>
* <th id="matches">Matches</th>
* </tr>
* </thead>
* <tbody style="text-align:left">
*
* <tr><th colspan="2" style="padding-top:20px" id="characters">Characters</th></tr>
*
* <tr><th style="vertical-align:top; font-weight: normal" id="x"><i>x</i></th>
* <td headers="matches characters x">The character <i>x</i></td></tr>
* <tr><th style="vertical-align:top; font-weight: normal" id="backslash">{@code \\}</th>
* <td headers="matches characters backslash">The backslash character</td></tr>
* <tr><th style="vertical-align:top; font-weight: normal" id="octal_n">{@code \0}<i>n</i></th>
* <td headers="matches characters octal_n">The character with octal value {@code 0}<i>n</i>
* (0&nbsp;{@code <=}&nbsp;<i>n</i>&nbsp;{@code <=}&nbsp;7)</td></tr>
* <tr><th style="vertical-align:top; font-weight: normal" id="octal_nn">{@code \0}<i>nn</i></th>
* <td headers="matches characters octal_nn">The character with octal value {@code 0}<i>nn</i>
* (0&nbsp;{@code <=}&nbsp;<i>n</i>&nbsp;{@code <=}&nbsp;7)</td></tr>
* <tr><th style="vertical-align:top; font-weight: normal" id="octal_nnn">{@code \0}<i>mnn</i></th>
* <td headers="matches characters octal_nnn">The character with octal value {@code 0}<i>mnn</i>
* (0&nbsp;{@code <=}&nbsp;<i>m</i>&nbsp;{@code <=}&nbsp;3,
* 0&nbsp;{@code <=}&nbsp;<i>n</i>&nbsp;{@code <=}&nbsp;7)</td></tr>
* <tr><th style="vertical-align:top; font-weight: normal" id="hex_hh">{@code \x}<i>hh</i></th>
* <td headers="matches characters hex_hh">The character with hexadecimal value {@code 0x}<i>hh</i></td></tr>
* <tr><th style="vertical-align:top; font-weight: normal" id="hex_hhhh"><code>&#92;u</code><i>hhhh</i></th>
* <td headers="matches characters hex_hhhh">The character with hexadecimal&nbsp;value&nbsp;{@code 0x}<i>hhhh</i></td></tr>
* <tr><th style="vertical-align:top; font-weight: normal" id="hex_h_h"><code>&#92;x</code><i>{h...h}</i></th>
* <td headers="matches characters hex_h_h">The character with hexadecimal value {@code 0x}<i>h...h</i>
* ({@link java.lang.Character#MIN_CODE_POINT Character.MIN_CODE_POINT}
* &nbsp;&lt;=&nbsp;{@code 0x}<i>h...h</i>&nbsp;&lt;=&nbsp;
* {@link java.lang.Character#MAX_CODE_POINT Character.MAX_CODE_POINT})</td></tr>
* <tr><th style="vertical-align:top; font-weight: normal" id="unicode_name"><code>&#92;N{</code><i>name</i><code>}</code></th>
* <td headers="matches characters unicode_name">The character with Unicode character name <i>'name'</i></td></tr>
* <tr><th style="vertical-align:top; font-weight:normal" id="tab">{@code \t}</th>
* <td headers="matches characters tab">The tab character (<code>'&#92;u0009'</code>)</td></tr>
* <tr><th style="vertical-align:top; font-weight:normal" id="newline">{@code \n}</th>
* <td headers="matches characters newline">The newline (line feed) character (<code>'&#92;u000A'</code>)</td></tr>
* <tr><th style="vertical-align:top; font-weight:normal" id="return">{@code \r}</th>
* <td headers="matches characters return">The carriage-return character (<code>'&#92;u000D'</code>)</td></tr>
* <tr><th style="vertical-align:top; font-weight:normal" id="form_feed">{@code \f}</th>
* <td headers="matches characters form_feed">The form-feed character (<code>'&#92;u000C'</code>)</td></tr>
* <tr><th style="vertical-align:top; font-weight:normal" id="bell">{@code \a}</th>
* <td headers="matches characters bell">The alert (bell) character (<code>'&#92;u0007'</code>)</td></tr>
* <tr><th style="vertical-align:top; font-weight:normal" id="escape">{@code \e}</th>
* <td headers="matches characters escape">The escape character (<code>'&#92;u001B'</code>)</td></tr>
* <tr><th style="vertical-align:top; font-weight:normal" id="ctrl_x">{@code \c}<i>x</i></th>
* <td headers="matches characters ctrl_x">The control character corresponding to <i>x</i></td></tr>
*
* <tr><th colspan="2" style="padding-top:20px" id="classes">Character classes</th></tr>
*
* <tr><th style="vertical-align:top; font-weight:normal" id="simple">{@code [abc]}</th>
* <td headers="matches classes simple">{@code a}, {@code b}, or {@code c} (simple class)</td></tr>
* <tr><th style="vertical-align:top; font-weight:normal" id="negation">{@code [^abc]}</th>
* <td headers="matches classes negation">Any character except {@code a}, {@code b}, or {@code c} (negation)</td></tr>
* <tr><th style="vertical-align:top; font-weight:normal" id="range">{@code [a-zA-Z]}</th>
* <td headers="matches classes range">{@code a} through {@code z}
* or {@code A} through {@code Z}, inclusive (range)</td></tr>
* <tr><th style="vertical-align:top; font-weight:normal" id="union">{@code [a-d[m-p]]}</th>
* <td headers="matches classes union">{@code a} through {@code d},
* or {@code m} through {@code p}: {@code [a-dm-p]} (union)</td></tr>
* <tr><th style="vertical-align:top; font-weight:normal" id="intersection">{@code [a-z&&[def]]}</th>
* <td headers="matches classes intersection">{@code d}, {@code e}, or {@code f} (intersection)</tr>
* <tr><th style="vertical-align:top; font-weight:normal" id="subtraction1">{@code [a-z&&[^bc]]}</th>
* <td headers="matches classes subtraction1">{@code a} through {@code z},
* except for {@code b} and {@code c}: {@code [ad-z]} (subtraction)</td></tr>
* <tr><th style="vertical-align:top; font-weight:normal" id="subtraction2">{@code [a-z&&[^m-p]]}</th>
* <td headers="matches classes subtraction2">{@code a} through {@code z},
* and not {@code m} through {@code p}: {@code [a-lq-z]}(subtraction)</td></tr>
*
* <tr><th colspan="2" style="padding-top:20px" id="predef">Predefined character classes</th></tr>
*
* <tr><th style="vertical-align:top; font-weight:normal" id="any">{@code .}</th>
* <td headers="matches predef any">Any character (may or may not match <a href="#lt">line terminators</a>)</td></tr>
* <tr><th style="vertical-align:top; font-weight:normal" id="digit">{@code \d}</th>
* <td headers="matches predef digit">A digit: {@code \p{IsDigit}}</td></tr>
* <tr><th style="vertical-align:top; font-weight:normal" id="non_digit">{@code \D}</th>
* <td headers="matches predef non_digit">A non-digit: {@code [^\d]}</td></tr>
* <tr><th style="vertical-align:top; font-weight:normal" id="horiz_white">{@code \h}</th>
* <td headers="matches predef horiz_white">A horizontal whitespace character:
* <code>[ \t\xA0&#92;u1680&#92;u180e&#92;u2000-&#92;u200a&#92;u202f&#92;u205f&#92;u3000]</code></td></tr>
* <tr><th style="vertical-align:top; font-weight:normal" id="non_horiz_white">{@code \H}</th>
* <td headers="matches predef non_horiz_white">A non-horizontal whitespace character: {@code [^\h]}</td></tr>
* <tr><th style="vertical-align:top; font-weight:normal" id="white">{@code \s}</th>
* <td headers="matches predef white">A whitespace character: {@code \p{IsWhite_Space}}</td></tr>
* <tr><th style="vertical-align:top; font-weight:normal" id="non_white">{@code \S}</th>
* <td headers="matches predef non_white">A non-whitespace character: {@code [^\s]}</td></tr>
* <tr><th style="vertical-align:top; font-weight:normal" id="vert_white">{@code \v}</th>
* <td headers="matches predef vert_white">A vertical whitespace character: <code>[\n\x0B\f\r\x85&#92;u2028&#92;u2029]</code>
* </td></tr>
* <tr><th style="vertical-align:top; font-weight:normal" id="non_vert_white">{@code \V}</th>
* <td headers="matches predef non_vert_white">A non-vertical whitespace character: {@code [^\v]}</td></tr>
* <tr><th style="vertical-align:top; font-weight:normal" id="word">{@code \w}</th>
* <td headers="matches predef word">A word character: {@code [\p{alpha}\p{gc=Mark}\p{digit}\p{gc=Connector_Punctuation}\p{Join_Control}]}</td></tr>
* <tr><th style="vertical-align:top; font-weight:normal" id="non_word">{@code \W}</th>
* <td headers="matches predef non_word">A non-word character: {@code [^\w]}</td></tr>
*
* <tr><th colspan="2" style="padding-top:20px" id="posix"><b>POSIX character classes (Unicode-aware)</b></th></tr>
*
* <tr><th style="vertical-align:top; font-weight:normal" id="Lower">{@code \p{Lower}}</th>
* <td headers="matches posix Lower">A lower-case alphabetic character: {@code \p{IsLowercase}}</td></tr>
* <tr><th style="vertical-align:top; font-weight:normal" id="Upper">{@code \p{Upper}}</th>
* <td headers="matches posix Upper">An upper-case alphabetic character:{@code \p{IsUppercase}}</td></tr>
* <tr><th style="vertical-align:top; font-weight:normal" id="ASCII">{@code \p{ASCII}}</th>
* <td headers="matches posix ASCII">All ASCII:{@code [\x00-\x7F]}</td></tr>
* <tr><th style="vertical-align:top; font-weight:normal" id="Alpha">{@code \p{Alpha}}</th>
* <td headers="matches posix Alpha">An alphabetic character:{@code [\p{IsAlphabetic}]}</td></tr>
* <tr><th style="vertical-align:top; font-weight:normal" id="Digit">{@code \p{IsDigit}}</th>
* <td headers="matches posix Digit">A decimal digit: {@code \p{gc=Decimal_Number}}</td></tr>
* <tr><th style="vertical-align:top; font-weight:normal" id="Alnum">{@code \p{Alnum}}</th>
* <td headers="matches posix Alnum">An alphanumeric character:{@code [\p{Alpha}\p{Digit}]}</td></tr>
* <tr><th style="vertical-align:top; font-weight:normal" id="Punct">{@code \p{Punct}}</th>
* <td headers="matches posix Punct">Punctuation: {@code \p{IsPunctuation}}</td></tr>
* <tr><th style="vertical-align:top; font-weight:normal" id="Graph">{@code \p{Graph}}</th>
* <td headers="matches posix Graph">A visible character:
* {@code [^p{space}\p{gc=Control}\p{gc=Surrogate}\p{gc=Unassigned}]}</td></tr>
* <tr><th style="vertical-align:top; font-weight:normal" id="Print">{@code \p{Print}}</th>
* <td headers="matches posix Print">A printable character: {@code [\p{Graph}\p{Blank}&&[^\p{Cntrl}]]}</td></tr>
* <tr><th style="vertical-align:top; font-weight:normal" id="Blank">{@code \p{Blank}}</th>
* <td headers="matches posix Blank">A space or a tab: {@code [\p{gc=Space_Separator}\N{CHARACTER TABULATION}]}</td></tr>
* <tr><th style="vertical-align:top; font-weight:normal" id="Cntrl">{@code \p{Cntrl}}</th>
* <td headers="matches posix Cntrl">A control character: {@code \p{gc=Control}}</td></tr>
* <tr><th style="vertical-align:top; font-weight:normal" id="XDigit">{@code \p{XDigit}}</th>
* <td headers="matches posix XDigit">A hexadecimal digit: {@code [\p{gc=Decimal_Number}\p{IsHex_Digit}]}</td></tr>
* <tr><th style="vertical-align:top; font-weight:normal" id="Space">{@code \p{Space}}</th>
* <td headers="matches posix Space">A whitespace character: {@code \p{IsWhite_Space}}</td></tr>
* <tr><th style="vertical-align:top; font-weight:normal" id="PosixCompatible">POSIX-Compatible expression</th>
* <td headers="matches posix PosixCompatible">See <a href="http://www.unicode.org/reports/tr18/#Compatibility_Properties">Unicode documentation</a></td></tr>
*
* <tr><th colspan="2" style="padding-top:20px" id="java">java.lang.Character classes (simple <a href="#jcc">java character type</a>)</th></tr>
*
* <tr><th style="vertical-align:top; font-weight:normal" id="javaLowerCase">{@code \p{javaLowerCase}}</th>
* <td headers="matches java javaLowerCase">Equivalent to java.lang.Character.isLowerCase()</td></tr>
* <tr><th style="vertical-align:top; font-weight:normal" id="javaUpperCase">{@code \p{javaUpperCase}}</th>
* <td headers="matches java javaUpperCase">Equivalent to java.lang.Character.isUpperCase()</td></tr>
* <tr><th style="vertical-align:top; font-weight:normal" id="javaWhitespace">{@code \p{javaWhitespace}}</th>
* <td headers="matches java javaWhitespace">Equivalent to java.lang.Character.isWhitespace()</td></tr>
* <tr><th style="vertical-align:top; font-weight:normal" id="javaMirrored">{@code \p{javaMirrored}}</th>
* <td headers="matches java javaMirrored">Equivalent to java.lang.Character.isMirrored()</td></tr>
*
* <tr><th colspan="2" style="padding-top:20px" id="unicode">Classes for Unicode scripts, blocks, categories and binary properties</th></tr>
*
* <tr><th style="vertical-align:top; font-weight:normal" id="IsLatin">{@code \p{IsLatin}}</th>
* <td headers="matches unicode IsLatin">A Latin&nbsp;script character (<a href="#usc">script</a>)</td></tr>
* <tr><th style="vertical-align:top; font-weight:normal" id="InGreek">{@code \p{InGreek}}</th>
* <td headers="matches unicode InGreek">A character in the Greek&nbsp;block (<a href="#ubc">block</a>)</td></tr>
* <tr><th style="vertical-align:top; font-weight:normal" id="Lu">{@code \p{Lu}}</th>
* <td headers="matches unicode Lu">An uppercase letter (<a href="#ucc">category</a>)</td></tr>
* <tr><th style="vertical-align:top; font-weight:normal" id="IsAlphabetic">{@code \p{IsAlphabetic}}</th>
* <td headers="matches unicode IsAlphabetic">An alphabetic character (<a href="#ubpc">binary property</a>)</td></tr>
* <tr><th style="vertical-align:top; font-weight:normal" id="Sc">{@code \p{Sc}}</th>
* <td headers="matches unicode Sc">A currency symbol</td></tr>
* <tr><th style="vertical-align:top; font-weight:normal" id="not_InGreek">{@code \P{InGreek}}</th>
* <td headers="matches unicode not_InGreek">Any character except one in the Greek block (negation)</td></tr>
* <tr><th style="vertical-align:top; font-weight:normal" id="not_uppercase">{@code [\p{L}&&[^\p{Lu}]]}</th>
* <td headers="matches unicode not_uppercase">Any letter except an uppercase letter (subtraction)</td></tr>
*
* <tr><th colspan="2" style="padding-top:20px" id="bounds">Boundary matchers</th></tr>
*
* <tr><th style="vertical-align:top; font-weight:normal" id="begin_line">{@code ^}</th>
* <td headers="matches bounds begin_line">The beginning of a line</td></tr>
* <tr><th style="vertical-align:top; font-weight:normal" id="end_line">{@code $}</th>
* <td headers="matches bounds end_line">The end of a line</td></tr>
* <tr><th style="vertical-align:top; font-weight:normal" id="word_boundary">{@code \b}</th>
* <td headers="matches bounds word_boundary">A word boundary</td></tr>
* <tr><th style="vertical-align:top; font-weight:normal" id="non_word_boundary">{@code \B}</th>
* <td headers="matches bounds non_word_boundary">A non-word boundary</td></tr>
* <tr><th style="vertical-align:top; font-weight:normal" id="begin_input">{@code \A}</th>
* <td headers="matches bounds begin_input">The beginning of the input</td></tr>
* <tr><th style="vertical-align:top; font-weight:normal" id="end_prev_match">{@code \G}</th>
* <td headers="matches bounds end_prev_match">The end of the previous match</td></tr>
* <tr><th style="vertical-align:top; font-weight:normal" id="end_input_except_term">{@code \Z}</th>
* <td headers="matches bounds end_input_except_term">The end of the input but for the final
* <a href="#lt">terminator</a>, if&nbsp;any</td></tr>
* <tr><th style="vertical-align:top; font-weight:normal" id="end_input">{@code \z}</th>
* <td headers="matches bounds end_input">The end of the input</td></tr>
*
* <tr><th colspan="2" style="padding-top:20px" id="linebreak">Linebreak matcher</th></tr>
*
* <tr><th style="vertical-align:top; font-weight:normal" id="any_unicode_linebreak">{@code \R}</th>
* <td headers="matches linebreak any_unicode_linebreak">Any Unicode linebreak sequence, is equivalent to
* <code>&#92;u000D&#92;u000A|[&#92;u000A&#92;u000B&#92;u000C&#92;u000D&#92;u0085&#92;u2028&#92;u2029]
* </code></td></tr>
*
* <tr><th colspan="2" style="padding-top:20px" id="grapheme">Unicode Extended Grapheme matcher</th></tr>
*
* <tr><th style="vertical-align:top; font-weight:normal" id="grapheme_any">{@code \X}</th>
* <td headers="matches grapheme grapheme_any">Any Unicode extended grapheme cluster</td></tr>
*
* <tr><th colspan="2" style="padding-top:20px" id="greedy">Greedy quantifiers</th></tr>
*
* <tr><th style="vertical-align:top; font-weight:normal" id="greedy_once_or_not"><i>X</i>{@code ?}</th>
* <td headers="matches greedy greedy_once_or_not"><i>X</i>, once or not at all</td></tr>
* <tr><th style="vertical-align:top; font-weight:normal" id="greedy_zero_or_more"><i>X</i>{@code *}</th>
* <td headers="matches greedy greedy_zero_or_more"><i>X</i>, zero or more times</td></tr>
* <tr><th style="vertical-align:top; font-weight:normal" id="greedy_one_or_more"><i>X</i>{@code +}</th>
* <td headers="matches greedy greedy_one_or_more"><i>X</i>, one or more times</td></tr>
* <tr><th style="vertical-align:top; font-weight:normal" id="greedy_exactly"><i>X</i><code>{</code><i>n</i><code>}</code></th>
* <td headers="matches greedy greedy_exactly"><i>X</i>, exactly <i>n</i> times</td></tr>
* <tr><th style="vertical-align:top; font-weight:normal" id="greedy_at_least"><i>X</i><code>{</code><i>n</i>{@code ,}}</th>
* <td headers="matches greedy greedy_at_least"><i>X</i>, at least <i>n</i> times</td></tr>
* <tr><th style="vertical-align:top; font-weight:normal" id="greedy_at_least_up_to"><i>X</i><code>{</code><i>n</i>{@code ,}<i>m</i><code>}</code></th>
* <td headers="matches greedy greedy_at_least_up_to"><i>X</i>, at least <i>n</i> but not more than <i>m</i> times</td></tr>
*
* <tr><th colspan="2" style="padding-top:20px" id="reluc">Reluctant quantifiers</th></tr>
*
* <tr><th style="vertical-align:top; font-weight:normal" id="reluc_once_or_not"><i>X</i>{@code ??}</th>
* <td headers="matches reluc reluc_once_or_not"><i>X</i>, once or not at all</td></tr>
* <tr><th style="vertical-align:top; font-weight:normal" id="reluc_zero_or_more"><i>X</i>{@code *?}</th>
* <td headers="matches reluc reluc_zero_or_more"><i>X</i>, zero or more times</td></tr>
* <tr><th style="vertical-align:top; font-weight:normal" id="reluc_one_or_more"><i>X</i>{@code +?}</th>
* <td headers="matches reluc reluc_one_or_more"><i>X</i>, one or more times</td></tr>
* <tr><th style="vertical-align:top; font-weight:normal" id="reluc_exactly"><i>X</i><code>{</code><i>n</i><code>}?</code></th>
* <td headers="matches reluc reluc_exactly"><i>X</i>, exactly <i>n</i> times</td></tr>
* <tr><th style="vertical-align:top; font-weight:normal" id="reluc_at_least"><i>X</i><code>{</code><i>n</i><code>,}?</code></th>
* <td headers="matches reluc reluc_at_least"><i>X</i>, at least <i>n</i> times</td></tr>
* <tr><th style="vertical-align:top; font-weight:normal" id="reluc_at_least_up_to"><i>X</i><code>{</code><i>n</i>{@code ,}<i>m</i><code>}?</code></th>
* <td headers="matches reluc reluc_at_least_up_to"><i>X</i>, at least <i>n</i> but not more than <i>m</i> times</td></tr>
*
* <tr><th colspan="2" style="padding-top:20px" id="poss">Possessive quantifiers</th></tr>
*
* <tr><th style="vertical-align:top; font-weight:normal" id="poss_once_or_not"><i>X</i>{@code ?+}</th>
* <td headers="matches poss poss_once_or_not"><i>X</i>, once or not at all</td></tr>
* <tr><th style="vertical-align:top; font-weight:normal" id="poss_zero_or_more"><i>X</i>{@code *+}</th>
* <td headers="matches poss poss_zero_or_more"><i>X</i>, zero or more times</td></tr>
* <tr><th style="vertical-align:top; font-weight:normal" id="poss_one_or_more"><i>X</i>{@code ++}</th>
* <td headers="matches poss poss_one_or_more"><i>X</i>, one or more times</td></tr>
* <tr><th style="vertical-align:top; font-weight:normal" id="poss_exactly"><i>X</i><code>{</code><i>n</i><code>}+</code></th>
* <td headers="matches poss poss_exactly"><i>X</i>, exactly <i>n</i> times</td></tr>
* <tr><th style="vertical-align:top; font-weight:normal" id="poss_at_least"><i>X</i><code>{</code><i>n</i><code>,}+</code></th>
* <td headers="matches poss poss_at_least"><i>X</i>, at least <i>n</i> times</td></tr>
* <tr><th style="vertical-align:top; font-weight:normal" id="poss_at_least_up_to"><i>X</i><code>{</code><i>n</i>{@code ,}<i>m</i><code>}+</code></th>
* <td headers="matches poss poss_at_least_up_to"><i>X</i>, at least <i>n</i> but not more than <i>m</i> times</td></tr>
*
* <tr><th colspan="2" style="padding-top:20px" id="logical">Logical operators</th></tr>
*
* <tr><th style="vertical-align:top; font-weight:normal" id="concat"><i>XY</i></th>
* <td headers="matches logical concat"><i>X</i> followed by <i>Y</i></td></tr>
* <tr><th style="vertical-align:top; font-weight:normal" id="alternate"><i>X</i>{@code |}<i>Y</i></th>
* <td headers="matches logical alternate">Either <i>X</i> or <i>Y</i></td></tr>
* <tr><th style="vertical-align:top; font-weight:normal" id="group">{@code (}<i>X</i>{@code )}</th>
* <td headers="matches logical group">X, as a <a href="#cg">capturing group</a></td></tr>
*
* <tr><th colspan="2" style="padding-top:20px" id="backref">Back references</th></tr>
*
* <tr><th style="vertical-align:top; font-weight:normal" id="back_nth">{@code \}<i>n</i></th>
* <td headers="matches backref back_nth">Whatever the <i>n</i><sup>th</sup>
* <a href="#cg">capturing group</a> matched</td></tr>
* <tr><th style="vertical-align:top; font-weight:normal" id="back_named">{@code \}<i>k</i>&lt;<i>name</i>&gt;</th>
* <td headers="matches backref back_named">Whatever the
* <a href="#groupname">named-capturing group</a> "name" matched. Only available for API 26 or above</td></tr>
*
* <tr><th colspan="2" style="padding-top:20px" id="quote">Quotation</th></tr>
*
* <tr><th style="vertical-align:top; font-weight:normal" id="quote_follow">{@code \}</th>
* <td headers="matches quote quote_follow">Nothing, but quotes the following character</td></tr>
* <tr><th style="vertical-align:top; font-weight:normal" id="quote_begin">{@code \Q}</th>
* <td headers="matches quote quote_begin">Nothing, but quotes all characters until {@code \E}</td></tr>
* <tr><th style="vertical-align:top; font-weight:normal" id="quote_end">{@code \E}</th>
* <td headers="matches quote quote_end">Nothing, but ends quoting started by {@code \Q}</td></tr>
* <!-- Metachars: !$()*+.<>?[\]^{|} -->
*
* <tr><th colspan="2" style="padding-top:20px" id="special">Special constructs (named-capturing and non-capturing)</th></tr>
*
* <tr><th style="vertical-align:top; font-weight:normal" id="named_group"><code>(?&lt;<a href="#groupname">name</a>&gt;</code><i>X</i>{@code )}</th>
* <td headers="matches special named_group"><i>X</i>, as a named-capturing group. Only available for API 26 or above.</td></tr>
* <tr><th style="vertical-align:top; font-weight:normal" id="non_capture_group">{@code (?:}<i>X</i>{@code )}</th>
* <td headers="matches special non_capture_group"><i>X</i>, as a non-capturing group</td></tr>
* <tr><th style="vertical-align:top; font-weight:normal" id="flags"><code>(?idmsux-idmsux)&nbsp;</code></th>
* <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><th style="vertical-align:top; font-weight:normal" id="non_capture_group_flags">{@code (?idmsuxU-idmsuxU:}<i>X</i>{@code )}&nbsp;&nbsp;</th>
* <td headers="matches special non_capture_group_flags"><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> <a href="#UNICODE_CHARACTER_CLASS">U</a> on - off</td></tr>
* <tr><th style="vertical-align:top; font-weight:normal" id="pos_lookahead">{@code (?=}<i>X</i>{@code )}</th>
* <td headers="matches special pos_lookahead"><i>X</i>, via zero-width positive lookahead</td></tr>
* <tr><th style="vertical-align:top; font-weight:normal" id="neg_lookahead">{@code (?!}<i>X</i>{@code )}</th>
* <td headers="matches special neg_lookahead"><i>X</i>, via zero-width negative lookahead</td></tr>
* <tr><th style="vertical-align:top; font-weight:normal" id="pos_lookbehind">{@code (?<=}<i>X</i>{@code )}</th>
* <td headers="matches special pos_lookbehind"><i>X</i>, via zero-width positive lookbehind</td></tr>
* <tr><th style="vertical-align:top; font-weight:normal" id="neg_lookbehind">{@code (?<!}<i>X</i>{@code )}</th>
* <td headers="matches special neg_lookbehind"><i>X</i>, via zero-width negative lookbehind</td></tr>
* <tr><th style="vertical-align:top; font-weight:normal" id="indep_non_capture_group">{@code (?>}<i>X</i>{@code )}</th>
* <td headers="matches special indep_non_capture_group"><i>X</i>, as an independent, non-capturing group</td></tr>
*
* </tbody>
* </table>
*
* <hr>
*
*
* <h2><a id="bs">Backslashes, escapes, and quoting</a></h2>
*
* <p> The backslash character ({@code '\'}) 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 {@code \\} matches a single backslash and <code>\{</code> 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 {@jls 3.3}) or other character escapes (section {@jls 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
* <code>"&#92;b"</code>, for example, matches a single backspace character when
* interpreted as a regular expression, while {@code "\\b"} matches a
* word boundary. The string literal {@code "\(hello\)"} is illegal
* and leads to a compile-time error; in order to match the string
* {@code (hello)} the string literal {@code "\\(hello\\)"}
* must be used.
*
* <h2><a id="cc">Character Classes</a></h2>
*
* <p> Character classes may appear within other character classes, and
* may be composed by the union operator (implicit) and the intersection
* operator ({@code &&}).
* 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:
*
* <table class="striped" style="margin-left: 2em;">
* <caption style="display:none">Precedence of character class operators.</caption>
* <thead>
* <tr><th scope="col">Precedence<th scope="col">Name<th scope="col">Example
* </thead>
* <tbody>
* <tr><th scope="row">1</th>
* <td>Literal escape&nbsp;&nbsp;&nbsp;&nbsp;</td>
* <td>{@code \x}</td></tr>
* <tr><th scope="row">2</th>
* <td>Grouping</td>
* <td>{@code [...]}</td></tr>
* <tr><th scope="row">3</th>
* <td>Range</td>
* <td>{@code a-z}</td></tr>
* <tr><th scope="row">4</th>
* <td>Union</td>
* <td>{@code [a-e][i-u]}</td></tr>
* <tr><th scope="row">5</th>
* <td>Intersection</td>
* <td>{@code [a-z&&[aeiou]]}</td></tr>
* </tbody>
* </table>
*
* <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 {@code .} loses its special meaning inside a
* character class, while the expression {@code -} becomes a range
* forming metacharacter.
*
* <h2><a id="lt">Line terminators</a></h2>
*
* <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 ({@code '\n'}),
*
* <li> A carriage-return character followed immediately by a newline
* character ({@code "\r\n"}),
*
* <li> A standalone carriage-return character ({@code '\r'}),
*
* <li> A next-line character (<code>'&#92;u0085'</code>),
*
* <li> A line-separator character (<code>'&#92;u2028'</code>), or
*
* <li> A paragraph-separator character (<code>'&#92;u2029'</code>).
*
* </ul>
* <p>If {@link #UNIX_LINES} mode is activated, then the only line terminators
* recognized are newline characters.
*
* <p> The regular expression {@code .} matches any character except a line
* terminator unless the {@link #DOTALL} flag is specified.
*
* <p> By default, the regular expressions {@code ^} and {@code $} 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
* {@code ^} matches at the beginning of input and after any line terminator
* except at the end of input. When in {@link #MULTILINE} mode {@code $}
* matches just before a line terminator or the end of the input sequence.
*
* <h2><a id="cg">Groups and capturing</a></h2>
*
* <h3><a id="gnumber">Group number</a></h3>
* <p> Capturing groups are numbered by counting their opening parentheses from
* left to right. In the expression {@code ((A)(B(C)))}, for example, there
* are four such groups: </p>
*
* <ol style="margin-left:2em;">
* <li> {@code ((A)(B(C)))}
* <li> {@code (A)}
* <li> {@code (B(C))}
* <li> {@code (C)}
* </ol>
*
* <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.
*
* <h3><a id="groupname">Group name</a></h3>
* <p>The constructs and APIs are available since API level 26. A capturing group
* can also be assigned a "name", a {@code named-capturing group},
* and then be back-referenced later by the "name". Group names are composed of
* the following characters. The first character must be a {@code letter}.
*
* <ul>
* <li> The uppercase letters {@code 'A'} through {@code 'Z'}
* (<code>'&#92;u0041'</code>&nbsp;through&nbsp;<code>'&#92;u005a'</code>),
* <li> The lowercase letters {@code 'a'} through {@code 'z'}
* (<code>'&#92;u0061'</code>&nbsp;through&nbsp;<code>'&#92;u007a'</code>),
* <li> The digits {@code '0'} through {@code '9'}
* (<code>'&#92;u0030'</code>&nbsp;through&nbsp;<code>'&#92;u0039'</code>),
* </ul>
*
* <p> A {@code named-capturing group} 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
* {@code "aba"} against the expression {@code (a(b)?)+}, for example, leaves
* group two set to {@code "b"}. All captured input is discarded at the
* beginning of each match.
*
* <p> Groups beginning with {@code (?} 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.
*
* <h2> Unicode support </h2>
*
* <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 Expressions</i></a>, plus RL2.1
* Canonical Equivalents and RL2.2 Extended Grapheme Clusters.
* <p>
* <b>Unicode escape sequences</b> such as <code>&#92;u2014</code> in Java source code
* are processed as described in section {@jls 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 <code>"&#92;u2014"</code> and
* {@code "\\u2014"}, while not equal, compile into the same pattern, which
* matches the character with hexadecimal value {@code 0x2014}.
* <p>
* A Unicode character can also be represented by using its <b>Hex notation</b>
* (hexadecimal code point value) directly as described in construct
* <code>&#92;x{...}</code>, for example a supplementary character U+2011F can be
* specified as <code>&#92;x{2011F}</code>, instead of two consecutive Unicode escape
* sequences of the surrogate pair <code>&#92;uD840</code><code>&#92;uDD1F</code>.
* <p>
* <b>Unicode character names</b> are supported by the named character construct
* <code>\N{</code>...<code>}</code>, for example, <code>\N{WHITE SMILING FACE}</code>
* specifies character <code>&#92;u263A</code>. The character names supported
* by this class are the valid Unicode character names matched by
* {@code java.lang.Character.codePointOf(String) Character.codePointOf(name)}.
* <p>
* <a href="http://www.unicode.org/reports/tr18/#Default_Grapheme_Clusters">
* <b>Unicode extended grapheme clusters</b></a> are supported by the grapheme
* cluster matcher {@code \X}.
* <p>
* Unicode scripts, blocks, categories and binary properties are written with
* the {@code \p} and {@code \P} constructs as in Perl.
* <code>\p{</code><i>prop</i><code>}</code> matches if
* the input has the property <i>prop</i>, while <code>\P{</code><i>prop</i><code>}</code>
* 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.
*
* <p>
* <b><a id="usc">Scripts</a></b> are specified either with the prefix {@code Is} supported since
* Android 10, 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} are the valid script names
* accepted and defined by
* {@link java.lang.Character.UnicodeScript#forName(String) UnicodeScript.forName}.
*
* <p>
* <b><a id="ubc">Blocks</a></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} are the valid block names
* accepted and defined by
* {@link java.lang.Character.UnicodeBlock#forName(String) UnicodeBlock.forName}.
* <p>
*
* <b><a id="ucc">Categories</a></b> may be specified with the optional prefix {@code Is}:
* Both {@code \p{IsL}} supported since Android 10 and {@code \p{L}} 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/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>
*
* <b><a id="ubpc">Binary properties</a></b> are specified with the prefix {@code Is} since
* Android 10, as in {@code IsAlphabetic}. The prefix {@code Is} isn't needed before Android 10,
* as in {@code Alphabetic}. The supported binary properties by {@code Pattern}
* 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> Join_Control
* <li> Noncharacter_Code_Point
* <li> Assigned
* </ul>
* <p>
* The <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 Technical Standard #18:
* Unicode Regular Expressions</i></a>.
*
* <p>
* <a id="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 <code>\p{</code><i>prop</i><code>}</code> syntax where
* the specified property has the name <code>java<i>methodname</i></code></a>.
*
* <h3> Behavior starting from API level 10 (Android 2.3) </h3>
*
* <p> Starting from Android 2.3 Gingerbread, ICU4C becomes the backend of the regular expression
* implementation. Android could behave differently compared with other regex implementation, e.g.
* literal right brace ('}') has to be escaped on Android.</p>
*
* <p> Some other behavior differences can be found in the
* <a href="https://unicode-org.github.io/icu/userguide/strings/regexp.html#differences-with-java-regular-expressions">
* ICU documentation</a>. </p>
*
* <h2> Comparison to Perl 5 </h2>
*
* <p>The {@code Pattern} 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> The backreference constructs, <code>\g{</code><i>n</i><code>}</code> for
* the <i>n</i><sup>th</sup><a href="#cg">capturing group</a> and
* <code>\g{</code><i>name</i><code>}</code> for
* <a href="#groupname">named-capturing group</a>.
* </p></li>
*
* <li><p> The conditional constructs
* {@code (?(}<i>condition</i>{@code )}<i>X</i>{@code )} and
* {@code (?(}<i>condition</i>{@code )}<i>X</i>{@code |}<i>Y</i>{@code )},
* </p></li>
*
* <li><p> The embedded code constructs <code>(?{</code><i>code</i><code>})</code>
* and <code>(??{</code><i>code</i><code>})</code>,</p></li>
*
* <li><p> The embedded comment syntax {@code (?#comment)}, and </p></li>
*
* <li><p> The preprocessing operations {@code \l} <code>&#92;u</code>,
* {@code \L}, and {@code \U}. </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, {@code \1} through {@code \9} are always interpreted
* as back references; a backslash-escaped number greater than {@code 9} 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,
* {@link #compile(String)} throws {@link PatternSyntaxException} for any
* non-existent back references. Please use {@code \Q} and {@code \E} to
* quote any digit literals followed by back references.
* </p></li>
*
* <li><p> Perl uses the {@code g} 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, 3rd 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
*/
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.
*
* Pattern p1 = Pattern.compile("abc", Pattern.CASE_INSENSITIVE|Pattern.MULTILINE);
* Pattern p2 = Pattern.compile("(?im)abc", 0);
*/
/**
* Enables Unix lines mode.
*
* <p> In this mode, only the {@code '\n'} line terminator is recognized
* in the behavior of {@code .}, {@code ^}, and {@code $}.
*
* <p> Unix lines mode can also be enabled via the embedded flag
* expression&nbsp;{@code (?d)}.
*/
public static final int UNIX_LINES = 0x01;
// Android-changed: CASE_INSENSITIVE is Unicode-aware on Android.
/**
* Enables case-insensitive matching.
*
* <p> Case-insensitive matching is Unicode-aware on Android.
*
* <p> Case-insensitive matching can also be enabled via the embedded flag
* expression&nbsp;{@code (?i)}.
*
* <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 {@code #} are ignored until the end of a line.
*
* <p> Comments mode can also be enabled via the embedded flag
* expression&nbsp;{@code (?x)}.
*/
public static final int COMMENTS = 0x04;
/**
* Enables multiline mode.
*
* <p> In multiline mode the expressions {@code ^} and {@code $} 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&nbsp;{@code (?m)}. </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 {@code .} 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&nbsp;{@code (?s)}. (The {@code s} is a mnemonic for
* "single-line" mode, which is what this is called in Perl.) </p>
*/
public static final int DOTALL = 0x20;
// Android-changed: UNICODE_CASE flag is ignored.
/**
* Enables Unicode-aware case folding. This flag is ignoredon Android.
* When {@link #CASE_INSENSITIVE} flag is provided, case-insensitive
* matching is always done in a manner consistent with the Unicode Standard.
*
* <p> The embedded flag &nbsp;{@code (?u)} is ignored.
*
* <p> Specifying this flag may impose a performance penalty. </p>
*/
public static final int UNICODE_CASE = 0x40;
// Android-changed: Android does not support CANON_EQ flag.
/**
* This flag is not supported on Android.
*/
public static final int CANON_EQ = 0x80;
// Android-changed: Android always uses unicode character classes.
/**
* This flag is not supported on Android, and Unicode character classes are always
* used.
* <p>
* See the Unicode version of
* <i>Predefined character classes</i> and <i>POSIX character classes</i>
* are in conformance with
* <a href="http://www.unicode.org/reports/tr18/"><i>Unicode Technical
* Standard #18: Unicode Regular Expressions</i></a>
* <i>Annex C: Compatibility Properties</i>.
* <p>
* @since 1.7
*/
public static final int UNICODE_CHARACTER_CLASS = 0x100;
/**
* Contains all possible flags for compile(regex, flags).
*/
private static final int ALL_FLAGS = CASE_INSENSITIVE | MULTILINE |
// Android-changed: CANON_EQ and UNICODE_CHARACTER_CLASS flags aren't supported.
// DOTALL | UNICODE_CASE | CANON_EQ | UNIX_LINES | LITERAL |
// UNICODE_CHARACTER_CLASS | COMMENTS;
DOTALL | UNICODE_CASE | UNIX_LINES | LITERAL | COMMENTS;
/* 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 */
@java.io.Serial
private static final long serialVersionUID = 5073258162644648461L;
/**
* The original regular-expression pattern string.
*
* @serial
*/
// Android-changed: reimplement matching logic natively via ICU.
// private String pattern;
private final String pattern;
/**
* The original pattern flags.
*
* @serial
*/
// Android-changed: reimplement matching logic natively via ICU.
// private int flags;
private final int flags;
// BEGIN Android-changed: reimplement matching logic natively via ICU.
// We only need some tie-ins to native memory, instead of a large number
// of fields on the .java side.
/* package */ transient PatternNative nativePattern;
// END Android-changed: reimplement matching logic natively via ICU.
/**
* Compiles the given regular expression into a pattern.
*
* @param regex
* The expression to be compiled
* @return the given regular expression compiled into a pattern
* @throws PatternSyntaxException
* If the expression's syntax is invalid
*/
public static Pattern compile(String regex) {
return new Pattern(regex, 0);
}
// Android-changed: Android doesn't support CANON_EQ and UNICODE_CHARACTER_CLASS flags.
/**
* Compiles the given regular expression into a pattern with the given
* flags.
*
* @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 #UNIX_LINES}, {@link #LITERAL},
* and {@link #COMMENTS}
*
* @return the given regular expression compiled into a pattern with the given flags
* @throws IllegalArgumentException
* If bit values other than those corresponding to the defined
* match flags are set in {@code flags}
*
* @throws PatternSyntaxException
* If the expression's syntax is invalid
*/
public static Pattern compile(String regex, int flags) {
return new Pattern(regex, flags);
}
/**
* Returns the regular expression from which this pattern was compiled.
*
* @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.
*
* @param input
* The character sequence to be matched
*
* @return A new matcher for this pattern
*/
public Matcher matcher(CharSequence input) {
// Android-removed: Pattern is eagerly compiled() upon construction.
/*
if (!compiled) {
synchronized(this) {
if (!compiled)
compile();
}
}
*/
Matcher m = new Matcher(this, input);
return m;
}
/**
* Returns this pattern's match flags.
*
* @return The match flags specified when this pattern was compiled
*/
public int flags() {
// Android-changed: We don't need the temporary pattern flags0.
// return flags0;
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
* @return whether or not the regular expression matches on the input
* @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();
}
// Android-changed: Adopt split() behavior change only for apps targeting API > 28.
// http://b/109659282#comment7
/**
* 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> 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 resulting array. A zero-width match at the beginning however
* can only produce such an empty leading substring for apps running on or
* targeting API versions <= 28.
*
* <p> The {@code limit} parameter controls the number of times the
* pattern is applied and therefore affects the length of the resulting
* array.
* <ul>
* <li><p>
* If the <i>limit</i> is positive then the pattern will be applied
* at most <i>limit</i>&nbsp;-&nbsp;1 times, the array's length will be
* no greater than <i>limit</i>, and the array's last entry will contain
* all input beyond the last matched delimiter.</p></li>
*
* <li><p>
* If the <i>limit</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></li>
*
* <li><p>
* If the <i>limit</i> is negative then the pattern will be applied
* as many times as possible and the array can have any length.</p></li>
* </ul>
*
* <p> The input {@code "boo:and:foo"}, for example, yields the following
* results with these parameters:
*
* <table class="plain" style="margin-left:2em;">
* <caption style="display:none">Split example showing regex, limit, and result</caption>
* <thead>
* <tr>
* <th scope="col">Regex</th>
* <th scope="col">Limit</th>
* <th scope="col">Result</th>
* </tr>
* </thead>
* <tbody>
* <tr><th scope="row" rowspan="3" style="font-weight:normal">:</th>
* <th scope="row" style="font-weight:normal; text-align:right; padding-right:1em">2</th>
* <td>{@code { "boo", "and:foo" }}</td></tr>
* <tr><!-- : -->
* <th scope="row" style="font-weight:normal; text-align:right; padding-right:1em">5</th>
* <td>{@code { "boo", "and", "foo" }}</td></tr>
* <tr><!-- : -->
* <th scope="row" style="font-weight:normal; text-align:right; padding-right:1em">-2</th>
* <td>{@code { "boo", "and", "foo" }}</td></tr>
* <tr><th scope="row" rowspan="3" style="font-weight:normal">o</th>
* <th scope="row" style="font-weight:normal; text-align:right; padding-right:1em">5</th>
* <td>{@code { "b", "", ":and:f", "", "" }}</td></tr>
* <tr><!-- o -->
* <th scope="row" style="font-weight:normal; text-align:right; padding-right:1em">-2</th>
* <td>{@code { "b", "", ":and:f", "", "" }}</td></tr>
* <tr><!-- o -->
* <th scope="row" style="font-weight:normal; text-align:right; padding-right:1em">0</th>
* <td>{@code { "b", "", ":and:f" }}</td></tr>
* </tbody>
* </table>
*
* @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) {
// BEGIN Android-added: fastSplit() to speed up simple cases.
String[] fast = fastSplit(pattern, input.toString(), limit);
if (fast != null) {
return fast;
}
// END Android-added: fastSplit() to speed up simple cases.
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) {
if (index == 0 && index == m.start() && m.start() == m.end()) {
// no empty leading substring included for zero-width match
// at the beginning of the input char sequence.
// BEGIN Android-changed: split() compat behavior for apps targeting <= 28.
// continue;
int targetSdkVersion = VMRuntime.getRuntime().getTargetSdkVersion();
if (targetSdkVersion > 28) {
continue;
}
// END Android-changed: split() compat behavior for apps targeting <= 28.
}
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).isEmpty())
resultSize--;
String[] result = new String[resultSize];
return matchList.subList(0, resultSize).toArray(result);
}
// BEGIN Android-added: fastSplit() to speed up simple cases.
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) {
if (Character.isSurrogate(ch)) {
// Single surrogate is an invalid UTF-16 sequence.
return null;
} else if (FASTSPLIT_METACHARACTERS.indexOf(ch) != -1) {
// We don't allow a single metacharacter.
return null;
}
// pass through
} 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;
}
// END Android-added: fastSplit() to speed up simple cases.
/**
* 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 {@code "boo:and:foo"}, for example, yields the following
* results with these expressions:
*
* <table class="plain" style="margin-left:2em">
* <caption style="display:none">Split examples showing regex and result</caption>
* <thead>
* <tr>
* <th scope="col">Regex</th>
* <th scope="col">Result</th>
* </tr>
* </thead>
* <tbody>
* <tr><th scope="row" style="text-weight:normal">:</th>
* <td>{@code { "boo", "and", "foo" }}</td></tr>
* <tr><th scope="row" style="text-weight:normal">o</th>
* <td>{@code { "b", "", ":and:f" }}</td></tr>
* </tbody>
* </table>
*
*
* @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} for the specified
* {@code String}.
*
* <p>This method produces a {@code String} that can be used to
* create a {@code Pattern} that would match the string
* {@code s} 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";
int lenHint = s.length();
lenHint = (lenHint < Integer.MAX_VALUE - 8 - lenHint) ?
(lenHint << 1) : (Integer.MAX_VALUE - 8);
StringBuilder sb = new StringBuilder(lenHint);
sb.append("\\Q");
int current = 0;
do {
sb.append(s, current, slashEIndex)
.append("\\E\\\\E\\Q");
current = slashEIndex + 2;
} while ((slashEIndex = s.indexOf("\\E", current)) != -1);
return sb.append(s, current, s.length())
.append("\\E")
.toString();
}
/**
* Recompile the Pattern instance from a stream. The original pattern
* string is read in and the object tree is recompiled from it.
*/
@java.io.Serial
private void readObject(java.io.ObjectInputStream s)
throws java.io.IOException, ClassNotFoundException {
// Read in all fields
s.defaultReadObject();
// Android-removed: reimplement matching logic natively via ICU.
/*
// reset the flags
flags0 = flags;
// Initialize counts
capturingGroupCount = 1;
localCount = 0;
localTCNCount = 0;
*/
// Android-changed: Pattern is eagerly compiled() upon construction.
/*
// if length > 0, the Pattern is lazily compiled
if (pattern.isEmpty()) {
root = new Start(lastAccept);
matchRoot = lastAccept;
compiled = true;
}
*/
compile();
}
// Android-changed: reimplement matching logic natively via ICU.
// Dropped documentation reference to Start and LastNode implementation
// details which do not apply on Android.
/**
* 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) {
// BEGIN Android-added: CANON_EQ and UNICODE_CHARACTER_CLASS flags are not supported.
if ((f & CANON_EQ) != 0) {
throw new IllegalArgumentException("CANON_EQ flag isn't supported");
}
if ((f & UNICODE_CHARACTER_CLASS) != 0) {
throw new IllegalArgumentException("UNICODE_CHARACTER_CLASS flag not supported");
}
// END Android-added: CANON_EQ and UNICODE_CHARACTER_CLASS flags are not supported.
if ((f & ~ALL_FLAGS) != 0) {
throw new IllegalArgumentException("Unknown flag 0x"
+ Integer.toHexString(f));
}
pattern = p;
flags = f;
// Android-changed: Pattern is eagerly compiled() upon construction.
// BEGIN Android-changed: Reimplement matching logic via ICU4C, and shouldn't overflow.
/*
// to use UNICODE_CASE if UNICODE_CHARACTER_CLASS present
if ((flags & UNICODE_CHARACTER_CLASS) != 0)
flags |= UNICODE_CASE;
// 'flags' for compiling
flags0 = flags;
// Reset group index count
capturingGroupCount = 1;
localCount = 0;
localTCNCount = 0;
if (!pattern.isEmpty()) {
try {
compile();
} catch (StackOverflowError soe) {
throw error("Stack overflow during pattern compilation");
}
} else {
root = new Start(lastAccept);
matchRoot = lastAccept;
}
*/
compile();
// END Android-changed: Reimplement matching logic via ICU4C, and shouldn't overflow.
}
// BEGIN Android-removed: Reimplement matching logic via ICU4C.
/**
* The pattern is converted to normalized form ({@link
* java.text.Normalizer.Form#NFC NFC}, canonical decomposition,
* followed by canonical composition for the character class
* part, and {@link java.text.Normalizer.Form#NFD NFD},
* canonical decomposition for the rest), and then a pure
* group is constructed to match canonical equivalences of the
* characters.
*
private static String normalize(String pattern) {
int plen = pattern.length();
StringBuilder pbuf = new StringBuilder(plen);
char last = 0;
int lastStart = 0;
char cc = 0;
for (int i = 0; i < plen;) {
char c = pattern.charAt(i);
if (cc == 0 && // top level
c == '\\' && i + 1 < plen && pattern.charAt(i + 1) == '\\') {
i += 2; last = 0;
continue;
}
if (c == '[' && last != '\\') {
if (cc == 0) {
if (lastStart < i)
normalizeSlice(pattern, lastStart, i, pbuf);
lastStart = i;
}
cc++;
} else if (c == ']' && last != '\\') {
cc--;
if (cc == 0) {
normalizeClazz(pattern, lastStart, i + 1, pbuf);
lastStart = i + 1;
}
}
last = c;
i++;
}
assert (cc == 0);
if (lastStart < plen)
normalizeSlice(pattern, lastStart, plen, pbuf);
return pbuf.toString();
}
private static void normalizeSlice(String src, int off, int limit,
StringBuilder dst)
{
int len = src.length();
int off0 = off;
while (off < limit && ASCII.isAscii(src.charAt(off))) {
off++;
}
if (off == limit) {
dst.append(src, off0, limit);
return;
}
off--;
if (off < off0)
off = off0;
else
dst.append(src, off0, off);
while (off < limit) {
int ch0 = src.codePointAt(off);
if (".$|()[]{}^?*+\\".indexOf(ch0) != -1) {
dst.append((char)ch0);
off++;
continue;
}
int j = Grapheme.nextBoundary(src, off, limit);
int ch1;
String seq = src.substring(off, j);
String nfd = Normalizer.normalize(seq, Normalizer.Form.NFD);
off = j;
if (nfd.codePointCount(0, nfd.length()) > 1) {
ch0 = nfd.codePointAt(0);
ch1 = nfd.codePointAt(Character.charCount(ch0));
if (Character.getType(ch1) == Character.NON_SPACING_MARK) {
Set<String> altns = new LinkedHashSet<>();
altns.add(seq);
produceEquivalentAlternation(nfd, altns);
dst.append("(?:");
altns.forEach( s -> dst.append(s).append('|'));
dst.delete(dst.length() - 1, dst.length());
dst.append(")");
continue;
}
}
String nfc = Normalizer.normalize(seq, Normalizer.Form.NFC);
if (!seq.equals(nfc) && !nfd.equals(nfc))
dst.append("(?:" + seq + "|" + nfd + "|" + nfc + ")");
else if (!seq.equals(nfd))
dst.append("(?:" + seq + "|" + nfd + ")");
else
dst.append(seq);
}
}
private static void normalizeClazz(String src, int off, int limit,
StringBuilder dst)
{
dst.append(Normalizer.normalize(src.substring(off, limit), Form.NFC));
}
/**
* Given a specific sequence composed of a regular character and
* combining marks that follow it, produce the alternation that will
* match all canonical equivalences of that sequence.
*
private static void produceEquivalentAlternation(String src,
Set<String> dst)
{
int len = countChars(src, 0, 1);
if (src.length() == len) {
dst.add(src); // source has one character.
return;
}
String base = src.substring(0,len);
String combiningMarks = src.substring(len);
String[] perms = producePermutations(combiningMarks);
// Add combined permutations
for(int x = 0; x < perms.length; x++) {
String next = base + perms[x];
dst.add(next);
next = composeOneStep(next);
if (next != null) {
produceEquivalentAlternation(next, dst);
}
}
}
/**
* Returns an array of strings that have all the possible
* permutations of the characters in the input string.
* This is used to get a list of all possible orderings
* of a set of combining marks. Note that some of the permutations
* are invalid because of combining class collisions, and these
* possibilities must be removed because they are not canonically
* equivalent.
*
private static String[] producePermutations(String input) {
if (input.length() == countChars(input, 0, 1))
return new String[] {input};
if (input.length() == countChars(input, 0, 2)) {
int c0 = Character.codePointAt(input, 0);
int c1 = Character.codePointAt(input, Character.charCount(c0));
if (getClass(c1) == getClass(c0)) {
return new String[] {input};
}
String[] result = new String[2];
result[0] = input;
StringBuilder sb = new StringBuilder(2);
sb.appendCodePoint(c1);
sb.appendCodePoint(c0);
result[1] = sb.toString();
return result;
}
int length = 1;
int nCodePoints = countCodePoints(input);
for(int x=1; x<nCodePoints; x++)
length = length * (x+1);
String[] temp = new String[length];
int combClass[] = new int[nCodePoints];
for(int x=0, i=0; x<nCodePoints; x++) {
int c = Character.codePointAt(input, i);
combClass[x] = getClass(c);
i += Character.charCount(c);
}
// For each char, take it out and add the permutations
// of the remaining chars
int index = 0;
int len;
// offset maintains the index in code units.
loop: for(int x=0, offset=0; x<nCodePoints; x++, offset+=len) {
len = countChars(input, offset, 1);
for(int y=x-1; y>=0; y--) {
if (combClass[y] == combClass[x]) {
continue loop;
}
}
StringBuilder sb = new StringBuilder(input);
String otherChars = sb.delete(offset, offset+len).toString();
String[] subResult = producePermutations(otherChars);
String prefix = input.substring(offset, offset+len);
for (String sre : subResult)
temp[index++] = prefix + sre;
}
String[] result = new String[index];
System.arraycopy(temp, 0, result, 0, index);
return result;
}
private static int getClass(int c) {
return sun.text.Normalizer.getCombiningClass(c);
}
/**
* Attempts to compose input by combining the first character
* with the first combining mark following it. Returns a String
* that is the composition of the leading character with its first
* combining mark followed by the remaining combining marks. Returns
* null if the first two characters cannot be further composed.
*
private static String composeOneStep(String input) {
int len = countChars(input, 0, 2);
String firstTwoCharacters = input.substring(0, len);
String result = Normalizer.normalize(firstTwoCharacters, Normalizer.Form.NFC);
if (result.equals(firstTwoCharacters))
return null;
else {
String remainder = input.substring(len);
return result + remainder;
}
}
/**
* Preprocess any \Q...\E sequences in `temp', meta-quoting them.
* See the description of `quotemeta' in perlfunc(1).
*
private void RemoveQEQuoting() {
final int pLen = patternLength;
int i = 0;
while (i < pLen-1) {
if (temp[i] != '\\')
i += 1;
else if (temp[i + 1] != 'Q')
i += 2;
else
break;
}
if (i >= pLen - 1) // No \Q sequence found
return;
int j = i;
i += 2;
int newTempLen;
try {
newTempLen = Math.addExact(j + 2, Math.multiplyExact(3, pLen - i));
} catch (ArithmeticException ae) {
throw new OutOfMemoryError("Required pattern length too large");
}
int[] newtemp = new int[newTempLen];
System.arraycopy(temp, 0, newtemp, 0, j);
boolean inQuote = true;
boolean beginQuote = true;
while (i < pLen) {
int c = temp[i++];
if (!ASCII.isAscii(c) || ASCII.isAlpha(c)) {
newtemp[j++] = c;
} else if (ASCII.isDigit(c)) {
if (beginQuote) {
/*
* A unicode escape \[0xu] could be before this quote,
* and we don't want this numeric char to processed as
* part of the escape.
*
newtemp[j++] = '\\';
newtemp[j++] = 'x';
newtemp[j++] = '3';
}
newtemp[j++] = c;
} else if (c != '\\') {
if (inQuote) newtemp[j++] = '\\';
newtemp[j++] = c;
} else if (inQuote) {
if (temp[i] == 'E') {
i++;
inQuote = false;
} else {
newtemp[j++] = '\\';
newtemp[j++] = '\\';
}
} else {
if (temp[i] == 'Q') {
i++;
inQuote = true;
beginQuote = true;
continue;
} else {
newtemp[j++] = c;
if (i != pLen)
newtemp[j++] = temp[i++];
}
}
beginQuote = false;
}
patternLength = j;
temp = Arrays.copyOf(newtemp, j + 2); // double zero termination
}
/**
* Copies regular expression to an int array and invokes the parsing
* of the expression which will create the object tree.
*
private void compile() {
// Handle canonical equivalences
if (has(CANON_EQ) && !has(LITERAL)) {
normalizedPattern = normalize(pattern);
} else {
normalizedPattern = pattern;
}
patternLength = normalizedPattern.length();
// Copy pattern to int array for convenience
// Use double zero to terminate pattern
temp = new int[patternLength + 2];
hasSupplementary = false;
int c, count = 0;
// Convert all chars into code points
for (int x = 0; x < patternLength; x += Character.charCount(c)) {
c = normalizedPattern.codePointAt(x);
if (isSupplementary(c)) {
hasSupplementary = true;
}
temp[count++] = c;
}
patternLength = count; // patternLength now in code points
if (! has(LITERAL))
RemoveQEQuoting();
// Allocate all temporary objects here.
buffer = new int[32];
groupNodes = new GroupHead[10];
namedGroups = null;
topClosureNodes = new ArrayList<>(10);
if (has(LITERAL)) {
// Literal pattern handling
matchRoot = newSlice(temp, patternLength, hasSupplementary);
matchRoot.next = lastAccept;
} else {
// Start recursive descent parsing
matchRoot = expr(lastAccept);
// Check extra pattern characters
if (patternLength != cursor) {
if (peek() == ')') {
throw error("Unmatched closing ')'");
} else {
throw error("Unexpected internal error");
}
}
}
// Peephole optimization
if (matchRoot instanceof Slice) {
root = BnM.optimize(matchRoot);
if (root == matchRoot) {
root = hasSupplementary ? new StartS(matchRoot) : new Start(matchRoot);
}
} else if (matchRoot instanceof Begin || matchRoot instanceof First) {
root = matchRoot;
} else {
root = hasSupplementary ? new StartS(matchRoot) : new Start(matchRoot);
}
// Optimize the greedy Loop to prevent exponential backtracking, IF there
// is no group ref in this pattern. With a non-negative localTCNCount value,
// the greedy type Loop, Curly will skip the backtracking for any starting
// position "i" that failed in the past.
if (!hasGroupRef) {
for (Node node : topClosureNodes) {
if (node instanceof Loop) {
// non-deterministic-greedy-group
((Loop)node).posIndex = localTCNCount++;
}
}
}
// Release temporary storage
temp = null;
buffer = null;
groupNodes = null;
patternLength = 0;
compiled = true;
topClosureNodes = null;
}
Map<String, Integer> namedGroups() {
Map<String, Integer> groups = namedGroups;
if (groups == null) {
namedGroups = groups = new HashMap<>(2);
}
return groups;
}
/**
* Used to accumulate information about a subtree of the object graph
* so that optimizations can be applied to the subtree.
*
static final class TreeInfo {
int minLength;
int maxLength;
boolean maxValid;
boolean deterministic;
TreeInfo() {
reset();
}
void reset() {
minLength = 0;
maxLength = 0;
maxValid = true;
deterministic = true;
}
}
/*
* The following private methods are mainly used to improve the
* readability of the code. In order to let the Java compiler easily
* inline them, we should not put many assertions or error checks in them.
*
/**
* Indicates whether a particular flag is set or not.
*
private boolean has(int f) {
return (flags0 & f) != 0;
}
/**
* Match next character, signal error if failed.
*
private void accept(int ch, String s) {
int testChar = temp[cursor++];
if (has(COMMENTS))
testChar = parsePastWhitespace(testChar);
if (ch != testChar) {
throw error(s);
}
}
/**
* Mark the end of pattern with a specific character.
*
private void mark(int c) {
temp[patternLength] = c;
}
/**
* Peek the next character, and do not advance the cursor.
*
private int peek() {
int ch = temp[cursor];
if (has(COMMENTS))
ch = peekPastWhitespace(ch);
return ch;
}
/**
* Read the next character, and advance the cursor by one.
*
private int read() {
int ch = temp[cursor++];
if (has(COMMENTS))
ch = parsePastWhitespace(ch);
return ch;
}
/**
* Read the next character, and advance the cursor by one,
* ignoring the COMMENTS setting
*
private int readEscaped() {
int ch = temp[cursor++];
return ch;
}
/**
* Advance the cursor by one, and peek the next character.
*
private int next() {
int ch = temp[++cursor];
if (has(COMMENTS))
ch = peekPastWhitespace(ch);
return ch;
}
/**
* Advance the cursor by one, and peek the next character,
* ignoring the COMMENTS setting
*
private int nextEscaped() {
int ch = temp[++cursor];
return ch;
}
/**
* If in xmode peek past whitespace and comments.
*
private int peekPastWhitespace(int ch) {
while (ASCII.isSpace(ch) || ch == '#') {
while (ASCII.isSpace(ch))
ch = temp[++cursor];
if (ch == '#') {
ch = peekPastLine();
}
}
return ch;
}
/**
* If in xmode parse past whitespace and comments.
*
private int parsePastWhitespace(int ch) {
while (ASCII.isSpace(ch) || ch == '#') {
while (ASCII.isSpace(ch))
ch = temp[cursor++];
if (ch == '#')
ch = parsePastLine();
}
return ch;
}
/**
* xmode parse past comment to end of line.
*
private int parsePastLine() {
int ch = temp[cursor++];
while (ch != 0 && !isLineSeparator(ch))
ch = temp[cursor++];
if (ch == 0 && cursor > patternLength) {
cursor = patternLength;
ch = temp[cursor++];
}
return ch;
}
/**
* xmode peek past comment to end of line.
*
private int peekPastLine() {
int ch = temp[++cursor];
while (ch != 0 && !isLineSeparator(ch))
ch = temp[++cursor];
if (ch == 0 && cursor > patternLength) {
cursor = patternLength;
ch = temp[cursor];
}
return ch;
}
/**
* Determines if character is a line separator in the current mode
*
private boolean isLineSeparator(int ch) {
if (has(UNIX_LINES)) {
return ch == '\n';
} else {
return (ch == '\n' ||
ch == '\r' ||
(ch|1) == '\u2029' ||
ch == '\u0085');
}
}
/**
* Read the character after the next one, and advance the cursor by two.
*
private int skip() {
int i = cursor;
int ch = temp[i+1];
cursor = i + 2;
return ch;
}
/**
* Unread one next character, and retreat cursor by one.
*
private void unread() {
cursor--;
}
/**
* Internal method used for handling all syntax errors. The pattern is
* displayed with a pointer to aid in locating the syntax error.
*
private PatternSyntaxException error(String s) {
return new PatternSyntaxException(s, normalizedPattern, cursor - 1);
}
/**
* Determines if there is any supplementary character or unpaired
* surrogate in the specified range.
*
private boolean findSupplementary(int start, int end) {
for (int i = start; i < end; i++) {
if (isSupplementary(temp[i]))
return true;
}
return false;
}
/**
* Determines if the specified code point is a supplementary
* character or unpaired surrogate.
*
private static final boolean isSupplementary(int ch) {
return ch >= Character.MIN_SUPPLEMENTARY_CODE_POINT ||
Character.isSurrogate((char)ch);
}
/**
* The following methods handle the main parsing. They are sorted
* according to their precedence order, the lowest one first.
*
/**
* The expression is parsed with branch nodes added for alternations.
* This may be called recursively to parse sub expressions that may
* contain alternations.
*
private Node expr(Node end) {
Node prev = null;
Node firstTail = null;
Branch branch = null;
Node branchConn = null;
for (;;) {
Node node = sequence(end);
Node nodeTail = root; //double return
if (prev == null) {
prev = node;
firstTail = nodeTail;
} else {
// Branch
if (branchConn == null) {
branchConn = new BranchConn();
branchConn.next = end;
}
if (node == end) {
// if the node returned from sequence() is "end"
// we have an empty expr, set a null atom into
// the branch to indicate to go "next" directly.
node = null;
} else {
// the "tail.next" of each atom goes to branchConn
nodeTail.next = branchConn;
}
if (prev == branch) {
branch.add(node);
} else {
if (prev == end) {
prev = null;
} else {
// replace the "end" with "branchConn" at its tail.next
// when put the "prev" into the branch as the first atom.
firstTail.next = branchConn;
}
prev = branch = new Branch(prev, node, branchConn);
}
}
if (peek() != '|') {
return prev;
}
next();
}
}
@SuppressWarnings("fallthrough")
/**
* Parsing of sequences between alternations.
*
private Node sequence(Node end) {
Node head = null;
Node tail = null;
Node node;
LOOP:
for (;;) {
int ch = peek();
switch (ch) {
case '(':
// Because group handles its own closure,
// we need to treat it differently
node = group0();
// Check for comment or flag group
if (node == null)
continue;
if (head == null)
head = node;
else
tail.next = node;
// Double return: Tail was returned in root
tail = root;
continue;
case '[':
if (has(CANON_EQ) && !has(LITERAL))
node = new NFCCharProperty(clazz(true));
else
node = newCharProperty(clazz(true));
break;
case '\\':
ch = nextEscaped();
if (ch == 'p' || ch == 'P') {
boolean oneLetter = true;
boolean comp = (ch == 'P');
ch = next(); // Consume { if present
if (ch != '{') {
unread();
} else {
oneLetter = false;
}
// node = newCharProperty(family(oneLetter, comp));
if (has(CANON_EQ) && !has(LITERAL))
node = new NFCCharProperty(family(oneLetter, comp));
else
node = newCharProperty(family(oneLetter, comp));
} else {
unread();
node = atom();
}
break;
case '^':
next();
if (has(MULTILINE)) {
if (has(UNIX_LINES))
node = new UnixCaret();
else
node = new Caret();
} else {
node = new Begin();
}
break;
case '$':
next();
if (has(UNIX_LINES))
node = new UnixDollar(has(MULTILINE));
else
node = new Dollar(has(MULTILINE));
break;
case '.':
next();
if (has(DOTALL)) {
node = new CharProperty(ALL());
} else {
if (has(UNIX_LINES)) {
node = new CharProperty(UNIXDOT());
} else {
node = new CharProperty(DOT());
}
}
break;
case '|':
case ')':
break LOOP;
case ']': // Now interpreting dangling ] and } as literals
case '}':
node = atom();
break;
case '?':
case '*':
case '+':
next();
throw error("Dangling meta character '" + ((char)ch) + "'");
case 0:
if (cursor >= patternLength) {
break LOOP;
}
// Fall through
default:
node = atom();
break;
}
node = closure(node);
/* save the top dot-greedy nodes (.*, .+) as well
if (node instanceof GreedyCharProperty &&
((GreedyCharProperty)node).cp instanceof Dot) {
topClosureNodes.add(node);
}
*
if (head == null) {
head = tail = node;
} else {
tail.next = node;
tail = node;
}
}
if (head == null) {
return end;
}
tail.next = end;
root = tail; //double return
return head;
}
@SuppressWarnings("fallthrough")
/**
* Parse and add a new Single or Slice.
*
private Node atom() {
int first = 0;
int prev = -1;
boolean hasSupplementary = false;
int ch = peek();
for (;;) {
switch (ch) {
case '*':
case '+':
case '?':
case '{':
if (first > 1) {
cursor = prev; // Unwind one character
first--;
}
break;
case '$':
case '.':
case '^':
case '(':
case '[':
case '|':
case ')':
break;
case '\\':
ch = nextEscaped();
if (ch == 'p' || ch == 'P') { // Property
if (first > 0) { // Slice is waiting; handle it first
unread();
break;
} else { // No slice; just return the family node
boolean comp = (ch == 'P');
boolean oneLetter = true;
ch = next(); // Consume { if present
if (ch != '{')
unread();
else
oneLetter = false;
if (has(CANON_EQ) && !has(LITERAL))
return new NFCCharProperty(family(oneLetter, comp));
else
return newCharProperty(family(oneLetter, comp));
}
}
unread();
prev = cursor;
ch = escape(false, first == 0, false);
if (ch >= 0) {
append(ch, first);
first++;
if (isSupplementary(ch)) {
hasSupplementary = true;
}
ch = peek();
continue;
} else if (first == 0) {
return root;
}
// Unwind meta escape sequence
cursor = prev;
break;
case 0:
if (cursor >= patternLength) {
break;
}
// Fall through
default:
prev = cursor;
append(ch, first);
first++;
if (isSupplementary(ch)) {
hasSupplementary = true;
}
ch = next();
continue;
}
break;
}
if (first == 1) {
return newCharProperty(single(buffer[0]));
} else {
return newSlice(buffer, first, hasSupplementary);
}
}
private void append(int ch, int index) {
int len = buffer.length;
if (index - len >= 0) {
len = ArraysSupport.newLength(len,
1 + index - len, /* minimum growth * /
len /* preferred growth * /);
buffer = Arrays.copyOf(buffer, len);
}
buffer[index] = ch;
}
/**
* Parses a backref greedily, taking as many numbers as it
* can. The first digit is always treated as a backref, but
* multi digit numbers are only treated as a backref if at
* least that many backrefs exist at this point in the regex.
*
private Node ref(int refNum) {
boolean done = false;
while(!done) {
int ch = peek();
switch (ch) {
case '0', '1', '2', '3', '4', '5', '6', '7', '8', '9' -> {
int newRefNum = (refNum * 10) + (ch - '0');
// Add another number if it doesn't make a group
// that doesn't exist
if (capturingGroupCount - 1 < newRefNum) {
done = true;
break;
}
refNum = newRefNum;
read();
}
default -> done = true;
}
}
hasGroupRef = true;
if (has(CASE_INSENSITIVE))
return new CIBackRef(refNum, has(UNICODE_CASE));
else
return new BackRef(refNum);
}
/**
* Parses an escape sequence to determine the actual value that needs
* to be matched.
* If -1 is returned and create was true a new object was added to the tree
* to handle the escape sequence.
* If the returned value is greater than zero, it is the value that
* matches the escape sequence.
*
private int escape(boolean inclass, boolean create, boolean isrange) {
int ch = skip();
switch (ch) {
case '0':
return o();
case '1':
case '2':
case '3':
case '4':
case '5':
case '6':
case '7':
case '8':
case '9':
if (inclass) break;
if (create) {
root = ref((ch - '0'));
}
return -1;
case 'A':
if (inclass) break;
if (create) root = new Begin();
return -1;
case 'B':
if (inclass) break;
if (create) root = new Bound(Bound.NONE, has(UNICODE_CHARACTER_CLASS));
return -1;
case 'C':
break;
case 'D':
if (create) {
predicate = has(UNICODE_CHARACTER_CLASS) ?
CharPredicates.DIGIT() : CharPredicates.ASCII_DIGIT();
predicate = predicate.negate();
if (!inclass)
root = newCharProperty(predicate);
}
return -1;
case 'E':
case 'F':
break;
case 'G':
if (inclass) break;
if (create) root = new LastMatch();
return -1;
case 'H':
if (create) {
predicate = HorizWS().negate();
if (!inclass)
root = newCharProperty(predicate);
}
return -1;
case 'I':
case 'J':
case 'K':
case 'L':
case 'M':
break;
case 'N':
return N();
case 'O':
case 'P':
case 'Q':
break;
case 'R':
if (inclass) break;
if (create) root = new LineEnding();
return -1;
case 'S':
if (create) {
predicate = has(UNICODE_CHARACTER_CLASS) ?
CharPredicates.WHITE_SPACE() : CharPredicates.ASCII_SPACE();
predicate = predicate.negate();
if (!inclass)
root = newCharProperty(predicate);
}
return -1;
case 'T':
case 'U':
break;
case 'V':
if (create) {
predicate = VertWS().negate();
if (!inclass)
root = newCharProperty(predicate);
}
return -1;
case 'W':
if (create) {
predicate = has(UNICODE_CHARACTER_CLASS) ?
CharPredicates.WORD() : CharPredicates.ASCII_WORD();
predicate = predicate.negate();
if (!inclass)
root = newCharProperty(predicate);
}
return -1;
case 'X':
if (inclass) break;
if (create) {
root = new XGrapheme();
}
return -1;
case 'Y':
break;
case 'Z':
if (inclass) break;
if (create) {
if (has(UNIX_LINES))
root = new UnixDollar(false);
else
root = new Dollar(false);
}
return -1;
case 'a':
return '\007';
case 'b':
if (inclass) break;
if (create) {
if (peek() == '{') {
if (skip() == 'g') {
if (read() == '}') {
root = new GraphemeBound();
return -1;
}
break; // error missing trailing }
}
unread(); unread();
}
root = new Bound(Bound.BOTH, has(UNICODE_CHARACTER_CLASS));
}
return -1;
case 'c':
return c();
case 'd':
if (create) {
predicate = has(UNICODE_CHARACTER_CLASS) ?
CharPredicates.DIGIT() : CharPredicates.ASCII_DIGIT();
if (!inclass)
root = newCharProperty(predicate);
}
return -1;
case 'e':
return '\033';
case 'f':
return '\f';
case 'g':
break;
case 'h':
if (create) {
predicate = HorizWS();
if (!inclass)
root = newCharProperty(predicate);
}
return -1;
case 'i':
case 'j':
break;
case 'k':
if (inclass)
break;
if (read() != '<')
throw error("\\k is not followed by '<' for named capturing group");
String name = groupname(read());
if (!namedGroups().containsKey(name))
throw error("named capturing group <" + name + "> does not exist");
if (create) {
hasGroupRef = true;
if (has(CASE_INSENSITIVE))
root = new CIBackRef(namedGroups().get(name), has(UNICODE_CASE));
else
root = new BackRef(namedGroups().get(name));
}
return -1;
case 'l':
case 'm':
break;
case 'n':
return '\n';
case 'o':
case 'p':
case 'q':
break;
case 'r':
return '\r';
case 's':
if (create) {
predicate = has(UNICODE_CHARACTER_CLASS) ?
CharPredicates.WHITE_SPACE() : CharPredicates.ASCII_SPACE();
if (!inclass)
root = newCharProperty(predicate);
}
return -1;
case 't':
return '\t';
case 'u':
return u();
case 'v':
// '\v' was implemented as VT/0x0B in releases < 1.8 (though
// undocumented). In JDK8 '\v' is specified as a predefined
// character class for all vertical whitespace characters.
// So [-1, root=VertWS node] pair is returned (instead of a
// single 0x0B). This breaks the range if '\v' is used as
// the start or end value, such as [\v-...] or [...-\v], in
// which a single definite value (0x0B) is expected. For
// compatibility concern '\013'/0x0B is returned if isrange.
if (isrange)
return '\013';
if (create) {
predicate = VertWS();
if (!inclass)
root = newCharProperty(predicate);
}
return -1;
case 'w':
if (create) {
predicate = has(UNICODE_CHARACTER_CLASS) ?
CharPredicates.WORD() : CharPredicates.ASCII_WORD();
if (!inclass)
root = newCharProperty(predicate);
}
return -1;
case 'x':
return x();
case 'y':
break;
case 'z':
if (inclass) break;
if (create) root = new End();
return -1;
default:
return ch;
}
throw error("Illegal/unsupported escape sequence");
}
/**
* Parse a character class, and return the node that matches it.
*
* Consumes a ] on the way out if consume is true. Usually consume
* is true except for the case of [abc&&def] where def is a separate
* right hand node with "understood" brackets.
*
private CharPredicate clazz(boolean consume) {
CharPredicate prev = null;
CharPredicate curr = null;
BitClass bits = new BitClass();
boolean isNeg = false;
boolean hasBits = false;
int ch = next();
// Negates if first char in a class, otherwise literal
if (ch == '^' && temp[cursor-1] == '[') {
ch = next();
isNeg = true;
}
for (;;) {
switch (ch) {
case '[':
curr = clazz(true);
if (prev == null)
prev = curr;
else
prev = prev.union(curr);
ch = peek();
continue;
case '&':
ch = next();
if (ch == '&') {
ch = next();
CharPredicate right = null;
while (ch != ']' && ch != '&') {
if (ch == '[') {
if (right == null)
right = clazz(true);
else
right = right.union(clazz(true));
} else { // abc&&def
unread();
if (right == null) {
right = clazz(false);
} else {
right = right.union(clazz(false));
}
}
ch = peek();
}
if (hasBits) {
// bits used, union has high precedence
if (prev == null) {
prev = curr = bits;
} else {
prev = prev.union(bits);
}
hasBits = false;
}
if (right != null)
curr = right;
if (prev == null) {
if (right == null)
throw error("Bad class syntax");
else
prev = right;
} else {
prev = prev.and(curr);
}
} else {
// treat as a literal &
unread();
break;
}
continue;
case 0:
if (cursor >= patternLength)
throw error("Unclosed character class");
break;
case ']':
if (prev != null || hasBits) {
if (consume)
next();
if (prev == null)
prev = bits;
else if (hasBits)
prev = prev.union(bits);
if (isNeg)
return prev.negate();
return prev;
}
break;
default:
break;
}
curr = range(bits);
if (curr == null) { // the bits used
hasBits = true;
} else {
if (prev == null)
prev = curr;
else if (prev != curr)
prev = prev.union(curr);
}
ch = peek();
}
}
private CharPredicate bitsOrSingle(BitClass bits, int ch) {
/* Bits can only handle codepoints in [u+0000-u+00ff] range.
Use "single" node instead of bits when dealing with unicode
case folding for codepoints listed below.
(1)Uppercase out of range: u+00ff, u+00b5
toUpperCase(u+00ff) -> u+0178
toUpperCase(u+00b5) -> u+039c
(2)LatinSmallLetterLongS u+17f
toUpperCase(u+017f) -> u+0053
(3)LatinSmallLetterDotlessI u+131
toUpperCase(u+0131) -> u+0049
(4)LatinCapitalLetterIWithDotAbove u+0130
toLowerCase(u+0130) -> u+0069
(5)KelvinSign u+212a
toLowerCase(u+212a) ==> u+006B
(6)AngstromSign u+212b
toLowerCase(u+212b) ==> u+00e5
*
if (ch < 256 &&
!(has(CASE_INSENSITIVE) && has(UNICODE_CASE) &&
(ch == 0xff || ch == 0xb5 ||
ch == 0x49 || ch == 0x69 || //I and i
ch == 0x53 || ch == 0x73 || //S and s
ch == 0x4b || ch == 0x6b || //K and k
ch == 0xc5 || ch == 0xe5))) { //A+ring
bits.add(ch, flags0);
return null;
}
return single(ch);
}
/**
* Returns a suitably optimized, single character predicate
*
private CharPredicate single(final int ch) {
if (has(CASE_INSENSITIVE)) {
int lower, upper;
if (has(UNICODE_CASE)) {
upper = Character.toUpperCase(ch);
lower = Character.toLowerCase(upper);
// Unicode case insensitive matches
if (upper != lower)
return SingleU(lower);
} else if (ASCII.isAscii(ch)) {
lower = ASCII.toLower(ch);
upper = ASCII.toUpper(ch);
// Case insensitive matches a given BMP character
if (lower != upper)
return SingleI(lower, upper);
}
}
if (isSupplementary(ch))
return SingleS(ch);
return Single(ch); // Match a given BMP character
}
/**
* Parse a single character or a character range in a character class
* and return its representative node.
*
private CharPredicate range(BitClass bits) {
int ch = peek();
if (ch == '\\') {
ch = nextEscaped();
if (ch == 'p' || ch == 'P') { // A property
boolean comp = (ch == 'P');
boolean oneLetter = true;
// Consume { if present
ch = next();
if (ch != '{')
unread();
else
oneLetter = false;
return family(oneLetter, comp);
} else { // ordinary escape
boolean isrange = temp[cursor+1] == '-';
unread();
ch = escape(true, true, isrange);
if (ch == -1)
return predicate;
}
} else {
next();
}
if (ch >= 0) {
if (peek() == '-') {
int endRange = temp[cursor+1];
if (endRange == '[') {
return bitsOrSingle(bits, ch);
}
if (endRange != ']') {
next();
int m = peek();
if (m == '\\') {
m = escape(true, false, true);
} else {
next();
}
if (m < ch) {
throw error("Illegal character range");
}
if (has(CASE_INSENSITIVE)) {
if (has(UNICODE_CASE))
return CIRangeU(ch, m);
return CIRange(ch, m);
} else {
return Range(ch, m);
}
}
}
return bitsOrSingle(bits, ch);
}
throw error("Unexpected character '"+((char)ch)+"'");
}
/**
* Parses a Unicode character family and returns its representative node.
*
private CharPredicate family(boolean singleLetter, boolean isComplement) {
next();
String name;
CharPredicate p = null;
if (singleLetter) {
int c = temp[cursor];
if (!Character.isSupplementaryCodePoint(c)) {
name = String.valueOf((char)c);
} else {
name = new String(temp, cursor, 1);
}
read();
} else {
int i = cursor;
mark('}');
while(read() != '}') {
}
mark('\000');
int j = cursor;
if (j > patternLength)
throw error("Unclosed character family");
if (i + 1 >= j)
throw error("Empty character family");
name = new String(temp, i, j-i-1);
}
int i = name.indexOf('=');
if (i != -1) {
// property construct \p{name=value}
String value = name.substring(i + 1);
name = name.substring(0, i).toLowerCase(Locale.ENGLISH);
switch (name) {
case "sc":
case "script":
p = CharPredicates.forUnicodeScript(value);
break;
case "blk":
case "block":
p = CharPredicates.forUnicodeBlock(value);
break;
case "gc":
case "general_category":
p = CharPredicates.forProperty(value, has(CASE_INSENSITIVE));
break;
default:
break;
}
if (p == null)
throw error("Unknown Unicode property {name=<" + name + ">, "
+ "value=<" + value + ">}");
} else {
if (name.startsWith("In")) {
// \p{InBlockName}
p = CharPredicates.forUnicodeBlock(name.substring(2));
} else if (name.startsWith("Is")) {
// \p{IsGeneralCategory} and \p{IsScriptName}
String shortName = name.substring(2);
p = CharPredicates.forUnicodeProperty(shortName, has(CASE_INSENSITIVE));
if (p == null)
p = CharPredicates.forProperty(shortName, has(CASE_INSENSITIVE));
if (p == null)
p = CharPredicates.forUnicodeScript(shortName);
} else {
if (has(UNICODE_CHARACTER_CLASS))
p = CharPredicates.forPOSIXName(name, has(CASE_INSENSITIVE));
if (p == null)
p = CharPredicates.forProperty(name, has(CASE_INSENSITIVE));
}
if (p == null)
throw error("Unknown character property name {" + name + "}");
}
if (isComplement) {
// it might be too expensive to detect if a complement of
// CharProperty can match "certain" supplementary. So just
// go with StartS.
hasSupplementary = true;
p = p.negate();
}
return p;
}
private CharProperty newCharProperty(CharPredicate p) {
if (p == null)
return null;
if (p instanceof BmpCharPredicate)
return new BmpCharProperty((BmpCharPredicate)p);
else {
hasSupplementary = true;
return new CharProperty(p);
}
}
/**
* Parses and returns the name of a "named capturing group", the trailing
* ">" is consumed after parsing.
*
private String groupname(int ch) {
StringBuilder sb = new StringBuilder();
if (!ASCII.isAlpha(ch))
throw error("capturing group name does not start with a Latin letter");
do {
sb.append((char) ch);
} while (ASCII.isAlnum(ch=read()));
if (ch != '>')
throw error("named capturing group is missing trailing '>'");
return sb.toString();
}
/**
* Parses a group and returns the head node of a set of nodes that process
* the group. Sometimes a double return system is used where the tail is
* returned in root.
*
private Node group0() {
boolean capturingGroup = false;
Node head;
Node tail;
int save = flags0;
int saveTCNCount = topClosureNodes.size();
root = null;
int ch = next();
if (ch == '?') {
ch = skip();
switch (ch) {
case ':' -> { // (?:xxx) pure group
head = createGroup(true);
tail = root;
head.next = expr(tail);
}
case '=', '!' -> { // (?=xxx) and (?!xxx) lookahead
head = createGroup(true);
tail = root;
head.next = expr(tail);
if (ch == '=') {
head = tail = new Pos(head);
} else {
head = tail = new Neg(head);
}
}
case '>' -> { // (?>xxx) independent group
head = createGroup(true);
tail = root;
head.next = expr(tail);
head = tail = new Ques(head, Qtype.INDEPENDENT);
}
case '<' -> { // (?<xxx) look behind
ch = read();
if (ch != '=' && ch != '!') {
// named captured group
String name = groupname(ch);
if (namedGroups().containsKey(name))
throw error("Named capturing group <" + name
+ "> is already defined");
capturingGroup = true;
head = createGroup(false);
tail = root;
namedGroups().put(name, capturingGroupCount - 1);
head.next = expr(tail);
break;
}
int start = cursor;
head = createGroup(true);
tail = root;
head.next = expr(tail);
tail.next = LookBehindEndNode.INSTANCE;
TreeInfo info = new TreeInfo();
head.study(info);
if (info.maxValid == false) {
throw error("Look-behind group does not have "
+ "an obvious maximum length");
}
boolean hasSupplementary = findSupplementary(start, patternLength);
if (ch == '=') {
head = tail = (hasSupplementary ?
new BehindS(head, info.maxLength,
info.minLength) :
new Behind(head, info.maxLength,
info.minLength));
} else { // if (ch == '!')
head = tail = (hasSupplementary ?
new NotBehindS(head, info.maxLength,
info.minLength) :
new NotBehind(head, info.maxLength,
info.minLength));
}
// clear all top-closure-nodes inside lookbehind
if (saveTCNCount < topClosureNodes.size())
topClosureNodes.subList(saveTCNCount, topClosureNodes.size()).clear();
}
case '$', '@' -> throw error("Unknown group type");
default -> { // (?xxx:) inlined match flags
unread();
addFlag();
ch = read();
if (ch == ')') {
return null; // Inline modifier only
}
if (ch != ':') {
throw error("Unknown inline modifier");
}
head = createGroup(true);
tail = root;
head.next = expr(tail);
}
}
} else { // (xxx) a regular group
capturingGroup = true;
head = createGroup(false);
tail = root;
head.next = expr(tail);
}
accept(')', "Unclosed group");
flags0 = save;
// Check for quantifiers
Node node = closure(head);
if (node == head) { // No closure
root = tail;
return node; // Dual return
}
if (head == tail) { // Zero length assertion
root = node;
return node; // Dual return
}
// have group closure, clear all inner closure nodes from the
// top list (no backtracking stopper optimization for inner
if (saveTCNCount < topClosureNodes.size())
topClosureNodes.subList(saveTCNCount, topClosureNodes.size()).clear();
if (node instanceof Ques ques) {
if (ques.type == Qtype.POSSESSIVE) {
root = node;
return node;
}
tail.next = new BranchConn();
tail = tail.next;
if (ques.type == Qtype.GREEDY) {
head = new Branch(head, null, tail);
} else { // Reluctant quantifier
head = new Branch(null, head, tail);
}
root = tail;
return head;
} else if (node instanceof Curly curly) {
if (curly.type == Qtype.POSSESSIVE) {
root = node;
return node;
}
// Discover if the group is deterministic
TreeInfo info = new TreeInfo();
if (head.study(info)) { // Deterministic
GroupTail temp = (GroupTail) tail;
head = root = new GroupCurly(head.next, curly.cmin,
curly.cmax, curly.type,
((GroupTail)tail).localIndex,
((GroupTail)tail).groupIndex,
capturingGroup);
return head;
} else { // Non-deterministic
int temp = ((GroupHead) head).localIndex;
Loop loop;
if (curly.type == Qtype.GREEDY) {
loop = new Loop(this.localCount, temp);
// add the max_reps greedy to the top-closure-node list
if (curly.cmax == MAX_REPS)
topClosureNodes.add(loop);
} else { // Reluctant Curly
loop = new LazyLoop(this.localCount, temp);
}
Prolog prolog = new Prolog(loop);
this.localCount += 1;
loop.cmin = curly.cmin;
loop.cmax = curly.cmax;
loop.body = head;
tail.next = loop;
root = loop;
return prolog; // Dual return
}
}
throw error("Internal logic error");
}
/**
* Create group head and tail nodes using double return. If the group is
* created with anonymous true then it is a pure group and should not
* affect group counting.
*
private Node createGroup(boolean anonymous) {
int localIndex = localCount++;
int groupIndex = 0;
if (!anonymous)
groupIndex = capturingGroupCount++;
GroupHead head = new GroupHead(localIndex);
root = new GroupTail(localIndex, groupIndex);
// for debug/print only, head.match does NOT need the "tail" info
head.tail = (GroupTail)root;
if (!anonymous && groupIndex < 10)
groupNodes[groupIndex] = head;
return head;
}
@SuppressWarnings("fallthrough")
/**
* Parses inlined match flags and set them appropriately.
*
private void addFlag() {
int ch = peek();
for (;;) {
switch (ch) {
case 'i':
flags0 |= CASE_INSENSITIVE;
break;
case 'm':
flags0 |= MULTILINE;
break;
case 's':
flags0 |= DOTALL;
break;
case 'd':
flags0 |= UNIX_LINES;
break;
case 'u':
flags0 |= UNICODE_CASE;
break;
case 'c':
flags0 |= CANON_EQ;
break;
case 'x':
flags0 |= COMMENTS;
break;
case 'U':
flags0 |= (UNICODE_CHARACTER_CLASS | UNICODE_CASE);
break;
case '-': // subFlag then fall through
ch = next();
subFlag();
default:
return;
}
ch = next();
}
}
@SuppressWarnings("fallthrough")
/**
* Parses the second part of inlined match flags and turns off
* flags appropriately.
*
private void subFlag() {
int ch = peek();
for (;;) {
switch (ch) {
case 'i':
flags0 &= ~CASE_INSENSITIVE;
break;
case 'm':
flags0 &= ~MULTILINE;
break;
case 's':
flags0 &= ~DOTALL;
break;
case 'd':
flags0 &= ~UNIX_LINES;
break;
case 'u':
flags0 &= ~UNICODE_CASE;
break;
case 'c':
flags0 &= ~CANON_EQ;
break;
case 'x':
flags0 &= ~COMMENTS;
break;
case 'U':
flags0 &= ~(UNICODE_CHARACTER_CLASS | UNICODE_CASE);
break;
default:
return;
}
ch = next();
}
}
static final int MAX_REPS = 0x7FFFFFFF;
static enum Qtype {
GREEDY, LAZY, POSSESSIVE, INDEPENDENT
}
private Qtype qtype() {
int ch = next();
if (ch == '?') {
next();
return Qtype.LAZY;
} else if (ch == '+') {
next();
return Qtype.POSSESSIVE;
}
return Qtype.GREEDY;
}
private Node curly(Node prev, int cmin) {
Qtype qtype = qtype();
if (qtype == Qtype.GREEDY) {
if (prev instanceof BmpCharProperty) {
return new BmpCharPropertyGreedy((BmpCharProperty)prev, cmin);
} else if (prev instanceof CharProperty) {
return new CharPropertyGreedy((CharProperty)prev, cmin);
}
}
return new Curly(prev, cmin, MAX_REPS, qtype);
}
/**
* Processes repetition. If the next character peeked is a quantifier
* then new nodes must be appended to handle the repetition.
* Prev could be a single or a group, so it could be a chain of nodes.
*
private Node closure(Node prev) {
int ch = peek();
switch (ch) {
case '?':
return new Ques(prev, qtype());
case '*':
return curly(prev, 0);
case '+':
return curly(prev, 1);
case '{':
ch = skip();
if (ASCII.isDigit(ch)) {
int cmin = 0, cmax;
try {
do {
cmin = Math.addExact(Math.multiplyExact(cmin, 10),
ch - '0');
} while (ASCII.isDigit(ch = read()));
if (ch == ',') {
ch = read();
if (ch == '}') {
unread();
return curly(prev, cmin);
} else {
cmax = 0;
while (ASCII.isDigit(ch)) {
cmax = Math.addExact(Math.multiplyExact(cmax, 10),
ch - '0');
ch = read();
}
}
} else {
cmax = cmin;
}
} catch (ArithmeticException ae) {
throw error("Illegal repetition range");
}
if (ch != '}')
throw error("Unclosed counted closure");
if (cmax < cmin)
throw error("Illegal repetition range");
unread();
return (cmin == 0 && cmax == 1)
? new Ques(prev, qtype())
: new Curly(prev, cmin, cmax, qtype());
} else {
throw error("Illegal repetition");
}
default:
return prev;
}
}
/**
* Utility method for parsing control escape sequences.
*
private int c() {
if (cursor < patternLength) {
return read() ^ 64;
}
throw error("Illegal control escape sequence");
}
/**
* Utility method for parsing octal escape sequences.
*
private int o() {
int n = read();
if (((n-'0')|('7'-n)) >= 0) {
int m = read();
if (((m-'0')|('7'-m)) >= 0) {
int o = read();
if ((((o-'0')|('7'-o)) >= 0) && (((n-'0')|('3'-n)) >= 0)) {
return (n - '0') * 64 + (m - '0') * 8 + (o - '0');
}
unread();
return (n - '0') * 8 + (m - '0');
}
unread();
return (n - '0');
}
throw error("Illegal octal escape sequence");
}
/**
* Utility method for parsing hexadecimal escape sequences.
*
private int x() {
int n = read();
if (ASCII.isHexDigit(n)) {
int m = read();
if (ASCII.isHexDigit(m)) {
return ASCII.toDigit(n) * 16 + ASCII.toDigit(m);
}
} else if (n == '{' && ASCII.isHexDigit(peek())) {
int ch = 0;
while (ASCII.isHexDigit(n = read())) {
ch = (ch << 4) + ASCII.toDigit(n);
if (ch > Character.MAX_CODE_POINT)
throw error("Hexadecimal codepoint is too big");
}
if (n != '}')
throw error("Unclosed hexadecimal escape sequence");
return ch;
}
throw error("Illegal hexadecimal escape sequence");
}
/**
* Utility method for parsing unicode escape sequences.
*
private int cursor() {
return cursor;
}
private void setcursor(int pos) {
cursor = pos;
}
private int uxxxx() {
int n = 0;
for (int i = 0; i < 4; i++) {
int ch = read();
if (!ASCII.isHexDigit(ch)) {
throw error("Illegal Unicode escape sequence");
}
n = n * 16 + ASCII.toDigit(ch);
}
return n;
}
private int u() {
int n = uxxxx();
if (Character.isHighSurrogate((char)n)) {
int cur = cursor();
if (read() == '\\' && read() == 'u') {
int n2 = uxxxx();
if (Character.isLowSurrogate((char)n2))
return Character.toCodePoint((char)n, (char)n2);
}
setcursor(cur);
}
return n;
}
private int N() {
if (read() == '{') {
int i = cursor;
while (read() != '}') {
if (cursor >= patternLength)
throw error("Unclosed character name escape sequence");
}
String name = new String(temp, i, cursor - i - 1);
try {
return Character.codePointOf(name);
} catch (IllegalArgumentException x) {
throw error("Unknown character name [" + name + "]");
}
}
throw error("Illegal character name escape sequence");
}
//
// Utility methods for code point support
//
private static final int countChars(CharSequence seq, int index,
int lengthInCodePoints) {
// optimization
if (lengthInCodePoints == 1 && index >= 0 && index < seq.length() &&
!Character.isHighSurrogate(seq.charAt(index))) {
return 1;
}
int length = seq.length();
int x = index;
if (lengthInCodePoints >= 0) {
assert ((length == 0 && index == 0) || index >= 0 && index < length);
for (int i = 0; x < length && i < lengthInCodePoints; i++) {
if (Character.isHighSurrogate(seq.charAt(x++))) {
if (x < length && Character.isLowSurrogate(seq.charAt(x))) {
x++;
}
}
}
return x - index;
}
assert (index >= 0 && index <= length);
if (index == 0) {
return 0;
}
int len = -lengthInCodePoints;
for (int i = 0; x > 0 && i < len; i++) {
if (Character.isLowSurrogate(seq.charAt(--x))) {
if (x > 0 && Character.isHighSurrogate(seq.charAt(x-1))) {
x--;
}
}
}
return index - x;
}
private static final int countCodePoints(CharSequence seq) {
int length = seq.length();
int n = 0;
for (int i = 0; i < length; ) {
n++;
if (Character.isHighSurrogate(seq.charAt(i++))) {
if (i < length && Character.isLowSurrogate(seq.charAt(i))) {
i++;
}
}
}
return n;
}
/**
* Creates a bit vector for matching Latin-1 values. A normal BitClass
* never matches values above Latin-1, and a complemented BitClass always
* matches values above Latin-1.
*
static final class BitClass implements BmpCharPredicate {
final boolean[] bits;
BitClass() {
bits = new boolean[256];
}
BitClass add(int c, int flags) {
assert c >= 0 && c <= 255;
if ((flags & CASE_INSENSITIVE) != 0) {
if (ASCII.isAscii(c)) {
bits[ASCII.toUpper(c)] = true;
bits[ASCII.toLower(c)] = true;
} else if ((flags & UNICODE_CASE) != 0) {
bits[Character.toLowerCase(c)] = true;
bits[Character.toUpperCase(c)] = true;
}
}
bits[c] = true;
return this;
}
public boolean is(int ch) {
return ch < 256 && bits[ch];
}
}
/**
* Utility method for creating a string slice matcher.
*
private Node newSlice(int[] buf, int count, boolean hasSupplementary) {
int[] tmp = new int[count];
if (has(CASE_INSENSITIVE)) {
if (has(UNICODE_CASE)) {
for (int i = 0; i < count; i++) {
tmp[i] = Character.toLowerCase(
Character.toUpperCase(buf[i]));
}
return hasSupplementary? new SliceUS(tmp) : new SliceU(tmp);
}
for (int i = 0; i < count; i++) {
tmp[i] = ASCII.toLower(buf[i]);
}
return hasSupplementary? new SliceIS(tmp) : new SliceI(tmp);
}
for (int i = 0; i < count; i++) {
tmp[i] = buf[i];
}
return hasSupplementary ? new SliceS(tmp) : new Slice(tmp);
}
*/
// END Android-removed: Reimplement matching logic via ICU4C.
// BEGIN Android-changed: reimplement matching logic natively via ICU.
// Use native implementation instead of > 3000 lines of helper methods.
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);
nativePattern = PatternNative.create(icuPattern, icuFlags);
}
// END Android-changed: reimplement matching logic natively via ICU.
// BEGIN Android-removed: Reimplement matching logic via ICU4C.
/**
* Node to anchor at the beginning of input. This object implements the
* match for a \A sequence, and the caret anchor will use this if not in
* multiline mode.
*
static final class Begin extends Node {
boolean match(Matcher matcher, int i, CharSequence seq) {
int fromIndex = (matcher.anchoringBounds) ?
matcher.from : 0;
if (i == fromIndex && next.match(matcher, i, seq)) {
matcher.first = i;
matcher.groups[0] = i;
matcher.groups[1] = matcher.last;
return true;
} else {
return false;
}
}
}
/**
* Node to anchor at the end of input. This is the absolute end, so this
* should not match at the last newline before the end as $ will.
*
static final class End extends Node {
boolean match(Matcher matcher, int i, CharSequence seq) {
int endIndex = (matcher.anchoringBounds) ?
matcher.to : matcher.getTextLength();
if (i == endIndex) {
matcher.hitEnd = true;
return next.match(matcher, i, seq);
}
return false;
}
}
/**
* Node to anchor at the beginning of a line. This is essentially the
* object to match for the multiline ^.
*
static final class Caret extends Node {
boolean match(Matcher matcher, int i, CharSequence seq) {
int startIndex = matcher.from;
int endIndex = matcher.to;
if (!matcher.anchoringBounds) {
startIndex = 0;
endIndex = matcher.getTextLength();
}
// Perl does not match ^ at end of input even after newline
if (i == endIndex) {
matcher.hitEnd = true;
return false;
}
if (i > startIndex) {
char ch = seq.charAt(i-1);
if (ch != '\n' && ch != '\r'
&& (ch|1) != '\u2029'
&& ch != '\u0085' ) {
return false;
}
// Should treat /r/n as one newline
if (ch == '\r' && seq.charAt(i) == '\n')
return false;
}
return next.match(matcher, i, seq);
}
}
/**
* Node to anchor at the beginning of a line when in unixdot mode.
*
static final class UnixCaret extends Node {
boolean match(Matcher matcher, int i, CharSequence seq) {
int startIndex = matcher.from;
int endIndex = matcher.to;
if (!matcher.anchoringBounds) {
startIndex = 0;
endIndex = matcher.getTextLength();
}
// Perl does not match ^ at end of input even after newline
if (i == endIndex) {
matcher.hitEnd = true;
return false;
}
if (i > startIndex) {
char ch = seq.charAt(i-1);
if (ch != '\n') {
return false;
}
}
return next.match(matcher, i, seq);
}
}
/**
* Node to match the location where the last match ended.
* This is used for the \G construct.
*
static final class LastMatch extends Node {
boolean match(Matcher matcher, int i, CharSequence seq) {
if (i != matcher.oldLast)
return false;
return next.match(matcher, i, seq);
}
}
/**
* Node to anchor at the end of a line or the end of input based on the
* multiline mode.
*
* When not in multiline mode, the $ can only match at the very end
* of the input, unless the input ends in a line terminator in which
* it matches right before the last line terminator.
*
* Note that \r\n is considered an atomic line terminator.
*
* Like ^ the $ operator matches at a position, it does not match the
* line terminators themselves.
*
static final class Dollar extends Node {
boolean multiline;
Dollar(boolean mul) {
multiline = mul;
}
boolean match(Matcher matcher, int i, CharSequence seq) {
int endIndex = (matcher.anchoringBounds) ?
matcher.to : matcher.getTextLength();
if (!multiline) {
if (i < endIndex - 2)
return false;
if (i == endIndex - 2) {
char ch = seq.charAt(i);
if (ch != '\r')
return false;
ch = seq.charAt(i + 1);
if (ch != '\n')
return false;
}
}
// Matches before any line terminator; also matches at the
// end of input
// Before line terminator:
// If multiline, we match here no matter what
// If not multiline, fall through so that the end
// is marked as hit; this must be a /r/n or a /n
// at the very end so the end was hit; more input
// could make this not match here
if (i < endIndex) {
char ch = seq.charAt(i);
if (ch == '\n') {
// No match between \r\n
if (i > 0 && seq.charAt(i-1) == '\r')
return false;
if (multiline)
return next.match(matcher, i, seq);
} else if (ch == '\r' || ch == '\u0085' ||
(ch|1) == '\u2029') {
if (multiline)
return next.match(matcher, i, seq);
} else { // No line terminator, no match
return false;
}
}
// Matched at current end so hit end
matcher.hitEnd = true;
// If a $ matches because of end of input, then more input
// could cause it to fail!
matcher.requireEnd = true;
return next.match(matcher, i, seq);
}
boolean study(TreeInfo info) {
next.study(info);
return info.deterministic;
}
}
/**
* Node to anchor at the end of a line or the end of input based on the
* multiline mode when in unix lines mode.
*
static final class UnixDollar extends Node {
boolean multiline;
UnixDollar(boolean mul) {
multiline = mul;
}
boolean match(Matcher matcher, int i, CharSequence seq) {
int endIndex = (matcher.anchoringBounds) ?
matcher.to : matcher.getTextLength();
if (i < endIndex) {
char ch = seq.charAt(i);
if (ch == '\n') {
// If not multiline, then only possible to
// match at very end or one before end
if (multiline == false && i != endIndex - 1)
return false;
// If multiline return next.match without setting
// matcher.hitEnd
if (multiline)
return next.match(matcher, i, seq);
} else {
return false;
}
}
// Matching because at the end or 1 before the end;
// more input could change this so set hitEnd
matcher.hitEnd = true;
// If a $ matches because of end of input, then more input
// could cause it to fail!
matcher.requireEnd = true;
return next.match(matcher, i, seq);
}
boolean study(TreeInfo info) {
next.study(info);
return info.deterministic;
}
}
/**
* Node class that matches a Unicode line ending '\R'
*
static final class LineEnding extends Node {
boolean match(Matcher matcher, int i, CharSequence seq) {
// (u+000Du+000A|[u+000Au+000Bu+000Cu+000Du+0085u+2028u+2029])
if (i < matcher.to) {
int ch = seq.charAt(i);
if (ch == 0x0A || ch == 0x0B || ch == 0x0C ||
ch == 0x85 || ch == 0x2028 || ch == 0x2029)
return next.match(matcher, i + 1, seq);
if (ch == 0x0D) {
i++;
if (i < matcher.to) {
if (seq.charAt(i) == 0x0A &&
next.match(matcher, i + 1, seq)) {
return true;
}
} else {
matcher.hitEnd = true;
}
return next.match(matcher, i, seq);
}
} else {
matcher.hitEnd = true;
}
return false;
}
boolean study(TreeInfo info) {
info.minLength++;
info.maxLength += 2;
return next.study(info);
}
}
/**
* Abstract node class to match one character satisfying some
* boolean property.
*
static class CharProperty extends Node {
final CharPredicate predicate;
CharProperty (CharPredicate predicate) {
this.predicate = predicate;
}
boolean match(Matcher matcher, int i, CharSequence seq) {
if (i < matcher.to) {
int ch = Character.codePointAt(seq, i);
i += Character.charCount(ch);
if (i <= matcher.to) {
return predicate.is(ch) &&
next.match(matcher, i, seq);
}
}
matcher.hitEnd = true;
return false;
}
boolean study(TreeInfo info) {
info.minLength++;
info.maxLength++;
return next.study(info);
}
}
/**
* Optimized version of CharProperty that works only for
* properties never satisfied by Supplementary characters.
*
private static class BmpCharProperty extends CharProperty {
BmpCharProperty (BmpCharPredicate predicate) {
super(predicate);
}
boolean match(Matcher matcher, int i, CharSequence seq) {
if (i < matcher.to) {
return predicate.is(seq.charAt(i)) &&
next.match(matcher, i + 1, seq);
} else {
matcher.hitEnd = true;
return false;
}
}
}
private static class NFCCharProperty extends Node {
CharPredicate predicate;
NFCCharProperty (CharPredicate predicate) {
this.predicate = predicate;
}
boolean match(Matcher matcher, int i, CharSequence seq) {
if (i < matcher.to) {
int ch0 = Character.codePointAt(seq, i);
int n = Character.charCount(ch0);
int j = Grapheme.nextBoundary(seq, i, matcher.to);
if (i + n == j) { // single cp grapheme, assume nfc
if (predicate.is(ch0))
return next.match(matcher, j, seq);
} else {
while (i + n < j) {
String nfc = Normalizer.normalize(
seq.toString().substring(i, j), Normalizer.Form.NFC);
if (nfc.codePointCount(0, nfc.length()) == 1) {
if (predicate.is(nfc.codePointAt(0)) &&
next.match(matcher, j, seq)) {
return true;
}
}
ch0 = Character.codePointBefore(seq, j);
j -= Character.charCount(ch0);
}
}
if (j < matcher.to)
return false;
}
matcher.hitEnd = true;
return false;
}
boolean study(TreeInfo info) {
info.minLength++;
info.deterministic = false;
return next.study(info);
}
}
/**
* Node class that matches an unicode extended grapheme cluster
*
static class XGrapheme extends Node {
boolean match(Matcher matcher, int i, CharSequence seq) {
if (i < matcher.to) {
i = Grapheme.nextBoundary(seq, i, matcher.to);
return next.match(matcher, i, seq);
}
matcher.hitEnd = true;
return false;
}
boolean study(TreeInfo info) {
info.minLength++;
info.deterministic = false;
return next.study(info);
}
}
/**
* Node class that handles grapheme boundaries
*
static class GraphemeBound extends Node {
boolean match(Matcher matcher, int i, CharSequence seq) {
int startIndex = matcher.from;
int endIndex = matcher.to;
if (matcher.transparentBounds) {
startIndex = 0;
endIndex = matcher.getTextLength();
}
if (i == startIndex) {
// continue with return below
} else if (i < endIndex) {
if (Character.isSurrogatePair(seq.charAt(i - 1), seq.charAt(i))) {
return false;
}
if (Grapheme.nextBoundary(seq, matcher.last, endIndex) > i) {
return false;
}
} else {
matcher.hitEnd = true;
matcher.requireEnd = true;
}
return next.match(matcher, i, seq);
}
}
/**
* Base class for all Slice nodes
*
static class SliceNode extends Node {
int[] buffer;
SliceNode(int[] buf) {
buffer = buf;
}
boolean study(TreeInfo info) {
info.minLength += buffer.length;
info.maxLength += buffer.length;
return next.study(info);
}
}
/**
* Node class for a case sensitive/BMP-only sequence of literal
* characters.
*
static class Slice extends SliceNode {
Slice(int[] buf) {
super(buf);
}
boolean match(Matcher matcher, int i, CharSequence seq) {
int[] buf = buffer;
int len = buf.length;
for (int j=0; j<len; j++) {
if ((i+j) >= matcher.to) {
matcher.hitEnd = true;
return false;
}
if (buf[j] != seq.charAt(i+j))
return false;
}
return next.match(matcher, i+len, seq);
}
}
/**
* Node class for a case_insensitive/BMP-only sequence of literal
* characters.
*
static class SliceI extends SliceNode {
SliceI(int[] buf) {
super(buf);
}
boolean match(Matcher matcher, int i, CharSequence seq) {
int[] buf = buffer;
int len = buf.length;
for (int j=0; j<len; j++) {
if ((i+j) >= matcher.to) {
matcher.hitEnd = true;
return false;
}
int c = seq.charAt(i+j);
if (buf[j] != c &&
buf[j] != ASCII.toLower(c))
return false;
}
return next.match(matcher, i+len, seq);
}
}
/**
* Node class for a unicode_case_insensitive/BMP-only sequence of
* literal characters. Uses unicode case folding.
*
static final class SliceU extends SliceNode {
SliceU(int[] buf) {
super(buf);
}
boolean match(Matcher matcher, int i, CharSequence seq) {
int[] buf = buffer;
int len = buf.length;
for (int j=0; j<len; j++) {
if ((i+j) >= matcher.to) {
matcher.hitEnd = true;
return false;
}
int c = seq.charAt(i+j);
if (buf[j] != c &&
buf[j] != Character.toLowerCase(Character.toUpperCase(c)))
return false;
}
return next.match(matcher, i+len, seq);
}
}
/**
* Node class for a case sensitive sequence of literal characters
* including supplementary characters.
*
static final class SliceS extends Slice {
SliceS(int[] buf) {
super(buf);
}
boolean match(Matcher matcher, int i, CharSequence seq) {
int[] buf = buffer;
int x = i;
for (int j = 0; j < buf.length; j++) {
if (x >= matcher.to) {
matcher.hitEnd = true;
return false;
}
int c = Character.codePointAt(seq, x);
if (buf[j] != c)
return false;
x += Character.charCount(c);
if (x > matcher.to) {
matcher.hitEnd = true;
return false;
}
}
return next.match(matcher, x, seq);
}
}
/**
* Node class for a case insensitive sequence of literal characters
* including supplementary characters.
*
static class SliceIS extends SliceNode {
SliceIS(int[] buf) {
super(buf);
}
int toLower(int c) {
return ASCII.toLower(c);
}
boolean match(Matcher matcher, int i, CharSequence seq) {
int[] buf = buffer;
int x = i;
for (int j = 0; j < buf.length; j++) {
if (x >= matcher.to) {
matcher.hitEnd = true;
return false;
}
int c = Character.codePointAt(seq, x);
if (buf[j] != c && buf[j] != toLower(c))
return false;
x += Character.charCount(c);
if (x > matcher.to) {
matcher.hitEnd = true;
return false;
}
}
return next.match(matcher, x, seq);
}
}
/**
* Node class for a case insensitive sequence of literal characters.
* Uses unicode case folding.
*
static final class SliceUS extends SliceIS {
SliceUS(int[] buf) {
super(buf);
}
int toLower(int c) {
return Character.toLowerCase(Character.toUpperCase(c));
}
}
/**
* The 0 or 1 quantifier. This one class implements all three types.
*
static final class Ques extends Node {
Node atom;
Qtype type;
Ques(Node node, Qtype type) {
this.atom = node;
this.type = type;
}
boolean match(Matcher matcher, int i, CharSequence seq) {
switch (type) {
case GREEDY:
return (atom.match(matcher, i, seq) && next.match(matcher, matcher.last, seq))
|| next.match(matcher, i, seq);
case LAZY:
return next.match(matcher, i, seq)
|| (atom.match(matcher, i, seq) && next.match(matcher, matcher.last, seq));
case POSSESSIVE:
if (atom.match(matcher, i, seq)) i = matcher.last;
return next.match(matcher, i, seq);
default:
return atom.match(matcher, i, seq) && next.match(matcher, matcher.last, seq);
}
}
boolean study(TreeInfo info) {
if (type != Qtype.INDEPENDENT) {
int minL = info.minLength;
atom.study(info);
info.minLength = minL;
info.deterministic = false;
return next.study(info);
} else {
atom.study(info);
return next.study(info);
}
}
}
/**
* Handles the greedy style repetition with the specified minimum
* and the maximum equal to MAX_REPS, for *, + and {N,} quantifiers.
*
static class CharPropertyGreedy extends Node {
final CharPredicate predicate;
final int cmin;
CharPropertyGreedy(CharProperty cp, int cmin) {
this.predicate = cp.predicate;
this.cmin = cmin;
}
boolean match(Matcher matcher, int i, CharSequence seq) {
int starti = i;
int n = 0;
int to = matcher.to;
// greedy, all the way down
while (i < to) {
int ch = Character.codePointAt(seq, i);
int len = Character.charCount(ch);
if (i + len > to) {
// the region cut off the high half of a surrogate pair
matcher.hitEnd = true;
ch = seq.charAt(i);
len = 1;
}
if (!predicate.is(ch))
break;
i += len;
n++;
}
if (i >= to) {
matcher.hitEnd = true;
}
while (n >= cmin) {
if (next.match(matcher, i, seq))
return true;
if (n == cmin)
return false;
// backing off if match fails
int ch = Character.codePointBefore(seq, i);
// check if the region cut off the low half of a surrogate pair
i = Math.max(starti, i - Character.charCount(ch));
n--;
}
return false;
}
boolean study(TreeInfo info) {
info.minLength += cmin;
if (info.maxValid) {
info.maxLength += MAX_REPS;
}
info.deterministic = false;
return next.study(info);
}
}
static final class BmpCharPropertyGreedy extends CharPropertyGreedy {
BmpCharPropertyGreedy(BmpCharProperty bcp, int cmin) {
super(bcp, cmin);
}
boolean match(Matcher matcher, int i, CharSequence seq) {
int n = 0;
int to = matcher.to;
while (i < to && predicate.is(seq.charAt(i))) {
i++; n++;
}
if (i >= to) {
matcher.hitEnd = true;
}
while (n >= cmin) {
if (next.match(matcher, i, seq))
return true;
i--; n--; // backing off if match fails
}
return false;
}
}
/**
* Handles the curly-brace style repetition with a specified minimum and
* maximum occurrences. The * quantifier is handled as a special case.
* This class handles the three types.
*
static final class Curly extends Node {
Node atom;
Qtype type;
int cmin;
int cmax;
Curly(Node node, int cmin, int cmax, Qtype type) {
this.atom = node;
this.type = type;
this.cmin = cmin;
this.cmax = cmax;
}
boolean match(Matcher matcher, int i, CharSequence seq) {
int j;
for (j = 0; j < cmin; j++) {
if (atom.match(matcher, i, seq)) {
i = matcher.last;
continue;
}
return false;
}
if (type == Qtype.GREEDY)
return match0(matcher, i, j, seq);
else if (type == Qtype.LAZY)
return match1(matcher, i, j, seq);
else
return match2(matcher, i, j, seq);
}
// Greedy match.
// i is the index to start matching at
// j is the number of atoms that have matched
boolean match0(Matcher matcher, int i, int j, CharSequence seq) {
if (j >= cmax) {
// We have matched the maximum... continue with the rest of
// the regular expression
return next.match(matcher, i, seq);
}
int backLimit = j;
while (atom.match(matcher, i, seq)) {
// k is the length of this match
int k = matcher.last - i;
if (k == 0) // Zero length match
break;
// Move up index and number matched
i = matcher.last;
j++;
// We are greedy so match as many as we can
while (j < cmax) {
if (!atom.match(matcher, i, seq))
break;
if (i + k != matcher.last) {
if (match0(matcher, matcher.last, j+1, seq))
return true;
break;
}
i += k;
j++;
}
// Handle backing off if match fails
while (j >= backLimit) {
if (next.match(matcher, i, seq))
return true;
i -= k;
j--;
}
return false;
}
return next.match(matcher, i, seq);
}
// Reluctant match. At this point, the minimum has been satisfied.
// i is the index to start matching at
// j is the number of atoms that have matched
boolean match1(Matcher matcher, int i, int j, CharSequence seq) {
for (;;) {
// Try finishing match without consuming any more
if (next.match(matcher, i, seq))
return true;
// At the maximum, no match found
if (j >= cmax)
return false;
// Okay, must try one more atom
if (!atom.match(matcher, i, seq))
return false;
// If we haven't moved forward then must break out
if (i == matcher.last)
return false;
// Move up index and number matched
i = matcher.last;
j++;
}
}
boolean match2(Matcher matcher, int i, int j, CharSequence seq) {
for (; j < cmax; j++) {
if (!atom.match(matcher, i, seq))
break;
if (i == matcher.last)
break;
i = matcher.last;
}
return next.match(matcher, i, seq);
}
boolean study(TreeInfo info) {
// Save original info
int minL = info.minLength;
int maxL = info.maxLength;
boolean maxV = info.maxValid;
boolean detm = info.deterministic;
info.reset();
atom.study(info);
int temp = info.minLength * cmin + minL;
if (temp < minL) {
temp = 0xFFFFFFF; // arbitrary large number
}
info.minLength = temp;
if (maxV & info.maxValid) {
temp = info.maxLength * cmax + maxL;
info.maxLength = temp;
if (temp < maxL) {
info.maxValid = false;
}
} else {
info.maxValid = false;
}
if (info.deterministic && cmin == cmax)
info.deterministic = detm;
else
info.deterministic = false;
return next.study(info);
}
}
/**
* Handles the curly-brace style repetition with a specified minimum and
* maximum occurrences in deterministic cases. This is an iterative
* optimization over the Prolog and Loop system which would handle this
* in a recursive way. The * quantifier is handled as a special case.
* If capture is true then this class saves group settings and ensures
* that groups are unset when backing off of a group match.
*
static final class GroupCurly extends Node {
Node atom;
Qtype type;
int cmin;
int cmax;
int localIndex;
int groupIndex;
boolean capture;
GroupCurly(Node node, int cmin, int cmax, Qtype type, int local,
int group, boolean capture) {
this.atom = node;
this.type = type;
this.cmin = cmin;
this.cmax = cmax;
this.localIndex = local;
this.groupIndex = group;
this.capture = capture;
}
boolean match(Matcher matcher, int i, CharSequence seq) {
int[] groups = matcher.groups;
int[] locals = matcher.locals;
int save0 = locals[localIndex];
int save1 = 0;
int save2 = 0;
if (capture) {
save1 = groups[groupIndex];
save2 = groups[groupIndex+1];
}
// Notify GroupTail there is no need to setup group info
// because it will be set here
locals[localIndex] = -1;
boolean ret = true;
for (int j = 0; j < cmin; j++) {
if (atom.match(matcher, i, seq)) {
if (capture) {
groups[groupIndex] = i;
groups[groupIndex+1] = matcher.last;
}
i = matcher.last;
} else {
ret = false;
break;
}
}
if (ret) {
if (type == Qtype.GREEDY) {
ret = match0(matcher, i, cmin, seq);
} else if (type == Qtype.LAZY) {
ret = match1(matcher, i, cmin, seq);
} else {
ret = match2(matcher, i, cmin, seq);
}
}
if (!ret) {
locals[localIndex] = save0;
if (capture) {
groups[groupIndex] = save1;
groups[groupIndex+1] = save2;
}
}
return ret;
}
// Aggressive group match
boolean match0(Matcher matcher, int i, int j, CharSequence seq) {
// don't back off passing the starting "j"
int min = j;
int[] groups = matcher.groups;
int save0 = 0;
int save1 = 0;
if (capture) {
save0 = groups[groupIndex];
save1 = groups[groupIndex+1];
}
for (;;) {
if (j >= cmax)
break;
if (!atom.match(matcher, i, seq))
break;
int k = matcher.last - i;
if (k <= 0) {
if (capture) {
groups[groupIndex] = i;
groups[groupIndex+1] = i + k;
}
i = i + k;
break;
}
for (;;) {
if (capture) {
groups[groupIndex] = i;
groups[groupIndex+1] = i + k;
}
i = i + k;
if (++j >= cmax)
break;
if (!atom.match(matcher, i, seq))
break;
if (i + k != matcher.last) {
if (match0(matcher, i, j, seq))
return true;
break;
}
}
while (j > min) {
if (next.match(matcher, i, seq)) {
if (capture) {
groups[groupIndex+1] = i;
groups[groupIndex] = i - k;
}
return true;
}
// backing off
i = i - k;
if (capture) {
groups[groupIndex+1] = i;
groups[groupIndex] = i - k;
}
j--;
}
break;
}
if (capture) {
groups[groupIndex] = save0;
groups[groupIndex+1] = save1;
}
return next.match(matcher, i, seq);
}
// Reluctant matching
boolean match1(Matcher matcher, int i, int j, CharSequence seq) {
for (;;) {
if (next.match(matcher, i, seq))
return true;
if (j >= cmax)
return false;
if (!atom.match(matcher, i, seq))
return false;
if (i == matcher.last)
return false;
if (capture) {
matcher.groups[groupIndex] = i;
matcher.groups[groupIndex+1] = matcher.last;
}
i = matcher.last;
j++;
}
}
// Possessive matching
boolean match2(Matcher matcher, int i, int j, CharSequence seq) {
for (; j < cmax; j++) {
if (!atom.match(matcher, i, seq)) {
break;
}
if (capture) {
matcher.groups[groupIndex] = i;
matcher.groups[groupIndex+1] = matcher.last;
}
if (i == matcher.last) {
break;
}
i = matcher.last;
}
return next.match(matcher, i, seq);
}
boolean study(TreeInfo info) {
// Save original info
int minL = info.minLength;
int maxL = info.maxLength;
boolean maxV = info.maxValid;
boolean detm = info.deterministic;
info.reset();
atom.study(info);
int temp = info.minLength * cmin + minL;
if (temp < minL) {
temp = 0xFFFFFFF; // Arbitrary large number
}
info.minLength = temp;
if (maxV & info.maxValid) {
temp = info.maxLength * cmax + maxL;
info.maxLength = temp;
if (temp < maxL) {
info.maxValid = false;
}
} else {
info.maxValid = false;
}
if (info.deterministic && cmin == cmax) {
info.deterministic = detm;
} else {
info.deterministic = false;
}
return next.study(info);
}
}
/**
* A Guard node at the end of each atom node in a Branch. It
* serves the purpose of chaining the "match" operation to
* "next" but not the "study", so we can collect the TreeInfo
* of each atom node without including the TreeInfo of the
* "next".
*
static final class BranchConn extends Node {
BranchConn() {}
boolean match(Matcher matcher, int i, CharSequence seq) {
return next.match(matcher, i, seq);
}
boolean study(TreeInfo info) {
return info.deterministic;
}
}
/**
* Handles the branching of alternations. Note this is also used for
* the ? quantifier to branch between the case where it matches once
* and where it does not occur.
*
static final class Branch extends Node {
Node[] atoms = new Node[2];
int size = 2;
Node conn;
Branch(Node first, Node second, Node branchConn) {
conn = branchConn;
atoms[0] = first;
atoms[1] = second;
}
void add(Node node) {
if (size >= atoms.length) {
Node[] tmp = new Node[atoms.length*2];
System.arraycopy(atoms, 0, tmp, 0, atoms.length);
atoms = tmp;
}
atoms[size++] = node;
}
boolean match(Matcher matcher, int i, CharSequence seq) {
for (int n = 0; n < size; n++) {
if (atoms[n] == null) {
if (conn.next.match(matcher, i, seq))
return true;
} else if (atoms[n].match(matcher, i, seq)) {
return true;
}
}
return false;
}
boolean study(TreeInfo info) {
int minL = info.minLength;
int maxL = info.maxLength;
boolean maxV = info.maxValid;
int minL2 = Integer.MAX_VALUE; //arbitrary large enough num
int maxL2 = -1;
for (int n = 0; n < size; n++) {
info.reset();
if (atoms[n] != null)
atoms[n].study(info);
minL2 = Math.min(minL2, info.minLength);
maxL2 = Math.max(maxL2, info.maxLength);
maxV = (maxV & info.maxValid);
}
minL += minL2;
maxL += maxL2;
info.reset();
conn.next.study(info);
info.minLength += minL;
info.maxLength += maxL;
info.maxValid &= maxV;
info.deterministic = false;
return false;
}
}
/**
* The GroupHead saves the location where the group begins in the locals
* and restores them when the match is done.
*
* The matchRef is used when a reference to this group is accessed later
* in the expression. The locals will have a negative value in them to
* indicate that we do not want to unset the group if the reference
* doesn't match.
*
static final class GroupHead extends Node {
int localIndex;
GroupTail tail; // for debug/print only, match does not need to know
GroupHead(int localCount) {
localIndex = localCount;
}
boolean match(Matcher matcher, int i, CharSequence seq) {
int save = matcher.locals[localIndex];
matcher.locals[localIndex] = i;
boolean ret = next.match(matcher, i, seq);
matcher.locals[localIndex] = save;
return ret;
}
}
/**
* The GroupTail handles the setting of group beginning and ending
* locations when groups are successfully matched. It must also be able to
* unset groups that have to be backed off of.
*
* The GroupTail node is also used when a previous group is referenced,
* and in that case no group information needs to be set.
*
static final class GroupTail extends Node {
int localIndex;
int groupIndex;
GroupTail(int localCount, int groupCount) {
localIndex = localCount;
groupIndex = groupCount + groupCount;
}
boolean match(Matcher matcher, int i, CharSequence seq) {
int tmp = matcher.locals[localIndex];
if (tmp >= 0) { // This is the normal group case.
// Save the group so we can unset it if it
// backs off of a match.
int groupStart = matcher.groups[groupIndex];
int groupEnd = matcher.groups[groupIndex+1];
matcher.groups[groupIndex] = tmp;
matcher.groups[groupIndex+1] = i;
if (next.match(matcher, i, seq)) {
return true;
}
matcher.groups[groupIndex] = groupStart;
matcher.groups[groupIndex+1] = groupEnd;
return false;
} else {
// This is a group reference case. We don't need to save any
// group info because it isn't really a group.
matcher.last = i;
return true;
}
}
}
/**
* This sets up a loop to handle a recursive quantifier structure.
*
static final class Prolog extends Node {
Loop loop;
Prolog(Loop loop) {
this.loop = loop;
}
boolean match(Matcher matcher, int i, CharSequence seq) {
return loop.matchInit(matcher, i, seq);
}
boolean study(TreeInfo info) {
return loop.study(info);
}
}
/**
* Handles the repetition count for a greedy Curly. The matchInit
* is called from the Prolog to save the index of where the group
* beginning is stored. A zero length group check occurs in the
* normal match but is skipped in the matchInit.
*
static class Loop extends Node {
Node body;
int countIndex; // local count index in matcher locals
int beginIndex; // group beginning index
int cmin, cmax;
int posIndex;
Loop(int countIndex, int beginIndex) {
this.countIndex = countIndex;
this.beginIndex = beginIndex;
this.posIndex = -1;
}
boolean match(Matcher matcher, int i, CharSequence seq) {
// Avoid infinite loop in zero-length case.
if (i > matcher.locals[beginIndex]) {
int count = matcher.locals[countIndex];
// This block is for before we reach the minimum
// iterations required for the loop to match
if (count < cmin) {
matcher.locals[countIndex] = count + 1;
boolean b = body.match(matcher, i, seq);
// If match failed we must backtrack, so
// the loop count should NOT be incremented
if (!b)
matcher.locals[countIndex] = count;
// Return success or failure since we are under
// minimum
return b;
}
// This block is for after we have the minimum
// iterations required for the loop to match
if (count < cmax) {
// Let's check if we have already tried and failed
// at this starting position "i" in the past.
// If yes, then just return false wihtout trying
// again, to stop the exponential backtracking.
if (posIndex != -1 &&
matcher.localsPos[posIndex].contains(i)) {
return next.match(matcher, i, seq);
}
matcher.locals[countIndex] = count + 1;
boolean b = body.match(matcher, i, seq);
// If match failed we must backtrack, so
// the loop count should NOT be incremented
if (b)
return true;
matcher.locals[countIndex] = count;
// save the failed position
if (posIndex != -1) {
matcher.localsPos[posIndex].add(i);
}
}
}
return next.match(matcher, i, seq);
}
boolean matchInit(Matcher matcher, int i, CharSequence seq) {
int save = matcher.locals[countIndex];
boolean ret;
if (posIndex != -1 && matcher.localsPos[posIndex] == null) {
matcher.localsPos[posIndex] = new IntHashSet();
}
if (0 < cmin) {
matcher.locals[countIndex] = 1;
ret = body.match(matcher, i, seq);
} else if (0 < cmax) {
matcher.locals[countIndex] = 1;
ret = body.match(matcher, i, seq);
if (ret == false)
ret = next.match(matcher, i, seq);
} else {
ret = next.match(matcher, i, seq);
}
matcher.locals[countIndex] = save;
return ret;
}
boolean study(TreeInfo info) {
info.maxValid = false;
info.deterministic = false;
return false;
}
}
/**
* Handles the repetition count for a reluctant Curly. The matchInit
* is called from the Prolog to save the index of where the group
* beginning is stored. A zero length group check occurs in the
* normal match but is skipped in the matchInit.
*
static final class LazyLoop extends Loop {
LazyLoop(int countIndex, int beginIndex) {
super(countIndex, beginIndex);
}
boolean match(Matcher matcher, int i, CharSequence seq) {
// Check for zero length group
if (i > matcher.locals[beginIndex]) {
int count = matcher.locals[countIndex];
if (count < cmin) {
matcher.locals[countIndex] = count + 1;
boolean result = body.match(matcher, i, seq);
// If match failed we must backtrack, so
// the loop count should NOT be incremented
if (!result)
matcher.locals[countIndex] = count;
return result;
}
if (next.match(matcher, i, seq))
return true;
if (count < cmax) {
matcher.locals[countIndex] = count + 1;
boolean result = body.match(matcher, i, seq);
// If match failed we must backtrack, so
// the loop count should NOT be incremented
if (!result)
matcher.locals[countIndex] = count;
return result;
}
return false;
}
return next.match(matcher, i, seq);
}
boolean matchInit(Matcher matcher, int i, CharSequence seq) {
int save = matcher.locals[countIndex];
boolean ret = false;
if (0 < cmin) {
matcher.locals[countIndex] = 1;
ret = body.match(matcher, i, seq);
} else if (next.match(matcher, i, seq)) {
ret = true;
} else if (0 < cmax) {
matcher.locals[countIndex] = 1;
ret = body.match(matcher, i, seq);
}
matcher.locals[countIndex] = save;
return ret;
}
boolean study(TreeInfo info) {
info.maxValid = false;
info.deterministic = false;
return false;
}
}
/**
* Refers to a group in the regular expression. Attempts to match
* whatever the group referred to last matched.
*
static class BackRef extends Node {
int groupIndex;
BackRef(int groupCount) {
super();
groupIndex = groupCount + groupCount;
}
boolean match(Matcher matcher, int i, CharSequence seq) {
int j = matcher.groups[groupIndex];
int k = matcher.groups[groupIndex+1];
int groupSize = k - j;
// If the referenced group didn't match, neither can this
if (j < 0)
return false;
// If there isn't enough input left no match
if (i + groupSize > matcher.to) {
matcher.hitEnd = true;
return false;
}
// Check each new char to make sure it matches what the group
// referenced matched last time around
for (int index=0; index<groupSize; index++)
if (seq.charAt(i+index) != seq.charAt(j+index))
return false;
return next.match(matcher, i+groupSize, seq);
}
boolean study(TreeInfo info) {
info.maxValid = false;
return next.study(info);
}
}
static class CIBackRef extends Node {
int groupIndex;
boolean doUnicodeCase;
CIBackRef(int groupCount, boolean doUnicodeCase) {
super();
groupIndex = groupCount + groupCount;
this.doUnicodeCase = doUnicodeCase;
}
boolean match(Matcher matcher, int i, CharSequence seq) {
int j = matcher.groups[groupIndex];
int k = matcher.groups[groupIndex+1];
int groupSize = k - j;
// If the referenced group didn't match, neither can this
if (j < 0)
return false;
// If there isn't enough input left no match
if (i + groupSize > matcher.to) {
matcher.hitEnd = true;
return false;
}
// Check each new char to make sure it matches what the group
// referenced matched last time around
int x = i;
for (int index=0; index<groupSize; index++) {
int c1 = Character.codePointAt(seq, x);
int c2 = Character.codePointAt(seq, j);
if (c1 != c2) {
if (doUnicodeCase) {
int cc1 = Character.toUpperCase(c1);
int cc2 = Character.toUpperCase(c2);
if (cc1 != cc2 &&
Character.toLowerCase(cc1) !=
Character.toLowerCase(cc2))
return false;
} else {
if (ASCII.toLower(c1) != ASCII.toLower(c2))
return false;
}
}
x += Character.charCount(c1);
j += Character.charCount(c2);
}
return next.match(matcher, i+groupSize, seq);
}
boolean study(TreeInfo info) {
info.maxValid = false;
return next.study(info);
}
}
/**
* Searches until the next instance of its atom. This is useful for
* finding the atom efficiently without passing an instance of it
* (greedy problem) and without a lot of wasted search time (reluctant
* problem).
*
static final class First extends Node {
Node atom;
First(Node node) {
this.atom = BnM.optimize(node);
}
boolean match(Matcher matcher, int i, CharSequence seq) {
if (atom instanceof BnM) {
return atom.match(matcher, i, seq)
&& next.match(matcher, matcher.last, seq);
}
for (;;) {
if (i > matcher.to) {
matcher.hitEnd = true;
return false;
}
if (atom.match(matcher, i, seq)) {
return next.match(matcher, matcher.last, seq);
}
i += countChars(seq, i, 1);
matcher.first++;
}
}
boolean study(TreeInfo info) {
atom.study(info);
info.maxValid = false;
info.deterministic = false;
return next.study(info);
}
}
/**
* Zero width positive lookahead.
*
static final class Pos extends Node {
Node cond;
Pos(Node cond) {
this.cond = cond;
}
boolean match(Matcher matcher, int i, CharSequence seq) {
int savedTo = matcher.to;
boolean conditionMatched;
// Relax transparent region boundaries for lookahead
if (matcher.transparentBounds)
matcher.to = matcher.getTextLength();
try {
conditionMatched = cond.match(matcher, i, seq);
} finally {
// Reinstate region boundaries
matcher.to = savedTo;
}
return conditionMatched && next.match(matcher, i, seq);
}
}
/**
* Zero width negative lookahead.
*
static final class Neg extends Node {
Node cond;
Neg(Node cond) {
this.cond = cond;
}
boolean match(Matcher matcher, int i, CharSequence seq) {
int savedTo = matcher.to;
boolean conditionMatched;
// Relax transparent region boundaries for lookahead
if (matcher.transparentBounds)
matcher.to = matcher.getTextLength();
try {
if (i < matcher.to) {
conditionMatched = !cond.match(matcher, i, seq);
} else {
// If a negative lookahead succeeds then more input
// could cause it to fail!
matcher.requireEnd = true;
conditionMatched = !cond.match(matcher, i, seq);
}
} finally {
// Reinstate region boundaries
matcher.to = savedTo;
}
return conditionMatched && next.match(matcher, i, seq);
}
}
/**
* For use with lookbehinds; matches the position where the lookbehind
* was encountered.
*
static class LookBehindEndNode extends Node {
private LookBehindEndNode() {} // Singleton
static LookBehindEndNode INSTANCE = new LookBehindEndNode();
boolean match(Matcher matcher, int i, CharSequence seq) {
return i == matcher.lookbehindTo;
}
}
/**
* Zero width positive lookbehind.
*
static class Behind extends Node {
Node cond;
int rmax, rmin;
Behind(Node cond, int rmax, int rmin) {
this.cond = cond;
this.rmax = rmax;
this.rmin = rmin;
}
boolean match(Matcher matcher, int i, CharSequence seq) {
int savedFrom = matcher.from;
boolean conditionMatched = false;
int startIndex = (!matcher.transparentBounds) ?
matcher.from : 0;
int from = Math.max(i - rmax, startIndex);
// Set end boundary
int savedLBT = matcher.lookbehindTo;
matcher.lookbehindTo = i;
// Relax transparent region boundaries for lookbehind
if (matcher.transparentBounds)
matcher.from = 0;
for (int j = i - rmin; !conditionMatched && j >= from; j--) {
conditionMatched = cond.match(matcher, j, seq);
}
matcher.from = savedFrom;
matcher.lookbehindTo = savedLBT;
return conditionMatched && next.match(matcher, i, seq);
}
}
/**
* Zero width positive lookbehind, including supplementary
* characters or unpaired surrogates.
*
static final class BehindS extends Behind {
BehindS(Node cond, int rmax, int rmin) {
super(cond, rmax, rmin);
}
boolean match(Matcher matcher, int i, CharSequence seq) {
int rmaxChars = countChars(seq, i, -rmax);
int rminChars = countChars(seq, i, -rmin);
int savedFrom = matcher.from;
int startIndex = (!matcher.transparentBounds) ?
matcher.from : 0;
boolean conditionMatched = false;
int from = Math.max(i - rmaxChars, startIndex);
// Set end boundary
int savedLBT = matcher.lookbehindTo;
matcher.lookbehindTo = i;
// Relax transparent region boundaries for lookbehind
if (matcher.transparentBounds)
matcher.from = 0;
for (int j = i - rminChars;
!conditionMatched && j >= from;
j -= j>from ? countChars(seq, j, -1) : 1) {
conditionMatched = cond.match(matcher, j, seq);
}
matcher.from = savedFrom;
matcher.lookbehindTo = savedLBT;
return conditionMatched && next.match(matcher, i, seq);
}
}
/**
* Zero width negative lookbehind.
*
static class NotBehind extends Node {
Node cond;
int rmax, rmin;
NotBehind(Node cond, int rmax, int rmin) {
this.cond = cond;
this.rmax = rmax;
this.rmin = rmin;
}
boolean match(Matcher matcher, int i, CharSequence seq) {
int savedLBT = matcher.lookbehindTo;
int savedFrom = matcher.from;
boolean conditionMatched = false;
int startIndex = (!matcher.transparentBounds) ?
matcher.from : 0;
int from = Math.max(i - rmax, startIndex);
matcher.lookbehindTo = i;
// Relax transparent region boundaries for lookbehind
if (matcher.transparentBounds)
matcher.from = 0;
for (int j = i - rmin; !conditionMatched && j >= from; j--) {
conditionMatched = cond.match(matcher, j, seq);
}
// Reinstate region boundaries
matcher.from = savedFrom;
matcher.lookbehindTo = savedLBT;
return !conditionMatched && next.match(matcher, i, seq);
}
}
/**
* Zero width negative lookbehind, including supplementary
* characters or unpaired surrogates.
*
static final class NotBehindS extends NotBehind {
NotBehindS(Node cond, int rmax, int rmin) {
super(cond, rmax, rmin);
}
boolean match(Matcher matcher, int i, CharSequence seq) {
int rmaxChars = countChars(seq, i, -rmax);
int rminChars = countChars(seq, i, -rmin);
int savedFrom = matcher.from;
int savedLBT = matcher.lookbehindTo;
boolean conditionMatched = false;
int startIndex = (!matcher.transparentBounds) ?
matcher.from : 0;
int from = Math.max(i - rmaxChars, startIndex);
matcher.lookbehindTo = i;
// Relax transparent region boundaries for lookbehind
if (matcher.transparentBounds)
matcher.from = 0;
for (int j = i - rminChars;
!conditionMatched && j >= from;
j -= j>from ? countChars(seq, j, -1) : 1) {
conditionMatched = cond.match(matcher, j, seq);
}
//Reinstate region boundaries
matcher.from = savedFrom;
matcher.lookbehindTo = savedLBT;
return !conditionMatched && next.match(matcher, i, seq);
}
}
/**
* Handles word boundaries. Includes a field to allow this one class to
* deal with the different types of word boundaries we can match. The word
* characters include underscores, letters, and digits. Non spacing marks
* can are also part of a word if they have a base character, otherwise
* they are ignored for purposes of finding word boundaries.
*
static final class Bound extends Node {
static int LEFT = 0x1;
static int RIGHT= 0x2;
static int BOTH = 0x3;
static int NONE = 0x4;
int type;
boolean useUWORD;
Bound(int n, boolean useUWORD) {
type = n;
this.useUWORD = useUWORD;
}
boolean isWord(int ch) {
return useUWORD ? CharPredicates.WORD().is(ch)
: (ch == '_' || Character.isLetterOrDigit(ch));
}
int check(Matcher matcher, int i, CharSequence seq) {
int ch;
boolean left = false;
int startIndex = matcher.from;
int endIndex = matcher.to;
if (matcher.transparentBounds) {
startIndex = 0;
endIndex = matcher.getTextLength();
}
if (i > startIndex) {
ch = Character.codePointBefore(seq, i);
left = (isWord(ch) ||
((Character.getType(ch) == Character.NON_SPACING_MARK)
&& hasBaseCharacter(matcher, i-1, seq)));
}
boolean right = false;
if (i < endIndex) {
ch = Character.codePointAt(seq, i);
right = (isWord(ch) ||
((Character.getType(ch) == Character.NON_SPACING_MARK)
&& hasBaseCharacter(matcher, i, seq)));
} else {
// Tried to access char past the end
matcher.hitEnd = true;
// The addition of another char could wreck a boundary
matcher.requireEnd = true;
}
return ((left ^ right) ? (right ? LEFT : RIGHT) : NONE);
}
boolean match(Matcher matcher, int i, CharSequence seq) {
return (check(matcher, i, seq) & type) > 0
&& next.match(matcher, i, seq);
}
}
/**
* Non spacing marks only count as word characters in bounds calculations
* if they have a base character.
*
private static boolean hasBaseCharacter(Matcher matcher, int i,
CharSequence seq)
{
int start = (!matcher.transparentBounds) ?
matcher.from : 0;
for (int x=i; x >= start; x--) {
int ch = Character.codePointAt(seq, x);
if (Character.isLetterOrDigit(ch))
return true;
if (Character.getType(ch) == Character.NON_SPACING_MARK)
continue;
return false;
}
return false;
}
/**
* Attempts to match a slice in the input using the Boyer-Moore string
* matching algorithm. The algorithm is based on the idea that the
* pattern can be shifted farther ahead in the search text if it is
* matched right to left.
* <p>
* The pattern is compared to the input one character at a time, from
* the rightmost character in the pattern to the left. If the characters
* all match the pattern has been found. If a character does not match,
* the pattern is shifted right a distance that is the maximum of two
* functions, the bad character shift and the good suffix shift. This
* shift moves the attempted match position through the input more
* quickly than a naive one position at a time check.
* <p>
* The bad character shift is based on the character from the text that
* did not match. If the character does not appear in the pattern, the
* pattern can be shifted completely beyond the bad character. If the
* character does occur in the pattern, the pattern can be shifted to
* line the pattern up with the next occurrence of that character.
* <p>
* The good suffix shift is based on the idea that some subset on the right
* side of the pattern has matched. When a bad character is found, the
* pattern can be shifted right by the pattern length if the subset does
* not occur again in pattern, or by the amount of distance to the
* next occurrence of the subset in the pattern.
*
* Boyer-Moore search methods adapted from code by Amy Yu.
*
static class BnM extends Node {
int[] buffer;
int[] lastOcc;
int[] optoSft;
/**
* Pre calculates arrays needed to generate the bad character
* shift and the good suffix shift. Only the last seven bits
* are used to see if chars match; This keeps the tables small
* and covers the heavily used ASCII range, but occasionally
* results in an aliased match for the bad character shift.
*
static Node optimize(Node node) {
if (!(node instanceof Slice)) {
return node;
}
int[] src = ((Slice) node).buffer;
int patternLength = src.length;
// The BM algorithm requires a bit of overhead;
// If the pattern is short don't use it, since
// a shift larger than the pattern length cannot
// be used anyway.
if (patternLength < 4) {
return node;
}
int i, j;
int[] lastOcc = new int[128];
int[] optoSft = new int[patternLength];
// Precalculate part of the bad character shift
// It is a table for where in the pattern each
// lower 7-bit value occurs
for (i = 0; i < patternLength; i++) {
lastOcc[src[i]&0x7F] = i + 1;
}
// Precalculate the good suffix shift
// i is the shift amount being considered
NEXT: for (i = patternLength; i > 0; i--) {
// j is the beginning index of suffix being considered
for (j = patternLength - 1; j >= i; j--) {
// Testing for good suffix
if (src[j] == src[j-i]) {
// src[j..len] is a good suffix
optoSft[j-1] = i;
} else {
// No match. The array has already been
// filled up with correct values before.
continue NEXT;
}
}
// This fills up the remaining of optoSft
// any suffix can not have larger shift amount
// then its sub-suffix. Why???
while (j > 0) {
optoSft[--j] = i;
}
}
// Set the guard value because of unicode compression
optoSft[patternLength-1] = 1;
if (node instanceof SliceS)
return new BnMS(src, lastOcc, optoSft, node.next);
return new BnM(src, lastOcc, optoSft, node.next);
}
BnM(int[] src, int[] lastOcc, int[] optoSft, Node next) {
this.buffer = src;
this.lastOcc = lastOcc;
this.optoSft = optoSft;
this.next = next;
}
boolean match(Matcher matcher, int i, CharSequence seq) {
int[] src = buffer;
int patternLength = src.length;
int last = matcher.to - patternLength;
// Loop over all possible match positions in text
NEXT: while (i <= last) {
// Loop over pattern from right to left
for (int j = patternLength - 1; j >= 0; j--) {
int ch = seq.charAt(i+j);
if (ch != src[j]) {
// Shift search to the right by the maximum of the
// bad character shift and the good suffix shift
i += Math.max(j + 1 - lastOcc[ch&0x7F], optoSft[j]);
continue NEXT;
}
}
// Entire pattern matched starting at i
matcher.first = i;
boolean ret = next.match(matcher, i + patternLength, seq);
if (ret) {
matcher.first = i;
matcher.groups[0] = matcher.first;
matcher.groups[1] = matcher.last;
return true;
}
i++;
}
// BnM is only used as the leading node in the unanchored case,
// and it replaced its Start() which always searches to the end
// if it doesn't find what it's looking for, so hitEnd is true.
matcher.hitEnd = true;
return false;
}
boolean study(TreeInfo info) {
info.minLength += buffer.length;
info.maxValid = false;
return next.study(info);
}
}
/**
* Supplementary support version of BnM(). Unpaired surrogates are
* also handled by this class.
*
static final class BnMS extends BnM {
int lengthInChars;
BnMS(int[] src, int[] lastOcc, int[] optoSft, Node next) {
super(src, lastOcc, optoSft, next);
for (int cp : buffer) {
lengthInChars += Character.charCount(cp);
}
}
boolean match(Matcher matcher, int i, CharSequence seq) {
int[] src = buffer;
int patternLength = src.length;
int last = matcher.to - lengthInChars;
// Loop over all possible match positions in text
NEXT: while (i <= last) {
// Loop over pattern from right to left
int ch;
for (int j = countChars(seq, i, patternLength), x = patternLength - 1;
j > 0; j -= Character.charCount(ch), x--) {
ch = Character.codePointBefore(seq, i+j);
if (ch != src[x]) {
// Shift search to the right by the maximum of the
// bad character shift and the good suffix shift
int n = Math.max(x + 1 - lastOcc[ch&0x7F], optoSft[x]);
i += countChars(seq, i, n);
continue NEXT;
}
}
// Entire pattern matched starting at i
matcher.first = i;
boolean ret = next.match(matcher, i + lengthInChars, seq);
if (ret) {
matcher.first = i;
matcher.groups[0] = matcher.first;
matcher.groups[1] = matcher.last;
return true;
}
i += countChars(seq, i, 1);
}
matcher.hitEnd = true;
return false;
}
}
@FunctionalInterface
static interface CharPredicate {
boolean is(int ch);
default CharPredicate and(CharPredicate p) {
return ch -> is(ch) && p.is(ch);
}
default CharPredicate union(CharPredicate p) {
return ch -> is(ch) || p.is(ch);
}
default CharPredicate union(CharPredicate p1,
CharPredicate p2) {
return ch -> is(ch) || p1.is(ch) || p2.is(ch);
}
default CharPredicate negate() {
return ch -> !is(ch);
}
}
static interface BmpCharPredicate extends CharPredicate {
default CharPredicate and(CharPredicate p) {
if (p instanceof BmpCharPredicate)
return (BmpCharPredicate)(ch -> is(ch) && p.is(ch));
return ch -> is(ch) && p.is(ch);
}
default CharPredicate union(CharPredicate p) {
if (p instanceof BmpCharPredicate)
return (BmpCharPredicate)(ch -> is(ch) || p.is(ch));
return ch -> is(ch) || p.is(ch);
}
static CharPredicate union(CharPredicate... predicates) {
CharPredicate cp = ch -> {
for (CharPredicate p : predicates) {
if (!p.is(ch))
return false;
}
return true;
};
for (CharPredicate p : predicates) {
if (! (p instanceof BmpCharPredicate))
return cp;
}
return (BmpCharPredicate)cp;
}
}
/**
* matches a Perl vertical whitespace
*
static BmpCharPredicate VertWS() {
return cp -> (cp >= 0x0A && cp <= 0x0D) ||
cp == 0x85 || cp == 0x2028 || cp == 0x2029;
}
/**
* matches a Perl horizontal whitespace
*
static BmpCharPredicate HorizWS() {
return cp ->
cp == 0x09 || cp == 0x20 || cp == 0xa0 || cp == 0x1680 ||
cp == 0x180e || cp >= 0x2000 && cp <= 0x200a || cp == 0x202f ||
cp == 0x205f || cp == 0x3000;
}
/**
* for the Unicode category ALL and the dot metacharacter when
* in dotall mode.
*
static CharPredicate ALL() {
return ch -> true;
}
/**
* for the dot metacharacter when dotall is not enabled.
*
static CharPredicate DOT() {
return ch ->
(ch != '\n' && ch != '\r'
&& (ch|1) != '\u2029'
&& ch != '\u0085');
}
/**
* the dot metacharacter when dotall is not enabled but UNIX_LINES is enabled.
*
static CharPredicate UNIXDOT() {
return ch -> ch != '\n';
}
/**
* Indicate that matches a Supplementary Unicode character
*
static CharPredicate SingleS(int c) {
return ch -> ch == c;
}
/**
* A bmp/optimized predicate of single
*
static BmpCharPredicate Single(int c) {
return ch -> ch == c;
}
/**
* Case insensitive matches a given BMP character
*
static BmpCharPredicate SingleI(int lower, int upper) {
return ch -> ch == lower || ch == upper;
}
/**
* Unicode case insensitive matches a given Unicode character
*
static CharPredicate SingleU(int lower) {
return ch -> lower == ch ||
lower == Character.toLowerCase(Character.toUpperCase(ch));
}
private static boolean inRange(int lower, int ch, int upper) {
return lower <= ch && ch <= upper;
}
/**
* Characters within a explicit value range
*
static CharPredicate Range(int lower, int upper) {
if (upper < Character.MIN_HIGH_SURROGATE ||
lower > Character.MAX_LOW_SURROGATE &&
upper < Character.MIN_SUPPLEMENTARY_CODE_POINT)
return (BmpCharPredicate)(ch -> inRange(lower, ch, upper));
return ch -> inRange(lower, ch, upper);
}
/**
* Characters within a explicit value range in a case insensitive manner.
*
static CharPredicate CIRange(int lower, int upper) {
return ch -> inRange(lower, ch, upper) ||
ASCII.isAscii(ch) &&
(inRange(lower, ASCII.toUpper(ch), upper) ||
inRange(lower, ASCII.toLower(ch), upper));
}
static CharPredicate CIRangeU(int lower, int upper) {
return ch -> {
if (inRange(lower, ch, upper))
return true;
int up = Character.toUpperCase(ch);
return inRange(lower, up, upper) ||
inRange(lower, Character.toLowerCase(up), upper);
};
}
/**
* This must be the very first initializer.
*
static final Node accept = new Node();
static final Node lastAccept = new LastNode();
*/
// END Android-removed: Reimplement matching logic via ICU4C.
/**
* Creates a predicate that tests if this pattern is found in a given input
* string.
*
* @apiNote
* This method creates a predicate that behaves as if it creates a matcher
* from the input sequence and then calls {@code find}, for example a
* predicate of the form:
* <pre>{@code
* s -> matcher(s).find();
* }</pre>
*
* @return The predicate which can be used for finding a match on a
* subsequence of a string
* @since 1.8
* @see Matcher#find
*/
public Predicate<String> asPredicate() {
return s -> matcher(s).find();
}
/**
* Creates a predicate that tests if this pattern matches a given input string.
*
* @apiNote
* This method creates a predicate that behaves as if it creates a matcher
* from the input sequence and then calls {@code matches}, for example a
* predicate of the form:
* <pre>{@code
* s -> matcher(s).matches();
* }</pre>
*
* @return The predicate which can be used for matching an input string
* against this pattern.
* @since 11
* @see Matcher#matches
*/
public Predicate<String> asMatchPredicate() {
return s -> matcher(s).matches();
}
/**
* 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 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;
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 (matcher == null) {
matcher = matcher(input);
// If the input is an empty string then the result can only be a
// stream of the input. Induce that by setting the empty
// element count to 1
// Android-changed: Keep old behavior on Android 13 or below. http://b/286499139
// emptyElementCount = input.length() == 0 ? 1 : 0;
if (input.length() == 0
&& VMRuntime.getSdkVersion() >= VersionCodes.UPSIDE_DOWN_CAKE
&& Compatibility.isChangeEnabled(
SPLIT_AS_STREAM_RETURNS_SINGLE_EMPTY_STRING)) {
emptyElementCount = 1;
} else {
emptyElementCount = 0;
}
}
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);
}
// Android-added: Backward-compatible flag for splitAsStream() API.
/**
* Since Android 14, {@link Pattern#splitAsStream(CharSequence)} return a stream of a single
* empty String as described in the API documentation. Previously, given an empty string input,
* the method returns an empty stream.
*
* This flag is enabled for apps targeting Android 14+.
*
* @hide
*/
@ChangeId
@EnabledSince(targetSdkVersion = VersionCodes.UPSIDE_DOWN_CAKE)
public static final long SPLIT_AS_STREAM_RETURNS_SINGLE_EMPTY_STRING = 288845345L;
}
Reference in New Issue View Git Blame Copy Permalink