public final class Pattern

/*
 * Copyright (c) 1999, 2017, Oracle and/or its affiliates. All rights reserved.
 * ORACLE PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
 *
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 */

package java.util.regex;

import java.text.Normalizer;
import java.util.Locale;
import java.util.Iterator;
import java.util.Map;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.Arrays;
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;


/**
 * A compiled representation of a regular expression.
 *
 * 

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. * *

A typical invocation sequence is thus * *

 * Pattern p = Pattern.{@link #compile compile}("a*b");
 * Matcher m = p.{@link #matcher matcher}("aaaaab");
 * boolean b = m.{@link Matcher#matches matches}();
* *

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 * *

 * boolean b = Pattern.matches("a*b", "aaaaab");
* * 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. * *

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. * * *

Summary of regular-expression constructs

* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
ConstructMatches
 
Characters
xThe character x
\\The backslash character
\0nThe character with octal value 0n * (0 <= n <= 7)
\0nnThe character with octal value 0nn * (0 <= n <= 7)
\0mnnThe character with octal value 0mnn * (0 <= m <= 3, * 0 <= n <= 7)
\xhhThe character with hexadecimal value 0xhh
\uhhhhThe character with hexadecimal value 0xhhhh
\x{h...h}The character with hexadecimal value 0xh...h * ({@link java.lang.Character#MIN_CODE_POINT Character.MIN_CODE_POINT} *  <= 0xh...h <=  * {@link java.lang.Character#MAX_CODE_POINT Character.MAX_CODE_POINT})
\tThe tab character ('\u0009')
\nThe newline (line feed) character ('\u000A')
\rThe carriage-return character ('\u000D')
\fThe form-feed character ('\u000C')
\aThe alert (bell) character ('\u0007')
\eThe escape character ('\u001B')
\cxThe control character corresponding to x
 
Character classes
{@code [abc]}{@code a}, {@code b}, or {@code c} (simple class)
{@code [^abc]}Any character except {@code a}, {@code b}, or {@code c} (negation)
{@code [a-zA-Z]}{@code a} through {@code z} * or {@code A} through {@code Z}, inclusive (range)
{@code [a-d[m-p]]}{@code a} through {@code d}, * or {@code m} through {@code p}: {@code [a-dm-p]} (union)
{@code [a-z&&[def]]}{@code d}, {@code e}, or {@code f} (intersection)
{@code [a-z&&[^bc]]}{@code a} through {@code z}, * except for {@code b} and {@code c}: {@code [ad-z]} (subtraction)
{@code [a-z&&[^m-p]]}{@code a} through {@code z}, * and not {@code m} through {@code p}: {@code [a-lq-z]}(subtraction)
 
Predefined character classes
.Any character (may or may not match line terminators)
\dA digit: [0-9]
\DA non-digit: [^0-9]
\hA horizontal whitespace character: * [ \t\xA0\u1680\u180e\u2000-\u200a\u202f\u205f\u3000]
\HA non-horizontal whitespace character: [^\h]
\sA whitespace character: [ \t\n\x0B\f\r]
\SA non-whitespace character: [^\s]
\vA vertical whitespace character: [\n\x0B\f\r\x85\u2028\u2029] *
\VA non-vertical whitespace character: [^\v]
\wA word character: [a-zA-Z_0-9]
\WA non-word character: [^\w]
 
POSIX character classes (US-ASCII only)
{@code \p{Lower}}A lower-case alphabetic character: {@code [a-z]}
{@code \p{Upper}}An upper-case alphabetic character:{@code [A-Z]}
{@code \p{ASCII}}All ASCII:{@code [\x00-\x7F]}
{@code \p{Alpha}}An alphabetic character:{@code [\p{Lower}\p{Upper}]}
{@code \p{Digit}}A decimal digit: {@code [0-9]}
{@code \p{Alnum}}An alphanumeric character:{@code [\p{Alpha}\p{Digit}]}
{@code \p{Punct}}Punctuation: One of {@code !"#$%&'()*+,-./:;<=>?@[\]^_`{|}~}
{@code \p{Graph}}A visible character: {@code [\p{Alnum}\p{Punct}]}
{@code \p{Print}}A printable character: {@code [\p{Graph}\x20]}
{@code \p{Blank}}A space or a tab: {@code [ \t]}
{@code \p{Cntrl}}A control character: {@code [\x00-\x1F\x7F]}
{@code \p{XDigit}}A hexadecimal digit: {@code [0-9a-fA-F]}
{@code \p{Space}}A whitespace character: {@code [ \t\n\x0B\f\r]}
 
java.lang.Character classes (simple java character type)
\p{javaLowerCase}Equivalent to java.lang.Character.isLowerCase()
\p{javaUpperCase}Equivalent to java.lang.Character.isUpperCase()
\p{javaWhitespace}Equivalent to java.lang.Character.isWhitespace()
\p{javaMirrored}Equivalent to java.lang.Character.isMirrored()
 
Classes for Unicode scripts, blocks, categories and binary properties
{@code \p{IsLatin}}A Latin script character (script)
{@code \p{InGreek}}A character in the Greek block (block)
{@code \p{Lu}}An uppercase letter (category)
{@code \p{IsAlphabetic}}An alphabetic character (binary property)
{@code \p{Sc}}A currency symbol
{@code \P{InGreek}}Any character except one in the Greek block (negation)
{@code [\p{L}&&[^\p{Lu}]]}Any letter except an uppercase letter (subtraction)
 
Boundary matchers
^The beginning of a line
$The end of a line
\bA word boundary
\BA non-word boundary
\AThe beginning of the input
\GThe end of the previous match
\ZThe end of the input but for the final * terminator, if any
\zThe end of the input
 
Linebreak matcher
\RAny Unicode linebreak sequence, is equivalent to * \u000D\u000A|[\u000A\u000B\u000C\u000D\u0085\u2028\u2029] *
 
Greedy quantifiers
X?X, once or not at all
X*X, zero or more times
X+X, one or more times
X{n}X, exactly n times
X{n,}X, at least n times
X{n,m}X, at least n but not more than m times
 
Reluctant quantifiers
X??X, once or not at all
X*?X, zero or more times
X+?X, one or more times
X{n}?X, exactly n times
X{n,}?X, at least n times
X{n,m}?X, at least n but not more than m times
 
Possessive quantifiers
X?+X, once or not at all
X*+X, zero or more times
X++X, one or more times
X{n}+X, exactly n times
X{n,}+X, at least n times
X{n,m}+X, at least n but not more than m times
 
Logical operators
XYX followed by Y
X|YEither X or Y
(X)X, as a capturing group
 
Back references
\nWhatever the nth * capturing group matched
\k<name>Whatever the * named-capturing group "name" matched
 
Quotation
\Nothing, but quotes the following character
\QNothing, but quotes all characters until \E
\ENothing, but ends quoting started by \Q
 
Special constructs (named-capturing and non-capturing)
(?<name>X)X, as a named-capturing group
(?:X)X, as a non-capturing group
(?idmsuxU-idmsuxU) Nothing, but turns match flags i * d m s * u x U * on - off
(?idmsux-idmsux:X)  X, as a non-capturing group with the * given flags i d * m s u * x on - off
(?=X)X, via zero-width positive lookahead
(?!X)X, via zero-width negative lookahead
(?<=X)X, via zero-width positive lookbehind
(?<!X)X, via zero-width negative lookbehind
(?>X)X, as an independent, non-capturing group
* *
* * *

Backslashes, escapes, and quoting

* *

The backslash character ('\') 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 \\ matches a single backslash and \{ matches a * left brace. * *

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. * *

Backslashes within string literals in Java source code are interpreted * as required by * The Java™ Language Specification * as either Unicode escapes (section 3.3) or other character escapes (section 3.10.6) * It is therefore necessary to double backslashes in string * literals that represent regular expressions to protect them from * interpretation by the Java bytecode compiler. The string literal * "\b", for example, matches a single backspace character when * interpreted as a regular expression, while "\\b" matches a * word boundary. The string literal "\(hello\)" is illegal * and leads to a compile-time error; in order to match the string * (hello) the string literal "\\(hello\\)" * must be used. * *

Character Classes

* *

Character classes may appear within other character classes, and * may be composed by the union operator (implicit) and the intersection * operator (&&). * 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. * *

The precedence of character-class operators is as follows, from * highest to lowest: * *

* * * * * * * * * * * * * * * *
1    Literal escape    \x
2    Grouping[...]
3    Rangea-z
4    Union[a-e][i-u]
5    Intersection{@code [a-z&&[aeiou]]}
* *

Note that a different set of metacharacters are in effect inside * a character class than outside a character class. For instance, the * regular expression . loses its special meaning inside a * character class, while the expression - becomes a range * forming metacharacter. * *

Line terminators

* *

A line terminator 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: * *

    * *
  • A newline (line feed) character ('\n'), * *
  • A carriage-return character followed immediately by a newline * character ("\r\n"), * *
  • A standalone carriage-return character ('\r'), * *
  • A next-line character ('\u0085'), * *
  • A line-separator character ('\u2028'), or * *
  • A paragraph-separator character ('\u2029). * *
*

If {@link #UNIX_LINES} mode is activated, then the only line terminators * recognized are newline characters. * *

The regular expression . matches any character except a line * terminator unless the {@link #DOTALL} flag is specified. * *

By default, the regular expressions ^ and $ 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 * ^ matches at the beginning of input and after any line terminator * except at the end of input. When in {@link #MULTILINE} mode $ * matches just before a line terminator or the end of the input sequence. * *

Groups and capturing

* *

Group number

*

Capturing groups are numbered by counting their opening parentheses from * left to right. In the expression ((A)(B(C))), for example, there * are four such groups:

* *
* * * * * * * * *
1    ((A)(B(C)))
2    (A)
3    (B(C))
4    (C)
* *

Group zero always stands for the entire expression. * *

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. * *

Group name

*

A capturing group can also be assigned a "name", a 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 letter. * *

    *
  • The uppercase letters 'A' through 'Z' * ('\u0041' through '\u005a'), *
  • The lowercase letters 'a' through 'z' * ('\u0061' through '\u007a'), *
  • The digits '0' through '9' * ('\u0030' through '\u0039'), *
* *

A named-capturing group is still numbered as described in * Group number. * *

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 * "aba" against the expression (a(b)?)+, for example, leaves * group two set to "b". All captured input is discarded at the * beginning of each match. * *

Groups beginning with (? are either pure, non-capturing groups * that do not capture text and do not count towards the group total, or * named-capturing group. * *

Unicode support

* *

This class is in conformance with Level 1 of Unicode Technical * Standard #18: Unicode Regular Expression, plus RL2.1 * Canonical Equivalents. *

* Unicode escape sequences such as \u2014 in Java source code * are processed as described in section 3.3 of * The Java™ Language Specification. * 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 "\u2014" and * "\\u2014", while not equal, compile into the same pattern, which * matches the character with hexadecimal value 0x2014. *

* A Unicode character can also be represented in a regular-expression by * using its Hex notation(hexadecimal code point value) directly as described in construct * \x{...}, for example a supplementary character U+2011F * can be specified as \x{2011F}, instead of two consecutive * Unicode escape sequences of the surrogate pair * \uD840\uDD1F. *

* Unicode scripts, blocks, categories and binary properties are written with * the \p and \P constructs as in Perl. * \p{prop} matches if * the input has the property prop, while \P{prop} * does not match if the input has that property. *

* Scripts, blocks, categories and binary properties can be used both inside * and outside of a character class. * *

* Scripts are specified either with the prefix {@code Is}, as in * {@code IsHiragana}, or by using the {@code script} keyword (or its short * form {@code sc})as in {@code script=Hiragana} or {@code sc=Hiragana}. *

* The script names supported by Pattern are the valid script names * accepted and defined by * {@link java.lang.Character.UnicodeScript#forName(String) UnicodeScript.forName}. * *

* Blocks 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}. *

* The block names supported by Pattern are the valid block names * accepted and defined by * {@link java.lang.Character.UnicodeBlock#forName(String) UnicodeBlock.forName}. *

* * Categories may be specified with the optional prefix {@code Is}: * Both {@code \p{L}} and {@code \p{IsL}} denote the category of Unicode * letters. Same as scripts and blocks, categories can also be specified * by using the keyword {@code general_category} (or its short form * {@code gc}) as in {@code general_category=Lu} or {@code gc=Lu}. *

* The supported categories are those of * * The Unicode Standard 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. *

* * Binary properties are specified with the prefix {@code Is}, as in * {@code IsAlphabetic}. The supported binary properties by Pattern * are *

    *
  • Alphabetic *
  • Ideographic *
  • Letter *
  • Lowercase *
  • Uppercase *
  • Titlecase *
  • Punctuation *
  • Control *
  • White_Space *
  • Digit *
  • Hex_Digit *
  • Join_Control *
  • Noncharacter_Code_Point *
  • Assigned *
*

* The following Predefined Character classes and POSIX character classes * are in conformance with the recommendation of Annex C: Compatibility Properties * of Unicode Regular Expression * , when {@link #UNICODE_CHARACTER_CLASS} flag is specified. * *

* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
ClassesMatches
\p{Lower}A lowercase character:\p{IsLowercase}
\p{Upper}An uppercase character:\p{IsUppercase}
\p{ASCII}All ASCII:[\x00-\x7F]
\p{Alpha}An alphabetic character:\p{IsAlphabetic}
\p{Digit}A decimal digit character:p{IsDigit}
\p{Alnum}An alphanumeric character:[\p{IsAlphabetic}\p{IsDigit}]
\p{Punct}A punctuation character:p{IsPunctuation}
\p{Graph}A visible character: [^\p{IsWhite_Space}\p{gc=Cc}\p{gc=Cs}\p{gc=Cn}]
\p{Print}A printable character: {@code [\p{Graph}\p{Blank}&&[^\p{Cntrl}]]}
\p{Blank}A space or a tab: {@code [\p{IsWhite_Space}&&[^\p{gc=Zl}\p{gc=Zp}\x0a\x0b\x0c\x0d\x85]]}
\p{Cntrl}A control character: \p{gc=Cc}
\p{XDigit}A hexadecimal digit: [\p{gc=Nd}\p{IsHex_Digit}]
\p{Space}A whitespace character:\p{IsWhite_Space}
\dA digit: \p{IsDigit}
\DA non-digit: [^\d]
\sA whitespace character: \p{IsWhite_Space}
\SA non-whitespace character: [^\s]
\wA word character: [\p{Alpha}\p{gc=Mn}\p{gc=Me}\p{gc=Mc}\p{Digit}\p{gc=Pc}\p{IsJoin_Control}]
\WA non-word character: [^\w]
*

* * Categories that behave like the java.lang.Character * boolean ismethodname methods (except for the deprecated ones) are * available through the same \p{prop} syntax where * the specified property has the name javamethodname. * *

Comparison to Perl 5

* *

The Pattern engine performs traditional NFA-based matching * with ordered alternation as occurs in Perl 5. * *

Perl constructs not supported by this class:

* *
    *
  • Predefined character classes (Unicode character) *

    \X    Match Unicode * * extended grapheme cluster *

  • * *
  • The backreference constructs, \g{n} for * the nthcapturing group and * \g{name} for * named-capturing group. *

  • * *
  • The named character construct, \N{name} * for a Unicode character by its name. *

  • * *
  • The conditional constructs * (?(condition)X) and * (?(condition)X|Y), *

  • * *
  • The embedded code constructs (?{code}) * and (??{code}),

  • * *
  • The embedded comment syntax (?#comment), and

  • * *
  • The preprocessing operations \l \u, * \L, and \U.

  • * *
* *

Constructs supported by this class but not by Perl:

* *
    * *
  • Character-class union and intersection as described * above.

  • * *
* *

Notable differences from Perl:

* *
    * *
  • In Perl, \1 through \9 are always interpreted * as back references; a backslash-escaped number greater than 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, * \1 through \9 are always interpreted as back * references, and a larger number is accepted as a back reference if at * least that many subexpressions exist at that point in the regular * expression, otherwise the parser will drop digits until the number is * smaller or equal to the existing number of groups or it is one digit. *

  • * *
  • Perl uses the 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.

  • * *
  • 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.

  • * *
* * *

For a more precise description of the behavior of regular expression * constructs, please see * Mastering Regular Expressions, 3nd Edition, Jeffrey E. F. Friedl, * O'Reilly and Associates, 2006. *

* * @see java.lang.String#split(String, int) * @see java.lang.String#split(String) * * @author Mike McCloskey * @author Mark Reinhold * @author JSR-51 Expert Group * @since 1.4 * @spec JSR-51 */ public final class Pattern implements java.io.Serializable { /** * Regular expression modifier values. Instead of being passed as * arguments, they can also be passed as inline modifiers. * For example, the following statements have the same effect. *
     * RegExp r1 = RegExp.compile("abc", Pattern.I|Pattern.M);
     * RegExp r2 = RegExp.compile("(?im)abc", 0);
     * 
* * The flags are duplicated so that the familiar Perl match flag * names are available. */ /** * Enables Unix lines mode. * *

In this mode, only the '\n' line terminator is recognized * in the behavior of ., ^, and $. * *

Unix lines mode can also be enabled via the embedded flag * expression (?d). */ public static final int UNIX_LINES = 0x01; /** * Enables case-insensitive matching. * *

By default, case-insensitive matching assumes that only characters * in the US-ASCII charset are being matched. Unicode-aware * case-insensitive matching can be enabled by specifying the {@link * #UNICODE_CASE} flag in conjunction with this flag. * *

Case-insensitive matching can also be enabled via the embedded flag * expression (?i). * *

Specifying this flag may impose a slight performance penalty.

*/ public static final int CASE_INSENSITIVE = 0x02; /** * Permits whitespace and comments in pattern. * *

In this mode, whitespace is ignored, and embedded comments starting * with # are ignored until the end of a line. * *

Comments mode can also be enabled via the embedded flag * expression (?x). */ public static final int COMMENTS = 0x04; /** * Enables multiline mode. * *

In multiline mode the expressions ^ and $ 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. * *

Multiline mode can also be enabled via the embedded flag * expression (?m).

*/ public static final int MULTILINE = 0x08; /** * Enables literal parsing of the pattern. * *

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. * *

The flags CASE_INSENSITIVE and UNICODE_CASE retain their impact on * matching when used in conjunction with this flag. The other flags * become superfluous. * *

There is no embedded flag character for enabling literal parsing. * @since 1.5 */ public static final int LITERAL = 0x10; /** * Enables dotall mode. * *

In dotall mode, the expression . matches any character, * including a line terminator. By default this expression does not match * line terminators. * *

Dotall mode can also be enabled via the embedded flag * expression (?s). (The s is a mnemonic for * "single-line" mode, which is what this is called in Perl.)

*/ public static final int DOTALL = 0x20; /** * Enables Unicode-aware case folding. * *

When this flag is specified then case-insensitive matching, when * enabled by the {@link #CASE_INSENSITIVE} flag, is done in a manner * consistent with the Unicode Standard. By default, case-insensitive * matching assumes that only characters in the US-ASCII charset are being * matched. * *

Unicode-aware case folding can also be enabled via the embedded flag * expression (?u). * *

Specifying this flag may impose a performance penalty.

*/ public static final int UNICODE_CASE = 0x40; /** * Enables canonical equivalence. * *

When this flag is specified then two characters will be considered * to match if, and only if, their full canonical decompositions match. * The expression "a\u030A", for example, will match the * string "\u00E5" when this flag is specified. By default, * matching does not take canonical equivalence into account. * *

There is no embedded flag character for enabling canonical * equivalence. * *

Specifying this flag may impose a performance penalty.

*/ public static final int CANON_EQ = 0x80; /** * Enables the Unicode version of Predefined character classes and * POSIX character classes. * *

When this flag is specified then the (US-ASCII only) * Predefined character classes and POSIX character classes * are in conformance with * Unicode Technical * Standard #18: Unicode Regular Expression * Annex C: Compatibility Properties. *

* The UNICODE_CHARACTER_CLASS mode can also be enabled via the embedded * flag expression (?U). *

* The flag implies UNICODE_CASE, that is, it enables Unicode-aware case * folding. *

* Specifying this flag may impose a performance penalty.

* @since 1.7 */ public static final int UNICODE_CHARACTER_CLASS = 0x100; /* Pattern has only two serialized components: The pattern string * and the flags, which are all that is needed to recompile the pattern * when it is deserialized. */ /** use serialVersionUID from Merlin b59 for interoperability */ private static final long serialVersionUID = 5073258162644648461L; /** * The original regular-expression pattern string. * * @serial */ private String pattern; /** * The original pattern flags. * * @serial */ private int flags; /** * Boolean indicating this Pattern is compiled; this is necessary in order * to lazily compile deserialized Patterns. */ private transient volatile boolean compiled = false; /** * The normalized pattern string. */ private transient String normalizedPattern; /** * The starting point of state machine for the find operation. This allows * a match to start anywhere in the input. */ transient Node root; /** * The root of object tree for a match operation. The pattern is matched * at the beginning. This may include a find that uses BnM or a First * node. */ transient Node matchRoot; /** * Temporary storage used by parsing pattern slice. */ transient int[] buffer; /** * Map the "name" of the "named capturing group" to its group id * node. */ transient volatile Map namedGroups; /** * Temporary storage used while parsing group references. */ transient GroupHead[] groupNodes; /** * Temporary null terminated code point array used by pattern compiling. */ private transient int[] temp; /** * The number of capturing groups in this Pattern. Used by matchers to * allocate storage needed to perform a match. */ transient int capturingGroupCount; /** * The local variable count used by parsing tree. Used by matchers to * allocate storage needed to perform a match. */ transient int localCount; /** * Index into the pattern string that keeps track of how much has been * parsed. */ private transient int cursor; /** * Holds the length of the pattern string. */ private transient int patternLength; /** * If the Start node might possibly match supplementary characters. * It is set to true during compiling if * (1) There is supplementary char in pattern, or * (2) There is complement node of Category or Block */ private transient boolean hasSupplementary; /** * 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); } /** * 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 #CANON_EQ}, {@link #UNIX_LINES}, * {@link #LITERAL}, {@link #UNICODE_CHARACTER_CLASS} * 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 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; } /** *

Returns the string representation of this pattern. This * is the regular expression from which this pattern was * compiled.

* * @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) { 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() { return flags; } /** * Compiles the given regular expression and attempts to match the given * input against it. * *

An invocation of this convenience method of the form * *

     * Pattern.matches(regex, input);
* * behaves in exactly the same way as the expression * *
     * Pattern.compile(regex).matcher(input).matches()
* *

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.

* * @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(); } /** * Splits the given input sequence around matches of this pattern. * *

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. * *

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 * never produces such empty leading substring. * *

The limit parameter controls the number of times the * pattern is applied and therefore affects the length of the resulting * array. If the limit n is greater than zero then the pattern * will be applied at most n - 1 times, the array's * length will be no greater than n, and the array's last entry * will contain all input beyond the last matched delimiter. If n * is non-positive then the pattern will be applied as many times as * possible and the array can have any length. If n 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. * *

The input "boo:and:foo", for example, yields the following * results with these parameters: * *

* * * * * * * * * * * * * * * * * * * * * *
Regex    Limit    Result    
:2{ "boo", "and:foo" }
:5{ "boo", "and", "foo" }
:-2{ "boo", "and", "foo" }
o5{ "b", "", ":and:f", "", "" }
o-2{ "b", "", ":and:f", "", "" }
o0{ "b", "", ":and:f" }
* * @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) { int index = 0; boolean matchLimited = limit > 0; ArrayList 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. continue; } String match = input.subSequence(index, m.start()).toString(); matchList.add(match); index = m.end(); } else if (matchList.size() == limit - 1) { // last one String match = input.subSequence(index, input.length()).toString(); matchList.add(match); index = m.end(); } } // If no match was found, return this if (index == 0) return new String[] {input.toString()}; // Add remaining segment if (!matchLimited || matchList.size() < limit) matchList.add(input.subSequence(index, input.length()).toString()); // Construct result int resultSize = matchList.size(); if (limit == 0) while (resultSize > 0 && matchList.get(resultSize-1).equals("")) resultSize--; String[] result = new String[resultSize]; return matchList.subList(0, resultSize).toArray(result); } /** * Splits the given input sequence around matches of this pattern. * *

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.

* *

The input "boo:and:foo", for example, yields the following * results with these expressions: * *

* * * * * * *
Regex    Result
:{ "boo", "and", "foo" }
o{ "b", "", ":and:f" }
* * * @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 String for the specified * String. * *

This method produces a String that can be used to * create a Pattern that would match the string * s as if it were a literal pattern.

Metacharacters * or escape sequences in the input sequence will be given no special * meaning. * * @param s The string to be literalized * @return A literal string replacement * @since 1.5 */ public static String quote(String s) { int slashEIndex = s.indexOf("\\E"); if (slashEIndex == -1) return "\\Q" + s + "\\E"; StringBuilder sb = new StringBuilder(s.length() * 2); sb.append("\\Q"); slashEIndex = 0; int current = 0; while ((slashEIndex = s.indexOf("\\E", current)) != -1) { sb.append(s.substring(current, slashEIndex)); current = slashEIndex + 2; sb.append("\\E\\\\E\\Q"); } sb.append(s.substring(current, s.length())); sb.append("\\E"); return sb.toString(); } /** * Recompile the Pattern instance from a stream. The original pattern * string is read in and the object tree is recompiled from it. */ private void readObject(java.io.ObjectInputStream s) throws java.io.IOException, ClassNotFoundException { // Read in all fields s.defaultReadObject(); // Initialize counts capturingGroupCount = 1; localCount = 0; // if length > 0, the Pattern is lazily compiled compiled = false; if (pattern.length() == 0) { root = new Start(lastAccept); matchRoot = lastAccept; compiled = true; } } /** * 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. An empty pattern string results in an object tree with * only a Start node and a LastNode node. */ private Pattern(String p, int f) { pattern = p; flags = f; // to use UNICODE_CASE if UNICODE_CHARACTER_CLASS present if ((flags & UNICODE_CHARACTER_CLASS) != 0) flags |= UNICODE_CASE; // Reset group index count capturingGroupCount = 1; localCount = 0; if (pattern.length() > 0) { compile(); } else { root = new Start(lastAccept); matchRoot = lastAccept; } } /** * The pattern is converted to normalizedD form and then a pure group * is constructed to match canonical equivalences of the characters. */ private void normalize() { boolean inCharClass = false; int lastCodePoint = -1; // Convert pattern into normalizedD form normalizedPattern = Normalizer.normalize(pattern, Normalizer.Form.NFD); patternLength = normalizedPattern.length(); // Modify pattern to match canonical equivalences StringBuilder newPattern = new StringBuilder(patternLength); for(int i=0; i= patternLength) break; c = normalizedPattern.codePointAt(i); sequenceBuffer.appendCodePoint(c); } String ea = produceEquivalentAlternation( sequenceBuffer.toString()); newPattern.setLength(newPattern.length()-Character.charCount(lastCodePoint)); newPattern.append("(?:").append(ea).append(")"); } else if (c == '[' && lastCodePoint != '\\') { i = normalizeCharClass(newPattern, i); } else { newPattern.appendCodePoint(c); } lastCodePoint = c; i += Character.charCount(c); } normalizedPattern = newPattern.toString(); } /** * Complete the character class being parsed and add a set * of alternations to it that will match the canonical equivalences * of the characters within the class. */ private int normalizeCharClass(StringBuilder newPattern, int i) { StringBuilder charClass = new StringBuilder(); StringBuilder eq = null; int lastCodePoint = -1; String result; i++; if (i == normalizedPattern.length()) throw error("Unclosed character class"); charClass.append("["); while(true) { int c = normalizedPattern.codePointAt(i); StringBuilder sequenceBuffer; if (c == ']' && lastCodePoint != '\\') { charClass.append((char)c); break; } else if (Character.getType(c) == Character.NON_SPACING_MARK) { sequenceBuffer = new StringBuilder(); sequenceBuffer.appendCodePoint(lastCodePoint); while(Character.getType(c) == Character.NON_SPACING_MARK) { sequenceBuffer.appendCodePoint(c); i += Character.charCount(c); if (i >= normalizedPattern.length()) break; c = normalizedPattern.codePointAt(i); } String ea = produceEquivalentAlternation( sequenceBuffer.toString()); charClass.setLength(charClass.length()-Character.charCount(lastCodePoint)); if (eq == null) eq = new StringBuilder(); eq.append('|'); eq.append(ea); } else { charClass.appendCodePoint(c); i++; } if (i == normalizedPattern.length()) throw error("Unclosed character class"); lastCodePoint = c; } if (eq != null) { result = "(?:"+charClass.toString()+eq.toString()+")"; } else { result = charClass.toString(); } newPattern.append(result); return i; } /** * 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 String produceEquivalentAlternation(String source) { int len = countChars(source, 0, 1); if (source.length() == len) // source has one character. return source; String base = source.substring(0,len); String combiningMarks = source.substring(len); String[] perms = producePermutations(combiningMarks); StringBuilder result = new StringBuilder(source); // Add combined permutations for(int x=0; x0) result.append("|"+next); next = composeOneStep(next); if (next != null) result.append("|"+produceEquivalentAlternation(next)); } return result.toString(); } /** * 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 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=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(int y=0; y= pLen - 1) // No \Q sequence found return; int j = i; i += 2; int[] newtemp = new int[j + 3*(pLen-i) + 2]; 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)) { normalize(); } 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; 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); } // Release temporary storage temp = null; buffer = null; groupNodes = null; patternLength = 0; compiled = true; } Map namedGroups() { if (namedGroups == null) namedGroups = new HashMap<>(2); return namedGroups; } /** * Used to print out a subtree of the Pattern to help with debugging. */ private static void printObjectTree(Node node) { while(node != null) { if (node instanceof Prolog) { System.out.println(node); printObjectTree(((Prolog)node).loop); System.out.println("**** end contents prolog loop"); } else if (node instanceof Loop) { System.out.println(node); printObjectTree(((Loop)node).body); System.out.println("**** end contents Loop body"); } else if (node instanceof Curly) { System.out.println(node); printObjectTree(((Curly)node).atom); System.out.println("**** end contents Curly body"); } else if (node instanceof GroupCurly) { System.out.println(node); printObjectTree(((GroupCurly)node).atom); System.out.println("**** end contents GroupCurly body"); } else if (node instanceof GroupTail) { System.out.println(node); System.out.println("Tail next is "+node.next); return; } else { System.out.println(node); } node = node.next; if (node != null) System.out.println("->next:"); if (node == Pattern.accept) { System.out.println("Accept Node"); node = null; } } } /** * 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 (flags & 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++]; 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]; 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 = null; 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 '[': node = 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 = 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 '$': next(); if (has(UNIX_LINES)) node = new UnixDollar(has(MULTILINE)); else node = new Dollar(has(MULTILINE)); break; case '.': next(); if (has(DOTALL)) { node = new All(); } else { if (has(UNIX_LINES)) node = new UnixDot(); else { node = new Dot(); } } break; case '|': case ')': break LOOP; case ']': // Now interpreting dangling ] and } as literals case '}': node = atom(); break; case '?': case '*': case '+': next(); throw error("Dangling meta character '" + ((char)ch) + "'"); case 0: if (cursor >= patternLength) { break LOOP; } // Fall through default: node = atom(); break; } node = closure(node); if (head == null) { head = tail = node; } else { tail.next = node; tail = node; } } if (head == null) { return end; } tail.next = end; root = tail; //double return return head; } @SuppressWarnings("fallthrough") /** * Parse and add a new Single or Slice. */ private Node atom() { int first = 0; int prev = -1; boolean hasSupplementary = false; int ch = peek(); for (;;) { switch (ch) { case '*': case '+': case '?': case '{': if (first > 1) { cursor = prev; // Unwind one character first--; } break; case '$': 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; return 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 newSingle(buffer[0]); } else { return newSlice(buffer, first, hasSupplementary); } } private void append(int ch, int len) { if (len >= buffer.length) { int[] tmp = new int[len+len]; System.arraycopy(buffer, 0, tmp, 0, len); buffer = tmp; } buffer[len] = 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': case '1': case '2': case '3': case '4': case '5': case '6': case '7': case '8': case '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(); break; default: done = true; break; } } 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) root = has(UNICODE_CHARACTER_CLASS) ? new Utype(UnicodeProp.DIGIT).complement() : new Ctype(ASCII.DIGIT).complement(); return -1; case 'E': case 'F': break; case 'G': if (inclass) break; if (create) root = new LastMatch(); return -1; case 'H': if (create) root = new HorizWS().complement(); return -1; case 'I': case 'J': case 'K': case 'L': case 'M': case 'N': case 'O': case 'P': case 'Q': break; case 'R': if (inclass) break; if (create) root = new LineEnding(); return -1; case 'S': if (create) root = has(UNICODE_CHARACTER_CLASS) ? new Utype(UnicodeProp.WHITE_SPACE).complement() : new Ctype(ASCII.SPACE).complement(); return -1; case 'T': case 'U': break; case 'V': if (create) root = new VertWS().complement(); return -1; case 'W': if (create) root = has(UNICODE_CHARACTER_CLASS) ? new Utype(UnicodeProp.WORD).complement() : new Ctype(ASCII.WORD).complement(); return -1; case 'X': 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) root = new Bound(Bound.BOTH, has(UNICODE_CHARACTER_CLASS)); return -1; case 'c': return c(); case 'd': if (create) root = has(UNICODE_CHARACTER_CLASS) ? new Utype(UnicodeProp.DIGIT) : new Ctype(ASCII.DIGIT); return -1; case 'e': return '\033'; case 'f': return '\f'; case 'g': break; case 'h': if (create) root = new HorizWS(); 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 exit"); if (create) { 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) root = has(UNICODE_CHARACTER_CLASS) ? new Utype(UnicodeProp.WHITE_SPACE) : new Ctype(ASCII.SPACE); 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) root = new VertWS(); return -1; case 'w': if (create) root = has(UNICODE_CHARACTER_CLASS) ? new Utype(UnicodeProp.WORD) : new Ctype(ASCII.WORD); 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 CharProperty clazz(boolean consume) { CharProperty prev = null; CharProperty node = null; BitClass bits = new BitClass(); boolean include = true; boolean firstInClass = true; int ch = next(); for (;;) { switch (ch) { case '^': // Negates if first char in a class, otherwise literal if (firstInClass) { if (temp[cursor-1] != '[') break; ch = next(); include = !include; continue; } else { // ^ not first in class, treat as literal break; } case '[': firstInClass = false; node = clazz(true); if (prev == null) prev = node; else prev = union(prev, node); ch = peek(); continue; case '&': firstInClass = false; ch = next(); if (ch == '&') { ch = next(); CharProperty rightNode = null; while (ch != ']' && ch != '&') { if (ch == '[') { if (rightNode == null) rightNode = clazz(true); else rightNode = union(rightNode, clazz(true)); } else { // abc&&def unread(); rightNode = clazz(false); } ch = peek(); } if (rightNode != null) node = rightNode; if (prev == null) { if (rightNode == null) throw error("Bad class syntax"); else prev = rightNode; } else { prev = intersection(prev, node); } } else { // treat as a literal & unread(); break; } continue; case 0: firstInClass = false; if (cursor >= patternLength) throw error("Unclosed character class"); break; case ']': firstInClass = false; if (prev != null) { if (consume) next(); return prev; } break; default: firstInClass = false; break; } node = range(bits); if (include) { if (prev == null) { prev = node; } else { if (prev != node) prev = union(prev, node); } } else { if (prev == null) { prev = node.complement(); } else { if (prev != node) prev = setDifference(prev, node); } } ch = peek(); } } private CharProperty 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 */ int d; 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 return bits.add(ch, flags()); return newSingle(ch); } /** * Parse a single character or a character range in a character class * and return its representative node. */ private CharProperty 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 (CharProperty) root; } } 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)) return caseInsensitiveRangeFor(ch, m); else return rangeFor(ch, m); } } return bitsOrSingle(bits, ch); } throw error("Unexpected character '"+((char)ch)+"'"); } /** * Parses a Unicode character family and returns its representative node. */ private CharProperty family(boolean singleLetter, boolean maybeComplement) { next(); String name; CharProperty node = 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); if ("sc".equals(name) || "script".equals(name)) { node = unicodeScriptPropertyFor(value); } else if ("blk".equals(name) || "block".equals(name)) { node = unicodeBlockPropertyFor(value); } else if ("gc".equals(name) || "general_category".equals(name)) { node = charPropertyNodeFor(value); } else { throw error("Unknown Unicode property {name=<" + name + ">, " + "value=<" + value + ">}"); } } else { if (name.startsWith("In")) { // \p{inBlockName} node = unicodeBlockPropertyFor(name.substring(2)); } else if (name.startsWith("Is")) { // \p{isGeneralCategory} and \p{isScriptName} name = name.substring(2); UnicodeProp uprop = UnicodeProp.forName(name); if (uprop != null) node = new Utype(uprop); if (node == null) node = CharPropertyNames.charPropertyFor(name); if (node == null) node = unicodeScriptPropertyFor(name); } else { if (has(UNICODE_CHARACTER_CLASS)) { UnicodeProp uprop = UnicodeProp.forPOSIXName(name); if (uprop != null) node = new Utype(uprop); } if (node == null) node = charPropertyNodeFor(name); } } if (maybeComplement) { if (node instanceof Category || node instanceof Block) hasSupplementary = true; node = node.complement(); } return node; } /** * Returns a CharProperty matching all characters belong to * a UnicodeScript. */ private CharProperty unicodeScriptPropertyFor(String name) { final Character.UnicodeScript script; try { script = Character.UnicodeScript.forName(name); } catch (IllegalArgumentException iae) { throw error("Unknown character script name {" + name + "}"); } return new Script(script); } /** * Returns a CharProperty matching all characters in a UnicodeBlock. */ private CharProperty unicodeBlockPropertyFor(String name) { final Character.UnicodeBlock block; try { block = Character.UnicodeBlock.forName(name); } catch (IllegalArgumentException iae) { throw error("Unknown character block name {" + name + "}"); } return new Block(block); } /** * Returns a CharProperty matching all characters in a named property. */ private CharProperty charPropertyNodeFor(String name) { CharProperty p = CharPropertyNames.charPropertyFor(name); if (p == null) throw error("Unknown character property name {" + name + "}"); return 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(); sb.append(Character.toChars(ch)); while (ASCII.isLower(ch=read()) || ASCII.isUpper(ch) || ASCII.isDigit(ch)) { sb.append(Character.toChars(ch)); } if (sb.length() == 0) throw error("named capturing group has 0 length name"); 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 = null; Node tail = null; int save = flags; root = null; int ch = next(); if (ch == '?') { ch = skip(); switch (ch) { case ':': // (?:xxx) pure group head = createGroup(true); tail = root; head.next = expr(tail); break; case '=': // (?=xxx) and (?!xxx) lookahead case '!': head = createGroup(true); tail = root; head.next = expr(tail); if (ch == '=') { head = tail = new Pos(head); } else { head = tail = new Neg(head); } break; case '>': // (?>xxx) independent group head = createGroup(true); tail = root; head.next = expr(tail); head = tail = new Ques(head, INDEPENDENT); break; case '<': // (? 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 = lookbehindEnd; 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)); } else { throw error("Unknown look-behind group"); } break; case '$': 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); break; } } else { // (xxx) a regular group capturingGroup = true; head = createGroup(false); tail = root; head.next = expr(tail); } accept(')', "Unclosed group"); flags = 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 } if (node instanceof Ques) { Ques ques = (Ques) node; if (ques.type == POSSESSIVE) { root = node; return node; } tail.next = new BranchConn(); tail = tail.next; if (ques.type == 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 curly = (Curly) node; if (curly.type == 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 == GREEDY) loop = new Loop(this.localCount, temp); 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); 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': flags |= CASE_INSENSITIVE; break; case 'm': flags |= MULTILINE; break; case 's': flags |= DOTALL; break; case 'd': flags |= UNIX_LINES; break; case 'u': flags |= UNICODE_CASE; break; case 'c': flags |= CANON_EQ; break; case 'x': flags |= COMMENTS; break; case 'U': flags |= (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': flags &= ~CASE_INSENSITIVE; break; case 'm': flags &= ~MULTILINE; break; case 's': flags &= ~DOTALL; break; case 'd': flags &= ~UNIX_LINES; break; case 'u': flags &= ~UNICODE_CASE; break; case 'c': flags &= ~CANON_EQ; break; case 'x': flags &= ~COMMENTS; break; case 'U': flags &= ~(UNICODE_CHARACTER_CLASS | UNICODE_CASE); default: return; } ch = next(); } } static final int MAX_REPS = 0x7FFFFFFF; static final int GREEDY = 0; static final int LAZY = 1; static final int POSSESSIVE = 2; static final int INDEPENDENT = 3; /** * 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) { Node atom; int ch = peek(); switch (ch) { case '?': ch = next(); if (ch == '?') { next(); return new Ques(prev, LAZY); } else if (ch == '+') { next(); return new Ques(prev, POSSESSIVE); } return new Ques(prev, GREEDY); case '*': ch = next(); if (ch == '?') { next(); return new Curly(prev, 0, MAX_REPS, LAZY); } else if (ch == '+') { next(); return new Curly(prev, 0, MAX_REPS, POSSESSIVE); } return new Curly(prev, 0, MAX_REPS, GREEDY); case '+': ch = next(); if (ch == '?') { next(); return new Curly(prev, 1, MAX_REPS, LAZY); } else if (ch == '+') { next(); return new Curly(prev, 1, MAX_REPS, POSSESSIVE); } return new Curly(prev, 1, MAX_REPS, GREEDY); case '{': ch = temp[cursor+1]; if (ASCII.isDigit(ch)) { skip(); int cmin = 0; do { cmin = cmin * 10 + (ch - '0'); } while (ASCII.isDigit(ch = read())); int cmax = cmin; if (ch == ',') { ch = read(); cmax = MAX_REPS; if (ch != '}') { cmax = 0; while (ASCII.isDigit(ch)) { cmax = cmax * 10 + (ch - '0'); ch = read(); } } } if (ch != '}') throw error("Unclosed counted closure"); if (((cmin) | (cmax) | (cmax - cmin)) < 0) throw error("Illegal repetition range"); Curly curly; ch = peek(); if (ch == '?') { next(); curly = new Curly(prev, cmin, cmax, LAZY); } else if (ch == '+') { next(); curly = new Curly(prev, cmin, cmax, POSSESSIVE); } else { curly = new Curly(prev, cmin, cmax, GREEDY); } return curly; } 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; } // // Utility methods for code point support // private static final int countChars(CharSequence seq, int index, int lengthInCodePoints) { // optimization if (lengthInCodePoints == 1 && !Character.isHighSurrogate(seq.charAt(index))) { assert (index >= 0 && index < seq.length()); return 1; } int length = seq.length(); int x = index; if (lengthInCodePoints >= 0) { assert (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. */ private static final class BitClass extends BmpCharProperty { final boolean[] bits; BitClass() { bits = new boolean[256]; } private BitClass(boolean[] bits) { this.bits = bits; } 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; } boolean isSatisfiedBy(int ch) { return ch < 256 && bits[ch]; } } /** * Returns a suitably optimized, single character matcher. */ private CharProperty newSingle(final int ch) { if (has(CASE_INSENSITIVE)) { int lower, upper; if (has(UNICODE_CASE)) { upper = Character.toUpperCase(ch); lower = Character.toLowerCase(upper); if (upper != lower) return new SingleU(lower); } else if (ASCII.isAscii(ch)) { lower = ASCII.toLower(ch); upper = ASCII.toUpper(ch); if (lower != upper) return new SingleI(lower, upper); } } if (isSupplementary(ch)) return new SingleS(ch); // Match a given Unicode character return new Single(ch); // Match a given BMP character } /** * 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); } /** * The following classes are the building components of the object * tree that represents a compiled regular expression. The object tree * is made of individual elements that handle constructs in the Pattern. * Each type of object knows how to match its equivalent construct with * the match() method. */ /** * Base class for all node classes. Subclasses should override the match() * method as appropriate. This class is an accepting node, so its match() * always returns true. */ static class Node extends Object { Node next; Node() { next = Pattern.accept; } /** * This method implements the classic accept node. */ boolean match(Matcher matcher, int i, CharSequence seq) { matcher.last = i; matcher.groups[0] = matcher.first; matcher.groups[1] = matcher.last; return true; } /** * This method is good for all zero length assertions. */ boolean study(TreeInfo info) { if (next != null) { return next.study(info); } else { return info.deterministic; } } } static class LastNode extends Node { /** * This method implements the classic accept node with * the addition of a check to see if the match occurred * using all of the input. */ boolean match(Matcher matcher, int i, CharSequence seq) { if (matcher.acceptMode == Matcher.ENDANCHOR && i != matcher.to) return false; matcher.last = i; matcher.groups[0] = matcher.first; matcher.groups[1] = matcher.last; return true; } } /** * Used for REs that can start anywhere within the input string. * This basically tries to match repeatedly at each spot in the * input string, moving forward after each try. An anchored search * or a BnM will bypass this node completely. */ static class Start extends Node { int minLength; Start(Node node) { this.next = node; TreeInfo info = new TreeInfo(); next.study(info); minLength = info.minLength; } boolean match(Matcher matcher, int i, CharSequence seq) { if (i > matcher.to - minLength) { matcher.hitEnd = true; return false; } int guard = matcher.to - minLength; for (; i <= guard; i++) { if (next.match(matcher, i, seq)) { matcher.first = i; matcher.groups[0] = matcher.first; matcher.groups[1] = matcher.last; return true; } } matcher.hitEnd = true; return false; } boolean study(TreeInfo info) { next.study(info); info.maxValid = false; info.deterministic = false; return false; } } /* * StartS supports supplementary characters, including unpaired surrogates. */ static final class StartS extends Start { StartS(Node node) { super(node); } boolean match(Matcher matcher, int i, CharSequence seq) { if (i > matcher.to - minLength) { matcher.hitEnd = true; return false; } int guard = matcher.to - minLength; while (i <= guard) { //if ((ret = next.match(matcher, i, seq)) || i == guard) if (next.match(matcher, i, seq)) { matcher.first = i; matcher.groups[0] = matcher.first; matcher.groups[1] = matcher.last; return true; } if (i == guard) break; // Optimization to move to the next character. This is // faster than countChars(seq, i, 1). if (Character.isHighSurrogate(seq.charAt(i++))) { if (i < seq.length() && Character.isLowSurrogate(seq.charAt(i))) { i++; } } } matcher.hitEnd = true; return false; } } /** * 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 && seq.charAt(i) == 0x0A) i++; 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. */ private static abstract class CharProperty extends Node { abstract boolean isSatisfiedBy(int ch); CharProperty complement() { return new CharProperty() { boolean isSatisfiedBy(int ch) { return ! CharProperty.this.isSatisfiedBy(ch);}}; } boolean match(Matcher matcher, int i, CharSequence seq) { if (i < matcher.to) { int ch = Character.codePointAt(seq, i); return isSatisfiedBy(ch) && next.match(matcher, i+Character.charCount(ch), seq); } else { 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 abstract class BmpCharProperty extends CharProperty { boolean match(Matcher matcher, int i, CharSequence seq) { if (i < matcher.to) { return isSatisfiedBy(seq.charAt(i)) && next.match(matcher, i+1, seq); } else { matcher.hitEnd = true; return false; } } } /** * Node class that matches a Supplementary Unicode character */ static final class SingleS extends CharProperty { final int c; SingleS(int c) { this.c = c; } boolean isSatisfiedBy(int ch) { return ch == c; } } /** * Optimization -- matches a given BMP character */ static final class Single extends BmpCharProperty { final int c; Single(int c) { this.c = c; } boolean isSatisfiedBy(int ch) { return ch == c; } } /** * Case insensitive matches a given BMP character */ static final class SingleI extends BmpCharProperty { final int lower; final int upper; SingleI(int lower, int upper) { this.lower = lower; this.upper = upper; } boolean isSatisfiedBy(int ch) { return ch == lower || ch == upper; } } /** * Unicode case insensitive matches a given Unicode character */ static final class SingleU extends CharProperty { final int lower; SingleU(int lower) { this.lower = lower; } boolean isSatisfiedBy(int ch) { return lower == ch || lower == Character.toLowerCase(Character.toUpperCase(ch)); } } /** * Node class that matches a Unicode block. */ static final class Block extends CharProperty { final Character.UnicodeBlock block; Block(Character.UnicodeBlock block) { this.block = block; } boolean isSatisfiedBy(int ch) { return block == Character.UnicodeBlock.of(ch); } } /** * Node class that matches a Unicode script */ static final class Script extends CharProperty { final Character.UnicodeScript script; Script(Character.UnicodeScript script) { this.script = script; } boolean isSatisfiedBy(int ch) { return script == Character.UnicodeScript.of(ch); } } /** * Node class that matches a Unicode category. */ static final class Category extends CharProperty { final int typeMask; Category(int typeMask) { this.typeMask = typeMask; } boolean isSatisfiedBy(int ch) { return (typeMask & (1 << Character.getType(ch))) != 0; } } /** * Node class that matches a Unicode "type" */ static final class Utype extends CharProperty { final UnicodeProp uprop; Utype(UnicodeProp uprop) { this.uprop = uprop; } boolean isSatisfiedBy(int ch) { return uprop.is(ch); } } /** * Node class that matches a POSIX type. */ static final class Ctype extends BmpCharProperty { final int ctype; Ctype(int ctype) { this.ctype = ctype; } boolean isSatisfiedBy(int ch) { return ch < 128 && ASCII.isType(ch, ctype); } } /** * Node class that matches a Perl vertical whitespace */ static final class VertWS extends BmpCharProperty { boolean isSatisfiedBy(int cp) { return (cp >= 0x0A && cp <= 0x0D) || cp == 0x85 || cp == 0x2028 || cp == 0x2029; } } /** * Node class that matches a Perl horizontal whitespace */ static final class HorizWS extends BmpCharProperty { boolean isSatisfiedBy(int cp) { return cp == 0x09 || cp == 0x20 || cp == 0xa0 || cp == 0x1680 || cp == 0x180e || cp >= 0x2000 && cp <= 0x200a || cp == 0x202f || cp == 0x205f || cp == 0x3000; } } /** * 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 final 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= 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= 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= 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 SliceNode { 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)); } } private static boolean inRange(int lower, int ch, int upper) { return lower <= ch && ch <= upper; } /** * Returns node for matching characters within an explicit value range. */ private static CharProperty rangeFor(final int lower, final int upper) { return new CharProperty() { boolean isSatisfiedBy(int ch) { return inRange(lower, ch, upper);}}; } /** * Returns node for matching characters within an explicit value * range in a case insensitive manner. */ private CharProperty caseInsensitiveRangeFor(final int lower, final int upper) { if (has(UNICODE_CASE)) return new CharProperty() { boolean isSatisfiedBy(int ch) { if (inRange(lower, ch, upper)) return true; int up = Character.toUpperCase(ch); return inRange(lower, up, upper) || inRange(lower, Character.toLowerCase(up), upper);}}; return new CharProperty() { boolean isSatisfiedBy(int ch) { return inRange(lower, ch, upper) || ASCII.isAscii(ch) && (inRange(lower, ASCII.toUpper(ch), upper) || inRange(lower, ASCII.toLower(ch), upper)); }}; } /** * Implements the Unicode category ALL and the dot metacharacter when * in dotall mode. */ static final class All extends CharProperty { boolean isSatisfiedBy(int ch) { return true; } } /** * Node class for the dot metacharacter when dotall is not enabled. */ static final class Dot extends CharProperty { boolean isSatisfiedBy(int ch) { return (ch != '\n' && ch != '\r' && (ch|1) != '\u2029' && ch != '\u0085'); } } /** * Node class for the dot metacharacter when dotall is not enabled * but UNIX_LINES is enabled. */ static final class UnixDot extends CharProperty { boolean isSatisfiedBy(int ch) { return ch != '\n'; } } /** * The 0 or 1 quantifier. This one class implements all three types. */ static final class Ques extends Node { Node atom; int type; Ques(Node node, int 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 != 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 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; int type; int cmin; int cmax; Curly(Node node, int cmin, int cmax, int 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 == GREEDY) return match0(matcher, i, j, seq); else if (type == 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; int type; int cmin; int cmax; int localIndex; int groupIndex; boolean capture; GroupCurly(Node node, int cmin, int cmax, int 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 == GREEDY) { ret = match0(matcher, i, cmin, seq); } else if (type == 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; 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; } boolean matchRef(Matcher matcher, int i, CharSequence seq) { int save = matcher.locals[localIndex]; matcher.locals[localIndex] = ~i; // HACK boolean ret = next.match(matcher, i, seq); matcher.locals[localIndex] = save; return ret; } } /** * Recursive reference to a group in the regular expression. It calls * matchRef because if the reference fails to match we would not unset * the group. */ static final class GroupRef extends Node { GroupHead head; GroupRef(GroupHead head) { this.head = head; } boolean match(Matcher matcher, int i, CharSequence seq) { return head.matchRef(matcher, i, seq) && next.match(matcher, matcher.last, seq); } boolean study(TreeInfo info) { info.maxValid = false; info.deterministic = false; return next.study(info); } } /** * 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; Loop(int countIndex, int beginIndex) { this.countIndex = countIndex; this.beginIndex = beginIndex; } 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) { 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; else return true; } } 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 (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 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 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); } } static final class Conditional extends Node { Node cond, yes, not; Conditional(Node cond, Node yes, Node not) { this.cond = cond; this.yes = yes; this.not = not; } boolean match(Matcher matcher, int i, CharSequence seq) { if (cond.match(matcher, i, seq)) { return yes.match(matcher, i, seq); } else { return not.match(matcher, i, seq); } } boolean study(TreeInfo info) { int minL = info.minLength; int maxL = info.maxLength; boolean maxV = info.maxValid; info.reset(); yes.study(info); int minL2 = info.minLength; int maxL2 = info.maxLength; boolean maxV2 = info.maxValid; info.reset(); not.study(info); info.minLength = minL + Math.min(minL2, info.minLength); info.maxLength = maxL + Math.max(maxL2, info.maxLength); info.maxValid = (maxV & maxV2 & info.maxValid); 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 = false; // 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 = false; // 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 Node lookbehindEnd = new Node() { 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); } } /** * Returns the set union of two CharProperty nodes. */ private static CharProperty union(final CharProperty lhs, final CharProperty rhs) { return new CharProperty() { boolean isSatisfiedBy(int ch) { return lhs.isSatisfiedBy(ch) || rhs.isSatisfiedBy(ch);}}; } /** * Returns the set intersection of two CharProperty nodes. */ private static CharProperty intersection(final CharProperty lhs, final CharProperty rhs) { return new CharProperty() { boolean isSatisfiedBy(int ch) { return lhs.isSatisfiedBy(ch) && rhs.isSatisfiedBy(ch);}}; } /** * Returns the set difference of two CharProperty nodes. */ private static CharProperty setDifference(final CharProperty lhs, final CharProperty rhs) { return new CharProperty() { boolean isSatisfiedBy(int ch) { return ! rhs.isSatisfiedBy(ch) && lhs.isSatisfiedBy(ch);}}; } /** * 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 ? UnicodeProp.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. *

* 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. *

* 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. *

* 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, k; 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 x = 0; x < buffer.length; x++) { lengthInChars += Character.charCount(buffer[x]); } } 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; } } /// /// /** * This must be the very first initializer. */ static Node accept = new Node(); static Node lastAccept = new LastNode(); private static class CharPropertyNames { static CharProperty charPropertyFor(String name) { CharPropertyFactory m = map.get(name); return m == null ? null : m.make(); } private static abstract class CharPropertyFactory { abstract CharProperty make(); } private static void defCategory(String name, final int typeMask) { map.put(name, new CharPropertyFactory() { CharProperty make() { return new Category(typeMask);}}); } private static void defRange(String name, final int lower, final int upper) { map.put(name, new CharPropertyFactory() { CharProperty make() { return rangeFor(lower, upper);}}); } private static void defCtype(String name, final int ctype) { map.put(name, new CharPropertyFactory() { CharProperty make() { return new Ctype(ctype);}}); } private static abstract class CloneableProperty extends CharProperty implements Cloneable { public CloneableProperty clone() { try { return (CloneableProperty) super.clone(); } catch (CloneNotSupportedException e) { throw new AssertionError(e); } } } private static void defClone(String name, final CloneableProperty p) { map.put(name, new CharPropertyFactory() { CharProperty make() { return p.clone();}}); } private static final HashMap map = new HashMap<>(); static { // Unicode character property aliases, defined in // http://www.unicode.org/Public/UNIDATA/PropertyValueAliases.txt defCategory("Cn", 1< asPredicate() { return s -> matcher(s).find(); } /** * Creates a stream from the given input sequence around matches of this * pattern. * *

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. * *

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. * *

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. * *

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 splitAsStream(final CharSequence input) { class MatcherIterator implements Iterator { private final Matcher matcher; // The start position of the next sub-sequence of input // when current == input.length there are no more elements private int current; // null if the next element, if any, needs to obtained private String nextElement; // > 0 if there are N next empty elements private int emptyElementCount; MatcherIterator() { this.matcher = matcher(input); } public String next() { if (!hasNext()) throw new NoSuchElementException(); if (emptyElementCount == 0) { String n = nextElement; nextElement = null; return n; } else { emptyElementCount--; return ""; } } public boolean hasNext() { if (nextElement != null || emptyElementCount > 0) return true; if (current == input.length()) return false; // Consume the next matching element // Count sequence of matching empty elements while (matcher.find()) { nextElement = input.subSequence(current, matcher.start()).toString(); current = matcher.end(); if (!nextElement.isEmpty()) { return true; } else if (current > 0) { // no empty leading substring for zero-width // match at the beginning of the input emptyElementCount++; } } // Consume last matching element nextElement = input.subSequence(current, input.length()).toString(); current = input.length(); if (!nextElement.isEmpty()) { return true; } else { // Ignore a terminal sequence of matching empty elements emptyElementCount = 0; nextElement = null; return false; } } } return StreamSupport.stream(Spliterators.spliteratorUnknownSize( new MatcherIterator(), Spliterator.ORDERED | Spliterator.NONNULL), false); } }

 

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