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RE2 Syntax
In re2r: RE2 Regular Expression
library(re2r)
This page lists the regular expression syntax accepted by RE2. It also lists syntax accepted by PCRE, PERL, and VIM.
Grayed out expressions are not supported by RE2.
## RE Engine Compare
**Feature**
**ICU**
**PCRE**
**TRE**
**RE2**
**Boost.Regex**
"+" quantifier
o
o
o
o
o
Negated character classes
o
o
o
o
o
Non-greedy quantifiers
o
o
o
o
o
non-capturing groups
o
o
o
o
o
Recursion
x
o
x
x
o
Look-ahead
o
o
x
x
o
Look-behind
o
o
x
x
o
Backreferences
o
o
o
x
o
>9 indexable captures
o
o
x
o
o
Flags modifiers
o
o
o
o
o
Conditionals
x
o
x
x
o
Independent sub-expressions
o
o
x
x
o
Named capture
x
o
x
o
o
Comments
o
o
o
x
o
Embedded code
x
o
x
x
x
Unicode property support
o
o
?
Some
Some
Balancing groups
x
x
x
x
x
Variable-length look-behinds
x
x
x
x
x
## Single Character
kinds of single-character expressions examples any character, possibly including newline (s=true) .character class [xyz]negated character class [^xyz]Perl character class (link) \\dnegated Perl character class \\DASCII character class (link) [[:alpha:]]negated ASCII character class [[:^alpha:]]Unicode character class (one-letter name) \\pNUnicode character class \\p{Greek}negated Unicode character class (one-letter name) \\PNnegated Unicode character class \\P{Greek}
## Composites
Composites xyx followed by yx|yx or y (prefer x)
## Repetitions
Repetitions x*zero or more x, prefer more x+one or more x, prefer more x?zero or one x, prefer one x{n,m}n or n+1 or ... or m x, prefer morex{n,}n or more x, prefer morex{n}exactly n x x*?zero or more x, prefer fewer x+?one or more x, prefer fewer x??zero or one x, prefer zero x{n,m}?n or n+1 or ... or m x, prefer fewerx{n,}?n or more x, prefer fewerx{n}?exactly n x x{}(≡ x*) (NOT SUPPORTED) VIM x{-}(≡ x*?) (NOT SUPPORTED) VIM x{-n}(≡ x{n}?) (NOT SUPPORTED) VIM x=(≡ x?) (NOT SUPPORTED) VIM
Implementation restriction: The counting forms x{n,m}, x{n,}, and x{n} reject forms that create a minimum or maximum repetition count above 1000. Unlimited repetitions are not subject to this restriction.
## Possessive repetitions
Possessive repetitions x*+zero or more x, possessive (NOT SUPPORTED) x++one or more x, possessive (NOT SUPPORTED) x?+zero or one x, possessive (NOT SUPPORTED) x{n,m}+n or ... or m x, possessive (NOT SUPPORTED)x{n,}+n or more x, possessive (NOT SUPPORTED)x{n}+exactly n x, possessive (NOT SUPPORTED)
## Grouping
Grouping (re)numbered capturing group (submatch) (?P<name>re)named & numbered capturing group (submatch) (?<name>re)named & numbered capturing group (submatch) (NOT SUPPORTED) (?'name're)named & numbered capturing group (submatch) (NOT SUPPORTED) (?:re)non-capturing group (?flags)set flags within current group; non-capturing (?flags:re)set flags during re; non-capturing (?#text)comment (NOT SUPPORTED) (?|x|y|z)branch numbering reset (NOT SUPPORTED) (?>re)possessive match of re (NOT SUPPORTED) re@>possessive match of re (NOT SUPPORTED) VIM %(re)non-capturing group (NOT SUPPORTED) VIM
## Flags
Flags icase-insensitive (default false) mmulti-line mode: ^ and dollar symbol match begin/end line in addition to begin/end text (default false) slet . match \\n (default false) Uungreedy: swap meaning of x* and x*?, x+ and x+?, etc (default false)
Flag syntax is xyz (set) or -xyz (clear) or xy-z (set xy, clear z).
## Empty Strings
Empty strings ^at beginning of text or line (m=true) dollar symbolat end of text (like \\z not \\Z) or line (m=true) \\Aat beginning of text \\bat ASCII word boundary (\\w on one side and \\W, \A, or \\z on the other) \\Bnot at ASCII word boundary \\gat beginning of subtext being searched (NOT SUPPORTED) PCRE \\Gat end of last match (NOT SUPPORTED) PERL \\Zat end of text, or before newline at end of text (NOT SUPPORTED) \\zat end of text (?=re)before text matching re (NOT SUPPORTED) (?!re)before text not matching re (NOT SUPPORTED) (?<=re)after text matching re (NOT SUPPORTED) (?<!re)after text not matching re (NOT SUPPORTED) re&before text matching re (NOT SUPPORTED) VIM re@=before text matching re (NOT SUPPORTED) VIM re@!before text not matching re (NOT SUPPORTED) VIM re@<=after text matching re (NOT SUPPORTED) VIM re@<!after text not matching re (NOT SUPPORTED) VIM \\zssets start of match (= \\K) (NOT SUPPORTED) VIM \\zesets end of match (NOT SUPPORTED) VIM \\%^beginning of file (NOT SUPPORTED) VIM \\%$end of file (NOT SUPPORTED) VIM \\%Von screen (NOT SUPPORTED) VIM \\%#cursor position (NOT SUPPORTED) VIM \\%'mmark m position (NOT SUPPORTED) VIM \\%23lin line 23 (NOT SUPPORTED) VIM \\%23cin column 23 (NOT SUPPORTED) VIM \\%23vin virtual column 23 (NOT SUPPORTED) VIM
## Escape Sequences
Escape sequences \\abell (≡ \\007) \\fform feed (≡ \\014) \\thorizontal tab (≡ \\011) \\nnewline (≡ \\012) \\rcarriage return (≡ \\015) \\vvertical tab character (≡ \\013) \\*literal *, for any punctuation character * \\123octal character code (up to three digits) \\x7Fhex character code (exactly two digits) \\x{10FFFF}hex character code \\Cmatch a single byte even in UTF-8 mode \\Q...\\Eliteral text ... even if ... has punctuation \\1backreference (NOT SUPPORTED) \\bbackspace (NOT SUPPORTED) (use \\010) \\cKcontrol char ^K (NOT SUPPORTED) (use \\001 etc) \\eescape (NOT SUPPORTED) (use \\033) \\g1backreference (NOT SUPPORTED) \\g{1}backreference (NOT SUPPORTED) \\g{+1}backreference (NOT SUPPORTED) \\g{-1}backreference (NOT SUPPORTED) \\g{name}named backreference (NOT SUPPORTED) \\g<name>subroutine call (NOT SUPPORTED) \\g'name'subroutine call (NOT SUPPORTED) \\k<name>named backreference (NOT SUPPORTED) \\k'name'named backreference (NOT SUPPORTED) \\lXlowercase X (NOT SUPPORTED) \uxuppercase x (NOT SUPPORTED) \\L...\\Elowercase text ... (NOT SUPPORTED) \\Kreset beginning of $0 (NOT SUPPORTED) \\N{name}named Unicode character (NOT SUPPORTED) \\Rline break (NOT SUPPORTED) \\U...\\Eupper case text ... (NOT SUPPORTED) \\Xextended Unicode sequence (NOT SUPPORTED) \\%d123decimal character 123 (NOT SUPPORTED) VIM \\%xFFhex character FF (NOT SUPPORTED) VIM \\%o123octal character 123 (NOT SUPPORTED) VIM \\%u1234Unicode character 0x1234 (NOT SUPPORTED) VIM \\%U12345678Unicode character 0x12345678 (NOT SUPPORTED) VIM
## Character Class Elements
Character class elements xsingle character A-Zcharacter range (inclusive) \\dPerl character class [:foo:]ASCII character class foo \\p{Foo}Unicode character class Foo \\pFUnicode character class F (one-letter name)
## Named Character Classes
Named character classes as character class elements [\\d]digits (≡ \\d) [^\\d]not digits (≡ \\D) [\\D]not digits (≡ \D) [^\\D]not not digits (≡ \\d) [[:name:]]named ASCII class inside character class (≡ [:name:]) [^[:name:]]named ASCII class inside negated character class (≡ [:^name:]) [\\p{Name}]named Unicode property inside character class (≡ \\p{Name}) [^\\p{Name}]named Unicode property inside negated character class (≡ \\P{Name})
## Perl Character Classes
Perl character classes (all ASCII-only) \\ddigits (≡ [0-9]) \\Dnot digits (≡ [^0-9]) \\swhitespace (≡ [\\t\\n\\f\\r ]) \\Snot whitespace (≡ [^\\t\\n\\f\\r ]) \\wword characters (≡ [0-9A-Za-z_]) \\Wnot word characters (≡ [^0-9A-Za-z_]) \\hhorizontal space (NOT SUPPORTED) \\Hnot horizontal space (NOT SUPPORTED) \\vvertical space (NOT SUPPORTED) \\Vnot vertical space (NOT SUPPORTED)
## ASCII Character Classes
ASCII character classes [[:alnum:]]alphanumeric (≡ [0-9A-Za-z]) [[:alpha:]]alphabetic (≡ [A-Za-z]) [[:ascii:]]ASCII (≡ [\\x00-\\x7F]) [[:blank:]]blank (≡ [\\t ]) [[:cntrl:]]control (≡ [\\x00-\\x1F\\x7F]) [[:digit:]]digits (≡ [0-9]) [[:graph:]]graphical [[:lower:]]lower case (≡ [a-z]) [[:print:]]printable (≡ [ -~] == [ [:graph:]]) [[:punct:]]punctuation (≡ [!-/:-@[-`{-~]) [[:space:]]whitespace (≡ [\\t\\n\\v\\f\\r ]) [[:upper:]]upper case (≡ [A-Z]) [[:word:]]word characters (≡ [0-9A-Za-z_]) [[:xdigit:]]hex digit (≡ [0-9A-Fa-f])
## Unicode Character Classes
Unicode character class names--general category Cother Cccontrol Cfformat Cnunassigned code points (NOT SUPPORTED) Coprivate use Cssurrogate Lletter LCcased letter (NOT SUPPORTED) L&cased letter (NOT SUPPORTED) Lllowercase letter Lmmodifier letter Loother letter Lttitlecase letter Luuppercase letter Mmark Mcspacing mark Meenclosing mark Mnnon-spacing mark Nnumber Nddecimal number Nlletter number Noother number Ppunctuation Pcconnector punctuation Pddash punctuation Peclose punctuation Pffinal punctuation Piinitial punctuation Poother punctuation Psopen punctuation Ssymbol Sccurrency symbol Skmodifier symbol Smmath symbol Soother symbol Zseparator Zlline separator Zpparagraph separator Zsspace separator
Unicode character class names--scripts AhomAnatolian_HieroglyphsArabicArmenianAvestanBalineseBamumBassa_VahBatakBengaliBopomofoBrahmiBrailleBugineseBuhidCanadian_AboriginalCarianCaucasian_AlbanianChakmaChamCherokeeCommonCopticCuneiformCypriotCyrillicDeseretDevanagariDuployanEgyptian_HieroglyphsElbasanEthiopicGeorgianGlagoliticGothicGranthaGreekGujaratiGurmukhiHanHangulHanunooHatranHebrewHiraganaImperial_AramaicInheritedInscriptional_PahlaviInscriptional_ParthianJavaneseKaithiKannadaKatakanaKayah_LiKharoshthiKhmerKhojkiKhudawadiLaoLatinLepchaLimbuLinear_ALinear_BLisuLycianLydianMahajaniMalayalamMandaicManichaeanMeetei_MayekMende_KikakuiMeroitic_CursiveMeroitic_HieroglyphsMiaoModiMongolianMroMultaniMyanmarNabataeanNew_Tai_LueNkoOghamOl_ChikiOld_HungarianOld_ItalicOld_North_ArabianOld_PermicOld_PersianOld_South_ArabianOld_TurkicOriyaOsmanyaPahawh_HmongPalmyrenePau_Cin_HauPhags_PaPhoenicianPsalter_PahlaviRejangRunicSamaritanSaurashtraSharadaShavianSiddhamSignWritingSinhalaSora_SompengSundaneseSyloti_NagriSyriacTagalogTagbanwaTai_LeTai_ThamTai_VietTakriTamilTeluguThaanaThaiTibetanTifinaghTirhutaUgariticVaiWarang_CitiYi
## Vim Character Classes
Vim character classes \\iidentifier character (NOT SUPPORTED) VIM \\I\\i except digits (NOT SUPPORTED) VIM\\kkeyword character (NOT SUPPORTED) VIM \\K\\k except digits (NOT SUPPORTED) VIM\\ffile name character (NOT SUPPORTED) VIM \\F\\f except digits (NOT SUPPORTED) VIM\\pprintable character (NOT SUPPORTED) VIM \\P\p except digits (NOT SUPPORTED) VIM\swhitespace character (≡ [ \\t]) (NOT SUPPORTED) VIM \\Snon-white space character (≡ [^ \\t]) (NOT SUPPORTED) VIM \\ddigits (≡ [0-9]) VIM \\Dnot \\d VIM \\xhex digits (≡ [0-9A-Fa-f]) (NOT SUPPORTED) VIM \\Xnot \\x (NOT SUPPORTED) VIM \\ooctal digits (≡ [0-7]) (NOT SUPPORTED) VIM \\Onot \\o (NOT SUPPORTED) VIM \\wword character VIM \\Wnot \\w VIM \\hhead of word character (NOT SUPPORTED) VIM \\Hnot \\h (NOT SUPPORTED) VIM \\aalphabetic (NOT SUPPORTED) VIM \\Anot \\a (NOT SUPPORTED) VIM \\llowercase (NOT SUPPORTED) VIM \\Lnot lowercase (NOT SUPPORTED) VIM \\uuppercase (NOT SUPPORTED) VIM \\Unot uppercase (NOT SUPPORTED) VIM \\_x\\x plus newline, for any x (NOT SUPPORTED) VIM\\cignore case (NOT SUPPORTED) VIM \\Cmatch case (NOT SUPPORTED) VIM \\mmagic (NOT SUPPORTED) VIM \\Mnomagic (NOT SUPPORTED) VIM \\vverymagic (NOT SUPPORTED) VIM \\Vverynomagic (NOT SUPPORTED) VIM \\Zignore differences in Unicode combining characters (NOT SUPPORTED) VIM
## Magic
Magic (?{code})arbitrary Perl code (NOT SUPPORTED) PERL (??{code})postponed arbitrary Perl code (NOT SUPPORTED) PERL (?n)recursive call to regexp capturing group n (NOT SUPPORTED) (?+n)recursive call to relative group +n (NOT SUPPORTED) (?-n)recursive call to relative group -n (NOT SUPPORTED) (?C)PCRE callout (NOT SUPPORTED) PCRE (?R)recursive call to entire regexp (≡ (?0)) (NOT SUPPORTED) (?&name)recursive call to named group (NOT SUPPORTED) (?P=name)named backreference (NOT SUPPORTED) (?P>name)recursive call to named group (NOT SUPPORTED) (?(cond)true|false)conditional branch (NOT SUPPORTED) (?(cond)true)conditional branch (NOT SUPPORTED) (*ACCEPT)make regexps more like Prolog (NOT SUPPORTED) (*COMMIT)(NOT SUPPORTED) (*F)(NOT SUPPORTED) (*FAIL)(NOT SUPPORTED) (*MARK)(NOT SUPPORTED) (*PRUNE)(NOT SUPPORTED) (*SKIP)(NOT SUPPORTED) (*THEN)(NOT SUPPORTED) (*ANY)set newline convention (NOT SUPPORTED) (*ANYCRLF)(NOT SUPPORTED) (*CR)(NOT SUPPORTED) (*CRLF)(NOT SUPPORTED) (*LF)(NOT SUPPORTED) (*BSR_ANYCRLF)set \\R convention (NOT SUPPORTED) PCRE (*BSR_UNICODE)(NOT SUPPORTED) PCRE
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library(re2r)
This page lists the regular expression syntax accepted by RE2. It also lists syntax accepted by PCRE, PERL, and VIM.
Grayed out expressions are not supported by RE2.
## RE Engine Compare
## Single Character
## Composites
## Repetitions
## Grouping
## Flags
## Escape Sequences
## Character Class Elements
## Named Character Classes
## Perl Character Classes
## ASCII Character Classes
## Unicode Character Classes
## Vim Character Classes
## Magic
| **Feature** | **ICU** | **PCRE** | **TRE** | **RE2** | **Boost.Regex** |
| "+" quantifier | o | o | o | o | o |
| Negated character classes | o | o | o | o | o |
| Non-greedy quantifiers | o | o | o | o | o |
| non-capturing groups | o | o | o | o | o |
| Recursion | x | o | x | x | o |
| Look-ahead | o | o | x | x | o |
| Look-behind | o | o | x | x | o |
| Backreferences | o | o | o | x | o |
| >9 indexable captures | o | o | x | o | o |
| Flags modifiers | o | o | o | o | o |
| Conditionals | x | o | x | x | o |
| Independent sub-expressions | o | o | x | x | o |
| Named capture | x | o | x | o | o |
| Comments | o | o | o | x | o |
| Embedded code | x | o | x | x | x |
| Unicode property support | o | o | ? | Some | Some |
| Balancing groups | x | x | x | x | x |
| Variable-length look-behinds | x | x | x | x | x |
| kinds of single-character expressions | examples |
|---|---|
| any character, possibly including newline (s=true) | . |
| character class | [xyz] |
| negated character class | [^xyz] |
| Perl character class (link) | \\d |
| negated Perl character class | \\D |
| ASCII character class (link) | [[:alpha:]] |
| negated ASCII character class | [[:^alpha:]] |
| Unicode character class (one-letter name) | \\pN |
| Unicode character class | \\p{Greek} |
| negated Unicode character class (one-letter name) | \\PN |
| negated Unicode character class | \\P{Greek} |
| Composites | |
|---|---|
xy | x followed by y |
x|y | x or y (prefer x) |
| Repetitions | |
|---|---|
x* | zero or more x, prefer more |
x+ | one or more x, prefer more |
x? | zero or one x, prefer one |
x{n,m} | n or n+1 or ... or m x, prefer more |
x{n,} | n or more x, prefer more |
x{n} | exactly n x |
x*? | zero or more x, prefer fewer |
x+? | one or more x, prefer fewer |
x?? | zero or one x, prefer zero |
x{n,m}? | n or n+1 or ... or m x, prefer fewer |
x{n,}? | n or more x, prefer fewer |
x{n}? | exactly n x |
x{} | (≡ x*) (NOT SUPPORTED) VIM |
x{-} | (≡ x*?) (NOT SUPPORTED) VIM |
x{-n} | (≡ x{n}?) (NOT SUPPORTED) VIM |
x= | (≡ x?) (NOT SUPPORTED) VIM |
Implementation restriction: The counting forms x{n,m}, x{n,}, and x{n} reject forms that create a minimum or maximum repetition count above 1000. Unlimited repetitions are not subject to this restriction.
## Possessive repetitions
| Possessive repetitions | |
|---|---|
x*+ | zero or more x, possessive (NOT SUPPORTED) |
x++ | one or more x, possessive (NOT SUPPORTED) |
x?+ | zero or one x, possessive (NOT SUPPORTED) |
x{n,m}+ | n or ... or m x, possessive (NOT SUPPORTED) |
x{n,}+ | n or more x, possessive (NOT SUPPORTED) |
x{n}+ | exactly n x, possessive (NOT SUPPORTED) |
| Grouping | |
|---|---|
(re) | numbered capturing group (submatch) |
(?P<name>re) | named & numbered capturing group (submatch) |
(?<name>re) | named & numbered capturing group (submatch) (NOT SUPPORTED) |
(?'name're) | named & numbered capturing group (submatch) (NOT SUPPORTED) |
(?:re) | non-capturing group |
(?flags) | set flags within current group; non-capturing |
(?flags:re) | set flags during re; non-capturing |
(?#text) | comment (NOT SUPPORTED) |
(?|x|y|z) | branch numbering reset (NOT SUPPORTED) |
(?>re) | possessive match of re (NOT SUPPORTED) |
re@> | possessive match of re (NOT SUPPORTED) VIM |
%(re) | non-capturing group (NOT SUPPORTED) VIM |
| Flags | |
|---|---|
i | case-insensitive (default false) |
m | multi-line mode: ^ and dollar symbol match begin/end line in addition to begin/end text (default false) |
s | let . match \\n (default false) |
U | ungreedy: swap meaning of x* and x*?, x+ and x+?, etc (default false) |
Flag syntax is xyz (set) or -xyz (clear) or xy-z (set xy, clear z).
## Empty Strings
| Empty strings | |
|---|---|
^ | at beginning of text or line (m=true) |
dollar symbol | at end of text (like \\z not \\Z) or line (m=true) |
\\A | at beginning of text |
\\b | at ASCII word boundary (\\w on one side and \\W, \A, or \\z on the other) |
\\B | not at ASCII word boundary |
\\g | at beginning of subtext being searched (NOT SUPPORTED) PCRE |
\\G | at end of last match (NOT SUPPORTED) PERL |
\\Z | at end of text, or before newline at end of text (NOT SUPPORTED) |
\\z | at end of text |
(?=re) | before text matching re (NOT SUPPORTED) |
(?!re) | before text not matching re (NOT SUPPORTED) |
(?<=re) | after text matching re (NOT SUPPORTED) |
(?<!re) | after text not matching re (NOT SUPPORTED) |
re& | before text matching re (NOT SUPPORTED) VIM |
re@= | before text matching re (NOT SUPPORTED) VIM |
re@! | before text not matching re (NOT SUPPORTED) VIM |
re@<= | after text matching re (NOT SUPPORTED) VIM |
re@<! | after text not matching re (NOT SUPPORTED) VIM |
\\zs | sets start of match (= \\K) (NOT SUPPORTED) VIM |
\\ze | sets end of match (NOT SUPPORTED) VIM |
\\%^ | beginning of file (NOT SUPPORTED) VIM |
\\%$ | end of file (NOT SUPPORTED) VIM |
\\%V | on screen (NOT SUPPORTED) VIM |
\\%# | cursor position (NOT SUPPORTED) VIM |
\\%'m | mark m position (NOT SUPPORTED) VIM |
\\%23l | in line 23 (NOT SUPPORTED) VIM |
\\%23c | in column 23 (NOT SUPPORTED) VIM |
\\%23v | in virtual column 23 (NOT SUPPORTED) VIM |
| Escape sequences | |
|---|---|
\\a | bell (≡ \\007) |
\\f | form feed (≡ \\014) |
\\t | horizontal tab (≡ \\011) |
\\n | newline (≡ \\012) |
\\r | carriage return (≡ \\015) |
\\v | vertical tab character (≡ \\013) |
\\* | literal *, for any punctuation character * |
\\123 | octal character code (up to three digits) |
\\x7F | hex character code (exactly two digits) |
\\x{10FFFF} | hex character code |
\\C | match a single byte even in UTF-8 mode |
\\Q...\\E | literal text ... even if ... has punctuation |
\\1 | backreference (NOT SUPPORTED) |
\\b | backspace (NOT SUPPORTED) (use \\010) |
\\cK | control char ^K (NOT SUPPORTED) (use \\001 etc) |
\\e | escape (NOT SUPPORTED) (use \\033) |
\\g1 | backreference (NOT SUPPORTED) |
\\g{1} | backreference (NOT SUPPORTED) |
\\g{+1} | backreference (NOT SUPPORTED) |
\\g{-1} | backreference (NOT SUPPORTED) |
\\g{name} | named backreference (NOT SUPPORTED) |
\\g<name> | subroutine call (NOT SUPPORTED) |
\\g'name' | subroutine call (NOT SUPPORTED) |
\\k<name> | named backreference (NOT SUPPORTED) |
\\k'name' | named backreference (NOT SUPPORTED) |
\\lX | lowercase X (NOT SUPPORTED) |
\ux | uppercase x (NOT SUPPORTED) |
\\L...\\E | lowercase text ... (NOT SUPPORTED) |
\\K | reset beginning of $0 (NOT SUPPORTED) |
\\N{name} | named Unicode character (NOT SUPPORTED) |
\\R | line break (NOT SUPPORTED) |
\\U...\\E | upper case text ... (NOT SUPPORTED) |
\\X | extended Unicode sequence (NOT SUPPORTED) |
\\%d123 | decimal character 123 (NOT SUPPORTED) VIM |
\\%xFF | hex character FF (NOT SUPPORTED) VIM |
\\%o123 | octal character 123 (NOT SUPPORTED) VIM |
\\%u1234 | Unicode character 0x1234 (NOT SUPPORTED) VIM |
\\%U12345678 | Unicode character 0x12345678 (NOT SUPPORTED) VIM |
| Character class elements | |
|---|---|
x | single character |
A-Z | character range (inclusive) |
\\d | Perl character class |
[:foo:] | ASCII character class foo |
\\p{Foo} | Unicode character class Foo |
\\pF | Unicode character class F (one-letter name) |
| Named character classes as character class elements | |
|---|---|
[\\d] | digits (≡ \\d) |
[^\\d] | not digits (≡ \\D) |
[\\D] | not digits (≡ \D) |
[^\\D] | not not digits (≡ \\d) |
[[:name:]] | named ASCII class inside character class (≡ [:name:]) |
[^[:name:]] | named ASCII class inside negated character class (≡ [:^name:]) |
[\\p{Name}] | named Unicode property inside character class (≡ \\p{Name}) |
[^\\p{Name}] | named Unicode property inside negated character class (≡ \\P{Name}) |
| Perl character classes (all ASCII-only) | |
|---|---|
\\d | digits (≡ [0-9]) |
\\D | not digits (≡ [^0-9]) |
\\s | whitespace (≡ [\\t\\n\\f\\r ]) |
\\S | not whitespace (≡ [^\\t\\n\\f\\r ]) |
\\w | word characters (≡ [0-9A-Za-z_]) |
\\W | not word characters (≡ [^0-9A-Za-z_]) |
\\h | horizontal space (NOT SUPPORTED) |
\\H | not horizontal space (NOT SUPPORTED) |
\\v | vertical space (NOT SUPPORTED) |
\\V | not vertical space (NOT SUPPORTED) |
| ASCII character classes | |
|---|---|
[[:alnum:]] | alphanumeric (≡ [0-9A-Za-z]) |
[[:alpha:]] | alphabetic (≡ [A-Za-z]) |
[[:ascii:]] | ASCII (≡ [\\x00-\\x7F]) |
[[:blank:]] | blank (≡ [\\t ]) |
[[:cntrl:]] | control (≡ [\\x00-\\x1F\\x7F]) |
[[:digit:]] | digits (≡ [0-9]) |
[[:graph:]] | graphical |
[[:lower:]] | lower case (≡ [a-z]) |
[[:print:]] | printable (≡ [ -~] == [ [:graph:]]) |
[[:punct:]] | punctuation (≡ [!-/:-@[-`{-~]) |
[[:space:]] | whitespace (≡ [\\t\\n\\v\\f\\r ]) |
[[:upper:]] | upper case (≡ [A-Z]) |
[[:word:]] | word characters (≡ [0-9A-Za-z_]) |
[[:xdigit:]] | hex digit (≡ [0-9A-Fa-f]) |
| Unicode character class names--general category | |
|---|---|
C | other |
Cc | control |
Cf | format |
Cn | unassigned code points (NOT SUPPORTED) |
Co | private use |
Cs | surrogate |
L | letter |
LC | cased letter (NOT SUPPORTED) |
L& | cased letter (NOT SUPPORTED) |
Ll | lowercase letter |
Lm | modifier letter |
Lo | other letter |
Lt | titlecase letter |
Lu | uppercase letter |
M | mark |
Mc | spacing mark |
Me | enclosing mark |
Mn | non-spacing mark |
N | number |
Nd | decimal number |
Nl | letter number |
No | other number |
P | punctuation |
Pc | connector punctuation |
Pd | dash punctuation |
Pe | close punctuation |
Pf | final punctuation |
Pi | initial punctuation |
Po | other punctuation |
Ps | open punctuation |
S | symbol |
Sc | currency symbol |
Sk | modifier symbol |
Sm | math symbol |
So | other symbol |
Z | separator |
Zl | line separator |
Zp | paragraph separator |
Zs | space separator |
| Unicode character class names--scripts |
|---|
Ahom |
Anatolian_Hieroglyphs |
Arabic |
Armenian |
Avestan |
Balinese |
Bamum |
Bassa_Vah |
Batak |
Bengali |
Bopomofo |
Brahmi |
Braille |
Buginese |
Buhid |
Canadian_Aboriginal |
Carian |
Caucasian_Albanian |
Chakma |
Cham |
Cherokee |
Common |
Coptic |
Cuneiform |
Cypriot |
Cyrillic |
Deseret |
Devanagari |
Duployan |
Egyptian_Hieroglyphs |
Elbasan |
Ethiopic |
Georgian |
Glagolitic |
Gothic |
Grantha |
Greek |
Gujarati |
Gurmukhi |
Han |
Hangul |
Hanunoo |
Hatran |
Hebrew |
Hiragana |
Imperial_Aramaic |
Inherited |
Inscriptional_Pahlavi |
Inscriptional_Parthian |
Javanese |
Kaithi |
Kannada |
Katakana |
Kayah_Li |
Kharoshthi |
Khmer |
Khojki |
Khudawadi |
Lao |
Latin |
Lepcha |
Limbu |
Linear_A |
Linear_B |
Lisu |
Lycian |
Lydian |
Mahajani |
Malayalam |
Mandaic |
Manichaean |
Meetei_Mayek |
Mende_Kikakui |
Meroitic_Cursive |
Meroitic_Hieroglyphs |
Miao |
Modi |
Mongolian |
Mro |
Multani |
Myanmar |
Nabataean |
New_Tai_Lue |
Nko |
Ogham |
Ol_Chiki |
Old_Hungarian |
Old_Italic |
Old_North_Arabian |
Old_Permic |
Old_Persian |
Old_South_Arabian |
Old_Turkic |
Oriya |
Osmanya |
Pahawh_Hmong |
Palmyrene |
Pau_Cin_Hau |
Phags_Pa |
Phoenician |
Psalter_Pahlavi |
Rejang |
Runic |
Samaritan |
Saurashtra |
Sharada |
Shavian |
Siddham |
SignWriting |
Sinhala |
Sora_Sompeng |
Sundanese |
Syloti_Nagri |
Syriac |
Tagalog |
Tagbanwa |
Tai_Le |
Tai_Tham |
Tai_Viet |
Takri |
Tamil |
Telugu |
Thaana |
Thai |
Tibetan |
Tifinagh |
Tirhuta |
Ugaritic |
Vai |
Warang_Citi |
Yi |
| Vim character classes | |
|---|---|
\\i | identifier character (NOT SUPPORTED) VIM |
\\I | \\i except digits (NOT SUPPORTED) VIM |
\\k | keyword character (NOT SUPPORTED) VIM |
\\K | \\k except digits (NOT SUPPORTED) VIM |
\\f | file name character (NOT SUPPORTED) VIM |
\\F | \\f except digits (NOT SUPPORTED) VIM |
\\p | printable character (NOT SUPPORTED) VIM |
\\P | \p except digits (NOT SUPPORTED) VIM |
\s | whitespace character (≡ [ \\t]) (NOT SUPPORTED) VIM |
\\S | non-white space character (≡ [^ \\t]) (NOT SUPPORTED) VIM |
\\d | digits (≡ [0-9]) VIM |
\\D | not \\d VIM |
\\x | hex digits (≡ [0-9A-Fa-f]) (NOT SUPPORTED) VIM |
\\X | not \\x (NOT SUPPORTED) VIM |
\\o | octal digits (≡ [0-7]) (NOT SUPPORTED) VIM |
\\O | not \\o (NOT SUPPORTED) VIM |
\\w | word character VIM |
\\W | not \\w VIM |
\\h | head of word character (NOT SUPPORTED) VIM |
\\H | not \\h (NOT SUPPORTED) VIM |
\\a | alphabetic (NOT SUPPORTED) VIM |
\\A | not \\a (NOT SUPPORTED) VIM |
\\l | lowercase (NOT SUPPORTED) VIM |
\\L | not lowercase (NOT SUPPORTED) VIM |
\\u | uppercase (NOT SUPPORTED) VIM |
\\U | not uppercase (NOT SUPPORTED) VIM |
\\_x | \\x plus newline, for any x (NOT SUPPORTED) VIM |
\\c | ignore case (NOT SUPPORTED) VIM |
\\C | match case (NOT SUPPORTED) VIM |
\\m | magic (NOT SUPPORTED) VIM |
\\M | nomagic (NOT SUPPORTED) VIM |
\\v | verymagic (NOT SUPPORTED) VIM |
\\V | verynomagic (NOT SUPPORTED) VIM |
\\Z | ignore differences in Unicode combining characters (NOT SUPPORTED) VIM |
| Magic | |
|---|---|
(?{code}) | arbitrary Perl code (NOT SUPPORTED) PERL |
(??{code}) | postponed arbitrary Perl code (NOT SUPPORTED) PERL |
(?n) | recursive call to regexp capturing group n (NOT SUPPORTED) |
(?+n) | recursive call to relative group +n (NOT SUPPORTED) |
(?-n) | recursive call to relative group -n (NOT SUPPORTED) |
(?C) | PCRE callout (NOT SUPPORTED) PCRE |
(?R) | recursive call to entire regexp (≡ (?0)) (NOT SUPPORTED) |
(?&name) | recursive call to named group (NOT SUPPORTED) |
(?P=name) | named backreference (NOT SUPPORTED) |
(?P>name) | recursive call to named group (NOT SUPPORTED) |
(?(cond)true|false) | conditional branch (NOT SUPPORTED) |
(?(cond)true) | conditional branch (NOT SUPPORTED) |
(*ACCEPT) | make regexps more like Prolog (NOT SUPPORTED) |
(*COMMIT) | (NOT SUPPORTED) |
(*F) | (NOT SUPPORTED) |
(*FAIL) | (NOT SUPPORTED) |
(*MARK) | (NOT SUPPORTED) |
(*PRUNE) | (NOT SUPPORTED) |
(*SKIP) | (NOT SUPPORTED) |
(*THEN) | (NOT SUPPORTED) |
(*ANY) | set newline convention (NOT SUPPORTED) |
(*ANYCRLF) | (NOT SUPPORTED) |
(*CR) | (NOT SUPPORTED) |
(*CRLF) | (NOT SUPPORTED) |
(*LF) | (NOT SUPPORTED) |
(*BSR_ANYCRLF) | set \\R convention (NOT SUPPORTED) PCRE |
(*BSR_UNICODE) | (NOT SUPPORTED) PCRE |
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