diff options
Diffstat (limited to 'doc/RE')
| -rw-r--r-- | doc/RE | 50 |
1 files changed, 31 insertions, 19 deletions
@@ -1,6 +1,6 @@ -Oniguruma Regular Expressions Version 6.9.4 2019/10/31 +Oniguruma Regular Expressions Version 6.9.5 2020/04/09 -syntax: ONIG_SYNTAX_ONIGURUMA (default) +syntax: ONIG_SYNTAX_ONIGURUMA (default syntax) 1. Syntax elements @@ -21,19 +21,28 @@ syntax: ONIG_SYNTAX_ONIGURUMA (default) \f form feed (0x0C) \a bell (0x07) \e escape (0x1B) - \nnn octal char (encoded byte value) - \o{17777777777} wide octal char (character code point value) - \uHHHH wide hexadecimal char (character code point value) - \xHH hexadecimal char (encoded byte value) - \x{7HHHHHHH} wide hexadecimal char (character code point value) - \cx control char (character code point value) - \C-x control char (character code point value) - \M-x meta (x|0x80) (character code point value) - \M-\C-x meta control char (character code point value) + \nnn octal char (encoded byte value) + \xHH hexadecimal char (encoded byte value) + \x{7HHHHHHH} (1-8 digits) hexadecimal char (code point value) + \o{17777777777} (1-11 digits) octal char (code point value) + \uHHHH hexadecimal char (code point value) + \cx control char (code point value) + \C-x control char (code point value) + \M-x meta (x|0x80) (code point value) + \M-\C-x meta control char (code point value) (* \b as backspace is effective in character class only) +2.1 Code point sequences + + Hexadecimal code point (1-8 digits) + \x{7HHHHHHH 7HHHHHHH ... 7HHHHHHH} + + Octal code point (1-11 digits) + \o{17777777777 17777777777 ... 17777777777} + + 3. Character types . any character (except newline) @@ -132,6 +141,7 @@ syntax: ONIG_SYNTAX_ONIGURUMA (default) {,n} at least 0 but no more than n times ({0,n}) {n} n times + reluctant ?? 0 or 1 times @@ -141,6 +151,11 @@ syntax: ONIG_SYNTAX_ONIGURUMA (default) {n,}? at least n times {,n}? at least 0 but not more than n times (== {0,n}?) + {n}? is reluctant operator in ONIG_SYNTAX_JAVA and ONIG_SYNTAX_PERL only. + (In that case, it doesn't make sense to write so.) + In default syntax, /a{n}?/ === /(?:a{n})?/ + + possessive (greedy and does not backtrack once match) ?+ 1 or 0 times @@ -148,8 +163,8 @@ syntax: ONIG_SYNTAX_ONIGURUMA (default) ++ 1 or more times {n,m} (n > m) at least m but not more than n times - {n,m}+, {n,}+, {n}+ are possessive operators in ONIG_SYNTAX_JAVA and - ONIG_SYNTAX_PERL only. + {n,m}+, {n,}+, {n}+ are possessive operators in ONIG_SYNTAX_JAVA and + ONIG_SYNTAX_PERL only. ex. /a*+/ === /(?>a*)/ @@ -279,15 +294,12 @@ syntax: ONIG_SYNTAX_ONIGURUMA (default) (?=subexp) look-ahead (?!subexp) negative look-ahead + (?<=subexp) look-behind (?<!subexp) negative look-behind - Subexp of look-behind must be fixed-width. - But top-level alternatives can be of various lengths. - ex. (?<=a|bc) is OK. (?<=aaa(?:b|cd)) is not allowed. - - In negative look-behind, capturing group isn't allowed, - but non-capturing group (?:) is allowed. + * Cannot use Absent stopper (?~|expr) and Range clear + (?~|) operators in look-behind and negative look-behind. * In look-behind and negative look-behind, support for ignore-case option is limited. Only supports conversion |