Rustexp

Regex

Subject Use fancy-regex.

Reference

. non-newline char
^ start of line
$ end of line
\b word boundary
\B non-word boundary
\A start of subject
\z end of subject
\d decimal digit
\D non-decimal digit
\s whitespace
\S non-whitespace
\w word character
\W non-word character
(a|z) a or z
[az] a or z
[^az] not a or z
[a-z] a through z
(foo) capture foo
a? 0 or 1 a
a* 0 or more a
a+ 1 or more a
a{3} 3 of a
a{3,} 3 or more a
a{3,5} 3 through 5 a

Modifiers (enable: (?a), disable: (?-a))

u unicode
i case insensitive
s dot matches newline
m multiline
x whitespace ignored

For more information see the documentation for the regex crate .

Additional escapes

\h hex digit ([0-9A-Fa-f])
\H not hex digit ([^0-9A-Fa-f])
\e escape control character
\K keep text out of match
\G anchor to previous match

Capture groups and backreferences

\1 match first capture group
\2 match second capture group
\{N} match Nth capture group
(?<name> exp) capture group named name
\k<name> match capture group name

Lookaround

(?=exp) look-head for exp
(?!exp) negative look-head for exp
(?<=exp) look-behind for exp
(?<!exp) negative look-behind for exp

Atomic groups

(?>exp) no backtracking in exp

Conditions

(?(1)) continue if first capture group matched
(?(<name>)) continue if capture group name matched
(?(1)true|false) if the first capture group matched then execute the true regex expression, else execute false
(?(condition)true|false) if the condition matches then execute the true regex expression, else execute false

For more information see the documentation for the fancy-regex crate .