Regex

NFA-based regular expression.

Build

Build with clang 3.4.

cmake -G "Unix Makefiles" && make

Syntax

The following syntax features have been supported.

Metacharacter	Description
.	Matches any single character exclude \n.
|	Alternation, "abc|def" matches abc or def.
[ ]	A bracket expression. Matches a single character that is contained within the brackets. For example, [abcx-z] matches a b c x y z.
[^ ]	Matches a single character that is not contained within the brackets. For example, [^abc] matches any character other than a b c.
^	Matches the beginning of a line or string.
$	Matches the end of a line or string.
( )	Group a series of pattern elements and capture the match result.
(?:)	Group a series of pattern elements, no capture.
?	Matches the preceding pattern element zero or one times.
*	Matches the preceding pattern element zero or more times.
+	Matches the preceding pattern element one or more times.
{m,n}	Matches the preceding pattern element at least m and not more than n times. {3,5} matches 3 to 5 times, {3,} matches 3 or more times, {3} matches 3 times.
(?=)	Group a series of pattern elements as prediction, matches not within the match result.
(?<=)	Group a series of pattern elements as preceding prediction, matches not within the math result.
\b	Matches a word boundary.
\B	Matches boundary except word boundary.
\d	Matches [0-9].
\D	Matches [^0-9].
\f	Matches \f.
\n	Matches \n.
\r	Matches \r.
\s	Matches [\f\n\r\t\v].
\S	Matches [^\f\n\r\t\v].
\t	Matches \t.
\v	Matches \v.
\w	Matches [A-Za-z0-9_].
\W	Matches [^A-Za-z0-9_].

Character classes	ASCII	Description
[:alnum:]	[A-Z a-z 0-9]	Alphanumeric characters
[:alpha:]	[A-Z a-z]	Alphabetic characters
[:blank:]	[ \t]	Space and tab
[:cntrl:]	[\x00-\x1F\x7F]	Control characters
[:digit:]	[0-9]	Digits
[:graph:]	[\x21-\x7E]	Visible characters
[:lower:]	[a-z]	Lowercase letters
[:print:]	[\x20-\x7E]	Visible characters and the space character
[:punct:]	[][!"#$%&'()*+,./:;<=>?@\^_`{|}~-]	Punctuation characters
[:space:]	[ \t\r\n\v\f]	Whitespace characters
[:upper:]	[A-Z]	Uppercase letters
[:word:]	[A-Za-z0-9_]	Alphanumeric characters plus "_"
[:xdigit:]	[A-Fa-f0-9]	Hexadecimal digits