A tiny regex engine.
Plan to be compatible with "Secret Labs' Regular Expression Engine"(SRE for python).
warning: the project already works fine, but slow
Features:
-
utf-8 support
Cheers for unicode! -
no octal number
\1 means group 1, \1-100 means group n, \01 match \1, \07 match \7, \08 match ['\0', '8'], \377 match 0o377, but \400 isn't match with 0o400 and [chr(0o40), '\0']!
What the hell ... I choose go die! Go away octal number! -
custom maximum number of backtracking
An evil regex: 'a?'*n+'a'*n against 'a'*n
For example: 'a?a?a?a?a?a?a?a?a?a?a?a?a?a?a?a?a?a?a?a?a?a?a?a?a?aaaaaaaaaaaaaaaaaaaaaaaaa' matches 'aaaaaaaaaaaaaaaaaaaaaaaaa'
It will takes a long time because of too many times of backtracking. Perl/Python/PCRE requires over 10^15 years to match a 29-character string.
You can set a limit to backtracking times to avoid this situation, and the match will be falied. -
more than 100 groups ...
but who cares?
Supported:
- "." Matches any character except a newline.
- "^" Matches the start of the string.
- "$" Matches the end of the string or just before the newline at the end of the string.
- "*" Matches 0 or more (greedy) repetitions of the preceding RE. Greedy means that it will match as many repetitions as possible.
- "+" Matches 1 or more (greedy) repetitions of the preceding RE.
- "?" Matches 0 or 1 (greedy) of the preceding RE.
- *?,+?,?? Non-greedy versions of the previous three special characters.
- {m} Matches m copies of the previous RE.
- {m,n} Matches from m to n repetitions of the preceding RE.
- {m,n}? Non-greedy version of the above.
- "\" Either escapes special characters or signals a special sequence.
- "\1-N" Matches the text matched earlier by the group index.
- [] Indicates a set of characters.
- [^] A "^" as the first character indicates a complementing set.
- "|" A|B, creates an RE that will match either A or B.
- (...) Matches the RE inside the parentheses. The contents can be retrieved or matched later in the string.
- (?ims) Set the I, M or S flag for the RE (see below).
- (?:...) Non-grouping version of regular parentheses.
- (?P...) The substring matched by the group is accessible by name.
- (?P=name) Matches the text matched earlier by the group named name.
- (?#...) A comment; ignored.
- (?=...) Matches if ... matches next, but doesn't consume the string.
- (?!...) Matches if ... doesn't match next.
- (?<=...) Matches if preceded by ... (must be fixed length).
- (?<!...) Matches if not preceded by ... (must be fixed length).
- (?(id/name)yes|no) Matches yes pattern if the group with id/name matched, the (optional) no pattern otherwise.
- \d \D \w \W \s \S
- Flag: DOTALL
- Flag: IGNORECASE
- Flag: MULTILINE
Some of the functions in this module takes flags as optional parameters:
- I IGNORECASE Perform case-insensitive matching.
- M MULTILINE "^" matches the beginning of lines (after a newline) as well as the string. "$" matches the end of lines (before a newline) as well as the end of the string.
- S DOTALL "." matches any character at all, including the newline.
C/C++
#include "tinyre.h"
tre_Pattern* pattern;
tre_Match* match;
pattern = tre_compile("^(bb)*a", 0);
match = tre_match(pattern, "bbbbabc", 0);
// Group 0: bbbba
// Group 1: bb
Python
Edit CMakefile.txt, change build_target to py3lib, disable debug
project (tinyre)
#set(CMAKE_BUILD_TYPE Debug)
#set(build_target demo)
set(build_target py3lib)
mkdir build
cd build && cmake .. && make
cp ./_tinyre.so ../lib_py3
cd ../lib_py3
python3
import tre
tre.match("^(bb)*a", "bbbbabc")
License:zlib