README.md
# tinyre ver 0.9.2
[](https://travis-ci.org/fy0/tinyre)
[](https://codeclimate.com/github/fy0/tinyre)
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.
* "$" Matches the end of the string or just before the newline at the end of the string.
* "*" Matches 0 or more (greedy) repetitions of the preceding RE. Greedy means that it will match as many repetitions as possible.
* "+" Matches 1 or more (greedy) repetitions of the preceding RE.
* "?" Matches 0 or 1 (greedy) of the preceding RE.
* *?,+?,?? Non-greedy versions of the previous three special characters.
* {m} Matches m copies of the previous RE.
* {m,n} Matches from m to n repetitions of the preceding RE.
* {m,n}? Non-greedy version of the above.
* "\\" Either escapes special characters or signals a special sequence.
* "\\1-N" Matches the text matched earlier by the group index.
* [] Indicates a set of characters.
* [^] A "^" as the first character indicates a complementing set.
* "|" A|B, creates an RE that will match either A or B.
* (...) Matches the RE inside the parentheses. The contents can be retrieved or matched later in the string.
* (?ims) Set the I, M or S flag for the RE (see below).
* (?:...) Non-grouping version of regular parentheses.
* (?P<name>...) The substring matched by the group is accessible by name.
* (?P=name) Matches the text matched earlier by the group named name.
* (?#...) A comment; ignored.
* (?=...) Matches if ... matches next, but doesn't consume the string.
* (?!...) Matches if ... doesn't match next.
* (?<=...) Matches if preceded by ... (must be fixed length).
* (?<!...) Matches if not preceded by ... (must be fixed length).
* (?(id/name)yes|no) Matches yes pattern if the group with id/name matched, the (optional) no pattern otherwise.
* \\d \\D \\w \\W \\s \\S
* Flag: DOTALL
* Flag: IGNORECASE
* Flag: MULTILINE
Some of the functions in this module takes flags as optional parameters:
* I IGNORECASE Perform case-insensitive matching.
* M MULTILINE "^" matches the beginning of lines (after a newline) as well as the string. "$" 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.
## Use
**C/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
```cmake
project (tinyre)
#set(CMAKE_BUILD_TYPE Debug)
#set(build_target demo)
set(build_target py3lib)
```
```bash
mkdir build
cd build && cmake .. && make
cp ./_tinyre.so ../lib_py3
cd ../lib_py3
python3
```
```Python
import tre
tre.match("^(bb)*a", "bbbbabc")
```
## Doc
[基础设计](https://github.com/fy0/tinyre/wiki/%E5%9F%BA%E7%A1%80%E8%AE%BE%E8%AE%A1)
[TODO列表](https://github.com/fy0/tinyre/wiki/todo-%E5%88%97%E8%A1%A8)
[更新记录](https://github.com/fy0/tinyre/wiki/%E6%9B%B4%E6%96%B0%E8%AE%B0%E5%BD%95)
License：zlib