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https://github.com/khchen/tinyre
Tiny Regex for Nim
https://github.com/khchen/tinyre
Last synced: 21 days ago
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Tiny Regex for Nim
- Host: GitHub
- URL: https://github.com/khchen/tinyre
- Owner: khchen
- License: mit
- Created: 2022-12-11T09:48:49.000Z (almost 2 years ago)
- Default Branch: main
- Last Pushed: 2024-08-11T12:47:39.000Z (about 1 month ago)
- Last Synced: 2024-08-11T13:58:52.459Z (about 1 month ago)
- Language: Nim
- Size: 195 KB
- Stars: 36
- Watchers: 2
- Forks: 1
- Open Issues: 0
-
Metadata Files:
- Readme: readme.md
- Changelog: changelog.md
- License: license.txt
Awesome Lists containing this project
- awesome-nim - tinyre - A tiny regex engine based on Rob Pike's VM implementation. (Language Features / Pattern Matching)
README
[](https://paypal.me/khchen0915?country.x=TW&locale.x=zh_TW)
# TinyRE
TinyRE is a Nim wrap for a tiny regex engine based on Rob Pike's VM
implementation. Compare to other small regex engines, this engine supports
unicode and most of common regex syntax, in less than 10K code size (LOC < 1K),
and guarantees that input regex will scale O(n) with the size of the string.
## Features
* Support unicode.
* Support case-insensitive matching.
* Support global matching.
* Support most common regex syntax, including:
* Greedy and non-greedy expressions: `*`, `+`, `?`, `*?`, `+?`, `??`.
* Characters sets: `[xyz]`, `[a-z]`, `[^xyz]`, `[^m-z]`.
* Meta characters: `\s`, `\S` ,`\w`, `\W`, `\d`, `\D`, `\n`, `\r`, `\t` etc.
* Ascii or unicode characters: `\x00`, `\u0000`, `\U00000000`
* Alternation operator: `|`.
* Beginning and end assertions: `^`, `$`.
* Repetition operators: `{n}`, `{n,m}`, `{n,}`.
* Non-greedy repetition operators: `{n,m}?`, `{n,}?`.
* Group and non-capture group: `(...)`, `(?:...)`.
* Start-of-word, end-of-word, and word/nonword boundary assertions: `\<`, `\>`, `\b`, `\B`.
## Examples
```nim
import tinyre
doAssert match("abc123", re"\d+") == @["123"]
doAssert bounds("abc123", re"\d+") == @[3..5]
doAssert contains("abc123", re"\d+") == true
doAssert startsWith("abc123", re"[a-z]+") == true
doAssert endsWith("abc123", re"\d+") == true
doAssert split("abc123", re"\d+") == @["abc", ""]
doAssert replacef("abc123", re"([a-z]+)(\d+)", "$2$1") == "123abc"
# reG for global matching
doAssert match("abc123", reG".") == @["a", "b", "c", "1", "2", "3"]
# reI for case insensitive matching
doAssert match("abc123", reI"ABC") == @["abc"]
# reU for utf8 matching
doAssert match("中文", reU"..") == @["中文"]
```
## Code Size
Comparing the code size of different regex library.
```nim
# gcc: version 11.1.0 MinGW-W64
# compile options: -d:release -d:danger --opt:size -d:lto -d:strip
# test codes
echo contains("abc123def", "123") # for strutils
echo contains("abc123def", re"\d+") # for regex library
# Results
strutils: 65,536 bytes (no dependence)
std/re: 68,608 bytes (dependence: pcre64.dll: 526,336 bytes)
tinyre: 75,264 bytes (no dependence)
nim regex: 296,448 bytes (no dependence)
```
## Performance
In summary, faster than `std/re` in small string, but slower than `std/re`
in large string. Here is the benchmark result on my computer. The test file
and pattern is from https://github.com/mariomka/regex-benchmark.
```nim
# small string: "abc123def".contains("\d+")
# large string: 6.71 MB text file
# email: [\w\.+-]+@[\w\.-]+\.[\w\.-]+
# uri: [\w]+://[^/\s?#]+[^\s?#]+(?:\?[^\s#]*)?(?:#[^\s]*)?
# ipv4: (?:(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9])\.){3}(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9])
# compile options: -d:release -d:danger --opt:speed -d:lto
name ............................... min time avg time std dv runs
tinyre (small string) .............. 0.366 ms 0.379 ms ±0.018 x1000
std/re (small string) .............. 5.862 ms 6.218 ms ±0.171 x797
nim-regex (small string) .......... 16.132 ms 17.067 ms ±0.580 x288
tinyre (large string, email) ..... 140.684 ms 151.663 ms ±8.625 x33
std/re (large string, email) ...... 44.793 ms 48.884 ms ±2.716 x102
nim-regex (large string, email) .... 3.680 ms 3.921 ms ±0.132 x1000
tinyre (large string, uri) ....... 127.465 ms 131.721 ms ±2.110 x38
std/re (large string, uri) ........ 40.380 ms 42.812 ms ±1.175 x117
nim-regex (large string, uri) ..... 21.400 ms 22.205 ms ±0.344 x225
tinyre (large string, ipv4) ...... 182.995 ms 186.441 ms ±1.057 x27
std/re (large string, ipv4) ........ 4.854 ms 5.965 ms ±0.903 x838
nim-regex (large string, ipv4) ..... 7.569 ms 7.849 ms ±0.159 x635
```
## Docs
* https://khchen.github.io/tinyre
## Reference
* [pikevm](https://github.com/kyx0r/pikevm "pikevm") by Kyryl Melekhin
* [re1.5](https://github.com/pfalcon/re1.5 "re1.5") by Paul Sokolovsky
* [re1.0](https://code.google.com/archive/p/re1/ "re1.0") by Russel Cox
* [Regular Expression Matching: the Virtual Machine Approach](https://swtch.com/~rsc/regexp/regexp2.html "Regular Expression Matching: the Virtual Machine Approach") by Russel Cox
## License
Copyright (c) Chen Kai-Hung, Ward. All rights reserved.
## Donate
If this project help you reduce time to develop, you can give me a cup of coffee :)
[](https://paypal.me/khchen0915?country.x=TW&locale.x=zh_TW)