https://github.com/cloudflare/lua-re2

RE2's C and Lua interface
https://github.com/cloudflare/lua-re2

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RE2's C and Lua interface

• Host: GitHub
• URL: https://github.com/cloudflare/lua-re2
• Owner: cloudflare
• License: bsd-3-clause
• Created: 2014-07-11T20:07:33.000Z (over 10 years ago)
• Default Branch: master
• Last Pushed: 2023-03-21T13:12:36.000Z (over 1 year ago)
• Last Synced: 2024-04-14T22:17:10.831Z (7 months ago)
• Language: Lua
• Size: 24.4 KB
• Stars: 34
• Watchers: 18
• Forks: 17
• Open Issues: 3
• Metadata Files:
  • Readme: README.md
  • License: LICENSE

Awesome Lists containing this project

• awesome-resty - lua-re2

README

        
C and Lua wrappers for RE2

=========================

C and Lua wrapper for RE2 regular expression library. The Lua wrapper is built on

top of C wrapper.

Lua Functions

=============

The Lua wrapper (lua-re2.lua) exposes following functions:

new

---

`syntax: instance = new()`

Create an instance which pre-allocate some data structures for captures, to obviate

the need of allocating them each time `match` is called.

The default value of the parameter `max-capture` is 40.

compile

-------

`syntax: pattern, capture_num, err_msg = compile(pattern, [options, max_mem])`

Pre-compile the pattern string. Additional options for the regex engine can be passed by

the `options` and `max_mem`; they are corresponding to RE2's `re2::RE2::Options` except

that the `options` is using single character, instead of bitmask, to pass the boolean

options. The respondance between `options` and RE2's `re2::RE2::Options` are following:

|option char|re2::RE2::Options| meaning| default value|

|-----------|-----------------|--------|--------------|

| u         | utf8            |text and pattern are UTF-8; otherwise Latin-1 | true |

| a         | longest_match   |search for longest match, not first match | false |

| e         | log_errors      |log syntax and execution errors to ERROR | true |

| l         | literal         |interpret string as literal, not regexp  | false |

| n         | never_nl        |never match \n, even if it is in regexp  | false |

| s         | dot_nl          |dot matches everything including new line | false |

| c         | never_capture   |parse all parens as non-capturing         | false |

| i         | case_sensitive  |match is case-sensitive (regexp can override with (?i) unless in posix_syntax mode) | true |

| m         | multi-line-mode |^ match after any newline, and $ match any before newline | false |

match

------

`syntax: captures, errmsg = match(instance, pattern, text, cap_idx)`

Match the given pre-compiled `pattern` against the `text`. It returns three variables:

 | `captures` | the specified capture(s), see bellow |

 | `errmsg`   | error message if something wrong took place |

The input parameter `cap_idx` can take one of the following values:

 | -1 | return all captures in an array, i-th (i>=0) element contains i-th capture, and 0-th element is the sub-string which tighly matches the entire pattern|

 | 1 .. the-number-of-capture | return particular capture |

find

-----

`syntax: match_or_not = find(pattern, text)`

return non-nil if match, nil otherwise

match_r

------

`syntax: captures = match_r(instance, pattern, text)`

Match the given pre-compiled `pattern` repeatedly through the full `text`. 

It returns all captures in an array if match, nil otherwise.

C Funtions

==========

  The interface functions are self-descriptive. Please check the `re2c_c.h` for details.