lua-regex

simple regular expression module for lua.

Installation

luarocks install regex

---

re, err = regex.new( pattern [, flgs] )

creates a new regex object.

Parameters

• pattern:string: string containing expression to be compiled.
• flgs:string: regular expression flags that can be combined with any of the following characters.
  • i: Do caseless matching.
  • s: . matches anything including NL.
  • m: ^ and $ match newlines within data.
  • u: Treat pattern and subjects as UTF strings.
  • U: Do not check the pattern for UTF valid.
  • x: Ignore white space and # comments.
  • o: compile-once mode that caching a compiled regex.
  • g: global match.
  • j: enable JIT compilation.

Returns

• re:table: regex object.
• err:string: error message.

Example

local regex = require('regex')
local re, err = regex.new('a(b+)(c+)', 'i')
if re then
    local arr, err = re:match('ABBBCCC')
    if arr then
        print(arr[1]) -- 'ABBBCCC'
        print(arr[2]) -- 'BBB'
        print(arr[3]) -- 'CCC'
    else
        print(err)
    end
else
    print(err)
end

arr, err = regex:match( sbj [, offset] )

matches a compiled regular expression against a given subject string. It returns matched substrings.

Parameters

• sbj:string: the subject string.
• offset:number: offset in the subject at which to start matching.

Returns

• arr:table: array of matched substrings.
• err:string: error message.

arr, err = regex:matches( sbj [, offset] )

almost same as match method but it returns all matched substrings except capture strings.

Parameters

• sbj:string: the subject string.
• offset:number: offset in the subject at which to start matching.

Returns

• arr:table: array of matched substrings.
• err:string: error message.

arr, err = regex:indexof( sbj [, offset] )

almost same as match method but it returns offsets of matched substrings.

Parameters

• sbj:string: the subject string.
• offset:number: offset in the subject at which to start matching.

Returns

• arr:table: array of offsets of matched substrings. 1st index is the start offset of matched substring, and 2nd index is the end offset of matched substring, and 3rd index is the start offset of 1st capture string, and 4th index is the end offset of 1st capture string, and so on.
• err:string: error message.

arr, err = regex:indexesof( sbj [, offset] )

almost same as match method but it returns all offsets of matched substrings except capture strings.

Parameters

• sbj:string: the subject string.
• offset:number: offset in the subject at which to start matching.

Returns

• arr:table: array of offsets of matched substrings. 1st index is the start offset of matched substring, and 2nd index is the end offset of matched substring, and so on.
• err:string: error message.

ok, err = regex:test( sbj [, offset] )

returns true if there is a matched.

Parameters

• sbj:string: the subject string.
• offset:number: offset in the subject at which to start matching.

Returns

• ok:boolean: true on matched.
• err:string: error message.

Static Methods

arr, err = regex.match( sbj, pattern [, flgs [, offset]] )

same as the following code:

local re, err = regex.new( pattern, flgs )
if re then
    return re:match( sbj, offset )
end
return nil, err

arr, err = regex.matches( sbj, pattern [, flgs [, offset]] )

same as the following code:

local re, err = regex.new( pattern, flgs )
if re then
    return re:matches( sbj, offset )
end
return nil, err

arr, err = regex.indexof( sbj, pattern [, flgs [, offset]] )

same as the following code:

local re, err = regex.new( pattern, flgs )
if re then
    return re:indexof( sbj, offset )
end
return nil, err

arr, err = regex.indexesof( sbj, pattern [, flgs [, offset]] )

same as the following code:

local re, err = regex.new( pattern, flgs )
if re then
    return re:indexesof( sbj, offset )
end
return nil, err

ok, err = regex.test( sbj, pattern [, flgs [, offset]] )

same as the following code:

local re, err = regex.new( pattern, flgs )
if re then
    return re:test( sbj, offset )
end
return nil, err