---@meta

---
---@meta
---The definitions are developed in this repository: https://github.com/LuaCATS/lpeg

---
---This type definition is based on the [HTML documentation](http://www.inf.puc-rio.br/~roberto/lpeg/) of the LPeg library. A different HTML documentation can be found at http://stevedonovan.github.io/lua-stdlibs/modules/lpeg.html.
---
---*LPeg* is a new pattern-matching library for Lua,
---based on
---[Parsing Expression Grammars](https://bford.info/packrat/) (PEGs).
---This text is a reference manual for the library.
---For a more formal treatment of LPeg,
---as well as some discussion about its implementation,
---see
---[A Text Pattern-Matching Tool based on Parsing Expression Grammars](http://www.inf.puc-rio.br/~roberto/docs/peg.pdf).
---(You may also be interested in my
---[talk about LPeg](https://vimeo.com/1485123)
---given at the III Lua Workshop.)
---
---Following the Snobol tradition,
---LPeg defines patterns as first-class objects.
---That is, patterns are regular Lua values
---(represented by userdata).
---The library offers several functions to create
---and compose patterns.
---With the use of metamethods,
---several of these functions are provided as infix or prefix
---operators.
---On the one hand,
---the result is usually much more verbose than the typical
---encoding of patterns using the so called
---*regular expressions*
---(which typically are not regular expressions in the formal sense).
---On the other hand,
---first-class patterns allow much better documentation
---(as it is easy to comment the code,
---to break complex definitions in smaller parts, etc.)
---and are extensible,
---as we can define new functions to create and compose patterns.
---
---😱 [Types](https://github.com/LuaCATS/lpeg/blob/main/library/lpeg.lua) incomplete or incorrect? 🙏 [Please contribute!](https://github.com/LuaCATS/lpeg/pulls)
local lpeg = {}

---
---😱 [Types](https://github.com/LuaCATS/lpeg/blob/main/library/lpeg.lua) incomplete or incorrect? 🙏 [Please contribute!](https://github.com/LuaCATS/lpeg/pulls)
---@class Pattern
---@operator unm: Pattern
---@operator add(Pattern): Pattern
---@operator sub(Pattern): Pattern
---@operator mul(Pattern): Pattern
---@operator mul(Capture): Pattern
---@operator div(string): Capture
---@operator div(number): Capture
---@operator div(table): Capture
---@operator div(function): Capture
---@operator pow(number): Pattern
---@operator mod(function): nil
local Pattern = {}

---
---😱 [Types](https://github.com/LuaCATS/lpeg/blob/main/library/lpeg.lua) incomplete or incorrect? 🙏 [Please contribute!](https://github.com/LuaCATS/lpeg/pulls)
---@alias Capture Pattern
---@operator add(Capture): Pattern
---@operator mul(Capture): Pattern
---@operator mul(Pattern): Pattern
---@operator div(string): Capture
---@operator div(number): Capture
---@operator div(table): Capture
---@operator div(function): Capture
---@operator pow(number): Pattern

---
---Match the given `pattern` against the `subject` string.
---
---If the match succeeds,
---returns the index in the subject of the first character after the match,
---or the captured values
---(if the pattern captured any value).
---
---An optional numeric argument `init` makes the match
---start at that position in the subject string.
---As usual in Lua libraries,
---a negative value counts from the end.
---
---Unlike typical pattern-matching functions,
---`match` works only in anchored mode;
---that is, it tries to match the pattern with a prefix of
---the given subject string (at position `init`),
---not with an arbitrary substring of the subject.
---So, if we want to find a pattern anywhere in a string,
---we must either write a loop in Lua or write a pattern that
---matches anywhere.
---This second approach is easy and quite efficient;
---
---__Example:__
---
---```lua
---local pattern = lpeg.R('az') ^ 1 * -1
---assert(pattern:match('hello') == 6)
---assert(lpeg.match(pattern, 'hello') == 6)
---assert(pattern:match('1 hello') == nil)
---```
---
---@param pattern Pattern
---@param subject string
---@param init? integer
---
---@return any ...
---
---😱 [Types](https://github.com/LuaCATS/lpeg/blob/main/library/lpeg.lua) incomplete or incorrect? 🙏 [Please contribute!](https://github.com/LuaCATS/lpeg/pulls)
function lpeg.match(pattern, subject, init) end

---
---Match the given `pattern` against the `subject` string.
---
---If the match succeeds,
---returns the index in the subject of the first character after the match,
---or the captured values
---(if the pattern captured any value).
---
---An optional numeric argument `init` makes the match
---start at that position in the subject string.
---As usual in Lua libraries,
---a negative value counts from the end.
---
---Unlike typical pattern-matching functions,
---`match` works only in anchored mode;
---that is, it tries to match the pattern with a prefix of
---the given subject string (at position `init`),
---not with an arbitrary substring of the subject.
---So, if we want to find a pattern anywhere in a string,
---we must either write a loop in Lua or write a pattern that
---matches anywhere.
---This second approach is easy and quite efficient;
---
---__Example:__
---
---```lua
---local pattern = lpeg.R('az') ^ 1 * -1
---assert(pattern:match('hello') == 6)
---assert(lpeg.match(pattern, 'hello') == 6)
---assert(pattern:match('1 hello') == nil)
---```
---
---@param subject string
---@param init? integer
---
---@return any ...
---
---😱 [Types](https://github.com/LuaCATS/lpeg/blob/main/library/lpeg.lua) incomplete or incorrect? 🙏 [Please contribute!](https://github.com/LuaCATS/lpeg/pulls)
function Pattern:match(subject, init) end

---
---Return the string `"pattern"` if the given value is a pattern, otherwise `nil`.
---
---@return 'pattern'|nil
---
---😱 [Types](https://github.com/LuaCATS/lpeg/blob/main/library/lpeg.lua) incomplete or incorrect? 🙏 [Please contribute!](https://github.com/LuaCATS/lpeg/pulls)
function lpeg.type(value) end

---
---Return a string with the running version of LPeg.
---
---@return string
---
---😱 [Types](https://github.com/LuaCATS/lpeg/blob/main/library/lpeg.lua) incomplete or incorrect? 🙏 [Please contribute!](https://github.com/LuaCATS/lpeg/pulls)
function lpeg.version() end

---
---Set a limit for the size of the backtrack stack used by LPeg to
---track calls and choices.
---
---The default limit is `400`.
---Most well-written patterns need little backtrack levels and
---therefore you seldom need to change this limit;
---before changing it you should try to rewrite your
---pattern to avoid the need for extra space.
---Nevertheless, a few useful patterns may overflow.
---Also, with recursive grammars,
---subjects with deep recursion may also need larger limits.
---
---@param max integer
---
---😱 [Types](https://github.com/LuaCATS/lpeg/blob/main/library/lpeg.lua) incomplete or incorrect? 🙏 [Please contribute!](https://github.com/LuaCATS/lpeg/pulls)
function lpeg.setmaxstack(max) end

---
---Convert the given value into a proper pattern.
---
---The following rules are applied:
---
---* If the argument is a pattern,
---it is returned unmodified.
---
---* If the argument is a string,
---it is translated to a pattern that matches the string literally.
---
---* If the argument is a non-negative number `n`,
---the result is a pattern that matches exactly `n` characters.
---
---* If the argument is a negative number `-n`,
---the result is a pattern that
---succeeds only if the input string has less than `n` characters left:
---`lpeg.P(-n)`
---is equivalent to `-lpeg.P(n)`
---(see the unary minus operation).
---
---* If the argument is a boolean,
---the result is a pattern that always succeeds or always fails
---(according to the boolean value),
---without consuming any input.
---
---* If the argument is a table,
---it is interpreted as a grammar
---(see Grammars).
---
---* If the argument is a function,
---returns a pattern equivalent to a
---match-time capture over the empty string.
---
---@param value Pattern|string|integer|boolean|table|function
---
---@return Pattern
---
---😱 [Types](https://github.com/LuaCATS/lpeg/blob/main/library/lpeg.lua) incomplete or incorrect? 🙏 [Please contribute!](https://github.com/LuaCATS/lpeg/pulls)
function lpeg.P(value) end

---
---Return a pattern that
---matches only if the input string at the current position
---is preceded by `patt`.
---
---Pattern `patt` must match only strings
---with some fixed length,
---and it cannot contain captures.
---
---Like the `and` predicate,
---this pattern never consumes any input,
---independently of success or failure.
---
---@param pattern Pattern|string|integer|boolean|table
---
---@return Pattern
---
---😱 [Types](https://github.com/LuaCATS/lpeg/blob/main/library/lpeg.lua) incomplete or incorrect? 🙏 [Please contribute!](https://github.com/LuaCATS/lpeg/pulls)
function lpeg.B(pattern) end

---
---Return a pattern that matches any single character
---belonging to one of the given ranges.
---
---Each `range` is a string `xy` of length 2,
---representing all characters with code
---between the codes of `x` and `y`
---(both inclusive).
---
---As an example, the pattern
---`lpeg.R('09')` matches any digit,
---and `lpeg.R('az', 'AZ')` matches any ASCII letter.
---
---__Example:__
---
---```lua
---local pattern = lpeg.R('az') ^ 1 * -1
---assert(pattern:match('hello') == 6)
---```
---
---@param ... string
---
---@return Pattern
---
---😱 [Types](https://github.com/LuaCATS/lpeg/blob/main/library/lpeg.lua) incomplete or incorrect? 🙏 [Please contribute!](https://github.com/LuaCATS/lpeg/pulls)
function lpeg.R(...) end

---
---Return a pattern that matches any single character that
---appears in the given string.
---(The `S` stands for Set.)
---
---As an example, the pattern
---`lpeg.S('+-*/')` matches any arithmetic operator.
---
---Note that, if `s` is a character
---(that is, a string of length 1),
---then `lpeg.P(s)` is equivalent to `lpeg.S(s)`
---which is equivalent to `lpeg.R(s..s)`.
---Note also that both `lpeg.S('')` and `lpeg.R()`
---are patterns that always fail.
---
---@param string string
---
---@return Pattern
---
---😱 [Types](https://github.com/LuaCATS/lpeg/blob/main/library/lpeg.lua) incomplete or incorrect? 🙏 [Please contribute!](https://github.com/LuaCATS/lpeg/pulls)
function lpeg.S(string) end

---
---Create a non-terminal (a variable) for a grammar.
---
---This operation creates a non-terminal (a variable)
---for a grammar.
---The created non-terminal refers to the rule indexed by `v`
---in the enclosing grammar.
---
---__Example:__
---
---```lua
---local b = lpeg.P({'(' * ((1 - lpeg.S '()') + lpeg.V(1)) ^ 0 * ')'})
---assert(b:match('((string))') == 11)
---assert(b:match('(') == nil)
---```
---
---@param v string|integer
---
---@return Pattern
---
---😱 [Types](https://github.com/LuaCATS/lpeg/blob/main/library/lpeg.lua) incomplete or incorrect? 🙏 [Please contribute!](https://github.com/LuaCATS/lpeg/pulls)
function lpeg.V(v) end

---
---@class Locale
---@field alnum userdata
---@field alpha userdata
---@field cntrl userdata
---@field digit userdata
---@field graph userdata
---@field lower userdata
---@field print userdata
---@field punct userdata
---@field space userdata
---@field upper userdata
---@field xdigit userdata

---
---Return a table with patterns for matching some character classes
---according to the current locale.
---
---The table has fields named
---`alnum`,
---`alpha`,
---`cntrl`,
---`digit`,
---`graph`,
---`lower`,
---`print`,
---`punct`,
---`space`,
---`upper`, and
---`xdigit`,
---each one containing a correspondent pattern.
---Each pattern matches any single character that belongs to its class.
--
---If called with an argument `table`,
---then it creates those fields inside the given table and
---returns that table.
---
---__Example:__
---
---```lua
---lpeg.locale(lpeg)
---local space = lpeg.space ^ 0
---local name = lpeg.C(lpeg.alpha ^ 1) * space
---local sep = lpeg.S(',;') * space
---local pair = lpeg.Cg(name * '=' * space * name) * sep ^ -1
---local list = lpeg.Cf(lpeg.Ct('') * pair ^ 0, rawset)
---local t = list:match('a=b, c = hi; next = pi')
---assert(t.a == 'b')
---assert(t.c == 'hi')
---assert(t.next == 'pi')
---
---local locale = lpeg.locale()
---assert(type(locale.digit) == 'userdata')
---```
---
---@param tab? table
---
---@return Locale
---
---😱 [Types](https://github.com/LuaCATS/lpeg/blob/main/library/lpeg.lua) incomplete or incorrect? 🙏 [Please contribute!](https://github.com/LuaCATS/lpeg/pulls)
function lpeg.locale(tab) end

---
---Create a simple capture.
---
---Creates a simple capture,
---which captures the substring of the subject that matches `patt`.
---The captured value is a string.
---If `patt` has other captures,
---their values are returned after this one.
---
---__Example:__
---
---```lua
---local function split (s, sep)
---  sep = lpeg.P(sep)
---  local elem = lpeg.C((1 - sep) ^ 0)
---  local p = elem * (sep * elem) ^ 0
---  return lpeg.match(p, s)
---end
---
---local a, b, c = split('a,b,c', ',')
---assert(a == 'a')
---assert(b == 'b')
---assert(c == 'c')
---```
---
---@param patt Pattern|string|integer|boolean|table|function
---
---@return Capture
---
---😱 [Types](https://github.com/LuaCATS/lpeg/blob/main/library/lpeg.lua) incomplete or incorrect? 🙏 [Please contribute!](https://github.com/LuaCATS/lpeg/pulls)
function lpeg.C(patt) end

---
---Create an argument capture.
---
---This pattern matches the empty string and
---produces the value given as the nth extra
---argument given in the call to `lpeg.match`.
---
---@param n integer
---
---@return Capture
---
---😱 [Types](https://github.com/LuaCATS/lpeg/blob/main/library/lpeg.lua) incomplete or incorrect? 🙏 [Please contribute!](https://github.com/LuaCATS/lpeg/pulls)
function lpeg.Carg(n) end

---
---Create a back capture.
---
---This pattern matches the empty string and
---produces the values produced by the most recent
---group capture named `name`
---(where `name` can be any Lua value).
---
---Most recent means the last
---complete
---outermost
---group capture with the given name.
---A Complete capture means that the entire pattern
---corresponding to the capture has matched.
---An Outermost capture means that the capture is not inside
---another complete capture.
---
---In the same way that LPeg does not specify when it evaluates captures,
---it does not specify whether it reuses
---values previously produced by the group
---or re-evaluates them.
---
---@param name any
---
---@return Capture
---
---😱 [Types](https://github.com/LuaCATS/lpeg/blob/main/library/lpeg.lua) incomplete or incorrect? 🙏 [Please contribute!](https://github.com/LuaCATS/lpeg/pulls)
function lpeg.Cb(name) end

---
---Create a constant capture.
---
---This pattern matches the empty string and
---produces all given values as its captured values.
---
---@param ... any
---
---@return Capture
---
---😱 [Types](https://github.com/LuaCATS/lpeg/blob/main/library/lpeg.lua) incomplete or incorrect? 🙏 [Please contribute!](https://github.com/LuaCATS/lpeg/pulls)
function lpeg.Cc(...) end

---
---Create a fold capture.
---
---If `patt` produces a list of captures
---C1 C2 ... Cn,
---this capture will produce the value
---`func(...func(func(C1, C2), C3)...,Cn)`,
---that is, it will fold
---(or accumulate, or reduce)
---the captures from `patt` using function `func`.
---
---This capture assumes that `patt` should produce
---at least one capture with at least one value (of any type),
---which becomes the initial value of an accumulator.
---(If you need a specific initial value,
---you may prefix a constant capture to `patt`.)
---For each subsequent capture,
---LPeg calls `func`
---with this accumulator as the first argument and all values produced
---by the capture as extra arguments;
---the first result from this call
---becomes the new value for the accumulator.
---The final value of the accumulator becomes the captured value.
---
---__Example:__
---
---```lua
---local number = lpeg.R('09') ^ 1 / tonumber
---local list = number * (',' * number) ^ 0
---local function add(acc, newvalue) return acc + newvalue end
---local sum = lpeg.Cf(list, add)
---assert(sum:match('10,30,43') == 83)
---```
---
---@param patt Pattern|string|number|boolean|table|function
---@param func fun(acc, newvalue): (acc: any)
---
---@return Capture
---
---😱 [Types](https://github.com/LuaCATS/lpeg/blob/main/library/lpeg.lua) incomplete or incorrect? 🙏 [Please contribute!](https://github.com/LuaCATS/lpeg/pulls)
function lpeg.Cf(patt, func) end

---
---Create a group capture.
---
---It groups all values returned by `patt`
---into a single capture.
---The group may be anonymous (if no name is given)
---or named with the given name
---(which can be any non-nil Lua value).
---
---@param patt Pattern|string|number|boolean|table|function
---@param name? string
---
---@return Capture
---
---😱 [Types](https://github.com/LuaCATS/lpeg/blob/main/library/lpeg.lua) incomplete or incorrect? 🙏 [Please contribute!](https://github.com/LuaCATS/lpeg/pulls)
function lpeg.Cg(patt, name) end

---
---Create a position capture.
---
---It matches the empty string and
---captures the position in the subject where the match occurs.
---The captured value is a number.
---
---__Example:__
---
---```lua
---local I = lpeg.Cp()
---local function anywhere(p) return lpeg.P({I * p * I + 1 * lpeg.V(1)}) end
---
---local match_start, match_end = anywhere('world'):match('hello world!')
---assert(match_start == 7)
---assert(match_end == 12)
---```
---
---@return Capture
---
---😱 [Types](https://github.com/LuaCATS/lpeg/blob/main/library/lpeg.lua) incomplete or incorrect? 🙏 [Please contribute!](https://github.com/LuaCATS/lpeg/pulls)
function lpeg.Cp() end

---
---Create a substitution capture.
---
---This function creates a substitution capture,
---which captures the substring of the subject that matches `patt`,
---with substitutions.
---For any capture inside `patt` with a value,
---the substring that matched the capture is replaced by the capture value
---(which should be a string).
---The final captured value is the string resulting from
---all replacements.
---
---__Example:__
---
---```lua
---local function gsub (s, patt, repl)
---  patt = lpeg.P(patt)
---  patt = lpeg.Cs((patt / repl + 1) ^ 0)
---  return lpeg.match(patt, s)
---end
---assert(gsub('Hello, xxx!', 'xxx', 'World') == 'Hello, World!')
---```
---
---@param patt Pattern|string|number|boolean|table|function
---
---@return Capture
---
---😱 [Types](https://github.com/LuaCATS/lpeg/blob/main/library/lpeg.lua) incomplete or incorrect? 🙏 [Please contribute!](https://github.com/LuaCATS/lpeg/pulls)
function lpeg.Cs(patt) end

---
---Create a table capture.
---
---This capture returns a table with all values from all anonymous captures
---made by `patt` inside this table in successive integer keys,
---starting at 1.
---Moreover,
---for each named capture group created by `patt`,
---the first value of the group is put into the table
---with the group name as its key.
---The captured value is only the table.
---
---@param patt Pattern|string|number|boolean|table|function
---
---@return Capture
---
---😱 [Types](https://github.com/LuaCATS/lpeg/blob/main/library/lpeg.lua) incomplete or incorrect? 🙏 [Please contribute!](https://github.com/LuaCATS/lpeg/pulls)
function lpeg.Ct(patt) end

---
---Create a match-time capture.
---
---Unlike all other captures,
---this one is evaluated immediately when a match occurs
---(even if it is part of a larger pattern that fails later).
---It forces the immediate evaluation of all its nested captures
---and then calls `function`.
---
---The given function gets as arguments the entire subject,
---the current position (after the match of `patt`),
---plus any capture values produced by `patt`.
---
---The first value returned by `fn`
---defines how the match happens.
---If the call returns a number,
---the match succeeds
---and the returned number becomes the new current position.
---(Assuming a subject and current position `i`,
---the returned number must be in the range `[i, len(s) + 1]`.)
---If the call returns true,
---the match succeeds without consuming any input.
---(So, to return true is equivalent to return `i`.)
---If the call returns `false`, `nil`, or no value,
---the match fails.
---
---Any extra values returned by the function become the
---values produced by the capture.
---
---@param patt Pattern|string|number|boolean|table|function
---@param fn fun(s: string, i: integer, ...: any): (position: boolean|number, ...: any)
---
---@return Capture
---
---😱 [Types](https://github.com/LuaCATS/lpeg/blob/main/library/lpeg.lua) incomplete or incorrect? 🙏 [Please contribute!](https://github.com/LuaCATS/lpeg/pulls)
function lpeg.Cmt(patt, fn) end

return lpeg
