Tuple Module

wiki

--[[



	(...) -> tuple

	wrap(t, [n]) -> tuple



]]



local setmetatable, select, table, tostring =

	  setmetatable, select, table, tostring



setfenv(1, {})



local meta = {__type = 'tuple'}



local function wrap(t, n)

	t.n = n or t.n or #t

	setmetatable(t, meta)

	return t

end



local function new(...)

	return wrap({n=select('#',...),...})

end



function meta:__eq(other)

	if self.n ~= other.n then

		return false

	end

	for i=1,self.n do

		if self[i] ~= other[i] then

			return false

		end

	end

	return true

end



function meta:__tostring()

	local t = {}

	for i=1,self.n do

		t[i] = tostring(self[i])

	end

	return '('..table.concat(t, ', ', 1, self.n)..')'

end



local M = {

	meta = meta,

	wrap = wrap,

	new = new,

}



return setmetatable(M, {__call = function(_,...) return new(...) end})

See also

A similar approach by Renato Maia: http://www.tecgraf.puc-rio.br/~maia/lua/tuple/