README.md

Compatible with Lua 5.3

example.lua

local S = require "sequence".new

local a = S(1,2,nil,4);
a:remove(3);
for i,v in ipairs(a) do print(i,v) end

sequence.lua

local sequence_methods = {}

local sequence_mt = {
	__name = "sequence";
	__index = sequence_methods;
	__len = function(t) return t.n end;
}

local function new(...)
	return setmetatable(table.pack(...), sequence_mt)
end

sequence_methods.concat = table.concat
sequence_methods.unpack = table.unpack
sequence_methods.sort = table.sort

-- Functions that mutate

function sequence_methods:insert(...)
	table.insert(self, ...)
	self.n = self.n + 1
end

function sequence_methods:remove(pos)
	if pos == nil then
		pos = self.n
	elseif pos > self.n + 1 then
		error("bad argument #1 to 'remove' (position out of bounds)")
	end
	local v = table.remove(self, pos)
	if self.n > 0 then
		self.n = self.n - 1
	end
	return v
end

function sequence_methods:move(f, e, t, dest)
	dest = dest or self
	table.move(self, f, e, t, dest)
	if getmetatable(dest) == sequence_mt then
		local dest_last = e-f+t
		if dest_last > dest.n then
			dest.n = dest_last
		end
	end
end

-- __ipairs was deprecated in 5.3, support may be compiled out.
local function inext(self, last)
	if last >= #self then return end
	local i = last+1
	return i, self[i]
end
function sequence_mt:__ipairs()
	return inext, self, 0
end

return {
	new = new;
}