A stack implementation in Roblox

rStack.lua

local rStack = {}
rStack.__index = rStack

function rStack.new()
	local self = setmetatable({}, rStack)
	self.Stack = {}
	return self
end

function rStack:append(value : number)
	table.insert(self.Stack, value)
end

function rStack:pop()
	assert(#self.Stack >= 1, "Stack underflow")
	local ret = self.Stack[#self.Stack]
	table.remove(self.Stack)
	return ret
end

function rStack:add()
	assert(#self.Stack >= 2, "Stack underflow")
	self:append(self:pop()+self:pop())
end

function rStack:sub()
	assert(#self.Stack >= 2, "Stack underflow")
	self:append(self:pop()-self:pop())
end

function rStack:mul()
	assert(#self.Stack >= 2, "Stack underflow")
	self:append(self:pop()*self:pop())
end

function rStack:div()
	assert(#self.Stack >= 2, "Stack underflow")
	self:append(self:pop()/self:pop())
end

function rStack:print()
	assert(#self.Stack >= 1, "Stack underflow")
	print(self:pop())
end

return rStack