This is a fun thing that allows select Ruby code (namely loops with ranges) to execute as valid Lua code.

luby.lua

--Luby 1.0

function construct_iterator(n)
	local at = 0

	return function()
		at = at + 1
		return n[at]
	end, n
end

local p_meta = {
	__concat = function(first, second)
		local out = {}

		for index = first[1], second[1] do
			out[#out + 1] = index
		end

		return construct_iterator(out)
	end,
	__add = function(first, second)
		return ((type(first) == "table") and first[1] or first) + ((type(second) == "table") and second[1] or second)
	end,
	__sub = function(first, second)
		return ((type(first) == "table") and first[1] or first) - ((type(second) == "table") and second[1] or second)
	end,
	__div = function(first, second)
		return ((type(first) == "table") and first[1] or first) / ((type(second) == "table") and second[1] or second)
	end,
	__mult = function(first, second)
		return ((type(first) == "table") and first[1] or first) * ((type(second) == "table") and second[1] or second)
	end,
}

setmetatable(getfenv(), {
	__newindex = function(self, key, value)
		if (type(value) == "number") then
			rawset(getfenv(), "out", {value})
			setmetatable(out, p_meta)
		end

		rawset(self, key, out or value)
	end
})

return {}

main.rb.lua

print(#require("luby")
)

a = 1
b = 10

for i in (a..b) do
	print(i)
end