How would I make this shifting variable function work?

Help and Feedback Scripting Support
#1

I am trying to achieve a way that a new variable is being shifted to left, left to middle, and middle to right, the problem is I can’t quite wrap my head around this function and am therefore stuck with this current function and have no idea how to actually do what I am trying to achieve nor how to properly call it, any help is appreciated.

local Left,Middle,Right = "","",""
local function ShiftNewVarls()
	local Next = ""
	URLTable = TableModule.Shift(URLTable,DirectBool)
	IDTable = TableModule.Shift(IDTable,DirectBool)
	Next = {
		Url = URLTable[1],
		Id = IDTable[1]
	}
				
	if Left == "" or Left == nil then
		Left = Next
	elseif Middle == "" or Middle == nil then
		Middle = Left
	elseif Right == "" or Middle == nil then
		Right = Middle
	end
end
#2

I believe a table-type approach to this would be a more intuitive approach
Whether you have left,middle,right or {1,2,3} it should not matter because you can convert the phrase left,middle,right to {left,middle,right}

I would imagine a table based approach would go something like this:

local lmr = {"a","b","c"}
function shift()
    local temp = {} --create a temporary table so it doesnt interfere w/ itself
    for i = 1,#lmr do --iterate through the whole tables indices
        temp[i % #lmr + 1] = lmr[i] 
        --i % #lmr gets the remainder of the index and the number of items in lmr
        --this allows the "remaining" (remainder) index (from when you move the last to first)
        --to wrap around to the beginning again
        --beyond this more confusing line it obviously just adds one to the index then assigns it
    end
    lmr = temp
    --after all is said and done, you can finally give lmr temps value
    --it cant interfere with itself anymore
end
shift()
print(lmr) --> c a b

If youre unsure how to convert Left,Middle,Right to a table, assuming your program requires a specific left middle and right variable for whatever reason, I would do something along the following lines:

local left,middle,right = "a","b","c"
function shift()
    local lmr = {left,middle,right}
    local temp = {}
    for i = 1,#lmr do
        temp[i % #lmr + 1] = lmr[i]
    end
    left,middle,right = unpack(temp)
end
shift()
print(lmr) --> c a b