Turtle Inventory Sorting

local s = 0
local l = 16

local function stack()
    print("Stacking Items")
    for i=1,15 do
        s = turtle.getItemSpace(i)
        for j=i+1,l do
            turtle.select(j)
            if turtle.compareTo(i) then
                turtle.transferTo(i,s)
                if turtle.getItemSpace(i) == 0 then
                    break
                end
            end
        end
    end
end

local function compact()
    print("Compressing Open Space")
    for i=1,l do
        if turtle.getItemCount(i) == 0 then
            for j=i+1,l do
                if turtle.getItemCount(j) > 0 then
                    turtle.select(j)
                    turtle.transferTo(i)
                    break
                end
            end
        end
    end
end

local function vSpace()
    if s == 1 then
        print("Verified space")
        return
    else
        print("Not enough space. Please clear at least 1 slot and press enter")
        read()
        space()
    end
end

local function space()
    print("Checking for available space")

    s = 0

    for i=1,16 do
        if turtle.getItemCount(i) == 0 then
            s = 1
            l = i-1
            break
        end
    end
    vSpace()
end

local function sort()
    print("Commensing sorting")
    for i=1,l-1 do
        for j=i+2,l+1 do
            turtle.select(j)
            if turtle.compareTo(i) then
                turtle.select(i+1)
                turtle.transferTo(l+1,64)
                turtle.select(j)
                turtle.transferTo(i+1,64)
                turtle.select(l+1)
                turtle.transferTo(j,64)
                break
            end
        end
    end
    l=l+1
    compact()
    stack()
    turtle.select(1)
end

stack()
compact()
space()
sort()