local function replace_or_place_block( direction )

    if direction == "up" then
        if turtle.detectUp() then
            if ( not(turtle.compareUp()) ) then turtle.digUp() turtle.placeUp()
            end

            else turtle.placeUp()
    end

    elseif direction == "down" then
if turtle.detectDown() then
    if ( not(turtle.compareDown()) ) then turtle.digDown() turtle.placeDown()
    end

    else turtle.placeDown()
end

elseif direction == "forward" then
if turtle.detect() then
    if ( not(turtle.compare()) ) then turtle.dig() turtle.place()
    end

    else turtle.place()
end

else
throw("Invalid direction")
end

end

local function buildFloor(length, width)

    for w = 1, width do
        for l = 1, length do
        end

    end

end

return {floorBuilder = buildFloor}

ssdasdasd

Test