FRPath

# dig/bridge forward and then right
lenF=18
lenR=123
slot = 1

function DoOne()
    turtle.digUp()
    turtle.dig()
    if not turtle.detectDown() then
        success, errStr = turtle.placeDown()
        wrapped = False
        while errStr == "No items to place" do
            slot = slot + 1
            if slot==17 and wrapped then
                print(errStr)
                error()
            elseif slot==17 then
                slot=1
                wrap=True
            end
            turtle.select(slot)
            errStr = ''
            success, errStr = turtle.placeDown()
        end
    end
    turtle.forward()
end

if lenF>0 then
    for i=1,lenF do
       DoOne()
    end
end

if lenR>0 then
    turtle.turnRight()
    for i=1,lenR do
        DoOne()
    end
    turtle.turnRight()
    DoOne()
    turtle.turnRight()
    for i=1,lenR-1 do
        DoOne()
    end
end
if lenF>0 then
    turtle.turnLeft()
    for i=1,lenF-1 do
        DoOne()
    end
end