rotate

dirTable = {{0, 1, 2, -1}, {-1, 0, 1, 2}, {2, -1, 0, 1}, {1, 2, -1, 0}}

function faceDir(dir, from)
    print("rotating to " .. dir .. " from " .. from)
    turn = dirTable[from][dir]
    turnABS = math.abs(turn)

    if turn == 0 then
        return
    end

    if turn > 0 then
        for i=1, turnABS do
            turtle.turnRight()
        end
    else
        for i=1, turnABS do
            turtle.turnLeft()
        end
    end
    return dir
end