basic_quarry

local function move(direction, steps)
    if direction == "frwd" then
        for i = 1, steps, 1 do
            turtle.forward()
        end
    elseif direction == "back" then
        for i = 1, steps, 1 do
            turtle.back()
        end
    elseif direction == "up" then
        for i = 1, steps, 1 do
            turtle.up()
        end
    elseif direction == "down" then
        for i = 1, steps, 1 do
            turtle.down()
        end
    else
        error("err: invalid direction")
    end
end

local function turn(direction, steps)
    if direction == "left" then
        for i = 1, steps, 1 do
            turtle.turnLeft()
        end
    elseif direction == "right" then
        for i = 1, steps, 1 do
            turtle.turnRight()
        end
    else
        error("err: invalid direction")
    end
end

-- Depth is positive
local function mine_quarry(max_depth)
    local current_depth = 0

    while current_depth < max_depth do
        turtle.digDown()
        move("down", 1)
        current_depth = current_depth + 1
        turn("right", 1)
        turtle.dig()
        move("frwd", 1)
        turtle.dig()
        move("frwd", 1)
        turn("left", 1)
        turtle.dig()
        move("frwd", 1)
        turn("left", 1)
        turtle.dig()
        move("frwd", 1)
        turtle.dig()
        move("frwd", 1)
        turn("right", 1)
        turtle.dig()
        move("frwd", 1)
        turn("right", 1)
        turtle.dig()
        move("frwd", 1)
        turtle.dig()
        move("frwd", 1)
        turn("right", 1)
        move("frwd", 2)
        turn("right", 1)
        move("frwd", 2)
        turn("right", 1)
    end
end

mine_quarry(3)

print("All done!")