Simple mining program

--[[
        mine program
        by Big SHiny Toys
]]--

local function getNumber(title)
    local nOut
    repeat
        write(title)
        nOut = tonumber(read())
    until nOut and nOut > 0
    return nOut
end

local ver = 0.9
local tArgs = {...}

print("\n ---- Basic miner ----\n\tby  : BigSHinyToys\n\tver : "..tostring(ver).."\n")

local depth = tArgs[1] and tonumber(tArgs[1]) or getNumber("Depth  : ")
local length = tArgs[2] and tonumber(tArgs[2]) or getNumber("Length : ")
local width = tArgs[3] and tonumber(tArgs[3]) or getNumber("Width  : ")

turtle.turnLeft()

local function force(dig,move,atk)
    turtle[dig]()
    while not turtle[move]() do
        turtle[move]()
        turtle[atk]()
        sleep(0.5)
    end
end

local right = true
for z = 1,depth do
    force("digDown","down","attackDown")
    right = not right
    for y = 1,length do
        right = not right
        local _ = right and turtle.turnRight() or turtle.turnLeft()
        _ = y == 1 or force("dig","forward","attack")
        _ = right and turtle.turnRight() or turtle.turnLeft()
        for x = 1,width - 1 do
            force("dig","forward","attack")
        end
    end
end