RoadWarrior v 0.07

args = { ... }

if not args[0] and not args[1] then
  write("Usage: RoadWarrior <width> <distance>\n")
  exit()
end

width = tonumber(args[1])
distance = tonumber(args[2])
currentSelection = 1

turningRight = true
currentX = 1
currentY = 1

function determineMaxSelection ()
  for i=1,16 do
    if turtle.getItemCount(i) == nil or turtle.getItemCount(i) == 0 then
      return i - 1
    end
  end

  return 16
end

maxSelection = determineMaxSelection()
if maxSelection < 1 then
  write("\nMust place the road blocks you wish to lay in the turtle, starting in the upper left corner.\n\n")
  exit()
end

function moveForward()
  if turtle.detect() then
    turtle.dig()
  end

  return turtle.forward()
end


function layBlock (selection)
  if selection > maxSelection then
    write("Ran out of blocks to lay.  Stopping.\n\n")
    return false
  end

  leftToDrop = turtle.getItemCount(selection)
  if leftToDrop > 0 then
    if currentSelection ~= selection then
      turtle.select(selection)
    end

    turtle.digDown()
    turtle.placeDown()
    return selection
  else
    layBlock(selection + 1)
    return selection + 1
  end
end

function advance ()
  if currentX == 1 then
    turtle.turnRight()
    moveForward()
    currentX = currentX + 1
  elseif currentX == width then
    turtle.turnLeft()
    turtle.turnLeft()

    for i=1,(width - 1) do
      moveForward()
    end
    turtle.turnRight()
    moveForward()
    currentX = 1
    currentY = currentY + 1
  else
    moveForward()
    currentX = currentX + 1
  end
end


for currentY=1,distance do
  write("\nLaying row "..currentY.." of "..distance..".\n")

  for currentX=1,width do
    write(" laying position ("..currentX..", "..currentY..").\n")
    currentSelection = layBlock(currentSelection)
    if currentSelection == false then
      exit()
    end

    if turtle.detect() then
      turtle.dig()
    end
    advance()
  end
end