lib_neko_0.1.1

dofile("lib_turtle_0.2.3");

local function digBack()
  local rslt;
  turtle.turnLeft();
  turtle.turnLeft();
  rslt = myDig();
  turtle.turnRight();
  turtle.turnRight();
  return rslt;
end

local function dir(name_, fromDir_, compareFunc_, detectFunc_,
                   forwardFunc_, digFunc_, backFunc_, backDigFunc_)
  return
    {
      name        = name_,
      fromDir     = fromDir_,
      compareFunc = compareFunc_,
      detectFunc  = detectFunc_,
      forwardFunc = forwardFunc_,
      digFunc     = digFunc_,
      backFunc    = backFunc_,
      backDigFunc = backDigFunc_,
    };
end

local dirInfo = { };
dirInfo[0] = dir("top",    2, turtle.compareUp,   turtle.detectUp,   myUp,      myDigUp,   myDown, myDigDown);
dirInfo[1] = dir("front",  4, turtle.compare,     turtle.detect,     myForward, myDig,     myBack, digBack);
dirInfo[2] = dir("bottom", 0, turtle.compareDown, turtle.detectDown, myDown,    myDigDown, myUp,   myDigUp);
dirInfo[3] = dir("left",   4, turtle.compare,     turtle.detect,     myForward, myDig,     myBack, digBack);
dirInfo[4] = dir("back",   4, turtle.compare,     turtle.detect,     myForward, myDig,     myBack, digBack);
dirInfo[5] = dir("right",  4, turtle.compare,     turtle.detect,     myForward, myDig,     myBack, digBack);

local stack = { };

local function doCompare(posiFlg, compareFunc, detectFunc, slotAry)
  for i, slot in ipairs(slotAry) do
    turtle.select(slot);
    if compareFunc() then
      return posiFlg;
    end
  end
  if posiFlg then
    return false;
  else
    return detectFunc();
  end
end

local function doNekosogi(posiFlg, dirCode, slotAry)

  local dcDI = dirInfo[dirCode];
  if not doCompare(posiFlg, dcDI.compareFunc, dcDI.detectFunc, slotAry) then
    return;
  end
  if false == dcDI.digFunc() then
    return;
  end
  dcDI.forwardFunc();

  table.insert(stack, { toDir = dirCode, progress = 0 });
  local current = stack[table.maxn(stack)];

  while true do
    if 6 <= current.progress then
      turtle.turnLeft();
      if not dirInfo[current.toDir].backDigFunc() then
        error("Since the return path was shut by unbreakable block, turtle cannot move.");
      end
      dirInfo[current.toDir].backFunc();
      table.remove(stack);

      current = stack[table.maxn(stack)];
      if nil == current then
        break;
      end
    else
      if 3 <= current.progress then
        turtle.turnLeft();
      end
      local curStaIdx = table.maxn(stack);
      if current.progress ~= dirInfo[current.toDir].fromDir then
        local cpDI = dirInfo[current.progress];
        if doCompare(posiFlg, cpDI.compareFunc, cpDI.detectFunc, slotAry) then
          if cpDI.digFunc() then
            cpDI.forwardFunc();
            table.insert(stack, { toDir = current.progress, progress = 0 });
            current = stack[table.maxn(stack)];
          end
        end
      end
      stack[curStaIdx].progress = stack[curStaIdx].progress + 1;
    end
  end
end

-- dirCode : 0(top), 1(front), 2(bottom)
function nekoPosi(dirCode, slotAry)
  doNekosogi(true, dirCode, slotAry);
end

-- dirCode : 0(top), 1(front), 2(bottom)
function nekoNega(dirCode, slotAry)
  doNekosogi(false, dirCode, slotAry);
end