where there = step here direction
-- robot = _droid $ hull!here
-- robot = fromJust $ preview (at here . _Just . isGoal) hull
- robot = fromJust $ hull ^? at here . _Just . droid
+ -- robot = fromJust $ hull ^? at here . _Just . droid
+ robot = fromJust $ hull ^? ix here . droid
-- distance = _fromStart $ hull!here
- distance = fromJust $ hull ^? at here . _Just . fromStart
+ distance = fromJust $ hull ^? ix here . fromStart
(robot', found) = runDroid robot direction
-- newCell = Vacant { _droid = robot'
-- , _fromStart = distance + 1