Automatic exclusion marking

{
function c_answer_prompt(prompt)
  if prompt == "Really walk into a travel-excluded area?" then
    return true
  end
end
}

{
function unmark_monsters()
los = you.los()
 for i = -los,los do
    for j = -los,los do
      m = monster.get_monster_at(i,j)
      if m then
        local feat = view.feature_at(i,j)
        if not feat_is_stair(feat) then
          travel.del_exclude(i,j,0)
        end
      end
    end
  end
end
}


{
function unmark_feet()
  local feat = view.feature_at(0,0)
  los = you.los()
  if not feat_is_stair(feat) then
    travel.del_exclude(0,0,0)
  end
end
}
{
function mark_all()
  los = you.los()
  for i = -los-1,los+1 do
    for j = -los-1,los+1 do
      local feat = view.feature_at(i,j)
      if should_exclude(feat) then
	travel.set_exclude(i,j,0)
      end
      if should_unexclude(feat) then
        travel.del_exclude(i,j,0)
      end
    end
  end
end
}


{
function ready()
  mark_all()
  unmark_monsters()
  unmark_feet()
end
}

{
function should_exclude(feat)
  return (not feat_is_floor(feat))
end
}

{
function should_unexclude(feat)
  return feat_is_stair(feat) or feat_is_door(feat)
end
}

{
function feat_is_floor(feat)
  return feat:find("floor")
         or feat:find("water")
         or feat:find("lava")
         or feat:find("altar")
end
}

{
function feat_is_door(feat)
  return feat:find("door")
end
}

{
function feat_is_stair(feat)
  return (feat:find("stone_stairs_up") or
         (feat:find("exit_") and (feat == "exit_hell" or feat == "exit_vaults"
          or feat == "exit_zot" or feat == "exit_slime_pits"
          or feat == "exit_orcish_mines" or feat == "exit_lair"
          or feat == "exit_crypt" or feat == "exit_snake_pit"
          or feat == "exit_elven_halls" or feat == "exit_tomb"
          or feat == "exit_swamp" or feat == "exit_shoals"
          or feat == "exit_spider_nest" or feat == "exit_depths"
          or feat == "exit_temple" or feat == "exit_dungeon"))
          or feat == "escape_hatch_up"
          or feat:find("stone_stairs_down")
          or feat:find("enter_")
          or feat == "escape_hatch_down")
end
}