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module Battlemap.Navigator.Path exposing
(
Type,
new,
get_current_location,
get_remaining_points,
follow_directions
)
import Set
import Battlemap.Direction
import Battlemap.Location
import Battlemap.Tile
--------------------------------------------------------------------------------
-- TYPES -----------------------------------------------------------------------
--------------------------------------------------------------------------------
type alias Type =
{
current_location : Battlemap.Location.Type,
visited_locations : (Set.Set Battlemap.Location.Ref),
previous_directions : (List Battlemap.Direction.Type),
remaining_points : Int
}
--------------------------------------------------------------------------------
-- LOCAL -----------------------------------------------------------------------
--------------------------------------------------------------------------------
has_not_been_to : (
Type ->
Battlemap.Location.Type ->
Bool
)
has_not_been_to path location =
(
(path.current_location /= location)
&&
(not
(Set.member
(Battlemap.Location.get_ref location)
path.visited_locations
)
)
)
move_to : (
Type ->
Battlemap.Direction.Type ->
Battlemap.Location.Type ->
Int ->
Type
)
move_to path dir next_loc cost =
{path |
current_location = next_loc,
visited_locations =
(Set.insert
(Battlemap.Location.get_ref path.current_location)
path.visited_locations
),
previous_directions = (dir :: path.previous_directions),
remaining_points = (path.remaining_points - cost)
}
battlemap_backtrack : (
Battlemap.Type ->
Battlemap.Location.Type ->
Battlemap.Type
)
battlemap_backtrack battlemap current_loc =
(Battlemap.apply_to_tile_unsafe
battlemap
current_loc
(Battlemap.Tile.set_direction
Battlemap.Direction.None
)
)
navigator_backtrack : (
Battlemap.Navigator.Type ->
Battlemap.Location.Type ->
(List Battlemap.Direction.Type) ->
Battlemap.Navigator.Type
)
try_backtracking_to path location dir =
case (Util.List.pop nav.previous_directions) of
(Just (head, tail)) ->
if (head == (Battlemap.Direction.opposite_of dir))
then
(backtrack_to
nav
next_location
tail
)
)
else
(battlemap, nav)
Nothing -> (battlemap, nav)
move_to path next_location
if (can_move_to_new_tile path next_location)
then
else
{nav |
current_location = next_loc,
visited_locations =
(Set.remove
(Battlemap.Location.get_ref next_loc)
nav.visited_locations
),
previous_directions = prev_dir_tail,
remaining_points = (nav.remaining_points + 1)
}
to : (
Type ->
Battlemap.Direction.Type ->
(Battlemap.Type, Battlemap.Navigator.Type)
)
to battlemap nav dir char_list =
--------------------------------------------------------------------------------
-- EXPORTED --------------------------------------------------------------------
--------------------------------------------------------------------------------
new : Battlemap.Location.Type -> Int -> Type
new start points =
{
current_location = start,
visited_locations = Set.empty,
previous_directions = [],
remaining_points = points
}
get_current_location : Type -> Battlemap.Location.Type
get_current_location path = path.current_location
get_remaining_points : Type -> Int
get_remaining_points path = path.remaining_points
follow_direction : (
(Battlemap.Location.Type -> Bool) ->
(Maybe Type) ->
Battlemap.Direction.Type ->
(Maybe Type)
)
follow_direction can_cross cost_fun maybe_path dir =
case maybe_path of
(Just path) ->
let
next_location =
(Battlemap.Location.neighbor
nav.current_location
dir
)
in
if (can_cross path next_location)
then
if (has_not_been_to path next_location)
then
(Just (move_to path next_location dir))
else
(try_backtracking_to path next_location dir)
else
Nothing
else
(battlemap, nav)
Nothing -> Nothing
|