1 files changed, 50 insertions, 0 deletions
diff --git a/client/elm/battlemap/src/Battlemap/Navigator.elm b/client/elm/battlemap/src/Battlemap/Navigator.elm
new file mode 100644
index 0000000..ffd52cc
--- /dev/null
+++ b/client/elm/battlemap/src/Battlemap/Navigator.elm
@@ -0,0 +1,50 @@
+module Battlemap.Navigator exposing (Navigator, new_navigator, go)
+
+import Set exposing (Set, member, empty)
+
+import Battlemap exposing (Battlemap, has_location)
+import Battlemap.Location exposing (..)
+import Battlemap.Direction exposing (..)
+import Battlemap.Tile exposing (set_tile_direction)
+
+type alias Navigator =
+   {
+      current_location : Location,
+      visited_locations : (Set Location)
+   }
+
+new_navigator : Location -> Navigator
+new_navigator start =
+   {
+      current_location = start,
+      visited_locations = empty
+   }
+
+go : Navigator -> Direction -> (Battlemap, Navigator)
+go battlemap nav dir =
+   let
+      next_location = (neighbor nav.current_location dir)
+   in
+      if
+      (
+         (has_location battlemap next_location)
+         && (current_location != next_location)
+         && (not (member next_location nav.visited_locations))
+      )
+      then
+         (
+            (set_tile_direction
+               nav.current_location
+               dir
+            ),
+            {
+               current_location = next_location,
+               visited_locations =
+                  (insert
+                     nav.current_location
+                     nav.visited_locations
+                  )
+            }
+         )
+      else
+         nav