implement wheat !

src/map.ml

@@ -8,6 +8,7 @@ type background =
   | Grass
   | Water
   | Black
+  | Wheat
 
 let pp_dir fmt dir =
   let s =
@@ -21,7 +22,11 @@ let pp_dir fmt dir =
 
 let pp_background fmt b =
   let s =
-    match b with Grass -> "Grass" | Water -> "Water" | Black -> "Black"
+    match b with
+    | Grass -> "Grass"
+    | Water -> "Water"
+    | Black -> "Black"
+    | Wheat -> "Wheat"
   in
   Format.pp_print_string fmt s
 
@@ -53,6 +58,19 @@ let init () =
 let get_tile_kind ~x ~y map =
   try map.tiles.(x).(y) with Invalid_argument _ -> Black
 
+let count_wheat map =
+  Array.fold_left
+    (fun count a ->
+      let count' =
+        Array.fold_left
+          (fun count -> function
+            | Wheat -> succ count
+            | Black | Grass | Water -> count )
+          0 a
+      in
+      count + count' )
+    0 map
+
 let check_move map ({ x; y; _ } as pos) movement_dir =
   let x, y =
     match movement_dir with
@@ -64,4 +82,4 @@ let check_move map ({ x; y; _ } as pos) movement_dir =
   match get_tile_kind ~x ~y map with
   | (Black | Water) as bg ->
     Error (Format.asprintf "can't move on %a" pp_background bg)
-  | Grass -> Ok { pos with x; y }
+  | Grass | Wheat -> Ok { pos with x; y }