move Grid into its own file

src/day12.ml

@@ -15,10 +15,10 @@ let parse_grid start_anywhere =
   let unvisited = ref [] in
   let grid =
     Utils.lines_of_input 12
-    |> Vec2.parse_grid (fun char -> { char; visited = false; distance = infinity })
+    |> Grid.of_lines (fun char -> { char; visited = false; distance = infinity })
   in
-  Vec2.iter_grid grid (fun pos ->
+  Grid.iter grid (fun pos ->
-    let n = Vec2.at_e grid pos in
+    let n = Grid.at_e grid pos in
     match n.char with
     | 'E' -> e := pos
     | 'S' ->
@@ -42,11 +42,11 @@ let reachable f t =
 ;;
 
 let rec path grid goal current unvisited =
-  let current_node = Vec2.at_e grid current in
+  let current_node = Grid.at_e grid current in
   Vec2.directions
   |> List.map (fun dir -> Vec2.(current + dir))
   |> List.iter (fun neighbor ->
-    match Vec2.at grid neighbor with
+    match Grid.at grid neighbor with
     | Some node when (not node.visited) && reachable current_node.char node.char ->
       let new_distance = current_node.distance + 1 in
       if new_distance < node.distance then node.distance <- new_distance;
@@ -57,12 +57,12 @@ let rec path grid goal current unvisited =
   unvisited
     := List.sort
          (fun a b ->
-           let a = Vec2.at_e grid a in
+           let a = Grid.at_e grid a in
-           let b = Vec2.at_e grid b in
+           let b = Grid.at_e grid b in
            a.distance - b.distance)
          !unvisited;
   match !unvisited with
-  | shortest :: _ when Vec2.(shortest = goal) -> Vec2.at grid shortest
+  | shortest :: _ when Vec2.(shortest = goal) -> Grid.at grid shortest
   | shortest :: rest -> path grid goal shortest @@ ref rest
   | [] -> None
 ;;

src/day8.ml

@@ -1,17 +1,17 @@
 open Containers
 
 let parse_grid () =
-  Vec2.parse_grid Fun.(Char.to_string %> int_of_string) @@ Utils.lines_of_input 8
+  Grid.of_lines Fun.(Char.to_string %> int_of_string) @@ Utils.lines_of_input 8
 ;;
 
 let part1 () =
   let grid = parse_grid () in
   let num_visible = ref 0 in
-  Vec2.iter_grid grid (fun start ->
+  Grid.iter grid (fun start ->
-    let start_height = Option.get_exn_or "unreachable" @@ Vec2.at grid start in
+    let start_height = Option.get_exn_or "unreachable" @@ Grid.at grid start in
     let rec walk_shorter_trees start step =
       let next = Vec2.(start + step) in
-      match Vec2.at grid next with
+      match Grid.at grid next with
       | Some height when height < start_height -> walk_shorter_trees next step
       | opt -> opt
     in
@@ -28,11 +28,11 @@ let part1 () =
 let part2 () =
   let grid = parse_grid () in
   let best_score = ref 0 in
-  Vec2.iter_grid grid (fun start ->
+  Grid.iter grid (fun start ->
-    let start_height = Option.get_exn_or "unreachable" @@ Vec2.at grid start in
+    let start_height = Option.get_exn_or "unreachable" @@ Grid.at grid start in
     let rec trees_in_view start in_view step =
       let next = Vec2.(start + step) in
-      match Vec2.at grid next with
+      match Grid.at grid next with
       | Some height when height < start_height -> trees_in_view next (in_view + 1) step
       | Some _ -> in_view + 1
       | None -> in_view

src/grid.ml

@@ -0,0 +1,63 @@
+open Containers
+open Vec2
+
+type 'a t =
+  { width : int
+  ; height : int
+  ; items : 'a array
+  }
+[@@deriving show]
+
+let grid_vec2_of_idx ~width ~idx =
+  let y = idx / width in
+  let x = idx mod width in
+  Vec2.of_tuple (x, y)
+;;
+
+let at (grid : 'a t) (point : Vec2.t) =
+  let x, y = Vec2.to_tuple point in
+  if x >= 0 && x < grid.width && y >= 0 && y < grid.height
+  then Array.get_safe grid.items @@ Int.((grid.width * y) + x)
+  else None
+;;
+
+let at_e (grid : 'a t) (point : Vec2.t) =
+  Option.get_exn_or "out of bounds!" @@ at grid point
+;;
+
+let find (grid : 'a t) pred =
+  let open Option.Infix in
+  let* idx, item = Array.find_idx pred grid.items in
+  Some (grid_vec2_of_idx ~width:grid.width ~idx, item)
+;;
+
+let init ~width ~height init =
+  { width
+  ; height
+  ; items = Array.init (width * height) (fun idx -> init @@ grid_vec2_of_idx ~width ~idx)
+  }
+;;
+
+let of_lines parse_char lines : 'a t =
+  match lines with
+  | first_line :: _ ->
+    let width = String.length first_line in
+    let height = List.length lines in
+    let yeet =
+      lines
+      |> List.map String.to_list
+      |> List.flatten
+      |> List.map parse_char
+      |> Array.of_list
+    in
+    { width; height; items = yeet }
+  | _ -> failwith "somethin fucd up"
+;;
+
+let iter grid callback =
+  for y = 0 to Int.(grid.height - 1) do
+    for x = 0 to Int.(grid.width - 1) do
+      callback @@ Vec2.of_tuple (x, y)
+    done
+  done
+;;

src/grid.mli

@@ -0,0 +1,8 @@
+type 'a t [@@deriving show]
+
+val at : 'a t -> Vec2.t -> 'a option
+val at_e : 'a t -> Vec2.t -> 'a
+val init : width:int -> height:int -> (Vec2.t -> 'a) -> 'a t
+val of_lines : (char -> 'a) -> string list -> 'a t
+val find : 'a t -> ('a -> bool) -> (Vec2.t * 'a) option
+val iter : 'a t -> (Vec2.t -> unit) -> unit

src/vec2.ml

@@ -2,13 +2,6 @@ open Containers
 
 type t = int * int [@@deriving show]
 
-type 'a grid =
-  { width : int
-  ; height : int
-  ; items : 'a array
-  }
-[@@deriving show]
-
 let origin = 0, 0
 let up = 0, 1
 let down = 0, -1
@@ -20,57 +13,3 @@ let to_tuple x = x
 let ( + ) a b = Pair.map_same2 ( + ) a b
 let ( - ) a b = Pair.map_same2 ( - ) a b
 let ( = ) a b = Pair.equal ( = ) ( = ) a b
-
-let grid_vec2_of_idx ~width ~idx =
-  let y = idx / width in
-  let x = idx mod width in
-  x, y
-;;
-
-let at (grid : 'a grid) (point : t) =
-  let x, y = point in
-  if x >= 0 && x < grid.width && y >= 0 && y < grid.height
-  then Array.get_safe grid.items @@ Int.((grid.width * y) + x)
-  else None
-;;
-
-let at_e (grid : 'a grid) (point : t) =
-  Option.get_exn_or "out of bounds!" @@ at grid point
-;;
-
-let find (grid : 'a grid) pred =
-  let open Option.Infix in
-  let* idx, item = Array.find_idx pred grid.items in
-  Some (grid_vec2_of_idx ~width:grid.width ~idx, item)
-;;
-
-let init_grid ~width ~height init =
-  { width
-  ; height
-  ; items = Array.init (width * height) (fun idx -> init @@ grid_vec2_of_idx ~width ~idx)
-  }
-;;
-
-let parse_grid parse_char lines : 'a grid =
-  match lines with
-  | first_line :: _ ->
-    let width = String.length first_line in
-    let height = List.length lines in
-    let yeet =
-      lines
-      |> List.map String.to_list
-      |> List.flatten
-      |> List.map parse_char
-      |> Array.of_list
-    in
-    { width; height; items = yeet }
-  | _ -> failwith "somethin fucd up"
-;;
-
-let iter_grid (grid : 'a grid) callback =
-  for y = 0 to Int.(grid.height - 1) do
-    for x = 0 to Int.(grid.width - 1) do
-      callback (x, y)
-    done
-  done
-;;

src/vec2.mli

@@ -1,5 +1,4 @@
 type t [@@deriving show]
-type 'a grid [@@deriving show]
 
 val origin : t
 val up : t
@@ -12,9 +11,3 @@ val to_tuple : t -> int * int
 val ( + ) : t -> t -> t
 val ( - ) : t -> t -> t
 val ( = ) : t -> t -> bool
-val at : 'a grid -> t -> 'a option
-val at_e : 'a grid -> t -> 'a
-val init_grid : width:int -> height:int -> (t -> 'a) -> 'a grid
-val parse_grid : (char -> 'a) -> string list -> 'a grid
-val find : 'a grid -> ('a -> bool) -> (t * 'a) option
-val iter_grid : 'a grid -> (t -> unit) -> unit