2 files changed, 72 insertions, 0 deletions

diff --git a/src/marker.ml b/src/marker.ml
new file mode 100644
index 0000000..19b1be0
--- /dev/null
+++ b/src/marker.ml
@@ -0,0 +1,36 @@
+module type Marker = sig
+    type t
+    val of_string : string -> t
+    val pp        : out_channel -> t -> unit
+end
+
+module Marker = struct
+    type t = Point
+           | Pixel
+           | Circle
+           | TriangleDown
+           | TriangleUp
+           | TriangleLeft
+           | TriangleRight
+           | Custom of string
+
+    exception Invalid_marker_length
+    let of_string s = 
+        if String.length s <> 1
+        then raise Invalid_marker_length
+        else Custom(s)
+
+    let pp channel n =
+        (match n with
+            | Point         -> "."
+            | Pixel         -> ","
+            | Circle        -> "o"
+            | TriangleDown  -> "v"
+            | TriangleUp    -> "^"
+            | TriangleLeft  -> ">"
+            | TriangleRight -> "<"
+            | Custom(s)     -> s) 
+        |> Printf.fprintf channel "%s"
+
+end
+
diff --git a/src/utils.ml b/src/utils.ml
new file mode 100644
index 0000000..8d1094e
--- /dev/null
+++ b/src/utils.ml
@@ -0,0 +1,36 @@
+module Utils = struct
+    exception Empty_list
+    let fold fn = function
+        | [] -> raise Empty_list
+        | head :: tail -> List.fold_left fn head tail
+
+    let list_min ls = fold Stdlib.min ls
+    let list_max ls = fold Stdlib.max ls
+
+    let rec repeat n a =
+        if n <= 0
+        then []
+        else a :: repeat (n - 1) a
+
+    let empty ls = (ls = [])
+
+    let rec zip l1 l2 =
+        match (l1, l2) with
+        | ([], _) -> []
+        | (_, []) -> []
+        | (h1 :: t1, h2 :: t2) -> (h1, h2) :: zip t1 t2
+
+    let rec transpose = function
+        | [] :: _ -> []
+        | ls -> List.(map hd ls) :: transpose List.(map tl ls)
+
+    let flip f a b = f b a
+
+    let rot_right ls = List.(rev ls |> transpose)
+    let rot_left ls  = List.(transpose ls |> rev)
+
+    let saturating_sub b a =
+        if a < b then 0
+        else a - b
+end
+