1 files changed, 36 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
+