create env module

bin/main.ml

@@ -1,17 +1,3 @@
 open Culr
 
-let to_sixteen = Seq.ints 0 |> Seq.take 16 |> Array.of_seq
-
-let colours =
-  let init_default =
-    to_sixteen |> Array.map (fun x -> Types.Simple x)
-  in
-  Sys.getenv_opt "CULRS"
-  |> Option.fold ~none:init_default ~some:Parse.parse_env_colours
-
-let order =
-  let init_default = to_sixteen in
-  Sys.getenv_opt "CULR_ORDER"
-  |> Option.fold ~none:init_default ~some:Parse.parse_env_order
-
-let () = Pipes.read_all colours order
+let () = Pipes.read_all Env.colours Env.order

lib/env.ml

@@ -0,0 +1,17 @@
+open Seq
+
+let to_sixteen f = ints 0 |> take 16 |> f |> Array.of_seq
+let ( >>= ) = Option.bind
+let mem = Fun.flip Array.mem
+
+let colours =
+  let init_default = to_sixteen (map (fun x -> Types.Simple x)) in
+  Sys.getenv_opt "CULRS"
+  >>= (fun s -> if String.length s > 0 then Some s else None)
+  |> Option.fold ~none:init_default ~some:Parse.parse_env_colours
+
+let order =
+  let init_default = to_sixteen (filter (fun i -> i |> mem [| 0; 8 |])) in
+  Sys.getenv_opt "CULR_ORDER"
+  >>= (fun s -> if String.length s > 0 then Some s else None)
+  |> Option.fold ~none:init_default ~some:Parse.parse_env_order