serialise colour directly, use arrays throughout

lib/processing.ml

@@ -12,12 +12,7 @@ let ansi_filter s =
 let permute order a = Array.mapi (fun i _ -> a.(order.(i))) a
 
 (* TODO: implement this so cli can use a dsl to specify colourising patterns *)
-type culr = {
-  colours : colour array;
-  sz : int;
-  mutable current : int;
-  mutable first : bool;
-}
+type culr = { colours : colour array; sz : int; mutable current : int }
 
 module Culriser = struct
   type filter = (colour -> bool) list
@@ -28,32 +23,28 @@ module Culriser = struct
 
   let create ?(s = [| 0; 1; 2; 3; 4; 5; 6; 7; 8; 9; 10; 11; 12; 13; 14; 15 |])
       ?(f = []) c =
+    let ( @ ) = Array.append in
     let colours =
-      c
-      |> List.fold_left
-           (fun acc el -> if run_filters f el then acc @ [ el ] else acc)
-           []
-      |> Array.of_list |> permute s
+      c |> permute s
+      |> Array.fold_left
+           (fun acc el -> if run_filters f el then acc @ [| el |] else acc)
+           [||]
     in
-    { colours; sz = Array.length colours; current = 0; first = true }
+    { colours; sz = Array.length colours; current = 0 }
 
   let next t =
-    let nv = t.current + 1 in
+    let ret = t.current and nv = t.current + 1 in
     if nv >= t.sz then t.current <- 0 else t.current <- nv;
-    t.colours.(t.current)
+    t.colours.(ret)
 
   let reset t = t.current <- 0
 
-  let add_colour t chunk =
-    if t.first then (
-      t.first <- false;
-      Ansi [ Fg (next t) ] :: [ chunk ])
-    else
-      match chunk with
-      | Separator _ -> chunk :: [ Ansi [ Fg (next t) ] ]
-      | Delimiter _ ->
-          reset t;
-          chunk :: [ Ansi [ Fg (next t) ] ]
-      | Ansi _ -> [ chunk ]
-      | Text _ -> [ chunk ]
+  let add_colour t serialiser chunk =
+    (match chunk with
+    | Separator _ -> Emitter.serialise serialiser (Ansi [ Fg (next t) ])
+    | Delimiter _ ->
+        reset t;
+        Emitter.serialise serialiser (Ansi [ Fg (next t) ])
+    | _ -> ());
+    chunk
 end