improve behaviour around indented data

lib/pipes.ml

@@ -4,7 +4,7 @@ let read_all colours =
   In_channel.set_binary_mode stdin true;
   let open Types in
   let t = Emitter.create and culr = Culriser.create colours in
-  Emitter.serialise t (Ansi [ Fg (Culriser.next culr) ]);
+  Emitter.serialise t (Ansi [ Fg (Culriser.current culr) ]);
   Angstrom_unix.parse_many ~buf_size:4096 Parse.culr_parse
     (fun c -> c |> ansi_filter culr |> Culriser.serialise_with_colour culr t)
     stdin

lib/processing.ml

@@ -2,7 +2,12 @@ open Types
 open Array
 
 (* TODO: implement this so cli can use a dsl to specify colourising patterns *)
-type culr = { colours : colour array; sz : int; mutable current : int }
+type culr = {
+  colours : colour array;
+  sz : int;
+  mutable current : int;
+  mutable first : bool;
+}
 
 module Culriser = struct
   type filter = (colour -> bool) list
@@ -20,25 +25,28 @@ module Culriser = struct
           [||] c
       else c
     in
-    { colours; sz = length colours; current = 0 }
+    { colours; sz = length colours; current = 0; first = true }
 
   let current t = t.colours.(t.current)
 
   let next t =
-    let ret = t.current and nv = t.current + 1 in
-    if nv >= t.sz then t.current <- 0 else t.current <- nv;
-    t.colours.(ret)
+    t.current <- (t.current + 1) mod t.sz;
+    t.colours.(t.current)
 
-  let reset t = t.current <- 0
+  let reset t =
+    t.current <- 0;
+    t.first <- true
 
   let serialise_with_colour t serialiser chunk =
+    Emitter.serialise serialiser chunk;
     (match chunk with
-    | Separator _ -> Emitter.serialise serialiser (Ansi [ Fg (next t) ])
+    | Separator _ ->
+        if not t.first then Emitter.serialise serialiser (Ansi [ Fg (next t) ])
     | Delimiter _ ->
         reset t;
-        Emitter.serialise serialiser (Ansi [ Fg (next t) ])
-    | _ -> ());
-    Emitter.serialise serialiser chunk
+        Emitter.serialise serialiser (Ansi [ Fg (current t) ]);
+    | Text _ -> if t.first then t.first <- false
+    | _ -> ())
 end
 
 let ansi_filter t s =