1 files changed, 162 insertions, 144 deletions

diff --git a/lib/editor.ml b/lib/editor.ml
index c34d558..230f13a 100644
--- a/lib/editor.ml
+++ b/lib/editor.ml
@@ -12,13 +12,13 @@ type editor = {
   cursor : cursor;
   buffer : Buffer.t option;
   rendered : bool;
-  pending : Key.t Sequence.t;
-  i_pending : Command.t Sequence.t;
-  n_pending : Command.t Sequence.t;
+  istream : Command.t Sequence.t;
+  nstream : Command.t Sequence.t;
   status_size : int;
   message : string option;
   message_timestamp : float;
   message_duration : float;
+  pending_command : string;
 }
 
 type t = editor
@@ -31,13 +31,13 @@ let init (c : Config.t) : editor =
     cursor = (1, 1);
     buffer = List.hd c.files |> Option.map ~f:Buffer.from_file;
     rendered = true;
-    pending = Key.stream;
-    i_pending = Command.i_stream;
-    n_pending = Command.n_stream;
+    istream = Command.i_stream;
+    nstream = Command.n_stream;
     status_size = 2;
     message = Some "Hello, control line!";
     message_timestamp = Unix.time ();
     message_duration = 5.;
+    pending_command = "";
   }
 
 let string_of_mode = function
@@ -80,8 +80,9 @@ let statusbar e =
       ~fill:' ' w
     |> invert
   and control =
-    let msg = Option.value ~default:"" e.message |> sequence_of_string in
-    spread ~l:msg ~fill:' ' w
+    let msg = Option.value ~default:"" e.message |> sequence_of_string
+    and cmd = e.pending_command |> sequence_of_string in
+    spread ~l:msg ~r:cmd ~fill:' ' w
   in
   Sequence.(take (of_list [ status; control ]) e.status_size)
 
@@ -187,6 +188,14 @@ module Action = struct
   let set_message m e =
     ((), { e with message = m; message_timestamp = Unix.time () })
 
+  let get_pending_command e = (e.pending_command, e)
+  let set_pending_command p e = ((), { e with pending_command = p })
+
+  let append_pending_command k =
+    let aux p = p ^ Key.to_string k in
+    get_pending_command >>| aux >>= set_pending_command
+
+  let clear_pending_command = set_pending_command ""
 
   let tick =
     let check_message_timestamp e =
@@ -285,6 +294,7 @@ let handle_insert_command =
       (Buffer.Action.move_left |> on_focused_buffer) *> set_mode Normal
   | Simple Page_down | Simple (Ctrl 'F') ->
       fun e ->
+        (* TODO consider using the buffer window size (i.e., subtract status_size) *)
         let (n, _), e = get_terminal_size e in
         on_focused_buffer (Buffer.Action.move_down ~n) e
   | Simple Page_up | Simple (Ctrl 'B') ->
@@ -305,151 +315,159 @@ let handle_insert_command =
   | Type k -> Buffer.Action.insert k |> on_focused_buffer
   | _ -> noop
 
-let handle_normal_command =
+let handle_normal_command c =
   let open Command in
   let open Action in
-  function
-  (* Movements *)
-  | Chord (_, n, Noop, _, Down) ->
-      Buffer.Action.move_down ?n |> on_focused_buffer
-  | Chord (_, n, Noop, _, Left) ->
-      Buffer.Action.move_left ?n |> on_focused_buffer
-  | Chord (_, n, Noop, _, Right) ->
-      Buffer.Action.move_right ?n |> on_focused_buffer
-  | Chord (_, n, Noop, _, Up) -> Buffer.Action.move_up ?n |> on_focused_buffer
-  | Chord (_, n, Noop, _, To_bol) ->
-      let n = Option.value ~default:1 n - 1 in
-      Buffer.Action.(move_down ~n &> bol) |> on_focused_buffer
-  | Chord (_, n, Noop, _, To_eol) ->
-      let n = Option.value ~default:1 n - 1 in
-      Buffer.Action.(move_down ~n &> eol) |> on_focused_buffer
-  | Simple Page_down | Simple (Ctrl 'F') ->
-      fun e ->
-        let (n, _), e = get_terminal_size e in
-        on_focused_buffer (Buffer.Action.move_down ~n) e
-  | Simple Page_up | Simple (Ctrl 'B') ->
-      fun e ->
-        let (n, _), e = get_terminal_size e in
-        on_focused_buffer (Buffer.Action.move_up ~n) e
-  | Simple (Ctrl 'D') ->
-      fun e ->
-        let (r, _), e = get_terminal_size e in
-        on_focused_buffer (Buffer.Action.move_down ~n:(r / 2)) e
-  | Simple (Ctrl 'U') ->
-      fun e ->
-        let (r, _), e = get_terminal_size e in
-        on_focused_buffer (Buffer.Action.move_up ~n:(r / 2)) e
-  (* Change *)
-  | Shortcut (_, n, Change) ->
-      let n = Option.value ~default:1 n - 1 in
-      (Buffer.Action.(
-         delete_to_eol &> move_down &> delete_lines ~n &> move_up &> eol)
-      |> on_focused_buffer_or_new)
-      *> set_mode Insert
-  | Chord (_, n1, Change, n2, Line) ->
-      let n = Option.((value ~default:1 n1 * value ~default:1 n2) - 1) in
-      (Buffer.Action.(delete_lines ~n &> bol &> delete_to_eol)
-      |> on_focused_buffer_or_new)
-      *> set_mode Insert
-  | Chord (_, n1, Change, n2, Down) ->
-      let n = Option.(value ~default:1 n1 * value ~default:1 n2) in
-      (Buffer.Action.(delete_lines ~n &> bol &> delete_to_eol)
-      |> on_focused_buffer_or_new)
-      *> set_mode Insert
-  | Chord (_, n1, Change, n2, Left) ->
-      let n = Option.(value ~default:1 n1 * value ~default:1 n2) in
-      (Buffer.Action.delete_before ~n |> on_focused_buffer_or_new)
-      *> set_mode Insert
-  | Chord (_, n1, Change, n2, Right) ->
-      let n = Option.(value ~default:1 n1 * value ~default:1 n2) in
-      (Buffer.Action.delete_after ~n |> on_focused_buffer_or_new)
-      *> set_mode Insert
-  | Chord (_, n1, Change, n2, Up) ->
-      let n = Option.(value ~default:1 n1 * value ~default:1 n2) in
-      (Buffer.Action.(bol &> delete_to_eol &> delete_lines_before ~n)
-      |> on_focused_buffer_or_new)
-      *> set_mode Insert
-  | Chord (_, n1, Change, n2, To_bol) ->
-      let n = Option.((value ~default:1 n1 * value ~default:1 n2) - 1) in
-      (Buffer.Action.(
-         delete_to_bol &> move_down &> delete_lines ~n &> move_up &> bol)
-      |> on_focused_buffer_or_new)
-      *> set_mode Insert
-  | Chord (_, n1, Change, n2, To_eol) ->
-      let n = Option.((value ~default:1 n1 * value ~default:1 n2) - 1) in
-      (Buffer.Action.(
-         delete_to_eol &> move_down &> delete_lines ~n &> move_up &> eol)
-      |> on_focused_buffer_or_new)
-      *> set_mode Insert
-  (* Delete *)
-  | Shortcut (_, n, Delete) ->
-      let n = Option.value ~default:1 n - 1 in
-      Buffer.Action.(
-        delete_to_eol &> move_down &> delete_lines ~n &> move_up &> eol)
-      |> on_focused_buffer_or_new
-  | Chord (_, n1, Delete, n2, Line) ->
-      let n = Option.(value ~default:1 n1 * value ~default:1 n2) in
-      Buffer.Action.delete_lines ~n |> on_focused_buffer_or_new
-  | Chord (_, n1, Delete, n2, Down) ->
-      let n = Option.((value ~default:1 n1 * value ~default:1 n2) + 1) in
-      Buffer.Action.delete_lines ~n |> on_focused_buffer_or_new
-  | Chord (_, n1, Delete, n2, Left) ->
-      let n = Option.(value ~default:1 n1 * value ~default:1 n2) in
-      Buffer.Action.delete_before ~n |> on_focused_buffer_or_new
-  | Shortcut (_, n, Erase_before) ->
-      let n = Option.(value ~default:1 n) in
-      Buffer.Action.delete_before ~n |> on_focused_buffer_or_new
-  | Chord (_, n1, Delete, n2, Right) ->
-      let n = Option.(value ~default:1 n1 * value ~default:1 n2) in
-      Buffer.Action.delete_after ~n |> on_focused_buffer_or_new
-  | Shortcut (_, n, Erase_after) ->
-      let n = Option.(value ~default:1 n) in
-      Buffer.Action.delete_after ~n |> on_focused_buffer_or_new
-  | Chord (_, n1, Delete, n2, Up) ->
-      let n = Option.(value ~default:1 n1 * value ~default:1 n2) in
-      Buffer.Action.(delete_lines ~n:1 &> delete_lines_before ~n)
-      |> on_focused_buffer_or_new
-  | Chord (_, n1, Delete, n2, To_bol) ->
-      let n = Option.((value ~default:1 n1 * value ~default:1 n2) - 1) in
-      Buffer.Action.(
-        delete_to_bol &> move_down &> delete_lines ~n &> move_up &> bol)
-      |> on_focused_buffer_or_new
-  | Chord (_, n1, Delete, n2, To_eol) ->
-      let n = Option.((value ~default:1 n1 * value ~default:1 n2) - 1) in
-      Buffer.Action.(
-        delete_to_eol &> move_down &> delete_lines ~n &> move_up &> eol)
-      |> on_focused_buffer_or_new
-  (* Join *)
-  | Shortcut (_, n, Join) ->
-      let n = Option.(value ~default:1 n) in
-      Buffer.Action.join_lines ~n |> on_focused_buffer_or_new
-  (* Quit *)
-  | Simple (Ctrl 'Q') -> quit 0
-  (* Misc *)
-  | Simple (Key 'A') ->
-      (Buffer.Action.eol |> on_focused_buffer_or_new) *> set_mode Insert
-  | Simple (Key 'a') ->
-      (Buffer.Action.move_right |> on_focused_buffer_or_new) *> set_mode Insert
-  (* | Key 'G' -> Buffer.Action.eof |> on_focused_buffer_or_new *)
-  (* | Key 'I' -> noop *)
-  | Simple (Key 'i') -> (Fn.id |> on_focused_buffer_or_new) *> set_mode Insert
-  (* | Key 's' -> *)
-  (*     (Buffer.Action.delete_after |> on_focused_buffer_or_new) *)
-  (* *> set_mode Insert *)
-  (* Debug *)
-  | Simple (Ctrl 'R') -> toggle_rendered
-  | _ -> noop
+  let update_command_cue =
+    match c with
+    | Partial k -> append_pending_command k
+    | _ -> clear_pending_command
+  and compute_action =
+    match c with
+    (* Movements *)
+    | Chord (_, n, Noop, _, Down) ->
+        Buffer.Action.move_down ?n |> on_focused_buffer
+    | Chord (_, n, Noop, _, Left) ->
+        Buffer.Action.move_left ?n |> on_focused_buffer
+    | Chord (_, n, Noop, _, Right) ->
+        Buffer.Action.move_right ?n |> on_focused_buffer
+    | Chord (_, n, Noop, _, Up) -> Buffer.Action.move_up ?n |> on_focused_buffer
+    | Chord (_, n, Noop, _, To_bol) ->
+        let n = Option.value ~default:1 n - 1 in
+        Buffer.Action.(move_down ~n &> bol) |> on_focused_buffer
+    | Chord (_, n, Noop, _, To_eol) ->
+        let n = Option.value ~default:1 n - 1 in
+        Buffer.Action.(move_down ~n &> eol) |> on_focused_buffer
+    | Simple Page_down | Simple (Ctrl 'F') ->
+        fun e ->
+          let (n, _), e = get_terminal_size e in
+          on_focused_buffer (Buffer.Action.move_down ~n) e
+    | Simple Page_up | Simple (Ctrl 'B') ->
+        fun e ->
+          let (n, _), e = get_terminal_size e in
+          on_focused_buffer (Buffer.Action.move_up ~n) e
+    | Simple (Ctrl 'D') ->
+        fun e ->
+          let (r, _), e = get_terminal_size e in
+          on_focused_buffer (Buffer.Action.move_down ~n:(r / 2)) e
+    | Simple (Ctrl 'U') ->
+        fun e ->
+          let (r, _), e = get_terminal_size e in
+          on_focused_buffer (Buffer.Action.move_up ~n:(r / 2)) e
+    (* Change *)
+    | Shortcut (_, n, Change) ->
+        let n = Option.value ~default:1 n - 1 in
+        (Buffer.Action.(
+           delete_to_eol &> move_down &> delete_lines ~n &> move_up &> eol)
+        |> on_focused_buffer_or_new)
+        *> set_mode Insert
+    | Chord (_, n1, Change, n2, Line) ->
+        let n = Option.((value ~default:1 n1 * value ~default:1 n2) - 1) in
+        (Buffer.Action.(delete_lines ~n &> bol &> delete_to_eol)
+        |> on_focused_buffer_or_new)
+        *> set_mode Insert
+    | Chord (_, n1, Change, n2, Down) ->
+        let n = Option.(value ~default:1 n1 * value ~default:1 n2) in
+        (Buffer.Action.(delete_lines ~n &> bol &> delete_to_eol)
+        |> on_focused_buffer_or_new)
+        *> set_mode Insert
+    | Chord (_, n1, Change, n2, Left) ->
+        let n = Option.(value ~default:1 n1 * value ~default:1 n2) in
+        (Buffer.Action.delete_before ~n |> on_focused_buffer_or_new)
+        *> set_mode Insert
+    | Chord (_, n1, Change, n2, Right) ->
+        let n = Option.(value ~default:1 n1 * value ~default:1 n2) in
+        (Buffer.Action.delete_after ~n |> on_focused_buffer_or_new)
+        *> set_mode Insert
+    | Chord (_, n1, Change, n2, Up) ->
+        let n = Option.(value ~default:1 n1 * value ~default:1 n2) in
+        (Buffer.Action.(bol &> delete_to_eol &> delete_lines_before ~n)
+        |> on_focused_buffer_or_new)
+        *> set_mode Insert
+    | Chord (_, n1, Change, n2, To_bol) ->
+        let n = Option.((value ~default:1 n1 * value ~default:1 n2) - 1) in
+        (Buffer.Action.(
+           delete_to_bol &> move_down &> delete_lines ~n &> move_up &> bol)
+        |> on_focused_buffer_or_new)
+        *> set_mode Insert
+    | Chord (_, n1, Change, n2, To_eol) ->
+        let n = Option.((value ~default:1 n1 * value ~default:1 n2) - 1) in
+        (Buffer.Action.(
+           delete_to_eol &> move_down &> delete_lines ~n &> move_up &> eol)
+        |> on_focused_buffer_or_new)
+        *> set_mode Insert
+    (* Delete *)
+    | Shortcut (_, n, Delete) ->
+        let n = Option.value ~default:1 n - 1 in
+        Buffer.Action.(
+          delete_to_eol &> move_down &> delete_lines ~n &> move_up &> eol)
+        |> on_focused_buffer_or_new
+    | Chord (_, n1, Delete, n2, Line) ->
+        let n = Option.(value ~default:1 n1 * value ~default:1 n2) in
+        Buffer.Action.delete_lines ~n |> on_focused_buffer_or_new
+    | Chord (_, n1, Delete, n2, Down) ->
+        let n = Option.((value ~default:1 n1 * value ~default:1 n2) + 1) in
+        Buffer.Action.delete_lines ~n |> on_focused_buffer_or_new
+    | Chord (_, n1, Delete, n2, Left) ->
+        let n = Option.(value ~default:1 n1 * value ~default:1 n2) in
+        Buffer.Action.delete_before ~n |> on_focused_buffer_or_new
+    | Shortcut (_, n, Erase_before) ->
+        let n = Option.(value ~default:1 n) in
+        Buffer.Action.delete_before ~n |> on_focused_buffer_or_new
+    | Chord (_, n1, Delete, n2, Right) ->
+        let n = Option.(value ~default:1 n1 * value ~default:1 n2) in
+        Buffer.Action.delete_after ~n |> on_focused_buffer_or_new
+    | Shortcut (_, n, Erase_after) ->
+        let n = Option.(value ~default:1 n) in
+        Buffer.Action.delete_after ~n |> on_focused_buffer_or_new
+    | Chord (_, n1, Delete, n2, Up) ->
+        let n = Option.(value ~default:1 n1 * value ~default:1 n2) in
+        Buffer.Action.(delete_lines ~n:1 &> delete_lines_before ~n)
+        |> on_focused_buffer_or_new
+    | Chord (_, n1, Delete, n2, To_bol) ->
+        let n = Option.((value ~default:1 n1 * value ~default:1 n2) - 1) in
+        Buffer.Action.(
+          delete_to_bol &> move_down &> delete_lines ~n &> move_up &> bol)
+        |> on_focused_buffer_or_new
+    | Chord (_, n1, Delete, n2, To_eol) ->
+        let n = Option.((value ~default:1 n1 * value ~default:1 n2) - 1) in
+        Buffer.Action.(
+          delete_to_eol &> move_down &> delete_lines ~n &> move_up &> eol)
+        |> on_focused_buffer_or_new
+    (* Join *)
+    | Shortcut (_, n, Join) ->
+        let n = Option.(value ~default:1 n) in
+        Buffer.Action.join_lines ~n |> on_focused_buffer_or_new
+    (* Quit *)
+    | Simple (Ctrl 'Q') -> quit 0
+    (* Misc *)
+    | Simple (Key 'A') ->
+        (Buffer.Action.eol |> on_focused_buffer_or_new) *> set_mode Insert
+    | Simple (Key 'a') ->
+        (Buffer.Action.move_right |> on_focused_buffer_or_new)
+        *> set_mode Insert
+    (* | Key 'G' -> Buffer.Action.eof |> on_focused_buffer_or_new *)
+    (* | Key 'I' -> noop *)
+    | Simple (Key 'i') -> (Fn.id |> on_focused_buffer_or_new) *> set_mode Insert
+    (* | Key 's' -> *)
+    (*     (Buffer.Action.delete_after |> on_focused_buffer_or_new) *)
+    (* *> set_mode Insert *)
+    (* Debug *)
+    | Simple (Ctrl 'R') -> toggle_rendered
+    | _ -> noop
+  in
+  compute_action *> update_command_cue
 
 let handle_next_command m e =
   match m with
   | Insert -> (
-      match Sequence.next e.i_pending with
+      match Sequence.next e.istream with
       | None -> ((), e)
-      | Some (h, t) -> handle_insert_command h { e with i_pending = t })
+      | Some (h, t) -> handle_insert_command h { e with istream = t })
   | Normal -> (
-      match Sequence.next e.n_pending with
+      match Sequence.next e.nstream with
       | None -> ((), e)
-      | Some (h, t) -> handle_normal_command h { e with n_pending = t })
+      | Some (h, t) -> handle_normal_command h { e with nstream = t })
   | Control -> failwith "unimplemented"
 
 let handle_next_command =