feat: allow backspace and delete to span multiple lines in insert mode

2 files changed, 26 insertions, 5 deletions

diff --git a/lib/editor.ml b/lib/editor.ml
index 9078a09..2e031e1 100644
--- a/lib/editor.ml
+++ b/lib/editor.ml
@@ -186,13 +186,15 @@ let handle_insert_command =
   let open Command in
   let open Action in
   function
-  | Simple Backspace -> Buffer.Action.delete_before ~n:1 |> on_focused_buffer
   | Simple Arrow_down -> Buffer.Action.move_down |> on_focused_buffer
   | Simple Arrow_left -> Buffer.Action.move_left |> on_focused_buffer
   | Simple Arrow_right -> Buffer.Action.move_right |> on_focused_buffer
   | Simple Arrow_up -> Buffer.Action.move_up |> on_focused_buffer
+  | Simple Backspace ->
+      Buffer.Action.delete_before ~cross_lines:true ~n:1 |> on_focused_buffer
   | Simple (Ctrl 'Q') -> quit 0
-  | Simple Delete -> Buffer.Action.delete_after ~n:1 |> on_focused_buffer
+  | Simple Delete ->
+      Buffer.Action.delete_after ~cross_lines:true ~n:1 |> on_focused_buffer
   | Simple Enter -> Buffer.Action.newline |> on_focused_buffer
   | Simple Esc ->
       (Buffer.Action.move_left |> on_focused_buffer) *> set_mode Normal
@@ -223,7 +225,7 @@ let handle_normal_command =
   (* | Key 's' -> *)
   (*     (Buffer.Action.delete_after |> on_focused_buffer_or_new) *)
   (* *> set_mode Insert *)
-  (* | Key 'x' -> Buffer.Action.delete_after |> on_focused_buffer_or_new *)
+  (* | Key 'x' | Delete -> Buffer.Action.delete_after |> on_focused_buffer_or_new *)
   (* | Key 'X' -> Buffer.Action.delete_before |> on_focused_buffer_or_new *)
   (* | Key '$' -> Buffer.Action.eol |> on_focused_buffer_or_new *)
   | Shortcut (_, n, Change, Line) ->
diff --git a/lib/editorBuffer.ml b/lib/editorBuffer.ml
index 2e2b4b6..b682116 100644
--- a/lib/editorBuffer.ml
+++ b/lib/editorBuffer.ml
@@ -29,8 +29,27 @@ module Action = struct
   let bof = far_left |> on_content
   let eof = far_right |> on_content
   let insert k = map_focus (push k) |> on_content
-  let delete_after ~n = Fn.apply_n_times ~n (map_focus pop_after) |> on_content
-  let delete_before ~n = Fn.apply_n_times ~n (map_focus pop) |> on_content
+
+  let delete_after ?(cross_lines = false) ~n =
+    let aux z =
+      let line = focus_or ~default:Zipper.empty z in
+      if cross_lines && is_far_right line && not (is_far_right z) then
+        (* let next = right z |> focus_or ~default:Zipper.empty |> far_left in *)
+        (* right z |> pop_after |> left |> map_focus (Fn.flip join next) *)
+        pop_after z |> map_focus_or ~default:line (far_left &> join line)
+      else map_focus pop_after z
+    in
+    Fn.apply_n_times ~n aux |> on_content
+
+  let delete_before ?(cross_lines = false) ~n =
+    let aux z =
+      let line = focus_or ~default:Zipper.empty z in
+      if cross_lines && is_far_left line && not (is_far_left z) then
+        pop_after z |> left |> map_focus (far_right &> Fn.flip join line)
+      else map_focus pop z
+    in
+    Fn.apply_n_times ~n aux |> on_content
+
   let delete_to_eol = map_focus (split &> fst) |> on_content
   let delete_to_bol = map_focus (split &> snd) |> on_content
   let delete_lines ~n = Fn.apply_n_times ~n pop_after |> on_content