From 53916fc3f7dcbefd90e3d0340a2a8f32bf331d1d Mon Sep 17 00:00:00 2001
From: Federico Igne <undyamon@disroot.org>
Date: Sun, 28 Jan 2024 01:22:52 +0100
Subject: feat: add plain search functionality (with history)

---
 lib/editorBuffer.ml | 60 +++++++++++++++++++++++++++++++++++++++++++++++++++--
 1 file changed, 58 insertions(+), 2 deletions(-)

(limited to 'lib/editorBuffer.ml')

diff --git a/lib/editorBuffer.ml b/lib/editorBuffer.ml
index 52b1115..1f363ef 100644
--- a/lib/editorBuffer.ml
+++ b/lib/editorBuffer.ml
@@ -88,8 +88,10 @@ module Action = struct
   let ( let+ ) b f = map b ~f
   let get b = (b, b)
   let put b _ = ((), b)
-  let modify ~f = get >>= (put &> f)
-  let on_content f b = ((), { b with content = Result.map ~f b.content })
+  let modify ~f = get >>| f >>= put
+  let get_content b = (b.content, b)
+  let set_content c b = ((), { b with content = c })
+  let on_content f = get_content >>| Result.map ~f >>= set_content
 
   let on_content_with_output ~default f b =
     match b.content with
@@ -143,6 +145,11 @@ module Action = struct
     in
     (horizontal left, horizontal right)
 
+  let goto r c =
+    let change_content = Zipper.(goto r &> map_focus (goto c)) |> on_content
+    and change_rendered = Zipper.goto r |> on_rendered in
+    change_content *> change_rendered
+
   let bol ?(n = 0) = move_down ~n *> (map_focus far_left |> on_content)
   let eol ?(n = 0) = move_down ~n *> (map_focus far_right |> on_content)
 
@@ -374,6 +381,55 @@ module Action = struct
     in
     bind_n_times ~n (change_content *> change_rendered)
 
+  let search forward word =
+    let rec tails s =
+      match Sequence.next s with
+      | None -> Sequence.empty
+      | Some (_, t) -> Sequence.shift_right (tails t) s
+    and prefix p l =
+      match Sequence.(next p, next l) with
+      | Some (ph, pt), Some (lh, lt) when Char.(ph = lh) -> prefix pt lt
+      | None, _ -> true
+      | _ -> false
+    in
+    let search_line w l =
+      Sequence.findi ~f:(fun _ -> prefix w) (tails l) |> Option.map ~f:fst
+    in
+    let* b = get in
+    let cr, cc = cursor ~rendered:false b in
+    let* c = get_content in
+    match c with
+    | Error _ -> return None
+    | Ok c -> (
+        if forward then
+          match Sequence.next (Zipper.after c) with
+          | None -> return None
+          | Some (h, t) -> (
+              match Zipper.(h |> right |> after) |> search_line word with
+              | Some i -> return (Some (cr, cc + i + 1))
+              | None ->
+                  let f r z =
+                    z |> to_seq |> search_line word
+                    |> Option.map ~f:(fun c -> (cr + r + 1, c))
+                  in
+                  return (Sequence.find_mapi t ~f))
+        else
+          let word = Sequence.(word |> to_list_rev |> of_list) in
+          let wlen = Sequence.length word in
+          match Zipper.(c |> right |> before) |> Sequence.next with
+          | None -> return None
+          | Some (h, t) -> (
+              match h |> Zipper.before |> search_line word with
+              | Some i -> return (Some (cr, cc - wlen - i))
+              | None ->
+                  let f r z =
+                    let z = z |> far_right in
+                    let len = left_length z in
+                    z |> before |> search_line word
+                    |> Option.map ~f:(fun c -> (cr - r - 1, len - wlen - c))
+                  in
+                  return (Sequence.find_mapi t ~f)))
+
   (* let save_history_to ?(clear = true) r = () *)
 end
 
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