bulk: add PoC of vim-like modular editor

1 files changed, 18 insertions, 0 deletions

diff --git a/lib/modes.ml b/lib/modes.ml
new file mode 100644
index 0000000..3d0e354
--- /dev/null
+++ b/lib/modes.ml
@@ -0,0 +1,18 @@
+type mode = Normal | Insert
+type t = mode
+type state = int
+type 'a state_monad = state -> 'a * state
+
+let run (f : 'a state_monad) (s : state) : 'a = f s |> fst
+let return (a : 'a) : 'a state_monad = fun s -> (a, s)
+
+let ( >>= ) (f : 'a state_monad) (g : 'a -> 'b state_monad) : 'b state_monad =
+ fun s ->
+  let a, s' = f s in
+  g a s'
+
+let draw () : unit state_monad = return ()
+let get_keypress () : char state_monad = return 'a'
+let handle_key (_ : char) : unit state_monad = return ()
+let rec loop () = () |> draw >>= get_keypress >>= handle_key >>= loop
+let test = run (loop ()) 0