=== modified file 'Makefile'
--- Makefile	2019-04-15 17:00:06 +0000
+++ Makefile	2019-04-12 23:47:50 +0000
@@ -3,11 +3,8 @@
 clean:
 	rm -rf _build *.o *.bc *.cm[iox]
 
-.PHONY: all clean
-
-OBJ:= ring.cmo subprocess.cmo ppio.cmo
-ppio.bc: $(OBJ) compile
-	./compile $(OBJ) -o ppio.bc
+ppio.bc: subprocess.cmo ppio.cmo compile
+	./compile subprocess.cmo ppio.cmo -o ppio.bc
 
 %.cmo: %.ml compile
 	./compile -c $<

=== modified file 'ppio.ml'
--- ppio.ml	2019-04-15 17:00:06 +0000
+++ ppio.ml	2019-04-13 08:40:40 +0000
@@ -58,7 +58,6 @@
 
 type display_mode = NoFormat | Normal | Escaped;;
 type pretty_state = {to_print: Buffer.t; mutable dm: display_mode};;
-module CharSet = Set.Make(Char);;
 
 let pp_writer hideendl endl colors =
   let s = {to_print = Buffer.create 80; dm = NoFormat} in
@@ -122,51 +121,7 @@
         if c = endl then add_char '\n' else pp_char c;
       done;
       write_out ()))
-  | (l, false) -> (
-    let ring = Ring.create l in
-    fun (len:int) (buffer:Bytes.t) -> (
-      for n = 0 to len - 1 do
-        let c = Bytes.get buffer n in
-        pp_char c;
-        let _ = Ring.add_char ring c in
-        if Ring.compare ring endl = 0 then (
-          add_char '\n';
-          Ring.clear ring;
-        )
-      done;
-      write_out ()
-    )
-  )
-  | (l, true) -> (
-    let ring = Ring.create l
-    and endl_chars = String.fold ~init:CharSet.empty ~f:CharSet.add endl
-    in
-    fun (len:int) (buffer:Bytes.t) -> if len = 0 then (
-      (* end of input, dump ring buffer *)
-      Sequence.iter ~f:pp_char (Ring.fwd ring);
-      Ring.clear ring;
-      write_out ();
-    ) else (
-      for n = 0 to len - 1 do
-        let c = Bytes.get buffer n in
-        if CharSet.mem endl_chars c then (
-          (match Ring.add_char ring c with
-            Some buffered_c -> pp_char c | None -> ());
-          if Ring.compare ring endl = 0 then (
-            add_char '\n';
-            Ring.clear ring;
-          )
-        ) else (
-          if Ring.length ring > 0 then (
-            Sequence.iter ~f:pp_char (Ring.fwd ring);
-            Ring.clear ring
-          );
-          pp_char c
-        )
-      done;
-      write_out ();
-    )
-  )
+  | _ -> failwith "Not implemented"
 ;;
 
 (* Copy data from the reader to the writer, using the provided buffer

=== removed file 'ring.ml'
--- ring.ml	2019-04-15 17:00:06 +0000
+++ ring.ml	1970-01-01 00:00:00 +0000
@@ -1,76 +0,0 @@
-open Base;;
-
-type ring = {
-  buf: char Array.t;  (* array serving as data store *)
-  mutable len: int;  (* amount of characters currently retained *)
-  mutable pos: int;  (* position in buffer of last character written *)
-};;
-
-let create size = {
-  buf = Array.create size '\x00';
-  len = 0;
-  pos = -1;
-};;
-
-let length r = r.len;;
-
-let clear r = 
-  r.len <- 0;
-  r.pos <- -1;
-;;
-
-let add_char r ch =
-  if r.len < Array.length r.buf then (
-    r.pos <- r.pos + 1;
-    Array.set r.buf r.pos ch;
-    r.len <- r.pos + 1;
-    None
-  ) else (
-    r.pos <- (r.pos + 1) % (Array.length r.buf);
-    let prev_ch = Array.get r.buf r.pos in
-    Array.set r.buf r.pos ch;
-    Some prev_ch
-  )
-;;
-
-let rev_str s = Sequence.unfold_step ~init:(String.length s - 1) ~f:(
-  function n -> 
-    if n < 0
-      then Sequence.Step.Done
-      else Sequence.Step.Yield (String.get s n, n - 1)
-  )
-;;
-
-let rev r = Sequence.unfold_step ~init:(r.len, r.pos) ~f:(
-  function (remaining, pos) -> 
-    if remaining <= 0
-    then Sequence.Step.Done
-    else Sequence.Step.Yield (
-      Array.get r.buf pos,
-      (remaining - 1, (pos - 1) % (Array.length r.buf))
-    )
-  )
-;;
-
-let fwd r =
-  Sequence.unfold_step
-  ~init:(
-    r.len,
-    if r.len < (Array.length r.buf) then 0 else (r.pos + 1) % (Array.length r.buf)
-  )
-  ~f:(function (remaining, pos) ->
-    if remaining <= 0
-    then Sequence.Step.Done
-    else Sequence.Step.Yield (
-      Array.get r.buf pos,
-      (remaining - 1, (pos + 1) % (Array.length r.buf))
-    )
-  )
-;;
-
-let compare (r:ring) (s:string) =
-  let size_diff = r.len - (String.length s) in
-  if size_diff = 0 then (
-    Sequence.compare Char.compare (rev r) (rev_str s)
-  ) else if size_diff < 0 then -1 else 1
-;;