1 files changed, 28 insertions, 0 deletions
diff --git a/lib/Utilities.ml b/lib/Utilities.ml
index a6b36c7..e4ee9c3 100644
--- a/lib/Utilities.ml
+++ b/lib/Utilities.ml
@@ -1,3 +1,9 @@
+module Ordering = struct
+  type t = Equal | Smaller | Greater
+
+  let of_int x = if x < 0 then Smaller else if x > 0 then Greater else Equal
+end
+
 module Result = struct
   let ( let* ) = Result.bind
   let fmap f m = Result.bind m f
@@ -69,3 +75,25 @@ module FingerTree = struct
     BatFingerTree.print ~first:"" ~last:"" ~sep:sep BatIO.nwrite
     |> Fun.flip BatIO.to_string ss
 end
+
+module Option = struct
+  let ( let* ) = Option.bind
+  let fmap f m = Option.bind m f
+end
+
+module Atomic = struct
+  let rec swap atom f =
+    let v = Atomic.get atom in
+    let v' = f v in
+    if Atomic.compare_and_set atom v v'
+    then atom
+    else swap atom f
+
+  let rec mswap atom f =
+    let open Result in
+    let v = Atomic.get atom in
+    let* v' = f v in
+    if Atomic.compare_and_set atom v v'
+    then Ok atom
+    else mswap atom f
+end