From 88af43d37b6b3166b357333a87e4aa990db35c4a Mon Sep 17 00:00:00 2001
From: Mindy <meetup@yomimono.org>
Date: Tue, 26 Mar 2019 12:42:46 -0500
Subject: [PATCH] use results instead of local polyvars

---
 lib/blkback.ml  |  4 ++--
 lib/blkproto.ml | 38 +++++++++++++++++---------------------
 2 files changed, 19 insertions(+), 23 deletions(-)

diff --git a/lib/blkback.ml b/lib/blkback.ml
index 99448c5..734c9a7 100644
--- a/lib/blkback.ml
+++ b/lib/blkback.ml
@@ -447,8 +447,8 @@ let run ?(max_indirect_segments=256) t name (domid,devid) =
     readv client frontend_path Blkproto.RingInfo.keys
     >>= fun frontend ->
     let ring_info = match Blkproto.RingInfo.of_assoc_list frontend with
-      | `OK x -> x
-      | `Error x -> failwith x in
+      | Ok x -> x
+      | Error (`Msg x) -> failwith x in
     Log.info (fun f-> f "%s" (Blkproto.RingInfo.to_string ring_info));
     let device_read ofs bufs =
       Lwt.catch
diff --git a/lib/blkproto.ml b/lib/blkproto.ml
index 2985951..bbee0af 100644
--- a/lib/blkproto.ml
+++ b/lib/blkproto.ml
@@ -15,20 +15,16 @@
  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  *)
 
-type ('a, 'b) result = [
-  | `OK of 'a
-  | `Error of 'b
-]
 let ( >>= ) x f = match x with
-  | `Error _ as y -> y
-  | `OK x -> f x
+  | Error _ as y -> y
+  | Ok x -> f x
 let list l k =
   if not(List.mem_assoc k l)
-  then `Error (Printf.sprintf "missing %s key" k)
-  else `OK (List.assoc k l)
-let int x = try `OK (int_of_string x) with _ -> `Error ("not an int: " ^ x)
-let int32 x = try `OK (Int32.of_string x) with _ -> `Error ("not an int32: " ^ x)
-let int64 x = try `OK (Int64.of_string x) with _ -> `Error ("not an int64: " ^ x)
+  then Error (`Msg (Printf.sprintf "missing %s key" k))
+  else Ok (List.assoc k l)
+let int x = try Ok (int_of_string x) with _ -> Error (`Msg ("not an int: " ^ x))
+let int32 x = try Ok (Int32.of_string x) with _ -> Error (`Msg ("not an int32: " ^ x))
+let int64 x = try Ok (Int64.of_string x) with _ -> Error (`Msg ("not an int64: " ^ x))
 
 (* Control messages via xenstore *)
 
@@ -78,8 +74,8 @@ module State = struct
 
   let of_int x =
     if List.mem_assoc x table
-    then `OK (List.assoc x table)
-    else `Error (Printf.sprintf "unknown device state: %d" x)
+    then Ok (List.assoc x table)
+    else Error (`Msg (Printf.sprintf "unknown device state: %d" x))
 
   let _state = "state"
   let keys = [ _state ]
@@ -132,10 +128,10 @@ module Protocol = struct
   type t = X86_64 | X86_32 | Native
 
   let of_string = function
-    | "x86_32-abi" -> `OK X86_32
-    | "x86_64-abi" -> `OK X86_64
-    | "native"     -> `OK Native
-    | x            -> `Error ("unknown protocol: " ^ x)
+    | "x86_32-abi" -> Ok X86_32
+    | "x86_64-abi" -> Ok X86_64
+    | "native"     -> Ok Native
+    | x            -> Error (`Msg ("unknown protocol: " ^ x))
 
   let to_string = function
     | X86_64 -> "x86_64-abi"
@@ -159,11 +155,11 @@ module FeatureIndirect = struct
 
   let of_assoc_list l =
     if not(List.mem_assoc _max_indirect_segments l)
-    then `OK { max_indirect_segments = 0 }
+    then Ok { max_indirect_segments = 0 }
     else
       let x = List.assoc _max_indirect_segments l in
       int x >>= fun max_indirect_segments ->
-      `OK { max_indirect_segments }
+      Ok { max_indirect_segments }
 end
 
 module DiskInfo = struct
@@ -193,7 +189,7 @@ module DiskInfo = struct
     >>= fun info ->
     let media = Media.of_int info
     and mode = Mode.of_int info in
-    `OK { sectors; sector_size; media; mode }
+    Ok { sectors; sector_size; media; mode }
 end
 
 module RingInfo = struct
@@ -230,7 +226,7 @@ module RingInfo = struct
     >>= fun event_channel ->
     list l _protocol >>= fun x -> Protocol.of_string x
     >>= fun protocol ->
-    `OK { ref; event_channel; protocol }
+    Ok { ref; event_channel; protocol }
 end
 
 module Hotplug = struct