From 55a4c7ef7a8604b91d184792adbdf99da5a80e89 Mon Sep 17 00:00:00 2001
From: Simon Cruanes <simon.cruanes.2007@m4x.org>
Date: Mon, 11 Apr 2016 20:56:39 +0200
Subject: [PATCH] add `Result.{to,of}_err`

---
 src/core/CCResult.ml  | 10 ++++++++++
 src/core/CCResult.mli |  8 ++++++++
 2 files changed, 18 insertions(+)

diff --git a/src/core/CCResult.ml b/src/core/CCResult.ml
index 57e48752..da374da6 100644
--- a/src/core/CCResult.ml
+++ b/src/core/CCResult.ml
@@ -245,6 +245,16 @@ let to_seq e k = match e with
   | Ok x -> k x
   | Error _ -> ()
 
+type ('a, 'b) error = [`Ok of 'a | `Error of 'b]
+
+let of_err = function
+  | `Ok x -> Ok x
+  | `Error y -> Error y
+
+let to_err = function
+  | Ok x -> `Ok x
+  | Error y -> `Error y
+
 (** {2 IO} *)
 
 let pp pp_x buf e = match e with
diff --git a/src/core/CCResult.mli b/src/core/CCResult.mli
index 1a72e3a3..7a4a2c28 100644
--- a/src/core/CCResult.mli
+++ b/src/core/CCResult.mli
@@ -181,6 +181,14 @@ val of_opt : 'a option -> ('a, string) t
 
 val to_seq : ('a, _) t -> 'a sequence
 
+type ('a, 'b) error = [`Ok of 'a | `Error of 'b]
+
+val of_err : ('a, 'b) error -> ('a, 'b) t
+(** @since NEXT_RELEASE *)
+
+val to_err : ('a, 'b) t -> ('a, 'b) error
+(** @since NEXT_RELEASE *)
+
 (** {2 IO} *)
 
 val pp : 'a printer -> ('a, string) t printer