From 945583ff43e6025cc323e87cee5a6304ce26118b Mon Sep 17 00:00:00 2001
From: Jeremie Dimino <jdimino@janestreet.com>
Date: Thu, 1 Mar 2018 20:16:46 +0000
Subject: [PATCH] Add Arg_spec.of_result{,_map}

---
 src/arg_spec.ml  | 9 +++++++++
 src/arg_spec.mli | 3 +++
 2 files changed, 12 insertions(+)

diff --git a/src/arg_spec.ml b/src/arg_spec.ml
index cd5ff93b..87fc4fe2 100644
--- a/src/arg_spec.ml
+++ b/src/arg_spec.ml
@@ -71,3 +71,12 @@ let quote_args =
     | arg :: args -> quote :: arg :: loop quote args
   in
   fun quote args -> As (loop quote args)
+
+let of_result = function
+  | Ok x -> x
+  | Error e -> Dyn (fun _ -> raise e)
+
+let of_result_map res ~f =
+  match res with
+  | Ok    x -> f x
+  | Error e -> Dyn (fun _ -> raise e)
diff --git a/src/arg_spec.mli b/src/arg_spec.mli
index 120ed502..1c2ce11a 100644
--- a/src/arg_spec.mli
+++ b/src/arg_spec.mli
@@ -46,3 +46,6 @@ val expand      : dir:Path.t -> 'a t list -> 'a -> string list * Path.Set.t
 
 (** [quote_args quote args] is [As \[quote; arg1; quote; arg2; ...\]] *)
 val quote_args : string -> string list -> _ t
+
+val of_result : ('a t, exn) result -> 'a t
+val of_result_map : ('a, exn) result -> f:('a -> 'b t) -> 'b t