From f145c4b196074bd6fb18ad8b728e180c759fbd28 Mon Sep 17 00:00:00 2001
From: Benjamin Canou <benjamin@canou.fr>
Date: Wed, 22 Nov 2017 18:29:51 +0100
Subject: [PATCH] Utils: add Lwt_pipe.pop_all_now

---
 src/lib_stdlib_lwt/lwt_pipe.ml  | 15 +++++++++------
 src/lib_stdlib_lwt/lwt_pipe.mli |  4 ++++
 2 files changed, 13 insertions(+), 6 deletions(-)

diff --git a/src/lib_stdlib_lwt/lwt_pipe.ml b/src/lib_stdlib_lwt/lwt_pipe.ml
index bb44b12fb..a06b0eea1 100644
--- a/src/lib_stdlib_lwt/lwt_pipe.ml
+++ b/src/lib_stdlib_lwt/lwt_pipe.ml
@@ -162,14 +162,17 @@ let rec values_available q =
   else
     Lwt.return_unit
 
+let rec pop_all_loop q acc =
+  match pop_now_exn q with
+  | exception Empty -> List.rev acc
+  | e -> pop_all_loop q (e :: acc)
+
 let pop_all q =
-  let rec loop acc =
-    match pop_now_exn q with
-    | exception Empty -> List.rev acc
-    | e -> loop (e :: acc)
-  in
   pop q >>= fun e ->
-  Lwt.return (loop [e])
+  Lwt.return (pop_all_loop q [e])
+
+let pop_all_now q =
+  pop_all_loop q []
 
 let close q =
   if not q.closed then begin
diff --git a/src/lib_stdlib_lwt/lwt_pipe.mli b/src/lib_stdlib_lwt/lwt_pipe.mli
index 452e581da..3db991380 100644
--- a/src/lib_stdlib_lwt/lwt_pipe.mli
+++ b/src/lib_stdlib_lwt/lwt_pipe.mli
@@ -34,6 +34,10 @@ val pop_all : 'a t -> 'a list Lwt.t
     removes and returns all the element in [q] (in the order they
     were inserted). *)
 
+val pop_all_now : 'a t -> 'a list
+(** [pop_all_now q] returns all the element in [q] (in the order they
+    were inserted), or [[]] if [q] is empty. *)
+
 val peek : 'a t -> 'a Lwt.t
 (** [peek] is like [pop] except it does not removes the first
     element. *)