From 9c375ed93e6f89141ad26536a3192603e16aa250 Mon Sep 17 00:00:00 2001
From: Fardale <fardale+git@crans.org>
Date: Mon, 28 Oct 2019 13:03:22 +0100
Subject: [PATCH] add `CCList.to_string`

---
 src/core/CCList.ml  | 12 ++++++++++++
 src/core/CCList.mli |  6 ++++++
 2 files changed, 18 insertions(+)

diff --git a/src/core/CCList.ml b/src/core/CCList.ml
index fb483d73..96548f8e 100644
--- a/src/core/CCList.ml
+++ b/src/core/CCList.ml
@@ -1649,6 +1649,18 @@ let random_choose l = match l with
 
 let random_sequence l st = map (fun g -> g st) l
 
+let to_string ?(start="") ?(stop="") ?(sep=", ") item_to_string l =
+  let l = List.map item_to_string l in
+  start ^ (String.concat sep l) ^ stop
+
+(*$= to_string & ~printer:(fun s -> s)
+  (to_string string_of_int []) ""
+  (to_string ~start:"[" ~stop:"]" string_of_int []) "[]"
+  (to_string ~start:"[" ~stop:"]" string_of_int [1]) "[1]"
+  (to_string ~start:"[" ~stop:"]" string_of_int [1;2;3;4]) "[1, 2, 3, 4]"
+  (to_string ~sep:" " string_of_int [1;2;3;4]) "1 2 3 4"
+*)
+
 let to_seq l k = List.iter k l
 let of_seq seq =
   let l = ref [] in
diff --git a/src/core/CCList.mli b/src/core/CCList.mli
index 9d331dbe..6391e0b1 100644
--- a/src/core/CCList.mli
+++ b/src/core/CCList.mli
@@ -685,6 +685,12 @@ val random_choose : 'a t -> 'a random_gen
 
 val random_sequence : 'a random_gen t -> 'a t random_gen
 
+val to_string : ?start:string -> ?stop:string -> ?sep:string ->
+  ('a -> string) -> 'a t -> string
+(** [to_string ~start ~stop ~sep item_to_string l] print [l] to a string using
+    [sep] as a separator between elements of [l].
+    @since NEXT_RELEASE *)
+
 val to_seq : 'a t -> 'a sequence
 (** Return a [sequence] of the elements of the list. *)