From a9b91943e854cd63b23f290634cb9b0771fb71df Mon Sep 17 00:00:00 2001
From: Simon Cruanes <simon.cruanes.2007@m4x.org>
Date: Wed, 6 Apr 2016 11:23:21 +0200
Subject: [PATCH] add `CCFormat.within`

---
 src/core/CCFormat.ml  | 17 +++++++++++------
 src/core/CCFormat.mli | 15 ++++++++++++---
 2 files changed, 23 insertions(+), 9 deletions(-)

diff --git a/src/core/CCFormat.ml b/src/core/CCFormat.ml
index 8fd37a8e..01a1fdcd 100644
--- a/src/core/CCFormat.ml
+++ b/src/core/CCFormat.ml
@@ -76,14 +76,19 @@ let opt pp fmt x = match x with
   | None -> Format.pp_print_string fmt "none"
   | Some x -> Format.fprintf fmt "some %a" pp x
 
-let pair ppa ppb fmt (a, b) =
-  Format.fprintf fmt "(%a,@ %a)" ppa a ppb b
+let pair ?(sep=", ") ppa ppb fmt (a, b) =
+  Format.fprintf fmt "(%a%s@,%a)" ppa a sep ppb b
 
-let triple ppa ppb ppc fmt (a, b, c) =
-  Format.fprintf fmt "(%a,@ %a,@ %a)" ppa a ppb b ppc c
+let triple ?(sep=", ") ppa ppb ppc fmt (a, b, c) =
+  Format.fprintf fmt "(%a%s@,%a%s@,%a)" ppa a sep ppb b sep ppc c
 
-let quad ppa ppb ppc ppd fmt (a, b, c, d) =
-  Format.fprintf fmt "(%a,@ %a,@ %a,@ %a)" ppa a ppb b ppc c ppd d
+let quad ?(sep=", ") ppa ppb ppc ppd fmt (a, b, c, d) =
+  Format.fprintf fmt "(%a%s@,%a%s@,%a%s@,%a)" ppa a sep ppb b sep ppc c sep ppd d
+
+let within a b p out x =
+  string out a;
+  p out x;
+  string out b
 
 let map f pp fmt x =
   pp fmt (f x);
diff --git a/src/core/CCFormat.mli b/src/core/CCFormat.mli
index e678a779..414fe4aa 100644
--- a/src/core/CCFormat.mli
+++ b/src/core/CCFormat.mli
@@ -38,9 +38,18 @@ val seq : ?start:string -> ?stop:string -> ?sep:string -> 'a printer -> 'a seque
 
 val opt : 'a printer -> 'a option printer
 
-val pair : 'a printer -> 'b printer -> ('a * 'b) printer
-val triple : 'a printer -> 'b printer -> 'c printer -> ('a * 'b * 'c) printer
-val quad : 'a printer -> 'b printer -> 'c printer -> 'd printer -> ('a * 'b * 'c * 'd) printer
+(** In the tuple printers, the [sep] argument is only available
+    @since NEXT_RELEASE *)
+
+val pair : ?sep:string -> 'a printer -> 'b printer -> ('a * 'b) printer
+val triple : ?sep:string -> 'a printer -> 'b printer -> 'c printer -> ('a * 'b * 'c) printer
+val quad : ?sep:string -> 'a printer -> 'b printer ->
+            'c printer -> 'd printer -> ('a * 'b * 'c * 'd) printer
+
+val within : string -> string -> 'a printer -> 'a printer
+(** [within a b p] wraps [p] inside the strings [a] and [b]. Convenient,
+    for instances, for brackets, parenthesis, quotes, etc.
+    @since NEXT_RELEASE *)
 
 val map : ('a -> 'b) -> 'b printer -> 'a printer