better printing and doc

src/data/CCBitField.ml

@@ -186,15 +186,17 @@ module Make(X : EMPTY) : BITFIELD = struct
   let pp out x =
     let ppf = Format.fprintf in
     ppf out "{@[<hv>";
+    let first=ref true in
     Queue.iter
       (fun (AnyField f) ->
+        if !first then first := false else ppf out ",@ ";
         match f.kind with
         | Bool ->
             let b = get f x in
-            ppf out "%s: %b,@ " f.name b
+            ppf out "%s=%b" f.name b
         | Int ->
             let i = get f x in
-            ppf out "%s: %ui@, " f.name i
+            ppf out "%s=%u" f.name i
       ) fields_;
     ppf out "@]}"
 end

src/data/CCBitField.mli

@@ -75,7 +75,27 @@ module type BITFIELD = sig
   (** Print the bitfield using the current list of fields *)
 end
 
-(** Create a new bitfield type *)
+(** Create a new bitfield type,
+
+{[
+module B = CCBitField.Make(struct end);;
+
+#install_printer B.pp;;
+
+let x = B.int ~name:"x" ~width:3;;
+let y = B.int ~name:"y" ~width:2;;
+let z = B.bool ~name:"z" ();;
+
+let f = B.(empty |> set x 3 |> set y 1);;
+
+B.get z f ;;
+
+B.(f |> set z true |> get z) ;;
+
+]}
+
+
+*)
 module Make(X : EMPTY) : BITFIELD
 
 (*$R