expose blocking decoder in CCSexpM

src/sexp/CCSexpM.ml

@@ -309,11 +309,13 @@ module MakeDecode(M : MONAD) = struct
     expr_or_end (fun _ x -> M.return (`Ok x)) t
 end
 
-module D = MakeDecode(struct
+module ID_MONAD = struct
   type 'a t = 'a
   let return x = x
   let (>>=) x f = f x
-end)
+end
+
+module D = MakeDecode(ID_MONAD)
 
 let parse_string s : t or_error =
   let n = String.length s in

src/sexp/CCSexpM.mli

@@ -86,6 +86,14 @@ module MakeDecode(M : MONAD) : sig
       long enough or isn't a proper S-expression *)
 end
 
+module ID_MONAD : MONAD
+(** The monad that just uses blocking calls as bind
+    @since NEXT_RELEASE *)
+
+module D : module type of MakeDecode(ID_MONAD)
+(** Decoder that just blocks when input is not available
+    @since NEXT_RELEASE *)
+
 val parse_string : string -> t or_error
 (** Parse a string *)