easier to use interface for Bij.Sexpr

bij.ml

@@ -395,11 +395,19 @@ module SexpStr = struct
   module SexpEncodeBuf = SexpEncode(SinkBuf)
   module SexpDecodeString = SexpDecode(SourceStr)
 
-  let to_string ~bij x =
+  let to_string ?(bufsize=64) ~bij x =
-    let b = Buffer.create 15 in
+    let b = Buffer.create bufsize in
     SexpEncodeBuf.encode ~bij b x;
     Buffer.contents b
 
   let of_string ~bij s =
     SexpDecodeString.decode ~bij (SourceStr.create s)
 end
+
+module SexpChan = struct
+  module SexpEncodeChan = SexpEncode(SinkChan)
+  module SexpDecodeChan = SexpDecode(SourceChan)
+
+  include SexpEncodeChan
+  include SexpDecodeChan
+end

bij.mli

@@ -94,9 +94,9 @@ module type SINK = sig
   val write_float : t -> float -> unit
 end
 
-module SinkBuf : SINK with type t := Buffer.t
+module SinkBuf : SINK with type t = Buffer.t
 
-module SinkChan : SINK with type t := out_channel
+module SinkChan : SINK with type t = out_channel
 
 (** {2 Encoding/decoding} *)
 
@@ -115,6 +115,12 @@ module SexpDecode(Source : SOURCE) : DECODE with type source = Source.t
 
 (** Specific instance for encoding to/from strings *)
 module SexpStr : sig
-  val to_string : bij:'a t -> 'a -> string
+  val to_string : ?bufsize:int -> bij:'a t -> 'a -> string
   val of_string : bij:'a t -> string -> 'a
 end 
+
+(** Specific instance for encoding to/from channels *)
+module SexpChan : sig
+  include ENCODE with type sink = SinkChan.t
+  include DECODE with type source = SourceChan.t
+end