Adding "float" argument type

src/action.mli

@@ -233,6 +233,9 @@ module Args : sig
   (** An integer cell. *)
   val int : int cell
 
+  (** A floating-point cell. *)
+  val float : float cell
+
   (** The type of an argument parser. 
   *)
   type 'args t = ('args -> string list) * (string list -> 'args option)

src/action_Args.ml

@@ -2,7 +2,8 @@ type 'a cell = ('a -> string) * (string -> 'a option)
 type 'args t = ('args -> string list) * (string list -> 'args option)
 
 let string = (fun str -> str), (fun str -> Some str) 
-let int    = string_of_int, (fun i -> try Some (int_of_string i) with _ -> None)
+let int    = string_of_int,   (fun i -> try Some (  int_of_string i) with _ -> None)
+let float  = string_of_float, (fun i -> try Some (float_of_string i) with _ -> None)
 
 let parse (_,f) list = f list
 let generate (g,_) args = g args