OUnit user guide : OUnitDiff

`sig
module type DIFF_ELEMENT =
sig
type t
val pp_printer : Format.formatter -> OUnitDiff.DIFF_ELEMENT.t -> unit
val compare :
OUnitDiff.DIFF_ELEMENT.t -> OUnitDiff.DIFF_ELEMENT.t -> int
val pp_print_sep : Format.formatter -> unit -> unit
end
module type S =
sig
type e
type t
val compare : OUnitDiff.S.t -> OUnitDiff.S.t -> int
val pp_printer : Format.formatter -> OUnitDiff.S.t -> unit
val pp_diff : Format.formatter -> OUnitDiff.S.t * OUnitDiff.S.t -> unit
val assert_equal :
?msg:string -> OUnitDiff.S.t -> OUnitDiff.S.t -> unit
val of_list : OUnitDiff.S.e list -> OUnitDiff.S.t
end
module SetMake :
functor (D : DIFF_ELEMENT) ->
sig
type e = D.t
type t
val compare : t -> t -> int
val pp_printer : Format.formatter -> t -> unit
val pp_diff : Format.formatter -> t * t -> unit
val assert_equal : ?msg:string -> t -> t -> unit
val of_list : e list -> t
end
module ListSimpleMake :
functor (D : DIFF_ELEMENT) ->
sig
type e = D.t
type t = D.t list
val compare : t -> t -> int
val pp_printer : Format.formatter -> t -> unit
val pp_diff : Format.formatter -> t * t -> unit
val assert_equal : ?msg:string -> t -> t -> unit
val of_list : e list -> t
end
val pp_comma_separator : Format.formatter -> unit -> unit
end`