(*
copyright (c) 2013, simon cruanes
all rights reserved.

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*)

(** {1 GADT Description of Printers}

This module provides combinators to build printers for user-defined types.
It doesn't try to do {b pretty}-printing (see for instance Pprint for this),
but a simple way to print complicated values without writing a lot of code.
*)

type 'a sequence = ('a -> unit) -> unit

type 'a t = Buffer.t -> 'a -> unit
  (** A printer for the type ['a] *)

(** {2 Combinators} *)

val unit : unit t  (* prints nothing! *)
val int : int t
val string : string t
val bool : bool t
val float3 : float t (* 3 digits after . *)
val float : float t

val list : ?start:string -> ?stop:string -> ?sep:string -> 'a t -> 'a list t
val array : ?start:string -> ?stop:string -> ?sep:string -> 'a t -> 'a array t
val arrayi : ?start:string -> ?stop:string -> ?sep:string -> (int * 'a) t -> 'a array t
val seq : ?start:string -> ?stop:string -> ?sep:string -> 'a t -> 'a sequence t

val opt : 'a t -> 'a option t

val pair : 'a t -> 'b t -> ('a * 'b) t
val triple : 'a t -> 'b t -> 'c t -> ('a * 'b * 'c) t
val quad : 'a t -> 'b t -> 'c t -> 'd t -> ('a * 'b * 'c * 'd) t

val map : ('a -> 'b) -> 'b t -> 'a t


(** {2 IO} *)

val output : out_channel -> 'a t -> 'a -> unit
val to_string : 'a t -> 'a -> string

val sprintf : ('a, Buffer.t, unit, string) format4 -> 'a
  (** print into a string *)

val fprintf : out_channel -> ('a, Buffer.t, unit, unit) format4 -> 'a
  (** Print on a channel *)

val printf : ('a, Buffer.t, unit, unit) format4 -> 'a
val eprintf : ('a, Buffer.t, unit, unit) format4 -> 'a