(*
copyright (c) 2013-2014, simon cruanes
all rights reserved.

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modification, are permitted provided that the following conditions are met:

redistributions of source code must retain the above copyright notice, this
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*)

(** {1 Basic String Utils}
Consider using KMP instead. *)

type t = string

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

val is_sub : sub:t -> int -> t -> int -> bool
(** [is_sub ~sub i s j] returns [true] iff [sub] is a substring of [s] starting
    at position [j] *)

val split : by:t -> t -> t list
(** split the given string along the given separator [by]. Should only
    be used with very small separators, otherwise use {!KMP}.
    @raise Failure if [by = ""] *)

val split_gen : by:t -> t -> t gen

val split_seq : by:t -> t -> t sequence

val find : ?start:int -> sub:t -> t -> int
(** Find [sub] in the string, returns its first index or -1.
    Should only be used with very small [sub] *)

val repeat : t -> int -> t
(** The same string, repeated n times *)

val prefix : pre:t -> t -> bool
(** [str_prefix ~pre s] returns [true] iff [pre] is a prefix of [s] *)

val to_gen : t -> char gen
val of_gen : char gen -> t

val to_seq : t -> char sequence
val of_seq : char sequence -> t

val pp : Buffer.t -> t -> unit