module Bytes: BytesLabelsval length : bytes -> intval get : bytes -> int -> charget s n returns the byte at index n in argument s.
    Raise Invalid_argument if n is not a valid index in s.
val set : bytes -> int -> char -> unitset s n c modifies s in place, replacing the byte at index n
    with c.
    Raise Invalid_argument if n is not a valid index in s.
val create : int -> bytescreate n returns a new byte sequence of length n. The
    sequence is uninitialized and contains arbitrary bytes.
    Raise Invalid_argument if n < 0 or n > Sys.max_string_length.
val make : int -> char -> bytesmake n c returns a new byte sequence of length n, filled with
    the byte c.
    Raise Invalid_argument if n < 0 or n > Sys.max_string_length.
val init : int -> f:(int -> char) -> bytesinit n f returns a fresh byte sequence of length n,
    with character i initialized to the result of f i.
    Raise Invalid_argument if n < 0 or n > Sys.max_string_length.
val empty : bytesval copy : bytes -> bytesval of_string : string -> bytesval to_string : bytes -> stringval sub : bytes -> pos:int -> len:int -> bytessub s start len returns a new byte sequence of length len,
    containing the subsequence of s that starts at position start
    and has length len.
    Raise Invalid_argument if start and len do not designate a
    valid range of s.
val sub_string : bytes -> int -> int -> stringsub but return a string instead of a byte sequence.val extend : bytes -> left:int -> right:int -> bytesextend s left right returns a new byte sequence that contains
    the bytes of s, with left uninitialized bytes prepended and
    right uninitialized bytes appended to it. If left or right
    is negative, then bytes are removed (instead of appended) from
    the corresponding side of s.
    Raise Invalid_argument if the result length is negative or
    longer than Sys.max_string_length bytes.
Since 4.05.0
val fill : bytes -> pos:int -> len:int -> char -> unitfill s start len c modifies s in place, replacing len
    characters with c, starting at start.
    Raise Invalid_argument if start and len do not designate a
    valid range of s.
val blit : src:bytes -> src_pos:int -> dst:bytes -> dst_pos:int -> len:int -> unitblit src srcoff dst dstoff len copies len bytes from sequence
    src, starting at index srcoff, to sequence dst, starting at
    index dstoff. It works correctly even if src and dst are the
    same byte sequence, and the source and destination intervals
    overlap.
    Raise Invalid_argument if srcoff and len do not
    designate a valid range of src, or if dstoff and len
    do not designate a valid range of dst.
val blit_string : src:string -> src_pos:int -> dst:bytes -> dst_pos:int -> len:int -> unitblit src srcoff dst dstoff len copies len bytes from string
    src, starting at index srcoff, to byte sequence dst,
    starting at index dstoff.
    Raise Invalid_argument if srcoff and len do not
    designate a valid range of src, or if dstoff and len
    do not designate a valid range of dst.
Since 4.05.0
val concat : sep:bytes -> bytes list -> bytesconcat sep sl concatenates the list of byte sequences sl,
    inserting the separator byte sequence sep between each, and
    returns the result as a new byte sequence.val cat : bytes -> bytes -> bytescat s1 s2 concatenates s1 and s2 and returns the result
     as new byte sequence.
    Raise Invalid_argument if the result is longer than
    Sys.max_string_length bytes.
Since 4.05.0
val iter : f:(char -> unit) -> bytes -> unititer f s applies function f in turn to all the bytes of s.
    It is equivalent to f (get s 0); f (get s 1); ...; f (get s
    (length s - 1)); ().val iteri : f:(int -> char -> unit) -> bytes -> unitBytes.iter, but the function is applied to the index of
    the byte as first argument and the byte itself as second
    argument.val map : f:(char -> char) -> bytes -> bytesmap f s applies function f in turn to all the bytes of s and
    stores the resulting bytes in a new sequence that is returned as
    the result.val mapi : f:(int -> char -> char) -> bytes -> bytesmapi f s calls f with each character of s and its
    index (in increasing index order) and stores the resulting bytes
    in a new sequence that is returned as the result.val trim : bytes -> bytes' ', '\012', '\n', '\r', and '\t'.val escaped : bytes -> bytesval index : bytes -> char -> intindex s c returns the index of the first occurrence of byte c
    in s.
    Raise Not_found if c does not occur in s.
val index_opt : bytes -> char -> int optionindex_opt s c returns the index of the first occurrence of byte c
    in s or None if c does not occur in s.val rindex : bytes -> char -> intrindex s c returns the index of the last occurrence of byte c
    in s.
    Raise Not_found if c does not occur in s.
val rindex_opt : bytes -> char -> int optionrindex_opt s c returns the index of the last occurrence of byte c
    in s or None if c does not occur in s.val index_from : bytes -> int -> char -> intindex_from s i c returns the index of the first occurrence of
    byte c in s after position i.  Bytes.index s c is
    equivalent to Bytes.index_from s 0 c.
    Raise Invalid_argument if i is not a valid position in s.
    Raise Not_found if c does not occur in s after position i.
val index_from_opt : bytes -> int -> char -> int optionindex_from _opts i c returns the index of the first occurrence of
    byte c in s after position i or None if c does not occur in s after position i.
    Bytes.index_opt s c is equivalent to Bytes.index_from_opt s 0 c.
    Raise Invalid_argument if i is not a valid position in s.
Since 4.05
val rindex_from : bytes -> int -> char -> intrindex_from s i c returns the index of the last occurrence of
    byte c in s before position i+1.  rindex s c is equivalent
    to rindex_from s (Bytes.length s - 1) c.
    Raise Invalid_argument if i+1 is not a valid position in s.
    Raise Not_found if c does not occur in s before position i+1.
val rindex_from_opt : bytes -> int -> char -> int optionrindex_from_opt s i c returns the index of the last occurrence
    of byte c in s before position i+1 or None if c does not
    occur in s before position i+1.  rindex_opt s c is equivalent to
    rindex_from s (Bytes.length s - 1) c.
    Raise Invalid_argument if i+1 is not a valid position in s.
Since 4.05
val contains : bytes -> char -> boolcontains s c tests if byte c appears in s.val contains_from : bytes -> int -> char -> boolcontains_from s start c tests if byte c appears in s after
    position start.  contains s c is equivalent to contains_from
    s 0 c.
    Raise Invalid_argument if start is not a valid position in s.
val rcontains_from : bytes -> int -> char -> boolrcontains_from s stop c tests if byte c appears in s before
    position stop+1.
    Raise Invalid_argument if stop < 0 or stop+1 is not a valid
    position in s.
val uppercase : bytes -> bytesval lowercase : bytes -> bytesval capitalize : bytes -> bytesval uncapitalize : bytes -> bytesval uppercase_ascii : bytes -> bytesval lowercase_ascii : bytes -> bytesval capitalize_ascii : bytes -> bytesval uncapitalize_ascii : bytes -> bytestypet =bytes
val compare : t -> t -> intcompare.  Along with the type t,
    this function compare allows the module Bytes to be passed as
    argument to the functors Set.Make and Map.Make.val equal : t -> t -> bool