Module Bytes

module Bytes: sig .. end
Byte sequence operations.

A byte sequence is a mutable data structure that contains a fixed-length sequence of bytes. Each byte can be indexed in constant time for reading or writing.

Given a byte sequence s of length l, we can access each of the l bytes of s via its index in the sequence. Indexes start at 0, and we will call an index valid in s if it falls within the range [0...l-1] (inclusive). A position is the point between two bytes or at the beginning or end of the sequence. We call a position valid in s if it falls within the range [0...l] (inclusive). Note that the byte at index n is between positions n and n+1.

Two parameters start and len are said to designate a valid range of s if len >= 0 and start and start+len are valid positions in s.

Byte sequences can be modified in place, for instance via the set and blit functions described below. See also strings (module String), which are almost the same data structure, but cannot be modified in place.

Bytes are represented by the OCaml type char.
Since 4.02.0


val length : bytes -> int
Return the length (number of bytes) of the argument.
val get : bytes -> int -> char
get s n returns the byte at index n in argument s.

Raise Invalid_argument if n not a valid index in s.

val set : bytes -> int -> char -> unit
set 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 -> bytes
create 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 -> bytes
make 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 empty : bytes
A byte sequence of size 0.
val copy : bytes -> bytes
Return a new byte sequence that contains the same bytes as the argument.
val of_string : string -> bytes
Return a new byte sequence that contains the same bytes as the given string.
val to_string : bytes -> string
Return a new string that contains the same bytes as the given byte sequence.
val sub : bytes -> int -> int -> bytes
sub 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 -> string
Same as sub but return a string instead of a byte sequence.
val extend : bytes -> int -> int -> bytes
extend 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.

val fill : bytes -> int -> int -> char -> unit
fill 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 : bytes -> int -> bytes -> int -> int -> unit
blit 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 : string -> int -> bytes -> int -> int -> unit
blit 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.

val concat : bytes -> bytes list -> bytes
concat 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.

Raise Invalid_argument if the result is longer than Sys.max_string_length bytes.

val cat : bytes -> bytes -> bytes
cat 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.

val iter : (char -> unit) -> bytes -> unit
iter 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 : (int -> char -> unit) -> bytes -> unit
Same as Bytes.iter, but the function is applied to the index of the byte as first argument and the byte itself as second argument.
val map : (char -> char) -> bytes -> bytes
map 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 trim : bytes -> bytes
Return a copy of the argument, without leading and trailing whitespace. The bytes regarded as whitespace are the ASCII characters ' ', '\012', '\n', '\r', and '\t'.
val escaped : bytes -> bytes
Return a copy of the argument, with special characters represented by escape sequences, following the lexical conventions of OCaml.

Raise Invalid_argument if the result is longer than Sys.max_string_length bytes.

val index : bytes -> char -> int
index 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 rindex : bytes -> char -> int
rindex 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 index_from : bytes -> int -> char -> int
index_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 rindex_from : bytes -> int -> char -> int
rindex_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 contains : bytes -> char -> bool
contains s c tests if byte c appears in s.
val contains_from : bytes -> int -> char -> bool
contains_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 -> bool
rcontains_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 -> bytes
Return a copy of the argument, with all lowercase letters translated to uppercase, including accented letters of the ISO Latin-1 (8859-1) character set.
val lowercase : bytes -> bytes
Return a copy of the argument, with all uppercase letters translated to lowercase, including accented letters of the ISO Latin-1 (8859-1) character set.
val capitalize : bytes -> bytes
Return a copy of the argument, with the first byte set to uppercase.
val uncapitalize : bytes -> bytes
Return a copy of the argument, with the first byte set to lowercase.
type t = bytes 
An alias for the type of byte sequences.
val compare : t -> t -> int
The comparison function for byte sequences, with the same specification as compare. 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.