module Bytes:sig
..end
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
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
val copy : bytes -> bytes
val of_string : string -> bytes
val to_string : bytes -> string
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
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
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
' '
, '\012'
, '\n'
, '\r'
, and '\t'
.val escaped : bytes -> bytes
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
val lowercase : bytes -> bytes
val capitalize : bytes -> bytes
val uncapitalize : bytes -> bytes
typet =
bytes
val compare : t -> t -> int