val create : int -> t
create n
returns a fresh buffer, initially empty. The n
parameter is the initial size of the internal byte sequence that holds the buffer contents. That byte sequence is automatically reallocated when more than n
characters are stored in the buffer, but shrinks back to n
characters when reset
is called. For best performance, n
should be of the same order of magnitude as the number of characters that are expected to be stored in the buffer (for instance, 80 for a buffer that holds one output line). Nothing bad will happen if the buffer grows beyond that limit, however. In doubt, take n = 16
for instance. If n
is not between 1 and Sys.max_string_length
, it will be clipped to that interval.
val contents : t -> string
Return a copy of the current contents of the buffer. The buffer itself is unchanged.
val to_bytes : t -> bytes
Return a copy of the current contents of the buffer. The buffer itself is unchanged.
- since
- 4.02
val sub : t -> int -> int -> string
Buffer.sub b off len
returns a copy of len
bytes from the current contents of the buffer b
, starting at offset off
.
Raise Invalid_argument
if srcoff
and len
do not designate a valid range of b
.
val blit : t -> int -> bytes -> int -> int -> unit
Buffer.blit src srcoff dst dstoff len
copies len
characters from the current contents of the buffer src
, starting at offset srcoff
to dst
, starting at character 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
- 3.11.2
val nth : t -> int -> char
Get the n-th character of the buffer. Raise Invalid_argument
if index out of bounds
val length : t -> int
Return the number of characters currently contained in the buffer.
val clear : t -> unit
Empty the buffer.
val reset : t -> unit
Empty the buffer and deallocate the internal byte sequence holding the buffer contents, replacing it with the initial internal byte sequence of length n
that was allocated by Buffer.create
n
. For long-lived buffers that may have grown a lot, reset
allows faster reclamation of the space used by the buffer.
val add_char : t -> char -> unit
add_char b c
appends the character c
at the end of buffer b
.
val add_utf_8_uchar : t -> Stdlib.Uchar.t -> unit
add_utf_8_uchar b u
appends the UTF-8 encoding of u
at the end of buffer b
.
- since
- 4.06.0
val add_utf_16le_uchar : t -> Stdlib.Uchar.t -> unit
add_utf_16le_uchar b u
appends the UTF-16LE encoding of u
at the end of buffer b
.
- since
- 4.06.0
val add_utf_16be_uchar : t -> Stdlib.Uchar.t -> unit
add_utf_16be_uchar b u
appends the UTF-16BE encoding of u
at the end of buffer b
.
- since
- 4.06.0
val add_string : t -> string -> unit
add_string b s
appends the string s
at the end of buffer b
.
val add_bytes : t -> bytes -> unit
add_bytes b s
appends the byte sequence s
at the end of buffer b
.
- since
- 4.02
val add_substring : t -> string -> int -> int -> unit
add_substring b s ofs len
takes len
characters from offset ofs
in string s
and appends them at the end of buffer b
.
val add_subbytes : t -> bytes -> int -> int -> unit
add_subbytes b s ofs len
takes len
characters from offset ofs
in byte sequence s
and appends them at the end of buffer b
.
- since
- 4.02
val add_substitute : t -> (string -> string) -> string -> unit
add_substitute b f s
appends the string pattern s
at the end of buffer b
with substitution. The substitution process looks for variables into the pattern and substitutes each variable name by its value, as obtained by applying the mapping f
to the variable name. Inside the string pattern, a variable name immediately follows a non-escaped $
character and is one of the following:
- a non empty sequence of alphanumeric or
_
characters, - an arbitrary sequence of characters enclosed by a pair of matching parentheses or curly brackets. An escaped
$
character is a$
that immediately follows a backslash character; it then stands for a plain$
. RaiseNot_found
if the closing character of a parenthesized variable cannot be found.
add_buffer b1 b2
appends the current contents of buffer b2
at the end of buffer b1
. b2
is not modified.
val add_channel : t -> Stdlib.in_channel -> int -> unit
add_channel b ic n
reads at most n
characters from the input channel ic
and stores them at the end of buffer b
. Raise End_of_file
if the channel contains fewer than n
characters. In this case, the characters are still added to the buffer, so as to avoid loss of data.
val output_buffer : Stdlib.out_channel -> t -> unit
output_buffer oc b
writes the current contents of buffer b
on the output channel oc
.
val truncate : t -> int -> unit
truncate b len
truncates the length of b
to len
Note: the internal byte sequence is not shortened. Raise Invalid_argument
if len < 0
or len > length b
.
- since
- 4.05.0
Iterators
val to_seq : t -> char Stdlib.Seq.t
Iterate on the buffer, in increasing order. Modification of the buffer during iteration is undefined behavior.
- since
- 4.07
val to_seqi : t -> (int * char) Stdlib.Seq.t
Iterate on the buffer, in increasing order, yielding indices along chars. Modification of the buffer during iteration is undefined behavior.
- since
- 4.07
val add_seq : t -> char Stdlib.Seq.t -> unit
Add chars to the buffer
- since
- 4.07
val of_seq : char Stdlib.Seq.t -> t
Create a buffer from the generator
- since
- 4.07
Binary encoding of integers
val add_uint8 : t -> int -> unit
add_uint8 b i
appends a binary unsigned 8-bit integer i
to b
.
- since
- 4.08
val add_int8 : t -> int -> unit
add_int8 b i
appends a binary signed 8-bit integer i
to b
.
- since
- 4.08
val add_uint16_ne : t -> int -> unit
add_uint16_ne b i
appends a binary native-endian unsigned 16-bit integer i
to b
.
- since
- 4.08
val add_uint16_be : t -> int -> unit
add_uint16_be b i
appends a binary big-endian unsigned 16-bit integer i
to b
.
- since
- 4.08
val add_uint16_le : t -> int -> unit
add_uint16_le b i
appends a binary little-endian unsigned 16-bit integer i
to b
.
- since
- 4.08
val add_int16_ne : t -> int -> unit
add_int16_ne b i
appends a binary native-endian signed 16-bit integer i
to b
.
- since
- 4.08
val add_int16_be : t -> int -> unit
add_int16_be b i
appends a binary big-endian signed 16-bit integer i
to b
.
- since
- 4.08
val add_int16_le : t -> int -> unit
add_int16_le b i
appends a binary little-endian signed 16-bit integer i
to b
.
- since
- 4.08
val add_int32_ne : t -> int32 -> unit
add_int32_ne b i
appends a binary native-endian 32-bit integer i
to b
.
- since
- 4.08
val add_int32_be : t -> int32 -> unit
add_int32_be b i
appends a binary big-endian 32-bit integer i
to b
.
- since
- 4.08
val add_int32_le : t -> int32 -> unit
add_int32_le b i
appends a binary little-endian 32-bit integer i
to b
.
- since
- 4.08
val add_int64_ne : t -> int64 -> unit
add_int64_ne b i
appends a binary native-endian 64-bit integer i
to b
.
- since
- 4.08
val add_int64_be : t -> int64 -> unit
add_int64_be b i
appends a binary big-endian 64-bit integer i
to b
.
- since
- 4.08
val add_int64_le : t -> int64 -> unit
add_int64_ne b i
appends a binary little-endian 64-bit integer i
to b
.
- since
- 4.08