String type based on Bigarray
, for use in I/O and C-bindings
include module type of sig ... end
type t
= (Core_kernel__.Import.char, Bigarray.int8_unsigned_elt, Bigarray.c_layout) Bigarray.Array1.t
val t_of_sexp : Sexplib.Sexp.t ‑> t
val sexp_of_t : t ‑> Sexplib.Sexp.t
val compare : t ‑> t ‑> Core_kernel__.Import.int
val bin_t : t Bin_prot.Type_class.t
val bin_read_t : t Bin_prot.Read.reader
val __bin_read_t__ : (Core_kernel__.Import.int ‑> t) Bin_prot.Read.reader
val bin_reader_t : t Bin_prot.Type_class.reader
val bin_size_t : t Bin_prot.Size.sizer
val bin_write_t : t Bin_prot.Write.writer
val bin_writer_t : t Bin_prot.Type_class.writer
val bin_shape_t : Bin_prot.Shape.t
val t_frozen_of_sexp : Sexplib.Sexp.t ‑> t_frozen
val sexp_of_t_frozen : t_frozen ‑> Sexplib.Sexp.t
val hash_fold_t_frozen : Ppx_hash_lib.Std.Hash.state ‑> t_frozen ‑> Ppx_hash_lib.Std.Hash.state
val hash_t_frozen : t_frozen ‑> Ppx_hash_lib.Std.Hash.hash_value
val compare_t_frozen : t_frozen ‑> t_frozen ‑> Core_kernel__.Import.int
val bin_t_frozen : t_frozen Bin_prot.Type_class.t
val bin_read_t_frozen : t_frozen Bin_prot.Read.reader
val __bin_read_t_frozen__ : (Core_kernel__.Import.int ‑> t_frozen) Bin_prot.Read.reader
val bin_reader_t_frozen : t_frozen Bin_prot.Type_class.reader
val bin_size_t_frozen : t_frozen Bin_prot.Size.sizer
val bin_write_t_frozen : t_frozen Bin_prot.Write.writer
val bin_writer_t_frozen : t_frozen Bin_prot.Type_class.writer
val bin_shape_t_frozen : Bin_prot.Shape.t
val equal : t Core_kernel__.Import.Equal.equal
module Hexdump = Core_kernel__Bigstring.Hexdump
val create : ?max_mem_waiting_gc:Core_kernel.Byte_units.t ‑> Core_kernel__.Import.int ‑> t
val init : Core_kernel__.Import.int ‑> f:(Core_kernel__.Import.int ‑> Core_kernel__.Import.char) ‑> t
val of_string : ?pos:Core_kernel__.Import.int ‑> ?len:Core_kernel__.Import.int ‑> Core_kernel__.Import.string ‑> t
val to_string : ?pos:Core_kernel__.Import.int ‑> ?len:Core_kernel__.Import.int ‑> t ‑> Core_kernel__.Import.string
val concat : ?sep:t ‑> t Core_kernel__.Import.list ‑> t
val check_args : loc:Core_kernel__.Import.string ‑> pos:Core_kernel__.Import.int ‑> len:Core_kernel__.Import.int ‑> t ‑> Core_kernel__.Import.unit
val get_opt_len : t ‑> pos:Core_kernel__.Import.int ‑> Core_kernel__.Import.int Core_kernel__.Import.option ‑> Core_kernel__.Import.int
val length : t ‑> Core_kernel__.Import.int
external get : t ‑> Core_kernel__.Import.int ‑> Core_kernel__.Import.char =
external set : t ‑> Core_kernel__.Import.int ‑> Core_kernel__.Import.char ‑> Core_kernel__.Import.unit =
external is_mmapped : t ‑> Core_kernel__.Import.bool =
val blit : (t, t) Base.Blit_intf.blit
val blito : (t, t) Base.Blit_intf.blito
val unsafe_blit : (t, t) Base.Blit_intf.blit
val sub : (t, t) Base.Blit_intf.sub
val subo : (t, t) Base.Blit_intf.subo
val write_bin_prot : t ‑> ?pos:Core_kernel__.Import.int ‑> 'a Bin_prot.Type_class.writer ‑> 'a ‑> Core_kernel__.Import.int
val read_bin_prot : t ‑> ?pos:Core_kernel__.Import.int ‑> ?len:Core_kernel__.Import.int ‑> 'a Bin_prot.Type_class.reader ‑> ('a * Core_kernel__.Import.int) Core_kernel.Or_error.t
val read_bin_prot_verbose_errors : t ‑> ?pos:Core_kernel__.Import.int ‑> ?len:Core_kernel__.Import.int ‑> 'a Bin_prot.Type_class.reader ‑> [ `Invalid_data of Core_kernel.Error.t | `Not_enough_data | `Ok of 'a * Core_kernel__.Import.int ]
val map_file : shared:Core_kernel__.Import.bool ‑> Unix.file_descr ‑> Core_kernel__.Import.int ‑> t
val find : ?pos:Core_kernel__.Import.int ‑> ?len:Core_kernel__.Import.int ‑> Core_kernel__.Import.char ‑> t ‑> Core_kernel__.Import.int Core_kernel__.Import.option
external unsafe_find : t ‑> Core_kernel__.Import.char ‑> pos:Core_kernel__.Import.int ‑> len:Core_kernel__.Import.int ‑> Core_kernel__.Import.int =
external unsafe_destroy : t ‑> Core_kernel__.Import.unit =
val unsafe_get_int8 : t ‑> pos:Core_kernel__.Import.int ‑> Core_kernel__.Import.int
val unsafe_set_int8 : t ‑> pos:Core_kernel__.Import.int ‑> Core_kernel__.Import.int ‑> Core_kernel__.Import.unit
val unsafe_get_uint8 : t ‑> pos:Core_kernel__.Import.int ‑> Core_kernel__.Import.int
val unsafe_set_uint8 : t ‑> pos:Core_kernel__.Import.int ‑> Core_kernel__.Import.int ‑> Core_kernel__.Import.unit
val unsafe_get_int16_le : t ‑> pos:Core_kernel__.Import.int ‑> Core_kernel__.Import.int
val unsafe_get_int16_be : t ‑> pos:Core_kernel__.Import.int ‑> Core_kernel__.Import.int
val unsafe_set_int16_le : t ‑> pos:Core_kernel__.Import.int ‑> Core_kernel__.Import.int ‑> Core_kernel__.Import.unit
val unsafe_set_int16_be : t ‑> pos:Core_kernel__.Import.int ‑> Core_kernel__.Import.int ‑> Core_kernel__.Import.unit
val unsafe_get_uint16_le : t ‑> pos:Core_kernel__.Import.int ‑> Core_kernel__.Import.int
val unsafe_get_uint16_be : t ‑> pos:Core_kernel__.Import.int ‑> Core_kernel__.Import.int
val unsafe_set_uint16_le : t ‑> pos:Core_kernel__.Import.int ‑> Core_kernel__.Import.int ‑> Core_kernel__.Import.unit
val unsafe_set_uint16_be : t ‑> pos:Core_kernel__.Import.int ‑> Core_kernel__.Import.int ‑> Core_kernel__.Import.unit
val unsafe_get_int32_le : t ‑> pos:Core_kernel__.Import.int ‑> Core_kernel__.Import.int
val unsafe_get_int32_be : t ‑> pos:Core_kernel__.Import.int ‑> Core_kernel__.Import.int
val unsafe_set_int32_le : t ‑> pos:Core_kernel__.Import.int ‑> Core_kernel__.Import.int ‑> Core_kernel__.Import.unit
val unsafe_set_int32_be : t ‑> pos:Core_kernel__.Import.int ‑> Core_kernel__.Import.int ‑> Core_kernel__.Import.unit
val unsafe_get_uint32_le : t ‑> pos:Core_kernel__.Import.int ‑> Core_kernel__.Import.int
val unsafe_get_uint32_be : t ‑> pos:Core_kernel__.Import.int ‑> Core_kernel__.Import.int
val unsafe_set_uint32_le : t ‑> pos:Core_kernel__.Import.int ‑> Core_kernel__.Import.int ‑> Core_kernel__.Import.unit
val unsafe_set_uint32_be : t ‑> pos:Core_kernel__.Import.int ‑> Core_kernel__.Import.int ‑> Core_kernel__.Import.unit
val unsafe_get_int64_le_exn : t ‑> pos:Core_kernel__.Import.int ‑> Core_kernel__.Import.int
val unsafe_get_int64_be_exn : t ‑> pos:Core_kernel__.Import.int ‑> Core_kernel__.Import.int
val unsafe_get_int64_le_trunc : t ‑> pos:Core_kernel__.Import.int ‑> Core_kernel__.Import.int
val unsafe_get_int64_be_trunc : t ‑> pos:Core_kernel__.Import.int ‑> Core_kernel__.Import.int
val unsafe_set_int64_le : t ‑> pos:Core_kernel__.Import.int ‑> Core_kernel__.Import.int ‑> Core_kernel__.Import.unit
val unsafe_set_int64_be : t ‑> pos:Core_kernel__.Import.int ‑> Core_kernel__.Import.int ‑> Core_kernel__.Import.unit
val unsafe_get_uint64_be_exn : t ‑> pos:Core_kernel__.Import.int ‑> Core_kernel__.Import.int
val unsafe_get_uint64_le_exn : t ‑> pos:Core_kernel__.Import.int ‑> Core_kernel__.Import.int
val unsafe_set_uint64_le : t ‑> pos:Core_kernel__.Import.int ‑> Core_kernel__.Import.int ‑> Core_kernel__.Import.unit
val unsafe_set_uint64_be : t ‑> pos:Core_kernel__.Import.int ‑> Core_kernel__.Import.int ‑> Core_kernel__.Import.unit
val unsafe_get_int32_t_le : t ‑> pos:Core_kernel__.Import.int ‑> Int32.t
val unsafe_get_int32_t_be : t ‑> pos:Core_kernel__.Import.int ‑> Int32.t
val unsafe_set_int32_t_le : t ‑> pos:Core_kernel__.Import.int ‑> Int32.t ‑> Core_kernel__.Import.unit
val unsafe_set_int32_t_be : t ‑> pos:Core_kernel__.Import.int ‑> Int32.t ‑> Core_kernel__.Import.unit
val unsafe_get_int64_t_le : t ‑> pos:Core_kernel__.Import.int ‑> Int64.t
val unsafe_get_int64_t_be : t ‑> pos:Core_kernel__.Import.int ‑> Int64.t
val unsafe_set_int64_t_le : t ‑> pos:Core_kernel__.Import.int ‑> Int64.t ‑> Core_kernel__.Import.unit
val unsafe_set_int64_t_be : t ‑> pos:Core_kernel__.Import.int ‑> Int64.t ‑> Core_kernel__.Import.unit
val get_tail_padded_fixed_string : padding:Core_kernel__.Import.char ‑> t ‑> pos:Core_kernel__.Import.int ‑> len:Core_kernel__.Import.int ‑> Core_kernel__.Import.unit ‑> Core_kernel__.Import.string
val set_tail_padded_fixed_string : padding:Core_kernel__.Import.char ‑> t ‑> pos:Core_kernel__.Import.int ‑> len:Core_kernel__.Import.int ‑> Core_kernel__.Import.string ‑> Core_kernel__.Import.unit
val get_head_padded_fixed_string : padding:Core_kernel__.Import.char ‑> t ‑> pos:Core_kernel__.Import.int ‑> len:Core_kernel__.Import.int ‑> Core_kernel__.Import.unit ‑> Core_kernel__.Import.string
val set_head_padded_fixed_string : padding:Core_kernel__.Import.char ‑> t ‑> pos:Core_kernel__.Import.int ‑> len:Core_kernel__.Import.int ‑> Core_kernel__.Import.string ‑> Core_kernel__.Import.unit
exception
IOError of int * exn
Type of I/O errors
In IOError (n, exn)
, n
is the number of bytes successfully read/written before
the error and exn
is the occured exception (e.g. Unix_error, End_of_file)
val read : ?min_len:int ‑> Unix.file_descr ‑> ?pos:int ‑> ?len:int ‑> t ‑> int
read ?min_len fd ?pos ?len bstr
reads at least min_len
(must be
greater than or equal zero) and at most len
(must be greater than
or equal to min_len
) bytes from file descriptor fd
, and writes
them to bigstring bstr
starting at position pos
.
Returns the number of bytes actually read.
read
returns zero only if len = 0
. If len > 0
and there's nothing left to read,
read
raises to indicate EOF even if min_len = 0
.
NOTE: even if len
is zero, there may still be errors when reading
from the descriptor!
length bstr - pos
val really_read : Unix.file_descr ‑> ?pos:int ‑> ?len:int ‑> t ‑> unit
really_read fd ?pos ?len bstr
reads len
bytes from file descriptor
fd
, and writes them to bigstring bstr
starting at position pos
.
length bstr - pos
val really_recv : Unix.file_descr ‑> ?pos:int ‑> ?len:int ‑> t ‑> unit
really_recv sock ?pos ?len bstr
receives len
bytes from socket
sock
, and writes them to bigstring bstr
starting at position
pos
. If len
is zero, the function returns immediately without
performing the underlying system call.
length bstr - pos
val recvfrom_assume_fd_is_nonblocking : Unix.file_descr ‑> ?pos:int ‑> ?len:int ‑> t ‑> int * Unix.sockaddr
recvfrom_assume_fd_is_nonblocking sock ?pos ?len bstr
reads up to
len
bytes into bigstring bstr
starting at position pos
from
socket sock
without yielding to other OCaml-threads.
length bstr - pos
val read_assume_fd_is_nonblocking : Unix.file_descr ‑> ?pos:int ‑> ?len:int ‑> t ‑> Core__.Syscall_result.Int.t
read_assume_fd_is_nonblocking fd ?pos ?len bstr
reads up to
len
bytes into bigstring bstr
starting at position pos
from
file descriptor fd
without yielding to other OCaml-threads.
length bstr - pos
val pread_assume_fd_is_nonblocking : Unix.file_descr ‑> offset:int ‑> ?pos:int ‑> ?len:int ‑> t ‑> int
pread_assume_fd_is_nonblocking fd ~offset ?pos ?len bstr
reads up to len
bytes
from file descriptor fd
at offset offset
, and writes them to bigstring bstr
starting at position pos
. The fd must be capable of seeking, and the current file
offset used for a regular read()
is unchanged. Please see 'man pread' for more
information.
length bstr - pos
val input : ?min_len:int ‑> Core__.Import.In_channel.t ‑> ?pos:int ‑> ?len:int ‑> t ‑> int
input ?min_len ic ?pos ?len bstr
tries to read len
bytes
(guarantees to read at least min_len
bytes (must be greater than
or equal to zero and smaller or equal to len
), if possible, before
returning) from input channel ic
, and writes them to bigstring
bstr
starting at position pos
.
Returns the number of bytes actually read.
NOTE: even if len
is zero, there may still be errors when reading
from the descriptor, which will be done if the internal buffer
is empty!
NOTE: if at least len
characters are available in the input channel
buffer and if len
is not zero, data will only be fetched from the
channel buffer. Otherwise data will be read until at least min_len
characters are available.
length bstr - pos
val really_input : Core__.Import.In_channel.t ‑> ?pos:int ‑> ?len:int ‑> t ‑> unit
really_input ic ?pos ?len bstr
reads exactly len
bytes from
input channel ic
, and writes them to bigstring bstr
starting at
position pos
.
length bstr - pos
val really_write : Unix.file_descr ‑> ?pos:int ‑> ?len:int ‑> t ‑> unit
really_write fd ?pos ?len bstr
writes len
bytes in bigstring
bstr
starting at position pos
to file descriptor fd
.
length bstr - pos
val really_send_no_sigpipe : (Unix.file_descr ‑> ?pos:int ‑> ?len:int ‑> t ‑> unit) Core__.Import.Or_error.t
really_send_no_sigpipe sock ?pos ?len bstr
sends len
bytes in
bigstring bstr
starting at position pos
to socket sock
without
blocking and ignoring SIGPIPE
.
Parameter len: default = length bstr - pos
really_send_no_sigpipe
is not implemented on some platforms, in which
case it is an Error
value that indicates that it is unimplemented.
val send_nonblocking_no_sigpipe : (Unix.file_descr ‑> ?pos:int ‑> ?len:int ‑> t ‑> Core__.Syscall_result.Int.t) Core__.Import.Or_error.t
send_nonblocking_no_sigpipe sock ?pos ?len bstr
tries to send
len
bytes in bigstring bstr
starting at position pos
to socket
sock
.
bytes_written
.length bstr - pos
val sendto_nonblocking_no_sigpipe : (Unix.file_descr ‑> ?pos:int ‑> ?len:int ‑> t ‑> Unix.sockaddr ‑> Core__.Syscall_result.Int.t) Core__.Import.Or_error.t
sendto_nonblocking_no_sigpipe sock ?pos ?len bstr sockaddr
tries
to send len
bytes in bigstring bstr
starting at position pos
to socket sock
using address addr
.
bytes_written
.length bstr - pos
val write : Unix.file_descr ‑> ?pos:int ‑> ?len:int ‑> t ‑> int
write fd ?pos ?len bstr
writes len
bytes in bigstring bstr
starting at position pos
to file
descriptor fd
.
length bstr - pos
val pwrite_assume_fd_is_nonblocking : Unix.file_descr ‑> offset:int ‑> ?pos:int ‑> ?len:int ‑> t ‑> int
pwrite_assume_fd_is_nonblocking fd ~offset ?pos ?len bstr
writes up to len
bytes
of bigstring bstr
starting at position pos
to file descriptor fd
at position
offset
. The fd must be capable of seeking, and the current file offset used for
non-positional read()
/write()
calls is unchanged.
length bstr - pos
val write_assume_fd_is_nonblocking : Unix.file_descr ‑> ?pos:int ‑> ?len:int ‑> t ‑> int
write_assume_fd_is_nonblocking fd ?pos ?len bstr
writes len
bytes in bigstring bstr
starting at position pos
to file
descriptor fd
without yielding to other OCaml-threads.
length bstr - pos
val writev : Unix.file_descr ‑> ?count:int ‑> t Core__.Core_unix.IOVec.t array ‑> int
writev fd ?count iovecs
writes count
iovecs
of
bigstrings to file descriptor fd
.
Array.length iovecs
val writev_assume_fd_is_nonblocking : Unix.file_descr ‑> ?count:int ‑> t Core__.Core_unix.IOVec.t array ‑> int
writev_assume_fd_is_nonblocking fd ?count iovecs
writes count
iovecs
of bigstrings to file descriptor fd
without yielding to
other OCaml-threads.
Array.length iovecs
val recvmmsg_assume_fd_is_nonblocking : (Unix.file_descr ‑> ?count:int ‑> ?srcs:Unix.sockaddr array ‑> t Core__.Core_unix.IOVec.t array ‑> lens:int array ‑> int) Core__.Import.Or_error.t
recvmmsg_assume_fd_is_nonblocking fd iovecs ~count ~lens
receives up to count
messages into iovecs
from file descriptor fd
without yielding to other OCaml
threads. If ~count
is supplied, it must be that 0 <= count <= Array.length
iovecs
. If ~srcs
is supplied, save the source addresses for corresponding received
messages there. If supplied, Array.length srcs
must be >= count
. Save the
lengths of the received messages in lens
. It is required that Array.length lens >=
count
.
If an IOVec isn't long enough for its corresponding message, excess bytes may be
discarded, depending on the type of socket the message is received from. While the
recvmmsg
system call itself does return details of such truncation, etc., those
details are not (yet) passed through this interface.
recvmmsg
.Array.length iovecs
val sendmsg_nonblocking_no_sigpipe : (Unix.file_descr ‑> ?count:int ‑> t Core__.Core_unix.IOVec.t array ‑> int option) Core__.Import.Or_error.t
sendmsg_nonblocking_no_sigpipe sock ?count iovecs
sends
count
iovecs
of bigstrings to socket sock
.
Some
bytes_written
, or None
if the operation would have blocked.
This system call will not cause signal SIGPIPE
if an attempt is
made to write to a socket that was closed by the other side.count
is out of range.Array.length iovecs
val output : ?min_len:int ‑> Core__.Import.Out_channel.t ‑> ?pos:int ‑> ?len:int ‑> t ‑> int
output ?min_len oc ?pos ?len bstr
tries to output
len
bytes (guarantees to write at least min_len
bytes (must be
equal to or greater than zero), if possible, before returning) from
bigstring bstr
starting at position pos
to output channel oc
.
Returns the number of bytes actually written.
NOTE: you may need to flush oc
to make sure that the data is
actually sent.
NOTE: if len
characters fit into the channel buffer completely,
they will be buffered. Otherwise writes will be attempted until at
least min_len
characters have been sent.
IOError
-argument
counting the number of successful bytes includes those that have
been transferred to the channel buffer before the error.length bstr - pos
val really_output : Core__.Import.Out_channel.t ‑> ?pos:int ‑> ?len:int ‑> t ‑> unit
really_output oc ?pos ?len bstr
outputs exactly len
bytes from bigstring bstr
starting at position pos
to output
channel oc
.
IOError
-argument
counting the number of successful bytes includes those that have
been transferred to the channel buffer before the error.length bstr - pos
external unsafe_read_assume_fd_is_nonblocking : Unix.file_descr ‑> pos:int ‑> len:int ‑> t ‑> Core__.Syscall_result.Int.t = "bigstring_read_assume_fd_is_nonblocking_stub"
unsafe_read_assume_fd_is_nonblocking fd ~pos ~len bstr
similar to Bigstring.read_assume_fd_is_nonblocking, but does
not perform any bounds checks. Will crash on bounds errors!
external unsafe_write : Unix.file_descr ‑> pos:int ‑> len:int ‑> t ‑> int = "bigstring_write_stub"
unsafe_write fd ~pos ~len bstr
similar to
Bigstring.write, but does not perform any bounds checks.
Will crash on bounds errors!
external unsafe_write_assume_fd_is_nonblocking : Unix.file_descr ‑> pos:int ‑> len:int ‑> t ‑> int = "bigstring_write_assume_fd_is_nonblocking_stub"
unsafe_write_assume_fd_is_nonblocking fd ~pos ~len bstr
similar to Bigstring.write_assume_fd_is_nonblocking, but does
not perform any bounds checks. Will crash on bounds errors!
external unsafe_read : min_len:int ‑> Unix.file_descr ‑> pos:int ‑> len:int ‑> t ‑> int = "bigstring_read_stub"
unsafe_read ~min_len fd ~pos ~len bstr
similar to
Bigstring.read, but does not perform any bounds checks.
Will crash on bounds errors!
external unsafe_really_recv : Unix.file_descr ‑> pos:int ‑> len:int ‑> t ‑> unit = "bigstring_really_recv_stub"
unsafe_really_recv sock ~pos ~len bstr
similar to
Bigstring.really_recv, but does not perform any
bounds checks. Will crash on bounds errors!
external unsafe_really_write : Unix.file_descr ‑> pos:int ‑> len:int ‑> t ‑> unit = "bigstring_really_write_stub"
unsafe_really_write fd ~pos ~len bstr
similar to
Bigstring.write, but does not perform any bounds checks.
Will crash on bounds errors!
val unsafe_really_send_no_sigpipe : (Unix.file_descr ‑> pos:int ‑> len:int ‑> t ‑> unit) Core__.Import.Or_error.t
unsafe_really_send_no_sigpipe sock ~pos ~len bstr
similar to Bigstring.send, but does not perform any
bounds checks. Will crash on bounds errors!
val unsafe_send_nonblocking_no_sigpipe : (Unix.file_descr ‑> pos:int ‑> len:int ‑> t ‑> Core__.Syscall_result.Int.t) Core__.Import.Or_error.t
unsafe_send_nonblocking_no_sigpipe sock ~pos ~len bstr
similar to
Bigstring.send_nonblocking_no_sigpipe, but does not perform any
bounds checks. Will crash on bounds errors!
external unsafe_writev : Unix.file_descr ‑> t Core__.Core_unix.IOVec.t array ‑> int ‑> int = "bigstring_writev_stub"
unsafe_writev fd iovecs count
similar to
Bigstring.writev, but does not perform any bounds checks.
Will crash on bounds errors!
val unsafe_sendmsg_nonblocking_no_sigpipe : (Unix.file_descr ‑> t Core__.Core_unix.IOVec.t array ‑> int ‑> int option) Core__.Import.Or_error.t
unsafe_sendmsg_nonblocking_no_sigpipe fd iovecs count
similar to Bigstring.sendmsg_nonblocking_no_sigpipe, but
does not perform any bounds checks. Will crash on bounds errors!
external unsafe_input : min_len:int ‑> Core__.Import.In_channel.t ‑> pos:int ‑> len:int ‑> t ‑> int = "bigstring_input_stub"
unsafe_input ~min_len ic ~pos ~len bstr
similar to
Bigstring.input, but does not perform any bounds checks.
Will crash on bounds errors!
external unsafe_output : min_len:int ‑> Core__.Import.Out_channel.t ‑> pos:int ‑> len:int ‑> t ‑> int = "bigstring_output_stub"
unsafe_output ~min_len oc ~pos ~len bstr
similar to
Bigstring.output, but does not perform any bounds checks.
Will crash on bounds errors!