Stdlib.BufferSourceExtensible buffers.
This module implements buffers that automatically expand as necessary. It provides accumulative concatenation of strings in linear time (instead of quadratic time when strings are concatenated pairwise). For example:
let concat_strings ss =
let b = Buffer.create 16 in
List.iter (Buffer.add_string b) ss;
Buffer.contents b
Unsynchronized accesses
Unsynchronized accesses to a buffer may lead to an invalid buffer state. Thus, concurrent accesses to a buffer must be synchronized (for instance with a Mutex.t).
The abstract type of buffers.
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.
Return a copy of the current contents of the buffer. The buffer itself is unchanged.
Return a copy of the current contents of the buffer. The buffer itself is unchanged.
Buffer.sub b off len returns a copy of len bytes from the current contents of the buffer b, starting at offset off.
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.
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.
output_buffer oc b writes the current contents of buffer b on the output channel oc.
truncate b len truncates the length of b to len Note: the internal byte sequence is not shortened.
Note: all add_* operations can raise Failure if the internal byte sequence of the buffer would need to grow beyond Sys.max_string_length.
add_utf_8_uchar b u appends the UTF-8 encoding of u at the end of buffer b.
add_utf_16le_uchar b u appends the UTF-16LE encoding of u at the end of buffer b.
add_utf_16be_uchar b u appends the UTF-16BE encoding of u at the end of buffer b.
add_string b s appends the string s at the end of buffer b.
add_bytes b s appends the byte sequence s at the end of buffer b.
add_substring b s ofs len takes len characters from offset ofs in string s and appends them at the end of buffer b.
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.
add_substitute b f s appends the string pattern s at the end of buffer b with substitution. The substitution process looks for variable references in the pattern and substitutes each variable reference with its value, as obtained by applying the mapping f to the variable name. Inside the string pattern, a variable reference is a non-escaped $ immediately followed by a variable name, which is one of the following:
_ characters,$ character is a $ that immediately follows a backslash character; the two characters together stand for a plain $.add_buffer b1 b2 appends the current contents of buffer b2 at the end of buffer b1. b2 is not modified.
add_channel b ic n reads at most n characters from the input channel ic and stores them at the end of buffer b.
Iterate on the buffer, in increasing order.
The behavior is not specified if the buffer is modified during iteration.
Iterate on the buffer, in increasing order, yielding indices along chars.
The behavior is not specified if the buffer is modified during iteration.
The functions in this section append binary encodings of integers to buffers.
Little-endian (resp. big-endian) encoding means that least (resp. most) significant bytes are stored first. Big-endian is also known as network byte order. Native-endian encoding is either little-endian or big-endian depending on Sys.big_endian.
32-bit and 64-bit integers are represented by the int32 and int64 types, which can be interpreted either as signed or unsigned numbers.
8-bit and 16-bit integers are represented by the int type, which has more bits than the binary encoding. Functions that encode these values truncate their inputs to their least significant bytes.
add_uint16_ne b i appends a binary native-endian unsigned 16-bit integer i to b.
add_uint16_be b i appends a binary big-endian unsigned 16-bit integer i to b.
add_uint16_le b i appends a binary little-endian unsigned 16-bit integer i to b.
add_int16_ne b i appends a binary native-endian signed 16-bit integer i to b.
add_int16_be b i appends a binary big-endian signed 16-bit integer i to b.
add_int16_le b i appends a binary little-endian signed 16-bit integer i to b.
add_int32_ne b i appends a binary native-endian 32-bit integer i to b.
add_int32_be b i appends a binary big-endian 32-bit integer i to b.
add_int32_le b i appends a binary little-endian 32-bit integer i to b.
add_int64_ne b i appends a binary native-endian 64-bit integer i to b.
add_int64_be b i appends a binary big-endian 64-bit integer i to b.