package octez-proto-libs
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.
The labeled version of this module can be used as described in the StdLabels module.
set s n c modifies s in place, replacing the byte at index n with c.
make n c returns a new byte sequence of length n, filled with the byte c.
init n f returns a fresh byte sequence of length n, with character i initialized to the result of f i (in increasing index order).
Return a new byte sequence that contains the same bytes as the given string.
Return a new string that contains the same bytes as the given byte sequence.
sub s pos len returns a new byte sequence of length len, containing the subsequence of s that starts at position pos and has length len.
Same as sub but return a string instead of a byte sequence.
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.
fill s pos len c modifies s in place, replacing len characters with c, starting at pos.
blit src src_pos dst dst_pos len copies len bytes from sequence src, starting at index src_pos, to sequence dst, starting at index dst_pos. It works correctly even if src and dst are the same byte sequence, and the source and destination intervals overlap.
blit src src_pos dst dst_pos len copies len bytes from string src, starting at index src_pos, to byte sequence dst, starting at index dst_pos.
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.
cat s1 s2 concatenates s1 and s2 and returns the result as a new byte sequence.
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)); ().
Same as iter, but the function is applied to the index of the byte as first argument and the byte itself as second argument.
map f s applies function f in turn to all the bytes of s (in increasing index order) and stores the resulting bytes in a new sequence that is returned as the result.
mapi f s calls f with each character of s and its index (in increasing index order) and stores the resulting bytes in a new sequence that is returned as the result.
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'.
Return a copy of the argument, with special characters represented by escape sequences, following the lexical conventions of OCaml. All characters outside the ASCII printable range (32..126) are escaped, as well as backslash and double-quote.
index_opt s c returns the index of the first occurrence of byte c in s or None if c does not occur in s.
rindex_opt s c returns the index of the last occurrence of byte c in s or None if c does not occur in s.
index_from_opt s i c returns the index of the first occurrence of byte c in s after position i or None if c does not occur in s after position i. index_opt s c is equivalent to index_from_opt s 0 c.
rindex_from_opt s i c returns the index of the last occurrence of byte c in s before position i+1 or None if c does not occur in s before position i+1. rindex_opt s c is equivalent to rindex_from s (length s - 1) c.
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.
rcontains_from s stop c tests if byte c appears in s before position stop+1.
Return a copy of the argument, with all lowercase letters translated to uppercase, using the US-ASCII character set.
Return a copy of the argument, with all uppercase letters translated to lowercase, using the US-ASCII character set.
Return a copy of the argument, with the first character set to uppercase, using the US-ASCII character set.
Return a copy of the argument, with the first character set to lowercase, using the US-ASCII character set.
The comparison function for byte sequences, with the same specification as Stdlib.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.
Bitwise AND on bytes.
If the arguments have different lengths, the prefix of the longer bytes is cut to have the same length as the shorter one before taking bitwise AND.
ex. 0xff0f AND 0xff = 0x0f AND 0xff = 0x0f
Bitwise OR on bytes.
If the arguments have different lengths, the shorter bytes is 0-padded on the left to have the same length before taking bitwise OR.
ex. 0xf000 OR 0x0f = 0xf000 OR 0x000f = 0xf00f
Bitwise XOR on bytes.
If the arguments have different lengths, the shorter bytes is 0-padded on the left to have the same length before taking bitwise XOR.
ex. 0xf0ff XOR 0x0f = 0xf0ff XOR 0x000f = 0xf0f0
Logical shift left on bytes, using big-endian encoding. shift_left bs nbits returns a bytes longer than bs when nbits > 0. It raises Invalid_argument "shift_left" when nbits < 0.
ex. 0x1234 LSL 0 = 0x1234 0x1234 LSL 1 = 0x002468 (not 0x2468) 0x1234 LSL 8 = 0x123400 0x001234 LSL 1 = 0x00002468 (not 0x002468) 0x (empty bytes) LSL 1 = 0x00