Make.Bytes
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.