module Bitpath: sig .. end
The Bitpath module implements strings of booleans. The bits are
compactly represented packed into native words. Core functions are
written in C to operate on full words.
type
The type of a bit-string, which represents zero or more consecutive
boolean values, indexed from 0.
val length : t -> int
length s is the number of bits contained in s.
val length8 : t -> int
length8 s = ⌈length s / 8⌉.
val length16 : t -> int
length16 s = ⌈length s / 16⌉.
val get : int -> t -> bool
get i s is true iff the ith bit of s is set.
val get8 : int -> t -> int
get8 i s is the integer with bit number 7 - j equal to bit number
8*i + j of s.
val get16 : int -> t -> int
get16 i s is the integer with bit number 15 - j equal to bit number
16*i + j of s.
val compare : t -> t -> int
compare sA sB returns -1, 0, or 1 when sA is less, equal, or
greater than sB, respectively, according to lexicographical ordering of
bits.
val equal : t -> t -> bool
equal sA sB is true iff sA and sB are bitwise equal.
val empty : t
The empty bit-string.
val is_empty : t -> bool
True on the empty path, elsewhere false.
val init : int -> (int -> bool) -> t
init n f turns the predicate f into a bit-string s of length n
such that f i = get f i for 0 ≤ i < n.
val init8 : int -> (int -> int) -> t
init8 n f is the n-bit string s such that get (8*i + j) s is
true iff bit number 7 - j of f i is set. If n is not a multiple
of 8, then the n mod 8 most significant bits of f (n / 8) are used;
the rest are ignored.
val init16 : int -> (int -> int) -> t
init16 n f is the n-bit string s such that get (16*i + j) s is
true iff bit number 15 - j of f i is set. If n is not a multiple
of 16, then the n mod 16 most significant bits of f (n / 16) are
used; the rest are ignored.
val const : int -> bool -> t
const n x is the n-bit string of x.
val c0 : t
The constant const 1 false.
val c1 : t
The constant const 1 true.
val bitnot : t -> t
bitnot s is the string s' such that get i s = not (get i s').
val slice : int -> int -> t -> t
slice i j s is the sub-string of bit i to j - 1 of s.
val prefix : int -> t -> t
prefix i s is the substring containing the i first bits of s.
val suffix : int -> t -> t
suffix i s is the substring containing all but the i first bits
of s.
val has_slice : t -> int -> t -> bool
has_slice s0 i s is true iff s contains a substring equal to s0
starting at bit number i.
val has_prefix : t -> t -> bool
has_prefix s0 s is true iff s starts with s0.
val has_suffix : t -> t -> bool
has_suffix s0 s is true iff s ends with s0.
val coprefix_length : t -> t -> int
coprefix_length sA sB is the largest n such that
get i sA = get i sB for i < n.
val coprefix : t -> t -> t
val coslice_length : int -> t -> int -> t -> int
coslice_length iA sA iB sB is the largest n such that
get (iA + i) sA = get (iB + i) sB for i < n.
val cat : t -> t -> t
cat s0 s1 is the concatenation of s0 and s1.
val map : (bool -> bool) -> t -> t
Given s of length n, then map f s is the n-bit string s' such
that get i s' = f (get i s) for 0 ≤ i < n.
val mapi : (int -> bool -> bool) -> t -> t
Given s of length n, then mapi f s is the n-bit string s' such
that get i s' = f i (get i s) for 0 ≤ i < n.
val fold : (bool -> 'a -> 'a) -> t -> 'a -> 'a
Given a string s of length n, fold f s returns
f (get (n - 1) s) ∘ ⋯ ∘ f (get 0 s).
val foldi : (int -> bool -> 'a -> 'a) -> t -> 'a -> 'a
Given a string s of length n, foldi f s is the function
f (n - 1) (get (n - 1) s) ∘ ⋯ ∘ f 0 (get 0 s).
val foldi8 : (int -> int -> 'a -> 'a) -> t -> 'a -> 'a
Given a string s of length n, foldi8 f s is the function
f (⌈n/8⌉ - 1) (get (⌈n/8⌉ - 1) s) ∘ ⋯ ∘ f 0 (get 0 s).
val foldi16 : (int -> int -> 'a -> 'a) -> t -> 'a -> 'a
Given a string s of length n, foldi16 f s is the function
f (⌈n/16⌉ - 1) (get (⌈n/16⌉ - 1) s) ∘ ⋯ ∘ f 0 (get 0 s).
val iter : (bool -> unit) -> t -> unit
iter f s calls f on each element of s in order.
val iteri : (int -> bool -> unit) -> t -> unit
iteri f s calls f i (get i s) for 0 ≤ i < length s in order.
val of_array8 : int array -> t
of_array8 xa forms a bitpath by composing the octets from xa, starting
with the most significant.
val of_array16 : int array -> t
of_array16 xa forms a bitpath by composing hexadecatets of xa, staring
with the most significant.
val of_string : string -> t
of_string s interprets a string s of '0' and '1' characters as a
bit string.
val to_string : t -> string
to_string s turns s to a textual representation of '0' and '1'
characters, starting with the lowest index.
val of_hex_string : ?n:int -> string -> t
of_hex_string ~n str returns the bitstring described by the hexadecimal
string str, clipped to n bits if specified.
val to_hex_string : ?n:int -> t -> string
to_hex_string ~n s is the hexadecimal encoding of s padded with zeros
to the next quartet, or clipped or padded to n bits if specified.
val of_bin_string : ?n:int -> string -> t
of_bin_string ~n s8 converts an octet string s8 to a bit string s1,
where get (8*i + j) s1 equals bit number 7 - j of String.get i s8.
The result is clipped or padded with zeros to n bits.
val to_bin_string : ?n:int -> t -> string
to_bin_string ~n s converts a bit string to an octet string using the
same representation as of_bit_string. The result it clipped or padded
with zeros to (n + 7) / 8 octets.