BitArray

A dynamic array of bits. Each bit in a BitArray can be manipulated individually or by the standard bitwise operators &, |, ^, ~, >>, << and also by other effective member functions; most of them work relative to the BitArray's dimension (see dim), instead of its length.

struct BitArray {

this(bool[] ba);

this(void[] v, size_t numbits);

size_t dim [@property getter];

size_t length [@property getter];

size_t length [@property setter];

bool opIndex(size_t i);

bool opIndexAssign(bool b, size_t i);

void opSliceAssign(bool val);

void opSliceAssign(bool val, size_t start, size_t end);

void flip();

void flip(size_t pos);

size_t count();

BitArray dup [@property getter];

int opApply(int delegate(ref bool) dg);

int opApply(int delegate(bool) dg);

int opApply(int delegate(size_t, ref bool) dg);

int opApply(int delegate(size_t, bool) dg);

BitArray reverse [@property getter];

BitArray sort [@property getter];

bool opEquals(BitArray a2);

int opCmp(BitArray a2);

size_t toHash();

inout(void)[] opCast();

inout(size_t)[] opCast();

BitArray opUnary();

BitArray opBinary(BitArray e2);

BitArray opOpAssign(BitArray e2);

BitArray opOpAssign(bool b);

BitArray opOpAssign(BitArray b);

BitArray opBinary(bool b);

BitArray opBinaryRight(bool b);

BitArray opBinary(BitArray b);

void opOpAssign(size_t nbits);

void toString(W sink, FormatSpec!char fmt);

auto bitsSet [@property getter];

}

Constructors

this this(bool[] ba): Creates a BitArray from a bool array, such that bool values read from left to right correspond to subsequent bits in the BitArray.
this this(void[] v, size_t numbits): Creates a BitArray from the raw contents of the source array. The source array is not copied but simply acts as the underlying array of bits, which stores data as size_t units.

Members

Functions

count size_t count(): Counts all the set bits in the BitArray
flip void flip(): Flips all the bits in the BitArray
flip void flip(size_t pos): Flips a single bit, specified by pos
opApply int opApply(int delegate(ref bool) dg)
int opApply(int delegate(bool) dg)
int opApply(int delegate(size_t, ref bool) dg)
int opApply(int delegate(size_t, bool) dg): Support for foreach loops for BitArray.
opBinary BitArray opBinary(BitArray e2): Support for binary bitwise operators for BitArray.
opBinary BitArray opBinary(bool b)
BitArray opBinary(BitArray b)
opBinaryRight BitArray opBinaryRight(bool b): Support for binary operator ~ for BitArray.
opCast inout(void)[] opCast(): Convert to void[].
opCast inout(size_t)[] opCast(): Convert to size_t[].
opCmp int opCmp(BitArray a2): Supports comparison operators for BitArray.
opEquals bool opEquals(BitArray a2): Support for operators == and != for BitArray.
opIndex bool opIndex(size_t i): Gets the i'th bit in the BitArray.
opIndexAssign bool opIndexAssign(bool b, size_t i): Sets the i'th bit in the BitArray.
opOpAssign BitArray opOpAssign(BitArray e2): Support for operator op= for BitArray.
opOpAssign BitArray opOpAssign(bool b)
BitArray opOpAssign(BitArray b): Support for operator ~= for BitArray. Warning: This will overwrite a bit in the final word of the current underlying data regardless of whether it is shared between BitArray objects. i.e. D dynamic array concatenation semantics are not followed
opOpAssign void opOpAssign(size_t nbits): Operator <<= support.
opOpAssign void opOpAssign(size_t nbits): Operator >>= support.
opSliceAssign void opSliceAssign(bool val): Sets all the values in the BitArray to the value specified by val.
opSliceAssign void opSliceAssign(bool val, size_t start, size_t end): Sets the bits of a slice of BitArray starting at index start and ends at index ($D end - 1) with the values specified by val.
opUnary BitArray opUnary(): Support for unary operator ~ for BitArray.
toHash size_t toHash(): Support for hashing for BitArray.
toString void toString(W sink, FormatSpec!char fmt): Return a string representation of this BitArray.

Properties

bitsSet auto bitsSet [@property getter]: Return a lazy range of the indices of set bits.
dim size_t dim [@property getter]
dup BitArray dup [@property getter]: Duplicates the BitArray and its contents.
length size_t length [@property getter]
length size_t length [@property setter]: Sets the amount of bits in the BitArray. Warning: increasing length may overwrite bits in the final word of the current underlying data regardless of whether it is shared between BitArray objects. i.e. D dynamic array extension semantics are not followed.
reverse BitArray reverse [@property getter]: Reverses the bits of the BitArray.
sort BitArray sort [@property getter]: Sorts the BitArray's elements.

Examples

Slicing & bitsSet

import std.algorithm.comparison : equal;
import std.range : iota;

bool[] buf = new bool[64 * 3];
buf[0 .. 64] = true;
BitArray b = BitArray(buf);
assert(b.bitsSet.equal(iota(0, 64)));
b <<= 64;
assert(b.bitsSet.equal(iota(64, 128)));

Concatenation and appending

import std.algorithm.comparison : equal;

auto b = BitArray([1, 0]);
b ~= true;
assert(b[2] == 1);
b ~= BitArray([0, 1]);
auto c = BitArray([1, 0, 1, 0, 1]);
assert(b == c);
assert(b.bitsSet.equal([0, 2, 4]));

Bit flipping

import std.algorithm.comparison : equal;

auto b = BitArray([1, 1, 0, 1]);
b &= BitArray([0, 1, 1, 0]);
assert(b.bitsSet.equal([1]));
b.flip;
assert(b.bitsSet.equal([0, 2, 3]));

String format of bitarrays

import std.format : format;
auto b = BitArray([1, 0, 0, 0, 0, 1, 1, 1, 1, 0, 0, 0, 0, 1, 1, 1, 1]);
assert(format("%b", b) == "1_00001111_00001111");

import std.format : format;

BitArray b;

b = BitArray([]);
assert(format("%s", b) == "[]");
assert(format("%b", b) is null);

b = BitArray([1]);
assert(format("%s", b) == "[1]");
assert(format("%b", b) == "1");

b = BitArray([0, 0, 0, 0]);
assert(format("%b", b) == "0000");

b = BitArray([0, 0, 0, 0, 1, 1, 1, 1]);
assert(format("%s", b) == "[0, 0, 0, 0, 1, 1, 1, 1]");
assert(format("%b", b) == "00001111");

b = BitArray([0, 0, 0, 0, 1, 1, 1, 1, 0, 0, 0, 0, 1, 1, 1, 1]);
assert(format("%s", b) == "[0, 0, 0, 0, 1, 1, 1, 1, 0, 0, 0, 0, 1, 1, 1, 1]");
assert(format("%b", b) == "00001111_00001111");

b = BitArray([1, 0, 0, 0, 0, 1, 1, 1, 1]);
assert(format("%b", b) == "1_00001111");

b = BitArray([1, 0, 0, 0, 0, 1, 1, 1, 1, 0, 0, 0, 0, 1, 1, 1, 1]);
assert(format("%b", b) == "1_00001111_00001111");