BitSet



Typescript version of infusion's BitSet.js Typings seem bugged for official.

BitSet is an infinite Bit-Array (aka bit vector, bit string, bit set) implementation in JavaScript. That means that if you invert a bit vector, the leading ones get remembered.

Examples
===

Basic usage
---
``javascript
var bs = new BitSet();
bs.set(128, 1); // Set bit at position 128
console.log(bs.toString(16)); // Print out a hex dump with one bit set
`

Flipping bits
---
`javascript
var bs = new BitSet();
bs
.flip(0, 62)
.flip(29, 35);

var str = bs.toString();

if (str === "111111111111111111111111111000000011111111111111111111111111111") {
console.log("YES!");
}
`

Range Set
---
`javascript
var bs = new BitSet;
bs.setRange(10, 18, 1); // Set a 1 between 10 and 18, inclusive
`

User permissions
---
If you want to store user permissions in your database and use BitSet for the bit twiddling, you can start with the following Linux-style snippet:
`javascript
var P_READ = 2; // Bit pos
var P_WRITE = 1;
var P_EXEC = 0;

var user = new BitSet;
user.set(P_READ); // Give read perms
user.set(P_WRITE); // Give write perms

var group = new BitSet(P_READ);
var world = new BitSet(P_EXEC);

console.log("0" + user.toString(8) + group.toString(8) + world.toString(8));
`

Installation
===

`
npm install bitset
`
or
`
bower install BitSet
`

Using BitSet with the browser
===
`html


`

Using BitSet with require.js
===
`html


`

Parser
===
The parser accepts the following types of values in either function

Strings
- Binary strings "010101"
- Binary strings with prefix "0b100101"
- Hexadecimal strings with prefix "0xaffe"

Arrays
- The values of the array are the indizes to be set to 1

Uint8Array
- A binary representation in 8 bit form

Number
- A binary value

BitSet
- A BitSet object, which get copied over


Functions
===

The data type Mixed can be either a BitSet object, a String or an integer representing a native bitset with 31 bits.


BitSet set(ndx[, value=0])
---
Mutable; Sets value 0 or 1 to index ndx of the bitset

int get(ndx)
---
Gets the value at index ndx

BitSet setRange(from, to[, value=1])
---
Mutable; Helper function for set, to set an entire range to a given value

BitSet clear([from[, to]])
---
Mutable; Sets a portion of a given bitset to zero

- If no param is given, the whole bitset gets cleared
- If one param is given, the bit at this index gets cleared
- If two params are given, the range is cleared

BitSet slice([from[, to]])
---
Immutable; Extracts a portion of a given bitset as a new bitset

- If no param is given, the bitset is getting cloned
- If one param is given, the index is used as offset
- If two params are given, the range is returned as new BitSet

BitSet flip([from[, to]])
---
Mutable; Toggles a portion of a given bitset

- If no param is given, the bitset is inverted
- If one param is given, the bit at the index is toggled
- If two params are given, the bits in the given range are toggled

BitSet not()
---
Immutable; Calculates the bitwise complement

BitSet and(Mixed x)
---
Immutable; Calculates the bitwise intersection of two bitsets

BitSet or(Mixed x)
---
Immutable; Calculates the bitwise union of two bitsets

BitSet xor(Mixed x)
---
Immutable; Calculates the bitwise xor between two bitsets

BitSet andNot(Mixed x)
---
Immutable; Calculates the bitwise difference of two bitsets (this is not the nand operation!)

BitSet clone()
---
Immutable; Clones the actual object

Array toArray()
---
Returns an array with all indexes set in the bitset

String toString([base=2])
---
Returns a string representation with respect to the base

int cardinality()
---
Calculates the number of bits set

int msb()
---
Calculates the most significant bit (the left most)

int ntz()
---
Calculates the number of trailing zeros (zeros on the right). If all digits are zero, Infinity is returned, since BitSet is an arbitrary large bit vector implementation.

int lsb()
---
Calculates the least significant bit (the right most)

bool isEmpty()
---
Checks if the bitset has all bits set to zero

bool equals()
---
Checks if two bitsets are the same

BitSet.fromBinaryString(str)
---
Alternative constructor to pass with a binary string

BitSet.fromHexString(str)
---
Alternative constructor to pass a hex string

BitSet.Random([n=32])
---
Create a random BitSet with a maximum length of n bits

Coding Style
===
As every library I publish, BitSet is also built to be as small as possible after compressing it with Google Closure Compiler in advanced mode. Thus the coding style orientates a little on maxing-out the compression rate. Please make sure you keep this style if you plan to extend the library.

Build the library
===
Gulp is optional for minifying with Google Closure Compiler. After cloning the Git repository, do:

`
npm install
gulp
`

Run a test
===
Testing the source against the shipped test suite is as easy as

`
npm test
``

Copyright and licensing
===
BitSet.js : Copyright (c) 2014-2018, Robert Eisele