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Big bit mask

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When bits is not enough ...

This library implements a bitmask serializable into a base64-like, url-safe string.

Other platform compatibility

Platform Repository Package
PHP php-big-bit-mask Packagist
.NET BigBitMask.NET NuGet

Install

> npm install big-bit-mask

or

> yarn add big-bit-mask

Usage

Module import

import { BigBitMask } from "big-bit-mask";

Or require:

var BigBitMask = require("big-bit-mask").BigBitMask;

Or simple script without anything else:

<html>
    <head>
        <script src="./node_modules/big-bit-mask/dist/big-bit-mask.es5.min.js"></script>
    </head>
    <body>
        <script>
            var BigBitMask = BIGBITMASK.BigBitMask;
        </script>
    </body>
</html>

What next?

Now we can create new empty bitmask

var bitmask = new BigBitMask();

or load it from string

var bitmask = new BigBitMask("CE3fG_gE-56");

//Let's see what inside now
var content = "";
for(var i = 0; i < 11 * 6; i++) { // Each character contains 6 bits, as in base64
    content += bitmask.get(i) ? "1" : "0";
}
console.info(content);

output: 010000001000111011111110011000111111000001001000011111100111010111

Then we can change some bits and get back our string representation

bitmask.set(65, false);
bitmask.set(64, false);
bitmask.set(63, false);
bitmask.set(61, false);

bitmask.set(19, false);
bitmask.set(5, true);

console.info(bitmask.toString());

output: iE3dG_gE-5

But what if I want to have a named flags?

You can extend BigBitMask with your model:

class MyCoolCheckboxes extends BigBitMask {
    static get CHECKBOX_0() { return 0; }
    static get CHECKBOX_1() { return 1; }
    static get CHECKBOX_2() { return 2; }
    static get CHECKBOX_3() { return 3; }
    static get CHECKBOX_4() { return 4; }
    static get CHECKBOX_5() { return 5; }
    static get CHECKBOX_6() { return 6; }
    static get CHECKBOX_7() { return 7; }
    static get CHECKBOX_8() { return 8; }
    static get CHECKBOX_9() { return 9; }

    get checkbox0() { return this.get(MyCoolCheckboxes.CHECKBOX_0); }
    set checkbox0(value) { return this.set(MyCoolCheckboxes.CHECKBOX_0, value); }

    get checkbox1() { return this.get(MyCoolCheckboxes.CHECKBOX_1); }
    set checkbox1(value) { return this.set(MyCoolCheckboxes.CHECKBOX_1, value); }

    get checkbox2() { return this.get(MyCoolCheckboxes.CHECKBOX_2); }
    set checkbox2(value) { return this.set(MyCoolCheckboxes.CHECKBOX_2, value); }

    get checkbox3() { return this.get(MyCoolCheckboxes.CHECKBOX_3); }
    set checkbox3(value) { return this.set(MyCoolCheckboxes.CHECKBOX_3, value); }

    get checkbox4() { return this.get(MyCoolCheckboxes.CHECKBOX_4); }
    set checkbox4(value) { return this.set(MyCoolCheckboxes.CHECKBOX_4, value); }

    get checkbox5() { return this.get(MyCoolCheckboxes.CHECKBOX_5); }
    set checkbox5(value) { return this.set(MyCoolCheckboxes.CHECKBOX_5, value); }

    get checkbox6() { return this.get(MyCoolCheckboxes.CHECKBOX_6); }
    set checkbox6(value) { return this.set(MyCoolCheckboxes.CHECKBOX_6, value); }

    get checkbox7() { return this.get(MyCoolCheckboxes.CHECKBOX_7); }
    set checkbox7(value) { return this.set(MyCoolCheckboxes.CHECKBOX_7, value); }

    get checkbox8() { return this.get(MyCoolCheckboxes.CHECKBOX_8); }
    set checkbox8(value) { return this.set(MyCoolCheckboxes.CHECKBOX_8, value); }

    get checkbox9() { return this.get(MyCoolCheckboxes.CHECKBOX_9); }
    set checkbox9(value) { return this.set(MyCoolCheckboxes.CHECKBOX_9, value); }
}

var checkboxes = new MyCoolCheckboxes();
checkboxes.checkbox5 = true;
checkboxes.checkbox7 = true;
checkboxes.checkbox8 = true;

console.info(checkboxes.toString());

output: gG

Or with TypeScript:

class MyCoolCheckboxes extends BigBitMask {
    public static readonly CHECKBOX_0 = 0;
    public static readonly CHECKBOX_1 = 1;
    public static readonly CHECKBOX_2 = 2;

    public get checkbox0(): boolean { return this.get(MyCoolCheckboxes.CHECKBOX_0); }
    public set checkbox0(value: boolean) { this.set(MyCoolCheckboxes.CHECKBOX_0, value); }

    public get checkbox1(): boolean { return this.get(MyCoolCheckboxes.CHECKBOX_1); }
    public set checkbox1(value: boolean) { this.set(MyCoolCheckboxes.CHECKBOX_1, value); }

    public get checkbox2(): boolean { return this.get(MyCoolCheckboxes.CHECKBOX_2); }
    public set checkbox2(value: boolean) { this.set(MyCoolCheckboxes.CHECKBOX_2, value); }
}

Useful properties and methods

isEmpty

Returns: boolean

Indicates that the BigBitMask instance has none of its flags set to true.

equals(otherMask)

Returns: boolean

Compares the current BigBitMask instance to another.

or(otherMask)

Returns: void

Assigns to the current instance the result of a bitwise OR operation between the current BigBitMask instance and another.

and(otherMask)

Returns: void

Assigns to the current instance the result of a bitwise AND operation between the current BigBitMask instance and another.

xor(otherMask)

Returns: void

Assigns to the current instance the result of a bitwise XOR operation between the current BigBitMask instance and another.

BigBitMask.EQUALS(maskA, maskB)

Returns: boolean

Compares two BigBitMask instances.

BigBitMask.OR(arg, ...)

Returns: new instance of BigBitMask

Applies a bitwise OR operation between BigBitMask instances and returns the result as a new BigBitMask instance. The arguments are expected to be BigBitMask instances or a single non-empty BigBitMask array.

BigBitMask.AND(arg, ...)

Returns: new instance of BigBitMask

Applies a bitwise AND operation between BigBitMask instances and returns the result as a new BigBitMask instance. The arguments are expected to be BigBitMask instances or a single non-empty BigBitMask array.

BigBitMask.XOR(arg, ...)

Returns: new instance of BigBitMask

Applies a bitwise XOR operation between BigBitMask instances and returns the result as a new BigBitMask instance. The arguments are expected to be BigBitMask instances or a single non-empty BigBitMask array.

License

MIT

Copyright (C) 2020-2022 Aleksej Solomatin