@sapphire/bitfield
BitField utilities for JavaScript.
Table of Contents
Features
- Written in TypeScript
- Bundled with esbuild so it can be used in NodeJS and browsers
- Offers CommonJS, ESM and UMD bundles
- Fully tested
Installation
You can use the following command to install this package, or replace npm install with your package manager of choice.
npm install @sapphire/bitfieldUsage
Note: While this section uses require, the imports match 1:1 with ESM imports. For example const { BitField } = require('@sapphire/bitfield') equals import { BitField } from '@sapphire/bitfield'.
// Require the BitField class
const { BitField } = require('@sapphire/bitfield');
const PermissionFlags = {
Read: 1 << 0,
Write: 1 << 1,
Edit: 1 << 2,
Delete: 1 << 3
};
const PermissionsBitField = new BitField(PermissionFlags);
const DetailedPermissionsFlags = {
ReadMessages: 1n << 0n,
ReadChannels: 1n << 1n,
CreateMessages: 1n << 2n,
CreateChannels: 1n << 3n
// ...
};
const DetailedPermissionsBitField = new BitField(DetailedPermissionsFlags);Warning: If the source is a TypeScript enum of numbers, you may use the
enumToObjectutility to turn it into a strict typed 1-way object.
const { BitField, enumToObject } = require('@sapphire/bitfield');
const { ActivityFlags } = require('discord-api-types/v10');
const PermissionsBitField = new BitField(enumToObject(ActivityFlags));Note: An exception will be thrown in the constructor if a non-object, null, empty object, or objects with values that aren't all numbers or all bigints.
Resolving
You can resolve bitfields from raw numbers, strings, or arrays of them. All of BitField's methods call resolve internally, making the usage a lot easier.
PermissionsBitField.resolve(PermissionFlags.Read);
PermissionsBitField.resolve(1);
PermissionsBitField.resolve('Read');
PermissionsBitField.resolve([1]);
PermissionsBitField.resolve(['Read']);
// 1 [Read]
PermissionsBitField.resolve(PermissionFlags.Read | PermissionFlags.Write);
PermissionsBitField.resolve([PermissionFlags.Read, PermissionFlags.Write]);
PermissionsBitField.resolve(['Read', 'Write']);
// 3 [Read + Write]
PermissionsBitField.resolve([]);
PermissionsBitField.zero;
// 0 [∅]
// Out-of-bounds fields are masked by `PermissionsBitField.mask`:
PermissionsBitField.resolve(17);
// 0b10001 (17) -> ~~0b10000 (16, invalid)~~ | 0b0001 (1, Read)
// 1 [Read]
// Invalid names will cause a `RangeError` to be thrown:
PermissionsBitField.resolve(['Execute']);
// thrown RangeError('Received a name that could not be resolved to a property of flags')
// Invalid types, or non-array objects will cause a `TypeError` to be thrown:
PermissionsBitField.resolve(true);
PermissionsBitField.resolve(null);
PermissionsBitField.resolve({});
// Number BitFields do not accept bigints:
PermissionsBitField.resolve(1n);
// BigInt BitFields do not accept numbers:
DetailedPermissionsBitField.resolve(1);For simplicity, we will be using arrays of strings for the rest of the README, but any of the above alternatives are available.
Checking for the existence of any bit
Useful for checking if at least one of B's bits are included in A.
PermissionsBitField.any(['Read', 'Write'], ['Read']);
PermissionsBitField.any(['Read', 'Write'], ['Write']);
PermissionsBitField.any(['Read', 'Write'], ['Write', 'Edit']);
// true
PermissionsBitField.any(['Read', 'Write'], ['Edit']);
PermissionsBitField.any(['Read', 'Write'], ['Delete']);
PermissionsBitField.any(['Read', 'Write'], ['Edit', 'Delete']);
// falseChecking for the existence of one or multiple bits
Useful for checking if all of B's bits are included in A, or in other words, A is a superset of B.
PermissionsBitField.any(['Read', 'Write'], ['Read']);
PermissionsBitField.any(['Read', 'Write'], ['Write']);
// true
PermissionsBitField.any(['Read', 'Write'], ['Write', 'Edit']);
PermissionsBitField.any(['Read', 'Write'], ['Edit']);
PermissionsBitField.any(['Read', 'Write'], ['Delete']);
PermissionsBitField.any(['Read', 'Write'], ['Edit', 'Delete']);
// falseGetting the field's complement
Gets the complement of a field, or the result of excluding A from all of the BitField's mask.
PermissionsBitField.complement(['Read']);
// 14 [Write + Edit + Delete]
PermissionsBitField.complement(['Read', 'Write']);
// 12 [Edit + Delete]
PermissionsBitField.complement(['Read', 'Write', 'Edit', 'Delete']);
// 0 [∅]Getting the union of different fields
Useful for adding multiple fields into one.
PermissionsBitField.union(['Read'], ['Write'], ['Edit']);
// 7 [Read + Write + Edit]
PermissionsBitField.union();
// 0 [∅]Getting the intersection between different fields
Gets the intersection of all the fields.
PermissionsBitField.intersection(['Read', 'Write'], ['Write']);
// 2 [Write]
PermissionsBitField.intersection(['Read'], ['Write']);
// 0 [∅]Getting the symmetric difference between different fields
The summetric difference is basically the union of the difference between A and B and vice versa (bits from A that aren't in B, and bits from B that aren't in A), or XOR, useful for retrieving the bit difference between two fields.
PermissionsBitField.intersection(['Read', 'Write'], ['Write', 'Edit']);
// 5 [Read + Edit]
PermissionsBitField.intersection(['Write'], ['Write']);
// 0 [∅]Formatting a field
We can format fields in two ways, one is with arrays:
PermissionsBitField.toArray(PermissionFlags.Read | PermissionFlags.Write);
PermissionsBitField.toArray([PermissionFlags.Read, PermissionFlags.Write]);
PermissionsBitField.toArray(['Read', 'Write']);
// ['Read', 'Write']And another is with objects:
PermissionsBitField.toObject(PermissionFlags.Read | PermissionFlags.Write);
PermissionsBitField.toObject([PermissionFlags.Read, PermissionFlags.Write]);
PermissionsBitField.toObject(['Read', 'Write']);
// {
// Read: true,
// Write: true,
// Edit: false,
// Delete: false
// }Buy us some doughnuts
Sapphire Community is and always will be open source, even if we don't get donations. That being said, we know there are amazing people who may still want to donate just to show their appreciation. Thank you very much in advance!
We accept donations through Open Collective, Ko-fi, PayPal, Patreon and GitHub Sponsorships. You can use the buttons below to donate through your method of choice.
| Donate With | Address |
|---|---|
| Open Collective | Click Here |
| Ko-fi | Click Here |
| Patreon | Click Here |
| PayPal | Click Here |
Contributors
Please make sure to read the Contributing Guide before making a pull request.
Thank you to all the people who already contributed to Sapphire!