spacebar/src/util/BitField.ts
Flam3rboy ea41892fef 🔧 build
2021-02-05 22:01:01 +01:00

139 lines
3.7 KiB
TypeScript

"use strict";
// https://github.com/discordjs/discord.js/blob/master/src/util/BitField.js
// Apache License Version 2.0 Copyright 2015 - 2021 Amish Shah
export type BitFieldResolvable = number | BigInt | BitField | string | BitFieldResolvable[];
/**
* Data structure that makes it easy to interact with a bitfield.
*/
export class BitField {
public bitfield: bigint = BigInt(0);
public static FLAGS: Record<string, bigint>;
constructor(bits: BitFieldResolvable = 0) {
this.bitfield = BitField.resolve(bits);
}
/**
* Checks whether the bitfield has a bit, or any of multiple bits.
*/
any(bit: BitFieldResolvable): boolean {
return (this.bitfield & BitField.resolve(bit)) !== 0n;
}
/**
* Checks if this bitfield equals another
*/
equals(bit: BitFieldResolvable): boolean {
return this.bitfield === BitField.resolve(bit);
}
/**
* Checks whether the bitfield has a bit, or multiple bits.
*/
has(bit: BitFieldResolvable): boolean {
if (Array.isArray(bit)) return bit.every((p) => this.has(p));
const BIT = BitField.resolve(bit);
return (this.bitfield & BIT) === BIT;
}
/**
* Gets all given bits that are missing from the bitfield.
*/
missing(bits: BitFieldResolvable) {
if (!Array.isArray(bits)) bits = new BitField(bits).toArray();
return bits.filter((p) => !this.has(p));
}
/**
* Freezes these bits, making them immutable.
*/
freeze(): Readonly<BitField> {
return Object.freeze(this);
}
/**
* Adds bits to these ones.
* @param {...BitFieldResolvable} [bits] Bits to add
* @returns {BitField} These bits or new BitField if the instance is frozen.
*/
add(...bits: BitFieldResolvable[]): BitField {
let total = 0n;
for (const bit of bits) {
total |= BitField.resolve(bit);
}
if (Object.isFrozen(this)) return new BitField(this.bitfield | total);
this.bitfield |= total;
return this;
}
/**
* Removes bits from these.
* @param {...BitFieldResolvable} [bits] Bits to remove
*/
remove(...bits: BitFieldResolvable[]) {
let total = 0n;
for (const bit of bits) {
total |= BitField.resolve(bit);
}
if (Object.isFrozen(this)) return new BitField(this.bitfield & ~total);
this.bitfield &= ~total;
return this;
}
/**
* Gets an object mapping field names to a {@link boolean} indicating whether the
* bit is available.
* @param {...*} hasParams Additional parameters for the has method, if any
*/
serialize() {
const serialized: Record<string, boolean> = {};
for (const [flag, bit] of Object.entries(BitField.FLAGS)) serialized[flag] = this.has(bit);
return serialized;
}
/**
* Gets an {@link Array} of bitfield names based on the bits available.
*/
toArray(): string[] {
return Object.keys(BitField.FLAGS).filter((bit) => this.has(bit));
}
toJSON() {
return this.bitfield;
}
valueOf() {
return this.bitfield;
}
*[Symbol.iterator]() {
yield* this.toArray();
}
/**
* Data that can be resolved to give a bitfield. This can be:
* * A bit number (this can be a number literal or a value taken from {@link BitField.FLAGS})
* * An instance of BitField
* * An Array of BitFieldResolvable
* @typedef {number|BitField|BitFieldResolvable[]} BitFieldResolvable
*/
/**
* Resolves bitfields to their numeric form.
* @param {BitFieldResolvable} [bit=0] - bit(s) to resolve
* @returns {number}
*/
static resolve(bit: BitFieldResolvable = 0n): bigint {
if ((typeof bit === "number" || typeof bit === "bigint") && bit >= 0n) return BigInt(bit);
if (bit instanceof BitField) return bit.bitfield;
if (Array.isArray(bit))
return bit.map((p) => this.resolve(p)).reduce((prev, p) => BigInt(prev) | BigInt(p), 0n);
if (typeof bit === "string" && typeof this.FLAGS[bit] !== "undefined") return this.FLAGS[bit];
throw new RangeError("BITFIELD_INVALID: " + bit);
}
}