二进制和Flags转换类

binary-flags.js

class Bin extends Set {
	static #typeError_Constructor = "传入的不是 number 和 bigint 类型或这个两个类型的数组";
	static #typeError_FlagsNum = "传入的不是 number 和 bigint 类型";
	static #typeError_FlagsArray = "传入的不是 number 类型的数组";
	static #typeError_NotInteger = "传入的不是 整数";
	static #rangeError_NotSafe = "传入的 number 大于 53 位";
	/**
	 * 构建函数
	 * @param {(number | bigint | number[])} arg 传入参数
	 */
	constructor (arg) {
		if (typeof arg === "number" || typeof arg === "bigint") {
			super(Bin.unflags(arg));
		} else if (Array.isArray(arg) &&
			arg.every(item=>typeof item === "number" && Number.isSafeInteger(item))
		){
			super(arg);
		} else {
			throw new TypeError(Bin.#typeError_Constructor);
		}
	}
	/**
	 * 将数字或大整形flag转换为数组
	 * @param {(number | bigint)} number 输入的数字
 	 * @returns {number[]} 输出数组
	 */
	static unflags(number) {
		const inputType = typeof number;
		if (inputType === "number" || inputType === "bigint"){
			if (inputType === "number" && number > Number.MAX_SAFE_INTEGER) {
				throw new RangeError(Bin.#rangeError_NotSafe);
			}
			const isBigint = inputType === "bigint";
			const arr = [];
			for (let i = 0, flag = isBigint ? 1n : 1; flag <= number; i++, flag = (isBigint ? 2n : 2) ** (isBigint ? BigInt(i) : i)) {
				if (number & flag) {
					arr.push(i);
				}
			}
			return arr;
		} else {
			throw new TypeError(Bin.#typeError_FlagsNum);
		}
	}
	/**
	 * 将数字序号转换为数字
	 * @param {number[]} indexArr 输入的序号数组
	 * @returns {(number | bigint)} 输出的数字
	 */
	static enflags(indexArr) {
		if (Array.isArray(indexArr) &&
			indexArr.every(item=>typeof item === "number" && Number.isSafeInteger(item))
		){
			let result = 0, isBigint = false, baseNum = 2;
			for (let i = 0; i < indexArr.length; i++) {
				let value = indexArr[i];
				//当数值大于52位，即需要换BigInt
				if (value > 52 && !isBigint) {
					isBigint = true;
					result = BigInt(result);
					baseNum = BigInt(baseNum);
				}
				isBigint && (value = BigInt(value)); //一旦需要BigInt了，就转换
				result = result + baseNum ** value; //用乘方相加而不是位移的优点是可以得到 0xFFFFFFFF 而不是 -1
			}
			return result;
		} else {
			throw new TypeError(Bin.#typeError_FlagsArray);
		}
	}
	get int() {
		return Bin.enflags(Array.from(this.values()));
	}
	add(index) {
		if (typeof index === "number" && Number.isSafeInteger(index)){
			super.add(index);
		} else {
			throw new TypeError(Bin.#typeError_NotInteger);
		}
	}
}