true-math/src/main/floor.js

True Math - math library for numbers of arbitrary length

import {normalizeNumber, sign, split} from "../helpers/helpers.js";
import {difference2nums} from "./difference.js";
import {ifValidNum, isSpecificValue} from "../checkers/checkers.js";

export function floorUnsafe(num) {

	const [integerPart, decimalPart] = split(num);

	if (sign(num) === -1) {

		if (decimalPart.length === 0) return integerPart;

		return difference2nums(integerPart, '1');
	}

	return integerPart;
}

export default function floor(num) {

	ifValidNum(num);

	if (isSpecificValue(num)) return num;

	return floorUnsafe(normalizeNumber(num))
}