@numio/bigmath/src/operations/div/utils.js

@numio/bigmath is an arbitrary-precision arithmetic library. It can be used for basic operations with decimal numbers (integers and float)

import { tryBigInt } from "../../shared/utils.js";
export const divInner = (array, precision, def) => {
    let bigInt = def ? def[0] : array[0][0];
    let fpe = def ? def[1] : array[0][1];
    const isNeg = bigInt < 0n;
    for (let i = def ? 0 : 1; i < array.length; i++) {
        let [bigCurrent, dpLen] = array[i];
        let r = 0n;
        if (bigInt === 0n && fpe === 0)
            return [0n, 0];
        if (fpe === dpLen) {
            fpe = 0;
            dpLen = 0;
        }
        if (dpLen > 0 && fpe < dpLen) {
            bigInt *= 10n ** tryBigInt(dpLen - fpe);
            fpe = 0;
        }
        if (dpLen > 0 && fpe > dpLen)
            fpe = fpe - dpLen;
        while ((bigInt < 0 ? bigInt * -1n : bigInt) < bigCurrent) {
            if (precision <= fpe)
                return [bigInt / bigCurrent, fpe];
            fpe += 1;
            bigInt *= 10n;
        }
        const q = bigInt / bigCurrent;
        r = bigInt - q * bigCurrent;
        bigInt = q;
        while ((isNeg ? r < 0n : r > 0n) && fpe < precision) {
            const nextBigInt = r * 10n;
            const nextQ = nextBigInt / bigCurrent;
            const nextRemained = nextBigInt - nextQ * bigCurrent;
            bigInt = bigInt * 10n + nextQ;
            r = nextRemained;
            fpe += 1;
        }
    }
    return [bigInt, fpe];
};