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import { abs_bigint } from "./abs_bigint.ts";
export default function fractionToDecimal(    numerator: number,    denominator: number,): string {    let a = BigInt(numerator);    let b = BigInt(denominator);
    if (a % b === 0n) return String(a / b);
    const sb: string[] = [];    if (a * b < 0) sb.push("-");    a = abs_bigint(a);    b = abs_bigint(b);    sb.push(...(String(a / b) + "."));    a %= b;    const map = new Map<bigint, number>();
    while (a !== 0n) {        map.set(a, sb.length);        a *= 10n;        sb.push(...String(a / b));        a %= b;        const u = map.get(a);        if (typeof u === "number") {            return sb.slice(0, u).join("") + `(${sb.slice(u).join("")})`;        }    }    return sb.join("");}