Method eq

src/big-decimal/big-decimal.ts:346–369

* Returns true if this value equals other. * NaN === NaN → false (standard NaN semantics).

(other: BigDecimal | number)

   * NaN === NaN → false (standard NaN semantics).
   */
  eq(other: BigDecimal | number): boolean {
    if (typeof other === 'number') {
      // The 0/1/-1 fast paths use exponent===0 which excludes NaN (exp=NaN).
      if (other === 0) return this.significand === 0n && this.exponent === 0;
      if (other === 1) return this.significand === 1n && this.exponent === 0;
      if (other === -1) return this.significand === -1n && this.exponent === 0;
      // Integer fast path: compare directly when possible
      if (
        Number.isInteger(other) &&
        Number.isFinite(this.exponent) &&
        this.exponent >= 0 &&
        this.exponent <= 15
      ) {
        return this.significand * pow10(this.exponent) === BigInt(other);
      }
      // cmp returns NaN for NaN inputs, so NaN === 0 → false (correct)
      return this.cmp(other) === 0;
    }
    // Both normalized → equal values have identical (significand, exponent)
    // NaN: exponent is NaN, and NaN !== NaN, so the === check returns false
    return (
      this.significand === other.significand && this.exponent === other.exponent
    );
  }

  /** Returns true if this value is strictly less than other. */
  lt(other: BigDecimal | number): boolean {