Function evenRound

lib/internal/webidl.js:185–199

* Rounds to the nearest integer, choosing the even integer on ties. * @param {number} x Numeric value. * @returns {number}

(x)

 * @returns {number}
 */
function evenRound(x) {
  // Web IDL ConvertToInt step 7.2: round to the nearest integer,
  // choosing the even integer on ties and +0 rather than -0.
  const i = integerPart(x);
  const remainder = MathAbs(x % 1);
  const sign = MathSign(x);
  if (remainder === 0.5) {
    return i % 2 === 0 ? i : i + sign;
  }
  const r = remainder < 0.5 ? i : i + sign;
  if (r === 0) {
    return 0;
  }
  return r;
}

/**
 * Returns 2 to the power of the given exponent.