Function atPrecision

test/big-decimal/ln-agm.test.ts:16–24

(p: number, fn: () => T)

});

function atPrecision<T>(p: number, fn: () => T): T {
  const saved = BigDecimal.precision;
  BigDecimal.precision = p;
  try {
    return fn();
  } finally {
    BigDecimal.precision = saved;
  }
}

function firstDigits(x: BigDecimal, n: number): string {
  return x.toPrecision(n).toString();