approximate method

Rational approximate([
  1. int? digits
])

Approximate the result to a fraction.

Implementation

Rational approximate([int? digits]) {
  if (dirtyParts.isEmpty) {
    return clean;
  }

  return dirtyParts.entries.fold(
      clean,
      (previousValue, element) =>
          previousValue +
          element.key.approximate(digits) *
              Rational.parse(element.value.toString()));
}