mergeNestedWithAdditions method

Map<String, dynamic> mergeNestedWithAdditions(Map<String, dynamic> other)

Merges the current map with another map recursively, handling numerical instructions. If there are duplicate keys and both values are maps, they are merged recursively. If a value in the other map is a NumericalAddition and the corresponding value in the current map is a number, the addition is performed and the value will be a number. Otherwise, the values from the other map will overwrite those in the current map. If other is null, the current map is returned unchanged.

Example usage:

void main() {
  final Map<String, dynamic> map1 = {
    'a': 1,
    'b': {'c': 2, 'd': 3},
    'f': 4,
  };
  final Map<String, dynamic> map2 = {
    'b': {'c': 3, 'd': 4},
    'f': const NumericalAddition(5),
  };
  final Map<String, dynamic> mergedMap = map1.mergeNestedWithAdditions(map2);
  print(mergedMap); // Output: {a: 1, b: {c: 3, d: 4}, f: 9}
}

Implementation

Map<String, dynamic> mergeNestedWithAdditions(Map<String, dynamic> other) {
  final result = Map<String, dynamic>.from(this);
  other.forEach((key, otherValue) {
    if (result.containsKey(key)) {
      final thisValue = result[key];
      if (thisValue is Map<String, dynamic> && otherValue is Map<String, dynamic>) {
        result[key] = thisValue.mergeNestedWithAdditions(otherValue);
      } else if (thisValue is num && otherValue is NumericalAddition) {
        result[key] = thisValue + otherValue.amount;
      } else if (otherValue != null) {
        if (otherValue is NumericalAddition) {
          result[key] = otherValue.amount;
        } else if (otherValue is Map<String, dynamic>) {
          result[key] = <String, dynamic>{}.mergeNestedWithAdditions(otherValue);
        } else {
          result[key] = otherValue;
        }
      }
    } else {
      if (otherValue is NumericalAddition) {
        result[key] = otherValue.amount;
      } else if (otherValue is Map<String, dynamic>) {
        result[key] = <String, dynamic>{}.mergeNestedWithAdditions(otherValue);
      } else {
        result[key] = otherValue;
      }
    }
  });
  return result;
}