Replace n occurrence of a substring in a string

main.dart

void main() {
  const subject = 'I have a dog. I have a cat. I have a bird.';
  final result = replaceStringByOccurrence(subject, 'have', '*have no*', 0);
  print(result);
}

/// Looks for `occurrence` of `search` in `subject` and replace it with `replace`.
///
/// The occurrence index is started from 0.
String replaceStringByOccurrence(
    String subject, String search, String replace, int occurence) {
  if (occurence.isNegative) {
    throw ArgumentError.value(occurence, 'occurrence', 'Cannot be negative');
  }
  final regex = RegExp(r'have');
  final matches = regex.allMatches(subject);
  if (occurence >= matches.length) {
    throw IndexError(occurence, matches, 'occurrence',
        'Cannot be more than count of matches');
  }
  int index = -1;
  return subject.replaceAllMapped(regex, (match) {
    index += 1;
    return index == occurence ? replace : match.group(0)!;
  });
}