separate<To> method

Iterable<To> separate<To>({ required To convert(E), required To separator, int groupSize = 1, })

Apply convert to each item and insert the separator between each <groupSize> items (not including the beginning and the end).

Returns a new Iterable (not lazy) with the converted items and separators.

Example

final nums = [1, 2, 3];
final result = nums.separate(convert: (n) => n * 2, separator: -1);
print(result);

// Output:
// (2, -1, 4, -1, 6)

Implementation

Iterable<To> separate<To>({
  required To Function(E) convert,
  required To separator,
  int groupSize = 1,
}) sync* {
  assert(groupSize > 0);

  int counter = 0;
  for (final E entry in this) {
    if (counter == groupSize) {
      counter = 0;
      yield separator;
    }

    counter += 1;
    yield convert(entry);
  }
}