indexed method

Iterable<Indexed<E>> indexed({ int start = 0, int step = 1, @Deprecated('Use `start` instead of `offset`') int? offset, })

Returns a iterable that combines the index and value of this Iterable.

By default the index is zero based, but an arbitrary offset can be provided.

For example, the expression

['a', 'b'].indexed(start: 1)
  .map((each) => '${each.index}: ${each.value}')
  .join(', ');

returns

'1: a, 2: b'

Implementation

Iterable<Indexed<E>> indexed({
  int start = 0,
  int step = 1,
  @Deprecated('Use `start` instead of `offset`') int? offset,
}) sync* {
  var index = offset ?? start;
  for (final element in this) {
    yield Indexed<E>(index, element);
    index += step;
  }
}