flattenDeep method

  1. @useResult
Iterable flattenDeep([
  1. int? depth
])

Flattens recursively to depth levels. depth 1 = one level; null = fully deep.

Returns a lazy Iterable of elements with nested iterables flattened up to depth levels, or fully when depth is null.

Implementation

@useResult
Iterable<dynamic> flattenDeep([int? depth]) {
  final int? limit = depth;
  return expand((dynamic element) {
    if (limit != null && limit <= 0) {
      return [element];
    }
    if (element is Iterable<dynamic>) {
      final int? nextDepth = limit == null ? null : limit - 1;
      return element.flattenDeep(nextDepth);
    }
    return [element];
  });
}