mapSequential<A, B> function
Sequential async map (one after another). Roadmap #181.
Implementation
Future<List<B>> mapSequential<A, B>(Iterable<A> items, Future<B> Function(A) fn) async {
final List<B> out = <B>[];
for (final A item in items) {
out.add(await fn(item));
}
return out;
}