cajurabi / dart-merge-all

An alternative interface to the merge stream transformer

Merge All

An alternative interface to the merge stream transformer. It merges multiple streams together into one wiht a given concurrency. This is interface is useful when all streams to be merged are known up front, while the base merge interface is useful when the streams to merge aren't known up front and are the results of other streams.

Example

import 'dart:async';
import 'package:merge_all/merge_all.dart';

main() {
  var numbers    = new StreamController();
  var letters    = new StreamController();
  var animals    = new StreamController();

  // The streams to merge with the numbers stream
  var others = [letters.stream, animals.stream];

  // create a merged stream with a concurrency of 2
  var merged = numbers.stream
                      .transform(new MergeAll(2, others))
                      .listen(print);

  // Pump data through the animal stream first, nothing should happen
  // due to it being the third item w/ a concurrency of 2
  animals.add("Cat");
  animals.add("Dog");

  // Now lets push some numbers and letters through and close those streams
  numbers.add(1);
  letters.add('a');
  numbers.add(2);
  letters.add('b');
  numbers.close();
  letters.close();

  // push some more animals through and close that stream
  animals.add("Bird");
  animals.add("Fish");
  animals.close();
}