slices method
- int length
Creates a stream whose elements are contiguous slices of this
.
Each slice is length
elements long, except for the last one which may be
shorter if this
emits too few elements. Each slice begins after the
last one ends.
For example, Stream.fromIterable([1, 2, 3, 4, 5]).slices(2)
emits
([1, 2], [3, 4], [5])
.
Errors are forwarded to the result stream immediately when they occur, even if previous data events have not been emitted because the next slice is not complete yet.
Implementation
Stream<List<T>> slices(int length) {
if (length < 1) throw RangeError.range(length, 1, null, 'length');
var slice = <T>[];
return transform(StreamTransformer.fromHandlers(handleData: (data, sink) {
slice.add(data);
if (slice.length == length) {
sink.add(slice);
slice = [];
}
}, handleDone: (sink) {
if (slice.isNotEmpty) sink.add(slice);
sink.close();
}));
}