keys property
The keys of this
.
The returned iterable has efficient contains
operations, assuming the
iterables returned by the wrapped maps have efficient contains
operations for their keys
iterables.
The length
must do deduplication and thus is not optimized.
The order of iteration is defined by the individual Map
implementations,
but must be consistent between changes to the maps.
Unlike most Map implementations, modifying an individual map while iterating the keys will sometimes throw. This behavior may change in the future.
Implementation
@override
Iterable<K> get keys => _DeduplicatingIterableView(
CombinedIterableView(_maps.map((m) => m.keys)));