An item satisfying type constraints of RootState but where a child item
at Keyalso satisfies RootState. A Store with a
PartitionableState can therefore be partitioned into a child Store by
Key.
Partitioning enables hierarchy and logical isolation of a Store, so that
higher-level stores can be composed of multiple lower-level stores. Logic
relying on some Store<T> need not know whether <T> is the whole app state
or just some part of it.
Partitioning can also make eventing more efficient. When a parent Store's
RootState changes, implementations can omit notifications for all
Watchers of a child partition if the child RootState has not
changed, meaning no value within the child partition has changed.
An item satisfying type constraints of RootState but where a child item at
Key
also satisfiesRootState
. A Store with a PartitionableState can therefore be partitioned into a child Store byKey
.Partitioning enables hierarchy and logical isolation of a Store, so that higher-level stores can be composed of multiple lower-level stores. Logic relying on some
Store<T>
need not know whether<T>
is the whole app state or just some part of it.Partitioning can also make eventing more efficient. When a parent Store's
RootState
changes, implementations can omit notifications for all Watchers of a child partition if the child RootState has not changed, meaning no value within the child partition has changed.See also createStorePartition.