T
- The type of value being stored.public interface ValueState<T> extends ReadableState<T>, State
ReadableState
cell containing a single value.Modifier and Type | Method and Description |
---|---|
T |
read()
Read the current value, blocking until it is available.
|
ValueState<T> |
readLater()
Indicate that the value will be read later.
|
void |
write(T input)
Set the value.
|
void write(T input)
T read()
If there will be many calls to ReadableState.read()
for different state in short succession, you
should first call ReadableState.readLater()
for all of them so the reads can potentially be batched
(depending on the underlying implementation}.
The returned object should be independent of the underlying state. Any direct modification of the returned object should not modify state without going through the appropriate state interface, and modification to the state should not be mirrored in the returned object.
Note that null
will be returned if the value has never been written.
read
in interface ReadableState<T>
ValueState<T> readLater()
ReadableState
This allows an implementation to start an asynchronous prefetch or to include this state in the next batch of reads.
readLater
in interface ReadableState<T>