Concrete implementations of Var implement observe.
Concrete implementations of Var implement observe. This is called for each toplevel observe. Depths indicate the relative structural depth of the observation, from the frame of reference of the root call to observe. (Each Var derived via flatMap increases the depth.) Depths are used to order the invocation of update callbacks. This is used to ensure that updates proceed in topological order so that every input variable is fully resolved before recomputing a derived variable.
An Event where changes in Var are emitted.
An Event where changes in Var are emitted. The current value of this Var is emitted synchronously upon subscription.
All changes to this Var are guaranteed to be published to the Event.
Create a dependent Var which behaves as f
applied to the
current value of this Var.
Create a dependent Var which behaves as f
applied to the
current value of this Var. FlatMap manages a dynamic dependency
graph: the dependent Var is detached and recomputed whenever
the outer Var changes, but only if there are any observers. An
unobserved Var returned by flatMap will not invoke f
Create a derived variable by applying f
to the contained
value.
Synonymous with observe
Synonymous with observe
(Since version 6.8.2) Use changes (Event)
Observe this Var.
Observe this Var. f
is invoked each time the variable changes,
and synchronously with the first call to this method.
(Since version 6.8.2) Use changes (Event)
Observe this Var into the given AtomicReference.
Observe this Var into the given AtomicReference. Observation stops when the returned closable is closed.
(Since version 6.8.2) Use changes (Event)
A one-shot predicate observation.
A one-shot predicate observation. The returned future
is satisfied with the first observed value of Var that obtains
the predicate pred
. Observation stops when the future is
satisfied.
Interrupting the future will also satisfy the future (with the interrupt exception) and close the observation.
(Since version 6.8.2) Use changes (Event)
Trait Var represents a variable. It is a reference cell which is composable: dependent Vars (derived through flatMap) are recomputed automatically when independent variables change -- they implement a form of self-adjusting computation.
Vars are observed, notifying users whenever the variable changes.
There are no well-defined error semantics for Var. Vars are computed lazily, and the updating thread will receive any exceptions thrown while computing derived Vars.
,Vars do not always perform the minimum amount of re-computation.