api/dev.s7a.strata.state

Package-level declarations

Types

interface DerivedStateSource<out T> : StateSource<T>

Runtime capability for a pure, single-input derived observation. The source and transformation are immutable and caller-owned; runtimes evaluate committed inputs on their owner thread. Implementations must also implement ordinary StateSource.subscribe with its complete lifetime contract.

StateRevision

@JvmInline

value class StateRevision(val value: Long) : Comparable<StateRevision>

Identifies one observation in the ordered history of a state source.

StateSnapshot

data class StateSnapshot<out T>(val revision: StateRevision, val value: T)

Carries a source observation and its publication revision.

StateSource

fun interface StateSource<out T>

An externally owned source of revisioned state snapshots.

StateSubscription

class StateSubscription<out T>(val initialSnapshot: StateSnapshot<T>, closeAction: () -> Unit) : AutoCloseable

The atomic result of subscribing to a StateSource.

Functions

map

fun <T, R> StateSource<T>.map(transform: (T) -> R): StateSource<R>

Creates a lazy, caller-owned projection of this source, supporting nullable values and chained projections. Construction does not subscribe or evaluate transform. Keep the returned identity when consumers share a projection. The transformation must be deterministic, side-effect-free, and return normally; ordinary subscriptions may transform on any notifying thread. Ordinary subscriptions preserve every revision, including equal results. Retained UI consumers instead share the upstream subscription, transform a frame-committed input, and suppress dependent UI work when the transformed result is equal by ==. No source history or global cache is retained. Heavy work and I/O belong outside the transformation.