solve-concurrent/it.unibo.tuprolog.solve.concurrent.fsm/EndState

EndState

A terminal State for one branch of the search tree: it carries the Solution that branch produced (StateEnd for a successful/failed one, StateHalt for one aborted by an uncaught exception) and has no successors.

Reaching an EndState is what triggers publishing solution onto the resolution's shared solution channel (see it.unibo.tuprolog.solve.concurrent.ConcurrentResolutionHandle.publishSolutionAndTerminateResolutionIfNeed); every other branch of the tree keeps running independently until it, too, reaches its own EndState.

Inheritors

StateEnd

StateHalt

Properties

context

abstract val context: ConcurrentExecutionContext

The execution context this state operates on.

isEndState

open override val isEndState: Boolean

Whether this state is a terminal one for the current branch, i.e. an EndState.

solution

abstract val solution: Solution

The Solution produced by this branch of the search tree.

Functions

asEndState

open override fun asEndState(): EndState

This state as an EndState, or null if isEndState is false.

castToEndState

open fun castToEndState(): EndState

This state as an EndState.

clone

abstract fun clone(context: ConcurrentExecutionContext = this.context): State

Returns a copy of this state, replacing context with the given one (defaulting to the current context).

open override fun next(): Iterable<State>

Computes every state this branch may transition into from here, one per alternative (matching clause, disjunct, primitive solution, ...) available at this point; empty only for EndStates. Each element is meant to be explored independently (and, in :solve-concurrent's solver, concurrently) of the others.