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

StateGoalSelection

data class StateGoalSelection(val context: ConcurrentExecutionContext) : AbstractState

"Goal Selection": the entry point of every resolution step, deciding what to do with ConcurrentExecutionContext.goals. If the current context's goals are exhausted, either the whole branch succeeded (root context: moves to a successful StateEnd) or control returns to the parent context to resolve its remaining goals; otherwise, the current substitution is applied to the remaining goals and the branch moves on to StatePrimitiveSelection to resolve the next one.

Constructors

StateGoalSelection

constructor(context: ConcurrentExecutionContext)

Properties

context

open override val context: ConcurrentExecutionContext

The execution context this state operates on.

isEndState

open val isEndState: Boolean

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

Functions

asEndState

open 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

open override fun clone(context: ConcurrentExecutionContext = this.context): StateGoalSelection

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.