Coverage Summary for Class: Intersection (it.unibo.tuprolog.argumentation.core.primitives.utils)

 package it.unibo.tuprolog.argumentation.core.primitives.utils
 
 import it.unibo.tuprolog.core.List
 import it.unibo.tuprolog.core.Substitution
 import it.unibo.tuprolog.core.Term
 import it.unibo.tuprolog.solve.ExecutionContext
 import it.unibo.tuprolog.solve.primitive.BinaryRelation
 import it.unibo.tuprolog.solve.primitive.Solve
 
 /**
  * intersection(+Sets, -Intersection): the elements of the first list in Sets that are in all of them, in its order
  * (elements compared as ground terms); fails if Sets is empty
  */
 internal object Intersection : BinaryRelation.WithoutSideEffects<ExecutionContext>("intersection") {
     override fun Solve.Request<ExecutionContext>.computeAllSubstitutions(
         first: Term,
         second: Term,
     ): Sequence<Substitution> {
         if (first !is List) return emptySequence()
         val sets = first.toList().map { (it as? List)?.toList() ?: return emptySequence() }
         if (sets.isEmpty()) return emptySequence()
         val others = sets.drop(1).map { it.toSet() }
         return unifyWith(second, List.of(sets.first().filter { y -> others.all { y in it } }))
     }
 }