Coverage Summary for Class: ConflictFreeSubset (it.unibo.tuprolog.argumentation.core.primitives.labelling.argument)

 package it.unibo.tuprolog.argumentation.core.primitives.labelling.argument
 
 import it.unibo.tuprolog.argumentation.core.primitives.graph.conflictGraph
 import it.unibo.tuprolog.argumentation.core.primitives.ids
 import it.unibo.tuprolog.argumentation.core.primitives.replyList
 import it.unibo.tuprolog.core.Term
 import it.unibo.tuprolog.solve.ExecutionContext
 import it.unibo.tuprolog.solve.Signature
 import it.unibo.tuprolog.solve.primitive.Primitive
 import it.unibo.tuprolog.solve.primitive.Solve
 
 /**
  * conflictFreeSubset(+Args, +Forced, -Set): the subsets of Args including Forced where no argument attacks another
  * one (itself included), each once. The search only adds arguments compatible with those already chosen, so every
  * branch ends in a solution: the cost grows with the number of sets, not with the subsets of Args.
  */
 internal object ConflictFreeSubset : Primitive {
     val signature: Signature = Signature("conflictFreeSubset", 3)
 
     override fun solve(request: Solve.Request<ExecutionContext>): Sequence<Solve.Response> {
         val args = request.ids(0)
         val forced = request.ids(1).toSet()
         val graph = request.conflictGraph()
 
         fun subsets(
             i: Int,
             chosen: List<Term>,
         ): Sequence<List<Term>> =
             sequence {
                 if (i == args.size) {
                     yield(chosen)
                     return@sequence
                 }
                 val a = args[i]
                 if (!graph.selfAttacking(a) && chosen.none { graph.conflict(a, it) }) yieldAll(subsets(i + 1, chosen + a))
                 if (a !in forced) yieldAll(subsets(i + 1, chosen))
             }
         return subsets(0, emptyList()).mapNotNull { request.replyList(2, it) }
     }
 }