Tutorial Project. Release 7. Class Computer0

From wiki.visual-prolog.com

Tutorial Project. Release 7
/******************************************************
Class computer0
 
Predicate SuccessfullStep implementation
Written by Elena Efimova
*******************************************************/
class computer0:player
open core
 
predicates
    getPlayerDescriptor:(game::language_D)->string Descriptor.
 
end class computer0
 
implement computer0
    inherits genericComputer
open core
 
clauses
    new():-
        PolyLineBraneObj=polylineStrategy0::new(),
        setpolylineStrategy(PolyLineBraneObj).
 
clauses
   getPlayerDescriptor(game::en)=polylineStrategy0::playerDescriptorEn_C.
   getPlayerDescriptor(game::ru)=polylineStrategy0::playerDescriptorRu_C.
 
end implement computer0
 
/******************************************
  Class polylineStrategy0
******************************************/
class polylineStrategy0:polylineStrategy
    open core
 
constants
    playerDescriptorEn_C="Computer0: Unlimited Depth. Despair move - first possible in the list".
    playerDescriptorRu_C="Computer0: Неограниченный поиск. Ход отчаяния - по возможному правилу".
 
end class polylineStrategy0
 
implement polylineStrategy0
open core, exception
 
facts
    genericComputer_V:genericComputer:=erroneous.
 
clauses
    setGenericComputer(GenericComputerObj):-
        genericComputer_V:=GenericComputerObj.
 
clauses
    successfulStep(PolyLine)=BestMove:-
        BestMove=successfulStep1(PolyLine),
        !.
    successfulStep(PolyLine)=SomeMove:-
        genericComputer_V:stepCandidate(PolyLine, _PolyLine1,SomeMove),
        !.
 
predicates
    successfulStep1:(juniourJudge::cell* PolyLine)->juniourJudge::cell determ.
clauses
    successfulStep1(PolyLine)=BestMove:-
        genericComputer_V:stepCandidate(PolyLine, _PolyLine1,BestMove),
        list::isMember(BestMove, PolyLine),
        !.
    successfulStep1(PolyLine)=Cell:-
        genericComputer_V:stepCandidate(PolyLine, PolyLine1,Cell),
            not(_=successfulStep1(PolyLine1)),
            !.
 
clauses
    randomStep()=Cell:-
        findAll(NewCell,genericComputer_V:stepCandidate(juniourJudge::polyline_P,_Polyline1, NewCell),CellCandidateListWithDuplicates),
        CellCandidateList=list::removeDuplicates(CellCandidateListWithDuplicates),
        not(CellCandidateList=[]),
        NoOfVariants=list::length(CellCandidateList),
        ChoiceNo=math::random(NoOfVariants-1),
        Cell=list::nth(ChoiceNo+1,CellCandidateList).
 
end implement polylineStrategy0