Tutorial Project. Release 7. Class Computer2

From wiki.visual-prolog.com

Tutorial Project. Release 7
/******************************************
Class computer2
 
Predicate SuccessfullStep implementation
written by Elena Efimova
******************************************/
class computer2:player
open core
 
predicates
    getPlayerDescriptor:(game::language_D)->string Descriptor.
 
end class computer2
 
implement computer2
    inherits genericComputer
open core
 
clauses
    new():-
        PolyLineBraneObj=polylineStrategy2::new(),
        setpolylineStrategy(PolyLineBraneObj).
 
clauses
   getPlayerDescriptor(game::en)=polylineStrategy2::playerDescriptorEn_C.
   getPlayerDescriptor(game::ru)=polylineStrategy2::playerDescriptorRu_C.
 
end implement computer2
 
/******************************************
  Class polylineStrategy2
******************************************/
class polylineStrategy2:polylineStrategy
open core
constants
    playerDescriptorEn_C="Computer2: Limited Depth. Despair move - random".
    playerDescriptorRu_C="Computer2: Ограниченная глубина. Ход отчаяния - случайный".
 
end class polylineStrategy2
 
implement polylineStrategy2
open core, exception
 
facts
    maxDepth_V:positive:=5.
    genericComputer_V:genericComputer:=erroneous.
 
clauses
    new():-
        defineSearchDepth().
 
clauses
    setGenericComputer(GenericComputerObj):-
        genericComputer_V:=GenericComputerObj.
 
predicates
    defineSearchDepth:().
clauses
    defineSearchDepth():-
        DepthStr=humanInterface::getInput(humanInterface::searchDepth_S,toString(maxDepth_V)),
        not(DepthStr=""),
        !,
        try
            maxDepth_V:=toTerm(DepthStr),
            if maxDepth_V mod 2 = 0 then
                maxDepth_V:=maxDepth_V+1
            end if    
        catch _TraceID1 do
            humanInterface::announce(humanInterface::errorMustBeNumber_S,""),
            defineSearchDepth()
        end try.
    defineSearchDepth().
 
clauses
    successfulStep(PolyLine)=BestMove:-
        BestMove=successfulStep(maxDepth_V,PolyLine).
 
predicates
    successfulStep: (integer Counter, juniourJudge::cell*)->juniourJudge::cell nondeterm.
clauses
    successfulStep(Counter,PolyLine)=BestMove:-
        genericComputer_V:stepCandidate(PolyLine,_PolyLine1,BestMove),
        isStepSuccessful(Counter,PolyLine,BestMove),
        !.
    successfulStep(Counter,PolyLine)=Cell:-
        genericComputer_V:stepCandidate(PolyLine, PolyLine1,Cell),
            not(_=successfulStep(Counter-1,PolyLine1)).
 
class predicates
    isStepSuccessful:(integer Counter,juniourJudge::cell* PolyLine,juniourJudge::cell BestMove) determ.
clauses
    isStepSuccessful(_Counter,PolyLine,BestMove):-
        list::isMember(BestMove, PolyLine),
        !.
    isStepSuccessful(Counter,_PolyLine,_BestMove):-
        Counter<=1.
 
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 polylineStrategy2

References