public SearchResult Evaluate(IState startState, SearchContext searchContext)
{
if (startState.Turn == Player.Empty)
{
throw new EmptyPlayerException(nameof(startState.Turn) + " can't be " + nameof(Player.Empty));
}
if (searchContext.CurrentDepth > 0)
{
var cachedResult = CheckCacheForEvaluation(startState, searchContext);
if (cachedResult != null)
{
return(cachedResult);
}
}
if (searchOptions.Pruners.Any(pruner => pruner.ShouldPrune(startState, searchContext.CurrentDepth, searchContext.StatesUpTillNow)))
{
var evaluation = startState.Evaluate(searchContext.CurrentDepth, searchContext.StatesUpTillNow, searchOptions);
return(new SearchResult(evaluation, startState, true, true, false));
}
if (ShouldStop(startState, searchContext))
{
var evaluation = startState.Evaluate(searchContext.CurrentDepth, searchContext.StatesUpTillNow, searchOptions);
return(new SearchResult(evaluation, new List <IState> {
startState
}, 1, 0, false, false, false));
}
SearchResult result;
switch (startState)
{
case IDeterministicState deterministicState:
result = deterministicSearchUtils.EvaluateChildren(deterministicState, searchContext);
break;
case IProbabilisticState probabilisticState:
result = probabilisticSearchUtils.EvaluateChildren(probabilisticState, searchContext);
break;
default:
throw new BadStateTypeException($"State must implement {nameof(IDeterministicState)} or {nameof(IProbabilisticState)}");
}
AddResultToCach(startState, searchContext.CurrentDepth, searchContext.StatesUpTillNow, result);
return(result);
}
public SearchResult EvaluateChildren(IProbabilisticState startState, SearchContext searchContext)
{
var neighbors = startState.GetNeighbors().ToArray();
if (!neighbors.Any())
{
var evaluation = startState.Evaluate(searchContext.CurrentDepth, searchContext.StatesUpTillNow, searchOptions);
return(new SearchResult(evaluation, startState));
}
var storedStates = new ConcurrentDictionary <IState, double>();
var results = new List <Tuple <double, Task <SearchResult> > >();
foreach (var neighbor in neighbors)
{
var wrappedState = new ProbablisticStateWrapper(neighbor.Item2, startState);
var searchResult = threadManager.Invoke(() =>
deterministicSearchUtils.EvaluateChildren(wrappedState, searchContext.CloneWithMaxAlphaAndBeta(), storedStates), searchContext.CurrentDepth);
results.Add(new Tuple <double, Task <SearchResult> >(neighbor.Item1, searchResult));
}
return(Reduce(results, startState));
}
