private static IEnumerable <PredictionTreeBranch> PushIntersection(
PredictionTreeBranch sourceMasterPath,
FiniteAutomataMultiTargetTransitionTable <GrammarVocabulary, Tuple <int, PredictionTreeBranch> > transitionTableResult,
Stack <Tuple <int, PredictionTreeBranch> > toProcess,
HashSet <PredictionTreeBranch> seen,
Tuple <int, PredictionTreeBranch> currentPathTuple,
PredictionTreeBranch currentPath,
PredictionTreeBranch path,
GrammarVocabulary intersection,
GrammarVocabulary transitionKey = null)
{
/* * * * * * * * * * * * * * * * * * * * * * * * * *\
* Construct the transition table with the matching *
* paths. *
* * * * * * * * * * * * * * * * * * * * * * * * * */
var intersectingCurrent = from key in currentPath.CurrentNode.Veins.Keys
let intersect = key.Intersect(intersection)
where !intersect.IsEmpty
let subPathSet = currentPath.CurrentNode.Veins[key]
from subPath in subPathSet.UnalteredOriginals
let rPath = new PredictionTreeBranch(sourceMasterPath.Take(currentPath.Depth).Concat(subPath).ToList(), currentPath.Depth + subPath.Depth, true, false, currentPath.GetDeviationsUpTo(currentPath.Depth), minDepth: currentPath.Depth)
where rPath.Valid
select rPath;
var set = new List <Tuple <int, PredictionTreeBranch> >(from ip in intersectingCurrent
select Tuple.Create(currentPathTuple.Item1, ip))
{
Tuple.Create(currentPathTuple.Item1 + 1, new PredictionTreeBranch(path.baseList, path.Depth, false, false, minDepth: path.Depth))
};
var distinctNodeArray = (from element in set
select element.Item2).Distinct().ToArray();
foreach (var element in distinctNodeArray)
{
yield return(element);
}
transitionTableResult.Add(transitionKey ?? intersection, set);
/* * * * * * * * * * * * * * * * * * * * * * * * * * * *\
* If the current point is an edge, walk further *
* up the parse tree to see what else lies in store. *
* * * * * * * * * * * * * * * * * * * * * * * * * * * **
* Further ambiguities might result in additional look- *
* ahead being necessary. *
* * * * * * * * * * * * * * * * * * * * * * * * * * * */
if (seen.Add(path) && path.CurrentNode.Veins.DFAOriginState.IsEdge)
{
toProcess.Push(Tuple.Create(currentPathTuple.Item1 + 1, path));
}
}
internal PredictionTreeBranch GetTransitionPath(PredictionTreeBranch targetPath, PredictionTreeLeaf[] previousNodes, PredictionTreeBranch currentSubPath, Dictionary <IOilexerGrammarProductionRuleEntry, GrammarVocabulary> ruleLookup, bool usePrevious, bool isEpsilonTransition = false, bool incrementDeviations = true)
{
var currentNode = currentSubPath[0];
if (previousNodes.Length > 0)
{
Debug.Assert(previousNodes[previousNodes.Length - 1].Veins.DFAOriginState.OutTransitions.Keys.Any(k => !k.Intersect(ruleLookup[currentNode.Rule]).IsEmpty));
}
short[] deviations = incrementDeviations ? targetPath.IncrementDeviations(previousNodes.Length, isEpsilonTransition) : targetPath.GetDeviationsUpTo(previousNodes.Length);
var result = new PredictionTreeBranch(previousNodes.Concat(currentSubPath).ToArray(), targetPath.Depth + currentSubPath.Depth, passAlong: false, deviations: deviations);
result.MinDepth = targetPath.MinDepth;
return(result);
}