private TokenChanges FindBestPath(ParsedSequence seq, int end, Dictionary<ParsedSequenceKey, SequenceTokenChanges> memiozation)
{
if (_parseResult.TerminateParsing)
throw new OperationCanceledException();
SequenceTokenChanges result;
var key = new ParsedSequenceKey(seq, end);
if (memiozation.TryGetValue(key, out result))
return result.TotalTokenChanges;
if (seq.StartPos == end)
{
var tokenChanges = new TokenChanges(seq.ParsingSequence.MandatoryTokenCount, 0);
memiozation.Add(key, new SequenceTokenChanges(new SubrulesTokenChanges(), tokenChanges));
return tokenChanges;
}
var results = new SubrulesTokenChanges();
var validSubrules = seq.GetValidSubrules(end).ToList();
if (validSubrules.Count == 0)
{
var tokenChanges = new TokenChanges();
memiozation.Add(key, new SequenceTokenChanges(results, tokenChanges));
return tokenChanges;
}
memiozation.Add(key, new SequenceTokenChanges(results, TokenChanges.Fail));
foreach (var subrule in validSubrules)
{
TokenChanges localMin = TokenChanges.Fail;
if (_deletedToken.ContainsKey(new ParsedSequenceAndSubrule(seq, subrule)))
localMin = new TokenChanges(0, 1);
else
localMin = LocalMinForSubSequence(seq, memiozation, subrule, localMin);
results[subrule] = localMin;
}
TokenChanges comulativeMin;
if (results.Count == 0)
{ }
var bestResults = RemoveWorstPaths(seq, end, results, out comulativeMin);
var result2 = new SequenceTokenChanges(bestResults, comulativeMin);
memiozation[key] = result2;
return result2.TotalTokenChanges;
}
