/// <summary>
/// Constructs the initial look-ahead for the transitions.
/// </summary>
/// <remarks></remarks>
public void ConstructInitialLookahead(GrammarSymbolSet grammarSymbols, Dictionary <SyntacticalDFAState, PredictionTreeLeaf> fullSeries, Dictionary <IOilexerGrammarProductionRuleEntry, GrammarVocabulary> ruleVocabulary)
{
/* *
* Left-recursive rules will use the relevant rule
* paths within their projections within a loop to avoid
* stack overflow.
* */
bool includeRules = this.RootLeaf.Veins.LeftRecursionType != ProductionRuleLeftRecursionType.None;
var result = new ControlledDictionary <GrammarVocabulary, PredictionTree>();
this.LookAhead = result;
if (includeRules)
{
/* *
* On left-recursive rules, the requirements change.
* *
* The rules must be considered at the start to
* ensure that the left recursive branches
* can be switched 'off' to allow for reductions
* to function properly.
* */
foreach (var key in this.Veins.Keys)
{
var targets = this.Veins[key];
if (targets.Any(k => k.GetRecursionType() != ProductionRuleLeftRecursionType.None && this.RootLeaf == this))
{
var intersection = key.Intersect(this.Veins.DFAOriginState.OutTransitions.FullCheck);
var reducedRules = key.GetRuleVariant().GetSymbols().Select(k => (IGrammarRuleSymbol)k).Select(k => new { Node = fullSeries.GetRuleNodeFromFullSeries(k.Source), Symbol = k }).Where(k => k.Node.HasBeenReduced || k.Node == k.Node.RootLeaf && k.Node.Veins.LeftRecursionType != ProductionRuleLeftRecursionType.None).Select(k => k.Symbol);
var ruleVar = new GrammarVocabulary(key.symbols, reducedRules.ToArray());
intersection |= (key.GetTokenVariant() | ruleVar);
if (!intersection.IsEmpty)
{
result._Add(intersection, targets);
}
}
else
{
DoReductionAware(fullSeries, result, key);
}
}
}
else
{
foreach (var key in this.Veins.Keys.ToArray())
{
DoReductionAware(fullSeries, result, key);
}
}
/* *
* Lexical ambiguity handling follows after the full transition table is known.
* */
SyntacticAnalysisCore.CreateLexicalAmbiguityTransitions(grammarSymbols, result, null, this, fullSeries, ruleVocabulary);
}
private void DoReductionAware(Dictionary <SyntacticalDFAState, PredictionTreeLeaf> fullSeries, ControlledDictionary <GrammarVocabulary, PredictionTree> result, GrammarVocabulary key)
{
var tokenVar = key.GetTokenVariant();
var reducedRules =
key
.GetRuleVariant()
.GetSymbols()
.Select(k => (IGrammarRuleSymbol)k)
.Select(k => new { Node = fullSeries.GetRuleNodeFromFullSeries(k.Source), Symbol = k })
.Where(k => k.Node.HasBeenReduced).Select(k => k.Symbol);// || k.Node == k.Node.RootLeaf && k.Node.Value.LeftRecursionType != ProductionRuleLeftRecursionType.None && this == this.RootLeaf
var ruleVar = new GrammarVocabulary(key.symbols, reducedRules.ToArray());
if (!tokenVar.IsEmpty)
{
result._Add(tokenVar, this.Veins[key]);
}
if (!ruleVar.IsEmpty)
{
result._Add(ruleVar, this.Veins[key]);
}
}
public IControlledCollection <ICliMetadataCustomAttributeTableRow> GetTaggedEntries(CliMetadataHasCustomAttributeTag hasCustomAttrTag)
{
lock (this.syncObject)
{
TaggedEntryCollection result;
if (!lookupTable.TryGetValue(hasCustomAttrTag, out result))
{
lookupTable._Add(hasCustomAttrTag, result = new TaggedEntryCollection(this, hasCustomAttrTag));
}
return(result);
}
}
protected static void Reduce(TDFAState target, bool recognizer, Func <TDFAState, TDFAState, bool> additionalReducer = null)
{
int last = 0;
Repeat:
Dictionary <TDFAState, List <TDFAState> > forwardDuplications = new Dictionary <TDFAState, List <TDFAState> >();
List <TDFAState> flatForm = new List <TDFAState>();
flatForm.Add(target);
FlatlineState(target, flatForm);
flatForm = flatForm.Distinct().ToList();
bool[] found = new bool[flatForm.Count];
Parallel.For(0, flatForm.Count, i =>
//for (int i = 0; i < flatForm.Count; i++)
{
lock (found)
{
if (found[i])
{
return;
}
}
TDFAState iItem = flatForm[i];
/* *
* If the state is already being replaced,
* no need to check it again.
* */
if (recognizer)
{
/* *
* Merge backwards as well as forwards on cases where the
* exact way the match occurred is not important
* */
if (RecognizerTerminalEquivalencyCheck(iItem, i, flatForm, found, forwardDuplications))
{
return;
}
}
//Merge forward.
StateEquivalencyCheck(iItem, i, flatForm, found, recognizer, forwardDuplications, additionalReducer);
});
var maxReduces = (from f in flatForm
where f.IsReductionSite
where !forwardDuplications.Values.Any(reducedSet => reducedSet.Contains(f))
select f).ToArray();
var reductionZones = new ControlledDictionary <TDFAState, List <TDFAState> >();
foreach (var maximalReducer in maxReduces)
{
if (reductionZones.Values.Any(zone => zone.Contains(maximalReducer)))
{
continue;
}
reductionZones._Add(maximalReducer, (from k in maximalReducer.GetReductionZone()
where !forwardDuplications.Values.Any(reducedSet => reducedSet.Contains(k))
select k).ToList());
}
/* *
* Now we have the zones which need reduced to the max.
* *
* These are for optimization purposes where you know
* the order isn't important, but the data itself is.
* */
for (int i = 0; i < reductionZones.Count; i++)
{
var maxReduceSet = reductionZones.Values[i];
bool[] maxFound = new bool[maxReduceSet.Count];
for (int j = 0; j < maxReduceSet.Count; j++)
{
var iItem = maxReduceSet[j];
if (maxFound[j])
{
continue;
}
if (RecognizerTerminalEquivalencyCheck(iItem, i, maxReduceSet, maxFound, forwardDuplications))
{
continue;
}
StateEquivalencyCheck(iItem, j, maxReduceSet, maxFound, true, forwardDuplications, additionalReducer);
}
}
/* *
* Replace the states that are considered extraneous.
* */
foreach (var masterState in forwardDuplications.Keys)
{
var currentSet = forwardDuplications[masterState];
for (int i = 0; i < currentSet.Count; i++)
{
ReplaceState(masterState, currentSet[i]);
}
}
/* *
* If there were reductions performed in this step, repeat
* the process, since two states that didn't pass the equivalency
* examination pointed to two different, yet similar, states,
* the process can be repeated on these, now redundant, states.
* */
CondenseTransitions(target);
last = flatForm.Count;
flatForm.Clear();
if (forwardDuplications.Count > 0)
{
forwardDuplications.Clear();
//Reduces recursive dependency. No need to call the method again.
goto Repeat;
}
}