private HashSet <ISymbol> CreateRightRecursiveSymbols(
IDottedRuleRegistry dottedRuleRegistry,
Dictionary <ISymbol, UniqueList <ISymbol> > symbolPaths)
{
var hashSet = new HashSet <ISymbol>();
for (var p = 0; p < _productions.Count; p++)
{
var production = _productions[p];
var position = production.RightHandSide.Count;
var completed = dottedRuleRegistry.Get(production, position);
var symbolPath = symbolPaths[production.LeftHandSide];
for (var s = position; s > 0; s--)
{
var preDotSymbol = production.RightHandSide[s - 1];
if (preDotSymbol.SymbolType != SymbolType.NonTerminal)
{
break;
}
var preDotNonTerminal = preDotSymbol as INonTerminal;
if (symbolPath.Contains(preDotNonTerminal))
{
hashSet.Add(production.LeftHandSide);
break;
}
if (!IsTransativeNullable(preDotNonTerminal))
{
break;
}
}
}
return(hashSet);
}
public Grammar(
INonTerminal start,
IReadOnlyList <IProduction> productions,
IReadOnlyList <ILexerRule> ignoreRules,
IReadOnlyList <ILexerRule> triviaRules)
{
_productions = new IndexedList <IProduction>();
_ignores = new IndexedList <ILexerRule>();
_trivia = new IndexedList <ILexerRule>();
_transativeNullableSymbols = new UniqueList <INonTerminal>();
_symbolsReverseLookup = new Dictionary <INonTerminal, UniqueList <IProduction> >();
_lexerRules = new IndexedList <ILexerRule>();
_leftHandSideToProductions = new Dictionary <INonTerminal, List <IProduction> >();
_dottedRuleRegistry = new DottedRuleRegistry();
_symbolPaths = new Dictionary <ISymbol, UniqueList <ISymbol> >();
Start = start;
AddProductions(productions ?? EmptyProductionArray);
AddIgnoreRules(ignoreRules ?? EmptyLexerRuleArray);
AddTriviaRules(triviaRules ?? EmptyLexerRuleArray);
_rightRecursiveSymbols = CreateRightRecursiveSymbols(_dottedRuleRegistry, _symbolPaths);
FindNullableSymbols(_symbolsReverseLookup, _transativeNullableSymbols);
}
public ParseEngine(IGrammar grammar, ParseEngineOptions options)
{
_dottedRuleRegistry = new GrammarSeededDottedRuleRegistry(grammar);
StateFactory = new StateFactory(_dottedRuleRegistry);
Options = options;
_nodeSet = new ForestNodeSet();
Grammar = grammar;
Initialize();
}
public StateFactory(IDottedRuleRegistry dottedRuleRegistry)
{
DottedRuleRegistry = dottedRuleRegistry;
}
