public ParserEngine(TransitionTable transitions, SyntaxErrors errorDef)
{
CodeContract.RequiresArgumentNotNull(transitions, "transitions");
CodeContract.RequiresArgumentNotNull(errorDef, "errorDef");
m_transitions = transitions;
m_reducer = new ReduceVisitor(transitions);
m_heads = new List <ParserHead>();
m_shiftedHeads = new List <ParserHead>();
m_acceptedHeads = new List <ParserHead>();
m_errorCandidates = new List <ParserHead>();
m_tempHeads = new List <ParserHead>();
m_reducedHeads = new List <ParserHead>();
m_recoverReducedHeads = new List <ParserHead>();
m_errorDef = errorDef;
m_cleaner = new ParserHeadCleaner();
EnableDeletionRecovery = true;
EnableInsertionRecovery = true;
EnableReplacementRecovery = true;
//init state
m_heads.Add(new ParserHead(new StackNode(0, null, null)));
}
public void Reduce(IProduction production, ReduceVisitor reducer, Lexeme lookahead)
{
#if HISTORY
var from = m_topStack.StateIndex;
#endif
if (production == null)
{
//Accept
Debug.Assert(m_topStack.PrevNode.StateIndex == 0);
//TODO: accepted
IsAccepted = true;
return;
}
if (production.AggregatesAmbiguities)
{
AmbiguityAggregator = ((ProductionBase)production).CreateAggregator();
}
var reduceResult = production.Accept(reducer, m_topStack);
m_topStack = reduceResult.NewTopStack;
var reduceError = reduceResult.ReduceError;
if (reduceError != null)
{
IncreaseErrorRecoverLevel();
if (reduceError.ErrorPosition == null)
{
reduceError = new ErrorRecord(reduceError.ErrorId, lookahead.Value.Span);
}
AddError(reduceError);
}
#if HISTORY
var to = m_topStack.StateIndex;
History.Add(String.Format("R{0}:{1}", from, to));
#endif
}