public bool Parse()
{
bool fret = false;
Production pp = null;
object sym = Stack.Top();
SynthesizedAttribute syn = sym as SynthesizedAttribute;
if (syn != null)
{
if (syn.FireAction != null)
{
fret = syn.FireAction(Stack, pp);
if (fret == false)
{
return(fret);
}
}
Stack.Pop();
//DumpStack();
return(true);
}
SemanticAction sma = sym as SemanticAction;
if (sma != null)
{
Stack.Pop();
sym = Stack.Top();
}
InheritedAttribute inh = sym as InheritedAttribute;
if (inh != null)
{
if (token != TokenLookup.TokenKind.UnKnown)
{
pp = (Production)M[(int)inh.nTerm.Category, (int)token];
}
if (pp == null)
{
MessageBox.Show(" syntax error !");
return(false);
}
if (sma != null)
{
fret = sma.FireAction(Stack, pp, lexx.TokenValue); // copy inherited top down into next production fields
if (fret == false)
{
return(fret);
}
}
Stack.Pop();
for (int j = pp.rhs.Count - 1; j >= 0; j--)
{
Terminal tt = pp.rhs[j] as Terminal;
if (tt != null && tt.Token == TokenLookup.TokenKind.Lambda)
{
continue;
}
if (pp.synth != null && pp.synth[j] != null)
{
if (pp.synth[j] is SDeclTypeAttribute)
{
SDeclTypeAttribute sa = (SDeclTypeAttribute)pp.synth[j] as SDeclTypeAttribute;
Stack.Push(new SDeclTypeAttribute(sa));
}
pp.synth[j].Clear();
}
if (tt != null)
{
Stack.Push(pp.rhs[j]);
}
if (pp.inh != null && pp.inh[j] != null)
{
if (pp.inh[j] is IDeclTypeAttribute)
{
IDeclTypeAttribute ie = pp.inh[j] as IDeclTypeAttribute;
Stack.Push(new IDeclTypeAttribute(ie));
}
else
{
Stack.Push(new InheritedAttribute(pp.inh[j]));
}
pp.inh[j].Clear();
}
//}
if (pp.action != null && pp.action[j] != null)
{
Stack.Push(pp.action[j]);
}
}
//DumpStack();
}
else // is a Terminal or EOI
{
Terminal tt = sym as Terminal;
if (token == TokenLookup.TokenKind.EOI)
{
_curline = 1;
MessageBox.Show("stream successfully parsed ");
return(false);
}
else
if (token == tt.Token)
{
if (sma != null)
{
fret = sma.FireAction(Stack, null, lexx.TokenValue);
if (fret == false)
{
return(fret);
}
}
Stack.Pop();
token = lexx.getToken();
return(true);
}
else
{
MessageBox.Show("Unexpected token : " + token + ", expected : " + tt.Token);
return(false);
}
}
return(true);
}
