public List <State> advanceOneObject()
{
if (completedStack
// || minimumTerminalsLeftToComplete() > terminalsLeft()
)
{
return(new List <State>());
}
//if(completedStack) return new List<State> {this};
SyntaticObject syntaticObject = stack.Pop();
State nextState = new State(this);
ParseNode nextAvailable = nextState.findNextAvailableNode();
if (syntaticObject is Terminal)
{
Terminal terminal = syntaticObject as Terminal;
if (terminal.token == currentChar + "")
{
nextState.advanceOneChar();
new StringNode(nextAvailable as CategoryNode, terminal.token);
return(new List <State> {
nextState
});
}
return(new List <State>());
}
if (syntaticObject is Token)
{
Token terminal = syntaticObject as Token;
if (terminal.token == currentToken)
{
nextState.advanceOneToken();
new StringNode(nextAvailable as CategoryNode, terminal.token);
return(new List <State> {
nextState
});
}
return(new List <State>());
}
if (syntaticObject is Category)
{
Category category = syntaticObject as Category;
List <State> output = new List <State>();
if (!category.StrictTokenUsage)
{
foreach (SyntaticObject[] syntaticObjects in category)
{
nextState = new State(this);
Stack <SyntaticObject> s = nextState.stack;
for (var i = syntaticObjects.Length - 1; i >= 0; i--)
{
s.Push(syntaticObjects[i]);
}
new CategoryNode(nextState.findNextAvailableNode(), category, syntaticObjects.Length);
nextState.index = index;
output.Add(nextState);
}
}
else
{
PushDownAutomata internalDriver = new PushDownAutomata(new string[0], nextState.currentToken, category);
ParseTree tokenParse = internalDriver.parse();
if (tokenParse != null && tokenParse.success)
{
nextState.findNextAvailableNode().Add(tokenParse);
nextState.advanceOneToken();
output.Add(nextState);
}
}
return(output);
}
return(null);
}