public string[] Generate()
{
List <string> generatedString = new List <string>();
var results = new HashSet <PDAResult>();
string[] startStackArray = new string[] { initialStackSymbol };
var condition = new PDACondition(new Stack <string>(), new Stack <string>(startStackArray), 0);
while (true)
{
var nextTransitions = FindNextTransitionsForGenerating(condition);
if (nextTransitions.Any())
{
int index = random.Next(0, nextTransitions.Count());
var nextTransition = nextTransitions.ElementAt(index);
if (nextTransition.readFromInput != "")
{
generatedString.Add(nextTransition.readFromInput);
condition.currentInput.Push(nextTransition.readFromInput);
}
condition = ApplyTransition(nextTransition, condition);
}
else
{
break;
}
}
return(generatedString.ToArray());
}
private static PDACondition ApplyTransition(PDATransition transition, PDACondition condition)
{
var newCurrentInput = new Stack <string>(new Stack <string>(condition.currentInput));
var newStack = new Stack <string>(new Stack <string>(condition.stack));
//We always pop something from stack
newStack.Pop();
//If we should read something from input, we remove it from current input
if (transition.readFromInput != "")
{
newCurrentInput.Pop();
}
//Pushing elements to stack
foreach (string elementToPush in transition.pushToStack.Reverse())
{
if (elementToPush != "")
{
newStack.Push(elementToPush);
}
}
return(new PDACondition(newCurrentInput, newStack, transition.nextState));
}
private IEnumerable <PDATransition> FindNextTransitionsForGenerating(PDACondition condition)
{
return(from transition in transitions
where transition.IsSuitableForGenerating(condition)
select transition);
}
private IEnumerable <PDACondition> FindNextConditions(PDACondition condition)
{
return(from transition in transitions
where transition.IsSuitable(condition)
select ApplyTransition(transition, condition));
}
public bool IsSuitableForGenerating(PDACondition condition)
{
return(condition.stack.Count > 0 && condition.state == state && condition.stack.Peek() == popFromStack);
}
public bool IsSuitable(PDACondition condition)
{
return((condition.stack.Count > 0 && condition.state == state && condition.stack.Peek() == popFromStack) && (readFromInput == "" || (condition.currentInput.Count > 0 && readFromInput == condition.currentInput.Peek())));
}
