internal void removeDigrams(HashSet <Digram> removedDigrams)
{
foreach (var digram in removedDigrams)
{
if (!FirstOccurances.ContainsKey(digram))
{
continue;
}
//Debug.Assert(!FirstOccurances[digram].IsRule);
if (!FirstOccurances[digram].IsRule)
{
FirstOccurances.Remove(digram);
}
}
}
internal RecursionPoint setRule(LinkedListNode <Symbol> linkedListNode, Rule rule)
{
RecursionPoint todo = new RecursionPoint();
var adigramEntry = new DigramEntry(linkedListNode);
var olddigram = new Digram(linkedListNode.List.First);
{
var prev = adigramEntry.StartPoint.Previous;
if (prev != null)
{
todo.RemovedDigrams.Add(new Digram(prev));
}
var next = adigramEntry.StartPoint.Next;
if (next != null && next.Next != null)
{
todo.RemovedDigrams.Add(new Digram(next));
}
}
adigramEntry.Rule = rule;
var symbolpntr = rule.Symbols.First;
bool substituted = false;
while (symbolpntr != null)
{
var symbol = symbolpntr.Value;
if (!symbol.IsTerminal)
{
Rule pointedRule = (symbol as RuleInstance).Content;
pointedRule.deuse();
if (pointedRule.Count <= 1)
{
Debug.Assert(pointedRule.ID != rule.ID);
Debug.Print("substituting a rule:" + pointedRule.ID);
Debug.Print("into a rule:" + rule.ID);
substituted = true;
todo.DigramsToCheck.Add(symbolpntr.Previous);
var digram = new Digram(pointedRule.Symbols.First);
if (FirstOccurances.ContainsKey(digram))
{
FirstOccurances.Remove(digram);
}
if (RuleAnchors.ContainsKey(pointedRule.Symbols))
{
RuleAnchors.Remove(pointedRule.Symbols);
}
var movedsymbol = pointedRule.Symbols.First;
while (movedsymbol != null)
{
var next = movedsymbol.Next;
symbolpntr.List.AddBefore(symbolpntr, movedsymbol.Value);
todo.DigramsToCheck.Add(symbolpntr.Previous);
movedsymbol = next;
}
symbolpntr = symbolpntr.Previous;
rule.Symbols.Remove(symbolpntr.Next);
}
}
symbolpntr = symbolpntr.Next;
}
if (substituted)
{
Debug.Print("Removing old substitute rule " + olddigram.ToString());
this._FirstOccurances.Remove(olddigram);
todo.DigramsToCheck.Add(adigramEntry.StartPoint.Previous);
todo.DigramsToCheck.Add(adigramEntry.StartPoint);
}
else
{
if (adigramEntry.StartPoint.List.First.Next == adigramEntry.StartPoint.List.Last &&
this.RuleAnchors.ContainsKey(adigramEntry.StartPoint.List))
{
Debug.Print("refreshin a substitute rule:" + adigramEntry.ToString() + " -> " + this.RuleAnchors[adigramEntry.StartPoint.List].ToString());
this.FirstOccurances[new Digram(adigramEntry.StartPoint)] = this.RuleAnchors[adigramEntry.StartPoint.List];
}
else
{
todo.DigramsToCheck.Add(adigramEntry.StartPoint.Previous);
todo.DigramsToCheck.Add(adigramEntry.StartPoint);
}
}
return(todo);
}