public void AddProductionRule(string[] ProductionVector)
{
foreach (var ProdRule in _ProductionRules)
{
if (ProdRule._LHS == ProductionVector[0])
{
ProdRule._RHS.Add(ProductionVector[1]);
return;
}
}
ProductionRule NewRule = new ProductionRule(ProductionVector);
_ProductionRules.Add(NewRule);
}
private void RemoveLeftRecursion(string NonTermianl)
{
//facem o copie a listei de reguli de productie pentru Nonterminalul dat ca parametru
List <string> ProdRules = new List <string>();
foreach (var Rules in _Grammar._ProductionRules)
{
if (Rules._LHS == NonTermianl)
{
Rules._RHS.ForEach(s => ProdRules.Add(s));
break;
}
}
//Cream lista cu regulile de productie ce au recursivitate stanga
var LeftRec = (from Rule in ProdRules
where Rule.StartsWith(NonTermianl)
select Rule).ToList();
if (LeftRec.Count() == 0)
{
return;
}
//Cream lista cu regulile de productie ce nu au recursivitate stanga
var NoLeftRec = ProdRules.Except(LeftRec).ToList();
//Cream Nonterminul care trebuie adaugat
string ToAddNonTerminal = _Grammar.CreateNewNonterminal(NonTermianl);
_Grammar._Nonterminals.Add(ToAddNonTerminal);
//Scoatem din regulile de productie Nonterminalul care creeaza problema si adaug noul nonterminal
for (int i = 0; i < LeftRec.Count(); i++)
{
LeftRec[i] = LeftRec[i].Substring(NonTermianl.Length + 1) + " " + ToAddNonTerminal;
}
//Creez Regulile de productie pentru noul terminal si le adaug
LeftRec.Add("ε");
ProductionRule NewRules = new ProductionRule(ToAddNonTerminal, LeftRec);
_Grammar._ProductionRules.Add(NewRules);
//Golesc lista de reguli de productie pentru Nonterminalul dat ca parametru
int IndexOfNonterm = _Grammar._ProductionRules.FindIndex(a => a._LHS == NonTermianl);
_Grammar._ProductionRules.ElementAt(IndexOfNonterm)._RHS.Clear();
if (NoLeftRec == null)
{
_Grammar._ProductionRules.ElementAt(IndexOfNonterm)._RHS.Add(ToAddNonTerminal);
}
else
{
for (int i = 0; i < NoLeftRec.Count(); i++)
{
if (NoLeftRec[i] == "ε")
{
NoLeftRec[i] = ToAddNonTerminal;
}
else
{
NoLeftRec[i] += " " + ToAddNonTerminal;
}
}
_Grammar._ProductionRules.ElementAt(IndexOfNonterm)._RHS = NoLeftRec;
}
return;
}
