public Grammar transformToNonnullableGrammar(Grammar g)
{
List<Nonterminal> nonterminals = bulidNonterminalsForNonnullableGrammar(g);
Nonterminal distinguishedSymbol = distinguishedSymbolForNonnullableGrammar(g);
List<Rule> rules = buildRulesForNonnullableGrammar(g);
Grammar g1 = new Grammar(nonterminals, g.Terminals, rules, distinguishedSymbol);
g1.removeUnreachableSymbols();
g1.findVanishingSymbols();
return g1;
}
public override Grammar read(string fname)
{
Grammar g = new Grammar();
StreamReader sr = new StreamReader(fname);
string line;
// читаем нетерминалы
List<string> nonTerms = readBlock(sr);
nonTerms.ForEach(s => g.Nonterminals.Add(new Nonterminal(s)));
// читаем терминалы
List<string> terms = readBlock(sr);
terms.ForEach(s => g.Terminals.Add(new Terminal(s)));
// читаем правила
List<string> rules = readBlock(sr);
g.Rules = parseRules(rules, terms, nonTerms);
// читаем аксиому
string axiom = readAxiom(sr);
if (!nonTerms.Contains(axiom))
throw new FormatException("Некорректный формат файла.");
g.DistinguishedSymbol = new Nonterminal(axiom);
sr.Close();
g.findVanishingSymbols();
return g;
}