public static void ExprGrammarCh4DragonBook()
{
var grammar = DragonBook_ExprGrammarCh4.GetGrammar();
// Create NFA (digraph of items labeled by symbols)
var characteristicStringsNfa = grammar.GetLr0AutomatonNfa();
SaveFile("DragonNCG.dot", DotLanguagePrinter.ToDotLanguage(characteristicStringsNfa, DotRankDirection.TopBottom));
var dfa = characteristicStringsNfa.ToDfa();
SaveFile("DragonDCG.dot", DotLanguagePrinter.ToDotLanguage(dfa, DotRankDirection.LeftRight, skipStateLabeling: true));
var dfa2 = grammar.GetLr0AutomatonDfa();
SaveFile("DragonDCGLr.dot", DotLanguagePrinter.ToDotLanguage(dfa2, DotRankDirection.LeftRight, skipStateLabeling: true));
var lexer = DragonBook_ExprGrammarCh4.GetLexer("a*a+a");
grammar.ComputeSlrParsingTable().Parse(lexer, Console.Out);
}
public void CreateSlrTable()
{
var grammar = DragonBook_ExprGrammarCh4.GetGrammar();
// Grammar is not LR(0)
grammar.ComputeLr0ParsingTable().AnyConflicts.ShouldBeTrue();
var parser = grammar.ComputeSlrParsingTable();
// Grammar is not SLR(1)
parser.AnyConflicts.ShouldBeFalse();
var writer = new TestWriter();
parser.PrintParsingTable(writer);
writer.WriteLine();
writer.WriteLine();
// "a*a+a"
var lexer = new FakeLexer <Sym>((Sym.ID, "a"), (Sym.ASTERISK, "*"), (Sym.ID, "a"), (Sym.PLUS, "+"),
(Sym.ID, "a"));
parser.Parse(lexer, writer);
}
