static void Parse(GrammarSymbol symbol)
{
if (!errorEncountered)
{
if (symbol is Nonterminal)
{
Nonterminal n = symbol as Nonterminal;
/*Console.WriteLine(n.name);
* Console.ReadLine();*/
int currentPaths = 0;
foreach (Transition t in n.transitions)
{
currentPaths++;
//Console.WriteLine("I am {0} paths deep in {1}.", currentPaths, n.name);
wrongPath = false;
foreach (GrammarSymbol g in t.symbols)
{
Parse(g);
if (wrongPath)
{
break;
}
}
if (!wrongPath)
{
break;
}
}
}
else
{
Terminal term = symbol as Terminal;
Token t = tz.GetNextToken();
if (t.type == TokenType.ERROR)
{
errorEncountered = true;
}
else
{
/*Console.WriteLine("{0} vs {1}", t.type.ToString(), term.matchesToken.type.ToString());
* Console.ReadLine();*/
if (t.type != term.matchesToken.type)
{
wrongPath = true;
}
else
{
tz.GetNextToken(true);
}
}
}
}
}
/// <summary>
/// Создание нового экземпляра инструкции компилятору.
/// </summary>
/// <param name="Source">Источник, кто добавил в компилятор запись.</param>
/// <param name="Helper">Дополнительная информация о результатах парсера.</param>
public ParserToken(Nonterminal Source, RuleOperator CurrentRule, int Helper = int.MinValue, ulong Id = ulong.MaxValue)
{
this.Source = Source;
this.CurrentRule = CurrentRule;
this.Helper = Helper;
if (Id != ulong.MaxValue)
{
this.Id = Id;
}
else
{
this.Id = ran.NextULong();
}
}
public ParserLang(Nonterminal mainNonterminal) => this.mainNonterminal = mainNonterminal ?? throw new ArgumentNullException(nameof(mainNonterminal));
static void Main(string[] args)
{
if (args.Length != 1) //Wrong number of command line arguments
{
Console.WriteLine("Usage: Parser.exe <name of file>");
}
else
{
#region GrammarSetup
//Terminals
Terminal grammarOperator = new Terminal(new Token(TokenType.OPERATOR));
Terminal identifier = new Terminal(new Token(TokenType.IDENTIFIER));
Terminal integer = new Terminal(new Token(TokenType.INT));
Terminal openParen = new Terminal(new Token(TokenType.OPEN_PAREN));
Terminal closeParen = new Terminal(new Token(TokenType.CLOSE_PAREN));
Terminal begin = new Terminal(new Token(TokenType.BEGIN));
Terminal end = new Terminal(new Token(TokenType.END));
Terminal read = new Terminal(new Token(TokenType.READ));
Terminal write = new Terminal(new Token(TokenType.WRITE));
Terminal comma = new Terminal(new Token(TokenType.COMMA));
Terminal semicolon = new Terminal(new Token(TokenType.SEMICOLON));
Terminal assignment = new Terminal(new Token(TokenType.ASSIGNMENT));
//Nonterminals
Nonterminal expr = new Nonterminal();
expr.name = "expr";
Nonterminal ident = new Nonterminal(new Transition(identifier));
ident.name = "ident";
Nonterminal op = new Nonterminal(new Transition(grammarOperator));
op.name = "op";
Nonterminal factor = new Nonterminal(new Transition(openParen, expr, closeParen), new Transition(integer), new Transition(ident));
factor.name = "factor";
Nonterminal expr_tail = new Nonterminal();
expr_tail.name = "expr_tail";
expr_tail.AddTransition(new Transition(op, factor, expr_tail));
expr_tail.AddTransition(new Transition());
expr.AddTransition(new Transition(factor, expr_tail));
expr.AddTransition(new Transition());
Nonterminal expr_list_tail = new Nonterminal();
expr_list_tail.name = "expr_list_tail";
expr_list_tail.AddTransition(new Transition(comma, expr, expr_list_tail));
expr_list_tail.AddTransition(new Transition());
Nonterminal expr_list = new Nonterminal(new Transition(expr, expr_list_tail));
expr_list.name = "expr_tail";
Nonterminal id_list_tail = new Nonterminal();
id_list_tail.name = "id_list_tail";
id_list_tail.AddTransition(new Transition(comma, ident, id_list_tail));
id_list_tail.AddTransition(new Transition());
Nonterminal id_list = new Nonterminal(new Transition(ident, id_list_tail));
id_list.name = "id_list";
Nonterminal stmt = new Nonterminal(new Transition(ident, assignment, expr, semicolon), new Transition(read, openParen, id_list, closeParen, semicolon), new Transition(write, openParen, expr_list, closeParen, semicolon));
stmt.name = "stmt";
Nonterminal stmt_list_tail = new Nonterminal();
stmt_list_tail.name = "stmt_list_tail";
stmt_list_tail.AddTransition(new Transition(stmt, stmt_list_tail));
stmt_list_tail.AddTransition(new Transition());
Nonterminal stmt_list = new Nonterminal(new Transition(stmt, stmt_list_tail));
stmt_list.name = "stmt_list";
Nonterminal program = new Nonterminal(new Transition(begin, stmt_list, end));
program.name = "program";
#endregion
tz = new Tokenizer(File.ReadAllText(args[0]));
Parse(program);
if (errorEncountered)
{
Console.WriteLine(tz.GetNextToken().name);
}
else if (tz.sourceString.Length != 0)
{
switch (tz.GetNextToken().type)
{
case TokenType.ASSIGNMENT:
Console.WriteLine("Error 2: Unexpected assignment at position {0}.", tz.currentPosition);
break;
case TokenType.BEGIN:
Console.WriteLine("Error 3: Unexpected BEGIN at position {0}.", tz.currentPosition);
break;
case TokenType.CLOSE_PAREN:
Console.WriteLine("Error 4: Unexpected ) at position {0}.", tz.currentPosition);
break;
case TokenType.COMMA:
Console.WriteLine("Error 5: Unexpected , at position {0}.", tz.currentPosition);
break;
case TokenType.IDENTIFIER:
Console.WriteLine("Error 6: Unexpected identifier {0} at position {1}.", tz.GetNextToken().name, tz.currentPosition);
break;
case TokenType.INT:
Console.WriteLine("Error 7: Unexpected integer at position {0}.", tz.currentPosition);
break;
case TokenType.OPEN_PAREN:
Console.WriteLine("Error 8: Unexpected ( at position {0}.", tz.currentPosition);
break;
case TokenType.OPERATOR:
Console.WriteLine("Error 9: Unexpected {0} at position {1}.", tz.GetNextToken().name, tz.currentPosition);
break;
case TokenType.READ:
Console.WriteLine("Error 10: Unexpected read at position {0}.", tz.currentPosition);
break;
case TokenType.SEMICOLON:
Console.WriteLine("Error 11: Unexpected ; at position {0}.", tz.currentPosition);
break;
case TokenType.WRITE:
Console.WriteLine("Error 12: Unexpected write at position {0}.", tz.currentPosition);
break;
}
}
else
{
Console.WriteLine("File parsed successfully with no errors.");
}
}
}