// <Factor> ::= "PRODNAME" |
// "STRING" |
// "(" <Expression> ")" |
// "[" <Expression> "]" |
// "{" <Expression> "}" .
private void ParseFactor()
{
ParseAction();
_astBuilder.BeginFactor(_scanner.CurrentToken);
switch (_scanner.CurrentToken.TokenKind)
{
case TokenKind.Identifier:
_astBuilder.FoundProduction(_scanner.CurrentToken);
_scanner.Advance();
break;
case TokenKind.String:
_astBuilder.FoundTerminal(_scanner.CurrentToken);
_scanner.Advance();
break;
case TokenKind.LeftParen:
_astBuilder.BeginParens(_scanner.CurrentToken);
_scanner.Advance();
ParseExpression();
Match(TokenKind.RightParen);
_astBuilder.EndParens();
_scanner.Advance();
break;
case TokenKind.LeftBracket:
_astBuilder.BeginOption(_scanner.CurrentToken);
_scanner.Advance();
ParseExpression();
Match(TokenKind.RightBracket);
_astBuilder.EndOption();
_scanner.Advance();
break;
case TokenKind.LeftBrace:
_astBuilder.BeginKleene(_scanner.CurrentToken);
_scanner.Advance();
ParseExpression();
Match(TokenKind.RightBrace);
_astBuilder.EndKleene();
_scanner.Advance();
break;
}
ParseAction();
_astBuilder.EndFactor();
}
