示例#1
0
        void ScanToken()
        {
            var character = Consume();

            switch (character)
            {
            case '(':
                ProduceToken(TokenType.LeftParen);
                break;

            case ')':
                ProduceToken(TokenType.RightParen);
                break;

            case '{':
                ProduceToken(TokenType.LeftBrace);
                break;

            case '}':
                ProduceToken(TokenType.RightBrace);
                break;

            case ',':
                ProduceToken(TokenType.Comma);
                break;

            case '.':
                ProduceToken(TokenType.Dot);
                break;

            case '-':
                ProduceToken(TokenType.Minus);
                break;

            case '+':
                ProduceToken(TokenType.Plus);
                break;

            case ';':
                ProduceToken(TokenType.SemiColon);
                break;

            case '*':
                ProduceToken(TokenType.Star);
                break;

            case '!':
                ProduceToken(MaybeConsume('=') ? TokenType.BangEqual : TokenType.Bang);
                break;

            case '=':
                ProduceToken(MaybeConsume('=') ? TokenType.EqualEqual : TokenType.Equal);
                break;

            case '<':
                ProduceToken(MaybeConsume('=') ? TokenType.LessEqual : TokenType.Less);
                break;

            case '>':
                ProduceToken(MaybeConsume('=') ? TokenType.GreaterEqual : TokenType.Greater);
                break;

            case '/':
                if (MaybeConsume('/'))
                {
                    while (Peek() != '\n' && !IsAtEnd())
                    {
                        Consume();
                    }
                }
                else
                {
                    ProduceToken(TokenType.Slash);
                }

                break;

            case '"':
                ProduceStringLiteral();
                break;

            case char digit when char.IsDigit(digit):
                ProduceNumericLiteral();

                break;

            case char alpha when char.IsLetter(alpha):
                ProduceIdentifier();

                break;

            case ' ':
            case '\t':
            case '\r':
                break;

            case '\n':
                _line++;
                break;

            default:
                Lox.StaticError(_line, $"Unexpected character '{character}'.");
                break;
            }
        }
示例#2
0
文件: Parser.cs 项目: mamidon/nlox
 Exception CreateStaticError(Token badToken, string message)
 {
     Lox.StaticError(badToken.Line, $"At '{badToken.Lexeme}'. {message}");
     return(new LoxStaticErrorException(badToken, message));
 }