C# (CSharp) Lexing.Scanners Scanner 예제들

예제 #1

        public static bool Scan(Lexer lexer, ref Token token)
        {
#if DEBUG
            if (lexer == null)
            {
                throw new ArgumentNullException(nameof(lexer));
            }

            Scanner.EnsureCurrent(lexer,
                                  '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', '.');
#endif

            Source src            = lexer.Src;
            string value          = string.Empty;
            bool   dotEncountered = false;
            bool   success        = true;

            while (!src.ReachedEnd())
            {
                char current = src.Current;
                char next    = src.Peek();

                if (dotEncountered && (next == '.'))
                {
                    src.Advance();
                    success = false;
                    break;
                }

                if (current == '.')
                {
                    dotEncountered = true;

                    if (!char.IsDigit(next))
                    {
                        success = false;
                        break;
                    }
                }
                else if (!char.IsDigit(current))
                {
                    break;
                }

                value += current;

                src.Advance();
            }

            if (success)
            {
                src.Reverse();
            }

            TokenType tokenType = dotEncountered
                ? TokenType.Float
                : TokenType.Int;

            token.Type  = tokenType;
            token.Value = value;

            return(success);
        }