コード例 #1
0
ファイル: MalReader.cs プロジェクト: KineticLensman/JK-s-Lisp
 static public MalVal read_str_multiline(Reader rdr)
 {
     return(read_form(rdr));
 }
コード例 #2
0
ファイル: MalReader.cs プロジェクト: KineticLensman/JK-s-Lisp
        static public MalVal read_atom(Reader reader)
        {
            // "If you have a problem and you think regex is the answer, now you have two problems!"
            // Unlike the referenceC#-Mal, read_atom handles floats and badly-formed symbols.
            string tokenToRead = reader.Next();

            if (tokenToRead.Length <= 0)
            {
                throw new MalInternalError("Reader has returned empty string");
            }
            switch (tokenToRead[0])
            {
            case '+':
                if (tokenToRead.Length == 1)
                {
                    // Token is a solo '+', not the beginning of a number.
                    return(new MalSym(tokenToRead));
                }
                // Skip the sign and extract a positive number;
                return(ParseNumber(tokenToRead.Substring(1), true));

            case '-':
                if (tokenToRead.Length == 1)
                {
                    // Token is a solo '-', not the beginning of a number.
                    return(new MalSym(tokenToRead));
                }
                // Skip the sign and extract a negative number;
                return(ParseNumber(tokenToRead.Substring(1), false));

            case '.':
                // An initial '.' is only allowed at the start of a number, as in '.2'.
                return(ParseNumber(tokenToRead, true));

            case '\"':
                if (tokenToRead.EndsWith("\""))
                {
                    return(new MalString(tokenToRead));
                }
                // TODO - never reaches this point. The reader regex seems to throw away '"' chars if there is only 1.
                throw new MalParseError("String '" + tokenToRead + "' lacks a closing thingy");

            case ':':
                // Handle a keyword
                if (tokenToRead.Length == 1)
                {
                    // Can't have a solo colon.
                    throw new MalParseError("':' must be followed by a keyword");
                }
                return(new MalKeyword(tokenToRead));

            default:
                if (IsDigit(tokenToRead[0].ToString()))
                {
                    // Token seems to be an unsigned number.
                    return(ParseNumber(tokenToRead, true));
                }
                else if (tokenToRead == "nil")
                {
                    return(malNil);
                }
                else if (tokenToRead == "true")
                {
                    return(malTrue);
                }
                else if (tokenToRead == "false")
                {
                    return(malFalse);
                }
                else
                {
                    // If here it is 'just' a symbol.
                    return(new MalSym(tokenToRead));
                }
            }
            throw new MalInternalError("Can't process '" + tokenToRead + "'");
        }