Exemplo n.º 1
0
        /// <summary>
        /// Get the identifier type of token
        /// </summary>
        private Token GetIdentifierToken()
        {
            Token token = new Token();

            do
            {
                token.Value += Char.ToUpper(GetSourceChar());
                SourceIndex++;
            }
            while (Char.IsLetterOrDigit(GetSourceChar()) || GetSourceChar().Equals('_'));

            token.Type = TokenType.Identifier;
            return token;
        }
Exemplo n.º 2
0
        /// <summary>
        /// Gets the number type of token
        /// </summary>
        private Token GetNumberToken()
        {
            Token token = new Token();

            do
            {
                token.Value += GetSourceChar();
                SourceIndex++;
            }
            while (Char.IsDigit(GetSourceChar()));

            token.Type = TokenType.Number;
            return token;
        }
Exemplo n.º 3
0
        /// <summary>
        /// Reads the next token from the code
        /// </summary>
        private Token ReadNextToken()
        {
            //Skip redundant data
            SkipWhitespace();

            Token nextToken = null;

            if (GetSourceChar().Equals('\n'))
            {
                CurrentLine++;
                nextToken = new Token();
                nextToken.Type = TokenType.EOL;
                nextToken.Line = CurrentLine - 1;
                SourceIndex++;
                return nextToken;
            }
            else if (Char.IsLetter(GetSourceChar()))
            {
                nextToken = GetIdentifierToken();
            }
            else if (Char.IsDigit(GetSourceChar()))
            {
                nextToken = GetNumberToken();
            }
            else if (GetSourceChar().Equals('\"'))
            {
                nextToken = GetStringToken();
            }
            else if ("(){}.,;*&[]<>=!+-/?".Contains(GetSourceChar()))
            {
                nextToken = GetSymbolToken();
            }
            else
            {
                Console.WriteLine("Error - undefined token");
            }

            nextToken.Line = CurrentLine;
            return nextToken;
        }
Exemplo n.º 4
0
        /// <summary>
        /// Gets the symbol type of token
        /// </summary>
        private Token GetSymbolToken()
        {
            Token token = new Token();

            token.Value += GetSourceChar();

            //In case of <=, >=, == or != we have two characters as token
            if ((GetSourceChar().Equals('<') || GetSourceChar().Equals('>') ||
                 GetSourceChar().Equals('!') || GetSourceChar().Equals('='))
                && GetNextSourceChar().Equals('='))
            {
                SourceIndex++;
                token.Value += GetSourceChar();
            }

            SourceIndex++;
            token.Type = TokenType.Symbol;

            return token;
        }
Exemplo n.º 5
0
        /// <summary>
        /// Gets the string type of token
        /// </summary>
        private Token GetStringToken()
        {
            //Skip the first quote mark
            SourceIndex++;

            Token token = new Token();

            do
            {
                //Can't EOL in middle of string
                if (GetSourceChar().Equals('\n'))
                    Console.WriteLine("Error - expected ending quotation mark");

                token.Value += GetSourceChar();
                SourceIndex++;
            }
            //Scan until end quote mark
            while (!GetSourceChar().Equals('\"'));

            SourceIndex++;
            token.Type = TokenType.String;

            return token;
        }
Exemplo n.º 6
0
        /// <summary>
        /// Parses all the tokens
        /// </summary>
        public void ParseProgram()
        {
            //Last Token must be EOL so add one in case
            Token eol = new Token();
            eol.Line = Tokens[Tokens.Count - 1].Line + 1;
            eol.Type = TokenType.EOL;
            eol.Value = "\n";
            Tokens.Add(eol);

            //Start at the first Token
            TokenIndex = 0;

            for (int line = 0; line < LineCount && GetCurrentToken() != null; line++)
            {

                Node currentNode = new Node();
                Node currentNodeMarker;

                if (!GetCurrentToken().Type.Equals(TokenType.EOL))
                {
                    currentNodeMarker = null;

                    if (line == LineCount - 1)
                    {
                        currentNode = ParseStatement(currentNode, ref currentNodeMarker);
                        RootNode.InsertFinal(currentNode);

                        if (currentNodeMarker != null)
                            RootNode.CurrentNode = currentNodeMarker;
                    }
                    else
                    {
                        RootNode.Insert("STATEMENTS", ParseStatement(currentNode, ref currentNodeMarker));

                        if (currentNodeMarker != null)
                            RootNode.CurrentNode = currentNodeMarker;
                    }
                }

                TokenIndex++;
            }

            RootNode.NullifyEmptyChildren();
        }