Ejemplo n.º 1
0
        /// <summary>
        /// Fastforwards to the source code's end.
        /// </summary>
        /// <returns>The last token, namely the EOF token.</returns>
        /// <param name="ex">An UnexpectedTokenException.</param>
        private Token FastForwardToSourceEnd(UnexpectedTokenException ex)
        {
            // report the error
            notifyError(new SyntaxError(ex.Token, ex.ExpectedType, ex.ExpectationSet));

            syntaxTreeBuilt = false;
            Token token;

            // ask for new token's until the end of file has been reached
            do
            {
                token = scanner.getNextToken(null);
            } while (token.Type != TokenType.END_OF_FILE);

            return(token);
        }
Ejemplo n.º 2
0
        /// <summary>
        /// Fastforwards to the end of a for-loop block.
        /// </summary>
        /// <returns>The token that ends the for-loop block</returns>
        /// <param name="ex">An UnexpectedTokenException.</param>
        private Token FastForwardToEndOfBlock(UnexpectedTokenException ex)
        {
            notifyError(new SyntaxError(ex.Token, ex.ExpectedType, ex.ExpectationSet));
            Token token = ex.Token;
            // since blocks can be nested, we must track the depth we're in to make sure
            // we find the correct end statement
            int  blockDepth    = 0;
            bool blockEndFound = false;

            while (token.Type != TokenType.END_OF_FILE)
            {
                if (token.Type == TokenType.END_OF_BLOCK)                               // if an end of block is found
                {
                    if (blockDepth == 0)                                                // and the depth matches
                    {
                        return(scanner.getNextToken(null));                             // return the next token
                    }
                    blockEndFound = true;
                }
                else if (token.Type == TokenType.FOR_LOOP)                      // if we find another for-loop token
                {
                    if (blockEndFound)                                          // and the last token was an end block token
                    {
                        blockDepth--;                                           // decrease the depth
                        blockEndFound = false;
                    }
                    else
                    {
                        blockDepth++;                                                                           // otherwise, increase the depth
                    }
                }
                else
                {
                    blockEndFound = false;
                }
                token = scanner.getNextToken(null);
            }

            return(token);
        }
Ejemplo n.º 3
0
        /// <summary>
        /// Fastforwards to the statement's end.
        /// </summary>
        /// <returns>The token that ends the statement.</returns>
        /// <param name="ex">An UnexpectedTokenException.</param>
        private Token FastForwardToStatementEnd(UnexpectedTokenException ex)
        {
            notifyError(new SyntaxError(ex.Token, ex.ExpectedType, ex.ExpectationSet));

            return(FastForwardTo(ParserConstants.STATEMENT_FASTFORWARD_TO, ex.Token));
        }