/// <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);
}
/// <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);
}
/// <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));
}