/// <summary>
/// Reads the next token from the stream and returns a Const Int that
/// it represents. If it doens't, throws an exception.
/// </summary>
public int ReadNextAsConstInt()
{
Token nextToken = PeekNextToken();
if (nextToken.Type == TokenType.Constant)
{
ReadNextToken();
return((int)nextToken.Value);
}
LiteralToken next = ReadNextAsLiteral();
if (!next.IsInteger)
{
throw new CompilerMessage(ErrorCode.ConstIntExpected, "A constant integer was expected at '" + next.Name + "'");
}
return(Convert.ToInt32(next.Name));
}
/// <summary>
/// Reads the next token from the stream. If it's not a literal,
/// throws an exception.
/// </summary>
private LiteralToken ReadNextAsLiteral()
{
Token nextToken = ReadNextToken();
bool isNegative = false;
if ((nextToken is OperatorToken) &&
(nextToken.Name == "-"))
{
isNegative = true;
nextToken = ReadNextToken();
}
if (!(nextToken is LiteralToken))
{
throw new CompilerMessage(ErrorCode.UnexpectedToken, "Literal expected at '" + nextToken.Name + "'");
}
Token tokenToReturn = nextToken;
if (isNegative)
{
if (_source == null)
{
throw new CompilerMessage(ErrorCode.InternalError, "Internal error: attempted to use tokenized script with no source");
}
tokenToReturn = _source.FindTokenWithName("-" + nextToken.Name);
if (tokenToReturn == null)
{
tokenToReturn = new LiteralToken("-" + nextToken.Name);
_source.AddToken(tokenToReturn);
}
}
return (LiteralToken)tokenToReturn;
}