private void SkipWhitespace()
{
while (CharPredicates.IsWhitespace(_scanner.Peek()))
{
_scanner.Advance();
}
}
private void ReadIdentifier()
{
while (CharPredicates.IsLetterOrDigit(_scanner.Peek()))
{
// TODO string builder
next.Value += _scanner.Advance();
}
}
private TokenType GetOneCharToken(char c)
{
return
(oneCharTokenMap.ContainsKey(c) ? oneCharTokenMap[c] :
CharPredicates.IsDecimalPoint(c) ? TokenType.POINT :
CharPredicates.IsDigit(c) ? TokenType.NUMBER :
CharPredicates.IsWhitespace(c) ? TokenType.WHITESPACE :
CharPredicates.IsLetter(c) ? TokenType.INDETIFIER :
c == '\0' ? TokenType.EOE :
TokenType.ILLEGAL);
}
private bool ReadDigits()
{
bool read = false;
while (CharPredicates.IsDigit(_scanner.Peek()))
{
read = true;
next.Value += _scanner.Advance();
}
return(read);
}
private TokenType ReadNumber()
{
// TODO returning bool instead of token type
bool hasDigitsBeforePoint = false;
// bool hasDecimalPoint = false;
bool hasDigitsAfterPoint = false;
// bool hasExponentialNotation = false;
hasDigitsBeforePoint = ReadDigits();
if (CharPredicates.IsDecimalPoint(_scanner.Peek()))
{
// hasDecimalPoint = true;
next.Value += _scanner.Advance();
hasDigitsAfterPoint = ReadDigits();
}
if (!hasDigitsBeforePoint && !hasDigitsAfterPoint)
{
return(TokenType.ILLEGAL);
}
if (CharPredicates.IsExponentialNotation(_scanner.Peek()))
{
// hasExponentialNotation = true;
next.Value += _scanner.Advance();
if (CharPredicates.IsSignOperator(_scanner.Peek()))
{
next.Value += _scanner.Advance();
}
if (!CharPredicates.IsDigit(_scanner.Peek()))
{
return(TokenType.ILLEGAL);
}
ReadDigits();
}
return(TokenType.NUMBER);
}
