internal static int HandleHex(CharacterStream cs, int start)
{
while (CharacterStream.IsHex(cs.CurrentChar))
{
cs.MoveToNextChar();
}
// TODO: handle C99 floating point hex syntax like 0x1.1p-2
if (cs.CurrentChar == 'L')
{
cs.MoveToNextChar();
}
return(cs.Position - start);
}
// public static object CharacterSteam { get; private set; }
public static int HandleNumber(CharacterStream cs)
{
int start = cs.Position;
if (cs.CurrentChar == '-' || cs.CurrentChar == '+')
{
cs.MoveToNextChar();
}
if (cs.CurrentChar == '0' && cs.NextChar == 'x')
{
cs.Advance(2);
return(HandleHex(cs, start));
}
if (cs.CurrentChar == 'x' && CharacterStream.IsHex(cs.NextChar))
{
cs.MoveToNextChar();
return(HandleHex(cs, start));
}
int integerPartStart = cs.Position;
int integerPartLength = 0;
int fractionPartLength = 0;
bool isDouble = false;
// collect decimals (there may be none like in .1e+20
while (cs.IsDecimal())
{
cs.MoveToNextChar();
integerPartLength++;
}
if (cs.CurrentChar == '.')
{
isDouble = true;
// float/double
cs.MoveToNextChar();
// If we've seen don we need to collect factional part of any
while (cs.IsDecimal())
{
cs.MoveToNextChar();
fractionPartLength++;
}
}
if (integerPartLength + fractionPartLength == 0)
{
return(0); // +e or +.e is not a number and neither is lonely + or -
}
int numberLength;
if (cs.CurrentChar == 'e' || cs.CurrentChar == 'E')
{
isDouble = true;
numberLength = HandleExponent(cs, start);
}
else
{
numberLength = cs.Position - start;
}
// Verify double format
if (isDouble && !IsValidDouble(cs, start, cs.Position))
{
numberLength = 0;
}
if (numberLength > 0)
{
// skip over trailing 'L' if any
if (cs.CurrentChar == 'L')
{
cs.MoveToNextChar();
numberLength++;
}
}
return(numberLength);
}