public static String ScanDecimalString(this TextReader reader, NumericSignMode mode, CultureInfo culture)
{
CultureInfo usedCulture = culture == null ? CultureInfo.CurrentCulture : culture;
String numeric = reader.ScanNumericString(mode);
if (numeric == null)
{
return(null);
}
if (!reader.Skip(usedCulture.NumberFormat.NumberDecimalSeparator))
{
return(numeric);
}
String decimals = reader.ScanNumericString(NumericSignMode.AllowNone);
if (decimals == null)
{
return(null);
}
StringBuilder builder = new StringBuilder().Append(numeric).Append(usedCulture.NumberFormat.NumberDecimalSeparator).Append(decimals);
if (reader.Skip('e'))
{
String shifterNumeric = reader.ScanNumericString(NumericSignMode.RequireOne);
if (shifterNumeric != null)
{
builder.Append('e').Append(shifterNumeric);
}
}
return(builder.ToString());
}
public static String ScanDecimalString(this TextReader reader, NumericSignMode mode)
{
return(ScanDecimalString(reader, mode, null));
}
public static String ScanNumericString(this TextReader reader, NumericSignMode mode)
{
StringBuilder builder = new StringBuilder();
while (true)
{
int intCh = reader.Peek();
if (intCh == '-' || intCh == '+')
{
if (builder.Length > 0)
{
return(builder.ToString());
}
switch (mode)
{
case NumericSignMode.AllowNone:
return(null);
default:
if (intCh == '-' && (mode == NumericSignMode.AllowPlusOnly || mode == NumericSignMode.RequirePlus))
{
return(null);
}
else if (intCh == '+' && (mode == NumericSignMode.AllowMinusOnly || mode == NumericSignMode.RequireMinus))
{
return(null);
}
break;
}
}
else if (intCh == -1 || (intCh < '0' || intCh > '9'))
{
if (builder.Length == 0)
{
return(null);
}
return(builder.ToString());
}
if (builder.Length == 0)
{
switch (mode)
{
case NumericSignMode.RequireOne:
if (intCh != '-' && intCh != '+')
{
return(null);
}
break;
case NumericSignMode.RequirePlus:
if (intCh != '+')
{
return(null);
}
break;
case NumericSignMode.RequireMinus:
if (intCh != '-')
{
return(null);
}
break;
}
}
builder.Append((Char)reader.Read());
}
}
