public static string LexCsharpUnicodeVariableLenCharEscape(LexReader reader)
{
string sequence = reader.ConsumeStringWhile(IsHexadecimalDigit, 4);
if (sequence.Length == 0)
{
throw new LexException(reader.GetPosition(), "Unicode escape sequence is too short (requires at least one hex digit).");
}
return(((char)int.Parse(sequence, NumberStyles.HexNumber)).ToString());
}
public static string Lex0xHexInteger(LexReader reader)
{
if (!reader.ContinuesWith("0x") && !reader.ContinuesWith("0X"))
return null;
reader.Consume(2);
string result = reader.ConsumeStringWhile(IsHexadecimalDigit);
if (result.Length == 0)
throw new LexException(reader.GetPosition(-2), "Hexadecimal integers starting with the \"0x\" prefix must have at least one hex digit.");
return (result.Length == 0) ? null : result;
}
public static string Lex0xHexInteger(LexReader reader)
{
if (!reader.ContinuesWith("0x") && !reader.ContinuesWith("0X"))
{
return(null);
}
reader.Consume(2);
string result = reader.ConsumeStringWhile(IsHexadecimalDigit);
if (result.Length == 0)
{
throw new LexException(reader.GetPosition(-2), "Hexadecimal integers starting with the \"0x\" prefix must have at least one hex digit.");
}
return((result.Length == 0) ? null : result);
}
public static string LexCsharpUnicodeFixedLenCharEscape(LexReader reader, bool islong)
{
string numberOfChars = islong ? "eight" : "four";
int numChars = islong ? 8 : 4;
string sequence = reader.ConsumeStringWhile(IsHexadecimalDigit, numChars);
if (sequence.Length < numChars)
{
throw new LexException(reader.GetPosition(), "Unicode escape sequence is too short (requires {0} hex digits).".Fmt(numberOfChars));
}
if (islong)
{
return(char.ConvertFromUtf32(int.Parse(sequence, NumberStyles.HexNumber)));
}
else
{
return(new string((char)int.Parse(sequence, NumberStyles.HexNumber), 1));
}
}
public static string LexDecimalInteger(LexReader reader)
{
string result = reader.ConsumeStringWhile(IsDecimalDigit);
return((result.Length == 0) ? null : result);
}
public static string LexDecimalInteger(LexReader reader)
{
string result = reader.ConsumeStringWhile(IsDecimalDigit);
return (result.Length == 0) ? null : result;
}
public static string LexCsharpUnicodeVariableLenCharEscape(LexReader reader)
{
string sequence = reader.ConsumeStringWhile(IsHexadecimalDigit, 4);
if (sequence.Length == 0)
throw new LexException(reader.GetPosition(), "Unicode escape sequence is too short (requires at least one hex digit).");
return ((char) int.Parse(sequence, NumberStyles.HexNumber)).ToString();
}
public static string LexCsharpUnicodeFixedLenCharEscape(LexReader reader, bool islong)
{
string numberOfChars = islong ? "eight" : "four";
int numChars = islong ? 8 : 4;
string sequence = reader.ConsumeStringWhile(IsHexadecimalDigit, numChars);
if (sequence.Length < numChars)
throw new LexException(reader.GetPosition(), "Unicode escape sequence is too short (requires {0} hex digits).".Fmt(numberOfChars));
if (islong)
return char.ConvertFromUtf32(int.Parse(sequence, NumberStyles.HexNumber));
else
return new string((char) int.Parse(sequence, NumberStyles.HexNumber), 1);
}
