public static DecodedChar DecodeCurrentChar(CharacterStream cs)
{
if (AtUnicodeEscape(cs))
{
// Find out how many hex chars are part of the encoded char
int startPos = cs.Position;
SkipUnicodeEscape(cs);
int endPos = cs.Position;
cs.Position = startPos;
// Convert the hex characters into an integer
int encodedLength = endPos - startPos;
int decodedChar = 0;
for (int i = 1; i < encodedLength; i++)
{
char ch = cs.Peek(i);
if (TextHelper.IsHexDigit(ch))
{
decodedChar *= 16;
if (char.IsDigit(ch))
{
decodedChar += ch - '0';
}
else
{
decodedChar += char.ToLowerInvariant(ch) - 'a' + 10;
}
}
else
{
Debug.Assert(char.IsWhiteSpace(ch));
break;
}
}
return(new DecodedChar(decodedChar, encodedLength));
}
else if (AtEscape(cs))
{
return(new DecodedChar(cs.Peek(1), 2));
}
return(new DecodedChar(cs.CurrentChar, 1));
}
public static bool SkipWhitespaceReverse(CharacterStream cs)
{
int start = cs.Position;
while (TextHelper.IsWhiteSpace(cs.Peek(-1)))
{
cs.Advance(-1);
}
return(start != cs.Position);
}
public static bool AtEscapedNewLine(CharacterStream cs)
{
if (cs.CurrentChar == '\\')
{
switch (cs.Peek(1))
{
case '\r':
case '\n':
case '\f':
return(true);
default:
return(false);
}
}
return(false);
}
public static bool AtUnicodeEscape(CharacterStream cs)
{
return(cs.CurrentChar == '\\' && TextHelper.IsHexDigit(cs.Peek(1)));
}