public static bool TryParseUnicodeRange(IEnumerator <CssToken> tokenEnum, ref CssUnicodeRange result)
{
var token = tokenEnum.MoveNext() ? tokenEnum.Current : EofToken;
if (!token.HasValue('u'))
{
return(false);
}
token = tokenEnum.MoveNext() ? tokenEnum.Current : EofToken;
if (!token.StartsWith('+'))
{
return(false);
}
var text = new StringBuilder(14);
token.ToString(text);
if (token.IsDelimiter('+'))
{
token = tokenEnum.MoveNext() ? tokenEnum.Current : EofToken;
if (token.IsIdentifier)
{
token.ToString(text);
token = tokenEnum.MoveNext() ? tokenEnum.Current : EofToken;
}
else if (!token.IsDelimiter('?'))
{
return(false);
}
}
else if (token.IsDimension)
{
token = tokenEnum.MoveNext() ? tokenEnum.Current : EofToken;
}
else if (token.IsNumber)
{
token = tokenEnum.MoveNext() ? tokenEnum.Current : EofToken;
if (token.IsDimension || token.IsNumber)
{
token.ToString(text);
return(TryParseUnicodeRange(text, ref result));
}
}
while (token.IsDelimiter('?'))
{
text.Append('?');
token = tokenEnum.MoveNext() ? tokenEnum.Current : EofToken;
}
return(TryParseUnicodeRange(text, ref result));
}
private static bool TryParseUnicodeRange(StringBuilder text, ref CssUnicodeRange result)
{
if (text.Length < 2 || text.Length > 14 || text[0] != '+')
{
return(false);
}
var pos = 1;
var len = 0;
var ch = Peek(text, pos);
while (IsHexDigit(ch))
{
len++;
ch = Peek(text, pos + len);
}
if (len > 6)
{
return(false);
}
int rangeStart, rangeEnd;
if (ch == '?')
{
do
{
len++;
ch = Peek(text, len);
} while (ch == '?');
if (len > 6 || len < text.Length)
{
return(false);
}
var hexNumber = text.ToString(pos, len);
rangeStart = int.Parse(hexNumber.Replace('?', '0'), NumberStyles.AllowHexSpecifier);
rangeEnd = int.Parse(hexNumber.Replace('?', 'F'), NumberStyles.AllowHexSpecifier);
}
else
{
rangeStart = rangeEnd = int.Parse(text.ToString(pos, len), NumberStyles.AllowHexSpecifier);
pos = len + 1;
len = 0;
if (ch == '-' && IsHexDigit(Peek(text, pos)))
{
do
{
len++;
ch = Peek(text, pos + len);
} while (IsHexDigit(ch));
if (len > 6 || len < text.Length)
{
return(false);
}
var hexNumber = text.ToString(pos, len);
rangeEnd = int.Parse(hexNumber, NumberStyles.AllowHexSpecifier);
}
}
result = new CssUnicodeRange(rangeStart, rangeEnd);
return(true);
}
