private string ScanName()
{
Debug.Assert(XmlCharType.IsStartNcNameChar(CurrentChar));
var start = _XpathExprIndex - 1;
var len = 0;
while (XmlCharType.IsNcNameChar(CurrentChar))
{
NextChar();
len++;
}
return(SourceText.Substring(start, len));
}
public bool NextLex()
{
SkipSpace();
switch (CurrentChar)
{
case '\0':
Kind = LexKind.Eof;
return(false);
case ',':
case '@':
case '(':
case ')':
case '|':
case '*':
case '[':
case ']':
case '+':
case '-':
case '=':
case '#':
case '$':
Kind = (LexKind)Convert.ToInt32(CurrentChar);
NextChar();
break;
case '<':
Kind = LexKind.Lt;
NextChar();
if (CurrentChar == '=')
{
Kind = LexKind.Le;
NextChar();
}
break;
case '>':
Kind = LexKind.Gt;
NextChar();
if (CurrentChar == '=')
{
Kind = LexKind.Ge;
NextChar();
}
break;
case '!':
Kind = LexKind.Bang;
NextChar();
if (CurrentChar == '=')
{
Kind = LexKind.Ne;
NextChar();
}
break;
case '.':
Kind = LexKind.Dot;
NextChar();
if (CurrentChar == '.')
{
Kind = LexKind.DotDot;
NextChar();
}
else if (XmlCharType.IsDigit(CurrentChar))
{
Kind = LexKind.Number;
_NumberValue = ScanFraction();
}
break;
case '/':
Kind = LexKind.Slash;
NextChar();
if (CurrentChar == '/')
{
Kind = LexKind.SlashSlash;
NextChar();
}
break;
case '"':
case '\'':
Kind = LexKind.String;
_StringValue = ScanString();
break;
default:
if (XmlCharType.IsDigit(CurrentChar))
{
Kind = LexKind.Number;
_NumberValue = ScanNumber();
}
else if (XmlCharType.IsStartNcNameChar(CurrentChar))
{
Kind = LexKind.Name;
_Name = ScanName();
_Prefix = string.Empty;
// "foo:bar" is one lexem not three because it doesn't allow spaces in between
// We should distinct it from "foo::" and need process "foo ::" as well
if (CurrentChar == ':')
{
NextChar();
// can be "foo:bar" or "foo::"
if (CurrentChar == ':')
{
// "foo::"
NextChar();
Kind = LexKind.Axe;
}
else
{
// "foo:*", "foo:bar" or "foo: "
_Prefix = _Name;
if (CurrentChar == '*')
{
NextChar();
_Name = "*";
}
else if (XmlCharType.IsStartNcNameChar(CurrentChar))
{
_Name = ScanName();
}
else
{
throw new XPathException($"'{SourceText}' has an invalid qualified name.");
}
}
}
else
{
SkipSpace();
if (CurrentChar == ':')
{
NextChar();
// it can be "foo ::" or just "foo :"
if (CurrentChar == ':')
{
NextChar();
Kind = LexKind.Axe;
}
else
{
throw new XPathException($"'{SourceText}' has an invalid qualified name.");
}
}
}
SkipSpace();
_CanBeFunction = CurrentChar == '(';
}
else
{
throw new XPathException($"'{SourceText}' has an invalid token.");
}
break;
}
return(true);
}
