private static (State, ISyntax) ParseColon(ref CharacterReader r)
{
var identifier = r.ParseStyleClass();
if (identifier.IsEmpty)
{
throw new ExpressionParseException(r.Position, "Expected class name, is, nth-child or nth-last-child selector after ':'.");
}
const string IsKeyword = "is";
const string NotKeyword = "not";
const string NthChildKeyword = "nth-child";
const string NthLastChildKeyword = "nth-last-child";
if (identifier.SequenceEqual(IsKeyword.AsSpan()) && r.TakeIf('('))
{
var syntax = ParseType(ref r, new IsSyntax());
Expect(ref r, ')');
return(State.CanHaveType, syntax);
}
if (identifier.SequenceEqual(NotKeyword.AsSpan()) && r.TakeIf('('))
{
var argument = Parse(ref r, ')');
Expect(ref r, ')');
var syntax = new NotSyntax {
Argument = argument
};
return(State.Middle, syntax);
}
if (identifier.SequenceEqual(NthChildKeyword.AsSpan()) && r.TakeIf('('))
{
var(step, offset) = ParseNthChildArguments(ref r);
var syntax = new NthChildSyntax {
Step = step, Offset = offset
};
return(State.Middle, syntax);
}
if (identifier.SequenceEqual(NthLastChildKeyword.AsSpan()) && r.TakeIf('('))
{
var(step, offset) = ParseNthChildArguments(ref r);
var syntax = new NthLastChildSyntax {
Step = step, Offset = offset
};
return(State.Middle, syntax);
}
else
{
return(
State.CanHaveType,
new ClassSyntax
{
Class = ":" + identifier.ToString()
});
}
}
private static (State, ISyntax) ParseColon(ref CharacterReader r)
{
var identifier = r.ParseIdentifier();
if (identifier.IsEmpty)
{
throw new ExpressionParseException(r.Position, "Expected class name or is selector after ':'.");
}
const string IsKeyword = "is";
const string NotKeyword = "not";
if (identifier.SequenceEqual(IsKeyword.AsSpan()) && r.TakeIf('('))
{
var syntax = ParseType(ref r, new IsSyntax());
Expect(ref r, ')');
return(State.CanHaveType, syntax);
}
if (identifier.SequenceEqual(NotKeyword.AsSpan()) && r.TakeIf('('))
{
var argument = Parse(ref r, ')');
Expect(ref r, ')');
var syntax = new NotSyntax {
Argument = argument
};
return(State.Middle, syntax);
}
else
{
return(
State.CanHaveType,
new ClassSyntax
{
Class = ":" + identifier.ToString()
});
}
}