private void ReadSectionHeader()
{
if (_sections.Peek() is Mode)
{
throw new ParseException(Location, "Cannot start section inside mode.");
}
ReadSome(' ');
var sectionType = ReadIdentifier();
ReadSome(' ');
var argument = ReadArguments().Require(targetCount: 1, delimiter: Constants.ArgumentDelimiter);
Read('\n');
var section = CreateSection(sectionType, argument);
if (section is Mode mode)
{
if (_sections.Count > 1)
{
throw new ParseException(sectionType.Location, "A mode is only valid at the top level.");
}
section = _parserOutput.AddMode(mode);
}
_sections.Push(section);
}
