private static List <State> ParseCharacterClass(IPrattParseContext <char> ctx, List <State>?states)
{
var invertResult = ctx.TryParse(MatchChar('^'));
var ranges = new List <(char low, char high)>();
while (true)
{
if (ctx.Input.IsAtEnd)
{
throw new RegexException("Incomplete character class");
}
var c = ctx.Input.GetNext();
if (c == ']')
{
break;
}
c = GetUnescapedCharacter(ctx, c);
var range = ParseCharacterRange(ctx, c);
ranges.Add(range);
}
if (ranges.Count == 0)
{
throw new RegexException("Empty character class");
}
var matcher = new CharacterMatcher(invertResult.Success, ranges);
return(State.AddMatch(states, c => matcher.IsMatch(c), "class"));
}
public TextBlock()
{
CharacterMatcher.Initialize();
}
