System.Text.RegularExpressions.RegexFC.GetFirstChars C# (CSharp) Method

        internal String GetFirstChars(CultureInfo culture)
        {
            if (_caseInsensitive)
                _cc.AddLowercase(culture);

            return _cc.ToStringClass();
        }

        /*
         * This is the one of the only two functions that should be called from outside.
         * It takes a RegexTree and computes the set of chars that can start it.
         */
        internal static RegexPrefix FirstChars(RegexTree t)
        {
            RegexFCD s  = new RegexFCD();
            RegexFC  fc = s.RegexFCFromRegexTree(t);

            if (fc == null || fc._nullable)
            {
                return(null);
            }

            CultureInfo culture = ((t._options & RegexOptions.CultureInvariant) != 0) ? CultureInfo.InvariantCulture : CultureInfo.CurrentCulture;

            return(new RegexPrefix(fc.GetFirstChars(culture), fc.IsCaseInsensitive()));
        }