System.Text.RegularExpressions.RegexCharClass.AddCharClass C# (CSharp) Method

        internal void AddCharClass(RegexCharClass cc) {
            int i;

            Debug.Assert(cc.CanMerge && this.CanMerge, "Both character classes added together must be able to merge" );
            
            if (!cc._canonical) {
                // if the new char class to add isn't canonical, we're not either.
                _canonical = false;
            }
            else if (_canonical && RangeCount() > 0 && cc.RangeCount() > 0 && cc.GetRangeAt(0)._first <= GetRangeAt(RangeCount() - 1)._last)
                _canonical = false;

            for (i = 0; i < cc.RangeCount(); i += 1) {
                _rangelist.Add(cc.GetRangeAt(i));
            }

            _categories.Append(cc._categories.ToString());
        }

        internal bool AddFC(RegexFC fc, bool concatenate)
        {
            if (!_cc.CanMerge || !fc._cc.CanMerge)
            {
                return(false);
            }

            if (concatenate)
            {
                if (!_nullable)
                {
                    return(true);
                }

                if (!fc._nullable)
                {
                    _nullable = false;
                }
            }
            else
            {
                if (fc._nullable)
                {
                    _nullable = true;
                }
            }

            _caseInsensitive |= fc._caseInsensitive;
            _cc.AddCharClass(fc._cc);
            return(true);
        }