System.Text.RegularExpressions.RegexNode.UseOptionR C# (CSharp) Method

        internal bool UseOptionR()
        {
            return (_options & RegexOptions.RightToLeft) != 0;
        }

        /// <summary>
        /// The main RegexCode generator. It does a depth-first walk
        /// through the tree and calls EmitFragment to emits code before
        /// and after each child of an interior node, and at each leaf.
        /// </summary>
        private void EmitFragment(int nodetype, RegexNode node, int curIndex)
        {
            int bits = 0;

            if (nodetype <= RegexNode.Ref)
            {
                if (node.UseOptionR())
                {
                    bits |= RegexCode.Rtl;
                }
                if ((node.Options & RegexOptions.IgnoreCase) != 0)
                {
                    bits |= RegexCode.Ci;
                }
            }

            switch (nodetype)
            {
            case RegexNode.Concatenate | BeforeChild:
            case RegexNode.Concatenate | AfterChild:
            case RegexNode.Empty:
                break;

            case RegexNode.Alternate | BeforeChild:
                if (curIndex < node.Children !.Count - 1)
                {
                    _intStack.Append(_emitted.Length);
                    Emit(RegexCode.Lazybranch, 0);
                }
                break;

            case RegexNode.Alternate | AfterChild:
            {
                if (curIndex < node.Children !.Count - 1)
                {
                    int LBPos = _intStack.Pop();
                    _intStack.Append(_emitted.Length);
                    Emit(RegexCode.Goto, 0);
                    PatchJump(LBPos, _emitted.Length);
                }