YuriyGuts.RegexBuilder.RegexNode.Add C# (CSharp) Method

        public static RegexNode Add(RegexNode node1, RegexNode node2)
        {
            if (node1 == null || node2 == null)
            {
                throw new ArgumentException("Both nodes must be not null.");
            }

            RegexNodeConcatenation node1AsConcatenation = node1 as RegexNodeConcatenation;
            RegexNodeConcatenation node2AsConcatenation = node2 as RegexNodeConcatenation;

            if (node1AsConcatenation != null && node2AsConcatenation != null)
            {
                List<RegexNode> newChildNodes = new List<RegexNode>();
                newChildNodes.AddRange(node1AsConcatenation.ChildNodes);
                newChildNodes.AddRange(node2AsConcatenation.ChildNodes);

                RegexNodeConcatenation result = new RegexNodeConcatenation(newChildNodes);
                return result;
            }

            if (node1AsConcatenation != null)
            {
                List<RegexNode> newChildNodes = new List<RegexNode>(node1AsConcatenation.ChildNodes);
                newChildNodes.Add(node2);

                RegexNodeConcatenation result = new RegexNodeConcatenation(newChildNodes);
                return result;
            }

            if (node2AsConcatenation != null)
            {
                List<RegexNode> newChildNodes = new List<RegexNode>();
                newChildNodes.Add(node1);
                newChildNodes.AddRange(node2AsConcatenation.ChildNodes);

                RegexNodeConcatenation result = new RegexNodeConcatenation(newChildNodes);
                return result;
            }

            return new RegexNodeConcatenation(node1, node2);
        }