tlang-interperter-cs/tlanglib/AddNode.cs

namespace tlang
{
    internal class AddNode : Node
    {
        public Node Left {get;set;}
        public Node Right {get;set;}

        public AddNode(Node left, Node right)
        {
            this.Left = left;
            this.Right = right;
        }

        public override TObject Execute(IScopeEnvironment nodeEnv)
        {
            var l=Left.Execute(nodeEnv);
            var r = Right.Execute(nodeEnv);
            var lNum = l as TNumber;
            var rNum = r as TNumber;
            var lStr = l as TString;
            var rStr = r as TString;
            var dleft = l as TDictionary;

            if(dleft != null)
            {
                if(dleft.MemberExists("add"))
                {
                    var mbm = dleft["add"] as ICallable;
                    if(mbm != null)
                    {
                        return mbm.Call(r);
                    }
                }
            }

        
            if(lNum != null && rNum != null)
            return new TNumber(lNum.Value + rNum.Value);

            if(lStr != null && rStr != null)
            return new TString(lStr.Value + rStr.Value);
            if(lStr != null && rNum != null)
            return new TString(lStr.Value + rNum.Value.ToString());
            if(lNum != null && rStr != null)
            return new TString(lNum.Value.ToString() + rStr.Value);

            

            return new TNull();
        }
    }
}