Danmaku_no_Kyojin.BulletEngine.Equationator.BaseNode.Parse C# (CSharp) Method

        public static BaseNode Parse(List<Token> tokenList, ref int curIndex, Equation owner)
        {
            Debug.Assert(null != tokenList);
            Debug.Assert(null != owner);
            Debug.Assert(curIndex < tokenList.Count);

            //first get a value, which will be a number, function, param, or equation node
            BaseNode myNumNode = BaseNode.ParseValueNode(tokenList, ref curIndex, owner);
            Debug.Assert(null != myNumNode);

            //if there are any tokens left, get an operator
            if (curIndex < tokenList.Count)
            {
                BaseNode myOperNode = BaseNode.ParseOperNode(tokenList, ref curIndex, owner);

                if (null != myOperNode)
                {
                    //add that node to the end of the list
                    myNumNode.AppendNextNode(myOperNode);

                    //If it was able to pull an operator out, there has to be a number after it.
                    if (curIndex >= tokenList.Count)
                    {
                        throw new FormatException("Can't end an equation with an operator.");
                    }

                    //Recurse into the parse function and sort out the rest of the tokens
                    BaseNode nextNode = BaseNode.Parse(tokenList, ref curIndex, owner);
                    Debug.Assert(null != nextNode);

                    //add that node to the end of the list
                    myOperNode.AppendNextNode(nextNode);
                }
            }

            //return the head node that I found
            return myNumNode;
        }

        /// <summary>
        /// Parse the specified equationText.
        /// </summary>
        /// <param name="equationText">Equation text.</param>
        public void Parse(string equationText)
        {
            //grab the equation text
            TextEquation = equationText;

            //straight up tokenize the equation: operators, numbers, parens, functions, params
            List <Token> tokenList = Tokenize(equationText);

            //sort out those tokens into a linked list of equation nodes
            int      index        = 0;
            BaseNode listRootNode = BaseNode.Parse(tokenList, ref index, this);

            //take that linked list and bend it into a binary tree.  Grab the root node
            RootNode = listRootNode.Treeify();
        }