MathsEngine/MathEngine/MathEngine/AST/ExpressionTree.cs

using MathEngine.AST.Nodes;
using MathEngine.Tokenizer;
using System.Linq.Expressions;
namespace MathEngine.AST
{
    /// <summary>
    /// Represents an Abstract Syntax tree for expresison evaluation
    /// </summary>
    internal class ExpressionTree
    {   
        /// <summary>
        /// The root node of the expression tree;
        /// </summary>
        private readonly BaseNode rootNode;


        /// <summary>
        /// Initialises a new instance of the MathEngine.Parser.Parser.Node class with a given Token
        /// <param name="value">The token for the nodes value</param>
        /// </summary>
        /// <param name="expression">String representing the Mathematical expression</param>
        public ExpressionTree(string expression)
        {
            rootNode = this.FromString(expression);
        }

        public ExpressionTree(BaseNode rootNode)
        {
            this.rootNode = rootNode;
        }


        private BaseNode FromString(string expression)
        {
            List<Token> tokens = ExpressionTokenizer.Tokenize(expression);
            Queue<Token> rpnForm = Parser.Parser.Parse(tokens);
            return TreeGenerator.TreeFromRPN(rpnForm);
        }

        public ExpressionTree Evaluate()
        {
            return new ExpressionTree(rootNode.Evaluate());
        }
    }
}