Feature/implement exponentiation (#6)

* Modified System to make each numeric node a non-generic for now.

Implemented decimal exponentation. This is a draft implementation and is not intended for final release

* Reverted change to NumericNode and fixed tests

MathEngine/EngineTests/Parser Tests/Nodes/NodeFactoryTests.cs

@@ -78,10 +78,8 @@ namespace EngineTests.Parser_Tests.Nodes
         [TestMethod]
         public void TestNodeFactoryNumericNodesOnDefinedTypes()
         {
-            Token test_token1 = new("100", Token.Type.Numeric, Token.NumericType.Integer, 0);
             Token test_token2 = new("100.5", Token.Type.Numeric, Token.NumericType.Decimal, 0);
 
-            BaseNode testNode1 = NodeFactory.CreateNumericNode(test_token1);
             BaseNode testNode2 = NodeFactory.CreateNumericNode(test_token2);
         }
 

MathEngine/MathEngine/MathEngine.csproj

@@ -8,6 +8,7 @@
   </PropertyGroup>
 
   <ItemGroup>
+    <Compile Remove="Parser\Nodes\NumericIntegerNode.cs" />
     <Compile Remove="Parser\Nodes\TreeNode.cs" />
   </ItemGroup>
   <ItemGroup>

MathEngine/MathEngine/Parser/Nodes/BaseNode.cs

@@ -105,6 +105,28 @@ namespace MathEngine.Parser.Parser
             return lhs.Divide(rhs);
         }
 
+        /// <summary>
+        /// Base method for exponentiating two nodes, returning another BaseNode object
+        /// </summary>
+        /// <param name="otherNode">The node which will be the power to raise the current instance to</param>
+        /// <returns></returns>
+        /// <exception cref="InvalidOperationException"></exception>
+        protected virtual BaseNode Exponentiate(BaseNode otherNode)
+        {
+            throw new InvalidOperationException("Attempted to call BaseNode _exponentiate, which is invalid!");
+        }
+
+        /// <summary>
+        /// Base operator for exponentiating two Base Nodes
+        /// </summary>
+        /// <param name="lhs">The left BaseNode</param>
+        /// <param name="rhs">The right BaseNode</param>
+        /// <returns>The exponentiating of the two BaseNodes, as defined by the calling type</returns>
+        public static BaseNode operator ^(BaseNode lhs, BaseNode rhs)
+        {
+            return lhs.Exponentiate(rhs);
+        }
+
         /// <summary>
         /// Abstract Base method that evaluates the current Node
         /// </summary>

MathEngine/MathEngine/Parser/Nodes/NodeFactory.cs

@@ -27,7 +27,7 @@ namespace MathEngine.Parser.Parser
                 case Token.Type.Division:
                     return new BinaryNode(LeftBranch, RightBranch, (a, b) => a / b);
                 case Token.Type.Exponentiation:
-                    throw new NotImplementedException("Exponentiation is not implemented at this time");
+                    return new BinaryNode(LeftBranch, RightBranch, (a, b) => a ^ b);
                 default:
                     throw new NotImplementedException("Attempted to create a BinaryNode with an invalid operation!");
             }
@@ -43,9 +43,9 @@ namespace MathEngine.Parser.Parser
             switch (CurrentToken.NumericalType)
             {
                 case Token.NumericType.Integer:
-                    return new NumericNode<Int64>(Int64.Parse(CurrentToken.TokenValue));
+                    throw new NotImplementedException("Integer Numbers are not implemented at this time");
                 case Token.NumericType.Decimal:
-                    return new NumericNode<Decimal>(Decimal.Parse(CurrentToken.TokenValue));
+                    return new NumericNode<decimal>(Decimal.Parse(CurrentToken.TokenValue));
                 case Token.NumericType.Complex:
                     throw new NotImplementedException("Complex Numbers are not implemented at this time");
                 default:

MathEngine/MathEngine/Parser/Nodes/NumericIntegerNode.cs

@@ -0,0 +1,90 @@
+using MathEngine.Parser.Parser;
+using MathEngine.Parser.Parser.Nodes;
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace MathEngine.Parser.Nodes
+{
+    internal class NumericIntegerNode: BaseNode
+    {
+        private readonly decimal Value;
+
+        /// <summary>
+        /// Initialises a new instance of a NumericNode with a given Token
+        /// </summary>
+        /// <param name="value">The token for the nodes value</param>
+        public NumericIntegerNode(decimal value)
+        {
+            this.Children = null;
+            this.Value = value;
+        }
+
+        protected override BaseNode Add(BaseNode otherNode)
+        {
+            if (otherNode is NumericIntegerNode)
+            {
+                NumericIntegerNode rhs = (NumericIntegerNode)otherNode;
+                return new NumericIntegerNode(Value + rhs.Value);
+            }
+            throw new InvalidOperationException("Attempted Invalid operation");
+        }
+
+        protected override BaseNode Subtract(BaseNode otherNode)
+        {
+            if (otherNode is NumericIntegerNode)
+            {
+                NumericIntegerNode rhs = (NumericIntegerNode)otherNode;
+                return new NumericIntegerNode(Value - rhs.Value);
+            }
+            throw new InvalidOperationException("Attempted Invalid operation");
+        }
+
+        protected override BaseNode Multiply(BaseNode otherNode)
+        {
+            if (otherNode is NumericIntegerNode)
+            {
+                NumericIntegerNode rhs = (NumericIntegerNode)otherNode;
+                return new NumericIntegerNode(Value * rhs.Value);
+            }
+            throw new InvalidOperationException("Attempted Invalid operation");
+        }
+
+        protected override BaseNode Divide(BaseNode otherNode)
+        {
+            if (otherNode is NumericIntegerNode)
+            {
+                NumericIntegerNode rhs = (NumericIntegerNode)otherNode;
+                return new NumericIntegerNode(Value / rhs.Value);
+            }
+            throw new InvalidOperationException("Attempted Invalid operation");
+        }
+
+        protected override BaseNode Exponentiate(BaseNode otherNode)
+        {
+            if (otherNode is NumericIntegerNode)
+            {
+                NumericIntegerNode rhs = (NumericIntegerNode)otherNode;
+                return new NumericIntegerNode((Int64)(Math.Pow((double)(Value), (double)rhs.Value)));
+            }
+            throw new InvalidOperationException("Attempted Invalid operation");
+        }
+
+        /// <summary>
+        /// Evaluates the Numeric Node by simply returning the current instance
+        /// </summary>
+        /// <returns></returns>
+        public override BaseNode Evaluate()
+        {
+            return this;
+        }
+
+        public override string ToString()
+        {
+            return Value.ToString();
+        }
+
+    }
+}

MathEngine/MathEngine/Parser/Nodes/NumericNode.cs

@@ -7,13 +7,13 @@ namespace MathEngine.Parser.Parser.Nodes
     /// </summary>
     internal class NumericNode<T> : BaseNode where T: INumber<T> 
     {
-        private readonly T Value;
+        private readonly decimal Value;
 
         /// <summary>
         /// Initialises a new instance of a NumericNode with a given Token
         /// </summary>
         /// <param name="value">The token for the nodes value</param>
-        public NumericNode(T value)
+        public NumericNode(decimal value)
         {
             this.Children = null;
             this.Value = value;
@@ -21,40 +21,50 @@ namespace MathEngine.Parser.Parser.Nodes
 
         protected override BaseNode Add(BaseNode otherNode)
         {
-            if (otherNode is NumericNode<T>)
+            if (otherNode is NumericNode<decimal>)
             {
-                NumericNode<T> rhs = (NumericNode<T>)otherNode;
-                return new NumericNode<T>(Value + rhs.Value);
+                NumericNode<decimal> rhs = (NumericNode<decimal>)otherNode;
+                return new NumericNode<decimal>(Value + rhs.Value);
             }
             throw new InvalidOperationException("Attempted Invalid operation");
         }
 
         protected override BaseNode Subtract(BaseNode otherNode)
         {
-            if (otherNode is NumericNode<T>)
+            if (otherNode is NumericNode<decimal>)
             {
-                NumericNode<T> rhs = (NumericNode<T>)otherNode;
-                return new NumericNode<T>(Value - rhs.Value);
+                NumericNode<decimal> rhs = (NumericNode<decimal>)otherNode;
+                return new NumericNode<decimal>(Value - rhs.Value);
             }
             throw new InvalidOperationException("Attempted Invalid operation");
         }
 
         protected override BaseNode Multiply(BaseNode otherNode)
         {
-            if (otherNode is NumericNode<T>)
+            if (otherNode is NumericNode<decimal>)
             {
-                NumericNode<T> rhs = (NumericNode<T>)otherNode;
-                return new NumericNode<T>(Value * rhs.Value);
+                NumericNode<decimal> rhs = (NumericNode<decimal>)otherNode;
+                return new NumericNode<decimal>(Value * rhs.Value);
             }
             throw new InvalidOperationException("Attempted Invalid operation");
         }
 
         protected override BaseNode Divide(BaseNode otherNode)
         {
-            if (otherNode is NumericNode<T>)
+            if (otherNode is NumericNode<decimal>)
             {
-                NumericNode<T> rhs = (NumericNode<T>)otherNode;
-                return new NumericNode<T>(Value / rhs.Value);
+                NumericNode<decimal> rhs = (NumericNode<decimal>)otherNode;
+                return new NumericNode<decimal>(Value / rhs.Value);
+            }
+            throw new InvalidOperationException("Attempted Invalid operation");
+        }
+
+        protected override BaseNode Exponentiate(BaseNode otherNode)
+        {
+            if (otherNode is NumericNode<decimal>)
+            {
+                NumericNode<decimal> rhs = (NumericNode<decimal>)otherNode;
+                return new NumericNode<decimal>((decimal)(Math.Pow((double)Value, (double)(rhs.Value))));
             }
             throw new InvalidOperationException("Attempted Invalid operation");
         }

MathEngine/MathEngine/Parser/Parser/Parser.cs

@@ -119,6 +119,7 @@ namespace MathEngine.Parser.Parser
                     case Token.Type.Subtraction:
                     case Token.Type.Multiplication:
                     case Token.Type.Division:
+                    case Token.Type.Exponentiation:
                         while ((OperatorStack.Count != 0 && ((((OperatorStack.Peek().Token_Type == Token.Type.Function) | (OperatorPrecedence(OperatorStack.Peek()) > OperatorPrecedence(CurrentToken)) | ((OperatorPrecedence(OperatorStack.Peek()) == OperatorPrecedence(CurrentToken)) & (IsLeftAssociatve(CurrentToken)))) && !(OperatorStack.Peek().Token_Type == Token.Type.LeftParenthesis)))))
                         {
                             OutputStack.Push(OperatorStack.Pop());

MathEngine/MathEngine/Parser/Tokeniser/Token.cs

@@ -25,6 +25,11 @@
         /// </summary>
         public static readonly Token Divide = new("/", Type.Division, NumericType.NaN, 0);
 
+        /// <summary>
+        /// Represents the token for ^
+        /// </summary>
+        public static readonly Token Exponentiation = new("^", Type.Exponentiation, NumericType.NaN, 0);
+
         /// <summary>
         /// Enum representing the token type
         /// </summary>

MathEngine/MathEngine/Parser/Tokeniser/Tokeniser.cs

@@ -31,6 +31,7 @@
                 '-' => Token.Minus,
                 '*' => Token.Multiply,
                 '/' => Token.Divide,
+                '^' => Token.Exponentiation,
                 _ => throw new Exception(String.Format("Character {0} is not a defined operator", curChar)),
             };
         }