I don't remember what changed here but I believe the core logic for parsing the math expression was updated to be 'better', perhaps more 'robust'. I don't think you can really call it that though considering it doesn't even make use of a syntax tree of any kind at the very least.

Engine/Form1.Designer.cs

@@ -47,17 +47,19 @@
             // 
             // textBox1
             // 
-            this.textBox1.Location = new System.Drawing.Point(921, 33);
+            this.textBox1.Location = new System.Drawing.Point(613, 21);
+            this.textBox1.Margin = new System.Windows.Forms.Padding(2, 2, 2, 2);
             this.textBox1.Name = "textBox1";
-            this.textBox1.Size = new System.Drawing.Size(447, 26);
+            this.textBox1.Size = new System.Drawing.Size(299, 20);
             this.textBox1.TabIndex = 0;
-            this.textBox1.Text = "2 * 5 / 2(1 + 2)";
+            this.textBox1.Text = "5000(2(2(1.08^10)-1)/0.08)";
             // 
             // button1
             // 
-            this.button1.Location = new System.Drawing.Point(921, 758);
+            this.button1.Location = new System.Drawing.Point(613, 492);
+            this.button1.Margin = new System.Windows.Forms.Padding(2, 2, 2, 2);
             this.button1.Name = "button1";
-            this.button1.Size = new System.Drawing.Size(155, 92);
+            this.button1.Size = new System.Drawing.Size(103, 60);
             this.button1.TabIndex = 1;
             this.button1.Text = "button1";
             this.button1.UseVisualStyleBackColor = true;
@@ -77,13 +79,14 @@
             this.mainLayout.Controls.Add(this.ActionsListView, 1, 3);
             this.mainLayout.Dock = System.Windows.Forms.DockStyle.Fill;
             this.mainLayout.Location = new System.Drawing.Point(0, 0);
+            this.mainLayout.Margin = new System.Windows.Forms.Padding(2, 2, 2, 2);
             this.mainLayout.Name = "mainLayout";
             this.mainLayout.RowCount = 4;
-            this.mainLayout.RowStyles.Add(new System.Windows.Forms.RowStyle(System.Windows.Forms.SizeType.Absolute, 30F));
+            this.mainLayout.RowStyles.Add(new System.Windows.Forms.RowStyle(System.Windows.Forms.SizeType.Absolute, 19F));
             this.mainLayout.RowStyles.Add(new System.Windows.Forms.RowStyle(System.Windows.Forms.SizeType.Percent, 33F));
             this.mainLayout.RowStyles.Add(new System.Windows.Forms.RowStyle(System.Windows.Forms.SizeType.Percent, 34F));
             this.mainLayout.RowStyles.Add(new System.Windows.Forms.RowStyle(System.Windows.Forms.SizeType.Percent, 33F));
-            this.mainLayout.Size = new System.Drawing.Size(1371, 1113);
+            this.mainLayout.Size = new System.Drawing.Size(914, 723);
             this.mainLayout.TabIndex = 3;
             // 
             // ExpressionBreakdownListView
@@ -94,10 +97,11 @@
             this.ExpressionBreakdownListView.Dock = System.Windows.Forms.DockStyle.Fill;
             this.ExpressionBreakdownListView.HeaderStyle = System.Windows.Forms.ColumnHeaderStyle.Nonclickable;
             this.ExpressionBreakdownListView.HideSelection = false;
-            this.ExpressionBreakdownListView.Location = new System.Drawing.Point(3, 33);
+            this.ExpressionBreakdownListView.Location = new System.Drawing.Point(2, 21);
+            this.ExpressionBreakdownListView.Margin = new System.Windows.Forms.Padding(2, 2, 2, 2);
             this.ExpressionBreakdownListView.Name = "ExpressionBreakdownListView";
             this.mainLayout.SetRowSpan(this.ExpressionBreakdownListView, 2);
-            this.ExpressionBreakdownListView.Size = new System.Drawing.Size(446, 719);
+            this.ExpressionBreakdownListView.Size = new System.Drawing.Size(297, 467);
             this.ExpressionBreakdownListView.TabIndex = 3;
             this.ExpressionBreakdownListView.UseCompatibleStateImageBehavior = false;
             this.ExpressionBreakdownListView.View = System.Windows.Forms.View.Details;
@@ -119,10 +123,11 @@
             this.columnHeader4});
             this.StepsListView.Dock = System.Windows.Forms.DockStyle.Fill;
             this.StepsListView.HideSelection = false;
-            this.StepsListView.Location = new System.Drawing.Point(455, 33);
+            this.StepsListView.Location = new System.Drawing.Point(303, 21);
+            this.StepsListView.Margin = new System.Windows.Forms.Padding(2, 2, 2, 2);
             this.StepsListView.Name = "StepsListView";
             this.mainLayout.SetRowSpan(this.StepsListView, 2);
-            this.StepsListView.Size = new System.Drawing.Size(460, 719);
+            this.StepsListView.Size = new System.Drawing.Size(306, 467);
             this.StepsListView.TabIndex = 4;
             this.StepsListView.UseCompatibleStateImageBehavior = false;
             this.StepsListView.View = System.Windows.Forms.View.Details;
@@ -144,9 +149,10 @@
             this.columnHeader6});
             this.SymbolsListView.Dock = System.Windows.Forms.DockStyle.Fill;
             this.SymbolsListView.HideSelection = false;
-            this.SymbolsListView.Location = new System.Drawing.Point(3, 758);
+            this.SymbolsListView.Location = new System.Drawing.Point(2, 492);
+            this.SymbolsListView.Margin = new System.Windows.Forms.Padding(2, 2, 2, 2);
             this.SymbolsListView.Name = "SymbolsListView";
-            this.SymbolsListView.Size = new System.Drawing.Size(446, 352);
+            this.SymbolsListView.Size = new System.Drawing.Size(297, 229);
             this.SymbolsListView.TabIndex = 5;
             this.SymbolsListView.UseCompatibleStateImageBehavior = false;
             this.SymbolsListView.View = System.Windows.Forms.View.Details;
@@ -167,9 +173,10 @@
             this.columnHeader7});
             this.ActionsListView.Dock = System.Windows.Forms.DockStyle.Fill;
             this.ActionsListView.HideSelection = false;
-            this.ActionsListView.Location = new System.Drawing.Point(455, 758);
+            this.ActionsListView.Location = new System.Drawing.Point(303, 492);
+            this.ActionsListView.Margin = new System.Windows.Forms.Padding(2, 2, 2, 2);
             this.ActionsListView.Name = "ActionsListView";
-            this.ActionsListView.Size = new System.Drawing.Size(460, 352);
+            this.ActionsListView.Size = new System.Drawing.Size(306, 229);
             this.ActionsListView.TabIndex = 6;
             this.ActionsListView.UseCompatibleStateImageBehavior = false;
             this.ActionsListView.View = System.Windows.Forms.View.Details;
@@ -181,10 +188,11 @@
             // 
             // Form1
             // 
-            this.AutoScaleDimensions = new System.Drawing.SizeF(9F, 20F);
+            this.AutoScaleDimensions = new System.Drawing.SizeF(6F, 13F);
             this.AutoScaleMode = System.Windows.Forms.AutoScaleMode.Font;
-            this.ClientSize = new System.Drawing.Size(1371, 1113);
+            this.ClientSize = new System.Drawing.Size(914, 723);
             this.Controls.Add(this.mainLayout);
+            this.Margin = new System.Windows.Forms.Padding(2, 2, 2, 2);
             this.Name = "Form1";
             this.Text = "Form1";
             this.mainLayout.ResumeLayout(false);

Engine/Form1.cs

@@ -6,17 +6,14 @@ using System.Data;
 using System.Drawing;
 using System.Linq;
 using System.Text;
-using System.Threading.Tasks;
+using System.Runtime.CompilerServices;
 using System.Windows.Forms;
 
 namespace Engine
 {
     public partial class Form1 : Form
     {
-        //Invert over all expression (i + 7) ^ 2 -> -(i + 7) ^ 2
+        private Dictionary<string, double> Symbols { get; set; } = new Dictionary<string, double>();
-
-        private Stack<Node> Tree = new Stack<Node>();
-        private Dictionary<string, double> Symbols = new Dictionary<string, double>();
 
         public Form1()
         {
@@ -31,37 +28,8 @@ namespace Engine
             f.Reverse();
             var stack = new Stack<Token>(f);
             ActionsListView.Items.Clear();
-
+            PrintSymbolsTable();
-            button1.Text = "Result: " + NewCalc(stack);
+            button1.Text = "Result: " + HandleAddAndSub(stack);
-            //var f2 = GetSubExpressions(f);
-            //PrintSteps(f2);
-            //PrintSymbolsTable();
-            //var result = Calc(f2);
-            //button1.Text = $"Result: {result}";
-            //var result = Calc(FlattenInput(s));            
-        }
-
-        void PrintSteps(List<List<Node>> expressions)
-        {
-            StepsListView.Items.Clear();
-
-            for(var i = 0; i < expressions.Count; i++)
-            {
-                var expression = expressions[i];
-                var item = new ListViewItem($"Step {i + 1}");
-                var ex = string.Empty;
-
-                foreach (var token in expression)
-                {
-                    if (!token.IsCoefficent)
-                        ex += token.Value + " ";
-                    else
-                        ex += token.Value;
-                }
-
-                item.SubItems.Add(ex);
-                StepsListView.Items.Add(item);
-            }
         }
 
         void PrintSymbolsTable()
@@ -84,274 +52,264 @@ namespace Engine
             foreach(var token in tokens)
             {  
                 var item = new ListViewItem(token.Value);
-                if(!token.IsCoefficent) item.SubItems.Add(token.Type.ToString());
+                item.SubItems.Add(token.Type.ToString());
-                else item.SubItems.Add(token.Type.ToString() + " (Coefficent)");
 
                 ExpressionBreakdownListView.Items.Add(item);
             }
         }
 
-        double NewCalc(Stack<Token> tokens, double co = 1)
+        double HandleParenthesis(Stack<Token> tokens, bool callerHasPriority = false)
         {
-            var previousToken = new Token() { Type = TokenType.Unknown };
             var runningValue = 0d;
+            var previousToken = new Token() { Type = TokenType.Unknown };
 
-            while(tokens.Count > 0)
+            for(; ;)
             {
-                var token = tokens.Pop();
+                if (tokens.Count == 0) break;
 
-                if (token.Type == TokenType.ExpEnd)
+                var currentToken = tokens.Pop();
+
+                if(currentToken.Type == TokenType.Constant)
+                {
+                    previousToken = currentToken;
+                    continue;
+                }
+                else if(currentToken.Type == TokenType.ExpStart)
+                {
+                    var tmp = HandleParenthesis(tokens);
+                    runningValue = tmp;
+                }
+                else if(currentToken.Type == TokenType.Add || currentToken.Type == TokenType.Subtract)
+                {
+                    var lookAHead = tokens.Pop();
+
+                    if(lookAHead.Type == TokenType.ExpStart)
+                    {
+                        var tmp = HandleParenthesis(tokens);
+
+                        if (runningValue == 0) runningValue = Operate(Convert.ToDouble(previousToken.Value), tmp, currentToken.Type);
+                        else runningValue = Operate(runningValue, tmp, currentToken.Type);
+                        continue;
+                    }
+
+                    tokens.Push(lookAHead);
+                    tokens.Push(currentToken);
+                    if (previousToken.Type != TokenType.Unknown) tokens.Push(previousToken);
+                    else tokens.Push(new Token { Type = TokenType.Constant, Value = runningValue.ToString() });
+                    runningValue = HandleAddAndSub(tokens);
+
+                    previousToken.Type = TokenType.Unknown;
+                }
+                else if (currentToken.Type == TokenType.Power)
+                {
+                    var lookAHead = tokens.Pop();
+
+                    if(lookAHead.Type == TokenType.ExpStart)
+                    {
+                        var powerOf = HandleParenthesis(tokens, true);
+
+                        runningValue = Operate(Convert.ToDouble(previousToken.Value), powerOf, currentToken.Type);
+                        previousToken.Type = TokenType.Unknown;
+
+                        continue;
+                    }
+
+                    var tmp = Operate(Convert.ToDouble(previousToken.Value), Convert.ToDouble(lookAHead.Value), currentToken.Type);
+                    previousToken.Type = TokenType.Unknown;
+
+                    runningValue = tmp;
+                }
+                else if (currentToken.Type == TokenType.Multiply || currentToken.Type == TokenType.Divide)
+                {
+                    var lookAHead = tokens.Peek();
+
+                    if (lookAHead.Type == TokenType.ExpStart)
+                    {
+                        tokens.Pop();
+
+                        var tmpe = Operate(Convert.ToDouble(previousToken.Value), HandleParenthesis(tokens), currentToken.Type);
+                        previousToken.Type = TokenType.Unknown;
+
+                        runningValue = tmpe;
+
+                        continue;
+                    }
+
+                    tokens.Push(currentToken);
+                    if (previousToken.Type != TokenType.Unknown) tokens.Push(previousToken);
+                    else tokens.Push(new Token { Type = TokenType.Constant, Value = runningValue.ToString() });
+
+                    var tmp = HandleMultAndDiv(tokens);
+                    previousToken.Type = TokenType.Unknown;
+
+                    runningValue = tmp;
+                }
+                else if (currentToken.Type == TokenType.ExpEnd)
                 {
                     if(tokens.Count > 0 && tokens.Peek().Type == TokenType.Power)
                     {
-                        var op = tokens.Pop();
+                        //Pop the power of token before returning.
-                        var powerOf = tokens.Pop();
+                        tokens.Pop();
+                        runningValue = Operate(runningValue, Convert.ToDouble(tokens.Pop().Value), TokenType.Power);
+                    }
 
-                        if(powerOf.Type == TokenType.Constant)
+                    if(!callerHasPriority && tokens.Count > 0 && (tokens.Peek().Type == TokenType.Multiply || tokens.Peek().Type == TokenType.Divide))
+                    {
+                        var op = tokens.Pop();
+                        var twoAHead = tokens.Pop();
+                        
+                        if(twoAHead.Type == TokenType.ExpStart)
                         {
-                            ActionsListView.Items.Add($"Taking {runningValue} to the power of {powerOf.Value}.");
+                            runningValue = Operate(runningValue, HandleParenthesis(tokens, true), op.Type);
-                            runningValue = Operate(runningValue, Convert.ToDouble(powerOf.Value), op.Type);
+                        }
+                        else
+                        {
+                            runningValue = Operate(runningValue, Convert.ToDouble(twoAHead.Value), op.Type);
                         }
                     }
 
                     break;
                 }
-
-                if(token.Type == TokenType.ExpStart)
-                {
-                    runningValue = NewCalc(tokens);
-                    continue;
-                }
-
-                if(token.IsCoefficent)
-                {
-                    var lookAHead = tokens.Pop();
-
-                    if (lookAHead.Type == TokenType.Variable)
-                    {
-                        ActionsListView.Items.Add($"{token.Value} is a coeffiecent, multiplying it against {Symbols[lookAHead.Value]} (Symbol '{lookAHead.Value}').");
-                        runningValue += Convert.ToDouble(token.Value) * Symbols[lookAHead.Value];
-                        if (previousToken.Type != TokenType.Unknown) throw new Exception("Token shouldn't have a valid value!");
-                        //2a(
-                        if(tokens.Count != 0 && tokens.Peek().Type == TokenType.ExpStart)
-                        {
-                            runningValue += NewCalc(tokens, runningValue);
-                        }
-
-                        previousToken = new Token() { Type = TokenType.Constant, Value = runningValue.ToString(), IsCoefficent = false };
-                        continue;
-                    }
-                    else if (lookAHead.Type == TokenType.ExpStart)
-                    {
-                        runningValue += NewCalc(tokens, Convert.ToDouble(token.Value));
-                        previousToken = new Token() { Type = TokenType.Constant, Value = runningValue.ToString(), IsCoefficent = false };
-                        continue;
-                    }
-                    else throw new Exception("Invalid grammar!");
-                }
-                //If token is an operator
-                if(GetOperator(token.Value[0]) != TokenType.Unknown)
-                {
-                    //Operator found
-                    var lookAHead = tokens.Pop();
-
-                    if(lookAHead.Type == TokenType.Constant && !lookAHead.IsCoefficent)
-                    {
-                        var tmpValue = 0d;
-
-                        while (tokens.Count > 0 && (tokens.Peek().Type == TokenType.Multiply || tokens.Peek().Type == TokenType.Divide || tokens.Peek().Type == TokenType.Power))
-                        {                            
-                            var op = tokens.Pop();
-
-                            if (op.Type != TokenType.Power)
-                            {
-                                var next = tokens.Pop();
-
-                                if (next.Type == TokenType.ExpStart)
-                                {
-                                    var returnValue = NewCalc(tokens);
-
-                                    if (tmpValue != 0)
-                                    {
-                                        ActionsListView.Items.Add($"{GetOperatorVerb(op.Type)} {tmpValue} (tmp) and {returnValue} (returnValue).");
-                                        tmpValue = Operate(tmpValue, returnValue, op.Type);
-                                        lookAHead.Value = tmpValue.ToString();
-                                    }
-                                    else
-                                    {
-                                        ActionsListView.Items.Add($"{GetOperatorVerb(op.Type)} {Convert.ToDouble(lookAHead.Value) * co} (lookAHead) and {returnValue} (returnValue).");
-                                        tmpValue = Operate(Convert.ToDouble(lookAHead.Value) * co, returnValue, op.Type);
-                                        lookAHead.Value = tmpValue.ToString();
-                                    }
-
-                                    continue;
-                                }
-
-                                if (tmpValue != 0)
-                                {
-                                    ActionsListView.Items.Add($"{GetOperatorVerb(op.Type)} {tmpValue} (tmp) and {Convert.ToDouble(next.Value) * co} (next).");
-                                    tmpValue = Operate(tmpValue, Convert.ToDouble(next.Value) * co, op.Type);
-                                    lookAHead.Value = tmpValue.ToString();
-                                }
-                                else
-                                {
-                                    ActionsListView.Items.Add($"{GetOperatorVerb(op.Type)} {Convert.ToDouble(lookAHead.Value) *co} (lookAHead) and {next.Value} (next).");
-                                    tmpValue = Operate(Convert.ToDouble(lookAHead.Value) *co, Convert.ToDouble(next.Value) *co, op.Type);
-                                    lookAHead.Value = tmpValue.ToString();
-                                }
-                            }
-                            else if (op.Type == TokenType.Power)
-                            {
-
-                            }
-                        }
-
-                        //if(tokens.Count > 0 && (tokens.Peek().Type == TokenType.Divide || tokens.Peek().Type == TokenType.Multiply || tokens.Peek().Type == TokenType.Power))
-                        //{
-                        //    var op = tokens.Pop();
-                        //    var con = tokens.Pop();
-                        //    //TODO: check if "con" is a variable, right now we're assuming its a constant.
-                        //    ActionsListView.Items.Add($"{GetOperatorVerb(op.Type)} {Convert.ToDouble(lookAHead.Value) * co} and {Convert.ToDouble(con.Value) * co} (Oder of Operations).");
-                        //    var tmp = Operate(Convert.ToDouble(lookAHead.Value) * co, Convert.ToDouble(con.Value) * co, op.Type);
-
-                        //    ActionsListView.Items.Add($"{GetOperatorVerb(token.Type)} {Convert.ToDouble(previousToken.Value) * co} and {tmp}.");
-                        //    runningValue += Operate(Convert.ToDouble(previousToken.Value) * co, tmp, token.Type);
-                        //    previousToken = new Token { Type = TokenType.Unknown };
-                        //}
-                        //else
-                        //{
-                        if (previousToken.Type != TokenType.Unknown)
-                        {
-                            ActionsListView.Items.Add($"{GetOperatorVerb(token.Type)} {Convert.ToDouble(previousToken.Value) * co} and {Convert.ToDouble(lookAHead.Value) * co}.");
-                            runningValue += Operate(Convert.ToDouble(previousToken.Value) * co, Convert.ToDouble(lookAHead.Value) * co, token.Type);
-                        }
-                        else
-                        {
-                            ActionsListView.Items.Add($"{GetOperatorVerb(token.Type)} {runningValue} and {Convert.ToDouble(lookAHead.Value) * co}.");
-                            runningValue = Operate(runningValue, Convert.ToDouble(lookAHead.Value) * co, token.Type);
-                        }
-                        //}
-                    }
-                }
-                else if(token.Type == TokenType.Constant)
-                {
-                    previousToken = token;
-                }
             }
 
             return runningValue;
         }
 
-        List<List<Node>> GetSubExpressions(List<Node> tokens)
+        double HandleMultAndDiv(Stack<Token> tokens)
         {
-            var expressions = new List<List<Node>>();
+            var runningValue = 0d;
-            var stack = new Stack<List<Node>>();
+            var previousToken = new Token() { Type = TokenType.Unknown };
-            var tmp = new List<Node>();
-            var skipCount = 0;
-            var nestingLevel = 0;
 
-            for(var i = 0; i < tokens.Count; i++)
+            for(; ;)
             {
-                if(skipCount > 0)
+                if (tokens.Count == 0) break;
+                //"Current" token.
+                if (tokens.Peek().Type != TokenType.Multiply && tokens.Peek().Type != TokenType.Divide && tokens.Peek().Type != TokenType.Constant && tokens.Peek().Type != TokenType.Variable)
                 {
-                    skipCount--;
+                    break;
+                }
+
+                var currentToken = tokens.Pop();
+
+                if (currentToken.Type == TokenType.Constant)
+                {
+                    previousToken = currentToken;
+                    continue;
+                }
+                else if (currentToken.Type == TokenType.Multiply || currentToken.Type == TokenType.Divide)
+                {
+                    var lookAHead = tokens.Pop();
+
+                    if (lookAHead.Type == TokenType.ExpStart)
+                    {
+                        var tmp = HandleParenthesis(tokens, true);
+
+                        if (runningValue == 0) runningValue = Operate(Convert.ToDouble(previousToken.Value), tmp, currentToken.Type);
+                        else runningValue = Operate(runningValue, tmp, currentToken.Type);
+                        previousToken.Type = TokenType.Unknown;
+
+                        continue;
+                    }
+
+                    if (lookAHead.Type ==  TokenType.Constant)
+                    {
+                        if (runningValue == 0) runningValue = Operate(Convert.ToDouble(previousToken.Value), Convert.ToDouble(lookAHead.Value), currentToken.Type);
+                        else runningValue = Operate(runningValue, Convert.ToDouble(lookAHead.Value), currentToken.Type);
+
+                        previousToken.Type = TokenType.Unknown;
+                    }
+                    else if(lookAHead.Type == TokenType.ExpStart)
+                    {
+                        var tmp = HandleParenthesis(tokens, true);
+
+                        if (runningValue == 0) runningValue = Operate(Convert.ToDouble(previousToken.Value), tmp, currentToken.Type);
+                        else runningValue = Operate(runningValue, tmp, currentToken.Type);
+
+                        previousToken.Type = TokenType.Unknown;
+                    }
+                }
+            }
+
+            return runningValue;
+        }
+
+        double HandleAddAndSub(Stack<Token> tokens)
+        {
+            var runningValue = 0d;
+            var previousToken = new Token() { Type = TokenType.Unknown };
+
+            for(; ;)
+            {
+                if (tokens.Count == 0) break;
+
+                var currentToken = tokens.Pop();
+
+                if(currentToken.Type == TokenType.Constant)
+                {
+                    previousToken = currentToken;
                     continue;
                 }
 
-                var token = tokens[i];
+                if (currentToken.Type == TokenType.ExpEnd)
-
-                //if (stack.Count > 0 && nestingLevel == 0)
-                //{
-                //    if (!stack.Peek()[0].IsCoefficent)
-                //    {
-                //        var offset = 0;
-
-                //        while(stack.Count > 0)
-                //        {
-                //            expressions.Insert(0, stack.Pop());
-
-                //            offset++;
-                //        }
-                //    }
-                //}
-
-                if (token.IsCoefficent)
                 {
-                    //var lookAhead = tokens[i + 1];
+                    tokens.Push(currentToken);
-
+                    break;
-                    //if(lookAhead.Type != Node.Token.ExpStart)
-                    //{
-                        if (tmp.Count > 0) expressions.Add(new List<Node>(tmp));
-                        expressions.Add(new List<Node>() { token });
-                    //}
-                    //else
-                    //{
-                    //    stack.Push(new List<Node>(tmp));
-                    //}
-
-                    tmp.Clear();
                 }
-                else if (token.Type == Node.Token.ExpStart)
+
+                if(currentToken.Type == TokenType.ExpStart)
                 {
-                    nestingLevel++;
+                    var tmp = HandleParenthesis(tokens);
 
-                    //if (i - 1 >= 0)
+                    runningValue = tmp;
-                    //{
-                    //    var lookBehind = tokens[i - 1];
-
-                    //    if (lookBehind.IsCoefficent)
-                    //    {
-                    //        tmp.Remove(tmp.Last());
-                    //        expressions.Add(new List<Node>(tmp));
-                    //        tmp.Clear();
-                    //        stack.Push(new List<Node> { lookBehind });
-                    //        //tmp.Add(token);
-                    //        continue;
-                    //    }
-                    //}
-
-                    if (tmp.Count > 0) expressions.Add(new List<Node>(tmp));
-                    tmp.Clear();
-                    tmp.Add(token);
                 }
-                else if(token.Type == Node.Token.ExpEnd)
+                else if(currentToken.Type == TokenType.Add || currentToken.Type == TokenType.Subtract)
                 {
-                    nestingLevel--;
+                    var lookAHead = tokens.Pop();
 
-                    if (i + 1 < tokens.Count)
+                    if (lookAHead.Type == TokenType.ExpStart)
                     {
-                        var lookAHead = tokens[i + 1];
+                        var tmp = HandleParenthesis(tokens);
 
-                        if (lookAHead.Type == Node.Token.Power)
+                        if (runningValue == 0) runningValue = Operate(Convert.ToDouble(previousToken.Value), tmp, currentToken.Type);
-                        {
+                        else runningValue = Operate(runningValue, tmp, currentToken.Type);
-                            var toPowerOf = tokens[i + 2];
 
-                            tmp.Add(token);
+                        previousToken.Type = TokenType.Unknown;
-                            tmp.Add(lookAHead);
+
-                            tmp.Add(toPowerOf);
+                        continue;
-                            expressions.Add(new List<Node>(tmp));
-                            tmp.Clear();
-                            skipCount = 2;
-                            continue;
-                        }
                     }
 
-                    tmp.Add(token);
+                    if (tokens.Count > 0 && (tokens.Peek().Type == TokenType.Multiply || tokens.Peek().Type == TokenType.Divide))
-                    if (tmp.Count > 0) expressions.Add(new List<Node>(tmp));
+                    {
-                    tmp.Clear();
+                        tokens.Push(lookAHead);
+                        var tmp = HandleMultAndDiv(tokens);
+
+                        if (runningValue == 0) runningValue = Operate(Convert.ToDouble(previousToken.Value), tmp, currentToken.Type);
+                        else runningValue = Operate(runningValue, tmp, currentToken.Type);
+
+                        previousToken.Type = TokenType.Unknown;
+                    }
+                    else
+                    {
+                        if (runningValue == 0) runningValue = Operate(Convert.ToDouble(previousToken.Value), Convert.ToDouble(lookAHead.Value), currentToken.Type);
+                        else runningValue = Operate(runningValue, Convert.ToDouble(lookAHead.Value), currentToken.Type);
+
+                        previousToken.Type = TokenType.Unknown;
+                    }
                 }
-                else
+                else if (currentToken.Type == TokenType.Multiply || currentToken.Type == TokenType.Divide)
                 {
-                    tmp.Add(token);
+                    tokens.Push(currentToken);
+                    if (previousToken.Type != TokenType.Unknown) tokens.Push(previousToken);
+                    else tokens.Push(new Token { Type = TokenType.Constant, Value = runningValue.ToString() });
+                    var tmp = HandleMultAndDiv(tokens);
+
+                    previousToken.Type = TokenType.Unknown;
+                    //TODO: this is wrong I'm sure.
+                    runningValue = tmp;
                 }
             }
 
-            if(tmp.Count > 0)
+            return runningValue;
-            {
-                expressions.Add(new List<Node>(tmp));
-            }
-
-            return expressions;
         }
 
         List<Token> FlattenInput(string expression)
@@ -377,13 +335,13 @@ namespace Engine
 
                         if(lookBehind.Type == TokenType.ExpEnd)
                         {
-                            tokens.Add(new Token() { Value = "^", Type = TokenType.Power, IsCoefficent = false });
+                            tokens.Add(new Token() { Value = "^", Type = TokenType.Power });
                         }
                     }
 
                     if((i + 1) == expression.Length)
                     {
-                        tokens.Add(new Token() { Value = $"{tmp}{c}", Type = TokenType.Constant, IsCoefficent = false });//new Node($"{tmp}{c}", Node.Token.Constant));
+                        tokens.Add(new Token() { Value = $"{tmp}{c}", Type = TokenType.Constant });//new Node($"{tmp}{c}", Node.Token.Constant));
                     }
 
                     parsingNumber = true;
@@ -395,10 +353,11 @@ namespace Engine
                 {
                     if (parsingNumber)
                     {
-                        tokens.Add(new Token() { Value = tmp, Type = TokenType.Constant, IsCoefficent = true });//new Node(tmp, Node.Token.Constant) { IsCoefficent = true });
+                        tokens.Add(new Token() { Value = tmp, Type = TokenType.Constant });
+                        tokens.Add(new Token() { Value = "*", Type = TokenType.Multiply });                        
                     }
 
-                    tokens.Add(new Token() { Value = "(", Type = TokenType.ExpStart, IsCoefficent = false });//new Node("(", Node.Token.ExpStart));
+                    tokens.Add(new Token() { Value = "(", Type = TokenType.ExpStart });//new Node("(", Node.Token.ExpStart));
                     parsingNumber = false;
                     tmp = string.Empty;
                     continue;
@@ -407,10 +366,10 @@ namespace Engine
                 {
                     if (parsingNumber)
                     {
-                        tokens.Add(new Token() { Value = tmp, Type = TokenType.Constant, IsCoefficent = false }); //new Node(tmp, Node.Token.Constant));                        
+                        tokens.Add(new Token() { Value = tmp, Type = TokenType.Constant }); //new Node(tmp, Node.Token.Constant));                        
                     }
 
-                    tokens.Add(new Token() { Value = ")", Type = TokenType.ExpEnd, IsCoefficent = false }); //new Node(c.ToString(), Node.Token.ExpEnd));
+                    tokens.Add(new Token() { Value = ")", Type = TokenType.ExpEnd }); //new Node(c.ToString(), Node.Token.ExpEnd));
                     parsingNumber = false;
                     tmp = string.Empty;
                     continue;
@@ -419,10 +378,10 @@ namespace Engine
                 {
                     if(parsingNumber)
                     {
-                        tokens.Add(new Token() { Value = tmp, Type = TokenType.Constant, IsCoefficent = false }); //new Node(tmp, Node.Token.Constant));
+                        tokens.Add(new Token() { Value = tmp, Type = TokenType.Constant }); //new Node(tmp, Node.Token.Constant));
                     }
 
-                    tokens.Add(new Token() { Value = c.ToString(), Type = op, IsCoefficent = false });//new Node(c.ToString(), op));
+                    tokens.Add(new Token() { Value = c.ToString(), Type = op });//new Node(c.ToString(), op));
                     parsingNumber = false;
                     tmp = string.Empty;
                     continue;
@@ -444,7 +403,7 @@ namespace Engine
 
                         if (lookBehind.Type == TokenType.ExpEnd)
                         {
-                            tokens.Add(new Token() { Value = "^", Type = TokenType.Power, IsCoefficent = false });//new Node("^", Node.Token.Power));
+                            tokens.Add(new Token() { Value = "^", Type = TokenType.Power });
                         }
                     }
 
@@ -454,7 +413,8 @@ namespace Engine
 
                         if(lookAHead == '(')
                         {
-                            tokens.Add(new Token() { Value = c.ToString(), Type = TokenType.Variable, IsCoefficent = true });
+                            tokens.Add(new Token() { Value = c.ToString(), Type = TokenType.Variable });
+                            tokens.Add(new Token() { Value = "*", Type = TokenType.Multiply });
                             tmp = string.Empty;
                             parsingNumber = false;
                             continue;
@@ -463,10 +423,11 @@ namespace Engine
 
                     if (parsingNumber)
                     {
-                        tokens.Add(new Token() {Value = tmp, Type = TokenType.Constant, IsCoefficent = true });
+                        tokens.Add(new Token() { Value = tmp, Type = TokenType.Constant });
+                        tokens.Add(new Token() { Value = "*", Type = TokenType.Multiply });
                     }
 
-                    tokens.Add(new Token() { Value = c.ToString(), Type = TokenType.Variable, IsCoefficent = false });
+                    tokens.Add(new Token() { Value = c.ToString(), Type = TokenType.Variable });
                     parsingNumber = false;
                     tmp = string.Empty;
                 }
@@ -475,102 +436,24 @@ namespace Engine
             return tokens;
         }
 
-        //double Calc(List<List<Node>> expressions, double co = 1)
+        double Operate(double n1, double n2, TokenType operation, [CallerMemberName] string source = "")
-        //{
-        //    //Assumption: an operator is never last in the list.
-        //    //double runningTotal = 0;
-        //    double lastValue = 0;
-        //    var next = true;
-        //    Node previousToken = new Node("zzzz", Node.Token.Unknown);
-
-        //    for(var i = 0; i < expressions.Count;)
-        //    {
-        //        if (!next) break;
-
-        //        var tokens = expressions[i];
-        //        expressions.RemoveAt(i);
-
-        //        for (var j = 0; j < tokens.Count; j++)
-        //        {
-        //            var token = tokens[j];
-
-        //            if(token.IsCoefficent)
-        //            {
-        //                if(tokens.Count == 1)
-        //                {
-        //                    return Calc(expressions, Convert.ToDouble(token.Value));
-        //                }
-        //            }
-        //            else if(token.Type == Node.Token.Constant)
-        //            {
-        //                previousToken = token;
-        //            }
-        //            else if(token.Type == Node.Token.Variable)
-        //            {
-        //                //TODO: do symbol lookup to get value for this variale.
-        //                previousToken = new Node("666", Node.Token.Variable);
-        //            }
-        //            else if(GetOperator(token.Value[0]) != Node.Token.Unknown)
-        //            {
-        //                if(tokens.Count > j + 1)
-        //                {
-        //                    j++;
-        //                    var lookAHead = tokens[j];
-
-        //                    if(lookAHead.Type == Node.Token.Constant)
-        //                    {
-        //                        if (previousToken.Type != Node.Token.Unknown)
-        //                        {
-        //                            lastValue = Operate(Convert.ToDouble(previousToken.Value) * co, Convert.ToDouble(lookAHead.Value) * co, token.Type);
-        //                            previousToken = new Node("zzzz", Node.Token.Unknown);
-        //                        }
-        //                        else
-        //                            lastValue = Operate(lastValue * co, Convert.ToDouble(lookAHead.Value) * co, token.Type);
-        //                    }
-        //                }
-        //                else
-        //                {
-        //                    lastValue = Operate(Convert.ToDouble(previousToken.Value), Calc(expressions), token.Type);
-        //                }
-        //            }
-        //            else if(token.Type == Node.Token.ExpStart)
-        //            {
-
-        //            }
-        //            else if(token.Type == Node.Token.ExpEnd)
-        //            {
-        //                if(tokens.Count > j + 1)
-        //                {
-        //                    var lookAHead = tokens[j + 1];
-
-        //                    if(lookAHead.Type == Node.Token.Power)
-        //                    {
-        //                        lookAHead = tokens[j + 2];
-        //                        lastValue = Operate(lastValue, Convert.ToDouble(lookAHead.Value), Node.Token.Power);
-        //                    }
-        //                }
-
-        //                next = false;
-        //            }
-        //        }
-        //    }
-
-        //    return lastValue;
-        //}
-
-        double Operate(double n1, double n2, TokenType operation)
         {
             switch(operation)
             {
                 case TokenType.Add:
+                    ActionsListView.Items.Add($"From {source} {GetOperatorVerb(operation)} {n1} and {n2} to get {n1 + n2}");
                     return n1 + n2;
                 case TokenType.Divide:
+                    ActionsListView.Items.Add($"From {source} {GetOperatorVerb(operation)} {n1} and {n2} to get {n1 / n2}");
                     return n1 / n2;
                 case TokenType.Multiply:
+                    ActionsListView.Items.Add($"From {source} {GetOperatorVerb(operation)} {n1} and {n2} to get {n1 * n2}");
                     return n1 * n2;
                 case TokenType.Power:
+                    ActionsListView.Items.Add($"From {source} {GetOperatorVerb(operation)} {n1} to the power of {n2} to get {Math.Pow(n1, n2)}");
                     return Math.Pow(n1, n2);
                 case TokenType.Subtract:
+                    ActionsListView.Items.Add($"From {source} {GetOperatorVerb(operation)} {n1} and {n2} to get {n1 - n2}");
                     return n1 - n2;
                 default:
                     throw new Exception("Token must be an operator!");
@@ -618,7 +501,6 @@ namespace Engine
         struct Token
         {
             public string Value;
-            public bool IsCoefficent;
             public TokenType Type;
         }
 

readme.md

@@ -1,7 +1,7 @@
 A very terrible first go at parsing and calculating mathamtical expressions.
 
-This project evolved into the [calc_engine](https://gitea.copyrightcrusader.org/glm94/calc_engine) project.
+This project evolved into the [calc_engine](https://gitea.copyrightcrusader.org/glm94/calc_engine) project which started as a striaght
-This code was eventually ported into Python to create the calc_engine. That later evolved into the [terrain_generator](https://gitea.copyrightcrusader.org/glm94/terrain_generator).
+C# to Python port, complete with the very horrible logic this repo shows off. The calc_engine later evolved into the [terrain_generator](https://gitea.copyrightcrusader.org/glm94/terrain_generator).
 
 However, this project is offically abandoned and no longer active. Its only here as a archive of what I've done, and how much I learned since
 writing this code. Which, to be frank, is very bad.