More Arithmetic, Better sectioning of code

machine.hpp

@@ -31,6 +31,9 @@ enum : int {
   // Two Arguments
   IncrementBy,
   DecrementBy,
+  MultiplyBy,
+  DivideBy,
+  ModulusBy,
   SetTo,
   Print,
 
@@ -57,21 +60,29 @@ private:
   void Execute(int command) {
     switch (State) {
     case NoCommand:
-      break;
-
-    case IncrementBy:
-      memory[currentPosition] += command;
-      State = NoCommand;
+      processCommand(command);
       return;
 
-    case DecrementBy:
-      memory[currentPosition] -= command;
-      State = NoCommand;
-      return;
+    // Arithmatic
     case SetTo:
       memory[currentPosition] = command;
-      State = NoCommand;
-      return;
+      break;
+    case IncrementBy:
+      memory[currentPosition] += command;
+      break;
+    case DecrementBy:
+      memory[currentPosition] -= command;
+      break;
+    case MultiplyBy:
+      memory[currentPosition] *= command;
+      break;
+    case DivideBy:
+      memory[currentPosition] /= command;
+      break;
+    case ModulusBy:
+      memory[currentPosition] %= command;
+      break;
+
     case Print:
       handlePrint(command);
       State = NoCommand;
@@ -82,7 +93,14 @@ private:
       return;
     }
 
-    // State: NoCommand
+    // This is only called after multi-argument functions are done
+    if (State != NoCommand) {
+      State = NoCommand;
+      return;
+    }
+  }
+
+  void processCommand(int command) {
     switch (command) {
     case MoveLeft:
       // Underflow wrap
@@ -106,8 +124,12 @@ private:
 
     // Double Argument Commands
     case Print:
+    case SetTo:
     case IncrementBy:
     case DecrementBy:
+    case MultiplyBy:
+    case DivideBy:
+    case ModulusBy:
       State = static_cast<Command>(command);
       return;