Add interactive exit function

src/cs-mic-cli/ExitRequestedState.cs

@@ -0,0 +1,7 @@
+namespace cs_mic_cli
+{
+    internal class ExitRequestedState
+    {
+        public bool Requested { get; set; }
+    }
+}

src/cs-mic-cli/Functions/Exit.cs

@@ -0,0 +1,45 @@
+using CSMic;
+
+namespace cs_mic_cli.Functions
+{
+    internal class Exit : ICodedFunction
+    {
+        private readonly ExitRequestedState exitRequestedState;
+
+        public string Name
+        {
+            get
+            {
+                return "exit";
+            }
+        }
+
+        public IEnumerable<FunctionArgument> ExpectedArguments
+        {
+            get
+            {
+                yield break;
+            }
+        }
+
+        public FunctionValue ReturnValue
+        {
+            get
+            {
+                return FunctionValue.NONE;
+            }
+        }
+
+        public Exit(ExitRequestedState exitRequestedState)
+        {
+            this.exitRequestedState = exitRequestedState;
+        }
+
+        public FunctionValue Execute(params FunctionArgument[] args)
+        {
+            this.exitRequestedState.Requested = true;
+
+            return FunctionValue.NONE;
+        }
+    }
+}

src/cs-mic-cli/Program.cs

@@ -71,16 +71,17 @@ namespace cs_mic_cli
             if (string.IsNullOrWhiteSpace(fullExpression) || options.Interactive)
             {
                 // console mode
-                bool exitRequested = false;
+                var exitRequestedState = new ExitRequestedState();
+                inputInterpreter.RegisterFunction(new Exit(exitRequestedState));
 
                 Console.CancelKeyPress += (_, e) =>
                 {
-                    e.Cancel = true;
-                    exitRequested = true;
+                    e.Cancel = false;
+                    exitRequestedState.Requested = true;
                     Console.WriteLine();
                 };
 
-                while (!exitRequested)
+                while (!exitRequestedState.Requested)
                 {
                     Console.Write("csmic> ");
 
@@ -92,7 +93,7 @@ namespace cs_mic_cli
                         break;
                     }
 
-                    Calculate(inputInterpreter, options, fullExpression);
+                    Calculate(inputInterpreter, options, fullExpression, exitRequestedState);
                 }
             }
             else
@@ -104,10 +105,15 @@ namespace cs_mic_cli
             return 0;
         }
 
-        private static void Calculate(InputInterpreter inputInterpreter, Options options, string expression)
+        private static void Calculate(InputInterpreter inputInterpreter, Options options, string expression, ExitRequestedState? exitRequestedState = null)
         {
             inputInterpreter.Interpret(expression);
 
+            if (exitRequestedState?.Requested == true)
+            {
+                return;
+            }
+
             Console.WriteLine(inputInterpreter.NumericValue);
             if(options.Verbose)
             {