Update ListEvalValue to handle length unary operator

PorygonSharp/EvalValues/EvalValueCreator.cs

@@ -63,8 +63,8 @@ namespace PorygonSharp.EvalValues
         private static EvalValue CreateListEvalValue(IList collection, Type type)
         {
             var helper = new ListEvalValue(collection, type);
-            var ptr = CreateCollectionValue(IntPtr.Zero, helper.ParentCollection, helper.Getter, helper.Setter,
-                helper.GetIterator);
+            var ptr = CreateCollectionValue(IntPtr.Zero, helper.ParentCollectionPtr, helper.GetterPtr, helper.SetterPtr,
+                helper.GetIteratorPtr, helper.GetLengthPtr);
             return new EvalValue(ptr);
         }
         
@@ -86,6 +86,6 @@ namespace PorygonSharp.EvalValues
 
         [DllImport("PorygonLang", EntryPoint = "CreateCollectionValue", CallingConvention = CallingConvention.Cdecl)]
         private static extern IntPtr CreateCollectionValue(IntPtr type, IntPtr parent, IntPtr getter, IntPtr setter,
-            IntPtr iterator);
+            IntPtr iterator, IntPtr size);
     }
 }

PorygonSharp/EvalValues/ListEvalValue.cs

@@ -6,36 +6,69 @@ namespace PorygonSharp.EvalValues
 {
     internal class ListEvalValue
     {
+        private readonly IList _list;
+        private readonly Type _valueType;
+        
         private delegate IntPtr GetterDelegate(IntPtr parent, IntPtr index);
         private delegate void SetterDelegate(IntPtr parent, IntPtr index, IntPtr value);
-        public delegate IntPtr GetIteratorDelegate(IntPtr parent);
+        private delegate IntPtr GetIteratorDelegate(IntPtr parent);
+        private delegate int GetLengthDelegate(IntPtr parent);
+
+        // ReSharper disable PrivateFieldCanBeConvertedToLocalVariable
+        private readonly GetterDelegate _getter; 
+        private readonly SetterDelegate _setter; 
+        private readonly GetIteratorDelegate _getIterator; 
+        private readonly GetLengthDelegate _getLength; 
+        // ReSharper restore PrivateFieldCanBeConvertedToLocalVariable
+
+        public readonly IntPtr ParentCollectionPtr;
+        public readonly IntPtr GetterPtr;
+        public readonly IntPtr SetterPtr;
+        public readonly IntPtr GetIteratorPtr;
+        public readonly IntPtr GetLengthPtr;
         
-        public readonly IntPtr ParentCollection;
-        public readonly IntPtr Getter;
-        public readonly IntPtr Setter;
-        public readonly IntPtr GetIterator;
         
         public ListEvalValue(IList list, Type type)
         {
-            var valueType = type.IsArray ? type.GetElementType() : type.GetGenericArguments()[0];
-            if (valueType == null)
+            _list = list;
+            _valueType = type.IsArray ? type.GetElementType() : type.GetGenericArguments()[0];
+            if (_valueType == null)
                 throw new ArgumentNullException();
 
-            ParentCollection = ObjectEvalValueHandler.GetObjectPtr(list);
-            Getter = Marshal.GetFunctionPointerForDelegate(new GetterDelegate((parent, index) =>
-            {
-                var val = new EvalValue(index).EvaluateInteger();
-                return EvalValueCreator.CreateValue(list[(int) val - 1]).GetPointer();
-            }));
-            Setter = Marshal.GetFunctionPointerForDelegate(new SetterDelegate((parent, index, value) =>
-            {
-                var key = new EvalValue(index).EvaluateInteger();
-                var val = new EvalValue(value).GetObjectValue();
-                list[(int) key - 1] = Convert.ChangeType(val, valueType);
-            }));
-            GetIterator =
-                Marshal.GetFunctionPointerForDelegate(new GetIteratorDelegate(parent =>
-                    ListIterator.CreateListIterator(list)));
+            ParentCollectionPtr = IntPtr.Zero;
+            _getter = Getter;
+            _setter = Setter;
+            _getIterator = GetIterator;
+            _getLength = GetLength;
+
+            GetterPtr = Marshal.GetFunctionPointerForDelegate(_getter);
+            GetterPtr = Marshal.GetFunctionPointerForDelegate(_getter);
+            SetterPtr = Marshal.GetFunctionPointerForDelegate(_setter);
+            GetIteratorPtr = Marshal.GetFunctionPointerForDelegate(_getIterator);
+            GetLengthPtr = Marshal.GetFunctionPointerForDelegate(_getLength);
+        }
+
+        private IntPtr Getter(IntPtr parent, IntPtr index)
+        {
+            var val = new EvalValue(index).EvaluateInteger();
+            return EvalValueCreator.CreateValue(_list[(int) val - 1]).GetPointer();
+        }
+        
+        private void Setter(IntPtr parent, IntPtr index, IntPtr value)
+        {
+            var key = new EvalValue(index).EvaluateInteger();
+            var val = new EvalValue(value).GetObjectValue();
+            _list[(int) key - 1] = Convert.ChangeType(val, _valueType);
+        }
+        
+        private IntPtr GetIterator(IntPtr parent)
+        {
+            return ListIterator.CreateListIterator(_list);
+        }
+
+        private int GetLength(IntPtr parent)
+        {
+            return _list.Count;
         }
     }
 }