sebastienros · lahma · Nov 17, 2022 · Nov 17, 2022
diff --git a/Jint.Benchmark/ForBenchmark.cs b/Jint.Benchmark/ForBenchmark.cs
@@ -0,0 +1,51 @@
+using BenchmarkDotNet.Attributes;
+
+namespace Jint.Benchmark;
+
+[MemoryDiagnoser]
+public class ForBencmark
+{
+    private const string script = @"
+var stringArray = ['1', '2', '3', '4', '5', '6', '7', '8', '9', '10', '11', '12', '13', '14', '15', '16', '17', '18', '19', '20', '21', '22', '23', '24', '25', '26', '27', '28', '29', '30', '31', '32', '33', '34', '35', '36', '37', '38', '39', '40', '41', '42', '43', '44', '45', '46', '47', '48', '49', '50', '51', '52', '53', '54', '55', '56', '57', '58', '59', '60', '61', '62', '63', '64', '65', '66', '67', '68', '69', '70', '71', '72', '73', '74', '75', '76', '77', '78', '79', '80', '81', '82', '83', '84', '85', '86', '87', '88', '89', '90', '91', '92', '93', '94', '95', '96', '97', '98', '99', '100', '101', '102', '103', '104', '105', '106', '107', '108', '109', '110', '111', '112', '113', '114', '115', '116', '117', '118', '119', '120', '121', '122', '123', '124', '125', '126', '127', '128', '129', '130', '131', '132', '133', '134', '135', '136', '137', '138', '139', '140', '141', '142', '143', '144', '145', '146', '147', '148', '149', '150', '151', '152', '153', '154', '155', '156', '157', '158', '159', '160', '161', '162', '163', '164', '165', '166', '167', '168', '169', '170', '171', '172', '173', '174', '175', '176', '177', '178', '179', '180', '181', '182', '183', '184', '185', '186', '187', '188', '189', '190', '191', '192', '193', '194', '195', '196', '197', '198', '199', '200', '201', '202', '203', '204', '205', '206', '207', '208', '209', '210', '211', '212', '213', '214', '215', '216', '217', '218', '219', '220', '221', '222', '223', '224', '225', '226', '227', '228', '229', '230', '231', '232', '233', '234', '235', '236', '237', '238', '239', '240', '241', '242', '243', '244', '245', '246', '247', '248', '249', '250', '251', '252', '253', '254', '255', '256', '257', '258', '259', '260', '261', '262', '263', '264', '265', '266', '267', '268', '269', '270', '271', '272', '273', '274', '275', '276', '277', '278', '279', '280', '281', '282', '283', '284', '285', '286', '287', '288', '289', '290', '291', '292', '293', '294', '295', '296', '297', '298', '299', '300', '301', '302', '303', '304', '305', '306', '307', '308', '309', '310', '311', '312', '313', '314', '315', '316', '317', '318', '319', '320', '321', '322', '323', '324', '325', '326', '327', '328', '329', '330', '331', '332', '333', '334', '335', '336', '337', '338', '339', '340', '341', '342', '343', '344', '345', '346', '347', '348', '349', '350', '351', '352', '353', '354', '355', '356', '357', '358', '359', '360', '361', '362', '363', '364', '365', '366', '367', '368', '369', '370', '371', '372', '373', '374', '375', '376', '377', '378', '379', '380', '381', '382', '383', '384', '385', '386', '387', '388', '389', '390', '391', '392', '393', '394', '395', '396', '397', '398', '399', '400', '401', '402', '403', '404', '405', '406', '407', '408', '409', '410', '411', '412', '413', '414', '415', '416', '417', '418', '419', '420', '421', '422', '423', '424', '425', '426', '427', '428', '429', '430', '431', '432', '433', '434', '435', '436', '437', '438', '439', '440', '441', '442', '443', '444', '445', '446', '447', '448', '449', '450', '451', '452', '453', '454', '455', '456', '457', '458', '459', '460', '461', '462', '463', '464', '465', '466', '467', '468', '469', '470', '471', '472', '473', '474', '475', '476', '477', '478', '479', '480', '481', '482', '483', '484', '485', '486', '487', '488', '489', '490', '491', '492', '493', '494', '495', '496', '497', '498', '499', '500', '501', '502', '503', '504', '505', '506', '507', '508', '509', '510', '511', '512', '513', '514', '515', '516', '517', '518', '519', '520', '521', '522', '523', '524', '525', '526', '527', '528', '529', '530', '531', '532', '533', '534', '535', '536', '537', '538', '539', '540', '541', '542', '543', '544', '545', '546', '547', '548', '549', '550', '551', '552', '553', '554', '555', '556', '557', '558', '559', '560', '561', '562', '563', '564', '565', '566', '567', '568', '569', '570', '571', '572', '573', '574', '575', '576', '577', '578', '579', '580', '581', '582', '583', '584', '585', '586', '587', '588', '589', '590', '591', '592', '593', '594', '595', '596', '597', '598', '599', '600', '601', '602', '603', '604', '605', '606', '607', '608', '609', '610', '611', '612', '613', '614', '615', '616', '617', '618', '619', '620', '621', '622', '623', '624', '625', '626', '627', '628', '629', '630', '631', '632', '633', '634', '635', '636', '637', '638', '639', '640', '641', '642', '643', '644', '645', '646', '647', '648', '649', '650', '651', '652', '653', '654', '655', '656', '657', '658', '659', '660', '661', '662', '663', '664', '665', '666', '667', '668', '669', '670', '671', '672', '673', '674', '675', '676', '677', '678', '679', '680', '681', '682', '683', '684', '685', '686', '687', '688', '689', '690', '691', '692', '693', '694', '695', '696', '697', '698', '699', '700', '701', '702', '703', '704', '705', '706', '707', '708', '709', '710', '711', '712', '713', '714', '715', '716', '717', '718', '719', '720', '721', '722', '723', '724', '725', '726', '727', '728', '729', '730', '731', '732', '733', '734', '735', '736', '737', '738', '739', '740', '741', '742', '743', '744', '745', '746', '747', '748', '749', '750', '751', '752', '753', '754', '755', '756', '757', '758', '759', '760', '761', '762', '763', '764', '765', '766', '767', '768', '769', '770', '771', '772', '773', '774', '775', '776', '777', '778', '779', '780', '781', '782', '783', '784', '785', '786', '787', '788', '789', '790', '791', '792', '793', '794', '795', '796', '797', '798', '799', '800', '801', '802', '803', '804', '805', '806', '807', '808', '809', '810', '811', '812', '813', '814', '815', '816', '817', '818', '819', '820', '821', '822', '823', '824', '825', '826', '827', '828', '829', '830', '831', '832', '833', '834', '835', '836', '837', '838', '839', '840', '841', '842', '843', '844', '845', '846', '847', '848', '849', '850', '851', '852', '853', '854', '855', '856', '857', '858', '859', '860', '861', '862', '863', '864', '865', '866', '867', '868', '869', '870', '871', '872', '873', '874', '875', '876', '877', '878', '879', '880', '881', '882', '883', '884', '885', '886', '887', '888', '889', '890', '891', '892', '893', '894', '895', '896', '897', '898', '899', '900', '901', '902', '903', '904', '905', '906', '907', '908', '909', '910', '911', '912', '913', '914', '915', '916', '917', '918', '919', '920', '921', '922', '923', '924', '925', '926', '927', '928', '929', '930', '931', '932', '933', '934', '935', '936', '937', '938', '939', '940', '941', '942', '943', '944', '945', '946', '947', '948', '949', '950', '951', '952', '953', '954', '955', '956', '957', '958', '959', '960', '961', '962', '963', '964', '965', '966', '967', '968', '969', '970', '971', '972', '973', '974', '975', '976', '977', '978', '979', '980', '981', '982', '983', '984', '985', '986', '987', '988', '989', '990', '991', '992', '993', '994', '995', '996', '997', '998', '999', '1000'];
+";
+
+    private Engine engine;
+
+
+    [GlobalSetup]
+    public void Setup()
+    {
+        engine = new Engine();
+        engine.Execute(script);
+    }
+
+    [Benchmark]
+    public void ForOfVar()
+    {
+        engine.Execute("for (var value of stringArray) { }");
+    }
+
+    [Benchmark]
+    public void ForOfLet()
+    {
+        engine.Execute("for (let value of stringArray) { }");
+    }
+
+    [Benchmark]
+    public void ForOfConst()
+    {
+        engine.Execute("for (const value of stringArray) { }");
+    }
+
+    [Benchmark]
+    public void ForVar()
+    {
+        engine.Execute("for (var i = 0; i < stringArray.length; ++i) { }");
+    }
+
+    [Benchmark]
+    public void ForLet()
+    {
+        engine.Execute("for (let i = 0; i < stringArray.length; ++i) { }");
+    }
+}
diff --git a/Jint.Tests/Runtime/EngineTests.cs b/Jint.Tests/Runtime/EngineTests.cs
@@ -868,7 +868,7 @@ public void ShouldInvokeAFunctionValueThatBelongsToAnObject()
             ");
 
             var obj = _engine.GetValue("obj").AsObject();
-            var getFoo = obj.Get("getFoo", obj);
+            var getFoo = obj.Get("getFoo");
 
             Assert.Equal("foo is 5, bar is 7", _engine.Invoke(getFoo, obj, new object[] { 7 }).AsString());
         }
@@ -881,7 +881,7 @@ public void ShouldNotInvokeNonFunctionValueThatBelongsToAnObject()
             ");
 
             var obj = _engine.GetValue("obj").AsObject();
-            var foo = obj.Get("foo", obj);
+            var foo = obj.Get("foo");
 
             Assert.Throws<JavaScriptException>(() => _engine.Invoke(foo, obj, new object[] { }));
         }

diff --git a/Jint.Tests/Runtime/JsValueConversionTests.cs b/Jint.Tests/Runtime/JsValueConversionTests.cs
@@ -33,7 +33,7 @@ public void ShouldBeAnArray()
         [Fact]
         public void ShouldBeABoolean()
         {
-            var value = new JsBoolean(true);
+            var value = JsBoolean.True;
             Assert.Equal(true, value.IsBoolean());
             Assert.Equal(false, value.IsArray());
             Assert.Equal(false, value.IsDate());

diff --git a/Jint/Native/Array/ArrayInstance.cs b/Jint/Native/Array/ArrayInstance.cs
@@ -474,6 +474,15 @@ public sealed override JsValue Get(JsValue property, JsValue receiver)
                 return value;
             }
 
+            if (property == CommonProperties.Length)
+            {
+                var length = _length?._value;
+                if (length is not null)
+                {
+                    return length;
+                }
+            }
+
             return base.Get(property, receiver);
         }
 

diff --git a/Jint/Native/Array/ArrayIteratorPrototype.cs b/Jint/Native/Array/ArrayIteratorPrototype.cs
@@ -85,25 +85,25 @@ public override bool TryIteratorStep(out ObjectInstance nextItem)
                 {
                     nextItem = _kind switch
                     {
-                        ArrayIteratorType.Key => new ValueIteratorPosition(_engine, _position),
-                        ArrayIteratorType.Value => new ValueIteratorPosition(_engine, _typedArray[(int) _position]),
-                        _ => new KeyValueIteratorPosition(_engine, _position, _typedArray[(int) _position])
+                        ArrayIteratorType.Key => IteratorResult.CreateValueIteratorPosition(_engine, JsNumber.Create(_position)),
+                        ArrayIteratorType.Value => IteratorResult.CreateValueIteratorPosition(_engine, _typedArray[(int) _position]),
+                        _ => IteratorResult.CreateKeyValueIteratorPosition(_engine, JsNumber.Create(_position), _typedArray[(int) _position])
                     };
                 }
                 else
                 {
                     _operations!.TryGetValue(_position, out var value);
                     if (_kind == ArrayIteratorType.Key)
                     {
-                        nextItem = new ValueIteratorPosition(_engine, _position);
+                        nextItem = IteratorResult.CreateValueIteratorPosition(_engine, JsNumber.Create(_position));
                     }
                     else if (_kind == ArrayIteratorType.Value)
                     {
-                        nextItem = new ValueIteratorPosition(_engine, value);
+                        nextItem = IteratorResult.CreateValueIteratorPosition(_engine, value);
                     }
                     else
                     {
-                        nextItem = new KeyValueIteratorPosition(_engine, _position, value);
+                        nextItem = IteratorResult.CreateKeyValueIteratorPosition(_engine, JsNumber.Create(_position), value);
                     }
                 }
 
@@ -112,7 +112,7 @@ public override bool TryIteratorStep(out ObjectInstance nextItem)
             }
 
             _closed = true;
-            nextItem = KeyValueIteratorPosition.Done(_engine);
+            nextItem = IteratorResult.CreateKeyValueIteratorPosition(_engine);
             return false;
         }
     }

diff --git a/Jint/Native/Array/ArrayOperations.cs b/Jint/Native/Array/ArrayOperations.cs
@@ -146,7 +146,7 @@ public ObjectInstanceOperations(ObjectInstance target) : base(target)
 
             private double GetIntegerLength()
             {
-                var descValue = _target.Get(CommonProperties.Length, _target);
+                var descValue = _target.Get(CommonProperties.Length);
                 if (!ReferenceEquals(descValue, null))
                 {
                     return TypeConverter.ToInteger(descValue);
@@ -185,7 +185,7 @@ public override void EnsureCapacity(ulong capacity)
             }
 
             public override JsValue Get(ulong index)
-                => _target.Get(JsString.Create(index), _target);
+                => _target.Get(JsString.Create(index));
 
             public override bool TryGetValue(ulong index, out JsValue value)
             {
@@ -297,7 +297,7 @@ public override uint GetLength()
                     return _target.Length;
                 }
 
-                var descValue = _target.Get(CommonProperties.Length, _target);
+                var descValue = _target.Get(CommonProperties.Length);
                 if (!ReferenceEquals(descValue, null))
                 {
                     return (uint) TypeConverter.ToInteger(descValue);

diff --git a/Jint/Native/Array/ArrayPrototype.cs b/Jint/Native/Array/ArrayPrototype.cs
@@ -1273,7 +1273,7 @@ private JsValue ToLocaleString(JsValue thisObj, JsValue[] arguments)
             else
             {
                 var elementObj = TypeConverter.ToObject(_realm, firstElement);
-                var func = elementObj.Get("toLocaleString", elementObj) as ICallable;
+                var func = elementObj.Get("toLocaleString") as ICallable;
                 if (func is null)
                 {
                     ExceptionHelper.ThrowTypeError(_realm);
@@ -1292,7 +1292,7 @@ private JsValue ToLocaleString(JsValue thisObj, JsValue[] arguments)
                 else
                 {
                     var elementObj = TypeConverter.ToObject(_realm, nextElement);
-                    var func = elementObj.Get("toLocaleString", elementObj) as ICallable;
+                    var func = elementObj.Get("toLocaleString") as ICallable;
                     if (func is null)
                     {
                         ExceptionHelper.ThrowTypeError(_realm);

diff --git a/Jint/Native/Date/DatePrototype.cs b/Jint/Native/Date/DatePrototype.cs
@@ -815,7 +815,7 @@ private JsValue ToJSON(JsValue thisObj, JsValue[] arguments)
                 return Null;
             }
 
-            var toIso = o.Get("toISOString", o);
+            var toIso = o.Get("toISOString");
             var callable = toIso as ICallable;
             if (callable is null)
             {

diff --git a/Jint/Native/Function/FunctionInstance.cs b/Jint/Native/Function/FunctionInstance.cs
@@ -229,7 +229,7 @@ internal void SetFunctionName(JsValue name, string? prefix = null, bool force =
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
         internal ObjectInstance GetPrototypeFromConstructor(JsValue constructor, Func<Intrinsics, ObjectInstance> intrinsicDefaultProto)
         {
-            if (constructor.Get(CommonProperties.Prototype, constructor) is not ObjectInstance proto)
+            if (constructor.Get(CommonProperties.Prototype) is not ObjectInstance proto)
             {
                 var realm = GetFunctionRealm(constructor);
                 proto = intrinsicDefaultProto(realm.Intrinsics);

diff --git a/Jint/Native/Iterator/IteratorInstance.cs b/Jint/Native/Iterator/IteratorInstance.cs
@@ -2,7 +2,6 @@
 using Jint.Native.Object;
 using Jint.Native.RegExp;
 using Jint.Runtime;
-using Jint.Runtime.Descriptors;
 
 namespace Jint.Native.Iterator
 {
@@ -33,11 +32,11 @@ public virtual bool TryIteratorStep(out ObjectInstance nextItem)
         {
             if (_enumerable.MoveNext())
             {
-                nextItem = new ValueIteratorPosition(_engine, _enumerable.Current);
+                nextItem = IteratorResult.CreateValueIteratorPosition(_engine, _enumerable.Current);
                 return true;
             }
 
-            nextItem = ValueIteratorPosition.Done(_engine);
+            nextItem = IteratorResult.CreateValueIteratorPosition(_engine, done: JsBoolean.True);
             return false;
         }
 
@@ -50,40 +49,7 @@ public virtual void Close(CompletionType completion)
         /// </summary>
         private ObjectInstance CreateIterResultObject(JsValue value, bool done)
         {
-            return new IteratorResult(_engine, value, done ? JsBoolean.True :  JsBoolean.False);
-        }
-
-        internal sealed class KeyValueIteratorPosition : ObjectInstance
-        {
-            internal static ObjectInstance Done(Engine engine) => new KeyValueIteratorPosition(engine, null, null);
-
-            public KeyValueIteratorPosition(Engine engine, JsValue? key, JsValue? value) : base(engine)
-            {
-                var done = ReferenceEquals(null, key) && ReferenceEquals(null, value);
-                if (!done)
-                {
-                    var arrayInstance = engine.Realm.Intrinsics.Array.ArrayCreate(2);
-                    arrayInstance.SetIndexValue(0, key!, false);
-                    arrayInstance.SetIndexValue(1, value!, false);
-                    SetProperty("value", new PropertyDescriptor(arrayInstance, PropertyFlag.AllForbidden));
-                }
-                SetProperty("done", done ? PropertyDescriptor.AllForbiddenDescriptor.BooleanTrue : PropertyDescriptor.AllForbiddenDescriptor.BooleanFalse);
-            }
-        }
-
-        internal sealed class ValueIteratorPosition : ObjectInstance
-        {
-            internal static ObjectInstance Done(Engine engine, JsValue? value = null)
-                => new ValueIteratorPosition(engine, value ?? Undefined, true);
-
-            public ValueIteratorPosition(Engine engine, JsValue value, bool? done = null) : base(engine)
-            {
-                if (value is not null)
-                {
-                    SetProperty("value", new PropertyDescriptor(value, PropertyFlag.AllForbidden));
-                }
-                SetProperty("done", new PropertyDescriptor(done ?? value is null, PropertyFlag.AllForbidden));
-            }
+            return new IteratorResult(_engine, value, JsBoolean.Create(done));
         }
 
         internal sealed class ObjectIterator : IteratorInstance
@@ -94,7 +60,7 @@ internal sealed class ObjectIterator : IteratorInstance
             public ObjectIterator(ObjectInstance target) : base(target.Engine)
             {
                 _target = target;
-                if (target.Get(CommonProperties.Next, target) is not ICallable callable)
+                if (target.Get(CommonProperties.Next) is not ICallable callable)
                 {
                     ExceptionHelper.ThrowTypeError(target.Engine.Realm);
                     return;
@@ -173,11 +139,11 @@ public override bool TryIteratorStep(out ObjectInstance nextItem)
             {
                 if (_iterator.MoveNext())
                 {
-                    nextItem = new ValueIteratorPosition(_engine, (string) _iterator.Current);
+                    nextItem = IteratorResult.CreateValueIteratorPosition(_engine, (string) _iterator.Current);
                     return true;
                 }
 
-                nextItem = KeyValueIteratorPosition.Done(_engine);
+                nextItem = IteratorResult.CreateKeyValueIteratorPosition(_engine);
                 return false;
             }
         }