Implement dict.clear() (#135)

runtime/dict.go

@@ -508,6 +508,18 @@ func dictsAreEqual(f *Frame, d1, d2 *Dict) (bool, *BaseException) {
 	return result, nil
 }
 
+func dictClear(f *Frame, args Args, _ KWArgs) (*Object, *BaseException) {
+	if raised := checkMethodArgs(f, "clear", args, DictType); raised != nil {
+		return nil, raised
+	}
+	d := toDictUnsafe(args[0])
+	d.mutex.Lock(f)
+	d.table = newDictTable(0)
+	d.incVersion()
+	d.mutex.Unlock(f)
+	return None, nil
+}
+
 func dictContains(f *Frame, seq, value *Object) (*Object, *BaseException) {
 	item, raised := toDictUnsafe(seq).GetItem(f, value)
 	if raised != nil {
@@ -713,6 +725,7 @@ func dictUpdate(f *Frame, args Args, kwargs KWArgs) (*Object, *BaseException) {
 }
 
 func initDictType(dict map[string]*Object) {
+	dict["clear"] = newBuiltinFunction("clear", dictClear).ToObject()
 	dict["get"] = newBuiltinFunction("get", dictGet).ToObject()
 	dict["items"] = newBuiltinFunction("items", dictItems).ToObject()
 	dict["iteritems"] = newBuiltinFunction("iteritems", dictIterItems).ToObject()

runtime/dict_test.go

@@ -46,6 +46,29 @@ func TestNewStringDict(t *testing.T) {
 	}
 }
 
+func TestDictClear(t *testing.T) {
+	clear := mustNotRaise(GetAttr(NewRootFrame(), DictType.ToObject(), NewStr("clear"), nil))
+	fun := newBuiltinFunction("TestDictClear", func(f *Frame, args Args, _ KWArgs) (*Object, *BaseException) {
+		if _, raised := clear.Call(f, args, nil); raised != nil {
+			return nil, raised
+		}
+		return args[0], nil
+	}).ToObject()
+	cases := []invokeTestCase{
+		{args: wrapArgs(NewDict()), want: NewDict().ToObject()},
+		{args: wrapArgs(newStringDict(map[string]*Object{"foo": NewInt(1).ToObject()})), want: NewDict().ToObject()},
+		{args: wrapArgs(newTestDict(2, None, "baz", 3.14)), want: NewDict().ToObject()},
+		{args: wrapArgs(NewDict(), NewList()), wantExc: mustCreateException(TypeErrorType, "'clear' of 'dict' requires 1 arguments")},
+		{args: wrapArgs(NewDict(), None), wantExc: mustCreateException(TypeErrorType, "'clear' of 'dict' requires 1 arguments")},
+		{args: wrapArgs(None), wantExc: mustCreateException(TypeErrorType, "unbound method clear() must be called with dict instance as first argument (got NoneType instance instead)")},
+	}
+	for _, cas := range cases {
+		if err := runInvokeTestCase(fun, &cas); err != "" {
+			t.Error(err)
+		}
+	}
+}
+
 func TestDictContains(t *testing.T) {
 	cases := []invokeTestCase{
 		{args: wrapArgs(NewDict(), "foo"), want: False.ToObject()},

testing/dict_test.py

@@ -50,3 +50,14 @@ except KeyError:
   pass
 else:
   raise AssertionError
+
+# Test clear
+d = {1: 1, 2: 2, 3: 3}
+d.clear()
+assert d == {}
+
+try:
+  d.clear()
+  assert AssertionError
+except TypeError:
+  pass