class modifiers

learn_dart/test/types/class-modifiers/base.dart

@@ -0,0 +1,20 @@
+// ignore_for_file: unnecessary_type_check
+
+import 'dart:core';
+
+import 'package:test/test.dart';
+
+void main() {
+  group("base ", () {
+    test("description", () {});
+  });
+}
+
+base mixin BaseMixin {}
+base class BaseClass {}
+
+// base具有传播性，父类base，子类也必须base
+base class AA with BaseMixin {}
+
+// base具有传播性，父类base，子类也必须base
+base class ImplA implements BaseMixin {}

learn_dart/test/types/class-modifiers/base_client.dart

@@ -0,0 +1,10 @@
+import 'base.dart';
+
+// 编译错误无法implement一个base mixin 或class
+// 非常棒，这就是要的效果
+// base class ImplA implements BaseMixin {}
+// base class ExtendBaseClass implements BaseClass {}
+
+base class WithBaseMixin with BaseMixin {}
+
+base class ExtendBaseClass extends BaseClass {}

learn_dart/test/types/class-modifiers/interface.dart

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+// ignore_for_file: unnecessary_type_check
+
+import 'dart:core';
+
+import 'package:checks/checks.dart';
+import 'package:test/test.dart';
+
+void main() {
+  group("interface ", () {
+    test("description", () {
+      A a = A();
+      check(a.x()).equals("x");
+      AA aa = AA();
+      check(aa.x()).equals("x");
+
+    });
+  });
+}
+
+interface class A {
+  x() => "x";
+}
+ class AA extends A {
+}
+// implements 就得实现父类所有方法
+class ImplA implements A {
+  @override
+  x() => throw UnimplementedError();
+}

learn_dart/test/types/class-modifiers/mixin.dart

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+// ignore_for_file: unnecessary_type_check
+
+import 'dart:core';
+
+import 'package:test/test.dart';
+
+void main() {
+  group("base ", () {
+    test("description", () {});
+  });
+}
+
+mixin A {
+  x() => "x";
+}
+
+// base具有传播性，父类base，子类也必须base
+class AA with A {}
+
+// base具有传播性，父类base，子类也必须base
+class ImplA implements A {
+  @override
+  x() => throw UnimplementedError();
+}

learn_dart/test/types/class-modifiers/sealed.dart

@@ -0,0 +1,24 @@
+// ignore_for_file: unnecessary_type_check
+
+import 'dart:core';
+
+import 'package:test/test.dart';
+
+void main() {
+  group("base ", () {
+    test("description", () {});
+  });
+}
+
+sealed class A {
+  x() => "x";
+}
+
+// base具有传播性，父类base，子类也必须base
+class AA extends A {}
+
+// base具有传播性，父类base，子类也必须base
+class ImplA implements A {
+  @override
+  x() => throw UnimplementedError();
+}

learn_dart/test/types/class-modifiers/sealed_client.dart

@@ -0,0 +1,6 @@
+
+// 编译错误，sealed 的类无法被继承或实现
+// class ImplA implements A {
+// }
+// class WithA extends A {
+// }