If you get the same error, just change the “with” with the “implements” like this: class MyAppBar extends StatelessWidget implements PreferredSizeWidget { … } Description: In Dart 3, the rules around mixins have been made stricter compared to previous versions. As mentioned in the release notes, any class could be used as a mixin before … Read more
You can create mixin-like constructs in C# 4.0 without using dynamic, with extension methods on interfaces and the ConditionalWeakTable class to store state. Take a look here for the idea. Here’s an example: public interface MNamed { // required members go here } public static class MNamedCode { // provided methods go here, as extension … Read more
To supply a parameter that far down the string of arguments, you have to also supply the expected variable it is to define. So this: .fontStyle(‘NimbusSansNovCon-Reg’, 12px, @letter-spacing: 0.1em); Produces this (note how color, font-weight, and font-style used the defaults): font-family: ‘NimbusSansNovCon-Reg’; font-size: 12px; color: #ffffff; font-weight: normal; font-style: normal; letter-spacing: 0.1em;
One approach would be to come up with directory structure like this: (root dir) ├── a │ ├── first.rb │ ├── second.rb │ └── third.rb └── a.rb Files contents: # a.rb require_relative ‘./a/first.rb’ require_relative ‘./a/second.rb’ require_relative ‘./a/third.rb’ module A end # a/first.rb module A class First # … end end # a/second.rb module A class … Read more
What features of Module are defined as append and prepend? As specified in the text you quoted: the constants, methods, and module variables How they differ functionally? Both add methods of the mixed-in module to the passed module (class). The difference is in the lookup order of these methods, in case that the target class … Read more
Shouldn’t the inheritance be the other way round? In the MRO foo currently comes before bar_for_foo_mixin, and then rightfully complains. With class myfoo(bar_for_foo_mixin, foo) it should work. And I am not sure if your class design is the right way to do it. Since you use a mixin for implementing bar it might be better … Read more
You can change the declaration of your mixin to: mixin Salt { int get pitches; } And then define the field inside the implementation class class Meat with Salt { final int pitches; Meat(this.pitches); }
This can be done with macros (that are officially a part of Scala since 2.10.0-M3). Here’s a gist example of what you are looking for. 1) My macro generates a local class that inherits from the provided case class and Persisted, much like new T with Persisted would do. Then it caches its argument (to … Read more
Mixins are a concept from Lisp. A good explanation from Dr. Dobbs: A mixin is a fragment of a class in the sense that it is intended to be composed with other classes or mixins. […] The difference between a regular, stand-alone class (such as Person) and a mixin is that a mixin models some … Read more