Traits in Rust seem at least superficially similar to typeclasses in Haskell, however I’ve seen people write that there are some differences between them. I was wondering exactly what these differences are. 3 Answers 3
Sealed classes are described in ‘Programming in Scala’, but sealed traits are not. Where can I find more information about a sealed trait? I would like to know, if a sealed trait is the same as a sealed class? Or, if not, what are the differences? When is it a good idea to use a … Read more
I’ve been trying to study up on PHP lately, and I find myself getting hung up on traits. I understand the concept of horizontal code reuse and not wanting to necessarily inherit from an abstract class. What I don’t understand is: What is the crucial difference between using traits versus interfaces? I’ve tried searching for … Read more
What is the advantage of using an abstract class instead of a trait (apart from performance)? It seems like abstract classes can be replaced by traits in most cases. 8 Answers 8
A self-type for a trait A: trait B trait A { this: B => } says that “A cannot be mixed into a concrete class that does not also extend B“. On the other hand, the following: trait B trait A extends B says that “any (concrete or abstract) class mixing in A will also … Read more
Scenario: trait A { function calc($v) { return $v+1; } } class MyClass { use A; function calc($v) { $v++; return A::calc($v); } } print (new MyClass())->calc(2); // should print 4 This code doesn’t work, and I cannot find a way to call a trait function like it was inherited. I tried calling self::calc($v), static::calc($v), … Read more
