Re: Specify abstract parent methods for traits

> On Sep 18, 2022, at 7:51 AM, Mohammad Amin Chitgarha <machitgarhaa@gmail.com> wrote: > > Hi. > > Currently, it's possible that, inside a trait's function, use the parent method of a > class using the trait. This way, not only it's implicitly supposed the trait is used in a class > having a parent, but also the parent class has such a method. It doesn't seem to be a good > practice, as stated in the answers of this question > (https://softwareengineering.stackexchange.com/questions/371067/should-a-trait-refer-to-parent-methods). > Also, it's almost impossible to override a parent method (using the same signature) using > a trait. This is useful if you have to inherit multiple classes from a base class, but also override > one (or more) of the base methods with a common functionality provided by a trait. > There are some workarounds to these problems (specially talking about the later one), but they > have their own disadvantages: > Define a trait function with the same signature but a different name and use it. The main > disadvantage is that it's a different method, and is not polymorphic. > Do (1), include the trait in the derived class(es), then override the parent method in all > derived classes and manually call the trait function. Not perfect because you have to copy the same > code for all derived classes. > > Stick with parent:: in the trait function. Implicit and not good (e.g. static analyzers and > IDEs cannot help). > > Change the parent class to use traits. This is not always possible, as it might be someone > else's code. How often have you (or anyone else?) found a need to inherit someone else's class and then need to override one of their methods via a trait? A need that you felt you could not easily work around in some other reasonable way? If yes, could you please give some examples? -Mike