FWIW the author discussed this idea on Twitter with Matz:
Nick Sutterer (@apotonick): Hi @yukihiro_matz - what do you think about this? https://apotonick.wordpress.com/2018/01/17/dear-ruby-1-what-about-arguments-when-inheriting/ (I’m probably not the first one with this idea?!)
Yukihiro Matsumoto (@yukihiro_matz): @apotonick How about generating a class to be a superclass?
where Bar() is a method that returns a class.
Nick Sutterer (@apotonick): @yukihiro_matz Yes, that’s the current approach in many gems. However, this implies some meta programming and an anonymous class, whereas the extended ::included signature would be consistent and in-line with #initialize, right? Thanks Matz!
Yukihiro Matsumoto (@yukihiro_matz): @apotonick I am afraid that I don’t share that “consistent and in-line with” feeling.
Nick Sutterer (@apotonick): @yukihiro_matz 😬 It’s
“create an intermediate, anonymous class between A and subclass B”
“allow passing explicit arguments and set variables on B after B is inherited, the way you do it when creating object instances”
Nick Sutterer (@apotonick): @yukihiro_matz Ok, let’s forget the “consistent” argument. What’s better: passing arguments to a method, or having to create a temporary anonymous class to transport those arguments?
Yukihiro Matsumoto (@yukihiro_matz): @apotonick Yours consumes less memory. That is good. But it may make the language more complex.
Besides that, considering potential code breakage, I cannot simply say yours is “better”.
Nick Sutterer (@apotonick): @yukihiro_matz Thanks, agreeing. ✌️My idea introduces a syntactical change, true. Does that make the language more complex? Yes.
Creating an intermediate class instead: makes the USE of the language more complex.
Could there be any incompat, though? 🤔🤓🧐
Yukihiro Matsumoto (@yukihiro_matz): @apotonick Your particular example
class Memo::Render < Render, engine: Render::JSON
does not conflict with existing syntax (due to the comma after ‘Render’), but I am not positive with a comma here because it reminds me multiple inheritance.
Nick Sutterer (@apotonick): @yukihiro_matz Many thanks, I will elaborate more on this idea and talk to other gem authors about whether or not it would be cool to have that, etc. So there is no other proposal for this, yet? Haha, maybe I’m crazy 🤪 thanks!
Here’s the approach Matz is referring to: https://gist.github.com/bkudria/82e3721d4ec2b62a2a3d95050e964d84