But I have used the similar feature in Python for years. And I love it.
Is it just me, or are a lot of these languages starting to all feel a lot like each other?
Lest folks think this is a new feature, it was invented by Barbara Liskov in her CLU language, as explained in this 1977 paper: https://web.eecs.umich.edu/~weimerw/2011-6610/reading/liskov... (PDF, see section 4.2.)
The only problem, what if your language adopts an idea which prevents you from having a better API?
As far as I know, coroutine/generator doesn't prevent you from doing anything.
Usually when I look at a language One of the first things I do is look for familiarity: How to map, filter and reduce - and how to work with collections and lazy enumerables, whatever they may be called - IEnumerable, generator, Stream, etc.
It’s amazing how similar many popular languages are these days, at least in terms of developer experience. This doesn’t mean they are trivially interchangeable of course. You can’t write Elixir in an idiomatic C# style and you shouldn’t try to!