[dkarl]

I think you should read this report. They made heavy use of many advanced features of Scala 2. Few codebases look like this (and very, very few need to) yet they were able to do it.

Moreover, they didn't need to do it. What makes it similar to the Python 2 -> 3 situation is the lack of urgency to migrate, because nobody suffers for not migrating. That's a good thing.

[merb]

Most people used advanced features, even if they were hidden behind libraries. Even if you’ve just had a codebase which only used playframework.

[jodersky]

The article mentions they used an experimental language feature, which is enabled via a special compilation flag and came with a big warning from the start that it was in fact experimental and could be removed any time. I highly doubt that most people use any libraries that use those.

As a side note, I've personally had the experience of migrating several projects to Scala3 (when it was still called Dotty), and never had any issues with 3rd party dependencies, since Scala 3 is binary-backwards compatible with Scala 2.13

[noelwelsh]

If they are in libraries it doesn't matter, because you can use Scala 2.13 code in Scala 3.

[AlexITC]

It definitely took a while for most libraries to catch-up with Scala 3, now, I don't see anything is missing in the main area I work with (web development), playframework already works for Scala 3.

[foolfoolz]

i was surprised to see such advanced type features. i worked at a large scala company. we wouldn’t let most of this stuff through code review. it generally is the kind of magic that saves a tiny amount of code at a high cost of complexity. sounds like this was the authors pet project and wanted to explore instead of write maintainable code