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Scala 3 Migration: Report from the field

blog.pierre-ricadat.com

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Re: Scala 3 Migration: Report from the field

#21

Post by merb »

dkarl wrote: post #11
dtech wrote: post #7

I left the Scala ecosystems (mostly) a year or 4 ago, right around the release of Scala 3. It's a shame that the compatibility and tooling situation doesn't seem to have improved much since then. The Scala devs always said they wanted to avoid a Python 2->3 situation, but it seemed like they didn't quite achieve that.

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.

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

Re: Scala 3 Migration: Report from the field

#22

Post by Pet_Ant »

adamwk wrote: post #14
kokada wrote: post #12

Earlier quoted context omitted.

I don't know, if anything the Scala situation seems much worse than the Python situation. The language looks completely different and there is no easy migration path (not that Python had one, but at least the language was almost the same and you could with some effort write code that worked in both versions). We are in Scala 2.13 and while there are talks about migrating there is no actual plan. Looking at this blog…

Odersky forcing through major syntax changes for Scala 3 was such an unforced error. It's baffling add new syntax on top of major semantic changes to the type system.

But did it provide a gain in power and soundness? There issues with the 2.x system.

Re: Scala 3 Migration: Report from the field

#23

Post by jeremyjh »

theLiminator wrote: post #18

Back when I used to use Scala, the biggest PITA was how every minor version bump you'd run into binary version incompatibilities that you'd only run into at runtime. Has that situation changed? I've always felt that Scala the language was always pretty nice, but Scala the ecosystem/tooling was moderately painful to work with. It was getting better over time, but they lost all the momentum they had.

It still seems bizarre to me that the Java ecosystem relies upon code-sharing through precompiled binary packages. Compared to for example Rust or Elixir where you only download source and build it locally so that everything is built with the same compiler and environment. This makes it absolutely trivial to debug your dependencies and even fork them when necessary. Most Java programmers wouldn't ever dream of doing that.

Re: Scala 3 Migration: Report from the field

#24

Post by merb »

Pet_Ant wrote: post #22
adamwk wrote: post #14

Earlier quoted context omitted.

Odersky forcing through major syntax changes for Scala 3 was such an unforced error. It's baffling add new syntax on top of major semantic changes to the type system.

But did it provide a gain in power and soundness? There issues with the 2.x system.

Most programming languages have unsound features.

Re: Scala 3 Migration: Report from the field

#25

Post by sidkshatriya »

kokada wrote: post #12
dtech wrote: post #7

I left the Scala ecosystems (mostly) a year or 4 ago, right around the release of Scala 3. It's a shame that the compatibility and tooling situation doesn't seem to have improved much since then. The Scala devs always said they wanted to avoid a Python 2->3 situation, but it seemed like they didn't quite achieve that.

I don't know, if anything the Scala situation seems much worse than the Python situation. The language looks completely different and there is no easy migration path (not that Python had one, but at least the language was almost the same and you could with some effort write code that worked in both versions). We are in Scala 2.13 and while there are talks about migrating there is no actual plan. Looking at this blog…

I don’t use Scala but it will always be better than Python 2/3 because of compile time type checks. If it compiles it should work. In the case of Python 2/3 you could often encounter upgrade issues during runtime !

Re: Scala 3 Migration: Report from the field

#26

Post by adamc »

sidkshatriya wrote: post #25
kokada wrote: post #12

Earlier quoted context omitted.

I don't know, if anything the Scala situation seems much worse than the Python situation. The language looks completely different and there is no easy migration path (not that Python had one, but at least the language was almost the same and you could with some effort write code that worked in both versions). We are in Scala 2.13 and while there are talks about migrating there is no actual plan. Looking at this blog…

I don’t use Scala but it will always be better than Python 2/3 because of compile time type checks. If it compiles it should work. In the case of Python 2/3 you could often encounter upgrade issues during runtime !

That can happen in Scala as well because of shared binaries, as is reported in this thread.

Re: Scala 3 Migration: Report from the field

#27

Post by AlexITC »

dtech wrote: post #7

I left the Scala ecosystems (mostly) a year or 4 ago, right around the release of Scala 3. It's a shame that the compatibility and tooling situation doesn't seem to have improved much since then. The Scala devs always said they wanted to avoid a Python 2->3 situation, but it seemed like they didn't quite achieve that.

While the tooling isn't perfect, it has improved considerably over the last years, I remember when IntelliJ couldn't deal with Scala 3 but now, it rarely complains.

Related to Python 2->3, I don't see how Scala 2->3 compares, there are clear migration guides + tools to help re-writing to switch between the new/old syntax, I have done many migrations and I have used these tools since the time when Scala 3 was launched (I admit that I reverted a migration at that time).

Re: Scala 3 Migration: Report from the field

#28

Post by noelwelsh »

merb wrote: post #21
dkarl wrote: post #11

Earlier quoted context omitted.

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.

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

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

Re: Scala 3 Migration: Report from the field

#29

Post by virtualwhys »

Migrated a Scala 2.8(!) era codebase to Scala 3.

As OP explains, macros and abstract type projections tend to be the biggest pain points in complex applications; otherwise, with Scala Rewrite tool it's pretty straightforward.

I think it's more inertia than anything else that more Scala 2 companies don't migrate.

Unpopular opinion, but setting a Scala 2 sunset time would spur companies into action :)

As it stands Akka (previously Lightbend, previously TypeSafe) is the maintainer of Scala 2, and derives part of its revenue from Scala 2 support contracts so there's even less incentive to migrate when there's no EOL date as Python 2 (eventually) had.

Re: Scala 3 Migration: Report from the field

#30

Post by hawk_ »

adamwk wrote: post #14
kokada wrote: post #12

Earlier quoted context omitted.

I don't know, if anything the Scala situation seems much worse than the Python situation. The language looks completely different and there is no easy migration path (not that Python had one, but at least the language was almost the same and you could with some effort write code that worked in both versions). We are in Scala 2.13 and while there are talks about migrating there is no actual plan. Looking at this blog…

Odersky forcing through major syntax changes for Scala 3 was such an unforced error. It's baffling add new syntax on top of major semantic changes to the type system.

Stroustrup said "There's two kinds of PLs, ones that people complain about and ones that nobody uses."

Odersky made Scala3 become a language that nobody uses and people complain about!

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