The ruby::box thing looks pretty interesting, from a cursory glance you can run two simultaneous versions of something like a feature or rollout much more conveniently.
Also being able to do
if condition1
&& condition2
...
end
on multiple lines rather than one - this is pretty nifty too!
Personally && in the new line seems to be much better readability. Can’t wait to use some smart cop to convert all existing multiline ifs in my codebase.
Ruby is amazing. I recently built a layer on top of Rails that can generate an API from a single markdown file. I did the same thing in python but it was much harder and JavaScript would have been a beast. Ruby can meta program like nothing else.
I'm happy to see v4.0, but 2025 was the year I switched from Ruby to Python after gradually drifting back to it more and more. The tipping point was when I had Claude Code automatically convert one of my Ruby projects to 100% Python - and after that, I just had no Ruby left.
I spent over a decade enjoying Ruby and even wrote a book about it. At this point, though, Python has won for me: fastapi, pytorch, langchain, streamlit, and so on and on.
It's a bit sad, but I'll always remember the Christmas gifts, and the syntax that is always so much better than Python.
To me it seems very few people use ractors. A bit more use fibers though.
It's a bit of a mess IMO. I'd much prefer everything be simplified
aggressively in regards to threads + GIL; and Ractors integrated on
top of Ruby::Box to provide not only namespaced container-like entities
but also thread-support as a first-class citizen at all times. The API
of ractors is weird and really not fun to use.
I really enjoyed using them for my Ruby file-matching library where I wanted to read `shared-mime-info` XML source package files directly and on the fly as opposed to using the pre-processed secondary files that the upstream `update-mime-database` tool spits out. The problem is that a type definition can be spread out over multiple XML packages in both system and user paths, so the naïve implementation of reading them all at once wastes a massive amount of memory and a massive number of object allocations (slow) when most people use maybe 5% of the full set of supported types (the JPEGs and HTMLs and ZIPs of the world).
I wanted to read the source package files directly because I always found `shared-mime-info`'s usual two-step process for adding or editing any of the XML type data to be annoyingly difficult and fragile. One must run `update-mime-database` to decompose arbitrarily-many XML packages into a set of secondary files, one all-file-extensions, one all-magic-sequences, one all-aliases, etc. System package managers usually script that step when installing software that come with their own type data. I've accidentally nuked my entire MATE session with `update-mime-database` before when I wanted to pick up a manual addition and regenerated the secondary files while accidentally excluding the system path that had most of the data.
I ended up doing it with four Ractors:
- a Ractor matching inputs (MIME Type strings, file extensions, String or Pathname or URL paths for sniffing) against its loaded fully-formed type definition objects.
- a Ractor for parsing MIME Type strings (e.g. "application/xml") into Hash-keying Structs, a task for which the raw String is unsuitable since it may be overloaded with extra syntax like "+encoding_name" or fragment ";key=value" pairs.
- a fast XML-parser Ractor that takes in the key Structs (multiple at once to minimize necessary number of passes) and figures out whether or not any of those types are defined at all, and if so in which XML packages.
- a slow XML-parser Ractor that takes the same set of multiple key Structs and loads their full definition into a complete type object, then passes the loaded objects back to the matcher Ractor.
The cool part of doing it this way is that it frees up the matcher Ractor to continue servicing other callers off its already-loaded data when it gets a request for a novel type and needs to have its loader Ractors do their comparatively-slow work. The matcher sets the unmatched inputs aside until the loaders get back to it with either a loaded type object or `nil` for each key Struct, and it remembers `nil`s for a while to avoid having to re-run the loading process for inputs that would be a waste of time.
I think a lot of the barrier to entry for Ractors isn't the API for the Ractors themselves but in figuring out how to interact with Ractorized code from code that hasn't been explicitly Ractorized (i.e. is running in the invisible “main” Ractor). To that end I found it easiest to emulate my traditional library API by providing synchronous entry-point methods that make it feel no different to use than any other library despite all the stuff that goes on behind the scenes. The entry methods compose a message to the matcher Ractor then block waiting for a result or a timeout.
I also use Ractors in a more lightweight way in my UUID/GUID library where there's a Ractor serving the incrementing sequence value that serves as a disambiguator for time-based UUIDs in case multiple other Ractors (including invisible “main”) generate two UUIDs with the same timestamp. Speaking of which, I'm going to have to work on this one for Ruby 4.0, because it uses the removed `Ractor.take` method.
I haven't looked at Ruby for a long time. I've moved away due to the lack of typing. Any degree of typing would be helpful. Does it support typing yet?
_low_type_ is early days still, but I think this approach is clearly the future of ruby typing. If this gets baked into the language for full “compile” time support and minimal performance impact, it will be amazing: https://github.com/low-rb/low_type
It is definitely better than RBS and Sorbet. But unless Github / 37Signals or Shopify decide to use it, it is highly unlikely Ruby Core will consider it.
Out of all three I think Shopify have the highest possibilities. There may be additional usefulness interms of ZJIT.
There's an official format for defining types in separate files (RBS) and some tooling to type check them (matz doesn't like types next to the source code).
There's a pretty battle tested tool to define inline types as ruby syntax and type check both statically and at runtime[0].
It's still not a particularly nice situation imvho compared to typescript or python, but there's been some movement, and there's a newsletter that follows static typing developments [1] which may give you some insights.
I’ve used Sorbet on a project for 2 years recently and it honestly was the final nail in the coffin for Ruby for me.
Really rough around the edges, lots of stubs have to be added because support for gems is lackluster but whatever Sorbet generates are hit or miss etc. So you end up writing a lot of hard to understand annotations and/or people get frustrated and try to skip them etc.
Overall a very bad DX, compared to even typed Python. Don’t even want to compare it to TS because then it becomes really unfair.
There is [RBS](https://sorbet.org/) (part of ruby 3) and [sorbet](https://sorbet.org/). To be honest, these aren't widely used as far as I am aware. I don't know if it is runtime overhead, ergonomics, lack of type checking interest in the ruby community or something else. Type enforcement isn't a big part of ruby, and doesn't seem to be gaining much momentum.
Python is one the most popular programming languages. Ruby fits into a similar category as Python (high level, interpreted scripting language, very dynamic, has a rich ecosystem with tons of existing code). Being faster than Python makes it more attractive to use, or port Python codebases to.
Right now it is just the foundation I guess. That is, more
work to be put on top of it. byroot kind of pointed that out
that the proposal reminds him of containers and I think this
is the long-term goal eventually, e. g. namespaced isolated
containers. At a later time, I think, the syntax for refinements
may be simplified and also be integrated into Ruby::Box, since
Ruby::Box is kind of a stronger refinement in the long run. But
that's my take; ultimately one has to ask matz about the changes.
What he did say on the bugtracker was that this is to be considered
a low-level API e. g. a foundation work. So things will be put on
top of that eventually.
The ruby::box thing looks pretty interesting, from a cursory glance you can run two simultaneous versions of something like a feature or rollout much more conveniently.
Also being able to do
on multiple lines rather than one - this is pretty nifty too!I spent over a decade enjoying Ruby and even wrote a book about it. At this point, though, Python has won for me: fastapi, pytorch, langchain, streamlit, and so on and on.
It's a bit sad, but I'll always remember the Christmas gifts, and the syntax that is always so much better than Python.
I vaguely remember reading Shopify is using Fiber / Rack / Async in their codebase. I am wondering if Rails will get more Fiber usage by default.
It's a bit of a mess IMO. I'd much prefer everything be simplified aggressively in regards to threads + GIL; and Ractors integrated on top of Ruby::Box to provide not only namespaced container-like entities but also thread-support as a first-class citizen at all times. The API of ractors is weird and really not fun to use.
I wanted to read the source package files directly because I always found `shared-mime-info`'s usual two-step process for adding or editing any of the XML type data to be annoyingly difficult and fragile. One must run `update-mime-database` to decompose arbitrarily-many XML packages into a set of secondary files, one all-file-extensions, one all-magic-sequences, one all-aliases, etc. System package managers usually script that step when installing software that come with their own type data. I've accidentally nuked my entire MATE session with `update-mime-database` before when I wanted to pick up a manual addition and regenerated the secondary files while accidentally excluding the system path that had most of the data.
I ended up doing it with four Ractors:
- a Ractor matching inputs (MIME Type strings, file extensions, String or Pathname or URL paths for sniffing) against its loaded fully-formed type definition objects.
- a Ractor for parsing MIME Type strings (e.g. "application/xml") into Hash-keying Structs, a task for which the raw String is unsuitable since it may be overloaded with extra syntax like "+encoding_name" or fragment ";key=value" pairs.
- a fast XML-parser Ractor that takes in the key Structs (multiple at once to minimize necessary number of passes) and figures out whether or not any of those types are defined at all, and if so in which XML packages.
- a slow XML-parser Ractor that takes the same set of multiple key Structs and loads their full definition into a complete type object, then passes the loaded objects back to the matcher Ractor.
The cool part of doing it this way is that it frees up the matcher Ractor to continue servicing other callers off its already-loaded data when it gets a request for a novel type and needs to have its loader Ractors do their comparatively-slow work. The matcher sets the unmatched inputs aside until the loaders get back to it with either a loaded type object or `nil` for each key Struct, and it remembers `nil`s for a while to avoid having to re-run the loading process for inputs that would be a waste of time.
I think a lot of the barrier to entry for Ractors isn't the API for the Ractors themselves but in figuring out how to interact with Ractorized code from code that hasn't been explicitly Ractorized (i.e. is running in the invisible “main” Ractor). To that end I found it easiest to emulate my traditional library API by providing synchronous entry-point methods that make it feel no different to use than any other library despite all the stuff that goes on behind the scenes. The entry methods compose a message to the matcher Ractor then block waiting for a result or a timeout.
I also use Ractors in a more lightweight way in my UUID/GUID library where there's a Ractor serving the incrementing sequence value that serves as a disambiguator for time-based UUIDs in case multiple other Ractors (including invisible “main”) generate two UUIDs with the same timestamp. Speaking of which, I'm going to have to work on this one for Ruby 4.0, because it uses the removed `Ractor.take` method.
Out of all three I think Shopify have the highest possibilities. There may be additional usefulness interms of ZJIT.
There's a pretty battle tested tool to define inline types as ruby syntax and type check both statically and at runtime[0].
It's still not a particularly nice situation imvho compared to typescript or python, but there's been some movement, and there's a newsletter that follows static typing developments [1] which may give you some insights.
0: https://sorbet.org/
1: https://newsletters.eremin.eu/posts
Really rough around the edges, lots of stubs have to be added because support for gems is lackluster but whatever Sorbet generates are hit or miss etc. So you end up writing a lot of hard to understand annotations and/or people get frustrated and try to skip them etc.
Overall a very bad DX, compared to even typed Python. Don’t even want to compare it to TS because then it becomes really unfair.
It’s not like Ruby becomes Haskell. But it does provide a good deal of additional saftey, less testing, LSP integration is good, and it is gradual.
There is a performance hit but we found it to be quite small and not an issue.
But there are area of our application that use Grape and it is too meta for Sorbet so we don’t try and use it there.
I think most people who cared just moved to typescript.
I am installing it now. Thank you Matz and team.