Fairly hardcore rubyist here. Ruby-lsp is excellent. But in no way is RBS becoming standard. Maybe it will, I don’t know. But adoption is very, very low as of today. Rbs-inline is just someone’s pet project and has very little activity (though it does appear that the person who wrote it is trying to implement it directly into Rbs now, which would be great)

Personally I can’t see any comment based typing system gaining real traction.

As long as Matz is firmly against, inline typing should never be a part of Ruby. I started working on a large Rails codebase that adopted Sorbet and it is nothing but an impediment to progress.

I work in a large Sorbet codebase (though it isn't a Rails one) and it's a huge boon IMO. The number of tests we don't need to write because of Sorbet is really nice.

It does occasionally require structuring your code differently, but I find the type-system-encouraged approach often gives a more elegant and harder-to-misuse interface in the end.

You work in a large Ruby codebase that _isn't_ Rails?! Are you hiring??

I was assuming Stripe, but would love to hear of others!

Very curious to hear about the specific cases where types make tests unnecessary.

I spend my working life swapping between Ruby and typescript projects and the typescript project is utter garbage with poor test coverage that needs a day of human QA for every build whereas the Ruby project is well tested such that we know that CI passing means it’s good to be released.

Types don't make testing in general unnecessary, but it removes a class of error handling that runtime type checking handles for you. You can really trust the types when using Sorbet.

(I also work in a 40m+ loc non-rails ruby codebase that is almost entirely typed with Sorbet.)

Haha “tell me you work at Stripe without telling me you work at Stripe”

I think it will need to be a strong 3rd party that basically gives it the Typescript treatment.

Adds type annotations to the core language syntax. The compiler does type checking, strips the annotations, and outputs plain Ruby.

Sorbet is backed by Stripe.

Why is it important to be a separate layer that compiles to plain untyped Ruby?

So that it doesn’t have to go through the Ruby development process. Matz doesn’t want it, and even if he did it would take years just to get people to agree on a syntax, much less actually get it implemented and rolled out.

Same reason Typescript was made and we didn’t add types to JavaScript.

Is Sorbet not what you’re describing?

And RBS is officially part of Ruby…

Neither of them integrate annotations into the language. They’re both bolt-ons and it shows, badly. If either of them were good developer experiences one would have caught on. But they’re both way off the beaten path in terms of what engineers expect in a type system and not in a good way.

Type annotations in the language as syntax. Static type checker with an emphasis on inference. Compiles into Ruby so that it integrates with the entire existing Ruby ecosystem, so unlike Crystal as well.

Those are the general features you need/want and why TS caught on and none of the existing solutions hit the mark.

You might find https://blog.jez.io/history-of-sorbet-syntax/ interesting, written by one of the primary contributors to Sorbet.

Sorbet is a bit different from TypeScript because it has runtime type checking, not just static.

DHH also doesn’t like typing in Ruby at all, and Rails is designed around what he likes.

> adopted Sorbet and it is nothing but an impediment to progress

How so?

I never really missed types in Ruby, even if I like them a lot in typescript, but right now I'm doing some "vibe coding" on a personal project and I was thinking about trying Sorbet. I think that it could help Claude Code avoid some mistakes it often makes which make it waste a lot of time fixing.

Interesting: how is CC in your experience at writing tests and then using them to avoid mistakes?

When writing non-vibe-coded software I use CC a lot to write tests, but I have a skill to tell it not to create redundant tests, which otherwise it tends to do, and I have to check them anyway to ensure that they cover what needs to be covered, and sometimes to trim them down.

When vibe coding, what I noticed is that CC tends to make mistakes which it does catch with tests and fix on its own, but my hope is that using Sorbet this will happen much less, and thus development will go faster with less (slow) test cycles.

Very interested to read the blog post about the results.

It’s not a huge impediment but it adds up through: extra lines of sig code I now need to essentially ignore as I read as well as waiting for precommit hooks to check a giant codebase for compliance, plus extra rbi files in git. If engineers followed convention over config and tested types where necessary, no need for inline types. Just use TS if you want types.

Maybe I wasn't clear, but until now there were 2 types of type notations being debated, RBS and sorbet/RBI. Sorbet adopting RBS means that's the lowest common denominator. Typing is definitely not a standard, not yet. rbs-inline is definitely not a pet project, it's the RBS creator response to the main complaint about RbS , its the reason sorbet finally adopted it, and will be part of mainline rbs gem.

It’s just inferior to Python, nobody is making a more complex argument than that. Why ever use Ruby when there’s a virtually identical system that’s faster with a bigger community.

In what ways is it inferior? Neither Ruby or Python are 'fast', so if that is one of your qualifiers you've already made a suboptimal choice.

As for a bigger community, what does that serve? The large python community adds misdirection and more voices to a language that lacks some basic features still. Async/sync code models are still being finalized whereas Ruby has been stable in this regard for 10+ years. Same with tooling - the Ruby side is more consistent and stable: Sidekiq for background jobs (Celery is barely coming to maturity), Bundler for dependencies (pip? poetry? uv?). Mature auth + other frameworks like Devise.

Having worked in both languages professionally, I strongly disagree with your take.

Blanket statements like this are unhelpfully tribal. Ruby has its uses, and underpins one of the most successful (and cloned) MVC frameworks of all time. But yeah, Python received the attention of data scientists early on and now it's a lingua franca of sorts in that domain. Since AI is so hot right now that makes Python seem superior, but really that's just contingency.

If you're going to make claims, support them.

Because Ruby is just a better thought out language than Python is. It had a sane package management story 15 years before Python. It doesn't rely on weird hacks like exception throwing for iterator control flow. It doesn't have nearly as many warts and footguns on basic operations (for example, in Python csv.writer(file).writerows(rows) is broken unless you remembered to set the newline mode on the file; in Ruby file.write(rows.to_csv) just works). Thanks to a sane VM design it's mainline JIT can actually run code faster than interpreted code (something that CPython's JIT can't do [1])

Many Pythonistas are woefully ignorant of what's going on outside their siloed community.

[1] https://fidget-spinner.github.io/posts/jit-reflections.html

Everything being mutable by default, including strings, is about as big a foot gun as you can find in a high level language.

Having immutable objects by default isn’t incredibly commonplace outside of functional languages. It certainly isn’t unique to Ruby and seems out of place in a discussion comparing Ruby to Python. Fortunately, you can defensively freeze any objects you’re passing around to avoid the most common issues with mutable objects.

Immutable strings is a more popular programming language feature and Ruby has a mechanism for opting into that. It’s so commonplace that the complaint usually isn’t that a string can be modified, but rather that every source file includes a magic comment to prevent that. Besides data safety, the VM can optimize frozen strings, so popular linters will flip that setting on for you. String mutability isn’t a practical issue for modern codebases. And, as language design goes, it’s kinda nice not needing to use a parallel set of classes for mutable and immutable string data IMHO.

With that said, the magic comment is a wart and folks are looking at making immutable strings the default. But, there’s a strong desire to avoid breaking the world. The Ruby Core team is keen to keep the lessons learned from the Python 2 -> 3 migration in mind.

> With that said, the magic comment is a wart

Not only a wart but a massive foot gun, not shared by any other language, as I said. It is incredibly common to create hash tables using strings as keys, and Ruby makes this dangerous by default.

> Having immutable objects by default isn’t incredibly commonplace outside of functional languages

They make it easy to create immutable objects. Python has tuples and immutable data classes. Strings are immutable.

> The Ruby Core team is keen to keep the lessons learned from the Python 2 -> 3 migration in mind.

In the meantime, this ridiculous foot gun that no other language shares exists. That is a fact, and the fix being hard does not make it any less of a fact.

Ruby is a lot less awful than Python in my opinion. That is of course a very subjective opinion. The only reason I write more Python than Ruby is that ruby lacks the libraries I need.

Somewhere along the line Python got all the momentum, and ruby got none and now python is better if you just want to get shit done.

But man. I wish it was the other way around. I have one code snippet that summarises what I dislike about python:

    if input() == "dynamic scope?":
        defined = "happyhappy"
    print(defined)
    

Seeing that I understand why I see yuck in just about every corner of python.

Edit: in ruby it also works, but the variable is at least always defined.

> in ruby it also works, but the variable is at least always defined.

How is this even a pro? I agree that Python scoping rules are frustrating, but tbh not sure if I would prefer Ruby's behavior in this case

Well. If python is a dynamically scoped language, what they do is correct. If they are lexically scoped (which python is described as) the variable defined in the if should never have different visibility in the same scope.

In a lexically scoped language you don't define variables conditionally. What ruby does is also icky, but obviously the developers of both python and ruby wanted to save the developer an extra declaration. The ruby version is at least more correct from a lexical standpoint (it is set to nil if left "nondefined").

I’m sure I’ll get downvoted for it, but strict technical merits aside, Python to me seems built by engineers who lacked any sense of taste. Ruby is beautiful.

Python is great and I love writing glue in it, but Ruby is just a better designed language and ecosystem overall.

Why? Because Python is generally slower, uses significant whitespace in its syntax, and lacks the metaprogramming features of Ruby.

A lot of times 2-3 lines of Ruby needs 5-8 lines in Python.

> that’s faster

In every test I've done, Ruby has been faster than Python. In my experience that's been the case since Ruby 1.9, with the move to YARV.

I don't think anyone says: "I switched from Python to Ruby" (of vice versa) for performance.

True. Choosing between the two languages usually comes down to their library ecosystems - or more bluntly, to Rails on one hand vs NumPy on the other.

Nonetheless, it's still common for people to talk about the relative performance of the two languages, and to claim that Ruby is slower than Python. As someone who's actually tested this, it hasn't been true for 15 years.

Ruby/rails has always felt fragile to me. Like you have to write the same tests over and over to make up for the looseness of it, not to mention the culture of breaking changes adds insult to injury. Just seems like a mess and the nice syntax (subjectively) isn't nearly enough to win when better options exist.

> Why ever use Ruby when there’s a virtually identical system [...] with a bigger community.

There was a time in the history of Python when people who chose Python did so primarily because they found it beautiful or pleasant to work with. These are reasonable factors in choosing a language, and they continue to be popular reasons for choosing relatively unpopular languages today.

A related essay has made the rounds on HN before. It might be worth revisiting if this question is on your mind: https://www.johndcook.com/blog/2011/10/26/python-is-a-volunt...