On: RBS, Ruby’s new type signature language

[welearnednothng]

It's worth noting that while the article is coming from Square, this is an official Ruby project and is "Ruby 3’s new language for type signatures".

https://github.com/ruby/rbs

[rattray → welearnednothng]

Yeah, I was wondering why this was being announced on Square's website. Seems it's because Square happens to employ Soutaro Matsumoto, who wrote the post and is also the creator of Steep[0] (an implementation of a typechecker for RBS files).

It's not clear to me whether Soutaro is a member of the Ruby core team, so it feels a bit odd that the post is written like an announcement from the Ruby maintainers.

[0] https://github.com/soutaro/steep

[baweaver → rattray]

Soutaro is indeed a code member of the Ruby team, he also happens to work at Square. Soutaro is also one of the main contributors to RBS and helped define that standard.

He was going to keynote on this at RubyKaigi this year until it was cancelled, and had a talk at RubyConf as well on this.

[rattray → baweaver]

Thanks for clarifying! It's great that Square is funding work like this.

[baweaver → rattray]

Yep, and glad to see the work Stripe is doing on things as well. Always enjoy seeing where you all are going.

Soutaro has been great to work with over here (Square), and he has a ton of really amazing things coming soon that we're working on OSS'ing later.

[rattray → baweaver]

> you all

Just to clarify, I left Stripe several months ago (and did not work on ruby infra), so we both get to cheer from the sidelines!

[baweaver → welearnednothng]

This. RBS is the underlying language for defining type checkers. Sorbet and Steep both utilize it, and this allows future type checkers to evolve from a known-base instead of having to reinvent everything.