Static Typing in Ruby: It's Not a Cult, It's a Choice (You Should Probably Make)

Alright, let's talk about static typing in Ruby, and let's get one thing straight right off the bat: it is not an all-or-nothing game! I've seen the arguments from the dynamically-typed purists. They scream, "But Ruby is about freedom! Flexibility! Programmer happiness!" And yeah, sure, that's cute. But guess what else makes programmers happy? Not spending hours debugging runtime errors that a simple type check could have caught. The dinosaurs in the room will tell you that adding static typing to Ruby is like putting a saddle on a unicorn. They'll whine about how it goes against the very nature of the language. To that, I say: grow up. Ruby has always been about pragmatism, about taking the best ideas from other languages and making them work for us. Remember where Matz got his inspiration? He explicitly mentioned Perl, Smalltalk, Eiffel, Ada, and Lisp as influences. Notice anything interesting there? Eiffel and Ada are statically typed! So this idea that Ruby can't be touched by the type system is utter nonsense. It's in the language's DNA, you just didn't know it. Fast forward to the modern era, and the Ruby community has given us not one, but two fantastic options for bringing static typing into our beloved language. We've got RBS, the official type signature language spearheaded by the Ruby core team, released about five years ago. Then there's Sorbet, the brainchild of Stripe. And this is pure Ruby magic right here. We're not being forced into a single, dogmatic approach. You can pick your poison. Like the official, more declarative style of RBS? Go for it. Prefer the gradual, more integrated approach of Sorbet? Knock yourself out. Or, you know, you can keep writing code like it's 1999.

Mar 24, 2025 - 10:17

Static Typing in Ruby: It's Not a Cult, It's a Choice (You Should Probably Make)

Alright, let's talk about static typing in Ruby, and let's get one thing straight right off the bat: it is not an all-or-nothing game!

I've seen the arguments from the dynamically-typed purists. They scream, "But Ruby is about freedom! Flexibility! Programmer happiness!" And yeah, sure, that's cute. But guess what else makes programmers happy? Not spending hours debugging runtime errors that a simple type check could have caught.

The dinosaurs in the room will tell you that adding static typing to Ruby is like putting a saddle on a unicorn. They'll whine about how it goes against the very nature of the language. To that, I say: grow up.

Ruby has always been about pragmatism, about taking the best ideas from other languages and making them work for us. Remember where Matz got his inspiration? He explicitly mentioned Perl, Smalltalk, Eiffel, Ada, and Lisp as influences. Notice anything interesting there? Eiffel and Ada are statically typed! So this idea that Ruby can't be touched by the type system is utter nonsense. It's in the language's DNA, you just didn't know it.

Fast forward to the modern era, and the Ruby community has given us not one, but two fantastic options for bringing static typing into our beloved language. We've got RBS, the official type signature language spearheaded by the Ruby core team, released about five years ago. Then there's Sorbet, the brainchild of Stripe.

And this is pure Ruby magic right here. We're not being forced into a single, dogmatic approach. You can pick your poison. Like the official, more declarative style of RBS? Go for it. Prefer the gradual, more integrated approach of Sorbet? Knock yourself out. Or, you know, you can keep writing code like it's 1999.