Sorta? Like you're right, there's not compiled machine code that does a jump. But Ruby's case statement has nice semantics to make clear code out of what could be a complex if/elsif/else chain. The use of the === function is powerful, and lets the reader of the code focus on the condition, not the function call to check it.
if (patternA.match(input))
elsif (patternB.match(input))
else
end
vs
case input
when patternA
when patternB
else
end
And since it uses ===, you can define that on your own classes too. Hypothetically for instance, you can make fairly complex policy type classes to make reusable boolean statements.
case current_user
when NotValidatedEmail
when NotCompletedOnboarding
when SomethingElse
else
end
and then you can use those elsewhere in the code by leveraging the more global use of ===
> there's not compiled machine code that does a jump
It's more of an implementation detail, but the Ruby VM actually does a jump if all the cases are "keyable"(typically integers, strings, symbols, etc). It does a hash lookup and jump to the returning address.
That's cool, thanks for the code pointer. I knew I was probably wrong in the strictest sense, especially with all the work that's gone into the various approaches to JIT and performance work in Ruby.
I should go read some of the interpreter code at some point - fun work going on there.
