Ruby, Source Code of Splat?

Question

Someone asked about the splat operator yesterday, and I wanted to see the source code... would that be written in C or in Ruby? Where would it be found?

Answer 1

The splat operator is poorly documented in the core Ruby documentation as of Ruby 2.4. It's a core feature of the language, though, and the source code for the splat operator can be found in vm_eval.c under rb_yield_splat(VALUE values).

The unit test for rb_yield_splat makes it clearer what is happening:

it "yields with passed array's contents" do
  ret = nil
  @s.rb_yield_splat([1, 2]) { |x, y| ret = x + y }
  ret.should == 3
end

Answer 2

Some quick Google searching turned up that it's implemented in eval.c. You can find references to "splat" in a few places in the file, but I'm not familiar enough with the inner workings of Ruby to make any sense of it.