You’re right. It hasn’t been updated for either Ruby or Crystal.
I don’t want to change this thread to about documentation (keep it about Rosetta Code) so I’ll make a last comment here about Crystal documentation.
I spent almost 3 hrs before giving up because of deficiencies in website ref docs. Ruby’s std docs, in contrast, are more detailed, and more people write about its features/nuances.
I’ve been encouraging the devs to TAKE THE TIME to at least write regular blog entries on the website on small issues like this, to document these things in at least one location for users.
For example, I’m really impressed with the quality and breadth of the Sidef language and documentation, which I hadn’t even heard of until Rosetta Code exposure.
Again, I don’t want to hijack this thread away from Rosetta Code. If there’s an existing one dedicated to documentation I can contribute these point there, but good documentation is essential to enable users to come up to speed fast. Lastly, here are some helpful resources.