Let's read some Rails code: OrderedOptions
Curious about Rails' internals? In the screencast below, I take you on a 5-minute tour of the OrderedOptions and InheritedOptions classes in ActiveSupport. Check it out for a code-level tour of an interesting bit of Rails.
By the way, this is an excerpt of a longer screencast I'm creating of guided tour through the best parts of the Rails source. If you'd like to be notified when the full screencast is released, drop your email in this form. (One email, ever.)
UPDATE: Youtube's compression isn't looking so hot, so if you prefer, you can download the high quality version here. (43MB)