This is a Ruby tree! It shows every object from the Ruby Programming Language in a tree format.

classify 

        # Set.classify

(from ruby core)
---
    classify() { |o| ... }

---

Classifies the set by the return value of the given block and
returns a hash of {value => set of elements} pairs. The block is
called once for each element of the set, passing the element as
parameter.
    require 'set'
    files = Set.new(Dir.glob("*.rb"))
    hash = files.classify { |f| File.mtime(f).year }
    hash       #=> {2000=>#<Set: {"a.rb", "b.rb"}>,
               #    2001=>#<Set: {"c.rb", "d.rb", "e.rb"}>,
               #    2002=>#<Set: {"f.rb"}>}

Returns an enumerator if no block is given.

This is MURDOC! A Ruby documentation browser inspired by Smalltalk-80. It allows you to learn about Ruby by browsing through its class hierarchies, and see any of its methods.