From: Dave Thomas <dave@...>
Date: 2003-05-15T12:48:33+09:00
Subject: 1.8-intense class tree

I was trying to come up with some example code for 'prettyprint' and I 
remembered Hal's class diagram. This is somewhat ugly in the details, 
but it does show some 1.7/1.8 features: prettyprint, Hashes with blocks 
for unknown values, and Enumerable#sort_by.

Cheers


Dave

require 'prettyprint'

@children = Hash.new { |h,k| h[k] = Array.new }
ObjectSpace.each_object(Class) { |cls| @children[cls.superclass] << cls}

def print_children_of(pp, cls)
   pp.group do
     pp.text(cls.name)
     pp.group do
       kids = @children[cls].sort_by {|k| k.name}
       unless kids.empty?
         pp.text ' ['
         pp.nest(3) do
           pp.breakable
           kids.each do |k|
             next if k == Exception || k.name =~ /^Pretty/
             unless pp.first?
               pp.text ','
               pp.breakable
             end
             print_children_of(pp, k)
           end
         end
         pp.breakable
         pp.text ']'
       end
     end
   end
end

pp = PrettyPrint.new($stdout, 40)
print_children_of(pp, Object)
pp.flush
puts