From: Joel VanderWerf <vjoel@...>
Date: 2004-03-20T16:39:32+09:00
Subject: YAML serialization of modules


I know _why is away for a bit, but maybe someone else can shoot down 
this idea :) Let's serialize modules with this code:

-----
require 'yaml'

class Module
   def is_complex_yaml?
     false
   end
   def to_yaml( opts = {} )
     YAML::quick_emit( nil, opts ) { |out|
       out << "!ruby/module "
       self.name.to_yaml( :Emitter => out )
     }
   end
end
YAML.add_ruby_type(/^module/) do |type, val|
   subtype, subclass = YAML.read_type_class(type, Module)
   val.split(/::/).inject(Object) { |p, n| p.const_get(n)}
end

class Class
   def to_yaml( opts = {} )
     YAML::quick_emit( nil, opts ) { |out|
       out << "!ruby/class "
       self.name.to_yaml( :Emitter => out )
     }
   end
end
YAML.add_ruby_type(/^class/) do |type, val|
   subtype, subclass = YAML.read_type_class(type, Class)
   val.split(/::/).inject(Object) { |p, n| p.const_get(n)}
end

module M; class C; end; end

x = [String, Object, File, Process, Enumerable, M::C]

y x

p YAML.load(YAML.dump(x))

__END__

Output:

---
- !ruby/class String
- !ruby/class Object
- !ruby/class File
- !ruby/module Process
- !ruby/module Enumerable
- !ruby/class M::C
[String, Object, File, Process, Enumerable, M::C]
-----

Maybe the code should also check whether const_get returns the right 
thing each time. Other than that, any pitfalls?