class Module
  METHODS_SYMBOLS = [ :inherited, :ancestors, :local, :no_acestors, :public, :private, :protected ]
  # Provides an improved method lookup routnine.
  # It returns a list of methods according to symbol(s) given. 
  #
  # Usable symbols include:
  #
  # * <tt>:inherited</tt> or <tt>:ancestors</tt>
  # * <tt>:local</tt> or <tt>:no_ancestors</tt>
  # * <tt>:public</tt>
  # * <tt>:private</tt>
  # * <tt>:protected</tt>
  # * <tt>:all</tt>
  #
  # If no symbol is given then :public is assumed. 
  # Unrecognized symbols raise an error.
  #
  #   require 'facet/module/methods'
  #
  #   module Demo
  #     def test
  #       puts("Hello World!")
  #     end
  #   end
  #  
  #   Demo.methods(:local)    #=> ['test']
  #
  def methods(*args)
    args = [ :public ] if args.empty?
    raise ArgumentError if args.any?{ |a| ! METHODS_SYMBOLS.include?(a) }
    m = []
    a = args.include?( :all )
    i = ( args.include?( :inherited ) or args.include?( :ancestors ) )
    l = ( args.include?( :local ) or args.include?( :no_ancestors ) )
    if a
      m |= public_instance_methods( true )
      m |= private_instance_methods( true )
      m |= protected_instance_methods( true )
    elsif i and l
      m |= public_instance_methods( true ) if args.include?( :public )
      m |= private_instance_methods( true ) if args.include?( :private )
      m |= protected_instance_methods( true ) if args.include?( :protected )
    elsif i
      m |= (public_instance_methods( true ) - public_instance_methods( false )) if args.include?( :public )
      m |= (private_instance_methods( true ) - private_instance_methods( false )) if args.include?( :private )
      m |= (protected_instance_methods( true ) - protected_instance_methods( false )) if args.include?( :protected )
    else
      m |= public_instance_methods( ! l ) if args.include?( :public )
      m |= private_instance_methods( ! l ) if args.include?( :private )
      m |= protected_instance_methods( ! l ) if args.include?( :protected )
      m
    end
  end
end

class Object
  alias_method( :object_methods, :methods )
  # Returns a list of methods according to symbol(s) given.
  # Note that this method derives from 'facet/module/methods'.
  #
  # Usable symbols include:
  #
  # * <tt>:inherited</tt> or <tt>:ancestors</tt>
  # * <tt>:local</tt> or <tt>:no_ancestors</tt>
  # * <tt>:public</tt>
  # * <tt>:private</tt>
  # * <tt>:protected</tt>
  # * <tt>:singleton</tt>
  # * <tt>:all</tt>
  #
  # It no symbol is given then :public is assumed. Unrecognized symbols raise an error.
  #
  #  require 'facet/module/methods'
  #
  #   def test
  #     puts("Hello World!")
  #   end
  #  
  #   methods(:local)    #=> ['test']
  #
  def methods(*args)
    args = [ :public ] if args.empty?
    m = self.class.methods( *args )
    m |= singleton_methods if args.include?( :singleton ) or args.include?( :all )
    m
  end
end


=begin
#__TEST__

if $0 == __FILE__

 p Object.methods

end
=end