module ActiveSupport::Dependencies::ModuleConstMissing

def self.append_features(base)

:nodoc:
Module includes this module. 
def self.append_features(base)
  base.class_eval do
    # Emulate #exclude via an ivar
    return if defined?(@_const_missing) && @_const_missing
    @_const_missing = instance_method(:const_missing)
    remove_method(:const_missing)
  end
  super
end

def self.exclude_from(base) 

def self.exclude_from(base)
  base.class_eval do
    define_method :const_missing, @_const_missing
    @_const_missing = nil
  end
end

def const_missing(const_name) 

def const_missing(const_name)
  from_mod = anonymous? ? guess_for_anonymous(const_name) : self
  Dependencies.load_missing_constant(from_mod, const_name)
end

def guess_for_anonymous(const_name)

top-level constant.
conventions and therefore we assume that the user wants to refer to a
that defines the constant. Anonymous modules cannot follow these
(unless it can be proven that is not the case) and the path to the file
We assume that the name of the module reflects the nesting 
def guess_for_anonymous(const_name)
  if Object.const_defined?(const_name)
    raise NameError.new "#{const_name} cannot be autoloaded from an anonymous class or module", const_name
  else
    Object
  end
end

def unloadable(const_desc = self) 

def unloadable(const_desc = self)
  super(const_desc)
end