old_contents: # Copyright (c) 2010 Mark Sandstrom
  #
  # Permission is hereby granted, free of charge, to any person obtaining a copy
  # of this software and associated documentation files (the "Software"), to deal
  # in the Software without restriction, including without limitation the rights
  # to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  # copies of the Software, and to permit persons to whom the Software is
  # furnished to do so, subject to the following conditions:
  #
  # The above copyright notice and this permission notice shall be included in
  # all copies or substantial portions of the Software.
  #
  # THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  # IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  # FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  # AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  # LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  # OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  # THE SOFTWARE.
  
  class OrderedDeclaration(object):
      '''A factory declaration.
  
      Ordered declarations keep track of the order in which they're defined so that later declarations
      can refer to attributes created by earlier declarations when the declarations are evaluated.'''
      _next_order = 0
  
      def __init__(self):
          self.order = self.next_order()
  
      @classmethod
      def next_order(cls):
          next_order = cls._next_order
          cls._next_order += 1
          return next_order
  
      def evaluate(self, factory, attributes):
          '''Evaluate this declaration.
  
          Args:
              factory: The factory this declaration was defined in.
              attributes: The attributes created by the unordered and ordered declarations up to this point.'''
  
          raise NotImplementedError('This is an abstract method')
  
  class LazyAttribute(OrderedDeclaration):
      def __init__(self, function):
          super(LazyAttribute, self).__init__()
          self.function = function
  
      def evaluate(self, factory, attributes):
          return self.function(attributes)
  
  class Sequence(OrderedDeclaration):
      def __init__(self, function, type=str):
          super(Sequence, self).__init__()
          self.function = function
          self.type = type
  
      def evaluate(self, factory, attributes):
          return self.function(self.type(factory.sequence))
  
  class LazyAttributeSequence(Sequence):
      def evaluate(self, factory, attributes):
          return self.function(attributes, self.type(factory.sequence))
  
  # Decorators... in case lambdas don't cut it
  
  def lazy_attribute(func):
      return LazyAttribute(func)
  
  def sequence(func):
      return Sequence(func)
  
  def lazy_attribute_sequence(func):
      return LazyAttributeSequence(func)
  
new_contents: # Copyright (c) 2010 Mark Sandstrom
  #
  # Permission is hereby granted, free of charge, to any person obtaining a copy
  # of this software and associated documentation files (the "Software"), to deal
  # in the Software without restriction, including without limitation the rights
  # to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  # copies of the Software, and to permit persons to whom the Software is
  # furnished to do so, subject to the following conditions:
  #
  # The above copyright notice and this permission notice shall be included in
  # all copies or substantial portions of the Software.
  #
  # THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  # IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  # FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  # AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  # LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  # OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  # THE SOFTWARE.
  
  import threading
  
  global_counter_lock = threading.Lock()
  
  class GlobalCounter(object):
      """A simple global counter."""
  
      _value = 0
  
      @classmethod
      def step(cls):
          with global_counter_lock:
              current = cls._value
              cls._value += 1
          return current
  
  
  class OrderedDeclaration(object):
      '''A factory declaration.
  
      Ordered declarations keep track of the order in which they're defined so that later declarations
      can refer to attributes created by earlier declarations when the declarations are evaluated.'''
      _next_order = 0
  
      def __init__(self):
          self.order = GlobalCounter.step()
  
      def evaluate(self, factory, attributes):
          '''Evaluate this declaration.
  
          Args:
              factory: The factory this declaration was defined in.
              attributes: The attributes created by the unordered and ordered declarations up to this point.'''
  
          raise NotImplementedError('This is an abstract method')
  
  class LazyAttribute(OrderedDeclaration):
      def __init__(self, function):
          super(LazyAttribute, self).__init__()
          self.function = function
  
      def evaluate(self, factory, attributes):
          return self.function(attributes)
  
  class Sequence(OrderedDeclaration):
      def __init__(self, function, type=str):
          super(Sequence, self).__init__()
          self.function = function
          self.type = type
  
      def evaluate(self, factory, attributes):
          return self.function(self.type(factory.sequence))
  
  class LazyAttributeSequence(Sequence):
      def evaluate(self, factory, attributes):
          return self.function(attributes, self.type(factory.sequence))
  
  # Decorators... in case lambdas don't cut it
  
  def lazy_attribute(func):
      return LazyAttribute(func)
  
  def sequence(func):
      return Sequence(func)
  
  def lazy_attribute_sequence(func):
      return LazyAttributeSequence(func)
  
subject: Fix concurrency between declarations for LazyAttributes and Sequence.