old_contents: # Copyright (c) 2013 Paul Tagliamonte <paultag@debian.org>
  #
  # 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 HyObject(object):
      """
      Generic Hy Object model. This is helpful to inject things into all the
      Hy lexing Objects at once.
      """
  
      def replace(self, other):
          if isinstance(other, HyObject):
              for attr in ["start_line", "end_line",
                           "start_column", "end_column"]:
                  if not hasattr(self, attr) and hasattr(other, attr):
                      setattr(self, attr, getattr(other, attr))
          else:
              raise TypeError("Can't replace a non Hy object with a Hy object")
  
          return self
  
  _wrappers = {}
  
  
  def wrap_value(x):
      """Wrap `x` into the corresponding Hy type.
  
      This allows replace_hy_obj to convert a non Hy object to a Hy object.
  
      This also allows a macro to return an unquoted expression transparently.
  
      """
  
      wrapper = _wrappers.get(type(x))
      if wrapper is None:
          return x
      else:
          return wrapper(x)
  
  
  def replace_hy_obj(obj, other):
  
      if isinstance(obj, HyObject):
          return obj.replace(other)
  
      wrapped_obj = wrap_value(obj)
  
      if isinstance(wrapped_obj, HyObject):
          return wrapped_obj.replace(other)
      else:
          raise TypeError("Can't replace a Hy object "
                          "with a non wrappable non Hy object")
  
new_contents: # Copyright (c) 2013 Paul Tagliamonte <paultag@debian.org>
  #
  # 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 HyObject(object):
      """
      Generic Hy Object model. This is helpful to inject things into all the
      Hy lexing Objects at once.
      """
  
      def replace(self, other):
          if isinstance(other, HyObject):
              for attr in ["start_line", "end_line",
                           "start_column", "end_column"]:
                  if not hasattr(self, attr) and hasattr(other, attr):
                      setattr(self, attr, getattr(other, attr))
          else:
              raise TypeError("Can't replace a non Hy object with a Hy object")
  
          return self
  
  _wrappers = {}
  
  
  def wrap_value(x):
      """Wrap `x` into the corresponding Hy type.
  
      This allows replace_hy_obj to convert a non Hy object to a Hy object.
  
      This also allows a macro to return an unquoted expression transparently.
  
      """
  
      wrapper = _wrappers.get(type(x))
      if wrapper is None:
          return x
      else:
          return wrapper(x)
  
  
  def replace_hy_obj(obj, other):
  
      if isinstance(obj, HyObject):
          return obj.replace(other)
  
      wrapped_obj = wrap_value(obj)
  
      if isinstance(wrapped_obj, HyObject):
          return wrapped_obj.replace(other)
      else:
          raise TypeError("Don't know how to wrap a %s object to a HyObject"
                          % (type obj))
  
subject: Make error messages clearer