code.delx.au - bg-scripts/blob - lib/Enum.py

   1 #! python
   2 # Copyright 2007 Greg Darke <gdar9540@usyd.edu.au>
   3 # Licensed for distribution under the GPL version 2, check COPYING for details
   4 # An enum like interface
   5
   6 """
   7 An enum like interface
   8 """
   9
  10 __all__ = ('enum', )
  11
  12 import itertools
  13
  14 def enum(*args):
  15         return EnumContainer(*args)
  16
  17 class EnumElement(object):
  18         __slots__ = ('enumName', 'enumContainer')
  19         def __init__(self, enumName, enumContainer):
  20                 self.enumName = enumName
  21                 self.enumContainer = enumContainer
  22         def __repr__(self):
  23                 return '%s(%s)' % (self.__class__.__name__, self.enumName)
  24         def __str__(self):
  25                 return self.enumName
  26         def __eq__(self, other):
  27                 if not isinstance(other, self.__class__): return NotImplemented
  28                 return other is self
  29         def __hash__(self):
  30                 return hash(self.enumName) ^ hash(self.enumContainer)
  31
  32 class EnumContainer(object):
  33         def __init__(self, *enums):
  34                 self.enumList = tuple( EnumElement(enumName, self) for enumName in enums)
  35                 for enumName, enumElement in itertools.izip(enums, self.enumList):
  36                         setattr(self, enumName, enumElement)
  37
  38         def __contains__(self, enum):
  39                 return enum in self.enumList
  40
  41         def __repr__(self):
  42                 return '%s(%s)' % (self.__class__.__name__, ', '.join(self.enumList))
  43
  44         def explode(self):
  45                 """Places contents of this enum into the callers global namespace"""
  46                 import inspect
  47                 frameObject, _, _, _, _ = inspect.stack[1] # The stackframe of who called us
  48                 global_dict = frameObject.f_globals
  49                 del frameObject
  50                 for enum in self.enumList:
  51                         if str(enum) in global_dict:
  52                                 raise ValueError, '%s is already in your global dict' % enum
  53                 for enum in self.enumList:
  54                         global_dict[str(enum)] = enum