Added base for all iteratable objects

Author: Byron

lib/git/utils.py

@@ -27,6 +27,12 @@ def is_git_dir(d):
 
 
 class LazyMixin(object):
+	"""
+	Base class providing an interface to lazily retrieve attribute values upon 
+	first access. If slots are used, memory will only be reserved once the attribute
+	is actually accessed and retrieved the first time. All future accesses will 
+	return the cached value as stored in the Instance's dict or slot.
+	"""
 	__slots__ = tuple()
 
 	def __getattr__(self, attr):
@@ -49,3 +55,35 @@ def _set_cache_(self, attr):
 		in the single attribute."""
 		pass
 
+
+class Iterable(object):
+	"""
+	Defines an interface for iterable items which is to assure a uniform 
+	way to retrieve and iterate items within the git repository
+	"""
+	__slots__ = tuple()
+	
+	@classmethod
+	def list_items(cls, repo, *args, **kwargs):
+		"""
+		Find all items of this type - subclasses can specify args and kwargs differently.
+		If no args are given, subclasses are obliged to return all items if no additional 
+		arguments arg given.
+		
+		Note: Favor the iter_items method as it will 
+		
+		Returns:
+			list(Item,...) list of item instances 
+		"""
+		return list(cls.iter_items, repo, *args, **kwargs)
+		
+		
+	@classmethod
+	def iter_items(cls, repo, *args, **kwargs):
+		"""
+		For more information about the arguments, see find_all
+		Return: 
+			iterator yielding Items
+		"""
+		raise NotImplementedError("To be implemented by Subclass")
+