def get_or_create(needle,haystack,default):
	"""
	This is a wrapper for filter that can add stuff. Nothing special. Needle is a function, default isn't. Haystack is a list. I might fix that later.
	"""
	f=filter(needle,haystack)
	try: return next(f)
	except StopIteration: pass
	haystack.append(default)
	return default