id	summary	reporter	owner	description	type	status	component	version	severity	resolution	keywords	cc	stage	has_patch	needs_docs	needs_tests	needs_better_patch	easy	ui_ux
23627	Add a decorator for lookup registration.	Marc Tamlyn	nobody	"Instead of:

{{{
class MyLookup(Lookup):
    lookup_name = 'foo'
    ...

MyField.register_lookup(MyLookup)
}}}

Allow:

{{{
@MyField.register_lookup
class MyLookup(Lookup):
    lookup_name = 'foo'
    ...
}}}

I guess we should be able to convert the existing function to work properly for both. We need to then use this functionality everywhere we do lookup registration.

Proposed by Aymeric and +1 from Anssi in https://github.com/django/django/pull/3219"	Cleanup/optimization	closed	Database layer (models, ORM)	1.7	Normal	fixed			Ready for checkin	1	0	0	0	0	0