mirror of
https://github.com/facebook/sapling.git
synced 2024-10-11 01:07:15 +03:00
37 lines
1.3 KiB
Python
37 lines
1.3 KiB
Python
|
# extutil.py - useful utility methods for extensions
|
||
|
#
|
||
|
# Copyright 2016 Facebook
|
||
|
#
|
||
|
# This software may be used and distributed according to the terms of the
|
||
|
# GNU General Public License version 2 or any later version.
|
||
|
|
||
|
def replaceclass(container, classname):
|
||
|
'''Replace a class with another in a module, and interpose it into
|
||
|
the hierarchies of all loaded subclasses. This function is
|
||
|
intended for use as a decorator.
|
||
|
|
||
|
import mymodule
|
||
|
@replaceclass(mymodule, 'myclass')
|
||
|
class mysubclass(mymodule.myclass):
|
||
|
def foo(self):
|
||
|
f = super(mysubclass, self).foo()
|
||
|
return f + ' bar'
|
||
|
|
||
|
Existing instances of the class being replaced will not have their
|
||
|
__class__ modified, so call this function before creating any
|
||
|
objects of the target type.
|
||
|
'''
|
||
|
def wrap(cls):
|
||
|
oldcls = getattr(container, classname)
|
||
|
for subcls in oldcls.__subclasses__():
|
||
|
if subcls is not cls:
|
||
|
assert oldcls in subcls.__bases__
|
||
|
newbases = [oldbase
|
||
|
for oldbase in subcls.__bases__
|
||
|
if oldbase != oldcls]
|
||
|
newbases.append(cls)
|
||
|
subcls.__bases__ = tuple(newbases)
|
||
|
setattr(container, classname, cls)
|
||
|
return cls
|
||
|
return wrap
|