1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
|
# Copyright (c) 2000-2004 LOGILAB S.A. (Paris, FRANCE).
# http://www.logilab.fr/ -- mailto:contact@logilab.fr
#
# This program is free software; you can redistribute it and/or modify it under
# the terms of the GNU General Public License as published by the Free Software
# Foundation; either version 2 of the License, or (at your option) any later
# version.
#
# This program is distributed in the hope that it will be useful, but WITHOUT
# ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
# FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License along with
# this program; if not, write to the Free Software Foundation, Inc.,
# 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
"""
bases class for interfaces
TODO:
_ implements a check method which check that an object implements the
interface
_ Attribute objects
This module requires at least python 2.2
"""
from types import ListType, TupleType
class Interface:
"""base class for interfaces"""
def is_implemented_by(cls, instance):
return implements(instance, cls)
is_implemented_by = classmethod(is_implemented_by)
def implements(instance, interface):
"""return true if the instance implements the interface
"""
if hasattr(instance, "__implements__") and \
(interface is instance.__implements__ or
(type(instance.__implements__) in (ListType, TupleType) and \
interface in instance.__implements__)):
return 1
return 0
|
