forget the past.

forget the past.

1 files changed, 47 insertions, 0 deletions

diff --git a/interface.py b/interface.py
new file mode 100644
index 0000000..f4800f0
--- /dev/null
+++ b/interface.py
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+# 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
+"""
+
+__revision__ = "$Id: interface.py,v 1.6 2004-05-10 14:40:50 syt Exp $"
+
+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
+
+