Added printing requirements

zope/interface/exceptions.py

@@ -0,0 +1,67 @@
+##############################################################################
+#
+# Copyright (c) 2002 Zope Foundation and Contributors.
+# All Rights Reserved.
+#
+# This software is subject to the provisions of the Zope Public License,
+# Version 2.1 (ZPL).  A copy of the ZPL should accompany this distribution.
+# THIS SOFTWARE IS PROVIDED "AS IS" AND ANY AND ALL EXPRESS OR IMPLIED
+# WARRANTIES ARE DISCLAIMED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+# WARRANTIES OF TITLE, MERCHANTABILITY, AGAINST INFRINGEMENT, AND FITNESS
+# FOR A PARTICULAR PURPOSE.
+#
+##############################################################################
+"""Interface-specific exceptions
+"""
+
+class Invalid(Exception):
+    """A specification is violated
+    """
+
+class DoesNotImplement(Invalid):
+    """ This object does not implement """
+    def __init__(self, interface):
+        self.interface = interface
+
+    def __str__(self):
+        return """An object does not implement interface %(interface)s
+
+        """ % self.__dict__
+
+class BrokenImplementation(Invalid):
+    """An attribute is not completely implemented.
+    """
+
+    def __init__(self, interface, name):
+        self.interface=interface
+        self.name=name
+
+    def __str__(self):
+        return """An object has failed to implement interface %(interface)s
+
+        The %(name)s attribute was not provided.
+        """ % self.__dict__
+
+class BrokenMethodImplementation(Invalid):
+    """An method is not completely implemented.
+    """
+
+    def __init__(self, method, mess):
+        self.method=method
+        self.mess=mess
+
+    def __str__(self):
+        return """The implementation of %(method)s violates its contract
+        because %(mess)s.
+        """ % self.__dict__
+
+class InvalidInterface(Exception):
+    """The interface has invalid contents
+    """
+
+class BadImplements(TypeError):
+    """An implementation assertion is invalid
+
+    because it doesn't contain an interface or a sequence of valid
+    implementation assertions.
+    """