############################################################################## # # Copyright (c) 2001, 2002 Zope Corporation 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. # ############################################################################## from Exceptions import BrokenImplementation, DoesNotImplement from Exceptions import BrokenMethodImplementation from types import FunctionType from Method import fromMethod, fromFunction from _object import MethodTypes def _verify(iface, candidate, tentative=0, vtype=None): """ Verify that 'candidate' might correctly implements 'iface'. This involves: o Making sure the candidate defines all the necessary methods o Making sure the methods have the correct signature o Making sure the candidate asserts that it implements the interface Note that this isn't the same as verifying that the class does implement the interface. If optional tentative is true, suppress the "is implemented by" test. """ if vtype is 'c': tester = iface.isImplementedByInstancesOf else: tester = iface.isImplementedBy if not tentative and not tester( candidate ): raise DoesNotImplement(iface) for n, d in iface.namesAndDescriptions(1): if not hasattr(candidate, n): raise BrokenImplementation(iface, n) attr = getattr(candidate, n) if type(attr) is FunctionType: # should never get here meth = fromFunction(attr, n) elif type(attr) in MethodTypes: meth = fromMethod(attr, n) else: continue # must be an attribute... d=d.getSignatureInfo() meth = meth.getSignatureInfo() mess = _incompat(d, meth) if mess: raise BrokenMethodImplementation(n, mess) return 1 def verifyClass(iface, candidate, tentative=0): return _verify(iface, candidate, tentative, vtype='c') def verifyObject(iface, candidate, tentative=0): return _verify(iface, candidate, tentative, vtype='o') def _incompat(required, implemented): #if (required['positional'] != # implemented['positional'][:len(required['positional'])] # and implemented['kwargs'] is None): # return 'imlementation has different argument names' if len(implemented['required']) > len(required['required']): return 'implementation requires too many arguments' if ((len(implemented['positional']) < len(required['positional'])) and not implemented['varargs']): return "implementation doesn't allow enough arguments" if required['kwargs'] and not implemented['kwargs']: return "implementation doesn't support keyword arguments" if required['varargs'] and not implemented['varargs']: return "implementation doesn't support variable arguments"