r''' // (C) Copyright David Abrahams 2000. Permission to copy, use, modify, sell and // distribute this software is granted provided this copyright notice appears // in all copies. This software is provided "as is" without express or implied // warranty, and with no claim as to its suitability for any purpose. // // The author gratefully acknowleges the support of Dragon Systems, Inc., in // producing this work. Automatic checking of the number and type of arguments. Foo's constructor takes a single long parameter. >>> ext = Foo() Traceback (innermost last): File "", line 1, in ? TypeError: function requires exactly 1 argument; 0 given >>> try: ext = Foo('foo') ... except TypeError, err: ... assert re.match( ... '(illegal argument type for built-in operation)|(an integer is required)', str(err)) ... else: print 'no exception' >>> ext = Foo(1) Call a virtual function. This call takes a trip into C++ where FooCallback::add_len() looks up the Python "add_len" attribute and finds the wrapper for FooCallback::default_add_len(), which in turn calls Foo::add_len(). >>> ext.add_len('hello') 6 >>> ext.set(3) >>> ext.add_len('hello') 8 Call a pure virtual function which should have been overridden, but was not. >>> ext.call_pure() Traceback (innermost last): File "", line 1, in ? AttributeError: pure We can subclass Foo. >>> class Subclass(Foo): ... def __init__(self, seq): ... Foo.__init__(self, len(seq)) ... ... def pure(self): ... return 'not pure anymore!' ... ... def get(self): ... return Foo.add_len(self, '') ... ... def add_len(self, s): ... print 'called add_len()' ... return self.get() + len(s) ... >>> b = Subclass('yippee') >>> b.get() 6 >>> b.mumble() 'mumble' >>> b.call_pure() 'not pure anymore!' If no __init__ function is defined, the one from the base class takes effect, just like in a Python class. >>> class DemonstrateInitPassthru(Foo): pass ... >>> q = DemonstrateInitPassthru(1) >>> q.add_len("x") 2 If we don't initialize the base class, we'll get a RuntimeError when we try to use its methods. The test illustrates the kind of error to expect. >>> class BadSubclass(Foo): ... def __init__(self): pass ... >>> barf = BadSubclass() >>> barf.set(4) Traceback (innermost last): ... RuntimeError: __init__ function for extension class 'Foo' was never called. Here we are tesing that the simple definition procedure used in the C++ demo file for classes without any virtual functions actually worked. >>> bar = Bar(3, 4) >>> bar.first() 3 >>> bar.second() 4 >>> baz = Baz() We can actually return the wrapped classes by value >>> baz.pass_bar(bar).first() 3 >>> bar.pass_baz(baz) is baz # A copy of the return value is made. 0 >>> type(bar.pass_baz(baz)) is type(baz) 1 And, yes, we can multiply inherit from these classes. >>> class MISubclass(Subclass, Bar): ... def __init__(self, s): ... Subclass.__init__(self, s) ... Bar.__init__(self, 0, len(s)) ... >>> mi = MISubclass('xx') >>> mi.first() 0 >>> mi.second() 2 >>> mi.mumble() 'mumble' Any object whose class is derived from Bar can be passed to a function expecting a Bar parameter: >>> baz.pass_bar(mi).first() 0 But objects not derived from Bar cannot: >>> baz.pass_bar(baz) Traceback (innermost last): ... TypeError: extension class 'Baz' is not convertible into 'Bar'. The clone function on Baz returns a smart pointer; we wrap it into an ExtensionInstance and make it look just like any other Baz instance. >>> baz_clone = baz.clone() >>> baz_clone.pass_bar(mi).first() 0 Functions expecting an std::auto_ptr parameter will not accept a raw Baz >>> try: baz.eat_baz(Baz()) ... except RuntimeError, err: ... assert re.match("Object of extension class 'Baz' does not wrap <.*>.", ... str(err)) ... else: ... print 'no exception' We can pass std::auto_ptr where it is expected >>> baz.eat_baz(baz_clone) And if the auto_ptr has given up ownership? # MSVC6 ships with an outdated auto_ptr that doesn't get zeroed out when it # gives up ownership. If you are using MSVC6 without the new Dinkumware # library, SGI STL or the STLport, expect this test to crash unless you put # --broken-auto-ptr on the command line. >>> if not '--broken-auto-ptr' in sys.argv: ... try: baz_clone.clone() ... except RuntimeError, err: ... assert re.match('Converting from python, pointer or smart pointer to <.*> is NULL.', str(err)) ... else: ... print 'no exeption' Polymorphism also works: >>> polymorphic_foo = baz.create_foo() >>> polymorphic_foo.call_pure() 'this was never pure!' >>> baz.get_foo_value(polymorphic_foo) 1000 Special member functions in action >>> m = StringMap() __getitem__() >>> m[1] Traceback (innermost last): File "", line 1, in ? KeyError: 1 __setitem__() >>> m[1] = 'hello' __getitem__() >>> m[1] 'hello' __delitem__() >>> del m[1] >>> m[1] # prove that it's gone Traceback (innermost last): File "", line 1, in ? KeyError: 1 __delitem__() >>> del m[2] Traceback (innermost last): File "", line 1, in ? KeyError: 2 __length__() >>> len(m) 0 >>> m[3] = 'farther' >>> len(m) 1 Check for sequence/mapping confusion: >>> for x in m: ... print x ... Traceback (innermost last): File "", line 1, in ? KeyError: 0 Overloading tests: >>> r = Range(3) >>> print str(r) (3, 3) >>> r.start 3 >>> r.finish 3 >>> r.__len__() 0 >>> r.__len__(4) >>> r.finish 7 >>> try: r = Range('yikes') ... except TypeError, e: ... assert re.match( ... 'No overloaded functions match [(]Range, string[)]\. Candidates are:\n.*\n.*', ... str(e)) ... else: print 'no exception' Sequence tests: >>> len(Range(3, 10)) 7 >>> map(lambda x:x, Range(3, 10)) [3, 4, 5, 6, 7, 8, 9] >>> map(lambda x:x, Range(3, 10)[-2:]) [8, 9] >>> map(lambda x:x, Range(3, 10)[:-4]) [3, 4, 5] >>> map(lambda x:x, Range(3, 10)[4:]) [7, 8, 9] >>> map(lambda x:x, Range(3, 10)[4:100]) [7, 8, 9] >>> map(lambda x:x, Range(3, 10)[20:]) [] >>> map(lambda x:x, Range(3, 10)[0:4]) [3, 4, 5, 6] Numeric tests: >>> x = Rational(2,3) >>> y = Rational(1,4) >>> print x + y 11/12 >>> print x - y 5/12 >>> print x * y 1/6 >>> print x / y 8/3 >>> print x + 1 # testing coercion 5/3 >>> print 1 + x # coercion the other way 5/3 delete non-existent attribute: del m.foobar Traceback (innermost last): File "", line 1, in ? AttributeError: delete non-existing instance attribute Testing __getattr__ and __getattr__: >>> n = IntPair(1, 2) >>> n.first 1 >>> n.second 2 >>> n.third Traceback (innermost last): File "", line 1, in ? AttributeError: third Testing __setattr__ and __setattr__: >>> n.first = 33 # N.B __setattr__first sets first to >>> n.first # the negative of its argument. -33 >>> n.second = 66 >>> n.second 66 Testing __delattr__ and __delattr__: >>> del n.first Traceback (innermost last): File "", line 1, in ? AttributeError: first can't be deleted! >>> del n.second Traceback (innermost last): File "", line 1, in ? AttributeError: Attributes can't be deleted! >>> del n.third Traceback (innermost last): File "", line 1, in ? AttributeError: Attributes can't be deleted! # Now show that we can override it. >>> class IntTriple(IntPair): ... def __getattr__(self, s): ... if s in ['first', 'second']: ... return IntPair.__getattr__(self, s) ... elif s == 'third': ... return 3 ... else: ... raise AttributeError(s) ... ... # Also show that __setattr__ is supported ... def __setattr__(self, name, value): ... raise AttributeError('no writable attributes') ... >>> p = IntTriple(0, 1) >>> p.first 0 >>> p.second 1 >>> p.third 3 >>> p.bax Traceback (innermost last): File "", line 1, in ? AttributeError: bax >>> p.third = 'yes' Traceback (innermost last): File "", line 1, in ? AttributeError: no writable attributes >>> del p.third Traceback (innermost last): File "", line 1, in ? AttributeError: Attributes can't be deleted! demonstrate def_readonly, def_read_write: >>> sp = StringPair("hello", "world") >>> sp.first # first is read-only 'hello' >>> first_string(sp) # prove that we're not just looking in sp's __dict__ 'hello' >>> sp.first = 'hi' # we're not allowed to change it Traceback (innermost last): File "", line 1, in ? AttributeError: 'first' attribute is read-only >>> first_string(sp) # prove that it hasn't changed 'hello' >>> sp.second # second is read/write 'world' >>> second_string(sp) 'world' >>> sp.second = 'universe' # set the second attribute >>> sp.second 'universe' >>> second_string(sp) # this proves we didn't just set it in sp's __dict__ 'universe' some __str__ and __repr__ tests: >>> sp ('hello', 'universe') >>> repr(sp) "('hello', 'universe')" >>> str(sp) "('hello', 'universe')" Range has a __str__ function but not a __repr__ function >>> range = Range(5, 20) >>> str(range) '(5, 20)' >>> assert re.match('', repr(range)) __hash__ and __cmp__ tests: # Range has both __hash__ and __cmp__, thus is hashable >>> colors = { Range(3,4): 'blue', Range(7,9): 'red' } >>> colors[Range(3,4)] 'blue' # StringPair has only __cmp__ >>> { StringPair('yo', 'eddy'): 1 } Traceback (innermost last): File "", line 1, in ? TypeError: unhashable type # But it can be sorted >>> stringpairs = [ StringPair('yo', 'eddy'), StringPair('yo', 'betty'), sp ] >>> stringpairs.sort() >>> stringpairs [('hello', 'universe'), ('yo', 'betty'), ('yo', 'eddy')] make_pair is a global function in the module. >>> couple = make_pair(3,12) >>> couple.first 3 >>> couple.second 12 Testing __call__: >>> couple2 = make_pair(3, 7) >>> comparator = CompareIntPair() >>> comparator(couple, couple) 0 >>> comparator(couple, couple2) 0 >>> comparator(couple2, couple) 1 Testing overloaded free functions >>> overloaded() 'Hello world!' >>> overloaded(1) 1 >>> overloaded('foo') 'foo' >>> overloaded(1,2) 3 >>> overloaded(1,2,3) 6 >>> overloaded(1,2,3,4) 10 >>> overloaded(1,2,3,4,5) 15 >>> try: overloaded(1, 'foo') ... except TypeError, err: ... assert re.match("No overloaded functions match \(int, string\)\. Candidates are:", ... str(err)) ... else: ... print 'no exception' Testing overloaded constructors >>> over = OverloadTest() >>> over.getX() 1000 >>> over = OverloadTest(1) >>> over.getX() 1 >>> over = OverloadTest(1,1) >>> over.getX() 2 >>> over = OverloadTest(1,1,1) >>> over.getX() 3 >>> over = OverloadTest(1,1,1,1) >>> over.getX() 4 >>> over = OverloadTest(1,1,1,1,1) >>> over.getX() 5 >>> over = OverloadTest(over) >>> over.getX() 5 >>> try: over = OverloadTest(1, 'foo') ... except TypeError, err: ... assert re.match("No overloaded functions match \(OverloadTest, int, string\)\. Candidates are:", ... str(err)) ... else: ... print 'no exception' Testing overloaded methods >>> over.setX(3) >>> over.overloaded() 3 >>> over.overloaded(1) 1 >>> over.overloaded(1,1) 2 >>> over.overloaded(1,1,1) 3 >>> over.overloaded(1,1,1,1) 4 >>> over.overloaded(1,1,1,1,1) 5 >>> try: over.overloaded(1,'foo') ... except TypeError, err: ... assert re.match("No overloaded functions match \(OverloadTest, int, string\)\. Candidates are:", ... str(err)) ... else: ... print 'no exception' Testing base class conversions >>> testUpcast(over) Traceback (innermost last): TypeError: extension class 'OverloadTest' is not convertible into 'Base'. >>> der1 = Derived1(333) >>> der1.x() 333 >>> testUpcast(der1) 333 >>> der1 = derived1Factory(1000) >>> testDowncast1(der1) 1000 >>> testDowncast2(der1) Traceback (innermost last): TypeError: extension class 'Base' is not convertible into 'Derived2'. >>> der2 = Derived2(444) >>> der2.x() 444 >>> testUpcast(der2) 444 >>> der2 = derived2Factory(1111) >>> testDowncast2(der2) Traceback (innermost last): TypeError: extension class 'Base' is not convertible into 'Derived2'. Testing interaction between callbacks, base declarations, and overloading - testCallback() calls callback() (within C++) - callback() is overloaded (in the wrapped class CallbackTest) - callback() is redefined in RedefineCallback (overloading is simulated by type casing) - testCallback() should use the redefined callback() >>> c = CallbackTest() >>> c.testCallback(1) 2 >>> c.testCallback('foo') Traceback (innermost last): File "", line 1, in ? TypeError: illegal argument type for built-in operation >>> c.callback(1) 2 >>> c.callback('foo') 'foo 1' >>> import types >>> class RedefineCallback(CallbackTest): ... def callback(self, x): ... if type(x) is types.IntType: ... return x - 2 ... else: ... return CallbackTest.callback(self,x) ... >>> r = RedefineCallback() >>> r.callback(1) -1 >>> r.callback('foo') 'foo 1' >>> r.testCallback('foo') Traceback (innermost last): File "", line 1, in ? TypeError: illegal argument type for built-in operation >>> r.testCallback(1) -1 >>> testCallback(r, 1) -1 ''' from demo import * import string import re import sys def run(args = None): if args is not None: sys.argv = args import doctest, test_extclass doctest.testmod(test_extclass) if __name__ == '__main__': run()