in reply to The Null Mull (or, when OO needs more O)

I couldn't turn up any great links on the subject, but Objective-C (as used in Apple's Cocoa development) uses this pattern. Calling a method on a nil object returns nil. It'd be similar to this Perl, which would print undefined:
# this would work if it were Objective-C # using Perl's syntax my $foo = undef; my $result = $foo->message; print "undefined\n" if not defined $result;
I happen to like it.