On Tue, 29 Jul 2008 13:53:07 -0700, Carl Banks wrote: > Bzzt. "if len(x)!=0" is a simple explicit that would work for this > class and all built-in containers. (Or should--Steven D'Aprano's > objections notwithstanding, any reasonable container type should support > this invariant.
What's the length of an empty list with a sentinel at the end? What's the length of a binary tree? Does it even have a length? What's the length of a constant-sized table where each position might be in use or free? You're making assumptions about what an empty object "should" look like. I say, just ask the object if it's empty, don't try to guess how you would find out. Maybe the object carries around a flag x.isempty. Who knows? Why do you care? You're basing your code on implementation details. That should be avoided whenever possible. [...] > Once again, I'm invoking the contraint against simply using x in a > boolean context, So, to put it another way... you want us to give you an example of using x in a boolean context, but you're excluding any example where we use x in a boolean context. Right-o, I've had enough of your trolling. I'm out of here. -- Steven -- http://mail.python.org/mailman/listinfo/python-list
