PEP 285: Adding a bool type: yes, but not as int subtype

[Kris J. Zaragoza]

In article <a8akqh$8bk$0 at 216.39.172.122>, Bengt Richter wrote:
> Of course the 'hidden property' is only rhetoric here, but why not
> make this a clear and controllable unified mechanism instead of a
> collection of special effects? I would like to see an overridable
> __bool__ method (not actually a programmatic property) for the base
> object class, perhaps making deprecation of __nonzero__ possible.

Now this is an idea with some merit.  I can see some real advantages
to being able to define the truth value of a given object, or at least
control its conversion to a bool.  But then, Guido's PEP already shows
this as possible when creating a bool.  If you look at the __new__()
constructor, it checks the truth value of the object when deciding
which global value to return.  If this is how things are implemented
in the C code (and I haven't checked), then __nonzero__() (or
__len__()) is called if defined.  This gives us the control we're
looking for.

> Well, what do you think of the above?

It certainly clarifies matters a bit, but I still have to wonder
whether it's worth the effort.  The way I see it, the mechanism for
the customizations you describe is already present, albeit badly
named.

I certainly don't object to implementing the bool type.  I guess I
just don't see it as a significant advantage.

Kris

-- 
Kris J. Zaragoza       | On the face of it, Microsoft complaining about
kzaragoza at attbi.com    | the source license used by Linux is like the
                       | event horizon calling the kettle black.
                       | -- Adam Barr, article on kuro5hin.org