callable classes

[Michael Hudson]

"Duncan Smith" <buzzard at urubu.freeserve.co.uk> writes:

> I recently started to rewrite a class and decided to take a bunch of related
> methods and put them in a separate callable class.  (They're all what I
> would call pointwise operations on pairs of instances, they raise exceptions
> for identical reasons, and they all return a new instance).  It seemed like
> a good idea at the time, but now I'm not so sure.  So my very general
> questions are:
> 
> Is this a reasonable use for a callable class?

It's hard (for me at least) to see what you mean.  Post some code?

> In what circumstances are callable classes particularly useful?

Well, I guess you could say when you have a callable with state.  I
must admit I prefer to use a bound method in these circumstances, but
I'm not really sure why.

Cheers,
mwh

-- 
  Exam invigilation - it doesn't come much harder than that, esp if
  the book you're reading turns out to be worse than expected.
                                  -- Dirk Bruere, sci.physics.research