range() is not the best way to check range?

[Antoon Pardon]

On 2006-07-23, Paul Boddie <paul at boddie.org.uk> wrote:
> Antoon Pardon wrote:
>>
>> Except that if you write your own class from scratch, you can't use
>> it as a slice.
>
> Correct, but we were actually discussing subclassing built-in classes
> for use as a replacement for range/xrange. :-)

I think a slice could be very usefull for that.

To me it feel very natural that a slice would be iterable and
could be used in a form like:

  for i in slice(10,20):

or if the slice notation would be usable

  for i in (10:20):

And why not make a slice indexable too?


Whether slices really are the tool to use here or not
I don know for sure. But the problem is, that you
can't easily experiment with this idea because slices
are not subclassable.

> It may be "hard work" writing all those methods in a totally new
> range/xrange class, but passing objects of that class around should
> prove satisfactory for the use of most programs.

But the parameters you will have to give such a class are the same
you have to pass to a slice. IMO that means that you should at least
consider giving slices this functionality. At least it should be
easy to convert from one to the other and back.

-- 
Antoon Pardon