enhancing slicing

[gbreed at cix.compulink.co.uk]

In article <9m2sij$1f8s$1 at ID-102451.news.dfncis.de>, juanv at posta.unizar.es 
(Juan Valiño) wrote:

> My proposal is to introduce a new operator, for instance # (count):
> v[5 # 2]
> Extract 2 elements starting at 5: [ v[5], v[6] ]. Equivalent to v[5:5+2]

I don't think # is right, because it's already used for comments.  But 
perhaps :][: would do the trick.  So it'd be v[5 :][: 2].  It's more 
complex, but looks nice.  And doesn't introduce any new punctuation into 
the language.  Shall I start on the PEP?

> v[5 # -2]
> Extract 2 elements ending at (but not including the) 5: [ v[3], v[4] ].
> Equivalent to v[5-2:5]

I'm not sure the the :][: operator would be appropriate here, but maybe 
the variation v[:5 ][ -2:] could be made to work.

> I think that this little syntactic sugar allows programs more compact 
> and
> readable. Also, I had less "start and end point paranoias". I suppose 
> that
> the implementation is easy and the current programs are not affected at 
> all.

Would my suggestions be much harder to implement?


                  Graham