[Python-Dev] Iterable String Redux (aka String ABC)

[Antoine Pitrou]

Georg Brandl <g.brandl <at> gmx.net> writes:
> You wrote:
> 
>  > If we stay minimalistic we could consider that the three basic
operations that
>  > define a string are:
>  > - testing for substring containment
>  > - splitting on a substring into a list of substrings
>  > - slicing in order to extract a substring
> 
> I argued that instead of split, find belongs into that list.
> (BTW, length inquiry would be a fourth.)

Well, find() does test for substring containment, so in essence it is in that
list, although in my first post I chose '__contains__' as the canonical
representative of substring containment :-)
And, you are right, length inquiry belongs into it too.

> That the other methods, among them split, can be implemented in terms
> of those, follows from both sets of basic operations.

When I wrote "the three basic operations that define a string", perhaps I
should have written "the three essential operations" instead. I was not 
attempting to give implementation guidelines but to propose a semantic 
definition of what constitutes a string and distinguishes it from other kinds
of objects.

Anyway, I think we are picking on words here.

Do we agree on the following basic String interface : 
['__len__', '__contains__', '__getitem__', 'find', 'index', 'split', 'rsplit']?

cheers

Antoine.