[Python-Dev] Re: PEP 322: Reverse Iteration

Brett C. bac at OCF.Berkeley.EDU
Wed Nov 5 23:22:45 EST 2003

Guido van Rossum wrote:
>>Unless some _opportune_ (i.e., truly good:-) use case of "naturally 
>>reversible nonsequence" (doubly linked list...?-) arises (and the
>>__reversed__ idea can inserted then -- just as it could be removed
>>if reversed started out with it -- as long as we do it before the beta)
>>reversed with or without __reversed__ seem anyway fine to me --
>>arguments being so finely balanced on both sides.
> It's more effort to add something later than to remove it (since
> there's always *someone* who's already dependent on it), so I see the
> argument about adding __reversed__ far from balanced.  I see at most a
> 5% chance that reversed() would be removed before 2.3b1.  If we add
> __reversed__ now I doubt that we'll remove it (assuming reversed()
> stays), but I still am unconvinced of the need (and I *am* convinced
> of the danger).
> So:
> - I am +1 on adding reversed() provisionally
> - I am -1 on adding __reversed__ at the same time

Been following this from afar (crazy week with homework; fun).  In case 
anyone cares about my opinion:

+0 on reversed(): wouldn't hurt having it but I still don't see it as 
critical enough to be a built-in
-1 on __reversed__: I like my iterator protocol **simple**.

OK, back to studying for my midterm.


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