ooc-dev team mailing list archive

[Noel Cower <ncower@xxxxxxxxx>]

I like Josh and Rubin's ideas, although I think forward and backward don't really communicate that the iterator is going to be at one end or the other of the list.  Not all iterables are going to have the ability to go forward/backward, so it would make sense, to me at least, to put those in List, but then things like HashMap, which are iterable and can have reverse iteration, won't have those methods.

Maybe another subclass of Iterable is necessary to give List and HashMap the same backing without having them be treated as different in terms of their ability to iterate forwards/backwards?  Like BidirectionalIterable or EndedIterable (the former being too long and the latter seems a little odd to me).

If we do use forward/backward, should backward always be a reverse iterator?

Also, iterable iterators sound nice, and I don't really see why we ought to not do that - wouldn't cost anything, just have the iterator return itself when iterator() is called.

-noel

On May 28, 2010, at 9:48 AM, Amos Wenger wrote:

> I like the proposal of Rubin.
> 
> Maybe iterator should be iterable? (they would just return themselves)
> 
> In that case we could write:
> 
> for(element in list backward())
> 
> And ex-Java programmers could even write
> 
> for(element in list forward())
> 
> If they wanted.
> 
> Amos
> 
> On Fri, May 28, 2010 at 5:59 PM, cd rubin <launchpad@xxxxxxxxxxxxxxxx> wrote:
> 
> Hey all
> 
> In which case shouldn't the methods be called 'forwards' and 'backwards'? I think that fits better with the language : 
> 
> "iterate over a list backwards"
> 
> iter := list backwards()
> 
> and it removes possible confusion stemming from calling the method 'front' and getting an iterator instead of the first item of the list!
> 
>  - Daniel (cdrubin) 
> 
> On Fri, May 28, 2010 at 11:21 AM, Josh Roesslein <jroesslein@xxxxxxxxx> wrote:
> Bart makes a good point that not all Iterables will have an ordered structure (ex: socket input/output streams).
> I think it would make more sense having front() and back() methods in List that returns Iterators that either traverse
> the list head to tail or vice versa.
> 
> Josh
> 
> On Fri, May 28, 2010 at 9:33 AM, Amos Wenger <amoswenger@xxxxxxxxx> wrote:
> So what then? iterator~back() ?
> 
> 
> On Fri, May 28, 2010 at 2:53 PM, Bart van der Werf <bluelive@xxxxxxxxx> wrote:
> I'm not sure.
> 
> Alot of iterables have no order, so if front/back is the default way to get an iterator it would make little sense.
> 
> 
> _______________________________________________
> Mailing list: https://launchpad.net/~ooc-dev
> Post to     : ooc-dev@xxxxxxxxxxxxxxxxxxx
> Unsubscribe : https://launchpad.net/~ooc-dev
> More help   : https://help.launchpad.net/ListHelp
> 
> 
> 
> _______________________________________________
> Mailing list: https://launchpad.net/~ooc-dev
> Post to     : ooc-dev@xxxxxxxxxxxxxxxxxxx
> Unsubscribe : https://launchpad.net/~ooc-dev
> More help   : https://help.launchpad.net/ListHelp
> 
> 
> 
> _______________________________________________
> Mailing list: https://launchpad.net/~ooc-dev
> Post to     : ooc-dev@xxxxxxxxxxxxxxxxxxx
> Unsubscribe : https://launchpad.net/~ooc-dev
> More help   : https://help.launchpad.net/ListHelp
> 
> 
> _______________________________________________
> Mailing list: https://launchpad.net/~ooc-dev
> Post to     : ooc-dev@xxxxxxxxxxxxxxxxxxx
> Unsubscribe : https://launchpad.net/~ooc-dev
> More help   : https://help.launchpad.net/ListHelp