[Glass] Collection for reduced conflicts, allow indexes and #sort: ?

[Mariano Martinez Peck]

On Thu, Dec 5, 2013 at 7:36 PM, Dale K. Henrichs <
dale.henrichs at gemtalksystems.com> wrote:

>
>
> ------------------------------
>
> *From: *"Mariano Martinez Peck" <marianopeck at gmail.com>
> *To: *glass at lists.gemtalksystems.com
> *Sent: *Thursday, December 5, 2013 8:06:08 AM
> *Subject: *[Glass] Collection for reduced conflicts, allow indexes and
> #sort: ?
>
>
> Hi guys. So...at some point in my app, I have a collection in which I
> store instances of a persistent class. Imagine class Client, so at some
> point I have a persistent collection of clients.
>
> Now... I want:
>
> 1) Reduced conflict collections
> 2) Be able to use indexes if I happen to need them later on (as far as I
> read it needs to be an unordered collection)
>
> correct
>
> 3) Be able to sort the collection given a closure
>
> You can use #sorted: (has the advantage of being defined in Grease so it
> is "common" between GemStone and Pharo) which takes a standard sort block.
>

Thanks for the tip. Indeed, using #sorted: is better!



> If you have an indexed collection, you cannot use an arbitrary block to
> take advantage of the index ... you have to define a query against the
> collection ...
>
>
>
Yes, what a pity :( It would be so cool if normal closures received by
select: could detect that you have an index there and use it :)

BTW... (I should test it instead of asking)... indexes are not used
automagically neither for sorting? say I do a normal #sorted: over a
unordered collection over a field in which I have an index...would that
help?  Or I need to explicitly use #sortAscending:  #sortDescending:
 #sortWith:  etc in order to take advantage of the index?


>
>
> Just taking into account 1) and 2) it seems the only option is
> RcIdentityBag. Problem is that I cannot sort such collection with a simple
> #sort: aBlockClosure. I saw I have #sortWith:, #sortAsending: etc, but
> that's not what I need. I need to receive a block closure.
>
> I can send #asSortedCollection: aClosure to the RcIdentityBag but that
> answers an instance of a SortedCollection, not a RcIdentityBag sorted,
> which is different.
>
>  Bags, by definition are not ordered, so to get a sorted result you will
> end up with some sort of SequenceableCollection as a result, by necessity
> ...
>
>
Indeed, I know it makes sense :)
I wonder why there isn't any ordered collection that supports RC and
indexes. Technically, I can understand the latter (I think) but not that
much the former.

Thanks Dale  and Richard for your answers,


-- 
Mariano
http://marianopeck.wordpress.com
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.gemtalksystems.com/mailman/private/glass/attachments/20131205/871ebeb5/attachment.html>