[m-users.] lists and sets, unordered or ordered.

[Sean Charles (emacstheviking)]

In my detection, the same missile might hit more than one object if they are close: thus I only wanted to process it once even of it hits five things, so I wanted deduped list just to save setting the hit flag five times if that makes sense.

I checked out all the others sets, the only one I saw that looked good was set_unordlist but is says 'may contain duplicates'.

How do I get an unsorted deduped list from a set then, educate me, i sure as hell need it!

HAHA It's possible I have missed it in the melee, like 'cirle' not 'circle' las week, it's late, I'm tired
:D

> On 3 Oct 2023, at 22:04, Volker Wysk <post at volker-wysk.de> wrote:
> 
> Hi
> 
> You can get a sorted de-duped list from a set. Why do you need an unsorted
> one? If it's efficiency, you need to have it sorted, unless you have only a
> few elements.
> 
> But be aware that there is the "set" module and five "set_*" modules. The
> "set" is using ordered lists. That's inefficient for large sets. Use the
> other modules when you have a big set.
> 
> Cheers,
> Volker
> 
> Am Dienstag, dem 03.10.2023 um 21:55 +0100 schrieb Sean Charles
> (emacstheviking):
>> Indeed. nothing in my drafts folder and I swear it was complete before I hit send... well,
>> basically,
>> is there a reason you can't get an unsorted de-duped list from a set?
>> 
>> That's all...   :D
>> 
>>> On 3 Oct 2023, at 21:53, Volker Wysk <post at volker-wysk.de> wrote:
>>> 
>>> Hi, Sean
>>> 
>>> Your message suddenly stops in the middle of a sentence.
>>> 
>>> Volker
>>> 
>>> Am Dienstag, dem 03.10.2023 um 21:39 +0100 schrieb Sean Charles
>>> (emacstheviking):
>>>> I've just completed a generic typeclass based collision detection system and learned quite a bit doing it!
>>>> 
>>>> As I was reading the module docs, it seems that there is no 'unordered set without duplicates' unless I missed it, which is entirely reasonable.
>>>> 
>>>> The output from the collision detection  is two sets of integers, these are the identifiers of the missiles and the things that were hit at the moment. I now want to take this list and then set the '^hit' flag for every missile in that list, for example, the existing code will then no longer render it and remove it on the next iteration.
>>>> 
>>>> I used sets because they de-dupe as you go, meaning that my checking process is simply iterating two loops, m x n, m missiles and n moving targets, for now it is naive and will probably always be fine given the limited numbers of things on screen at any one time.
>>>> 
>>>> There seems to be no way to get an unordered, deduplicated list from a set, I can use set_unordlist but that leaves duplicates.
>>>> 
>>>> 
>>>> For now I've decided to use set_unordlist, at the cost of maybe updating the same missile record more than once poost-collision detection, it's not going to kill anything really but mentally, and from a purity point of view it feels 'less optimal' than I wanted. Failing that I might just usr  list.member and use lists for everything like I did!
>>>> 
>>>> I just wondered what the reasons were for not having the ability to get an unsorted 
>>>> _______________________________________________
>>>> users mailing list
>>>> users at lists.mercurylang.org
>>>> https://lists.mercurylang.org/listinfo/users
>>> 
>>> _______________________________________________
>>> users mailing list
>>> users at lists.mercurylang.org
>>> https://lists.mercurylang.org/listinfo/users
>> 
> 
> _______________________________________________
> users mailing list
> users at lists.mercurylang.org
> https://lists.mercurylang.org/listinfo/users