Re: [m-users.] lists and sets, unordered or ordered.
"Sean Charles (emacstheviking)" <[email protected]>
| Newsgroups | gmane.comp.lang.mercury.general |
|---|---|
| Message-ID | <[email protected]> |
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 <[email protected]> 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 <[email protected]> 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 >>>> [email protected] >>>> https://lists.mercurylang.org/listinfo/users >>> >>> _______________________________________________ >>> users mailing list >>> [email protected] >>> https://lists.mercurylang.org/listinfo/users >> > > _______________________________________________ > users mailing list > [email protected] > https://lists.mercurylang.org/listinfo/users _______________________________________________ users mailing list [email protected] https://lists.mercurylang.org/listinfo/users