Oh I completely agree! I used MapSet because it has clean semantics for the problem domain, I expect with small datasets there won't be any performance difference. But looking at my code now I'm not using pop (because `MapSet.pop/2` ecause this doesn't exist, so this may not be helpful to the original discussion about `List.pop/2`
I apologize as I've taken this thread offtopic -- Nathan if it's helpful to you my suggestion/selection implementation is here: https://github.com/bikebrigade/dispatch/blob/main/lib/bike_brigade_web/live/rider_live/index.ex#L21-L90 . Happy to respond to direct emails about it if you have any questions! Again sorry for veering us offtopic :) On Tue, Mar 8, 2022 at 9:22 AM Ben Wilson <benwilson...@gmail.com> wrote: > I would benchmark to make sure that you're actually gaining something. If > you are relying on it to be small, then at that specific size a list might > also just be fine, and you won't be relying on behavior that could change > in a future release. > > On Monday, March 7, 2022 at 11:49:06 AM UTC-5 Max Veytsman wrote: > >> For what it's worth, I use MapSets for these kinds of autocompletion >> suggestion lists in LiveView. It's worth noting that these aren't >> guaranteed to preserve insertion order, and I'm relying on a implementation >> detail that they will for a small number of keys. >> >> On Mon, Mar 7, 2022 at 10:51 AM h...@nathanmlong.com < >> h...@nathanmlong.com> wrote: >> >>> Hmm. I can't give too much detail, but the basic context is a LiveView >>> form where the user selects some ports and the form provides suggestions as >>> they type. Eg, if they type `2` it will suggest `22 - SSH`, `25 - SMTP`, >>> etc. >>> >>> The currently-selected ports are a list of integers. If `22` is already >>> selected, the LiveView won't suggest it. So if the LiveView gets a message >>> to deselect `22`, it tries to pop it out of the `selections` list. If the >>> pop succeeds, the `suggestions` list can be updated to include port `22` >>> again. If the pop doesn't succeed, we can ignore the message; we can't >>> deselect a port that wasn't selected to start with. >>> >>> I can't combine `selected` and `suggested` (eg by flagging the >>> suggestions which are also selected) because both collections can contain >>> elements that the other doesn't contain; the user may select ports that are >>> not in the suggestions list. And it's not practical to have a top-level >>> list of every possible port and flag each as `selected`, `suggested`, or >>> both, because there are are 65,535 possible ports. >>> >>> So the core of my use case is: I get a user message to remove an item >>> from a list, and after attempting to remove it, I want to take a follow-up >>> action only if the item was was actually in the list. >>> >>> On Friday, March 4, 2022 at 11:05:35 AM UTC-5 José Valim wrote: >>> >>>> Hi Nathan, thanks for the email. Can you please show some examples of >>>> where they could be handy with some context around them? Thank you! >>>> >>>> On Fri, Mar 4, 2022 at 3:45 PM h...@nathanmlong.com < >>>> h...@nathanmlong.com> wrote: >>>> >>>>> This is a modified version of what I proposed in >>>>> https://github.com/elixir-lang/elixir/pull/11681 >>>>> >>>>> Similar to `Map.pop/2` and and `Keyword.pop/2`, I propose adding >>>>> `List.pop/2`. >>>>> >>>>> I also propose adding `List.find_and_pop/2`, which is more generalized >>>>> since it takes a function. >>>>> >>>>> Here are possible implementations. >>>>> >>>>> ```elixir >>>>> @doc """ >>>>> Returns and removes the first value matching `item` in the `list`. >>>>> >>>>> ## Examples >>>>> iex> List.pop([1, 2, 2, 3], 2) >>>>> {2, [1, 2, 3]} >>>>> iex> List.pop([1, 2, 3, 4], 20) >>>>> {nil, [1, 2, 3, 4]} >>>>> """ >>>>> def pop(list, item) do >>>>> find_and_pop(list, &(&1 == item)) >>>>> end >>>>> >>>>> @doc """ >>>>> Returns and removes the first value matching `fun` in the `list`. >>>>> >>>>> ## Examples >>>>> iex> List.find_and_pop([1, 2, 3, 4], &(&1 > 2)) >>>>> {3, [1, 2, 4]} >>>>> iex> List.find_and_pop([1, 2, 3, 4], &(&1 > 20)) >>>>> {nil, [1, 2, 3, 4]} >>>>> """ >>>>> def find_and_pop(list, fun) do >>>>> case Enum.find_index(list, fun) do >>>>> nil -> {nil, list} >>>>> i -> pop_at(list, i) >>>>> end >>>>> end >>>>> ``` >>>>> >>>>> -- >>>>> You received this message because you are subscribed to the Google >>>>> Groups "elixir-lang-core" group. >>>>> To unsubscribe from this group and stop receiving emails from it, send >>>>> an email to elixir-lang-co...@googlegroups.com. >>>>> To view this discussion on the web visit >>>>> https://groups.google.com/d/msgid/elixir-lang-core/bdc98b8c-fc73-40d7-8287-eb0b5d3ea97en%40googlegroups.com >>>>> <https://groups.google.com/d/msgid/elixir-lang-core/bdc98b8c-fc73-40d7-8287-eb0b5d3ea97en%40googlegroups.com?utm_medium=email&utm_source=footer> >>>>> . >>>>> >>>> -- >>> You received this message because you are subscribed to the Google >>> Groups "elixir-lang-core" group. >>> To unsubscribe from this group and stop receiving emails from it, send >>> an email to elixir-lang-co...@googlegroups.com. >>> >> To view this discussion on the web visit >>> https://groups.google.com/d/msgid/elixir-lang-core/57bc38e4-2596-415c-8dbf-a235330d459an%40googlegroups.com >>> <https://groups.google.com/d/msgid/elixir-lang-core/57bc38e4-2596-415c-8dbf-a235330d459an%40googlegroups.com?utm_medium=email&utm_source=footer> >>> . >>> >> -- > You received this message because you are subscribed to the Google Groups > "elixir-lang-core" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to elixir-lang-core+unsubscr...@googlegroups.com. > To view this discussion on the web visit > https://groups.google.com/d/msgid/elixir-lang-core/fa78cd65-804d-4160-99fb-58d0e0994ddan%40googlegroups.com > <https://groups.google.com/d/msgid/elixir-lang-core/fa78cd65-804d-4160-99fb-58d0e0994ddan%40googlegroups.com?utm_medium=email&utm_source=footer> > . > -- You received this message because you are subscribed to the Google Groups "elixir-lang-core" group. 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