Yep! I really like it :) On Thu, Dec 3, 2020 at 7:52 PM eksperimental <eksperimen...@autistici.org> wrote:
> On Thu, 3 Dec 2020 19:06:18 -0500 > Allen Madsen <allen.c.mad...@gmail.com> wrote: > > > Enum.compare_count([], 1) #=> :lt > > Enum.compare_count([1], 1) #=> :eq > > Enum.compare_count([1, 2], 1) #=> :gt > > This is the way to go, because in one function call we can determine the > course of the action, such as in > > case Enum.compare_count(list, n) do > :lt -> ... > :eq -> ... > :gt -> ... > end > > when using the predicate functions it would require at least two > function calls. > > > > > Allen Madsen > > http://www.allenmadsen.com > > > > > > On Thu, Dec 3, 2020 at 6:51 PM Zach Daniel > > <zachary.s.dan...@gmail.com> wrote: > > > > > Well, List.count doesn’t exist yet, but either way it sounds like > > > not a great idea :) I couldn’t find examples in other Lang’s, so > > > maybe I’ll just throw out some other names: > > > > > > Enum.at_least?/2 > > > > > > Enum.at_most?/2 > > > > > > Enum.has_count?/2 > > > > > > On Thu, Dec 3, 2020 at 5:14 PM Michał Muskała <mic...@muskala.eu> > > > wrote: > > > > > >> Unfortunately this can’t be done automatically since it has subtle > > >> semantic differences. In particular Enum.count/1 (or length/1) not > > >> only traverses the list to count its size, but also verifies it’s > > >> a proper list raising an exception for improper lists. The > > >> difference could be seen for value like: > > >> > > >> > > >> > > >> [1, 2, 3 | :invalid] > > >> > > >> > > >> > > >> Calling length/1 or Enum.count/1 on this raises. If compiler did > > >> the optimisation you propose, for something like length(list) > 0, > > >> it wouldn’t fully traverse the list and wouldn’t raise. Thus such > > >> an optimisation is not possible in the general case. > > >> > > >> > > >> > > >> *From: *elixir-lang-core@googlegroups.com < > > >> elixir-lang-core@googlegroups.com> > > >> *Date: *Thursday, 3 December 2020 at 22:04 > > >> *To: *elixir-lang-core@googlegroups.com < > > >> elixir-lang-core@googlegroups.com> > > >> *Subject: *Re: [elixir-core:9802] Proposal `Enum.more_than?/2` or > > >> `List.more_than?/2` > > >> > > >> This probably off the table/unreasonable, but it also seems like > > >> something that could be statically solved and people would never > > >> need to know as it is just an optimization. E.g Enum.count(list) > > > >> n could optimized by the compiler? Probably wouldn’t be good for > > >> all Enums, since counting would be expected to enumerate them, so > > >> maybe only something like List.count 🤷♂️ > > >> > > >> > > >> > > >> On Thu, Dec 3, 2020 at 1:42 PM Zach Daniel > > >> <zachary.s.dan...@gmail.com> wrote: > > >> > > >> Another benefit to the options list would be supporting it for > > >> count with a predicate, e.g Enum.count(enum, &some_predicate/1, > > >> max: 4) > > >> > > >> > > >> > > >> On Thu, Dec 3, 2020 at 1:35 PM Zach Daniel > > >> <zachary.s.dan...@gmail.com> wrote: > > >> > > >> Nothing is jumping out at me from elsewhere yet, but another > > >> option might be accepting options in `Enum.count`, like > > >> `Enum.count(list, max: 4)`. I’ll keep searching though. > > >> > > >> > > >> > > >> On Thu, Dec 3, 2020 at 1:31 PM Zach Daniel > > >> <zachary.s.dan...@gmail.com> wrote: > > >> > > >> I agree on the name feeling subpar :) I’ll take a look and see if > > >> I can find other examples. > > >> > > >> > > >> > > >> On Thu, Dec 3, 2020 at 12:21 PM José Valim <jose.va...@dashbit.co> > > >> wrote: > > >> > > >> Thanks Zach! I like this idea but the proposed name, for some > > >> reason, doesn't sit right with me. Is there any prior art from > > >> other langs we could look at? > > >> > > >> > > >> > > >> On Thu, Dec 3, 2020 at 6:15 PM Zachary Daniel > > >> <zachary.s.dan...@gmail.com> wrote: > > >> > > >> Counting a list, especially a large one, to know if there are > > >> "more than x" or "less than x" items is inefficient. > > >> > > >> > > >> > > >> Right now I often see things like `if Enum.count(list) > 4 ...`, > > >> mostly because writing a recursive `more_than?` check is tedious, > > >> or doing something like `Enum.empty?(Enum.drop(list, 4))` is not > > >> very expressive. > > >> > > >> > > >> > > >> I think it would be nice to have an `Enum.more_than?` that does > > >> that work for you. It could also be `List.more_than?/2` if we > > >> don't want it in Enum. Any thoughts? > > >> > > >> -- > > >> 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/263d7c39-a32b-4294-93d8-40f248c9b3c8n%40googlegroups.com > > >> < > https://groups.google.com/d/msgid/elixir-lang-core/263d7c39-a32b-4294-93d8-40f248c9b3c8n%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/CAGnRm4JX4NE1yWH1G5L_DjF18v8zejF0%2BSkb_oz%3DPiUHM8Mz1w%40mail.gmail.com > > >> < > https://groups.google.com/d/msgid/elixir-lang-core/CAGnRm4JX4NE1yWH1G5L_DjF18v8zejF0%2BSkb_oz%3DPiUHM8Mz1w%40mail.gmail.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/CAK-yb0BBGCrgbZamFs%2BeqLUis6mFQgvUHkKK1htSN5rDDWwMRQ%40mail.gmail.com > > >> < > https://groups.google.com/d/msgid/elixir-lang-core/CAK-yb0BBGCrgbZamFs%2BeqLUis6mFQgvUHkKK1htSN5rDDWwMRQ%40mail.gmail.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/DB7PR07MB3899C92933992464F17898E1FAF20%40DB7PR07MB3899.eurprd07.prod.outlook.com > > >> < > https://groups.google.com/d/msgid/elixir-lang-core/DB7PR07MB3899C92933992464F17898E1FAF20%40DB7PR07MB3899.eurprd07.prod.outlook.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/CAK-yb0BO2QESHcaL7-svOoAGqvr6hJi%3D8AHFqi-qNZdoFEMMwA%40mail.gmail.com > > > < > https://groups.google.com/d/msgid/elixir-lang-core/CAK-yb0BO2QESHcaL7-svOoAGqvr6hJi%3D8AHFqi-qNZdoFEMMwA%40mail.gmail.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/5fc98859.1c69fb81.3cf33.11a4SMTPIN_ADDED_MISSING%40gmr-mx.google.com > . > -- You received this message because you are subscribed to the Google Groups "elixir-lang-core" group. 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