then_if has no meaning to me and breaks my brain. Seems not to flow with other pipeline commands.
Dr. Jim Freeze, Ph.D. ElixirConf® ElixirConf.com ElixirConf.eu (m) 512 949 9683 On Fri, Dec 6, 2024 at 10:58 AM José Valim <jose.va...@gmail.com> wrote: > Thank you Zach. When I wrote the proposal I felt it was missing something > still and I think you nailed it. > > Passing two anonymous functions would help with the pipeline but it feels > it would be detrimental to other cases. > > > > *José Valimhttps://dashbit.co/ <https://dashbit.co/>* > > > On Fri, Dec 6, 2024 at 17:41 Zach Daniel <zachary.s.dan...@gmail.com> > wrote: > >> Despite typically being a "put it in the standard library" guy, I don't >> think that `then_if` actually composes as well as it looks like it does on >> the tin due to the fact that `then` is often used in pipelines, where some >> transformation has happened and you want to check a condition *on that >> result*. For example: >> >> ```elixir >> changeset >> |> do_some_checking() >> |> then_if(<is_valid>, &do_more/1) >> ``` >> >> I think that `then` is kind of "already" the composition tool that we >> need for expressive pipes. >> >> ```elixir >> changeset >> |> do_some_checking() >> |> then(fn changeset -> >> If changeset.valid do >> do_more(changeset) >> else >> changeset >> end >> end) >> ``` >> >> I can see an argument that it is very verbose, but its also about as >> flexible as it can get. My suggestion would be to, if added, have `then_if` >> take a function as its first argument. >> >> ```elixir >> changeset >> |> do_some_checking() >> |> then_if(&(&1.valid?), &do_more/1) >> ``` >> >> >> On Dec 6, 2024, at 10:30 AM, Ben Wilson <benwilson...@gmail.com> wrote: >> >> Exploring what that looks concretely in this case: >> >> ``` >> map >> |> other_stuff >> |> then_if(opts[:foo], &Map.put(&1, :key, value)) >> ``` >> >> I like it! Conditional map insert helper functions are definitely >> something we've written over and over again in our code bases and while >> it's easy to do, I think in some cases this is cleaner looking than a >> proliferation of `maybe_put_foo` functions. >> >> - Ben >> >> On Friday, December 6, 2024 at 9:59:40 AM UTC-5 José Valim wrote: >> >>> Hi Juan! >>> >>> My initial gut feeling is that this approach does not scale. What if you >>> want to delete a key conditionally? Should we have delete_if? >>> >>> It feels a more general approach would be to introduce `then_if`: >>> >>> then_if(subject, condition?, function) >>> >>> Or similar. :) >>> >>> *José Valimhttps://dashbit.co/ <https://dashbit.co/>* >>> >>> >>> On Fri, Dec 6, 2024 at 3:27 PM Juan Manuel Azambuja <ju...@mimiquate.com> >>> wrote: >>> >>>> Hello, >>>> >>>> After working with Elixir for some time I have found myself repeating >>>> some patterns when dealing with maps. >>>> >>>> One pattern I see repeated constantly in different apps developed by >>>> myself or others is adding values to a map conditionally or returning the >>>> map unchanged. This comes in different flavors: >>>> >>>> [image: Screenshot 2024-12-06 at 11.13.23 AM.png] >>>> or >>>> [image: Screenshot 2024-12-06 at 11.14.32 AM.png] >>>> >>>> When this pattern gets used enough in an app, it's normal to see it >>>> abstracted in a MapUtils module that updates the map conditionally if a >>>> condition is met or returns the map unchanged otherwise. >>>> >>>> My proposal is to include Map.put_if/4 which would abstract the >>>> condition check and return the map unchanged if the condition is not met: >>>> >>>> [image: Screenshot 2024-12-06 at 11.17.21 AM.png] >>>> >>>> Enhancing the API by doing this will result in less code and more >>>> readable solutions. >>>> >>>> Thanks for reading! >>>> >>>> -- >>>> 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 visit >>>> https://groups.google.com/d/msgid/elixir-lang-core/ed7da716-b9f5-4f64-a77d-d32696326b9en%40googlegroups.com >>>> <https://groups.google.com/d/msgid/elixir-lang-core/ed7da716-b9f5-4f64-a77d-d32696326b9en%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 visit >> https://groups.google.com/d/msgid/elixir-lang-core/e9e799a2-ad69-4791-bd9a-22bca327652fn%40googlegroups.com >> <https://groups.google.com/d/msgid/elixir-lang-core/e9e799a2-ad69-4791-bd9a-22bca327652fn%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 visit >> https://groups.google.com/d/msgid/elixir-lang-core/61753088-63E3-4DA0-8CEF-925149D789C6%40gmail.com >> <https://groups.google.com/d/msgid/elixir-lang-core/61753088-63E3-4DA0-8CEF-925149D789C6%40gmail.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 visit > https://groups.google.com/d/msgid/elixir-lang-core/CAGnRm4JSE7vhfHukf2EZ6bmi4%3DNrfX28q3%2BKpQGZMgFoCM%3D%2BWg%40mail.gmail.com > <https://groups.google.com/d/msgid/elixir-lang-core/CAGnRm4JSE7vhfHukf2EZ6bmi4%3DNrfX28q3%2BKpQGZMgFoCM%3D%2BWg%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. 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