It seems like an identity function would be a better default for both Enum.filter and Enum.reject. Then instead of using Enum.reject(&is_nil/1) you would use Enum.filter. I'm not sure if defaulting to identity could return surprising results. But it seems like it might be OK since thats what Enum.any? and Enum.all? already do.
On Friday, November 18, 2016 at 4:04:55 PM UTC-5, Peter Hamilton wrote: > > Bruce: As pointed out previously, It's a bad default for Enum.reject. It > would leave you with just the nil values. It might be an ok default for > Enum.filter though. > > On Fri, Nov 18, 2016 at 1:01 PM Bruce Tate <[email protected] > <javascript:>> wrote: > >> The identify function is effectively already the default for Enum.all? >> and any?, and a few others as well. >> >> Why not make it the default for Enum.reject too? >> >> -bt >> >> On Thu, Nov 17, 2016 at 4:13 PM, OvermindDL1 <[email protected] >> <javascript:>> wrote: >> >>> Yeah you could do `&(&1)` or so for an inline identity, though >>> definitely not as clear. :-) >>> >>> Constant is not as succinct though: `&(fn->&1 end)` >>> And still not clear. ^.^ >>> >>> >>> On Thursday, November 17, 2016 at 12:14:39 PM UTC-7, Drew Olson wrote: >>>> >>>> Ignore my comment about not being about to use the shorter function >>>> syntax. I was confused about the precedence of &. >>>> >>>> On Thu, Nov 17, 2016 at 1:08 PM, Drew Olson <[email protected]> >>>> wrote: >>>> >>>>> I've also often wished for an identity/1 in Kernel, especially because >>>>> you cannot easily represent it with the short function syntax. >>>>> >>>>> On Thu, Nov 17, 2016 at 12:33 PM, OvermindDL1 <[email protected]> >>>>> wrote: >>>>> >>>>>> `identity : 'a -> 'a` is the most common function declaration like >>>>>> that in almost every functional language, would be nice to have in >>>>>> kernel. >>>>>> >>>>>> >>>>>> On Thursday, November 17, 2016 at 10:48:20 AM UTC-7, Louis Pop wrote: >>>>>>> >>>>>>> Hiya >>>>>>> >>>>>>> I'd like an identity function in Kernel, that's for sure. >>>>>>> >>>>>>> I think an identity function being the default argument to filter >>>>>>> would be quite nice. I find reject a bit strange, I don't set why it >>>>>>> exists >>>>>>> when we have filter. >>>>>>> >>>>>>> Cheers, >>>>>>> Louis >>>>>>> >>>>>>> On Thu, 17 Nov 2016, 17:40 Tallak Tveide, <[email protected]> wrote: >>>>>>> >>>>>>>> I assume you mean the default function should be >>>>>>>> >>>>>>>> ''' >>>>>>>> fn x -> !x end >>>>>>>> ''' >>>>>>>> >>>>>>>> To reject any falsey value. It does seem reasonable, but I dont >>>>>>>> think it is nearly as readable as 'compact', so I vote nay to this >>>>>>>> one... >>>>>>>> >>>>>>>> In fact, isn't this a better option? (Or equally good) >>>>>>>> >>>>>>>> ''' >>>>>>>> def filter(enum, fun \\ fn x -> x end) >>>>>>>> ''' >>>>>>>> >>>>>>>> Actually I have also thought that a 'unity' or 'itself' function >>>>>>>> should be part of stdlib, to make this possible as: >>>>>>>> >>>>>>>> ''' >>>>>>>> list >>>>>>>> |> Enum.filter(&itself) >>>>>>>> ''' >>>>>>>> >>>>>>>> -- >>>>>>>> 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 [email protected]. >>>>>>>> To view this discussion on the web visit >>>>>>>> https://groups.google.com/d/msgid/elixir-lang-core/06bc7738-3ed9-4a21-9fce-b7eb3fecd600%40googlegroups.com >>>>>>>> . >>>>>>>> For more options, visit https://groups.google.com/d/optout. >>>>>>>> >>>>>>> -- >>>>>> 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 [email protected]. >>>>>> To view this discussion on the web visit >>>>>> https://groups.google.com/d/msgid/elixir-lang-core/07571247-7dba-4a21-948d-89f7ac335f92%40googlegroups.com >>>>>> >>>>>> <https://groups.google.com/d/msgid/elixir-lang-core/07571247-7dba-4a21-948d-89f7ac335f92%40googlegroups.com?utm_medium=email&utm_source=footer> >>>>>> . >>>>>> >>>>>> For more options, visit https://groups.google.com/d/optout. >>>>>> >>>>> >>>>> >>>> -- >>> 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 [email protected] <javascript:>. >>> To view this discussion on the web visit >>> https://groups.google.com/d/msgid/elixir-lang-core/8c4a990c-77be-4d00-857b-9a26c59715f9%40googlegroups.com >>> >>> <https://groups.google.com/d/msgid/elixir-lang-core/8c4a990c-77be-4d00-857b-9a26c59715f9%40googlegroups.com?utm_medium=email&utm_source=footer> >>> . >>> >>> For more options, visit https://groups.google.com/d/optout. >>> >> >> >> >> -- >> Bruce Tate >> President, RapidRed, LLC >> Phone: 512.772.4312 >> Fax: 512 857-0415 >> >> Author of Seven Languages in Seven Weeks, Deploying Rails Applications, >> From Java to Ruby, Rails: Up and Running, Beyond Java, 6 others. >> >> -- >> 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 [email protected] <javascript:>. >> To view this discussion on the web visit >> https://groups.google.com/d/msgid/elixir-lang-core/CAMp4_igw0oQsX3Q0i8KZ0mZqBMsdsxdzMGtSM-r4eGa7QtS5Yg%40mail.gmail.com >> >> <https://groups.google.com/d/msgid/elixir-lang-core/CAMp4_igw0oQsX3Q0i8KZ0mZqBMsdsxdzMGtSM-r4eGa7QtS5Yg%40mail.gmail.com?utm_medium=email&utm_source=footer> >> . >> For more options, visit https://groups.google.com/d/optout. >> > -- 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 [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/elixir-lang-core/e39b0bb3-02af-4036-a875-e10eec876c39%40googlegroups.com. For more options, visit https://groups.google.com/d/optout.
