Re: The feature to find the value inside the nested map.
Ivan Uemlianin <[email protected]>
| Newsgroups | gmane.comp.lang.erlang.general |
|---|---|
| Message-ID | <[email protected]> |
Looks good, thanks! -- festina lente > On 16 Jun 2021, at 16:42, Krukoff, John <[email protected]> wrote: > > > FWIW, > > I also gave this a try a while a back, and tried to create a version that was easier to use at the expense of more complexity on the lens construction. > > https://github.com/jkrukoff/optic > > I found the complexity of lens composition to be a bit painful without a strict type checker, so took a slightly different approach for an Erlang library. The above library includes ready made modules for all the stdlib data types. > > Thanks, > John K. > > From: erlang-questions <[email protected]> On Behalf Of Ivan Uemlianin > Sent: Wednesday, June 16, 2021 1:11 AM > To: [email protected] > Subject: Re: The feature to find the value inside the nested map. > > Agree. Haskellers call them lenses. > > There was a discussion about them here a few years ago: > > http://erlang.org/pipermail/erlang-questions/2015-November/086879.html > > And there have been a few implementation attempts: > > 2020 https://github.com/slepher/lenses > 2015 https://www.cs.otago.ac.nz/staffpriv/ok/lens.erl > 2012 https://github.com/jlouis/erl-lenses > > Best wishes > > Ivan > > > On 16/06/2021 03:04, 瀬川昂弘 wrote: > Assuming, > Map = #{a => b,c => #{1 => 2,3 => 4,5 => #{x => y}}}. > > Expected: > maps:new_find_fun(Key = 5, Map) = {ok,#{x => y}}. > > It's useful there is the above feature, in my guess. > > -- > Takahiro Segawa. > E-mail:[email protected] > > > -- > ============================================================ > Ivan A. Uemlianin PhD > Llaisdy > > Ymchwil a Datblygu Technoleg Lleferydd > Speech Technology Research and Development > > [email protected] > @llaisdy > llaisdy.wordpress.com > github.com/llaisdy > www.linkedin.com/in/ivanuemlianin > > festina lente > ============================================================ > > ************************************************************************* > This e-mail may contain confidential or privileged information. > If you are not the intended recipient, please notify the sender immediately and then delete it. > > TIAA > *************************************************************************