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
>  
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