Great finding.
Regardless the benchmarks, Map.new/2 should be optimized for maps using
:maps.map/2, because as of now we are doing: map |> Enum.to_list() |>
reduce list |> :lists.reverse() |> :maps.from_list()
On Tue, 12 Jan 2021 14:09:26 -0800 (PST)
"jonar...@gmail.com" <jonarnet...@gmail.com> wrote:
> This usage of Map.new/2 is news to me (pun somewhat intended) and
> pretty neat! However, I think that the naming alone may make it less
> discoverable and a bit harder to grok when first encountered. There
> also *might* be some performance gains from using Erlang's maps:map
> for this task instead of maps:from_list but I'm not sure. I'll do
> some profiling and find out.
>
> On Tuesday, January 12, 2021 at 5:01:51 PM UTC-5 halos...@gmail.com
> wrote:
>
> > It’s not implemented with maps:map/2, but Map.new/2 should do the
> > trick.
> >
> > `Map.new(map, fn {k, v} -> {k, v * 2} end)`
> >
> > That said, `maps:map/2` is available:
> >
> > `:maps.map(fn _k, v -> v * 2 end, %{x: 1, y: 2, z: 3})`
> >
> > It might be worth exploring whether `Map.map` would be
> > useful/efficient enough to add for piping purposes.
> >
> > -a
> >
> > On Tue, Jan 12, 2021 at 4:51 PM jonar...@gmail.com
> > <jonar...@gmail.com> wrote:
> >
> >> A common task is to iterate over a map performing some operation
> >> thereby producing a new map. There are some ways to do this in
> >> Elixir presently, the simplest probably being for...into:
> >>
> >> for {key, val} <- map, into: %{} do
> >> {key, val * 2}
> >> end
> >>
> >> Enum.reduce/3 is also an option. However, Erlang provides a simple
> >> function to replace the values of a map with maps:map function:
> >>
> >> maps:map(fun(Key, Val) -> 2 * Val end, Map)
> >>
> >> I think an equivalent of this in Elixir would be very useful
> >> either as Map.map/2 or Map.transform_values/2 like so:
> >>
> >> Map.transform_values(map, fn {_key, val} -> val * 2 end)
> >>
> >> I'm interested to hear if the community considers this a
> >> worthwhile addition!
> >>
> >> --
> >>
> > 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 on the web visit
> >> https://groups.google.com/d/msgid/elixir-lang-core/d843c44b-e658-4d71-bb66-00c1e0a21ef7n%40googlegroups.com
> >>
> >> <https://groups.google.com/d/msgid/elixir-lang-core/d843c44b-e658-4d71-bb66-00c1e0a21ef7n%40googlegroups.com?utm_medium=email&utm_source=footer>
> >> .
> >>
> >
> >
> > --
> > Austin Ziegler • halos...@gmail.com • aus...@halostatue.ca
> > http://www.halostatue.ca/ • http://twitter.com/halostatue
> >
>
--
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/5fff9633.1c69fb81.eec7e.37f2SMTPIN_ADDED_MISSING%40gmr-mx.google.com.
