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 [email protected] 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 [email protected] <[email protected]> > 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 [email protected]. >> 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 • [email protected] • [email protected] > 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 [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/elixir-lang-core/26eb12ac-99c2-4119-aa3f-c0a7e712d762n%40googlegroups.com.
