Please do submit a pull request. It should be similar to "all/0" except it expects a map instead (and then traverses only values). Thank you!
*José Valimhttps://dashbit.co/ <https://dashbit.co/>* On Tue, Mar 18, 2025 at 3:03 PM David Pavlík <d.pa...@gmail.com> wrote: > Hi! > > I've recently discovered that get_and_update_in/3 and friends can access > multiple items at once via Access.all/0, Access.filter/1, and similar. > It's a game changer for accessing deeply nested structures. > > However, there is no function in the standard library for accessing > multiple items of a map (similarly to items of a list). For maps where keys > are something item IDs and not predefined atoms, I think such accessors > would be very useful. In our codebase, for example, we often manipulate > deeply nested structures that include such maps and want to access all > values in such maps (e.g., when migrating data). > > It's easy to write an accessor that accesses all values in a map (and > similarly for keys or both keys and values): > > @doc """ > Returns a function that accesses all values in a map. > > The returned function is typically passed as an accessor to > `Kernel.get_in/2`, > `Kernel.get_and_update_in/3`, and friends. > > ## Examples > > iex> users = %{"john" => %{age: 27}, "meg" => %{age: 23}} > iex> get_in(users, [AccessUtils.values(), :age]) > [27, 23] > iex> update_in(users, [AccessUtils.values(), :age], fn age -> age + 1 > end) > %{"john" => %{age: 28}, "meg" => %{age: 24}} > iex> put_in(users, [AccessUtils.values(), :phone], nil) > %{"john" => %{age: 27, phone: nil}, "meg" => %{age: 23, phone: nil}} > > """ > @spec values() :: Access.access_fun(data :: map(), current_value :: list()) > def values do > fn > :get, %{} = data, next -> > Enum.map(data, fn {_key, value} -> next.(value) end) > > :get_and_update, %{} = data, next -> > {reverse_gets, updated_data} = > Enum.reduce(data, {[], %{}}, fn {key, value}, {gets, data_acc} -> > case next.(value) do > {get, update} -> {[get | gets], Map.put(data_acc, key, update)} > :pop -> {[value | gets], data_acc} > end > end) > > {Enum.reverse(reverse_gets), updated_data} > end > end > > Nevertheless, I think it might be useful to include it in the Access > module of the standard library. What do you think? > > Note that something similar has already been discussed on Elixir Forum > <https://elixirforum.com/t/how-to-use-update-in-on-multiple-map-keys-at-once-re-access-all/63963> > . > > Best regards, > David > > -- > 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 visit > https://groups.google.com/d/msgid/elixir-lang-core/847b6461-aaf4-4d2c-abbd-6b2ddee73b21n%40googlegroups.com > <https://groups.google.com/d/msgid/elixir-lang-core/847b6461-aaf4-4d2c-abbd-6b2ddee73b21n%40googlegroups.com?utm_medium=email&utm_source=footer> > . > -- 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 visit https://groups.google.com/d/msgid/elixir-lang-core/CAGnRm4LYkUMdADcdA0q_M-eHOiizzMHYT%3D6e94qUqbTyHAf_Pw%40mail.gmail.com.
