[Proposal] Add function Kernel.delete_in/2

[Jonathan Arnett]

It would be useful to have a function that uses the Access protocol to delete elements within nested data structures. This is similar in concept to Kernel.pop_in/2, but Kernel.delete_in/2 should just return the data structure without the specified element, whereas Kernel.pop_in/2 returns a tuple whose first element is the removed value and second element is the data structure without the specified element. The return structure of Kernel.delete_in/2 would allow it to be more easily chained than Kernel.pop_in/2.

Expected behavior

Kernel.delete_in(%{foo: "bar", baz: "qux"}, [:foo])
#=> %{baz: "qux"}

Kernel.delete_in(%{foo: %{bar: "baz", qux: "quux"}}, [:foo, :qux])
#=> %{foo: %{bar: "baz"}}

[Louis Pilfold]

Hey

How would it know how to delete a value from the given data structure? The Access protocol could be implemented for any term.

Cheers,

Louis

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[José Valim]

Hi Jonathan,

We had this discussion when we added pop_in/2. The reason why we choose pop_in/2 is because it provides more features than delete_in on its own and we want to avoid overloading Kernel with too many functions. If your concern is chaining, you can always perform a |> elem(1) after popping.

Thanks for the proposal!

José Valim

www.plataformatec.com.br

Skype: jv.ptec

Founder and Director of R&D