Traverse nested list and if the list has two elements apply function

Questions & Help Questions
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1

Hi!

I have been dealing with some problem where I have a nested list, I want to keep the nested structure, but if the list is a two elements list, then i want to apply a custom function (I’m dealing with multypolygon coordinates and want to apply some transform to the coordinates’ system)

So far, I came up with something using recursion:

defmodule NiceModule do
  def apply_function(nested_list) do
    update_in(nested_list, [Access.all()], fn item ->
      case item do
        [x, y] when is_number(x) and is_number(y) -> fun_fun(x, y)  
        sublist when is_list(sublist) -> apply_function(sublist)  
        other -> other  
      end
    end)
  end
  def fun_fun(x,y) do
    {a,b} ={ x+3 , y+2}
    [a,b]
  end
end

aa = [
  [2, 5.0 , [ 1 , 1 ]],
  [[13.0, 17.0], [25.0, 0.0], [0, 0]] ,
  [ 2 ,2 ]
]

NiceModule.apply_function(aa)

Which I think works, but I’m wondering if I’m doing something anti-elixir or if there is a better way (needless to say, I’m new)

Thanks for your time and answers :slight_smile: