Last active
June 5, 2019 13:51
-
-
Save IvanIvanoff/b4f58f35ccba003e752a6076999628e7 to your computer and use it in GitHub Desktop.
Search where is located a key-value pair in deeply nested structs
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
defmodule MapUtils do | |
def find_pair_path(map, key, value) when is_map(map) do | |
do_find_pair_path(map, key, value, []) | |
|> Enum.map(&(&1 |> List.flatten() |> Enum.reverse())) | |
|> Enum.reject(&(&1 == nil || &1 == [])) | |
end | |
defp do_find_pair_path(map, key, value, path) when is_map(map) do | |
keys = Map.keys(map) | |
if key in keys and Map.get(map, key) == value do | |
[key | path] | |
else | |
Enum.map(keys, fn subkey -> | |
Map.get(map, subkey) | |
|> do_find_pair_path(key, value, [subkey | path]) | |
end) | |
end | |
end | |
defp do_find_pair_path(list, key, value, path) when is_list(list) do | |
Enum.with_index(list) | |
|> Enum.map(fn {elem, index} -> | |
do_find_pair_path(elem, key, value, [{:at, index} | path]) | |
end) | |
end | |
defp do_find_pair_path(_, _, _, _), do: [] | |
end | |
# [[:a, :b, "name"]] | |
%{a: %{b: %{"name" => "ivan"}}} |> MapUtils.find_pair_path("name", "ivan") | |
# [[:a, :b, {:at, 0}, "name"]] | |
%{a: %{b: [%{"name" => "ivan"}]}} |> MapUtils.find_pair_path("name", "ivan") | |
# [[:a, {:at, 0}, :b, {:at, 0}, "name"]] | |
%{a: [%{b: [%{"name" => "ivan"}]}]} |> MapUtils.find_pair_path("name", "ivan") |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment