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Indifferent access in elixir
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defmodule Access do | |
def indifferent_key(key) do | |
fn | |
:get, data, next -> | |
get_atom_or_string_key!(data, key) | |
|> case do | |
nil -> next.(nil) | |
key -> next.(Map.get(data, key)) | |
end | |
:get_and_update, data, next -> | |
{key, value} = | |
get_atom_or_string_key!(data, key) | |
|> case do | |
nil -> {key, nil} | |
key -> {key, Map.get(data, key)} | |
end | |
case next.(value) do | |
{get, update} -> {get, Map.put(data, key, update)} | |
:pop -> {value, Map.delete(data, key)} | |
end | |
end | |
end | |
defp map_indifferent_get(data, key) do | |
get_atom_or_string_key!(data, key) | |
|> case do | |
nil -> nil | |
key -> Map.get(data, key) | |
end | |
end | |
defp get_atom_or_string_key!(data, key) do | |
{atom_key, string_key} = | |
cond do | |
is_atom(key) -> {key, to_string(key)} | |
is_binary(key) -> {String.to_existing_atom(key), key} | |
true -> raise "Indifferent key must be an atom or string" | |
end | |
{Map.has_key?(data, atom_key), Map.has_key?(data, string_key)} | |
|> case do | |
{true, true} -> raise "Map contains both string and atom key: #{string_key}" | |
{false, false} -> nil | |
{true, false} -> atom_key | |
{false, true} -> string_key | |
end | |
end | |
end |
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update_in(attrs, [City.Access.indifferent_key(field)], fn value -> | |
... | |
end) |
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