Elixir: clean deps

Source: How to remove unused deps from mix.lock
This removes the unused files, as well as cleans mix.lock.

1	> mix deps.clean --unused --unlock

Elixir: rename_keys

Elixir equivalent of Clojure rename_keys()

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@doc """ Returns the map with the keys in kmap renamed to the values in kmap. """ def rename_keys(map, kmap) when is_map(map) and is_map(kmap) do   for {key, value} <- map,       into: %{},       do: if(new_key = Map.get(kmap, key), do: {new_key, value}, else: {key, value}) end

Elixir: if key exists: update, otherwise: assoc

Remember Clojure: if key exists: update, otherwise: assoc? Let's do that with Elixir.

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@doc """ If `key` exists in `map`, updates its value (assumed to be a list) by concatenating `value`. If `key` does not exist in `map`, creates `{key => [value]}` in `map`. ## Examples     iex(35)> Tap.Worker.update_conj!(%{a: [1]}, :a, 2)   %{a: [1, 2]}     iex(36)> Tap.Worker.update_conj!(%{a: [1]}, :b, 2)   %{a: [1], b: [2]}   """ @spec update_conj!(map, any, any) :: map def update_conj!(map, key, value) when is_map(map) do   Map.update(map, key, [value], fn     existing_values when is_list(existing_values) ->       existing_values ++ [value]       existing_value ->       raise(ArgumentError, "Value is not a list: #{inspect(existing_value)}")   end) end

Elixir: map to struct

Courtesy of Jose Valim: (https://groups.google.com/forum/#!msg/elixir-lang-talk/6geXOLUeIpI/L9einu4EEAAJ).

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def to_struct(kind, attrs) do   struct = struct(kind)     Logger.debug("attrs = #{inspect(attrs)}")     Enum.reduce(Map.to_list(struct), struct, fn {k, _}, acc ->     case Map.fetch(attrs, k) do       {:ok, v} -> %{acc | k => v}       :error -> acc     end   end) end