Elixirの関数に無名関数を定義して、List.foldlに使う例

elixir_anonymous_function.ex

defmodule Hhfuns do
  def a(o, p, q) do
   fn(num, acc) ->
     IO.puts "#{inspect o}, #{inspect p} #{inspect q}"
     num + acc
   end
  end
end
x = Hhfuns.a("ooo", "ppp", "qqq")
IO.puts "x = #{inspect x}"　## x = #Function<0.111962536/2 in Hhfuns.a/3>
y = List.foldl([1,2,3], 0, x)
IO.puts "y = #{inspect y}"　## y = 6

## 実行結果
## $ elixir hhfuns.ex
## x = #Function<0.111962536/2 in Hhfuns.a/3>
## "ooo", "ppp" "qqq"
## "ooo", "ppp" "qqq"
## "ooo", "ppp" "qqq"
## y = 6