Filter words with specified characters in a file

filter_in_file.exs

# Filter words with specified characters in a file
# Usage : `filter_in_file("thai.txt", "ทงกานเ")`

def filter_in_file(filename, chars) do
  File.read!(filename)
  |> filter(chars)
end

def filter(words, chars) do
  words
  |> String.split(~r{[ \n]}, trim: true)
  |> Enum.filter(fn(word) ->
    Enum.all?(String.codepoints(word), fn(c) ->
      String.contains?(chars, c)
    end)
  end)
  |> Enum.join(" ")
end