unlines package:termonad

Appends a n character to each input string, then concatenates the results. Equivalent to foldMap (s -> s ++ "n").
>>> unlines ["Hello", "World", "!"]
"Hello\nWorld\n!\n"

Note

unlines . lines /= id when the input is not n-terminated:
>>> unlines . lines $ "foo\nbar"
"foo\nbar\n"