:: [String] -> String package:test-framework

Like unlines, but does not append a trailing newline if there is at least one line. For example:

unlinesConcise ["A", "B"] == "A\nB"
unlinesConcise [] == ""

Whereas:

unlines ["A", "B"] == "A\nB\n"
unlines [] == ""

This is closer to the behaviour of unwords, which does not append a trailing space.