That single line of magic is still a Thing, just a thing without a name or any way to check that you didn't make a mistake in writing it. If this magic single

That single line of magic is still a Thing, just a thing without a name or any way to check that you didn't make a mistake in writing it. If this magic single line is a map over a list, that's fine - but I've seen some deeply unholy one-liners. Like, 600 characters for no reason. Don't do that!