JavaScript (ES7) LOC counter
Ok, first, you've gone overboard. :D

You have a lot of regular expressions, but on first glance, I don't even know what they're for. What are they matching? It's best if you name them by putting them in const.

I see you have some personal touch on the code, like the ending parens being on the very last line. Makes the code look like CoffeeScript at first look. Anyways, code is for humans. Put some whitespace, break code into logically grouped lines, add some comments why you do things this way. One cannot really comprehend without tracing through (which is a sign of bad things to come).

Also, you're running this through Node, size doesn't matter there. If you run JS on a browser, there's what they call a minifier.

Also, variable names. Some make sense, some don't. l, v1, v0, pv, i80, they don't really tell me what they are. One terrible mistake devs often do is they assume the reader knows the context. Sure, pv means "previous value", but I only knew that because I know how reduce works. For someone that doesn't, that's a different story.

80% and 20% are hardcoded.