Plan 9 from Bell Labs’s /usr/web/sources/contrib/fernan/nhc98/src/prelude/List/Unzip4.hs
module List where unzip4 :: [(a,b,c,d)] -> ([a],[b],[c],[d]) unzip4 = foldr (\(b,c,d,e) ~(bs,cs,ds,es) -> (b:bs,c:cs,d:ds,e:es)) ([],[],[],[])
