在实际实践中如何使用groupBy和zip？

import Data.List.Split
import Data.List(nub, groupBy)

z = splitOn \"+\" \"x^2+2*x^3+x^2\"

y = map (splitOn \"*\") z

x = map head y

toInt :: [String] -> [Int]
toInt = map read

u1 = filter ((< 2) . length) y
u2 = filter ((> 1) . length) y

v = map (\"1\" :) u1

q = u2 ++ v
q2 = zip toInt(map head q) (map last q)
q6 = groupBy nub(map tail q) q
q3 = map tail q
q5 = nub(q3)

q1 = map head q

zip toInt(map head q) (map last q)

[[1,\"x^3\"],[2,\"x^2\"],[1,\"x^2\"]]

*Main Data.List> zip [2,1,1] [\"x^3\",\"x^2\",\"x^2\"]
[(2,\"x^3\"),(1,\"x^2\"),(1,\"x^2\")]

()

[]

groupBy

groupBy (nub(map tail q)) q

a0 -> a0 -> Bool\'
                with actual type

nub\'
    In the first argument of