{-# OPTIONS_GHC -F -pgmFhsx2hs #-}
{-# LANGUAGE RegularPatterns #-}
module RegularPatterns where

f :: [Int] -> [[Int]]
f [0+!, b+, 1?, (| 2, 3 |)] = [b]
f [1+, (| x | x `mod` 2 == 0 |)] = [[x]]
f [2, a@(| b@:_, _ |)*] = b : a
f _ = []