1: { lib }:
2:
3: with lib;
4: with rec {
5: go = pred: l:
6: if l == [ ] then [ ] else if pred (head l) then go pred (tail l) else l;
7: };
8: assert go (x: elem x [ 1 2 ]) [ 1 2 1 2 1 3 1 2 3 1 ] == [ 3 1 2 3 1 ];
9: assert go (abort "fail") [ ] == [ ];
10: assert go (x: x > 2) [ 5 4 3 2 1 ] == [ 2 1 ];
11: go