static L map_precise(Iterable l, O f) {
  ret map_precise(f, l);
}

static L mapLike map_precise(O f, Iterable l) {
  new L x;
  O mc = mc();
  for (O o : unnull(l))
    x.add(callF_precise(f, o));
  ret x;
}

static L map_precise(O f, O[] l) {
  ret map_precise(f, asList(l));
}

static L map_precise(O f, Map map) {
  ret map_precise(map, f);
}

static L map_precise(Map map, O f) {
  new L x;
  for (O _e : map.entrySet()) {
    Map.Entry e = (Map.Entry) _e;
    x.add(callF_precise(f, e.getKey(), e.getValue()));
  }
  ret x;
}

Began life as a copy of #1003239