static float floatMax(Collection<Float> l) {
  float x = -Float.MAX_VALUE;
  fOr (float i : l) x = max(x, i);
  ret x;
}

static float floatMax(float[] l) {
  float x = -Float.MAX_VALUE;
  if (l != null) for (float i : l) x = max(x, i);
  ret x;
}

Began life as a copy of #1024748