function partitionByExample () {
  var xf = t.partitionBy(function(x: string|number) { return typeof x == "string"; });
  t.into([], xf, [0,1,"foo","bar",2,3,"bar","baz"]); // [[0,1],["foo","bar"],[2,3],["bar","baz"]];
}
function partitionByExample() {
  const xf = t.partitionBy((x: string|number) => typeof x === "string");
  t.into([], xf, [0, 1, "foo", "bar", 2, 3, "bar", "baz"]); // [[0, 1], ["foo", "bar"], [2, 3], ["bar", "baz"]];
}