T.enum

A literal: a random member from a set of values.

T.enum.uniform(["electronics", "clothing", "food"]);
 
T.enum.weighted([
  [6, "USD"],
  [3, "YEN"],
  [1, "GBP"],
]);

There's no bare T.enum(...) — pick .uniform (equal probability) or .weighted (relative probability via [weight, member] pairs). Weights are relative between members: each value can be read as the numerator over the sum of all values. In the example above, "YEN" is 3× more likely than "GBP"; "USD" is 2× more likely than "YEN"; "USD" is 6× more likely than "GBP". A weight of 0 disables that member (the remaining members still draw). Every weight zero throws; negative weights, NaN, and Infinity are invalid.

Like T.always, an enum's members can be any value, not just primitives.

To pick among schemas rather than values, see T.choice.