A tuple groups a few values by position. Use it when the group is small and the order is obvious.

let status := (8080, "ready");
let empty := ();
status;

A pair like (8080, "ready") can work for a quick return value. If the values need names, use a record instead.

() is unit. It means there is no useful data to carry. You may see it when an action matters more than a returned value.

A tuple is like holding two tickets in one hand. Unit is like an empty hand.

Tuple positions

Tuple values are read by position, not by field name. Keep tuples small so the positions stay obvious.

let server := (8080, "ready");
let fallback := (3000, "fallback");

Use a tuple when the meaning is clear from the surrounding code. A return like (port, label) is fine inside a small helper. A value that travels across files should usually be a record.

Unit

() is a real value. It says "nothing useful is returned."

let empty := ();
empty;

Use unit when the expression has no useful data to carry.

Tuples and unit

Tuple positions

Unit