Union types

Union types are types that

src/strings.duck

use std::io::println;

fn main() {
    let int_or_string: Int | String = 10;
    match int_or_string {
        Int @i => println(f"it is an int. value: {i.to_string()}"),
        String @s => println(f"it is a string. value: {s}"),
    }

    // Matches must be exhaustive. If you want to have a "fallthrough" case, use else
    int_or_string = "hello";
    match int_or_string {
        Int @i => println(f"it is an int. value: {i.to_string()}"),
        else => println("it was something else"),
    }

    // The else branch can also take an identifier
    match int_or_string {
        Int @i => println(f"it is an int. value: {i.to_string()}"),
        else @other => println(f"it was something else: {other.to_string()}"),
    }
}