Slide 11 of 37

Result<T, E>

func half(n: Int): Result<Int, Str> {
	if n % 2 == 0 { return Result.Ok(n / 2) }
	return Result.Error("not even")
}

proc main(): void {
	if half(4) is Result.Ok(v)      { echo v }
	else if half(4) is Result.Error(why) { echo why }
}

Result is the language's one built-in generic union, and it is how every fallible operation reports itself: Result.Ok(value) or Result.Error(payload). Matching both variants with `is` is exhaustive, which lets a function written over a Result skip a dead else branch entirely.

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