fn Items

The fn item form — a reusable named function declaration.

A reusable function is declared once with the fn item form — sugar for let name = fn(...) with two extras: the name shows up in editor tooling and it can carry a @doc decorator. Like a let, an fn item is a composition helper, not data.

@doc("Clamp a value into [lo, hi].")
fn clamp_to(x: f64, lo: f64, hi: f64) -> f64 {
  min(max(x, lo), hi)
}

gain = clamp_to(raw_gain, 0.0, 1.0)