Function lazy

packages/effect-app/src/Function.ts:164–175

(f: () => A)

}

export function lazy<A>(f: () => A): () => A {
  let tmp: A | undefined
  let done = false
  return () => {
    if (done) {
      return tmp!
    }
    tmp = f()
    done = true
    return tmp
  }
}