Function union

packages/effect/src/internal/hashSet.ts:116–123

(self: HashSet<V0>, that: HashSet<V1>)

/** @internal */
export const union = <V0, V1>(self: HashSet<V0>, that: HashSet<V1>): HashSet<V0 | V1> => {
  const map = keyMap(self)
  let result = map as HashMap.HashMap<V0 | V1, boolean>
  for (const value of that) {
    result = HashMap.set(result, value, true)
  }
  return makeImpl(result)
}

/** @internal */
export const intersection = <V0, V1>(self: HashSet<V0>, that: HashSet<V1>): HashSet<V0 & V1> => {