Function intersection

repos/effect/packages/effect/src/internal/hashSet.ts:126–134

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

/** @internal */
export const intersection = <V0, V1>(self: HashSet<V0>, that: HashSet<V1>): HashSet<V0 & V1> => {
  let result = HashMap.empty<V0 & V1, boolean>()
  for (const value of self) {
    if (has(that, value as any)) {
      result = HashMap.set(result, value as V0 & V1, true)
    }
  }
  return makeImpl(result)
}

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