Function intersection_

packages/effect-app/src/Set.ts:44–58

(E: Equivalence.Equivalence<A>)

 * The set of elements which are in both the first and second set
 */
export function intersection_<A>(E: Equivalence.Equivalence<A>): (l: Set<A>, r: Set<A>) => Set<A> {
  const elemE = elem_(E)
  return (x, y) => {
    if (x === empty || y === empty) {
      return empty
    }
    const r = new Set<A>()
    x.forEach((e) => {
      if (elemE(y, e)) {
        r.add(e)
      }
    })
    return r
  }
}

/**
 * The set of elements which are in both the first and second set