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// Copyright 2018-2021 the Deno authors. All rights reserved. MIT license.
import { filterInPlace } from "./_utils.ts";
/** * Returns all distinct elements that appear at least once in each of the given arrays * * Example: * * ```typescript * const lisaInterests = [ 'Cooking', 'Music', 'Hiking' ] * const kimInterests = [ 'Music', 'Tennis', 'Cooking' ] * const commonInterests = intersectTest(lisaInterests, kimInterests) * * console.assert(commonInterests === [ 'Cooking', 'Music' ]) * ``` */export function intersect<T>(...arrays: Array<Array<T>>): Array<T> {  if (arrays.length === 0) {    return [];  }
  const [originalHead, ...tail] = arrays;  const head = [...originalHead];  const tailSets = tail.map((it) => new Set(it));
  for (const set of tailSets) {    filterInPlace(head, (it) => set.has(it));  }
  return head;}