/**
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* A collection of shims that provide minimal functionality of the ES6 collections.
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*
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* These implementations are not meant to be used outside of the ResizeObserver
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* modules as they cover only a limited range of use cases.
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*/
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/* eslint-disable require-jsdoc, valid-jsdoc */
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const MapShim = (() => {
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if (typeof Map !== 'undefined') {
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return Map;
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}
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/**
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* Returns index in provided array that matches the specified key.
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*
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* @param {Array<Array>} arr
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* @param {*} key
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* @returns {number}
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*/
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function getIndex(arr, key) {
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let result = -1;
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arr.some((entry, index) => {
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if (entry[0] === key) {
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result = index;
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return true;
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}
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return false;
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});
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return result;
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}
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return class {
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constructor() {
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this.__entries__ = [];
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}
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/**
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* @returns {boolean}
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*/
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get size() {
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return this.__entries__.length;
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}
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/**
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* @param {*} key
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* @returns {*}
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*/
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get(key) {
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const index = getIndex(this.__entries__, key);
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const entry = this.__entries__[index];
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return entry && entry[1];
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}
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/**
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* @param {*} key
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* @param {*} value
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* @returns {void}
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*/
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set(key, value) {
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const index = getIndex(this.__entries__, key);
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if (~index) {
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this.__entries__[index][1] = value;
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} else {
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this.__entries__.push([key, value]);
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}
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}
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/**
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* @param {*} key
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* @returns {void}
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*/
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delete(key) {
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const entries = this.__entries__;
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const index = getIndex(entries, key);
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if (~index) {
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entries.splice(index, 1);
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}
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}
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/**
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* @param {*} key
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* @returns {void}
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*/
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has(key) {
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return !!~getIndex(this.__entries__, key);
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}
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/**
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* @returns {void}
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*/
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clear() {
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this.__entries__.splice(0);
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}
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/**
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* @param {Function} callback
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* @param {*} [ctx=null]
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* @returns {void}
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*/
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forEach(callback, ctx = null) {
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for (const entry of this.__entries__) {
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callback.call(ctx, entry[1], entry[0]);
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}
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}
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};
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})();
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export {MapShim as Map};
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