mirror of https://github.com/jkjoy/sunpeiwen.git
48 lines
1.2 KiB
JavaScript
48 lines
1.2 KiB
JavaScript
'use strict';
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var hasSymbols = require('has-symbols')();
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var GetIntrinsic = require('get-intrinsic');
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var callBound = require('call-bind/callBound');
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var isString = require('is-string');
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var $iterator = GetIntrinsic('%Symbol.iterator%', true);
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var $stringSlice = callBound('String.prototype.slice');
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var $String = GetIntrinsic('%String%');
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module.exports = function getIteratorMethod(ES, iterable) {
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var usingIterator;
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if (hasSymbols) {
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usingIterator = ES.GetMethod(iterable, $iterator);
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} else if (ES.IsArray(iterable)) {
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usingIterator = function () {
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var i = -1;
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var arr = this; // eslint-disable-line no-invalid-this
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return {
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next: function () {
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i += 1;
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return {
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done: i >= arr.length,
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value: arr[i]
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};
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}
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};
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};
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} else if (isString(iterable)) {
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usingIterator = function () {
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var i = 0;
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return {
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next: function () {
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var nextIndex = ES.AdvanceStringIndex($String(iterable), i, true);
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var value = $stringSlice(iterable, i, nextIndex);
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i = nextIndex;
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return {
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done: nextIndex > iterable.length,
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value: value
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};
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}
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};
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};
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}
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return usingIterator;
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};
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