39 lines
936 B
JavaScript
39 lines
936 B
JavaScript
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var wellKnownSymbol = require('../internals/well-known-symbol');
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var ITERATOR = wellKnownSymbol('iterator');
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var SAFE_CLOSING = false;
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try {
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var called = 0;
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var iteratorWithReturn = {
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next: function () {
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return { done: !!called++ };
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},
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'return': function () {
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SAFE_CLOSING = true;
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}
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};
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iteratorWithReturn[ITERATOR] = function () {
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return this;
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};
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// eslint-disable-next-line no-throw-literal
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Array.from(iteratorWithReturn, function () { throw 2; });
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} catch (error) { /* empty */ }
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module.exports = function (exec, SKIP_CLOSING) {
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if (!SKIP_CLOSING && !SAFE_CLOSING) return false;
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var ITERATION_SUPPORT = false;
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try {
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var object = {};
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object[ITERATOR] = function () {
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return {
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next: function () {
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return { done: ITERATION_SUPPORT = true };
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}
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};
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};
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exec(object);
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} catch (error) { /* empty */ }
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return ITERATION_SUPPORT;
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};
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