53 lines
1.3 KiB
JavaScript
53 lines
1.3 KiB
JavaScript
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/**
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* Copyright (c) 2013-present, Facebook, Inc.
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* All rights reserved.
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*
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* This source code is licensed under the BSD-style license found in the
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* LICENSE file in the root directory of this source tree. An additional grant
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* of patent rights can be found in the PATENTS file in the same directory.
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*
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*
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*/
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'use strict';
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var Set = require('./Set');
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var emptyFunction = require('./emptyFunction');
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/**
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* Returns the count of distinct elements selected from an array.
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*/
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function countDistinct(iter, selector) {
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selector = selector || emptyFunction.thatReturnsArgument;
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var set = new Set();
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var _iteratorNormalCompletion = true;
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var _didIteratorError = false;
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var _iteratorError = undefined;
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try {
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for (var _iterator = iter[Symbol.iterator](), _step; !(_iteratorNormalCompletion = (_step = _iterator.next()).done); _iteratorNormalCompletion = true) {
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var val = _step.value;
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set.add(selector(val));
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}
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} catch (err) {
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_didIteratorError = true;
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_iteratorError = err;
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} finally {
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try {
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if (!_iteratorNormalCompletion && _iterator['return']) {
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_iterator['return']();
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}
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} finally {
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if (_didIteratorError) {
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throw _iteratorError;
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}
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}
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}
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return set.size;
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}
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module.exports = countDistinct;
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