50 lines
1.0 KiB
JavaScript
50 lines
1.0 KiB
JavaScript
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'use strict';
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var _require = require('../helpers/is'),
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isArray = _require.isArray,
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isObject = _require.isObject;
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var deleteKeys = require('../helpers/deleteKeys');
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module.exports = function shift() {
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var _this = this;
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var count = arguments.length > 0 && arguments[0] !== undefined ? arguments[0] : 1;
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if (this.isEmpty()) {
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return null;
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}
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if (isArray(this.items)) {
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if (count === 1) {
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return this.items.shift();
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}
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return new this.constructor(this.items.splice(0, count));
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}
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if (isObject(this.items)) {
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if (count === 1) {
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var key = Object.keys(this.items)[0];
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var value = this.items[key];
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delete this.items[key];
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return value;
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}
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var keys = Object.keys(this.items);
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var poppedKeys = keys.slice(0, count);
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var newObject = poppedKeys.reduce(function (acc, current) {
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acc[current] = _this.items[current];
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return acc;
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}, {});
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deleteKeys(this.items, poppedKeys);
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return new this.constructor(newObject);
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}
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return null;
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};
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