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48 lines
1.3 KiB
48 lines
1.3 KiB
"use strict"; |
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var isPlainArray = require("../../is-plain-array") |
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, toPosInt = require("../../../number/to-pos-integer") |
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, isObject = require("../../../object/is-object") |
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, isConcatSpreadable = require("es6-symbol").isConcatSpreadable |
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, isArray = Array.isArray |
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, concat = Array.prototype.concat |
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, forEach = Array.prototype.forEach |
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, isSpreadable; |
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isSpreadable = function (value) { |
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if (!value) return false; |
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if (!isObject(value)) return false; |
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if (value[isConcatSpreadable] !== undefined) { |
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return Boolean(value[isConcatSpreadable]); |
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} |
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return isArray(value); |
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}; |
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// eslint-disable-next-line no-unused-vars |
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module.exports = function (item /*, …items*/) { |
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var result; |
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if (!this || !isArray(this) || isPlainArray(this)) { |
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return concat.apply(this, arguments); |
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} |
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result = new this.constructor(); |
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if (isSpreadable(this)) { |
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forEach.call(this, function (val, i) { |
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result[i] = val; |
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}); |
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} else { |
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result[0] = this; |
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} |
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forEach.call(arguments, function (arg) { |
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var base; |
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if (isSpreadable(arg)) { |
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base = result.length; |
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result.length += toPosInt(arg.length); |
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forEach.call(arg, function (val, i) { |
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result[base + i] = val; |
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}); |
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return; |
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} |
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result.push(arg); |
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}); |
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return result; |
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};
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