29 lines
613 B
JavaScript
29 lines
613 B
JavaScript
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// Inspired by Underscore's groupBy:
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// http://documentcloud.github.com/underscore/#groupBy
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"use strict";
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var callable = require("../../object/valid-callable")
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, value = require("../../object/valid-value")
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, forEach = Array.prototype.forEach
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, apply = Function.prototype.apply;
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module.exports = function (cb/*, thisArg*/) {
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var result;
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value(this);
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callable(cb);
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result = Object.create(null);
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forEach.call(
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this,
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function (item) {
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var key = apply.call(cb, this, arguments);
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if (!result[key]) result[key] = [];
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result[key].push(item);
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},
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arguments[1]
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);
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return result;
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};
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