42 lines
1.3 KiB
JavaScript
42 lines
1.3 KiB
JavaScript
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var bindCallback = require('./bindCallback'),
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isIterateeCall = require('./isIterateeCall'),
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restParam = require('../function/restParam');
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/**
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* Creates a `_.assign`, `_.defaults`, or `_.merge` function.
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*
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* @private
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* @param {Function} assigner The function to assign values.
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* @returns {Function} Returns the new assigner function.
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*/
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function createAssigner(assigner) {
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return restParam(function(object, sources) {
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var index = -1,
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length = object == null ? 0 : sources.length,
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customizer = length > 2 ? sources[length - 2] : undefined,
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guard = length > 2 ? sources[2] : undefined,
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thisArg = length > 1 ? sources[length - 1] : undefined;
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if (typeof customizer == 'function') {
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customizer = bindCallback(customizer, thisArg, 5);
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length -= 2;
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} else {
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customizer = typeof thisArg == 'function' ? thisArg : undefined;
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length -= (customizer ? 1 : 0);
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}
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if (guard && isIterateeCall(sources[0], sources[1], guard)) {
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customizer = length < 3 ? undefined : customizer;
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length = 1;
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}
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while (++index < length) {
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var source = sources[index];
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if (source) {
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assigner(object, source, customizer);
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}
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}
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return object;
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});
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}
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module.exports = createAssigner;
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