lodash内部方法getFuncName及setToString剖析详解

import realNames from './_realNames.js';
var objectProto = Object.prototype;
var hasOwnProperty = objectProto.hasOwnProperty;
function getFuncName(func) {
  var result = (func.name + ''),
      array = realNames[result],
      length = hasOwnProperty.call(realNames, result) ? array.length : 0;
  while (length--) {
    var data = array[length],
        otherFunc = data.func;
    if (otherFunc == null || otherFunc == func) {
      return data.name;
    }
  }
  return result;
}

var realNames = {};

import baseSetToString from './_baseSetToString.js';
import shortOut from './_shortOut.js';
var setToString = shortOut(baseSetToString);

import constant from './constant.js';
import defineProperty from './_defineProperty.js';
import identity from './identity.js';
var baseSetToString = !defineProperty ? identity : function(func, string) {
  return defineProperty(func, 'toString', {
    'configurable': true,
    'enumerable': false,
    'value': constant(string),
    'writable': true
  });
};

var objects = _.times(2, _.constant({ 'a': 1 }));
console.log(objects);
// => [{ 'a': 1 }, { 'a': 1 }]
console.log(objects[0] === objects[1]);
// => true

function constant(value) {
  return function() {
    return value;
  };
}

import getNative from './_getNative.js';
var defineProperty = (function() {
  try {
    var func = getNative(Object, 'defineProperty');
    func({}, '', {});
    return func;
  } catch (e) {}
}());

function identity(value) {
  return value;
}