emacs/lisp/emacs-application-framework/app/netease-cloud-music/node_modules/indexof/index.js

var indexOf = [].indexOf;

module.exports = function(arr, obj){
  if (indexOf) return arr.indexOf(obj);
  for (var i = 0; i < arr.length; ++i) {
    if (arr[i] === obj) return i;
  }
  return -1;
};