wishthis/node_modules/es5-ext/array/#/e-index-of.js

"use strict";

var numberIsNaN       = require("../../number/is-nan")
  , toPosInt          = require("../../number/to-pos-integer")
  , value             = require("../../object/valid-value")
  , indexOf           = Array.prototype.indexOf
  , objHasOwnProperty = Object.prototype.hasOwnProperty
  , abs               = Math.abs
  , floor             = Math.floor;

module.exports = function (searchElement /*, fromIndex*/) {
	var i, length, fromIndex, val;
	if (!numberIsNaN(searchElement)) return indexOf.apply(this, arguments);

	length = toPosInt(value(this).length);
	fromIndex = arguments[1];
	if (isNaN(fromIndex)) fromIndex = 0;
	else if (fromIndex >= 0) fromIndex = floor(fromIndex);
	else fromIndex = toPosInt(this.length) - floor(abs(fromIndex));

	for (i = fromIndex; i < length; ++i) {
		if (objHasOwnProperty.call(this, i)) {
			val = this[i];
			if (numberIsNaN(val)) return i; // Jslint: ignore
		}
	}
	return -1;
};