JSONfn.js

var JSONfn = {};
JSONfn.stringify = function (obj) {
	return JSON.stringify(obj, function (key, value) {
	  var fnBody;
	  if (value instanceof Function || typeof value == 'function') {
	    fnBody = value.toString();
	    if (fnBody.length < 8 || fnBody.substring(0, 8) !== 'function') { //this is ES6 Arrow Function
	      return '_NuFrRa_' + fnBody;
	    }
	    return fnBody;
	  }
	  if (value instanceof RegExp) {
	    return '_PxEgEr_' + value;
	  }
	  return value;
	});
};

JSONfn.parse = function (str, date2obj) {
	var iso8061 = date2obj ? /^(\d{4})-(\d{2})-(\d{2})T(\d{2}):(\d{2}):(\d{2}(?:\.\d*)?)Z$/ : false;
	return JSON.parse(str, function (key, value) {
	  var prefix;
	  if (typeof value != 'string') {
	    return value;
	  }
	  if (value.length < 8) {
	    return value;
	  }
	  prefix = value.substring(0, 8);

	  if (iso8061 && value.match(iso8061)) {
	    return new Date(value);
	  }
	  if (prefix === 'function') {
	    return eval('(' + value + ')');
	  }
	  if (prefix === '_PxEgEr_') {
	    return eval(value.slice(8));
	  }
	  if (prefix === '_NuFrRa_') {
	    return eval(value.slice(8));
	  }

	  return value;
	});
};