Function memoizeStringOnly

transformjs/react/example/index.js:12584–12592

* Memoizes the return value of a function that accepts one string argument.

(callback)

	 */

	function memoizeStringOnly(callback) {
	  var cache = {};
	  return function (string) {
	    if (!cache.hasOwnProperty(string)) {
	      cache[string] = callback.call(this, string);
	    }
	    return cache[string];
	  };
	}

	module.exports = memoizeStringOnly;