Hashing is a technique to save space in bigger scripts by e.g. replacing "querySelectorAll" in document and all those other lengthy camelCase methods with shorter names like "qSA" . Reverse hashing just tries to find the method or property by their shorter name:
r(document,'qSA','div') // should return the result of document.querySelectorAll('div') r(this,'iW') // returns this(=window).innerWidth
Warning: the first found match for the short name will be used, which may lead to errors on multiple matches.