Allow token string alteration on-the-fly

It would be nice to add something like “filters” to tokens. For example, if I am creating file paths, I may want to convert certain chars to dashes, add some transliteration etc. Otherwise, token filters could convert the resulting string to title case or perform arbitrary operations on the token (some examples that come to mind are the conversion of numbers to written out text, case transformations, transliteration, truncating, …)