* Have you used the existing FilePath module
No, but I rolled my own (years ago) http://dfa.imn.htwk-leipzig.de/auto/tool/haddock/Util-Datei.html
* Will you be happy with a library that represents the file path as String?
No. (If I see data represented by String, chances are that someone forgot to define an ADT. See Refactoring, Code smells, primitive obsession.)
The disadvantage is that with the current IO library we should convert from ADT to String and back again each time when we have to do any IO.
Irrelevant for performance, I think. If I want to do heavy IO, then I'd open a file (once) to get a handle, and use only the handle afterwards. Best regards, -- -- Johannes Waldmann -- Tel/Fax (0341) 3076 6479/80 -- ---- http://www.imn.htwk-leipzig.de/~waldmann/ -------