On 6 May 2010 15:20,
well now it's obvious :-) I did have liftM in there, but just couldn't quite figure out how to tie things together.
to be completely clear : liftM takes modificationTime from
Status -> EpochTime
to
IO Status -> IO EpochTime
You can see it that way, yes (of course, liftM works on all monads, not just IO).
so now it can operate on the results of getFileStatus, which returns `IO Status`.
Operate directly on the returned values; you could always use something like "(return . modificationTime) =<< getFileStatus file" as well.
mapM gathers the [IO EpochTime] into `IO [EpochTime]` and then <- gives [EpochTime].
No, it's the sequence function that does that (but mapM f = sequence . map f). -- Ivan Lazar Miljenovic Ivan.Miljenovic@gmail.com IvanMiljenovic.wordpress.com