"Michael Ruth"
I need to sort a list of dates provided in an input file. [...]
--read in the lines one by one into a list --then iterate thru the list while breaking the strings into [Int] list -- of 3 elements [day,month,year] --then quicksort overall list --then print out overall list line by line
I understand this is a imperative approach, but this is the way I was taught how to program, well that and OOP. How do I go about writing this in a functional sense?
I don't think it's either functional nor imperative by itself. The question is how you structure it, do you say something like buffer x list y x = readFile ... y = parse x quickSort y print y (which would be imperative), or do you say something like print (quickSort (parse (readFile ...))) (in Haskell you might prefer the equivalent syntax print $ quickSort $ parse $ readFile ... or maybe sortDates = print . quickSort . parse . readFile sortDates ... ) which would be functional. Note that the only really imperative part is the sorting, which actually changes the content of y for the following part of the program. A functional implementation wouldn't destroy y, but create a new list with the elements from y in sorted order. I'm not sure if that made things clearer :-) (If you really want to implement it, look at the Prelude for some help, some of the things you wish to do is pretty standard fare. And sorting is perhaps made easier if you rearrange the list of dates a bit?) -kzm -- If I haven't seen further, it is by standing in the footprints of giants