gistfile1.hs

-- Product function
product' [] = 1
product' (x:xs) = 
  do putStrLn "testing"
     return ((product' xs) * x)

-- quicksort function using where clause
qsort [] = []
qsort (x:xs) = qsort smaller ++ [x] ++ qsort larger
               where
                 smaller = [a | a <- xs, a <= x]
                 larger = [b | b <- xs, b > x]

-- reverse quicksort function
rqsort [] = []
rqsort (x:xs) = rqsort (rqsort larger) ++ [x] ++ smaller
               where
                 smaller = [a | a <- xs,a <= x]
                 larger = [b | b <- xs,b > x]

-- quicksort done using filters vs. where clause
qsort' [] = []
qsort' (x:xs) = (filter (< x) xs) ++ [x] ++ qsort' (filter (>= x) xs)