Haskell counting elements of a list
report :: [[String]] -> String -> [String]
report (x:xs) typ = do
                    case typ of
                        "registrations" -> reportReg (map head xs)
                        "completions" -> reportReg (map head xs)

reportReg :: [String]
reportReg [x] = do
                    print x
                    print 1
reportReg (x:xs) = do
                    let count = instances x (x:xs)
                    print x
                    print count
                    let newlist = filter (==x) (x:xs)
                    reportReg newlist

instances::String->[String]->Int
instances x [] = 0
instances x (y:ys)
    | x==y = 1+(instances x ys)
    | otherwise = instances x ys

reportReg :: [String]

reportReg :: [String] -> IO ()

Prelude> :load typef.hs
[1 of 1] Compiling Main             ( typef.hs, interpreted )
Ok, modules loaded: Main.
*Main> :t report
report :: (Eq a, Show a) => [[a]] -> [Char] -> IO ()
*Main> :t reportReg
reportReg :: (Eq a, Show a) => [a] -> IO ()
*Main> :t instances
instances :: (Num t, Eq a) => a -> [a] -> t

reportReg :: [String]

reportReg :: [String] -> ???

reportReg :: [String] -> IO ()

reportReg :: [a] -> IO ()
reportReg [] = do return ()
reportReg xs = do print (head x)
                  print (count x xs)
                  reportReg (tail xs)

count :: a -> [a] -> Integer
count x xs = length (filter (==x) xs)