-- $Id: wordfreq.ghc,v 1.2 2001/02/27 04:04:35 doug Exp $
-- http://www.bagley.org/~doug/shootout/
-- from Julian Assange

-- compile with:
-- ghc -O -package data wordfreq.hs -o wordfreq

module Main where
import List(sortBy)
import Char(toLower,isLower)
import FiniteMap(fmToList,emptyFM,addToFM_C)

main = interact $ unlines . pretty . sort . fmToList . makemap . cwords . lower
 where
       pretty l  = [pad 7 (show n) ++ "\t" ++ w | (w,n) <- l]
                   where
                         pad n s = replicate (n - length s) ' ' ++ s

       sort      = sortBy (\(w0,n0) (w1,n1) -> case compare n1 n0 of
                                               EQ -> compare w1 w0
					       x  -> x)

       makemap   = addFM emptyFM
	           where addFM fm [] = fm
		         addFM fm (x:xs) = addFM (addToFM_C (+) fm x 1) xs

       cwords s  = case dropWhile (not . isLower) s of
		        "" -> []
                        s' -> w : (cwords s'')
                              where (w, s'') = span isLower s' 

       lower     = map toLower